| Message ID | 20190816130013.31154-8-hch@lst.de (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [01/11] xen/arm: use dma-noncoherent.h calls for xen-swiotlb cache maintainance | expand |
Hi, On 8/16/19 2:00 PM, Christoph Hellwig wrote: > Merge the various page-coherent.h files into a single one that either > provides prototypes or stubs depending on the need for cache > maintainance. > > For extra benefits alo include <xen/page-coherent.h> in the file > actually implementing the interfaces provided. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > arch/arm/include/asm/xen/page-coherent.h | 2 -- > arch/arm/xen/mm.c | 1 + > arch/arm64/include/asm/xen/page-coherent.h | 2 -- > arch/x86/include/asm/xen/page-coherent.h | 22 ------------------ > drivers/xen/swiotlb-xen.c | 4 +--- > include/Kbuild | 2 +- > include/xen/{arm => }/page-coherent.h | 27 +++++++++++++++++++--- I am not sure I agree with this rename. The implementation of the helpers are very Arm specific as this is assuming Dom0 is 1:1 mapped. This was necessary due to the lack of IOMMU on Arm platforms back then. But this is now a pain to get rid of it on newer platform... Cheers,
On Fri, Aug 16, 2019 at 11:40:43PM +0100, Julien Grall wrote: > I am not sure I agree with this rename. The implementation of the helpers > are very Arm specific as this is assuming Dom0 is 1:1 mapped. > > This was necessary due to the lack of IOMMU on Arm platforms back then. > But this is now a pain to get rid of it on newer platform... So if you look at the final version of the header after the whole series, what assumes a 1:1 mapping? It all just is if (pfn_valid()) local cache sync; else call into the arch code; are you concerned that the local cache sync might have to be split up more for a non-1:1 map in that case? We could just move the xen_dma_* routines into the arch instead of __xen_dma, but it really helps to have a common interface header.
Hi Christoph, On 8/17/19 7:50 AM, Christoph Hellwig wrote: > On Fri, Aug 16, 2019 at 11:40:43PM +0100, Julien Grall wrote: >> I am not sure I agree with this rename. The implementation of the helpers >> are very Arm specific as this is assuming Dom0 is 1:1 mapped. >> >> This was necessary due to the lack of IOMMU on Arm platforms back then. >> But this is now a pain to get rid of it on newer platform... > > So if you look at the final version of the header after the whole > series, what assumes a 1:1 mapping? It all just is > > if (pfn_valid()) > local cache sync; > else > call into the arch code; In the context of Xen Arm, the dev_addr is a host physical address. From my understanding pfn_valid() is dealing with a guest physical frame. Therefore by passing PFN_DOWN(dev_addr) in argument you assume that the host and guest address spaces are the same. > > are you concerned that the local cache sync might have to be split > up more for a non-1:1 map in that case? We could just movea > the xen_dma_* routines into the arch instead of __xen_dma, but it > really helps to have a common interface header. Moving xen_dma_* routines into the arch would be a good option. Although, I would still consider a stub version for arch not requiring specific DMA. Cheers,
diff --git a/arch/arm/include/asm/xen/page-coherent.h b/arch/arm/include/asm/xen/page-coherent.h deleted file mode 100644 index 27e984977402..000000000000 --- a/arch/arm/include/asm/xen/page-coherent.h +++ /dev/null @@ -1,2 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#include <xen/arm/page-coherent.h> diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index a59980f1aa54..85482cdda1e5 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -15,6 +15,7 @@ #include <xen/interface/grant_table.h> #include <xen/interface/memory.h> #include <xen/page.h> +#include <xen/page-coherent.h> #include <xen/swiotlb-xen.h> #include <asm/cacheflush.h> diff --git a/arch/arm64/include/asm/xen/page-coherent.h b/arch/arm64/include/asm/xen/page-coherent.h deleted file mode 100644 index 27e984977402..000000000000 --- a/arch/arm64/include/asm/xen/page-coherent.h +++ /dev/null @@ -1,2 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#include <xen/arm/page-coherent.h> diff --git a/arch/x86/include/asm/xen/page-coherent.h b/arch/x86/include/asm/xen/page-coherent.h deleted file mode 100644 index 8ee33c5edded..000000000000 --- a/arch/x86/include/asm/xen/page-coherent.h +++ /dev/null @@ -1,22 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _ASM_X86_XEN_PAGE_COHERENT_H -#define _ASM_X86_XEN_PAGE_COHERENT_H - -#include <asm/page.h> -#include <linux/dma-mapping.h> - -static inline void xen_dma_map_page(struct device *hwdev, struct page *page, - dma_addr_t dev_addr, unsigned long offset, size_t size, - enum dma_data_direction dir, unsigned long attrs) { } - -static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, - size_t size, enum dma_data_direction dir, - unsigned long attrs) { } - -static inline void xen_dma_sync_single_for_cpu(struct device *hwdev, - dma_addr_t handle, size_t size, enum dma_data_direction dir) { } - -static inline void xen_dma_sync_single_for_device(struct device *hwdev, - dma_addr_t handle, size_t size, enum dma_data_direction dir) { } - -#endif /* _ASM_X86_XEN_PAGE_COHERENT_H */ diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index f9dd4cb6e4b3..7b23929854e7 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -31,12 +31,10 @@ #include <linux/export.h> #include <xen/swiotlb-xen.h> #include <xen/page.h> +#include <xen/page-coherent.h> #include <xen/xen-ops.h> #include <xen/hvc-console.h> -#include <asm/dma-mapping.h> -#include <asm/xen/page-coherent.h> - #include <trace/events/swiotlb.h> /* * Used to do a quick range check in swiotlb_tbl_unmap_single and diff --git a/include/Kbuild b/include/Kbuild index c38f0d46b267..e2ae52ef9e1e 100644 --- a/include/Kbuild +++ b/include/Kbuild @@ -1189,7 +1189,6 @@ header-test- += video/vga.h header-test- += video/w100fb.h header-test- += xen/acpi.h header-test- += xen/arm/hypercall.h -header-test- += xen/arm/page-coherent.h header-test- += xen/arm/page.h header-test- += xen/balloon.h header-test- += xen/events.h @@ -1231,6 +1230,7 @@ header-test- += xen/interface/xen.h header-test- += xen/interface/xenpmu.h header-test- += xen/mem-reservation.h header-test- += xen/page.h +header-test- += xen/page-coherent.h header-test- += xen/platform_pci.h header-test- += xen/swiotlb-xen.h header-test- += xen/xen-front-pgdir-shbuf.h diff --git a/include/xen/arm/page-coherent.h b/include/xen/page-coherent.h similarity index 76% rename from include/xen/arm/page-coherent.h rename to include/xen/page-coherent.h index 4294a31305ca..7c32944de051 100644 --- a/include/xen/arm/page-coherent.h +++ b/include/xen/page-coherent.h @@ -1,10 +1,12 @@ /* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _XEN_ARM_PAGE_COHERENT_H -#define _XEN_ARM_PAGE_COHERENT_H +#ifndef _XEN_PAGE_COHERENT_H +#define _XEN_PAGE_COHERENT_H #include <linux/dma-mapping.h> #include <asm/page.h> +#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \ + defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) void __xen_dma_map_page(struct device *hwdev, struct page *page, dma_addr_t dev_addr, unsigned long offset, size_t size, enum dma_data_direction dir, unsigned long attrs); @@ -71,5 +73,24 @@ static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, else __xen_dma_unmap_page(hwdev, handle, size, dir, attrs); } +#else +static inline void xen_dma_map_page(struct device *hwdev, struct page *page, + dma_addr_t dev_addr, unsigned long offset, size_t size, + enum dma_data_direction dir, unsigned long attrs) +{ +} +static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle, + size_t size, enum dma_data_direction dir, unsigned long attrs) +{ +} +static inline void xen_dma_sync_single_for_cpu(struct device *hwdev, + dma_addr_t handle, size_t size, enum dma_data_direction dir) +{ +} +static inline void xen_dma_sync_single_for_device(struct device *hwdev, + dma_addr_t handle, size_t size, enum dma_data_direction dir) +{ +} +#endif -#endif /* _XEN_ARM_PAGE_COHERENT_H */ +#endif /* _XEN_PAGE_COHERENT_H */
Merge the various page-coherent.h files into a single one that either provides prototypes or stubs depending on the need for cache maintainance. For extra benefits alo include <xen/page-coherent.h> in the file actually implementing the interfaces provided. Signed-off-by: Christoph Hellwig <hch@lst.de> --- arch/arm/include/asm/xen/page-coherent.h | 2 -- arch/arm/xen/mm.c | 1 + arch/arm64/include/asm/xen/page-coherent.h | 2 -- arch/x86/include/asm/xen/page-coherent.h | 22 ------------------ drivers/xen/swiotlb-xen.c | 4 +--- include/Kbuild | 2 +- include/xen/{arm => }/page-coherent.h | 27 +++++++++++++++++++--- 7 files changed, 27 insertions(+), 33 deletions(-) delete mode 100644 arch/arm/include/asm/xen/page-coherent.h delete mode 100644 arch/arm64/include/asm/xen/page-coherent.h delete mode 100644 arch/x86/include/asm/xen/page-coherent.h rename include/xen/{arm => }/page-coherent.h (76%)