aaa6b7839f1e3541e2a36bb67c770bf343075de7
[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 static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
17                                         dma_addr_t *dma_handle, gfp_t flags)
18 {
19         void *vaddr;
20
21         vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags);
22         if (vaddr)
23                 return vaddr;
24
25         return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
26 }
27
28 static struct dma_map_ops swiotlb_dma_ops = {
29         .mapping_error = swiotlb_dma_mapping_error,
30         .alloc_coherent = x86_swiotlb_alloc_coherent,
31         .free_coherent = swiotlb_free_coherent,
32         .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
33         .sync_single_for_device = swiotlb_sync_single_for_device,
34         .sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
35         .sync_single_range_for_device = swiotlb_sync_single_range_for_device,
36         .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
37         .sync_sg_for_device = swiotlb_sync_sg_for_device,
38         .map_sg = swiotlb_map_sg_attrs,
39         .unmap_sg = swiotlb_unmap_sg_attrs,
40         .map_page = swiotlb_map_page,
41         .unmap_page = swiotlb_unmap_page,
42         .dma_supported = NULL,
43 };
44
45 void __init pci_swiotlb_init(void)
46 {
47         /* don't initialize swiotlb if iommu=off (no_iommu=1) */
48 #ifdef CONFIG_X86_64
49         if ((!iommu_detected && !no_iommu && max_pfn > MAX_DMA32_PFN))
50                 swiotlb = 1;
51 #endif
52         if (swiotlb_force)
53                 swiotlb = 1;
54         if (swiotlb) {
55                 printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
56                 swiotlb_init();
57                 dma_ops = &swiotlb_dma_ops;
58         }
59 }