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 bool enable_posted_msi __ro_after_init;
28
29 static int disable_irq_remap;
30 static struct irq_remap_ops *remap_ops;
31
irq_remapping_restore_boot_irq_mode(void)32 static void irq_remapping_restore_boot_irq_mode(void)
33 {
34 /*
35 * With interrupt-remapping, for now we will use virtual wire A
36 * mode, as virtual wire B is little complex (need to configure
37 * both IOAPIC RTE as well as interrupt-remapping table entry).
38 * As this gets called during crash dump, keep this simple for
39 * now.
40 */
41 if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config())
42 disconnect_bsp_APIC(0);
43 }
44
irq_remapping_modify_x86_ops(void)45 static void __init irq_remapping_modify_x86_ops(void)
46 {
47 x86_apic_ops.restore = irq_remapping_restore_boot_irq_mode;
48 }
49
setup_nointremap(char * str)50 static __init int setup_nointremap(char *str)
51 {
52 disable_irq_remap = 1;
53 return 0;
54 }
55 early_param("nointremap", setup_nointremap);
56
setup_irqremap(char * str)57 static __init int setup_irqremap(char *str)
58 {
59 if (!str)
60 return -EINVAL;
61
62 while (*str) {
63 if (!strncmp(str, "on", 2)) {
64 disable_irq_remap = 0;
65 disable_irq_post = 0;
66 } else if (!strncmp(str, "off", 3)) {
67 disable_irq_remap = 1;
68 disable_irq_post = 1;
69 } else if (!strncmp(str, "nosid", 5))
70 disable_sourceid_checking = 1;
71 else if (!strncmp(str, "no_x2apic_optout", 16))
72 no_x2apic_optout = 1;
73 else if (!strncmp(str, "nopost", 6))
74 disable_irq_post = 1;
75 else if (IS_ENABLED(CONFIG_X86_POSTED_MSI) && !strncmp(str, "posted_msi", 10))
76 enable_posted_msi = true;
77 str += strcspn(str, ",");
78 while (*str == ',')
79 str++;
80 }
81
82 return 0;
83 }
84 early_param("intremap", setup_irqremap);
85
set_irq_remapping_broken(void)86 void set_irq_remapping_broken(void)
87 {
88 irq_remap_broken = 1;
89 }
90
irq_remapping_cap(enum irq_remap_cap cap)91 bool irq_remapping_cap(enum irq_remap_cap cap)
92 {
93 if (!remap_ops || disable_irq_post)
94 return false;
95
96 return (remap_ops->capability & (1 << cap));
97 }
98 EXPORT_SYMBOL_GPL(irq_remapping_cap);
99
irq_remapping_prepare(void)100 int __init irq_remapping_prepare(void)
101 {
102 if (disable_irq_remap)
103 return -ENOSYS;
104
105 if (IS_ENABLED(CONFIG_INTEL_IOMMU) &&
106 intel_irq_remap_ops.prepare() == 0)
107 remap_ops = &intel_irq_remap_ops;
108 else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
109 amd_iommu_irq_ops.prepare() == 0)
110 remap_ops = &amd_iommu_irq_ops;
111 else if (IS_ENABLED(CONFIG_HYPERV_IOMMU) &&
112 hyperv_irq_remap_ops.prepare() == 0)
113 remap_ops = &hyperv_irq_remap_ops;
114 else
115 return -ENOSYS;
116
117 return 0;
118 }
119
irq_remapping_enable(void)120 int __init irq_remapping_enable(void)
121 {
122 int ret;
123
124 if (!remap_ops->enable)
125 return -ENODEV;
126
127 ret = remap_ops->enable();
128
129 if (irq_remapping_enabled)
130 irq_remapping_modify_x86_ops();
131
132 return ret;
133 }
134
irq_remapping_disable(void)135 void irq_remapping_disable(void)
136 {
137 if (irq_remapping_enabled && remap_ops->disable)
138 remap_ops->disable();
139 }
140
irq_remapping_reenable(int mode)141 int irq_remapping_reenable(int mode)
142 {
143 if (irq_remapping_enabled && remap_ops->reenable)
144 return remap_ops->reenable(mode);
145
146 return 0;
147 }
148
irq_remap_enable_fault_handling(void)149 int __init irq_remap_enable_fault_handling(void)
150 {
151 if (!irq_remapping_enabled)
152 return 0;
153
154 if (!remap_ops->enable_faulting)
155 return -ENODEV;
156
157 cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "dmar:enable_fault_handling",
158 remap_ops->enable_faulting, NULL);
159
160 return remap_ops->enable_faulting(smp_processor_id());
161 }
162
panic_if_irq_remap(const char * msg)163 void panic_if_irq_remap(const char *msg)
164 {
165 if (irq_remapping_enabled)
166 panic(msg);
167 }
168