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author | Christoph Hellwig <hch@lst.de> | 2021-03-01 10:44:25 +0300 |
---|---|---|
committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2021-03-17 03:29:41 +0300 |
commit | 2bdba622c351259317b0294c6e9fe243b2404316 (patch) | |
tree | b779ee4e5763d820f86572f09280bc2492d07b42 /kernel/dma | |
parent | 2973073a80b46daebc352c31d09d95d16cf6876e (diff) | |
download | linux-2bdba622c351259317b0294c6e9fe243b2404316.tar.xz |
swiotlb: move orig addr and size validation into swiotlb_bounce
Move the code to find and validate the original buffer address and size
from the callers into swiotlb_bounce. This means a tiny bit of extra
work in the swiotlb_map path, but avoids code duplication and a leads to
a better code structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'kernel/dma')
-rw-r--r-- | kernel/dma/swiotlb.c | 59 |
1 files changed, 23 insertions, 36 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 03aa614565e4..a431c6b64e82 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -460,12 +460,25 @@ void __init swiotlb_exit(void) /* * Bounce: copy the swiotlb buffer from or back to the original dma location */ -static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr, - size_t size, enum dma_data_direction dir) +static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size, + enum dma_data_direction dir) { + int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT; + size_t alloc_size = io_tlb_alloc_size[index]; + phys_addr_t orig_addr = io_tlb_orig_addr[index]; unsigned long pfn = PFN_DOWN(orig_addr); unsigned char *vaddr = phys_to_virt(tlb_addr); + if (orig_addr == INVALID_PHYS_ADDR) + return; + + if (size > alloc_size) { + dev_WARN_ONCE(dev, 1, + "Buffer overflow detected. Allocation size: %zu. Mapping size: %zu.\n", + alloc_size, size); + size = alloc_size; + } + if (PageHighMem(pfn_to_page(pfn))) { /* The buffer does not have a mapping. Map it in and copy */ unsigned int offset = orig_addr & ~PAGE_MASK; @@ -644,21 +657,10 @@ phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, tlb_addr = slot_addr(io_tlb_start, index) + offset; if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) - swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_TO_DEVICE); + swiotlb_bounce(dev, tlb_addr, mapping_size, DMA_TO_DEVICE); return tlb_addr; } -static void validate_sync_size_and_truncate(struct device *hwdev, size_t alloc_size, size_t *size) -{ - if (*size > alloc_size) { - /* Warn and truncate mapping_size */ - dev_WARN_ONCE(hwdev, 1, - "Attempt for buffer overflow. Original size: %zu. Mapping size: %zu.\n", - alloc_size, *size); - *size = alloc_size; - } -} - /* * tlb_addr is the physical address of the bounce buffer to unmap. */ @@ -669,19 +671,15 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr, unsigned long flags; unsigned int offset = swiotlb_align_offset(hwdev, tlb_addr); int index = (tlb_addr - offset - io_tlb_start) >> IO_TLB_SHIFT; - phys_addr_t orig_addr = io_tlb_orig_addr[index]; - size_t alloc_size = io_tlb_alloc_size[index]; - int i, count, nslots = nr_slots(alloc_size + offset); - - validate_sync_size_and_truncate(hwdev, alloc_size, &mapping_size); + int nslots = nr_slots(io_tlb_alloc_size[index] + offset); + int count, i; /* * First, sync the memory before unmapping the entry */ - if (orig_addr != INVALID_PHYS_ADDR && - !(attrs & DMA_ATTR_SKIP_CPU_SYNC) && - ((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL))) - swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_FROM_DEVICE); + if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && + (dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)) + swiotlb_bounce(hwdev, tlb_addr, mapping_size, DMA_FROM_DEVICE); /* * Return the buffer to the free list by setting the corresponding @@ -721,27 +719,16 @@ void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr, size_t size, enum dma_data_direction dir, enum dma_sync_target target) { - int index = (tlb_addr - io_tlb_start) >> IO_TLB_SHIFT; - size_t alloc_size = io_tlb_alloc_size[index]; - phys_addr_t orig_addr = io_tlb_orig_addr[index]; - - if (orig_addr == INVALID_PHYS_ADDR) - return; - - validate_sync_size_and_truncate(hwdev, alloc_size, &size); - switch (target) { case SYNC_FOR_CPU: if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL)) - swiotlb_bounce(orig_addr, tlb_addr, - size, DMA_FROM_DEVICE); + swiotlb_bounce(hwdev, tlb_addr, size, DMA_FROM_DEVICE); else BUG_ON(dir != DMA_TO_DEVICE); break; case SYNC_FOR_DEVICE: if (likely(dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) - swiotlb_bounce(orig_addr, tlb_addr, - size, DMA_TO_DEVICE); + swiotlb_bounce(hwdev, tlb_addr, size, DMA_TO_DEVICE); else BUG_ON(dir != DMA_FROM_DEVICE); break; |