Commit df336d1c authored Jul 21, 2007 by Keir Fraser Committed by Linus Torvalds Jul 21, 2007

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: Keir Fraser <keir.fraser@cl.cam.ac.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Acked-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 28de7948

lib/swiotlb.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -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))