drivers/iommu/irq_remapping.c

   1 #include <linux/cpumask.h>
   2 #include <linux/kernel.h>
   3 #include <linux/string.h>
   4 #include <linux/errno.h>
   5 #include <linux/msi.h>
   6 #include <linux/irq.h>
   7 #include <linux/pci.h>
   8 #include <linux/irqdomain.h>
   9
  10 #include <asm/hw_irq.h>
  11 #include <asm/irq_remapping.h>
  12 #include <asm/processor.h>
  13 #include <asm/x86_init.h>
  14 #include <asm/apic.h>
  15 #include <asm/hpet.h>
  16
  17 #include "irq_remapping.h"
  18
  19 int irq_remapping_enabled;
  20 int irq_remap_broken;
  21 int disable_sourceid_checking;
  22 int no_x2apic_optout;
  23
  24 int disable_irq_post = 0;
  25
  26 static int disable_irq_remap;
  27 static struct irq_remap_ops *remap_ops;
  28
  29 static void irq_remapping_restore_boot_irq_mode(void)
  30 {
  31         /*
  32          * With interrupt-remapping, for now we will use virtual wire A
  33          * mode, as virtual wire B is little complex (need to configure
  34          * both IOAPIC RTE as well as interrupt-remapping table entry).
  35          * As this gets called during crash dump, keep this simple for
  36          * now.
  37          */
  38         if (boot_cpu_has(X86_FEATURE_APIC) || apic_from_smp_config())
  39                 disconnect_bsp_APIC(0);
  40 }
  41
  42 static void __init irq_remapping_modify_x86_ops(void)
  43 {
  44         x86_apic_ops.restore = irq_remapping_restore_boot_irq_mode;
  45 }
  46
  47 static __init int setup_nointremap(char *str)
  48 {
  49         disable_irq_remap = 1;
  50         return 0;
  51 }
  52 early_param("nointremap", setup_nointremap);
  53
  54 static __init int setup_irqremap(char *str)
  55 {
  56         if (!str)
  57                 return -EINVAL;
  58
  59         while (*str) {
  60                 if (!strncmp(str, "on", 2)) {
  61                         disable_irq_remap = 0;
  62                         disable_irq_post = 0;
  63                 } else if (!strncmp(str, "off", 3)) {
  64                         disable_irq_remap = 1;
  65                         disable_irq_post = 1;
  66                 } else if (!strncmp(str, "nosid", 5))
  67                         disable_sourceid_checking = 1;
  68                 else if (!strncmp(str, "no_x2apic_optout", 16))
  69                         no_x2apic_optout = 1;
  70                 else if (!strncmp(str, "nopost", 6))
  71                         disable_irq_post = 1;
  72
  73                 str += strcspn(str, ",");
  74                 while (*str == ',')
  75                         str++;
  76         }
  77
  78         return 0;
  79 }
  80 early_param("intremap", setup_irqremap);
  81
  82 void set_irq_remapping_broken(void)
  83 {
  84         irq_remap_broken = 1;
  85 }
  86
  87 bool irq_remapping_cap(enum irq_remap_cap cap)
  88 {
  89         if (!remap_ops || disable_irq_post)
  90                 return false;
  91
  92         return (remap_ops->capability & (1 << cap));
  93 }
  94 EXPORT_SYMBOL_GPL(irq_remapping_cap);
  95
  96 int __init irq_remapping_prepare(void)
  97 {
  98         if (disable_irq_remap)
  99                 return -ENOSYS;
 100
 101         if (intel_irq_remap_ops.prepare() == 0)
 102                 remap_ops = &intel_irq_remap_ops;
 103         else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
 104                  amd_iommu_irq_ops.prepare() == 0)
 105                 remap_ops = &amd_iommu_irq_ops;
 106         else if (IS_ENABLED(CONFIG_HYPERV_IOMMU) &&
 107                  hyperv_irq_remap_ops.prepare() == 0)
 108                 remap_ops = &hyperv_irq_remap_ops;
 109         else
 110                 return -ENOSYS;
 111
 112         return 0;
 113 }
 114
 115 int __init irq_remapping_enable(void)
 116 {
 117         int ret;
 118
 119         if (!remap_ops->enable)
 120                 return -ENODEV;
 121
 122         ret = remap_ops->enable();
 123
 124         if (irq_remapping_enabled)
 125                 irq_remapping_modify_x86_ops();
 126
 127         return ret;
 128 }
 129
 130 void irq_remapping_disable(void)
 131 {
 132         if (irq_remapping_enabled && remap_ops->disable)
 133                 remap_ops->disable();
 134 }
 135
 136 int irq_remapping_reenable(int mode)
 137 {
 138         if (irq_remapping_enabled && remap_ops->reenable)
 139                 return remap_ops->reenable(mode);
 140
 141         return 0;
 142 }
 143
 144 int __init irq_remap_enable_fault_handling(void)
 145 {
 146         if (!irq_remapping_enabled)
 147                 return 0;
 148
 149         if (!remap_ops->enable_faulting)
 150                 return -ENODEV;
 151
 152         return remap_ops->enable_faulting();
 153 }
 154
 155 void panic_if_irq_remap(const char *msg)
 156 {
 157         if (irq_remapping_enabled)
 158                 panic(msg);
 159 }
 160
 161 /**
 162  * irq_remapping_get_ir_irq_domain - Get the irqdomain associated with the IOMMU
 163  *                                   device serving request @info
 164  * @info: interrupt allocation information, used to identify the IOMMU device
 165  *
 166  * It's used to get parent irqdomain for HPET and IOAPIC irqdomains.
 167  * Returns pointer to IRQ domain, or NULL on failure.
 168  */
 169 struct irq_domain *
 170 irq_remapping_get_ir_irq_domain(struct irq_alloc_info *info)
 171 {
 172         if (!remap_ops || !remap_ops->get_ir_irq_domain)
 173                 return NULL;
 174
 175         return remap_ops->get_ir_irq_domain(info);
 176 }
 177
 178 /**
 179  * irq_remapping_get_irq_domain - Get the irqdomain serving the request @info
 180  * @info: interrupt allocation information, used to identify the IOMMU device
 181  *
 182  * There will be one PCI MSI/MSIX irqdomain associated with each interrupt
 183  * remapping device, so this interface is used to retrieve the PCI MSI/MSIX
 184  * irqdomain serving request @info.
 185  * Returns pointer to IRQ domain, or NULL on failure.
 186  */
 187 struct irq_domain *
 188 irq_remapping_get_irq_domain(struct irq_alloc_info *info)
 189 {
 190         if (!remap_ops || !remap_ops->get_irq_domain)
 191                 return NULL;
 192
 193         return remap_ops->get_irq_domain(info);
 194 }