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 #include <linux/pci.h>
  33
  34 #include <asm/desc.h>
  35 #include <asm/ptrace.h>
  36 #include <asm/irq.h>
  37 #include <asm/idle.h>
  38 #include <asm/io_apic.h>
  39 #include <asm/sync_bitops.h>
  40 #include <asm/xen/pci.h>
  41 #include <asm/xen/hypercall.h>
  42 #include <asm/xen/hypervisor.h>
  43
  44 #include <xen/xen.h>
  45 #include <xen/hvm.h>
  46 #include <xen/xen-ops.h>
  47 #include <xen/events.h>
  48 #include <xen/interface/xen.h>
  49 #include <xen/interface/event_channel.h>
  50 #include <xen/interface/hvm/hvm_op.h>
  51 #include <xen/interface/hvm/params.h>
  52
  53 /*
  54  * This lock protects updates to the following mapping and reference-count
  55  * arrays. The lock does not need to be acquired to read the mapping tables.
  56  */
  57 static DEFINE_SPINLOCK(irq_mapping_update_lock);
  58
  59 /* IRQ <-> VIRQ mapping. */
  60 static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
  61
  62 /* IRQ <-> IPI mapping */
  63 static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
  64
  65 /* Interrupt types. */
  66 enum xen_irq_type {
  67         IRQT_UNBOUND = 0,
  68         IRQT_PIRQ,
  69         IRQT_VIRQ,
  70         IRQT_IPI,
  71         IRQT_EVTCHN
  72 };
  73
  74 /*
  75  * Packed IRQ information:
  76  * type - enum xen_irq_type
  77  * event channel - irq->event channel mapping
  78  * cpu - cpu this event channel is bound to
  79  * index - type-specific information:
  80  *    PIRQ - vector, with MSB being "needs EIO", or physical IRQ of the HVM
  81  *           guest, or GSI (real passthrough IRQ) of the device.
  82  *    VIRQ - virq number
  83  *    IPI - IPI vector
  84  *    EVTCHN -
  85  */
  86 struct irq_info
  87 {
  88         enum xen_irq_type type; /* type */
  89         unsigned short evtchn;  /* event channel */
  90         unsigned short cpu;     /* cpu bound */
  91
  92         union {
  93                 unsigned short virq;
  94                 enum ipi_vector ipi;
  95                 struct {
  96                         unsigned short pirq;
  97                         unsigned short gsi;
  98                         unsigned char vector;
  99                         unsigned char flags;
 100                 } pirq;
 101         } u;
 102 };
 103 #define PIRQ_NEEDS_EOI  (1 << 0)
 104 #define PIRQ_SHAREABLE  (1 << 1)
 105
 106 static struct irq_info *irq_info;
 107 static int *pirq_to_irq;
 108
 109 static int *evtchn_to_irq;
 110
 111 static DEFINE_PER_CPU(unsigned long [NR_EVENT_CHANNELS/BITS_PER_LONG],
 112                       cpu_evtchn_mask);
 113
 114 /* Xen will never allocate port zero for any purpose. */
 115 #define VALID_EVTCHN(chn)       ((chn) != 0)
 116
 117 static struct irq_chip xen_dynamic_chip;
 118 static struct irq_chip xen_percpu_chip;
 119 static struct irq_chip xen_pirq_chip;
 120
 121 /* Get info for IRQ */
 122 static struct irq_info *info_for_irq(unsigned irq)
 123 {
 124         return &irq_info[irq];
 125 }
 126
 127 /* Constructors for packed IRQ information. */
 128 static void xen_irq_info_common_init(struct irq_info *info,
 129                                      enum xen_irq_type type,
 130                                      unsigned short evtchn,
 131                                      unsigned short cpu)
 132 {
 133
 134         BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
 135
 136         info->type = type;
 137         info->evtchn = evtchn;
 138         info->cpu = cpu;
 139 }
 140
 141 static void xen_irq_info_evtchn_init(unsigned irq,
 142                                      unsigned short evtchn)
 143 {
 144         struct irq_info *info = info_for_irq(irq);
 145
 146         xen_irq_info_common_init(info, IRQT_EVTCHN, evtchn, 0);
 147 }
 148
 149 static void xen_irq_info_ipi_init(unsigned irq,
 150                                   unsigned short evtchn,
 151                                   enum ipi_vector ipi)
 152 {
 153         struct irq_info *info = info_for_irq(irq);
 154
 155         xen_irq_info_common_init(info, IRQT_IPI, evtchn, 0);
 156
 157         info->u.ipi = ipi;
 158 }
 159
 160 static void xen_irq_info_virq_init(unsigned irq,
 161                                    unsigned short evtchn,
 162                                    unsigned short virq)
 163 {
 164         struct irq_info *info = info_for_irq(irq);
 165
 166         xen_irq_info_common_init(info, IRQT_VIRQ, evtchn, 0);
 167
 168         info->u.virq = virq;
 169 }
 170
 171 static void xen_irq_info_pirq_init(unsigned irq,
 172                                    unsigned short evtchn,
 173                                    unsigned short pirq,
 174                                    unsigned short gsi,
 175                                    unsigned short vector,
 176                                    unsigned char flags)
 177 {
 178         struct irq_info *info = info_for_irq(irq);
 179
 180         xen_irq_info_common_init(info, IRQT_PIRQ, evtchn, 0);
 181
 182         info->u.pirq.pirq = pirq;
 183         info->u.pirq.gsi = gsi;
 184         info->u.pirq.vector = vector;
 185         info->u.pirq.flags = flags;
 186 }
 187
 188 /*
 189  * Accessors for packed IRQ information.
 190  */
 191 static unsigned int evtchn_from_irq(unsigned irq)
 192 {
 193         if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))
 194                 return 0;
 195
 196         return info_for_irq(irq)->evtchn;
 197 }
 198
 199 unsigned irq_from_evtchn(unsigned int evtchn)
 200 {
 201         return evtchn_to_irq[evtchn];
 202 }
 203 EXPORT_SYMBOL_GPL(irq_from_evtchn);
 204
 205 static enum ipi_vector ipi_from_irq(unsigned irq)
 206 {
 207         struct irq_info *info = info_for_irq(irq);
 208
 209         BUG_ON(info == NULL);
 210         BUG_ON(info->type != IRQT_IPI);
 211
 212         return info->u.ipi;
 213 }
 214
 215 static unsigned virq_from_irq(unsigned irq)
 216 {
 217         struct irq_info *info = info_for_irq(irq);
 218
 219         BUG_ON(info == NULL);
 220         BUG_ON(info->type != IRQT_VIRQ);
 221
 222         return info->u.virq;
 223 }
 224
 225 static unsigned pirq_from_irq(unsigned irq)
 226 {
 227         struct irq_info *info = info_for_irq(irq);
 228
 229         BUG_ON(info == NULL);
 230         BUG_ON(info->type != IRQT_PIRQ);
 231
 232         return info->u.pirq.pirq;
 233 }
 234
 235 static unsigned gsi_from_irq(unsigned irq)
 236 {
 237         struct irq_info *info = info_for_irq(irq);
 238
 239         BUG_ON(info == NULL);
 240         BUG_ON(info->type != IRQT_PIRQ);
 241
 242         return info->u.pirq.gsi;
 243 }
 244
 245 static enum xen_irq_type type_from_irq(unsigned irq)
 246 {
 247         return info_for_irq(irq)->type;
 248 }
 249
 250 static unsigned cpu_from_irq(unsigned irq)
 251 {
 252         return info_for_irq(irq)->cpu;
 253 }
 254
 255 static unsigned int cpu_from_evtchn(unsigned int evtchn)
 256 {
 257         int irq = evtchn_to_irq[evtchn];
 258         unsigned ret = 0;
 259
 260         if (irq != -1)
 261                 ret = cpu_from_irq(irq);
 262
 263         return ret;
 264 }
 265
 266 static bool pirq_needs_eoi(unsigned irq)
 267 {
 268         struct irq_info *info = info_for_irq(irq);
 269
 270         BUG_ON(info->type != IRQT_PIRQ);
 271
 272         return info->u.pirq.flags & PIRQ_NEEDS_EOI;
 273 }
 274
 275 static inline unsigned long active_evtchns(unsigned int cpu,
 276                                            struct shared_info *sh,
 277                                            unsigned int idx)
 278 {
 279         return (sh->evtchn_pending[idx] &
 280                 per_cpu(cpu_evtchn_mask, cpu)[idx] &
 281                 ~sh->evtchn_mask[idx]);
 282 }
 283
 284 static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
 285 {
 286         int irq = evtchn_to_irq[chn];
 287
 288         BUG_ON(irq == -1);
 289 #ifdef CONFIG_SMP
 290         cpumask_copy(irq_to_desc(irq)->irq_data.affinity, cpumask_of(cpu));
 291 #endif
 292
 293         clear_bit(chn, per_cpu(cpu_evtchn_mask, cpu_from_irq(irq)));
 294         set_bit(chn, per_cpu(cpu_evtchn_mask, cpu));
 295
 296         irq_info[irq].cpu = cpu;
 297 }
 298
 299 static void init_evtchn_cpu_bindings(void)
 300 {
 301         int i;
 302 #ifdef CONFIG_SMP
 303         struct irq_desc *desc;
 304
 305         /* By default all event channels notify CPU#0. */
 306         for_each_irq_desc(i, desc) {
 307                 cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
 308         }
 309 #endif
 310
 311         for_each_possible_cpu(i)
 312                 memset(per_cpu(cpu_evtchn_mask, i),
 313                        (i == 0) ? ~0 : 0, sizeof(*per_cpu(cpu_evtchn_mask, i)));
 314
 315 }
 316
 317 static inline void clear_evtchn(int port)
 318 {
 319         struct shared_info *s = HYPERVISOR_shared_info;
 320         sync_clear_bit(port, &s->evtchn_pending[0]);
 321 }
 322
 323 static inline void set_evtchn(int port)
 324 {
 325         struct shared_info *s = HYPERVISOR_shared_info;
 326         sync_set_bit(port, &s->evtchn_pending[0]);
 327 }
 328
 329 static inline int test_evtchn(int port)
 330 {
 331         struct shared_info *s = HYPERVISOR_shared_info;
 332         return sync_test_bit(port, &s->evtchn_pending[0]);
 333 }
 334
 335
 336 /**
 337  * notify_remote_via_irq - send event to remote end of event channel via irq
 338  * @irq: irq of event channel to send event to
 339  *
 340  * Unlike notify_remote_via_evtchn(), this is safe to use across
 341  * save/restore. Notifications on a broken connection are silently
 342  * dropped.
 343  */
 344 void notify_remote_via_irq(int irq)
 345 {
 346         int evtchn = evtchn_from_irq(irq);
 347
 348         if (VALID_EVTCHN(evtchn))
 349                 notify_remote_via_evtchn(evtchn);
 350 }
 351 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
 352
 353 static void mask_evtchn(int port)
 354 {
 355         struct shared_info *s = HYPERVISOR_shared_info;
 356         sync_set_bit(port, &s->evtchn_mask[0]);
 357 }
 358
 359 static void unmask_evtchn(int port)
 360 {
 361         struct shared_info *s = HYPERVISOR_shared_info;
 362         unsigned int cpu = get_cpu();
 363
 364         BUG_ON(!irqs_disabled());
 365
 366         /* Slow path (hypercall) if this is a non-local port. */
 367         if (unlikely(cpu != cpu_from_evtchn(port))) {
 368                 struct evtchn_unmask unmask = { .port = port };
 369                 (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
 370         } else {
 371                 struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
 372
 373                 sync_clear_bit(port, &s->evtchn_mask[0]);
 374
 375                 /*
 376                  * The following is basically the equivalent of
 377                  * 'hw_resend_irq'. Just like a real IO-APIC we 'lose
 378                  * the interrupt edge' if the channel is masked.
 379                  */
 380                 if (sync_test_bit(port, &s->evtchn_pending[0]) &&
 381                     !sync_test_and_set_bit(port / BITS_PER_LONG,
 382                                            &vcpu_info->evtchn_pending_sel))
 383                         vcpu_info->evtchn_upcall_pending = 1;
 384         }
 385
 386         put_cpu();
 387 }
 388
 389 static int xen_allocate_irq_dynamic(void)
 390 {
 391         int first = 0;
 392         int irq;
 393
 394 #ifdef CONFIG_X86_IO_APIC
 395         /*
 396          * For an HVM guest or domain 0 which see "real" (emulated or
 397          * actual repectively) GSIs we allocate dynamic IRQs
 398          * e.g. those corresponding to event channels or MSIs
 399          * etc. from the range above those "real" GSIs to avoid
 400          * collisions.
 401          */
 402         if (xen_initial_domain() || xen_hvm_domain())
 403                 first = get_nr_irqs_gsi();
 404 #endif
 405
 406 retry:
 407         irq = irq_alloc_desc_from(first, -1);
 408
 409         if (irq == -ENOMEM && first > NR_IRQS_LEGACY) {
 410                 printk(KERN_ERR "Out of dynamic IRQ space and eating into GSI space. You should increase nr_irqs\n");
 411                 first = max(NR_IRQS_LEGACY, first - NR_IRQS_LEGACY);
 412                 goto retry;
 413         }
 414
 415         if (irq < 0)
 416                 panic("No available IRQ to bind to: increase nr_irqs!\n");
 417
 418         return irq;
 419 }
 420
 421 static int xen_allocate_irq_gsi(unsigned gsi)
 422 {
 423         int irq;
 424
 425         /*
 426          * A PV guest has no concept of a GSI (since it has no ACPI
 427          * nor access to/knowledge of the physical APICs). Therefore
 428          * all IRQs are dynamically allocated from the entire IRQ
 429          * space.
 430          */
 431         if (xen_pv_domain() && !xen_initial_domain())
 432                 return xen_allocate_irq_dynamic();
 433
 434         /* Legacy IRQ descriptors are already allocated by the arch. */
 435         if (gsi < NR_IRQS_LEGACY)
 436                 return gsi;
 437
 438         irq = irq_alloc_desc_at(gsi, -1);
 439         if (irq < 0)
 440                 panic("Unable to allocate to IRQ%d (%d)\n", gsi, irq);
 441
 442         return irq;
 443 }
 444
 445 static void xen_free_irq(unsigned irq)
 446 {
 447         irq_info[irq].type = IRQT_UNBOUND;
 448
 449         /* Legacy IRQ descriptors are managed by the arch. */
 450         if (irq < NR_IRQS_LEGACY)
 451                 return;
 452
 453         irq_free_desc(irq);
 454 }
 455
 456 static void pirq_unmask_notify(int irq)
 457 {
 458         struct physdev_eoi eoi = { .irq = pirq_from_irq(irq) };
 459
 460         if (unlikely(pirq_needs_eoi(irq))) {
 461                 int rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
 462                 WARN_ON(rc);
 463         }
 464 }
 465
 466 static void pirq_query_unmask(int irq)
 467 {
 468         struct physdev_irq_status_query irq_status;
 469         struct irq_info *info = info_for_irq(irq);
 470
 471         BUG_ON(info->type != IRQT_PIRQ);
 472
 473         irq_status.irq = pirq_from_irq(irq);
 474         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
 475                 irq_status.flags = 0;
 476
 477         info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
 478         if (irq_status.flags & XENIRQSTAT_needs_eoi)
 479                 info->u.pirq.flags |= PIRQ_NEEDS_EOI;
 480 }
 481
 482 static bool probing_irq(int irq)
 483 {
 484         struct irq_desc *desc = irq_to_desc(irq);
 485
 486         return desc && desc->action == NULL;
 487 }
 488
 489 static unsigned int __startup_pirq(unsigned int irq)
 490 {
 491         struct evtchn_bind_pirq bind_pirq;
 492         struct irq_info *info = info_for_irq(irq);
 493         int evtchn = evtchn_from_irq(irq);
 494         int rc;
 495
 496         BUG_ON(info->type != IRQT_PIRQ);
 497
 498         if (VALID_EVTCHN(evtchn))
 499                 goto out;
 500
 501         bind_pirq.pirq = pirq_from_irq(irq);
 502         /* NB. We are happy to share unless we are probing. */
 503         bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
 504                                         BIND_PIRQ__WILL_SHARE : 0;
 505         rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
 506         if (rc != 0) {
 507                 if (!probing_irq(irq))
 508                         printk(KERN_INFO "Failed to obtain physical IRQ %d\n",
 509                                irq);
 510                 return 0;
 511         }
 512         evtchn = bind_pirq.port;
 513
 514         pirq_query_unmask(irq);
 515
 516         evtchn_to_irq[evtchn] = irq;
 517         bind_evtchn_to_cpu(evtchn, 0);
 518         info->evtchn = evtchn;
 519
 520 out:
 521         unmask_evtchn(evtchn);
 522         pirq_unmask_notify(irq);
 523
 524         return 0;
 525 }
 526
 527 static unsigned int startup_pirq(struct irq_data *data)
 528 {
 529         return __startup_pirq(data->irq);
 530 }
 531
 532 static void shutdown_pirq(struct irq_data *data)
 533 {
 534         struct evtchn_close close;
 535         unsigned int irq = data->irq;
 536         struct irq_info *info = info_for_irq(irq);
 537         int evtchn = evtchn_from_irq(irq);
 538
 539         BUG_ON(info->type != IRQT_PIRQ);
 540
 541         if (!VALID_EVTCHN(evtchn))
 542                 return;
 543
 544         mask_evtchn(evtchn);
 545
 546         close.port = evtchn;
 547         if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 548                 BUG();
 549
 550         bind_evtchn_to_cpu(evtchn, 0);
 551         evtchn_to_irq[evtchn] = -1;
 552         info->evtchn = 0;
 553 }
 554
 555 static void enable_pirq(struct irq_data *data)
 556 {
 557         startup_pirq(data);
 558 }
 559
 560 static void disable_pirq(struct irq_data *data)
 561 {
 562 }
 563
 564 static void ack_pirq(struct irq_data *data)
 565 {
 566         int evtchn = evtchn_from_irq(data->irq);
 567
 568         move_native_irq(data->irq);
 569
 570         if (VALID_EVTCHN(evtchn)) {
 571                 mask_evtchn(evtchn);
 572                 clear_evtchn(evtchn);
 573         }
 574 }
 575
 576 static int find_irq_by_gsi(unsigned gsi)
 577 {
 578         int irq;
 579
 580         for (irq = 0; irq < nr_irqs; irq++) {
 581                 struct irq_info *info = info_for_irq(irq);
 582
 583                 if (info == NULL || info->type != IRQT_PIRQ)
 584                         continue;
 585
 586                 if (gsi_from_irq(irq) == gsi)
 587                         return irq;
 588         }
 589
 590         return -1;
 591 }
 592
 593 int xen_allocate_pirq_gsi(unsigned gsi)
 594 {
 595         return gsi;
 596 }
 597
 598 /*
 599  * Do not make any assumptions regarding the relationship between the
 600  * IRQ number returned here and the Xen pirq argument.
 601  *
 602  * Note: We don't assign an event channel until the irq actually started
 603  * up.  Return an existing irq if we've already got one for the gsi.
 604  */
 605 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 606                              unsigned pirq, int shareable, char *name)
 607 {
 608         int irq = -1;
 609         struct physdev_irq irq_op;
 610
 611         spin_lock(&irq_mapping_update_lock);
 612
 613         if ((pirq > nr_irqs) || (gsi > nr_irqs)) {
 614                 printk(KERN_WARNING "xen_map_pirq_gsi: %s %s is incorrect!\n",
 615                         pirq > nr_irqs ? "pirq" :"",
 616                         gsi > nr_irqs ? "gsi" : "");
 617                 goto out;
 618         }
 619
 620         irq = find_irq_by_gsi(gsi);
 621         if (irq != -1) {
 622                 printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n",
 623                        irq, gsi);
 624                 goto out;       /* XXX need refcount? */
 625         }
 626
 627         irq = xen_allocate_irq_gsi(gsi);
 628
 629         set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
 630                                       handle_level_irq, name);
 631
 632         irq_op.irq = irq;
 633         irq_op.vector = 0;
 634
 635         /* Only the privileged domain can do this. For non-priv, the pcifront
 636          * driver provides a PCI bus that does the call to do exactly
 637          * this in the priv domain. */
 638         if (xen_initial_domain() &&
 639             HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
 640                 xen_free_irq(irq);
 641                 irq = -ENOSPC;
 642                 goto out;
 643         }
 644
 645         xen_irq_info_pirq_init(irq, 0, pirq, gsi, irq_op.vector,
 646                                shareable ? PIRQ_SHAREABLE : 0);
 647         pirq_to_irq[pirq] = irq;
 648
 649 out:
 650         spin_unlock(&irq_mapping_update_lock);
 651
 652         return irq;
 653 }
 654
 655 #ifdef CONFIG_PCI_MSI
 656 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
 657 {
 658         int rc;
 659         struct physdev_get_free_pirq op_get_free_pirq;
 660
 661         op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
 662         rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
 663
 664         WARN_ONCE(rc == -ENOSYS,
 665                   "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
 666
 667         return rc ? -1 : op_get_free_pirq.pirq;
 668 }
 669
 670 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
 671                              int pirq, int vector, const char *name)
 672 {
 673         int irq, ret;
 674
 675         spin_lock(&irq_mapping_update_lock);
 676
 677         irq = xen_allocate_irq_dynamic();
 678         if (irq == -1)
 679                 goto out;
 680
 681         set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
 682                                       handle_level_irq, name);
 683
 684         xen_irq_info_pirq_init(irq, 0, pirq, 0, vector, 0);
 685         pirq_to_irq[pirq] = irq;
 686         ret = set_irq_msi(irq, msidesc);
 687         if (ret < 0)
 688                 goto error_irq;
 689 out:
 690         spin_unlock(&irq_mapping_update_lock);
 691         return irq;
 692 error_irq:
 693         spin_unlock(&irq_mapping_update_lock);
 694         xen_free_irq(irq);
 695         return -1;
 696 }
 697 #endif
 698
 699 int xen_destroy_irq(int irq)
 700 {
 701         struct irq_desc *desc;
 702         struct physdev_unmap_pirq unmap_irq;
 703         struct irq_info *info = info_for_irq(irq);
 704         int rc = -ENOENT;
 705
 706         spin_lock(&irq_mapping_update_lock);
 707
 708         desc = irq_to_desc(irq);
 709         if (!desc)
 710                 goto out;
 711
 712         if (xen_initial_domain()) {
 713                 unmap_irq.pirq = info->u.pirq.pirq;
 714                 unmap_irq.domid = DOMID_SELF;
 715                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
 716                 if (rc) {
 717                         printk(KERN_WARNING "unmap irq failed %d\n", rc);
 718                         goto out;
 719                 }
 720         }
 721         pirq_to_irq[info->u.pirq.pirq] = -1;
 722
 723         xen_free_irq(irq);
 724
 725 out:
 726         spin_unlock(&irq_mapping_update_lock);
 727         return rc;
 728 }
 729
 730 int xen_irq_from_pirq(unsigned pirq)
 731 {
 732         return pirq_to_irq[pirq];
 733 }
 734
 735 int bind_evtchn_to_irq(unsigned int evtchn)
 736 {
 737         int irq;
 738
 739         spin_lock(&irq_mapping_update_lock);
 740
 741         irq = evtchn_to_irq[evtchn];
 742
 743         if (irq == -1) {
 744                 irq = xen_allocate_irq_dynamic();
 745
 746                 set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
 747                                               handle_fasteoi_irq, "event");
 748
 749                 evtchn_to_irq[evtchn] = irq;
 750                 xen_irq_info_evtchn_init(irq, evtchn);
 751         }
 752
 753         spin_unlock(&irq_mapping_update_lock);
 754
 755         return irq;
 756 }
 757 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
 758
 759 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 760 {
 761         struct evtchn_bind_ipi bind_ipi;
 762         int evtchn, irq;
 763
 764         spin_lock(&irq_mapping_update_lock);
 765
 766         irq = per_cpu(ipi_to_irq, cpu)[ipi];
 767
 768         if (irq == -1) {
 769                 irq = xen_allocate_irq_dynamic();
 770                 if (irq < 0)
 771                         goto out;
 772
 773                 set_irq_chip_and_handler_name(irq, &xen_percpu_chip,
 774                                               handle_percpu_irq, "ipi");
 775
 776                 bind_ipi.vcpu = cpu;
 777                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
 778                                                 &bind_ipi) != 0)
 779                         BUG();
 780                 evtchn = bind_ipi.port;
 781
 782                 evtchn_to_irq[evtchn] = irq;
 783                 xen_irq_info_ipi_init(irq, evtchn, ipi);
 784                 per_cpu(ipi_to_irq, cpu)[ipi] = irq;
 785
 786                 bind_evtchn_to_cpu(evtchn, cpu);
 787         }
 788
 789  out:
 790         spin_unlock(&irq_mapping_update_lock);
 791         return irq;
 792 }
 793
 794
 795 int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 796 {
 797         struct evtchn_bind_virq bind_virq;
 798         int evtchn, irq;
 799
 800         spin_lock(&irq_mapping_update_lock);
 801
 802         irq = per_cpu(virq_to_irq, cpu)[virq];
 803
 804         if (irq == -1) {
 805                 irq = xen_allocate_irq_dynamic();
 806
 807                 set_irq_chip_and_handler_name(irq, &xen_percpu_chip,
 808                                               handle_percpu_irq, "virq");
 809
 810                 bind_virq.virq = virq;
 811                 bind_virq.vcpu = cpu;
 812                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
 813                                                 &bind_virq) != 0)
 814                         BUG();
 815                 evtchn = bind_virq.port;
 816
 817                 evtchn_to_irq[evtchn] = irq;
 818                 xen_irq_info_virq_init(irq, evtchn, virq);
 819
 820                 per_cpu(virq_to_irq, cpu)[virq] = irq;
 821
 822                 bind_evtchn_to_cpu(evtchn, cpu);
 823         }
 824
 825         spin_unlock(&irq_mapping_update_lock);
 826
 827         return irq;
 828 }
 829
 830 static void unbind_from_irq(unsigned int irq)
 831 {
 832         struct evtchn_close close;
 833         int evtchn = evtchn_from_irq(irq);
 834
 835         spin_lock(&irq_mapping_update_lock);
 836
 837         if (VALID_EVTCHN(evtchn)) {
 838                 close.port = evtchn;
 839                 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 840                         BUG();
 841
 842                 switch (type_from_irq(irq)) {
 843                 case IRQT_VIRQ:
 844                         per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
 845                                 [virq_from_irq(irq)] = -1;
 846                         break;
 847                 case IRQT_IPI:
 848                         per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn))
 849                                 [ipi_from_irq(irq)] = -1;
 850                         break;
 851                 default:
 852                         break;
 853                 }
 854
 855                 /* Closed ports are implicitly re-bound to VCPU0. */
 856                 bind_evtchn_to_cpu(evtchn, 0);
 857
 858                 evtchn_to_irq[evtchn] = -1;
 859         }
 860
 861         BUG_ON(irq_info[irq].type == IRQT_UNBOUND);
 862
 863         xen_free_irq(irq);
 864
 865         spin_unlock(&irq_mapping_update_lock);
 866 }
 867
 868 int bind_evtchn_to_irqhandler(unsigned int evtchn,
 869                               irq_handler_t handler,
 870                               unsigned long irqflags,
 871                               const char *devname, void *dev_id)
 872 {
 873         unsigned int irq;
 874         int retval;
 875
 876         irq = bind_evtchn_to_irq(evtchn);
 877         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 878         if (retval != 0) {
 879                 unbind_from_irq(irq);
 880                 return retval;
 881         }
 882
 883         return irq;
 884 }
 885 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
 886
 887 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
 888                             irq_handler_t handler,
 889                             unsigned long irqflags, const char *devname, void *dev_id)
 890 {
 891         unsigned int irq;
 892         int retval;
 893
 894         irq = bind_virq_to_irq(virq, cpu);
 895         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 896         if (retval != 0) {
 897                 unbind_from_irq(irq);
 898                 return retval;
 899         }
 900
 901         return irq;
 902 }
 903 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
 904
 905 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
 906                            unsigned int cpu,
 907                            irq_handler_t handler,
 908                            unsigned long irqflags,
 909                            const char *devname,
 910                            void *dev_id)
 911 {
 912         int irq, retval;
 913
 914         irq = bind_ipi_to_irq(ipi, cpu);
 915         if (irq < 0)
 916                 return irq;
 917
 918         irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME;
 919         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 920         if (retval != 0) {
 921                 unbind_from_irq(irq);
 922                 return retval;
 923         }
 924
 925         return irq;
 926 }
 927
 928 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
 929 {
 930         free_irq(irq, dev_id);
 931         unbind_from_irq(irq);
 932 }
 933 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
 934
 935 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
 936 {
 937         int irq = per_cpu(ipi_to_irq, cpu)[vector];
 938         BUG_ON(irq < 0);
 939         notify_remote_via_irq(irq);
 940 }
 941
 942 irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
 943 {
 944         struct shared_info *sh = HYPERVISOR_shared_info;
 945         int cpu = smp_processor_id();
 946         unsigned long *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu);
 947         int i;
 948         unsigned long flags;
 949         static DEFINE_SPINLOCK(debug_lock);
 950         struct vcpu_info *v;
 951
 952         spin_lock_irqsave(&debug_lock, flags);
 953
 954         printk("\nvcpu %d\n  ", cpu);
 955
 956         for_each_online_cpu(i) {
 957                 int pending;
 958                 v = per_cpu(xen_vcpu, i);
 959                 pending = (get_irq_regs() && i == cpu)
 960                         ? xen_irqs_disabled(get_irq_regs())
 961                         : v->evtchn_upcall_mask;
 962                 printk("%d: masked=%d pending=%d event_sel %0*lx\n  ", i,
 963                        pending, v->evtchn_upcall_pending,
 964                        (int)(sizeof(v->evtchn_pending_sel)*2),
 965                        v->evtchn_pending_sel);
 966         }
 967         v = per_cpu(xen_vcpu, cpu);
 968
 969         printk("\npending:\n   ");
 970         for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
 971                 printk("%0*lx%s", (int)sizeof(sh->evtchn_pending[0])*2,
 972                        sh->evtchn_pending[i],
 973                        i % 8 == 0 ? "\n   " : " ");
 974         printk("\nglobal mask:\n   ");
 975         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
 976                 printk("%0*lx%s",
 977                        (int)(sizeof(sh->evtchn_mask[0])*2),
 978                        sh->evtchn_mask[i],
 979                        i % 8 == 0 ? "\n   " : " ");
 980
 981         printk("\nglobally unmasked:\n   ");
 982         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
 983                 printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
 984                        sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
 985                        i % 8 == 0 ? "\n   " : " ");
 986
 987         printk("\nlocal cpu%d mask:\n   ", cpu);
 988         for (i = (NR_EVENT_CHANNELS/BITS_PER_LONG)-1; i >= 0; i--)
 989                 printk("%0*lx%s", (int)(sizeof(cpu_evtchn[0])*2),
 990                        cpu_evtchn[i],
 991                        i % 8 == 0 ? "\n   " : " ");
 992
 993         printk("\nlocally unmasked:\n   ");
 994         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) {
 995                 unsigned long pending = sh->evtchn_pending[i]
 996                         & ~sh->evtchn_mask[i]
 997                         & cpu_evtchn[i];
 998                 printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
 999                        pending, i % 8 == 0 ? "\n   " : " ");
1000         }
1001
1002         printk("\npending list:\n");
1003         for (i = 0; i < NR_EVENT_CHANNELS; i++) {
1004                 if (sync_test_bit(i, sh->evtchn_pending)) {
1005                         int word_idx = i / BITS_PER_LONG;
1006                         printk("  %d: event %d -> irq %d%s%s%s\n",
1007                                cpu_from_evtchn(i), i,
1008                                evtchn_to_irq[i],
1009                                sync_test_bit(word_idx, &v->evtchn_pending_sel)
1010                                              ? "" : " l2-clear",
1011                                !sync_test_bit(i, sh->evtchn_mask)
1012                                              ? "" : " globally-masked",
1013                                sync_test_bit(i, cpu_evtchn)
1014                                              ? "" : " locally-masked");
1015                 }
1016         }
1017
1018         spin_unlock_irqrestore(&debug_lock, flags);
1019
1020         return IRQ_HANDLED;
1021 }
1022
1023 static DEFINE_PER_CPU(unsigned, xed_nesting_count);
1024
1025 /*
1026  * Search the CPUs pending events bitmasks.  For each one found, map
1027  * the event number to an irq, and feed it into do_IRQ() for
1028  * handling.
1029  *
1030  * Xen uses a two-level bitmap to speed searching.  The first level is
1031  * a bitset of words which contain pending event bits.  The second
1032  * level is a bitset of pending events themselves.
1033  */
1034 static void __xen_evtchn_do_upcall(void)
1035 {
1036         int cpu = get_cpu();
1037         struct shared_info *s = HYPERVISOR_shared_info;
1038         struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1039         unsigned count;
1040
1041         do {
1042                 unsigned long pending_words;
1043
1044                 vcpu_info->evtchn_upcall_pending = 0;
1045
1046                 if (__this_cpu_inc_return(xed_nesting_count) - 1)
1047                         goto out;
1048
1049 #ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
1050                 /* Clear master flag /before/ clearing selector flag. */
1051                 wmb();
1052 #endif
1053                 pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
1054                 while (pending_words != 0) {
1055                         unsigned long pending_bits;
1056                         int word_idx = __ffs(pending_words);
1057                         pending_words &= ~(1UL << word_idx);
1058
1059                         while ((pending_bits = active_evtchns(cpu, s, word_idx)) != 0) {
1060                                 int bit_idx = __ffs(pending_bits);
1061                                 int port = (word_idx * BITS_PER_LONG) + bit_idx;
1062                                 int irq = evtchn_to_irq[port];
1063                                 struct irq_desc *desc;
1064
1065                                 mask_evtchn(port);
1066                                 clear_evtchn(port);
1067
1068                                 if (irq != -1) {
1069                                         desc = irq_to_desc(irq);
1070                                         if (desc)
1071                                                 generic_handle_irq_desc(irq, desc);
1072                                 }
1073                         }
1074                 }
1075
1076                 BUG_ON(!irqs_disabled());
1077
1078                 count = __this_cpu_read(xed_nesting_count);
1079                 __this_cpu_write(xed_nesting_count, 0);
1080         } while (count != 1 || vcpu_info->evtchn_upcall_pending);
1081
1082 out:
1083
1084         put_cpu();
1085 }
1086
1087 void xen_evtchn_do_upcall(struct pt_regs *regs)
1088 {
1089         struct pt_regs *old_regs = set_irq_regs(regs);
1090
1091         exit_idle();
1092         irq_enter();
1093
1094         __xen_evtchn_do_upcall();
1095
1096         irq_exit();
1097         set_irq_regs(old_regs);
1098 }
1099
1100 void xen_hvm_evtchn_do_upcall(void)
1101 {
1102         __xen_evtchn_do_upcall();
1103 }
1104 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1105
1106 /* Rebind a new event channel to an existing irq. */
1107 void rebind_evtchn_irq(int evtchn, int irq)
1108 {
1109         struct irq_info *info = info_for_irq(irq);
1110
1111         /* Make sure the irq is masked, since the new event channel
1112            will also be masked. */
1113         disable_irq(irq);
1114
1115         spin_lock(&irq_mapping_update_lock);
1116
1117         /* After resume the irq<->evtchn mappings are all cleared out */
1118         BUG_ON(evtchn_to_irq[evtchn] != -1);
1119         /* Expect irq to have been bound before,
1120            so there should be a proper type */
1121         BUG_ON(info->type == IRQT_UNBOUND);
1122
1123         evtchn_to_irq[evtchn] = irq;
1124         xen_irq_info_evtchn_init(irq, evtchn);
1125
1126         spin_unlock(&irq_mapping_update_lock);
1127
1128         /* new event channels are always bound to cpu 0 */
1129         irq_set_affinity(irq, cpumask_of(0));
1130
1131         /* Unmask the event channel. */
1132         enable_irq(irq);
1133 }
1134
1135 /* Rebind an evtchn so that it gets delivered to a specific cpu */
1136 static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
1137 {
1138         struct evtchn_bind_vcpu bind_vcpu;
1139         int evtchn = evtchn_from_irq(irq);
1140
1141         if (!VALID_EVTCHN(evtchn))
1142                 return -1;
1143
1144         /*
1145          * Events delivered via platform PCI interrupts are always
1146          * routed to vcpu 0 and hence cannot be rebound.
1147          */
1148         if (xen_hvm_domain() && !xen_have_vector_callback)
1149                 return -1;
1150
1151         /* Send future instances of this interrupt to other vcpu. */
1152         bind_vcpu.port = evtchn;
1153         bind_vcpu.vcpu = tcpu;
1154
1155         /*
1156          * If this fails, it usually just indicates that we're dealing with a
1157          * virq or IPI channel, which don't actually need to be rebound. Ignore
1158          * it, but don't do the xenlinux-level rebind in that case.
1159          */
1160         if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1161                 bind_evtchn_to_cpu(evtchn, tcpu);
1162
1163         return 0;
1164 }
1165
1166 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1167                             bool force)
1168 {
1169         unsigned tcpu = cpumask_first(dest);
1170
1171         return rebind_irq_to_cpu(data->irq, tcpu);
1172 }
1173
1174 int resend_irq_on_evtchn(unsigned int irq)
1175 {
1176         int masked, evtchn = evtchn_from_irq(irq);
1177         struct shared_info *s = HYPERVISOR_shared_info;
1178
1179         if (!VALID_EVTCHN(evtchn))
1180                 return 1;
1181
1182         masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
1183         sync_set_bit(evtchn, s->evtchn_pending);
1184         if (!masked)
1185                 unmask_evtchn(evtchn);
1186
1187         return 1;
1188 }
1189
1190 static void enable_dynirq(struct irq_data *data)
1191 {
1192         int evtchn = evtchn_from_irq(data->irq);
1193
1194         if (VALID_EVTCHN(evtchn))
1195                 unmask_evtchn(evtchn);
1196 }
1197
1198 static void disable_dynirq(struct irq_data *data)
1199 {
1200         int evtchn = evtchn_from_irq(data->irq);
1201
1202         if (VALID_EVTCHN(evtchn))
1203                 mask_evtchn(evtchn);
1204 }
1205
1206 static void ack_dynirq(struct irq_data *data)
1207 {
1208         int evtchn = evtchn_from_irq(data->irq);
1209
1210         move_masked_irq(data->irq);
1211
1212         if (VALID_EVTCHN(evtchn))
1213                 unmask_evtchn(evtchn);
1214 }
1215
1216 static int retrigger_dynirq(struct irq_data *data)
1217 {
1218         int evtchn = evtchn_from_irq(data->irq);
1219         struct shared_info *sh = HYPERVISOR_shared_info;
1220         int ret = 0;
1221
1222         if (VALID_EVTCHN(evtchn)) {
1223                 int masked;
1224
1225                 masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
1226                 sync_set_bit(evtchn, sh->evtchn_pending);
1227                 if (!masked)
1228                         unmask_evtchn(evtchn);
1229                 ret = 1;
1230         }
1231
1232         return ret;
1233 }
1234
1235 static void restore_pirqs(void)
1236 {
1237         int pirq, rc, irq, gsi;
1238         struct physdev_map_pirq map_irq;
1239
1240         for (pirq = 0; pirq < nr_irqs; pirq++) {
1241                 irq = pirq_to_irq[pirq];
1242                 if (irq == -1)
1243                         continue;
1244
1245                 /* save/restore of PT devices doesn't work, so at this point the
1246                  * only devices present are GSI based emulated devices */
1247                 gsi = gsi_from_irq(irq);
1248                 if (!gsi)
1249                         continue;
1250
1251                 map_irq.domid = DOMID_SELF;
1252                 map_irq.type = MAP_PIRQ_TYPE_GSI;
1253                 map_irq.index = gsi;
1254                 map_irq.pirq = pirq;
1255
1256                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1257                 if (rc) {
1258                         printk(KERN_WARNING "xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1259                                         gsi, irq, pirq, rc);
1260                         xen_free_irq(irq);
1261                         pirq_to_irq[pirq] = -1;
1262                         continue;
1263                 }
1264
1265                 printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1266
1267                 __startup_pirq(irq);
1268         }
1269 }
1270
1271 static void restore_cpu_virqs(unsigned int cpu)
1272 {
1273         struct evtchn_bind_virq bind_virq;
1274         int virq, irq, evtchn;
1275
1276         for (virq = 0; virq < NR_VIRQS; virq++) {
1277                 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1278                         continue;
1279
1280                 BUG_ON(virq_from_irq(irq) != virq);
1281
1282                 /* Get a new binding from Xen. */
1283                 bind_virq.virq = virq;
1284                 bind_virq.vcpu = cpu;
1285                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1286                                                 &bind_virq) != 0)
1287                         BUG();
1288                 evtchn = bind_virq.port;
1289
1290                 /* Record the new mapping. */
1291                 evtchn_to_irq[evtchn] = irq;
1292                 xen_irq_info_virq_init(irq, evtchn, virq);
1293                 bind_evtchn_to_cpu(evtchn, cpu);
1294         }
1295 }
1296
1297 static void restore_cpu_ipis(unsigned int cpu)
1298 {
1299         struct evtchn_bind_ipi bind_ipi;
1300         int ipi, irq, evtchn;
1301
1302         for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1303                 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1304                         continue;
1305
1306                 BUG_ON(ipi_from_irq(irq) != ipi);
1307
1308                 /* Get a new binding from Xen. */
1309                 bind_ipi.vcpu = cpu;
1310                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1311                                                 &bind_ipi) != 0)
1312                         BUG();
1313                 evtchn = bind_ipi.port;
1314
1315                 /* Record the new mapping. */
1316                 evtchn_to_irq[evtchn] = irq;
1317                 xen_irq_info_ipi_init(irq, evtchn, ipi);
1318                 bind_evtchn_to_cpu(evtchn, cpu);
1319         }
1320 }
1321
1322 /* Clear an irq's pending state, in preparation for polling on it */
1323 void xen_clear_irq_pending(int irq)
1324 {
1325         int evtchn = evtchn_from_irq(irq);
1326
1327         if (VALID_EVTCHN(evtchn))
1328                 clear_evtchn(evtchn);
1329 }
1330 EXPORT_SYMBOL(xen_clear_irq_pending);
1331 void xen_set_irq_pending(int irq)
1332 {
1333         int evtchn = evtchn_from_irq(irq);
1334
1335         if (VALID_EVTCHN(evtchn))
1336                 set_evtchn(evtchn);
1337 }
1338
1339 bool xen_test_irq_pending(int irq)
1340 {
1341         int evtchn = evtchn_from_irq(irq);
1342         bool ret = false;
1343
1344         if (VALID_EVTCHN(evtchn))
1345                 ret = test_evtchn(evtchn);
1346
1347         return ret;
1348 }
1349
1350 /* Poll waiting for an irq to become pending with timeout.  In the usual case,
1351  * the irq will be disabled so it won't deliver an interrupt. */
1352 void xen_poll_irq_timeout(int irq, u64 timeout)
1353 {
1354         evtchn_port_t evtchn = evtchn_from_irq(irq);
1355
1356         if (VALID_EVTCHN(evtchn)) {
1357                 struct sched_poll poll;
1358
1359                 poll.nr_ports = 1;
1360                 poll.timeout = timeout;
1361                 set_xen_guest_handle(poll.ports, &evtchn);
1362
1363                 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1364                         BUG();
1365         }
1366 }
1367 EXPORT_SYMBOL(xen_poll_irq_timeout);
1368 /* Poll waiting for an irq to become pending.  In the usual case, the
1369  * irq will be disabled so it won't deliver an interrupt. */
1370 void xen_poll_irq(int irq)
1371 {
1372         xen_poll_irq_timeout(irq, 0 /* no timeout */);
1373 }
1374
1375 void xen_irq_resume(void)
1376 {
1377         unsigned int cpu, irq, evtchn;
1378
1379         init_evtchn_cpu_bindings();
1380
1381         /* New event-channel space is not 'live' yet. */
1382         for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1383                 mask_evtchn(evtchn);
1384
1385         /* No IRQ <-> event-channel mappings. */
1386         for (irq = 0; irq < nr_irqs; irq++)
1387                 irq_info[irq].evtchn = 0; /* zap event-channel binding */
1388
1389         for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1390                 evtchn_to_irq[evtchn] = -1;
1391
1392         for_each_possible_cpu(cpu) {
1393                 restore_cpu_virqs(cpu);
1394                 restore_cpu_ipis(cpu);
1395         }
1396
1397         restore_pirqs();
1398 }
1399
1400 static struct irq_chip xen_dynamic_chip __read_mostly = {
1401         .name                   = "xen-dyn",
1402
1403         .irq_disable            = disable_dynirq,
1404         .irq_mask               = disable_dynirq,
1405         .irq_unmask             = enable_dynirq,
1406
1407         .irq_eoi                = ack_dynirq,
1408         .irq_set_affinity       = set_affinity_irq,
1409         .irq_retrigger          = retrigger_dynirq,
1410 };
1411
1412 static struct irq_chip xen_pirq_chip __read_mostly = {
1413         .name                   = "xen-pirq",
1414
1415         .irq_startup            = startup_pirq,
1416         .irq_shutdown           = shutdown_pirq,
1417
1418         .irq_enable             = enable_pirq,
1419         .irq_unmask             = enable_pirq,
1420
1421         .irq_disable            = disable_pirq,
1422         .irq_mask               = disable_pirq,
1423
1424         .irq_ack                = ack_pirq,
1425
1426         .irq_set_affinity       = set_affinity_irq,
1427
1428         .irq_retrigger          = retrigger_dynirq,
1429 };
1430
1431 static struct irq_chip xen_percpu_chip __read_mostly = {
1432         .name                   = "xen-percpu",
1433
1434         .irq_disable            = disable_dynirq,
1435         .irq_mask               = disable_dynirq,
1436         .irq_unmask             = enable_dynirq,
1437
1438         .irq_ack                = ack_dynirq,
1439 };
1440
1441 int xen_set_callback_via(uint64_t via)
1442 {
1443         struct xen_hvm_param a;
1444         a.domid = DOMID_SELF;
1445         a.index = HVM_PARAM_CALLBACK_IRQ;
1446         a.value = via;
1447         return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1448 }
1449 EXPORT_SYMBOL_GPL(xen_set_callback_via);
1450
1451 #ifdef CONFIG_XEN_PVHVM
1452 /* Vector callbacks are better than PCI interrupts to receive event
1453  * channel notifications because we can receive vector callbacks on any
1454  * vcpu and we don't need PCI support or APIC interactions. */
1455 void xen_callback_vector(void)
1456 {
1457         int rc;
1458         uint64_t callback_via;
1459         if (xen_have_vector_callback) {
1460                 callback_via = HVM_CALLBACK_VECTOR(XEN_HVM_EVTCHN_CALLBACK);
1461                 rc = xen_set_callback_via(callback_via);
1462                 if (rc) {
1463                         printk(KERN_ERR "Request for Xen HVM callback vector"
1464                                         " failed.\n");
1465                         xen_have_vector_callback = 0;
1466                         return;
1467                 }
1468                 printk(KERN_INFO "Xen HVM callback vector for event delivery is "
1469                                 "enabled\n");
1470                 /* in the restore case the vector has already been allocated */
1471                 if (!test_bit(XEN_HVM_EVTCHN_CALLBACK, used_vectors))
1472                         alloc_intr_gate(XEN_HVM_EVTCHN_CALLBACK, xen_hvm_callback_vector);
1473         }
1474 }
1475 #else
1476 void xen_callback_vector(void) {}
1477 #endif
1478
1479 void __init xen_init_IRQ(void)
1480 {
1481         int i;
1482
1483         irq_info = kcalloc(nr_irqs, sizeof(*irq_info), GFP_KERNEL);
1484
1485         /* We are using nr_irqs as the maximum number of pirq available but
1486          * that number is actually chosen by Xen and we don't know exactly
1487          * what it is. Be careful choosing high pirq numbers. */
1488         pirq_to_irq = kcalloc(nr_irqs, sizeof(*pirq_to_irq), GFP_KERNEL);
1489         for (i = 0; i < nr_irqs; i++)
1490                 pirq_to_irq[i] = -1;
1491
1492         evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
1493                                     GFP_KERNEL);
1494         for (i = 0; i < NR_EVENT_CHANNELS; i++)
1495                 evtchn_to_irq[i] = -1;
1496
1497         init_evtchn_cpu_bindings();
1498
1499         /* No event channels are 'live' right now. */
1500         for (i = 0; i < NR_EVENT_CHANNELS; i++)
1501                 mask_evtchn(i);
1502
1503         if (xen_hvm_domain()) {
1504                 xen_callback_vector();
1505                 native_init_IRQ();
1506                 /* pci_xen_hvm_init must be called after native_init_IRQ so that
1507                  * __acpi_register_gsi can point at the right function */
1508                 pci_xen_hvm_init();
1509         } else {
1510                 irq_ctx_init(smp_processor_id());
1511                 if (xen_initial_domain())
1512                         xen_setup_pirqs();
1513         }
1514 }