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 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 45 static void __init irq_remapping_modify_x86_ops(void) 46 { 47 x86_apic_ops.restore = irq_remapping_restore_boot_irq_mode; 48 } 49 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 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 86 void set_irq_remapping_broken(void) 87 { 88 irq_remap_broken = 1; 89 } 90 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); 99 100 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 } 119 120 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 } 134 135 void irq_remapping_disable(void) 136 { 137 if (irq_remapping_enabled && remap_ops->disable) 138 remap_ops->disable(); 139 } 140 141 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 } 148 149 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 } 162 163 void panic_if_irq_remap(const char *msg) 164 { 165 if (irq_remapping_enabled) 166 panic(msg); 167 } 168