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author | Christoph Hellwig <hch@lst.de> | 2019-07-26 09:26:40 +0200 |
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committer | Christoph Hellwig <hch@lst.de> | 2019-08-10 19:52:45 +0200 |
commit | 33dcb37cef741294b481f4d889a465b8091f11bf (patch) | |
tree | 129f9cde5b52cd77e04382c99ff0421aa862354b /arch/powerpc/kernel/dma-common.c | |
parent | d8ad55538abe443919e20e0bb996561bca9cad84 (diff) | |
download | linux-33dcb37cef741294b481f4d889a465b8091f11bf.tar.bz2 |
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: 64ccc9c033c6 ("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
Diffstat (limited to 'arch/powerpc/kernel/dma-common.c')
-rw-r--r-- | arch/powerpc/kernel/dma-common.c | 17 |
1 files changed, 0 insertions, 17 deletions
diff --git a/arch/powerpc/kernel/dma-common.c b/arch/powerpc/kernel/dma-common.c deleted file mode 100644 index dc7ef6b17b69..000000000000 --- a/arch/powerpc/kernel/dma-common.c +++ /dev/null @@ -1,17 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * Contains common dma routines for all powerpc platforms. - * - * Copyright (C) 2019 Shawn Anastasio. - */ - -#include <linux/mm.h> -#include <linux/dma-noncoherent.h> - -pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot, - unsigned long attrs) -{ - if (!dev_is_dma_coherent(dev)) - return pgprot_noncached(prot); - return prot; -} |