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 static int disable_irq_remap;
  26 static struct irq_remap_ops *remap_ops;
  27
  28 static bool irq_remapped(struct irq_cfg *cfg)
  29 {
  30         return (cfg->remapped == 1);
  31 }
  32
  33 static void irq_remapping_disable_io_apic(void)
  34 {
  35         /*
  36          * With interrupt-remapping, for now we will use virtual wire A
  37          * mode, as virtual wire B is little complex (need to configure
  38          * both IOAPIC RTE as well as interrupt-remapping table entry).
  39          * As this gets called during crash dump, keep this simple for
  40          * now.
  41          */
  42         if (cpu_has_apic || apic_from_smp_config())
  43                 disconnect_bsp_APIC(0);
  44 }
  45
  46 static void eoi_ioapic_pin_remapped(int apic, int pin, int vector)
  47 {
  48         /*
  49          * Intr-remapping uses pin number as the virtual vector
  50          * in the RTE. Actual vector is programmed in
  51          * intr-remapping table entry. Hence for the io-apic
  52          * EOI we use the pin number.
  53          */
  54         io_apic_eoi(apic, pin);
  55 }
  56
  57 static void __init irq_remapping_modify_x86_ops(void)
  58 {
  59         x86_io_apic_ops.disable         = irq_remapping_disable_io_apic;
  60         x86_io_apic_ops.eoi_ioapic_pin  = eoi_ioapic_pin_remapped;
  61 }
  62
  63 static __init int setup_nointremap(char *str)
  64 {
  65         disable_irq_remap = 1;
  66         return 0;
  67 }
  68 early_param("nointremap", setup_nointremap);
  69
  70 static __init int setup_irqremap(char *str)
  71 {
  72         if (!str)
  73                 return -EINVAL;
  74
  75         while (*str) {
  76                 if (!strncmp(str, "on", 2))
  77                         disable_irq_remap = 0;
  78                 else if (!strncmp(str, "off", 3))
  79                         disable_irq_remap = 1;
  80                 else if (!strncmp(str, "nosid", 5))
  81                         disable_sourceid_checking = 1;
  82                 else if (!strncmp(str, "no_x2apic_optout", 16))
  83                         no_x2apic_optout = 1;
  84
  85                 str += strcspn(str, ",");
  86                 while (*str == ',')
  87                         str++;
  88         }
  89
  90         return 0;
  91 }
  92 early_param("intremap", setup_irqremap);
  93
  94 void set_irq_remapping_broken(void)
  95 {
  96         irq_remap_broken = 1;
  97 }
  98
  99 int __init irq_remapping_prepare(void)
 100 {
 101         if (disable_irq_remap)
 102                 return -ENOSYS;
 103
 104         if (intel_irq_remap_ops.prepare() == 0)
 105                 remap_ops = &intel_irq_remap_ops;
 106         else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
 107                  amd_iommu_irq_ops.prepare() == 0)
 108                 remap_ops = &amd_iommu_irq_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 free_remapped_irq(int irq)
 156 {
 157         struct irq_cfg *cfg = irq_cfg(irq);
 158
 159         if (irq_remapped(cfg) && remap_ops->free_irq)
 160                 remap_ops->free_irq(irq);
 161 }
 162
 163 void panic_if_irq_remap(const char *msg)
 164 {
 165         if (irq_remapping_enabled)
 166                 panic(msg);
 167 }
 168
 169 void ir_ack_apic_edge(struct irq_data *data)
 170 {
 171         ack_APIC_irq();
 172 }
 173
 174 static void ir_ack_apic_level(struct irq_data *data)
 175 {
 176         ack_APIC_irq();
 177         eoi_ioapic_irq(data->irq, irqd_cfg(data));
 178 }
 179
 180 static void ir_print_prefix(struct irq_data *data, struct seq_file *p)
 181 {
 182         seq_printf(p, " IR-%s", data->chip->name);
 183 }
 184
 185 void irq_remap_modify_chip_defaults(struct irq_chip *chip)
 186 {
 187         chip->irq_print_chip = ir_print_prefix;
 188         chip->irq_ack = ir_ack_apic_edge;
 189         chip->irq_eoi = ir_ack_apic_level;
 190 }
 191
 192 bool setup_remapped_irq(int irq, struct irq_cfg *cfg, struct irq_chip *chip)
 193 {
 194         if (!irq_remapped(cfg))
 195                 return false;
 196         irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
 197         irq_remap_modify_chip_defaults(chip);
 198         return true;
 199 }
 200
 201 /**
 202  * irq_remapping_get_ir_irq_domain - Get the irqdomain associated with the IOMMU
 203  *                                   device serving request @info
 204  * @info: interrupt allocation information, used to identify the IOMMU device
 205  *
 206  * It's used to get parent irqdomain for HPET and IOAPIC irqdomains.
 207  * Returns pointer to IRQ domain, or NULL on failure.
 208  */
 209 struct irq_domain *
 210 irq_remapping_get_ir_irq_domain(struct irq_alloc_info *info)
 211 {
 212         if (!remap_ops || !remap_ops->get_ir_irq_domain)
 213                 return NULL;
 214
 215         return remap_ops->get_ir_irq_domain(info);
 216 }
 217
 218 /**
 219  * irq_remapping_get_irq_domain - Get the irqdomain serving the request @info
 220  * @info: interrupt allocation information, used to identify the IOMMU device
 221  *
 222  * There will be one PCI MSI/MSIX irqdomain associated with each interrupt
 223  * remapping device, so this interface is used to retrieve the PCI MSI/MSIX
 224  * irqdomain serving request @info.
 225  * Returns pointer to IRQ domain, or NULL on failure.
 226  */
 227 struct irq_domain *
 228 irq_remapping_get_irq_domain(struct irq_alloc_info *info)
 229 {
 230         if (!remap_ops || !remap_ops->get_irq_domain)
 231                 return NULL;
 232
 233         return remap_ops->get_irq_domain(info);
 234 }