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| author | Christoph Hellwig <hch@lst.de> | 2021-11-09 15:47:56 +0100 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2021-12-07 12:50:06 +0100 |
| commit | 955f58f7406ad912825fc344c7825fd904b124a0 (patch) | |
| tree | a23e035d3fd7886c708f7bb0937990e0d30267bd /kernel/dma | |
| parent | dma-direct: refactor the !coherent checks in dma_direct_alloc (diff) | |
| download | linux-955f58f7406ad912825fc344c7825fd904b124a0.tar.xz linux-955f58f7406ad912825fc344c7825fd904b124a0.zip | |
dma-direct: fail allocations that can't be made coherent
If the architecture can't remap or set an address uncached there is no way
to fullfill a request for a coherent allocation. Return NULL in that case.
Note that this case currently does not happen, so this is a theoretical
fixup and/or a preparation for eventually supporting platforms that
can't support coherent allocations with the generic code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Diffstat (limited to 'kernel/dma')
| -rw-r--r-- | kernel/dma/direct.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index f9658fe18498..a13017656eca 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -233,8 +233,9 @@ void *dma_direct_alloc(struct device *dev, size_t size, return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp); } else { - if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED)) - set_uncached = true; + if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED)) + return NULL; + set_uncached = true; } } |