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
17void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
18					dma_addr_t *dma_handle, gfp_t flags,
19					struct dma_attrs *attrs)
20{
21	void *vaddr;
22
23	vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags,
24					   attrs);
25	if (vaddr)
26		return vaddr;
27
28	return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
29}
30
31void x86_swiotlb_free_coherent(struct device *dev, size_t size,
32				      void *vaddr, dma_addr_t dma_addr,
33				      struct dma_attrs *attrs)
34{
35	if (is_swiotlb_buffer(dma_to_phys(dev, dma_addr)))
36		swiotlb_free_coherent(dev, size, vaddr, dma_addr);
37	else
38		dma_generic_free_coherent(dev, size, vaddr, dma_addr, attrs);
39}
40
41static struct dma_map_ops swiotlb_dma_ops = {
42	.mapping_error = swiotlb_dma_mapping_error,
43	.alloc = x86_swiotlb_alloc_coherent,
44	.free = x86_swiotlb_free_coherent,
45	.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
46	.sync_single_for_device = swiotlb_sync_single_for_device,
47	.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
48	.sync_sg_for_device = swiotlb_sync_sg_for_device,
49	.map_sg = swiotlb_map_sg_attrs,
50	.unmap_sg = swiotlb_unmap_sg_attrs,
51	.map_page = swiotlb_map_page,
52	.unmap_page = swiotlb_unmap_page,
53	.dma_supported = NULL,
54};
55
56/*
57 * pci_swiotlb_detect_override - set swiotlb to 1 if necessary
58 *
59 * This returns non-zero if we are forced to use swiotlb (by the boot
60 * option).
61 */
62int __init pci_swiotlb_detect_override(void)
63{
64	int use_swiotlb = swiotlb | swiotlb_force;
65
66	if (swiotlb_force)
67		swiotlb = 1;
68
69	return use_swiotlb;
70}
71IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
72		  pci_xen_swiotlb_detect,
73		  pci_swiotlb_init,
74		  pci_swiotlb_late_init);
75
76/*
77 * if 4GB or more detected (and iommu=off not set) return 1
78 * and set swiotlb to 1.
79 */
80int __init pci_swiotlb_detect_4gb(void)
81{
82	/* don't initialize swiotlb if iommu=off (no_iommu=1) */
83#ifdef CONFIG_X86_64
84	if (!no_iommu && max_pfn > MAX_DMA32_PFN)
85		swiotlb = 1;
86#endif
87	return swiotlb;
88}
89IOMMU_INIT(pci_swiotlb_detect_4gb,
90	   pci_swiotlb_detect_override,
91	   pci_swiotlb_init,
92	   pci_swiotlb_late_init);
93
94void __init pci_swiotlb_init(void)
95{
96	if (swiotlb) {
97		swiotlb_init(0);
98		dma_ops = &swiotlb_dma_ops;
99	}
100}
101
102void __init pci_swiotlb_late_init(void)
103{
104	/* An IOMMU turned us off. */
105	if (!swiotlb)
106		swiotlb_free();
107	else {
108		printk(KERN_INFO "PCI-DMA: "
109		       "Using software bounce buffering for IO (SWIOTLB)\n");
110		swiotlb_print_info();
111	}
112}
113