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 }