arch/x86/kernel/apic/msi.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Support of MSI, HPET and DMAR interrupts.
   4  *
   5  * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
   6  *      Moved from arch/x86/kernel/apic/io_apic.c.
   7  * Jiang Liu <jiang.liu@linux.intel.com>
   8  *      Convert to hierarchical irqdomain
   9  */
  10 #include <linux/mm.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/irq.h>
  13 #include <linux/pci.h>
  14 #include <linux/dmar.h>
  15 #include <linux/hpet.h>
  16 #include <linux/msi.h>
  17 #include <asm/irqdomain.h>
  18 #include <asm/msidef.h>
  19 #include <asm/hpet.h>
  20 #include <asm/hw_irq.h>
  21 #include <asm/apic.h>
  22 #include <asm/irq_remapping.h>
  23
  24 static struct irq_domain *msi_default_domain;
  25
  26 static void __irq_msi_compose_msg(struct irq_cfg *cfg, struct msi_msg *msg)
  27 {
  28         msg->address_hi = MSI_ADDR_BASE_HI;
  29
  30         if (x2apic_enabled())
  31                 msg->address_hi |= MSI_ADDR_EXT_DEST_ID(cfg->dest_apicid);
  32
  33         msg->address_lo =
  34                 MSI_ADDR_BASE_LO |
  35                 ((apic->irq_dest_mode == 0) ?
  36                         MSI_ADDR_DEST_MODE_PHYSICAL :
  37                         MSI_ADDR_DEST_MODE_LOGICAL) |
  38                 MSI_ADDR_REDIRECTION_CPU |
  39                 MSI_ADDR_DEST_ID(cfg->dest_apicid);
  40
  41         msg->data =
  42                 MSI_DATA_TRIGGER_EDGE |
  43                 MSI_DATA_LEVEL_ASSERT |
  44                 MSI_DATA_DELIVERY_FIXED |
  45                 MSI_DATA_VECTOR(cfg->vector);
  46 }
  47
  48 static void irq_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
  49 {
  50         __irq_msi_compose_msg(irqd_cfg(data), msg);
  51 }
  52
  53 static void irq_msi_update_msg(struct irq_data *irqd, struct irq_cfg *cfg)
  54 {
  55         struct msi_msg msg[2] = { [1] = { }, };
  56
  57         __irq_msi_compose_msg(cfg, msg);
  58         irq_data_get_irq_chip(irqd)->irq_write_msi_msg(irqd, msg);
  59 }
  60
  61 static int
  62 msi_set_affinity(struct irq_data *irqd, const struct cpumask *mask, bool force)
  63 {
  64         struct irq_cfg old_cfg, *cfg = irqd_cfg(irqd);
  65         struct irq_data *parent = irqd->parent_data;
  66         unsigned int cpu;
  67         int ret;
  68
  69         /* Save the current configuration */
  70         cpu = cpumask_first(irq_data_get_effective_affinity_mask(irqd));
  71         old_cfg = *cfg;
  72
  73         /* Allocate a new target vector */
  74         ret = parent->chip->irq_set_affinity(parent, mask, force);
  75         if (ret < 0 || ret == IRQ_SET_MASK_OK_DONE)
  76                 return ret;
  77
  78         /*
  79          * For non-maskable and non-remapped MSI interrupts the migration
  80          * to a different destination CPU and a different vector has to be
  81          * done careful to handle the possible stray interrupt which can be
  82          * caused by the non-atomic update of the address/data pair.
  83          *
  84          * Direct update is possible when:
  85          * - The MSI is maskable (remapped MSI does not use this code path)).
  86          *   The quirk bit is not set in this case.
  87          * - The new vector is the same as the old vector
  88          * - The old vector is MANAGED_IRQ_SHUTDOWN_VECTOR (interrupt starts up)
  89          * - The new destination CPU is the same as the old destination CPU
  90          */
  91         if (!irqd_msi_nomask_quirk(irqd) ||
  92             cfg->vector == old_cfg.vector ||
  93             old_cfg.vector == MANAGED_IRQ_SHUTDOWN_VECTOR ||
  94             cfg->dest_apicid == old_cfg.dest_apicid) {
  95                 irq_msi_update_msg(irqd, cfg);
  96                 return ret;
  97         }
  98
  99         /*
 100          * Paranoia: Validate that the interrupt target is the local
 101          * CPU.
 102          */
 103         if (WARN_ON_ONCE(cpu != smp_processor_id())) {
 104                 irq_msi_update_msg(irqd, cfg);
 105                 return ret;
 106         }
 107
 108         /*
 109          * Redirect the interrupt to the new vector on the current CPU
 110          * first. This might cause a spurious interrupt on this vector if
 111          * the device raises an interrupt right between this update and the
 112          * update to the final destination CPU.
 113          *
 114          * If the vector is in use then the installed device handler will
 115          * denote it as spurious which is no harm as this is a rare event
 116          * and interrupt handlers have to cope with spurious interrupts
 117          * anyway. If the vector is unused, then it is marked so it won't
 118          * trigger the 'No irq handler for vector' warning in do_IRQ().
 119          *
 120          * This requires to hold vector lock to prevent concurrent updates to
 121          * the affected vector.
 122          */
 123         lock_vector_lock();
 124
 125         /*
 126          * Mark the new target vector on the local CPU if it is currently
 127          * unused. Reuse the VECTOR_RETRIGGERED state which is also used in
 128          * the CPU hotplug path for a similar purpose. This cannot be
 129          * undone here as the current CPU has interrupts disabled and
 130          * cannot handle the interrupt before the whole set_affinity()
 131          * section is done. In the CPU unplug case, the current CPU is
 132          * about to vanish and will not handle any interrupts anymore. The
 133          * vector is cleaned up when the CPU comes online again.
 134          */
 135         if (IS_ERR_OR_NULL(this_cpu_read(vector_irq[cfg->vector])))
 136                 this_cpu_write(vector_irq[cfg->vector], VECTOR_RETRIGGERED);
 137
 138         /* Redirect it to the new vector on the local CPU temporarily */
 139         old_cfg.vector = cfg->vector;
 140         irq_msi_update_msg(irqd, &old_cfg);
 141
 142         /* Now transition it to the target CPU */
 143         irq_msi_update_msg(irqd, cfg);
 144
 145         /*
 146          * All interrupts after this point are now targeted at the new
 147          * vector/CPU.
 148          *
 149          * Drop vector lock before testing whether the temporary assignment
 150          * to the local CPU was hit by an interrupt raised in the device,
 151          * because the retrigger function acquires vector lock again.
 152          */
 153         unlock_vector_lock();
 154
 155         /*
 156          * Check whether the transition raced with a device interrupt and
 157          * is pending in the local APICs IRR. It is safe to do this outside
 158          * of vector lock as the irq_desc::lock of this interrupt is still
 159          * held and interrupts are disabled: The check is not accessing the
 160          * underlying vector store. It's just checking the local APIC's
 161          * IRR.
 162          */
 163         if (lapic_vector_set_in_irr(cfg->vector))
 164                 irq_data_get_irq_chip(irqd)->irq_retrigger(irqd);
 165
 166         return ret;
 167 }
 168
 169 /*
 170  * IRQ Chip for MSI PCI/PCI-X/PCI-Express Devices,
 171  * which implement the MSI or MSI-X Capability Structure.
 172  */
 173 static struct irq_chip pci_msi_controller = {
 174         .name                   = "PCI-MSI",
 175         .irq_unmask             = pci_msi_unmask_irq,
 176         .irq_mask               = pci_msi_mask_irq,
 177         .irq_ack                = irq_chip_ack_parent,
 178         .irq_retrigger          = irq_chip_retrigger_hierarchy,
 179         .irq_compose_msi_msg    = irq_msi_compose_msg,
 180         .irq_set_affinity       = msi_set_affinity,
 181         .flags                  = IRQCHIP_SKIP_SET_WAKE,
 182 };
 183
 184 int native_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
 185 {
 186         struct irq_domain *domain;
 187         struct irq_alloc_info info;
 188
 189         init_irq_alloc_info(&info, NULL);
 190         info.type = X86_IRQ_ALLOC_TYPE_MSI;
 191         info.msi_dev = dev;
 192
 193         domain = irq_remapping_get_irq_domain(&info);
 194         if (domain == NULL)
 195                 domain = msi_default_domain;
 196         if (domain == NULL)
 197                 return -ENOSYS;
 198
 199         return msi_domain_alloc_irqs(domain, &dev->dev, nvec);
 200 }
 201
 202 void native_teardown_msi_irq(unsigned int irq)
 203 {
 204         irq_domain_free_irqs(irq, 1);
 205 }
 206
 207 static irq_hw_number_t pci_msi_get_hwirq(struct msi_domain_info *info,
 208                                          msi_alloc_info_t *arg)
 209 {
 210         return arg->msi_hwirq;
 211 }
 212
 213 int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
 214                     msi_alloc_info_t *arg)
 215 {
 216         struct pci_dev *pdev = to_pci_dev(dev);
 217         struct msi_desc *desc = first_pci_msi_entry(pdev);
 218
 219         init_irq_alloc_info(arg, NULL);
 220         arg->msi_dev = pdev;
 221         if (desc->msi_attrib.is_msix) {
 222                 arg->type = X86_IRQ_ALLOC_TYPE_MSIX;
 223         } else {
 224                 arg->type = X86_IRQ_ALLOC_TYPE_MSI;
 225                 arg->flags |= X86_IRQ_ALLOC_CONTIGUOUS_VECTORS;
 226         }
 227
 228         return 0;
 229 }
 230 EXPORT_SYMBOL_GPL(pci_msi_prepare);
 231
 232 void pci_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
 233 {
 234         arg->msi_hwirq = pci_msi_domain_calc_hwirq(arg->msi_dev, desc);
 235 }
 236 EXPORT_SYMBOL_GPL(pci_msi_set_desc);
 237
 238 static struct msi_domain_ops pci_msi_domain_ops = {
 239         .get_hwirq      = pci_msi_get_hwirq,
 240         .msi_prepare    = pci_msi_prepare,
 241         .set_desc       = pci_msi_set_desc,
 242 };
 243
 244 static struct msi_domain_info pci_msi_domain_info = {
 245         .flags          = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
 246                           MSI_FLAG_PCI_MSIX,
 247         .ops            = &pci_msi_domain_ops,
 248         .chip           = &pci_msi_controller,
 249         .handler        = handle_edge_irq,
 250         .handler_name   = "edge",
 251 };
 252
 253 void __init arch_init_msi_domain(struct irq_domain *parent)
 254 {
 255         struct fwnode_handle *fn;
 256
 257         if (disable_apic)
 258                 return;
 259
 260         fn = irq_domain_alloc_named_fwnode("PCI-MSI");
 261         if (fn) {
 262                 msi_default_domain =
 263                         pci_msi_create_irq_domain(fn, &pci_msi_domain_info,
 264                                                   parent);
 265                 irq_domain_free_fwnode(fn);
 266         }
 267         if (!msi_default_domain)
 268                 pr_warn("failed to initialize irqdomain for MSI/MSI-x.\n");
 269         else
 270                 msi_default_domain->flags |= IRQ_DOMAIN_MSI_NOMASK_QUIRK;
 271 }
 272
 273 #ifdef CONFIG_IRQ_REMAP
 274 static struct irq_chip pci_msi_ir_controller = {
 275         .name                   = "IR-PCI-MSI",
 276         .irq_unmask             = pci_msi_unmask_irq,
 277         .irq_mask               = pci_msi_mask_irq,
 278         .irq_ack                = irq_chip_ack_parent,
 279         .irq_retrigger          = irq_chip_retrigger_hierarchy,
 280         .irq_set_vcpu_affinity  = irq_chip_set_vcpu_affinity_parent,
 281         .flags                  = IRQCHIP_SKIP_SET_WAKE,
 282 };
 283
 284 static struct msi_domain_info pci_msi_ir_domain_info = {
 285         .flags          = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
 286                           MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX,
 287         .ops            = &pci_msi_domain_ops,
 288         .chip           = &pci_msi_ir_controller,
 289         .handler        = handle_edge_irq,
 290         .handler_name   = "edge",
 291 };
 292
 293 struct irq_domain *arch_create_remap_msi_irq_domain(struct irq_domain *parent,
 294                                                     const char *name, int id)
 295 {
 296         struct fwnode_handle *fn;
 297         struct irq_domain *d;
 298
 299         fn = irq_domain_alloc_named_id_fwnode(name, id);
 300         if (!fn)
 301                 return NULL;
 302         d = pci_msi_create_irq_domain(fn, &pci_msi_ir_domain_info, parent);
 303         irq_domain_free_fwnode(fn);
 304         return d;
 305 }
 306 #endif
 307
 308 #ifdef CONFIG_DMAR_TABLE
 309 static void dmar_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
 310 {
 311         dmar_msi_write(data->irq, msg);
 312 }
 313
 314 static struct irq_chip dmar_msi_controller = {
 315         .name                   = "DMAR-MSI",
 316         .irq_unmask             = dmar_msi_unmask,
 317         .irq_mask               = dmar_msi_mask,
 318         .irq_ack                = irq_chip_ack_parent,
 319         .irq_set_affinity       = msi_domain_set_affinity,
 320         .irq_retrigger          = irq_chip_retrigger_hierarchy,
 321         .irq_compose_msi_msg    = irq_msi_compose_msg,
 322         .irq_write_msi_msg      = dmar_msi_write_msg,
 323         .flags                  = IRQCHIP_SKIP_SET_WAKE,
 324 };
 325
 326 static irq_hw_number_t dmar_msi_get_hwirq(struct msi_domain_info *info,
 327                                           msi_alloc_info_t *arg)
 328 {
 329         return arg->dmar_id;
 330 }
 331
 332 static int dmar_msi_init(struct irq_domain *domain,
 333                          struct msi_domain_info *info, unsigned int virq,
 334                          irq_hw_number_t hwirq, msi_alloc_info_t *arg)
 335 {
 336         irq_domain_set_info(domain, virq, arg->dmar_id, info->chip, NULL,
 337                             handle_edge_irq, arg->dmar_data, "edge");
 338
 339         return 0;
 340 }
 341
 342 static struct msi_domain_ops dmar_msi_domain_ops = {
 343         .get_hwirq      = dmar_msi_get_hwirq,
 344         .msi_init       = dmar_msi_init,
 345 };
 346
 347 static struct msi_domain_info dmar_msi_domain_info = {
 348         .ops            = &dmar_msi_domain_ops,
 349         .chip           = &dmar_msi_controller,
 350 };
 351
 352 static struct irq_domain *dmar_get_irq_domain(void)
 353 {
 354         static struct irq_domain *dmar_domain;
 355         static DEFINE_MUTEX(dmar_lock);
 356         struct fwnode_handle *fn;
 357
 358         mutex_lock(&dmar_lock);
 359         if (dmar_domain)
 360                 goto out;
 361
 362         fn = irq_domain_alloc_named_fwnode("DMAR-MSI");
 363         if (fn) {
 364                 dmar_domain = msi_create_irq_domain(fn, &dmar_msi_domain_info,
 365                                                     x86_vector_domain);
 366                 irq_domain_free_fwnode(fn);
 367         }
 368 out:
 369         mutex_unlock(&dmar_lock);
 370         return dmar_domain;
 371 }
 372
 373 int dmar_alloc_hwirq(int id, int node, void *arg)
 374 {
 375         struct irq_domain *domain = dmar_get_irq_domain();
 376         struct irq_alloc_info info;
 377
 378         if (!domain)
 379                 return -1;
 380
 381         init_irq_alloc_info(&info, NULL);
 382         info.type = X86_IRQ_ALLOC_TYPE_DMAR;
 383         info.dmar_id = id;
 384         info.dmar_data = arg;
 385
 386         return irq_domain_alloc_irqs(domain, 1, node, &info);
 387 }
 388
 389 void dmar_free_hwirq(int irq)
 390 {
 391         irq_domain_free_irqs(irq, 1);
 392 }
 393 #endif
 394
 395 /*
 396  * MSI message composition
 397  */
 398 #ifdef CONFIG_HPET_TIMER
 399 static inline int hpet_dev_id(struct irq_domain *domain)
 400 {
 401         struct msi_domain_info *info = msi_get_domain_info(domain);
 402
 403         return (int)(long)info->data;
 404 }
 405
 406 static void hpet_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
 407 {
 408         hpet_msi_write(irq_data_get_irq_handler_data(data), msg);
 409 }
 410
 411 static struct irq_chip hpet_msi_controller __ro_after_init = {
 412         .name = "HPET-MSI",
 413         .irq_unmask = hpet_msi_unmask,
 414         .irq_mask = hpet_msi_mask,
 415         .irq_ack = irq_chip_ack_parent,
 416         .irq_set_affinity = msi_domain_set_affinity,
 417         .irq_retrigger = irq_chip_retrigger_hierarchy,
 418         .irq_compose_msi_msg = irq_msi_compose_msg,
 419         .irq_write_msi_msg = hpet_msi_write_msg,
 420         .flags = IRQCHIP_SKIP_SET_WAKE,
 421 };
 422
 423 static irq_hw_number_t hpet_msi_get_hwirq(struct msi_domain_info *info,
 424                                           msi_alloc_info_t *arg)
 425 {
 426         return arg->hpet_index;
 427 }
 428
 429 static int hpet_msi_init(struct irq_domain *domain,
 430                          struct msi_domain_info *info, unsigned int virq,
 431                          irq_hw_number_t hwirq, msi_alloc_info_t *arg)
 432 {
 433         irq_set_status_flags(virq, IRQ_MOVE_PCNTXT);
 434         irq_domain_set_info(domain, virq, arg->hpet_index, info->chip, NULL,
 435                             handle_edge_irq, arg->hpet_data, "edge");
 436
 437         return 0;
 438 }
 439
 440 static void hpet_msi_free(struct irq_domain *domain,
 441                           struct msi_domain_info *info, unsigned int virq)
 442 {
 443         irq_clear_status_flags(virq, IRQ_MOVE_PCNTXT);
 444 }
 445
 446 static struct msi_domain_ops hpet_msi_domain_ops = {
 447         .get_hwirq      = hpet_msi_get_hwirq,
 448         .msi_init       = hpet_msi_init,
 449         .msi_free       = hpet_msi_free,
 450 };
 451
 452 static struct msi_domain_info hpet_msi_domain_info = {
 453         .ops            = &hpet_msi_domain_ops,
 454         .chip           = &hpet_msi_controller,
 455 };
 456
 457 struct irq_domain *hpet_create_irq_domain(int hpet_id)
 458 {
 459         struct msi_domain_info *domain_info;
 460         struct irq_domain *parent, *d;
 461         struct irq_alloc_info info;
 462         struct fwnode_handle *fn;
 463
 464         if (x86_vector_domain == NULL)
 465                 return NULL;
 466
 467         domain_info = kzalloc(sizeof(*domain_info), GFP_KERNEL);
 468         if (!domain_info)
 469                 return NULL;
 470
 471         *domain_info = hpet_msi_domain_info;
 472         domain_info->data = (void *)(long)hpet_id;
 473
 474         init_irq_alloc_info(&info, NULL);
 475         info.type = X86_IRQ_ALLOC_TYPE_HPET;
 476         info.hpet_id = hpet_id;
 477         parent = irq_remapping_get_ir_irq_domain(&info);
 478         if (parent == NULL)
 479                 parent = x86_vector_domain;
 480         else
 481                 hpet_msi_controller.name = "IR-HPET-MSI";
 482
 483         fn = irq_domain_alloc_named_id_fwnode(hpet_msi_controller.name,
 484                                               hpet_id);
 485         if (!fn) {
 486                 kfree(domain_info);
 487                 return NULL;
 488         }
 489
 490         d = msi_create_irq_domain(fn, domain_info, parent);
 491         irq_domain_free_fwnode(fn);
 492         return d;
 493 }
 494
 495 int hpet_assign_irq(struct irq_domain *domain, struct hpet_channel *hc,
 496                     int dev_num)
 497 {
 498         struct irq_alloc_info info;
 499
 500         init_irq_alloc_info(&info, NULL);
 501         info.type = X86_IRQ_ALLOC_TYPE_HPET;
 502         info.hpet_data = hc;
 503         info.hpet_id = hpet_dev_id(domain);
 504         info.hpet_index = dev_num;
 505
 506         return irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, &info);
 507 }
 508 #endif