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 msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec);
  29 static int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
  30                                   int index, int sub_handle);
  31 static int set_remapped_irq_affinity(struct irq_data *data,
  32                                      const struct cpumask *mask,
  33                                      bool force);
  34
  35 static bool irq_remapped(struct irq_cfg *cfg)
  36 {
  37         return (cfg->remapped == 1);
  38 }
  39
  40 static void irq_remapping_disable_io_apic(void)
  41 {
  42         /*
  43          * With interrupt-remapping, for now we will use virtual wire A
  44          * mode, as virtual wire B is little complex (need to configure
  45          * both IOAPIC RTE as well as interrupt-remapping table entry).
  46          * As this gets called during crash dump, keep this simple for
  47          * now.
  48          */
  49         if (cpu_has_apic || apic_from_smp_config())
  50                 disconnect_bsp_APIC(0);
  51 }
  52
  53 #ifndef CONFIG_GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
  54 static unsigned int irq_alloc_hwirqs(int cnt, int node)
  55 {
  56         return irq_domain_alloc_irqs(NULL, -1, cnt, node, NULL);
  57 }
  58
  59 static void irq_free_hwirqs(unsigned int from, int cnt)
  60 {
  61         irq_domain_free_irqs(from, cnt);
  62 }
  63 #endif
  64
  65 static int do_setup_msi_irqs(struct pci_dev *dev, int nvec)
  66 {
  67         int ret, sub_handle, nvec_pow2, index = 0;
  68         unsigned int irq;
  69         struct msi_desc *msidesc;
  70
  71         msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
  72
  73         irq = irq_alloc_hwirqs(nvec, dev_to_node(&dev->dev));
  74         if (irq == 0)
  75                 return -ENOSPC;
  76
  77         nvec_pow2 = __roundup_pow_of_two(nvec);
  78         for (sub_handle = 0; sub_handle < nvec; sub_handle++) {
  79                 if (!sub_handle) {
  80                         index = msi_alloc_remapped_irq(dev, irq, nvec_pow2);
  81                         if (index < 0) {
  82                                 ret = index;
  83                                 goto error;
  84                         }
  85                 } else {
  86                         ret = msi_setup_remapped_irq(dev, irq + sub_handle,
  87                                                      index, sub_handle);
  88                         if (ret < 0)
  89                                 goto error;
  90                 }
  91                 ret = setup_msi_irq(dev, msidesc, irq, sub_handle);
  92                 if (ret < 0)
  93                         goto error;
  94         }
  95         return 0;
  96
  97 error:
  98         irq_free_hwirqs(irq, nvec);
  99
 100         /*
 101          * Restore altered MSI descriptor fields and prevent just destroyed
 102          * IRQs from tearing down again in default_teardown_msi_irqs()
 103          */
 104         msidesc->irq = 0;
 105
 106         return ret;
 107 }
 108
 109 static int do_setup_msix_irqs(struct pci_dev *dev, int nvec)
 110 {
 111         int node, ret, sub_handle, index = 0;
 112         struct msi_desc *msidesc;
 113         unsigned int irq;
 114
 115         node            = dev_to_node(&dev->dev);
 116         sub_handle      = 0;
 117
 118         list_for_each_entry(msidesc, &dev->msi_list, list) {
 119
 120                 irq = irq_alloc_hwirqs(1, node);
 121                 if (irq == 0)
 122                         return -1;
 123
 124                 if (sub_handle == 0)
 125                         ret = index = msi_alloc_remapped_irq(dev, irq, nvec);
 126                 else
 127                         ret = msi_setup_remapped_irq(dev, irq, index, sub_handle);
 128
 129                 if (ret < 0)
 130                         goto error;
 131
 132                 ret = setup_msi_irq(dev, msidesc, irq, 0);
 133                 if (ret < 0)
 134                         goto error;
 135
 136                 sub_handle += 1;
 137                 irq        += 1;
 138         }
 139
 140         return 0;
 141
 142 error:
 143         irq_free_hwirqs(irq, 1);
 144         return ret;
 145 }
 146
 147 static int irq_remapping_setup_msi_irqs(struct pci_dev *dev,
 148                                         int nvec, int type)
 149 {
 150         if (type == PCI_CAP_ID_MSI)
 151                 return do_setup_msi_irqs(dev, nvec);
 152         else
 153                 return do_setup_msix_irqs(dev, nvec);
 154 }
 155
 156 static void eoi_ioapic_pin_remapped(int apic, int pin, int vector)
 157 {
 158         /*
 159          * Intr-remapping uses pin number as the virtual vector
 160          * in the RTE. Actual vector is programmed in
 161          * intr-remapping table entry. Hence for the io-apic
 162          * EOI we use the pin number.
 163          */
 164         io_apic_eoi(apic, pin);
 165 }
 166
 167 static void __init irq_remapping_modify_x86_ops(void)
 168 {
 169         x86_io_apic_ops.disable         = irq_remapping_disable_io_apic;
 170         x86_io_apic_ops.set_affinity    = set_remapped_irq_affinity;
 171         x86_io_apic_ops.setup_entry     = setup_ioapic_remapped_entry;
 172         x86_io_apic_ops.eoi_ioapic_pin  = eoi_ioapic_pin_remapped;
 173         x86_msi.setup_hpet_msi          = setup_hpet_msi_remapped;
 174         x86_msi.compose_msi_msg         = compose_remapped_msi_msg;
 175 }
 176
 177 static __init int setup_nointremap(char *str)
 178 {
 179         disable_irq_remap = 1;
 180         return 0;
 181 }
 182 early_param("nointremap", setup_nointremap);
 183
 184 static __init int setup_irqremap(char *str)
 185 {
 186         if (!str)
 187                 return -EINVAL;
 188
 189         while (*str) {
 190                 if (!strncmp(str, "on", 2))
 191                         disable_irq_remap = 0;
 192                 else if (!strncmp(str, "off", 3))
 193                         disable_irq_remap = 1;
 194                 else if (!strncmp(str, "nosid", 5))
 195                         disable_sourceid_checking = 1;
 196                 else if (!strncmp(str, "no_x2apic_optout", 16))
 197                         no_x2apic_optout = 1;
 198
 199                 str += strcspn(str, ",");
 200                 while (*str == ',')
 201                         str++;
 202         }
 203
 204         return 0;
 205 }
 206 early_param("intremap", setup_irqremap);
 207
 208 void set_irq_remapping_broken(void)
 209 {
 210         irq_remap_broken = 1;
 211 }
 212
 213 int __init irq_remapping_prepare(void)
 214 {
 215         if (disable_irq_remap)
 216                 return -ENOSYS;
 217
 218         if (intel_irq_remap_ops.prepare() == 0)
 219                 remap_ops = &intel_irq_remap_ops;
 220         else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
 221                  amd_iommu_irq_ops.prepare() == 0)
 222                 remap_ops = &amd_iommu_irq_ops;
 223         else
 224                 return -ENOSYS;
 225
 226         return 0;
 227 }
 228
 229 int __init irq_remapping_enable(void)
 230 {
 231         int ret;
 232
 233         if (!remap_ops->enable)
 234                 return -ENODEV;
 235
 236         ret = remap_ops->enable();
 237
 238         if (irq_remapping_enabled)
 239                 irq_remapping_modify_x86_ops();
 240
 241         return ret;
 242 }
 243
 244 void irq_remapping_disable(void)
 245 {
 246         if (irq_remapping_enabled && remap_ops->disable)
 247                 remap_ops->disable();
 248 }
 249
 250 int irq_remapping_reenable(int mode)
 251 {
 252         if (irq_remapping_enabled && remap_ops->reenable)
 253                 return remap_ops->reenable(mode);
 254
 255         return 0;
 256 }
 257
 258 int __init irq_remap_enable_fault_handling(void)
 259 {
 260         if (!irq_remapping_enabled)
 261                 return 0;
 262
 263         if (!remap_ops->enable_faulting)
 264                 return -ENODEV;
 265
 266         return remap_ops->enable_faulting();
 267 }
 268
 269 int setup_ioapic_remapped_entry(int irq,
 270                                 struct IO_APIC_route_entry *entry,
 271                                 unsigned int destination, int vector,
 272                                 struct io_apic_irq_attr *attr)
 273 {
 274         if (!remap_ops->setup_ioapic_entry)
 275                 return -ENODEV;
 276
 277         return remap_ops->setup_ioapic_entry(irq, entry, destination,
 278                                              vector, attr);
 279 }
 280
 281 static int set_remapped_irq_affinity(struct irq_data *data,
 282                                      const struct cpumask *mask, bool force)
 283 {
 284         if (!config_enabled(CONFIG_SMP) || !remap_ops->set_affinity)
 285                 return 0;
 286
 287         return remap_ops->set_affinity(data, mask, force);
 288 }
 289
 290 void free_remapped_irq(int irq)
 291 {
 292         struct irq_cfg *cfg = irq_cfg(irq);
 293
 294         if (irq_remapped(cfg) && remap_ops->free_irq)
 295                 remap_ops->free_irq(irq);
 296 }
 297
 298 void compose_remapped_msi_msg(struct pci_dev *pdev,
 299                               unsigned int irq, unsigned int dest,
 300                               struct msi_msg *msg, u8 hpet_id)
 301 {
 302         struct irq_cfg *cfg = irq_cfg(irq);
 303
 304         if (!irq_remapped(cfg))
 305                 native_compose_msi_msg(pdev, irq, dest, msg, hpet_id);
 306         else if (remap_ops->compose_msi_msg)
 307                 remap_ops->compose_msi_msg(pdev, irq, dest, msg, hpet_id);
 308 }
 309
 310 static int msi_alloc_remapped_irq(struct pci_dev *pdev, int irq, int nvec)
 311 {
 312         if (!remap_ops->msi_alloc_irq)
 313                 return -ENODEV;
 314
 315         return remap_ops->msi_alloc_irq(pdev, irq, nvec);
 316 }
 317
 318 static int msi_setup_remapped_irq(struct pci_dev *pdev, unsigned int irq,
 319                                   int index, int sub_handle)
 320 {
 321         if (!remap_ops->msi_setup_irq)
 322                 return -ENODEV;
 323
 324         return remap_ops->msi_setup_irq(pdev, irq, index, sub_handle);
 325 }
 326
 327 int setup_hpet_msi_remapped(unsigned int irq, unsigned int id)
 328 {
 329         int ret;
 330
 331         if (!remap_ops->alloc_hpet_msi)
 332                 return -ENODEV;
 333
 334         ret = remap_ops->alloc_hpet_msi(irq, id);
 335         if (ret)
 336                 return -EINVAL;
 337
 338         return default_setup_hpet_msi(irq, id);
 339 }
 340
 341 void panic_if_irq_remap(const char *msg)
 342 {
 343         if (irq_remapping_enabled)
 344                 panic(msg);
 345 }
 346
 347 void ir_ack_apic_edge(struct irq_data *data)
 348 {
 349         ack_APIC_irq();
 350 }
 351
 352 static void ir_ack_apic_level(struct irq_data *data)
 353 {
 354         ack_APIC_irq();
 355         eoi_ioapic_irq(data->irq, irqd_cfg(data));
 356 }
 357
 358 void irq_remapping_print_chip(struct irq_data *data, struct seq_file *p)
 359 {
 360         /*
 361          * Assume interrupt is remapped if the parent irqdomain isn't the
 362          * vector domain, which is true for MSI, HPET and IOAPIC on x86
 363          * platforms.
 364          */
 365         if (data->domain && data->domain->parent != arch_get_ir_parent_domain())
 366                 seq_printf(p, " IR-%s", data->chip->name);
 367         else
 368                 seq_printf(p, " %s", data->chip->name);
 369 }
 370
 371 static void ir_print_prefix(struct irq_data *data, struct seq_file *p)
 372 {
 373         seq_printf(p, " IR-%s", data->chip->name);
 374 }
 375
 376 void irq_remap_modify_chip_defaults(struct irq_chip *chip)
 377 {
 378         chip->irq_print_chip = ir_print_prefix;
 379         chip->irq_ack = ir_ack_apic_edge;
 380         chip->irq_eoi = ir_ack_apic_level;
 381         chip->irq_set_affinity = x86_io_apic_ops.set_affinity;
 382 }
 383
 384 bool setup_remapped_irq(int irq, struct irq_cfg *cfg, struct irq_chip *chip)
 385 {
 386         if (!irq_remapped(cfg))
 387                 return false;
 388         irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
 389         irq_remap_modify_chip_defaults(chip);
 390         return true;
 391 }
 392
 393 /**
 394  * irq_remapping_get_ir_irq_domain - Get the irqdomain associated with the IOMMU
 395  *                                   device serving request @info
 396  * @info: interrupt allocation information, used to identify the IOMMU device
 397  *
 398  * It's used to get parent irqdomain for HPET and IOAPIC irqdomains.
 399  * Returns pointer to IRQ domain, or NULL on failure.
 400  */
 401 struct irq_domain *
 402 irq_remapping_get_ir_irq_domain(struct irq_alloc_info *info)
 403 {
 404         if (!remap_ops || !remap_ops->get_ir_irq_domain)
 405                 return NULL;
 406
 407         return remap_ops->get_ir_irq_domain(info);
 408 }
 409
 410 /**
 411  * irq_remapping_get_irq_domain - Get the irqdomain serving the request @info
 412  * @info: interrupt allocation information, used to identify the IOMMU device
 413  *
 414  * There will be one PCI MSI/MSIX irqdomain associated with each interrupt
 415  * remapping device, so this interface is used to retrieve the PCI MSI/MSIX
 416  * irqdomain serving request @info.
 417  * Returns pointer to IRQ domain, or NULL on failure.
 418  */
 419 struct irq_domain *
 420 irq_remapping_get_irq_domain(struct irq_alloc_info *info)
 421 {
 422         if (!remap_ops || !remap_ops->get_irq_domain)
 423                 return NULL;
 424
 425         return remap_ops->get_irq_domain(info);
 426 }