drivers/iommu/irq_remapping.c

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