linux/kernel/dma
Christoph Hellwig 33dcb37cef dma-mapping: fix page attributes for dma_mmap_*
All the way back to introducing dma_common_mmap we've defaulted to mark
the pages as uncached.  But this is wrong for DMA coherent devices.
Later on DMA_ATTR_WRITE_COMBINE also got incorrect treatment as that
flag is only treated special on the alloc side for non-coherent devices.

Introduce a new dma_pgprot helper that deals with the check for coherent
devices so that only the remapping cases ever reach arch_dma_mmap_pgprot
and we thus ensure no aliasing of page attributes happens, which makes
the powerpc version of arch_dma_mmap_pgprot obsolete and simplifies the
remaining ones.

Note that this means arch_dma_mmap_pgprot is a bit misnamed now, but
we'll phase it out soon.

Fixes: 64ccc9c033 ("common: dma-mapping: add support for generic dma_mmap_* calls")
Reported-by: Shawn Anastasio <shawn@anastas.io>
Reported-by: Gavin Li <git@thegavinli.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> # arm64
2019-08-10 19:52:45 +02:00
..
Kconfig dma-direct: Force unencrypted DMA under SME for certain DMA masks 2019-07-16 22:15:46 +02:00
Makefile dma-mapping: improve selection of dma_declare_coherent availability 2019-02-20 07:26:35 -07:00
coherent.c dma-mapping: remove the DMA_MEMORY_EXCLUSIVE flag 2019-02-20 07:27:00 -07:00
contiguous.c dma-contiguous: page-align the size in dma_free_contiguous() 2019-07-29 09:50:04 +03:00
debug.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
direct.c dma-direct: don't truncate dma_required_mask to bus addressing capabilities 2019-08-10 19:52:45 +02:00
dummy.c dma-mapping: factor out dummy DMA ops 2018-12-13 21:06:12 +01:00
mapping.c dma-mapping: fix page attributes for dma_mmap_* 2019-08-10 19:52:45 +02:00
remap.c dma-mapping: fix page attributes for dma_mmap_* 2019-08-10 19:52:45 +02:00
swiotlb.c Merge branch 'for-linus-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb 2019-07-18 11:48:05 -07:00
virt.c dma-mapping: zero memory returned from dma_alloc_* 2018-12-20 08:13:52 +01:00