1/* Glue code to lib/swiotlb-xen.c */
2
3#include <linux/dma-mapping.h>
4#include <linux/pci.h>
5#include <xen/swiotlb-xen.h>
6
7#include <asm/xen/hypervisor.h>
8#include <xen/xen.h>
9#include <asm/iommu_table.h>
10
11
12#include <asm/xen/swiotlb-xen.h>
13#ifdef CONFIG_X86_64
14#include <asm/iommu.h>
15#include <asm/dma.h>
16#endif
17#include <linux/export.h>
18
19int xen_swiotlb __read_mostly;
20
21static struct dma_map_ops xen_swiotlb_dma_ops = {
22	.mapping_error = xen_swiotlb_dma_mapping_error,
23	.alloc = xen_swiotlb_alloc_coherent,
24	.free = xen_swiotlb_free_coherent,
25	.sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu,
26	.sync_single_for_device = xen_swiotlb_sync_single_for_device,
27	.sync_sg_for_cpu = xen_swiotlb_sync_sg_for_cpu,
28	.sync_sg_for_device = xen_swiotlb_sync_sg_for_device,
29	.map_sg = xen_swiotlb_map_sg_attrs,
30	.unmap_sg = xen_swiotlb_unmap_sg_attrs,
31	.map_page = xen_swiotlb_map_page,
32	.unmap_page = xen_swiotlb_unmap_page,
33	.dma_supported = xen_swiotlb_dma_supported,
34};
35
36/*
37 * pci_xen_swiotlb_detect - set xen_swiotlb to 1 if necessary
38 *
39 * This returns non-zero if we are forced to use xen_swiotlb (by the boot
40 * option).
41 */
42int __init pci_xen_swiotlb_detect(void)
43{
44
45	if (!xen_pv_domain())
46		return 0;
47
48	/* If running as PV guest, either iommu=soft, or swiotlb=force will
49	 * activate this IOMMU. If running as PV privileged, activate it
50	 * irregardless.
51	 */
52	if ((xen_initial_domain() || swiotlb || swiotlb_force))
53		xen_swiotlb = 1;
54
55	/* If we are running under Xen, we MUST disable the native SWIOTLB.
56	 * Don't worry about swiotlb_force flag activating the native, as
57	 * the 'swiotlb' flag is the only one turning it on. */
58	swiotlb = 0;
59
60#ifdef CONFIG_X86_64
61	/* pci_swiotlb_detect_4gb turns on native SWIOTLB if no_iommu == 0
62	 * (so no iommu=X command line over-writes).
63	 * Considering that PV guests do not want the *native SWIOTLB* but
64	 * only Xen SWIOTLB it is not useful to us so set no_iommu=1 here.
65	 */
66	if (max_pfn > MAX_DMA32_PFN)
67		no_iommu = 1;
68#endif
69	return xen_swiotlb;
70}
71
72void __init pci_xen_swiotlb_init(void)
73{
74	if (xen_swiotlb) {
75		xen_swiotlb_init(1, true /* early */);
76		dma_ops = &xen_swiotlb_dma_ops;
77
78#ifdef CONFIG_PCI
79		/* Make sure ACS will be enabled */
80		pci_request_acs();
81#endif
82	}
83}
84
85int pci_xen_swiotlb_init_late(void)
86{
87	int rc;
88
89	if (xen_swiotlb)
90		return 0;
91
92	rc = xen_swiotlb_init(1, false /* late */);
93	if (rc)
94		return rc;
95
96	dma_ops = &xen_swiotlb_dma_ops;
97#ifdef CONFIG_PCI
98	/* Make sure ACS will be enabled */
99	pci_request_acs();
100#endif
101
102	return 0;
103}
104EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late);
105
106IOMMU_INIT_FINISH(pci_xen_swiotlb_detect,
107		  NULL,
108		  pci_xen_swiotlb_init,
109		  NULL);
110