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authorCatalin Marinas <catalin.marinas@arm.com>2023-06-12 16:31:58 +0100
committerAndrew Morton <akpm@linux-foundation.org>2023-06-19 16:19:23 -0700
commit370645f41e6e2fdd2fb6f6982530b04612c9793c (patch)
treed933588760e0bdde771efa04caab34d151b68039 /kernel/dma
parentcb147bbe22d2be9b49021c2e5dacdf2935745d1c (diff)
dma-mapping: force bouncing if the kmalloc() size is not cache-line-aligned
For direct DMA, if the size is small enough to have originated from a kmalloc() cache below ARCH_DMA_MINALIGN, check its alignment against dma_get_cache_alignment() and bounce if necessary. For larger sizes, it is the responsibility of the DMA API caller to ensure proper alignment. At this point, the kmalloc() caches are properly aligned but this will change in a subsequent patch. Architectures can opt in by selecting DMA_BOUNCE_UNALIGNED_KMALLOC. Link: https://lkml.kernel.org/r/20230612153201.554742-15-catalin.marinas@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Tested-by: Isaac J. Manjarres <isaacmanjarres@google.com> Cc: Alasdair Kergon <agk@redhat.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jerry Snitselaar <jsnitsel@redhat.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Lars-Peter Clausen <lars@metafoo.de> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Mark Brown <broonie@kernel.org> Cc: Mike Snitzer <snitzer@kernel.org> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel/dma')
-rw-r--r--kernel/dma/Kconfig4
-rw-r--r--kernel/dma/direct.h3
2 files changed, 6 insertions, 1 deletions
diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
index acc6f231259c..abea1823fe21 100644
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -90,6 +90,10 @@ config SWIOTLB
bool
select NEED_DMA_MAP_STATE
+config DMA_BOUNCE_UNALIGNED_KMALLOC
+ bool
+ depends on SWIOTLB
+
config DMA_RESTRICTED_POOL
bool "DMA Restricted Pool"
depends on OF && OF_RESERVED_MEM && SWIOTLB
diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h
index e38ffc5e6bdd..97ec892ea0b5 100644
--- a/kernel/dma/direct.h
+++ b/kernel/dma/direct.h
@@ -94,7 +94,8 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev,
return swiotlb_map(dev, phys, size, dir, attrs);
}
- if (unlikely(!dma_capable(dev, dma_addr, size, true))) {
+ if (unlikely(!dma_capable(dev, dma_addr, size, true)) ||
+ dma_kmalloc_needs_bounce(dev, size, dir)) {
if (is_pci_p2pdma_page(page))
return DMA_MAPPING_ERROR;
if (is_swiotlb_active(dev))