arch/x86_64/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 <asm/dma-mapping.h>
   7 #include <asm/proto.h>
   8 #include <asm/swiotlb.h>
   9 #include <asm/dma.h>
  10
  11 int swiotlb __read_mostly;
  12 EXPORT_SYMBOL(swiotlb);
  13
  14 struct dma_mapping_ops swiotlb_dma_ops = {
  15         .mapping_error = swiotlb_dma_mapping_error,
  16         .alloc_coherent = swiotlb_alloc_coherent,
  17         .free_coherent = swiotlb_free_coherent,
  18         .map_single = swiotlb_map_single,
  19         .unmap_single = swiotlb_unmap_single,
  20         .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
  21         .sync_single_for_device = swiotlb_sync_single_for_device,
  22         .sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
  23         .sync_single_range_for_device = swiotlb_sync_single_range_for_device,
  24         .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
  25         .sync_sg_for_device = swiotlb_sync_sg_for_device,
  26         .map_sg = swiotlb_map_sg,
  27         .unmap_sg = swiotlb_unmap_sg,
  28         .dma_supported = NULL,
  29 };
  30
  31 void pci_swiotlb_init(void)
  32 {
  33         /* don't initialize swiotlb if iommu=off (no_iommu=1) */
  34         if (!iommu_detected && !no_iommu && end_pfn > MAX_DMA32_PFN)
  35                swiotlb = 1;
  36         if (swiotlb_force)
  37                 swiotlb = 1;
  38         if (swiotlb) {
  39                 printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
  40                 swiotlb_init();
  41                 dma_ops = &swiotlb_dma_ops;
  42         }
  43 }