1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/dma-direct.h>
3 #include <linux/dma-debug.h>
4 #include <linux/iommu.h>
5 #include <linux/dmar.h>
6 #include <linux/export.h>
7 #include <linux/memblock.h>
8 #include <linux/gfp.h>
9 #include <linux/pci.h>
10
11 #include <asm/proto.h>
12 #include <asm/dma.h>
13 #include <asm/iommu.h>
14 #include <asm/gart.h>
15 #include <asm/calgary.h>
16 #include <asm/x86_init.h>
17 #include <asm/iommu_table.h>
18
19 static bool disable_dac_quirk __read_mostly;
20
21 const struct dma_map_ops *dma_ops;
22 EXPORT_SYMBOL(dma_ops);
23
24 #ifdef CONFIG_IOMMU_DEBUG
25 int panic_on_overflow __read_mostly = 1;
26 int force_iommu __read_mostly = 1;
27 #else
28 int panic_on_overflow __read_mostly = 0;
29 int force_iommu __read_mostly = 0;
30 #endif
31
32 int iommu_merge __read_mostly = 0;
33
34 int no_iommu __read_mostly;
35 /* Set this to 1 if there is a HW IOMMU in the system */
36 int iommu_detected __read_mostly = 0;
37
38 extern struct iommu_table_entry __iommu_table[], __iommu_table_end[];
39
pci_iommu_alloc(void)40 void __init pci_iommu_alloc(void)
41 {
42 struct iommu_table_entry *p;
43
44 sort_iommu_table(__iommu_table, __iommu_table_end);
45 check_iommu_entries(__iommu_table, __iommu_table_end);
46
47 for (p = __iommu_table; p < __iommu_table_end; p++) {
48 if (p && p->detect && p->detect() > 0) {
49 p->flags |= IOMMU_DETECTED;
50 if (p->early_init)
51 p->early_init();
52 if (p->flags & IOMMU_FINISH_IF_DETECTED)
53 break;
54 }
55 }
56 }
57
58 /*
59 * See <Documentation/x86/x86_64/boot-options.rst> for the iommu kernel
60 * parameter documentation.
61 */
iommu_setup(char * p)62 static __init int iommu_setup(char *p)
63 {
64 iommu_merge = 1;
65
66 if (!p)
67 return -EINVAL;
68
69 while (*p) {
70 if (!strncmp(p, "off", 3))
71 no_iommu = 1;
72 /* gart_parse_options has more force support */
73 if (!strncmp(p, "force", 5))
74 force_iommu = 1;
75 if (!strncmp(p, "noforce", 7)) {
76 iommu_merge = 0;
77 force_iommu = 0;
78 }
79
80 if (!strncmp(p, "biomerge", 8)) {
81 iommu_merge = 1;
82 force_iommu = 1;
83 }
84 if (!strncmp(p, "panic", 5))
85 panic_on_overflow = 1;
86 if (!strncmp(p, "nopanic", 7))
87 panic_on_overflow = 0;
88 if (!strncmp(p, "merge", 5)) {
89 iommu_merge = 1;
90 force_iommu = 1;
91 }
92 if (!strncmp(p, "nomerge", 7))
93 iommu_merge = 0;
94 if (!strncmp(p, "forcesac", 8))
95 pr_warn("forcesac option ignored.\n");
96 if (!strncmp(p, "allowdac", 8))
97 pr_warn("allowdac option ignored.\n");
98 if (!strncmp(p, "nodac", 5))
99 pr_warn("nodac option ignored.\n");
100 if (!strncmp(p, "usedac", 6)) {
101 disable_dac_quirk = true;
102 return 1;
103 }
104 #ifdef CONFIG_SWIOTLB
105 if (!strncmp(p, "soft", 4))
106 swiotlb = 1;
107 #endif
108 if (!strncmp(p, "pt", 2))
109 iommu_set_default_passthrough(true);
110 if (!strncmp(p, "nopt", 4))
111 iommu_set_default_translated(true);
112
113 gart_parse_options(p);
114
115 #ifdef CONFIG_CALGARY_IOMMU
116 if (!strncmp(p, "calgary", 7))
117 use_calgary = 1;
118 #endif /* CONFIG_CALGARY_IOMMU */
119
120 p += strcspn(p, ",");
121 if (*p == ',')
122 ++p;
123 }
124 return 0;
125 }
126 early_param("iommu", iommu_setup);
127
pci_iommu_init(void)128 static int __init pci_iommu_init(void)
129 {
130 struct iommu_table_entry *p;
131
132 x86_init.iommu.iommu_init();
133
134 for (p = __iommu_table; p < __iommu_table_end; p++) {
135 if (p && (p->flags & IOMMU_DETECTED) && p->late_init)
136 p->late_init();
137 }
138
139 return 0;
140 }
141 /* Must execute after PCI subsystem */
142 rootfs_initcall(pci_iommu_init);
143
144 #ifdef CONFIG_PCI
145 /* Many VIA bridges seem to corrupt data for DAC. Disable it here */
146
via_no_dac_cb(struct pci_dev * pdev,void * data)147 static int via_no_dac_cb(struct pci_dev *pdev, void *data)
148 {
149 pdev->dev.bus_dma_mask = DMA_BIT_MASK(32);
150 return 0;
151 }
152
via_no_dac(struct pci_dev * dev)153 static void via_no_dac(struct pci_dev *dev)
154 {
155 if (!disable_dac_quirk) {
156 dev_info(&dev->dev, "disabling DAC on VIA PCI bridge\n");
157 pci_walk_bus(dev->subordinate, via_no_dac_cb, NULL);
158 }
159 }
160 DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID,
161 PCI_CLASS_BRIDGE_PCI, 8, via_no_dac);
162 #endif
163