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authorChristoph Hellwig <hch@lst.de>2019-07-16 22:00:54 +0200
committerChristoph Hellwig <hch@lst.de>2019-07-17 08:25:45 +0200
commita5008b59cd9d8de12ab623cb5052bb4735330e5c (patch)
tree50f36841635531cb81255bc1ffad56b3e229512e /kernel/dma
parentdma-mapping: add a dma_addressing_limited helper (diff)
downloadlinux-a5008b59cd9d8de12ab623cb5052bb4735330e5c.tar.xz
linux-a5008b59cd9d8de12ab623cb5052bb4735330e5c.zip
dma-direct: only limit the mapping size if swiotlb could be used
Don't just check for a swiotlb buffer, but also if buffering might be required for this particular device. Fixes: 133d624b1cee ("dma: Introduce dma_max_mapping_size()") Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'kernel/dma')
-rw-r--r--kernel/dma/direct.c10
1 files changed, 4 insertions, 6 deletions
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index d7cec866d16b..e269b6f9b444 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -399,11 +399,9 @@ int dma_direct_supported(struct device *dev, u64 mask)
size_t dma_direct_max_mapping_size(struct device *dev)
{
- size_t size = SIZE_MAX;
-
/* If SWIOTLB is active, use its maximum mapping size */
- if (is_swiotlb_active())
- size = swiotlb_max_mapping_size(dev);
-
- return size;
+ if (is_swiotlb_active() &&
+ (dma_addressing_limited(dev) || swiotlb_force == SWIOTLB_FORCE))
+ return swiotlb_max_mapping_size(dev);
+ return SIZE_MAX;
}