Commit 9adc5374 ('common: dma-mapping: introduce mmap method') added a generic method for implementing mmap user call to dma_map_ops structure.

This patch converts ARM and PowerPC architectures (the only providers of dma_mmap_coherent/dma_mmap_writecombine calls) to use this generic dma_map_ops based call and adds a generic cross architecture definition for dma_mmap_attrs, dma_mmap_coherent, dma_mmap_writecombine functions.

The generic mmap virt_to_page-based fallback implementation is provided for architectures which don't provide their own implementation for mmap method.

Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Reviewed-by: Kyungmin Park kyungmin.park@samsung.com --- Hello,

This patch is a continuation of my works on dma-mapping cleanup and unification. Previous works (commit 58bca4a8fa ('Merge branch 'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping') has been merged to v3.4-rc2. Now I've focuses on providing implementation for all architectures so the drivers and some cross-architecture common helpers (like for example videobuf2) can start using this new api.

I'm not 100% sure if the PowerPC changes are correct. The cases of dma_iommu_ops and vio_dma_mapping_ops are a bit suspicious for me, but I have no way to test and check if my changes works for that hardware.

Best regards Marek Szyprowski Samsung Poland R&D Center

--- arch/arm/include/asm/dma-mapping.h | 19 --------------- arch/powerpc/include/asm/dma-mapping.h | 8 +++--- arch/powerpc/kernel/dma-iommu.c | 1 + arch/powerpc/kernel/dma-swiotlb.c | 1 + arch/powerpc/kernel/dma.c | 36 +++++++++++++++------------- arch/powerpc/kernel/vio.c | 1 + drivers/base/dma-mapping.c | 31 +++++++++++++++++++++++++ include/asm-generic/dma-coherent.h | 1 + include/asm-generic/dma-mapping-common.h | 37 ++++++++++++++++++++++++++++++ 9 files changed, 95 insertions(+), 40 deletions(-)

diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index bbef15d..8645088 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -186,17 +186,6 @@ extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs);

-#define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, NULL) - -static inline int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, - void *cpu_addr, dma_addr_t dma_addr, - size_t size, struct dma_attrs *attrs) -{ - struct dma_map_ops *ops = get_dma_ops(dev); - BUG_ON(!ops); - return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs); -} - static inline void *dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag) { @@ -213,14 +202,6 @@ static inline void dma_free_writecombine(struct device *dev, size_t size, return dma_free_attrs(dev, size, cpu_addr, dma_handle, &attrs); }

-static inline int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma, - void *cpu_addr, dma_addr_t dma_addr, size_t size) -{ - DEFINE_DMA_ATTRS(attrs); - dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs); - return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, &attrs); -} - /* * This can be called during boot to increase the size of the consistent * DMA region above it's default value of 2MB. It must be called before the diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h index 62678e3..7816087 100644 --- a/arch/powerpc/include/asm/dma-mapping.h +++ b/arch/powerpc/include/asm/dma-mapping.h @@ -27,7 +27,10 @@ extern void *dma_direct_alloc_coherent(struct device *dev, size_t size, extern void dma_direct_free_coherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle, struct dma_attrs *attrs); - +extern int dma_direct_mmap_coherent(struct device *dev, + struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t handle, + size_t size, struct dma_attrs *attrs);

#ifdef CONFIG_NOT_COHERENT_CACHE /* @@ -207,11 +210,8 @@ static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr) #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f) #define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)

-extern int dma_mmap_coherent(struct device *, struct vm_area_struct *, - void *, dma_addr_t, size_t); #define ARCH_HAS_DMA_MMAP_COHERENT

- static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size, enum dma_data_direction direction) { diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c index bcfdcd2..2d7bb8c 100644 --- a/arch/powerpc/kernel/dma-iommu.c +++ b/arch/powerpc/kernel/dma-iommu.c @@ -109,6 +109,7 @@ static u64 dma_iommu_get_required_mask(struct device *dev) struct dma_map_ops dma_iommu_ops = { .alloc = dma_iommu_alloc_coherent, .free = dma_iommu_free_coherent, + .mmap = dma_direct_mmap_coherent, .map_sg = dma_iommu_map_sg, .unmap_sg = dma_iommu_unmap_sg, .dma_supported = dma_iommu_dma_supported, diff --git a/arch/powerpc/kernel/dma-swiotlb.c b/arch/powerpc/kernel/dma-swiotlb.c index 4ab88da..4694365 100644 --- a/arch/powerpc/kernel/dma-swiotlb.c +++ b/arch/powerpc/kernel/dma-swiotlb.c @@ -49,6 +49,7 @@ static u64 swiotlb_powerpc_get_required(struct device *dev) struct dma_map_ops swiotlb_dma_ops = { .alloc = dma_direct_alloc_coherent, .free = dma_direct_free_coherent, + .mmap = dma_direct_mmap_coherent, .map_sg = swiotlb_map_sg_attrs, .unmap_sg = swiotlb_unmap_sg_attrs, .dma_supported = swiotlb_dma_supported, diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c index b1ec983..062bf20 100644 --- a/arch/powerpc/kernel/dma.c +++ b/arch/powerpc/kernel/dma.c @@ -65,6 +65,24 @@ void dma_direct_free_coherent(struct device *dev, size_t size, #endif }

+int dma_direct_mmap_coherent(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t handle, size_t size, + struct dma_attrs *attrs) +{ + unsigned long pfn; + +#ifdef CONFIG_NOT_COHERENT_CACHE + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + pfn = __dma_get_coherent_pfn((unsigned long)cpu_addr); +#else + pfn = page_to_pfn(virt_to_page(cpu_addr)); +#endif + return remap_pfn_range(vma, vma->vm_start, + pfn + vma->vm_pgoff, + vma->vm_end - vma->vm_start, + vma->vm_page_prot); +} + static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, enum dma_data_direction direction, struct dma_attrs *attrs) @@ -154,6 +172,7 @@ static inline void dma_direct_sync_single(struct device *dev, struct dma_map_ops dma_direct_ops = { .alloc = dma_direct_alloc_coherent, .free = dma_direct_free_coherent, + .mmap = dma_direct_mmap_coherent, .map_sg = dma_direct_map_sg, .unmap_sg = dma_direct_unmap_sg, .dma_supported = dma_direct_dma_supported, @@ -211,20 +230,3 @@ static int __init dma_init(void) } fs_initcall(dma_init);

-int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma, - void *cpu_addr, dma_addr_t handle, size_t size) -{ - unsigned long pfn; - -#ifdef CONFIG_NOT_COHERENT_CACHE - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); - pfn = __dma_get_coherent_pfn((unsigned long)cpu_addr); -#else - pfn = page_to_pfn(virt_to_page(cpu_addr)); -#endif - return remap_pfn_range(vma, vma->vm_start, - pfn + vma->vm_pgoff, - vma->vm_end - vma->vm_start, - vma->vm_page_prot); -} -EXPORT_SYMBOL_GPL(dma_mmap_coherent); diff --git a/arch/powerpc/kernel/vio.c b/arch/powerpc/kernel/vio.c index cb87301..dda3d9a 100644 --- a/arch/powerpc/kernel/vio.c +++ b/arch/powerpc/kernel/vio.c @@ -613,6 +613,7 @@ static u64 vio_dma_get_required_mask(struct device *dev) struct dma_map_ops vio_dma_mapping_ops = { .alloc = vio_dma_iommu_alloc_coherent, .free = vio_dma_iommu_free_coherent, + .mmap = dma_direct_mmap_coherent, .map_sg = vio_dma_iommu_map_sg, .unmap_sg = vio_dma_iommu_unmap_sg, .map_page = vio_dma_iommu_map_page, diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c index 6f3676f..db5db02 100644 --- a/drivers/base/dma-mapping.c +++ b/drivers/base/dma-mapping.c @@ -10,6 +10,7 @@ #include <linux/dma-mapping.h> #include <linux/export.h> #include <linux/gfp.h> +#include <asm-generic/dma-coherent.h>

/* * Managed DMA API @@ -218,3 +219,33 @@ void dmam_release_declared_memory(struct device *dev) EXPORT_SYMBOL(dmam_release_declared_memory);

#endif + +/* + * Create userspace mapping for the DMA-coherent memory. + */ +int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t dma_addr, size_t size) +{ + int ret = -ENXIO; +#ifdef CONFIG_MMU + unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; + unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; + unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr)); + unsigned long off = vma->vm_pgoff; + + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + + if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret)) + return ret; + + if (off < count && user_count <= (count - off)) { + ret = remap_pfn_range(vma, vma->vm_start, + pfn + off, + user_count << PAGE_SHIFT, + vma->vm_page_prot); + } +#endif /* CONFIG_MMU */ + + return ret; +} +EXPORT_SYMBOL(dma_common_mmap); diff --git a/include/asm-generic/dma-coherent.h b/include/asm-generic/dma-coherent.h index abfb268..2be8a2d 100644 --- a/include/asm-generic/dma-coherent.h +++ b/include/asm-generic/dma-coherent.h @@ -29,6 +29,7 @@ dma_mark_declared_memory_occupied(struct device *dev, #else #define dma_alloc_from_coherent(dev, size, handle, ret) (0) #define dma_release_from_coherent(dev, order, vaddr) (0) +#define dma_mmap_from_coherent(dev, vma, vaddr, order, ret) (0) #endif

#endif diff --git a/include/asm-generic/dma-mapping-common.h b/include/asm-generic/dma-mapping-common.h index 2e248d8..9073aeb 100644 --- a/include/asm-generic/dma-mapping-common.h +++ b/include/asm-generic/dma-mapping-common.h @@ -176,4 +176,41 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, #define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, NULL) #define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, NULL)

+extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t dma_addr, size_t size); + +/** + * dma_mmap_attrs - map a coherent DMA allocation into user space + * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices + * @vma: vm_area_struct describing requested user mapping + * @cpu_addr: kernel CPU-view address returned from dma_alloc_attrs + * @handle: device-view address returned from dma_alloc_attrs + * @size: size of memory originally requested in dma_alloc_attrs + * @attrs: attributes of mapping properties requested in dma_alloc_attrs + * + * Map a coherent DMA buffer previously allocated by dma_alloc_attrs + * into user space. The coherent DMA buffer must not be freed by the + * driver until the user space mapping has been released. + */ +static inline int +dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, + dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs) +{ + struct dma_map_ops *ops = get_dma_ops(dev); + BUG_ON(!ops); + if (ops->mmap) + return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs); + return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size); +} + +#define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, NULL) + +static inline int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t dma_addr, size_t size) +{ + DEFINE_DMA_ATTRS(attrs); + dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs); + return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, &attrs); +} + #endif