Messages in this thread Patch in this message | | | Date | Tue, 9 Sep 2008 03:06:44 +0900 | Subject | Re: [PATCH 0/3] fix alloc_coherent allocation issues (tip/x86/iommu) | From | FUJITA Tomonori <> |
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On Mon, 8 Sep 2008 19:35:25 +0200 Ingo Molnar <mingo@elte.hu> wrote:
> > btw., the build became very noisy - see the messages below. > > Ingo > > ----------> > init/initramfs.c:517: warning: 'clean_rootfs' defined but not used > In file included from include/linux/dma-mapping.h:53, > from include/linux/dmaengine.h:30, > from include/linux/skbuff.h:30, > from include/linux/netlink.h:156, > from include/linux/genetlink.h:5, > from include/net/genetlink.h:5, > from include/linux/taskstats_kern.h:13, > from init/main.c:48: > include/asm/dma-mapping.h: In function 'dma_alloc_coherent_gfp_flags': > include/asm/dma-mapping.h:258: warning: unused variable 'dma_mask' > In file included from include/linux/dma-mapping.h:53, > from arch/x86/kernel/pci-dma.c:2:
Very sorry, I should have compile this on X86_32...
Can you replace the fourth patch with this?
= From: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Subject: [PATCH] x86: dma_alloc_coherent sets gfp flags properly
Non real IOMMU implemenations (which doesn't do virtual mappings, e.g. swiotlb, pci-nommu, etc) need to use proper gfp flags and dma_mask to allocate pages in their own dma_alloc_coherent() (allocated page need to be suitable for device's coherent_dma_mask).
This patch makes dma_alloc_coherent do this job so that IOMMUs don't need to take care of it any more.
Real IOMMU implemenataions can simply ignore the gfp flags.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> --- arch/x86/kernel/pci-nommu.c | 19 ++----------------- include/asm-x86/dma-mapping.h | 32 ++++++++++++++++++++++++++++---- 2 files changed, 30 insertions(+), 21 deletions(-)
diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c index ada1c87..8e398b5 100644 --- a/arch/x86/kernel/pci-nommu.c +++ b/arch/x86/kernel/pci-nommu.c @@ -80,26 +80,11 @@ nommu_alloc_coherent(struct device *hwdev, size_t size, int node; struct page *page; - gfp |= __GFP_ZERO; - - dma_mask = hwdev->coherent_dma_mask; - if (!dma_mask) - dma_mask = *(hwdev->dma_mask); + dma_mask = dma_alloc_coherent_mask(hwdev, gfp); - if (dma_mask < DMA_24BIT_MASK) - return NULL; + gfp |= __GFP_ZERO; node = dev_to_node(hwdev); - -#ifdef CONFIG_X86_64 - if (dma_mask <= DMA_32BIT_MASK && !(gfp & GFP_DMA)) - gfp |= GFP_DMA32; -#endif - - /* No alloc-free penalty for ISA devices */ - if (dma_mask == DMA_24BIT_MASK) - gfp |= GFP_DMA; - again: page = alloc_pages_node(node, gfp, get_order(size)); if (!page) diff --git a/include/asm-x86/dma-mapping.h b/include/asm-x86/dma-mapping.h index 9d6dcf4..8bb3108 100644 --- a/include/asm-x86/dma-mapping.h +++ b/include/asm-x86/dma-mapping.h @@ -241,6 +241,29 @@ static inline int dma_get_cache_alignment(void) return boot_cpu_data.x86_clflush_size; } +static inline unsigned long dma_alloc_coherent_mask(struct device *dev, + gfp_t gfp) +{ + unsigned long dma_mask = 0; + + dma_mask = dev->coherent_dma_mask; + if (!dma_mask) + dma_mask = (gfp & GFP_DMA) ? DMA_24BIT_MASK : DMA_32BIT_MASK; + + return dma_mask; +} + +static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp) +{ +#ifdef CONFIG_X86_64 + unsigned long dma_mask = dma_alloc_coherent_mask(dev, gfp); + + if (dma_mask <= DMA_32BIT_MASK && !(gfp & GFP_DMA)) + gfp |= GFP_DMA32; +#endif + return gfp; +} + static inline void * dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp) @@ -261,10 +284,11 @@ dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, if (!dev->dma_mask) return NULL; - if (ops->alloc_coherent) - return ops->alloc_coherent(dev, size, - dma_handle, gfp); - return NULL; + if (!ops->alloc_coherent) + return NULL; + + return ops->alloc_coherent(dev, size, dma_handle, + dma_alloc_coherent_gfp_flags(dev, gfp)); } static inline void dma_free_coherent(struct device *dev, size_t size, -- 1.5.5.GIT
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