drivers/xen/events/events_base.c

   1 /*
   2  * Xen event channels
   3  *
   4  * Xen models interrupts with abstract event channels.  Because each
   5  * domain gets 1024 event channels, but NR_IRQ is not that large, we
   6  * must dynamically map irqs<->event channels.  The event channels
   7  * interface with the rest of the kernel by defining a xen interrupt
   8  * chip.  When an event is received, it is mapped to an irq and sent
   9  * through the normal interrupt processing path.
  10  *
  11  * There are four kinds of events which can be mapped to an event
  12  * channel:
  13  *
  14  * 1. Inter-domain notifications.  This includes all the virtual
  15  *    device events, since they're driven by front-ends in another domain
  16  *    (typically dom0).
  17  * 2. VIRQs, typically used for timers.  These are per-cpu events.
  18  * 3. IPIs.
  19  * 4. PIRQs - Hardware interrupts.
  20  *
  21  * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
  22  */
  23
  24 #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
  25
  26 #include <linux/linkage.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/irq.h>
  29 #include <linux/module.h>
  30 #include <linux/string.h>
  31 #include <linux/bootmem.h>
  32 #include <linux/slab.h>
  33 #include <linux/irqnr.h>
  34 #include <linux/pci.h>
  35
  36 #ifdef CONFIG_X86
  37 #include <asm/desc.h>
  38 #include <asm/ptrace.h>
  39 #include <asm/irq.h>
  40 #include <asm/idle.h>
  41 #include <asm/io_apic.h>
  42 #include <asm/xen/page.h>
  43 #include <asm/xen/pci.h>
  44 #endif
  45 #include <asm/sync_bitops.h>
  46 #include <asm/xen/hypercall.h>
  47 #include <asm/xen/hypervisor.h>
  48
  49 #include <xen/xen.h>
  50 #include <xen/hvm.h>
  51 #include <xen/xen-ops.h>
  52 #include <xen/events.h>
  53 #include <xen/interface/xen.h>
  54 #include <xen/interface/event_channel.h>
  55 #include <xen/interface/hvm/hvm_op.h>
  56 #include <xen/interface/hvm/params.h>
  57 #include <xen/interface/physdev.h>
  58 #include <xen/interface/sched.h>
  59 #include <xen/interface/vcpu.h>
  60 #include <asm/hw_irq.h>
  61
  62 #include "events_internal.h"
  63
  64 const struct evtchn_ops *evtchn_ops;
  65
  66 /*
  67  * This lock protects updates to the following mapping and reference-count
  68  * arrays. The lock does not need to be acquired to read the mapping tables.
  69  */
  70 static DEFINE_MUTEX(irq_mapping_update_lock);
  71
  72 static LIST_HEAD(xen_irq_list_head);
  73
  74 /* IRQ <-> VIRQ mapping. */
  75 static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
  76
  77 /* IRQ <-> IPI mapping */
  78 static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
  79
  80 int **evtchn_to_irq;
  81 #ifdef CONFIG_X86
  82 static unsigned long *pirq_eoi_map;
  83 #endif
  84 static bool (*pirq_needs_eoi)(unsigned irq);
  85
  86 #define EVTCHN_ROW(e)  (e / (PAGE_SIZE/sizeof(**evtchn_to_irq)))
  87 #define EVTCHN_COL(e)  (e % (PAGE_SIZE/sizeof(**evtchn_to_irq)))
  88 #define EVTCHN_PER_ROW (PAGE_SIZE / sizeof(**evtchn_to_irq))
  89
  90 /* Xen will never allocate port zero for any purpose. */
  91 #define VALID_EVTCHN(chn)       ((chn) != 0)
  92
  93 static struct irq_chip xen_dynamic_chip;
  94 static struct irq_chip xen_percpu_chip;
  95 static struct irq_chip xen_pirq_chip;
  96 static void enable_dynirq(struct irq_data *data);
  97 static void disable_dynirq(struct irq_data *data);
  98
  99 static void clear_evtchn_to_irq_row(unsigned row)
 100 {
 101         unsigned col;
 102
 103         for (col = 0; col < EVTCHN_PER_ROW; col++)
 104                 evtchn_to_irq[row][col] = -1;
 105 }
 106
 107 static void clear_evtchn_to_irq_all(void)
 108 {
 109         unsigned row;
 110
 111         for (row = 0; row < EVTCHN_ROW(xen_evtchn_max_channels()); row++) {
 112                 if (evtchn_to_irq[row] == NULL)
 113                         continue;
 114                 clear_evtchn_to_irq_row(row);
 115         }
 116 }
 117
 118 static int set_evtchn_to_irq(unsigned evtchn, unsigned irq)
 119 {
 120         unsigned row;
 121         unsigned col;
 122
 123         if (evtchn >= xen_evtchn_max_channels())
 124                 return -EINVAL;
 125
 126         row = EVTCHN_ROW(evtchn);
 127         col = EVTCHN_COL(evtchn);
 128
 129         if (evtchn_to_irq[row] == NULL) {
 130                 /* Unallocated irq entries return -1 anyway */
 131                 if (irq == -1)
 132                         return 0;
 133
 134                 evtchn_to_irq[row] = (int *)get_zeroed_page(GFP_KERNEL);
 135                 if (evtchn_to_irq[row] == NULL)
 136                         return -ENOMEM;
 137
 138                 clear_evtchn_to_irq_row(row);
 139         }
 140
 141         evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)] = irq;
 142         return 0;
 143 }
 144
 145 int get_evtchn_to_irq(unsigned evtchn)
 146 {
 147         if (evtchn >= xen_evtchn_max_channels())
 148                 return -1;
 149         if (evtchn_to_irq[EVTCHN_ROW(evtchn)] == NULL)
 150                 return -1;
 151         return evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)];
 152 }
 153
 154 /* Get info for IRQ */
 155 struct irq_info *info_for_irq(unsigned irq)
 156 {
 157         return irq_get_handler_data(irq);
 158 }
 159
 160 /* Constructors for packed IRQ information. */
 161 static int xen_irq_info_common_setup(struct irq_info *info,
 162                                      unsigned irq,
 163                                      enum xen_irq_type type,
 164                                      unsigned evtchn,
 165                                      unsigned short cpu)
 166 {
 167         int ret;
 168
 169         BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
 170
 171         info->type = type;
 172         info->irq = irq;
 173         info->evtchn = evtchn;
 174         info->cpu = cpu;
 175
 176         ret = set_evtchn_to_irq(evtchn, irq);
 177         if (ret < 0)
 178                 return ret;
 179
 180         irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN);
 181
 182         return xen_evtchn_port_setup(info);
 183 }
 184
 185 static int xen_irq_info_evtchn_setup(unsigned irq,
 186                                      unsigned evtchn)
 187 {
 188         struct irq_info *info = info_for_irq(irq);
 189
 190         return xen_irq_info_common_setup(info, irq, IRQT_EVTCHN, evtchn, 0);
 191 }
 192
 193 static int xen_irq_info_ipi_setup(unsigned cpu,
 194                                   unsigned irq,
 195                                   unsigned evtchn,
 196                                   enum ipi_vector ipi)
 197 {
 198         struct irq_info *info = info_for_irq(irq);
 199
 200         info->u.ipi = ipi;
 201
 202         per_cpu(ipi_to_irq, cpu)[ipi] = irq;
 203
 204         return xen_irq_info_common_setup(info, irq, IRQT_IPI, evtchn, 0);
 205 }
 206
 207 static int xen_irq_info_virq_setup(unsigned cpu,
 208                                    unsigned irq,
 209                                    unsigned evtchn,
 210                                    unsigned virq)
 211 {
 212         struct irq_info *info = info_for_irq(irq);
 213
 214         info->u.virq = virq;
 215
 216         per_cpu(virq_to_irq, cpu)[virq] = irq;
 217
 218         return xen_irq_info_common_setup(info, irq, IRQT_VIRQ, evtchn, 0);
 219 }
 220
 221 static int xen_irq_info_pirq_setup(unsigned irq,
 222                                    unsigned evtchn,
 223                                    unsigned pirq,
 224                                    unsigned gsi,
 225                                    uint16_t domid,
 226                                    unsigned char flags)
 227 {
 228         struct irq_info *info = info_for_irq(irq);
 229
 230         info->u.pirq.pirq = pirq;
 231         info->u.pirq.gsi = gsi;
 232         info->u.pirq.domid = domid;
 233         info->u.pirq.flags = flags;
 234
 235         return xen_irq_info_common_setup(info, irq, IRQT_PIRQ, evtchn, 0);
 236 }
 237
 238 static void xen_irq_info_cleanup(struct irq_info *info)
 239 {
 240         set_evtchn_to_irq(info->evtchn, -1);
 241         info->evtchn = 0;
 242 }
 243
 244 /*
 245  * Accessors for packed IRQ information.
 246  */
 247 unsigned int evtchn_from_irq(unsigned irq)
 248 {
 249         if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))
 250                 return 0;
 251
 252         return info_for_irq(irq)->evtchn;
 253 }
 254
 255 unsigned irq_from_evtchn(unsigned int evtchn)
 256 {
 257         return get_evtchn_to_irq(evtchn);
 258 }
 259 EXPORT_SYMBOL_GPL(irq_from_evtchn);
 260
 261 int irq_from_virq(unsigned int cpu, unsigned int virq)
 262 {
 263         return per_cpu(virq_to_irq, cpu)[virq];
 264 }
 265
 266 static enum ipi_vector ipi_from_irq(unsigned irq)
 267 {
 268         struct irq_info *info = info_for_irq(irq);
 269
 270         BUG_ON(info == NULL);
 271         BUG_ON(info->type != IRQT_IPI);
 272
 273         return info->u.ipi;
 274 }
 275
 276 static unsigned virq_from_irq(unsigned irq)
 277 {
 278         struct irq_info *info = info_for_irq(irq);
 279
 280         BUG_ON(info == NULL);
 281         BUG_ON(info->type != IRQT_VIRQ);
 282
 283         return info->u.virq;
 284 }
 285
 286 static unsigned pirq_from_irq(unsigned irq)
 287 {
 288         struct irq_info *info = info_for_irq(irq);
 289
 290         BUG_ON(info == NULL);
 291         BUG_ON(info->type != IRQT_PIRQ);
 292
 293         return info->u.pirq.pirq;
 294 }
 295
 296 static enum xen_irq_type type_from_irq(unsigned irq)
 297 {
 298         return info_for_irq(irq)->type;
 299 }
 300
 301 unsigned cpu_from_irq(unsigned irq)
 302 {
 303         return info_for_irq(irq)->cpu;
 304 }
 305
 306 unsigned int cpu_from_evtchn(unsigned int evtchn)
 307 {
 308         int irq = get_evtchn_to_irq(evtchn);
 309         unsigned ret = 0;
 310
 311         if (irq != -1)
 312                 ret = cpu_from_irq(irq);
 313
 314         return ret;
 315 }
 316
 317 #ifdef CONFIG_X86
 318 static bool pirq_check_eoi_map(unsigned irq)
 319 {
 320         return test_bit(pirq_from_irq(irq), pirq_eoi_map);
 321 }
 322 #endif
 323
 324 static bool pirq_needs_eoi_flag(unsigned irq)
 325 {
 326         struct irq_info *info = info_for_irq(irq);
 327         BUG_ON(info->type != IRQT_PIRQ);
 328
 329         return info->u.pirq.flags & PIRQ_NEEDS_EOI;
 330 }
 331
 332 static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
 333 {
 334         int irq = get_evtchn_to_irq(chn);
 335         struct irq_info *info = info_for_irq(irq);
 336
 337         BUG_ON(irq == -1);
 338 #ifdef CONFIG_SMP
 339         cpumask_copy(irq_get_irq_data(irq)->affinity, cpumask_of(cpu));
 340 #endif
 341         xen_evtchn_port_bind_to_cpu(info, cpu);
 342
 343         info->cpu = cpu;
 344 }
 345
 346 static void xen_evtchn_mask_all(void)
 347 {
 348         unsigned int evtchn;
 349
 350         for (evtchn = 0; evtchn < xen_evtchn_nr_channels(); evtchn++)
 351                 mask_evtchn(evtchn);
 352 }
 353
 354 /**
 355  * notify_remote_via_irq - send event to remote end of event channel via irq
 356  * @irq: irq of event channel to send event to
 357  *
 358  * Unlike notify_remote_via_evtchn(), this is safe to use across
 359  * save/restore. Notifications on a broken connection are silently
 360  * dropped.
 361  */
 362 void notify_remote_via_irq(int irq)
 363 {
 364         int evtchn = evtchn_from_irq(irq);
 365
 366         if (VALID_EVTCHN(evtchn))
 367                 notify_remote_via_evtchn(evtchn);
 368 }
 369 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
 370
 371 static void xen_irq_init(unsigned irq)
 372 {
 373         struct irq_info *info;
 374 #ifdef CONFIG_SMP
 375         /* By default all event channels notify CPU#0. */
 376         cpumask_copy(irq_get_irq_data(irq)->affinity, cpumask_of(0));
 377 #endif
 378
 379         info = kzalloc(sizeof(*info), GFP_KERNEL);
 380         if (info == NULL)
 381                 panic("Unable to allocate metadata for IRQ%d\n", irq);
 382
 383         info->type = IRQT_UNBOUND;
 384         info->refcnt = -1;
 385
 386         irq_set_handler_data(irq, info);
 387
 388         list_add_tail(&info->list, &xen_irq_list_head);
 389 }
 390
 391 static int __must_check xen_allocate_irqs_dynamic(int nvec)
 392 {
 393         int first = 0;
 394         int i, irq;
 395
 396 #ifdef CONFIG_X86_IO_APIC
 397         /*
 398          * For an HVM guest or domain 0 which see "real" (emulated or
 399          * actual respectively) GSIs we allocate dynamic IRQs
 400          * e.g. those corresponding to event channels or MSIs
 401          * etc. from the range above those "real" GSIs to avoid
 402          * collisions.
 403          */
 404         if (xen_initial_domain() || xen_hvm_domain())
 405                 first = get_nr_irqs_gsi();
 406 #endif
 407
 408         irq = irq_alloc_descs_from(first, nvec, -1);
 409
 410         if (irq >= 0) {
 411                 for (i = 0; i < nvec; i++)
 412                         xen_irq_init(irq + i);
 413         }
 414
 415         return irq;
 416 }
 417
 418 static inline int __must_check xen_allocate_irq_dynamic(void)
 419 {
 420
 421         return xen_allocate_irqs_dynamic(1);
 422 }
 423
 424 static int __must_check xen_allocate_irq_gsi(unsigned gsi)
 425 {
 426         int irq;
 427
 428         /*
 429          * A PV guest has no concept of a GSI (since it has no ACPI
 430          * nor access to/knowledge of the physical APICs). Therefore
 431          * all IRQs are dynamically allocated from the entire IRQ
 432          * space.
 433          */
 434         if (xen_pv_domain() && !xen_initial_domain())
 435                 return xen_allocate_irq_dynamic();
 436
 437         /* Legacy IRQ descriptors are already allocated by the arch. */
 438         if (gsi < NR_IRQS_LEGACY)
 439                 irq = gsi;
 440         else
 441                 irq = irq_alloc_desc_at(gsi, -1);
 442
 443         xen_irq_init(irq);
 444
 445         return irq;
 446 }
 447
 448 static void xen_free_irq(unsigned irq)
 449 {
 450         struct irq_info *info = irq_get_handler_data(irq);
 451
 452         if (WARN_ON(!info))
 453                 return;
 454
 455         list_del(&info->list);
 456
 457         irq_set_handler_data(irq, NULL);
 458
 459         WARN_ON(info->refcnt > 0);
 460
 461         kfree(info);
 462
 463         /* Legacy IRQ descriptors are managed by the arch. */
 464         if (irq < NR_IRQS_LEGACY)
 465                 return;
 466
 467         irq_free_desc(irq);
 468 }
 469
 470 static void xen_evtchn_close(unsigned int port)
 471 {
 472         struct evtchn_close close;
 473
 474         close.port = port;
 475         if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 476                 BUG();
 477 }
 478
 479 static void pirq_query_unmask(int irq)
 480 {
 481         struct physdev_irq_status_query irq_status;
 482         struct irq_info *info = info_for_irq(irq);
 483
 484         BUG_ON(info->type != IRQT_PIRQ);
 485
 486         irq_status.irq = pirq_from_irq(irq);
 487         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
 488                 irq_status.flags = 0;
 489
 490         info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
 491         if (irq_status.flags & XENIRQSTAT_needs_eoi)
 492                 info->u.pirq.flags |= PIRQ_NEEDS_EOI;
 493 }
 494
 495 static void eoi_pirq(struct irq_data *data)
 496 {
 497         int evtchn = evtchn_from_irq(data->irq);
 498         struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
 499         int rc = 0;
 500
 501         irq_move_irq(data);
 502
 503         if (VALID_EVTCHN(evtchn))
 504                 clear_evtchn(evtchn);
 505
 506         if (pirq_needs_eoi(data->irq)) {
 507                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
 508                 WARN_ON(rc);
 509         }
 510 }
 511
 512 static void mask_ack_pirq(struct irq_data *data)
 513 {
 514         disable_dynirq(data);
 515         eoi_pirq(data);
 516 }
 517
 518 static unsigned int __startup_pirq(unsigned int irq)
 519 {
 520         struct evtchn_bind_pirq bind_pirq;
 521         struct irq_info *info = info_for_irq(irq);
 522         int evtchn = evtchn_from_irq(irq);
 523         int rc;
 524
 525         BUG_ON(info->type != IRQT_PIRQ);
 526
 527         if (VALID_EVTCHN(evtchn))
 528                 goto out;
 529
 530         bind_pirq.pirq = pirq_from_irq(irq);
 531         /* NB. We are happy to share unless we are probing. */
 532         bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
 533                                         BIND_PIRQ__WILL_SHARE : 0;
 534         rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
 535         if (rc != 0) {
 536                 pr_warn("Failed to obtain physical IRQ %d\n", irq);
 537                 return 0;
 538         }
 539         evtchn = bind_pirq.port;
 540
 541         pirq_query_unmask(irq);
 542
 543         rc = set_evtchn_to_irq(evtchn, irq);
 544         if (rc != 0) {
 545                 pr_err("irq%d: Failed to set port to irq mapping (%d)\n",
 546                        irq, rc);
 547                 xen_evtchn_close(evtchn);
 548                 return 0;
 549         }
 550         bind_evtchn_to_cpu(evtchn, 0);
 551         info->evtchn = evtchn;
 552
 553 out:
 554         unmask_evtchn(evtchn);
 555         eoi_pirq(irq_get_irq_data(irq));
 556
 557         return 0;
 558 }
 559
 560 static unsigned int startup_pirq(struct irq_data *data)
 561 {
 562         return __startup_pirq(data->irq);
 563 }
 564
 565 static void shutdown_pirq(struct irq_data *data)
 566 {
 567         unsigned int irq = data->irq;
 568         struct irq_info *info = info_for_irq(irq);
 569         unsigned evtchn = evtchn_from_irq(irq);
 570
 571         BUG_ON(info->type != IRQT_PIRQ);
 572
 573         if (!VALID_EVTCHN(evtchn))
 574                 return;
 575
 576         mask_evtchn(evtchn);
 577         xen_evtchn_close(evtchn);
 578         xen_irq_info_cleanup(info);
 579 }
 580
 581 static void enable_pirq(struct irq_data *data)
 582 {
 583         startup_pirq(data);
 584 }
 585
 586 static void disable_pirq(struct irq_data *data)
 587 {
 588         disable_dynirq(data);
 589 }
 590
 591 int xen_irq_from_gsi(unsigned gsi)
 592 {
 593         struct irq_info *info;
 594
 595         list_for_each_entry(info, &xen_irq_list_head, list) {
 596                 if (info->type != IRQT_PIRQ)
 597                         continue;
 598
 599                 if (info->u.pirq.gsi == gsi)
 600                         return info->irq;
 601         }
 602
 603         return -1;
 604 }
 605 EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
 606
 607 static void __unbind_from_irq(unsigned int irq)
 608 {
 609         int evtchn = evtchn_from_irq(irq);
 610         struct irq_info *info = irq_get_handler_data(irq);
 611
 612         if (info->refcnt > 0) {
 613                 info->refcnt--;
 614                 if (info->refcnt != 0)
 615                         return;
 616         }
 617
 618         if (VALID_EVTCHN(evtchn)) {
 619                 unsigned int cpu = cpu_from_irq(irq);
 620
 621                 xen_evtchn_close(evtchn);
 622
 623                 switch (type_from_irq(irq)) {
 624                 case IRQT_VIRQ:
 625                         per_cpu(virq_to_irq, cpu)[virq_from_irq(irq)] = -1;
 626                         break;
 627                 case IRQT_IPI:
 628                         per_cpu(ipi_to_irq, cpu)[ipi_from_irq(irq)] = -1;
 629                         break;
 630                 default:
 631                         break;
 632                 }
 633
 634                 xen_irq_info_cleanup(info);
 635         }
 636
 637         BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
 638
 639         xen_free_irq(irq);
 640 }
 641
 642 /*
 643  * Do not make any assumptions regarding the relationship between the
 644  * IRQ number returned here and the Xen pirq argument.
 645  *
 646  * Note: We don't assign an event channel until the irq actually started
 647  * up.  Return an existing irq if we've already got one for the gsi.
 648  *
 649  * Shareable implies level triggered, not shareable implies edge
 650  * triggered here.
 651  */
 652 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 653                              unsigned pirq, int shareable, char *name)
 654 {
 655         int irq = -1;
 656         struct physdev_irq irq_op;
 657         int ret;
 658
 659         mutex_lock(&irq_mapping_update_lock);
 660
 661         irq = xen_irq_from_gsi(gsi);
 662         if (irq != -1) {
 663                 pr_info("%s: returning irq %d for gsi %u\n",
 664                         __func__, irq, gsi);
 665                 goto out;
 666         }
 667
 668         irq = xen_allocate_irq_gsi(gsi);
 669         if (irq < 0)
 670                 goto out;
 671
 672         irq_op.irq = irq;
 673         irq_op.vector = 0;
 674
 675         /* Only the privileged domain can do this. For non-priv, the pcifront
 676          * driver provides a PCI bus that does the call to do exactly
 677          * this in the priv domain. */
 678         if (xen_initial_domain() &&
 679             HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
 680                 xen_free_irq(irq);
 681                 irq = -ENOSPC;
 682                 goto out;
 683         }
 684
 685         ret = xen_irq_info_pirq_setup(irq, 0, pirq, gsi, DOMID_SELF,
 686                                shareable ? PIRQ_SHAREABLE : 0);
 687         if (ret < 0) {
 688                 __unbind_from_irq(irq);
 689                 irq = ret;
 690                 goto out;
 691         }
 692
 693         pirq_query_unmask(irq);
 694         /* We try to use the handler with the appropriate semantic for the
 695          * type of interrupt: if the interrupt is an edge triggered
 696          * interrupt we use handle_edge_irq.
 697          *
 698          * On the other hand if the interrupt is level triggered we use
 699          * handle_fasteoi_irq like the native code does for this kind of
 700          * interrupts.
 701          *
 702          * Depending on the Xen version, pirq_needs_eoi might return true
 703          * not only for level triggered interrupts but for edge triggered
 704          * interrupts too. In any case Xen always honors the eoi mechanism,
 705          * not injecting any more pirqs of the same kind if the first one
 706          * hasn't received an eoi yet. Therefore using the fasteoi handler
 707          * is the right choice either way.
 708          */
 709         if (shareable)
 710                 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 711                                 handle_fasteoi_irq, name);
 712         else
 713                 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 714                                 handle_edge_irq, name);
 715
 716 out:
 717         mutex_unlock(&irq_mapping_update_lock);
 718
 719         return irq;
 720 }
 721
 722 #ifdef CONFIG_PCI_MSI
 723 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
 724 {
 725         int rc;
 726         struct physdev_get_free_pirq op_get_free_pirq;
 727
 728         op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
 729         rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
 730
 731         WARN_ONCE(rc == -ENOSYS,
 732                   "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
 733
 734         return rc ? -1 : op_get_free_pirq.pirq;
 735 }
 736
 737 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
 738                              int pirq, int nvec, const char *name, domid_t domid)
 739 {
 740         int i, irq, ret;
 741
 742         mutex_lock(&irq_mapping_update_lock);
 743
 744         irq = xen_allocate_irqs_dynamic(nvec);
 745         if (irq < 0)
 746                 goto out;
 747
 748         for (i = 0; i < nvec; i++) {
 749                 irq_set_chip_and_handler_name(irq + i, &xen_pirq_chip, handle_edge_irq, name);
 750
 751                 ret = xen_irq_info_pirq_setup(irq + i, 0, pirq + i, 0, domid,
 752                                               i == 0 ? 0 : PIRQ_MSI_GROUP);
 753                 if (ret < 0)
 754                         goto error_irq;
 755         }
 756
 757         ret = irq_set_msi_desc(irq, msidesc);
 758         if (ret < 0)
 759                 goto error_irq;
 760 out:
 761         mutex_unlock(&irq_mapping_update_lock);
 762         return irq;
 763 error_irq:
 764         for (; i >= 0; i--)
 765                 __unbind_from_irq(irq + i);
 766         mutex_unlock(&irq_mapping_update_lock);
 767         return ret;
 768 }
 769 #endif
 770
 771 int xen_destroy_irq(int irq)
 772 {
 773         struct physdev_unmap_pirq unmap_irq;
 774         struct irq_info *info = info_for_irq(irq);
 775         int rc = -ENOENT;
 776
 777         mutex_lock(&irq_mapping_update_lock);
 778
 779         /*
 780          * If trying to remove a vector in a MSI group different
 781          * than the first one skip the PIRQ unmap unless this vector
 782          * is the first one in the group.
 783          */
 784         if (xen_initial_domain() && !(info->u.pirq.flags & PIRQ_MSI_GROUP)) {
 785                 unmap_irq.pirq = info->u.pirq.pirq;
 786                 unmap_irq.domid = info->u.pirq.domid;
 787                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
 788                 /* If another domain quits without making the pci_disable_msix
 789                  * call, the Xen hypervisor takes care of freeing the PIRQs
 790                  * (free_domain_pirqs).
 791                  */
 792                 if ((rc == -ESRCH && info->u.pirq.domid != DOMID_SELF))
 793                         pr_info("domain %d does not have %d anymore\n",
 794                                 info->u.pirq.domid, info->u.pirq.pirq);
 795                 else if (rc) {
 796                         pr_warn("unmap irq failed %d\n", rc);
 797                         goto out;
 798                 }
 799         }
 800
 801         xen_free_irq(irq);
 802
 803 out:
 804         mutex_unlock(&irq_mapping_update_lock);
 805         return rc;
 806 }
 807
 808 int xen_irq_from_pirq(unsigned pirq)
 809 {
 810         int irq;
 811
 812         struct irq_info *info;
 813
 814         mutex_lock(&irq_mapping_update_lock);
 815
 816         list_for_each_entry(info, &xen_irq_list_head, list) {
 817                 if (info->type != IRQT_PIRQ)
 818                         continue;
 819                 irq = info->irq;
 820                 if (info->u.pirq.pirq == pirq)
 821                         goto out;
 822         }
 823         irq = -1;
 824 out:
 825         mutex_unlock(&irq_mapping_update_lock);
 826
 827         return irq;
 828 }
 829
 830
 831 int xen_pirq_from_irq(unsigned irq)
 832 {
 833         return pirq_from_irq(irq);
 834 }
 835 EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
 836
 837 int bind_evtchn_to_irq(unsigned int evtchn)
 838 {
 839         int irq;
 840         int ret;
 841
 842         if (evtchn >= xen_evtchn_max_channels())
 843                 return -ENOMEM;
 844
 845         mutex_lock(&irq_mapping_update_lock);
 846
 847         irq = get_evtchn_to_irq(evtchn);
 848
 849         if (irq == -1) {
 850                 irq = xen_allocate_irq_dynamic();
 851                 if (irq < 0)
 852                         goto out;
 853
 854                 irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
 855                                               handle_edge_irq, "event");
 856
 857                 ret = xen_irq_info_evtchn_setup(irq, evtchn);
 858                 if (ret < 0) {
 859                         __unbind_from_irq(irq);
 860                         irq = ret;
 861                         goto out;
 862                 }
 863                 /* New interdomain events are bound to VCPU 0. */
 864                 bind_evtchn_to_cpu(evtchn, 0);
 865         } else {
 866                 struct irq_info *info = info_for_irq(irq);
 867                 WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
 868         }
 869
 870 out:
 871         mutex_unlock(&irq_mapping_update_lock);
 872
 873         return irq;
 874 }
 875 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
 876
 877 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 878 {
 879         struct evtchn_bind_ipi bind_ipi;
 880         int evtchn, irq;
 881         int ret;
 882
 883         mutex_lock(&irq_mapping_update_lock);
 884
 885         irq = per_cpu(ipi_to_irq, cpu)[ipi];
 886
 887         if (irq == -1) {
 888                 irq = xen_allocate_irq_dynamic();
 889                 if (irq < 0)
 890                         goto out;
 891
 892                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 893                                               handle_percpu_irq, "ipi");
 894
 895                 bind_ipi.vcpu = cpu;
 896                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
 897                                                 &bind_ipi) != 0)
 898                         BUG();
 899                 evtchn = bind_ipi.port;
 900
 901                 ret = xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
 902                 if (ret < 0) {
 903                         __unbind_from_irq(irq);
 904                         irq = ret;
 905                         goto out;
 906                 }
 907                 bind_evtchn_to_cpu(evtchn, cpu);
 908         } else {
 909                 struct irq_info *info = info_for_irq(irq);
 910                 WARN_ON(info == NULL || info->type != IRQT_IPI);
 911         }
 912
 913  out:
 914         mutex_unlock(&irq_mapping_update_lock);
 915         return irq;
 916 }
 917
 918 static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
 919                                           unsigned int remote_port)
 920 {
 921         struct evtchn_bind_interdomain bind_interdomain;
 922         int err;
 923
 924         bind_interdomain.remote_dom  = remote_domain;
 925         bind_interdomain.remote_port = remote_port;
 926
 927         err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
 928                                           &bind_interdomain);
 929
 930         return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
 931 }
 932
 933 static int find_virq(unsigned int virq, unsigned int cpu)
 934 {
 935         struct evtchn_status status;
 936         int port, rc = -ENOENT;
 937
 938         memset(&status, 0, sizeof(status));
 939         for (port = 0; port < xen_evtchn_max_channels(); port++) {
 940                 status.dom = DOMID_SELF;
 941                 status.port = port;
 942                 rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status);
 943                 if (rc < 0)
 944                         continue;
 945                 if (status.status != EVTCHNSTAT_virq)
 946                         continue;
 947                 if (status.u.virq == virq && status.vcpu == cpu) {
 948                         rc = port;
 949                         break;
 950                 }
 951         }
 952         return rc;
 953 }
 954
 955 /**
 956  * xen_evtchn_nr_channels - number of usable event channel ports
 957  *
 958  * This may be less than the maximum supported by the current
 959  * hypervisor ABI. Use xen_evtchn_max_channels() for the maximum
 960  * supported.
 961  */
 962 unsigned xen_evtchn_nr_channels(void)
 963 {
 964         return evtchn_ops->nr_channels();
 965 }
 966 EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
 967
 968 int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 969 {
 970         struct evtchn_bind_virq bind_virq;
 971         int evtchn, irq, ret;
 972
 973         mutex_lock(&irq_mapping_update_lock);
 974
 975         irq = per_cpu(virq_to_irq, cpu)[virq];
 976
 977         if (irq == -1) {
 978                 irq = xen_allocate_irq_dynamic();
 979                 if (irq < 0)
 980                         goto out;
 981
 982                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 983                                               handle_percpu_irq, "virq");
 984
 985                 bind_virq.virq = virq;
 986                 bind_virq.vcpu = cpu;
 987                 ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
 988                                                 &bind_virq);
 989                 if (ret == 0)
 990                         evtchn = bind_virq.port;
 991                 else {
 992                         if (ret == -EEXIST)
 993                                 ret = find_virq(virq, cpu);
 994                         BUG_ON(ret < 0);
 995                         evtchn = ret;
 996                 }
 997
 998                 ret = xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
 999                 if (ret < 0) {
1000                         __unbind_from_irq(irq);
1001                         irq = ret;
1002                         goto out;
1003                 }
1004
1005                 bind_evtchn_to_cpu(evtchn, cpu);
1006         } else {
1007                 struct irq_info *info = info_for_irq(irq);
1008                 WARN_ON(info == NULL || info->type != IRQT_VIRQ);
1009         }
1010
1011 out:
1012         mutex_unlock(&irq_mapping_update_lock);
1013
1014         return irq;
1015 }
1016
1017 static void unbind_from_irq(unsigned int irq)
1018 {
1019         mutex_lock(&irq_mapping_update_lock);
1020         __unbind_from_irq(irq);
1021         mutex_unlock(&irq_mapping_update_lock);
1022 }
1023
1024 int bind_evtchn_to_irqhandler(unsigned int evtchn,
1025                               irq_handler_t handler,
1026                               unsigned long irqflags,
1027                               const char *devname, void *dev_id)
1028 {
1029         int irq, retval;
1030
1031         irq = bind_evtchn_to_irq(evtchn);
1032         if (irq < 0)
1033                 return irq;
1034         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1035         if (retval != 0) {
1036                 unbind_from_irq(irq);
1037                 return retval;
1038         }
1039
1040         return irq;
1041 }
1042 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
1043
1044 int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
1045                                           unsigned int remote_port,
1046                                           irq_handler_t handler,
1047                                           unsigned long irqflags,
1048                                           const char *devname,
1049                                           void *dev_id)
1050 {
1051         int irq, retval;
1052
1053         irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
1054         if (irq < 0)
1055                 return irq;
1056
1057         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1058         if (retval != 0) {
1059                 unbind_from_irq(irq);
1060                 return retval;
1061         }
1062
1063         return irq;
1064 }
1065 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
1066
1067 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
1068                             irq_handler_t handler,
1069                             unsigned long irqflags, const char *devname, void *dev_id)
1070 {
1071         int irq, retval;
1072
1073         irq = bind_virq_to_irq(virq, cpu);
1074         if (irq < 0)
1075                 return irq;
1076         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1077         if (retval != 0) {
1078                 unbind_from_irq(irq);
1079                 return retval;
1080         }
1081
1082         return irq;
1083 }
1084 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
1085
1086 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
1087                            unsigned int cpu,
1088                            irq_handler_t handler,
1089                            unsigned long irqflags,
1090                            const char *devname,
1091                            void *dev_id)
1092 {
1093         int irq, retval;
1094
1095         irq = bind_ipi_to_irq(ipi, cpu);
1096         if (irq < 0)
1097                 return irq;
1098
1099         irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME | IRQF_EARLY_RESUME;
1100         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1101         if (retval != 0) {
1102                 unbind_from_irq(irq);
1103                 return retval;
1104         }
1105
1106         return irq;
1107 }
1108
1109 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
1110 {
1111         struct irq_info *info = irq_get_handler_data(irq);
1112
1113         if (WARN_ON(!info))
1114                 return;
1115         free_irq(irq, dev_id);
1116         unbind_from_irq(irq);
1117 }
1118 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
1119
1120 /**
1121  * xen_set_irq_priority() - set an event channel priority.
1122  * @irq:irq bound to an event channel.
1123  * @priority: priority between XEN_IRQ_PRIORITY_MAX and XEN_IRQ_PRIORITY_MIN.
1124  */
1125 int xen_set_irq_priority(unsigned irq, unsigned priority)
1126 {
1127         struct evtchn_set_priority set_priority;
1128
1129         set_priority.port = evtchn_from_irq(irq);
1130         set_priority.priority = priority;
1131
1132         return HYPERVISOR_event_channel_op(EVTCHNOP_set_priority,
1133                                            &set_priority);
1134 }
1135 EXPORT_SYMBOL_GPL(xen_set_irq_priority);
1136
1137 int evtchn_make_refcounted(unsigned int evtchn)
1138 {
1139         int irq = get_evtchn_to_irq(evtchn);
1140         struct irq_info *info;
1141
1142         if (irq == -1)
1143                 return -ENOENT;
1144
1145         info = irq_get_handler_data(irq);
1146
1147         if (!info)
1148                 return -ENOENT;
1149
1150         WARN_ON(info->refcnt != -1);
1151
1152         info->refcnt = 1;
1153
1154         return 0;
1155 }
1156 EXPORT_SYMBOL_GPL(evtchn_make_refcounted);
1157
1158 int evtchn_get(unsigned int evtchn)
1159 {
1160         int irq;
1161         struct irq_info *info;
1162         int err = -ENOENT;
1163
1164         if (evtchn >= xen_evtchn_max_channels())
1165                 return -EINVAL;
1166
1167         mutex_lock(&irq_mapping_update_lock);
1168
1169         irq = get_evtchn_to_irq(evtchn);
1170         if (irq == -1)
1171                 goto done;
1172
1173         info = irq_get_handler_data(irq);
1174
1175         if (!info)
1176                 goto done;
1177
1178         err = -EINVAL;
1179         if (info->refcnt <= 0)
1180                 goto done;
1181
1182         info->refcnt++;
1183         err = 0;
1184  done:
1185         mutex_unlock(&irq_mapping_update_lock);
1186
1187         return err;
1188 }
1189 EXPORT_SYMBOL_GPL(evtchn_get);
1190
1191 void evtchn_put(unsigned int evtchn)
1192 {
1193         int irq = get_evtchn_to_irq(evtchn);
1194         if (WARN_ON(irq == -1))
1195                 return;
1196         unbind_from_irq(irq);
1197 }
1198 EXPORT_SYMBOL_GPL(evtchn_put);
1199
1200 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
1201 {
1202         int irq;
1203
1204 #ifdef CONFIG_X86
1205         if (unlikely(vector == XEN_NMI_VECTOR)) {
1206                 int rc =  HYPERVISOR_vcpu_op(VCPUOP_send_nmi, cpu, NULL);
1207                 if (rc < 0)
1208                         printk(KERN_WARNING "Sending nmi to CPU%d failed (rc:%d)\n", cpu, rc);
1209                 return;
1210         }
1211 #endif
1212         irq = per_cpu(ipi_to_irq, cpu)[vector];
1213         BUG_ON(irq < 0);
1214         notify_remote_via_irq(irq);
1215 }
1216
1217 static DEFINE_PER_CPU(unsigned, xed_nesting_count);
1218
1219 static void __xen_evtchn_do_upcall(void)
1220 {
1221         struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1222         int cpu = get_cpu();
1223         unsigned count;
1224
1225         do {
1226                 vcpu_info->evtchn_upcall_pending = 0;
1227
1228                 if (__this_cpu_inc_return(xed_nesting_count) - 1)
1229                         goto out;
1230
1231                 xen_evtchn_handle_events(cpu);
1232
1233                 BUG_ON(!irqs_disabled());
1234
1235                 count = __this_cpu_read(xed_nesting_count);
1236                 __this_cpu_write(xed_nesting_count, 0);
1237         } while (count != 1 || vcpu_info->evtchn_upcall_pending);
1238
1239 out:
1240
1241         put_cpu();
1242 }
1243
1244 void xen_evtchn_do_upcall(struct pt_regs *regs)
1245 {
1246         struct pt_regs *old_regs = set_irq_regs(regs);
1247
1248         irq_enter();
1249 #ifdef CONFIG_X86
1250         exit_idle();
1251 #endif
1252         inc_irq_stat(irq_hv_callback_count);
1253
1254         __xen_evtchn_do_upcall();
1255
1256         irq_exit();
1257         set_irq_regs(old_regs);
1258 }
1259
1260 void xen_hvm_evtchn_do_upcall(void)
1261 {
1262         __xen_evtchn_do_upcall();
1263 }
1264 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1265
1266 /* Rebind a new event channel to an existing irq. */
1267 void rebind_evtchn_irq(int evtchn, int irq)
1268 {
1269         struct irq_info *info = info_for_irq(irq);
1270
1271         if (WARN_ON(!info))
1272                 return;
1273
1274         /* Make sure the irq is masked, since the new event channel
1275            will also be masked. */
1276         disable_irq(irq);
1277
1278         mutex_lock(&irq_mapping_update_lock);
1279
1280         /* After resume the irq<->evtchn mappings are all cleared out */
1281         BUG_ON(get_evtchn_to_irq(evtchn) != -1);
1282         /* Expect irq to have been bound before,
1283            so there should be a proper type */
1284         BUG_ON(info->type == IRQT_UNBOUND);
1285
1286         (void)xen_irq_info_evtchn_setup(irq, evtchn);
1287
1288         mutex_unlock(&irq_mapping_update_lock);
1289
1290         /* new event channels are always bound to cpu 0 */
1291         irq_set_affinity(irq, cpumask_of(0));
1292
1293         /* Unmask the event channel. */
1294         enable_irq(irq);
1295 }
1296
1297 /* Rebind an evtchn so that it gets delivered to a specific cpu */
1298 static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
1299 {
1300         struct evtchn_bind_vcpu bind_vcpu;
1301         int evtchn = evtchn_from_irq(irq);
1302         int masked;
1303
1304         if (!VALID_EVTCHN(evtchn))
1305                 return -1;
1306
1307         /*
1308          * Events delivered via platform PCI interrupts are always
1309          * routed to vcpu 0 and hence cannot be rebound.
1310          */
1311         if (xen_hvm_domain() && !xen_have_vector_callback)
1312                 return -1;
1313
1314         /* Send future instances of this interrupt to other vcpu. */
1315         bind_vcpu.port = evtchn;
1316         bind_vcpu.vcpu = tcpu;
1317
1318         /*
1319          * Mask the event while changing the VCPU binding to prevent
1320          * it being delivered on an unexpected VCPU.
1321          */
1322         masked = test_and_set_mask(evtchn);
1323
1324         /*
1325          * If this fails, it usually just indicates that we're dealing with a
1326          * virq or IPI channel, which don't actually need to be rebound. Ignore
1327          * it, but don't do the xenlinux-level rebind in that case.
1328          */
1329         if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1330                 bind_evtchn_to_cpu(evtchn, tcpu);
1331
1332         if (!masked)
1333                 unmask_evtchn(evtchn);
1334
1335         return 0;
1336 }
1337
1338 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1339                             bool force)
1340 {
1341         unsigned tcpu = cpumask_first_and(dest, cpu_online_mask);
1342
1343         return rebind_irq_to_cpu(data->irq, tcpu);
1344 }
1345
1346 static void enable_dynirq(struct irq_data *data)
1347 {
1348         int evtchn = evtchn_from_irq(data->irq);
1349
1350         if (VALID_EVTCHN(evtchn))
1351                 unmask_evtchn(evtchn);
1352 }
1353
1354 static void disable_dynirq(struct irq_data *data)
1355 {
1356         int evtchn = evtchn_from_irq(data->irq);
1357
1358         if (VALID_EVTCHN(evtchn))
1359                 mask_evtchn(evtchn);
1360 }
1361
1362 static void ack_dynirq(struct irq_data *data)
1363 {
1364         int evtchn = evtchn_from_irq(data->irq);
1365
1366         irq_move_irq(data);
1367
1368         if (VALID_EVTCHN(evtchn))
1369                 clear_evtchn(evtchn);
1370 }
1371
1372 static void mask_ack_dynirq(struct irq_data *data)
1373 {
1374         disable_dynirq(data);
1375         ack_dynirq(data);
1376 }
1377
1378 static int retrigger_dynirq(struct irq_data *data)
1379 {
1380         unsigned int evtchn = evtchn_from_irq(data->irq);
1381         int masked;
1382
1383         if (!VALID_EVTCHN(evtchn))
1384                 return 0;
1385
1386         masked = test_and_set_mask(evtchn);
1387         set_evtchn(evtchn);
1388         if (!masked)
1389                 unmask_evtchn(evtchn);
1390
1391         return 1;
1392 }
1393
1394 static void restore_pirqs(void)
1395 {
1396         int pirq, rc, irq, gsi;
1397         struct physdev_map_pirq map_irq;
1398         struct irq_info *info;
1399
1400         list_for_each_entry(info, &xen_irq_list_head, list) {
1401                 if (info->type != IRQT_PIRQ)
1402                         continue;
1403
1404                 pirq = info->u.pirq.pirq;
1405                 gsi = info->u.pirq.gsi;
1406                 irq = info->irq;
1407
1408                 /* save/restore of PT devices doesn't work, so at this point the
1409                  * only devices present are GSI based emulated devices */
1410                 if (!gsi)
1411                         continue;
1412
1413                 map_irq.domid = DOMID_SELF;
1414                 map_irq.type = MAP_PIRQ_TYPE_GSI;
1415                 map_irq.index = gsi;
1416                 map_irq.pirq = pirq;
1417
1418                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1419                 if (rc) {
1420                         pr_warn("xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1421                                 gsi, irq, pirq, rc);
1422                         xen_free_irq(irq);
1423                         continue;
1424                 }
1425
1426                 printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1427
1428                 __startup_pirq(irq);
1429         }
1430 }
1431
1432 static void restore_cpu_virqs(unsigned int cpu)
1433 {
1434         struct evtchn_bind_virq bind_virq;
1435         int virq, irq, evtchn;
1436
1437         for (virq = 0; virq < NR_VIRQS; virq++) {
1438                 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1439                         continue;
1440
1441                 BUG_ON(virq_from_irq(irq) != virq);
1442
1443                 /* Get a new binding from Xen. */
1444                 bind_virq.virq = virq;
1445                 bind_virq.vcpu = cpu;
1446                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1447                                                 &bind_virq) != 0)
1448                         BUG();
1449                 evtchn = bind_virq.port;
1450
1451                 /* Record the new mapping. */
1452                 (void)xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
1453                 bind_evtchn_to_cpu(evtchn, cpu);
1454         }
1455 }
1456
1457 static void restore_cpu_ipis(unsigned int cpu)
1458 {
1459         struct evtchn_bind_ipi bind_ipi;
1460         int ipi, irq, evtchn;
1461
1462         for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1463                 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1464                         continue;
1465
1466                 BUG_ON(ipi_from_irq(irq) != ipi);
1467
1468                 /* Get a new binding from Xen. */
1469                 bind_ipi.vcpu = cpu;
1470                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1471                                                 &bind_ipi) != 0)
1472                         BUG();
1473                 evtchn = bind_ipi.port;
1474
1475                 /* Record the new mapping. */
1476                 (void)xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
1477                 bind_evtchn_to_cpu(evtchn, cpu);
1478         }
1479 }
1480
1481 /* Clear an irq's pending state, in preparation for polling on it */
1482 void xen_clear_irq_pending(int irq)
1483 {
1484         int evtchn = evtchn_from_irq(irq);
1485
1486         if (VALID_EVTCHN(evtchn))
1487                 clear_evtchn(evtchn);
1488 }
1489 EXPORT_SYMBOL(xen_clear_irq_pending);
1490 void xen_set_irq_pending(int irq)
1491 {
1492         int evtchn = evtchn_from_irq(irq);
1493
1494         if (VALID_EVTCHN(evtchn))
1495                 set_evtchn(evtchn);
1496 }
1497
1498 bool xen_test_irq_pending(int irq)
1499 {
1500         int evtchn = evtchn_from_irq(irq);
1501         bool ret = false;
1502
1503         if (VALID_EVTCHN(evtchn))
1504                 ret = test_evtchn(evtchn);
1505
1506         return ret;
1507 }
1508
1509 /* Poll waiting for an irq to become pending with timeout.  In the usual case,
1510  * the irq will be disabled so it won't deliver an interrupt. */
1511 void xen_poll_irq_timeout(int irq, u64 timeout)
1512 {
1513         evtchn_port_t evtchn = evtchn_from_irq(irq);
1514
1515         if (VALID_EVTCHN(evtchn)) {
1516                 struct sched_poll poll;
1517
1518                 poll.nr_ports = 1;
1519                 poll.timeout = timeout;
1520                 set_xen_guest_handle(poll.ports, &evtchn);
1521
1522                 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1523                         BUG();
1524         }
1525 }
1526 EXPORT_SYMBOL(xen_poll_irq_timeout);
1527 /* Poll waiting for an irq to become pending.  In the usual case, the
1528  * irq will be disabled so it won't deliver an interrupt. */
1529 void xen_poll_irq(int irq)
1530 {
1531         xen_poll_irq_timeout(irq, 0 /* no timeout */);
1532 }
1533
1534 /* Check whether the IRQ line is shared with other guests. */
1535 int xen_test_irq_shared(int irq)
1536 {
1537         struct irq_info *info = info_for_irq(irq);
1538         struct physdev_irq_status_query irq_status;
1539
1540         if (WARN_ON(!info))
1541                 return -ENOENT;
1542
1543         irq_status.irq = info->u.pirq.pirq;
1544
1545         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
1546                 return 0;
1547         return !(irq_status.flags & XENIRQSTAT_shared);
1548 }
1549 EXPORT_SYMBOL_GPL(xen_test_irq_shared);
1550
1551 void xen_irq_resume(void)
1552 {
1553         unsigned int cpu;
1554         struct irq_info *info;
1555
1556         /* New event-channel space is not 'live' yet. */
1557         xen_evtchn_mask_all();
1558         xen_evtchn_resume();
1559
1560         /* No IRQ <-> event-channel mappings. */
1561         list_for_each_entry(info, &xen_irq_list_head, list)
1562                 info->evtchn = 0; /* zap event-channel binding */
1563
1564         clear_evtchn_to_irq_all();
1565
1566         for_each_possible_cpu(cpu) {
1567                 restore_cpu_virqs(cpu);
1568                 restore_cpu_ipis(cpu);
1569         }
1570
1571         restore_pirqs();
1572 }
1573
1574 static struct irq_chip xen_dynamic_chip __read_mostly = {
1575         .name                   = "xen-dyn",
1576
1577         .irq_disable            = disable_dynirq,
1578         .irq_mask               = disable_dynirq,
1579         .irq_unmask             = enable_dynirq,
1580
1581         .irq_ack                = ack_dynirq,
1582         .irq_mask_ack           = mask_ack_dynirq,
1583
1584         .irq_set_affinity       = set_affinity_irq,
1585         .irq_retrigger          = retrigger_dynirq,
1586 };
1587
1588 static struct irq_chip xen_pirq_chip __read_mostly = {
1589         .name                   = "xen-pirq",
1590
1591         .irq_startup            = startup_pirq,
1592         .irq_shutdown           = shutdown_pirq,
1593         .irq_enable             = enable_pirq,
1594         .irq_disable            = disable_pirq,
1595
1596         .irq_mask               = disable_dynirq,
1597         .irq_unmask             = enable_dynirq,
1598
1599         .irq_ack                = eoi_pirq,
1600         .irq_eoi                = eoi_pirq,
1601         .irq_mask_ack           = mask_ack_pirq,
1602
1603         .irq_set_affinity       = set_affinity_irq,
1604
1605         .irq_retrigger          = retrigger_dynirq,
1606 };
1607
1608 static struct irq_chip xen_percpu_chip __read_mostly = {
1609         .name                   = "xen-percpu",
1610
1611         .irq_disable            = disable_dynirq,
1612         .irq_mask               = disable_dynirq,
1613         .irq_unmask             = enable_dynirq,
1614
1615         .irq_ack                = ack_dynirq,
1616 };
1617
1618 int xen_set_callback_via(uint64_t via)
1619 {
1620         struct xen_hvm_param a;
1621         a.domid = DOMID_SELF;
1622         a.index = HVM_PARAM_CALLBACK_IRQ;
1623         a.value = via;
1624         return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1625 }
1626 EXPORT_SYMBOL_GPL(xen_set_callback_via);
1627
1628 #ifdef CONFIG_XEN_PVHVM
1629 /* Vector callbacks are better than PCI interrupts to receive event
1630  * channel notifications because we can receive vector callbacks on any
1631  * vcpu and we don't need PCI support or APIC interactions. */
1632 void xen_callback_vector(void)
1633 {
1634         int rc;
1635         uint64_t callback_via;
1636         if (xen_have_vector_callback) {
1637                 callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
1638                 rc = xen_set_callback_via(callback_via);
1639                 if (rc) {
1640                         pr_err("Request for Xen HVM callback vector failed\n");
1641                         xen_have_vector_callback = 0;
1642                         return;
1643                 }
1644                 pr_info("Xen HVM callback vector for event delivery is enabled\n");
1645                 /* in the restore case the vector has already been allocated */
1646                 if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
1647                         alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
1648                                         xen_hvm_callback_vector);
1649         }
1650 }
1651 #else
1652 void xen_callback_vector(void) {}
1653 #endif
1654
1655 #undef MODULE_PARAM_PREFIX
1656 #define MODULE_PARAM_PREFIX "xen."
1657
1658 static bool fifo_events = true;
1659 module_param(fifo_events, bool, 0);
1660
1661 void __init xen_init_IRQ(void)
1662 {
1663         int ret = -EINVAL;
1664
1665         if (fifo_events)
1666                 ret = xen_evtchn_fifo_init();
1667         if (ret < 0)
1668                 xen_evtchn_2l_init();
1669
1670         evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()),
1671                                 sizeof(*evtchn_to_irq), GFP_KERNEL);
1672         BUG_ON(!evtchn_to_irq);
1673
1674         /* No event channels are 'live' right now. */
1675         xen_evtchn_mask_all();
1676
1677         pirq_needs_eoi = pirq_needs_eoi_flag;
1678
1679 #ifdef CONFIG_X86
1680         if (xen_pv_domain()) {
1681                 irq_ctx_init(smp_processor_id());
1682                 if (xen_initial_domain())
1683                         pci_xen_initial_domain();
1684         }
1685         if (xen_feature(XENFEAT_hvm_callback_vector))
1686                 xen_callback_vector();
1687
1688         if (xen_hvm_domain()) {
1689                 native_init_IRQ();
1690                 /* pci_xen_hvm_init must be called after native_init_IRQ so that
1691                  * __acpi_register_gsi can point at the right function */
1692                 pci_xen_hvm_init();
1693         } else {
1694                 int rc;
1695                 struct physdev_pirq_eoi_gmfn eoi_gmfn;
1696
1697                 pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
1698                 eoi_gmfn.gmfn = virt_to_mfn(pirq_eoi_map);
1699                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn);
1700                 /* TODO: No PVH support for PIRQ EOI */
1701                 if (rc != 0) {
1702                         free_page((unsigned long) pirq_eoi_map);
1703                         pirq_eoi_map = NULL;
1704                 } else
1705                         pirq_needs_eoi = pirq_check_eoi_map;
1706         }
1707 #endif
1708 }