Messages in this thread Patch in this message | | | From | Christoph Hellwig <> | Subject | [PATCH 8/9] swiotlb: add support for non-coherent DMA | Date | Mon, 17 Sep 2018 17:38:25 +0200 |
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Handle architectures that are not cache coherent directly in the main swiotlb code. This involves two related changes:
- call arch_sync_dma_for_{device,cpu} in all the right places from the various dma_map/unmap/sync methods when the device is non-coherent - call arch_dma_{alloc,free} for devices that are non-coherent
Signed-off-by: Christoph Hellwig <hch@lst.de> --- arch/arm64/mm/dma-mapping.c | 6 ++--- include/linux/swiotlb.h | 4 ++-- kernel/dma/swiotlb.c | 44 ++++++++++++++++++++++++++++++------- 3 files changed, 41 insertions(+), 13 deletions(-)
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index abcae73eea50..07d9c2633f80 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -112,7 +112,7 @@ static void *__dma_alloc(struct device *dev, size_t size, return addr; } - ptr = swiotlb_alloc(dev, size, dma_handle, flags, attrs); + ptr = __swiotlb_alloc(dev, size, dma_handle, flags, attrs); if (!ptr) goto no_mem; @@ -133,7 +133,7 @@ static void *__dma_alloc(struct device *dev, size_t size, return coherent_ptr; no_map: - swiotlb_free(dev, size, ptr, *dma_handle, attrs); + __swiotlb_free(dev, size, ptr, *dma_handle, attrs); no_mem: return NULL; } @@ -151,7 +151,7 @@ static void __dma_free(struct device *dev, size_t size, return; vunmap(vaddr); } - swiotlb_free(dev, size, swiotlb_addr, dma_handle, attrs); + __swiotlb_free(dev, size, swiotlb_addr, dma_handle, attrs); } static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page, diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index f847c1b265c4..bc809d826d4f 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -67,9 +67,9 @@ extern void swiotlb_tbl_sync_single(struct device *hwdev, /* Accessory functions. */ -void *swiotlb_alloc(struct device *hwdev, size_t size, dma_addr_t *dma_handle, +void *__swiotlb_alloc(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t flags, unsigned long attrs); -void swiotlb_free(struct device *dev, size_t size, void *vaddr, +void __swiotlb_free(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_addr, unsigned long attrs); extern dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 4d7a4d85d71e..83e597101c6a 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -21,6 +21,7 @@ #include <linux/cache.h> #include <linux/dma-direct.h> +#include <linux/dma-noncoherent.h> #include <linux/mm.h> #include <linux/export.h> #include <linux/spinlock.h> @@ -749,6 +750,10 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, dma_addr = swiotlb_bounce_page(dev, &phys, size, dir, attrs); } + if (!dev_is_dma_coherent(dev) && + (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0) + arch_sync_dma_for_device(dev, phys, size, dir); + return dma_addr; } @@ -768,6 +773,10 @@ void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, BUG_ON(dir == DMA_NONE); + if (!dev_is_dma_coherent(hwdev) && + (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0) + arch_sync_dma_for_cpu(hwdev, paddr, size, dir); + if (is_swiotlb_buffer(paddr)) { swiotlb_tbl_unmap_single(hwdev, paddr, size, dir, attrs); return; @@ -804,15 +813,17 @@ swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr, BUG_ON(dir == DMA_NONE); - if (is_swiotlb_buffer(paddr)) { + if (!dev_is_dma_coherent(hwdev) && target == SYNC_FOR_CPU) + arch_sync_dma_for_cpu(hwdev, paddr, size, dir); + + if (is_swiotlb_buffer(paddr)) swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target); - return; - } - if (dir != DMA_FROM_DEVICE) - return; + if (!dev_is_dma_coherent(hwdev) && target == SYNC_FOR_DEVICE) + arch_sync_dma_for_device(hwdev, paddr, size, dir); - dma_mark_clean(phys_to_virt(paddr), size); + if (!is_swiotlb_buffer(paddr) && dir == DMA_FROM_DEVICE) + dma_mark_clean(phys_to_virt(paddr), size); } void @@ -928,7 +939,7 @@ swiotlb_dma_supported(struct device *hwdev, u64 mask) return __phys_to_dma(hwdev, io_tlb_end - 1) <= mask; } -void *swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, +void *__swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) { void *vaddr; @@ -950,13 +961,30 @@ void *swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, return vaddr; } -void swiotlb_free(struct device *dev, size_t size, void *vaddr, +static void *swiotlb_alloc(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) +{ + if (!dev_is_dma_coherent(dev)) + return arch_dma_alloc(dev, size, dma_handle, gfp, attrs); + return __swiotlb_alloc(dev, size, dma_handle, gfp, attrs); +} + +void __swiotlb_free(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_addr, unsigned long attrs) { if (!swiotlb_free_buffer(dev, size, dma_addr)) dma_direct_free(dev, size, vaddr, dma_addr, attrs); } +static void swiotlb_free(struct device *dev, size_t size, void *vaddr, + dma_addr_t dma_addr, unsigned long attrs) +{ + if (!dev_is_dma_coherent(dev)) + arch_dma_free(dev, size, vaddr, dma_addr, attrs); + else + __swiotlb_free(dev, size, vaddr, dma_addr, attrs); +} + const struct dma_map_ops swiotlb_dma_ops = { .mapping_error = dma_direct_mapping_error, .alloc = swiotlb_alloc, -- 2.18.0
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