Commit df336d1c authored by Keir Fraser's avatar Keir Fraser Committed by Linus Torvalds

Fix swiotlb_sync_single_range()

If the swiotlb maps a multi-slab region, swiotlb_sync_single_range() can be
invoked to sync a sub-region which does not include the first slab.
Unfortunately io_tlb_orig_addr[] is only initialised for the first slab,
and hence the call to sync_single() will read a garbage orig_addr in this
case.

This patch fixes the issue by initialising all mapped slabs in
io_tlb_orig_addr[].  It also correctly adjusts the buffer pointer in
sync_single() to handle the case that the given dma_addr is not aligned on
a slab boundary.
Signed-off-by: default avatarKeir Fraser <keir.fraser@cl.cam.ac.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Acked-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 28de7948
......@@ -357,7 +357,8 @@ map_single(struct device *hwdev, char *buffer, size_t size, int dir)
* This is needed when we sync the memory. Then we sync the buffer if
* needed.
*/
io_tlb_orig_addr[index] = buffer;
for (i = 0; i < nslots; i++)
io_tlb_orig_addr[index+i] = buffer + (i << IO_TLB_SHIFT);
if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
memcpy(dma_addr, buffer, size);
......@@ -418,6 +419,8 @@ sync_single(struct device *hwdev, char *dma_addr, size_t size,
int index = (dma_addr - io_tlb_start) >> IO_TLB_SHIFT;
char *buffer = io_tlb_orig_addr[index];
buffer += ((unsigned long)dma_addr & ((1 << IO_TLB_SHIFT) - 1));
switch (target) {
case SYNC_FOR_CPU:
if (likely(dir == DMA_FROM_DEVICE || dir == DMA_BIDIRECTIONAL))
......
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