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authorChristoph Hellwig <hch@lst.de>2019-03-15 19:56:43 +0300
committerChristoph Hellwig <hch@lst.de>2019-09-04 12:13:17 +0300
commit14451467014b4c8aff6570b44b6d0ee68cd49bc0 (patch)
tree66eec34dfcf1db31d85ebc9b1387e4ec43fe8a58 /arch/arm/mm/dma-mapping.c
parent392e879a445008e8e96b872dabaaf5b1eca58729 (diff)
downloadlinux-14451467014b4c8aff6570b44b6d0ee68cd49bc0.tar.xz
dma-mapping: move the dma_get_sgtable API comments from arm to common code
The comments are spot on and should be near the central API, not just near a single implementation. Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'arch/arm/mm/dma-mapping.c')
-rw-r--r--arch/arm/mm/dma-mapping.c11
1 files changed, 0 insertions, 11 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index d27b12f61737..0189a757a8f2 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -877,17 +877,6 @@ static void arm_coherent_dma_free(struct device *dev, size_t size, void *cpu_add
__arm_dma_free(dev, size, cpu_addr, handle, attrs, true);
}
-/*
- * The whole dma_get_sgtable() idea is fundamentally unsafe - it seems
- * that the intention is to allow exporting memory allocated via the
- * coherent DMA APIs through the dma_buf API, which only accepts a
- * scattertable. This presents a couple of problems:
- * 1. Not all memory allocated via the coherent DMA APIs is backed by
- * a struct page
- * 2. Passing coherent DMA memory into the streaming APIs is not allowed
- * as we will try to flush the memory through a different alias to that
- * actually being used (and the flushes are redundant.)
- */
int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t handle, size_t size,
unsigned long attrs)