| Message ID | 20180926145933.22034-4-noralf@tronnes.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: Add shmem GEM library | expand |
On Wed, Sep 26, 2018 at 04:59:32PM +0200, Noralf Trønnes wrote: > This adds a library for shmem backed GEM objects. > > Signed-off-by: Noralf Trønnes <noralf@tronnes.org> > --- > > Changes since version 3: > - Drop cache modes (Thomas Hellstrom) > - Add a GEM attached vtable > > Documentation/gpu/drm-kms-helpers.rst | 12 + > drivers/gpu/drm/Kconfig | 6 + > drivers/gpu/drm/Makefile | 1 + > drivers/gpu/drm/drm_gem_shmem_helper.c | 586 +++++++++++++++++++++++++++++++++ > include/drm/drm_gem_shmem_helper.h | 153 +++++++++ > 5 files changed, 758 insertions(+) > create mode 100644 drivers/gpu/drm/drm_gem_shmem_helper.c > create mode 100644 include/drm/drm_gem_shmem_helper.h > > diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst > index f9cfcdcdf024..bc24b1b5216a 100644 > --- a/Documentation/gpu/drm-kms-helpers.rst > +++ b/Documentation/gpu/drm-kms-helpers.rst > @@ -326,3 +326,15 @@ Legacy CRTC/Modeset Helper Functions Reference > > .. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c > :export: > + > +SHMEM GEM Helper Reference > +========================== > + > +.. kernel-doc:: drivers/gpu/drm/drm_gem_shmem_helper.c > + :doc: overview > + > +.. kernel-doc:: include/drm/drm_gem_shmem_helper.h > + :internal: > + > +.. kernel-doc:: drivers/gpu/drm/drm_gem_shmem_helper.c > + :export: > diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig > index cb88528e7b10..db588ae44bcc 100644 > --- a/drivers/gpu/drm/Kconfig > +++ b/drivers/gpu/drm/Kconfig > @@ -157,6 +157,12 @@ config DRM_KMS_CMA_HELPER > help > Choose this if you need the KMS CMA helper functions > > +config DRM_GEM_SHMEM_HELPER > + bool > + depends on DRM > + help > + Choose this if you need the GEM shmem helper functions > + > config DRM_VM > bool > depends on DRM && MMU > diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile > index bc6a16a3c36e..13777f22dc25 100644 > --- a/drivers/gpu/drm/Makefile > +++ b/drivers/gpu/drm/Makefile > @@ -25,6 +25,7 @@ drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o > drm-$(CONFIG_DRM_VM) += drm_vm.o > drm-$(CONFIG_COMPAT) += drm_ioc32.o > drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o > +drm-$(CONFIG_DRM_GEM_SHMEM_HELPER) += drm_gem_shmem_helper.o > drm-$(CONFIG_PCI) += ati_pcigart.o > drm-$(CONFIG_DRM_PANEL) += drm_panel.o > drm-$(CONFIG_OF) += drm_of.o > diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c > new file mode 100644 > index 000000000000..7471856d34ac > --- /dev/null > +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c > @@ -0,0 +1,586 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright 2018 Noralf Trønnes > + */ > + > +#include <linux/dma-buf.h> > +#include <linux/export.h> > +#include <linux/mutex.h> > +#include <linux/shmem_fs.h> > +#include <linux/slab.h> > +#include <linux/vmalloc.h> > + > +#include <drm/drm_device.h> > +#include <drm/drm_drv.h> > +#include <drm/drm_gem_shmem_helper.h> > +#include <drm/drm_prime.h> > +#include <drm/drm_print.h> > + > +/** > + * DOC: overview > + * > + * This library provides helpers for GEM objects backed by shmem buffers > + * allocated using anonymous pageable memory. > + */ > + > +static const struct drm_gem_object_funcs drm_gem_shmem_funcs = { > + .free = drm_gem_shmem_free_object, > + .print_info = drm_gem_shmem_print_info, > + .pin = drm_gem_shmem_pin, > + .unpin = drm_gem_shmem_unpin, > + .get_sg_table = drm_gem_shmem_get_sg_table, > + .vmap = drm_gem_shmem_vmap, > + .vunmap = drm_gem_shmem_vunmap, > + .prime_mmap = drm_gem_shmem_prime_mmap, > + .vm_ops = &drm_gem_shmem_vm_ops, > +}; > + > +/** > + * drm_gem_shmem_create - Allocate an object with the given size > + * @dev: DRM device > + * @size: Size of the object to allocate > + * > + * This function creates a shmem GEM object. > + * > + * Returns: > + * A struct drm_gem_shmem_object * on success or an ERR_PTR()-encoded negative > + * error code on failure. > + */ > +struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size) > +{ > + struct drm_gem_shmem_object *shmem; > + struct drm_gem_object *obj; > + int ret; > + > + size = PAGE_ALIGN(size); > + > + if (dev->driver->gem_create_object) > + obj = dev->driver->gem_create_object(dev, size); > + else > + obj = kzalloc(sizeof(*shmem), GFP_KERNEL); > + if (!obj) > + return ERR_PTR(-ENOMEM); > + > + if (!obj->funcs) > + obj->funcs = &drm_gem_shmem_funcs; > + > + ret = drm_gem_object_init(dev, obj, size); > + if (ret) > + goto err_free; > + > + ret = drm_gem_create_mmap_offset(obj); > + if (ret) > + goto err_release; > + > + shmem = to_drm_gem_shmem_obj(obj); > + mutex_init(&shmem->pages_lock); > + mutex_init(&shmem->vmap_lock); > + > + return shmem; > + > +err_release: > + drm_gem_object_release(obj); > +err_free: > + kfree(shmem); > + > + return ERR_PTR(ret); > +} > +EXPORT_SYMBOL_GPL(drm_gem_shmem_create); > + > +/** > + * drm_gem_shmem_free_object - Free resources associated with a shmem GEM object > + * @obj: GEM object to free > + * > + * This function cleans up the GEM object state and frees the memory used to > + * store the object itself. > + */ > +void drm_gem_shmem_free_object(struct drm_gem_object *obj) > +{ > + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); > + > + WARN_ON(shmem->vmap_use_count); > + > + if (obj->import_attach) { > + shmem->pages_use_count--; > + drm_prime_gem_destroy(obj, shmem->sgt); > + kvfree(shmem->pages); > + } > + > + WARN_ON(shmem->pages_use_count); > + > + drm_gem_object_release(obj); > + mutex_destroy(&shmem->pages_lock); > + mutex_destroy(&shmem->vmap_lock); > + kfree(shmem); > +} > +EXPORT_SYMBOL_GPL(drm_gem_shmem_free_object); > + > +static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem) > +{ > + struct drm_gem_object *obj = &shmem->base; > + struct page **pages; > + > + if (shmem->pages_use_count++ > 0) > + return 0; > + > + pages = drm_gem_get_pages(obj); > + if (IS_ERR(pages)) { > + DRM_DEBUG_KMS("Failed to get pages (%ld)\n", PTR_ERR(pages)); > + shmem->pages_use_count = 0; > + return PTR_ERR(pages); > + } > + > + shmem->pages = pages; > + > + return 0; > +} > + > +/* > + * drm_gem_shmem_get_pages - Allocate backing pages for a shmem GEM object > + * @shmem: shmem GEM object > + * > + * This function makes sure that backing pages exists for the shmem GEM object > + * and increases the use count. > + * > + * Returns: > + * 0 on success or a negative error code on failure. > + */ > +int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) > +{ > + int ret; > + > + ret = mutex_lock_interruptible(&shmem->pages_lock); > + if (ret) > + return ret; > + ret = drm_gem_shmem_get_pages_locked(shmem); > + mutex_unlock(&shmem->pages_lock); > + > + return ret; > +} > +EXPORT_SYMBOL(drm_gem_shmem_get_pages); > + > +static void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem) > +{ > + struct drm_gem_object *obj = &shmem->base; > + > + if (WARN_ON_ONCE(!shmem->pages_use_count)) > + return; > + > + if (--shmem->pages_use_count > 0) > + return; > + > + drm_gem_put_pages(obj, shmem->pages, > + shmem->pages_mark_dirty_on_put, > + shmem->pages_mark_accessed_on_put); > + shmem->pages = NULL; > +} > + > +/* > + * drm_gem_shmem_put_pages - Decrease use count on the backing pages for a shmem GEM object > + * @shmem: shmem GEM object > + * > + * This function decreases the use count and puts the backing pages when use drops to zero. > + */ > +void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem) > +{ > + mutex_lock(&shmem->pages_lock); > + drm_gem_shmem_put_pages_locked(shmem); > + mutex_unlock(&shmem->pages_lock); > +} > +EXPORT_SYMBOL(drm_gem_shmem_put_pages); > + > +/** > + * drm_gem_shmem_pin - Pin backing pages for a shmem GEM object > + * @obj: GEM object > + * > + * This function makes sure the backing pages are pinned in memory while the > + * buffer is exported. > + * > + * Returns: > + * 0 on success or a negative error code on failure. > + */ > +int drm_gem_shmem_pin(struct drm_gem_object *obj) > +{ > + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); > + > + return drm_gem_shmem_get_pages(shmem); > +} > +EXPORT_SYMBOL(drm_gem_shmem_pin); > + > +/** > + * drm_gem_shmem_unpin - Unpin backing pages for a shmem GEM object > + * @obj: GEM object > + * > + * This function removes the requirement that the backing pages are pinned in > + * memory. > + */ > +void drm_gem_shmem_unpin(struct drm_gem_object *obj) > +{ > + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); > + > + drm_gem_shmem_put_pages(shmem); > +} > +EXPORT_SYMBOL(drm_gem_shmem_unpin); > + > +static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem) > +{ > + struct drm_gem_object *obj = &shmem->base; > + int ret; > + > + if (shmem->vmap_use_count++ > 0) > + return shmem->vaddr; > + > + ret = drm_gem_shmem_get_pages(shmem); > + if (ret) > + goto err_zero_use; > + > + if (obj->import_attach) > + shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf); > + else > + shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT, VM_MAP, PAGE_KERNEL); > + > + if (!shmem->vaddr) { > + DRM_DEBUG_KMS("Failed to vmap pages\n"); > + ret = -ENOMEM; > + goto err_put_pages; > + } > + > + return shmem->vaddr; > + > +err_put_pages: > + drm_gem_shmem_put_pages(shmem); > +err_zero_use: > + shmem->vmap_use_count = 0; > + > + return ERR_PTR(ret); > +} > + > +/* > + * drm_gem_shmem_vmap - Create a virtual mapping for a shmem GEM object > + * @shmem: shmem GEM object > + * > + * This function makes sure that a virtual address exists for the buffer backing > + * the shmem GEM object. > + * > + * Returns: > + * 0 on success or a negative error code on failure. > + */ > +void *drm_gem_shmem_vmap(struct drm_gem_object *obj) > +{ > + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); > + void *vaddr; > + int ret; > + > + ret = mutex_lock_interruptible(&shmem->vmap_lock); > + if (ret) > + return ERR_PTR(ret); > + vaddr = drm_gem_shmem_vmap_locked(shmem); > + mutex_unlock(&shmem->vmap_lock); > + > + return vaddr; > +} > +EXPORT_SYMBOL(drm_gem_shmem_vmap); > + > +static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem) > +{ > + struct drm_gem_object *obj = &shmem->base; > + > + if (WARN_ON_ONCE(!shmem->vmap_use_count)) > + return; > + > + if (--shmem->vmap_use_count > 0) > + return; > + > + if (obj->import_attach) > + dma_buf_vunmap(obj->import_attach->dmabuf, shmem->vaddr); > + else > + vunmap(shmem->vaddr); > + > + shmem->vaddr = NULL; > + drm_gem_shmem_put_pages(shmem); > +} > + > +/* > + * drm_gem_shmem_vunmap - Unmap a virtual mapping fo a shmem GEM object > + * @shmem: shmem GEM object > + * > + * This function removes the virtual address when use count drops to zero. > + */ > +void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr) > +{ > + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); > + > + mutex_lock(&shmem->vmap_lock); > + drm_gem_shmem_vunmap_locked(shmem); > + mutex_unlock(&shmem->vmap_lock); > +} > +EXPORT_SYMBOL(drm_gem_shmem_vunmap); > + > +static struct drm_gem_shmem_object * > +drm_gem_shmem_create_with_handle(struct drm_file *file_priv, > + struct drm_device *dev, size_t size, > + uint32_t *handle) > +{ > + struct drm_gem_shmem_object *shmem; > + int ret; > + > + shmem = drm_gem_shmem_create(dev, size); > + if (IS_ERR(shmem)) > + return shmem; > + > + /* > + * Allocate an id of idr table where the obj is registered > + * and handle has the id what user can see. > + */ > + ret = drm_gem_handle_create(file_priv, &shmem->base, handle); > + /* drop reference from allocate - handle holds it now. */ > + drm_gem_object_put_unlocked(&shmem->base); > + if (ret) > + return ERR_PTR(ret); > + > + return shmem; > +} > + > +/** > + * drm_gem_shmem_dumb_create - Create a dumb shmem buffer object > + * @file: DRM file structure to create the dumb buffer for > + * @dev: DRM device > + * @args: IOCTL data > + * > + * This function computes the pitch of the dumb buffer and rounds it up to an > + * integer number of bytes per pixel. Drivers for hardware that doesn't have > + * any additional restrictions on the pitch can directly use this function as > + * their &drm_driver.dumb_create callback. > + * > + * For hardware with additional restrictions, drivers can adjust the fields > + * set up by userspace before calling into this function. > + * > + * Returns: > + * 0 on success or a negative error code on failure. > + */ > +int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev, > + struct drm_mode_create_dumb *args) > +{ > + u32 min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8); > + struct drm_gem_shmem_object *shmem; > + > + if (!args->pitch || !args->size) { > + args->pitch = min_pitch; > + args->size = args->pitch * args->height; > + } else { > + /* ensure sane minimum values */ > + if (args->pitch < min_pitch) > + args->pitch = min_pitch; > + if (args->size < args->pitch * args->height) > + args->size = args->pitch * args->height; > + } > + > + shmem = drm_gem_shmem_create_with_handle(file, dev, args->size, &args->handle); > + > + return PTR_ERR_OR_ZERO(shmem); > +} > +EXPORT_SYMBOL_GPL(drm_gem_shmem_dumb_create); > + > +static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) > +{ > + struct vm_area_struct *vma = vmf->vma; > + struct drm_gem_object *obj = vma->vm_private_data; > + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); > + /* We don't use vmf->pgoff since that has the fake offset: */ > + pgoff_t pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT; > + loff_t num_pages = obj->size >> PAGE_SHIFT; > + struct page *page; > + > + if (pgoff > num_pages || WARN_ON_ONCE(!shmem->pages)) > + return VM_FAULT_SIGBUS; > + > + page = shmem->pages[pgoff]; > + > + return vmf_insert_page(vma, vmf->address, page); > +} > + > +static void drm_gem_shmem_vm_close(struct vm_area_struct *vma) > +{ > + struct drm_gem_object *obj = vma->vm_private_data; > + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); > + > + drm_gem_shmem_put_pages(shmem); > + drm_gem_vm_close(vma); > +} > + > +const struct vm_operations_struct drm_gem_shmem_vm_ops = { > + .fault = drm_gem_shmem_fault, > + .open = drm_gem_vm_open, > + .close = drm_gem_shmem_vm_close, > +}; > +EXPORT_SYMBOL_GPL(drm_gem_shmem_vm_ops); > + > +static int drm_gem_shmem_mmap_obj(struct drm_gem_shmem_object *shmem, > + struct vm_area_struct *vma) > +{ > + int ret; > + > + ret = drm_gem_shmem_get_pages(shmem); > + if (ret) { > + drm_gem_vm_close(vma); > + return ret; > + } > + > + /* VM_PFNMAP was set by drm_gem_mmap() */ > + vma->vm_flags &= ~VM_PFNMAP; > + vma->vm_flags |= VM_MIXEDMAP; > + vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); > + > + fput(vma->vm_file); > + get_file(shmem->base.filp); > + vma->vm_pgoff = 0; > + vma->vm_file = shmem->base.filp; > + > + return 0; > +} > + > +/** > + * drm_gem_shmem_mmap - Memory-map a shmem GEM object > + * @filp: File object > + * @vma: VMA for the area to be mapped > + * > + * This function implements an augmented version of the GEM DRM file mmap > + * operation for shmem objects. Drivers which employ the shmem helpers should > + * use this function as their &file_operations.mmap handler in the DRM device file's > + * file_operations structure. > + * > + * Instead of directly referencing this function, drivers should use the > + * DEFINE_DRM_GEM_SHMEM_FOPS() macro. > + * > + * Returns: > + * 0 on success or a negative error code on failure. > + */ > +int drm_gem_shmem_mmap(struct file *filp, struct vm_area_struct *vma) > +{ > + struct drm_gem_shmem_object *shmem; > + int ret; > + > + ret = drm_gem_mmap(filp, vma); > + if (ret) > + return ret; > + > + shmem = to_drm_gem_shmem_obj(vma->vm_private_data); > + > + return drm_gem_shmem_mmap_obj(shmem, vma); > +} > +EXPORT_SYMBOL_GPL(drm_gem_shmem_mmap); > + > +/** > + * drm_gem_shmem_print_info() - Print &drm_gem_shmem_object info for debugfs > + * @p: DRM printer > + * @indent: Tab indentation level > + * @obj: GEM object > + */ > +void drm_gem_shmem_print_info(struct drm_printer *p, unsigned int indent, > + const struct drm_gem_object *obj) > +{ > + const struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); > + > + drm_printf_indent(p, indent, "pages_use_count=%u\n", shmem->pages_use_count); > + drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr); > + drm_printf_indent(p, indent, "vmap_use_count=%u\n", shmem->vmap_use_count); > +} > +EXPORT_SYMBOL(drm_gem_shmem_print_info); > + > +/** > + * drm_gem_shmem_get_sg_table - Provide a scatter/gather table of pinned > + * pages for a shmem GEM object > + * @obj: GEM object > + * > + * This function exports a scatter/gather table suitable for PRIME usage by > + * calling the standard DMA mapping API. > + * > + * Returns: > + * A pointer to the scatter/gather table of pinned pages or NULL on failure. > + */ > +struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_object *obj) > +{ > + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); > + > + return drm_prime_pages_to_sg(shmem->pages, obj->size >> PAGE_SHIFT); > +} > +EXPORT_SYMBOL_GPL(drm_gem_shmem_get_sg_table); > + > +/** > + * drm_gem_shmem_prime_import_sg_table - Produce a shmem GEM object from > + * another driver's scatter/gather table of pinned pages > + * @dev: Device to import into > + * @attach: DMA-BUF attachment > + * @sgt: Scatter/gather table of pinned pages > + * > + * This function imports a scatter/gather table exported via DMA-BUF by > + * another driver. Drivers that use the shmem helpers should set this as their > + * &drm_driver.gem_prime_import_sg_table callback. > + * > + * Returns: > + * A pointer to a newly created GEM object or an ERR_PTR-encoded negative > + * error code on failure. > + */ > +struct drm_gem_object * > +drm_gem_shmem_prime_import_sg_table(struct drm_device *dev, > + struct dma_buf_attachment *attach, > + struct sg_table *sgt) > +{ > + size_t size = PAGE_ALIGN(attach->dmabuf->size); > + size_t npages = size >> PAGE_SHIFT; > + struct drm_gem_shmem_object *shmem; > + int ret; > + > + shmem = drm_gem_shmem_create(dev, size); > + if (IS_ERR(shmem)) > + return ERR_CAST(shmem); > + > + shmem->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL); > + if (!shmem->pages) { > + ret = -ENOMEM; > + goto err_free_gem; > + } > + > + ret = drm_prime_sg_to_page_addr_arrays(sgt, shmem->pages, NULL, npages); > + if (ret < 0) > + goto err_free_array; > + > + shmem->sgt = sgt; > + shmem->pages_use_count = 1; /* Permanently pinned from our point of view */ > + > + DRM_DEBUG_PRIME("size = %zu\n", size); > + > + return &shmem->base; > + > +err_free_array: > + kvfree(shmem->pages); > +err_free_gem: > + drm_gem_object_put_unlocked(&shmem->base); > + > + return ERR_PTR(ret); > +} > +EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_sg_table); > + > +/** > + * drm_gem_shmem_prime_mmap - Memory-map an exported shmem GEM object > + * @obj: GEM object > + * @vma: VMA for the area to be mapped > + * > + * This function maps a buffer imported via DRM PRIME into a userspace > + * process's address space. > + * > + * Returns: > + * 0 on success or a negative error code on failure. > + */ > +int drm_gem_shmem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) > +{ > + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); > + int ret; > + > + ret = drm_gem_mmap_obj(obj, obj->size, vma); > + if (ret) > + return ret; > + > + return drm_gem_shmem_mmap_obj(shmem, vma); > +} If we'd use the gem vma offset manager and adjust offsets and then call into the gem mmap stuff I think we could make this 100% generic. That would also avoid the need to add the gem_ops->prime_mmap callback, since we'll have a default that should work for everyone. -Daniel > +EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_mmap); > diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h > new file mode 100644 > index 000000000000..94ec99fdcffc > --- /dev/null > +++ b/include/drm/drm_gem_shmem_helper.h > @@ -0,0 +1,153 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > + > +#ifndef __DRM_GEM_SHMEM_HELPER_H__ > +#define __DRM_GEM_SHMEM_HELPER_H__ > + > +#include <linux/fs.h> > +#include <linux/mm.h> > +#include <linux/mutex.h> > + > +#include <drm/drm_file.h> > +#include <drm/drm_gem.h> > +#include <drm/drm_ioctl.h> > +#include <drm/drm_prime.h> > + > +struct dma_buf_attachment; > +struct drm_mode_create_dumb; > +struct drm_printer; > +struct sg_table; > + > +/** > + * struct drm_gem_shmem_object - GEM object backed by shmem > + */ > +struct drm_gem_shmem_object { > + /** > + * @base: Base GEM object > + */ > + struct drm_gem_object base; > + > + /** > + * @pages_lock: Protects the page table and use count > + */ > + struct mutex pages_lock; > + > + /** > + * @pages: Page table > + */ > + struct page **pages; > + > + /** > + * @pages_use_count: > + * > + * Reference count on the pages table. > + * The pages are put when the count reaches zero. > + */ > + unsigned int pages_use_count; > + > + /** > + * @pages_mark_dirty_on_put: > + * > + * Mark pages as dirty when they are put. > + */ > + unsigned int pages_mark_dirty_on_put : 1; > + > + /** > + * @pages_mark_accessed_on_put: > + * > + * Mark pages as accessed when they are put. > + */ > + unsigned int pages_mark_accessed_on_put : 1; > + > + /** > + * @sgt: Scatter/gather table for imported PRIME buffers > + */ > + struct sg_table *sgt; > + > + /** > + * @vmap_lock: Protects the vmap address and use count > + */ > + struct mutex vmap_lock; > + > + /** > + * @vaddr: Kernel virtual address of the backing memory > + */ > + void *vaddr; > + > + /** > + * @vmap_use_count: > + * > + * Reference count on the virtual address. > + * The address are un-mapped when the count reaches zero. > + */ > + unsigned int vmap_use_count; > +}; > + > +#define to_drm_gem_shmem_obj(obj) \ > + container_of(obj, struct drm_gem_shmem_object, base) > + > +/** > + * DEFINE_DRM_GEM_SHMEM_FOPS() - Macro to generate file operations for shmem drivers > + * @name: name for the generated structure > + * > + * This macro autogenerates a suitable &struct file_operations for shmem based > + * drivers, which can be assigned to &drm_driver.fops. Note that this structure > + * cannot be shared between drivers, because it contains a reference to the > + * current module using THIS_MODULE. > + * > + * Note that the declaration is already marked as static - if you need a > + * non-static version of this you're probably doing it wrong and will break the > + * THIS_MODULE reference by accident. > + */ > +#define DEFINE_DRM_GEM_SHMEM_FOPS(name) \ > + static const struct file_operations name = {\ > + .owner = THIS_MODULE,\ > + .open = drm_open,\ > + .release = drm_release,\ > + .unlocked_ioctl = drm_ioctl,\ > + .compat_ioctl = drm_compat_ioctl,\ > + .poll = drm_poll,\ > + .read = drm_read,\ > + .llseek = noop_llseek,\ > + .mmap = drm_gem_shmem_mmap, \ > + } > + > +struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size); > +void drm_gem_shmem_free_object(struct drm_gem_object *obj); > + > +int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem); > +void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem); > +int drm_gem_shmem_pin(struct drm_gem_object *obj); > +void drm_gem_shmem_unpin(struct drm_gem_object *obj); > +void *drm_gem_shmem_vmap(struct drm_gem_object *obj); > +void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr); > + > +int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev, > + struct drm_mode_create_dumb *args); > + > +int drm_gem_shmem_mmap(struct file *filp, struct vm_area_struct *vma); > + > +extern const struct vm_operations_struct drm_gem_shmem_vm_ops; > + > +void drm_gem_shmem_print_info(struct drm_printer *p, unsigned int indent, > + const struct drm_gem_object *obj); > + > +struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_object *obj); > +struct drm_gem_object * > +drm_gem_shmem_prime_import_sg_table(struct drm_device *dev, > + struct dma_buf_attachment *attach, > + struct sg_table *sgt); > +int drm_gem_shmem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma); > + > +/** > + * DRM_GEM_SHMEM_DRIVER_OPS - Default shmem GEM operations > + * > + * This macro provides a shortcut for setting the shmem GEM operations in > + * the &drm_driver structure. > + */ > +#define DRM_GEM_SHMEM_DRIVER_OPS \ > + .prime_handle_to_fd = drm_gem_prime_handle_to_fd, \ > + .prime_fd_to_handle = drm_gem_prime_fd_to_handle, \ > + .gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table, \ > + .dumb_create = drm_gem_shmem_dumb_create > + > +#endif /* __DRM_GEM_SHMEM_HELPER_H__ */ > -- > 2.15.1 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
Den 01.10.2018 09.46, skrev Daniel Vetter: > On Wed, Sep 26, 2018 at 04:59:32PM +0200, Noralf Trønnes wrote: >> This adds a library for shmem backed GEM objects. >> >> Signed-off-by: Noralf Trønnes <noralf@tronnes.org> >> --- >> >> Changes since version 3: >> - Drop cache modes (Thomas Hellstrom) >> - Add a GEM attached vtable >> >> Documentation/gpu/drm-kms-helpers.rst | 12 + >> drivers/gpu/drm/Kconfig | 6 + >> drivers/gpu/drm/Makefile | 1 + >> drivers/gpu/drm/drm_gem_shmem_helper.c | 586 +++++++++++++++++++++++++++++++++ >> include/drm/drm_gem_shmem_helper.h | 153 +++++++++ >> 5 files changed, 758 insertions(+) >> create mode 100644 drivers/gpu/drm/drm_gem_shmem_helper.c >> create mode 100644 include/drm/drm_gem_shmem_helper.h >> >> diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst >> index f9cfcdcdf024..bc24b1b5216a 100644 >> --- a/Documentation/gpu/drm-kms-helpers.rst >> +++ b/Documentation/gpu/drm-kms-helpers.rst >> @@ -326,3 +326,15 @@ Legacy CRTC/Modeset Helper Functions Reference >> >> .. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c >> :export: >> + >> +SHMEM GEM Helper Reference >> +========================== >> + >> +.. kernel-doc:: drivers/gpu/drm/drm_gem_shmem_helper.c >> + :doc: overview >> + >> +.. kernel-doc:: include/drm/drm_gem_shmem_helper.h >> + :internal: >> + >> +.. kernel-doc:: drivers/gpu/drm/drm_gem_shmem_helper.c >> + :export: >> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig >> index cb88528e7b10..db588ae44bcc 100644 >> --- a/drivers/gpu/drm/Kconfig >> +++ b/drivers/gpu/drm/Kconfig >> @@ -157,6 +157,12 @@ config DRM_KMS_CMA_HELPER >> help >> Choose this if you need the KMS CMA helper functions >> >> +config DRM_GEM_SHMEM_HELPER >> + bool >> + depends on DRM >> + help >> + Choose this if you need the GEM shmem helper functions >> + >> config DRM_VM >> bool >> depends on DRM && MMU >> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile >> index bc6a16a3c36e..13777f22dc25 100644 >> --- a/drivers/gpu/drm/Makefile >> +++ b/drivers/gpu/drm/Makefile >> @@ -25,6 +25,7 @@ drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o >> drm-$(CONFIG_DRM_VM) += drm_vm.o >> drm-$(CONFIG_COMPAT) += drm_ioc32.o >> drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o >> +drm-$(CONFIG_DRM_GEM_SHMEM_HELPER) += drm_gem_shmem_helper.o >> drm-$(CONFIG_PCI) += ati_pcigart.o >> drm-$(CONFIG_DRM_PANEL) += drm_panel.o >> drm-$(CONFIG_OF) += drm_of.o >> diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c >> new file mode 100644 >> index 000000000000..7471856d34ac >> --- /dev/null >> +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c >> @@ -0,0 +1,586 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Copyright 2018 Noralf Trønnes >> + */ >> + >> +#include <linux/dma-buf.h> >> +#include <linux/export.h> >> +#include <linux/mutex.h> >> +#include <linux/shmem_fs.h> >> +#include <linux/slab.h> >> +#include <linux/vmalloc.h> >> + >> +#include <drm/drm_device.h> >> +#include <drm/drm_drv.h> >> +#include <drm/drm_gem_shmem_helper.h> >> +#include <drm/drm_prime.h> >> +#include <drm/drm_print.h> >> + >> +/** >> + * DOC: overview >> + * >> + * This library provides helpers for GEM objects backed by shmem buffers >> + * allocated using anonymous pageable memory. >> + */ >> + >> +static const struct drm_gem_object_funcs drm_gem_shmem_funcs = { >> + .free = drm_gem_shmem_free_object, >> + .print_info = drm_gem_shmem_print_info, >> + .pin = drm_gem_shmem_pin, >> + .unpin = drm_gem_shmem_unpin, >> + .get_sg_table = drm_gem_shmem_get_sg_table, >> + .vmap = drm_gem_shmem_vmap, >> + .vunmap = drm_gem_shmem_vunmap, >> + .prime_mmap = drm_gem_shmem_prime_mmap, >> + .vm_ops = &drm_gem_shmem_vm_ops, >> +}; >> + >> +/** >> + * drm_gem_shmem_create - Allocate an object with the given size >> + * @dev: DRM device >> + * @size: Size of the object to allocate >> + * >> + * This function creates a shmem GEM object. >> + * >> + * Returns: >> + * A struct drm_gem_shmem_object * on success or an ERR_PTR()-encoded negative >> + * error code on failure. >> + */ >> +struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size) >> +{ >> + struct drm_gem_shmem_object *shmem; >> + struct drm_gem_object *obj; >> + int ret; >> + >> + size = PAGE_ALIGN(size); >> + >> + if (dev->driver->gem_create_object) >> + obj = dev->driver->gem_create_object(dev, size); >> + else >> + obj = kzalloc(sizeof(*shmem), GFP_KERNEL); >> + if (!obj) >> + return ERR_PTR(-ENOMEM); >> + >> + if (!obj->funcs) >> + obj->funcs = &drm_gem_shmem_funcs; >> + >> + ret = drm_gem_object_init(dev, obj, size); >> + if (ret) >> + goto err_free; >> + >> + ret = drm_gem_create_mmap_offset(obj); >> + if (ret) >> + goto err_release; >> + >> + shmem = to_drm_gem_shmem_obj(obj); >> + mutex_init(&shmem->pages_lock); >> + mutex_init(&shmem->vmap_lock); >> + >> + return shmem; >> + >> +err_release: >> + drm_gem_object_release(obj); >> +err_free: >> + kfree(shmem); >> + >> + return ERR_PTR(ret); >> +} >> +EXPORT_SYMBOL_GPL(drm_gem_shmem_create); >> + >> +/** >> + * drm_gem_shmem_free_object - Free resources associated with a shmem GEM object >> + * @obj: GEM object to free >> + * >> + * This function cleans up the GEM object state and frees the memory used to >> + * store the object itself. >> + */ >> +void drm_gem_shmem_free_object(struct drm_gem_object *obj) >> +{ >> + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); >> + >> + WARN_ON(shmem->vmap_use_count); >> + >> + if (obj->import_attach) { >> + shmem->pages_use_count--; >> + drm_prime_gem_destroy(obj, shmem->sgt); >> + kvfree(shmem->pages); >> + } >> + >> + WARN_ON(shmem->pages_use_count); >> + >> + drm_gem_object_release(obj); >> + mutex_destroy(&shmem->pages_lock); >> + mutex_destroy(&shmem->vmap_lock); >> + kfree(shmem); >> +} >> +EXPORT_SYMBOL_GPL(drm_gem_shmem_free_object); >> + >> +static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem) >> +{ >> + struct drm_gem_object *obj = &shmem->base; >> + struct page **pages; >> + >> + if (shmem->pages_use_count++ > 0) >> + return 0; >> + >> + pages = drm_gem_get_pages(obj); >> + if (IS_ERR(pages)) { >> + DRM_DEBUG_KMS("Failed to get pages (%ld)\n", PTR_ERR(pages)); >> + shmem->pages_use_count = 0; >> + return PTR_ERR(pages); >> + } >> + >> + shmem->pages = pages; >> + >> + return 0; >> +} >> + >> +/* >> + * drm_gem_shmem_get_pages - Allocate backing pages for a shmem GEM object >> + * @shmem: shmem GEM object >> + * >> + * This function makes sure that backing pages exists for the shmem GEM object >> + * and increases the use count. >> + * >> + * Returns: >> + * 0 on success or a negative error code on failure. >> + */ >> +int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) >> +{ >> + int ret; >> + >> + ret = mutex_lock_interruptible(&shmem->pages_lock); >> + if (ret) >> + return ret; >> + ret = drm_gem_shmem_get_pages_locked(shmem); >> + mutex_unlock(&shmem->pages_lock); >> + >> + return ret; >> +} >> +EXPORT_SYMBOL(drm_gem_shmem_get_pages); >> + >> +static void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem) >> +{ >> + struct drm_gem_object *obj = &shmem->base; >> + >> + if (WARN_ON_ONCE(!shmem->pages_use_count)) >> + return; >> + >> + if (--shmem->pages_use_count > 0) >> + return; >> + >> + drm_gem_put_pages(obj, shmem->pages, >> + shmem->pages_mark_dirty_on_put, >> + shmem->pages_mark_accessed_on_put); >> + shmem->pages = NULL; >> +} >> + >> +/* >> + * drm_gem_shmem_put_pages - Decrease use count on the backing pages for a shmem GEM object >> + * @shmem: shmem GEM object >> + * >> + * This function decreases the use count and puts the backing pages when use drops to zero. >> + */ >> +void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem) >> +{ >> + mutex_lock(&shmem->pages_lock); >> + drm_gem_shmem_put_pages_locked(shmem); >> + mutex_unlock(&shmem->pages_lock); >> +} >> +EXPORT_SYMBOL(drm_gem_shmem_put_pages); >> + >> +/** >> + * drm_gem_shmem_pin - Pin backing pages for a shmem GEM object >> + * @obj: GEM object >> + * >> + * This function makes sure the backing pages are pinned in memory while the >> + * buffer is exported. >> + * >> + * Returns: >> + * 0 on success or a negative error code on failure. >> + */ >> +int drm_gem_shmem_pin(struct drm_gem_object *obj) >> +{ >> + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); >> + >> + return drm_gem_shmem_get_pages(shmem); >> +} >> +EXPORT_SYMBOL(drm_gem_shmem_pin); >> + >> +/** >> + * drm_gem_shmem_unpin - Unpin backing pages for a shmem GEM object >> + * @obj: GEM object >> + * >> + * This function removes the requirement that the backing pages are pinned in >> + * memory. >> + */ >> +void drm_gem_shmem_unpin(struct drm_gem_object *obj) >> +{ >> + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); >> + >> + drm_gem_shmem_put_pages(shmem); >> +} >> +EXPORT_SYMBOL(drm_gem_shmem_unpin); >> + >> +static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem) >> +{ >> + struct drm_gem_object *obj = &shmem->base; >> + int ret; >> + >> + if (shmem->vmap_use_count++ > 0) >> + return shmem->vaddr; >> + >> + ret = drm_gem_shmem_get_pages(shmem); >> + if (ret) >> + goto err_zero_use; >> + >> + if (obj->import_attach) >> + shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf); >> + else >> + shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT, VM_MAP, PAGE_KERNEL); >> + >> + if (!shmem->vaddr) { >> + DRM_DEBUG_KMS("Failed to vmap pages\n"); >> + ret = -ENOMEM; >> + goto err_put_pages; >> + } >> + >> + return shmem->vaddr; >> + >> +err_put_pages: >> + drm_gem_shmem_put_pages(shmem); >> +err_zero_use: >> + shmem->vmap_use_count = 0; >> + >> + return ERR_PTR(ret); >> +} >> + >> +/* >> + * drm_gem_shmem_vmap - Create a virtual mapping for a shmem GEM object >> + * @shmem: shmem GEM object >> + * >> + * This function makes sure that a virtual address exists for the buffer backing >> + * the shmem GEM object. >> + * >> + * Returns: >> + * 0 on success or a negative error code on failure. >> + */ >> +void *drm_gem_shmem_vmap(struct drm_gem_object *obj) >> +{ >> + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); >> + void *vaddr; >> + int ret; >> + >> + ret = mutex_lock_interruptible(&shmem->vmap_lock); >> + if (ret) >> + return ERR_PTR(ret); >> + vaddr = drm_gem_shmem_vmap_locked(shmem); >> + mutex_unlock(&shmem->vmap_lock); >> + >> + return vaddr; >> +} >> +EXPORT_SYMBOL(drm_gem_shmem_vmap); >> + >> +static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem) >> +{ >> + struct drm_gem_object *obj = &shmem->base; >> + >> + if (WARN_ON_ONCE(!shmem->vmap_use_count)) >> + return; >> + >> + if (--shmem->vmap_use_count > 0) >> + return; >> + >> + if (obj->import_attach) >> + dma_buf_vunmap(obj->import_attach->dmabuf, shmem->vaddr); >> + else >> + vunmap(shmem->vaddr); >> + >> + shmem->vaddr = NULL; >> + drm_gem_shmem_put_pages(shmem); >> +} >> + >> +/* >> + * drm_gem_shmem_vunmap - Unmap a virtual mapping fo a shmem GEM object >> + * @shmem: shmem GEM object >> + * >> + * This function removes the virtual address when use count drops to zero. >> + */ >> +void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr) >> +{ >> + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); >> + >> + mutex_lock(&shmem->vmap_lock); >> + drm_gem_shmem_vunmap_locked(shmem); >> + mutex_unlock(&shmem->vmap_lock); >> +} >> +EXPORT_SYMBOL(drm_gem_shmem_vunmap); >> + >> +static struct drm_gem_shmem_object * >> +drm_gem_shmem_create_with_handle(struct drm_file *file_priv, >> + struct drm_device *dev, size_t size, >> + uint32_t *handle) >> +{ >> + struct drm_gem_shmem_object *shmem; >> + int ret; >> + >> + shmem = drm_gem_shmem_create(dev, size); >> + if (IS_ERR(shmem)) >> + return shmem; >> + >> + /* >> + * Allocate an id of idr table where the obj is registered >> + * and handle has the id what user can see. >> + */ >> + ret = drm_gem_handle_create(file_priv, &shmem->base, handle); >> + /* drop reference from allocate - handle holds it now. */ >> + drm_gem_object_put_unlocked(&shmem->base); >> + if (ret) >> + return ERR_PTR(ret); >> + >> + return shmem; >> +} >> + >> +/** >> + * drm_gem_shmem_dumb_create - Create a dumb shmem buffer object >> + * @file: DRM file structure to create the dumb buffer for >> + * @dev: DRM device >> + * @args: IOCTL data >> + * >> + * This function computes the pitch of the dumb buffer and rounds it up to an >> + * integer number of bytes per pixel. Drivers for hardware that doesn't have >> + * any additional restrictions on the pitch can directly use this function as >> + * their &drm_driver.dumb_create callback. >> + * >> + * For hardware with additional restrictions, drivers can adjust the fields >> + * set up by userspace before calling into this function. >> + * >> + * Returns: >> + * 0 on success or a negative error code on failure. >> + */ >> +int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev, >> + struct drm_mode_create_dumb *args) >> +{ >> + u32 min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8); >> + struct drm_gem_shmem_object *shmem; >> + >> + if (!args->pitch || !args->size) { >> + args->pitch = min_pitch; >> + args->size = args->pitch * args->height; >> + } else { >> + /* ensure sane minimum values */ >> + if (args->pitch < min_pitch) >> + args->pitch = min_pitch; >> + if (args->size < args->pitch * args->height) >> + args->size = args->pitch * args->height; >> + } >> + >> + shmem = drm_gem_shmem_create_with_handle(file, dev, args->size, &args->handle); >> + >> + return PTR_ERR_OR_ZERO(shmem); >> +} >> +EXPORT_SYMBOL_GPL(drm_gem_shmem_dumb_create); >> + >> +static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) >> +{ >> + struct vm_area_struct *vma = vmf->vma; >> + struct drm_gem_object *obj = vma->vm_private_data; >> + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); >> + /* We don't use vmf->pgoff since that has the fake offset: */ >> + pgoff_t pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT; >> + loff_t num_pages = obj->size >> PAGE_SHIFT; >> + struct page *page; >> + >> + if (pgoff > num_pages || WARN_ON_ONCE(!shmem->pages)) >> + return VM_FAULT_SIGBUS; >> + >> + page = shmem->pages[pgoff]; >> + >> + return vmf_insert_page(vma, vmf->address, page); >> +} >> + >> +static void drm_gem_shmem_vm_close(struct vm_area_struct *vma) >> +{ >> + struct drm_gem_object *obj = vma->vm_private_data; >> + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); >> + >> + drm_gem_shmem_put_pages(shmem); >> + drm_gem_vm_close(vma); >> +} >> + >> +const struct vm_operations_struct drm_gem_shmem_vm_ops = { >> + .fault = drm_gem_shmem_fault, >> + .open = drm_gem_vm_open, >> + .close = drm_gem_shmem_vm_close, >> +}; >> +EXPORT_SYMBOL_GPL(drm_gem_shmem_vm_ops); >> + >> +static int drm_gem_shmem_mmap_obj(struct drm_gem_shmem_object *shmem, >> + struct vm_area_struct *vma) >> +{ >> + int ret; >> + >> + ret = drm_gem_shmem_get_pages(shmem); >> + if (ret) { >> + drm_gem_vm_close(vma); >> + return ret; >> + } >> + >> + /* VM_PFNMAP was set by drm_gem_mmap() */ >> + vma->vm_flags &= ~VM_PFNMAP; >> + vma->vm_flags |= VM_MIXEDMAP; >> + vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); >> + >> + fput(vma->vm_file); >> + get_file(shmem->base.filp); >> + vma->vm_pgoff = 0; >> + vma->vm_file = shmem->base.filp; >> + >> + return 0; >> +} >> + >> +/** >> + * drm_gem_shmem_mmap - Memory-map a shmem GEM object >> + * @filp: File object >> + * @vma: VMA for the area to be mapped >> + * >> + * This function implements an augmented version of the GEM DRM file mmap >> + * operation for shmem objects. Drivers which employ the shmem helpers should >> + * use this function as their &file_operations.mmap handler in the DRM device file's >> + * file_operations structure. >> + * >> + * Instead of directly referencing this function, drivers should use the >> + * DEFINE_DRM_GEM_SHMEM_FOPS() macro. >> + * >> + * Returns: >> + * 0 on success or a negative error code on failure. >> + */ >> +int drm_gem_shmem_mmap(struct file *filp, struct vm_area_struct *vma) >> +{ >> + struct drm_gem_shmem_object *shmem; >> + int ret; >> + >> + ret = drm_gem_mmap(filp, vma); >> + if (ret) >> + return ret; >> + >> + shmem = to_drm_gem_shmem_obj(vma->vm_private_data); >> + >> + return drm_gem_shmem_mmap_obj(shmem, vma); >> +} >> +EXPORT_SYMBOL_GPL(drm_gem_shmem_mmap); >> + >> +/** >> + * drm_gem_shmem_print_info() - Print &drm_gem_shmem_object info for debugfs >> + * @p: DRM printer >> + * @indent: Tab indentation level >> + * @obj: GEM object >> + */ >> +void drm_gem_shmem_print_info(struct drm_printer *p, unsigned int indent, >> + const struct drm_gem_object *obj) >> +{ >> + const struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); >> + >> + drm_printf_indent(p, indent, "pages_use_count=%u\n", shmem->pages_use_count); >> + drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr); >> + drm_printf_indent(p, indent, "vmap_use_count=%u\n", shmem->vmap_use_count); >> +} >> +EXPORT_SYMBOL(drm_gem_shmem_print_info); >> + >> +/** >> + * drm_gem_shmem_get_sg_table - Provide a scatter/gather table of pinned >> + * pages for a shmem GEM object >> + * @obj: GEM object >> + * >> + * This function exports a scatter/gather table suitable for PRIME usage by >> + * calling the standard DMA mapping API. >> + * >> + * Returns: >> + * A pointer to the scatter/gather table of pinned pages or NULL on failure. >> + */ >> +struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_object *obj) >> +{ >> + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); >> + >> + return drm_prime_pages_to_sg(shmem->pages, obj->size >> PAGE_SHIFT); >> +} >> +EXPORT_SYMBOL_GPL(drm_gem_shmem_get_sg_table); >> + >> +/** >> + * drm_gem_shmem_prime_import_sg_table - Produce a shmem GEM object from >> + * another driver's scatter/gather table of pinned pages >> + * @dev: Device to import into >> + * @attach: DMA-BUF attachment >> + * @sgt: Scatter/gather table of pinned pages >> + * >> + * This function imports a scatter/gather table exported via DMA-BUF by >> + * another driver. Drivers that use the shmem helpers should set this as their >> + * &drm_driver.gem_prime_import_sg_table callback. >> + * >> + * Returns: >> + * A pointer to a newly created GEM object or an ERR_PTR-encoded negative >> + * error code on failure. >> + */ >> +struct drm_gem_object * >> +drm_gem_shmem_prime_import_sg_table(struct drm_device *dev, >> + struct dma_buf_attachment *attach, >> + struct sg_table *sgt) >> +{ >> + size_t size = PAGE_ALIGN(attach->dmabuf->size); >> + size_t npages = size >> PAGE_SHIFT; >> + struct drm_gem_shmem_object *shmem; >> + int ret; >> + >> + shmem = drm_gem_shmem_create(dev, size); >> + if (IS_ERR(shmem)) >> + return ERR_CAST(shmem); >> + >> + shmem->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL); >> + if (!shmem->pages) { >> + ret = -ENOMEM; >> + goto err_free_gem; >> + } >> + >> + ret = drm_prime_sg_to_page_addr_arrays(sgt, shmem->pages, NULL, npages); >> + if (ret < 0) >> + goto err_free_array; >> + >> + shmem->sgt = sgt; >> + shmem->pages_use_count = 1; /* Permanently pinned from our point of view */ >> + >> + DRM_DEBUG_PRIME("size = %zu\n", size); >> + >> + return &shmem->base; >> + >> +err_free_array: >> + kvfree(shmem->pages); >> +err_free_gem: >> + drm_gem_object_put_unlocked(&shmem->base); >> + >> + return ERR_PTR(ret); >> +} >> +EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_sg_table); >> + >> +/** >> + * drm_gem_shmem_prime_mmap - Memory-map an exported shmem GEM object >> + * @obj: GEM object >> + * @vma: VMA for the area to be mapped >> + * >> + * This function maps a buffer imported via DRM PRIME into a userspace >> + * process's address space. >> + * >> + * Returns: >> + * 0 on success or a negative error code on failure. >> + */ >> +int drm_gem_shmem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) >> +{ >> + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); >> + int ret; >> + >> + ret = drm_gem_mmap_obj(obj, obj->size, vma); >> + if (ret) >> + return ret; >> + >> + return drm_gem_shmem_mmap_obj(shmem, vma); >> +} > If we'd use the gem vma offset manager and adjust offsets and then call > into the gem mmap stuff I think we could make this 100% generic. That > would also avoid the need to add the gem_ops->prime_mmap callback, since > we'll have a default that should work for everyone. Is this what you had in mind? int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) { /* Used by drm_gem_mmap() to lookup the GEM object */ struct drm_file priv = { .minor = obj->dev->primary, }; struct file fil = { .private_data = &priv, }; int ret; ret = drm_vma_node_allow(&obj->vma_node, &priv); if (ret) return ret; vma->vm_pgoff += drm_vma_node_start(&obj->vma_node); ret = obj->dev->driver->fops->mmap(&fil, vma); drm_vma_node_revoke(&obj->vma_node, &priv); return ret; } Noralf. > -Daniel > >> +EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_mmap); >> diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h >> new file mode 100644 >> index 000000000000..94ec99fdcffc >> --- /dev/null >> +++ b/include/drm/drm_gem_shmem_helper.h >> @@ -0,0 +1,153 @@ >> +/* SPDX-License-Identifier: GPL-2.0 */ >> + >> +#ifndef __DRM_GEM_SHMEM_HELPER_H__ >> +#define __DRM_GEM_SHMEM_HELPER_H__ >> + >> +#include <linux/fs.h> >> +#include <linux/mm.h> >> +#include <linux/mutex.h> >> + >> +#include <drm/drm_file.h> >> +#include <drm/drm_gem.h> >> +#include <drm/drm_ioctl.h> >> +#include <drm/drm_prime.h> >> + >> +struct dma_buf_attachment; >> +struct drm_mode_create_dumb; >> +struct drm_printer; >> +struct sg_table; >> + >> +/** >> + * struct drm_gem_shmem_object - GEM object backed by shmem >> + */ >> +struct drm_gem_shmem_object { >> + /** >> + * @base: Base GEM object >> + */ >> + struct drm_gem_object base; >> + >> + /** >> + * @pages_lock: Protects the page table and use count >> + */ >> + struct mutex pages_lock; >> + >> + /** >> + * @pages: Page table >> + */ >> + struct page **pages; >> + >> + /** >> + * @pages_use_count: >> + * >> + * Reference count on the pages table. >> + * The pages are put when the count reaches zero. >> + */ >> + unsigned int pages_use_count; >> + >> + /** >> + * @pages_mark_dirty_on_put: >> + * >> + * Mark pages as dirty when they are put. >> + */ >> + unsigned int pages_mark_dirty_on_put : 1; >> + >> + /** >> + * @pages_mark_accessed_on_put: >> + * >> + * Mark pages as accessed when they are put. >> + */ >> + unsigned int pages_mark_accessed_on_put : 1; >> + >> + /** >> + * @sgt: Scatter/gather table for imported PRIME buffers >> + */ >> + struct sg_table *sgt; >> + >> + /** >> + * @vmap_lock: Protects the vmap address and use count >> + */ >> + struct mutex vmap_lock; >> + >> + /** >> + * @vaddr: Kernel virtual address of the backing memory >> + */ >> + void *vaddr; >> + >> + /** >> + * @vmap_use_count: >> + * >> + * Reference count on the virtual address. >> + * The address are un-mapped when the count reaches zero. >> + */ >> + unsigned int vmap_use_count; >> +}; >> + >> +#define to_drm_gem_shmem_obj(obj) \ >> + container_of(obj, struct drm_gem_shmem_object, base) >> + >> +/** >> + * DEFINE_DRM_GEM_SHMEM_FOPS() - Macro to generate file operations for shmem drivers >> + * @name: name for the generated structure >> + * >> + * This macro autogenerates a suitable &struct file_operations for shmem based >> + * drivers, which can be assigned to &drm_driver.fops. Note that this structure >> + * cannot be shared between drivers, because it contains a reference to the >> + * current module using THIS_MODULE. >> + * >> + * Note that the declaration is already marked as static - if you need a >> + * non-static version of this you're probably doing it wrong and will break the >> + * THIS_MODULE reference by accident. >> + */ >> +#define DEFINE_DRM_GEM_SHMEM_FOPS(name) \ >> + static const struct file_operations name = {\ >> + .owner = THIS_MODULE,\ >> + .open = drm_open,\ >> + .release = drm_release,\ >> + .unlocked_ioctl = drm_ioctl,\ >> + .compat_ioctl = drm_compat_ioctl,\ >> + .poll = drm_poll,\ >> + .read = drm_read,\ >> + .llseek = noop_llseek,\ >> + .mmap = drm_gem_shmem_mmap, \ >> + } >> + >> +struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size); >> +void drm_gem_shmem_free_object(struct drm_gem_object *obj); >> + >> +int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem); >> +void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem); >> +int drm_gem_shmem_pin(struct drm_gem_object *obj); >> +void drm_gem_shmem_unpin(struct drm_gem_object *obj); >> +void *drm_gem_shmem_vmap(struct drm_gem_object *obj); >> +void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr); >> + >> +int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev, >> + struct drm_mode_create_dumb *args); >> + >> +int drm_gem_shmem_mmap(struct file *filp, struct vm_area_struct *vma); >> + >> +extern const struct vm_operations_struct drm_gem_shmem_vm_ops; >> + >> +void drm_gem_shmem_print_info(struct drm_printer *p, unsigned int indent, >> + const struct drm_gem_object *obj); >> + >> +struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_object *obj); >> +struct drm_gem_object * >> +drm_gem_shmem_prime_import_sg_table(struct drm_device *dev, >> + struct dma_buf_attachment *attach, >> + struct sg_table *sgt); >> +int drm_gem_shmem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma); >> + >> +/** >> + * DRM_GEM_SHMEM_DRIVER_OPS - Default shmem GEM operations >> + * >> + * This macro provides a shortcut for setting the shmem GEM operations in >> + * the &drm_driver structure. >> + */ >> +#define DRM_GEM_SHMEM_DRIVER_OPS \ >> + .prime_handle_to_fd = drm_gem_prime_handle_to_fd, \ >> + .prime_fd_to_handle = drm_gem_prime_fd_to_handle, \ >> + .gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table, \ >> + .dumb_create = drm_gem_shmem_dumb_create >> + >> +#endif /* __DRM_GEM_SHMEM_HELPER_H__ */ >> -- >> 2.15.1 >> >> _______________________________________________ >> dri-devel mailing list >> dri-devel@lists.freedesktop.org >> https://lists.freedesktop.org/mailman/listinfo/dri-devel
On Wed, Oct 10, 2018 at 09:14:50PM +0200, Noralf Trønnes wrote: > Den 01.10.2018 09.46, skrev Daniel Vetter: > > On Wed, Sep 26, 2018 at 04:59:32PM +0200, Noralf Trønnes wrote: > > > +int drm_gem_shmem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) > > > +{ > > > + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); > > > + int ret; > > > + > > > + ret = drm_gem_mmap_obj(obj, obj->size, vma); > > > + if (ret) > > > + return ret; > > > + > > > + return drm_gem_shmem_mmap_obj(shmem, vma); > > > +} > > If we'd use the gem vma offset manager and adjust offsets and then call > > into the gem mmap stuff I think we could make this 100% generic. That > > would also avoid the need to add the gem_ops->prime_mmap callback, since > > we'll have a default that should work for everyone. > > Is this what you had in mind? > > int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct > *vma) > { > /* Used by drm_gem_mmap() to lookup the GEM object */ > struct drm_file priv = { > .minor = obj->dev->primary, > }; > struct file fil = { > .private_data = &priv, > }; > int ret; > > ret = drm_vma_node_allow(&obj->vma_node, &priv); > if (ret) > return ret; > > vma->vm_pgoff += drm_vma_node_start(&obj->vma_node); Yup, this offset adjusting is what I had in mind. -Daniel > ret = obj->dev->driver->fops->mmap(&fil, vma); > > drm_vma_node_revoke(&obj->vma_node, &priv); > > return ret; > }
diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst index f9cfcdcdf024..bc24b1b5216a 100644 --- a/Documentation/gpu/drm-kms-helpers.rst +++ b/Documentation/gpu/drm-kms-helpers.rst @@ -326,3 +326,15 @@ Legacy CRTC/Modeset Helper Functions Reference .. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c :export: + +SHMEM GEM Helper Reference +========================== + +.. kernel-doc:: drivers/gpu/drm/drm_gem_shmem_helper.c + :doc: overview + +.. kernel-doc:: include/drm/drm_gem_shmem_helper.h + :internal: + +.. kernel-doc:: drivers/gpu/drm/drm_gem_shmem_helper.c + :export: diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index cb88528e7b10..db588ae44bcc 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -157,6 +157,12 @@ config DRM_KMS_CMA_HELPER help Choose this if you need the KMS CMA helper functions +config DRM_GEM_SHMEM_HELPER + bool + depends on DRM + help + Choose this if you need the GEM shmem helper functions + config DRM_VM bool depends on DRM && MMU diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index bc6a16a3c36e..13777f22dc25 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -25,6 +25,7 @@ drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o drm-$(CONFIG_DRM_VM) += drm_vm.o drm-$(CONFIG_COMPAT) += drm_ioc32.o drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o +drm-$(CONFIG_DRM_GEM_SHMEM_HELPER) += drm_gem_shmem_helper.o drm-$(CONFIG_PCI) += ati_pcigart.o drm-$(CONFIG_DRM_PANEL) += drm_panel.o drm-$(CONFIG_OF) += drm_of.o diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c new file mode 100644 index 000000000000..7471856d34ac --- /dev/null +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -0,0 +1,586 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2018 Noralf Trønnes + */ + +#include <linux/dma-buf.h> +#include <linux/export.h> +#include <linux/mutex.h> +#include <linux/shmem_fs.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> + +#include <drm/drm_device.h> +#include <drm/drm_drv.h> +#include <drm/drm_gem_shmem_helper.h> +#include <drm/drm_prime.h> +#include <drm/drm_print.h> + +/** + * DOC: overview + * + * This library provides helpers for GEM objects backed by shmem buffers + * allocated using anonymous pageable memory. + */ + +static const struct drm_gem_object_funcs drm_gem_shmem_funcs = { + .free = drm_gem_shmem_free_object, + .print_info = drm_gem_shmem_print_info, + .pin = drm_gem_shmem_pin, + .unpin = drm_gem_shmem_unpin, + .get_sg_table = drm_gem_shmem_get_sg_table, + .vmap = drm_gem_shmem_vmap, + .vunmap = drm_gem_shmem_vunmap, + .prime_mmap = drm_gem_shmem_prime_mmap, + .vm_ops = &drm_gem_shmem_vm_ops, +}; + +/** + * drm_gem_shmem_create - Allocate an object with the given size + * @dev: DRM device + * @size: Size of the object to allocate + * + * This function creates a shmem GEM object. + * + * Returns: + * A struct drm_gem_shmem_object * on success or an ERR_PTR()-encoded negative + * error code on failure. + */ +struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size) +{ + struct drm_gem_shmem_object *shmem; + struct drm_gem_object *obj; + int ret; + + size = PAGE_ALIGN(size); + + if (dev->driver->gem_create_object) + obj = dev->driver->gem_create_object(dev, size); + else + obj = kzalloc(sizeof(*shmem), GFP_KERNEL); + if (!obj) + return ERR_PTR(-ENOMEM); + + if (!obj->funcs) + obj->funcs = &drm_gem_shmem_funcs; + + ret = drm_gem_object_init(dev, obj, size); + if (ret) + goto err_free; + + ret = drm_gem_create_mmap_offset(obj); + if (ret) + goto err_release; + + shmem = to_drm_gem_shmem_obj(obj); + mutex_init(&shmem->pages_lock); + mutex_init(&shmem->vmap_lock); + + return shmem; + +err_release: + drm_gem_object_release(obj); +err_free: + kfree(shmem); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_create); + +/** + * drm_gem_shmem_free_object - Free resources associated with a shmem GEM object + * @obj: GEM object to free + * + * This function cleans up the GEM object state and frees the memory used to + * store the object itself. + */ +void drm_gem_shmem_free_object(struct drm_gem_object *obj) +{ + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + WARN_ON(shmem->vmap_use_count); + + if (obj->import_attach) { + shmem->pages_use_count--; + drm_prime_gem_destroy(obj, shmem->sgt); + kvfree(shmem->pages); + } + + WARN_ON(shmem->pages_use_count); + + drm_gem_object_release(obj); + mutex_destroy(&shmem->pages_lock); + mutex_destroy(&shmem->vmap_lock); + kfree(shmem); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_free_object); + +static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem) +{ + struct drm_gem_object *obj = &shmem->base; + struct page **pages; + + if (shmem->pages_use_count++ > 0) + return 0; + + pages = drm_gem_get_pages(obj); + if (IS_ERR(pages)) { + DRM_DEBUG_KMS("Failed to get pages (%ld)\n", PTR_ERR(pages)); + shmem->pages_use_count = 0; + return PTR_ERR(pages); + } + + shmem->pages = pages; + + return 0; +} + +/* + * drm_gem_shmem_get_pages - Allocate backing pages for a shmem GEM object + * @shmem: shmem GEM object + * + * This function makes sure that backing pages exists for the shmem GEM object + * and increases the use count. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) +{ + int ret; + + ret = mutex_lock_interruptible(&shmem->pages_lock); + if (ret) + return ret; + ret = drm_gem_shmem_get_pages_locked(shmem); + mutex_unlock(&shmem->pages_lock); + + return ret; +} +EXPORT_SYMBOL(drm_gem_shmem_get_pages); + +static void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem) +{ + struct drm_gem_object *obj = &shmem->base; + + if (WARN_ON_ONCE(!shmem->pages_use_count)) + return; + + if (--shmem->pages_use_count > 0) + return; + + drm_gem_put_pages(obj, shmem->pages, + shmem->pages_mark_dirty_on_put, + shmem->pages_mark_accessed_on_put); + shmem->pages = NULL; +} + +/* + * drm_gem_shmem_put_pages - Decrease use count on the backing pages for a shmem GEM object + * @shmem: shmem GEM object + * + * This function decreases the use count and puts the backing pages when use drops to zero. + */ +void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem) +{ + mutex_lock(&shmem->pages_lock); + drm_gem_shmem_put_pages_locked(shmem); + mutex_unlock(&shmem->pages_lock); +} +EXPORT_SYMBOL(drm_gem_shmem_put_pages); + +/** + * drm_gem_shmem_pin - Pin backing pages for a shmem GEM object + * @obj: GEM object + * + * This function makes sure the backing pages are pinned in memory while the + * buffer is exported. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +int drm_gem_shmem_pin(struct drm_gem_object *obj) +{ + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + return drm_gem_shmem_get_pages(shmem); +} +EXPORT_SYMBOL(drm_gem_shmem_pin); + +/** + * drm_gem_shmem_unpin - Unpin backing pages for a shmem GEM object + * @obj: GEM object + * + * This function removes the requirement that the backing pages are pinned in + * memory. + */ +void drm_gem_shmem_unpin(struct drm_gem_object *obj) +{ + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + drm_gem_shmem_put_pages(shmem); +} +EXPORT_SYMBOL(drm_gem_shmem_unpin); + +static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem) +{ + struct drm_gem_object *obj = &shmem->base; + int ret; + + if (shmem->vmap_use_count++ > 0) + return shmem->vaddr; + + ret = drm_gem_shmem_get_pages(shmem); + if (ret) + goto err_zero_use; + + if (obj->import_attach) + shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf); + else + shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT, VM_MAP, PAGE_KERNEL); + + if (!shmem->vaddr) { + DRM_DEBUG_KMS("Failed to vmap pages\n"); + ret = -ENOMEM; + goto err_put_pages; + } + + return shmem->vaddr; + +err_put_pages: + drm_gem_shmem_put_pages(shmem); +err_zero_use: + shmem->vmap_use_count = 0; + + return ERR_PTR(ret); +} + +/* + * drm_gem_shmem_vmap - Create a virtual mapping for a shmem GEM object + * @shmem: shmem GEM object + * + * This function makes sure that a virtual address exists for the buffer backing + * the shmem GEM object. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +void *drm_gem_shmem_vmap(struct drm_gem_object *obj) +{ + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + void *vaddr; + int ret; + + ret = mutex_lock_interruptible(&shmem->vmap_lock); + if (ret) + return ERR_PTR(ret); + vaddr = drm_gem_shmem_vmap_locked(shmem); + mutex_unlock(&shmem->vmap_lock); + + return vaddr; +} +EXPORT_SYMBOL(drm_gem_shmem_vmap); + +static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem) +{ + struct drm_gem_object *obj = &shmem->base; + + if (WARN_ON_ONCE(!shmem->vmap_use_count)) + return; + + if (--shmem->vmap_use_count > 0) + return; + + if (obj->import_attach) + dma_buf_vunmap(obj->import_attach->dmabuf, shmem->vaddr); + else + vunmap(shmem->vaddr); + + shmem->vaddr = NULL; + drm_gem_shmem_put_pages(shmem); +} + +/* + * drm_gem_shmem_vunmap - Unmap a virtual mapping fo a shmem GEM object + * @shmem: shmem GEM object + * + * This function removes the virtual address when use count drops to zero. + */ +void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr) +{ + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + mutex_lock(&shmem->vmap_lock); + drm_gem_shmem_vunmap_locked(shmem); + mutex_unlock(&shmem->vmap_lock); +} +EXPORT_SYMBOL(drm_gem_shmem_vunmap); + +static struct drm_gem_shmem_object * +drm_gem_shmem_create_with_handle(struct drm_file *file_priv, + struct drm_device *dev, size_t size, + uint32_t *handle) +{ + struct drm_gem_shmem_object *shmem; + int ret; + + shmem = drm_gem_shmem_create(dev, size); + if (IS_ERR(shmem)) + return shmem; + + /* + * Allocate an id of idr table where the obj is registered + * and handle has the id what user can see. + */ + ret = drm_gem_handle_create(file_priv, &shmem->base, handle); + /* drop reference from allocate - handle holds it now. */ + drm_gem_object_put_unlocked(&shmem->base); + if (ret) + return ERR_PTR(ret); + + return shmem; +} + +/** + * drm_gem_shmem_dumb_create - Create a dumb shmem buffer object + * @file: DRM file structure to create the dumb buffer for + * @dev: DRM device + * @args: IOCTL data + * + * This function computes the pitch of the dumb buffer and rounds it up to an + * integer number of bytes per pixel. Drivers for hardware that doesn't have + * any additional restrictions on the pitch can directly use this function as + * their &drm_driver.dumb_create callback. + * + * For hardware with additional restrictions, drivers can adjust the fields + * set up by userspace before calling into this function. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev, + struct drm_mode_create_dumb *args) +{ + u32 min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8); + struct drm_gem_shmem_object *shmem; + + if (!args->pitch || !args->size) { + args->pitch = min_pitch; + args->size = args->pitch * args->height; + } else { + /* ensure sane minimum values */ + if (args->pitch < min_pitch) + args->pitch = min_pitch; + if (args->size < args->pitch * args->height) + args->size = args->pitch * args->height; + } + + shmem = drm_gem_shmem_create_with_handle(file, dev, args->size, &args->handle); + + return PTR_ERR_OR_ZERO(shmem); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_dumb_create); + +static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf) +{ + struct vm_area_struct *vma = vmf->vma; + struct drm_gem_object *obj = vma->vm_private_data; + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + /* We don't use vmf->pgoff since that has the fake offset: */ + pgoff_t pgoff = (vmf->address - vma->vm_start) >> PAGE_SHIFT; + loff_t num_pages = obj->size >> PAGE_SHIFT; + struct page *page; + + if (pgoff > num_pages || WARN_ON_ONCE(!shmem->pages)) + return VM_FAULT_SIGBUS; + + page = shmem->pages[pgoff]; + + return vmf_insert_page(vma, vmf->address, page); +} + +static void drm_gem_shmem_vm_close(struct vm_area_struct *vma) +{ + struct drm_gem_object *obj = vma->vm_private_data; + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + drm_gem_shmem_put_pages(shmem); + drm_gem_vm_close(vma); +} + +const struct vm_operations_struct drm_gem_shmem_vm_ops = { + .fault = drm_gem_shmem_fault, + .open = drm_gem_vm_open, + .close = drm_gem_shmem_vm_close, +}; +EXPORT_SYMBOL_GPL(drm_gem_shmem_vm_ops); + +static int drm_gem_shmem_mmap_obj(struct drm_gem_shmem_object *shmem, + struct vm_area_struct *vma) +{ + int ret; + + ret = drm_gem_shmem_get_pages(shmem); + if (ret) { + drm_gem_vm_close(vma); + return ret; + } + + /* VM_PFNMAP was set by drm_gem_mmap() */ + vma->vm_flags &= ~VM_PFNMAP; + vma->vm_flags |= VM_MIXEDMAP; + vma->vm_page_prot = vm_get_page_prot(vma->vm_flags); + + fput(vma->vm_file); + get_file(shmem->base.filp); + vma->vm_pgoff = 0; + vma->vm_file = shmem->base.filp; + + return 0; +} + +/** + * drm_gem_shmem_mmap - Memory-map a shmem GEM object + * @filp: File object + * @vma: VMA for the area to be mapped + * + * This function implements an augmented version of the GEM DRM file mmap + * operation for shmem objects. Drivers which employ the shmem helpers should + * use this function as their &file_operations.mmap handler in the DRM device file's + * file_operations structure. + * + * Instead of directly referencing this function, drivers should use the + * DEFINE_DRM_GEM_SHMEM_FOPS() macro. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +int drm_gem_shmem_mmap(struct file *filp, struct vm_area_struct *vma) +{ + struct drm_gem_shmem_object *shmem; + int ret; + + ret = drm_gem_mmap(filp, vma); + if (ret) + return ret; + + shmem = to_drm_gem_shmem_obj(vma->vm_private_data); + + return drm_gem_shmem_mmap_obj(shmem, vma); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_mmap); + +/** + * drm_gem_shmem_print_info() - Print &drm_gem_shmem_object info for debugfs + * @p: DRM printer + * @indent: Tab indentation level + * @obj: GEM object + */ +void drm_gem_shmem_print_info(struct drm_printer *p, unsigned int indent, + const struct drm_gem_object *obj) +{ + const struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + drm_printf_indent(p, indent, "pages_use_count=%u\n", shmem->pages_use_count); + drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr); + drm_printf_indent(p, indent, "vmap_use_count=%u\n", shmem->vmap_use_count); +} +EXPORT_SYMBOL(drm_gem_shmem_print_info); + +/** + * drm_gem_shmem_get_sg_table - Provide a scatter/gather table of pinned + * pages for a shmem GEM object + * @obj: GEM object + * + * This function exports a scatter/gather table suitable for PRIME usage by + * calling the standard DMA mapping API. + * + * Returns: + * A pointer to the scatter/gather table of pinned pages or NULL on failure. + */ +struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_object *obj) +{ + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + + return drm_prime_pages_to_sg(shmem->pages, obj->size >> PAGE_SHIFT); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_get_sg_table); + +/** + * drm_gem_shmem_prime_import_sg_table - Produce a shmem GEM object from + * another driver's scatter/gather table of pinned pages + * @dev: Device to import into + * @attach: DMA-BUF attachment + * @sgt: Scatter/gather table of pinned pages + * + * This function imports a scatter/gather table exported via DMA-BUF by + * another driver. Drivers that use the shmem helpers should set this as their + * &drm_driver.gem_prime_import_sg_table callback. + * + * Returns: + * A pointer to a newly created GEM object or an ERR_PTR-encoded negative + * error code on failure. + */ +struct drm_gem_object * +drm_gem_shmem_prime_import_sg_table(struct drm_device *dev, + struct dma_buf_attachment *attach, + struct sg_table *sgt) +{ + size_t size = PAGE_ALIGN(attach->dmabuf->size); + size_t npages = size >> PAGE_SHIFT; + struct drm_gem_shmem_object *shmem; + int ret; + + shmem = drm_gem_shmem_create(dev, size); + if (IS_ERR(shmem)) + return ERR_CAST(shmem); + + shmem->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL); + if (!shmem->pages) { + ret = -ENOMEM; + goto err_free_gem; + } + + ret = drm_prime_sg_to_page_addr_arrays(sgt, shmem->pages, NULL, npages); + if (ret < 0) + goto err_free_array; + + shmem->sgt = sgt; + shmem->pages_use_count = 1; /* Permanently pinned from our point of view */ + + DRM_DEBUG_PRIME("size = %zu\n", size); + + return &shmem->base; + +err_free_array: + kvfree(shmem->pages); +err_free_gem: + drm_gem_object_put_unlocked(&shmem->base); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_sg_table); + +/** + * drm_gem_shmem_prime_mmap - Memory-map an exported shmem GEM object + * @obj: GEM object + * @vma: VMA for the area to be mapped + * + * This function maps a buffer imported via DRM PRIME into a userspace + * process's address space. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +int drm_gem_shmem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma) +{ + struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj); + int ret; + + ret = drm_gem_mmap_obj(obj, obj->size, vma); + if (ret) + return ret; + + return drm_gem_shmem_mmap_obj(shmem, vma); +} +EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_mmap); diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h new file mode 100644 index 000000000000..94ec99fdcffc --- /dev/null +++ b/include/drm/drm_gem_shmem_helper.h @@ -0,0 +1,153 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef __DRM_GEM_SHMEM_HELPER_H__ +#define __DRM_GEM_SHMEM_HELPER_H__ + +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/mutex.h> + +#include <drm/drm_file.h> +#include <drm/drm_gem.h> +#include <drm/drm_ioctl.h> +#include <drm/drm_prime.h> + +struct dma_buf_attachment; +struct drm_mode_create_dumb; +struct drm_printer; +struct sg_table; + +/** + * struct drm_gem_shmem_object - GEM object backed by shmem + */ +struct drm_gem_shmem_object { + /** + * @base: Base GEM object + */ + struct drm_gem_object base; + + /** + * @pages_lock: Protects the page table and use count + */ + struct mutex pages_lock; + + /** + * @pages: Page table + */ + struct page **pages; + + /** + * @pages_use_count: + * + * Reference count on the pages table. + * The pages are put when the count reaches zero. + */ + unsigned int pages_use_count; + + /** + * @pages_mark_dirty_on_put: + * + * Mark pages as dirty when they are put. + */ + unsigned int pages_mark_dirty_on_put : 1; + + /** + * @pages_mark_accessed_on_put: + * + * Mark pages as accessed when they are put. + */ + unsigned int pages_mark_accessed_on_put : 1; + + /** + * @sgt: Scatter/gather table for imported PRIME buffers + */ + struct sg_table *sgt; + + /** + * @vmap_lock: Protects the vmap address and use count + */ + struct mutex vmap_lock; + + /** + * @vaddr: Kernel virtual address of the backing memory + */ + void *vaddr; + + /** + * @vmap_use_count: + * + * Reference count on the virtual address. + * The address are un-mapped when the count reaches zero. + */ + unsigned int vmap_use_count; +}; + +#define to_drm_gem_shmem_obj(obj) \ + container_of(obj, struct drm_gem_shmem_object, base) + +/** + * DEFINE_DRM_GEM_SHMEM_FOPS() - Macro to generate file operations for shmem drivers + * @name: name for the generated structure + * + * This macro autogenerates a suitable &struct file_operations for shmem based + * drivers, which can be assigned to &drm_driver.fops. Note that this structure + * cannot be shared between drivers, because it contains a reference to the + * current module using THIS_MODULE. + * + * Note that the declaration is already marked as static - if you need a + * non-static version of this you're probably doing it wrong and will break the + * THIS_MODULE reference by accident. + */ +#define DEFINE_DRM_GEM_SHMEM_FOPS(name) \ + static const struct file_operations name = {\ + .owner = THIS_MODULE,\ + .open = drm_open,\ + .release = drm_release,\ + .unlocked_ioctl = drm_ioctl,\ + .compat_ioctl = drm_compat_ioctl,\ + .poll = drm_poll,\ + .read = drm_read,\ + .llseek = noop_llseek,\ + .mmap = drm_gem_shmem_mmap, \ + } + +struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size); +void drm_gem_shmem_free_object(struct drm_gem_object *obj); + +int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem); +void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem); +int drm_gem_shmem_pin(struct drm_gem_object *obj); +void drm_gem_shmem_unpin(struct drm_gem_object *obj); +void *drm_gem_shmem_vmap(struct drm_gem_object *obj); +void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr); + +int drm_gem_shmem_dumb_create(struct drm_file *file, struct drm_device *dev, + struct drm_mode_create_dumb *args); + +int drm_gem_shmem_mmap(struct file *filp, struct vm_area_struct *vma); + +extern const struct vm_operations_struct drm_gem_shmem_vm_ops; + +void drm_gem_shmem_print_info(struct drm_printer *p, unsigned int indent, + const struct drm_gem_object *obj); + +struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_object *obj); +struct drm_gem_object * +drm_gem_shmem_prime_import_sg_table(struct drm_device *dev, + struct dma_buf_attachment *attach, + struct sg_table *sgt); +int drm_gem_shmem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma); + +/** + * DRM_GEM_SHMEM_DRIVER_OPS - Default shmem GEM operations + * + * This macro provides a shortcut for setting the shmem GEM operations in + * the &drm_driver structure. + */ +#define DRM_GEM_SHMEM_DRIVER_OPS \ + .prime_handle_to_fd = drm_gem_prime_handle_to_fd, \ + .prime_fd_to_handle = drm_gem_prime_fd_to_handle, \ + .gem_prime_import_sg_table = drm_gem_shmem_prime_import_sg_table, \ + .dumb_create = drm_gem_shmem_dumb_create + +#endif /* __DRM_GEM_SHMEM_HELPER_H__ */
This adds a library for shmem backed GEM objects. Signed-off-by: Noralf Trønnes <noralf@tronnes.org> --- Changes since version 3: - Drop cache modes (Thomas Hellstrom) - Add a GEM attached vtable Documentation/gpu/drm-kms-helpers.rst | 12 + drivers/gpu/drm/Kconfig | 6 + drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/drm_gem_shmem_helper.c | 586 +++++++++++++++++++++++++++++++++ include/drm/drm_gem_shmem_helper.h | 153 +++++++++ 5 files changed, 758 insertions(+) create mode 100644 drivers/gpu/drm/drm_gem_shmem_helper.c create mode 100644 include/drm/drm_gem_shmem_helper.h