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 int set_remapped_irq_affinity(struct irq_data *data,
  29                                      const struct cpumask *mask,
  30                                      bool force);
  31
  32 static bool irq_remapped(struct irq_cfg *cfg)
  33 {
  34         return (cfg->remapped == 1);
  35 }
  36
  37 static void irq_remapping_disable_io_apic(void)
  38 {
  39         /*
  40          * With interrupt-remapping, for now we will use virtual wire A
  41          * mode, as virtual wire B is little complex (need to configure
  42          * both IOAPIC RTE as well as interrupt-remapping table entry).
  43          * As this gets called during crash dump, keep this simple for
  44          * now.
  45          */
  46         if (cpu_has_apic || apic_from_smp_config())
  47                 disconnect_bsp_APIC(0);
  48 }
  49
  50 static void eoi_ioapic_pin_remapped(int apic, int pin, int vector)
  51 {
  52         /*
  53          * Intr-remapping uses pin number as the virtual vector
  54          * in the RTE. Actual vector is programmed in
  55          * intr-remapping table entry. Hence for the io-apic
  56          * EOI we use the pin number.
  57          */
  58         io_apic_eoi(apic, pin);
  59 }
  60
  61 static void __init irq_remapping_modify_x86_ops(void)
  62 {
  63         x86_io_apic_ops.disable         = irq_remapping_disable_io_apic;
  64         x86_io_apic_ops.set_affinity    = set_remapped_irq_affinity;
  65         x86_io_apic_ops.eoi_ioapic_pin  = eoi_ioapic_pin_remapped;
  66 }
  67
  68 static __init int setup_nointremap(char *str)
  69 {
  70         disable_irq_remap = 1;
  71         return 0;
  72 }
  73 early_param("nointremap", setup_nointremap);
  74
  75 static __init int setup_irqremap(char *str)
  76 {
  77         if (!str)
  78                 return -EINVAL;
  79
  80         while (*str) {
  81                 if (!strncmp(str, "on", 2))
  82                         disable_irq_remap = 0;
  83                 else if (!strncmp(str, "off", 3))
  84                         disable_irq_remap = 1;
  85                 else if (!strncmp(str, "nosid", 5))
  86                         disable_sourceid_checking = 1;
  87                 else if (!strncmp(str, "no_x2apic_optout", 16))
  88                         no_x2apic_optout = 1;
  89
  90                 str += strcspn(str, ",");
  91                 while (*str == ',')
  92                         str++;
  93         }
  94
  95         return 0;
  96 }
  97 early_param("intremap", setup_irqremap);
  98
  99 void set_irq_remapping_broken(void)
 100 {
 101         irq_remap_broken = 1;
 102 }
 103
 104 int __init irq_remapping_prepare(void)
 105 {
 106         if (disable_irq_remap)
 107                 return -ENOSYS;
 108
 109         if (intel_irq_remap_ops.prepare() == 0)
 110                 remap_ops = &intel_irq_remap_ops;
 111         else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
 112                  amd_iommu_irq_ops.prepare() == 0)
 113                 remap_ops = &amd_iommu_irq_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         return remap_ops->enable_faulting();
 158 }
 159
 160 static int set_remapped_irq_affinity(struct irq_data *data,
 161                                      const struct cpumask *mask, bool force)
 162 {
 163         if (!config_enabled(CONFIG_SMP) || !remap_ops->set_affinity)
 164                 return 0;
 165
 166         return remap_ops->set_affinity(data, mask, force);
 167 }
 168
 169 void free_remapped_irq(int irq)
 170 {
 171         struct irq_cfg *cfg = irq_cfg(irq);
 172
 173         if (irq_remapped(cfg) && remap_ops->free_irq)
 174                 remap_ops->free_irq(irq);
 175 }
 176
 177 void panic_if_irq_remap(const char *msg)
 178 {
 179         if (irq_remapping_enabled)
 180                 panic(msg);
 181 }
 182
 183 void ir_ack_apic_edge(struct irq_data *data)
 184 {
 185         ack_APIC_irq();
 186 }
 187
 188 static void ir_ack_apic_level(struct irq_data *data)
 189 {
 190         ack_APIC_irq();
 191         eoi_ioapic_irq(data->irq, irqd_cfg(data));
 192 }
 193
 194 static void ir_print_prefix(struct irq_data *data, struct seq_file *p)
 195 {
 196         seq_printf(p, " IR-%s", data->chip->name);
 197 }
 198
 199 void irq_remap_modify_chip_defaults(struct irq_chip *chip)
 200 {
 201         chip->irq_print_chip = ir_print_prefix;
 202         chip->irq_ack = ir_ack_apic_edge;
 203         chip->irq_eoi = ir_ack_apic_level;
 204         chip->irq_set_affinity = x86_io_apic_ops.set_affinity;
 205 }
 206
 207 bool setup_remapped_irq(int irq, struct irq_cfg *cfg, struct irq_chip *chip)
 208 {
 209         if (!irq_remapped(cfg))
 210                 return false;
 211         irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
 212         irq_remap_modify_chip_defaults(chip);
 213         return true;
 214 }
 215
 216 /**
 217  * irq_remapping_get_ir_irq_domain - Get the irqdomain associated with the IOMMU
 218  *                                   device serving request @info
 219  * @info: interrupt allocation information, used to identify the IOMMU device
 220  *
 221  * It's used to get parent irqdomain for HPET and IOAPIC irqdomains.
 222  * Returns pointer to IRQ domain, or NULL on failure.
 223  */
 224 struct irq_domain *
 225 irq_remapping_get_ir_irq_domain(struct irq_alloc_info *info)
 226 {
 227         if (!remap_ops || !remap_ops->get_ir_irq_domain)
 228                 return NULL;
 229
 230         return remap_ops->get_ir_irq_domain(info);
 231 }
 232
 233 /**
 234  * irq_remapping_get_irq_domain - Get the irqdomain serving the request @info
 235  * @info: interrupt allocation information, used to identify the IOMMU device
 236  *
 237  * There will be one PCI MSI/MSIX irqdomain associated with each interrupt
 238  * remapping device, so this interface is used to retrieve the PCI MSI/MSIX
 239  * irqdomain serving request @info.
 240  * Returns pointer to IRQ domain, or NULL on failure.
 241  */
 242 struct irq_domain *
 243 irq_remapping_get_irq_domain(struct irq_alloc_info *info)
 244 {
 245         if (!remap_ops || !remap_ops->get_irq_domain)
 246                 return NULL;
 247
 248         return remap_ops->get_irq_domain(info);
 249 }