[PATCH 04/15] dma-direct: use dma_direct_map_page to implement dma_direct_map_sg

Christoph Hellwig
2018-12-07T19:07:09Z

No need to duplicate the mapping logic.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
kernel/dma/direct.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index edb24f94ea1e..d45306473c90 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -217,6 +217,7 @@ static void dma_direct_sync_single_for_device(struct device *dev,
arch_sync_dma_for_device(dev, dma_to_phys(dev, addr), size, dir);
}

+#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE)
static void dma_direct_sync_sg_for_device(struct device *dev,
struct scatterlist *sgl, int nents, enum dma_data_direction dir)
{
@@ -229,6 +230,7 @@ static void dma_direct_sync_sg_for_device(struct device *dev,
for_each_sg(sgl, sg, nents, i)
arch_sync_dma_for_device(dev, sg_phys(sg), sg->length, dir);
}
+#endif

#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
@@ -294,19 +296,13 @@ int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
struct scatterlist *sg;

for_each_sg(sgl, sg, nents, i) {
- BUG_ON(!sg_page(sg));
-
- sg_dma_address(sg) = phys_to_dma(dev, sg_phys(sg));
- if (unlikely(dev && !dma_capable(dev, sg_dma_address(sg),
- sg->length))) {
- report_addr(dev, sg_dma_address(sg), sg->length);
+ sg->dma_address = dma_direct_map_page(dev, sg_page(sg),
+ sg->offset, sg->length, dir, attrs);
+ if (sg->dma_address = DMA_MAPPING_ERROR)
return 0;
- }
sg_dma_len(sg) = sg->length;
}

- if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
- dma_direct_sync_sg_for_device(dev, sgl, nents, dir);
return nents;
}

--
2.19.1