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iv/linux

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Will Deacon c803069d48 swiotlb: Fix alignment checks when both allocation and DMA masks are present

[ Upstream commit 51b30ecb73b481d5fac6ccf2ecb4a309c9ee3310 ]

Nicolin reports that swiotlb buffer allocations fail for an NVME device
behind an IOMMU using 64KiB pages. This is because we end up with a
minimum allocation alignment of 64KiB (for the IOMMU to map the buffer
safely) but a minimum DMA alignment mask corresponding to a 4KiB NVME
page (i.e. preserving the 4KiB page offset from the original allocation).
If the original address is not 4KiB-aligned, the allocation will fail
because swiotlb_search_pool_area() erroneously compares these unmasked
bits with the 64KiB-aligned candidate allocation.

Tweak swiotlb_search_pool_area() so that the DMA alignment mask is
reduced based on the required alignment of the allocation.

Fixes: 82612d66d51d ("iommu: Allow the dma-iommu api to use bounce buffers")
Link: https://lore.kernel.org/r/cover.1707851466.git.nicolinc@nvidia.com
Reported-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

2024-04-03 15:28:51 +02:00

coherent.c

dma-mapping: clear dev->dma_mem to NULL after freeing it

2024-01-25 15:35:26 -08:00

contiguous.c

Revert "dma-contiguous: check for memory region overlap"

2023-09-08 05:58:32 -03:00

debug.c

dma-debug: don't call __dma_entry_alloc_check_leak() under free_entries_lock

2023-08-30 11:29:08 +02:00

debug.h

dma-debug: teach add_dma_entry() about DMA_ATTR_SKIP_CPU_SYNC