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authorChristoph Hellwig <hch@lst.de>2018-08-23 09:39:38 +0200
committerChristoph Hellwig <hch@lst.de>2018-09-20 09:01:17 +0200
commit9406a49fd1f4379409ed87b29fdaa259b0441912 (patch)
treeb159725e0441d30234c84eb6b3a061e0788febb8 /kernel/dma/mapping.c
parent58b0440663ec11372befb8ead0ee7099d8878590 (diff)
dma-mapping: support non-coherent devices in dma_common_get_sgtable
We can use the arch_dma_coherent_to_pfn hook to provide a ->get_sgtable implementation. Note that this isn't an endorsement of this interface (which is a horrible bad idea), but it is required to move arm64 over to the generic code without a loss of functionality. Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'kernel/dma/mapping.c')
-rw-r--r--kernel/dma/mapping.c23
1 files changed, 16 insertions, 7 deletions
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 42fd73aca305..58dec7a92b7b 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -202,17 +202,26 @@ EXPORT_SYMBOL(dmam_release_declared_memory);
* Create scatter-list for the already allocated DMA buffer.
*/
int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
- void *cpu_addr, dma_addr_t handle, size_t size)
+ void *cpu_addr, dma_addr_t dma_addr, size_t size,
+ unsigned long attrs)
{
- struct page *page = virt_to_page(cpu_addr);
+ struct page *page;
int ret;
- ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
- if (unlikely(ret))
- return ret;
+ if (!dev_is_dma_coherent(dev)) {
+ if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN))
+ return -ENXIO;
- sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
- return 0;
+ page = pfn_to_page(arch_dma_coherent_to_pfn(dev, cpu_addr,
+ dma_addr));
+ } else {
+ page = virt_to_page(cpu_addr);
+ }
+
+ ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
+ if (!ret)
+ sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
+ return ret;
}
EXPORT_SYMBOL(dma_common_get_sgtable);