diff options
| -rw-r--r-- | drivers/iommu/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/iommu/dma-iommu.c | 50 | ||||
| -rw-r--r-- | include/linux/scatterlist.h | 41 |
3 files changed, 81 insertions, 11 deletions
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 6de900776e24..74c45359869d 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -152,6 +152,7 @@ config IOMMU_DMA select IOMMU_IOVA select IRQ_MSI_IOMMU select NEED_SG_DMA_LENGTH + select NEED_SG_DMA_FLAGS if SWIOTLB # Shared Virtual Addressing config IOMMU_SVA diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index b8bba4aa196f..e86ae462cade 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -520,9 +520,38 @@ static bool dev_is_untrusted(struct device *dev) return dev_is_pci(dev) && to_pci_dev(dev)->untrusted; } -static bool dev_use_swiotlb(struct device *dev) +static bool dev_use_swiotlb(struct device *dev, size_t size, + enum dma_data_direction dir) { - return IS_ENABLED(CONFIG_SWIOTLB) && dev_is_untrusted(dev); + return IS_ENABLED(CONFIG_SWIOTLB) && + (dev_is_untrusted(dev) || + dma_kmalloc_needs_bounce(dev, size, dir)); +} + +static bool dev_use_sg_swiotlb(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir) +{ + struct scatterlist *s; + int i; + + if (!IS_ENABLED(CONFIG_SWIOTLB)) + return false; + + if (dev_is_untrusted(dev)) + return true; + + /* + * If kmalloc() buffers are not DMA-safe for this device and + * direction, check the individual lengths in the sg list. If any + * element is deemed unsafe, use the swiotlb for bouncing. + */ + if (!dma_kmalloc_safe(dev, dir)) { + for_each_sg(sg, s, nents, i) + if (!dma_kmalloc_size_aligned(s->length)) + return true; + } + + return false; } /** @@ -922,7 +951,7 @@ static void iommu_dma_sync_single_for_cpu(struct device *dev, { phys_addr_t phys; - if (dev_is_dma_coherent(dev) && !dev_use_swiotlb(dev)) + if (dev_is_dma_coherent(dev) && !dev_use_swiotlb(dev, size, dir)) return; phys = iommu_iova_to_phys(iommu_get_dma_domain(dev), dma_handle); @@ -938,7 +967,7 @@ static void iommu_dma_sync_single_for_device(struct device *dev, { phys_addr_t phys; - if (dev_is_dma_coherent(dev) && !dev_use_swiotlb(dev)) + if (dev_is_dma_coherent(dev) && !dev_use_swiotlb(dev, size, dir)) return; phys = iommu_iova_to_phys(iommu_get_dma_domain(dev), dma_handle); @@ -956,7 +985,7 @@ static void iommu_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg; int i; - if (dev_use_swiotlb(dev)) + if (sg_dma_is_swiotlb(sgl)) for_each_sg(sgl, sg, nelems, i) iommu_dma_sync_single_for_cpu(dev, sg_dma_address(sg), sg->length, dir); @@ -972,7 +1001,7 @@ static void iommu_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg; int i; - if (dev_use_swiotlb(dev)) + if (sg_dma_is_swiotlb(sgl)) for_each_sg(sgl, sg, nelems, i) iommu_dma_sync_single_for_device(dev, sg_dma_address(sg), @@ -998,7 +1027,8 @@ static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page, * If both the physical buffer start address and size are * page aligned, we don't need to use a bounce page. */ - if (dev_use_swiotlb(dev) && iova_offset(iovad, phys | size)) { + if (dev_use_swiotlb(dev, size, dir) && + iova_offset(iovad, phys | size)) { void *padding_start; size_t padding_size, aligned_size; @@ -1166,6 +1196,8 @@ static int iommu_dma_map_sg_swiotlb(struct device *dev, struct scatterlist *sg, struct scatterlist *s; int i; + sg_dma_mark_swiotlb(sg); + for_each_sg(sg, s, nents, i) { sg_dma_address(s) = iommu_dma_map_page(dev, sg_page(s), s->offset, s->length, dir, attrs); @@ -1210,7 +1242,7 @@ static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg, goto out; } - if (dev_use_swiotlb(dev)) + if (dev_use_sg_swiotlb(dev, sg, nents, dir)) return iommu_dma_map_sg_swiotlb(dev, sg, nents, dir, attrs); if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) @@ -1315,7 +1347,7 @@ static void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, struct scatterlist *tmp; int i; - if (dev_use_swiotlb(dev)) { + if (sg_dma_is_swiotlb(sg)) { iommu_dma_unmap_sg_swiotlb(dev, sg, nents, dir, attrs); return; } diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 2f06178996ba..ec46d8e8e49d 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -251,11 +251,13 @@ static inline void sg_unmark_end(struct scatterlist *sg) /* * One 64-bit architectures there is a 4-byte padding in struct scatterlist * (assuming also CONFIG_NEED_SG_DMA_LENGTH is set). Use this padding for DMA - * flags bits to indicate when a specific dma address is a bus address. + * flags bits to indicate when a specific dma address is a bus address or the + * buffer may have been bounced via SWIOTLB. */ #ifdef CONFIG_NEED_SG_DMA_FLAGS -#define SG_DMA_BUS_ADDRESS (1 << 0) +#define SG_DMA_BUS_ADDRESS (1 << 0) +#define SG_DMA_SWIOTLB (1 << 1) /** * sg_dma_is_bus_address - Return whether a given segment was marked @@ -298,6 +300,34 @@ static inline void sg_dma_unmark_bus_address(struct scatterlist *sg) sg->dma_flags &= ~SG_DMA_BUS_ADDRESS; } +/** + * sg_dma_is_swiotlb - Return whether the scatterlist was marked for SWIOTLB + * bouncing + * @sg: SG entry + * + * Description: + * Returns true if the scatterlist was marked for SWIOTLB bouncing. Not all + * elements may have been bounced, so the caller would have to check + * individual SG entries with is_swiotlb_buffer(). + */ +static inline bool sg_dma_is_swiotlb(struct scatterlist *sg) +{ + return sg->dma_flags & SG_DMA_SWIOTLB; +} + +/** + * sg_dma_mark_swiotlb - Mark the scatterlist for SWIOTLB bouncing + * @sg: SG entry + * + * Description: + * Marks a a scatterlist for SWIOTLB bounce. Not all SG entries may be + * bounced. + */ +static inline void sg_dma_mark_swiotlb(struct scatterlist *sg) +{ + sg->dma_flags |= SG_DMA_SWIOTLB; +} + #else static inline bool sg_dma_is_bus_address(struct scatterlist *sg) @@ -310,6 +340,13 @@ static inline void sg_dma_mark_bus_address(struct scatterlist *sg) static inline void sg_dma_unmark_bus_address(struct scatterlist *sg) { } +static inline bool sg_dma_is_swiotlb(struct scatterlist *sg) +{ + return false; +} +static inline void sg_dma_mark_swiotlb(struct scatterlist *sg) +{ +} #endif /* CONFIG_NEED_SG_DMA_FLAGS */ |