[38/67] x86/amd_gart: clean up gart_alloc_coherent

Commit Message

Christoph Hellwig Dec. 29, 2017, 8:18 a.m. UTC

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 <[e-mail]>
---
 arch/x86/kernel/amd_gart_64.c | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

Patch

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 */