From 9c5a3621427da68afe6a078cadf807d2c8cc1d12 Mon Sep 17 00:00:00 2001 From: Akinobu Mita Date: Wed, 4 Jun 2014 16:06:50 -0700 Subject: x86: enable DMA CMA with swiotlb The DMA Contiguous Memory Allocator support on x86 is disabled when swiotlb config option is enabled. So DMA CMA is always disabled on x86_64 because swiotlb is always enabled. This attempts to support for DMA CMA with enabling swiotlb config option. The contiguous memory allocator on x86 is integrated in the function dma_generic_alloc_coherent() which is .alloc callback in nommu_dma_ops for dma_alloc_coherent(). x86_swiotlb_alloc_coherent() which is .alloc callback in swiotlb_dma_ops tries to allocate with dma_generic_alloc_coherent() firstly and then swiotlb_alloc_coherent() is called as a fallback. The main part of supporting DMA CMA with swiotlb is that changing x86_swiotlb_free_coherent() which is .free callback in swiotlb_dma_ops for dma_free_coherent() so that it can distinguish memory allocated by dma_generic_alloc_coherent() from one allocated by swiotlb_alloc_coherent() and release it with dma_generic_free_coherent() which can handle contiguous memory. This change requires making is_swiotlb_buffer() global function. This also needs to change .free callback in the dma_map_ops for amd_gart and sta2x11, because these dma_ops are also using dma_generic_alloc_coherent(). Signed-off-by: Akinobu Mita Acked-by: Marek Szyprowski Acked-by: Konrad Rzeszutek Wilk Cc: David Woodhouse Cc: Don Dutile Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: Andi Kleen Cc: Yinghai Lu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/kernel/pci-swiotlb.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'arch/x86/kernel/pci-swiotlb.c') diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c index 6c483ba98b9c..77dd0ad58be4 100644 --- a/arch/x86/kernel/pci-swiotlb.c +++ b/arch/x86/kernel/pci-swiotlb.c @@ -14,7 +14,7 @@ #include int swiotlb __read_mostly; -static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size, +void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t flags, struct dma_attrs *attrs) { @@ -28,11 +28,14 @@ static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size, return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags); } -static void x86_swiotlb_free_coherent(struct device *dev, size_t size, +void x86_swiotlb_free_coherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_addr, struct dma_attrs *attrs) { - swiotlb_free_coherent(dev, size, vaddr, dma_addr); + if (is_swiotlb_buffer(dma_to_phys(dev, dma_addr))) + swiotlb_free_coherent(dev, size, vaddr, dma_addr); + else + dma_generic_free_coherent(dev, size, vaddr, dma_addr, attrs); } static struct dma_map_ops swiotlb_dma_ops = { -- cgit v1.2.3