Hi Everyone, Please find the following patch as refactoring of the common code out from arch/arm/mm/dma-mapping.c to lib/iommu-helper.c
This is just an initial version of patch to get more details and to know if this is how we want to plan refactoring iommu code to lib/iommu-helper. Please let me know the changes/suggestion which you think in this ? Taking out the common code of buffer allocation and mapping for iommu from arch/arm to lib/iommu-helper file. Signed-off-by: Ritesh Harjani <[email protected]> --- arch/arm/mm/dma-mapping.c | 159 +++++----------------------------------- include/linux/iommu-helper.h | 22 ++++++ lib/iommu-helper.c | 169 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 210 insertions(+), 140 deletions(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 11b3914..71e0dbd 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -26,6 +26,7 @@ #include <linux/io.h> #include <linux/vmalloc.h> #include <linux/sizes.h> +#include <linux/iommu-helper.h> #include <asm/memory.h> #include <asm/highmem.h> @@ -1119,124 +1120,26 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, { struct page **pages; int count = size >> PAGE_SHIFT; - int array_size = count * sizeof(struct page *); int i = 0; - if (array_size <= PAGE_SIZE) - pages = kzalloc(array_size, gfp); - else - pages = vzalloc(array_size); - if (!pages) - return NULL; - - if (dma_get_attr(DMA_ATTR_FORCE_CONTIGUOUS, attrs)) - { - unsigned long order = get_order(size); - struct page *page; - - page = dma_alloc_from_contiguous(dev, count, order); - if (!page) - goto error; - - __dma_clear_buffer(page, size); - - for (i = 0; i < count; i++) - pages[i] = page + i; + pages = iommu_lib_alloc_buffer(dev, size, gfp, attrs); - return pages; - } - - /* - * IOMMU can map any pages, so himem can also be used here - */ - gfp |= __GFP_NOWARN | __GFP_HIGHMEM; - - while (count) { - int j, order = __fls(count); - - pages[i] = alloc_pages(gfp, order); - while (!pages[i] && order) - pages[i] = alloc_pages(gfp, --order); - if (!pages[i]) - goto error; - - if (order) { - split_page(pages[i], order); - j = 1 << order; - while (--j) - pages[i + j] = pages[i] + j; + if (!pages) { + return NULL; + } else { + while (count--) { + __dma_clear_buffer(pages[i], PAGE_SIZE); + i++; } - - __dma_clear_buffer(pages[i], PAGE_SIZE << order); - i += 1 << order; - count -= 1 << order; } - return pages; -error: - while (i--) - if (pages[i]) - __free_pages(pages[i], 0); - if (array_size <= PAGE_SIZE) - kfree(pages); - else - vfree(pages); - return NULL; + } static int __iommu_free_buffer(struct device *dev, struct page **pages, size_t size, struct dma_attrs *attrs) { - int count = size >> PAGE_SHIFT; - int array_size = count * sizeof(struct page *); - int i; - - if (dma_get_attr(DMA_ATTR_FORCE_CONTIGUOUS, attrs)) { - dma_release_from_contiguous(dev, pages[0], count); - } else { - for (i = 0; i < count; i++) - if (pages[i]) - __free_pages(pages[i], 0); - } - - if (array_size <= PAGE_SIZE) - kfree(pages); - else - vfree(pages); - return 0; -} - -/* - * Create a CPU mapping for a specified pages - */ -static void * -__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot, - const void *caller) -{ - unsigned int i, nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; - struct vm_struct *area; - unsigned long p; - - area = get_vm_area_caller(size, VM_ARM_DMA_CONSISTENT | VM_USERMAP, - caller); - if (!area) - return NULL; - - area->pages = pages; - area->nr_pages = nr_pages; - p = (unsigned long)area->addr; - - for (i = 0; i < nr_pages; i++) { - phys_addr_t phys = __pfn_to_phys(page_to_pfn(pages[i])); - if (ioremap_page_range(p, p + PAGE_SIZE, phys, prot)) - goto err; - p += PAGE_SIZE; - } - return area->addr; -err: - unmap_kernel_range((unsigned long)area->addr, size); - vunmap(area->addr); - return NULL; + return iommu_lib_free_buffer(dev, pages, size, attrs); } /* @@ -1246,51 +1149,24 @@ static dma_addr_t __iommu_create_mapping(struct device *dev, struct page **pages, size_t size) { struct dma_iommu_mapping *mapping = dev->archdata.mapping; - unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; dma_addr_t dma_addr, iova; - int i, ret = DMA_ERROR_CODE; dma_addr = __alloc_iova(mapping, size); if (dma_addr == DMA_ERROR_CODE) return dma_addr; - iova = dma_addr; - for (i = 0; i < count; ) { - unsigned int next_pfn = page_to_pfn(pages[i]) + 1; - phys_addr_t phys = page_to_phys(pages[i]); - unsigned int len, j; - - for (j = i + 1; j < count; j++, next_pfn++) - if (page_to_pfn(pages[j]) != next_pfn) - break; + iova = iommu_lib_map(mapping->domain, pages, dma_addr, size); + if (iova == DMA_ERROR_CODE) + __free_iova(mapping, dma_addr, size); - len = (j - i) << PAGE_SHIFT; - ret = iommu_map(mapping->domain, iova, phys, len, - IOMMU_READ|IOMMU_WRITE); - if (ret < 0) - goto fail; - iova += len; - i = j; - } - return dma_addr; -fail: - iommu_unmap(mapping->domain, dma_addr, iova-dma_addr); - __free_iova(mapping, dma_addr, size); - return DMA_ERROR_CODE; + return iova; } static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t size) { struct dma_iommu_mapping *mapping = dev->archdata.mapping; - /* - * add optional in-page offset from iova to size and align - * result to page size - */ - size = PAGE_ALIGN((iova & ~PAGE_MASK) + size); - iova &= PAGE_MASK; - - iommu_unmap(mapping->domain, iova, size); + iommu_lib_unmap(mapping->domain, iova, size); __free_iova(mapping, iova, size); return 0; } @@ -1354,6 +1230,7 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size, pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL); struct page **pages; void *addr = NULL; + unsigned long flags = 0; *handle = DMA_ERROR_CODE; size = PAGE_ALIGN(size); @@ -1381,7 +1258,9 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size, if (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) return pages; - addr = __iommu_alloc_remap(pages, size, gfp, prot, + flags = VM_ARM_DMA_CONSISTENT | VM_USERMAP; + + addr = iommu_lib_alloc_remap(pages, size, flags, prot, __builtin_return_address(0)); if (!addr) goto err_mapping; diff --git a/include/linux/iommu-helper.h b/include/linux/iommu-helper.h index 86bdeff..55d4797 100644 --- a/include/linux/iommu-helper.h +++ b/include/linux/iommu-helper.h @@ -2,6 +2,7 @@ #define _LINUX_IOMMU_HELPER_H #include <linux/kernel.h> +#include <linux/iommu.h> static inline unsigned long iommu_device_max_index(unsigned long size, unsigned long offset, @@ -31,4 +32,25 @@ static inline unsigned long iommu_num_pages(unsigned long addr, return DIV_ROUND_UP(size, io_page_size); } +extern struct page **iommu_lib_alloc_buffer(struct device *dev, size_t size, + gfp_t gfp, struct dma_attrs *attrs); + +extern int iommu_lib_free_buffer(struct device *dev, struct page **pages, + size_t size, struct dma_attrs *attrs); + +extern dma_addr_t iommu_lib_map(struct iommu_domain *domain, + struct page **pages, dma_addr_t iova, size_t size); + +extern void iommu_lib_unmap(struct iommu_domain *domain, dma_addr_t iova, + size_t size); + +extern void *iommu_lib_alloc_remap(struct page **pages, size_t size, + unsigned long flags, pgprot_t prot, + const void *caller); + + + + + + #endif diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c index c27e269..4f80f9e 100644 --- a/lib/iommu-helper.c +++ b/lib/iommu-helper.c @@ -5,6 +5,13 @@ #include <linux/export.h> #include <linux/bitmap.h> #include <linux/bug.h> +#include <linux/dma-mapping.h> +#include <linux/dma-contiguous.h> +#include <linux/slab.h> +#include <linux/iommu.h> +#include <linux/io.h> +#include <linux/vmalloc.h> +#include <linux/sizes.h> int iommu_is_span_boundary(unsigned int index, unsigned int nr, unsigned long shift, @@ -39,3 +46,165 @@ again: return -1; } EXPORT_SYMBOL(iommu_area_alloc); + +struct page **iommu_lib_alloc_buffer(struct device *dev, size_t size, + gfp_t gfp, struct dma_attrs *attrs) +{ + struct page **pages; + int count = size >> PAGE_SHIFT; + int array_size = count * sizeof(struct page *); + int i = 0; + + if (array_size <= PAGE_SIZE) + pages = kzalloc(array_size, gfp); + else + pages = vzalloc(array_size); + if (!pages) + return NULL; + + if (dma_get_attr(DMA_ATTR_FORCE_CONTIGUOUS, attrs)) { + unsigned long order = get_order(size); + struct page *page; + + page = dma_alloc_from_contiguous(dev, count, order); + if (!page) + goto error; + + for (i = 0; i < count; i++) + pages[i] = page + i; + + return pages; + } + + /* + * IOMMU can map any pages, so himem can also be used here + */ + gfp |= __GFP_NOWARN | __GFP_HIGHMEM; + + while (count) { + int j, order = __fls(count); + + pages[i] = alloc_pages(gfp, order); + while (!pages[i] && order) + pages[i] = alloc_pages(gfp, --order); + if (!pages[i]) + goto error; + + if (order) { + split_page(pages[i], order); + j = 1 << order; + while (--j) + pages[i + j] = pages[i] + j; + } + + i += 1 << order; + count -= 1 << order; + } + + return pages; +error: + while (i--) + if (pages[i]) + __free_pages(pages[i], 0); + if (array_size <= PAGE_SIZE) + kfree(pages); + else + vfree(pages); + return NULL; +} + +int iommu_lib_free_buffer(struct device *dev, struct page **pages, + size_t size, struct dma_attrs *attrs) +{ + int count = size >> PAGE_SHIFT; + int array_size = count * sizeof(struct page *); + int i; + + if (dma_get_attr(DMA_ATTR_FORCE_CONTIGUOUS, attrs)) { + dma_release_from_contiguous(dev, pages[0], count); + } else { + for (i = 0; i < count; i++) + if (pages[i]) + __free_pages(pages[i], 0); + } + + if (array_size <= PAGE_SIZE) + kfree(pages); + else + vfree(pages); + return 0; +} + +dma_addr_t iommu_lib_map(struct iommu_domain *domain, struct page **pages, + dma_addr_t iova, size_t size) +{ + dma_addr_t dma_addr = iova; + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; + int i, ret = DMA_ERROR_CODE; + + for (i = 0; i < count; ) { + unsigned int next_pfn = page_to_pfn(pages[i]) + 1; + phys_addr_t phys = page_to_phys(pages[i]); + unsigned int len, j; + + for (j = i + 1; j < count; j++, next_pfn++) + if (page_to_pfn(pages[j]) != next_pfn) + break; + + len = (j - i) << PAGE_SHIFT; + ret = iommu_map(domain, iova, phys, len, + IOMMU_READ|IOMMU_WRITE); + if (ret < 0) + goto fail; + iova += len; + i = j; + } + return dma_addr; +fail: + iommu_unmap(domain, dma_addr, iova-dma_addr); + return DMA_ERROR_CODE; +} + +void iommu_lib_unmap(struct iommu_domain *domain, dma_addr_t iova, size_t size) +{ + /* + * add optional in-page offset from iova to size and align + * result to page size + */ + size = PAGE_ALIGN((iova & ~PAGE_MASK) + size); + iova &= PAGE_MASK; + + iommu_unmap(domain, iova, size); +} + +/* + * Create a CPU mapping for a specified pages + */ +void *iommu_lib_alloc_remap(struct page **pages, size_t size, unsigned long + flags, pgprot_t prot, const void *caller) +{ + unsigned int i, nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; + struct vm_struct *area; + unsigned long p; + + area = get_vm_area_caller(size, flags, caller); + + if (!area) + return NULL; + + area->pages = pages; + area->nr_pages = nr_pages; + p = (unsigned long)area->addr; + + for (i = 0; i < nr_pages; i++) { + phys_addr_t phys = __pfn_to_phys(page_to_pfn(pages[i])); + if (ioremap_page_range(p, p + PAGE_SIZE, phys, prot)) + goto err; + p += PAGE_SIZE; + } + return area->addr; +err: + unmap_kernel_range((unsigned long)area->addr, size); + vunmap(area->addr); + return NULL; +} -- 1.8.1.3 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
