ea675cfe76fe83538f784c04f2eb5700fb2be8b2
[linux-2.6.git] / arch / x86 / kernel / pci-swiotlb.c
1 /* Glue code to lib/swiotlb.c */
2
3 #include <linux/pci.h>
4 #include <linux/cache.h>
5 #include <linux/module.h>
6 #include <linux/swiotlb.h>
7 #include <linux/bootmem.h>
8 #include <linux/dma-mapping.h>
9
10 #include <asm/iommu.h>
11 #include <asm/swiotlb.h>
12 #include <asm/dma.h>
13
14 int swiotlb __read_mostly;
15
16 dma_addr_t swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
17 {
18         return paddr;
19 }
20
21 phys_addr_t swiotlb_bus_to_phys(struct device *hwdev, dma_addr_t baddr)
22 {
23         return baddr;
24 }
25
26 int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size)
27 {
28         return 0;
29 }
30
31 static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
32                                         dma_addr_t *dma_handle, gfp_t flags)
33 {
34         void *vaddr;
35
36         vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags);
37         if (vaddr)
38                 return vaddr;
39
40         return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
41 }
42
43 static struct dma_map_ops swiotlb_dma_ops = {
44         .mapping_error = swiotlb_dma_mapping_error,
45         .alloc_coherent = x86_swiotlb_alloc_coherent,
46         .free_coherent = swiotlb_free_coherent,
47         .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
48         .sync_single_for_device = swiotlb_sync_single_for_device,
49         .sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
50         .sync_single_range_for_device = swiotlb_sync_single_range_for_device,
51         .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
52         .sync_sg_for_device = swiotlb_sync_sg_for_device,
53         .map_sg = swiotlb_map_sg_attrs,
54         .unmap_sg = swiotlb_unmap_sg_attrs,
55         .map_page = swiotlb_map_page,
56         .unmap_page = swiotlb_unmap_page,
57         .dma_supported = NULL,
58 };
59
60 void __init pci_swiotlb_init(void)
61 {
62         /* don't initialize swiotlb if iommu=off (no_iommu=1) */
63 #ifdef CONFIG_X86_64
64         if ((!iommu_detected && !no_iommu && max_pfn > MAX_DMA32_PFN) ||
65                 iommu_pass_through)
66                swiotlb = 1;
67 #endif
68         if (swiotlb_force)
69                 swiotlb = 1;
70         if (swiotlb) {
71                 printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
72                 swiotlb_init();
73                 dma_ops = &swiotlb_dma_ops;
74         }
75 }