Instead of blindly running into a blocking operation for a non-blocking gfp,
return NULL and spew an error. Note that Kconfig prevents this for all
currently relevant platforms, and this is just a debug check.
Signed-off-by: Christoph Hellwig <h...@lst.de>
Reviewed-by: Robin Murphy <robin.mur...@arm.com>
---
kernel/dma/direct.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index a13017656ecae..84226a764471b 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -159,6 +159,9 @@ static void *dma_direct_alloc_from_pool(struct device *dev,
size_t size,
u64 phys_mask;
void *ret;
+ if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_DMA_COHERENT_POOL)))
+ return NULL;
+
gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
&phys_mask);
page = dma_alloc_from_pool(dev, size, &ret, gfp, dma_coherent_ok);
@@ -243,8 +246,7 @@ void *dma_direct_alloc(struct device *dev, size_t size,
* Decrypting memory may block, so allocate the memory from the atomic
* pools if we can't block.
*/
- if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&
- force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) &&
+ if (force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) &&
!is_swiotlb_for_alloc(dev))
return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
@@ -354,8 +356,7 @@ struct page *dma_direct_alloc_pages(struct device *dev,
size_t size,
struct page *page;
void *ret;
- if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&
- force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) &&
+ if (force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) &&
!is_swiotlb_for_alloc(dev))
return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
--
2.30.2
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