dma-direct: set decrypted flag for remapped DMA allocations

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Devices that are DMA non-coherent and require a remap were skipping
dma_set_decrypted(), leaving DMA buffers encrypted even when the device
requires unencrypted access. Move the call after the if (remap) branch
so that both the direct and remapped allocation paths correctly mark the
allocation as decrypted (or fail cleanly) before use.

Fix dma_direct_alloc() and dma_direct_free() to apply set_memory_*() to the
linear-map alias of the backing pages instead of the remapped CPU address.
Also disallow highmem pages for __DMA_ATTR_ALLOC_CC_SHARED, because highmem
buffers do not provide a usable linear-map address.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Jiri Pirko <jiri@nvidia.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Link: https://lore.kernel.org/r/20260717180442.110954-19-aneesh.kumar@kernel.org
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

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Aneesh Kumar K.V (Arm) 2026-07-17 23:34:36 +05:30 • committed by Marek Szyprowski

parent 30c5e45ee2

commit f253a83ff9

1 changed files with 44 additions and 12 deletions

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kernel/dma/direct.c

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