1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/cpumask.h>
3 #include <linux/kernel.h>
4 #include <linux/string.h>
5 #include <linux/errno.h>
6 #include <linux/msi.h>
7 #include <linux/irq.h>
8 #include <linux/pci.h>
9 #include <linux/irqdomain.h>
10
11 #include <asm/hw_irq.h>
12 #include <asm/irq_remapping.h>
13 #include <asm/processor.h>
14 #include <asm/x86_init.h>
15 #include <asm/apic.h>
16 #include <asm/hpet.h>
17
18 #include "irq_remapping.h"
19
20 int irq_remapping_enabled;
21 int irq_remap_broken;
22 int disable_sourceid_checking;
23 int no_x2apic_optout;
24
25 int disable_irq_post = 0;
26
27 static int disable_irq_remap;
28 static struct irq_remap_ops *remap_ops;
29
irq_remapping_restore_boot_irq_mode(void)30 static void irq_remapping_restore_boot_irq_mode(void)
31 {
32 /*
33 * With interrupt-remapping, for now we will use virtual wire A
34 * mode, as virtual wire B is little complex (need to configure
35 * both IOAPIC RTE as well as interrupt-remapping table entry).
36 * As this gets called during crash dump, keep this simple for
37 * now.
38 */
39 if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config())
40 disconnect_bsp_APIC(0);
41 }
42
irq_remapping_modify_x86_ops(void)43 static void __init irq_remapping_modify_x86_ops(void)
44 {
45 x86_apic_ops.restore = irq_remapping_restore_boot_irq_mode;
46 }
47
setup_nointremap(char * str)48 static __init int setup_nointremap(char *str)
49 {
50 disable_irq_remap = 1;
51 return 0;
52 }
53 early_param("nointremap", setup_nointremap);
54
setup_irqremap(char * str)55 static __init int setup_irqremap(char *str)
56 {
57 if (!str)
58 return -EINVAL;
59
60 while (*str) {
61 if (!strncmp(str, "on", 2)) {
62 disable_irq_remap = 0;
63 disable_irq_post = 0;
64 } else if (!strncmp(str, "off", 3)) {
65 disable_irq_remap = 1;
66 disable_irq_post = 1;
67 } else if (!strncmp(str, "nosid", 5))
68 disable_sourceid_checking = 1;
69 else if (!strncmp(str, "no_x2apic_optout", 16))
70 no_x2apic_optout = 1;
71 else if (!strncmp(str, "nopost", 6))
72 disable_irq_post = 1;
73
74 str += strcspn(str, ",");
75 while (*str == ',')
76 str++;
77 }
78
79 return 0;
80 }
81 early_param("intremap", setup_irqremap);
82
set_irq_remapping_broken(void)83 void set_irq_remapping_broken(void)
84 {
85 irq_remap_broken = 1;
86 }
87
irq_remapping_cap(enum irq_remap_cap cap)88 bool irq_remapping_cap(enum irq_remap_cap cap)
89 {
90 if (!remap_ops || disable_irq_post)
91 return false;
92
93 return (remap_ops->capability & (1 << cap));
94 }
95 EXPORT_SYMBOL_GPL(irq_remapping_cap);
96
irq_remapping_prepare(void)97 int __init irq_remapping_prepare(void)
98 {
99 if (disable_irq_remap)
100 return -ENOSYS;
101
102 if (IS_ENABLED(CONFIG_INTEL_IOMMU) &&
103 intel_irq_remap_ops.prepare() == 0)
104 remap_ops = &intel_irq_remap_ops;
105 else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
106 amd_iommu_irq_ops.prepare() == 0)
107 remap_ops = &amd_iommu_irq_ops;
108 else if (IS_ENABLED(CONFIG_HYPERV_IOMMU) &&
109 hyperv_irq_remap_ops.prepare() == 0)
110 remap_ops = &hyperv_irq_remap_ops;
111 else
112 return -ENOSYS;
113
114 return 0;
115 }
116
irq_remapping_enable(void)117 int __init irq_remapping_enable(void)
118 {
119 int ret;
120
121 if (!remap_ops->enable)
122 return -ENODEV;
123
124 ret = remap_ops->enable();
125
126 if (irq_remapping_enabled)
127 irq_remapping_modify_x86_ops();
128
129 return ret;
130 }
131
irq_remapping_disable(void)132 void irq_remapping_disable(void)
133 {
134 if (irq_remapping_enabled && remap_ops->disable)
135 remap_ops->disable();
136 }
137
irq_remapping_reenable(int mode)138 int irq_remapping_reenable(int mode)
139 {
140 if (irq_remapping_enabled && remap_ops->reenable)
141 return remap_ops->reenable(mode);
142
143 return 0;
144 }
145
irq_remap_enable_fault_handling(void)146 int __init irq_remap_enable_fault_handling(void)
147 {
148 if (!irq_remapping_enabled)
149 return 0;
150
151 if (!remap_ops->enable_faulting)
152 return -ENODEV;
153
154 return remap_ops->enable_faulting();
155 }
156
panic_if_irq_remap(const char * msg)157 void panic_if_irq_remap(const char *msg)
158 {
159 if (irq_remapping_enabled)
160 panic(msg);
161 }
162