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 <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 EXPORT_SYMBOL(swiotlb);
  14
  15 const struct dma_mapping_ops swiotlb_dma_ops = {
  16         .mapping_error = swiotlb_dma_mapping_error,
  17         .alloc_coherent = swiotlb_alloc_coherent,
  18         .free_coherent = swiotlb_free_coherent,
  19         .map_single = swiotlb_map_single,
  20         .unmap_single = swiotlb_unmap_single,
  21         .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
  22         .sync_single_for_device = swiotlb_sync_single_for_device,
  23         .sync_single_range_for_cpu = swiotlb_sync_single_range_for_cpu,
  24         .sync_single_range_for_device = swiotlb_sync_single_range_for_device,
  25         .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
  26         .sync_sg_for_device = swiotlb_sync_sg_for_device,
  27         .map_sg = swiotlb_map_sg,
  28         .unmap_sg = swiotlb_unmap_sg,
  29         .dma_supported = NULL,
  30 };
  31
  32 void __init pci_swiotlb_init(void)
  33 {
  34         /* don't initialize swiotlb if iommu=off (no_iommu=1) */
  35         if (!iommu_detected && !no_iommu && end_pfn > MAX_DMA32_PFN)
  36                swiotlb = 1;
  37         if (swiotlb_force)
  38                 swiotlb = 1;
  39         if (swiotlb) {
  40                 printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
  41                 swiotlb_init();
  42                 dma_ops = &swiotlb_dma_ops;
  43         }
  44 }