x86: add swiotlb allocation functions
[linux-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 *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 static dma_addr_t
27 swiotlb_map_single_phys(struct device *hwdev, phys_addr_t paddr, size_t size,
28                         int direction)
29 {
30         return swiotlb_map_single(hwdev, phys_to_virt(paddr), size, direction);
31 }
32
33 static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
34                                         dma_addr_t *dma_handle, gfp_t flags)
35 {
36         void *vaddr;
37
38         vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags);
39         if (vaddr)
40                 return vaddr;
41
42         return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
43 }
44
45 struct dma_mapping_ops swiotlb_dma_ops = {
46         .mapping_error = swiotlb_dma_mapping_error,
47         .alloc_coherent = x86_swiotlb_alloc_coherent,
48         .free_coherent = swiotlb_free_coherent,
49         .map_single = swiotlb_map_single_phys,
50         .unmap_single = swiotlb_unmap_single,
51         .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
52         .sync_single_for_device = swiotlb_sync_single_for_device,
53         .sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
54         .sync_single_range_for_device = swiotlb_sync_single_range_for_device,
55         .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
56         .sync_sg_for_device = swiotlb_sync_sg_for_device,
57         .map_sg = swiotlb_map_sg,
58         .unmap_sg = swiotlb_unmap_sg,
59         .dma_supported = NULL,
60 };
61
62 void __init pci_swiotlb_init(void)
63 {
64         /* don't initialize swiotlb if iommu=off (no_iommu=1) */
65         if (!iommu_detected && !no_iommu && max_pfn > MAX_DMA32_PFN)
66                swiotlb = 1;
67         if (swiotlb_force)
68                 swiotlb = 1;
69         if (swiotlb) {
70                 printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
71                 swiotlb_init();
72                 dma_ops = &swiotlb_dma_ops;
73         }
74 }