x86: add alloc_coherent dma_ops callback to NOMMU driver

[pandora-kernel.git] / arch / x86 / kernel / pci-nommu.c

diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
index 3f91f71..b8ce83c 100644 (file)
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -72,7 +72,62 @@ static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg,
        return nents;
 }
 
+static void *
+nommu_alloc_coherent(struct device *hwdev, size_t size,
+                    dma_addr_t *dma_addr, gfp_t gfp)
+{
+       unsigned long dma_mask;
+       int node;
+       struct page *page;
+
+       if (hwdev->dma_mask == NULL)
+               return NULL;
+
+       gfp &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
+       gfp |= __GFP_ZERO;
+
+       dma_mask = hwdev->coherent_dma_mask;
+       if (!dma_mask)
+               dma_mask = *(hwdev->dma_mask);
+
+       if (dma_mask < DMA_24BIT_MASK)
+               return NULL;
+
+       node = dev_to_node(hwdev);
+
+#ifdef CONFIG_X86_64
+       if (dma_mask <= DMA_32BIT_MASK)
+               gfp |= GFP_DMA32;
+#endif
+
+       /* No alloc-free penalty for ISA devices */
+       if (dma_mask == DMA_24BIT_MASK)
+               gfp |= GFP_DMA;
+
+again:
+       page = alloc_pages_node(node, gfp, get_order(size));
+       if (!page)
+               return NULL;
+
+       if ((page_to_phys(page) + size > dma_mask) && !(gfp & GFP_DMA)) {
+               free_pages((unsigned long)page_address(page), get_order(size));
+               gfp |= GFP_DMA;
+               goto again;
+       }
+
+       *dma_addr = page_to_phys(page);
+       if (check_addr("alloc_coherent", hwdev, *dma_addr, size)) {
+               flush_write_buffers();
+               return page_address(page);
+       }
+
+       free_pages((unsigned long)page_address(page), get_order(size));
+
+       return NULL;
+}
+
 struct dma_mapping_ops nommu_dma_ops = {
+       .alloc_coherent = nommu_alloc_coherent,
        .map_single = nommu_map_single,
        .map_sg = nommu_map_sg,
        .is_phys = 1,