x86: restore the old swiotlb alloc_coherent behavior
[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/dma-mapping.h>
7
8 #include <asm/iommu.h>
9 #include <asm/swiotlb.h>
10 #include <asm/dma.h>
11
12 int swiotlb __read_mostly;
13
14 static dma_addr_t
15 swiotlb_map_single_phys(struct device *hwdev, phys_addr_t paddr, size_t size,
16                         int direction)
17 {
18         return swiotlb_map_single(hwdev, phys_to_virt(paddr), size, direction);
19 }
20
21 static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
22                                         dma_addr_t *dma_handle, gfp_t flags)
23 {
24         void *vaddr;
25
26         vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags);
27         if (vaddr)
28                 return vaddr;
29
30         return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
31 }
32
33 struct dma_mapping_ops swiotlb_dma_ops = {
34         .mapping_error = swiotlb_dma_mapping_error,
35         .alloc_coherent = x86_swiotlb_alloc_coherent,
36         .free_coherent = swiotlb_free_coherent,
37         .map_single = swiotlb_map_single_phys,
38         .unmap_single = swiotlb_unmap_single,
39         .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
40         .sync_single_for_device = swiotlb_sync_single_for_device,
41         .sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
42         .sync_single_range_for_device = swiotlb_sync_single_range_for_device,
43         .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
44         .sync_sg_for_device = swiotlb_sync_sg_for_device,
45         .map_sg = swiotlb_map_sg,
46         .unmap_sg = swiotlb_unmap_sg,
47         .dma_supported = NULL,
48 };
49
50 void __init pci_swiotlb_init(void)
51 {
52         /* don't initialize swiotlb if iommu=off (no_iommu=1) */
53         if (!iommu_detected && !no_iommu && max_pfn > MAX_DMA32_PFN)
54                swiotlb = 1;
55         if (swiotlb_force)
56                 swiotlb = 1;
57         if (swiotlb) {
58                 printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
59                 swiotlb_init();
60                 dma_ops = &swiotlb_dma_ops;
61         }
62 }