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 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 43 static void __init irq_remapping_modify_x86_ops(void) 44 { 45 x86_apic_ops.restore = irq_remapping_restore_boot_irq_mode; 46 } 47 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 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 83 void set_irq_remapping_broken(void) 84 { 85 irq_remap_broken = 1; 86 } 87 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 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 } 115 116 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 } 130 131 void irq_remapping_disable(void) 132 { 133 if (irq_remapping_enabled && remap_ops->disable) 134 remap_ops->disable(); 135 } 136 137 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 } 144 145 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 } 155 156 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 * 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 * 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