Merge branch 'core/iommu' into core/urgent
[sfrench/cifs-2.6.git] / arch / x86 / kernel / pci-swiotlb_64.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(void *ptr, size_t size)
37 {
38         return 0;
39 }
40
41 static dma_addr_t
42 swiotlb_map_single_phys(struct device *hwdev, phys_addr_t paddr, size_t size,
43                         int direction)
44 {
45         return swiotlb_map_single(hwdev, phys_to_virt(paddr), size, direction);
46 }
47
48 static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
49                                         dma_addr_t *dma_handle, gfp_t flags)
50 {
51         void *vaddr;
52
53         vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags);
54         if (vaddr)
55                 return vaddr;
56
57         return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
58 }
59
60 struct dma_mapping_ops swiotlb_dma_ops = {
61         .mapping_error = swiotlb_dma_mapping_error,
62         .alloc_coherent = x86_swiotlb_alloc_coherent,
63         .free_coherent = swiotlb_free_coherent,
64         .map_single = swiotlb_map_single_phys,
65         .unmap_single = swiotlb_unmap_single,
66         .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
67         .sync_single_for_device = swiotlb_sync_single_for_device,
68         .sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
69         .sync_single_range_for_device = swiotlb_sync_single_range_for_device,
70         .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
71         .sync_sg_for_device = swiotlb_sync_sg_for_device,
72         .map_sg = swiotlb_map_sg,
73         .unmap_sg = swiotlb_unmap_sg,
74         .dma_supported = NULL,
75 };
76
77 void __init pci_swiotlb_init(void)
78 {
79         /* don't initialize swiotlb if iommu=off (no_iommu=1) */
80 #ifdef CONFIG_X86_64
81         if (!iommu_detected && !no_iommu && max_pfn > MAX_DMA32_PFN)
82                swiotlb = 1;
83 #endif
84         if (swiotlb_force)
85                 swiotlb = 1;
86         if (swiotlb) {
87                 printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
88                 swiotlb_init();
89                 dma_ops = &swiotlb_dma_ops;
90         }
91 }