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	/*
24	 * Don't print a warning when the first allocation attempt fails.
25	 * swiotlb_alloc_coherent() will print a warning when the DMA
26	 * memory allocation ultimately failed.
27	 */
28	flags |= __GFP_NOWARN;
29
30	vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags,
31					   attrs);
32	if (vaddr)
33		return vaddr;
34
35	return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
36}
37
38void x86_swiotlb_free_coherent(struct device *dev, size_t size,
39				      void *vaddr, dma_addr_t dma_addr,
40				      struct dma_attrs *attrs)
41{
42	if (is_swiotlb_buffer(dma_to_phys(dev, dma_addr)))
43		swiotlb_free_coherent(dev, size, vaddr, dma_addr);
44	else
45		dma_generic_free_coherent(dev, size, vaddr, dma_addr, attrs);
46}
47
48static struct dma_map_ops swiotlb_dma_ops = {
49	.mapping_error = swiotlb_dma_mapping_error,
50	.alloc = x86_swiotlb_alloc_coherent,
51	.free = x86_swiotlb_free_coherent,
52	.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
53	.sync_single_for_device = swiotlb_sync_single_for_device,
54	.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
55	.sync_sg_for_device = swiotlb_sync_sg_for_device,
56	.map_sg = swiotlb_map_sg_attrs,
57	.unmap_sg = swiotlb_unmap_sg_attrs,
58	.map_page = swiotlb_map_page,
59	.unmap_page = swiotlb_unmap_page,
60	.dma_supported = NULL,
61};
62
63/*
64 * pci_swiotlb_detect_override - set swiotlb to 1 if necessary
65 *
66 * This returns non-zero if we are forced to use swiotlb (by the boot
67 * option).
68 */
69int __init pci_swiotlb_detect_override(void)
70{
71	int use_swiotlb = swiotlb | swiotlb_force;
72
73	if (swiotlb_force)
74		swiotlb = 1;
75
76	return use_swiotlb;
77}
78IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
79		  pci_xen_swiotlb_detect,
80		  pci_swiotlb_init,
81		  pci_swiotlb_late_init);
82
83/*
84 * if 4GB or more detected (and iommu=off not set) return 1
85 * and set swiotlb to 1.
86 */
87int __init pci_swiotlb_detect_4gb(void)
88{
89	/* don't initialize swiotlb if iommu=off (no_iommu=1) */
90#ifdef CONFIG_X86_64
91	if (!no_iommu && max_pfn > MAX_DMA32_PFN)
92		swiotlb = 1;
93#endif
94	return swiotlb;
95}
96IOMMU_INIT(pci_swiotlb_detect_4gb,
97	   pci_swiotlb_detect_override,
98	   pci_swiotlb_init,
99	   pci_swiotlb_late_init);
100
101void __init pci_swiotlb_init(void)
102{
103	if (swiotlb) {
104		swiotlb_init(0);
105		dma_ops = &swiotlb_dma_ops;
106	}
107}
108
109void __init pci_swiotlb_late_init(void)
110{
111	/* An IOMMU turned us off. */
112	if (!swiotlb)
113		swiotlb_free();
114	else {
115		printk(KERN_INFO "PCI-DMA: "
116		       "Using software bounce buffering for IO (SWIOTLB)\n");
117		swiotlb_print_info();
118	}
119}
120