diff options
| -rw-r--r-- | arch/x86/kernel/pci-nommu.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c index 3f91f71cdc3..b8ce83c9821 100644 --- 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, |