From 53c92d793395fdab9edbd2f79b084bb6b2e6ae79 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Thu, 7 Apr 2016 18:42:05 +0100 Subject: iommu: of: enforce const-ness of struct iommu_ops As a set of driver-provided callbacks and static data, there is no compelling reason for struct iommu_ops to be mutable in core code, so enforce const-ness throughout. Acked-by: Thierry Reding Signed-off-by: Robin Murphy Acked-by: Will Deacon Signed-off-by: Joerg Roedel --- arch/arm64/include/asm/dma-mapping.h | 2 +- arch/arm64/mm/dma-mapping.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h index ba437f090a74..7dbea6c070ec 100644 --- a/arch/arm64/include/asm/dma-mapping.h +++ b/arch/arm64/include/asm/dma-mapping.h @@ -48,7 +48,7 @@ static inline struct dma_map_ops *get_dma_ops(struct device *dev) } void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, - struct iommu_ops *iommu, bool coherent); + const struct iommu_ops *iommu, bool coherent); #define arch_setup_dma_ops arch_setup_dma_ops #ifdef CONFIG_IOMMU_DMA diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index a6e757cbab77..5d36907f9b12 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -979,13 +979,13 @@ void arch_teardown_dma_ops(struct device *dev) #else static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, - struct iommu_ops *iommu) + const struct iommu_ops *iommu) { } #endif /* CONFIG_IOMMU_DMA */ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, - struct iommu_ops *iommu, bool coherent) + const struct iommu_ops *iommu, bool coherent) { if (!dev->archdata.dma_ops) dev->archdata.dma_ops = &swiotlb_dma_ops; -- cgit v1.2.3 From 3b6b7e19e31a816ee02a8d4372cbea9ad7db3784 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Wed, 13 Apr 2016 17:29:10 +0100 Subject: iommu/dma: Finish optimising higher-order allocations Now that we know exactly which page sizes our caller wants to use in the given domain, we can restrict higher-order allocation attempts to just those sizes, if any, and avoid wasting any time or effort on other sizes which offer no benefit. In the same vein, this also lets us accommodate a minimum order greater than 0 for special cases. Signed-off-by: Robin Murphy Acked-by: Will Deacon Tested-by: Yong Wu Signed-off-by: Joerg Roedel --- arch/arm64/mm/dma-mapping.c | 4 +-- drivers/iommu/dma-iommu.c | 60 +++++++++++++++++++++++++++++---------------- include/linux/dma-iommu.h | 4 +-- 3 files changed, 43 insertions(+), 25 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 5d36907f9b12..41d19a0fc9c0 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -562,8 +562,8 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size, struct page **pages; pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL, coherent); - pages = iommu_dma_alloc(dev, iosize, gfp, ioprot, handle, - flush_page); + pages = iommu_dma_alloc(dev, iosize, gfp, attrs, ioprot, + handle, flush_page); if (!pages) return NULL; diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 99432999b52f..ea5a9ebf0f78 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -190,11 +190,15 @@ static void __iommu_dma_free_pages(struct page **pages, int count) kvfree(pages); } -static struct page **__iommu_dma_alloc_pages(unsigned int count, gfp_t gfp) +static struct page **__iommu_dma_alloc_pages(unsigned int count, + unsigned long order_mask, gfp_t gfp) { struct page **pages; unsigned int i = 0, array_size = count * sizeof(*pages); - unsigned int order = MAX_ORDER; + + order_mask &= (2U << MAX_ORDER) - 1; + if (!order_mask) + return NULL; if (array_size <= PAGE_SIZE) pages = kzalloc(array_size, GFP_KERNEL); @@ -208,36 +212,38 @@ static struct page **__iommu_dma_alloc_pages(unsigned int count, gfp_t gfp) while (count) { struct page *page = NULL; - int j; + unsigned int order_size; /* * Higher-order allocations are a convenience rather * than a necessity, hence using __GFP_NORETRY until - * falling back to single-page allocations. + * falling back to minimum-order allocations. */ - for (order = min_t(unsigned int, order, __fls(count)); - order > 0; order--) { - page = alloc_pages(gfp | __GFP_NORETRY, order); + for (order_mask &= (2U << __fls(count)) - 1; + order_mask; order_mask &= ~order_size) { + unsigned int order = __fls(order_mask); + + order_size = 1U << order; + page = alloc_pages((order_mask - order_size) ? + gfp | __GFP_NORETRY : gfp, order); if (!page) continue; - if (PageCompound(page)) { - if (!split_huge_page(page)) - break; - __free_pages(page, order); - } else { + if (!order) + break; + if (!PageCompound(page)) { split_page(page, order); break; + } else if (!split_huge_page(page)) { + break; } + __free_pages(page, order); } - if (!page) - page = alloc_page(gfp); if (!page) { __iommu_dma_free_pages(pages, i); return NULL; } - j = 1 << order; - count -= j; - while (j--) + count -= order_size; + while (order_size--) pages[i++] = page++; } return pages; @@ -267,6 +273,7 @@ void iommu_dma_free(struct device *dev, struct page **pages, size_t size, * attached to an iommu_dma_domain * @size: Size of buffer in bytes * @gfp: Allocation flags + * @attrs: DMA attributes for this allocation * @prot: IOMMU mapping flags * @handle: Out argument for allocated DMA handle * @flush_page: Arch callback which must ensure PAGE_SIZE bytes from the @@ -278,8 +285,8 @@ void iommu_dma_free(struct device *dev, struct page **pages, size_t size, * Return: Array of struct page pointers describing the buffer, * or NULL on failure. */ -struct page **iommu_dma_alloc(struct device *dev, size_t size, - gfp_t gfp, int prot, dma_addr_t *handle, +struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp, + struct dma_attrs *attrs, int prot, dma_addr_t *handle, void (*flush_page)(struct device *, const void *, phys_addr_t)) { struct iommu_domain *domain = iommu_get_domain_for_dev(dev); @@ -288,11 +295,22 @@ struct page **iommu_dma_alloc(struct device *dev, size_t size, struct page **pages; struct sg_table sgt; dma_addr_t dma_addr; - unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; + unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap; *handle = DMA_ERROR_CODE; - pages = __iommu_dma_alloc_pages(count, gfp); + min_size = alloc_sizes & -alloc_sizes; + if (min_size < PAGE_SIZE) { + min_size = PAGE_SIZE; + alloc_sizes |= PAGE_SIZE; + } else { + size = ALIGN(size, min_size); + } + if (dma_get_attr(DMA_ATTR_ALLOC_SINGLE_PAGES, attrs)) + alloc_sizes = min_size; + + count = PAGE_ALIGN(size) >> PAGE_SHIFT; + pages = __iommu_dma_alloc_pages(count, alloc_sizes >> PAGE_SHIFT, gfp); if (!pages) return NULL; diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h index fc481037478a..8443bbb5c071 100644 --- a/include/linux/dma-iommu.h +++ b/include/linux/dma-iommu.h @@ -38,8 +38,8 @@ int dma_direction_to_prot(enum dma_data_direction dir, bool coherent); * These implement the bulk of the relevant DMA mapping callbacks, but require * the arch code to take care of attributes and cache maintenance */ -struct page **iommu_dma_alloc(struct device *dev, size_t size, - gfp_t gfp, int prot, dma_addr_t *handle, +struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp, + struct dma_attrs *attrs, int prot, dma_addr_t *handle, void (*flush_page)(struct device *, const void *, phys_addr_t)); void iommu_dma_free(struct device *dev, struct page **pages, size_t size, dma_addr_t *handle); -- cgit v1.2.3