drivers/xen/events.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 recieved, 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 #include <linux/linkage.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/irq.h>
  27 #include <linux/module.h>
  28 #include <linux/string.h>
  29 #include <linux/bootmem.h>
  30 #include <linux/slab.h>
  31 #include <linux/irqnr.h>
  32
  33 #include <asm/desc.h>
  34 #include <asm/ptrace.h>
  35 #include <asm/irq.h>
  36 #include <asm/idle.h>
  37 #include <asm/io_apic.h>
  38 #include <asm/sync_bitops.h>
  39 #include <asm/xen/hypercall.h>
  40 #include <asm/xen/hypervisor.h>
  41
  42 #include <xen/xen.h>
  43 #include <xen/hvm.h>
  44 #include <xen/xen-ops.h>
  45 #include <xen/events.h>
  46 #include <xen/interface/xen.h>
  47 #include <xen/interface/event_channel.h>
  48 #include <xen/interface/hvm/hvm_op.h>
  49 #include <xen/interface/hvm/params.h>
  50
  51 /*
  52  * This lock protects updates to the following mapping and reference-count
  53  * arrays. The lock does not need to be acquired to read the mapping tables.
  54  */
  55 static DEFINE_SPINLOCK(irq_mapping_update_lock);
  56
  57 /* IRQ <-> VIRQ mapping. */
  58 static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
  59
  60 /* IRQ <-> IPI mapping */
  61 static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
  62
  63 /* Interrupt types. */
  64 enum xen_irq_type {
  65         IRQT_UNBOUND = 0,
  66         IRQT_PIRQ,
  67         IRQT_VIRQ,
  68         IRQT_IPI,
  69         IRQT_EVTCHN
  70 };
  71
  72 /*
  73  * Packed IRQ information:
  74  * type - enum xen_irq_type
  75  * event channel - irq->event channel mapping
  76  * cpu - cpu this event channel is bound to
  77  * index - type-specific information:
  78  *    PIRQ - vector, with MSB being "needs EIO"
  79  *    VIRQ - virq number
  80  *    IPI - IPI vector
  81  *    EVTCHN -
  82  */
  83 struct irq_info
  84 {
  85         enum xen_irq_type type; /* type */
  86         unsigned short evtchn;  /* event channel */
  87         unsigned short cpu;     /* cpu bound */
  88
  89         union {
  90                 unsigned short virq;
  91                 enum ipi_vector ipi;
  92                 struct {
  93                         unsigned short pirq;
  94                         unsigned short gsi;
  95                         unsigned char vector;
  96                         unsigned char flags;
  97                 } pirq;
  98         } u;
  99 };
 100 #define PIRQ_NEEDS_EOI  (1 << 0)
 101 #define PIRQ_SHAREABLE  (1 << 1)
 102
 103 static struct irq_info *irq_info;
 104 static int *pirq_to_irq;
 105 static int nr_pirqs;
 106
 107 static int *evtchn_to_irq;
 108 struct cpu_evtchn_s {
 109         unsigned long bits[NR_EVENT_CHANNELS/BITS_PER_LONG];
 110 };
 111
 112 static __initdata struct cpu_evtchn_s init_evtchn_mask = {
 113         .bits[0 ... (NR_EVENT_CHANNELS/BITS_PER_LONG)-1] = ~0ul,
 114 };
 115 static struct cpu_evtchn_s *cpu_evtchn_mask_p = &init_evtchn_mask;
 116
 117 static inline unsigned long *cpu_evtchn_mask(int cpu)
 118 {
 119         return cpu_evtchn_mask_p[cpu].bits;
 120 }
 121
 122 /* Xen will never allocate port zero for any purpose. */
 123 #define VALID_EVTCHN(chn)       ((chn) != 0)
 124
 125 static struct irq_chip xen_dynamic_chip;
 126 static struct irq_chip xen_percpu_chip;
 127 static struct irq_chip xen_pirq_chip;
 128
 129 /* Constructor for packed IRQ information. */
 130 static struct irq_info mk_unbound_info(void)
 131 {
 132         return (struct irq_info) { .type = IRQT_UNBOUND };
 133 }
 134
 135 static struct irq_info mk_evtchn_info(unsigned short evtchn)
 136 {
 137         return (struct irq_info) { .type = IRQT_EVTCHN, .evtchn = evtchn,
 138                         .cpu = 0 };
 139 }
 140
 141 static struct irq_info mk_ipi_info(unsigned short evtchn, enum ipi_vector ipi)
 142 {
 143         return (struct irq_info) { .type = IRQT_IPI, .evtchn = evtchn,
 144                         .cpu = 0, .u.ipi = ipi };
 145 }
 146
 147 static struct irq_info mk_virq_info(unsigned short evtchn, unsigned short virq)
 148 {
 149         return (struct irq_info) { .type = IRQT_VIRQ, .evtchn = evtchn,
 150                         .cpu = 0, .u.virq = virq };
 151 }
 152
 153 static struct irq_info mk_pirq_info(unsigned short evtchn, unsigned short pirq,
 154                                     unsigned short gsi, unsigned short vector)
 155 {
 156         return (struct irq_info) { .type = IRQT_PIRQ, .evtchn = evtchn,
 157                         .cpu = 0,
 158                         .u.pirq = { .pirq = pirq, .gsi = gsi, .vector = vector } };
 159 }
 160
 161 /*
 162  * Accessors for packed IRQ information.
 163  */
 164 static struct irq_info *info_for_irq(unsigned irq)
 165 {
 166         return &irq_info[irq];
 167 }
 168
 169 static unsigned int evtchn_from_irq(unsigned irq)
 170 {
 171         return info_for_irq(irq)->evtchn;
 172 }
 173
 174 unsigned irq_from_evtchn(unsigned int evtchn)
 175 {
 176         return evtchn_to_irq[evtchn];
 177 }
 178 EXPORT_SYMBOL_GPL(irq_from_evtchn);
 179
 180 static enum ipi_vector ipi_from_irq(unsigned irq)
 181 {
 182         struct irq_info *info = info_for_irq(irq);
 183
 184         BUG_ON(info == NULL);
 185         BUG_ON(info->type != IRQT_IPI);
 186
 187         return info->u.ipi;
 188 }
 189
 190 static unsigned virq_from_irq(unsigned irq)
 191 {
 192         struct irq_info *info = info_for_irq(irq);
 193
 194         BUG_ON(info == NULL);
 195         BUG_ON(info->type != IRQT_VIRQ);
 196
 197         return info->u.virq;
 198 }
 199
 200 static unsigned pirq_from_irq(unsigned irq)
 201 {
 202         struct irq_info *info = info_for_irq(irq);
 203
 204         BUG_ON(info == NULL);
 205         BUG_ON(info->type != IRQT_PIRQ);
 206
 207         return info->u.pirq.pirq;
 208 }
 209
 210 static unsigned gsi_from_irq(unsigned irq)
 211 {
 212         struct irq_info *info = info_for_irq(irq);
 213
 214         BUG_ON(info == NULL);
 215         BUG_ON(info->type != IRQT_PIRQ);
 216
 217         return info->u.pirq.gsi;
 218 }
 219
 220 static unsigned vector_from_irq(unsigned irq)
 221 {
 222         struct irq_info *info = info_for_irq(irq);
 223
 224         BUG_ON(info == NULL);
 225         BUG_ON(info->type != IRQT_PIRQ);
 226
 227         return info->u.pirq.vector;
 228 }
 229
 230 static enum xen_irq_type type_from_irq(unsigned irq)
 231 {
 232         return info_for_irq(irq)->type;
 233 }
 234
 235 static unsigned cpu_from_irq(unsigned irq)
 236 {
 237         return info_for_irq(irq)->cpu;
 238 }
 239
 240 static unsigned int cpu_from_evtchn(unsigned int evtchn)
 241 {
 242         int irq = evtchn_to_irq[evtchn];
 243         unsigned ret = 0;
 244
 245         if (irq != -1)
 246                 ret = cpu_from_irq(irq);
 247
 248         return ret;
 249 }
 250
 251 static bool pirq_needs_eoi(unsigned irq)
 252 {
 253         struct irq_info *info = info_for_irq(irq);
 254
 255         BUG_ON(info->type != IRQT_PIRQ);
 256
 257         return info->u.pirq.flags & PIRQ_NEEDS_EOI;
 258 }
 259
 260 static inline unsigned long active_evtchns(unsigned int cpu,
 261                                            struct shared_info *sh,
 262                                            unsigned int idx)
 263 {
 264         return (sh->evtchn_pending[idx] &
 265                 cpu_evtchn_mask(cpu)[idx] &
 266                 ~sh->evtchn_mask[idx]);
 267 }
 268
 269 static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
 270 {
 271         int irq = evtchn_to_irq[chn];
 272
 273         BUG_ON(irq == -1);
 274 #ifdef CONFIG_SMP
 275         cpumask_copy(irq_to_desc(irq)->affinity, cpumask_of(cpu));
 276 #endif
 277
 278         __clear_bit(chn, cpu_evtchn_mask(cpu_from_irq(irq)));
 279         __set_bit(chn, cpu_evtchn_mask(cpu));
 280
 281         irq_info[irq].cpu = cpu;
 282 }
 283
 284 static void init_evtchn_cpu_bindings(void)
 285 {
 286 #ifdef CONFIG_SMP
 287         struct irq_desc *desc;
 288         int i;
 289
 290         /* By default all event channels notify CPU#0. */
 291         for_each_irq_desc(i, desc) {
 292                 cpumask_copy(desc->affinity, cpumask_of(0));
 293         }
 294 #endif
 295
 296         memset(cpu_evtchn_mask(0), ~0, sizeof(cpu_evtchn_mask(0)));
 297 }
 298
 299 static inline void clear_evtchn(int port)
 300 {
 301         struct shared_info *s = HYPERVISOR_shared_info;
 302         sync_clear_bit(port, &s->evtchn_pending[0]);
 303 }
 304
 305 static inline void set_evtchn(int port)
 306 {
 307         struct shared_info *s = HYPERVISOR_shared_info;
 308         sync_set_bit(port, &s->evtchn_pending[0]);
 309 }
 310
 311 static inline int test_evtchn(int port)
 312 {
 313         struct shared_info *s = HYPERVISOR_shared_info;
 314         return sync_test_bit(port, &s->evtchn_pending[0]);
 315 }
 316
 317
 318 /**
 319  * notify_remote_via_irq - send event to remote end of event channel via irq
 320  * @irq: irq of event channel to send event to
 321  *
 322  * Unlike notify_remote_via_evtchn(), this is safe to use across
 323  * save/restore. Notifications on a broken connection are silently
 324  * dropped.
 325  */
 326 void notify_remote_via_irq(int irq)
 327 {
 328         int evtchn = evtchn_from_irq(irq);
 329
 330         if (VALID_EVTCHN(evtchn))
 331                 notify_remote_via_evtchn(evtchn);
 332 }
 333 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
 334
 335 static void mask_evtchn(int port)
 336 {
 337         struct shared_info *s = HYPERVISOR_shared_info;
 338         sync_set_bit(port, &s->evtchn_mask[0]);
 339 }
 340
 341 static void unmask_evtchn(int port)
 342 {
 343         struct shared_info *s = HYPERVISOR_shared_info;
 344         unsigned int cpu = get_cpu();
 345
 346         BUG_ON(!irqs_disabled());
 347
 348         /* Slow path (hypercall) if this is a non-local port. */
 349         if (unlikely(cpu != cpu_from_evtchn(port))) {
 350                 struct evtchn_unmask unmask = { .port = port };
 351                 (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
 352         } else {
 353                 struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
 354
 355                 sync_clear_bit(port, &s->evtchn_mask[0]);
 356
 357                 /*
 358                  * The following is basically the equivalent of
 359                  * 'hw_resend_irq'. Just like a real IO-APIC we 'lose
 360                  * the interrupt edge' if the channel is masked.
 361                  */
 362                 if (sync_test_bit(port, &s->evtchn_pending[0]) &&
 363                     !sync_test_and_set_bit(port / BITS_PER_LONG,
 364                                            &vcpu_info->evtchn_pending_sel))
 365                         vcpu_info->evtchn_upcall_pending = 1;
 366         }
 367
 368         put_cpu();
 369 }
 370
 371 static int get_nr_hw_irqs(void)
 372 {
 373         int ret = 1;
 374
 375 #ifdef CONFIG_X86_IO_APIC
 376         ret = get_nr_irqs_gsi();
 377 #endif
 378
 379         return ret;
 380 }
 381
 382 /* callers of this function should make sure that PHYSDEVOP_get_nr_pirqs
 383  * succeeded otherwise nr_pirqs won't hold the right value */
 384 static int find_unbound_pirq(void)
 385 {
 386         int i;
 387         for (i = nr_pirqs-1; i >= 0; i--) {
 388                 if (pirq_to_irq[i] < 0)
 389                         return i;
 390         }
 391         return -1;
 392 }
 393
 394 static int find_unbound_irq(void)
 395 {
 396         struct irq_data *data;
 397         int irq, res;
 398         int start = get_nr_hw_irqs();
 399
 400         if (start == nr_irqs)
 401                 goto no_irqs;
 402
 403         /* nr_irqs is a magic value. Must not use it.*/
 404         for (irq = nr_irqs-1; irq > start; irq--) {
 405                 data = irq_get_irq_data(irq);
 406                 /* only 0->15 have init'd desc; handle irq > 16 */
 407                 if (!data)
 408                         break;
 409                 if (data->chip == &no_irq_chip)
 410                         break;
 411                 if (data->chip != &xen_dynamic_chip)
 412                         continue;
 413                 if (irq_info[irq].type == IRQT_UNBOUND)
 414                         return irq;
 415         }
 416
 417         if (irq == start)
 418                 goto no_irqs;
 419
 420         res = irq_alloc_desc_at(irq, 0);
 421
 422         if (WARN_ON(res != irq))
 423                 return -1;
 424
 425         return irq;
 426
 427 no_irqs:
 428         panic("No available IRQ to bind to: increase nr_irqs!\n");
 429 }
 430
 431 static bool identity_mapped_irq(unsigned irq)
 432 {
 433         /* identity map all the hardware irqs */
 434         return irq < get_nr_hw_irqs();
 435 }
 436
 437 static void pirq_unmask_notify(int irq)
 438 {
 439         struct physdev_eoi eoi = { .irq = pirq_from_irq(irq) };
 440
 441         if (unlikely(pirq_needs_eoi(irq))) {
 442                 int rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
 443                 WARN_ON(rc);
 444         }
 445 }
 446
 447 static void pirq_query_unmask(int irq)
 448 {
 449         struct physdev_irq_status_query irq_status;
 450         struct irq_info *info = info_for_irq(irq);
 451
 452         BUG_ON(info->type != IRQT_PIRQ);
 453
 454         irq_status.irq = pirq_from_irq(irq);
 455         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
 456                 irq_status.flags = 0;
 457
 458         info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
 459         if (irq_status.flags & XENIRQSTAT_needs_eoi)
 460                 info->u.pirq.flags |= PIRQ_NEEDS_EOI;
 461 }
 462
 463 static bool probing_irq(int irq)
 464 {
 465         struct irq_desc *desc = irq_to_desc(irq);
 466
 467         return desc && desc->action == NULL;
 468 }
 469
 470 static unsigned int startup_pirq(unsigned int irq)
 471 {
 472         struct evtchn_bind_pirq bind_pirq;
 473         struct irq_info *info = info_for_irq(irq);
 474         int evtchn = evtchn_from_irq(irq);
 475         int rc;
 476
 477         BUG_ON(info->type != IRQT_PIRQ);
 478
 479         if (VALID_EVTCHN(evtchn))
 480                 goto out;
 481
 482         bind_pirq.pirq = pirq_from_irq(irq);
 483         /* NB. We are happy to share unless we are probing. */
 484         bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
 485                                         BIND_PIRQ__WILL_SHARE : 0;
 486         rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
 487         if (rc != 0) {
 488                 if (!probing_irq(irq))
 489                         printk(KERN_INFO "Failed to obtain physical IRQ %d\n",
 490                                irq);
 491                 return 0;
 492         }
 493         evtchn = bind_pirq.port;
 494
 495         pirq_query_unmask(irq);
 496
 497         evtchn_to_irq[evtchn] = irq;
 498         bind_evtchn_to_cpu(evtchn, 0);
 499         info->evtchn = evtchn;
 500
 501 out:
 502         unmask_evtchn(evtchn);
 503         pirq_unmask_notify(irq);
 504
 505         return 0;
 506 }
 507
 508 static void shutdown_pirq(unsigned int irq)
 509 {
 510         struct evtchn_close close;
 511         struct irq_info *info = info_for_irq(irq);
 512         int evtchn = evtchn_from_irq(irq);
 513
 514         BUG_ON(info->type != IRQT_PIRQ);
 515
 516         if (!VALID_EVTCHN(evtchn))
 517                 return;
 518
 519         mask_evtchn(evtchn);
 520
 521         close.port = evtchn;
 522         if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 523                 BUG();
 524
 525         bind_evtchn_to_cpu(evtchn, 0);
 526         evtchn_to_irq[evtchn] = -1;
 527         info->evtchn = 0;
 528 }
 529
 530 static void enable_pirq(unsigned int irq)
 531 {
 532         startup_pirq(irq);
 533 }
 534
 535 static void disable_pirq(unsigned int irq)
 536 {
 537 }
 538
 539 static void ack_pirq(unsigned int irq)
 540 {
 541         int evtchn = evtchn_from_irq(irq);
 542
 543         move_native_irq(irq);
 544
 545         if (VALID_EVTCHN(evtchn)) {
 546                 mask_evtchn(evtchn);
 547                 clear_evtchn(evtchn);
 548         }
 549 }
 550
 551 static void end_pirq(unsigned int irq)
 552 {
 553         int evtchn = evtchn_from_irq(irq);
 554         struct irq_desc *desc = irq_to_desc(irq);
 555
 556         if (WARN_ON(!desc))
 557                 return;
 558
 559         if ((desc->status & (IRQ_DISABLED|IRQ_PENDING)) ==
 560             (IRQ_DISABLED|IRQ_PENDING)) {
 561                 shutdown_pirq(irq);
 562         } else if (VALID_EVTCHN(evtchn)) {
 563                 unmask_evtchn(evtchn);
 564                 pirq_unmask_notify(irq);
 565         }
 566 }
 567
 568 static int find_irq_by_gsi(unsigned gsi)
 569 {
 570         int irq;
 571
 572         for (irq = 0; irq < nr_irqs; irq++) {
 573                 struct irq_info *info = info_for_irq(irq);
 574
 575                 if (info == NULL || info->type != IRQT_PIRQ)
 576                         continue;
 577
 578                 if (gsi_from_irq(irq) == gsi)
 579                         return irq;
 580         }
 581
 582         return -1;
 583 }
 584
 585 int xen_allocate_pirq(unsigned gsi, int shareable, char *name)
 586 {
 587         return xen_map_pirq_gsi(gsi, gsi, shareable, name);
 588 }
 589
 590 /* xen_map_pirq_gsi might allocate irqs from the top down, as a
 591  * consequence don't assume that the irq number returned has a low value
 592  * or can be used as a pirq number unless you know otherwise.
 593  *
 594  * One notable exception is when xen_map_pirq_gsi is called passing an
 595  * hardware gsi as argument, in that case the irq number returned
 596  * matches the gsi number passed as second argument.
 597  *
 598  * Note: We don't assign an event channel until the irq actually started
 599  * up.  Return an existing irq if we've already got one for the gsi.
 600  */
 601 int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name)
 602 {
 603         int irq = 0;
 604         struct physdev_irq irq_op;
 605
 606         spin_lock(&irq_mapping_update_lock);
 607
 608         if ((pirq > nr_pirqs) || (gsi > nr_irqs)) {
 609                 printk(KERN_WARNING "xen_map_pirq_gsi: %s %s is incorrect!\n",
 610                         pirq > nr_pirqs ? "nr_pirqs" :"",
 611                         gsi > nr_irqs ? "nr_irqs" : "");
 612                 goto out;
 613         }
 614
 615         irq = find_irq_by_gsi(gsi);
 616         if (irq != -1) {
 617                 printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n",
 618                        irq, gsi);
 619                 goto out;       /* XXX need refcount? */
 620         }
 621
 622         /* If we are a PV guest, we don't have GSIs (no ACPI passed). Therefore
 623          * we are using the !xen_initial_domain() to drop in the function.*/
 624         if (identity_mapped_irq(gsi) || !xen_initial_domain()) {
 625                 irq = gsi;
 626                 irq_alloc_desc_at(irq, 0);
 627         } else
 628                 irq = find_unbound_irq();
 629
 630         set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
 631                                       handle_level_irq, name);
 632
 633         irq_op.irq = irq;
 634         irq_op.vector = 0;
 635
 636         /* Only the privileged domain can do this. For non-priv, the pcifront
 637          * driver provides a PCI bus that does the call to do exactly
 638          * this in the priv domain. */
 639         if (xen_initial_domain() &&
 640             HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
 641                 irq_free_desc(irq);
 642                 irq = -ENOSPC;
 643                 goto out;
 644         }
 645
 646         irq_info[irq] = mk_pirq_info(0, pirq, gsi, irq_op.vector);
 647         irq_info[irq].u.pirq.flags |= shareable ? PIRQ_SHAREABLE : 0;
 648         pirq_to_irq[pirq] = irq;
 649
 650 out:
 651         spin_unlock(&irq_mapping_update_lock);
 652
 653         return irq;
 654 }
 655
 656 int xen_destroy_irq(int irq)
 657 {
 658         struct irq_desc *desc;
 659         int rc = -ENOENT;
 660
 661         spin_lock(&irq_mapping_update_lock);
 662
 663         desc = irq_to_desc(irq);
 664         if (!desc)
 665                 goto out;
 666
 667         irq_info[irq] = mk_unbound_info();
 668
 669         irq_free_desc(irq);
 670
 671 out:
 672         spin_unlock(&irq_mapping_update_lock);
 673         return rc;
 674 }
 675
 676 int xen_vector_from_irq(unsigned irq)
 677 {
 678         return vector_from_irq(irq);
 679 }
 680
 681 int xen_gsi_from_irq(unsigned irq)
 682 {
 683         return gsi_from_irq(irq);
 684 }
 685
 686 int bind_evtchn_to_irq(unsigned int evtchn)
 687 {
 688         int irq;
 689
 690         spin_lock(&irq_mapping_update_lock);
 691
 692         irq = evtchn_to_irq[evtchn];
 693
 694         if (irq == -1) {
 695                 irq = find_unbound_irq();
 696
 697                 set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
 698                                               handle_edge_irq, "event");
 699
 700                 evtchn_to_irq[evtchn] = irq;
 701                 irq_info[irq] = mk_evtchn_info(evtchn);
 702         }
 703
 704         spin_unlock(&irq_mapping_update_lock);
 705
 706         return irq;
 707 }
 708 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
 709
 710 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 711 {
 712         struct evtchn_bind_ipi bind_ipi;
 713         int evtchn, irq;
 714
 715         spin_lock(&irq_mapping_update_lock);
 716
 717         irq = per_cpu(ipi_to_irq, cpu)[ipi];
 718
 719         if (irq == -1) {
 720                 irq = find_unbound_irq();
 721                 if (irq < 0)
 722                         goto out;
 723
 724                 set_irq_chip_and_handler_name(irq, &xen_percpu_chip,
 725                                               handle_percpu_irq, "ipi");
 726
 727                 bind_ipi.vcpu = cpu;
 728                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
 729                                                 &bind_ipi) != 0)
 730                         BUG();
 731                 evtchn = bind_ipi.port;
 732
 733                 evtchn_to_irq[evtchn] = irq;
 734                 irq_info[irq] = mk_ipi_info(evtchn, ipi);
 735                 per_cpu(ipi_to_irq, cpu)[ipi] = irq;
 736
 737                 bind_evtchn_to_cpu(evtchn, cpu);
 738         }
 739
 740  out:
 741         spin_unlock(&irq_mapping_update_lock);
 742         return irq;
 743 }
 744
 745
 746 static int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 747 {
 748         struct evtchn_bind_virq bind_virq;
 749         int evtchn, irq;
 750
 751         spin_lock(&irq_mapping_update_lock);
 752
 753         irq = per_cpu(virq_to_irq, cpu)[virq];
 754
 755         if (irq == -1) {
 756                 bind_virq.virq = virq;
 757                 bind_virq.vcpu = cpu;
 758                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
 759                                                 &bind_virq) != 0)
 760                         BUG();
 761                 evtchn = bind_virq.port;
 762
 763                 irq = find_unbound_irq();
 764
 765                 set_irq_chip_and_handler_name(irq, &xen_percpu_chip,
 766                                               handle_percpu_irq, "virq");
 767
 768                 evtchn_to_irq[evtchn] = irq;
 769                 irq_info[irq] = mk_virq_info(evtchn, virq);
 770
 771                 per_cpu(virq_to_irq, cpu)[virq] = irq;
 772
 773                 bind_evtchn_to_cpu(evtchn, cpu);
 774         }
 775
 776         spin_unlock(&irq_mapping_update_lock);
 777
 778         return irq;
 779 }
 780
 781 static void unbind_from_irq(unsigned int irq)
 782 {
 783         struct evtchn_close close;
 784         int evtchn = evtchn_from_irq(irq);
 785
 786         spin_lock(&irq_mapping_update_lock);
 787
 788         if (VALID_EVTCHN(evtchn)) {
 789                 close.port = evtchn;
 790                 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 791                         BUG();
 792
 793                 switch (type_from_irq(irq)) {
 794                 case IRQT_VIRQ:
 795                         per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
 796                                 [virq_from_irq(irq)] = -1;
 797                         break;
 798                 case IRQT_IPI:
 799                         per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn))
 800                                 [ipi_from_irq(irq)] = -1;
 801                         break;
 802                 default:
 803                         break;
 804                 }
 805
 806                 /* Closed ports are implicitly re-bound to VCPU0. */
 807                 bind_evtchn_to_cpu(evtchn, 0);
 808
 809                 evtchn_to_irq[evtchn] = -1;
 810         }
 811
 812         if (irq_info[irq].type != IRQT_UNBOUND) {
 813                 irq_info[irq] = mk_unbound_info();
 814
 815                 irq_free_desc(irq);
 816         }
 817
 818         spin_unlock(&irq_mapping_update_lock);
 819 }
 820
 821 int bind_evtchn_to_irqhandler(unsigned int evtchn,
 822                               irq_handler_t handler,
 823                               unsigned long irqflags,
 824                               const char *devname, void *dev_id)
 825 {
 826         unsigned int irq;
 827         int retval;
 828
 829         irq = bind_evtchn_to_irq(evtchn);
 830         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 831         if (retval != 0) {
 832                 unbind_from_irq(irq);
 833                 return retval;
 834         }
 835
 836         return irq;
 837 }
 838 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
 839
 840 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
 841                             irq_handler_t handler,
 842                             unsigned long irqflags, const char *devname, void *dev_id)
 843 {
 844         unsigned int irq;
 845         int retval;
 846
 847         irq = bind_virq_to_irq(virq, cpu);
 848         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 849         if (retval != 0) {
 850                 unbind_from_irq(irq);
 851                 return retval;
 852         }
 853
 854         return irq;
 855 }
 856 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
 857
 858 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
 859                            unsigned int cpu,
 860                            irq_handler_t handler,
 861                            unsigned long irqflags,
 862                            const char *devname,
 863                            void *dev_id)
 864 {
 865         int irq, retval;
 866
 867         irq = bind_ipi_to_irq(ipi, cpu);
 868         if (irq < 0)
 869                 return irq;
 870
 871         irqflags |= IRQF_NO_SUSPEND;
 872         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 873         if (retval != 0) {
 874                 unbind_from_irq(irq);
 875                 return retval;
 876         }
 877
 878         return irq;
 879 }
 880
 881 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
 882 {
 883         free_irq(irq, dev_id);
 884         unbind_from_irq(irq);
 885 }
 886 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
 887
 888 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
 889 {
 890         int irq = per_cpu(ipi_to_irq, cpu)[vector];
 891         BUG_ON(irq < 0);
 892         notify_remote_via_irq(irq);
 893 }
 894
 895 irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
 896 {
 897         struct shared_info *sh = HYPERVISOR_shared_info;
 898         int cpu = smp_processor_id();
 899         int i;
 900         unsigned long flags;
 901         static DEFINE_SPINLOCK(debug_lock);
 902
 903         spin_lock_irqsave(&debug_lock, flags);
 904
 905         printk("vcpu %d\n  ", cpu);
 906
 907         for_each_online_cpu(i) {
 908                 struct vcpu_info *v = per_cpu(xen_vcpu, i);
 909                 printk("%d: masked=%d pending=%d event_sel %08lx\n  ", i,
 910                         (get_irq_regs() && i == cpu) ? xen_irqs_disabled(get_irq_regs()) : v->evtchn_upcall_mask,
 911                         v->evtchn_upcall_pending,
 912                         v->evtchn_pending_sel);
 913         }
 914         printk("pending:\n   ");
 915         for(i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
 916                 printk("%08lx%s", sh->evtchn_pending[i],
 917                         i % 8 == 0 ? "\n   " : " ");
 918         printk("\nmasks:\n   ");
 919         for(i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
 920                 printk("%08lx%s", sh->evtchn_mask[i],
 921                         i % 8 == 0 ? "\n   " : " ");
 922
 923         printk("\nunmasked:\n   ");
 924         for(i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
 925                 printk("%08lx%s", sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
 926                         i % 8 == 0 ? "\n   " : " ");
 927
 928         printk("\npending list:\n");
 929         for(i = 0; i < NR_EVENT_CHANNELS; i++) {
 930                 if (sync_test_bit(i, sh->evtchn_pending)) {
 931                         printk("  %d: event %d -> irq %d\n",
 932                                cpu_from_evtchn(i), i,
 933                                evtchn_to_irq[i]);
 934                 }
 935         }
 936
 937         spin_unlock_irqrestore(&debug_lock, flags);
 938
 939         return IRQ_HANDLED;
 940 }
 941
 942 static DEFINE_PER_CPU(unsigned, xed_nesting_count);
 943
 944 /*
 945  * Search the CPUs pending events bitmasks.  For each one found, map
 946  * the event number to an irq, and feed it into do_IRQ() for
 947  * handling.
 948  *
 949  * Xen uses a two-level bitmap to speed searching.  The first level is
 950  * a bitset of words which contain pending event bits.  The second
 951  * level is a bitset of pending events themselves.
 952  */
 953 static void __xen_evtchn_do_upcall(void)
 954 {
 955         int cpu = get_cpu();
 956         struct shared_info *s = HYPERVISOR_shared_info;
 957         struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
 958         unsigned count;
 959
 960         do {
 961                 unsigned long pending_words;
 962
 963                 vcpu_info->evtchn_upcall_pending = 0;
 964
 965                 if (__get_cpu_var(xed_nesting_count)++)
 966                         goto out;
 967
 968 #ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
 969                 /* Clear master flag /before/ clearing selector flag. */
 970                 wmb();
 971 #endif
 972                 pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
 973                 while (pending_words != 0) {
 974                         unsigned long pending_bits;
 975                         int word_idx = __ffs(pending_words);
 976                         pending_words &= ~(1UL << word_idx);
 977
 978                         while ((pending_bits = active_evtchns(cpu, s, word_idx)) != 0) {
 979                                 int bit_idx = __ffs(pending_bits);
 980                                 int port = (word_idx * BITS_PER_LONG) + bit_idx;
 981                                 int irq = evtchn_to_irq[port];
 982                                 struct irq_desc *desc;
 983
 984                                 if (irq != -1) {
 985                                         desc = irq_to_desc(irq);
 986                                         if (desc)
 987                                                 generic_handle_irq_desc(irq, desc);
 988                                 }
 989                         }
 990                 }
 991
 992                 BUG_ON(!irqs_disabled());
 993
 994                 count = __get_cpu_var(xed_nesting_count);
 995                 __get_cpu_var(xed_nesting_count) = 0;
 996         } while (count != 1 || vcpu_info->evtchn_upcall_pending);
 997
 998 out:
 999
1000         put_cpu();
1001 }
1002
1003 void xen_evtchn_do_upcall(struct pt_regs *regs)
1004 {
1005         struct pt_regs *old_regs = set_irq_regs(regs);
1006
1007         exit_idle();
1008         irq_enter();
1009
1010         __xen_evtchn_do_upcall();
1011
1012         irq_exit();
1013         set_irq_regs(old_regs);
1014 }
1015
1016 void xen_hvm_evtchn_do_upcall(void)
1017 {
1018         __xen_evtchn_do_upcall();
1019 }
1020 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1021
1022 /* Rebind a new event channel to an existing irq. */
1023 void rebind_evtchn_irq(int evtchn, int irq)
1024 {
1025         struct irq_info *info = info_for_irq(irq);
1026
1027         /* Make sure the irq is masked, since the new event channel
1028            will also be masked. */
1029         disable_irq(irq);
1030
1031         spin_lock(&irq_mapping_update_lock);
1032
1033         /* After resume the irq<->evtchn mappings are all cleared out */
1034         BUG_ON(evtchn_to_irq[evtchn] != -1);
1035         /* Expect irq to have been bound before,
1036            so there should be a proper type */
1037         BUG_ON(info->type == IRQT_UNBOUND);
1038
1039         evtchn_to_irq[evtchn] = irq;
1040         irq_info[irq] = mk_evtchn_info(evtchn);
1041
1042         spin_unlock(&irq_mapping_update_lock);
1043
1044         /* new event channels are always bound to cpu 0 */
1045         irq_set_affinity(irq, cpumask_of(0));
1046
1047         /* Unmask the event channel. */
1048         enable_irq(irq);
1049 }
1050
1051 /* Rebind an evtchn so that it gets delivered to a specific cpu */
1052 static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
1053 {
1054         struct evtchn_bind_vcpu bind_vcpu;
1055         int evtchn = evtchn_from_irq(irq);
1056
1057         /* events delivered via platform PCI interrupts are always
1058          * routed to vcpu 0 */
1059         if (!VALID_EVTCHN(evtchn) ||
1060                 (xen_hvm_domain() && !xen_have_vector_callback))
1061                 return -1;
1062
1063         /* Send future instances of this interrupt to other vcpu. */
1064         bind_vcpu.port = evtchn;
1065         bind_vcpu.vcpu = tcpu;
1066
1067         /*
1068          * If this fails, it usually just indicates that we're dealing with a
1069          * virq or IPI channel, which don't actually need to be rebound. Ignore
1070          * it, but don't do the xenlinux-level rebind in that case.
1071          */
1072         if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1073                 bind_evtchn_to_cpu(evtchn, tcpu);
1074
1075         return 0;
1076 }
1077
1078 static int set_affinity_irq(unsigned irq, const struct cpumask *dest)
1079 {
1080         unsigned tcpu = cpumask_first(dest);
1081
1082         return rebind_irq_to_cpu(irq, tcpu);
1083 }
1084
1085 int resend_irq_on_evtchn(unsigned int irq)
1086 {
1087         int masked, evtchn = evtchn_from_irq(irq);
1088         struct shared_info *s = HYPERVISOR_shared_info;
1089
1090         if (!VALID_EVTCHN(evtchn))
1091                 return 1;
1092
1093         masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
1094         sync_set_bit(evtchn, s->evtchn_pending);
1095         if (!masked)
1096                 unmask_evtchn(evtchn);
1097
1098         return 1;
1099 }
1100
1101 static void enable_dynirq(unsigned int irq)
1102 {
1103         int evtchn = evtchn_from_irq(irq);
1104
1105         if (VALID_EVTCHN(evtchn))
1106                 unmask_evtchn(evtchn);
1107 }
1108
1109 static void disable_dynirq(unsigned int irq)
1110 {
1111         int evtchn = evtchn_from_irq(irq);
1112
1113         if (VALID_EVTCHN(evtchn))
1114                 mask_evtchn(evtchn);
1115 }
1116
1117 static void ack_dynirq(unsigned int irq)
1118 {
1119         int evtchn = evtchn_from_irq(irq);
1120
1121         move_native_irq(irq);
1122
1123         if (VALID_EVTCHN(evtchn))
1124                 clear_evtchn(evtchn);
1125 }
1126
1127 static int retrigger_dynirq(unsigned int irq)
1128 {
1129         int evtchn = evtchn_from_irq(irq);
1130         struct shared_info *sh = HYPERVISOR_shared_info;
1131         int ret = 0;
1132
1133         if (VALID_EVTCHN(evtchn)) {
1134                 int masked;
1135
1136                 masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
1137                 sync_set_bit(evtchn, sh->evtchn_pending);
1138                 if (!masked)
1139                         unmask_evtchn(evtchn);
1140                 ret = 1;
1141         }
1142
1143         return ret;
1144 }
1145
1146 static void restore_cpu_virqs(unsigned int cpu)
1147 {
1148         struct evtchn_bind_virq bind_virq;
1149         int virq, irq, evtchn;
1150
1151         for (virq = 0; virq < NR_VIRQS; virq++) {
1152                 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1153                         continue;
1154
1155                 BUG_ON(virq_from_irq(irq) != virq);
1156
1157                 /* Get a new binding from Xen. */
1158                 bind_virq.virq = virq;
1159                 bind_virq.vcpu = cpu;
1160                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1161                                                 &bind_virq) != 0)
1162                         BUG();
1163                 evtchn = bind_virq.port;
1164
1165                 /* Record the new mapping. */
1166                 evtchn_to_irq[evtchn] = irq;
1167                 irq_info[irq] = mk_virq_info(evtchn, virq);
1168                 bind_evtchn_to_cpu(evtchn, cpu);
1169
1170                 /* Ready for use. */
1171                 unmask_evtchn(evtchn);
1172         }
1173 }
1174
1175 static void restore_cpu_ipis(unsigned int cpu)
1176 {
1177         struct evtchn_bind_ipi bind_ipi;
1178         int ipi, irq, evtchn;
1179
1180         for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1181                 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1182                         continue;
1183
1184                 BUG_ON(ipi_from_irq(irq) != ipi);
1185
1186                 /* Get a new binding from Xen. */
1187                 bind_ipi.vcpu = cpu;
1188                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1189                                                 &bind_ipi) != 0)
1190                         BUG();
1191                 evtchn = bind_ipi.port;
1192
1193                 /* Record the new mapping. */
1194                 evtchn_to_irq[evtchn] = irq;
1195                 irq_info[irq] = mk_ipi_info(evtchn, ipi);
1196                 bind_evtchn_to_cpu(evtchn, cpu);
1197
1198                 /* Ready for use. */
1199                 unmask_evtchn(evtchn);
1200
1201         }
1202 }
1203
1204 /* Clear an irq's pending state, in preparation for polling on it */
1205 void xen_clear_irq_pending(int irq)
1206 {
1207         int evtchn = evtchn_from_irq(irq);
1208
1209         if (VALID_EVTCHN(evtchn))
1210                 clear_evtchn(evtchn);
1211 }
1212 EXPORT_SYMBOL(xen_clear_irq_pending);
1213 void xen_set_irq_pending(int irq)
1214 {
1215         int evtchn = evtchn_from_irq(irq);
1216
1217         if (VALID_EVTCHN(evtchn))
1218                 set_evtchn(evtchn);
1219 }
1220
1221 bool xen_test_irq_pending(int irq)
1222 {
1223         int evtchn = evtchn_from_irq(irq);
1224         bool ret = false;
1225
1226         if (VALID_EVTCHN(evtchn))
1227                 ret = test_evtchn(evtchn);
1228
1229         return ret;
1230 }
1231
1232 /* Poll waiting for an irq to become pending with timeout.  In the usual case,
1233  * the irq will be disabled so it won't deliver an interrupt. */
1234 void xen_poll_irq_timeout(int irq, u64 timeout)
1235 {
1236         evtchn_port_t evtchn = evtchn_from_irq(irq);
1237
1238         if (VALID_EVTCHN(evtchn)) {
1239                 struct sched_poll poll;
1240
1241                 poll.nr_ports = 1;
1242                 poll.timeout = timeout;
1243                 set_xen_guest_handle(poll.ports, &evtchn);
1244
1245                 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1246                         BUG();
1247         }
1248 }
1249 EXPORT_SYMBOL(xen_poll_irq_timeout);
1250 /* Poll waiting for an irq to become pending.  In the usual case, the
1251  * irq will be disabled so it won't deliver an interrupt. */
1252 void xen_poll_irq(int irq)
1253 {
1254         xen_poll_irq_timeout(irq, 0 /* no timeout */);
1255 }
1256
1257 void xen_irq_resume(void)
1258 {
1259         unsigned int cpu, irq, evtchn;
1260
1261         init_evtchn_cpu_bindings();
1262
1263         /* New event-channel space is not 'live' yet. */
1264         for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1265                 mask_evtchn(evtchn);
1266
1267         /* No IRQ <-> event-channel mappings. */
1268         for (irq = 0; irq < nr_irqs; irq++)
1269                 irq_info[irq].evtchn = 0; /* zap event-channel binding */
1270
1271         for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1272                 evtchn_to_irq[evtchn] = -1;
1273
1274         for_each_possible_cpu(cpu) {
1275                 restore_cpu_virqs(cpu);
1276                 restore_cpu_ipis(cpu);
1277         }
1278 }
1279
1280 static struct irq_chip xen_dynamic_chip __read_mostly = {
1281         .name           = "xen-dyn",
1282
1283         .disable        = disable_dynirq,
1284         .mask           = disable_dynirq,
1285         .unmask         = enable_dynirq,
1286
1287         .ack            = ack_dynirq,
1288         .set_affinity   = set_affinity_irq,
1289         .retrigger      = retrigger_dynirq,
1290 };
1291
1292 static struct irq_chip xen_pirq_chip __read_mostly = {
1293         .name           = "xen-pirq",
1294
1295         .startup        = startup_pirq,
1296         .shutdown       = shutdown_pirq,
1297
1298         .enable         = enable_pirq,
1299         .unmask         = enable_pirq,
1300
1301         .disable        = disable_pirq,
1302         .mask           = disable_pirq,
1303
1304         .ack            = ack_pirq,
1305         .end            = end_pirq,
1306
1307         .set_affinity   = set_affinity_irq,
1308
1309         .retrigger      = retrigger_dynirq,
1310 };
1311
1312 static struct irq_chip xen_percpu_chip __read_mostly = {
1313         .name           = "xen-percpu",
1314
1315         .disable        = disable_dynirq,
1316         .mask           = disable_dynirq,
1317         .unmask         = enable_dynirq,
1318
1319         .ack            = ack_dynirq,
1320 };
1321
1322 int xen_set_callback_via(uint64_t via)
1323 {
1324         struct xen_hvm_param a;
1325         a.domid = DOMID_SELF;
1326         a.index = HVM_PARAM_CALLBACK_IRQ;
1327         a.value = via;
1328         return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1329 }
1330 EXPORT_SYMBOL_GPL(xen_set_callback_via);
1331
1332 #ifdef CONFIG_XEN_PVHVM
1333 /* Vector callbacks are better than PCI interrupts to receive event
1334  * channel notifications because we can receive vector callbacks on any
1335  * vcpu and we don't need PCI support or APIC interactions. */
1336 void xen_callback_vector(void)
1337 {
1338         int rc;
1339         uint64_t callback_via;
1340         if (xen_have_vector_callback) {
1341                 callback_via = HVM_CALLBACK_VECTOR(XEN_HVM_EVTCHN_CALLBACK);
1342                 rc = xen_set_callback_via(callback_via);
1343                 if (rc) {
1344                         printk(KERN_ERR "Request for Xen HVM callback vector"
1345                                         " failed.\n");
1346                         xen_have_vector_callback = 0;
1347                         return;
1348                 }
1349                 printk(KERN_INFO "Xen HVM callback vector for event delivery is "
1350                                 "enabled\n");
1351                 /* in the restore case the vector has already been allocated */
1352                 if (!test_bit(XEN_HVM_EVTCHN_CALLBACK, used_vectors))
1353                         alloc_intr_gate(XEN_HVM_EVTCHN_CALLBACK, xen_hvm_callback_vector);
1354         }
1355 }
1356 #else
1357 void xen_callback_vector(void) {}
1358 #endif
1359
1360 void __init xen_init_IRQ(void)
1361 {
1362         int i, rc;
1363         struct physdev_nr_pirqs op_nr_pirqs;
1364
1365         cpu_evtchn_mask_p = kcalloc(nr_cpu_ids, sizeof(struct cpu_evtchn_s),
1366                                     GFP_KERNEL);
1367         irq_info = kcalloc(nr_irqs, sizeof(*irq_info), GFP_KERNEL);
1368
1369         rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_nr_pirqs, &op_nr_pirqs);
1370         if (rc < 0) {
1371                 nr_pirqs = nr_irqs;
1372                 if (rc != -ENOSYS)
1373                         printk(KERN_WARNING "PHYSDEVOP_get_nr_pirqs returned rc=%d\n", rc);
1374         } else {
1375                 if (xen_pv_domain() && !xen_initial_domain())
1376                         nr_pirqs = max((int)op_nr_pirqs.nr_pirqs, nr_irqs);
1377                 else
1378                         nr_pirqs = op_nr_pirqs.nr_pirqs;
1379         }
1380         pirq_to_irq = kcalloc(nr_pirqs, sizeof(*pirq_to_irq), GFP_KERNEL);
1381         for (i = 0; i < nr_pirqs; i++)
1382                 pirq_to_irq[i] = -1;
1383
1384         evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
1385                                     GFP_KERNEL);
1386         for (i = 0; i < NR_EVENT_CHANNELS; i++)
1387                 evtchn_to_irq[i] = -1;
1388
1389         init_evtchn_cpu_bindings();
1390
1391         /* No event channels are 'live' right now. */
1392         for (i = 0; i < NR_EVENT_CHANNELS; i++)
1393                 mask_evtchn(i);
1394
1395         if (xen_hvm_domain()) {
1396                 xen_callback_vector();
1397                 native_init_IRQ();
1398         } else {
1399                 irq_ctx_init(smp_processor_id());
1400         }
1401 }