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Subject[PATCH 38/67] x86/amd_gart: clean up gart_alloc_coherent
Date
Don't rely on the gfp mask from dma_alloc_coherent_gfp_flags to make the
fallback decision, and streamline the code flow a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/x86/kernel/amd_gart_64.c | 36 ++++++++++++++++++------------------
1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c
index 52e3abcf3e70..92054815023e 100644
--- a/arch/x86/kernel/amd_gart_64.c
+++ b/arch/x86/kernel/amd_gart_64.c
@@ -484,26 +484,26 @@ gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr,
unsigned long align_mask;
struct page *page;

- if (force_iommu && !(flag & GFP_DMA)) {
- flag &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
- page = alloc_pages(flag | __GFP_ZERO, get_order(size));
- if (!page)
- return NULL;
-
- align_mask = (1UL << get_order(size)) - 1;
- paddr = dma_map_area(dev, page_to_phys(page), size,
- DMA_BIDIRECTIONAL, align_mask);
-
- flush_gart();
- if (paddr != bad_dma_addr) {
- *dma_addr = paddr;
- return page_address(page);
- }
- __free_pages(page, get_order(size));
- } else
+ if (!force_iommu || dev->coherent_dma_mask <= DMA_BIT_MASK(24))
return dma_direct_alloc(dev, size, dma_addr, flag, attrs);

- return NULL;
+ flag &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
+ page = alloc_pages(flag | __GFP_ZERO, get_order(size));
+ if (!page)
+ return NULL;
+
+ align_mask = (1UL << get_order(size)) - 1;
+ paddr = dma_map_area(dev, page_to_phys(page), size, DMA_BIDIRECTIONAL,
+ align_mask);
+
+ flush_gart();
+ if (unlikely(paddr == bad_dma_addr)) {
+ __free_pages(page, get_order(size));
+ return NULL;
+ }
+
+ *dma_addr = paddr;
+ return page_address(page);
}

/* free a coherent mapping */
--
2.14.2
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