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 (intel_irq_remap_ops.prepare() == 0)
103 remap_ops = &intel_irq_remap_ops;
104 else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
105 amd_iommu_irq_ops.prepare() == 0)
106 remap_ops = &amd_iommu_irq_ops;
107 else if (IS_ENABLED(CONFIG_HYPERV_IOMMU) &&
108 hyperv_irq_remap_ops.prepare() == 0)
109 remap_ops = &hyperv_irq_remap_ops;
110 else
111 return -ENOSYS;
112
113 return 0;
114 }
115
irq_remapping_enable(void)116 int __init irq_remapping_enable(void)
117 {
118 int ret;
119
120 if (!remap_ops->enable)
121 return -ENODEV;
122
123 ret = remap_ops->enable();
124
125 if (irq_remapping_enabled)
126 irq_remapping_modify_x86_ops();
127
128 return ret;
129 }
130
irq_remapping_disable(void)131 void irq_remapping_disable(void)
132 {
133 if (irq_remapping_enabled && remap_ops->disable)
134 remap_ops->disable();
135 }
136
irq_remapping_reenable(int mode)137 int irq_remapping_reenable(int mode)
138 {
139 if (irq_remapping_enabled && remap_ops->reenable)
140 return remap_ops->reenable(mode);
141
142 return 0;
143 }
144
irq_remap_enable_fault_handling(void)145 int __init irq_remap_enable_fault_handling(void)
146 {
147 if (!irq_remapping_enabled)
148 return 0;
149
150 if (!remap_ops->enable_faulting)
151 return -ENODEV;
152
153 return remap_ops->enable_faulting();
154 }
155
panic_if_irq_remap(const char * msg)156 void panic_if_irq_remap(const char *msg)
157 {
158 if (irq_remapping_enabled)
159 panic(msg);
160 }
161
162 /**
163 * irq_remapping_get_ir_irq_domain - Get the irqdomain associated with the IOMMU
164 * device serving request @info
165 * @info: interrupt allocation information, used to identify the IOMMU device
166 *
167 * It's used to get parent irqdomain for HPET and IOAPIC irqdomains.
168 * Returns pointer to IRQ domain, or NULL on failure.
169 */
170 struct irq_domain *
irq_remapping_get_ir_irq_domain(struct irq_alloc_info * info)171 irq_remapping_get_ir_irq_domain(struct irq_alloc_info *info)
172 {
173 if (!remap_ops || !remap_ops->get_ir_irq_domain)
174 return NULL;
175
176 return remap_ops->get_ir_irq_domain(info);
177 }
178
179 /**
180 * irq_remapping_get_irq_domain - Get the irqdomain serving the request @info
181 * @info: interrupt allocation information, used to identify the IOMMU device
182 *
183 * There will be one PCI MSI/MSIX irqdomain associated with each interrupt
184 * remapping device, so this interface is used to retrieve the PCI MSI/MSIX
185 * irqdomain serving request @info.
186 * Returns pointer to IRQ domain, or NULL on failure.
187 */
188 struct irq_domain *
irq_remapping_get_irq_domain(struct irq_alloc_info * info)189 irq_remapping_get_irq_domain(struct irq_alloc_info *info)
190 {
191 if (!remap_ops || !remap_ops->get_irq_domain)
192 return NULL;
193
194 return remap_ops->get_irq_domain(info);
195 }
196