Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
[linux-2.6] / 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 void * __init swiotlb_alloc_boot(size_t size, unsigned long nslabs)
17 {
18         return alloc_bootmem_low_pages(size);
19 }
20
21 void *swiotlb_alloc(unsigned order, unsigned long nslabs)
22 {
23         return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
24 }
25
26 dma_addr_t swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
27 {
28         return paddr;
29 }
30
31 phys_addr_t swiotlb_bus_to_phys(dma_addr_t baddr)
32 {
33         return baddr;
34 }
35
36 int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size)
37 {
38         return 0;
39 }
40
41 static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
42                                         dma_addr_t *dma_handle, gfp_t flags)
43 {
44         void *vaddr;
45
46         vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags);
47         if (vaddr)
48                 return vaddr;
49
50         return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
51 }
52
53 static struct dma_map_ops swiotlb_dma_ops = {
54         .mapping_error = swiotlb_dma_mapping_error,
55         .alloc_coherent = x86_swiotlb_alloc_coherent,
56         .free_coherent = swiotlb_free_coherent,
57         .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
58         .sync_single_for_device = swiotlb_sync_single_for_device,
59         .sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
60         .sync_single_range_for_device = swiotlb_sync_single_range_for_device,
61         .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
62         .sync_sg_for_device = swiotlb_sync_sg_for_device,
63         .map_sg = swiotlb_map_sg_attrs,
64         .unmap_sg = swiotlb_unmap_sg_attrs,
65         .map_page = swiotlb_map_page,
66         .unmap_page = swiotlb_unmap_page,
67         .dma_supported = NULL,
68 };
69
70 void __init pci_swiotlb_init(void)
71 {
72         /* don't initialize swiotlb if iommu=off (no_iommu=1) */
73 #ifdef CONFIG_X86_64
74         if (!iommu_detected && !no_iommu && max_pfn > MAX_DMA32_PFN)
75                swiotlb = 1;
76 #endif
77         if (swiotlb_force)
78                 swiotlb = 1;
79         if (swiotlb) {
80                 printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
81                 swiotlb_init();
82                 dma_ops = &swiotlb_dma_ops;
83         }
84 }