Messages in this thread Patch in this message | | | Date | Thu, 4 Sep 2008 03:54:26 +0900 | Subject | Re: [PATCH 1/3] x86: remove the NULL device hack in dma-mapping.h | From | FUJITA Tomonori <> |
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On Thu, 4 Sep 2008 03:04:23 +0900 FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> wrote:
> dma_alloc_coherent in dma-mapping.h has a hack to use > x86_dma_fallback_dev if a pointer to a device is NULL. Some of IOMMUs > don't need such hack. The hack also makes it difficult for IOMMUs to > make a proper decision because the hack hides the information. > > Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> > --- > arch/x86/kernel/pci-swiotlb_64.c | 15 ++++++++++++++- > include/asm-x86/dma-mapping.h | 9 +-------- > 2 files changed, 15 insertions(+), 9 deletions(-) > > diff --git a/arch/x86/kernel/pci-swiotlb_64.c b/arch/x86/kernel/pci-swiotlb_64.c > index c4ce033..f3d8d0e 100644 > --- a/arch/x86/kernel/pci-swiotlb_64.c > +++ b/arch/x86/kernel/pci-swiotlb_64.c > @@ -11,6 +11,8 @@ > > int swiotlb __read_mostly; > > +extern struct device x86_dma_fallback_dev; > + > static dma_addr_t > swiotlb_map_single_phys(struct device *hwdev, phys_addr_t paddr, size_t size, > int direction) > @@ -18,9 +20,20 @@ swiotlb_map_single_phys(struct device *hwdev, phys_addr_t paddr, size_t size, > return swiotlb_map_single(hwdev, phys_to_virt(paddr), size, direction); > } > > +static void *x86_swiotlb_alloc_coherent(struct device *dev, size_t size, > + dma_addr_t *dma_handle, gfp_t gfp) > +{ > + if (!dev) { > + dev = &x86_dma_fallback_dev; > + gfp |= GFP_DMA; > + } > + > + return swiotlb_alloc_coherent(dev, size, dma_handle, gfp); > +} > + > struct dma_mapping_ops swiotlb_dma_ops = { > .mapping_error = swiotlb_dma_mapping_error, > - .alloc_coherent = swiotlb_alloc_coherent, > + .alloc_coherent = x86_swiotlb_alloc_coherent, > .free_coherent = swiotlb_free_coherent, > .map_single = swiotlb_map_single_phys, > .unmap_single = swiotlb_unmap_single, > diff --git a/include/asm-x86/dma-mapping.h b/include/asm-x86/dma-mapping.h > index bc6c8df..3463702 100644 > --- a/include/asm-x86/dma-mapping.h > +++ b/include/asm-x86/dma-mapping.h > @@ -14,7 +14,6 @@ > > extern dma_addr_t bad_dma_address; > extern int iommu_merge; > -extern struct device x86_dma_fallback_dev;
Oops, removing extern struct device x86_dma_fallback_dev breaks the GART IOMMU. Here's an updated patch.
= From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Subject: [PATCH] x86: remove the NULL device hack in dma-mapping.h
dma_alloc_coherent in dma-mapping.h has a hack to use x86_dma_fallback_dev if a pointer to a device is NULL. Some of IOMMUs don't need such hack. The hack also makes it difficult for IOMMUs to make a proper decision because the hack hides the information.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> --- arch/x86/kernel/pci-swiotlb_64.c | 13 ++++++++++++- include/asm-x86/dma-mapping.h | 8 +------- 2 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kernel/pci-swiotlb_64.c b/arch/x86/kernel/pci-swiotlb_64.c index c4ce033..d2463de 100644 --- a/arch/x86/kernel/pci-swiotlb_64.c +++ b/arch/x86/kernel/pci-swiotlb_64.c @@ -18,9 +18,20 @@ swiotlb_map_single_phys(struct device *hwdev, phys_addr_t paddr, size_t size, return swiotlb_map_single(hwdev, phys_to_virt(paddr), size, direction); } +static void *x86_swiotlb_alloc_coherent(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t gfp) +{ + if (!dev) { + dev = &x86_dma_fallback_dev; + gfp |= GFP_DMA; + } + + return swiotlb_alloc_coherent(dev, size, dma_handle, gfp); +} + struct dma_mapping_ops swiotlb_dma_ops = { .mapping_error = swiotlb_dma_mapping_error, - .alloc_coherent = swiotlb_alloc_coherent, + .alloc_coherent = x86_swiotlb_alloc_coherent, .free_coherent = swiotlb_free_coherent, .map_single = swiotlb_map_single_phys, .unmap_single = swiotlb_unmap_single, diff --git a/include/asm-x86/dma-mapping.h b/include/asm-x86/dma-mapping.h index bc6c8df..e59607d 100644 --- a/include/asm-x86/dma-mapping.h +++ b/include/asm-x86/dma-mapping.h @@ -251,14 +251,8 @@ dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, if (dma_alloc_from_coherent(dev, size, dma_handle, &memory)) return memory; - if (!dev) { - dev = &x86_dma_fallback_dev; - gfp |= GFP_DMA; - } - if (ops->alloc_coherent) - return ops->alloc_coherent(dev, size, - dma_handle, gfp); + return ops->alloc_coherent(dev, size, dma_handle, gfp); return NULL; } -- 1.5.5.GIT
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