This patch adds support for CMA to dma-mapping subsystem for x86 architecture that uses common pci-dma/pci-nommu implementation. This allows to test CMA on KVM/QEMU and a lot of common x86 boxes.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com CC: Michal Nazarewicz mina86@mina86.com --- arch/x86/Kconfig | 1 + arch/x86/include/asm/dma-contiguous.h | 13 +++++++++++++ arch/x86/include/asm/dma-mapping.h | 4 ++++ arch/x86/kernel/pci-dma.c | 18 ++++++++++++++++-- arch/x86/kernel/pci-nommu.c | 8 +------- arch/x86/kernel/setup.c | 2 ++ 6 files changed, 37 insertions(+), 9 deletions(-) create mode 100644 arch/x86/include/asm/dma-contiguous.h
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 82830ef..b120c80 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -29,6 +29,7 @@ config X86 select ARCH_WANT_OPTIONAL_GPIOLIB select ARCH_WANT_FRAME_POINTERS select HAVE_DMA_ATTRS + select HAVE_DMA_CONTIGUOUS if !SWIOTLB select HAVE_KRETPROBES select HAVE_OPTPROBES select HAVE_FTRACE_MCOUNT_RECORD diff --git a/arch/x86/include/asm/dma-contiguous.h b/arch/x86/include/asm/dma-contiguous.h new file mode 100644 index 0000000..8fb117d --- /dev/null +++ b/arch/x86/include/asm/dma-contiguous.h @@ -0,0 +1,13 @@ +#ifndef ASMX86_DMA_CONTIGUOUS_H +#define ASMX86_DMA_CONTIGUOUS_H + +#ifdef __KERNEL__ + +#include <linux/device.h> +#include <linux/dma-contiguous.h> +#include <asm-generic/dma-contiguous.h> + +static inline void dma_contiguous_early_fixup(phys_addr_t base, unsigned long size) { } + +#endif +#endif diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h index ed3065f..90ac6f0 100644 --- a/arch/x86/include/asm/dma-mapping.h +++ b/arch/x86/include/asm/dma-mapping.h @@ -13,6 +13,7 @@ #include <asm/io.h> #include <asm/swiotlb.h> #include <asm-generic/dma-coherent.h> +#include <linux/dma-contiguous.h>
#ifdef CONFIG_ISA # define ISA_DMA_BIT_MASK DMA_BIT_MASK(24) @@ -61,6 +62,9 @@ extern int dma_set_mask(struct device *dev, u64 mask); extern void *dma_generic_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr, gfp_t flag);
+extern void dma_generic_free_coherent(struct device *dev, size_t size, + void *vaddr, dma_addr_t dma_addr); + static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size) { if (!dev->dma_mask) diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c index 80dc793..f4abafc 100644 --- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -90,14 +90,18 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr, gfp_t flag) { unsigned long dma_mask; - struct page *page; + struct page *page = NULL; + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; dma_addr_t addr;
dma_mask = dma_alloc_coherent_mask(dev, flag);
flag |= __GFP_ZERO; again: - page = alloc_pages_node(dev_to_node(dev), flag, get_order(size)); + if (!(flag & GFP_ATOMIC)) + page = dma_alloc_from_contiguous(dev, count, get_order(size)); + if (!page) + page = alloc_pages_node(dev_to_node(dev), flag, get_order(size)); if (!page) return NULL;
@@ -117,6 +121,16 @@ again: return page_address(page); }
+void dma_generic_free_coherent(struct device *dev, size_t size, void *vaddr, + dma_addr_t dma_addr) +{ + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; + struct page *page = virt_to_page(vaddr); + + if (!dma_release_from_contiguous(dev, page, count)) + free_pages((unsigned long)vaddr, get_order(size)); +} + /* * See <Documentation/x86/x86_64/boot-options.txt> for the iommu kernel * parameter documentation. diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c index 3af4af8..656566f 100644 --- a/arch/x86/kernel/pci-nommu.c +++ b/arch/x86/kernel/pci-nommu.c @@ -74,12 +74,6 @@ static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg, return nents; }
-static void nommu_free_coherent(struct device *dev, size_t size, void *vaddr, - dma_addr_t dma_addr) -{ - free_pages((unsigned long)vaddr, get_order(size)); -} - static void nommu_sync_single_for_device(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir) @@ -97,7 +91,7 @@ static void nommu_sync_sg_for_device(struct device *dev,
struct dma_map_ops nommu_dma_ops = { .alloc_coherent = dma_generic_alloc_coherent, - .free_coherent = nommu_free_coherent, + .free_coherent = dma_generic_free_coherent, .map_sg = nommu_map_sg, .map_page = nommu_map_page, .sync_single_for_device = nommu_sync_single_for_device, diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index afaf384..6c9efb5 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -50,6 +50,7 @@ #include <asm/pci-direct.h> #include <linux/init_ohci1394_dma.h> #include <linux/kvm_para.h> +#include <linux/dma-contiguous.h>
#include <linux/errno.h> #include <linux/kernel.h> @@ -944,6 +945,7 @@ void __init setup_arch(char **cmdline_p) } #endif memblock.current_limit = get_max_mapped(); + dma_contiguous_reserve(0);
/* * NOTE: On x86-32, only from this point on, fixmaps are ready for use.