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| author | Christoph Hellwig <hch@lst.de> | 2019-06-14 16:06:10 +0200 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2019-06-25 08:14:43 +0200 |
| commit | 4b85faed211ccfbcc7f3adf1cd62f0b00d1a172b (patch) | |
| tree | dcc65552dd34f276ac4e20104f2f981da996bdc6 | |
| parent | 961729bfc73e698be19305834805592227bd09e3 (diff) | |
| download | linux-stable-4b85faed211ccfbcc7f3adf1cd62f0b00d1a172b.tar.gz linux-stable-4b85faed211ccfbcc7f3adf1cd62f0b00d1a172b.tar.bz2 linux-stable-4b85faed211ccfbcc7f3adf1cd62f0b00d1a172b.zip | |
dma-mapping: add a dma_alloc_need_uncached helper
Check if we need to allocate uncached memory for a device given the
allocation flags. Switch over the uncached segment check to this helper
to deal with architectures that do not support the dma_cache_sync
operation and thus should not returned cacheable memory for
DMA_ATTR_NON_CONSISTENT allocations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
| -rw-r--r-- | include/linux/dma-noncoherent.h | 14 | ||||
| -rw-r--r-- | kernel/dma/direct.c | 4 |
2 files changed, 16 insertions, 2 deletions
diff --git a/include/linux/dma-noncoherent.h b/include/linux/dma-noncoherent.h index 7e0126a04e02..732919ac5c11 100644 --- a/include/linux/dma-noncoherent.h +++ b/include/linux/dma-noncoherent.h @@ -20,6 +20,20 @@ static inline bool dev_is_dma_coherent(struct device *dev) } #endif /* CONFIG_ARCH_HAS_DMA_COHERENCE_H */ +/* + * Check if an allocation needs to be marked uncached to be coherent. + */ +static inline bool dma_alloc_need_uncached(struct device *dev, + unsigned long attrs) +{ + if (dev_is_dma_coherent(dev)) + return false; + if (IS_ENABLED(CONFIG_DMA_NONCOHERENT_CACHE_SYNC) && + (attrs & DMA_ATTR_NON_CONSISTENT)) + return false; + return true; +} + void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs); void arch_dma_free(struct device *dev, size_t size, void *cpu_addr, diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index b67f0aa08aa3..c2893713bf80 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -160,7 +160,7 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size, memset(ret, 0, size); if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) && - !dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_NON_CONSISTENT)) { + dma_alloc_need_uncached(dev, attrs)) { arch_dma_prep_coherent(page, size); ret = uncached_kernel_address(ret); } @@ -182,7 +182,7 @@ void dma_direct_free_pages(struct device *dev, size_t size, void *cpu_addr, set_memory_encrypted((unsigned long)cpu_addr, 1 << page_order); if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) && - !dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_NON_CONSISTENT)) + dma_alloc_need_uncached(dev, attrs)) cpu_addr = cached_kernel_address(cpu_addr); __dma_direct_free_pages(dev, size, virt_to_page(cpu_addr)); } |