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#include <asm/xen/swiotlb-xen.h>
 14#include <asm/iommu_table.h>
 15int swiotlb __read_mostly;
 16
 17static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 18					dma_addr_t *dma_handle, gfp_t flags)
 19{
 20	void *vaddr;
 21
 22	vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags);
 23	if (vaddr)
 24		return vaddr;
 25
 26	return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
 27}
 28
 29static struct dma_map_ops swiotlb_dma_ops = {
 30	.mapping_error = swiotlb_dma_mapping_error,
 31	.alloc_coherent = x86_swiotlb_alloc_coherent,
 32	.free_coherent = swiotlb_free_coherent,
 33	.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
 34	.sync_single_for_device = swiotlb_sync_single_for_device,
 35	.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
 36	.sync_sg_for_device = swiotlb_sync_sg_for_device,
 37	.map_sg = swiotlb_map_sg_attrs,
 38	.unmap_sg = swiotlb_unmap_sg_attrs,
 39	.map_page = swiotlb_map_page,
 40	.unmap_page = swiotlb_unmap_page,
 41	.dma_supported = NULL,
 42};
 43
 44/*
 45 * pci_swiotlb_detect_override - set swiotlb to 1 if necessary
 46 *
 47 * This returns non-zero if we are forced to use swiotlb (by the boot
 48 * option).
 49 */
 50int __init pci_swiotlb_detect_override(void)
 51{
 52	int use_swiotlb = swiotlb | swiotlb_force;
 53
 54	if (swiotlb_force)
 55		swiotlb = 1;
 56
 57	return use_swiotlb;
 58}
 59IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
 60		  pci_xen_swiotlb_detect,
 61		  pci_swiotlb_init,
 62		  pci_swiotlb_late_init);
 63
 64/*
 65 * if 4GB or more detected (and iommu=off not set) return 1
 66 * and set swiotlb to 1.
 67 */
 68int __init pci_swiotlb_detect_4gb(void)
 69{
 70	/* don't initialize swiotlb if iommu=off (no_iommu=1) */
 71#ifdef CONFIG_X86_64
 72	if (!no_iommu && max_pfn > MAX_DMA32_PFN)
 73		swiotlb = 1;
 74#endif
 75	return swiotlb;
 76}
 77IOMMU_INIT(pci_swiotlb_detect_4gb,
 78	   pci_swiotlb_detect_override,
 79	   pci_swiotlb_init,
 80	   pci_swiotlb_late_init);
 81
 82void __init pci_swiotlb_init(void)
 83{
 84	if (swiotlb) {
 85		swiotlb_init(0);
 86		dma_ops = &swiotlb_dma_ops;
 87	}
 88}
 89
 90void __init pci_swiotlb_late_init(void)
 91{
 92	/* An IOMMU turned us off. */
 93	if (!swiotlb)
 94		swiotlb_free();
 95	else {
 96		printk(KERN_INFO "PCI-DMA: "
 97		       "Using software bounce buffering for IO (SWIOTLB)\n");
 98		swiotlb_print_info();
 99	}
100}