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 received, it is mapped to an irq and sent
   9  * through the normal interrupt processing path.
  10  *
  11  * There are four kinds of events which can be mapped to an event
  12  * channel:
  13  *
  14  * 1. Inter-domain notifications.  This includes all the virtual
  15  *    device events, since they're driven by front-ends in another domain
  16  *    (typically dom0).
  17  * 2. VIRQs, typically used for timers.  These are per-cpu events.
  18  * 3. IPIs.
  19  * 4. PIRQs - Hardware interrupts.
  20  *
  21  * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
  22  */
  23
  24 #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 static LIST_HEAD(xen_irq_list_head);
  60
  61 /* IRQ <-> VIRQ mapping. */
  62 static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
  63
  64 /* IRQ <-> IPI mapping */
  65 static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
  66
  67 /* Interrupt types. */
  68 enum xen_irq_type {
  69         IRQT_UNBOUND = 0,
  70         IRQT_PIRQ,
  71         IRQT_VIRQ,
  72         IRQT_IPI,
  73         IRQT_EVTCHN
  74 };
  75
  76 /*
  77  * Packed IRQ information:
  78  * type - enum xen_irq_type
  79  * event channel - irq->event channel mapping
  80  * cpu - cpu this event channel is bound to
  81  * index - type-specific information:
  82  *    PIRQ - vector, with MSB being "needs EIO", or physical IRQ of the HVM
  83  *           guest, or GSI (real passthrough IRQ) of the device.
  84  *    VIRQ - virq number
  85  *    IPI - IPI vector
  86  *    EVTCHN -
  87  */
  88 struct irq_info {
  89         struct list_head list;
  90         enum xen_irq_type type; /* type */
  91         unsigned irq;
  92         unsigned short evtchn;  /* event channel */
  93         unsigned short cpu;     /* cpu bound */
  94
  95         union {
  96                 unsigned short virq;
  97                 enum ipi_vector ipi;
  98                 struct {
  99                         unsigned short pirq;
 100                         unsigned short gsi;
 101                         unsigned char vector;
 102                         unsigned char flags;
 103                         uint16_t domid;
 104                 } pirq;
 105         } u;
 106 };
 107 #define PIRQ_NEEDS_EOI  (1 << 0)
 108 #define PIRQ_SHAREABLE  (1 << 1)
 109
 110 static int *evtchn_to_irq;
 111
 112 static DEFINE_PER_CPU(unsigned long [NR_EVENT_CHANNELS/BITS_PER_LONG],
 113                       cpu_evtchn_mask);
 114
 115 /* Xen will never allocate port zero for any purpose. */
 116 #define VALID_EVTCHN(chn)       ((chn) != 0)
 117
 118 static struct irq_chip xen_dynamic_chip;
 119 static struct irq_chip xen_percpu_chip;
 120 static struct irq_chip xen_pirq_chip;
 121 static void enable_dynirq(struct irq_data *data);
 122 static void disable_dynirq(struct irq_data *data);
 123
 124 /* Get info for IRQ */
 125 static struct irq_info *info_for_irq(unsigned irq)
 126 {
 127         return irq_get_handler_data(irq);
 128 }
 129
 130 /* Constructors for packed IRQ information. */
 131 static void xen_irq_info_common_init(struct irq_info *info,
 132                                      unsigned irq,
 133                                      enum xen_irq_type type,
 134                                      unsigned short evtchn,
 135                                      unsigned short cpu)
 136 {
 137
 138         BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
 139
 140         info->type = type;
 141         info->irq = irq;
 142         info->evtchn = evtchn;
 143         info->cpu = cpu;
 144
 145         evtchn_to_irq[evtchn] = irq;
 146 }
 147
 148 static void xen_irq_info_evtchn_init(unsigned irq,
 149                                      unsigned short evtchn)
 150 {
 151         struct irq_info *info = info_for_irq(irq);
 152
 153         xen_irq_info_common_init(info, irq, IRQT_EVTCHN, evtchn, 0);
 154 }
 155
 156 static void xen_irq_info_ipi_init(unsigned cpu,
 157                                   unsigned irq,
 158                                   unsigned short evtchn,
 159                                   enum ipi_vector ipi)
 160 {
 161         struct irq_info *info = info_for_irq(irq);
 162
 163         xen_irq_info_common_init(info, irq, IRQT_IPI, evtchn, 0);
 164
 165         info->u.ipi = ipi;
 166
 167         per_cpu(ipi_to_irq, cpu)[ipi] = irq;
 168 }
 169
 170 static void xen_irq_info_virq_init(unsigned cpu,
 171                                    unsigned irq,
 172                                    unsigned short evtchn,
 173                                    unsigned short virq)
 174 {
 175         struct irq_info *info = info_for_irq(irq);
 176
 177         xen_irq_info_common_init(info, irq, IRQT_VIRQ, evtchn, 0);
 178
 179         info->u.virq = virq;
 180
 181         per_cpu(virq_to_irq, cpu)[virq] = irq;
 182 }
 183
 184 static void xen_irq_info_pirq_init(unsigned irq,
 185                                    unsigned short evtchn,
 186                                    unsigned short pirq,
 187                                    unsigned short gsi,
 188                                    unsigned short vector,
 189                                    uint16_t domid,
 190                                    unsigned char flags)
 191 {
 192         struct irq_info *info = info_for_irq(irq);
 193
 194         xen_irq_info_common_init(info, irq, IRQT_PIRQ, evtchn, 0);
 195
 196         info->u.pirq.pirq = pirq;
 197         info->u.pirq.gsi = gsi;
 198         info->u.pirq.vector = vector;
 199         info->u.pirq.domid = domid;
 200         info->u.pirq.flags = flags;
 201 }
 202
 203 /*
 204  * Accessors for packed IRQ information.
 205  */
 206 static unsigned int evtchn_from_irq(unsigned irq)
 207 {
 208         if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))
 209                 return 0;
 210
 211         return info_for_irq(irq)->evtchn;
 212 }
 213
 214 unsigned irq_from_evtchn(unsigned int evtchn)
 215 {
 216         return evtchn_to_irq[evtchn];
 217 }
 218 EXPORT_SYMBOL_GPL(irq_from_evtchn);
 219
 220 static enum ipi_vector ipi_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_IPI);
 226
 227         return info->u.ipi;
 228 }
 229
 230 static unsigned virq_from_irq(unsigned irq)
 231 {
 232         struct irq_info *info = info_for_irq(irq);
 233
 234         BUG_ON(info == NULL);
 235         BUG_ON(info->type != IRQT_VIRQ);
 236
 237         return info->u.virq;
 238 }
 239
 240 static unsigned pirq_from_irq(unsigned irq)
 241 {
 242         struct irq_info *info = info_for_irq(irq);
 243
 244         BUG_ON(info == NULL);
 245         BUG_ON(info->type != IRQT_PIRQ);
 246
 247         return info->u.pirq.pirq;
 248 }
 249
 250 static enum xen_irq_type type_from_irq(unsigned irq)
 251 {
 252         return info_for_irq(irq)->type;
 253 }
 254
 255 static unsigned cpu_from_irq(unsigned irq)
 256 {
 257         return info_for_irq(irq)->cpu;
 258 }
 259
 260 static unsigned int cpu_from_evtchn(unsigned int evtchn)
 261 {
 262         int irq = evtchn_to_irq[evtchn];
 263         unsigned ret = 0;
 264
 265         if (irq != -1)
 266                 ret = cpu_from_irq(irq);
 267
 268         return ret;
 269 }
 270
 271 static bool pirq_needs_eoi(unsigned irq)
 272 {
 273         struct irq_info *info = info_for_irq(irq);
 274
 275         BUG_ON(info->type != IRQT_PIRQ);
 276
 277         return info->u.pirq.flags & PIRQ_NEEDS_EOI;
 278 }
 279
 280 static inline unsigned long active_evtchns(unsigned int cpu,
 281                                            struct shared_info *sh,
 282                                            unsigned int idx)
 283 {
 284         return sh->evtchn_pending[idx] &
 285                 per_cpu(cpu_evtchn_mask, cpu)[idx] &
 286                 ~sh->evtchn_mask[idx];
 287 }
 288
 289 static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
 290 {
 291         int irq = evtchn_to_irq[chn];
 292
 293         BUG_ON(irq == -1);
 294 #ifdef CONFIG_SMP
 295         cpumask_copy(irq_to_desc(irq)->irq_data.affinity, cpumask_of(cpu));
 296 #endif
 297
 298         clear_bit(chn, per_cpu(cpu_evtchn_mask, cpu_from_irq(irq)));
 299         set_bit(chn, per_cpu(cpu_evtchn_mask, cpu));
 300
 301         info_for_irq(irq)->cpu = cpu;
 302 }
 303
 304 static void init_evtchn_cpu_bindings(void)
 305 {
 306         int i;
 307 #ifdef CONFIG_SMP
 308         struct irq_info *info;
 309
 310         /* By default all event channels notify CPU#0. */
 311         list_for_each_entry(info, &xen_irq_list_head, list) {
 312                 struct irq_desc *desc = irq_to_desc(info->irq);
 313                 cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
 314         }
 315 #endif
 316
 317         for_each_possible_cpu(i)
 318                 memset(per_cpu(cpu_evtchn_mask, i),
 319                        (i == 0) ? ~0 : 0, sizeof(*per_cpu(cpu_evtchn_mask, i)));
 320 }
 321
 322 static inline void clear_evtchn(int port)
 323 {
 324         struct shared_info *s = HYPERVISOR_shared_info;
 325         sync_clear_bit(port, &s->evtchn_pending[0]);
 326 }
 327
 328 static inline void set_evtchn(int port)
 329 {
 330         struct shared_info *s = HYPERVISOR_shared_info;
 331         sync_set_bit(port, &s->evtchn_pending[0]);
 332 }
 333
 334 static inline int test_evtchn(int port)
 335 {
 336         struct shared_info *s = HYPERVISOR_shared_info;
 337         return sync_test_bit(port, &s->evtchn_pending[0]);
 338 }
 339
 340
 341 /**
 342  * notify_remote_via_irq - send event to remote end of event channel via irq
 343  * @irq: irq of event channel to send event to
 344  *
 345  * Unlike notify_remote_via_evtchn(), this is safe to use across
 346  * save/restore. Notifications on a broken connection are silently
 347  * dropped.
 348  */
 349 void notify_remote_via_irq(int irq)
 350 {
 351         int evtchn = evtchn_from_irq(irq);
 352
 353         if (VALID_EVTCHN(evtchn))
 354                 notify_remote_via_evtchn(evtchn);
 355 }
 356 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
 357
 358 static void mask_evtchn(int port)
 359 {
 360         struct shared_info *s = HYPERVISOR_shared_info;
 361         sync_set_bit(port, &s->evtchn_mask[0]);
 362 }
 363
 364 static void unmask_evtchn(int port)
 365 {
 366         struct shared_info *s = HYPERVISOR_shared_info;
 367         unsigned int cpu = get_cpu();
 368
 369         BUG_ON(!irqs_disabled());
 370
 371         /* Slow path (hypercall) if this is a non-local port. */
 372         if (unlikely(cpu != cpu_from_evtchn(port))) {
 373                 struct evtchn_unmask unmask = { .port = port };
 374                 (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
 375         } else {
 376                 struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
 377
 378                 sync_clear_bit(port, &s->evtchn_mask[0]);
 379
 380                 /*
 381                  * The following is basically the equivalent of
 382                  * 'hw_resend_irq'. Just like a real IO-APIC we 'lose
 383                  * the interrupt edge' if the channel is masked.
 384                  */
 385                 if (sync_test_bit(port, &s->evtchn_pending[0]) &&
 386                     !sync_test_and_set_bit(port / BITS_PER_LONG,
 387                                            &vcpu_info->evtchn_pending_sel))
 388                         vcpu_info->evtchn_upcall_pending = 1;
 389         }
 390
 391         put_cpu();
 392 }
 393
 394 static void xen_irq_init(unsigned irq)
 395 {
 396         struct irq_info *info;
 397 #ifdef CONFIG_SMP
 398         struct irq_desc *desc = irq_to_desc(irq);
 399
 400         /* By default all event channels notify CPU#0. */
 401         cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
 402 #endif
 403
 404         info = kzalloc(sizeof(*info), GFP_KERNEL);
 405         if (info == NULL)
 406                 panic("Unable to allocate metadata for IRQ%d\n", irq);
 407
 408         info->type = IRQT_UNBOUND;
 409
 410         irq_set_handler_data(irq, info);
 411
 412         list_add_tail(&info->list, &xen_irq_list_head);
 413 }
 414
 415 static int __must_check xen_allocate_irq_dynamic(void)
 416 {
 417         int first = 0;
 418         int irq;
 419
 420 #ifdef CONFIG_X86_IO_APIC
 421         /*
 422          * For an HVM guest or domain 0 which see "real" (emulated or
 423          * actual respectively) GSIs we allocate dynamic IRQs
 424          * e.g. those corresponding to event channels or MSIs
 425          * etc. from the range above those "real" GSIs to avoid
 426          * collisions.
 427          */
 428         if (xen_initial_domain() || xen_hvm_domain())
 429                 first = get_nr_irqs_gsi();
 430 #endif
 431
 432         irq = irq_alloc_desc_from(first, -1);
 433
 434         xen_irq_init(irq);
 435
 436         return irq;
 437 }
 438
 439 static int __must_check xen_allocate_irq_gsi(unsigned gsi)
 440 {
 441         int irq;
 442
 443         /*
 444          * A PV guest has no concept of a GSI (since it has no ACPI
 445          * nor access to/knowledge of the physical APICs). Therefore
 446          * all IRQs are dynamically allocated from the entire IRQ
 447          * space.
 448          */
 449         if (xen_pv_domain() && !xen_initial_domain())
 450                 return xen_allocate_irq_dynamic();
 451
 452         /* Legacy IRQ descriptors are already allocated by the arch. */
 453         if (gsi < NR_IRQS_LEGACY)
 454                 irq = gsi;
 455         else
 456                 irq = irq_alloc_desc_at(gsi, -1);
 457
 458         xen_irq_init(irq);
 459
 460         return irq;
 461 }
 462
 463 static void xen_free_irq(unsigned irq)
 464 {
 465         struct irq_info *info = irq_get_handler_data(irq);
 466
 467         list_del(&info->list);
 468
 469         irq_set_handler_data(irq, NULL);
 470
 471         kfree(info);
 472
 473         /* Legacy IRQ descriptors are managed by the arch. */
 474         if (irq < NR_IRQS_LEGACY)
 475                 return;
 476
 477         irq_free_desc(irq);
 478 }
 479
 480 static void pirq_query_unmask(int irq)
 481 {
 482         struct physdev_irq_status_query irq_status;
 483         struct irq_info *info = info_for_irq(irq);
 484
 485         BUG_ON(info->type != IRQT_PIRQ);
 486
 487         irq_status.irq = pirq_from_irq(irq);
 488         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
 489                 irq_status.flags = 0;
 490
 491         info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
 492         if (irq_status.flags & XENIRQSTAT_needs_eoi)
 493                 info->u.pirq.flags |= PIRQ_NEEDS_EOI;
 494 }
 495
 496 static bool probing_irq(int irq)
 497 {
 498         struct irq_desc *desc = irq_to_desc(irq);
 499
 500         return desc && desc->action == NULL;
 501 }
 502
 503 static void eoi_pirq(struct irq_data *data)
 504 {
 505         int evtchn = evtchn_from_irq(data->irq);
 506         struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
 507         int rc = 0;
 508
 509         irq_move_irq(data);
 510
 511         if (VALID_EVTCHN(evtchn))
 512                 clear_evtchn(evtchn);
 513
 514         if (pirq_needs_eoi(data->irq)) {
 515                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
 516                 WARN_ON(rc);
 517         }
 518 }
 519
 520 static void mask_ack_pirq(struct irq_data *data)
 521 {
 522         disable_dynirq(data);
 523         eoi_pirq(data);
 524 }
 525
 526 static unsigned int __startup_pirq(unsigned int irq)
 527 {
 528         struct evtchn_bind_pirq bind_pirq;
 529         struct irq_info *info = info_for_irq(irq);
 530         int evtchn = evtchn_from_irq(irq);
 531         int rc;
 532
 533         BUG_ON(info->type != IRQT_PIRQ);
 534
 535         if (VALID_EVTCHN(evtchn))
 536                 goto out;
 537
 538         bind_pirq.pirq = pirq_from_irq(irq);
 539         /* NB. We are happy to share unless we are probing. */
 540         bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
 541                                         BIND_PIRQ__WILL_SHARE : 0;
 542         rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
 543         if (rc != 0) {
 544                 if (!probing_irq(irq))
 545                         printk(KERN_INFO "Failed to obtain physical IRQ %d\n",
 546                                irq);
 547                 return 0;
 548         }
 549         evtchn = bind_pirq.port;
 550
 551         pirq_query_unmask(irq);
 552
 553         evtchn_to_irq[evtchn] = irq;
 554         bind_evtchn_to_cpu(evtchn, 0);
 555         info->evtchn = evtchn;
 556
 557 out:
 558         unmask_evtchn(evtchn);
 559         eoi_pirq(irq_get_irq_data(irq));
 560
 561         return 0;
 562 }
 563
 564 static unsigned int startup_pirq(struct irq_data *data)
 565 {
 566         return __startup_pirq(data->irq);
 567 }
 568
 569 static void shutdown_pirq(struct irq_data *data)
 570 {
 571         struct evtchn_close close;
 572         unsigned int irq = data->irq;
 573         struct irq_info *info = info_for_irq(irq);
 574         int evtchn = evtchn_from_irq(irq);
 575
 576         BUG_ON(info->type != IRQT_PIRQ);
 577
 578         if (!VALID_EVTCHN(evtchn))
 579                 return;
 580
 581         mask_evtchn(evtchn);
 582
 583         close.port = evtchn;
 584         if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 585                 BUG();
 586
 587         bind_evtchn_to_cpu(evtchn, 0);
 588         evtchn_to_irq[evtchn] = -1;
 589         info->evtchn = 0;
 590 }
 591
 592 static void enable_pirq(struct irq_data *data)
 593 {
 594         startup_pirq(data);
 595 }
 596
 597 static void disable_pirq(struct irq_data *data)
 598 {
 599         disable_dynirq(data);
 600 }
 601
 602 static int find_irq_by_gsi(unsigned gsi)
 603 {
 604         struct irq_info *info;
 605
 606         list_for_each_entry(info, &xen_irq_list_head, list) {
 607                 if (info->type != IRQT_PIRQ)
 608                         continue;
 609
 610                 if (info->u.pirq.gsi == gsi)
 611                         return info->irq;
 612         }
 613
 614         return -1;
 615 }
 616
 617 /*
 618  * Do not make any assumptions regarding the relationship between the
 619  * IRQ number returned here and the Xen pirq argument.
 620  *
 621  * Note: We don't assign an event channel until the irq actually started
 622  * up.  Return an existing irq if we've already got one for the gsi.
 623  *
 624  * Shareable implies level triggered, not shareable implies edge
 625  * triggered here.
 626  */
 627 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 628                              unsigned pirq, int shareable, char *name)
 629 {
 630         int irq = -1;
 631         struct physdev_irq irq_op;
 632
 633         spin_lock(&irq_mapping_update_lock);
 634
 635         irq = find_irq_by_gsi(gsi);
 636         if (irq != -1) {
 637                 printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n",
 638                        irq, gsi);
 639                 goto out;       /* XXX need refcount? */
 640         }
 641
 642         irq = xen_allocate_irq_gsi(gsi);
 643         if (irq < 0)
 644                 goto out;
 645
 646         irq_op.irq = irq;
 647         irq_op.vector = 0;
 648
 649         /* Only the privileged domain can do this. For non-priv, the pcifront
 650          * driver provides a PCI bus that does the call to do exactly
 651          * this in the priv domain. */
 652         if (xen_initial_domain() &&
 653             HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
 654                 xen_free_irq(irq);
 655                 irq = -ENOSPC;
 656                 goto out;
 657         }
 658
 659         xen_irq_info_pirq_init(irq, 0, pirq, gsi, irq_op.vector, DOMID_SELF,
 660                                shareable ? PIRQ_SHAREABLE : 0);
 661
 662         pirq_query_unmask(irq);
 663         /* We try to use the handler with the appropriate semantic for the
 664          * type of interrupt: if the interrupt is an edge triggered
 665          * interrupt we use handle_edge_irq.
 666          *
 667          * On the other hand if the interrupt is level triggered we use
 668          * handle_fasteoi_irq like the native code does for this kind of
 669          * interrupts.
 670          *
 671          * Depending on the Xen version, pirq_needs_eoi might return true
 672          * not only for level triggered interrupts but for edge triggered
 673          * interrupts too. In any case Xen always honors the eoi mechanism,
 674          * not injecting any more pirqs of the same kind if the first one
 675          * hasn't received an eoi yet. Therefore using the fasteoi handler
 676          * is the right choice either way.
 677          */
 678         if (shareable)
 679                 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 680                                 handle_fasteoi_irq, name);
 681         else
 682                 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 683                                 handle_edge_irq, name);
 684
 685 out:
 686         spin_unlock(&irq_mapping_update_lock);
 687
 688         return irq;
 689 }
 690
 691 #ifdef CONFIG_PCI_MSI
 692 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
 693 {
 694         int rc;
 695         struct physdev_get_free_pirq op_get_free_pirq;
 696
 697         op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
 698         rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
 699
 700         WARN_ONCE(rc == -ENOSYS,
 701                   "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
 702
 703         return rc ? -1 : op_get_free_pirq.pirq;
 704 }
 705
 706 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
 707                              int pirq, int vector, const char *name,
 708                              domid_t domid)
 709 {
 710         int irq, ret;
 711
 712         spin_lock(&irq_mapping_update_lock);
 713
 714         irq = xen_allocate_irq_dynamic();
 715         if (irq == -1)
 716                 goto out;
 717
 718         irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_edge_irq,
 719                         name);
 720
 721         xen_irq_info_pirq_init(irq, 0, pirq, 0, vector, domid, 0);
 722         ret = irq_set_msi_desc(irq, msidesc);
 723         if (ret < 0)
 724                 goto error_irq;
 725 out:
 726         spin_unlock(&irq_mapping_update_lock);
 727         return irq;
 728 error_irq:
 729         spin_unlock(&irq_mapping_update_lock);
 730         xen_free_irq(irq);
 731         return -1;
 732 }
 733 #endif
 734
 735 int xen_destroy_irq(int irq)
 736 {
 737         struct irq_desc *desc;
 738         struct physdev_unmap_pirq unmap_irq;
 739         struct irq_info *info = info_for_irq(irq);
 740         int rc = -ENOENT;
 741
 742         spin_lock(&irq_mapping_update_lock);
 743
 744         desc = irq_to_desc(irq);
 745         if (!desc)
 746                 goto out;
 747
 748         if (xen_initial_domain()) {
 749                 unmap_irq.pirq = info->u.pirq.pirq;
 750                 unmap_irq.domid = info->u.pirq.domid;
 751                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
 752                 /* If another domain quits without making the pci_disable_msix
 753                  * call, the Xen hypervisor takes care of freeing the PIRQs
 754                  * (free_domain_pirqs).
 755                  */
 756                 if ((rc == -ESRCH && info->u.pirq.domid != DOMID_SELF))
 757                         printk(KERN_INFO "domain %d does not have %d anymore\n",
 758                                 info->u.pirq.domid, info->u.pirq.pirq);
 759                 else if (rc) {
 760                         printk(KERN_WARNING "unmap irq failed %d\n", rc);
 761                         goto out;
 762                 }
 763         }
 764
 765         xen_free_irq(irq);
 766
 767 out:
 768         spin_unlock(&irq_mapping_update_lock);
 769         return rc;
 770 }
 771
 772 int xen_irq_from_pirq(unsigned pirq)
 773 {
 774         int irq;
 775
 776         struct irq_info *info;
 777
 778         spin_lock(&irq_mapping_update_lock);
 779
 780         list_for_each_entry(info, &xen_irq_list_head, list) {
 781                 if (info == NULL || info->type != IRQT_PIRQ)
 782                         continue;
 783                 irq = info->irq;
 784                 if (info->u.pirq.pirq == pirq)
 785                         goto out;
 786         }
 787         irq = -1;
 788 out:
 789         spin_unlock(&irq_mapping_update_lock);
 790
 791         return irq;
 792 }
 793
 794
 795 int xen_pirq_from_irq(unsigned irq)
 796 {
 797         return pirq_from_irq(irq);
 798 }
 799 EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
 800 int bind_evtchn_to_irq(unsigned int evtchn)
 801 {
 802         int irq;
 803
 804         spin_lock(&irq_mapping_update_lock);
 805
 806         irq = evtchn_to_irq[evtchn];
 807
 808         if (irq == -1) {
 809                 irq = xen_allocate_irq_dynamic();
 810                 if (irq == -1)
 811                         goto out;
 812
 813                 irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
 814                                               handle_edge_irq, "event");
 815
 816                 xen_irq_info_evtchn_init(irq, evtchn);
 817         }
 818
 819 out:
 820         spin_unlock(&irq_mapping_update_lock);
 821
 822         return irq;
 823 }
 824 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
 825
 826 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 827 {
 828         struct evtchn_bind_ipi bind_ipi;
 829         int evtchn, irq;
 830
 831         spin_lock(&irq_mapping_update_lock);
 832
 833         irq = per_cpu(ipi_to_irq, cpu)[ipi];
 834
 835         if (irq == -1) {
 836                 irq = xen_allocate_irq_dynamic();
 837                 if (irq < 0)
 838                         goto out;
 839
 840                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 841                                               handle_percpu_irq, "ipi");
 842
 843                 bind_ipi.vcpu = cpu;
 844                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
 845                                                 &bind_ipi) != 0)
 846                         BUG();
 847                 evtchn = bind_ipi.port;
 848
 849                 xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
 850
 851                 bind_evtchn_to_cpu(evtchn, cpu);
 852         }
 853
 854  out:
 855         spin_unlock(&irq_mapping_update_lock);
 856         return irq;
 857 }
 858
 859 static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
 860                                           unsigned int remote_port)
 861 {
 862         struct evtchn_bind_interdomain bind_interdomain;
 863         int err;
 864
 865         bind_interdomain.remote_dom  = remote_domain;
 866         bind_interdomain.remote_port = remote_port;
 867
 868         err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
 869                                           &bind_interdomain);
 870
 871         return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
 872 }
 873
 874
 875 int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 876 {
 877         struct evtchn_bind_virq bind_virq;
 878         int evtchn, irq;
 879
 880         spin_lock(&irq_mapping_update_lock);
 881
 882         irq = per_cpu(virq_to_irq, cpu)[virq];
 883
 884         if (irq == -1) {
 885                 irq = xen_allocate_irq_dynamic();
 886                 if (irq == -1)
 887                         goto out;
 888
 889                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 890                                               handle_percpu_irq, "virq");
 891
 892                 bind_virq.virq = virq;
 893                 bind_virq.vcpu = cpu;
 894                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
 895                                                 &bind_virq) != 0)
 896                         BUG();
 897                 evtchn = bind_virq.port;
 898
 899                 xen_irq_info_virq_init(cpu, irq, evtchn, virq);
 900
 901                 bind_evtchn_to_cpu(evtchn, cpu);
 902         }
 903
 904 out:
 905         spin_unlock(&irq_mapping_update_lock);
 906
 907         return irq;
 908 }
 909
 910 static void unbind_from_irq(unsigned int irq)
 911 {
 912         struct evtchn_close close;
 913         int evtchn = evtchn_from_irq(irq);
 914
 915         spin_lock(&irq_mapping_update_lock);
 916
 917         if (VALID_EVTCHN(evtchn)) {
 918                 close.port = evtchn;
 919                 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 920                         BUG();
 921
 922                 switch (type_from_irq(irq)) {
 923                 case IRQT_VIRQ:
 924                         per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
 925                                 [virq_from_irq(irq)] = -1;
 926                         break;
 927                 case IRQT_IPI:
 928                         per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn))
 929                                 [ipi_from_irq(irq)] = -1;
 930                         break;
 931                 default:
 932                         break;
 933                 }
 934
 935                 /* Closed ports are implicitly re-bound to VCPU0. */
 936                 bind_evtchn_to_cpu(evtchn, 0);
 937
 938                 evtchn_to_irq[evtchn] = -1;
 939         }
 940
 941         BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
 942
 943         xen_free_irq(irq);
 944
 945         spin_unlock(&irq_mapping_update_lock);
 946 }
 947
 948 int bind_evtchn_to_irqhandler(unsigned int evtchn,
 949                               irq_handler_t handler,
 950                               unsigned long irqflags,
 951                               const char *devname, void *dev_id)
 952 {
 953         int irq, retval;
 954
 955         irq = bind_evtchn_to_irq(evtchn);
 956         if (irq < 0)
 957                 return irq;
 958         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 959         if (retval != 0) {
 960                 unbind_from_irq(irq);
 961                 return retval;
 962         }
 963
 964         return irq;
 965 }
 966 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
 967
 968 int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
 969                                           unsigned int remote_port,
 970                                           irq_handler_t handler,
 971                                           unsigned long irqflags,
 972                                           const char *devname,
 973                                           void *dev_id)
 974 {
 975         int irq, retval;
 976
 977         irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
 978         if (irq < 0)
 979                 return irq;
 980
 981         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 982         if (retval != 0) {
 983                 unbind_from_irq(irq);
 984                 return retval;
 985         }
 986
 987         return irq;
 988 }
 989 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
 990
 991 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
 992                             irq_handler_t handler,
 993                             unsigned long irqflags, const char *devname, void *dev_id)
 994 {
 995         int irq, retval;
 996
 997         irq = bind_virq_to_irq(virq, cpu);
 998         if (irq < 0)
 999                 return irq;
1000         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1001         if (retval != 0) {
1002                 unbind_from_irq(irq);
1003                 return retval;
1004         }
1005
1006         return irq;
1007 }
1008 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
1009
1010 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
1011                            unsigned int cpu,
1012                            irq_handler_t handler,
1013                            unsigned long irqflags,
1014                            const char *devname,
1015                            void *dev_id)
1016 {
1017         int irq, retval;
1018
1019         irq = bind_ipi_to_irq(ipi, cpu);
1020         if (irq < 0)
1021                 return irq;
1022
1023         irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME;
1024         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1025         if (retval != 0) {
1026                 unbind_from_irq(irq);
1027                 return retval;
1028         }
1029
1030         return irq;
1031 }
1032
1033 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
1034 {
1035         free_irq(irq, dev_id);
1036         unbind_from_irq(irq);
1037 }
1038 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
1039
1040 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
1041 {
1042         int irq = per_cpu(ipi_to_irq, cpu)[vector];
1043         BUG_ON(irq < 0);
1044         notify_remote_via_irq(irq);
1045 }
1046
1047 irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
1048 {
1049         struct shared_info *sh = HYPERVISOR_shared_info;
1050         int cpu = smp_processor_id();
1051         unsigned long *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu);
1052         int i;
1053         unsigned long flags;
1054         static DEFINE_SPINLOCK(debug_lock);
1055         struct vcpu_info *v;
1056
1057         spin_lock_irqsave(&debug_lock, flags);
1058
1059         printk("\nvcpu %d\n  ", cpu);
1060
1061         for_each_online_cpu(i) {
1062                 int pending;
1063                 v = per_cpu(xen_vcpu, i);
1064                 pending = (get_irq_regs() && i == cpu)
1065                         ? xen_irqs_disabled(get_irq_regs())
1066                         : v->evtchn_upcall_mask;
1067                 printk("%d: masked=%d pending=%d event_sel %0*lx\n  ", i,
1068                        pending, v->evtchn_upcall_pending,
1069                        (int)(sizeof(v->evtchn_pending_sel)*2),
1070                        v->evtchn_pending_sel);
1071         }
1072         v = per_cpu(xen_vcpu, cpu);
1073
1074         printk("\npending:\n   ");
1075         for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
1076                 printk("%0*lx%s", (int)sizeof(sh->evtchn_pending[0])*2,
1077                        sh->evtchn_pending[i],
1078                        i % 8 == 0 ? "\n   " : " ");
1079         printk("\nglobal mask:\n   ");
1080         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
1081                 printk("%0*lx%s",
1082                        (int)(sizeof(sh->evtchn_mask[0])*2),
1083                        sh->evtchn_mask[i],
1084                        i % 8 == 0 ? "\n   " : " ");
1085
1086         printk("\nglobally unmasked:\n   ");
1087         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
1088                 printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
1089                        sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
1090                        i % 8 == 0 ? "\n   " : " ");
1091
1092         printk("\nlocal cpu%d mask:\n   ", cpu);
1093         for (i = (NR_EVENT_CHANNELS/BITS_PER_LONG)-1; i >= 0; i--)
1094                 printk("%0*lx%s", (int)(sizeof(cpu_evtchn[0])*2),
1095                        cpu_evtchn[i],
1096                        i % 8 == 0 ? "\n   " : " ");
1097
1098         printk("\nlocally unmasked:\n   ");
1099         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) {
1100                 unsigned long pending = sh->evtchn_pending[i]
1101                         & ~sh->evtchn_mask[i]
1102                         & cpu_evtchn[i];
1103                 printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
1104                        pending, i % 8 == 0 ? "\n   " : " ");
1105         }
1106
1107         printk("\npending list:\n");
1108         for (i = 0; i < NR_EVENT_CHANNELS; i++) {
1109                 if (sync_test_bit(i, sh->evtchn_pending)) {
1110                         int word_idx = i / BITS_PER_LONG;
1111                         printk("  %d: event %d -> irq %d%s%s%s\n",
1112                                cpu_from_evtchn(i), i,
1113                                evtchn_to_irq[i],
1114                                sync_test_bit(word_idx, &v->evtchn_pending_sel)
1115                                              ? "" : " l2-clear",
1116                                !sync_test_bit(i, sh->evtchn_mask)
1117                                              ? "" : " globally-masked",
1118                                sync_test_bit(i, cpu_evtchn)
1119                                              ? "" : " locally-masked");
1120                 }
1121         }
1122
1123         spin_unlock_irqrestore(&debug_lock, flags);
1124
1125         return IRQ_HANDLED;
1126 }
1127
1128 static DEFINE_PER_CPU(unsigned, xed_nesting_count);
1129 static DEFINE_PER_CPU(unsigned int, current_word_idx);
1130 static DEFINE_PER_CPU(unsigned int, current_bit_idx);
1131
1132 /*
1133  * Mask out the i least significant bits of w
1134  */
1135 #define MASK_LSBS(w, i) (w & ((~0UL) << i))
1136
1137 /*
1138  * Search the CPUs pending events bitmasks.  For each one found, map
1139  * the event number to an irq, and feed it into do_IRQ() for
1140  * handling.
1141  *
1142  * Xen uses a two-level bitmap to speed searching.  The first level is
1143  * a bitset of words which contain pending event bits.  The second
1144  * level is a bitset of pending events themselves.
1145  */
1146 static void __xen_evtchn_do_upcall(void)
1147 {
1148         int start_word_idx, start_bit_idx;
1149         int word_idx, bit_idx;
1150         int i;
1151         int cpu = get_cpu();
1152         struct shared_info *s = HYPERVISOR_shared_info;
1153         struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1154         unsigned count;
1155
1156         do {
1157                 unsigned long pending_words;
1158
1159                 vcpu_info->evtchn_upcall_pending = 0;
1160
1161                 if (__this_cpu_inc_return(xed_nesting_count) - 1)
1162                         goto out;
1163
1164 #ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
1165                 /* Clear master flag /before/ clearing selector flag. */
1166                 wmb();
1167 #endif
1168                 pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
1169
1170                 start_word_idx = __this_cpu_read(current_word_idx);
1171                 start_bit_idx = __this_cpu_read(current_bit_idx);
1172
1173                 word_idx = start_word_idx;
1174
1175                 for (i = 0; pending_words != 0; i++) {
1176                         unsigned long pending_bits;
1177                         unsigned long words;
1178
1179                         words = MASK_LSBS(pending_words, word_idx);
1180
1181                         /*
1182                          * If we masked out all events, wrap to beginning.
1183                          */
1184                         if (words == 0) {
1185                                 word_idx = 0;
1186                                 bit_idx = 0;
1187                                 continue;
1188                         }
1189                         word_idx = __ffs(words);
1190
1191                         pending_bits = active_evtchns(cpu, s, word_idx);
1192                         bit_idx = 0; /* usually scan entire word from start */
1193                         if (word_idx == start_word_idx) {
1194                                 /* We scan the starting word in two parts */
1195                                 if (i == 0)
1196                                         /* 1st time: start in the middle */
1197                                         bit_idx = start_bit_idx;
1198                                 else
1199                                         /* 2nd time: mask bits done already */
1200                                         bit_idx &= (1UL << start_bit_idx) - 1;
1201                         }
1202
1203                         do {
1204                                 unsigned long bits;
1205                                 int port, irq;
1206                                 struct irq_desc *desc;
1207
1208                                 bits = MASK_LSBS(pending_bits, bit_idx);
1209
1210                                 /* If we masked out all events, move on. */
1211                                 if (bits == 0)
1212                                         break;
1213
1214                                 bit_idx = __ffs(bits);
1215
1216                                 /* Process port. */
1217                                 port = (word_idx * BITS_PER_LONG) + bit_idx;
1218                                 irq = evtchn_to_irq[port];
1219
1220                                 if (irq != -1) {
1221                                         desc = irq_to_desc(irq);
1222                                         if (desc)
1223                                                 generic_handle_irq_desc(irq, desc);
1224                                 }
1225
1226                                 bit_idx = (bit_idx + 1) % BITS_PER_LONG;
1227
1228                                 /* Next caller starts at last processed + 1 */
1229                                 __this_cpu_write(current_word_idx,
1230                                                  bit_idx ? word_idx :
1231                                                  (word_idx+1) % BITS_PER_LONG);
1232                                 __this_cpu_write(current_bit_idx, bit_idx);
1233                         } while (bit_idx != 0);
1234
1235                         /* Scan start_l1i twice; all others once. */
1236                         if ((word_idx != start_word_idx) || (i != 0))
1237                                 pending_words &= ~(1UL << word_idx);
1238
1239                         word_idx = (word_idx + 1) % BITS_PER_LONG;
1240                 }
1241
1242                 BUG_ON(!irqs_disabled());
1243
1244                 count = __this_cpu_read(xed_nesting_count);
1245                 __this_cpu_write(xed_nesting_count, 0);
1246         } while (count != 1 || vcpu_info->evtchn_upcall_pending);
1247
1248 out:
1249
1250         put_cpu();
1251 }
1252
1253 void xen_evtchn_do_upcall(struct pt_regs *regs)
1254 {
1255         struct pt_regs *old_regs = set_irq_regs(regs);
1256
1257         exit_idle();
1258         irq_enter();
1259
1260         __xen_evtchn_do_upcall();
1261
1262         irq_exit();
1263         set_irq_regs(old_regs);
1264 }
1265
1266 void xen_hvm_evtchn_do_upcall(void)
1267 {
1268         __xen_evtchn_do_upcall();
1269 }
1270 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1271
1272 /* Rebind a new event channel to an existing irq. */
1273 void rebind_evtchn_irq(int evtchn, int irq)
1274 {
1275         struct irq_info *info = info_for_irq(irq);
1276
1277         /* Make sure the irq is masked, since the new event channel
1278            will also be masked. */
1279         disable_irq(irq);
1280
1281         spin_lock(&irq_mapping_update_lock);
1282
1283         /* After resume the irq<->evtchn mappings are all cleared out */
1284         BUG_ON(evtchn_to_irq[evtchn] != -1);
1285         /* Expect irq to have been bound before,
1286            so there should be a proper type */
1287         BUG_ON(info->type == IRQT_UNBOUND);
1288
1289         xen_irq_info_evtchn_init(irq, evtchn);
1290
1291         spin_unlock(&irq_mapping_update_lock);
1292
1293         /* new event channels are always bound to cpu 0 */
1294         irq_set_affinity(irq, cpumask_of(0));
1295
1296         /* Unmask the event channel. */
1297         enable_irq(irq);
1298 }
1299
1300 /* Rebind an evtchn so that it gets delivered to a specific cpu */
1301 static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
1302 {
1303         struct evtchn_bind_vcpu bind_vcpu;
1304         int evtchn = evtchn_from_irq(irq);
1305
1306         if (!VALID_EVTCHN(evtchn))
1307                 return -1;
1308
1309         /*
1310          * Events delivered via platform PCI interrupts are always
1311          * routed to vcpu 0 and hence cannot be rebound.
1312          */
1313         if (xen_hvm_domain() && !xen_have_vector_callback)
1314                 return -1;
1315
1316         /* Send future instances of this interrupt to other vcpu. */
1317         bind_vcpu.port = evtchn;
1318         bind_vcpu.vcpu = tcpu;
1319
1320         /*
1321          * If this fails, it usually just indicates that we're dealing with a
1322          * virq or IPI channel, which don't actually need to be rebound. Ignore
1323          * it, but don't do the xenlinux-level rebind in that case.
1324          */
1325         if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1326                 bind_evtchn_to_cpu(evtchn, tcpu);
1327
1328         return 0;
1329 }
1330
1331 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1332                             bool force)
1333 {
1334         unsigned tcpu = cpumask_first(dest);
1335
1336         return rebind_irq_to_cpu(data->irq, tcpu);
1337 }
1338
1339 int resend_irq_on_evtchn(unsigned int irq)
1340 {
1341         int masked, evtchn = evtchn_from_irq(irq);
1342         struct shared_info *s = HYPERVISOR_shared_info;
1343
1344         if (!VALID_EVTCHN(evtchn))
1345                 return 1;
1346
1347         masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
1348         sync_set_bit(evtchn, s->evtchn_pending);
1349         if (!masked)
1350                 unmask_evtchn(evtchn);
1351
1352         return 1;
1353 }
1354
1355 static void enable_dynirq(struct irq_data *data)
1356 {
1357         int evtchn = evtchn_from_irq(data->irq);
1358
1359         if (VALID_EVTCHN(evtchn))
1360                 unmask_evtchn(evtchn);
1361 }
1362
1363 static void disable_dynirq(struct irq_data *data)
1364 {
1365         int evtchn = evtchn_from_irq(data->irq);
1366
1367         if (VALID_EVTCHN(evtchn))
1368                 mask_evtchn(evtchn);
1369 }
1370
1371 static void ack_dynirq(struct irq_data *data)
1372 {
1373         int evtchn = evtchn_from_irq(data->irq);
1374
1375         irq_move_irq(data);
1376
1377         if (VALID_EVTCHN(evtchn))
1378                 clear_evtchn(evtchn);
1379 }
1380
1381 static void mask_ack_dynirq(struct irq_data *data)
1382 {
1383         disable_dynirq(data);
1384         ack_dynirq(data);
1385 }
1386
1387 static int retrigger_dynirq(struct irq_data *data)
1388 {
1389         int evtchn = evtchn_from_irq(data->irq);
1390         struct shared_info *sh = HYPERVISOR_shared_info;
1391         int ret = 0;
1392
1393         if (VALID_EVTCHN(evtchn)) {
1394                 int masked;
1395
1396                 masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
1397                 sync_set_bit(evtchn, sh->evtchn_pending);
1398                 if (!masked)
1399                         unmask_evtchn(evtchn);
1400                 ret = 1;
1401         }
1402
1403         return ret;
1404 }
1405
1406 static void restore_pirqs(void)
1407 {
1408         int pirq, rc, irq, gsi;
1409         struct physdev_map_pirq map_irq;
1410         struct irq_info *info;
1411
1412         list_for_each_entry(info, &xen_irq_list_head, list) {
1413                 if (info->type != IRQT_PIRQ)
1414                         continue;
1415
1416                 pirq = info->u.pirq.pirq;
1417                 gsi = info->u.pirq.gsi;
1418                 irq = info->irq;
1419
1420                 /* save/restore of PT devices doesn't work, so at this point the
1421                  * only devices present are GSI based emulated devices */
1422                 if (!gsi)
1423                         continue;
1424
1425                 map_irq.domid = DOMID_SELF;
1426                 map_irq.type = MAP_PIRQ_TYPE_GSI;
1427                 map_irq.index = gsi;
1428                 map_irq.pirq = pirq;
1429
1430                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1431                 if (rc) {
1432                         printk(KERN_WARNING "xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1433                                         gsi, irq, pirq, rc);
1434                         xen_free_irq(irq);
1435                         continue;
1436                 }
1437
1438                 printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1439
1440                 __startup_pirq(irq);
1441         }
1442 }
1443
1444 static void restore_cpu_virqs(unsigned int cpu)
1445 {
1446         struct evtchn_bind_virq bind_virq;
1447         int virq, irq, evtchn;
1448
1449         for (virq = 0; virq < NR_VIRQS; virq++) {
1450                 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1451                         continue;
1452
1453                 BUG_ON(virq_from_irq(irq) != virq);
1454
1455                 /* Get a new binding from Xen. */
1456                 bind_virq.virq = virq;
1457                 bind_virq.vcpu = cpu;
1458                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1459                                                 &bind_virq) != 0)
1460                         BUG();
1461                 evtchn = bind_virq.port;
1462
1463                 /* Record the new mapping. */
1464                 xen_irq_info_virq_init(cpu, irq, evtchn, virq);
1465                 bind_evtchn_to_cpu(evtchn, cpu);
1466         }
1467 }
1468
1469 static void restore_cpu_ipis(unsigned int cpu)
1470 {
1471         struct evtchn_bind_ipi bind_ipi;
1472         int ipi, irq, evtchn;
1473
1474         for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1475                 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1476                         continue;
1477
1478                 BUG_ON(ipi_from_irq(irq) != ipi);
1479
1480                 /* Get a new binding from Xen. */
1481                 bind_ipi.vcpu = cpu;
1482                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1483                                                 &bind_ipi) != 0)
1484                         BUG();
1485                 evtchn = bind_ipi.port;
1486
1487                 /* Record the new mapping. */
1488                 xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
1489                 bind_evtchn_to_cpu(evtchn, cpu);
1490         }
1491 }
1492
1493 /* Clear an irq's pending state, in preparation for polling on it */
1494 void xen_clear_irq_pending(int irq)
1495 {
1496         int evtchn = evtchn_from_irq(irq);
1497
1498         if (VALID_EVTCHN(evtchn))
1499                 clear_evtchn(evtchn);
1500 }
1501 EXPORT_SYMBOL(xen_clear_irq_pending);
1502 void xen_set_irq_pending(int irq)
1503 {
1504         int evtchn = evtchn_from_irq(irq);
1505
1506         if (VALID_EVTCHN(evtchn))
1507                 set_evtchn(evtchn);
1508 }
1509
1510 bool xen_test_irq_pending(int irq)
1511 {
1512         int evtchn = evtchn_from_irq(irq);
1513         bool ret = false;
1514
1515         if (VALID_EVTCHN(evtchn))
1516                 ret = test_evtchn(evtchn);
1517
1518         return ret;
1519 }
1520
1521 /* Poll waiting for an irq to become pending with timeout.  In the usual case,
1522  * the irq will be disabled so it won't deliver an interrupt. */
1523 void xen_poll_irq_timeout(int irq, u64 timeout)
1524 {
1525         evtchn_port_t evtchn = evtchn_from_irq(irq);
1526
1527         if (VALID_EVTCHN(evtchn)) {
1528                 struct sched_poll poll;
1529
1530                 poll.nr_ports = 1;
1531                 poll.timeout = timeout;
1532                 set_xen_guest_handle(poll.ports, &evtchn);
1533
1534                 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1535                         BUG();
1536         }
1537 }
1538 EXPORT_SYMBOL(xen_poll_irq_timeout);
1539 /* Poll waiting for an irq to become pending.  In the usual case, the
1540  * irq will be disabled so it won't deliver an interrupt. */
1541 void xen_poll_irq(int irq)
1542 {
1543         xen_poll_irq_timeout(irq, 0 /* no timeout */);
1544 }
1545
1546 /* Check whether the IRQ line is shared with other guests. */
1547 int xen_test_irq_shared(int irq)
1548 {
1549         struct irq_info *info = info_for_irq(irq);
1550         struct physdev_irq_status_query irq_status = { .irq = info->u.pirq.pirq };
1551
1552         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
1553                 return 0;
1554         return !(irq_status.flags & XENIRQSTAT_shared);
1555 }
1556 EXPORT_SYMBOL_GPL(xen_test_irq_shared);
1557
1558 void xen_irq_resume(void)
1559 {
1560         unsigned int cpu, evtchn;
1561         struct irq_info *info;
1562
1563         init_evtchn_cpu_bindings();
1564
1565         /* New event-channel space is not 'live' yet. */
1566         for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1567                 mask_evtchn(evtchn);
1568
1569         /* No IRQ <-> event-channel mappings. */
1570         list_for_each_entry(info, &xen_irq_list_head, list)
1571                 info->evtchn = 0; /* zap event-channel binding */
1572
1573         for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1574                 evtchn_to_irq[evtchn] = -1;
1575
1576         for_each_possible_cpu(cpu) {
1577                 restore_cpu_virqs(cpu);
1578                 restore_cpu_ipis(cpu);
1579         }
1580
1581         restore_pirqs();
1582 }
1583
1584 static struct irq_chip xen_dynamic_chip __read_mostly = {
1585         .name                   = "xen-dyn",
1586
1587         .irq_disable            = disable_dynirq,
1588         .irq_mask               = disable_dynirq,
1589         .irq_unmask             = enable_dynirq,
1590
1591         .irq_ack                = ack_dynirq,
1592         .irq_mask_ack           = mask_ack_dynirq,
1593
1594         .irq_set_affinity       = set_affinity_irq,
1595         .irq_retrigger          = retrigger_dynirq,
1596 };
1597
1598 static struct irq_chip xen_pirq_chip __read_mostly = {
1599         .name                   = "xen-pirq",
1600
1601         .irq_startup            = startup_pirq,
1602         .irq_shutdown           = shutdown_pirq,
1603         .irq_enable             = enable_pirq,
1604         .irq_disable            = disable_pirq,
1605
1606         .irq_mask               = disable_dynirq,
1607         .irq_unmask             = enable_dynirq,
1608
1609         .irq_ack                = eoi_pirq,
1610         .irq_eoi                = eoi_pirq,
1611         .irq_mask_ack           = mask_ack_pirq,
1612
1613         .irq_set_affinity       = set_affinity_irq,
1614
1615         .irq_retrigger          = retrigger_dynirq,
1616 };
1617
1618 static struct irq_chip xen_percpu_chip __read_mostly = {
1619         .name                   = "xen-percpu",
1620
1621         .irq_disable            = disable_dynirq,
1622         .irq_mask               = disable_dynirq,
1623         .irq_unmask             = enable_dynirq,
1624
1625         .irq_ack                = ack_dynirq,
1626 };
1627
1628 int xen_set_callback_via(uint64_t via)
1629 {
1630         struct xen_hvm_param a;
1631         a.domid = DOMID_SELF;
1632         a.index = HVM_PARAM_CALLBACK_IRQ;
1633         a.value = via;
1634         return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1635 }
1636 EXPORT_SYMBOL_GPL(xen_set_callback_via);
1637
1638 #ifdef CONFIG_XEN_PVHVM
1639 /* Vector callbacks are better than PCI interrupts to receive event
1640  * channel notifications because we can receive vector callbacks on any
1641  * vcpu and we don't need PCI support or APIC interactions. */
1642 void xen_callback_vector(void)
1643 {
1644         int rc;
1645         uint64_t callback_via;
1646         if (xen_have_vector_callback) {
1647                 callback_via = HVM_CALLBACK_VECTOR(XEN_HVM_EVTCHN_CALLBACK);
1648                 rc = xen_set_callback_via(callback_via);
1649                 if (rc) {
1650                         printk(KERN_ERR "Request for Xen HVM callback vector"
1651                                         " failed.\n");
1652                         xen_have_vector_callback = 0;
1653                         return;
1654                 }
1655                 printk(KERN_INFO "Xen HVM callback vector for event delivery is "
1656                                 "enabled\n");
1657                 /* in the restore case the vector has already been allocated */
1658                 if (!test_bit(XEN_HVM_EVTCHN_CALLBACK, used_vectors))
1659                         alloc_intr_gate(XEN_HVM_EVTCHN_CALLBACK, xen_hvm_callback_vector);
1660         }
1661 }
1662 #else
1663 void xen_callback_vector(void) {}
1664 #endif
1665
1666 void __init xen_init_IRQ(void)
1667 {
1668         int i;
1669
1670         evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
1671                                     GFP_KERNEL);
1672         for (i = 0; i < NR_EVENT_CHANNELS; i++)
1673                 evtchn_to_irq[i] = -1;
1674
1675         init_evtchn_cpu_bindings();
1676
1677         /* No event channels are 'live' right now. */
1678         for (i = 0; i < NR_EVENT_CHANNELS; i++)
1679                 mask_evtchn(i);
1680
1681         if (xen_hvm_domain()) {
1682                 xen_callback_vector();
1683                 native_init_IRQ();
1684                 /* pci_xen_hvm_init must be called after native_init_IRQ so that
1685                  * __acpi_register_gsi can point at the right function */
1686                 pci_xen_hvm_init();
1687         } else {
1688                 irq_ctx_init(smp_processor_id());
1689                 if (xen_initial_domain())
1690                         pci_xen_initial_domain();
1691         }
1692 }