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cbf53074a5
core-api/dma-api-howto.rst states the following properties of
dma_alloc_coherent():
| The CPU virtual address and the DMA address are both guaranteed to
| be aligned to the smallest PAGE_SIZE order which is greater than or
| equal to the requested size.
However, swiotlb_alloc() passes zero for the 'alloc_align_mask'
parameter of swiotlb_find_slots() and so this property is not upheld.
Instead, allocations larger than a page are aligned to PAGE_SIZE,
Calculate the mask corresponding to the page order suitable for holding
the allocation and pass that to swiotlb_find_slots().
Fixes: e81e99bacc9f ("swiotlb: Support aligned swiotlb buffers")
Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>