[v3,1/2] drm/i915/gt: Split intel-gtt functions by arch

Message ID	20220329235830.1025100-2-casey.g.bowman@intel.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <intel-gfx-bounces@lists.freedesktop.org> From: Casey Bowman <casey.g.bowman@intel.com> To: intel-gfx@lists.freedesktop.org Date: Tue, 29 Mar 2022 16:58:29 -0700 Message-Id: <20220329235830.1025100-2-casey.g.bowman@intel.com> In-Reply-To: <20220329235830.1025100-1-casey.g.bowman@intel.com> References: <20220329235830.1025100-1-casey.g.bowman@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Intel-gfx] [PATCH v3 1/2] drm/i915/gt: Split intel-gtt functions by arch Precedence: list Cc: thomas.hellstrom@linux.intel.com, lucas.demarchi@intel.com, chris@chris-wilson.co.uk Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" <intel-gfx-bounces@lists.freedesktop.org>
Series	Splitting intel-gtt calls for non-x86 platforms \| expand [v3,0/2] Splitting intel-gtt calls for non-x86 platforms [v3,1/2] drm/i915/gt: Split intel-gtt functions by arch [v3,2/2] drm/i915: Require INTEL_GTT to depend on X86

Bowman, Casey G March 29, 2022, 11:58 p.m. UTC

Some functions defined in the intel-gtt module are used in several
areas, but is only supported on x86 platforms.

By separating these calls and their static underlying functions to
another area, we are able to compile out these functions for
non-x86 builds and provide stubs for the non-x86 implementations.

In addition to the problematic calls, we are moving the gmch-related
functions to the new area.

Signed-off-by: Casey Bowman <casey.g.bowman@intel.com>
---
 drivers/gpu/drm/i915/Makefile           |   2 +
 drivers/gpu/drm/i915/gt/intel_ggtt.c    | 665 +-----------------------
 drivers/gpu/drm/i915/gt/intel_gt.c      |   4 +-
 drivers/gpu/drm/i915/gt/intel_gt.h      |   9 +
 drivers/gpu/drm/i915/gt/intel_gt_gmch.c | 653 +++++++++++++++++++++++
 drivers/gpu/drm/i915/gt/intel_gt_gmch.h |  46 ++
 drivers/gpu/drm/i915/gt/intel_gtt.h     |   9 +
 7 files changed, 735 insertions(+), 653 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/gt/intel_gt_gmch.c
 create mode 100644 drivers/gpu/drm/i915/gt/intel_gt_gmch.h

Tvrtko Ursulin March 30, 2022, 9:55 a.m. UTC | #1

On 30/03/2022 00:58, Casey Bowman wrote:
> Some functions defined in the intel-gtt module are used in several
> areas, but is only supported on x86 platforms.
> 
> By separating these calls and their static underlying functions to
> another area, we are able to compile out these functions for
> non-x86 builds and provide stubs for the non-x86 implementations.
> 
> In addition to the problematic calls, we are moving the gmch-related
> functions to the new area.
> 
> Signed-off-by: Casey Bowman <casey.g.bowman@intel.com>
> ---
>   drivers/gpu/drm/i915/Makefile           |   2 +
>   drivers/gpu/drm/i915/gt/intel_ggtt.c    | 665 +-----------------------
>   drivers/gpu/drm/i915/gt/intel_gt.c      |   4 +-
>   drivers/gpu/drm/i915/gt/intel_gt.h      |   9 +
>   drivers/gpu/drm/i915/gt/intel_gt_gmch.c | 653 +++++++++++++++++++++++
>   drivers/gpu/drm/i915/gt/intel_gt_gmch.h |  46 ++
>   drivers/gpu/drm/i915/gt/intel_gtt.h     |   9 +
>   7 files changed, 735 insertions(+), 653 deletions(-)
>   create mode 100644 drivers/gpu/drm/i915/gt/intel_gt_gmch.c
>   create mode 100644 drivers/gpu/drm/i915/gt/intel_gt_gmch.h
> 
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index c837a29ffac8..b7bdaec99118 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -126,6 +126,8 @@ gt-y += \
>   	gt/intel_workarounds.o \
>   	gt/shmem_utils.o \
>   	gt/sysfs_engines.o
> +# x86 intel-gtt module support
> +gt-$(CONFIG_X86) += gt/intel_gt_gmch.o
>   # autogenerated null render state
>   gt-y += \
>   	gt/gen6_renderstate.o \
> diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
> index 04191fe2ee34..97a595e42135 100644
> --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
> @@ -3,18 +3,14 @@
>    * Copyright © 2020 Intel Corporation
>    */
>   
> -#include <linux/agp_backend.h>
> -#include <linux/stop_machine.h>
> -
> +#include <linux/types.h>
>   #include <asm/set_memory.h>
>   #include <asm/smp.h>
>   
> -#include <drm/i915_drm.h>
> -#include <drm/intel-gtt.h>
> -
>   #include "gem/i915_gem_lmem.h"
>   
>   #include "intel_gt.h"
> +#include "intel_gt_gmch.h"
>   #include "intel_gt_regs.h"
>   #include "i915_drv.h"
>   #include "i915_scatterlist.h"
> @@ -94,28 +90,6 @@ int i915_ggtt_init_hw(struct drm_i915_private *i915)
>   	return 0;
>   }
>   
> -/*
> - * Certain Gen5 chipsets require idling the GPU before
> - * unmapping anything from the GTT when VT-d is enabled.
> - */
> -static bool needs_idle_maps(struct drm_i915_private *i915)
> -{
> -	/*
> -	 * Query intel_iommu to see if we need the workaround. Presumably that
> -	 * was loaded first.
> -	 */
> -	if (!intel_vtd_active(i915))
> -		return false;
> -
> -	if (GRAPHICS_VER(i915) == 5 && IS_MOBILE(i915))
> -		return true;
> -
> -	if (GRAPHICS_VER(i915) == 12)
> -		return true; /* XXX DMAR fault reason 7 */
> -
> -	return false;
> -}
> -
>   /**
>    * i915_ggtt_suspend_vm - Suspend the memory mappings for a GGTT or DPT VM
>    * @vm: The VM to suspend the mappings for
> @@ -204,7 +178,7 @@ void gen6_ggtt_invalidate(struct i915_ggtt *ggtt)
>   	spin_unlock_irq(&uncore->lock);
>   }
>   
> -static void gen8_ggtt_invalidate(struct i915_ggtt *ggtt)
> +void gen8_ggtt_invalidate(struct i915_ggtt *ggtt)
>   {
>   	struct intel_uncore *uncore = ggtt->vm.gt->uncore;
>   
> @@ -229,11 +203,6 @@ static void guc_ggtt_invalidate(struct i915_ggtt *ggtt)
>   		intel_uncore_write_fw(uncore, GEN8_GTCR, GEN8_GTCR_INVALIDATE);
>   }
>   
> -static void gmch_ggtt_invalidate(struct i915_ggtt *ggtt)
> -{
> -	intel_gtt_chipset_flush();
> -}
> -
>   u64 gen8_ggtt_pte_encode(dma_addr_t addr,
>   			 enum i915_cache_level level,
>   			 u32 flags)
> @@ -246,258 +215,7 @@ u64 gen8_ggtt_pte_encode(dma_addr_t addr,
>   	return pte;
>   }
>   
> -static void gen8_set_pte(void __iomem *addr, gen8_pte_t pte)
> -{
> -	writeq(pte, addr);
> -}
> -
> -static void gen8_ggtt_insert_page(struct i915_address_space *vm,
> -				  dma_addr_t addr,
> -				  u64 offset,
> -				  enum i915_cache_level level,
> -				  u32 flags)
> -{
> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> -	gen8_pte_t __iomem *pte =
> -		(gen8_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
> -
> -	gen8_set_pte(pte, gen8_ggtt_pte_encode(addr, level, flags));
> -
> -	ggtt->invalidate(ggtt);
> -}
> -
> -static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
> -				     struct i915_vma_resource *vma_res,
> -				     enum i915_cache_level level,
> -				     u32 flags)
> -{
> -	const gen8_pte_t pte_encode = gen8_ggtt_pte_encode(0, level, flags);
> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> -	gen8_pte_t __iomem *gte;
> -	gen8_pte_t __iomem *end;
> -	struct sgt_iter iter;
> -	dma_addr_t addr;
> -
> -	/*
> -	 * Note that we ignore PTE_READ_ONLY here. The caller must be careful
> -	 * not to allow the user to override access to a read only page.
> -	 */
> -
> -	gte = (gen8_pte_t __iomem *)ggtt->gsm;
> -	gte += vma_res->start / I915_GTT_PAGE_SIZE;
> -	end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
> -
> -	for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
> -		gen8_set_pte(gte++, pte_encode | addr);
> -	GEM_BUG_ON(gte > end);
> -
> -	/* Fill the allocated but "unused" space beyond the end of the buffer */
> -	while (gte < end)
> -		gen8_set_pte(gte++, vm->scratch[0]->encode);
> -
> -	/*
> -	 * We want to flush the TLBs only after we're certain all the PTE
> -	 * updates have finished.
> -	 */
> -	ggtt->invalidate(ggtt);
> -}
> -
> -static void gen6_ggtt_insert_page(struct i915_address_space *vm,
> -				  dma_addr_t addr,
> -				  u64 offset,
> -				  enum i915_cache_level level,
> -				  u32 flags)
> -{
> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> -	gen6_pte_t __iomem *pte =
> -		(gen6_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
> -
> -	iowrite32(vm->pte_encode(addr, level, flags), pte);
> -
> -	ggtt->invalidate(ggtt);
> -}
> -
> -/*
> - * Binds an object into the global gtt with the specified cache level.
> - * The object will be accessible to the GPU via commands whose operands
> - * reference offsets within the global GTT as well as accessible by the GPU
> - * through the GMADR mapped BAR (i915->mm.gtt->gtt).
> - */
> -static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
> -				     struct i915_vma_resource *vma_res,
> -				     enum i915_cache_level level,
> -				     u32 flags)
> -{
> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> -	gen6_pte_t __iomem *gte;
> -	gen6_pte_t __iomem *end;
> -	struct sgt_iter iter;
> -	dma_addr_t addr;
> -
> -	gte = (gen6_pte_t __iomem *)ggtt->gsm;
> -	gte += vma_res->start / I915_GTT_PAGE_SIZE;
> -	end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
> -
> -	for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
> -		iowrite32(vm->pte_encode(addr, level, flags), gte++);
> -	GEM_BUG_ON(gte > end);
> -
> -	/* Fill the allocated but "unused" space beyond the end of the buffer */
> -	while (gte < end)
> -		iowrite32(vm->scratch[0]->encode, gte++);
> -
> -	/*
> -	 * We want to flush the TLBs only after we're certain all the PTE
> -	 * updates have finished.
> -	 */
> -	ggtt->invalidate(ggtt);
> -}
> -
> -static void nop_clear_range(struct i915_address_space *vm,
> -			    u64 start, u64 length)
> -{
> -}
> -
> -static void gen8_ggtt_clear_range(struct i915_address_space *vm,
> -				  u64 start, u64 length)
> -{
> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> -	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
> -	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
> -	const gen8_pte_t scratch_pte = vm->scratch[0]->encode;
> -	gen8_pte_t __iomem *gtt_base =
> -		(gen8_pte_t __iomem *)ggtt->gsm + first_entry;
> -	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
> -	int i;
> -
> -	if (WARN(num_entries > max_entries,
> -		 "First entry = %d; Num entries = %d (max=%d)\n",
> -		 first_entry, num_entries, max_entries))
> -		num_entries = max_entries;
> -
> -	for (i = 0; i < num_entries; i++)
> -		gen8_set_pte(&gtt_base[i], scratch_pte);
> -}
> -
> -static void bxt_vtd_ggtt_wa(struct i915_address_space *vm)
> -{
> -	/*
> -	 * Make sure the internal GAM fifo has been cleared of all GTT
> -	 * writes before exiting stop_machine(). This guarantees that
> -	 * any aperture accesses waiting to start in another process
> -	 * cannot back up behind the GTT writes causing a hang.
> -	 * The register can be any arbitrary GAM register.
> -	 */
> -	intel_uncore_posting_read_fw(vm->gt->uncore, GFX_FLSH_CNTL_GEN6);
> -}
> -
> -struct insert_page {
> -	struct i915_address_space *vm;
> -	dma_addr_t addr;
> -	u64 offset;
> -	enum i915_cache_level level;
> -};
> -
> -static int bxt_vtd_ggtt_insert_page__cb(void *_arg)
> -{
> -	struct insert_page *arg = _arg;
> -
> -	gen8_ggtt_insert_page(arg->vm, arg->addr, arg->offset, arg->level, 0);
> -	bxt_vtd_ggtt_wa(arg->vm);
> -
> -	return 0;
> -}
> -
> -static void bxt_vtd_ggtt_insert_page__BKL(struct i915_address_space *vm,
> -					  dma_addr_t addr,
> -					  u64 offset,
> -					  enum i915_cache_level level,
> -					  u32 unused)
> -{
> -	struct insert_page arg = { vm, addr, offset, level };
> -
> -	stop_machine(bxt_vtd_ggtt_insert_page__cb, &arg, NULL);
> -}
> -
> -struct insert_entries {
> -	struct i915_address_space *vm;
> -	struct i915_vma_resource *vma_res;
> -	enum i915_cache_level level;
> -	u32 flags;
> -};
> -
> -static int bxt_vtd_ggtt_insert_entries__cb(void *_arg)
> -{
> -	struct insert_entries *arg = _arg;
> -
> -	gen8_ggtt_insert_entries(arg->vm, arg->vma_res, arg->level, arg->flags);
> -	bxt_vtd_ggtt_wa(arg->vm);
> -
> -	return 0;
> -}
> -
> -static void bxt_vtd_ggtt_insert_entries__BKL(struct i915_address_space *vm,
> -					     struct i915_vma_resource *vma_res,
> -					     enum i915_cache_level level,
> -					     u32 flags)
> -{
> -	struct insert_entries arg = { vm, vma_res, level, flags };
> -
> -	stop_machine(bxt_vtd_ggtt_insert_entries__cb, &arg, NULL);
> -}
> -
> -static void gen6_ggtt_clear_range(struct i915_address_space *vm,
> -				  u64 start, u64 length)
> -{
> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> -	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
> -	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
> -	gen6_pte_t scratch_pte, __iomem *gtt_base =
> -		(gen6_pte_t __iomem *)ggtt->gsm + first_entry;
> -	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
> -	int i;
> -
> -	if (WARN(num_entries > max_entries,
> -		 "First entry = %d; Num entries = %d (max=%d)\n",
> -		 first_entry, num_entries, max_entries))
> -		num_entries = max_entries;
> -
> -	scratch_pte = vm->scratch[0]->encode;
> -	for (i = 0; i < num_entries; i++)
> -		iowrite32(scratch_pte, &gtt_base[i]);
> -}
> -
> -static void i915_ggtt_insert_page(struct i915_address_space *vm,
> -				  dma_addr_t addr,
> -				  u64 offset,
> -				  enum i915_cache_level cache_level,
> -				  u32 unused)
> -{
> -	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
> -		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
> -
> -	intel_gtt_insert_page(addr, offset >> PAGE_SHIFT, flags);
> -}
> -
> -static void i915_ggtt_insert_entries(struct i915_address_space *vm,
> -				     struct i915_vma_resource *vma_res,
> -				     enum i915_cache_level cache_level,
> -				     u32 unused)
> -{
> -	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
> -		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
> -
> -	intel_gtt_insert_sg_entries(vma_res->bi.pages, vma_res->start >> PAGE_SHIFT,
> -				    flags);
> -}
> -
> -static void i915_ggtt_clear_range(struct i915_address_space *vm,
> -				  u64 start, u64 length)
> -{
> -	intel_gtt_clear_range(start >> PAGE_SHIFT, length >> PAGE_SHIFT);
> -}
> -
> -static void ggtt_bind_vma(struct i915_address_space *vm,
> +void intel_ggtt_bind_vma(struct i915_address_space *vm,
>   			  struct i915_vm_pt_stash *stash,
>   			  struct i915_vma_resource *vma_res,
>   			  enum i915_cache_level cache_level,
> @@ -521,7 +239,7 @@ static void ggtt_bind_vma(struct i915_address_space *vm,
>   	vma_res->page_sizes_gtt = I915_GTT_PAGE_SIZE;
>   }
>   
> -static void ggtt_unbind_vma(struct i915_address_space *vm,
> +void intel_ggtt_unbind_vma(struct i915_address_space *vm,
>   			    struct i915_vma_resource *vma_res)
>   {
>   	vm->clear_range(vm, vma_res->start, vma_res->vma_size);
> @@ -724,10 +442,10 @@ static int init_aliasing_ppgtt(struct i915_ggtt *ggtt)
>   	ggtt->alias = ppgtt;
>   	ggtt->vm.bind_async_flags |= ppgtt->vm.bind_async_flags;
>   
> -	GEM_BUG_ON(ggtt->vm.vma_ops.bind_vma != ggtt_bind_vma);
> +	GEM_BUG_ON(ggtt->vm.vma_ops.bind_vma != intel_ggtt_bind_vma);
>   	ggtt->vm.vma_ops.bind_vma = aliasing_gtt_bind_vma;
>   
> -	GEM_BUG_ON(ggtt->vm.vma_ops.unbind_vma != ggtt_unbind_vma);
> +	GEM_BUG_ON(ggtt->vm.vma_ops.unbind_vma != intel_ggtt_unbind_vma);
>   	ggtt->vm.vma_ops.unbind_vma = aliasing_gtt_unbind_vma;
>   
>   	i915_vm_free_pt_stash(&ppgtt->vm, &stash);
> @@ -750,8 +468,8 @@ static void fini_aliasing_ppgtt(struct i915_ggtt *ggtt)
>   
>   	i915_vm_put(&ppgtt->vm);
>   
> -	ggtt->vm.vma_ops.bind_vma   = ggtt_bind_vma;
> -	ggtt->vm.vma_ops.unbind_vma = ggtt_unbind_vma;
> +	ggtt->vm.vma_ops.bind_vma   = intel_ggtt_bind_vma;
> +	ggtt->vm.vma_ops.unbind_vma = intel_ggtt_unbind_vma;
>   }
>   
>   int i915_init_ggtt(struct drm_i915_private *i915)
> @@ -839,364 +557,12 @@ void i915_ggtt_driver_late_release(struct drm_i915_private *i915)
>   	dma_resv_fini(&ggtt->vm._resv);
>   }
>   
> -static unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
> -{
> -	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
> -	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
> -	return snb_gmch_ctl << 20;
> -}
> -
> -static unsigned int gen8_get_total_gtt_size(u16 bdw_gmch_ctl)
> -{
> -	bdw_gmch_ctl >>= BDW_GMCH_GGMS_SHIFT;
> -	bdw_gmch_ctl &= BDW_GMCH_GGMS_MASK;
> -	if (bdw_gmch_ctl)
> -		bdw_gmch_ctl = 1 << bdw_gmch_ctl;
> -
> -#ifdef CONFIG_X86_32
> -	/* Limit 32b platforms to a 2GB GGTT: 4 << 20 / pte size * I915_GTT_PAGE_SIZE */
> -	if (bdw_gmch_ctl > 4)
> -		bdw_gmch_ctl = 4;
> -#endif
> -
> -	return bdw_gmch_ctl << 20;
> -}
> -
> -static unsigned int chv_get_total_gtt_size(u16 gmch_ctrl)
> -{
> -	gmch_ctrl >>= SNB_GMCH_GGMS_SHIFT;
> -	gmch_ctrl &= SNB_GMCH_GGMS_MASK;
> -
> -	if (gmch_ctrl)
> -		return 1 << (20 + gmch_ctrl);
> -
> -	return 0;
> -}
> -
> -static unsigned int gen6_gttmmadr_size(struct drm_i915_private *i915)
> -{
> -	/*
> -	 * GEN6: GTTMMADR size is 4MB and GTTADR starts at 2MB offset
> -	 * GEN8: GTTMMADR size is 16MB and GTTADR starts at 8MB offset
> -	 */
> -	GEM_BUG_ON(GRAPHICS_VER(i915) < 6);
> -	return (GRAPHICS_VER(i915) < 8) ? SZ_4M : SZ_16M;
> -}
> -
> -static unsigned int gen6_gttadr_offset(struct drm_i915_private *i915)
> -{
> -	return gen6_gttmmadr_size(i915) / 2;
> -}
> -
> -static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size)
> -{
> -	struct drm_i915_private *i915 = ggtt->vm.i915;
> -	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
> -	phys_addr_t phys_addr;
> -	u32 pte_flags;
> -	int ret;
> -
> -	GEM_WARN_ON(pci_resource_len(pdev, 0) != gen6_gttmmadr_size(i915));
> -	phys_addr = pci_resource_start(pdev, 0) + gen6_gttadr_offset(i915);
> -
> -	/*
> -	 * On BXT+/ICL+ writes larger than 64 bit to the GTT pagetable range
> -	 * will be dropped. For WC mappings in general we have 64 byte burst
> -	 * writes when the WC buffer is flushed, so we can't use it, but have to
> -	 * resort to an uncached mapping. The WC issue is easily caught by the
> -	 * readback check when writing GTT PTE entries.
> -	 */
> -	if (IS_GEN9_LP(i915) || GRAPHICS_VER(i915) >= 11)
> -		ggtt->gsm = ioremap(phys_addr, size);
> -	else
> -		ggtt->gsm = ioremap_wc(phys_addr, size);
> -	if (!ggtt->gsm) {
> -		drm_err(&i915->drm, "Failed to map the ggtt page table\n");
> -		return -ENOMEM;
> -	}
> -
> -	kref_init(&ggtt->vm.resv_ref);
> -	ret = setup_scratch_page(&ggtt->vm);
> -	if (ret) {
> -		drm_err(&i915->drm, "Scratch setup failed\n");
> -		/* iounmap will also get called at remove, but meh */
> -		iounmap(ggtt->gsm);
> -		return ret;
> -	}
> -
> -	pte_flags = 0;
> -	if (i915_gem_object_is_lmem(ggtt->vm.scratch[0]))
> -		pte_flags |= PTE_LM;
> -
> -	ggtt->vm.scratch[0]->encode =
> -		ggtt->vm.pte_encode(px_dma(ggtt->vm.scratch[0]),
> -				    I915_CACHE_NONE, pte_flags);
> -
> -	return 0;
> -}
> -
> -static void gen6_gmch_remove(struct i915_address_space *vm)
> -{
> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> -
> -	iounmap(ggtt->gsm);
> -	free_scratch(vm);
> -}
> -
> -static struct resource pci_resource(struct pci_dev *pdev, int bar)
> +struct resource pci_resource(struct pci_dev *pdev, int bar)
>   {
>   	return (struct resource)DEFINE_RES_MEM(pci_resource_start(pdev, bar),
>   					       pci_resource_len(pdev, bar));
>   }

Export with pci_ prefix is a bit dodgy - maybe intel_pci_resource? Not sure.

The rest looks okay to me.

I mean I could suggest to do something about the incosistency of:

static inline void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)

vs:

static inline int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)

Since I value more for function name to tell me on what it operates 
instead where it is placed. So I'd personally rename the second class to 
i915_ggtt. It would also be consistent with other exported functions 
which take struct i915_ggtt like i915_ggtt_enable_guc, i915_ggtt_resume 
and so. But opinions will differ so I can live with it as is as well.

Regards,

Tvrtko

>   
> -static int gen8_gmch_probe(struct i915_ggtt *ggtt)
> -{
> -	struct drm_i915_private *i915 = ggtt->vm.i915;
> -	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
> -	unsigned int size;
> -	u16 snb_gmch_ctl;
> -
> -	/* TODO: We're not aware of mappable constraints on gen8 yet */
> -	if (!HAS_LMEM(i915)) {
> -		ggtt->gmadr = pci_resource(pdev, 2);
> -		ggtt->mappable_end = resource_size(&ggtt->gmadr);
> -	}
> -
> -	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
> -	if (IS_CHERRYVIEW(i915))
> -		size = chv_get_total_gtt_size(snb_gmch_ctl);
> -	else
> -		size = gen8_get_total_gtt_size(snb_gmch_ctl);
> -
> -	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
> -	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
> -	ggtt->vm.lmem_pt_obj_flags = I915_BO_ALLOC_PM_EARLY;
> -
> -	ggtt->vm.total = (size / sizeof(gen8_pte_t)) * I915_GTT_PAGE_SIZE;
> -	ggtt->vm.cleanup = gen6_gmch_remove;
> -	ggtt->vm.insert_page = gen8_ggtt_insert_page;
> -	ggtt->vm.clear_range = nop_clear_range;
> -	if (intel_scanout_needs_vtd_wa(i915))
> -		ggtt->vm.clear_range = gen8_ggtt_clear_range;
> -
> -	ggtt->vm.insert_entries = gen8_ggtt_insert_entries;
> -
> -	/*
> -	 * Serialize GTT updates with aperture access on BXT if VT-d is on,
> -	 * and always on CHV.
> -	 */
> -	if (intel_vm_no_concurrent_access_wa(i915)) {
> -		ggtt->vm.insert_entries = bxt_vtd_ggtt_insert_entries__BKL;
> -		ggtt->vm.insert_page    = bxt_vtd_ggtt_insert_page__BKL;
> -		ggtt->vm.bind_async_flags =
> -			I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND;
> -	}
> -
> -	ggtt->invalidate = gen8_ggtt_invalidate;
> -
> -	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
> -	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
> -
> -	ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
> -
> -	setup_private_pat(ggtt->vm.gt->uncore);
> -
> -	return ggtt_probe_common(ggtt, size);
> -}
> -
> -static u64 snb_pte_encode(dma_addr_t addr,
> -			  enum i915_cache_level level,
> -			  u32 flags)
> -{
> -	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
> -
> -	switch (level) {
> -	case I915_CACHE_L3_LLC:
> -	case I915_CACHE_LLC:
> -		pte |= GEN6_PTE_CACHE_LLC;
> -		break;
> -	case I915_CACHE_NONE:
> -		pte |= GEN6_PTE_UNCACHED;
> -		break;
> -	default:
> -		MISSING_CASE(level);
> -	}
> -
> -	return pte;
> -}
> -
> -static u64 ivb_pte_encode(dma_addr_t addr,
> -			  enum i915_cache_level level,
> -			  u32 flags)
> -{
> -	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
> -
> -	switch (level) {
> -	case I915_CACHE_L3_LLC:
> -		pte |= GEN7_PTE_CACHE_L3_LLC;
> -		break;
> -	case I915_CACHE_LLC:
> -		pte |= GEN6_PTE_CACHE_LLC;
> -		break;
> -	case I915_CACHE_NONE:
> -		pte |= GEN6_PTE_UNCACHED;
> -		break;
> -	default:
> -		MISSING_CASE(level);
> -	}
> -
> -	return pte;
> -}
> -
> -static u64 byt_pte_encode(dma_addr_t addr,
> -			  enum i915_cache_level level,
> -			  u32 flags)
> -{
> -	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
> -
> -	if (!(flags & PTE_READ_ONLY))
> -		pte |= BYT_PTE_WRITEABLE;
> -
> -	if (level != I915_CACHE_NONE)
> -		pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
> -
> -	return pte;
> -}
> -
> -static u64 hsw_pte_encode(dma_addr_t addr,
> -			  enum i915_cache_level level,
> -			  u32 flags)
> -{
> -	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
> -
> -	if (level != I915_CACHE_NONE)
> -		pte |= HSW_WB_LLC_AGE3;
> -
> -	return pte;
> -}
> -
> -static u64 iris_pte_encode(dma_addr_t addr,
> -			   enum i915_cache_level level,
> -			   u32 flags)
> -{
> -	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
> -
> -	switch (level) {
> -	case I915_CACHE_NONE:
> -		break;
> -	case I915_CACHE_WT:
> -		pte |= HSW_WT_ELLC_LLC_AGE3;
> -		break;
> -	default:
> -		pte |= HSW_WB_ELLC_LLC_AGE3;
> -		break;
> -	}
> -
> -	return pte;
> -}
> -
> -static int gen6_gmch_probe(struct i915_ggtt *ggtt)
> -{
> -	struct drm_i915_private *i915 = ggtt->vm.i915;
> -	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
> -	unsigned int size;
> -	u16 snb_gmch_ctl;
> -
> -	ggtt->gmadr = pci_resource(pdev, 2);
> -	ggtt->mappable_end = resource_size(&ggtt->gmadr);
> -
> -	/*
> -	 * 64/512MB is the current min/max we actually know of, but this is
> -	 * just a coarse sanity check.
> -	 */
> -	if (ggtt->mappable_end < (64<<20) || ggtt->mappable_end > (512<<20)) {
> -		drm_err(&i915->drm, "Unknown GMADR size (%pa)\n",
> -			&ggtt->mappable_end);
> -		return -ENXIO;
> -	}
> -
> -	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
> -
> -	size = gen6_get_total_gtt_size(snb_gmch_ctl);
> -	ggtt->vm.total = (size / sizeof(gen6_pte_t)) * I915_GTT_PAGE_SIZE;
> -
> -	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
> -	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
> -
> -	ggtt->vm.clear_range = nop_clear_range;
> -	if (!HAS_FULL_PPGTT(i915) || intel_scanout_needs_vtd_wa(i915))
> -		ggtt->vm.clear_range = gen6_ggtt_clear_range;
> -	ggtt->vm.insert_page = gen6_ggtt_insert_page;
> -	ggtt->vm.insert_entries = gen6_ggtt_insert_entries;
> -	ggtt->vm.cleanup = gen6_gmch_remove;
> -
> -	ggtt->invalidate = gen6_ggtt_invalidate;
> -
> -	if (HAS_EDRAM(i915))
> -		ggtt->vm.pte_encode = iris_pte_encode;
> -	else if (IS_HASWELL(i915))
> -		ggtt->vm.pte_encode = hsw_pte_encode;
> -	else if (IS_VALLEYVIEW(i915))
> -		ggtt->vm.pte_encode = byt_pte_encode;
> -	else if (GRAPHICS_VER(i915) >= 7)
> -		ggtt->vm.pte_encode = ivb_pte_encode;
> -	else
> -		ggtt->vm.pte_encode = snb_pte_encode;
> -
> -	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
> -	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
> -
> -	return ggtt_probe_common(ggtt, size);
> -}
> -
> -static void i915_gmch_remove(struct i915_address_space *vm)
> -{
> -	intel_gmch_remove();
> -}
> -
> -static int i915_gmch_probe(struct i915_ggtt *ggtt)
> -{
> -	struct drm_i915_private *i915 = ggtt->vm.i915;
> -	phys_addr_t gmadr_base;
> -	int ret;
> -
> -	ret = intel_gmch_probe(i915->bridge_dev, to_pci_dev(i915->drm.dev), NULL);
> -	if (!ret) {
> -		drm_err(&i915->drm, "failed to set up gmch\n");
> -		return -EIO;
> -	}
> -
> -	intel_gtt_get(&ggtt->vm.total, &gmadr_base, &ggtt->mappable_end);
> -
> -	ggtt->gmadr =
> -		(struct resource)DEFINE_RES_MEM(gmadr_base, ggtt->mappable_end);
> -
> -	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
> -	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
> -
> -	if (needs_idle_maps(i915)) {
> -		drm_notice(&i915->drm,
> -			   "Flushing DMA requests before IOMMU unmaps; performance may be degraded\n");
> -		ggtt->do_idle_maps = true;
> -	}
> -
> -	ggtt->vm.insert_page = i915_ggtt_insert_page;
> -	ggtt->vm.insert_entries = i915_ggtt_insert_entries;
> -	ggtt->vm.clear_range = i915_ggtt_clear_range;
> -	ggtt->vm.cleanup = i915_gmch_remove;
> -
> -	ggtt->invalidate = gmch_ggtt_invalidate;
> -
> -	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
> -	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
> -
> -	if (unlikely(ggtt->do_idle_maps))
> -		drm_notice(&i915->drm,
> -			   "Applying Ironlake quirks for intel_iommu\n");
> -
> -	return 0;
> -}
> -
>   static int ggtt_probe_hw(struct i915_ggtt *ggtt, struct intel_gt *gt)
>   {
>   	struct drm_i915_private *i915 = gt->i915;
> @@ -1208,11 +574,11 @@ static int ggtt_probe_hw(struct i915_ggtt *ggtt, struct intel_gt *gt)
>   	dma_resv_init(&ggtt->vm._resv);
>   
>   	if (GRAPHICS_VER(i915) <= 5)
> -		ret = i915_gmch_probe(ggtt);
> +		ret = intel_gt_gmch_gen5_probe(ggtt);
>   	else if (GRAPHICS_VER(i915) < 8)
> -		ret = gen6_gmch_probe(ggtt);
> +		ret = intel_gt_gmch_gen6_probe(ggtt);
>   	else
> -		ret = gen8_gmch_probe(ggtt);
> +		ret = intel_gt_gmch_gen8_probe(ggtt);
>   	if (ret) {
>   		dma_resv_fini(&ggtt->vm._resv);
>   		return ret;
> @@ -1266,10 +632,7 @@ int i915_ggtt_probe_hw(struct drm_i915_private *i915)
>   
>   int i915_ggtt_enable_hw(struct drm_i915_private *i915)
>   {
> -	if (GRAPHICS_VER(i915) < 6 && !intel_enable_gtt())
> -		return -EIO;
> -
> -	return 0;
> +	return intel_gt_gmch_gen5_enable_hw(i915);
>   }
>   
>   void i915_ggtt_enable_guc(struct i915_ggtt *ggtt)
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
> index 5001a6168d56..f0014c5072c9 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gt.c
> @@ -4,7 +4,6 @@
>    */
>   
>   #include <drm/drm_managed.h>
> -#include <drm/intel-gtt.h>
>   
>   #include "gem/i915_gem_internal.h"
>   #include "gem/i915_gem_lmem.h"
> @@ -17,6 +16,7 @@
>   #include "intel_gt_buffer_pool.h"
>   #include "intel_gt_clock_utils.h"
>   #include "intel_gt_debugfs.h"
> +#include "intel_gt_gmch.h"
>   #include "intel_gt_pm.h"
>   #include "intel_gt_regs.h"
>   #include "intel_gt_requests.h"
> @@ -451,7 +451,7 @@ void intel_gt_chipset_flush(struct intel_gt *gt)
>   {
>   	wmb();
>   	if (GRAPHICS_VER(gt->i915) < 6)
> -		intel_gtt_chipset_flush();
> +		intel_gt_gmch_gen5_chipset_flush(gt);
>   }
>   
>   void intel_gt_driver_register(struct intel_gt *gt)
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt.h b/drivers/gpu/drm/i915/gt/intel_gt.h
> index e76168e10a21..8956dfc5afe0 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt.h
> @@ -13,6 +13,13 @@
>   struct drm_i915_private;
>   struct drm_printer;
>   
> +struct insert_entries {
> +	struct i915_address_space *vm;
> +	struct i915_vma_resource *vma_res;
> +	enum i915_cache_level level;
> +	u32 flags;
> +};
> +
>   #define GT_TRACE(gt, fmt, ...) do {					\
>   	const struct intel_gt *gt__ __maybe_unused = (gt);		\
>   	GEM_TRACE("%s " fmt, dev_name(gt__->i915->drm.dev),		\
> @@ -113,4 +120,6 @@ void intel_gt_watchdog_work(struct work_struct *work);
>   
>   void intel_gt_invalidate_tlbs(struct intel_gt *gt);
>   
> +struct resource pci_resource(struct pci_dev *pdev, int bar);
> +
>   #endif /* __INTEL_GT_H__ */
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_gmch.c b/drivers/gpu/drm/i915/gt/intel_gt_gmch.c
> new file mode 100644
> index 000000000000..b914ebb30166
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_gmch.c
> @@ -0,0 +1,653 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2022 Intel Corporation
> + */
> +
> +#include <drm/intel-gtt.h>
> +#include <drm/i915_drm.h>
> +
> +#include <linux/agp_backend.h>
> +#include <linux/stop_machine.h>
> +
> +#include "i915_drv.h"
> +#include "intel_gt_gmch.h"
> +#include "intel_gt_regs.h"
> +#include "intel_gt.h"
> +
> +#include "gen8_ppgtt.h"
> +
> +struct insert_page {
> +	struct i915_address_space *vm;
> +	dma_addr_t addr;
> +	u64 offset;
> +	enum i915_cache_level level;
> +};
> +
> +static void gen8_set_pte(void __iomem *addr, gen8_pte_t pte)
> +{
> +	writeq(pte, addr);
> +}
> +
> +static void nop_clear_range(struct i915_address_space *vm,
> +			    u64 start, u64 length)
> +{
> +}
> +
> +static u64 snb_pte_encode(dma_addr_t addr,
> +			  enum i915_cache_level level,
> +			  u32 flags)
> +{
> +	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
> +
> +	switch (level) {
> +	case I915_CACHE_L3_LLC:
> +	case I915_CACHE_LLC:
> +		pte |= GEN6_PTE_CACHE_LLC;
> +		break;
> +	case I915_CACHE_NONE:
> +		pte |= GEN6_PTE_UNCACHED;
> +		break;
> +	default:
> +		MISSING_CASE(level);
> +	}
> +
> +	return pte;
> +}
> +
> +static u64 ivb_pte_encode(dma_addr_t addr,
> +			  enum i915_cache_level level,
> +			  u32 flags)
> +{
> +	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
> +
> +	switch (level) {
> +	case I915_CACHE_L3_LLC:
> +		pte |= GEN7_PTE_CACHE_L3_LLC;
> +		break;
> +	case I915_CACHE_LLC:
> +		pte |= GEN6_PTE_CACHE_LLC;
> +		break;
> +	case I915_CACHE_NONE:
> +		pte |= GEN6_PTE_UNCACHED;
> +		break;
> +	default:
> +		MISSING_CASE(level);
> +	}
> +
> +	return pte;
> +}
> +
> +static u64 byt_pte_encode(dma_addr_t addr,
> +			  enum i915_cache_level level,
> +			  u32 flags)
> +{
> +	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
> +
> +	if (!(flags & PTE_READ_ONLY))
> +		pte |= BYT_PTE_WRITEABLE;
> +
> +	if (level != I915_CACHE_NONE)
> +		pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
> +
> +	return pte;
> +}
> +
> +static u64 hsw_pte_encode(dma_addr_t addr,
> +			  enum i915_cache_level level,
> +			  u32 flags)
> +{
> +	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
> +
> +	if (level != I915_CACHE_NONE)
> +		pte |= HSW_WB_LLC_AGE3;
> +
> +	return pte;
> +}
> +
> +static u64 iris_pte_encode(dma_addr_t addr,
> +			   enum i915_cache_level level,
> +			   u32 flags)
> +{
> +	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
> +
> +	switch (level) {
> +	case I915_CACHE_NONE:
> +		break;
> +	case I915_CACHE_WT:
> +		pte |= HSW_WT_ELLC_LLC_AGE3;
> +		break;
> +	default:
> +		pte |= HSW_WB_ELLC_LLC_AGE3;
> +		break;
> +	}
> +
> +	return pte;
> +}
> +
> +static void gen5_ggtt_insert_page(struct i915_address_space *vm,
> +				  dma_addr_t addr,
> +				  u64 offset,
> +				  enum i915_cache_level cache_level,
> +				  u32 unused)
> +{
> +	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
> +		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
> +
> +	intel_gtt_insert_page(addr, offset >> PAGE_SHIFT, flags);
> +}
> +
> +static void gen6_ggtt_insert_page(struct i915_address_space *vm,
> +				  dma_addr_t addr,
> +				  u64 offset,
> +				  enum i915_cache_level level,
> +				  u32 flags)
> +{
> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> +	gen6_pte_t __iomem *pte =
> +		(gen6_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
> +
> +	iowrite32(vm->pte_encode(addr, level, flags), pte);
> +
> +	ggtt->invalidate(ggtt);
> +}
> +
> +static void gen8_ggtt_insert_page(struct i915_address_space *vm,
> +				  dma_addr_t addr,
> +				  u64 offset,
> +				  enum i915_cache_level level,
> +				  u32 flags)
> +{
> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> +	gen8_pte_t __iomem *pte =
> +		(gen8_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
> +
> +	gen8_set_pte(pte, gen8_ggtt_pte_encode(addr, level, flags));
> +
> +	ggtt->invalidate(ggtt);
> +}
> +
> +static void gen5_ggtt_insert_entries(struct i915_address_space *vm,
> +				     struct i915_vma_resource *vma_res,
> +				     enum i915_cache_level cache_level,
> +				     u32 unused)
> +{
> +	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
> +		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
> +
> +	intel_gtt_insert_sg_entries(vma_res->bi.pages, vma_res->start >> PAGE_SHIFT,
> +				    flags);
> +}
> +
> +/*
> + * Binds an object into the global gtt with the specified cache level.
> + * The object will be accessible to the GPU via commands whose operands
> + * reference offsets within the global GTT as well as accessible by the GPU
> + * through the GMADR mapped BAR (i915->mm.gtt->gtt).
> + */
> +static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
> +				     struct i915_vma_resource *vma_res,
> +				     enum i915_cache_level level,
> +				     u32 flags)
> +{
> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> +	gen6_pte_t __iomem *gte;
> +	gen6_pte_t __iomem *end;
> +	struct sgt_iter iter;
> +	dma_addr_t addr;
> +
> +	gte = (gen6_pte_t __iomem *)ggtt->gsm;
> +	gte += vma_res->start / I915_GTT_PAGE_SIZE;
> +	end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
> +
> +	for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
> +		iowrite32(vm->pte_encode(addr, level, flags), gte++);
> +	GEM_BUG_ON(gte > end);
> +
> +	/* Fill the allocated but "unused" space beyond the end of the buffer */
> +	while (gte < end)
> +		iowrite32(vm->scratch[0]->encode, gte++);
> +
> +	/*
> +	 * We want to flush the TLBs only after we're certain all the PTE
> +	 * updates have finished.
> +	 */
> +	ggtt->invalidate(ggtt);
> +}
> +
> +static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
> +				     struct i915_vma_resource *vma_res,
> +				     enum i915_cache_level level,
> +				     u32 flags)
> +{
> +	const gen8_pte_t pte_encode = gen8_ggtt_pte_encode(0, level, flags);
> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> +	gen8_pte_t __iomem *gte;
> +	gen8_pte_t __iomem *end;
> +	struct sgt_iter iter;
> +	dma_addr_t addr;
> +
> +	/*
> +	 * Note that we ignore PTE_READ_ONLY here. The caller must be careful
> +	 * not to allow the user to override access to a read only page.
> +	 */
> +
> +	gte = (gen8_pte_t __iomem *)ggtt->gsm;
> +	gte += vma_res->start / I915_GTT_PAGE_SIZE;
> +	end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
> +
> +	for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
> +		gen8_set_pte(gte++, pte_encode | addr);
> +	GEM_BUG_ON(gte > end);
> +
> +	/* Fill the allocated but "unused" space beyond the end of the buffer */
> +	while (gte < end)
> +		gen8_set_pte(gte++, vm->scratch[0]->encode);
> +
> +	/*
> +	 * We want to flush the TLBs only after we're certain all the PTE
> +	 * updates have finished.
> +	 */
> +	ggtt->invalidate(ggtt);
> +}
> +
> +static void bxt_vtd_ggtt_wa(struct i915_address_space *vm)
> +{
> +	/*
> +	 * Make sure the internal GAM fifo has been cleared of all GTT
> +	 * writes before exiting stop_machine(). This guarantees that
> +	 * any aperture accesses waiting to start in another process
> +	 * cannot back up behind the GTT writes causing a hang.
> +	 * The register can be any arbitrary GAM register.
> +	 */
> +	intel_uncore_posting_read_fw(vm->gt->uncore, GFX_FLSH_CNTL_GEN6);
> +}
> +
> +static int bxt_vtd_ggtt_insert_page__cb(void *_arg)
> +{
> +	struct insert_page *arg = _arg;
> +
> +	gen8_ggtt_insert_page(arg->vm, arg->addr, arg->offset, arg->level, 0);
> +	bxt_vtd_ggtt_wa(arg->vm);
> +
> +	return 0;
> +}
> +
> +static void bxt_vtd_ggtt_insert_page__BKL(struct i915_address_space *vm,
> +					  dma_addr_t addr,
> +					  u64 offset,
> +					  enum i915_cache_level level,
> +					  u32 unused)
> +{
> +	struct insert_page arg = { vm, addr, offset, level };
> +
> +	stop_machine(bxt_vtd_ggtt_insert_page__cb, &arg, NULL);
> +}
> +
> +static int bxt_vtd_ggtt_insert_entries__cb(void *_arg)
> +{
> +	struct insert_entries *arg = _arg;
> +
> +	gen8_ggtt_insert_entries(arg->vm, arg->vma_res, arg->level, arg->flags);
> +	bxt_vtd_ggtt_wa(arg->vm);
> +
> +	return 0;
> +}
> +
> +static void bxt_vtd_ggtt_insert_entries__BKL(struct i915_address_space *vm,
> +					     struct i915_vma_resource *vma_res,
> +					     enum i915_cache_level level,
> +					     u32 flags)
> +{
> +	struct insert_entries arg = { vm, vma_res, level, flags };
> +
> +	stop_machine(bxt_vtd_ggtt_insert_entries__cb, &arg, NULL);
> +}
> +
> +void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)
> +{
> +	intel_gtt_chipset_flush();
> +}
> +
> +static void gmch_ggtt_invalidate(struct i915_ggtt *ggtt)
> +{
> +	intel_gtt_chipset_flush();
> +}
> +
> +static void gen5_ggtt_clear_range(struct i915_address_space *vm,
> +					 u64 start, u64 length)
> +{
> +	intel_gtt_clear_range(start >> PAGE_SHIFT, length >> PAGE_SHIFT);
> +}
> +
> +static void gen6_ggtt_clear_range(struct i915_address_space *vm,
> +				  u64 start, u64 length)
> +{
> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> +	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
> +	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
> +	gen6_pte_t scratch_pte, __iomem *gtt_base =
> +		(gen6_pte_t __iomem *)ggtt->gsm + first_entry;
> +	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
> +	int i;
> +
> +	if (WARN(num_entries > max_entries,
> +		 "First entry = %d; Num entries = %d (max=%d)\n",
> +		 first_entry, num_entries, max_entries))
> +		num_entries = max_entries;
> +
> +	scratch_pte = vm->scratch[0]->encode;
> +	for (i = 0; i < num_entries; i++)
> +		iowrite32(scratch_pte, &gtt_base[i]);
> +}
> +
> +static void gen8_ggtt_clear_range(struct i915_address_space *vm,
> +				  u64 start, u64 length)
> +{
> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> +	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
> +	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
> +	const gen8_pte_t scratch_pte = vm->scratch[0]->encode;
> +	gen8_pte_t __iomem *gtt_base =
> +		(gen8_pte_t __iomem *)ggtt->gsm + first_entry;
> +	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
> +	int i;
> +
> +	if (WARN(num_entries > max_entries,
> +		 "First entry = %d; Num entries = %d (max=%d)\n",
> +		 first_entry, num_entries, max_entries))
> +		num_entries = max_entries;
> +
> +	for (i = 0; i < num_entries; i++)
> +		gen8_set_pte(&gtt_base[i], scratch_pte);
> +}
> +
> +static void gen5_gmch_remove(struct i915_address_space *vm)
> +{
> +	intel_gmch_remove();
> +}
> +
> +static void gen6_gmch_remove(struct i915_address_space *vm)
> +{
> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
> +
> +	iounmap(ggtt->gsm);
> +	free_scratch(vm);
> +}
> +
> +/*
> + * Certain Gen5 chipsets require idling the GPU before
> + * unmapping anything from the GTT when VT-d is enabled.
> + */
> +static bool needs_idle_maps(struct drm_i915_private *i915)
> +{
> +	/*
> +	 * Query intel_iommu to see if we need the workaround. Presumably that
> +	 * was loaded first.
> +	 */
> +	if (!intel_vtd_active(i915))
> +		return false;
> +
> +	if (GRAPHICS_VER(i915) == 5 && IS_MOBILE(i915))
> +		return true;
> +
> +	if (GRAPHICS_VER(i915) == 12)
> +		return true; /* XXX DMAR fault reason 7 */
> +
> +	return false;
> +}
> +
> +static unsigned int gen6_gttmmadr_size(struct drm_i915_private *i915)
> +{
> +	/*
> +	 * GEN6: GTTMMADR size is 4MB and GTTADR starts at 2MB offset
> +	 * GEN8: GTTMMADR size is 16MB and GTTADR starts at 8MB offset
> +	 */
> +	GEM_BUG_ON(GRAPHICS_VER(i915) < 6);
> +	return (GRAPHICS_VER(i915) < 8) ? SZ_4M : SZ_16M;
> +}
> +
> +static unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
> +{
> +	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
> +	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
> +	return snb_gmch_ctl << 20;
> +}
> +
> +static unsigned int gen8_get_total_gtt_size(u16 bdw_gmch_ctl)
> +{
> +	bdw_gmch_ctl >>= BDW_GMCH_GGMS_SHIFT;
> +	bdw_gmch_ctl &= BDW_GMCH_GGMS_MASK;
> +	if (bdw_gmch_ctl)
> +		bdw_gmch_ctl = 1 << bdw_gmch_ctl;
> +
> +#ifdef CONFIG_X86_32
> +	/* Limit 32b platforms to a 2GB GGTT: 4 << 20 / pte size * I915_GTT_PAGE_SIZE */
> +	if (bdw_gmch_ctl > 4)
> +		bdw_gmch_ctl = 4;
> +#endif
> +
> +	return bdw_gmch_ctl << 20;
> +}
> +
> +static unsigned int gen6_gttadr_offset(struct drm_i915_private *i915)
> +{
> +	return gen6_gttmmadr_size(i915) / 2;
> +}
> +
> +static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size)
> +{
> +	struct drm_i915_private *i915 = ggtt->vm.i915;
> +	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
> +	phys_addr_t phys_addr;
> +	u32 pte_flags;
> +	int ret;
> +
> +	GEM_WARN_ON(pci_resource_len(pdev, 0) != gen6_gttmmadr_size(i915));
> +	phys_addr = pci_resource_start(pdev, 0) + gen6_gttadr_offset(i915);
> +
> +	/*
> +	 * On BXT+/ICL+ writes larger than 64 bit to the GTT pagetable range
> +	 * will be dropped. For WC mappings in general we have 64 byte burst
> +	 * writes when the WC buffer is flushed, so we can't use it, but have to
> +	 * resort to an uncached mapping. The WC issue is easily caught by the
> +	 * readback check when writing GTT PTE entries.
> +	 */
> +	if (IS_GEN9_LP(i915) || GRAPHICS_VER(i915) >= 11)
> +		ggtt->gsm = ioremap(phys_addr, size);
> +	else
> +		ggtt->gsm = ioremap_wc(phys_addr, size);
> +	if (!ggtt->gsm) {
> +		drm_err(&i915->drm, "Failed to map the ggtt page table\n");
> +		return -ENOMEM;
> +	}
> +
> +	kref_init(&ggtt->vm.resv_ref);
> +	ret = setup_scratch_page(&ggtt->vm);
> +	if (ret) {
> +		drm_err(&i915->drm, "Scratch setup failed\n");
> +		/* iounmap will also get called at remove, but meh */
> +		iounmap(ggtt->gsm);
> +		return ret;
> +	}
> +
> +	pte_flags = 0;
> +	if (i915_gem_object_is_lmem(ggtt->vm.scratch[0]))
> +		pte_flags |= PTE_LM;
> +
> +	ggtt->vm.scratch[0]->encode =
> +		ggtt->vm.pte_encode(px_dma(ggtt->vm.scratch[0]),
> +				    I915_CACHE_NONE, pte_flags);
> +
> +	return 0;
> +}
> +
> +int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
> +{
> +	struct drm_i915_private *i915 = ggtt->vm.i915;
> +	phys_addr_t gmadr_base;
> +	int ret;
> +
> +	ret = intel_gmch_probe(i915->bridge_dev, to_pci_dev(i915->drm.dev), NULL);
> +	if (!ret) {
> +		drm_err(&i915->drm, "failed to set up gmch\n");
> +		return -EIO;
> +	}
> +
> +	intel_gtt_get(&ggtt->vm.total, &gmadr_base, &ggtt->mappable_end);
> +
> +	ggtt->gmadr =
> +		(struct resource)DEFINE_RES_MEM(gmadr_base, ggtt->mappable_end);
> +
> +	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
> +	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
> +
> +	if (needs_idle_maps(i915)) {
> +		drm_notice(&i915->drm,
> +			   "Flushing DMA requests before IOMMU unmaps; performance may be degraded\n");
> +		ggtt->do_idle_maps = true;
> +	}
> +
> +	ggtt->vm.insert_page = gen5_ggtt_insert_page;
> +	ggtt->vm.insert_entries = gen5_ggtt_insert_entries;
> +	ggtt->vm.clear_range = gen5_ggtt_clear_range;
> +	ggtt->vm.cleanup = gen5_gmch_remove;
> +
> +	ggtt->invalidate = gmch_ggtt_invalidate;
> +
> +	ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
> +	ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
> +
> +	if (unlikely(ggtt->do_idle_maps))
> +		drm_notice(&i915->drm,
> +			   "Applying Ironlake quirks for intel_iommu\n");
> +
> +	return 0;
> +}
> +
> +int intel_gt_gmch_gen6_probe(struct i915_ggtt *ggtt)
> +{
> +	struct drm_i915_private *i915 = ggtt->vm.i915;
> +	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
> +	unsigned int size;
> +	u16 snb_gmch_ctl;
> +
> +	ggtt->gmadr = pci_resource(pdev, 2);
> +	ggtt->mappable_end = resource_size(&ggtt->gmadr);
> +
> +	/*
> +	 * 64/512MB is the current min/max we actually know of, but this is
> +	 * just a coarse sanity check.
> +	 */
> +	if (ggtt->mappable_end < (64<<20) || ggtt->mappable_end > (512<<20)) {
> +		drm_err(&i915->drm, "Unknown GMADR size (%pa)\n",
> +			&ggtt->mappable_end);
> +		return -ENXIO;
> +	}
> +
> +	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
> +
> +	size = gen6_get_total_gtt_size(snb_gmch_ctl);
> +	ggtt->vm.total = (size / sizeof(gen6_pte_t)) * I915_GTT_PAGE_SIZE;
> +
> +	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
> +	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
> +
> +	ggtt->vm.clear_range = nop_clear_range;
> +	if (!HAS_FULL_PPGTT(i915) || intel_scanout_needs_vtd_wa(i915))
> +		ggtt->vm.clear_range = gen6_ggtt_clear_range;
> +	ggtt->vm.insert_page = gen6_ggtt_insert_page;
> +	ggtt->vm.insert_entries = gen6_ggtt_insert_entries;
> +	ggtt->vm.cleanup = gen6_gmch_remove;
> +
> +	ggtt->invalidate = gen6_ggtt_invalidate;
> +
> +	if (HAS_EDRAM(i915))
> +		ggtt->vm.pte_encode = iris_pte_encode;
> +	else if (IS_HASWELL(i915))
> +		ggtt->vm.pte_encode = hsw_pte_encode;
> +	else if (IS_VALLEYVIEW(i915))
> +		ggtt->vm.pte_encode = byt_pte_encode;
> +	else if (GRAPHICS_VER(i915) >= 7)
> +		ggtt->vm.pte_encode = ivb_pte_encode;
> +	else
> +		ggtt->vm.pte_encode = snb_pte_encode;
> +
> +	ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
> +	ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
> +
> +	return ggtt_probe_common(ggtt, size);
> +}
> +
> +static unsigned int chv_get_total_gtt_size(u16 gmch_ctrl)
> +{
> +	gmch_ctrl >>= SNB_GMCH_GGMS_SHIFT;
> +	gmch_ctrl &= SNB_GMCH_GGMS_MASK;
> +
> +	if (gmch_ctrl)
> +		return 1 << (20 + gmch_ctrl);
> +
> +	return 0;
> +}
> +
> +int intel_gt_gmch_gen8_probe(struct i915_ggtt *ggtt)
> +{
> +	struct drm_i915_private *i915 = ggtt->vm.i915;
> +	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
> +	unsigned int size;
> +	u16 snb_gmch_ctl;
> +
> +	/* TODO: We're not aware of mappable constraints on gen8 yet */
> +	if (!HAS_LMEM(i915)) {
> +		ggtt->gmadr = pci_resource(pdev, 2);
> +		ggtt->mappable_end = resource_size(&ggtt->gmadr);
> +	}
> +
> +	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
> +	if (IS_CHERRYVIEW(i915))
> +		size = chv_get_total_gtt_size(snb_gmch_ctl);
> +	else
> +		size = gen8_get_total_gtt_size(snb_gmch_ctl);
> +
> +	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
> +	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
> +	ggtt->vm.lmem_pt_obj_flags = I915_BO_ALLOC_PM_EARLY;
> +
> +	ggtt->vm.total = (size / sizeof(gen8_pte_t)) * I915_GTT_PAGE_SIZE;
> +	ggtt->vm.cleanup = gen6_gmch_remove;
> +	ggtt->vm.insert_page = gen8_ggtt_insert_page;
> +	ggtt->vm.clear_range = nop_clear_range;
> +	if (intel_scanout_needs_vtd_wa(i915))
> +		ggtt->vm.clear_range = gen8_ggtt_clear_range;
> +
> +	ggtt->vm.insert_entries = gen8_ggtt_insert_entries;
> +
> +	/*
> +	 * Serialize GTT updates with aperture access on BXT if VT-d is on,
> +	 * and always on CHV.
> +	 */
> +	if (intel_vm_no_concurrent_access_wa(i915)) {
> +		ggtt->vm.insert_entries = bxt_vtd_ggtt_insert_entries__BKL;
> +		ggtt->vm.insert_page    = bxt_vtd_ggtt_insert_page__BKL;
> +		ggtt->vm.bind_async_flags =
> +			I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND;
> +	}
> +
> +	ggtt->invalidate = gen8_ggtt_invalidate;
> +
> +	ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
> +	ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
> +
> +	ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
> +
> +	setup_private_pat(ggtt->vm.gt->uncore);
> +
> +	return ggtt_probe_common(ggtt, size);
> +}
> +
> +int intel_gt_gmch_gen5_enable_hw(struct drm_i915_private *i915)
> +{
> +	if (GRAPHICS_VER(i915) < 6 && !intel_enable_gtt())
> +		return -EIO;
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_gmch.h b/drivers/gpu/drm/i915/gt/intel_gt_gmch.h
> new file mode 100644
> index 000000000000..02e5342d7ea3
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_gmch.h
> @@ -0,0 +1,46 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2022 Intel Corporation
> + */
> +
> +#ifndef __INTEL_GT_GMCH_H__
> +#define __INTEL_GT_GMCH_H__
> +
> +#include "intel_gtt.h"
> +
> +/* For x86 platforms */
> +#if IS_ENABLED(CONFIG_X86)
> +void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt);
> +int intel_gt_gmch_gen6_probe(struct i915_ggtt *ggtt);
> +int intel_gt_gmch_gen8_probe(struct i915_ggtt *ggtt);
> +int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt);
> +int intel_gt_gmch_gen5_enable_hw(struct drm_i915_private *i915);
> +
> +/* Stubs for non-x86 platforms */
> +#else
> +static inline void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)
> +{
> +}
> +static inline int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
> +{
> +	/* No HW should be probed for this case yet, return fail */
> +	return -1;
> +}
> +static inline int intel_gt_gmch_gen6_probe(struct i915_ggtt *ggtt)
> +{
> +	/* No HW should be probed for this case yet, return fail */
> +	return -1;
> +}
> +static inline int intel_gt_gmch_gen8_probe(struct i915_ggtt *ggtt)
> +{
> +	/* No HW should be probed for this case yet, return fail */
> +	return -1;
> +}
> +static inline int intel_gt_gmch_gen5_enable_hw(struct drm_i915_private *i915)
> +{
> +	/* No HW should be enabled for this case yet, return fail */
> +	return -1;
> +}
> +#endif
> +
> +#endif /* __INTEL_GT_GMCH_H__ */
> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
> index 4529b5e9f6e6..b4b9cc5a8ff6 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gtt.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
> @@ -547,6 +547,14 @@ i915_page_dir_dma_addr(const struct i915_ppgtt *ppgtt, const unsigned int n)
>   void ppgtt_init(struct i915_ppgtt *ppgtt, struct intel_gt *gt,
>   		unsigned long lmem_pt_obj_flags);
>   
> +void intel_ggtt_bind_vma(struct i915_address_space *vm,
> +			  struct i915_vm_pt_stash *stash,
> +			  struct i915_vma_resource *vma_res,
> +			  enum i915_cache_level cache_level,
> +			  u32 flags);
> +void intel_ggtt_unbind_vma(struct i915_address_space *vm,
> +			    struct i915_vma_resource *vma_res);
> +
>   int i915_ggtt_probe_hw(struct drm_i915_private *i915);
>   int i915_ggtt_init_hw(struct drm_i915_private *i915);
>   int i915_ggtt_enable_hw(struct drm_i915_private *i915);
> @@ -617,6 +625,7 @@ release_pd_entry(struct i915_page_directory * const pd,
>   		 struct i915_page_table * const pt,
>   		 const struct drm_i915_gem_object * const scratch);
>   void gen6_ggtt_invalidate(struct i915_ggtt *ggtt);
> +void gen8_ggtt_invalidate(struct i915_ggtt *ggtt);
>   
>   void ppgtt_bind_vma(struct i915_address_space *vm,
>   		    struct i915_vm_pt_stash *stash,

Jani Nikula March 30, 2022, 10:16 a.m. UTC | #2

On Tue, 29 Mar 2022, Casey Bowman <casey.g.bowman@intel.com> wrote:
> +/* Stubs for non-x86 platforms */
> +#else
> +static inline void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)
> +{
> +}
> +static inline int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
> +{
> +	/* No HW should be probed for this case yet, return fail */
> +	return -1;
> +}
> +static inline int intel_gt_gmch_gen6_probe(struct i915_ggtt *ggtt)
> +{
> +	/* No HW should be probed for this case yet, return fail */
> +	return -1;
> +}
> +static inline int intel_gt_gmch_gen8_probe(struct i915_ggtt *ggtt)
> +{
> +	/* No HW should be probed for this case yet, return fail */
> +	return -1;
> +}
> +static inline int intel_gt_gmch_gen5_enable_hw(struct drm_i915_private *i915)
> +{
> +	/* No HW should be enabled for this case yet, return fail */
> +	return -1;
> +}
> +#endif

Never use magic -1 for negative errno returns. That's -EPERM and not
what you mean. -ENODEV or -EINVAL are better here.

(As an exception, returning -1 is *maybe* fine for functions that return
an index or something, and have zero chance of propagating to somewhere
that actually interprets the number as a negative errno.)

BR,
Jani.

Jani Nikula March 30, 2022, 10:23 a.m. UTC | #3

On Wed, 30 Mar 2022, Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> wrote:
> On 30/03/2022 00:58, Casey Bowman wrote:
>> Some functions defined in the intel-gtt module are used in several
>> areas, but is only supported on x86 platforms.
>> 
>> By separating these calls and their static underlying functions to
>> another area, we are able to compile out these functions for
>> non-x86 builds and provide stubs for the non-x86 implementations.
>> 
>> In addition to the problematic calls, we are moving the gmch-related
>> functions to the new area.
>> 
>> Signed-off-by: Casey Bowman <casey.g.bowman@intel.com>
>> ---
>>   drivers/gpu/drm/i915/Makefile           |   2 +
>>   drivers/gpu/drm/i915/gt/intel_ggtt.c    | 665 +-----------------------
>>   drivers/gpu/drm/i915/gt/intel_gt.c      |   4 +-
>>   drivers/gpu/drm/i915/gt/intel_gt.h      |   9 +
>>   drivers/gpu/drm/i915/gt/intel_gt_gmch.c | 653 +++++++++++++++++++++++
>>   drivers/gpu/drm/i915/gt/intel_gt_gmch.h |  46 ++
>>   drivers/gpu/drm/i915/gt/intel_gtt.h     |   9 +
>>   7 files changed, 735 insertions(+), 653 deletions(-)
>>   create mode 100644 drivers/gpu/drm/i915/gt/intel_gt_gmch.c
>>   create mode 100644 drivers/gpu/drm/i915/gt/intel_gt_gmch.h
>> 
>> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
>> index c837a29ffac8..b7bdaec99118 100644
>> --- a/drivers/gpu/drm/i915/Makefile
>> +++ b/drivers/gpu/drm/i915/Makefile
>> @@ -126,6 +126,8 @@ gt-y += \
>>   	gt/intel_workarounds.o \
>>   	gt/shmem_utils.o \
>>   	gt/sysfs_engines.o
>> +# x86 intel-gtt module support
>> +gt-$(CONFIG_X86) += gt/intel_gt_gmch.o
>>   # autogenerated null render state
>>   gt-y += \
>>   	gt/gen6_renderstate.o \
>> diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
>> index 04191fe2ee34..97a595e42135 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
>> @@ -3,18 +3,14 @@
>>    * Copyright © 2020 Intel Corporation
>>    */
>>   
>> -#include <linux/agp_backend.h>
>> -#include <linux/stop_machine.h>
>> -
>> +#include <linux/types.h>
>>   #include <asm/set_memory.h>
>>   #include <asm/smp.h>
>>   
>> -#include <drm/i915_drm.h>
>> -#include <drm/intel-gtt.h>
>> -
>>   #include "gem/i915_gem_lmem.h"
>>   
>>   #include "intel_gt.h"
>> +#include "intel_gt_gmch.h"
>>   #include "intel_gt_regs.h"
>>   #include "i915_drv.h"
>>   #include "i915_scatterlist.h"
>> @@ -94,28 +90,6 @@ int i915_ggtt_init_hw(struct drm_i915_private *i915)
>>   	return 0;
>>   }
>>   
>> -/*
>> - * Certain Gen5 chipsets require idling the GPU before
>> - * unmapping anything from the GTT when VT-d is enabled.
>> - */
>> -static bool needs_idle_maps(struct drm_i915_private *i915)
>> -{
>> -	/*
>> -	 * Query intel_iommu to see if we need the workaround. Presumably that
>> -	 * was loaded first.
>> -	 */
>> -	if (!intel_vtd_active(i915))
>> -		return false;
>> -
>> -	if (GRAPHICS_VER(i915) == 5 && IS_MOBILE(i915))
>> -		return true;
>> -
>> -	if (GRAPHICS_VER(i915) == 12)
>> -		return true; /* XXX DMAR fault reason 7 */
>> -
>> -	return false;
>> -}
>> -
>>   /**
>>    * i915_ggtt_suspend_vm - Suspend the memory mappings for a GGTT or DPT VM
>>    * @vm: The VM to suspend the mappings for
>> @@ -204,7 +178,7 @@ void gen6_ggtt_invalidate(struct i915_ggtt *ggtt)
>>   	spin_unlock_irq(&uncore->lock);
>>   }
>>   
>> -static void gen8_ggtt_invalidate(struct i915_ggtt *ggtt)
>> +void gen8_ggtt_invalidate(struct i915_ggtt *ggtt)
>>   {
>>   	struct intel_uncore *uncore = ggtt->vm.gt->uncore;
>>   
>> @@ -229,11 +203,6 @@ static void guc_ggtt_invalidate(struct i915_ggtt *ggtt)
>>   		intel_uncore_write_fw(uncore, GEN8_GTCR, GEN8_GTCR_INVALIDATE);
>>   }
>>   
>> -static void gmch_ggtt_invalidate(struct i915_ggtt *ggtt)
>> -{
>> -	intel_gtt_chipset_flush();
>> -}
>> -
>>   u64 gen8_ggtt_pte_encode(dma_addr_t addr,
>>   			 enum i915_cache_level level,
>>   			 u32 flags)
>> @@ -246,258 +215,7 @@ u64 gen8_ggtt_pte_encode(dma_addr_t addr,
>>   	return pte;
>>   }
>>   
>> -static void gen8_set_pte(void __iomem *addr, gen8_pte_t pte)
>> -{
>> -	writeq(pte, addr);
>> -}
>> -
>> -static void gen8_ggtt_insert_page(struct i915_address_space *vm,
>> -				  dma_addr_t addr,
>> -				  u64 offset,
>> -				  enum i915_cache_level level,
>> -				  u32 flags)
>> -{
>> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> -	gen8_pte_t __iomem *pte =
>> -		(gen8_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
>> -
>> -	gen8_set_pte(pte, gen8_ggtt_pte_encode(addr, level, flags));
>> -
>> -	ggtt->invalidate(ggtt);
>> -}
>> -
>> -static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
>> -				     struct i915_vma_resource *vma_res,
>> -				     enum i915_cache_level level,
>> -				     u32 flags)
>> -{
>> -	const gen8_pte_t pte_encode = gen8_ggtt_pte_encode(0, level, flags);
>> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> -	gen8_pte_t __iomem *gte;
>> -	gen8_pte_t __iomem *end;
>> -	struct sgt_iter iter;
>> -	dma_addr_t addr;
>> -
>> -	/*
>> -	 * Note that we ignore PTE_READ_ONLY here. The caller must be careful
>> -	 * not to allow the user to override access to a read only page.
>> -	 */
>> -
>> -	gte = (gen8_pte_t __iomem *)ggtt->gsm;
>> -	gte += vma_res->start / I915_GTT_PAGE_SIZE;
>> -	end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
>> -
>> -	for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
>> -		gen8_set_pte(gte++, pte_encode | addr);
>> -	GEM_BUG_ON(gte > end);
>> -
>> -	/* Fill the allocated but "unused" space beyond the end of the buffer */
>> -	while (gte < end)
>> -		gen8_set_pte(gte++, vm->scratch[0]->encode);
>> -
>> -	/*
>> -	 * We want to flush the TLBs only after we're certain all the PTE
>> -	 * updates have finished.
>> -	 */
>> -	ggtt->invalidate(ggtt);
>> -}
>> -
>> -static void gen6_ggtt_insert_page(struct i915_address_space *vm,
>> -				  dma_addr_t addr,
>> -				  u64 offset,
>> -				  enum i915_cache_level level,
>> -				  u32 flags)
>> -{
>> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> -	gen6_pte_t __iomem *pte =
>> -		(gen6_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
>> -
>> -	iowrite32(vm->pte_encode(addr, level, flags), pte);
>> -
>> -	ggtt->invalidate(ggtt);
>> -}
>> -
>> -/*
>> - * Binds an object into the global gtt with the specified cache level.
>> - * The object will be accessible to the GPU via commands whose operands
>> - * reference offsets within the global GTT as well as accessible by the GPU
>> - * through the GMADR mapped BAR (i915->mm.gtt->gtt).
>> - */
>> -static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
>> -				     struct i915_vma_resource *vma_res,
>> -				     enum i915_cache_level level,
>> -				     u32 flags)
>> -{
>> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> -	gen6_pte_t __iomem *gte;
>> -	gen6_pte_t __iomem *end;
>> -	struct sgt_iter iter;
>> -	dma_addr_t addr;
>> -
>> -	gte = (gen6_pte_t __iomem *)ggtt->gsm;
>> -	gte += vma_res->start / I915_GTT_PAGE_SIZE;
>> -	end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
>> -
>> -	for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
>> -		iowrite32(vm->pte_encode(addr, level, flags), gte++);
>> -	GEM_BUG_ON(gte > end);
>> -
>> -	/* Fill the allocated but "unused" space beyond the end of the buffer */
>> -	while (gte < end)
>> -		iowrite32(vm->scratch[0]->encode, gte++);
>> -
>> -	/*
>> -	 * We want to flush the TLBs only after we're certain all the PTE
>> -	 * updates have finished.
>> -	 */
>> -	ggtt->invalidate(ggtt);
>> -}
>> -
>> -static void nop_clear_range(struct i915_address_space *vm,
>> -			    u64 start, u64 length)
>> -{
>> -}
>> -
>> -static void gen8_ggtt_clear_range(struct i915_address_space *vm,
>> -				  u64 start, u64 length)
>> -{
>> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> -	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
>> -	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
>> -	const gen8_pte_t scratch_pte = vm->scratch[0]->encode;
>> -	gen8_pte_t __iomem *gtt_base =
>> -		(gen8_pte_t __iomem *)ggtt->gsm + first_entry;
>> -	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
>> -	int i;
>> -
>> -	if (WARN(num_entries > max_entries,
>> -		 "First entry = %d; Num entries = %d (max=%d)\n",
>> -		 first_entry, num_entries, max_entries))
>> -		num_entries = max_entries;
>> -
>> -	for (i = 0; i < num_entries; i++)
>> -		gen8_set_pte(&gtt_base[i], scratch_pte);
>> -}
>> -
>> -static void bxt_vtd_ggtt_wa(struct i915_address_space *vm)
>> -{
>> -	/*
>> -	 * Make sure the internal GAM fifo has been cleared of all GTT
>> -	 * writes before exiting stop_machine(). This guarantees that
>> -	 * any aperture accesses waiting to start in another process
>> -	 * cannot back up behind the GTT writes causing a hang.
>> -	 * The register can be any arbitrary GAM register.
>> -	 */
>> -	intel_uncore_posting_read_fw(vm->gt->uncore, GFX_FLSH_CNTL_GEN6);
>> -}
>> -
>> -struct insert_page {
>> -	struct i915_address_space *vm;
>> -	dma_addr_t addr;
>> -	u64 offset;
>> -	enum i915_cache_level level;
>> -};
>> -
>> -static int bxt_vtd_ggtt_insert_page__cb(void *_arg)
>> -{
>> -	struct insert_page *arg = _arg;
>> -
>> -	gen8_ggtt_insert_page(arg->vm, arg->addr, arg->offset, arg->level, 0);
>> -	bxt_vtd_ggtt_wa(arg->vm);
>> -
>> -	return 0;
>> -}
>> -
>> -static void bxt_vtd_ggtt_insert_page__BKL(struct i915_address_space *vm,
>> -					  dma_addr_t addr,
>> -					  u64 offset,
>> -					  enum i915_cache_level level,
>> -					  u32 unused)
>> -{
>> -	struct insert_page arg = { vm, addr, offset, level };
>> -
>> -	stop_machine(bxt_vtd_ggtt_insert_page__cb, &arg, NULL);
>> -}
>> -
>> -struct insert_entries {
>> -	struct i915_address_space *vm;
>> -	struct i915_vma_resource *vma_res;
>> -	enum i915_cache_level level;
>> -	u32 flags;
>> -};
>> -
>> -static int bxt_vtd_ggtt_insert_entries__cb(void *_arg)
>> -{
>> -	struct insert_entries *arg = _arg;
>> -
>> -	gen8_ggtt_insert_entries(arg->vm, arg->vma_res, arg->level, arg->flags);
>> -	bxt_vtd_ggtt_wa(arg->vm);
>> -
>> -	return 0;
>> -}
>> -
>> -static void bxt_vtd_ggtt_insert_entries__BKL(struct i915_address_space *vm,
>> -					     struct i915_vma_resource *vma_res,
>> -					     enum i915_cache_level level,
>> -					     u32 flags)
>> -{
>> -	struct insert_entries arg = { vm, vma_res, level, flags };
>> -
>> -	stop_machine(bxt_vtd_ggtt_insert_entries__cb, &arg, NULL);
>> -}
>> -
>> -static void gen6_ggtt_clear_range(struct i915_address_space *vm,
>> -				  u64 start, u64 length)
>> -{
>> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> -	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
>> -	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
>> -	gen6_pte_t scratch_pte, __iomem *gtt_base =
>> -		(gen6_pte_t __iomem *)ggtt->gsm + first_entry;
>> -	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
>> -	int i;
>> -
>> -	if (WARN(num_entries > max_entries,
>> -		 "First entry = %d; Num entries = %d (max=%d)\n",
>> -		 first_entry, num_entries, max_entries))
>> -		num_entries = max_entries;
>> -
>> -	scratch_pte = vm->scratch[0]->encode;
>> -	for (i = 0; i < num_entries; i++)
>> -		iowrite32(scratch_pte, &gtt_base[i]);
>> -}
>> -
>> -static void i915_ggtt_insert_page(struct i915_address_space *vm,
>> -				  dma_addr_t addr,
>> -				  u64 offset,
>> -				  enum i915_cache_level cache_level,
>> -				  u32 unused)
>> -{
>> -	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
>> -		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
>> -
>> -	intel_gtt_insert_page(addr, offset >> PAGE_SHIFT, flags);
>> -}
>> -
>> -static void i915_ggtt_insert_entries(struct i915_address_space *vm,
>> -				     struct i915_vma_resource *vma_res,
>> -				     enum i915_cache_level cache_level,
>> -				     u32 unused)
>> -{
>> -	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
>> -		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
>> -
>> -	intel_gtt_insert_sg_entries(vma_res->bi.pages, vma_res->start >> PAGE_SHIFT,
>> -				    flags);
>> -}
>> -
>> -static void i915_ggtt_clear_range(struct i915_address_space *vm,
>> -				  u64 start, u64 length)
>> -{
>> -	intel_gtt_clear_range(start >> PAGE_SHIFT, length >> PAGE_SHIFT);
>> -}
>> -
>> -static void ggtt_bind_vma(struct i915_address_space *vm,
>> +void intel_ggtt_bind_vma(struct i915_address_space *vm,
>>   			  struct i915_vm_pt_stash *stash,
>>   			  struct i915_vma_resource *vma_res,
>>   			  enum i915_cache_level cache_level,
>> @@ -521,7 +239,7 @@ static void ggtt_bind_vma(struct i915_address_space *vm,
>>   	vma_res->page_sizes_gtt = I915_GTT_PAGE_SIZE;
>>   }
>>   
>> -static void ggtt_unbind_vma(struct i915_address_space *vm,
>> +void intel_ggtt_unbind_vma(struct i915_address_space *vm,
>>   			    struct i915_vma_resource *vma_res)
>>   {
>>   	vm->clear_range(vm, vma_res->start, vma_res->vma_size);
>> @@ -724,10 +442,10 @@ static int init_aliasing_ppgtt(struct i915_ggtt *ggtt)
>>   	ggtt->alias = ppgtt;
>>   	ggtt->vm.bind_async_flags |= ppgtt->vm.bind_async_flags;
>>   
>> -	GEM_BUG_ON(ggtt->vm.vma_ops.bind_vma != ggtt_bind_vma);
>> +	GEM_BUG_ON(ggtt->vm.vma_ops.bind_vma != intel_ggtt_bind_vma);
>>   	ggtt->vm.vma_ops.bind_vma = aliasing_gtt_bind_vma;
>>   
>> -	GEM_BUG_ON(ggtt->vm.vma_ops.unbind_vma != ggtt_unbind_vma);
>> +	GEM_BUG_ON(ggtt->vm.vma_ops.unbind_vma != intel_ggtt_unbind_vma);
>>   	ggtt->vm.vma_ops.unbind_vma = aliasing_gtt_unbind_vma;
>>   
>>   	i915_vm_free_pt_stash(&ppgtt->vm, &stash);
>> @@ -750,8 +468,8 @@ static void fini_aliasing_ppgtt(struct i915_ggtt *ggtt)
>>   
>>   	i915_vm_put(&ppgtt->vm);
>>   
>> -	ggtt->vm.vma_ops.bind_vma   = ggtt_bind_vma;
>> -	ggtt->vm.vma_ops.unbind_vma = ggtt_unbind_vma;
>> +	ggtt->vm.vma_ops.bind_vma   = intel_ggtt_bind_vma;
>> +	ggtt->vm.vma_ops.unbind_vma = intel_ggtt_unbind_vma;
>>   }
>>   
>>   int i915_init_ggtt(struct drm_i915_private *i915)
>> @@ -839,364 +557,12 @@ void i915_ggtt_driver_late_release(struct drm_i915_private *i915)
>>   	dma_resv_fini(&ggtt->vm._resv);
>>   }
>>   
>> -static unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
>> -{
>> -	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
>> -	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
>> -	return snb_gmch_ctl << 20;
>> -}
>> -
>> -static unsigned int gen8_get_total_gtt_size(u16 bdw_gmch_ctl)
>> -{
>> -	bdw_gmch_ctl >>= BDW_GMCH_GGMS_SHIFT;
>> -	bdw_gmch_ctl &= BDW_GMCH_GGMS_MASK;
>> -	if (bdw_gmch_ctl)
>> -		bdw_gmch_ctl = 1 << bdw_gmch_ctl;
>> -
>> -#ifdef CONFIG_X86_32
>> -	/* Limit 32b platforms to a 2GB GGTT: 4 << 20 / pte size * I915_GTT_PAGE_SIZE */
>> -	if (bdw_gmch_ctl > 4)
>> -		bdw_gmch_ctl = 4;
>> -#endif
>> -
>> -	return bdw_gmch_ctl << 20;
>> -}
>> -
>> -static unsigned int chv_get_total_gtt_size(u16 gmch_ctrl)
>> -{
>> -	gmch_ctrl >>= SNB_GMCH_GGMS_SHIFT;
>> -	gmch_ctrl &= SNB_GMCH_GGMS_MASK;
>> -
>> -	if (gmch_ctrl)
>> -		return 1 << (20 + gmch_ctrl);
>> -
>> -	return 0;
>> -}
>> -
>> -static unsigned int gen6_gttmmadr_size(struct drm_i915_private *i915)
>> -{
>> -	/*
>> -	 * GEN6: GTTMMADR size is 4MB and GTTADR starts at 2MB offset
>> -	 * GEN8: GTTMMADR size is 16MB and GTTADR starts at 8MB offset
>> -	 */
>> -	GEM_BUG_ON(GRAPHICS_VER(i915) < 6);
>> -	return (GRAPHICS_VER(i915) < 8) ? SZ_4M : SZ_16M;
>> -}
>> -
>> -static unsigned int gen6_gttadr_offset(struct drm_i915_private *i915)
>> -{
>> -	return gen6_gttmmadr_size(i915) / 2;
>> -}
>> -
>> -static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size)
>> -{
>> -	struct drm_i915_private *i915 = ggtt->vm.i915;
>> -	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>> -	phys_addr_t phys_addr;
>> -	u32 pte_flags;
>> -	int ret;
>> -
>> -	GEM_WARN_ON(pci_resource_len(pdev, 0) != gen6_gttmmadr_size(i915));
>> -	phys_addr = pci_resource_start(pdev, 0) + gen6_gttadr_offset(i915);
>> -
>> -	/*
>> -	 * On BXT+/ICL+ writes larger than 64 bit to the GTT pagetable range
>> -	 * will be dropped. For WC mappings in general we have 64 byte burst
>> -	 * writes when the WC buffer is flushed, so we can't use it, but have to
>> -	 * resort to an uncached mapping. The WC issue is easily caught by the
>> -	 * readback check when writing GTT PTE entries.
>> -	 */
>> -	if (IS_GEN9_LP(i915) || GRAPHICS_VER(i915) >= 11)
>> -		ggtt->gsm = ioremap(phys_addr, size);
>> -	else
>> -		ggtt->gsm = ioremap_wc(phys_addr, size);
>> -	if (!ggtt->gsm) {
>> -		drm_err(&i915->drm, "Failed to map the ggtt page table\n");
>> -		return -ENOMEM;
>> -	}
>> -
>> -	kref_init(&ggtt->vm.resv_ref);
>> -	ret = setup_scratch_page(&ggtt->vm);
>> -	if (ret) {
>> -		drm_err(&i915->drm, "Scratch setup failed\n");
>> -		/* iounmap will also get called at remove, but meh */
>> -		iounmap(ggtt->gsm);
>> -		return ret;
>> -	}
>> -
>> -	pte_flags = 0;
>> -	if (i915_gem_object_is_lmem(ggtt->vm.scratch[0]))
>> -		pte_flags |= PTE_LM;
>> -
>> -	ggtt->vm.scratch[0]->encode =
>> -		ggtt->vm.pte_encode(px_dma(ggtt->vm.scratch[0]),
>> -				    I915_CACHE_NONE, pte_flags);
>> -
>> -	return 0;
>> -}
>> -
>> -static void gen6_gmch_remove(struct i915_address_space *vm)
>> -{
>> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> -
>> -	iounmap(ggtt->gsm);
>> -	free_scratch(vm);
>> -}
>> -
>> -static struct resource pci_resource(struct pci_dev *pdev, int bar)
>> +struct resource pci_resource(struct pci_dev *pdev, int bar)
>>   {
>>   	return (struct resource)DEFINE_RES_MEM(pci_resource_start(pdev, bar),
>>   					       pci_resource_len(pdev, bar));
>>   }
>
> Export with pci_ prefix is a bit dodgy - maybe intel_pci_resource? Not sure.

Yeah, even static functions with such generic prefix and name are
discouraged. It's ugly if it ends up conflicting because we're abusing
their namespace.

BR,
Jani.



>
> The rest looks okay to me.
>
> I mean I could suggest to do something about the incosistency of:
>
> static inline void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)
>
> vs:
>
> static inline int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
>
> Since I value more for function name to tell me on what it operates 
> instead where it is placed. So I'd personally rename the second class to 
> i915_ggtt. It would also be consistent with other exported functions 
> which take struct i915_ggtt like i915_ggtt_enable_guc, i915_ggtt_resume 
> and so. But opinions will differ so I can live with it as is as well.
>
> Regards,
>
> Tvrtko
>
>>   
>> -static int gen8_gmch_probe(struct i915_ggtt *ggtt)
>> -{
>> -	struct drm_i915_private *i915 = ggtt->vm.i915;
>> -	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>> -	unsigned int size;
>> -	u16 snb_gmch_ctl;
>> -
>> -	/* TODO: We're not aware of mappable constraints on gen8 yet */
>> -	if (!HAS_LMEM(i915)) {
>> -		ggtt->gmadr = pci_resource(pdev, 2);
>> -		ggtt->mappable_end = resource_size(&ggtt->gmadr);
>> -	}
>> -
>> -	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
>> -	if (IS_CHERRYVIEW(i915))
>> -		size = chv_get_total_gtt_size(snb_gmch_ctl);
>> -	else
>> -		size = gen8_get_total_gtt_size(snb_gmch_ctl);
>> -
>> -	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>> -	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>> -	ggtt->vm.lmem_pt_obj_flags = I915_BO_ALLOC_PM_EARLY;
>> -
>> -	ggtt->vm.total = (size / sizeof(gen8_pte_t)) * I915_GTT_PAGE_SIZE;
>> -	ggtt->vm.cleanup = gen6_gmch_remove;
>> -	ggtt->vm.insert_page = gen8_ggtt_insert_page;
>> -	ggtt->vm.clear_range = nop_clear_range;
>> -	if (intel_scanout_needs_vtd_wa(i915))
>> -		ggtt->vm.clear_range = gen8_ggtt_clear_range;
>> -
>> -	ggtt->vm.insert_entries = gen8_ggtt_insert_entries;
>> -
>> -	/*
>> -	 * Serialize GTT updates with aperture access on BXT if VT-d is on,
>> -	 * and always on CHV.
>> -	 */
>> -	if (intel_vm_no_concurrent_access_wa(i915)) {
>> -		ggtt->vm.insert_entries = bxt_vtd_ggtt_insert_entries__BKL;
>> -		ggtt->vm.insert_page    = bxt_vtd_ggtt_insert_page__BKL;
>> -		ggtt->vm.bind_async_flags =
>> -			I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND;
>> -	}
>> -
>> -	ggtt->invalidate = gen8_ggtt_invalidate;
>> -
>> -	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
>> -	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
>> -
>> -	ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
>> -
>> -	setup_private_pat(ggtt->vm.gt->uncore);
>> -
>> -	return ggtt_probe_common(ggtt, size);
>> -}
>> -
>> -static u64 snb_pte_encode(dma_addr_t addr,
>> -			  enum i915_cache_level level,
>> -			  u32 flags)
>> -{
>> -	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> -
>> -	switch (level) {
>> -	case I915_CACHE_L3_LLC:
>> -	case I915_CACHE_LLC:
>> -		pte |= GEN6_PTE_CACHE_LLC;
>> -		break;
>> -	case I915_CACHE_NONE:
>> -		pte |= GEN6_PTE_UNCACHED;
>> -		break;
>> -	default:
>> -		MISSING_CASE(level);
>> -	}
>> -
>> -	return pte;
>> -}
>> -
>> -static u64 ivb_pte_encode(dma_addr_t addr,
>> -			  enum i915_cache_level level,
>> -			  u32 flags)
>> -{
>> -	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> -
>> -	switch (level) {
>> -	case I915_CACHE_L3_LLC:
>> -		pte |= GEN7_PTE_CACHE_L3_LLC;
>> -		break;
>> -	case I915_CACHE_LLC:
>> -		pte |= GEN6_PTE_CACHE_LLC;
>> -		break;
>> -	case I915_CACHE_NONE:
>> -		pte |= GEN6_PTE_UNCACHED;
>> -		break;
>> -	default:
>> -		MISSING_CASE(level);
>> -	}
>> -
>> -	return pte;
>> -}
>> -
>> -static u64 byt_pte_encode(dma_addr_t addr,
>> -			  enum i915_cache_level level,
>> -			  u32 flags)
>> -{
>> -	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> -
>> -	if (!(flags & PTE_READ_ONLY))
>> -		pte |= BYT_PTE_WRITEABLE;
>> -
>> -	if (level != I915_CACHE_NONE)
>> -		pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
>> -
>> -	return pte;
>> -}
>> -
>> -static u64 hsw_pte_encode(dma_addr_t addr,
>> -			  enum i915_cache_level level,
>> -			  u32 flags)
>> -{
>> -	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> -
>> -	if (level != I915_CACHE_NONE)
>> -		pte |= HSW_WB_LLC_AGE3;
>> -
>> -	return pte;
>> -}
>> -
>> -static u64 iris_pte_encode(dma_addr_t addr,
>> -			   enum i915_cache_level level,
>> -			   u32 flags)
>> -{
>> -	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> -
>> -	switch (level) {
>> -	case I915_CACHE_NONE:
>> -		break;
>> -	case I915_CACHE_WT:
>> -		pte |= HSW_WT_ELLC_LLC_AGE3;
>> -		break;
>> -	default:
>> -		pte |= HSW_WB_ELLC_LLC_AGE3;
>> -		break;
>> -	}
>> -
>> -	return pte;
>> -}
>> -
>> -static int gen6_gmch_probe(struct i915_ggtt *ggtt)
>> -{
>> -	struct drm_i915_private *i915 = ggtt->vm.i915;
>> -	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>> -	unsigned int size;
>> -	u16 snb_gmch_ctl;
>> -
>> -	ggtt->gmadr = pci_resource(pdev, 2);
>> -	ggtt->mappable_end = resource_size(&ggtt->gmadr);
>> -
>> -	/*
>> -	 * 64/512MB is the current min/max we actually know of, but this is
>> -	 * just a coarse sanity check.
>> -	 */
>> -	if (ggtt->mappable_end < (64<<20) || ggtt->mappable_end > (512<<20)) {
>> -		drm_err(&i915->drm, "Unknown GMADR size (%pa)\n",
>> -			&ggtt->mappable_end);
>> -		return -ENXIO;
>> -	}
>> -
>> -	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
>> -
>> -	size = gen6_get_total_gtt_size(snb_gmch_ctl);
>> -	ggtt->vm.total = (size / sizeof(gen6_pte_t)) * I915_GTT_PAGE_SIZE;
>> -
>> -	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>> -	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>> -
>> -	ggtt->vm.clear_range = nop_clear_range;
>> -	if (!HAS_FULL_PPGTT(i915) || intel_scanout_needs_vtd_wa(i915))
>> -		ggtt->vm.clear_range = gen6_ggtt_clear_range;
>> -	ggtt->vm.insert_page = gen6_ggtt_insert_page;
>> -	ggtt->vm.insert_entries = gen6_ggtt_insert_entries;
>> -	ggtt->vm.cleanup = gen6_gmch_remove;
>> -
>> -	ggtt->invalidate = gen6_ggtt_invalidate;
>> -
>> -	if (HAS_EDRAM(i915))
>> -		ggtt->vm.pte_encode = iris_pte_encode;
>> -	else if (IS_HASWELL(i915))
>> -		ggtt->vm.pte_encode = hsw_pte_encode;
>> -	else if (IS_VALLEYVIEW(i915))
>> -		ggtt->vm.pte_encode = byt_pte_encode;
>> -	else if (GRAPHICS_VER(i915) >= 7)
>> -		ggtt->vm.pte_encode = ivb_pte_encode;
>> -	else
>> -		ggtt->vm.pte_encode = snb_pte_encode;
>> -
>> -	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
>> -	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
>> -
>> -	return ggtt_probe_common(ggtt, size);
>> -}
>> -
>> -static void i915_gmch_remove(struct i915_address_space *vm)
>> -{
>> -	intel_gmch_remove();
>> -}
>> -
>> -static int i915_gmch_probe(struct i915_ggtt *ggtt)
>> -{
>> -	struct drm_i915_private *i915 = ggtt->vm.i915;
>> -	phys_addr_t gmadr_base;
>> -	int ret;
>> -
>> -	ret = intel_gmch_probe(i915->bridge_dev, to_pci_dev(i915->drm.dev), NULL);
>> -	if (!ret) {
>> -		drm_err(&i915->drm, "failed to set up gmch\n");
>> -		return -EIO;
>> -	}
>> -
>> -	intel_gtt_get(&ggtt->vm.total, &gmadr_base, &ggtt->mappable_end);
>> -
>> -	ggtt->gmadr =
>> -		(struct resource)DEFINE_RES_MEM(gmadr_base, ggtt->mappable_end);
>> -
>> -	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>> -	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>> -
>> -	if (needs_idle_maps(i915)) {
>> -		drm_notice(&i915->drm,
>> -			   "Flushing DMA requests before IOMMU unmaps; performance may be degraded\n");
>> -		ggtt->do_idle_maps = true;
>> -	}
>> -
>> -	ggtt->vm.insert_page = i915_ggtt_insert_page;
>> -	ggtt->vm.insert_entries = i915_ggtt_insert_entries;
>> -	ggtt->vm.clear_range = i915_ggtt_clear_range;
>> -	ggtt->vm.cleanup = i915_gmch_remove;
>> -
>> -	ggtt->invalidate = gmch_ggtt_invalidate;
>> -
>> -	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
>> -	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
>> -
>> -	if (unlikely(ggtt->do_idle_maps))
>> -		drm_notice(&i915->drm,
>> -			   "Applying Ironlake quirks for intel_iommu\n");
>> -
>> -	return 0;
>> -}
>> -
>>   static int ggtt_probe_hw(struct i915_ggtt *ggtt, struct intel_gt *gt)
>>   {
>>   	struct drm_i915_private *i915 = gt->i915;
>> @@ -1208,11 +574,11 @@ static int ggtt_probe_hw(struct i915_ggtt *ggtt, struct intel_gt *gt)
>>   	dma_resv_init(&ggtt->vm._resv);
>>   
>>   	if (GRAPHICS_VER(i915) <= 5)
>> -		ret = i915_gmch_probe(ggtt);
>> +		ret = intel_gt_gmch_gen5_probe(ggtt);
>>   	else if (GRAPHICS_VER(i915) < 8)
>> -		ret = gen6_gmch_probe(ggtt);
>> +		ret = intel_gt_gmch_gen6_probe(ggtt);
>>   	else
>> -		ret = gen8_gmch_probe(ggtt);
>> +		ret = intel_gt_gmch_gen8_probe(ggtt);
>>   	if (ret) {
>>   		dma_resv_fini(&ggtt->vm._resv);
>>   		return ret;
>> @@ -1266,10 +632,7 @@ int i915_ggtt_probe_hw(struct drm_i915_private *i915)
>>   
>>   int i915_ggtt_enable_hw(struct drm_i915_private *i915)
>>   {
>> -	if (GRAPHICS_VER(i915) < 6 && !intel_enable_gtt())
>> -		return -EIO;
>> -
>> -	return 0;
>> +	return intel_gt_gmch_gen5_enable_hw(i915);
>>   }
>>   
>>   void i915_ggtt_enable_guc(struct i915_ggtt *ggtt)
>> diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
>> index 5001a6168d56..f0014c5072c9 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_gt.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_gt.c
>> @@ -4,7 +4,6 @@
>>    */
>>   
>>   #include <drm/drm_managed.h>
>> -#include <drm/intel-gtt.h>
>>   
>>   #include "gem/i915_gem_internal.h"
>>   #include "gem/i915_gem_lmem.h"
>> @@ -17,6 +16,7 @@
>>   #include "intel_gt_buffer_pool.h"
>>   #include "intel_gt_clock_utils.h"
>>   #include "intel_gt_debugfs.h"
>> +#include "intel_gt_gmch.h"
>>   #include "intel_gt_pm.h"
>>   #include "intel_gt_regs.h"
>>   #include "intel_gt_requests.h"
>> @@ -451,7 +451,7 @@ void intel_gt_chipset_flush(struct intel_gt *gt)
>>   {
>>   	wmb();
>>   	if (GRAPHICS_VER(gt->i915) < 6)
>> -		intel_gtt_chipset_flush();
>> +		intel_gt_gmch_gen5_chipset_flush(gt);
>>   }
>>   
>>   void intel_gt_driver_register(struct intel_gt *gt)
>> diff --git a/drivers/gpu/drm/i915/gt/intel_gt.h b/drivers/gpu/drm/i915/gt/intel_gt.h
>> index e76168e10a21..8956dfc5afe0 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_gt.h
>> +++ b/drivers/gpu/drm/i915/gt/intel_gt.h
>> @@ -13,6 +13,13 @@
>>   struct drm_i915_private;
>>   struct drm_printer;
>>   
>> +struct insert_entries {
>> +	struct i915_address_space *vm;
>> +	struct i915_vma_resource *vma_res;
>> +	enum i915_cache_level level;
>> +	u32 flags;
>> +};
>> +
>>   #define GT_TRACE(gt, fmt, ...) do {					\
>>   	const struct intel_gt *gt__ __maybe_unused = (gt);		\
>>   	GEM_TRACE("%s " fmt, dev_name(gt__->i915->drm.dev),		\
>> @@ -113,4 +120,6 @@ void intel_gt_watchdog_work(struct work_struct *work);
>>   
>>   void intel_gt_invalidate_tlbs(struct intel_gt *gt);
>>   
>> +struct resource pci_resource(struct pci_dev *pdev, int bar);
>> +
>>   #endif /* __INTEL_GT_H__ */
>> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_gmch.c b/drivers/gpu/drm/i915/gt/intel_gt_gmch.c
>> new file mode 100644
>> index 000000000000..b914ebb30166
>> --- /dev/null
>> +++ b/drivers/gpu/drm/i915/gt/intel_gt_gmch.c
>> @@ -0,0 +1,653 @@
>> +// SPDX-License-Identifier: MIT
>> +/*
>> + * Copyright © 2022 Intel Corporation
>> + */
>> +
>> +#include <drm/intel-gtt.h>
>> +#include <drm/i915_drm.h>
>> +
>> +#include <linux/agp_backend.h>
>> +#include <linux/stop_machine.h>
>> +
>> +#include "i915_drv.h"
>> +#include "intel_gt_gmch.h"
>> +#include "intel_gt_regs.h"
>> +#include "intel_gt.h"
>> +
>> +#include "gen8_ppgtt.h"
>> +
>> +struct insert_page {
>> +	struct i915_address_space *vm;
>> +	dma_addr_t addr;
>> +	u64 offset;
>> +	enum i915_cache_level level;
>> +};
>> +
>> +static void gen8_set_pte(void __iomem *addr, gen8_pte_t pte)
>> +{
>> +	writeq(pte, addr);
>> +}
>> +
>> +static void nop_clear_range(struct i915_address_space *vm,
>> +			    u64 start, u64 length)
>> +{
>> +}
>> +
>> +static u64 snb_pte_encode(dma_addr_t addr,
>> +			  enum i915_cache_level level,
>> +			  u32 flags)
>> +{
>> +	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> +
>> +	switch (level) {
>> +	case I915_CACHE_L3_LLC:
>> +	case I915_CACHE_LLC:
>> +		pte |= GEN6_PTE_CACHE_LLC;
>> +		break;
>> +	case I915_CACHE_NONE:
>> +		pte |= GEN6_PTE_UNCACHED;
>> +		break;
>> +	default:
>> +		MISSING_CASE(level);
>> +	}
>> +
>> +	return pte;
>> +}
>> +
>> +static u64 ivb_pte_encode(dma_addr_t addr,
>> +			  enum i915_cache_level level,
>> +			  u32 flags)
>> +{
>> +	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> +
>> +	switch (level) {
>> +	case I915_CACHE_L3_LLC:
>> +		pte |= GEN7_PTE_CACHE_L3_LLC;
>> +		break;
>> +	case I915_CACHE_LLC:
>> +		pte |= GEN6_PTE_CACHE_LLC;
>> +		break;
>> +	case I915_CACHE_NONE:
>> +		pte |= GEN6_PTE_UNCACHED;
>> +		break;
>> +	default:
>> +		MISSING_CASE(level);
>> +	}
>> +
>> +	return pte;
>> +}
>> +
>> +static u64 byt_pte_encode(dma_addr_t addr,
>> +			  enum i915_cache_level level,
>> +			  u32 flags)
>> +{
>> +	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> +
>> +	if (!(flags & PTE_READ_ONLY))
>> +		pte |= BYT_PTE_WRITEABLE;
>> +
>> +	if (level != I915_CACHE_NONE)
>> +		pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
>> +
>> +	return pte;
>> +}
>> +
>> +static u64 hsw_pte_encode(dma_addr_t addr,
>> +			  enum i915_cache_level level,
>> +			  u32 flags)
>> +{
>> +	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> +
>> +	if (level != I915_CACHE_NONE)
>> +		pte |= HSW_WB_LLC_AGE3;
>> +
>> +	return pte;
>> +}
>> +
>> +static u64 iris_pte_encode(dma_addr_t addr,
>> +			   enum i915_cache_level level,
>> +			   u32 flags)
>> +{
>> +	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> +
>> +	switch (level) {
>> +	case I915_CACHE_NONE:
>> +		break;
>> +	case I915_CACHE_WT:
>> +		pte |= HSW_WT_ELLC_LLC_AGE3;
>> +		break;
>> +	default:
>> +		pte |= HSW_WB_ELLC_LLC_AGE3;
>> +		break;
>> +	}
>> +
>> +	return pte;
>> +}
>> +
>> +static void gen5_ggtt_insert_page(struct i915_address_space *vm,
>> +				  dma_addr_t addr,
>> +				  u64 offset,
>> +				  enum i915_cache_level cache_level,
>> +				  u32 unused)
>> +{
>> +	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
>> +		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
>> +
>> +	intel_gtt_insert_page(addr, offset >> PAGE_SHIFT, flags);
>> +}
>> +
>> +static void gen6_ggtt_insert_page(struct i915_address_space *vm,
>> +				  dma_addr_t addr,
>> +				  u64 offset,
>> +				  enum i915_cache_level level,
>> +				  u32 flags)
>> +{
>> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> +	gen6_pte_t __iomem *pte =
>> +		(gen6_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
>> +
>> +	iowrite32(vm->pte_encode(addr, level, flags), pte);
>> +
>> +	ggtt->invalidate(ggtt);
>> +}
>> +
>> +static void gen8_ggtt_insert_page(struct i915_address_space *vm,
>> +				  dma_addr_t addr,
>> +				  u64 offset,
>> +				  enum i915_cache_level level,
>> +				  u32 flags)
>> +{
>> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> +	gen8_pte_t __iomem *pte =
>> +		(gen8_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
>> +
>> +	gen8_set_pte(pte, gen8_ggtt_pte_encode(addr, level, flags));
>> +
>> +	ggtt->invalidate(ggtt);
>> +}
>> +
>> +static void gen5_ggtt_insert_entries(struct i915_address_space *vm,
>> +				     struct i915_vma_resource *vma_res,
>> +				     enum i915_cache_level cache_level,
>> +				     u32 unused)
>> +{
>> +	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
>> +		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
>> +
>> +	intel_gtt_insert_sg_entries(vma_res->bi.pages, vma_res->start >> PAGE_SHIFT,
>> +				    flags);
>> +}
>> +
>> +/*
>> + * Binds an object into the global gtt with the specified cache level.
>> + * The object will be accessible to the GPU via commands whose operands
>> + * reference offsets within the global GTT as well as accessible by the GPU
>> + * through the GMADR mapped BAR (i915->mm.gtt->gtt).
>> + */
>> +static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
>> +				     struct i915_vma_resource *vma_res,
>> +				     enum i915_cache_level level,
>> +				     u32 flags)
>> +{
>> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> +	gen6_pte_t __iomem *gte;
>> +	gen6_pte_t __iomem *end;
>> +	struct sgt_iter iter;
>> +	dma_addr_t addr;
>> +
>> +	gte = (gen6_pte_t __iomem *)ggtt->gsm;
>> +	gte += vma_res->start / I915_GTT_PAGE_SIZE;
>> +	end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
>> +
>> +	for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
>> +		iowrite32(vm->pte_encode(addr, level, flags), gte++);
>> +	GEM_BUG_ON(gte > end);
>> +
>> +	/* Fill the allocated but "unused" space beyond the end of the buffer */
>> +	while (gte < end)
>> +		iowrite32(vm->scratch[0]->encode, gte++);
>> +
>> +	/*
>> +	 * We want to flush the TLBs only after we're certain all the PTE
>> +	 * updates have finished.
>> +	 */
>> +	ggtt->invalidate(ggtt);
>> +}
>> +
>> +static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
>> +				     struct i915_vma_resource *vma_res,
>> +				     enum i915_cache_level level,
>> +				     u32 flags)
>> +{
>> +	const gen8_pte_t pte_encode = gen8_ggtt_pte_encode(0, level, flags);
>> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> +	gen8_pte_t __iomem *gte;
>> +	gen8_pte_t __iomem *end;
>> +	struct sgt_iter iter;
>> +	dma_addr_t addr;
>> +
>> +	/*
>> +	 * Note that we ignore PTE_READ_ONLY here. The caller must be careful
>> +	 * not to allow the user to override access to a read only page.
>> +	 */
>> +
>> +	gte = (gen8_pte_t __iomem *)ggtt->gsm;
>> +	gte += vma_res->start / I915_GTT_PAGE_SIZE;
>> +	end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
>> +
>> +	for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
>> +		gen8_set_pte(gte++, pte_encode | addr);
>> +	GEM_BUG_ON(gte > end);
>> +
>> +	/* Fill the allocated but "unused" space beyond the end of the buffer */
>> +	while (gte < end)
>> +		gen8_set_pte(gte++, vm->scratch[0]->encode);
>> +
>> +	/*
>> +	 * We want to flush the TLBs only after we're certain all the PTE
>> +	 * updates have finished.
>> +	 */
>> +	ggtt->invalidate(ggtt);
>> +}
>> +
>> +static void bxt_vtd_ggtt_wa(struct i915_address_space *vm)
>> +{
>> +	/*
>> +	 * Make sure the internal GAM fifo has been cleared of all GTT
>> +	 * writes before exiting stop_machine(). This guarantees that
>> +	 * any aperture accesses waiting to start in another process
>> +	 * cannot back up behind the GTT writes causing a hang.
>> +	 * The register can be any arbitrary GAM register.
>> +	 */
>> +	intel_uncore_posting_read_fw(vm->gt->uncore, GFX_FLSH_CNTL_GEN6);
>> +}
>> +
>> +static int bxt_vtd_ggtt_insert_page__cb(void *_arg)
>> +{
>> +	struct insert_page *arg = _arg;
>> +
>> +	gen8_ggtt_insert_page(arg->vm, arg->addr, arg->offset, arg->level, 0);
>> +	bxt_vtd_ggtt_wa(arg->vm);
>> +
>> +	return 0;
>> +}
>> +
>> +static void bxt_vtd_ggtt_insert_page__BKL(struct i915_address_space *vm,
>> +					  dma_addr_t addr,
>> +					  u64 offset,
>> +					  enum i915_cache_level level,
>> +					  u32 unused)
>> +{
>> +	struct insert_page arg = { vm, addr, offset, level };
>> +
>> +	stop_machine(bxt_vtd_ggtt_insert_page__cb, &arg, NULL);
>> +}
>> +
>> +static int bxt_vtd_ggtt_insert_entries__cb(void *_arg)
>> +{
>> +	struct insert_entries *arg = _arg;
>> +
>> +	gen8_ggtt_insert_entries(arg->vm, arg->vma_res, arg->level, arg->flags);
>> +	bxt_vtd_ggtt_wa(arg->vm);
>> +
>> +	return 0;
>> +}
>> +
>> +static void bxt_vtd_ggtt_insert_entries__BKL(struct i915_address_space *vm,
>> +					     struct i915_vma_resource *vma_res,
>> +					     enum i915_cache_level level,
>> +					     u32 flags)
>> +{
>> +	struct insert_entries arg = { vm, vma_res, level, flags };
>> +
>> +	stop_machine(bxt_vtd_ggtt_insert_entries__cb, &arg, NULL);
>> +}
>> +
>> +void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)
>> +{
>> +	intel_gtt_chipset_flush();
>> +}
>> +
>> +static void gmch_ggtt_invalidate(struct i915_ggtt *ggtt)
>> +{
>> +	intel_gtt_chipset_flush();
>> +}
>> +
>> +static void gen5_ggtt_clear_range(struct i915_address_space *vm,
>> +					 u64 start, u64 length)
>> +{
>> +	intel_gtt_clear_range(start >> PAGE_SHIFT, length >> PAGE_SHIFT);
>> +}
>> +
>> +static void gen6_ggtt_clear_range(struct i915_address_space *vm,
>> +				  u64 start, u64 length)
>> +{
>> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> +	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
>> +	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
>> +	gen6_pte_t scratch_pte, __iomem *gtt_base =
>> +		(gen6_pte_t __iomem *)ggtt->gsm + first_entry;
>> +	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
>> +	int i;
>> +
>> +	if (WARN(num_entries > max_entries,
>> +		 "First entry = %d; Num entries = %d (max=%d)\n",
>> +		 first_entry, num_entries, max_entries))
>> +		num_entries = max_entries;
>> +
>> +	scratch_pte = vm->scratch[0]->encode;
>> +	for (i = 0; i < num_entries; i++)
>> +		iowrite32(scratch_pte, &gtt_base[i]);
>> +}
>> +
>> +static void gen8_ggtt_clear_range(struct i915_address_space *vm,
>> +				  u64 start, u64 length)
>> +{
>> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> +	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
>> +	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
>> +	const gen8_pte_t scratch_pte = vm->scratch[0]->encode;
>> +	gen8_pte_t __iomem *gtt_base =
>> +		(gen8_pte_t __iomem *)ggtt->gsm + first_entry;
>> +	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
>> +	int i;
>> +
>> +	if (WARN(num_entries > max_entries,
>> +		 "First entry = %d; Num entries = %d (max=%d)\n",
>> +		 first_entry, num_entries, max_entries))
>> +		num_entries = max_entries;
>> +
>> +	for (i = 0; i < num_entries; i++)
>> +		gen8_set_pte(&gtt_base[i], scratch_pte);
>> +}
>> +
>> +static void gen5_gmch_remove(struct i915_address_space *vm)
>> +{
>> +	intel_gmch_remove();
>> +}
>> +
>> +static void gen6_gmch_remove(struct i915_address_space *vm)
>> +{
>> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> +
>> +	iounmap(ggtt->gsm);
>> +	free_scratch(vm);
>> +}
>> +
>> +/*
>> + * Certain Gen5 chipsets require idling the GPU before
>> + * unmapping anything from the GTT when VT-d is enabled.
>> + */
>> +static bool needs_idle_maps(struct drm_i915_private *i915)
>> +{
>> +	/*
>> +	 * Query intel_iommu to see if we need the workaround. Presumably that
>> +	 * was loaded first.
>> +	 */
>> +	if (!intel_vtd_active(i915))
>> +		return false;
>> +
>> +	if (GRAPHICS_VER(i915) == 5 && IS_MOBILE(i915))
>> +		return true;
>> +
>> +	if (GRAPHICS_VER(i915) == 12)
>> +		return true; /* XXX DMAR fault reason 7 */
>> +
>> +	return false;
>> +}
>> +
>> +static unsigned int gen6_gttmmadr_size(struct drm_i915_private *i915)
>> +{
>> +	/*
>> +	 * GEN6: GTTMMADR size is 4MB and GTTADR starts at 2MB offset
>> +	 * GEN8: GTTMMADR size is 16MB and GTTADR starts at 8MB offset
>> +	 */
>> +	GEM_BUG_ON(GRAPHICS_VER(i915) < 6);
>> +	return (GRAPHICS_VER(i915) < 8) ? SZ_4M : SZ_16M;
>> +}
>> +
>> +static unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
>> +{
>> +	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
>> +	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
>> +	return snb_gmch_ctl << 20;
>> +}
>> +
>> +static unsigned int gen8_get_total_gtt_size(u16 bdw_gmch_ctl)
>> +{
>> +	bdw_gmch_ctl >>= BDW_GMCH_GGMS_SHIFT;
>> +	bdw_gmch_ctl &= BDW_GMCH_GGMS_MASK;
>> +	if (bdw_gmch_ctl)
>> +		bdw_gmch_ctl = 1 << bdw_gmch_ctl;
>> +
>> +#ifdef CONFIG_X86_32
>> +	/* Limit 32b platforms to a 2GB GGTT: 4 << 20 / pte size * I915_GTT_PAGE_SIZE */
>> +	if (bdw_gmch_ctl > 4)
>> +		bdw_gmch_ctl = 4;
>> +#endif
>> +
>> +	return bdw_gmch_ctl << 20;
>> +}
>> +
>> +static unsigned int gen6_gttadr_offset(struct drm_i915_private *i915)
>> +{
>> +	return gen6_gttmmadr_size(i915) / 2;
>> +}
>> +
>> +static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size)
>> +{
>> +	struct drm_i915_private *i915 = ggtt->vm.i915;
>> +	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>> +	phys_addr_t phys_addr;
>> +	u32 pte_flags;
>> +	int ret;
>> +
>> +	GEM_WARN_ON(pci_resource_len(pdev, 0) != gen6_gttmmadr_size(i915));
>> +	phys_addr = pci_resource_start(pdev, 0) + gen6_gttadr_offset(i915);
>> +
>> +	/*
>> +	 * On BXT+/ICL+ writes larger than 64 bit to the GTT pagetable range
>> +	 * will be dropped. For WC mappings in general we have 64 byte burst
>> +	 * writes when the WC buffer is flushed, so we can't use it, but have to
>> +	 * resort to an uncached mapping. The WC issue is easily caught by the
>> +	 * readback check when writing GTT PTE entries.
>> +	 */
>> +	if (IS_GEN9_LP(i915) || GRAPHICS_VER(i915) >= 11)
>> +		ggtt->gsm = ioremap(phys_addr, size);
>> +	else
>> +		ggtt->gsm = ioremap_wc(phys_addr, size);
>> +	if (!ggtt->gsm) {
>> +		drm_err(&i915->drm, "Failed to map the ggtt page table\n");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	kref_init(&ggtt->vm.resv_ref);
>> +	ret = setup_scratch_page(&ggtt->vm);
>> +	if (ret) {
>> +		drm_err(&i915->drm, "Scratch setup failed\n");
>> +		/* iounmap will also get called at remove, but meh */
>> +		iounmap(ggtt->gsm);
>> +		return ret;
>> +	}
>> +
>> +	pte_flags = 0;
>> +	if (i915_gem_object_is_lmem(ggtt->vm.scratch[0]))
>> +		pte_flags |= PTE_LM;
>> +
>> +	ggtt->vm.scratch[0]->encode =
>> +		ggtt->vm.pte_encode(px_dma(ggtt->vm.scratch[0]),
>> +				    I915_CACHE_NONE, pte_flags);
>> +
>> +	return 0;
>> +}
>> +
>> +int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
>> +{
>> +	struct drm_i915_private *i915 = ggtt->vm.i915;
>> +	phys_addr_t gmadr_base;
>> +	int ret;
>> +
>> +	ret = intel_gmch_probe(i915->bridge_dev, to_pci_dev(i915->drm.dev), NULL);
>> +	if (!ret) {
>> +		drm_err(&i915->drm, "failed to set up gmch\n");
>> +		return -EIO;
>> +	}
>> +
>> +	intel_gtt_get(&ggtt->vm.total, &gmadr_base, &ggtt->mappable_end);
>> +
>> +	ggtt->gmadr =
>> +		(struct resource)DEFINE_RES_MEM(gmadr_base, ggtt->mappable_end);
>> +
>> +	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>> +	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>> +
>> +	if (needs_idle_maps(i915)) {
>> +		drm_notice(&i915->drm,
>> +			   "Flushing DMA requests before IOMMU unmaps; performance may be degraded\n");
>> +		ggtt->do_idle_maps = true;
>> +	}
>> +
>> +	ggtt->vm.insert_page = gen5_ggtt_insert_page;
>> +	ggtt->vm.insert_entries = gen5_ggtt_insert_entries;
>> +	ggtt->vm.clear_range = gen5_ggtt_clear_range;
>> +	ggtt->vm.cleanup = gen5_gmch_remove;
>> +
>> +	ggtt->invalidate = gmch_ggtt_invalidate;
>> +
>> +	ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
>> +	ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
>> +
>> +	if (unlikely(ggtt->do_idle_maps))
>> +		drm_notice(&i915->drm,
>> +			   "Applying Ironlake quirks for intel_iommu\n");
>> +
>> +	return 0;
>> +}
>> +
>> +int intel_gt_gmch_gen6_probe(struct i915_ggtt *ggtt)
>> +{
>> +	struct drm_i915_private *i915 = ggtt->vm.i915;
>> +	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>> +	unsigned int size;
>> +	u16 snb_gmch_ctl;
>> +
>> +	ggtt->gmadr = pci_resource(pdev, 2);
>> +	ggtt->mappable_end = resource_size(&ggtt->gmadr);
>> +
>> +	/*
>> +	 * 64/512MB is the current min/max we actually know of, but this is
>> +	 * just a coarse sanity check.
>> +	 */
>> +	if (ggtt->mappable_end < (64<<20) || ggtt->mappable_end > (512<<20)) {
>> +		drm_err(&i915->drm, "Unknown GMADR size (%pa)\n",
>> +			&ggtt->mappable_end);
>> +		return -ENXIO;
>> +	}
>> +
>> +	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
>> +
>> +	size = gen6_get_total_gtt_size(snb_gmch_ctl);
>> +	ggtt->vm.total = (size / sizeof(gen6_pte_t)) * I915_GTT_PAGE_SIZE;
>> +
>> +	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>> +	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>> +
>> +	ggtt->vm.clear_range = nop_clear_range;
>> +	if (!HAS_FULL_PPGTT(i915) || intel_scanout_needs_vtd_wa(i915))
>> +		ggtt->vm.clear_range = gen6_ggtt_clear_range;
>> +	ggtt->vm.insert_page = gen6_ggtt_insert_page;
>> +	ggtt->vm.insert_entries = gen6_ggtt_insert_entries;
>> +	ggtt->vm.cleanup = gen6_gmch_remove;
>> +
>> +	ggtt->invalidate = gen6_ggtt_invalidate;
>> +
>> +	if (HAS_EDRAM(i915))
>> +		ggtt->vm.pte_encode = iris_pte_encode;
>> +	else if (IS_HASWELL(i915))
>> +		ggtt->vm.pte_encode = hsw_pte_encode;
>> +	else if (IS_VALLEYVIEW(i915))
>> +		ggtt->vm.pte_encode = byt_pte_encode;
>> +	else if (GRAPHICS_VER(i915) >= 7)
>> +		ggtt->vm.pte_encode = ivb_pte_encode;
>> +	else
>> +		ggtt->vm.pte_encode = snb_pte_encode;
>> +
>> +	ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
>> +	ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
>> +
>> +	return ggtt_probe_common(ggtt, size);
>> +}
>> +
>> +static unsigned int chv_get_total_gtt_size(u16 gmch_ctrl)
>> +{
>> +	gmch_ctrl >>= SNB_GMCH_GGMS_SHIFT;
>> +	gmch_ctrl &= SNB_GMCH_GGMS_MASK;
>> +
>> +	if (gmch_ctrl)
>> +		return 1 << (20 + gmch_ctrl);
>> +
>> +	return 0;
>> +}
>> +
>> +int intel_gt_gmch_gen8_probe(struct i915_ggtt *ggtt)
>> +{
>> +	struct drm_i915_private *i915 = ggtt->vm.i915;
>> +	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>> +	unsigned int size;
>> +	u16 snb_gmch_ctl;
>> +
>> +	/* TODO: We're not aware of mappable constraints on gen8 yet */
>> +	if (!HAS_LMEM(i915)) {
>> +		ggtt->gmadr = pci_resource(pdev, 2);
>> +		ggtt->mappable_end = resource_size(&ggtt->gmadr);
>> +	}
>> +
>> +	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
>> +	if (IS_CHERRYVIEW(i915))
>> +		size = chv_get_total_gtt_size(snb_gmch_ctl);
>> +	else
>> +		size = gen8_get_total_gtt_size(snb_gmch_ctl);
>> +
>> +	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>> +	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>> +	ggtt->vm.lmem_pt_obj_flags = I915_BO_ALLOC_PM_EARLY;
>> +
>> +	ggtt->vm.total = (size / sizeof(gen8_pte_t)) * I915_GTT_PAGE_SIZE;
>> +	ggtt->vm.cleanup = gen6_gmch_remove;
>> +	ggtt->vm.insert_page = gen8_ggtt_insert_page;
>> +	ggtt->vm.clear_range = nop_clear_range;
>> +	if (intel_scanout_needs_vtd_wa(i915))
>> +		ggtt->vm.clear_range = gen8_ggtt_clear_range;
>> +
>> +	ggtt->vm.insert_entries = gen8_ggtt_insert_entries;
>> +
>> +	/*
>> +	 * Serialize GTT updates with aperture access on BXT if VT-d is on,
>> +	 * and always on CHV.
>> +	 */
>> +	if (intel_vm_no_concurrent_access_wa(i915)) {
>> +		ggtt->vm.insert_entries = bxt_vtd_ggtt_insert_entries__BKL;
>> +		ggtt->vm.insert_page    = bxt_vtd_ggtt_insert_page__BKL;
>> +		ggtt->vm.bind_async_flags =
>> +			I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND;
>> +	}
>> +
>> +	ggtt->invalidate = gen8_ggtt_invalidate;
>> +
>> +	ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
>> +	ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
>> +
>> +	ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
>> +
>> +	setup_private_pat(ggtt->vm.gt->uncore);
>> +
>> +	return ggtt_probe_common(ggtt, size);
>> +}
>> +
>> +int intel_gt_gmch_gen5_enable_hw(struct drm_i915_private *i915)
>> +{
>> +	if (GRAPHICS_VER(i915) < 6 && !intel_enable_gtt())
>> +		return -EIO;
>> +
>> +	return 0;
>> +}
>> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_gmch.h b/drivers/gpu/drm/i915/gt/intel_gt_gmch.h
>> new file mode 100644
>> index 000000000000..02e5342d7ea3
>> --- /dev/null
>> +++ b/drivers/gpu/drm/i915/gt/intel_gt_gmch.h
>> @@ -0,0 +1,46 @@
>> +/* SPDX-License-Identifier: MIT */
>> +/*
>> + * Copyright © 2022 Intel Corporation
>> + */
>> +
>> +#ifndef __INTEL_GT_GMCH_H__
>> +#define __INTEL_GT_GMCH_H__
>> +
>> +#include "intel_gtt.h"
>> +
>> +/* For x86 platforms */
>> +#if IS_ENABLED(CONFIG_X86)
>> +void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt);
>> +int intel_gt_gmch_gen6_probe(struct i915_ggtt *ggtt);
>> +int intel_gt_gmch_gen8_probe(struct i915_ggtt *ggtt);
>> +int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt);
>> +int intel_gt_gmch_gen5_enable_hw(struct drm_i915_private *i915);
>> +
>> +/* Stubs for non-x86 platforms */
>> +#else
>> +static inline void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)
>> +{
>> +}
>> +static inline int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
>> +{
>> +	/* No HW should be probed for this case yet, return fail */
>> +	return -1;
>> +}
>> +static inline int intel_gt_gmch_gen6_probe(struct i915_ggtt *ggtt)
>> +{
>> +	/* No HW should be probed for this case yet, return fail */
>> +	return -1;
>> +}
>> +static inline int intel_gt_gmch_gen8_probe(struct i915_ggtt *ggtt)
>> +{
>> +	/* No HW should be probed for this case yet, return fail */
>> +	return -1;
>> +}
>> +static inline int intel_gt_gmch_gen5_enable_hw(struct drm_i915_private *i915)
>> +{
>> +	/* No HW should be enabled for this case yet, return fail */
>> +	return -1;
>> +}
>> +#endif
>> +
>> +#endif /* __INTEL_GT_GMCH_H__ */
>> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
>> index 4529b5e9f6e6..b4b9cc5a8ff6 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_gtt.h
>> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
>> @@ -547,6 +547,14 @@ i915_page_dir_dma_addr(const struct i915_ppgtt *ppgtt, const unsigned int n)
>>   void ppgtt_init(struct i915_ppgtt *ppgtt, struct intel_gt *gt,
>>   		unsigned long lmem_pt_obj_flags);
>>   
>> +void intel_ggtt_bind_vma(struct i915_address_space *vm,
>> +			  struct i915_vm_pt_stash *stash,
>> +			  struct i915_vma_resource *vma_res,
>> +			  enum i915_cache_level cache_level,
>> +			  u32 flags);
>> +void intel_ggtt_unbind_vma(struct i915_address_space *vm,
>> +			    struct i915_vma_resource *vma_res);
>> +
>>   int i915_ggtt_probe_hw(struct drm_i915_private *i915);
>>   int i915_ggtt_init_hw(struct drm_i915_private *i915);
>>   int i915_ggtt_enable_hw(struct drm_i915_private *i915);
>> @@ -617,6 +625,7 @@ release_pd_entry(struct i915_page_directory * const pd,
>>   		 struct i915_page_table * const pt,
>>   		 const struct drm_i915_gem_object * const scratch);
>>   void gen6_ggtt_invalidate(struct i915_ggtt *ggtt);
>> +void gen8_ggtt_invalidate(struct i915_ggtt *ggtt);
>>   
>>   void ppgtt_bind_vma(struct i915_address_space *vm,
>>   		    struct i915_vm_pt_stash *stash,

Bowman, Casey G March 30, 2022, 4:31 p.m. UTC | #4

On 3/30/22 03:23, Jani Nikula wrote:
> On Wed, 30 Mar 2022, Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> wrote:
>> On 30/03/2022 00:58, Casey Bowman wrote:
>>> Some functions defined in the intel-gtt module are used in several
>>> areas, but is only supported on x86 platforms.
>>>
>>> By separating these calls and their static underlying functions to
>>> another area, we are able to compile out these functions for
>>> non-x86 builds and provide stubs for the non-x86 implementations.
>>>
>>> In addition to the problematic calls, we are moving the gmch-related
>>> functions to the new area.
>>>
>>> Signed-off-by: Casey Bowman <casey.g.bowman@intel.com>
>>> ---
>>>    drivers/gpu/drm/i915/Makefile           |   2 +
>>>    drivers/gpu/drm/i915/gt/intel_ggtt.c    | 665 +-----------------------
>>>    drivers/gpu/drm/i915/gt/intel_gt.c      |   4 +-
>>>    drivers/gpu/drm/i915/gt/intel_gt.h      |   9 +
>>>    drivers/gpu/drm/i915/gt/intel_gt_gmch.c | 653 +++++++++++++++++++++++
>>>    drivers/gpu/drm/i915/gt/intel_gt_gmch.h |  46 ++
>>>    drivers/gpu/drm/i915/gt/intel_gtt.h     |   9 +
>>>    7 files changed, 735 insertions(+), 653 deletions(-)
>>>    create mode 100644 drivers/gpu/drm/i915/gt/intel_gt_gmch.c
>>>    create mode 100644 drivers/gpu/drm/i915/gt/intel_gt_gmch.h
>>>
>>> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
>>> index c837a29ffac8..b7bdaec99118 100644
>>> --- a/drivers/gpu/drm/i915/Makefile
>>> +++ b/drivers/gpu/drm/i915/Makefile
>>> @@ -126,6 +126,8 @@ gt-y += \
>>>    	gt/intel_workarounds.o \
>>>    	gt/shmem_utils.o \
>>>    	gt/sysfs_engines.o
>>> +# x86 intel-gtt module support
>>> +gt-$(CONFIG_X86) += gt/intel_gt_gmch.o
>>>    # autogenerated null render state
>>>    gt-y += \
>>>    	gt/gen6_renderstate.o \
>>> diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
>>> index 04191fe2ee34..97a595e42135 100644
>>> --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
>>> +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
>>> @@ -3,18 +3,14 @@
>>>     * Copyright © 2020 Intel Corporation
>>>     */
>>>    
>>> -#include <linux/agp_backend.h>
>>> -#include <linux/stop_machine.h>
>>> -
>>> +#include <linux/types.h>
>>>    #include <asm/set_memory.h>
>>>    #include <asm/smp.h>
>>>    
>>> -#include <drm/i915_drm.h>
>>> -#include <drm/intel-gtt.h>
>>> -
>>>    #include "gem/i915_gem_lmem.h"
>>>    
>>>    #include "intel_gt.h"
>>> +#include "intel_gt_gmch.h"
>>>    #include "intel_gt_regs.h"
>>>    #include "i915_drv.h"
>>>    #include "i915_scatterlist.h"
>>> @@ -94,28 +90,6 @@ int i915_ggtt_init_hw(struct drm_i915_private *i915)
>>>    	return 0;
>>>    }
>>>    
>>> -/*
>>> - * Certain Gen5 chipsets require idling the GPU before
>>> - * unmapping anything from the GTT when VT-d is enabled.
>>> - */
>>> -static bool needs_idle_maps(struct drm_i915_private *i915)
>>> -{
>>> -	/*
>>> -	 * Query intel_iommu to see if we need the workaround. Presumably that
>>> -	 * was loaded first.
>>> -	 */
>>> -	if (!intel_vtd_active(i915))
>>> -		return false;
>>> -
>>> -	if (GRAPHICS_VER(i915) == 5 && IS_MOBILE(i915))
>>> -		return true;
>>> -
>>> -	if (GRAPHICS_VER(i915) == 12)
>>> -		return true; /* XXX DMAR fault reason 7 */
>>> -
>>> -	return false;
>>> -}
>>> -
>>>    /**
>>>     * i915_ggtt_suspend_vm - Suspend the memory mappings for a GGTT or DPT VM
>>>     * @vm: The VM to suspend the mappings for
>>> @@ -204,7 +178,7 @@ void gen6_ggtt_invalidate(struct i915_ggtt *ggtt)
>>>    	spin_unlock_irq(&uncore->lock);
>>>    }
>>>    
>>> -static void gen8_ggtt_invalidate(struct i915_ggtt *ggtt)
>>> +void gen8_ggtt_invalidate(struct i915_ggtt *ggtt)
>>>    {
>>>    	struct intel_uncore *uncore = ggtt->vm.gt->uncore;
>>>    
>>> @@ -229,11 +203,6 @@ static void guc_ggtt_invalidate(struct i915_ggtt *ggtt)
>>>    		intel_uncore_write_fw(uncore, GEN8_GTCR, GEN8_GTCR_INVALIDATE);
>>>    }
>>>    
>>> -static void gmch_ggtt_invalidate(struct i915_ggtt *ggtt)
>>> -{
>>> -	intel_gtt_chipset_flush();
>>> -}
>>> -
>>>    u64 gen8_ggtt_pte_encode(dma_addr_t addr,
>>>    			 enum i915_cache_level level,
>>>    			 u32 flags)
>>> @@ -246,258 +215,7 @@ u64 gen8_ggtt_pte_encode(dma_addr_t addr,
>>>    	return pte;
>>>    }
>>>    
>>> -static void gen8_set_pte(void __iomem *addr, gen8_pte_t pte)
>>> -{
>>> -	writeq(pte, addr);
>>> -}
>>> -
>>> -static void gen8_ggtt_insert_page(struct i915_address_space *vm,
>>> -				  dma_addr_t addr,
>>> -				  u64 offset,
>>> -				  enum i915_cache_level level,
>>> -				  u32 flags)
>>> -{
>>> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>>> -	gen8_pte_t __iomem *pte =
>>> -		(gen8_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
>>> -
>>> -	gen8_set_pte(pte, gen8_ggtt_pte_encode(addr, level, flags));
>>> -
>>> -	ggtt->invalidate(ggtt);
>>> -}
>>> -
>>> -static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
>>> -				     struct i915_vma_resource *vma_res,
>>> -				     enum i915_cache_level level,
>>> -				     u32 flags)
>>> -{
>>> -	const gen8_pte_t pte_encode = gen8_ggtt_pte_encode(0, level, flags);
>>> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>>> -	gen8_pte_t __iomem *gte;
>>> -	gen8_pte_t __iomem *end;
>>> -	struct sgt_iter iter;
>>> -	dma_addr_t addr;
>>> -
>>> -	/*
>>> -	 * Note that we ignore PTE_READ_ONLY here. The caller must be careful
>>> -	 * not to allow the user to override access to a read only page.
>>> -	 */
>>> -
>>> -	gte = (gen8_pte_t __iomem *)ggtt->gsm;
>>> -	gte += vma_res->start / I915_GTT_PAGE_SIZE;
>>> -	end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
>>> -
>>> -	for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
>>> -		gen8_set_pte(gte++, pte_encode | addr);
>>> -	GEM_BUG_ON(gte > end);
>>> -
>>> -	/* Fill the allocated but "unused" space beyond the end of the buffer */
>>> -	while (gte < end)
>>> -		gen8_set_pte(gte++, vm->scratch[0]->encode);
>>> -
>>> -	/*
>>> -	 * We want to flush the TLBs only after we're certain all the PTE
>>> -	 * updates have finished.
>>> -	 */
>>> -	ggtt->invalidate(ggtt);
>>> -}
>>> -
>>> -static void gen6_ggtt_insert_page(struct i915_address_space *vm,
>>> -				  dma_addr_t addr,
>>> -				  u64 offset,
>>> -				  enum i915_cache_level level,
>>> -				  u32 flags)
>>> -{
>>> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>>> -	gen6_pte_t __iomem *pte =
>>> -		(gen6_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
>>> -
>>> -	iowrite32(vm->pte_encode(addr, level, flags), pte);
>>> -
>>> -	ggtt->invalidate(ggtt);
>>> -}
>>> -
>>> -/*
>>> - * Binds an object into the global gtt with the specified cache level.
>>> - * The object will be accessible to the GPU via commands whose operands
>>> - * reference offsets within the global GTT as well as accessible by the GPU
>>> - * through the GMADR mapped BAR (i915->mm.gtt->gtt).
>>> - */
>>> -static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
>>> -				     struct i915_vma_resource *vma_res,
>>> -				     enum i915_cache_level level,
>>> -				     u32 flags)
>>> -{
>>> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>>> -	gen6_pte_t __iomem *gte;
>>> -	gen6_pte_t __iomem *end;
>>> -	struct sgt_iter iter;
>>> -	dma_addr_t addr;
>>> -
>>> -	gte = (gen6_pte_t __iomem *)ggtt->gsm;
>>> -	gte += vma_res->start / I915_GTT_PAGE_SIZE;
>>> -	end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
>>> -
>>> -	for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
>>> -		iowrite32(vm->pte_encode(addr, level, flags), gte++);
>>> -	GEM_BUG_ON(gte > end);
>>> -
>>> -	/* Fill the allocated but "unused" space beyond the end of the buffer */
>>> -	while (gte < end)
>>> -		iowrite32(vm->scratch[0]->encode, gte++);
>>> -
>>> -	/*
>>> -	 * We want to flush the TLBs only after we're certain all the PTE
>>> -	 * updates have finished.
>>> -	 */
>>> -	ggtt->invalidate(ggtt);
>>> -}
>>> -
>>> -static void nop_clear_range(struct i915_address_space *vm,
>>> -			    u64 start, u64 length)
>>> -{
>>> -}
>>> -
>>> -static void gen8_ggtt_clear_range(struct i915_address_space *vm,
>>> -				  u64 start, u64 length)
>>> -{
>>> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>>> -	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
>>> -	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
>>> -	const gen8_pte_t scratch_pte = vm->scratch[0]->encode;
>>> -	gen8_pte_t __iomem *gtt_base =
>>> -		(gen8_pte_t __iomem *)ggtt->gsm + first_entry;
>>> -	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
>>> -	int i;
>>> -
>>> -	if (WARN(num_entries > max_entries,
>>> -		 "First entry = %d; Num entries = %d (max=%d)\n",
>>> -		 first_entry, num_entries, max_entries))
>>> -		num_entries = max_entries;
>>> -
>>> -	for (i = 0; i < num_entries; i++)
>>> -		gen8_set_pte(&gtt_base[i], scratch_pte);
>>> -}
>>> -
>>> -static void bxt_vtd_ggtt_wa(struct i915_address_space *vm)
>>> -{
>>> -	/*
>>> -	 * Make sure the internal GAM fifo has been cleared of all GTT
>>> -	 * writes before exiting stop_machine(). This guarantees that
>>> -	 * any aperture accesses waiting to start in another process
>>> -	 * cannot back up behind the GTT writes causing a hang.
>>> -	 * The register can be any arbitrary GAM register.
>>> -	 */
>>> -	intel_uncore_posting_read_fw(vm->gt->uncore, GFX_FLSH_CNTL_GEN6);
>>> -}
>>> -
>>> -struct insert_page {
>>> -	struct i915_address_space *vm;
>>> -	dma_addr_t addr;
>>> -	u64 offset;
>>> -	enum i915_cache_level level;
>>> -};
>>> -
>>> -static int bxt_vtd_ggtt_insert_page__cb(void *_arg)
>>> -{
>>> -	struct insert_page *arg = _arg;
>>> -
>>> -	gen8_ggtt_insert_page(arg->vm, arg->addr, arg->offset, arg->level, 0);
>>> -	bxt_vtd_ggtt_wa(arg->vm);
>>> -
>>> -	return 0;
>>> -}
>>> -
>>> -static void bxt_vtd_ggtt_insert_page__BKL(struct i915_address_space *vm,
>>> -					  dma_addr_t addr,
>>> -					  u64 offset,
>>> -					  enum i915_cache_level level,
>>> -					  u32 unused)
>>> -{
>>> -	struct insert_page arg = { vm, addr, offset, level };
>>> -
>>> -	stop_machine(bxt_vtd_ggtt_insert_page__cb, &arg, NULL);
>>> -}
>>> -
>>> -struct insert_entries {
>>> -	struct i915_address_space *vm;
>>> -	struct i915_vma_resource *vma_res;
>>> -	enum i915_cache_level level;
>>> -	u32 flags;
>>> -};
>>> -
>>> -static int bxt_vtd_ggtt_insert_entries__cb(void *_arg)
>>> -{
>>> -	struct insert_entries *arg = _arg;
>>> -
>>> -	gen8_ggtt_insert_entries(arg->vm, arg->vma_res, arg->level, arg->flags);
>>> -	bxt_vtd_ggtt_wa(arg->vm);
>>> -
>>> -	return 0;
>>> -}
>>> -
>>> -static void bxt_vtd_ggtt_insert_entries__BKL(struct i915_address_space *vm,
>>> -					     struct i915_vma_resource *vma_res,
>>> -					     enum i915_cache_level level,
>>> -					     u32 flags)
>>> -{
>>> -	struct insert_entries arg = { vm, vma_res, level, flags };
>>> -
>>> -	stop_machine(bxt_vtd_ggtt_insert_entries__cb, &arg, NULL);
>>> -}
>>> -
>>> -static void gen6_ggtt_clear_range(struct i915_address_space *vm,
>>> -				  u64 start, u64 length)
>>> -{
>>> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>>> -	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
>>> -	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
>>> -	gen6_pte_t scratch_pte, __iomem *gtt_base =
>>> -		(gen6_pte_t __iomem *)ggtt->gsm + first_entry;
>>> -	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
>>> -	int i;
>>> -
>>> -	if (WARN(num_entries > max_entries,
>>> -		 "First entry = %d; Num entries = %d (max=%d)\n",
>>> -		 first_entry, num_entries, max_entries))
>>> -		num_entries = max_entries;
>>> -
>>> -	scratch_pte = vm->scratch[0]->encode;
>>> -	for (i = 0; i < num_entries; i++)
>>> -		iowrite32(scratch_pte, &gtt_base[i]);
>>> -}
>>> -
>>> -static void i915_ggtt_insert_page(struct i915_address_space *vm,
>>> -				  dma_addr_t addr,
>>> -				  u64 offset,
>>> -				  enum i915_cache_level cache_level,
>>> -				  u32 unused)
>>> -{
>>> -	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
>>> -		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
>>> -
>>> -	intel_gtt_insert_page(addr, offset >> PAGE_SHIFT, flags);
>>> -}
>>> -
>>> -static void i915_ggtt_insert_entries(struct i915_address_space *vm,
>>> -				     struct i915_vma_resource *vma_res,
>>> -				     enum i915_cache_level cache_level,
>>> -				     u32 unused)
>>> -{
>>> -	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
>>> -		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
>>> -
>>> -	intel_gtt_insert_sg_entries(vma_res->bi.pages, vma_res->start >> PAGE_SHIFT,
>>> -				    flags);
>>> -}
>>> -
>>> -static void i915_ggtt_clear_range(struct i915_address_space *vm,
>>> -				  u64 start, u64 length)
>>> -{
>>> -	intel_gtt_clear_range(start >> PAGE_SHIFT, length >> PAGE_SHIFT);
>>> -}
>>> -
>>> -static void ggtt_bind_vma(struct i915_address_space *vm,
>>> +void intel_ggtt_bind_vma(struct i915_address_space *vm,
>>>    			  struct i915_vm_pt_stash *stash,
>>>    			  struct i915_vma_resource *vma_res,
>>>    			  enum i915_cache_level cache_level,
>>> @@ -521,7 +239,7 @@ static void ggtt_bind_vma(struct i915_address_space *vm,
>>>    	vma_res->page_sizes_gtt = I915_GTT_PAGE_SIZE;
>>>    }
>>>    
>>> -static void ggtt_unbind_vma(struct i915_address_space *vm,
>>> +void intel_ggtt_unbind_vma(struct i915_address_space *vm,
>>>    			    struct i915_vma_resource *vma_res)
>>>    {
>>>    	vm->clear_range(vm, vma_res->start, vma_res->vma_size);
>>> @@ -724,10 +442,10 @@ static int init_aliasing_ppgtt(struct i915_ggtt *ggtt)
>>>    	ggtt->alias = ppgtt;
>>>    	ggtt->vm.bind_async_flags |= ppgtt->vm.bind_async_flags;
>>>    
>>> -	GEM_BUG_ON(ggtt->vm.vma_ops.bind_vma != ggtt_bind_vma);
>>> +	GEM_BUG_ON(ggtt->vm.vma_ops.bind_vma != intel_ggtt_bind_vma);
>>>    	ggtt->vm.vma_ops.bind_vma = aliasing_gtt_bind_vma;
>>>    
>>> -	GEM_BUG_ON(ggtt->vm.vma_ops.unbind_vma != ggtt_unbind_vma);
>>> +	GEM_BUG_ON(ggtt->vm.vma_ops.unbind_vma != intel_ggtt_unbind_vma);
>>>    	ggtt->vm.vma_ops.unbind_vma = aliasing_gtt_unbind_vma;
>>>    
>>>    	i915_vm_free_pt_stash(&ppgtt->vm, &stash);
>>> @@ -750,8 +468,8 @@ static void fini_aliasing_ppgtt(struct i915_ggtt *ggtt)
>>>    
>>>    	i915_vm_put(&ppgtt->vm);
>>>    
>>> -	ggtt->vm.vma_ops.bind_vma   = ggtt_bind_vma;
>>> -	ggtt->vm.vma_ops.unbind_vma = ggtt_unbind_vma;
>>> +	ggtt->vm.vma_ops.bind_vma   = intel_ggtt_bind_vma;
>>> +	ggtt->vm.vma_ops.unbind_vma = intel_ggtt_unbind_vma;
>>>    }
>>>    
>>>    int i915_init_ggtt(struct drm_i915_private *i915)
>>> @@ -839,364 +557,12 @@ void i915_ggtt_driver_late_release(struct drm_i915_private *i915)
>>>    	dma_resv_fini(&ggtt->vm._resv);
>>>    }
>>>    
>>> -static unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
>>> -{
>>> -	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
>>> -	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
>>> -	return snb_gmch_ctl << 20;
>>> -}
>>> -
>>> -static unsigned int gen8_get_total_gtt_size(u16 bdw_gmch_ctl)
>>> -{
>>> -	bdw_gmch_ctl >>= BDW_GMCH_GGMS_SHIFT;
>>> -	bdw_gmch_ctl &= BDW_GMCH_GGMS_MASK;
>>> -	if (bdw_gmch_ctl)
>>> -		bdw_gmch_ctl = 1 << bdw_gmch_ctl;
>>> -
>>> -#ifdef CONFIG_X86_32
>>> -	/* Limit 32b platforms to a 2GB GGTT: 4 << 20 / pte size * I915_GTT_PAGE_SIZE */
>>> -	if (bdw_gmch_ctl > 4)
>>> -		bdw_gmch_ctl = 4;
>>> -#endif
>>> -
>>> -	return bdw_gmch_ctl << 20;
>>> -}
>>> -
>>> -static unsigned int chv_get_total_gtt_size(u16 gmch_ctrl)
>>> -{
>>> -	gmch_ctrl >>= SNB_GMCH_GGMS_SHIFT;
>>> -	gmch_ctrl &= SNB_GMCH_GGMS_MASK;
>>> -
>>> -	if (gmch_ctrl)
>>> -		return 1 << (20 + gmch_ctrl);
>>> -
>>> -	return 0;
>>> -}
>>> -
>>> -static unsigned int gen6_gttmmadr_size(struct drm_i915_private *i915)
>>> -{
>>> -	/*
>>> -	 * GEN6: GTTMMADR size is 4MB and GTTADR starts at 2MB offset
>>> -	 * GEN8: GTTMMADR size is 16MB and GTTADR starts at 8MB offset
>>> -	 */
>>> -	GEM_BUG_ON(GRAPHICS_VER(i915) < 6);
>>> -	return (GRAPHICS_VER(i915) < 8) ? SZ_4M : SZ_16M;
>>> -}
>>> -
>>> -static unsigned int gen6_gttadr_offset(struct drm_i915_private *i915)
>>> -{
>>> -	return gen6_gttmmadr_size(i915) / 2;
>>> -}
>>> -
>>> -static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size)
>>> -{
>>> -	struct drm_i915_private *i915 = ggtt->vm.i915;
>>> -	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>>> -	phys_addr_t phys_addr;
>>> -	u32 pte_flags;
>>> -	int ret;
>>> -
>>> -	GEM_WARN_ON(pci_resource_len(pdev, 0) != gen6_gttmmadr_size(i915));
>>> -	phys_addr = pci_resource_start(pdev, 0) + gen6_gttadr_offset(i915);
>>> -
>>> -	/*
>>> -	 * On BXT+/ICL+ writes larger than 64 bit to the GTT pagetable range
>>> -	 * will be dropped. For WC mappings in general we have 64 byte burst
>>> -	 * writes when the WC buffer is flushed, so we can't use it, but have to
>>> -	 * resort to an uncached mapping. The WC issue is easily caught by the
>>> -	 * readback check when writing GTT PTE entries.
>>> -	 */
>>> -	if (IS_GEN9_LP(i915) || GRAPHICS_VER(i915) >= 11)
>>> -		ggtt->gsm = ioremap(phys_addr, size);
>>> -	else
>>> -		ggtt->gsm = ioremap_wc(phys_addr, size);
>>> -	if (!ggtt->gsm) {
>>> -		drm_err(&i915->drm, "Failed to map the ggtt page table\n");
>>> -		return -ENOMEM;
>>> -	}
>>> -
>>> -	kref_init(&ggtt->vm.resv_ref);
>>> -	ret = setup_scratch_page(&ggtt->vm);
>>> -	if (ret) {
>>> -		drm_err(&i915->drm, "Scratch setup failed\n");
>>> -		/* iounmap will also get called at remove, but meh */
>>> -		iounmap(ggtt->gsm);
>>> -		return ret;
>>> -	}
>>> -
>>> -	pte_flags = 0;
>>> -	if (i915_gem_object_is_lmem(ggtt->vm.scratch[0]))
>>> -		pte_flags |= PTE_LM;
>>> -
>>> -	ggtt->vm.scratch[0]->encode =
>>> -		ggtt->vm.pte_encode(px_dma(ggtt->vm.scratch[0]),
>>> -				    I915_CACHE_NONE, pte_flags);
>>> -
>>> -	return 0;
>>> -}
>>> -
>>> -static void gen6_gmch_remove(struct i915_address_space *vm)
>>> -{
>>> -	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>>> -
>>> -	iounmap(ggtt->gsm);
>>> -	free_scratch(vm);
>>> -}
>>> -
>>> -static struct resource pci_resource(struct pci_dev *pdev, int bar)
>>> +struct resource pci_resource(struct pci_dev *pdev, int bar)
>>>    {
>>>    	return (struct resource)DEFINE_RES_MEM(pci_resource_start(pdev, bar),
>>>    					       pci_resource_len(pdev, bar));
>>>    }
>> Export with pci_ prefix is a bit dodgy - maybe intel_pci_resource? Not sure.
> Yeah, even static functions with such generic prefix and name are
> discouraged. It's ugly if it ends up conflicting because we're abusing
> their namespace.
>
> BR,
> Jani.
>

Got it, thanks for catching that, I thought it might be questionable, 
but yes,
you both are right, it needs to stay consistent with this namespace.

I'll go with intel_pci_resource

Regards,
Casey

>
>> The rest looks okay to me.
>>
>> I mean I could suggest to do something about the incosistency of:
>>
>> static inline void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)
>>
>> vs:
>>
>> static inline int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
>>
>> Since I value more for function name to tell me on what it operates
>> instead where it is placed. So I'd personally rename the second class to
>> i915_ggtt. It would also be consistent with other exported functions
>> which take struct i915_ggtt like i915_ggtt_enable_guc, i915_ggtt_resume
>> and so. But opinions will differ so I can live with it as is as well.
>>
>> Regards,
>>
>> Tvrtko
>>
>>>    
>>> -static int gen8_gmch_probe(struct i915_ggtt *ggtt)
>>> -{
>>> -	struct drm_i915_private *i915 = ggtt->vm.i915;
>>> -	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>>> -	unsigned int size;
>>> -	u16 snb_gmch_ctl;
>>> -
>>> -	/* TODO: We're not aware of mappable constraints on gen8 yet */
>>> -	if (!HAS_LMEM(i915)) {
>>> -		ggtt->gmadr = pci_resource(pdev, 2);
>>> -		ggtt->mappable_end = resource_size(&ggtt->gmadr);
>>> -	}
>>> -
>>> -	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
>>> -	if (IS_CHERRYVIEW(i915))
>>> -		size = chv_get_total_gtt_size(snb_gmch_ctl);
>>> -	else
>>> -		size = gen8_get_total_gtt_size(snb_gmch_ctl);
>>> -
>>> -	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>>> -	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>>> -	ggtt->vm.lmem_pt_obj_flags = I915_BO_ALLOC_PM_EARLY;
>>> -
>>> -	ggtt->vm.total = (size / sizeof(gen8_pte_t)) * I915_GTT_PAGE_SIZE;
>>> -	ggtt->vm.cleanup = gen6_gmch_remove;
>>> -	ggtt->vm.insert_page = gen8_ggtt_insert_page;
>>> -	ggtt->vm.clear_range = nop_clear_range;
>>> -	if (intel_scanout_needs_vtd_wa(i915))
>>> -		ggtt->vm.clear_range = gen8_ggtt_clear_range;
>>> -
>>> -	ggtt->vm.insert_entries = gen8_ggtt_insert_entries;
>>> -
>>> -	/*
>>> -	 * Serialize GTT updates with aperture access on BXT if VT-d is on,
>>> -	 * and always on CHV.
>>> -	 */
>>> -	if (intel_vm_no_concurrent_access_wa(i915)) {
>>> -		ggtt->vm.insert_entries = bxt_vtd_ggtt_insert_entries__BKL;
>>> -		ggtt->vm.insert_page    = bxt_vtd_ggtt_insert_page__BKL;
>>> -		ggtt->vm.bind_async_flags =
>>> -			I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND;
>>> -	}
>>> -
>>> -	ggtt->invalidate = gen8_ggtt_invalidate;
>>> -
>>> -	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
>>> -	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
>>> -
>>> -	ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
>>> -
>>> -	setup_private_pat(ggtt->vm.gt->uncore);
>>> -
>>> -	return ggtt_probe_common(ggtt, size);
>>> -}
>>> -
>>> -static u64 snb_pte_encode(dma_addr_t addr,
>>> -			  enum i915_cache_level level,
>>> -			  u32 flags)
>>> -{
>>> -	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>>> -
>>> -	switch (level) {
>>> -	case I915_CACHE_L3_LLC:
>>> -	case I915_CACHE_LLC:
>>> -		pte |= GEN6_PTE_CACHE_LLC;
>>> -		break;
>>> -	case I915_CACHE_NONE:
>>> -		pte |= GEN6_PTE_UNCACHED;
>>> -		break;
>>> -	default:
>>> -		MISSING_CASE(level);
>>> -	}
>>> -
>>> -	return pte;
>>> -}
>>> -
>>> -static u64 ivb_pte_encode(dma_addr_t addr,
>>> -			  enum i915_cache_level level,
>>> -			  u32 flags)
>>> -{
>>> -	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>>> -
>>> -	switch (level) {
>>> -	case I915_CACHE_L3_LLC:
>>> -		pte |= GEN7_PTE_CACHE_L3_LLC;
>>> -		break;
>>> -	case I915_CACHE_LLC:
>>> -		pte |= GEN6_PTE_CACHE_LLC;
>>> -		break;
>>> -	case I915_CACHE_NONE:
>>> -		pte |= GEN6_PTE_UNCACHED;
>>> -		break;
>>> -	default:
>>> -		MISSING_CASE(level);
>>> -	}
>>> -
>>> -	return pte;
>>> -}
>>> -
>>> -static u64 byt_pte_encode(dma_addr_t addr,
>>> -			  enum i915_cache_level level,
>>> -			  u32 flags)
>>> -{
>>> -	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>>> -
>>> -	if (!(flags & PTE_READ_ONLY))
>>> -		pte |= BYT_PTE_WRITEABLE;
>>> -
>>> -	if (level != I915_CACHE_NONE)
>>> -		pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
>>> -
>>> -	return pte;
>>> -}
>>> -
>>> -static u64 hsw_pte_encode(dma_addr_t addr,
>>> -			  enum i915_cache_level level,
>>> -			  u32 flags)
>>> -{
>>> -	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>>> -
>>> -	if (level != I915_CACHE_NONE)
>>> -		pte |= HSW_WB_LLC_AGE3;
>>> -
>>> -	return pte;
>>> -}
>>> -
>>> -static u64 iris_pte_encode(dma_addr_t addr,
>>> -			   enum i915_cache_level level,
>>> -			   u32 flags)
>>> -{
>>> -	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>>> -
>>> -	switch (level) {
>>> -	case I915_CACHE_NONE:
>>> -		break;
>>> -	case I915_CACHE_WT:
>>> -		pte |= HSW_WT_ELLC_LLC_AGE3;
>>> -		break;
>>> -	default:
>>> -		pte |= HSW_WB_ELLC_LLC_AGE3;
>>> -		break;
>>> -	}
>>> -
>>> -	return pte;
>>> -}
>>> -
>>> -static int gen6_gmch_probe(struct i915_ggtt *ggtt)
>>> -{
>>> -	struct drm_i915_private *i915 = ggtt->vm.i915;
>>> -	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>>> -	unsigned int size;
>>> -	u16 snb_gmch_ctl;
>>> -
>>> -	ggtt->gmadr = pci_resource(pdev, 2);
>>> -	ggtt->mappable_end = resource_size(&ggtt->gmadr);
>>> -
>>> -	/*
>>> -	 * 64/512MB is the current min/max we actually know of, but this is
>>> -	 * just a coarse sanity check.
>>> -	 */
>>> -	if (ggtt->mappable_end < (64<<20) || ggtt->mappable_end > (512<<20)) {
>>> -		drm_err(&i915->drm, "Unknown GMADR size (%pa)\n",
>>> -			&ggtt->mappable_end);
>>> -		return -ENXIO;
>>> -	}
>>> -
>>> -	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
>>> -
>>> -	size = gen6_get_total_gtt_size(snb_gmch_ctl);
>>> -	ggtt->vm.total = (size / sizeof(gen6_pte_t)) * I915_GTT_PAGE_SIZE;
>>> -
>>> -	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>>> -	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>>> -
>>> -	ggtt->vm.clear_range = nop_clear_range;
>>> -	if (!HAS_FULL_PPGTT(i915) || intel_scanout_needs_vtd_wa(i915))
>>> -		ggtt->vm.clear_range = gen6_ggtt_clear_range;
>>> -	ggtt->vm.insert_page = gen6_ggtt_insert_page;
>>> -	ggtt->vm.insert_entries = gen6_ggtt_insert_entries;
>>> -	ggtt->vm.cleanup = gen6_gmch_remove;
>>> -
>>> -	ggtt->invalidate = gen6_ggtt_invalidate;
>>> -
>>> -	if (HAS_EDRAM(i915))
>>> -		ggtt->vm.pte_encode = iris_pte_encode;
>>> -	else if (IS_HASWELL(i915))
>>> -		ggtt->vm.pte_encode = hsw_pte_encode;
>>> -	else if (IS_VALLEYVIEW(i915))
>>> -		ggtt->vm.pte_encode = byt_pte_encode;
>>> -	else if (GRAPHICS_VER(i915) >= 7)
>>> -		ggtt->vm.pte_encode = ivb_pte_encode;
>>> -	else
>>> -		ggtt->vm.pte_encode = snb_pte_encode;
>>> -
>>> -	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
>>> -	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
>>> -
>>> -	return ggtt_probe_common(ggtt, size);
>>> -}
>>> -
>>> -static void i915_gmch_remove(struct i915_address_space *vm)
>>> -{
>>> -	intel_gmch_remove();
>>> -}
>>> -
>>> -static int i915_gmch_probe(struct i915_ggtt *ggtt)
>>> -{
>>> -	struct drm_i915_private *i915 = ggtt->vm.i915;
>>> -	phys_addr_t gmadr_base;
>>> -	int ret;
>>> -
>>> -	ret = intel_gmch_probe(i915->bridge_dev, to_pci_dev(i915->drm.dev), NULL);
>>> -	if (!ret) {
>>> -		drm_err(&i915->drm, "failed to set up gmch\n");
>>> -		return -EIO;
>>> -	}
>>> -
>>> -	intel_gtt_get(&ggtt->vm.total, &gmadr_base, &ggtt->mappable_end);
>>> -
>>> -	ggtt->gmadr =
>>> -		(struct resource)DEFINE_RES_MEM(gmadr_base, ggtt->mappable_end);
>>> -
>>> -	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>>> -	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>>> -
>>> -	if (needs_idle_maps(i915)) {
>>> -		drm_notice(&i915->drm,
>>> -			   "Flushing DMA requests before IOMMU unmaps; performance may be degraded\n");
>>> -		ggtt->do_idle_maps = true;
>>> -	}
>>> -
>>> -	ggtt->vm.insert_page = i915_ggtt_insert_page;
>>> -	ggtt->vm.insert_entries = i915_ggtt_insert_entries;
>>> -	ggtt->vm.clear_range = i915_ggtt_clear_range;
>>> -	ggtt->vm.cleanup = i915_gmch_remove;
>>> -
>>> -	ggtt->invalidate = gmch_ggtt_invalidate;
>>> -
>>> -	ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
>>> -	ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
>>> -
>>> -	if (unlikely(ggtt->do_idle_maps))
>>> -		drm_notice(&i915->drm,
>>> -			   "Applying Ironlake quirks for intel_iommu\n");
>>> -
>>> -	return 0;
>>> -}
>>> -
>>>    static int ggtt_probe_hw(struct i915_ggtt *ggtt, struct intel_gt *gt)
>>>    {
>>>    	struct drm_i915_private *i915 = gt->i915;
>>> @@ -1208,11 +574,11 @@ static int ggtt_probe_hw(struct i915_ggtt *ggtt, struct intel_gt *gt)
>>>    	dma_resv_init(&ggtt->vm._resv);
>>>    
>>>    	if (GRAPHICS_VER(i915) <= 5)
>>> -		ret = i915_gmch_probe(ggtt);
>>> +		ret = intel_gt_gmch_gen5_probe(ggtt);
>>>    	else if (GRAPHICS_VER(i915) < 8)
>>> -		ret = gen6_gmch_probe(ggtt);
>>> +		ret = intel_gt_gmch_gen6_probe(ggtt);
>>>    	else
>>> -		ret = gen8_gmch_probe(ggtt);
>>> +		ret = intel_gt_gmch_gen8_probe(ggtt);
>>>    	if (ret) {
>>>    		dma_resv_fini(&ggtt->vm._resv);
>>>    		return ret;
>>> @@ -1266,10 +632,7 @@ int i915_ggtt_probe_hw(struct drm_i915_private *i915)
>>>    
>>>    int i915_ggtt_enable_hw(struct drm_i915_private *i915)
>>>    {
>>> -	if (GRAPHICS_VER(i915) < 6 && !intel_enable_gtt())
>>> -		return -EIO;
>>> -
>>> -	return 0;
>>> +	return intel_gt_gmch_gen5_enable_hw(i915);
>>>    }
>>>    
>>>    void i915_ggtt_enable_guc(struct i915_ggtt *ggtt)
>>> diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
>>> index 5001a6168d56..f0014c5072c9 100644
>>> --- a/drivers/gpu/drm/i915/gt/intel_gt.c
>>> +++ b/drivers/gpu/drm/i915/gt/intel_gt.c
>>> @@ -4,7 +4,6 @@
>>>     */
>>>    
>>>    #include <drm/drm_managed.h>
>>> -#include <drm/intel-gtt.h>
>>>    
>>>    #include "gem/i915_gem_internal.h"
>>>    #include "gem/i915_gem_lmem.h"
>>> @@ -17,6 +16,7 @@
>>>    #include "intel_gt_buffer_pool.h"
>>>    #include "intel_gt_clock_utils.h"
>>>    #include "intel_gt_debugfs.h"
>>> +#include "intel_gt_gmch.h"
>>>    #include "intel_gt_pm.h"
>>>    #include "intel_gt_regs.h"
>>>    #include "intel_gt_requests.h"
>>> @@ -451,7 +451,7 @@ void intel_gt_chipset_flush(struct intel_gt *gt)
>>>    {
>>>    	wmb();
>>>    	if (GRAPHICS_VER(gt->i915) < 6)
>>> -		intel_gtt_chipset_flush();
>>> +		intel_gt_gmch_gen5_chipset_flush(gt);
>>>    }
>>>    
>>>    void intel_gt_driver_register(struct intel_gt *gt)
>>> diff --git a/drivers/gpu/drm/i915/gt/intel_gt.h b/drivers/gpu/drm/i915/gt/intel_gt.h
>>> index e76168e10a21..8956dfc5afe0 100644
>>> --- a/drivers/gpu/drm/i915/gt/intel_gt.h
>>> +++ b/drivers/gpu/drm/i915/gt/intel_gt.h
>>> @@ -13,6 +13,13 @@
>>>    struct drm_i915_private;
>>>    struct drm_printer;
>>>    
>>> +struct insert_entries {
>>> +	struct i915_address_space *vm;
>>> +	struct i915_vma_resource *vma_res;
>>> +	enum i915_cache_level level;
>>> +	u32 flags;
>>> +};
>>> +
>>>    #define GT_TRACE(gt, fmt, ...) do {					\
>>>    	const struct intel_gt *gt__ __maybe_unused = (gt);		\
>>>    	GEM_TRACE("%s " fmt, dev_name(gt__->i915->drm.dev),		\
>>> @@ -113,4 +120,6 @@ void intel_gt_watchdog_work(struct work_struct *work);
>>>    
>>>    void intel_gt_invalidate_tlbs(struct intel_gt *gt);
>>>    
>>> +struct resource pci_resource(struct pci_dev *pdev, int bar);
>>> +
>>>    #endif /* __INTEL_GT_H__ */
>>> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_gmch.c b/drivers/gpu/drm/i915/gt/intel_gt_gmch.c
>>> new file mode 100644
>>> index 000000000000..b914ebb30166
>>> --- /dev/null
>>> +++ b/drivers/gpu/drm/i915/gt/intel_gt_gmch.c
>>> @@ -0,0 +1,653 @@
>>> +// SPDX-License-Identifier: MIT
>>> +/*
>>> + * Copyright © 2022 Intel Corporation
>>> + */
>>> +
>>> +#include <drm/intel-gtt.h>
>>> +#include <drm/i915_drm.h>
>>> +
>>> +#include <linux/agp_backend.h>
>>> +#include <linux/stop_machine.h>
>>> +
>>> +#include "i915_drv.h"
>>> +#include "intel_gt_gmch.h"
>>> +#include "intel_gt_regs.h"
>>> +#include "intel_gt.h"
>>> +
>>> +#include "gen8_ppgtt.h"
>>> +
>>> +struct insert_page {
>>> +	struct i915_address_space *vm;
>>> +	dma_addr_t addr;
>>> +	u64 offset;
>>> +	enum i915_cache_level level;
>>> +};
>>> +
>>> +static void gen8_set_pte(void __iomem *addr, gen8_pte_t pte)
>>> +{
>>> +	writeq(pte, addr);
>>> +}
>>> +
>>> +static void nop_clear_range(struct i915_address_space *vm,
>>> +			    u64 start, u64 length)
>>> +{
>>> +}
>>> +
>>> +static u64 snb_pte_encode(dma_addr_t addr,
>>> +			  enum i915_cache_level level,
>>> +			  u32 flags)
>>> +{
>>> +	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>>> +
>>> +	switch (level) {
>>> +	case I915_CACHE_L3_LLC:
>>> +	case I915_CACHE_LLC:
>>> +		pte |= GEN6_PTE_CACHE_LLC;
>>> +		break;
>>> +	case I915_CACHE_NONE:
>>> +		pte |= GEN6_PTE_UNCACHED;
>>> +		break;
>>> +	default:
>>> +		MISSING_CASE(level);
>>> +	}
>>> +
>>> +	return pte;
>>> +}
>>> +
>>> +static u64 ivb_pte_encode(dma_addr_t addr,
>>> +			  enum i915_cache_level level,
>>> +			  u32 flags)
>>> +{
>>> +	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>>> +
>>> +	switch (level) {
>>> +	case I915_CACHE_L3_LLC:
>>> +		pte |= GEN7_PTE_CACHE_L3_LLC;
>>> +		break;
>>> +	case I915_CACHE_LLC:
>>> +		pte |= GEN6_PTE_CACHE_LLC;
>>> +		break;
>>> +	case I915_CACHE_NONE:
>>> +		pte |= GEN6_PTE_UNCACHED;
>>> +		break;
>>> +	default:
>>> +		MISSING_CASE(level);
>>> +	}
>>> +
>>> +	return pte;
>>> +}
>>> +
>>> +static u64 byt_pte_encode(dma_addr_t addr,
>>> +			  enum i915_cache_level level,
>>> +			  u32 flags)
>>> +{
>>> +	gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>>> +
>>> +	if (!(flags & PTE_READ_ONLY))
>>> +		pte |= BYT_PTE_WRITEABLE;
>>> +
>>> +	if (level != I915_CACHE_NONE)
>>> +		pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
>>> +
>>> +	return pte;
>>> +}
>>> +
>>> +static u64 hsw_pte_encode(dma_addr_t addr,
>>> +			  enum i915_cache_level level,
>>> +			  u32 flags)
>>> +{
>>> +	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>>> +
>>> +	if (level != I915_CACHE_NONE)
>>> +		pte |= HSW_WB_LLC_AGE3;
>>> +
>>> +	return pte;
>>> +}
>>> +
>>> +static u64 iris_pte_encode(dma_addr_t addr,
>>> +			   enum i915_cache_level level,
>>> +			   u32 flags)
>>> +{
>>> +	gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>>> +
>>> +	switch (level) {
>>> +	case I915_CACHE_NONE:
>>> +		break;
>>> +	case I915_CACHE_WT:
>>> +		pte |= HSW_WT_ELLC_LLC_AGE3;
>>> +		break;
>>> +	default:
>>> +		pte |= HSW_WB_ELLC_LLC_AGE3;
>>> +		break;
>>> +	}
>>> +
>>> +	return pte;
>>> +}
>>> +
>>> +static void gen5_ggtt_insert_page(struct i915_address_space *vm,
>>> +				  dma_addr_t addr,
>>> +				  u64 offset,
>>> +				  enum i915_cache_level cache_level,
>>> +				  u32 unused)
>>> +{
>>> +	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
>>> +		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
>>> +
>>> +	intel_gtt_insert_page(addr, offset >> PAGE_SHIFT, flags);
>>> +}
>>> +
>>> +static void gen6_ggtt_insert_page(struct i915_address_space *vm,
>>> +				  dma_addr_t addr,
>>> +				  u64 offset,
>>> +				  enum i915_cache_level level,
>>> +				  u32 flags)
>>> +{
>>> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>>> +	gen6_pte_t __iomem *pte =
>>> +		(gen6_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
>>> +
>>> +	iowrite32(vm->pte_encode(addr, level, flags), pte);
>>> +
>>> +	ggtt->invalidate(ggtt);
>>> +}
>>> +
>>> +static void gen8_ggtt_insert_page(struct i915_address_space *vm,
>>> +				  dma_addr_t addr,
>>> +				  u64 offset,
>>> +				  enum i915_cache_level level,
>>> +				  u32 flags)
>>> +{
>>> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>>> +	gen8_pte_t __iomem *pte =
>>> +		(gen8_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
>>> +
>>> +	gen8_set_pte(pte, gen8_ggtt_pte_encode(addr, level, flags));
>>> +
>>> +	ggtt->invalidate(ggtt);
>>> +}
>>> +
>>> +static void gen5_ggtt_insert_entries(struct i915_address_space *vm,
>>> +				     struct i915_vma_resource *vma_res,
>>> +				     enum i915_cache_level cache_level,
>>> +				     u32 unused)
>>> +{
>>> +	unsigned int flags = (cache_level == I915_CACHE_NONE) ?
>>> +		AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
>>> +
>>> +	intel_gtt_insert_sg_entries(vma_res->bi.pages, vma_res->start >> PAGE_SHIFT,
>>> +				    flags);
>>> +}
>>> +
>>> +/*
>>> + * Binds an object into the global gtt with the specified cache level.
>>> + * The object will be accessible to the GPU via commands whose operands
>>> + * reference offsets within the global GTT as well as accessible by the GPU
>>> + * through the GMADR mapped BAR (i915->mm.gtt->gtt).
>>> + */
>>> +static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
>>> +				     struct i915_vma_resource *vma_res,
>>> +				     enum i915_cache_level level,
>>> +				     u32 flags)
>>> +{
>>> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>>> +	gen6_pte_t __iomem *gte;
>>> +	gen6_pte_t __iomem *end;
>>> +	struct sgt_iter iter;
>>> +	dma_addr_t addr;
>>> +
>>> +	gte = (gen6_pte_t __iomem *)ggtt->gsm;
>>> +	gte += vma_res->start / I915_GTT_PAGE_SIZE;
>>> +	end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
>>> +
>>> +	for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
>>> +		iowrite32(vm->pte_encode(addr, level, flags), gte++);
>>> +	GEM_BUG_ON(gte > end);
>>> +
>>> +	/* Fill the allocated but "unused" space beyond the end of the buffer */
>>> +	while (gte < end)
>>> +		iowrite32(vm->scratch[0]->encode, gte++);
>>> +
>>> +	/*
>>> +	 * We want to flush the TLBs only after we're certain all the PTE
>>> +	 * updates have finished.
>>> +	 */
>>> +	ggtt->invalidate(ggtt);
>>> +}
>>> +
>>> +static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
>>> +				     struct i915_vma_resource *vma_res,
>>> +				     enum i915_cache_level level,
>>> +				     u32 flags)
>>> +{
>>> +	const gen8_pte_t pte_encode = gen8_ggtt_pte_encode(0, level, flags);
>>> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>>> +	gen8_pte_t __iomem *gte;
>>> +	gen8_pte_t __iomem *end;
>>> +	struct sgt_iter iter;
>>> +	dma_addr_t addr;
>>> +
>>> +	/*
>>> +	 * Note that we ignore PTE_READ_ONLY here. The caller must be careful
>>> +	 * not to allow the user to override access to a read only page.
>>> +	 */
>>> +
>>> +	gte = (gen8_pte_t __iomem *)ggtt->gsm;
>>> +	gte += vma_res->start / I915_GTT_PAGE_SIZE;
>>> +	end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
>>> +
>>> +	for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
>>> +		gen8_set_pte(gte++, pte_encode | addr);
>>> +	GEM_BUG_ON(gte > end);
>>> +
>>> +	/* Fill the allocated but "unused" space beyond the end of the buffer */
>>> +	while (gte < end)
>>> +		gen8_set_pte(gte++, vm->scratch[0]->encode);
>>> +
>>> +	/*
>>> +	 * We want to flush the TLBs only after we're certain all the PTE
>>> +	 * updates have finished.
>>> +	 */
>>> +	ggtt->invalidate(ggtt);
>>> +}
>>> +
>>> +static void bxt_vtd_ggtt_wa(struct i915_address_space *vm)
>>> +{
>>> +	/*
>>> +	 * Make sure the internal GAM fifo has been cleared of all GTT
>>> +	 * writes before exiting stop_machine(). This guarantees that
>>> +	 * any aperture accesses waiting to start in another process
>>> +	 * cannot back up behind the GTT writes causing a hang.
>>> +	 * The register can be any arbitrary GAM register.
>>> +	 */
>>> +	intel_uncore_posting_read_fw(vm->gt->uncore, GFX_FLSH_CNTL_GEN6);
>>> +}
>>> +
>>> +static int bxt_vtd_ggtt_insert_page__cb(void *_arg)
>>> +{
>>> +	struct insert_page *arg = _arg;
>>> +
>>> +	gen8_ggtt_insert_page(arg->vm, arg->addr, arg->offset, arg->level, 0);
>>> +	bxt_vtd_ggtt_wa(arg->vm);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static void bxt_vtd_ggtt_insert_page__BKL(struct i915_address_space *vm,
>>> +					  dma_addr_t addr,
>>> +					  u64 offset,
>>> +					  enum i915_cache_level level,
>>> +					  u32 unused)
>>> +{
>>> +	struct insert_page arg = { vm, addr, offset, level };
>>> +
>>> +	stop_machine(bxt_vtd_ggtt_insert_page__cb, &arg, NULL);
>>> +}
>>> +
>>> +static int bxt_vtd_ggtt_insert_entries__cb(void *_arg)
>>> +{
>>> +	struct insert_entries *arg = _arg;
>>> +
>>> +	gen8_ggtt_insert_entries(arg->vm, arg->vma_res, arg->level, arg->flags);
>>> +	bxt_vtd_ggtt_wa(arg->vm);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static void bxt_vtd_ggtt_insert_entries__BKL(struct i915_address_space *vm,
>>> +					     struct i915_vma_resource *vma_res,
>>> +					     enum i915_cache_level level,
>>> +					     u32 flags)
>>> +{
>>> +	struct insert_entries arg = { vm, vma_res, level, flags };
>>> +
>>> +	stop_machine(bxt_vtd_ggtt_insert_entries__cb, &arg, NULL);
>>> +}
>>> +
>>> +void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)
>>> +{
>>> +	intel_gtt_chipset_flush();
>>> +}
>>> +
>>> +static void gmch_ggtt_invalidate(struct i915_ggtt *ggtt)
>>> +{
>>> +	intel_gtt_chipset_flush();
>>> +}
>>> +
>>> +static void gen5_ggtt_clear_range(struct i915_address_space *vm,
>>> +					 u64 start, u64 length)
>>> +{
>>> +	intel_gtt_clear_range(start >> PAGE_SHIFT, length >> PAGE_SHIFT);
>>> +}
>>> +
>>> +static void gen6_ggtt_clear_range(struct i915_address_space *vm,
>>> +				  u64 start, u64 length)
>>> +{
>>> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>>> +	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
>>> +	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
>>> +	gen6_pte_t scratch_pte, __iomem *gtt_base =
>>> +		(gen6_pte_t __iomem *)ggtt->gsm + first_entry;
>>> +	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
>>> +	int i;
>>> +
>>> +	if (WARN(num_entries > max_entries,
>>> +		 "First entry = %d; Num entries = %d (max=%d)\n",
>>> +		 first_entry, num_entries, max_entries))
>>> +		num_entries = max_entries;
>>> +
>>> +	scratch_pte = vm->scratch[0]->encode;
>>> +	for (i = 0; i < num_entries; i++)
>>> +		iowrite32(scratch_pte, &gtt_base[i]);
>>> +}
>>> +
>>> +static void gen8_ggtt_clear_range(struct i915_address_space *vm,
>>> +				  u64 start, u64 length)
>>> +{
>>> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>>> +	unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
>>> +	unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
>>> +	const gen8_pte_t scratch_pte = vm->scratch[0]->encode;
>>> +	gen8_pte_t __iomem *gtt_base =
>>> +		(gen8_pte_t __iomem *)ggtt->gsm + first_entry;
>>> +	const int max_entries = ggtt_total_entries(ggtt) - first_entry;
>>> +	int i;
>>> +
>>> +	if (WARN(num_entries > max_entries,
>>> +		 "First entry = %d; Num entries = %d (max=%d)\n",
>>> +		 first_entry, num_entries, max_entries))
>>> +		num_entries = max_entries;
>>> +
>>> +	for (i = 0; i < num_entries; i++)
>>> +		gen8_set_pte(&gtt_base[i], scratch_pte);
>>> +}
>>> +
>>> +static void gen5_gmch_remove(struct i915_address_space *vm)
>>> +{
>>> +	intel_gmch_remove();
>>> +}
>>> +
>>> +static void gen6_gmch_remove(struct i915_address_space *vm)
>>> +{
>>> +	struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>>> +
>>> +	iounmap(ggtt->gsm);
>>> +	free_scratch(vm);
>>> +}
>>> +
>>> +/*
>>> + * Certain Gen5 chipsets require idling the GPU before
>>> + * unmapping anything from the GTT when VT-d is enabled.
>>> + */
>>> +static bool needs_idle_maps(struct drm_i915_private *i915)
>>> +{
>>> +	/*
>>> +	 * Query intel_iommu to see if we need the workaround. Presumably that
>>> +	 * was loaded first.
>>> +	 */
>>> +	if (!intel_vtd_active(i915))
>>> +		return false;
>>> +
>>> +	if (GRAPHICS_VER(i915) == 5 && IS_MOBILE(i915))
>>> +		return true;
>>> +
>>> +	if (GRAPHICS_VER(i915) == 12)
>>> +		return true; /* XXX DMAR fault reason 7 */
>>> +
>>> +	return false;
>>> +}
>>> +
>>> +static unsigned int gen6_gttmmadr_size(struct drm_i915_private *i915)
>>> +{
>>> +	/*
>>> +	 * GEN6: GTTMMADR size is 4MB and GTTADR starts at 2MB offset
>>> +	 * GEN8: GTTMMADR size is 16MB and GTTADR starts at 8MB offset
>>> +	 */
>>> +	GEM_BUG_ON(GRAPHICS_VER(i915) < 6);
>>> +	return (GRAPHICS_VER(i915) < 8) ? SZ_4M : SZ_16M;
>>> +}
>>> +
>>> +static unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
>>> +{
>>> +	snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
>>> +	snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
>>> +	return snb_gmch_ctl << 20;
>>> +}
>>> +
>>> +static unsigned int gen8_get_total_gtt_size(u16 bdw_gmch_ctl)
>>> +{
>>> +	bdw_gmch_ctl >>= BDW_GMCH_GGMS_SHIFT;
>>> +	bdw_gmch_ctl &= BDW_GMCH_GGMS_MASK;
>>> +	if (bdw_gmch_ctl)
>>> +		bdw_gmch_ctl = 1 << bdw_gmch_ctl;
>>> +
>>> +#ifdef CONFIG_X86_32
>>> +	/* Limit 32b platforms to a 2GB GGTT: 4 << 20 / pte size * I915_GTT_PAGE_SIZE */
>>> +	if (bdw_gmch_ctl > 4)
>>> +		bdw_gmch_ctl = 4;
>>> +#endif
>>> +
>>> +	return bdw_gmch_ctl << 20;
>>> +}
>>> +
>>> +static unsigned int gen6_gttadr_offset(struct drm_i915_private *i915)
>>> +{
>>> +	return gen6_gttmmadr_size(i915) / 2;
>>> +}
>>> +
>>> +static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size)
>>> +{
>>> +	struct drm_i915_private *i915 = ggtt->vm.i915;
>>> +	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>>> +	phys_addr_t phys_addr;
>>> +	u32 pte_flags;
>>> +	int ret;
>>> +
>>> +	GEM_WARN_ON(pci_resource_len(pdev, 0) != gen6_gttmmadr_size(i915));
>>> +	phys_addr = pci_resource_start(pdev, 0) + gen6_gttadr_offset(i915);
>>> +
>>> +	/*
>>> +	 * On BXT+/ICL+ writes larger than 64 bit to the GTT pagetable range
>>> +	 * will be dropped. For WC mappings in general we have 64 byte burst
>>> +	 * writes when the WC buffer is flushed, so we can't use it, but have to
>>> +	 * resort to an uncached mapping. The WC issue is easily caught by the
>>> +	 * readback check when writing GTT PTE entries.
>>> +	 */
>>> +	if (IS_GEN9_LP(i915) || GRAPHICS_VER(i915) >= 11)
>>> +		ggtt->gsm = ioremap(phys_addr, size);
>>> +	else
>>> +		ggtt->gsm = ioremap_wc(phys_addr, size);
>>> +	if (!ggtt->gsm) {
>>> +		drm_err(&i915->drm, "Failed to map the ggtt page table\n");
>>> +		return -ENOMEM;
>>> +	}
>>> +
>>> +	kref_init(&ggtt->vm.resv_ref);
>>> +	ret = setup_scratch_page(&ggtt->vm);
>>> +	if (ret) {
>>> +		drm_err(&i915->drm, "Scratch setup failed\n");
>>> +		/* iounmap will also get called at remove, but meh */
>>> +		iounmap(ggtt->gsm);
>>> +		return ret;
>>> +	}
>>> +
>>> +	pte_flags = 0;
>>> +	if (i915_gem_object_is_lmem(ggtt->vm.scratch[0]))
>>> +		pte_flags |= PTE_LM;
>>> +
>>> +	ggtt->vm.scratch[0]->encode =
>>> +		ggtt->vm.pte_encode(px_dma(ggtt->vm.scratch[0]),
>>> +				    I915_CACHE_NONE, pte_flags);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
>>> +{
>>> +	struct drm_i915_private *i915 = ggtt->vm.i915;
>>> +	phys_addr_t gmadr_base;
>>> +	int ret;
>>> +
>>> +	ret = intel_gmch_probe(i915->bridge_dev, to_pci_dev(i915->drm.dev), NULL);
>>> +	if (!ret) {
>>> +		drm_err(&i915->drm, "failed to set up gmch\n");
>>> +		return -EIO;
>>> +	}
>>> +
>>> +	intel_gtt_get(&ggtt->vm.total, &gmadr_base, &ggtt->mappable_end);
>>> +
>>> +	ggtt->gmadr =
>>> +		(struct resource)DEFINE_RES_MEM(gmadr_base, ggtt->mappable_end);
>>> +
>>> +	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>>> +	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>>> +
>>> +	if (needs_idle_maps(i915)) {
>>> +		drm_notice(&i915->drm,
>>> +			   "Flushing DMA requests before IOMMU unmaps; performance may be degraded\n");
>>> +		ggtt->do_idle_maps = true;
>>> +	}
>>> +
>>> +	ggtt->vm.insert_page = gen5_ggtt_insert_page;
>>> +	ggtt->vm.insert_entries = gen5_ggtt_insert_entries;
>>> +	ggtt->vm.clear_range = gen5_ggtt_clear_range;
>>> +	ggtt->vm.cleanup = gen5_gmch_remove;
>>> +
>>> +	ggtt->invalidate = gmch_ggtt_invalidate;
>>> +
>>> +	ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
>>> +	ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
>>> +
>>> +	if (unlikely(ggtt->do_idle_maps))
>>> +		drm_notice(&i915->drm,
>>> +			   "Applying Ironlake quirks for intel_iommu\n");
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +int intel_gt_gmch_gen6_probe(struct i915_ggtt *ggtt)
>>> +{
>>> +	struct drm_i915_private *i915 = ggtt->vm.i915;
>>> +	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>>> +	unsigned int size;
>>> +	u16 snb_gmch_ctl;
>>> +
>>> +	ggtt->gmadr = pci_resource(pdev, 2);
>>> +	ggtt->mappable_end = resource_size(&ggtt->gmadr);
>>> +
>>> +	/*
>>> +	 * 64/512MB is the current min/max we actually know of, but this is
>>> +	 * just a coarse sanity check.
>>> +	 */
>>> +	if (ggtt->mappable_end < (64<<20) || ggtt->mappable_end > (512<<20)) {
>>> +		drm_err(&i915->drm, "Unknown GMADR size (%pa)\n",
>>> +			&ggtt->mappable_end);
>>> +		return -ENXIO;
>>> +	}
>>> +
>>> +	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
>>> +
>>> +	size = gen6_get_total_gtt_size(snb_gmch_ctl);
>>> +	ggtt->vm.total = (size / sizeof(gen6_pte_t)) * I915_GTT_PAGE_SIZE;
>>> +
>>> +	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>>> +	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>>> +
>>> +	ggtt->vm.clear_range = nop_clear_range;
>>> +	if (!HAS_FULL_PPGTT(i915) || intel_scanout_needs_vtd_wa(i915))
>>> +		ggtt->vm.clear_range = gen6_ggtt_clear_range;
>>> +	ggtt->vm.insert_page = gen6_ggtt_insert_page;
>>> +	ggtt->vm.insert_entries = gen6_ggtt_insert_entries;
>>> +	ggtt->vm.cleanup = gen6_gmch_remove;
>>> +
>>> +	ggtt->invalidate = gen6_ggtt_invalidate;
>>> +
>>> +	if (HAS_EDRAM(i915))
>>> +		ggtt->vm.pte_encode = iris_pte_encode;
>>> +	else if (IS_HASWELL(i915))
>>> +		ggtt->vm.pte_encode = hsw_pte_encode;
>>> +	else if (IS_VALLEYVIEW(i915))
>>> +		ggtt->vm.pte_encode = byt_pte_encode;
>>> +	else if (GRAPHICS_VER(i915) >= 7)
>>> +		ggtt->vm.pte_encode = ivb_pte_encode;
>>> +	else
>>> +		ggtt->vm.pte_encode = snb_pte_encode;
>>> +
>>> +	ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
>>> +	ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
>>> +
>>> +	return ggtt_probe_common(ggtt, size);
>>> +}
>>> +
>>> +static unsigned int chv_get_total_gtt_size(u16 gmch_ctrl)
>>> +{
>>> +	gmch_ctrl >>= SNB_GMCH_GGMS_SHIFT;
>>> +	gmch_ctrl &= SNB_GMCH_GGMS_MASK;
>>> +
>>> +	if (gmch_ctrl)
>>> +		return 1 << (20 + gmch_ctrl);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +int intel_gt_gmch_gen8_probe(struct i915_ggtt *ggtt)
>>> +{
>>> +	struct drm_i915_private *i915 = ggtt->vm.i915;
>>> +	struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>>> +	unsigned int size;
>>> +	u16 snb_gmch_ctl;
>>> +
>>> +	/* TODO: We're not aware of mappable constraints on gen8 yet */
>>> +	if (!HAS_LMEM(i915)) {
>>> +		ggtt->gmadr = pci_resource(pdev, 2);
>>> +		ggtt->mappable_end = resource_size(&ggtt->gmadr);
>>> +	}
>>> +
>>> +	pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
>>> +	if (IS_CHERRYVIEW(i915))
>>> +		size = chv_get_total_gtt_size(snb_gmch_ctl);
>>> +	else
>>> +		size = gen8_get_total_gtt_size(snb_gmch_ctl);
>>> +
>>> +	ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>>> +	ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>>> +	ggtt->vm.lmem_pt_obj_flags = I915_BO_ALLOC_PM_EARLY;
>>> +
>>> +	ggtt->vm.total = (size / sizeof(gen8_pte_t)) * I915_GTT_PAGE_SIZE;
>>> +	ggtt->vm.cleanup = gen6_gmch_remove;
>>> +	ggtt->vm.insert_page = gen8_ggtt_insert_page;
>>> +	ggtt->vm.clear_range = nop_clear_range;
>>> +	if (intel_scanout_needs_vtd_wa(i915))
>>> +		ggtt->vm.clear_range = gen8_ggtt_clear_range;
>>> +
>>> +	ggtt->vm.insert_entries = gen8_ggtt_insert_entries;
>>> +
>>> +	/*
>>> +	 * Serialize GTT updates with aperture access on BXT if VT-d is on,
>>> +	 * and always on CHV.
>>> +	 */
>>> +	if (intel_vm_no_concurrent_access_wa(i915)) {
>>> +		ggtt->vm.insert_entries = bxt_vtd_ggtt_insert_entries__BKL;
>>> +		ggtt->vm.insert_page    = bxt_vtd_ggtt_insert_page__BKL;
>>> +		ggtt->vm.bind_async_flags =
>>> +			I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND;
>>> +	}
>>> +
>>> +	ggtt->invalidate = gen8_ggtt_invalidate;
>>> +
>>> +	ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
>>> +	ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
>>> +
>>> +	ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
>>> +
>>> +	setup_private_pat(ggtt->vm.gt->uncore);
>>> +
>>> +	return ggtt_probe_common(ggtt, size);
>>> +}
>>> +
>>> +int intel_gt_gmch_gen5_enable_hw(struct drm_i915_private *i915)
>>> +{
>>> +	if (GRAPHICS_VER(i915) < 6 && !intel_enable_gtt())
>>> +		return -EIO;
>>> +
>>> +	return 0;
>>> +}
>>> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_gmch.h b/drivers/gpu/drm/i915/gt/intel_gt_gmch.h
>>> new file mode 100644
>>> index 000000000000..02e5342d7ea3
>>> --- /dev/null
>>> +++ b/drivers/gpu/drm/i915/gt/intel_gt_gmch.h
>>> @@ -0,0 +1,46 @@
>>> +/* SPDX-License-Identifier: MIT */
>>> +/*
>>> + * Copyright © 2022 Intel Corporation
>>> + */
>>> +
>>> +#ifndef __INTEL_GT_GMCH_H__
>>> +#define __INTEL_GT_GMCH_H__
>>> +
>>> +#include "intel_gtt.h"
>>> +
>>> +/* For x86 platforms */
>>> +#if IS_ENABLED(CONFIG_X86)
>>> +void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt);
>>> +int intel_gt_gmch_gen6_probe(struct i915_ggtt *ggtt);
>>> +int intel_gt_gmch_gen8_probe(struct i915_ggtt *ggtt);
>>> +int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt);
>>> +int intel_gt_gmch_gen5_enable_hw(struct drm_i915_private *i915);
>>> +
>>> +/* Stubs for non-x86 platforms */
>>> +#else
>>> +static inline void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)
>>> +{
>>> +}
>>> +static inline int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
>>> +{
>>> +	/* No HW should be probed for this case yet, return fail */
>>> +	return -1;
>>> +}
>>> +static inline int intel_gt_gmch_gen6_probe(struct i915_ggtt *ggtt)
>>> +{
>>> +	/* No HW should be probed for this case yet, return fail */
>>> +	return -1;
>>> +}
>>> +static inline int intel_gt_gmch_gen8_probe(struct i915_ggtt *ggtt)
>>> +{
>>> +	/* No HW should be probed for this case yet, return fail */
>>> +	return -1;
>>> +}
>>> +static inline int intel_gt_gmch_gen5_enable_hw(struct drm_i915_private *i915)
>>> +{
>>> +	/* No HW should be enabled for this case yet, return fail */
>>> +	return -1;
>>> +}
>>> +#endif
>>> +
>>> +#endif /* __INTEL_GT_GMCH_H__ */
>>> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
>>> index 4529b5e9f6e6..b4b9cc5a8ff6 100644
>>> --- a/drivers/gpu/drm/i915/gt/intel_gtt.h
>>> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
>>> @@ -547,6 +547,14 @@ i915_page_dir_dma_addr(const struct i915_ppgtt *ppgtt, const unsigned int n)
>>>    void ppgtt_init(struct i915_ppgtt *ppgtt, struct intel_gt *gt,
>>>    		unsigned long lmem_pt_obj_flags);
>>>    
>>> +void intel_ggtt_bind_vma(struct i915_address_space *vm,
>>> +			  struct i915_vm_pt_stash *stash,
>>> +			  struct i915_vma_resource *vma_res,
>>> +			  enum i915_cache_level cache_level,
>>> +			  u32 flags);
>>> +void intel_ggtt_unbind_vma(struct i915_address_space *vm,
>>> +			    struct i915_vma_resource *vma_res);
>>> +
>>>    int i915_ggtt_probe_hw(struct drm_i915_private *i915);
>>>    int i915_ggtt_init_hw(struct drm_i915_private *i915);
>>>    int i915_ggtt_enable_hw(struct drm_i915_private *i915);
>>> @@ -617,6 +625,7 @@ release_pd_entry(struct i915_page_directory * const pd,
>>>    		 struct i915_page_table * const pt,
>>>    		 const struct drm_i915_gem_object * const scratch);
>>>    void gen6_ggtt_invalidate(struct i915_ggtt *ggtt);
>>> +void gen8_ggtt_invalidate(struct i915_ggtt *ggtt);
>>>    
>>>    void ppgtt_bind_vma(struct i915_address_space *vm,
>>>    		    struct i915_vm_pt_stash *stash,

Bowman, Casey G March 30, 2022, 4:32 p.m. UTC | #5

On 3/30/22 03:16, Jani Nikula wrote:
> On Tue, 29 Mar 2022, Casey Bowman <casey.g.bowman@intel.com> wrote:
>> +/* Stubs for non-x86 platforms */
>> +#else
>> +static inline void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)
>> +{
>> +}
>> +static inline int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
>> +{
>> +	/* No HW should be probed for this case yet, return fail */
>> +	return -1;
>> +}
>> +static inline int intel_gt_gmch_gen6_probe(struct i915_ggtt *ggtt)
>> +{
>> +	/* No HW should be probed for this case yet, return fail */
>> +	return -1;
>> +}
>> +static inline int intel_gt_gmch_gen8_probe(struct i915_ggtt *ggtt)
>> +{
>> +	/* No HW should be probed for this case yet, return fail */
>> +	return -1;
>> +}
>> +static inline int intel_gt_gmch_gen5_enable_hw(struct drm_i915_private *i915)
>> +{
>> +	/* No HW should be enabled for this case yet, return fail */
>> +	return -1;
>> +}
>> +#endif
> Never use magic -1 for negative errno returns. That's -EPERM and not
> what you mean. -ENODEV or -EINVAL are better here.
>
> (As an exception, returning -1 is *maybe* fine for functions that return
> an index or something, and have zero chance of propagating to somewhere
> that actually interprets the number as a negative errno.)
>
> BR,
> Jani.
>

Thanks for pointing this out, the error codes slipped my mind when
creating these stubs. I'll fix that.

Regards,
Casey

Bowman, Casey G March 30, 2022, 4:42 p.m. UTC | #6

On 3/30/22 02:55, Tvrtko Ursulin wrote:
>
> On 30/03/2022 00:58, Casey Bowman wrote:
>> Some functions defined in the intel-gtt module are used in several
>> areas, but is only supported on x86 platforms.
>>
>> By separating these calls and their static underlying functions to
>> another area, we are able to compile out these functions for
>> non-x86 builds and provide stubs for the non-x86 implementations.
>>
>> In addition to the problematic calls, we are moving the gmch-related
>> functions to the new area.
>>
>> Signed-off-by: Casey Bowman <casey.g.bowman@intel.com>
>> ---
>>   drivers/gpu/drm/i915/Makefile           |   2 +
>>   drivers/gpu/drm/i915/gt/intel_ggtt.c    | 665 +-----------------------
>>   drivers/gpu/drm/i915/gt/intel_gt.c      |   4 +-
>>   drivers/gpu/drm/i915/gt/intel_gt.h      |   9 +
>>   drivers/gpu/drm/i915/gt/intel_gt_gmch.c | 653 +++++++++++++++++++++++
>>   drivers/gpu/drm/i915/gt/intel_gt_gmch.h |  46 ++
>>   drivers/gpu/drm/i915/gt/intel_gtt.h     |   9 +
>>   7 files changed, 735 insertions(+), 653 deletions(-)
>>   create mode 100644 drivers/gpu/drm/i915/gt/intel_gt_gmch.c
>>   create mode 100644 drivers/gpu/drm/i915/gt/intel_gt_gmch.h
>>
>> diff --git a/drivers/gpu/drm/i915/Makefile 
>> b/drivers/gpu/drm/i915/Makefile
>> index c837a29ffac8..b7bdaec99118 100644
>> --- a/drivers/gpu/drm/i915/Makefile
>> +++ b/drivers/gpu/drm/i915/Makefile
>> @@ -126,6 +126,8 @@ gt-y += \
>>       gt/intel_workarounds.o \
>>       gt/shmem_utils.o \
>>       gt/sysfs_engines.o
>> +# x86 intel-gtt module support
>> +gt-$(CONFIG_X86) += gt/intel_gt_gmch.o
>>   # autogenerated null render state
>>   gt-y += \
>>       gt/gen6_renderstate.o \
>> diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c 
>> b/drivers/gpu/drm/i915/gt/intel_ggtt.c
>> index 04191fe2ee34..97a595e42135 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
>> @@ -3,18 +3,14 @@
>>    * Copyright © 2020 Intel Corporation
>>    */
>>   -#include <linux/agp_backend.h>
>> -#include <linux/stop_machine.h>
>> -
>> +#include <linux/types.h>
>>   #include <asm/set_memory.h>
>>   #include <asm/smp.h>
>>   -#include <drm/i915_drm.h>
>> -#include <drm/intel-gtt.h>
>> -
>>   #include "gem/i915_gem_lmem.h"
>>     #include "intel_gt.h"
>> +#include "intel_gt_gmch.h"
>>   #include "intel_gt_regs.h"
>>   #include "i915_drv.h"
>>   #include "i915_scatterlist.h"
>> @@ -94,28 +90,6 @@ int i915_ggtt_init_hw(struct drm_i915_private *i915)
>>       return 0;
>>   }
>>   -/*
>> - * Certain Gen5 chipsets require idling the GPU before
>> - * unmapping anything from the GTT when VT-d is enabled.
>> - */
>> -static bool needs_idle_maps(struct drm_i915_private *i915)
>> -{
>> -    /*
>> -     * Query intel_iommu to see if we need the workaround. 
>> Presumably that
>> -     * was loaded first.
>> -     */
>> -    if (!intel_vtd_active(i915))
>> -        return false;
>> -
>> -    if (GRAPHICS_VER(i915) == 5 && IS_MOBILE(i915))
>> -        return true;
>> -
>> -    if (GRAPHICS_VER(i915) == 12)
>> -        return true; /* XXX DMAR fault reason 7 */
>> -
>> -    return false;
>> -}
>> -
>>   /**
>>    * i915_ggtt_suspend_vm - Suspend the memory mappings for a GGTT or 
>> DPT VM
>>    * @vm: The VM to suspend the mappings for
>> @@ -204,7 +178,7 @@ void gen6_ggtt_invalidate(struct i915_ggtt *ggtt)
>>       spin_unlock_irq(&uncore->lock);
>>   }
>>   -static void gen8_ggtt_invalidate(struct i915_ggtt *ggtt)
>> +void gen8_ggtt_invalidate(struct i915_ggtt *ggtt)
>>   {
>>       struct intel_uncore *uncore = ggtt->vm.gt->uncore;
>>   @@ -229,11 +203,6 @@ static void guc_ggtt_invalidate(struct 
>> i915_ggtt *ggtt)
>>           intel_uncore_write_fw(uncore, GEN8_GTCR, 
>> GEN8_GTCR_INVALIDATE);
>>   }
>>   -static void gmch_ggtt_invalidate(struct i915_ggtt *ggtt)
>> -{
>> -    intel_gtt_chipset_flush();
>> -}
>> -
>>   u64 gen8_ggtt_pte_encode(dma_addr_t addr,
>>                enum i915_cache_level level,
>>                u32 flags)
>> @@ -246,258 +215,7 @@ u64 gen8_ggtt_pte_encode(dma_addr_t addr,
>>       return pte;
>>   }
>>   -static void gen8_set_pte(void __iomem *addr, gen8_pte_t pte)
>> -{
>> -    writeq(pte, addr);
>> -}
>> -
>> -static void gen8_ggtt_insert_page(struct i915_address_space *vm,
>> -                  dma_addr_t addr,
>> -                  u64 offset,
>> -                  enum i915_cache_level level,
>> -                  u32 flags)
>> -{
>> -    struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> -    gen8_pte_t __iomem *pte =
>> -        (gen8_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
>> -
>> -    gen8_set_pte(pte, gen8_ggtt_pte_encode(addr, level, flags));
>> -
>> -    ggtt->invalidate(ggtt);
>> -}
>> -
>> -static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
>> -                     struct i915_vma_resource *vma_res,
>> -                     enum i915_cache_level level,
>> -                     u32 flags)
>> -{
>> -    const gen8_pte_t pte_encode = gen8_ggtt_pte_encode(0, level, 
>> flags);
>> -    struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> -    gen8_pte_t __iomem *gte;
>> -    gen8_pte_t __iomem *end;
>> -    struct sgt_iter iter;
>> -    dma_addr_t addr;
>> -
>> -    /*
>> -     * Note that we ignore PTE_READ_ONLY here. The caller must be 
>> careful
>> -     * not to allow the user to override access to a read only page.
>> -     */
>> -
>> -    gte = (gen8_pte_t __iomem *)ggtt->gsm;
>> -    gte += vma_res->start / I915_GTT_PAGE_SIZE;
>> -    end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
>> -
>> -    for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
>> -        gen8_set_pte(gte++, pte_encode | addr);
>> -    GEM_BUG_ON(gte > end);
>> -
>> -    /* Fill the allocated but "unused" space beyond the end of the 
>> buffer */
>> -    while (gte < end)
>> -        gen8_set_pte(gte++, vm->scratch[0]->encode);
>> -
>> -    /*
>> -     * We want to flush the TLBs only after we're certain all the PTE
>> -     * updates have finished.
>> -     */
>> -    ggtt->invalidate(ggtt);
>> -}
>> -
>> -static void gen6_ggtt_insert_page(struct i915_address_space *vm,
>> -                  dma_addr_t addr,
>> -                  u64 offset,
>> -                  enum i915_cache_level level,
>> -                  u32 flags)
>> -{
>> -    struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> -    gen6_pte_t __iomem *pte =
>> -        (gen6_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
>> -
>> -    iowrite32(vm->pte_encode(addr, level, flags), pte);
>> -
>> -    ggtt->invalidate(ggtt);
>> -}
>> -
>> -/*
>> - * Binds an object into the global gtt with the specified cache level.
>> - * The object will be accessible to the GPU via commands whose operands
>> - * reference offsets within the global GTT as well as accessible by 
>> the GPU
>> - * through the GMADR mapped BAR (i915->mm.gtt->gtt).
>> - */
>> -static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
>> -                     struct i915_vma_resource *vma_res,
>> -                     enum i915_cache_level level,
>> -                     u32 flags)
>> -{
>> -    struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> -    gen6_pte_t __iomem *gte;
>> -    gen6_pte_t __iomem *end;
>> -    struct sgt_iter iter;
>> -    dma_addr_t addr;
>> -
>> -    gte = (gen6_pte_t __iomem *)ggtt->gsm;
>> -    gte += vma_res->start / I915_GTT_PAGE_SIZE;
>> -    end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
>> -
>> -    for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
>> -        iowrite32(vm->pte_encode(addr, level, flags), gte++);
>> -    GEM_BUG_ON(gte > end);
>> -
>> -    /* Fill the allocated but "unused" space beyond the end of the 
>> buffer */
>> -    while (gte < end)
>> -        iowrite32(vm->scratch[0]->encode, gte++);
>> -
>> -    /*
>> -     * We want to flush the TLBs only after we're certain all the PTE
>> -     * updates have finished.
>> -     */
>> -    ggtt->invalidate(ggtt);
>> -}
>> -
>> -static void nop_clear_range(struct i915_address_space *vm,
>> -                u64 start, u64 length)
>> -{
>> -}
>> -
>> -static void gen8_ggtt_clear_range(struct i915_address_space *vm,
>> -                  u64 start, u64 length)
>> -{
>> -    struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> -    unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
>> -    unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
>> -    const gen8_pte_t scratch_pte = vm->scratch[0]->encode;
>> -    gen8_pte_t __iomem *gtt_base =
>> -        (gen8_pte_t __iomem *)ggtt->gsm + first_entry;
>> -    const int max_entries = ggtt_total_entries(ggtt) - first_entry;
>> -    int i;
>> -
>> -    if (WARN(num_entries > max_entries,
>> -         "First entry = %d; Num entries = %d (max=%d)\n",
>> -         first_entry, num_entries, max_entries))
>> -        num_entries = max_entries;
>> -
>> -    for (i = 0; i < num_entries; i++)
>> -        gen8_set_pte(&gtt_base[i], scratch_pte);
>> -}
>> -
>> -static void bxt_vtd_ggtt_wa(struct i915_address_space *vm)
>> -{
>> -    /*
>> -     * Make sure the internal GAM fifo has been cleared of all GTT
>> -     * writes before exiting stop_machine(). This guarantees that
>> -     * any aperture accesses waiting to start in another process
>> -     * cannot back up behind the GTT writes causing a hang.
>> -     * The register can be any arbitrary GAM register.
>> -     */
>> -    intel_uncore_posting_read_fw(vm->gt->uncore, GFX_FLSH_CNTL_GEN6);
>> -}
>> -
>> -struct insert_page {
>> -    struct i915_address_space *vm;
>> -    dma_addr_t addr;
>> -    u64 offset;
>> -    enum i915_cache_level level;
>> -};
>> -
>> -static int bxt_vtd_ggtt_insert_page__cb(void *_arg)
>> -{
>> -    struct insert_page *arg = _arg;
>> -
>> -    gen8_ggtt_insert_page(arg->vm, arg->addr, arg->offset, 
>> arg->level, 0);
>> -    bxt_vtd_ggtt_wa(arg->vm);
>> -
>> -    return 0;
>> -}
>> -
>> -static void bxt_vtd_ggtt_insert_page__BKL(struct i915_address_space 
>> *vm,
>> -                      dma_addr_t addr,
>> -                      u64 offset,
>> -                      enum i915_cache_level level,
>> -                      u32 unused)
>> -{
>> -    struct insert_page arg = { vm, addr, offset, level };
>> -
>> -    stop_machine(bxt_vtd_ggtt_insert_page__cb, &arg, NULL);
>> -}
>> -
>> -struct insert_entries {
>> -    struct i915_address_space *vm;
>> -    struct i915_vma_resource *vma_res;
>> -    enum i915_cache_level level;
>> -    u32 flags;
>> -};
>> -
>> -static int bxt_vtd_ggtt_insert_entries__cb(void *_arg)
>> -{
>> -    struct insert_entries *arg = _arg;
>> -
>> -    gen8_ggtt_insert_entries(arg->vm, arg->vma_res, arg->level, 
>> arg->flags);
>> -    bxt_vtd_ggtt_wa(arg->vm);
>> -
>> -    return 0;
>> -}
>> -
>> -static void bxt_vtd_ggtt_insert_entries__BKL(struct 
>> i915_address_space *vm,
>> -                         struct i915_vma_resource *vma_res,
>> -                         enum i915_cache_level level,
>> -                         u32 flags)
>> -{
>> -    struct insert_entries arg = { vm, vma_res, level, flags };
>> -
>> -    stop_machine(bxt_vtd_ggtt_insert_entries__cb, &arg, NULL);
>> -}
>> -
>> -static void gen6_ggtt_clear_range(struct i915_address_space *vm,
>> -                  u64 start, u64 length)
>> -{
>> -    struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> -    unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
>> -    unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
>> -    gen6_pte_t scratch_pte, __iomem *gtt_base =
>> -        (gen6_pte_t __iomem *)ggtt->gsm + first_entry;
>> -    const int max_entries = ggtt_total_entries(ggtt) - first_entry;
>> -    int i;
>> -
>> -    if (WARN(num_entries > max_entries,
>> -         "First entry = %d; Num entries = %d (max=%d)\n",
>> -         first_entry, num_entries, max_entries))
>> -        num_entries = max_entries;
>> -
>> -    scratch_pte = vm->scratch[0]->encode;
>> -    for (i = 0; i < num_entries; i++)
>> -        iowrite32(scratch_pte, &gtt_base[i]);
>> -}
>> -
>> -static void i915_ggtt_insert_page(struct i915_address_space *vm,
>> -                  dma_addr_t addr,
>> -                  u64 offset,
>> -                  enum i915_cache_level cache_level,
>> -                  u32 unused)
>> -{
>> -    unsigned int flags = (cache_level == I915_CACHE_NONE) ?
>> -        AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
>> -
>> -    intel_gtt_insert_page(addr, offset >> PAGE_SHIFT, flags);
>> -}
>> -
>> -static void i915_ggtt_insert_entries(struct i915_address_space *vm,
>> -                     struct i915_vma_resource *vma_res,
>> -                     enum i915_cache_level cache_level,
>> -                     u32 unused)
>> -{
>> -    unsigned int flags = (cache_level == I915_CACHE_NONE) ?
>> -        AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
>> -
>> -    intel_gtt_insert_sg_entries(vma_res->bi.pages, vma_res->start >> 
>> PAGE_SHIFT,
>> -                    flags);
>> -}
>> -
>> -static void i915_ggtt_clear_range(struct i915_address_space *vm,
>> -                  u64 start, u64 length)
>> -{
>> -    intel_gtt_clear_range(start >> PAGE_SHIFT, length >> PAGE_SHIFT);
>> -}
>> -
>> -static void ggtt_bind_vma(struct i915_address_space *vm,
>> +void intel_ggtt_bind_vma(struct i915_address_space *vm,
>>                 struct i915_vm_pt_stash *stash,
>>                 struct i915_vma_resource *vma_res,
>>                 enum i915_cache_level cache_level,
>> @@ -521,7 +239,7 @@ static void ggtt_bind_vma(struct 
>> i915_address_space *vm,
>>       vma_res->page_sizes_gtt = I915_GTT_PAGE_SIZE;
>>   }
>>   -static void ggtt_unbind_vma(struct i915_address_space *vm,
>> +void intel_ggtt_unbind_vma(struct i915_address_space *vm,
>>                   struct i915_vma_resource *vma_res)
>>   {
>>       vm->clear_range(vm, vma_res->start, vma_res->vma_size);
>> @@ -724,10 +442,10 @@ static int init_aliasing_ppgtt(struct i915_ggtt 
>> *ggtt)
>>       ggtt->alias = ppgtt;
>>       ggtt->vm.bind_async_flags |= ppgtt->vm.bind_async_flags;
>>   -    GEM_BUG_ON(ggtt->vm.vma_ops.bind_vma != ggtt_bind_vma);
>> +    GEM_BUG_ON(ggtt->vm.vma_ops.bind_vma != intel_ggtt_bind_vma);
>>       ggtt->vm.vma_ops.bind_vma = aliasing_gtt_bind_vma;
>>   -    GEM_BUG_ON(ggtt->vm.vma_ops.unbind_vma != ggtt_unbind_vma);
>> +    GEM_BUG_ON(ggtt->vm.vma_ops.unbind_vma != intel_ggtt_unbind_vma);
>>       ggtt->vm.vma_ops.unbind_vma = aliasing_gtt_unbind_vma;
>>         i915_vm_free_pt_stash(&ppgtt->vm, &stash);
>> @@ -750,8 +468,8 @@ static void fini_aliasing_ppgtt(struct i915_ggtt 
>> *ggtt)
>>         i915_vm_put(&ppgtt->vm);
>>   -    ggtt->vm.vma_ops.bind_vma   = ggtt_bind_vma;
>> -    ggtt->vm.vma_ops.unbind_vma = ggtt_unbind_vma;
>> +    ggtt->vm.vma_ops.bind_vma   = intel_ggtt_bind_vma;
>> +    ggtt->vm.vma_ops.unbind_vma = intel_ggtt_unbind_vma;
>>   }
>>     int i915_init_ggtt(struct drm_i915_private *i915)
>> @@ -839,364 +557,12 @@ void i915_ggtt_driver_late_release(struct 
>> drm_i915_private *i915)
>>       dma_resv_fini(&ggtt->vm._resv);
>>   }
>>   -static unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
>> -{
>> -    snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
>> -    snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
>> -    return snb_gmch_ctl << 20;
>> -}
>> -
>> -static unsigned int gen8_get_total_gtt_size(u16 bdw_gmch_ctl)
>> -{
>> -    bdw_gmch_ctl >>= BDW_GMCH_GGMS_SHIFT;
>> -    bdw_gmch_ctl &= BDW_GMCH_GGMS_MASK;
>> -    if (bdw_gmch_ctl)
>> -        bdw_gmch_ctl = 1 << bdw_gmch_ctl;
>> -
>> -#ifdef CONFIG_X86_32
>> -    /* Limit 32b platforms to a 2GB GGTT: 4 << 20 / pte size * 
>> I915_GTT_PAGE_SIZE */
>> -    if (bdw_gmch_ctl > 4)
>> -        bdw_gmch_ctl = 4;
>> -#endif
>> -
>> -    return bdw_gmch_ctl << 20;
>> -}
>> -
>> -static unsigned int chv_get_total_gtt_size(u16 gmch_ctrl)
>> -{
>> -    gmch_ctrl >>= SNB_GMCH_GGMS_SHIFT;
>> -    gmch_ctrl &= SNB_GMCH_GGMS_MASK;
>> -
>> -    if (gmch_ctrl)
>> -        return 1 << (20 + gmch_ctrl);
>> -
>> -    return 0;
>> -}
>> -
>> -static unsigned int gen6_gttmmadr_size(struct drm_i915_private *i915)
>> -{
>> -    /*
>> -     * GEN6: GTTMMADR size is 4MB and GTTADR starts at 2MB offset
>> -     * GEN8: GTTMMADR size is 16MB and GTTADR starts at 8MB offset
>> -     */
>> -    GEM_BUG_ON(GRAPHICS_VER(i915) < 6);
>> -    return (GRAPHICS_VER(i915) < 8) ? SZ_4M : SZ_16M;
>> -}
>> -
>> -static unsigned int gen6_gttadr_offset(struct drm_i915_private *i915)
>> -{
>> -    return gen6_gttmmadr_size(i915) / 2;
>> -}
>> -
>> -static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size)
>> -{
>> -    struct drm_i915_private *i915 = ggtt->vm.i915;
>> -    struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>> -    phys_addr_t phys_addr;
>> -    u32 pte_flags;
>> -    int ret;
>> -
>> -    GEM_WARN_ON(pci_resource_len(pdev, 0) != gen6_gttmmadr_size(i915));
>> -    phys_addr = pci_resource_start(pdev, 0) + gen6_gttadr_offset(i915);
>> -
>> -    /*
>> -     * On BXT+/ICL+ writes larger than 64 bit to the GTT pagetable 
>> range
>> -     * will be dropped. For WC mappings in general we have 64 byte 
>> burst
>> -     * writes when the WC buffer is flushed, so we can't use it, but 
>> have to
>> -     * resort to an uncached mapping. The WC issue is easily caught 
>> by the
>> -     * readback check when writing GTT PTE entries.
>> -     */
>> -    if (IS_GEN9_LP(i915) || GRAPHICS_VER(i915) >= 11)
>> -        ggtt->gsm = ioremap(phys_addr, size);
>> -    else
>> -        ggtt->gsm = ioremap_wc(phys_addr, size);
>> -    if (!ggtt->gsm) {
>> -        drm_err(&i915->drm, "Failed to map the ggtt page table\n");
>> -        return -ENOMEM;
>> -    }
>> -
>> -    kref_init(&ggtt->vm.resv_ref);
>> -    ret = setup_scratch_page(&ggtt->vm);
>> -    if (ret) {
>> -        drm_err(&i915->drm, "Scratch setup failed\n");
>> -        /* iounmap will also get called at remove, but meh */
>> -        iounmap(ggtt->gsm);
>> -        return ret;
>> -    }
>> -
>> -    pte_flags = 0;
>> -    if (i915_gem_object_is_lmem(ggtt->vm.scratch[0]))
>> -        pte_flags |= PTE_LM;
>> -
>> -    ggtt->vm.scratch[0]->encode =
>> -        ggtt->vm.pte_encode(px_dma(ggtt->vm.scratch[0]),
>> -                    I915_CACHE_NONE, pte_flags);
>> -
>> -    return 0;
>> -}
>> -
>> -static void gen6_gmch_remove(struct i915_address_space *vm)
>> -{
>> -    struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> -
>> -    iounmap(ggtt->gsm);
>> -    free_scratch(vm);
>> -}
>> -
>> -static struct resource pci_resource(struct pci_dev *pdev, int bar)
>> +struct resource pci_resource(struct pci_dev *pdev, int bar)
>>   {
>>       return (struct resource)DEFINE_RES_MEM(pci_resource_start(pdev, 
>> bar),
>>                              pci_resource_len(pdev, bar));
>>   }
>
> Export with pci_ prefix is a bit dodgy - maybe intel_pci_resource? Not 
> sure.
>
> The rest looks okay to me.
>
> I mean I could suggest to do something about the incosistency of:
>
> static inline void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)
>
> vs:
>
> static inline int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
>
> Since I value more for function name to tell me on what it operates 
> instead where it is placed. So I'd personally rename the second class 
> to i915_ggtt. It would also be consistent with other exported 
> functions which take struct i915_ggtt like i915_ggtt_enable_guc, 
> i915_ggtt_resume and so. But opinions will differ so I can live with 
> it as is as well.
>

@Jani/Lucas, do you guys have any opinion on changing the prefix to a 
functionality-based name over location-based?

If we have any standard we're trying to adhere to here, I can change it 
for the standard.
I'd like to make everyone happy, if possible. :P

Regards,
Casey

> Regards,
>
> Tvrtko
>
>>   -static int gen8_gmch_probe(struct i915_ggtt *ggtt)
>> -{
>> -    struct drm_i915_private *i915 = ggtt->vm.i915;
>> -    struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>> -    unsigned int size;
>> -    u16 snb_gmch_ctl;
>> -
>> -    /* TODO: We're not aware of mappable constraints on gen8 yet */
>> -    if (!HAS_LMEM(i915)) {
>> -        ggtt->gmadr = pci_resource(pdev, 2);
>> -        ggtt->mappable_end = resource_size(&ggtt->gmadr);
>> -    }
>> -
>> -    pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
>> -    if (IS_CHERRYVIEW(i915))
>> -        size = chv_get_total_gtt_size(snb_gmch_ctl);
>> -    else
>> -        size = gen8_get_total_gtt_size(snb_gmch_ctl);
>> -
>> -    ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>> -    ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>> -    ggtt->vm.lmem_pt_obj_flags = I915_BO_ALLOC_PM_EARLY;
>> -
>> -    ggtt->vm.total = (size / sizeof(gen8_pte_t)) * I915_GTT_PAGE_SIZE;
>> -    ggtt->vm.cleanup = gen6_gmch_remove;
>> -    ggtt->vm.insert_page = gen8_ggtt_insert_page;
>> -    ggtt->vm.clear_range = nop_clear_range;
>> -    if (intel_scanout_needs_vtd_wa(i915))
>> -        ggtt->vm.clear_range = gen8_ggtt_clear_range;
>> -
>> -    ggtt->vm.insert_entries = gen8_ggtt_insert_entries;
>> -
>> -    /*
>> -     * Serialize GTT updates with aperture access on BXT if VT-d is on,
>> -     * and always on CHV.
>> -     */
>> -    if (intel_vm_no_concurrent_access_wa(i915)) {
>> -        ggtt->vm.insert_entries = bxt_vtd_ggtt_insert_entries__BKL;
>> -        ggtt->vm.insert_page    = bxt_vtd_ggtt_insert_page__BKL;
>> -        ggtt->vm.bind_async_flags =
>> -            I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND;
>> -    }
>> -
>> -    ggtt->invalidate = gen8_ggtt_invalidate;
>> -
>> -    ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
>> -    ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
>> -
>> -    ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
>> -
>> -    setup_private_pat(ggtt->vm.gt->uncore);
>> -
>> -    return ggtt_probe_common(ggtt, size);
>> -}
>> -
>> -static u64 snb_pte_encode(dma_addr_t addr,
>> -              enum i915_cache_level level,
>> -              u32 flags)
>> -{
>> -    gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> -
>> -    switch (level) {
>> -    case I915_CACHE_L3_LLC:
>> -    case I915_CACHE_LLC:
>> -        pte |= GEN6_PTE_CACHE_LLC;
>> -        break;
>> -    case I915_CACHE_NONE:
>> -        pte |= GEN6_PTE_UNCACHED;
>> -        break;
>> -    default:
>> -        MISSING_CASE(level);
>> -    }
>> -
>> -    return pte;
>> -}
>> -
>> -static u64 ivb_pte_encode(dma_addr_t addr,
>> -              enum i915_cache_level level,
>> -              u32 flags)
>> -{
>> -    gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> -
>> -    switch (level) {
>> -    case I915_CACHE_L3_LLC:
>> -        pte |= GEN7_PTE_CACHE_L3_LLC;
>> -        break;
>> -    case I915_CACHE_LLC:
>> -        pte |= GEN6_PTE_CACHE_LLC;
>> -        break;
>> -    case I915_CACHE_NONE:
>> -        pte |= GEN6_PTE_UNCACHED;
>> -        break;
>> -    default:
>> -        MISSING_CASE(level);
>> -    }
>> -
>> -    return pte;
>> -}
>> -
>> -static u64 byt_pte_encode(dma_addr_t addr,
>> -              enum i915_cache_level level,
>> -              u32 flags)
>> -{
>> -    gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> -
>> -    if (!(flags & PTE_READ_ONLY))
>> -        pte |= BYT_PTE_WRITEABLE;
>> -
>> -    if (level != I915_CACHE_NONE)
>> -        pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
>> -
>> -    return pte;
>> -}
>> -
>> -static u64 hsw_pte_encode(dma_addr_t addr,
>> -              enum i915_cache_level level,
>> -              u32 flags)
>> -{
>> -    gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> -
>> -    if (level != I915_CACHE_NONE)
>> -        pte |= HSW_WB_LLC_AGE3;
>> -
>> -    return pte;
>> -}
>> -
>> -static u64 iris_pte_encode(dma_addr_t addr,
>> -               enum i915_cache_level level,
>> -               u32 flags)
>> -{
>> -    gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> -
>> -    switch (level) {
>> -    case I915_CACHE_NONE:
>> -        break;
>> -    case I915_CACHE_WT:
>> -        pte |= HSW_WT_ELLC_LLC_AGE3;
>> -        break;
>> -    default:
>> -        pte |= HSW_WB_ELLC_LLC_AGE3;
>> -        break;
>> -    }
>> -
>> -    return pte;
>> -}
>> -
>> -static int gen6_gmch_probe(struct i915_ggtt *ggtt)
>> -{
>> -    struct drm_i915_private *i915 = ggtt->vm.i915;
>> -    struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>> -    unsigned int size;
>> -    u16 snb_gmch_ctl;
>> -
>> -    ggtt->gmadr = pci_resource(pdev, 2);
>> -    ggtt->mappable_end = resource_size(&ggtt->gmadr);
>> -
>> -    /*
>> -     * 64/512MB is the current min/max we actually know of, but this is
>> -     * just a coarse sanity check.
>> -     */
>> -    if (ggtt->mappable_end < (64<<20) || ggtt->mappable_end > 
>> (512<<20)) {
>> -        drm_err(&i915->drm, "Unknown GMADR size (%pa)\n",
>> -            &ggtt->mappable_end);
>> -        return -ENXIO;
>> -    }
>> -
>> -    pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
>> -
>> -    size = gen6_get_total_gtt_size(snb_gmch_ctl);
>> -    ggtt->vm.total = (size / sizeof(gen6_pte_t)) * I915_GTT_PAGE_SIZE;
>> -
>> -    ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>> -    ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>> -
>> -    ggtt->vm.clear_range = nop_clear_range;
>> -    if (!HAS_FULL_PPGTT(i915) || intel_scanout_needs_vtd_wa(i915))
>> -        ggtt->vm.clear_range = gen6_ggtt_clear_range;
>> -    ggtt->vm.insert_page = gen6_ggtt_insert_page;
>> -    ggtt->vm.insert_entries = gen6_ggtt_insert_entries;
>> -    ggtt->vm.cleanup = gen6_gmch_remove;
>> -
>> -    ggtt->invalidate = gen6_ggtt_invalidate;
>> -
>> -    if (HAS_EDRAM(i915))
>> -        ggtt->vm.pte_encode = iris_pte_encode;
>> -    else if (IS_HASWELL(i915))
>> -        ggtt->vm.pte_encode = hsw_pte_encode;
>> -    else if (IS_VALLEYVIEW(i915))
>> -        ggtt->vm.pte_encode = byt_pte_encode;
>> -    else if (GRAPHICS_VER(i915) >= 7)
>> -        ggtt->vm.pte_encode = ivb_pte_encode;
>> -    else
>> -        ggtt->vm.pte_encode = snb_pte_encode;
>> -
>> -    ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
>> -    ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
>> -
>> -    return ggtt_probe_common(ggtt, size);
>> -}
>> -
>> -static void i915_gmch_remove(struct i915_address_space *vm)
>> -{
>> -    intel_gmch_remove();
>> -}
>> -
>> -static int i915_gmch_probe(struct i915_ggtt *ggtt)
>> -{
>> -    struct drm_i915_private *i915 = ggtt->vm.i915;
>> -    phys_addr_t gmadr_base;
>> -    int ret;
>> -
>> -    ret = intel_gmch_probe(i915->bridge_dev, 
>> to_pci_dev(i915->drm.dev), NULL);
>> -    if (!ret) {
>> -        drm_err(&i915->drm, "failed to set up gmch\n");
>> -        return -EIO;
>> -    }
>> -
>> -    intel_gtt_get(&ggtt->vm.total, &gmadr_base, &ggtt->mappable_end);
>> -
>> -    ggtt->gmadr =
>> -        (struct resource)DEFINE_RES_MEM(gmadr_base, 
>> ggtt->mappable_end);
>> -
>> -    ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>> -    ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>> -
>> -    if (needs_idle_maps(i915)) {
>> -        drm_notice(&i915->drm,
>> -               "Flushing DMA requests before IOMMU unmaps; 
>> performance may be degraded\n");
>> -        ggtt->do_idle_maps = true;
>> -    }
>> -
>> -    ggtt->vm.insert_page = i915_ggtt_insert_page;
>> -    ggtt->vm.insert_entries = i915_ggtt_insert_entries;
>> -    ggtt->vm.clear_range = i915_ggtt_clear_range;
>> -    ggtt->vm.cleanup = i915_gmch_remove;
>> -
>> -    ggtt->invalidate = gmch_ggtt_invalidate;
>> -
>> -    ggtt->vm.vma_ops.bind_vma    = ggtt_bind_vma;
>> -    ggtt->vm.vma_ops.unbind_vma  = ggtt_unbind_vma;
>> -
>> -    if (unlikely(ggtt->do_idle_maps))
>> -        drm_notice(&i915->drm,
>> -               "Applying Ironlake quirks for intel_iommu\n");
>> -
>> -    return 0;
>> -}
>> -
>>   static int ggtt_probe_hw(struct i915_ggtt *ggtt, struct intel_gt *gt)
>>   {
>>       struct drm_i915_private *i915 = gt->i915;
>> @@ -1208,11 +574,11 @@ static int ggtt_probe_hw(struct i915_ggtt 
>> *ggtt, struct intel_gt *gt)
>>       dma_resv_init(&ggtt->vm._resv);
>>         if (GRAPHICS_VER(i915) <= 5)
>> -        ret = i915_gmch_probe(ggtt);
>> +        ret = intel_gt_gmch_gen5_probe(ggtt);
>>       else if (GRAPHICS_VER(i915) < 8)
>> -        ret = gen6_gmch_probe(ggtt);
>> +        ret = intel_gt_gmch_gen6_probe(ggtt);
>>       else
>> -        ret = gen8_gmch_probe(ggtt);
>> +        ret = intel_gt_gmch_gen8_probe(ggtt);
>>       if (ret) {
>>           dma_resv_fini(&ggtt->vm._resv);
>>           return ret;
>> @@ -1266,10 +632,7 @@ int i915_ggtt_probe_hw(struct drm_i915_private 
>> *i915)
>>     int i915_ggtt_enable_hw(struct drm_i915_private *i915)
>>   {
>> -    if (GRAPHICS_VER(i915) < 6 && !intel_enable_gtt())
>> -        return -EIO;
>> -
>> -    return 0;
>> +    return intel_gt_gmch_gen5_enable_hw(i915);
>>   }
>>     void i915_ggtt_enable_guc(struct i915_ggtt *ggtt)
>> diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c 
>> b/drivers/gpu/drm/i915/gt/intel_gt.c
>> index 5001a6168d56..f0014c5072c9 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_gt.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_gt.c
>> @@ -4,7 +4,6 @@
>>    */
>>     #include <drm/drm_managed.h>
>> -#include <drm/intel-gtt.h>
>>     #include "gem/i915_gem_internal.h"
>>   #include "gem/i915_gem_lmem.h"
>> @@ -17,6 +16,7 @@
>>   #include "intel_gt_buffer_pool.h"
>>   #include "intel_gt_clock_utils.h"
>>   #include "intel_gt_debugfs.h"
>> +#include "intel_gt_gmch.h"
>>   #include "intel_gt_pm.h"
>>   #include "intel_gt_regs.h"
>>   #include "intel_gt_requests.h"
>> @@ -451,7 +451,7 @@ void intel_gt_chipset_flush(struct intel_gt *gt)
>>   {
>>       wmb();
>>       if (GRAPHICS_VER(gt->i915) < 6)
>> -        intel_gtt_chipset_flush();
>> +        intel_gt_gmch_gen5_chipset_flush(gt);
>>   }
>>     void intel_gt_driver_register(struct intel_gt *gt)
>> diff --git a/drivers/gpu/drm/i915/gt/intel_gt.h 
>> b/drivers/gpu/drm/i915/gt/intel_gt.h
>> index e76168e10a21..8956dfc5afe0 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_gt.h
>> +++ b/drivers/gpu/drm/i915/gt/intel_gt.h
>> @@ -13,6 +13,13 @@
>>   struct drm_i915_private;
>>   struct drm_printer;
>>   +struct insert_entries {
>> +    struct i915_address_space *vm;
>> +    struct i915_vma_resource *vma_res;
>> +    enum i915_cache_level level;
>> +    u32 flags;
>> +};
>> +
>>   #define GT_TRACE(gt, fmt, ...) do {                    \
>>       const struct intel_gt *gt__ __maybe_unused = (gt); \
>>       GEM_TRACE("%s " fmt, dev_name(gt__->i915->drm.dev),        \
>> @@ -113,4 +120,6 @@ void intel_gt_watchdog_work(struct work_struct 
>> *work);
>>     void intel_gt_invalidate_tlbs(struct intel_gt *gt);
>>   +struct resource pci_resource(struct pci_dev *pdev, int bar);
>> +
>>   #endif /* __INTEL_GT_H__ */
>> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_gmch.c 
>> b/drivers/gpu/drm/i915/gt/intel_gt_gmch.c
>> new file mode 100644
>> index 000000000000..b914ebb30166
>> --- /dev/null
>> +++ b/drivers/gpu/drm/i915/gt/intel_gt_gmch.c
>> @@ -0,0 +1,653 @@
>> +// SPDX-License-Identifier: MIT
>> +/*
>> + * Copyright © 2022 Intel Corporation
>> + */
>> +
>> +#include <drm/intel-gtt.h>
>> +#include <drm/i915_drm.h>
>> +
>> +#include <linux/agp_backend.h>
>> +#include <linux/stop_machine.h>
>> +
>> +#include "i915_drv.h"
>> +#include "intel_gt_gmch.h"
>> +#include "intel_gt_regs.h"
>> +#include "intel_gt.h"
>> +
>> +#include "gen8_ppgtt.h"
>> +
>> +struct insert_page {
>> +    struct i915_address_space *vm;
>> +    dma_addr_t addr;
>> +    u64 offset;
>> +    enum i915_cache_level level;
>> +};
>> +
>> +static void gen8_set_pte(void __iomem *addr, gen8_pte_t pte)
>> +{
>> +    writeq(pte, addr);
>> +}
>> +
>> +static void nop_clear_range(struct i915_address_space *vm,
>> +                u64 start, u64 length)
>> +{
>> +}
>> +
>> +static u64 snb_pte_encode(dma_addr_t addr,
>> +              enum i915_cache_level level,
>> +              u32 flags)
>> +{
>> +    gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> +
>> +    switch (level) {
>> +    case I915_CACHE_L3_LLC:
>> +    case I915_CACHE_LLC:
>> +        pte |= GEN6_PTE_CACHE_LLC;
>> +        break;
>> +    case I915_CACHE_NONE:
>> +        pte |= GEN6_PTE_UNCACHED;
>> +        break;
>> +    default:
>> +        MISSING_CASE(level);
>> +    }
>> +
>> +    return pte;
>> +}
>> +
>> +static u64 ivb_pte_encode(dma_addr_t addr,
>> +              enum i915_cache_level level,
>> +              u32 flags)
>> +{
>> +    gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> +
>> +    switch (level) {
>> +    case I915_CACHE_L3_LLC:
>> +        pte |= GEN7_PTE_CACHE_L3_LLC;
>> +        break;
>> +    case I915_CACHE_LLC:
>> +        pte |= GEN6_PTE_CACHE_LLC;
>> +        break;
>> +    case I915_CACHE_NONE:
>> +        pte |= GEN6_PTE_UNCACHED;
>> +        break;
>> +    default:
>> +        MISSING_CASE(level);
>> +    }
>> +
>> +    return pte;
>> +}
>> +
>> +static u64 byt_pte_encode(dma_addr_t addr,
>> +              enum i915_cache_level level,
>> +              u32 flags)
>> +{
>> +    gen6_pte_t pte = GEN6_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> +
>> +    if (!(flags & PTE_READ_ONLY))
>> +        pte |= BYT_PTE_WRITEABLE;
>> +
>> +    if (level != I915_CACHE_NONE)
>> +        pte |= BYT_PTE_SNOOPED_BY_CPU_CACHES;
>> +
>> +    return pte;
>> +}
>> +
>> +static u64 hsw_pte_encode(dma_addr_t addr,
>> +              enum i915_cache_level level,
>> +              u32 flags)
>> +{
>> +    gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> +
>> +    if (level != I915_CACHE_NONE)
>> +        pte |= HSW_WB_LLC_AGE3;
>> +
>> +    return pte;
>> +}
>> +
>> +static u64 iris_pte_encode(dma_addr_t addr,
>> +               enum i915_cache_level level,
>> +               u32 flags)
>> +{
>> +    gen6_pte_t pte = HSW_PTE_ADDR_ENCODE(addr) | GEN6_PTE_VALID;
>> +
>> +    switch (level) {
>> +    case I915_CACHE_NONE:
>> +        break;
>> +    case I915_CACHE_WT:
>> +        pte |= HSW_WT_ELLC_LLC_AGE3;
>> +        break;
>> +    default:
>> +        pte |= HSW_WB_ELLC_LLC_AGE3;
>> +        break;
>> +    }
>> +
>> +    return pte;
>> +}
>> +
>> +static void gen5_ggtt_insert_page(struct i915_address_space *vm,
>> +                  dma_addr_t addr,
>> +                  u64 offset,
>> +                  enum i915_cache_level cache_level,
>> +                  u32 unused)
>> +{
>> +    unsigned int flags = (cache_level == I915_CACHE_NONE) ?
>> +        AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
>> +
>> +    intel_gtt_insert_page(addr, offset >> PAGE_SHIFT, flags);
>> +}
>> +
>> +static void gen6_ggtt_insert_page(struct i915_address_space *vm,
>> +                  dma_addr_t addr,
>> +                  u64 offset,
>> +                  enum i915_cache_level level,
>> +                  u32 flags)
>> +{
>> +    struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> +    gen6_pte_t __iomem *pte =
>> +        (gen6_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
>> +
>> +    iowrite32(vm->pte_encode(addr, level, flags), pte);
>> +
>> +    ggtt->invalidate(ggtt);
>> +}
>> +
>> +static void gen8_ggtt_insert_page(struct i915_address_space *vm,
>> +                  dma_addr_t addr,
>> +                  u64 offset,
>> +                  enum i915_cache_level level,
>> +                  u32 flags)
>> +{
>> +    struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> +    gen8_pte_t __iomem *pte =
>> +        (gen8_pte_t __iomem *)ggtt->gsm + offset / I915_GTT_PAGE_SIZE;
>> +
>> +    gen8_set_pte(pte, gen8_ggtt_pte_encode(addr, level, flags));
>> +
>> +    ggtt->invalidate(ggtt);
>> +}
>> +
>> +static void gen5_ggtt_insert_entries(struct i915_address_space *vm,
>> +                     struct i915_vma_resource *vma_res,
>> +                     enum i915_cache_level cache_level,
>> +                     u32 unused)
>> +{
>> +    unsigned int flags = (cache_level == I915_CACHE_NONE) ?
>> +        AGP_USER_MEMORY : AGP_USER_CACHED_MEMORY;
>> +
>> +    intel_gtt_insert_sg_entries(vma_res->bi.pages, vma_res->start >> 
>> PAGE_SHIFT,
>> +                    flags);
>> +}
>> +
>> +/*
>> + * Binds an object into the global gtt with the specified cache level.
>> + * The object will be accessible to the GPU via commands whose operands
>> + * reference offsets within the global GTT as well as accessible by 
>> the GPU
>> + * through the GMADR mapped BAR (i915->mm.gtt->gtt).
>> + */
>> +static void gen6_ggtt_insert_entries(struct i915_address_space *vm,
>> +                     struct i915_vma_resource *vma_res,
>> +                     enum i915_cache_level level,
>> +                     u32 flags)
>> +{
>> +    struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> +    gen6_pte_t __iomem *gte;
>> +    gen6_pte_t __iomem *end;
>> +    struct sgt_iter iter;
>> +    dma_addr_t addr;
>> +
>> +    gte = (gen6_pte_t __iomem *)ggtt->gsm;
>> +    gte += vma_res->start / I915_GTT_PAGE_SIZE;
>> +    end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
>> +
>> +    for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
>> +        iowrite32(vm->pte_encode(addr, level, flags), gte++);
>> +    GEM_BUG_ON(gte > end);
>> +
>> +    /* Fill the allocated but "unused" space beyond the end of the 
>> buffer */
>> +    while (gte < end)
>> +        iowrite32(vm->scratch[0]->encode, gte++);
>> +
>> +    /*
>> +     * We want to flush the TLBs only after we're certain all the PTE
>> +     * updates have finished.
>> +     */
>> +    ggtt->invalidate(ggtt);
>> +}
>> +
>> +static void gen8_ggtt_insert_entries(struct i915_address_space *vm,
>> +                     struct i915_vma_resource *vma_res,
>> +                     enum i915_cache_level level,
>> +                     u32 flags)
>> +{
>> +    const gen8_pte_t pte_encode = gen8_ggtt_pte_encode(0, level, 
>> flags);
>> +    struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> +    gen8_pte_t __iomem *gte;
>> +    gen8_pte_t __iomem *end;
>> +    struct sgt_iter iter;
>> +    dma_addr_t addr;
>> +
>> +    /*
>> +     * Note that we ignore PTE_READ_ONLY here. The caller must be 
>> careful
>> +     * not to allow the user to override access to a read only page.
>> +     */
>> +
>> +    gte = (gen8_pte_t __iomem *)ggtt->gsm;
>> +    gte += vma_res->start / I915_GTT_PAGE_SIZE;
>> +    end = gte + vma_res->node_size / I915_GTT_PAGE_SIZE;
>> +
>> +    for_each_sgt_daddr(addr, iter, vma_res->bi.pages)
>> +        gen8_set_pte(gte++, pte_encode | addr);
>> +    GEM_BUG_ON(gte > end);
>> +
>> +    /* Fill the allocated but "unused" space beyond the end of the 
>> buffer */
>> +    while (gte < end)
>> +        gen8_set_pte(gte++, vm->scratch[0]->encode);
>> +
>> +    /*
>> +     * We want to flush the TLBs only after we're certain all the PTE
>> +     * updates have finished.
>> +     */
>> +    ggtt->invalidate(ggtt);
>> +}
>> +
>> +static void bxt_vtd_ggtt_wa(struct i915_address_space *vm)
>> +{
>> +    /*
>> +     * Make sure the internal GAM fifo has been cleared of all GTT
>> +     * writes before exiting stop_machine(). This guarantees that
>> +     * any aperture accesses waiting to start in another process
>> +     * cannot back up behind the GTT writes causing a hang.
>> +     * The register can be any arbitrary GAM register.
>> +     */
>> +    intel_uncore_posting_read_fw(vm->gt->uncore, GFX_FLSH_CNTL_GEN6);
>> +}
>> +
>> +static int bxt_vtd_ggtt_insert_page__cb(void *_arg)
>> +{
>> +    struct insert_page *arg = _arg;
>> +
>> +    gen8_ggtt_insert_page(arg->vm, arg->addr, arg->offset, 
>> arg->level, 0);
>> +    bxt_vtd_ggtt_wa(arg->vm);
>> +
>> +    return 0;
>> +}
>> +
>> +static void bxt_vtd_ggtt_insert_page__BKL(struct i915_address_space 
>> *vm,
>> +                      dma_addr_t addr,
>> +                      u64 offset,
>> +                      enum i915_cache_level level,
>> +                      u32 unused)
>> +{
>> +    struct insert_page arg = { vm, addr, offset, level };
>> +
>> +    stop_machine(bxt_vtd_ggtt_insert_page__cb, &arg, NULL);
>> +}
>> +
>> +static int bxt_vtd_ggtt_insert_entries__cb(void *_arg)
>> +{
>> +    struct insert_entries *arg = _arg;
>> +
>> +    gen8_ggtt_insert_entries(arg->vm, arg->vma_res, arg->level, 
>> arg->flags);
>> +    bxt_vtd_ggtt_wa(arg->vm);
>> +
>> +    return 0;
>> +}
>> +
>> +static void bxt_vtd_ggtt_insert_entries__BKL(struct 
>> i915_address_space *vm,
>> +                         struct i915_vma_resource *vma_res,
>> +                         enum i915_cache_level level,
>> +                         u32 flags)
>> +{
>> +    struct insert_entries arg = { vm, vma_res, level, flags };
>> +
>> +    stop_machine(bxt_vtd_ggtt_insert_entries__cb, &arg, NULL);
>> +}
>> +
>> +void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)
>> +{
>> +    intel_gtt_chipset_flush();
>> +}
>> +
>> +static void gmch_ggtt_invalidate(struct i915_ggtt *ggtt)
>> +{
>> +    intel_gtt_chipset_flush();
>> +}
>> +
>> +static void gen5_ggtt_clear_range(struct i915_address_space *vm,
>> +                     u64 start, u64 length)
>> +{
>> +    intel_gtt_clear_range(start >> PAGE_SHIFT, length >> PAGE_SHIFT);
>> +}
>> +
>> +static void gen6_ggtt_clear_range(struct i915_address_space *vm,
>> +                  u64 start, u64 length)
>> +{
>> +    struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> +    unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
>> +    unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
>> +    gen6_pte_t scratch_pte, __iomem *gtt_base =
>> +        (gen6_pte_t __iomem *)ggtt->gsm + first_entry;
>> +    const int max_entries = ggtt_total_entries(ggtt) - first_entry;
>> +    int i;
>> +
>> +    if (WARN(num_entries > max_entries,
>> +         "First entry = %d; Num entries = %d (max=%d)\n",
>> +         first_entry, num_entries, max_entries))
>> +        num_entries = max_entries;
>> +
>> +    scratch_pte = vm->scratch[0]->encode;
>> +    for (i = 0; i < num_entries; i++)
>> +        iowrite32(scratch_pte, &gtt_base[i]);
>> +}
>> +
>> +static void gen8_ggtt_clear_range(struct i915_address_space *vm,
>> +                  u64 start, u64 length)
>> +{
>> +    struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> +    unsigned int first_entry = start / I915_GTT_PAGE_SIZE;
>> +    unsigned int num_entries = length / I915_GTT_PAGE_SIZE;
>> +    const gen8_pte_t scratch_pte = vm->scratch[0]->encode;
>> +    gen8_pte_t __iomem *gtt_base =
>> +        (gen8_pte_t __iomem *)ggtt->gsm + first_entry;
>> +    const int max_entries = ggtt_total_entries(ggtt) - first_entry;
>> +    int i;
>> +
>> +    if (WARN(num_entries > max_entries,
>> +         "First entry = %d; Num entries = %d (max=%d)\n",
>> +         first_entry, num_entries, max_entries))
>> +        num_entries = max_entries;
>> +
>> +    for (i = 0; i < num_entries; i++)
>> +        gen8_set_pte(&gtt_base[i], scratch_pte);
>> +}
>> +
>> +static void gen5_gmch_remove(struct i915_address_space *vm)
>> +{
>> +    intel_gmch_remove();
>> +}
>> +
>> +static void gen6_gmch_remove(struct i915_address_space *vm)
>> +{
>> +    struct i915_ggtt *ggtt = i915_vm_to_ggtt(vm);
>> +
>> +    iounmap(ggtt->gsm);
>> +    free_scratch(vm);
>> +}
>> +
>> +/*
>> + * Certain Gen5 chipsets require idling the GPU before
>> + * unmapping anything from the GTT when VT-d is enabled.
>> + */
>> +static bool needs_idle_maps(struct drm_i915_private *i915)
>> +{
>> +    /*
>> +     * Query intel_iommu to see if we need the workaround. 
>> Presumably that
>> +     * was loaded first.
>> +     */
>> +    if (!intel_vtd_active(i915))
>> +        return false;
>> +
>> +    if (GRAPHICS_VER(i915) == 5 && IS_MOBILE(i915))
>> +        return true;
>> +
>> +    if (GRAPHICS_VER(i915) == 12)
>> +        return true; /* XXX DMAR fault reason 7 */
>> +
>> +    return false;
>> +}
>> +
>> +static unsigned int gen6_gttmmadr_size(struct drm_i915_private *i915)
>> +{
>> +    /*
>> +     * GEN6: GTTMMADR size is 4MB and GTTADR starts at 2MB offset
>> +     * GEN8: GTTMMADR size is 16MB and GTTADR starts at 8MB offset
>> +     */
>> +    GEM_BUG_ON(GRAPHICS_VER(i915) < 6);
>> +    return (GRAPHICS_VER(i915) < 8) ? SZ_4M : SZ_16M;
>> +}
>> +
>> +static unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)
>> +{
>> +    snb_gmch_ctl >>= SNB_GMCH_GGMS_SHIFT;
>> +    snb_gmch_ctl &= SNB_GMCH_GGMS_MASK;
>> +    return snb_gmch_ctl << 20;
>> +}
>> +
>> +static unsigned int gen8_get_total_gtt_size(u16 bdw_gmch_ctl)
>> +{
>> +    bdw_gmch_ctl >>= BDW_GMCH_GGMS_SHIFT;
>> +    bdw_gmch_ctl &= BDW_GMCH_GGMS_MASK;
>> +    if (bdw_gmch_ctl)
>> +        bdw_gmch_ctl = 1 << bdw_gmch_ctl;
>> +
>> +#ifdef CONFIG_X86_32
>> +    /* Limit 32b platforms to a 2GB GGTT: 4 << 20 / pte size * 
>> I915_GTT_PAGE_SIZE */
>> +    if (bdw_gmch_ctl > 4)
>> +        bdw_gmch_ctl = 4;
>> +#endif
>> +
>> +    return bdw_gmch_ctl << 20;
>> +}
>> +
>> +static unsigned int gen6_gttadr_offset(struct drm_i915_private *i915)
>> +{
>> +    return gen6_gttmmadr_size(i915) / 2;
>> +}
>> +
>> +static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size)
>> +{
>> +    struct drm_i915_private *i915 = ggtt->vm.i915;
>> +    struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>> +    phys_addr_t phys_addr;
>> +    u32 pte_flags;
>> +    int ret;
>> +
>> +    GEM_WARN_ON(pci_resource_len(pdev, 0) != gen6_gttmmadr_size(i915));
>> +    phys_addr = pci_resource_start(pdev, 0) + gen6_gttadr_offset(i915);
>> +
>> +    /*
>> +     * On BXT+/ICL+ writes larger than 64 bit to the GTT pagetable 
>> range
>> +     * will be dropped. For WC mappings in general we have 64 byte 
>> burst
>> +     * writes when the WC buffer is flushed, so we can't use it, but 
>> have to
>> +     * resort to an uncached mapping. The WC issue is easily caught 
>> by the
>> +     * readback check when writing GTT PTE entries.
>> +     */
>> +    if (IS_GEN9_LP(i915) || GRAPHICS_VER(i915) >= 11)
>> +        ggtt->gsm = ioremap(phys_addr, size);
>> +    else
>> +        ggtt->gsm = ioremap_wc(phys_addr, size);
>> +    if (!ggtt->gsm) {
>> +        drm_err(&i915->drm, "Failed to map the ggtt page table\n");
>> +        return -ENOMEM;
>> +    }
>> +
>> +    kref_init(&ggtt->vm.resv_ref);
>> +    ret = setup_scratch_page(&ggtt->vm);
>> +    if (ret) {
>> +        drm_err(&i915->drm, "Scratch setup failed\n");
>> +        /* iounmap will also get called at remove, but meh */
>> +        iounmap(ggtt->gsm);
>> +        return ret;
>> +    }
>> +
>> +    pte_flags = 0;
>> +    if (i915_gem_object_is_lmem(ggtt->vm.scratch[0]))
>> +        pte_flags |= PTE_LM;
>> +
>> +    ggtt->vm.scratch[0]->encode =
>> +        ggtt->vm.pte_encode(px_dma(ggtt->vm.scratch[0]),
>> +                    I915_CACHE_NONE, pte_flags);
>> +
>> +    return 0;
>> +}
>> +
>> +int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
>> +{
>> +    struct drm_i915_private *i915 = ggtt->vm.i915;
>> +    phys_addr_t gmadr_base;
>> +    int ret;
>> +
>> +    ret = intel_gmch_probe(i915->bridge_dev, 
>> to_pci_dev(i915->drm.dev), NULL);
>> +    if (!ret) {
>> +        drm_err(&i915->drm, "failed to set up gmch\n");
>> +        return -EIO;
>> +    }
>> +
>> +    intel_gtt_get(&ggtt->vm.total, &gmadr_base, &ggtt->mappable_end);
>> +
>> +    ggtt->gmadr =
>> +        (struct resource)DEFINE_RES_MEM(gmadr_base, 
>> ggtt->mappable_end);
>> +
>> +    ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>> +    ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>> +
>> +    if (needs_idle_maps(i915)) {
>> +        drm_notice(&i915->drm,
>> +               "Flushing DMA requests before IOMMU unmaps; 
>> performance may be degraded\n");
>> +        ggtt->do_idle_maps = true;
>> +    }
>> +
>> +    ggtt->vm.insert_page = gen5_ggtt_insert_page;
>> +    ggtt->vm.insert_entries = gen5_ggtt_insert_entries;
>> +    ggtt->vm.clear_range = gen5_ggtt_clear_range;
>> +    ggtt->vm.cleanup = gen5_gmch_remove;
>> +
>> +    ggtt->invalidate = gmch_ggtt_invalidate;
>> +
>> +    ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
>> +    ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
>> +
>> +    if (unlikely(ggtt->do_idle_maps))
>> +        drm_notice(&i915->drm,
>> +               "Applying Ironlake quirks for intel_iommu\n");
>> +
>> +    return 0;
>> +}
>> +
>> +int intel_gt_gmch_gen6_probe(struct i915_ggtt *ggtt)
>> +{
>> +    struct drm_i915_private *i915 = ggtt->vm.i915;
>> +    struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>> +    unsigned int size;
>> +    u16 snb_gmch_ctl;
>> +
>> +    ggtt->gmadr = pci_resource(pdev, 2);
>> +    ggtt->mappable_end = resource_size(&ggtt->gmadr);
>> +
>> +    /*
>> +     * 64/512MB is the current min/max we actually know of, but this is
>> +     * just a coarse sanity check.
>> +     */
>> +    if (ggtt->mappable_end < (64<<20) || ggtt->mappable_end > 
>> (512<<20)) {
>> +        drm_err(&i915->drm, "Unknown GMADR size (%pa)\n",
>> +            &ggtt->mappable_end);
>> +        return -ENXIO;
>> +    }
>> +
>> +    pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
>> +
>> +    size = gen6_get_total_gtt_size(snb_gmch_ctl);
>> +    ggtt->vm.total = (size / sizeof(gen6_pte_t)) * I915_GTT_PAGE_SIZE;
>> +
>> +    ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>> +    ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>> +
>> +    ggtt->vm.clear_range = nop_clear_range;
>> +    if (!HAS_FULL_PPGTT(i915) || intel_scanout_needs_vtd_wa(i915))
>> +        ggtt->vm.clear_range = gen6_ggtt_clear_range;
>> +    ggtt->vm.insert_page = gen6_ggtt_insert_page;
>> +    ggtt->vm.insert_entries = gen6_ggtt_insert_entries;
>> +    ggtt->vm.cleanup = gen6_gmch_remove;
>> +
>> +    ggtt->invalidate = gen6_ggtt_invalidate;
>> +
>> +    if (HAS_EDRAM(i915))
>> +        ggtt->vm.pte_encode = iris_pte_encode;
>> +    else if (IS_HASWELL(i915))
>> +        ggtt->vm.pte_encode = hsw_pte_encode;
>> +    else if (IS_VALLEYVIEW(i915))
>> +        ggtt->vm.pte_encode = byt_pte_encode;
>> +    else if (GRAPHICS_VER(i915) >= 7)
>> +        ggtt->vm.pte_encode = ivb_pte_encode;
>> +    else
>> +        ggtt->vm.pte_encode = snb_pte_encode;
>> +
>> +    ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
>> +    ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
>> +
>> +    return ggtt_probe_common(ggtt, size);
>> +}
>> +
>> +static unsigned int chv_get_total_gtt_size(u16 gmch_ctrl)
>> +{
>> +    gmch_ctrl >>= SNB_GMCH_GGMS_SHIFT;
>> +    gmch_ctrl &= SNB_GMCH_GGMS_MASK;
>> +
>> +    if (gmch_ctrl)
>> +        return 1 << (20 + gmch_ctrl);
>> +
>> +    return 0;
>> +}
>> +
>> +int intel_gt_gmch_gen8_probe(struct i915_ggtt *ggtt)
>> +{
>> +    struct drm_i915_private *i915 = ggtt->vm.i915;
>> +    struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
>> +    unsigned int size;
>> +    u16 snb_gmch_ctl;
>> +
>> +    /* TODO: We're not aware of mappable constraints on gen8 yet */
>> +    if (!HAS_LMEM(i915)) {
>> +        ggtt->gmadr = pci_resource(pdev, 2);
>> +        ggtt->mappable_end = resource_size(&ggtt->gmadr);
>> +    }
>> +
>> +    pci_read_config_word(pdev, SNB_GMCH_CTRL, &snb_gmch_ctl);
>> +    if (IS_CHERRYVIEW(i915))
>> +        size = chv_get_total_gtt_size(snb_gmch_ctl);
>> +    else
>> +        size = gen8_get_total_gtt_size(snb_gmch_ctl);
>> +
>> +    ggtt->vm.alloc_pt_dma = alloc_pt_dma;
>> +    ggtt->vm.alloc_scratch_dma = alloc_pt_dma;
>> +    ggtt->vm.lmem_pt_obj_flags = I915_BO_ALLOC_PM_EARLY;
>> +
>> +    ggtt->vm.total = (size / sizeof(gen8_pte_t)) * I915_GTT_PAGE_SIZE;
>> +    ggtt->vm.cleanup = gen6_gmch_remove;
>> +    ggtt->vm.insert_page = gen8_ggtt_insert_page;
>> +    ggtt->vm.clear_range = nop_clear_range;
>> +    if (intel_scanout_needs_vtd_wa(i915))
>> +        ggtt->vm.clear_range = gen8_ggtt_clear_range;
>> +
>> +    ggtt->vm.insert_entries = gen8_ggtt_insert_entries;
>> +
>> +    /*
>> +     * Serialize GTT updates with aperture access on BXT if VT-d is on,
>> +     * and always on CHV.
>> +     */
>> +    if (intel_vm_no_concurrent_access_wa(i915)) {
>> +        ggtt->vm.insert_entries = bxt_vtd_ggtt_insert_entries__BKL;
>> +        ggtt->vm.insert_page    = bxt_vtd_ggtt_insert_page__BKL;
>> +        ggtt->vm.bind_async_flags =
>> +            I915_VMA_GLOBAL_BIND | I915_VMA_LOCAL_BIND;
>> +    }
>> +
>> +    ggtt->invalidate = gen8_ggtt_invalidate;
>> +
>> +    ggtt->vm.vma_ops.bind_vma    = intel_ggtt_bind_vma;
>> +    ggtt->vm.vma_ops.unbind_vma  = intel_ggtt_unbind_vma;
>> +
>> +    ggtt->vm.pte_encode = gen8_ggtt_pte_encode;
>> +
>> +    setup_private_pat(ggtt->vm.gt->uncore);
>> +
>> +    return ggtt_probe_common(ggtt, size);
>> +}
>> +
>> +int intel_gt_gmch_gen5_enable_hw(struct drm_i915_private *i915)
>> +{
>> +    if (GRAPHICS_VER(i915) < 6 && !intel_enable_gtt())
>> +        return -EIO;
>> +
>> +    return 0;
>> +}
>> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_gmch.h 
>> b/drivers/gpu/drm/i915/gt/intel_gt_gmch.h
>> new file mode 100644
>> index 000000000000..02e5342d7ea3
>> --- /dev/null
>> +++ b/drivers/gpu/drm/i915/gt/intel_gt_gmch.h
>> @@ -0,0 +1,46 @@
>> +/* SPDX-License-Identifier: MIT */
>> +/*
>> + * Copyright © 2022 Intel Corporation
>> + */
>> +
>> +#ifndef __INTEL_GT_GMCH_H__
>> +#define __INTEL_GT_GMCH_H__
>> +
>> +#include "intel_gtt.h"
>> +
>> +/* For x86 platforms */
>> +#if IS_ENABLED(CONFIG_X86)
>> +void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt);
>> +int intel_gt_gmch_gen6_probe(struct i915_ggtt *ggtt);
>> +int intel_gt_gmch_gen8_probe(struct i915_ggtt *ggtt);
>> +int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt);
>> +int intel_gt_gmch_gen5_enable_hw(struct drm_i915_private *i915);
>> +
>> +/* Stubs for non-x86 platforms */
>> +#else
>> +static inline void intel_gt_gmch_gen5_chipset_flush(struct intel_gt 
>> *gt)
>> +{
>> +}
>> +static inline int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
>> +{
>> +    /* No HW should be probed for this case yet, return fail */
>> +    return -1;
>> +}
>> +static inline int intel_gt_gmch_gen6_probe(struct i915_ggtt *ggtt)
>> +{
>> +    /* No HW should be probed for this case yet, return fail */
>> +    return -1;
>> +}
>> +static inline int intel_gt_gmch_gen8_probe(struct i915_ggtt *ggtt)
>> +{
>> +    /* No HW should be probed for this case yet, return fail */
>> +    return -1;
>> +}
>> +static inline int intel_gt_gmch_gen5_enable_hw(struct 
>> drm_i915_private *i915)
>> +{
>> +    /* No HW should be enabled for this case yet, return fail */
>> +    return -1;
>> +}
>> +#endif
>> +
>> +#endif /* __INTEL_GT_GMCH_H__ */
>> diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h 
>> b/drivers/gpu/drm/i915/gt/intel_gtt.h
>> index 4529b5e9f6e6..b4b9cc5a8ff6 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_gtt.h
>> +++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
>> @@ -547,6 +547,14 @@ i915_page_dir_dma_addr(const struct i915_ppgtt 
>> *ppgtt, const unsigned int n)
>>   void ppgtt_init(struct i915_ppgtt *ppgtt, struct intel_gt *gt,
>>           unsigned long lmem_pt_obj_flags);
>>   +void intel_ggtt_bind_vma(struct i915_address_space *vm,
>> +              struct i915_vm_pt_stash *stash,
>> +              struct i915_vma_resource *vma_res,
>> +              enum i915_cache_level cache_level,
>> +              u32 flags);
>> +void intel_ggtt_unbind_vma(struct i915_address_space *vm,
>> +                struct i915_vma_resource *vma_res);
>> +
>>   int i915_ggtt_probe_hw(struct drm_i915_private *i915);
>>   int i915_ggtt_init_hw(struct drm_i915_private *i915);
>>   int i915_ggtt_enable_hw(struct drm_i915_private *i915);
>> @@ -617,6 +625,7 @@ release_pd_entry(struct i915_page_directory * 
>> const pd,
>>            struct i915_page_table * const pt,
>>            const struct drm_i915_gem_object * const scratch);
>>   void gen6_ggtt_invalidate(struct i915_ggtt *ggtt);
>> +void gen8_ggtt_invalidate(struct i915_ggtt *ggtt);
>>     void ppgtt_bind_vma(struct i915_address_space *vm,
>>               struct i915_vm_pt_stash *stash,

Jani Nikula March 30, 2022, 5:25 p.m. UTC | #7

On Wed, 30 Mar 2022, Casey Bowman <casey.g.bowman@intel.com> wrote:
> On 3/30/22 02:55, Tvrtko Ursulin wrote:
>> I mean I could suggest to do something about the incosistency of:
>>
>> static inline void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)
>>
>> vs:
>>
>> static inline int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
>>
>> Since I value more for function name to tell me on what it operates 
>> instead where it is placed. So I'd personally rename the second class 
>> to i915_ggtt. It would also be consistent with other exported 
>> functions which take struct i915_ggtt like i915_ggtt_enable_guc, 
>> i915_ggtt_resume and so. But opinions will differ so I can live with 
>> it as is as well.
>>
>
> @Jani/Lucas, do you guys have any opinion on changing the prefix to a 
> functionality-based name over location-based?
>
> If we have any standard we're trying to adhere to here, I can change it 
> for the standard.
> I'd like to make everyone happy, if possible. :P

For display code I'm pretty strongly in favour of file name based symbol
prefixes. And basically a file should be a collection of related
functionality around a theme, so in that sense it's not merely location
based. Indeed the file name should be functionality based!

Also for display code we tend to have tons of functions that take
similar first (context) parameters, everywhere, and we also change the
parameters being passed while refactoring. It would be counter
productive to name the functions based on the first parameter.

Random example, display/intel_dp.h, it's all about display port, almost
all functions are named intel_dp_*, but if they were named by first
parameter, we'd have intel_dp, intel_encoder, intel_atomic_state,
drm_i915_private, intel_crtc_state, intel_digital_port, etc. It's the
intel_dp that best describes them as a group, so that's in the file and
function names.

Now, I'm not going to put my foot down on gem or gt stuff, but I
*personally* find the logic there confusing.

BR,
Jani.

Bowman, Casey G March 30, 2022, 6:36 p.m. UTC | #8

On 3/30/22 10:25, Jani Nikula wrote:
> On Wed, 30 Mar 2022, Casey Bowman <casey.g.bowman@intel.com> wrote:
>> On 3/30/22 02:55, Tvrtko Ursulin wrote:
>>> I mean I could suggest to do something about the incosistency of:
>>>
>>> static inline void intel_gt_gmch_gen5_chipset_flush(struct intel_gt *gt)
>>>
>>> vs:
>>>
>>> static inline int intel_gt_gmch_gen5_probe(struct i915_ggtt *ggtt)
>>>
>>> Since I value more for function name to tell me on what it operates
>>> instead where it is placed. So I'd personally rename the second class
>>> to i915_ggtt. It would also be consistent with other exported
>>> functions which take struct i915_ggtt like i915_ggtt_enable_guc,
>>> i915_ggtt_resume and so. But opinions will differ so I can live with
>>> it as is as well.
>>>
>> @Jani/Lucas, do you guys have any opinion on changing the prefix to a
>> functionality-based name over location-based?
>>
>> If we have any standard we're trying to adhere to here, I can change it
>> for the standard.
>> I'd like to make everyone happy, if possible. :P
> For display code I'm pretty strongly in favour of file name based symbol
> prefixes. And basically a file should be a collection of related
> functionality around a theme, so in that sense it's not merely location
> based. Indeed the file name should be functionality based!
>
> Also for display code we tend to have tons of functions that take
> similar first (context) parameters, everywhere, and we also change the
> parameters being passed while refactoring. It would be counter
> productive to name the functions based on the first parameter.
>
> Random example, display/intel_dp.h, it's all about display port, almost
> all functions are named intel_dp_*, but if they were named by first
> parameter, we'd have intel_dp, intel_encoder, intel_atomic_state,
> drm_i915_private, intel_crtc_state, intel_digital_port, etc. It's the
> intel_dp that best describes them as a group, so that's in the file and
> function names.
>
> Now, I'm not going to put my foot down on gem or gt stuff, but I
> *personally* find the logic there confusing.
>
>
> BR,
> Jani.
>
>
Ok, thank you for your perspectives!

Regards,
Casey

[v3,1/2] drm/i915/gt: Split intel-gtt functions by arch

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