diff options
| -rw-r--r-- | drivers/iommu/dma-iommu.c | 2 | ||||
| -rw-r--r-- | drivers/xen/swiotlb-xen.c | 2 | ||||
| -rw-r--r-- | include/linux/swiotlb.h | 2 | ||||
| -rw-r--r-- | kernel/dma/swiotlb.c | 56 |
4 files changed, 45 insertions, 17 deletions
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index e4cb26f6a943..7a9e814fc6b3 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -1165,7 +1165,7 @@ static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page, trace_swiotlb_bounced(dev, phys, size); aligned_size = iova_align(iovad, size); - phys = swiotlb_tbl_map_single(dev, phys, size, aligned_size, + phys = swiotlb_tbl_map_single(dev, phys, size, iova_mask(iovad), dir, attrs); if (phys == DMA_MAPPING_ERROR) diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 0e6c6c25d154..d4f1f8d1ebd8 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -216,7 +216,7 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, */ trace_swiotlb_bounced(dev, dev_addr, size); - map = swiotlb_tbl_map_single(dev, phys, size, size, 0, dir, attrs); + map = swiotlb_tbl_map_single(dev, phys, size, 0, dir, attrs); if (map == (phys_addr_t)DMA_MAPPING_ERROR) return DMA_MAPPING_ERROR; diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index ea23097e351f..14bc10c1bb23 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -43,7 +43,7 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask, extern void __init swiotlb_update_mem_attributes(void); phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t phys, - size_t mapping_size, size_t alloc_size, + size_t mapping_size, unsigned int alloc_aligned_mask, enum dma_data_direction dir, unsigned long attrs); diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index a5e0dfc44d24..046da973a7e2 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -1340,15 +1340,40 @@ static unsigned long mem_used(struct io_tlb_mem *mem) #endif /* CONFIG_DEBUG_FS */ +/** + * swiotlb_tbl_map_single() - bounce buffer map a single contiguous physical area + * @dev: Device which maps the buffer. + * @orig_addr: Original (non-bounced) physical IO buffer address + * @mapping_size: Requested size of the actual bounce buffer, excluding + * any pre- or post-padding for alignment + * @alloc_align_mask: Required start and end alignment of the allocated buffer + * @dir: DMA direction + * @attrs: Optional DMA attributes for the map operation + * + * Find and allocate a suitable sequence of IO TLB slots for the request. + * The allocated space starts at an alignment specified by alloc_align_mask, + * and the size of the allocated space is rounded up so that the total amount + * of allocated space is a multiple of (alloc_align_mask + 1). If + * alloc_align_mask is zero, the allocated space may be at any alignment and + * the size is not rounded up. + * + * The returned address is within the allocated space and matches the bits + * of orig_addr that are specified in the DMA min_align_mask for the device. As + * such, this returned address may be offset from the beginning of the allocated + * space. The bounce buffer space starting at the returned address for + * mapping_size bytes is initialized to the contents of the original IO buffer + * area. Any pre-padding (due to an offset) and any post-padding (due to + * rounding-up the size) is not initialized. + */ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, - size_t mapping_size, size_t alloc_size, - unsigned int alloc_align_mask, enum dma_data_direction dir, - unsigned long attrs) + size_t mapping_size, unsigned int alloc_align_mask, + enum dma_data_direction dir, unsigned long attrs) { struct io_tlb_mem *mem = dev->dma_io_tlb_mem; unsigned int offset; struct io_tlb_pool *pool; unsigned int i; + size_t size; int index; phys_addr_t tlb_addr; unsigned short pad_slots; @@ -1362,20 +1387,24 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, if (cc_platform_has(CC_ATTR_MEM_ENCRYPT)) pr_warn_once("Memory encryption is active and system is using DMA bounce buffers\n"); - if (mapping_size > alloc_size) { - dev_warn_once(dev, "Invalid sizes (mapping: %zd bytes, alloc: %zd bytes)", - mapping_size, alloc_size); - return (phys_addr_t)DMA_MAPPING_ERROR; - } + /* + * The default swiotlb memory pool is allocated with PAGE_SIZE + * alignment. If a mapping is requested with larger alignment, + * the mapping may be unable to use the initial slot(s) in all + * sets of IO_TLB_SEGSIZE slots. In such case, a mapping request + * of or near the maximum mapping size would always fail. + */ + dev_WARN_ONCE(dev, alloc_align_mask > ~PAGE_MASK, + "Alloc alignment may prevent fulfilling requests with max mapping_size\n"); offset = swiotlb_align_offset(dev, alloc_align_mask, orig_addr); - index = swiotlb_find_slots(dev, orig_addr, - alloc_size + offset, alloc_align_mask, &pool); + size = ALIGN(mapping_size + offset, alloc_align_mask + 1); + index = swiotlb_find_slots(dev, orig_addr, size, alloc_align_mask, &pool); if (index == -1) { if (!(attrs & DMA_ATTR_NO_WARN)) dev_warn_ratelimited(dev, "swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n", - alloc_size, mem->nslabs, mem_used(mem)); + size, mem->nslabs, mem_used(mem)); return (phys_addr_t)DMA_MAPPING_ERROR; } @@ -1388,7 +1417,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, offset &= (IO_TLB_SIZE - 1); index += pad_slots; pool->slots[index].pad_slots = pad_slots; - for (i = 0; i < nr_slots(alloc_size + offset); i++) + for (i = 0; i < (nr_slots(size) - pad_slots); i++) pool->slots[index + i].orig_addr = slot_addr(orig_addr, i); tlb_addr = slot_addr(pool->start, index) + offset; /* @@ -1543,8 +1572,7 @@ dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size, trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size); - swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, size, 0, dir, - attrs); + swiotlb_addr = swiotlb_tbl_map_single(dev, paddr, size, 0, dir, attrs); if (swiotlb_addr == (phys_addr_t)DMA_MAPPING_ERROR) return DMA_MAPPING_ERROR; |