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 {
  90         struct list_head list;
  91         enum xen_irq_type type; /* type */
  92         unsigned irq;
  93         unsigned short evtchn;  /* event channel */
  94         unsigned short cpu;     /* cpu bound */
  95
  96         union {
  97                 unsigned short virq;
  98                 enum ipi_vector ipi;
  99                 struct {
 100                         unsigned short pirq;
 101                         unsigned short gsi;
 102                         unsigned char vector;
 103                         unsigned char flags;
 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
 122 /* Get info for IRQ */
 123 static struct irq_info *info_for_irq(unsigned irq)
 124 {
 125         return irq_get_handler_data(irq);
 126 }
 127
 128 /* Constructors for packed IRQ information. */
 129 static void xen_irq_info_common_init(struct irq_info *info,
 130                                      unsigned irq,
 131                                      enum xen_irq_type type,
 132                                      unsigned short evtchn,
 133                                      unsigned short cpu)
 134 {
 135
 136         BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
 137
 138         info->type = type;
 139         info->irq = irq;
 140         info->evtchn = evtchn;
 141         info->cpu = cpu;
 142
 143         evtchn_to_irq[evtchn] = irq;
 144 }
 145
 146 static void xen_irq_info_evtchn_init(unsigned irq,
 147                                      unsigned short evtchn)
 148 {
 149         struct irq_info *info = info_for_irq(irq);
 150
 151         xen_irq_info_common_init(info, irq, IRQT_EVTCHN, evtchn, 0);
 152 }
 153
 154 static void xen_irq_info_ipi_init(unsigned cpu,
 155                                   unsigned irq,
 156                                   unsigned short evtchn,
 157                                   enum ipi_vector ipi)
 158 {
 159         struct irq_info *info = info_for_irq(irq);
 160
 161         xen_irq_info_common_init(info, irq, IRQT_IPI, evtchn, 0);
 162
 163         info->u.ipi = ipi;
 164
 165         per_cpu(ipi_to_irq, cpu)[ipi] = irq;
 166 }
 167
 168 static void xen_irq_info_virq_init(unsigned cpu,
 169                                    unsigned irq,
 170                                    unsigned short evtchn,
 171                                    unsigned short virq)
 172 {
 173         struct irq_info *info = info_for_irq(irq);
 174
 175         xen_irq_info_common_init(info, irq, IRQT_VIRQ, evtchn, 0);
 176
 177         info->u.virq = virq;
 178
 179         per_cpu(virq_to_irq, cpu)[virq] = irq;
 180 }
 181
 182 static void xen_irq_info_pirq_init(unsigned irq,
 183                                    unsigned short evtchn,
 184                                    unsigned short pirq,
 185                                    unsigned short gsi,
 186                                    unsigned short vector,
 187                                    unsigned char flags)
 188 {
 189         struct irq_info *info = info_for_irq(irq);
 190
 191         xen_irq_info_common_init(info, irq, IRQT_PIRQ, evtchn, 0);
 192
 193         info->u.pirq.pirq = pirq;
 194         info->u.pirq.gsi = gsi;
 195         info->u.pirq.vector = vector;
 196         info->u.pirq.flags = flags;
 197 }
 198
 199 /*
 200  * Accessors for packed IRQ information.
 201  */
 202 static unsigned int evtchn_from_irq(unsigned irq)
 203 {
 204         if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))
 205                 return 0;
 206
 207         return info_for_irq(irq)->evtchn;
 208 }
 209
 210 unsigned irq_from_evtchn(unsigned int evtchn)
 211 {
 212         return evtchn_to_irq[evtchn];
 213 }
 214 EXPORT_SYMBOL_GPL(irq_from_evtchn);
 215
 216 static enum ipi_vector ipi_from_irq(unsigned irq)
 217 {
 218         struct irq_info *info = info_for_irq(irq);
 219
 220         BUG_ON(info == NULL);
 221         BUG_ON(info->type != IRQT_IPI);
 222
 223         return info->u.ipi;
 224 }
 225
 226 static unsigned virq_from_irq(unsigned irq)
 227 {
 228         struct irq_info *info = info_for_irq(irq);
 229
 230         BUG_ON(info == NULL);
 231         BUG_ON(info->type != IRQT_VIRQ);
 232
 233         return info->u.virq;
 234 }
 235
 236 static unsigned pirq_from_irq(unsigned irq)
 237 {
 238         struct irq_info *info = info_for_irq(irq);
 239
 240         BUG_ON(info == NULL);
 241         BUG_ON(info->type != IRQT_PIRQ);
 242
 243         return info->u.pirq.pirq;
 244 }
 245
 246 static enum xen_irq_type type_from_irq(unsigned irq)
 247 {
 248         return info_for_irq(irq)->type;
 249 }
 250
 251 static unsigned cpu_from_irq(unsigned irq)
 252 {
 253         return info_for_irq(irq)->cpu;
 254 }
 255
 256 static unsigned int cpu_from_evtchn(unsigned int evtchn)
 257 {
 258         int irq = evtchn_to_irq[evtchn];
 259         unsigned ret = 0;
 260
 261         if (irq != -1)
 262                 ret = cpu_from_irq(irq);
 263
 264         return ret;
 265 }
 266
 267 static bool pirq_needs_eoi(unsigned irq)
 268 {
 269         struct irq_info *info = info_for_irq(irq);
 270
 271         BUG_ON(info->type != IRQT_PIRQ);
 272
 273         return info->u.pirq.flags & PIRQ_NEEDS_EOI;
 274 }
 275
 276 static inline unsigned long active_evtchns(unsigned int cpu,
 277                                            struct shared_info *sh,
 278                                            unsigned int idx)
 279 {
 280         return (sh->evtchn_pending[idx] &
 281                 per_cpu(cpu_evtchn_mask, cpu)[idx] &
 282                 ~sh->evtchn_mask[idx]);
 283 }
 284
 285 static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
 286 {
 287         int irq = evtchn_to_irq[chn];
 288
 289         BUG_ON(irq == -1);
 290 #ifdef CONFIG_SMP
 291         cpumask_copy(irq_to_desc(irq)->irq_data.affinity, cpumask_of(cpu));
 292 #endif
 293
 294         clear_bit(chn, per_cpu(cpu_evtchn_mask, cpu_from_irq(irq)));
 295         set_bit(chn, per_cpu(cpu_evtchn_mask, cpu));
 296
 297         info_for_irq(irq)->cpu = cpu;
 298 }
 299
 300 static void init_evtchn_cpu_bindings(void)
 301 {
 302         int i;
 303 #ifdef CONFIG_SMP
 304         struct irq_info *info;
 305
 306         /* By default all event channels notify CPU#0. */
 307         list_for_each_entry(info, &xen_irq_list_head, list) {
 308                 struct irq_desc *desc = irq_to_desc(info->irq);
 309                 cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
 310         }
 311 #endif
 312
 313         for_each_possible_cpu(i)
 314                 memset(per_cpu(cpu_evtchn_mask, i),
 315                        (i == 0) ? ~0 : 0, sizeof(*per_cpu(cpu_evtchn_mask, i)));
 316 }
 317
 318 static inline void clear_evtchn(int port)
 319 {
 320         struct shared_info *s = HYPERVISOR_shared_info;
 321         sync_clear_bit(port, &s->evtchn_pending[0]);
 322 }
 323
 324 static inline void set_evtchn(int port)
 325 {
 326         struct shared_info *s = HYPERVISOR_shared_info;
 327         sync_set_bit(port, &s->evtchn_pending[0]);
 328 }
 329
 330 static inline int test_evtchn(int port)
 331 {
 332         struct shared_info *s = HYPERVISOR_shared_info;
 333         return sync_test_bit(port, &s->evtchn_pending[0]);
 334 }
 335
 336
 337 /**
 338  * notify_remote_via_irq - send event to remote end of event channel via irq
 339  * @irq: irq of event channel to send event to
 340  *
 341  * Unlike notify_remote_via_evtchn(), this is safe to use across
 342  * save/restore. Notifications on a broken connection are silently
 343  * dropped.
 344  */
 345 void notify_remote_via_irq(int irq)
 346 {
 347         int evtchn = evtchn_from_irq(irq);
 348
 349         if (VALID_EVTCHN(evtchn))
 350                 notify_remote_via_evtchn(evtchn);
 351 }
 352 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
 353
 354 static void mask_evtchn(int port)
 355 {
 356         struct shared_info *s = HYPERVISOR_shared_info;
 357         sync_set_bit(port, &s->evtchn_mask[0]);
 358 }
 359
 360 static void unmask_evtchn(int port)
 361 {
 362         struct shared_info *s = HYPERVISOR_shared_info;
 363         unsigned int cpu = get_cpu();
 364
 365         BUG_ON(!irqs_disabled());
 366
 367         /* Slow path (hypercall) if this is a non-local port. */
 368         if (unlikely(cpu != cpu_from_evtchn(port))) {
 369                 struct evtchn_unmask unmask = { .port = port };
 370                 (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
 371         } else {
 372                 struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
 373
 374                 sync_clear_bit(port, &s->evtchn_mask[0]);
 375
 376                 /*
 377                  * The following is basically the equivalent of
 378                  * 'hw_resend_irq'. Just like a real IO-APIC we 'lose
 379                  * the interrupt edge' if the channel is masked.
 380                  */
 381                 if (sync_test_bit(port, &s->evtchn_pending[0]) &&
 382                     !sync_test_and_set_bit(port / BITS_PER_LONG,
 383                                            &vcpu_info->evtchn_pending_sel))
 384                         vcpu_info->evtchn_upcall_pending = 1;
 385         }
 386
 387         put_cpu();
 388 }
 389
 390 static void xen_irq_init(unsigned irq)
 391 {
 392         struct irq_info *info;
 393         struct irq_desc *desc = irq_to_desc(irq);
 394
 395 #ifdef CONFIG_SMP
 396         /* By default all event channels notify CPU#0. */
 397         cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
 398 #endif
 399
 400         info = kzalloc(sizeof(*info), GFP_KERNEL);
 401         if (info == NULL)
 402                 panic("Unable to allocate metadata for IRQ%d\n", irq);
 403
 404         info->type = IRQT_UNBOUND;
 405
 406         irq_set_handler_data(irq, info);
 407
 408         list_add_tail(&info->list, &xen_irq_list_head);
 409 }
 410
 411 static int __must_check xen_allocate_irq_dynamic(void)
 412 {
 413         int first = 0;
 414         int irq;
 415
 416 #ifdef CONFIG_X86_IO_APIC
 417         /*
 418          * For an HVM guest or domain 0 which see "real" (emulated or
 419          * actual respectively) GSIs we allocate dynamic IRQs
 420          * e.g. those corresponding to event channels or MSIs
 421          * etc. from the range above those "real" GSIs to avoid
 422          * collisions.
 423          */
 424         if (xen_initial_domain() || xen_hvm_domain())
 425                 first = get_nr_irqs_gsi();
 426 #endif
 427
 428         irq = irq_alloc_desc_from(first, -1);
 429
 430         xen_irq_init(irq);
 431
 432         return irq;
 433 }
 434
 435 static int __must_check xen_allocate_irq_gsi(unsigned gsi)
 436 {
 437         int irq;
 438
 439         /*
 440          * A PV guest has no concept of a GSI (since it has no ACPI
 441          * nor access to/knowledge of the physical APICs). Therefore
 442          * all IRQs are dynamically allocated from the entire IRQ
 443          * space.
 444          */
 445         if (xen_pv_domain() && !xen_initial_domain())
 446                 return xen_allocate_irq_dynamic();
 447
 448         /* Legacy IRQ descriptors are already allocated by the arch. */
 449         if (gsi < NR_IRQS_LEGACY)
 450                 irq = gsi;
 451         else
 452                 irq = irq_alloc_desc_at(gsi, -1);
 453
 454         xen_irq_init(irq);
 455
 456         return irq;
 457 }
 458
 459 static void xen_free_irq(unsigned irq)
 460 {
 461         struct irq_info *info = irq_get_handler_data(irq);
 462
 463         list_del(&info->list);
 464
 465         irq_set_handler_data(irq, NULL);
 466
 467         kfree(info);
 468
 469         /* Legacy IRQ descriptors are managed by the arch. */
 470         if (irq < NR_IRQS_LEGACY)
 471                 return;
 472
 473         irq_free_desc(irq);
 474 }
 475
 476 static void pirq_unmask_notify(int irq)
 477 {
 478         struct physdev_eoi eoi = { .irq = pirq_from_irq(irq) };
 479
 480         if (unlikely(pirq_needs_eoi(irq))) {
 481                 int rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
 482                 WARN_ON(rc);
 483         }
 484 }
 485
 486 static void pirq_query_unmask(int irq)
 487 {
 488         struct physdev_irq_status_query irq_status;
 489         struct irq_info *info = info_for_irq(irq);
 490
 491         BUG_ON(info->type != IRQT_PIRQ);
 492
 493         irq_status.irq = pirq_from_irq(irq);
 494         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
 495                 irq_status.flags = 0;
 496
 497         info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
 498         if (irq_status.flags & XENIRQSTAT_needs_eoi)
 499                 info->u.pirq.flags |= PIRQ_NEEDS_EOI;
 500 }
 501
 502 static bool probing_irq(int irq)
 503 {
 504         struct irq_desc *desc = irq_to_desc(irq);
 505
 506         return desc && desc->action == NULL;
 507 }
 508
 509 static unsigned int __startup_pirq(unsigned int irq)
 510 {
 511         struct evtchn_bind_pirq bind_pirq;
 512         struct irq_info *info = info_for_irq(irq);
 513         int evtchn = evtchn_from_irq(irq);
 514         int rc;
 515
 516         BUG_ON(info->type != IRQT_PIRQ);
 517
 518         if (VALID_EVTCHN(evtchn))
 519                 goto out;
 520
 521         bind_pirq.pirq = pirq_from_irq(irq);
 522         /* NB. We are happy to share unless we are probing. */
 523         bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
 524                                         BIND_PIRQ__WILL_SHARE : 0;
 525         rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
 526         if (rc != 0) {
 527                 if (!probing_irq(irq))
 528                         printk(KERN_INFO "Failed to obtain physical IRQ %d\n",
 529                                irq);
 530                 return 0;
 531         }
 532         evtchn = bind_pirq.port;
 533
 534         pirq_query_unmask(irq);
 535
 536         evtchn_to_irq[evtchn] = irq;
 537         bind_evtchn_to_cpu(evtchn, 0);
 538         info->evtchn = evtchn;
 539
 540 out:
 541         unmask_evtchn(evtchn);
 542         pirq_unmask_notify(irq);
 543
 544         return 0;
 545 }
 546
 547 static unsigned int startup_pirq(struct irq_data *data)
 548 {
 549         return __startup_pirq(data->irq);
 550 }
 551
 552 static void shutdown_pirq(struct irq_data *data)
 553 {
 554         struct evtchn_close close;
 555         unsigned int irq = data->irq;
 556         struct irq_info *info = info_for_irq(irq);
 557         int evtchn = evtchn_from_irq(irq);
 558
 559         BUG_ON(info->type != IRQT_PIRQ);
 560
 561         if (!VALID_EVTCHN(evtchn))
 562                 return;
 563
 564         mask_evtchn(evtchn);
 565
 566         close.port = evtchn;
 567         if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 568                 BUG();
 569
 570         bind_evtchn_to_cpu(evtchn, 0);
 571         evtchn_to_irq[evtchn] = -1;
 572         info->evtchn = 0;
 573 }
 574
 575 static void enable_pirq(struct irq_data *data)
 576 {
 577         startup_pirq(data);
 578 }
 579
 580 static void disable_pirq(struct irq_data *data)
 581 {
 582 }
 583
 584 static void ack_pirq(struct irq_data *data)
 585 {
 586         int evtchn = evtchn_from_irq(data->irq);
 587
 588         irq_move_irq(data);
 589
 590         if (VALID_EVTCHN(evtchn)) {
 591                 mask_evtchn(evtchn);
 592                 clear_evtchn(evtchn);
 593         }
 594 }
 595
 596 static int find_irq_by_gsi(unsigned gsi)
 597 {
 598         struct irq_info *info;
 599
 600         list_for_each_entry(info, &xen_irq_list_head, list) {
 601                 if (info->type != IRQT_PIRQ)
 602                         continue;
 603
 604                 if (info->u.pirq.gsi == gsi)
 605                         return info->irq;
 606         }
 607
 608         return -1;
 609 }
 610
 611 int xen_allocate_pirq_gsi(unsigned gsi)
 612 {
 613         return gsi;
 614 }
 615
 616 /*
 617  * Do not make any assumptions regarding the relationship between the
 618  * IRQ number returned here and the Xen pirq argument.
 619  *
 620  * Note: We don't assign an event channel until the irq actually started
 621  * up.  Return an existing irq if we've already got one for the gsi.
 622  */
 623 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 624                              unsigned pirq, int shareable, char *name)
 625 {
 626         int irq = -1;
 627         struct physdev_irq irq_op;
 628
 629         spin_lock(&irq_mapping_update_lock);
 630
 631         irq = find_irq_by_gsi(gsi);
 632         if (irq != -1) {
 633                 printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n",
 634                        irq, gsi);
 635                 goto out;       /* XXX need refcount? */
 636         }
 637
 638         irq = xen_allocate_irq_gsi(gsi);
 639         if (irq < 0)
 640                 goto out;
 641
 642         irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_level_irq,
 643                                       name);
 644
 645         irq_op.irq = irq;
 646         irq_op.vector = 0;
 647
 648         /* Only the privileged domain can do this. For non-priv, the pcifront
 649          * driver provides a PCI bus that does the call to do exactly
 650          * this in the priv domain. */
 651         if (xen_initial_domain() &&
 652             HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
 653                 xen_free_irq(irq);
 654                 irq = -ENOSPC;
 655                 goto out;
 656         }
 657
 658         xen_irq_info_pirq_init(irq, 0, pirq, gsi, irq_op.vector,
 659                                shareable ? PIRQ_SHAREABLE : 0);
 660
 661 out:
 662         spin_unlock(&irq_mapping_update_lock);
 663
 664         return irq;
 665 }
 666
 667 #ifdef CONFIG_PCI_MSI
 668 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
 669 {
 670         int rc;
 671         struct physdev_get_free_pirq op_get_free_pirq;
 672
 673         op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
 674         rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
 675
 676         WARN_ONCE(rc == -ENOSYS,
 677                   "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
 678
 679         return rc ? -1 : op_get_free_pirq.pirq;
 680 }
 681
 682 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
 683                              int pirq, int vector, const char *name)
 684 {
 685         int irq, ret;
 686
 687         spin_lock(&irq_mapping_update_lock);
 688
 689         irq = xen_allocate_irq_dynamic();
 690         if (irq == -1)
 691                 goto out;
 692
 693         irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_level_irq,
 694                                       name);
 695
 696         xen_irq_info_pirq_init(irq, 0, pirq, 0, vector, 0);
 697         ret = irq_set_msi_desc(irq, msidesc);
 698         if (ret < 0)
 699                 goto error_irq;
 700 out:
 701         spin_unlock(&irq_mapping_update_lock);
 702         return irq;
 703 error_irq:
 704         spin_unlock(&irq_mapping_update_lock);
 705         xen_free_irq(irq);
 706         return -1;
 707 }
 708 #endif
 709
 710 int xen_destroy_irq(int irq)
 711 {
 712         struct irq_desc *desc;
 713         struct physdev_unmap_pirq unmap_irq;
 714         struct irq_info *info = info_for_irq(irq);
 715         int rc = -ENOENT;
 716
 717         spin_lock(&irq_mapping_update_lock);
 718
 719         desc = irq_to_desc(irq);
 720         if (!desc)
 721                 goto out;
 722
 723         if (xen_initial_domain()) {
 724                 unmap_irq.pirq = info->u.pirq.pirq;
 725                 unmap_irq.domid = DOMID_SELF;
 726                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
 727                 if (rc) {
 728                         printk(KERN_WARNING "unmap irq failed %d\n", rc);
 729                         goto out;
 730                 }
 731         }
 732
 733         xen_free_irq(irq);
 734
 735 out:
 736         spin_unlock(&irq_mapping_update_lock);
 737         return rc;
 738 }
 739
 740 int xen_irq_from_pirq(unsigned pirq)
 741 {
 742         int irq;
 743
 744         struct irq_info *info;
 745
 746         spin_lock(&irq_mapping_update_lock);
 747
 748         list_for_each_entry(info, &xen_irq_list_head, list) {
 749                 if (info == NULL || info->type != IRQT_PIRQ)
 750                         continue;
 751                 irq = info->irq;
 752                 if (info->u.pirq.pirq == pirq)
 753                         goto out;
 754         }
 755         irq = -1;
 756 out:
 757         spin_unlock(&irq_mapping_update_lock);
 758
 759         return irq;
 760 }
 761
 762 int bind_evtchn_to_irq(unsigned int evtchn)
 763 {
 764         int irq;
 765
 766         spin_lock(&irq_mapping_update_lock);
 767
 768         irq = evtchn_to_irq[evtchn];
 769
 770         if (irq == -1) {
 771                 irq = xen_allocate_irq_dynamic();
 772                 if (irq == -1)
 773                         goto out;
 774
 775                 irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
 776                                               handle_fasteoi_irq, "event");
 777
 778                 xen_irq_info_evtchn_init(irq, evtchn);
 779         }
 780
 781 out:
 782         spin_unlock(&irq_mapping_update_lock);
 783
 784         return irq;
 785 }
 786 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
 787
 788 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 789 {
 790         struct evtchn_bind_ipi bind_ipi;
 791         int evtchn, irq;
 792
 793         spin_lock(&irq_mapping_update_lock);
 794
 795         irq = per_cpu(ipi_to_irq, cpu)[ipi];
 796
 797         if (irq == -1) {
 798                 irq = xen_allocate_irq_dynamic();
 799                 if (irq < 0)
 800                         goto out;
 801
 802                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 803                                               handle_percpu_irq, "ipi");
 804
 805                 bind_ipi.vcpu = cpu;
 806                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
 807                                                 &bind_ipi) != 0)
 808                         BUG();
 809                 evtchn = bind_ipi.port;
 810
 811                 xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
 812
 813                 bind_evtchn_to_cpu(evtchn, cpu);
 814         }
 815
 816  out:
 817         spin_unlock(&irq_mapping_update_lock);
 818         return irq;
 819 }
 820
 821 static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
 822                                           unsigned int remote_port)
 823 {
 824         struct evtchn_bind_interdomain bind_interdomain;
 825         int err;
 826
 827         bind_interdomain.remote_dom  = remote_domain;
 828         bind_interdomain.remote_port = remote_port;
 829
 830         err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
 831                                           &bind_interdomain);
 832
 833         return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
 834 }
 835
 836
 837 int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 838 {
 839         struct evtchn_bind_virq bind_virq;
 840         int evtchn, irq;
 841
 842         spin_lock(&irq_mapping_update_lock);
 843
 844         irq = per_cpu(virq_to_irq, cpu)[virq];
 845
 846         if (irq == -1) {
 847                 irq = xen_allocate_irq_dynamic();
 848                 if (irq == -1)
 849                         goto out;
 850
 851                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 852                                               handle_percpu_irq, "virq");
 853
 854                 bind_virq.virq = virq;
 855                 bind_virq.vcpu = cpu;
 856                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
 857                                                 &bind_virq) != 0)
 858                         BUG();
 859                 evtchn = bind_virq.port;
 860
 861                 xen_irq_info_virq_init(cpu, irq, evtchn, virq);
 862
 863                 bind_evtchn_to_cpu(evtchn, cpu);
 864         }
 865
 866 out:
 867         spin_unlock(&irq_mapping_update_lock);
 868
 869         return irq;
 870 }
 871
 872 static void unbind_from_irq(unsigned int irq)
 873 {
 874         struct evtchn_close close;
 875         int evtchn = evtchn_from_irq(irq);
 876
 877         spin_lock(&irq_mapping_update_lock);
 878
 879         if (VALID_EVTCHN(evtchn)) {
 880                 close.port = evtchn;
 881                 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 882                         BUG();
 883
 884                 switch (type_from_irq(irq)) {
 885                 case IRQT_VIRQ:
 886                         per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
 887                                 [virq_from_irq(irq)] = -1;
 888                         break;
 889                 case IRQT_IPI:
 890                         per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn))
 891                                 [ipi_from_irq(irq)] = -1;
 892                         break;
 893                 default:
 894                         break;
 895                 }
 896
 897                 /* Closed ports are implicitly re-bound to VCPU0. */
 898                 bind_evtchn_to_cpu(evtchn, 0);
 899
 900                 evtchn_to_irq[evtchn] = -1;
 901         }
 902
 903         BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
 904
 905         xen_free_irq(irq);
 906
 907         spin_unlock(&irq_mapping_update_lock);
 908 }
 909
 910 int bind_evtchn_to_irqhandler(unsigned int evtchn,
 911                               irq_handler_t handler,
 912                               unsigned long irqflags,
 913                               const char *devname, void *dev_id)
 914 {
 915         unsigned int irq;
 916         int retval;
 917
 918         irq = bind_evtchn_to_irq(evtchn);
 919         if (irq < 0)
 920                 return irq;
 921         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 922         if (retval != 0) {
 923                 unbind_from_irq(irq);
 924                 return retval;
 925         }
 926
 927         return irq;
 928 }
 929 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
 930
 931 int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
 932                                           unsigned int remote_port,
 933                                           irq_handler_t handler,
 934                                           unsigned long irqflags,
 935                                           const char *devname,
 936                                           void *dev_id)
 937 {
 938         int irq, retval;
 939
 940         irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
 941         if (irq < 0)
 942                 return irq;
 943
 944         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 945         if (retval != 0) {
 946                 unbind_from_irq(irq);
 947                 return retval;
 948         }
 949
 950         return irq;
 951 }
 952 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
 953
 954 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
 955                             irq_handler_t handler,
 956                             unsigned long irqflags, const char *devname, void *dev_id)
 957 {
 958         unsigned int irq;
 959         int retval;
 960
 961         irq = bind_virq_to_irq(virq, cpu);
 962         if (irq < 0)
 963                 return irq;
 964         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 965         if (retval != 0) {
 966                 unbind_from_irq(irq);
 967                 return retval;
 968         }
 969
 970         return irq;
 971 }
 972 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
 973
 974 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
 975                            unsigned int cpu,
 976                            irq_handler_t handler,
 977                            unsigned long irqflags,
 978                            const char *devname,
 979                            void *dev_id)
 980 {
 981         int irq, retval;
 982
 983         irq = bind_ipi_to_irq(ipi, cpu);
 984         if (irq < 0)
 985                 return irq;
 986
 987         irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME;
 988         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 989         if (retval != 0) {
 990                 unbind_from_irq(irq);
 991                 return retval;
 992         }
 993
 994         return irq;
 995 }
 996
 997 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
 998 {
 999         free_irq(irq, dev_id);
1000         unbind_from_irq(irq);
1001 }
1002 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
1003
1004 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
1005 {
1006         int irq = per_cpu(ipi_to_irq, cpu)[vector];
1007         BUG_ON(irq < 0);
1008         notify_remote_via_irq(irq);
1009 }
1010
1011 irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
1012 {
1013         struct shared_info *sh = HYPERVISOR_shared_info;
1014         int cpu = smp_processor_id();
1015         unsigned long *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu);
1016         int i;
1017         unsigned long flags;
1018         static DEFINE_SPINLOCK(debug_lock);
1019         struct vcpu_info *v;
1020
1021         spin_lock_irqsave(&debug_lock, flags);
1022
1023         printk("\nvcpu %d\n  ", cpu);
1024
1025         for_each_online_cpu(i) {
1026                 int pending;
1027                 v = per_cpu(xen_vcpu, i);
1028                 pending = (get_irq_regs() && i == cpu)
1029                         ? xen_irqs_disabled(get_irq_regs())
1030                         : v->evtchn_upcall_mask;
1031                 printk("%d: masked=%d pending=%d event_sel %0*lx\n  ", i,
1032                        pending, v->evtchn_upcall_pending,
1033                        (int)(sizeof(v->evtchn_pending_sel)*2),
1034                        v->evtchn_pending_sel);
1035         }
1036         v = per_cpu(xen_vcpu, cpu);
1037
1038         printk("\npending:\n   ");
1039         for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
1040                 printk("%0*lx%s", (int)sizeof(sh->evtchn_pending[0])*2,
1041                        sh->evtchn_pending[i],
1042                        i % 8 == 0 ? "\n   " : " ");
1043         printk("\nglobal mask:\n   ");
1044         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
1045                 printk("%0*lx%s",
1046                        (int)(sizeof(sh->evtchn_mask[0])*2),
1047                        sh->evtchn_mask[i],
1048                        i % 8 == 0 ? "\n   " : " ");
1049
1050         printk("\nglobally unmasked:\n   ");
1051         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
1052                 printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
1053                        sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
1054                        i % 8 == 0 ? "\n   " : " ");
1055
1056         printk("\nlocal cpu%d mask:\n   ", cpu);
1057         for (i = (NR_EVENT_CHANNELS/BITS_PER_LONG)-1; i >= 0; i--)
1058                 printk("%0*lx%s", (int)(sizeof(cpu_evtchn[0])*2),
1059                        cpu_evtchn[i],
1060                        i % 8 == 0 ? "\n   " : " ");
1061
1062         printk("\nlocally unmasked:\n   ");
1063         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) {
1064                 unsigned long pending = sh->evtchn_pending[i]
1065                         & ~sh->evtchn_mask[i]
1066                         & cpu_evtchn[i];
1067                 printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
1068                        pending, i % 8 == 0 ? "\n   " : " ");
1069         }
1070
1071         printk("\npending list:\n");
1072         for (i = 0; i < NR_EVENT_CHANNELS; i++) {
1073                 if (sync_test_bit(i, sh->evtchn_pending)) {
1074                         int word_idx = i / BITS_PER_LONG;
1075                         printk("  %d: event %d -> irq %d%s%s%s\n",
1076                                cpu_from_evtchn(i), i,
1077                                evtchn_to_irq[i],
1078                                sync_test_bit(word_idx, &v->evtchn_pending_sel)
1079                                              ? "" : " l2-clear",
1080                                !sync_test_bit(i, sh->evtchn_mask)
1081                                              ? "" : " globally-masked",
1082                                sync_test_bit(i, cpu_evtchn)
1083                                              ? "" : " locally-masked");
1084                 }
1085         }
1086
1087         spin_unlock_irqrestore(&debug_lock, flags);
1088
1089         return IRQ_HANDLED;
1090 }
1091
1092 static DEFINE_PER_CPU(unsigned, xed_nesting_count);
1093 static DEFINE_PER_CPU(unsigned int, current_word_idx);
1094 static DEFINE_PER_CPU(unsigned int, current_bit_idx);
1095
1096 /*
1097  * Mask out the i least significant bits of w
1098  */
1099 #define MASK_LSBS(w, i) (w & ((~0UL) << i))
1100
1101 /*
1102  * Search the CPUs pending events bitmasks.  For each one found, map
1103  * the event number to an irq, and feed it into do_IRQ() for
1104  * handling.
1105  *
1106  * Xen uses a two-level bitmap to speed searching.  The first level is
1107  * a bitset of words which contain pending event bits.  The second
1108  * level is a bitset of pending events themselves.
1109  */
1110 static void __xen_evtchn_do_upcall(void)
1111 {
1112         int start_word_idx, start_bit_idx;
1113         int word_idx, bit_idx;
1114         int i;
1115         int cpu = get_cpu();
1116         struct shared_info *s = HYPERVISOR_shared_info;
1117         struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1118         unsigned count;
1119
1120         do {
1121                 unsigned long pending_words;
1122
1123                 vcpu_info->evtchn_upcall_pending = 0;
1124
1125                 if (__this_cpu_inc_return(xed_nesting_count) - 1)
1126                         goto out;
1127
1128 #ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
1129                 /* Clear master flag /before/ clearing selector flag. */
1130                 wmb();
1131 #endif
1132                 pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
1133
1134                 start_word_idx = __this_cpu_read(current_word_idx);
1135                 start_bit_idx = __this_cpu_read(current_bit_idx);
1136
1137                 word_idx = start_word_idx;
1138
1139                 for (i = 0; pending_words != 0; i++) {
1140                         unsigned long pending_bits;
1141                         unsigned long words;
1142
1143                         words = MASK_LSBS(pending_words, word_idx);
1144
1145                         /*
1146                          * If we masked out all events, wrap to beginning.
1147                          */
1148                         if (words == 0) {
1149                                 word_idx = 0;
1150                                 bit_idx = 0;
1151                                 continue;
1152                         }
1153                         word_idx = __ffs(words);
1154
1155                         pending_bits = active_evtchns(cpu, s, word_idx);
1156                         bit_idx = 0; /* usually scan entire word from start */
1157                         if (word_idx == start_word_idx) {
1158                                 /* We scan the starting word in two parts */
1159                                 if (i == 0)
1160                                         /* 1st time: start in the middle */
1161                                         bit_idx = start_bit_idx;
1162                                 else
1163                                         /* 2nd time: mask bits done already */
1164                                         bit_idx &= (1UL << start_bit_idx) - 1;
1165                         }
1166
1167                         do {
1168                                 unsigned long bits;
1169                                 int port, irq;
1170                                 struct irq_desc *desc;
1171
1172                                 bits = MASK_LSBS(pending_bits, bit_idx);
1173
1174                                 /* If we masked out all events, move on. */
1175                                 if (bits == 0)
1176                                         break;
1177
1178                                 bit_idx = __ffs(bits);
1179
1180                                 /* Process port. */
1181                                 port = (word_idx * BITS_PER_LONG) + bit_idx;
1182                                 irq = evtchn_to_irq[port];
1183
1184                                 mask_evtchn(port);
1185                                 clear_evtchn(port);
1186
1187                                 if (irq != -1) {
1188                                         desc = irq_to_desc(irq);
1189                                         if (desc)
1190                                                 generic_handle_irq_desc(irq, desc);
1191                                 }
1192
1193                                 bit_idx = (bit_idx + 1) % BITS_PER_LONG;
1194
1195                                 /* Next caller starts at last processed + 1 */
1196                                 __this_cpu_write(current_word_idx,
1197                                                  bit_idx ? word_idx :
1198                                                  (word_idx+1) % BITS_PER_LONG);
1199                                 __this_cpu_write(current_bit_idx, bit_idx);
1200                         } while (bit_idx != 0);
1201
1202                         /* Scan start_l1i twice; all others once. */
1203                         if ((word_idx != start_word_idx) || (i != 0))
1204                                 pending_words &= ~(1UL << word_idx);
1205
1206                         word_idx = (word_idx + 1) % BITS_PER_LONG;
1207                 }
1208
1209                 BUG_ON(!irqs_disabled());
1210
1211                 count = __this_cpu_read(xed_nesting_count);
1212                 __this_cpu_write(xed_nesting_count, 0);
1213         } while (count != 1 || vcpu_info->evtchn_upcall_pending);
1214
1215 out:
1216
1217         put_cpu();
1218 }
1219
1220 void xen_evtchn_do_upcall(struct pt_regs *regs)
1221 {
1222         struct pt_regs *old_regs = set_irq_regs(regs);
1223
1224         exit_idle();
1225         irq_enter();
1226
1227         __xen_evtchn_do_upcall();
1228
1229         irq_exit();
1230         set_irq_regs(old_regs);
1231 }
1232
1233 void xen_hvm_evtchn_do_upcall(void)
1234 {
1235         __xen_evtchn_do_upcall();
1236 }
1237 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1238
1239 /* Rebind a new event channel to an existing irq. */
1240 void rebind_evtchn_irq(int evtchn, int irq)
1241 {
1242         struct irq_info *info = info_for_irq(irq);
1243
1244         /* Make sure the irq is masked, since the new event channel
1245            will also be masked. */
1246         disable_irq(irq);
1247
1248         spin_lock(&irq_mapping_update_lock);
1249
1250         /* After resume the irq<->evtchn mappings are all cleared out */
1251         BUG_ON(evtchn_to_irq[evtchn] != -1);
1252         /* Expect irq to have been bound before,
1253            so there should be a proper type */
1254         BUG_ON(info->type == IRQT_UNBOUND);
1255
1256         xen_irq_info_evtchn_init(irq, evtchn);
1257
1258         spin_unlock(&irq_mapping_update_lock);
1259
1260         /* new event channels are always bound to cpu 0 */
1261         irq_set_affinity(irq, cpumask_of(0));
1262
1263         /* Unmask the event channel. */
1264         enable_irq(irq);
1265 }
1266
1267 /* Rebind an evtchn so that it gets delivered to a specific cpu */
1268 static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
1269 {
1270         struct evtchn_bind_vcpu bind_vcpu;
1271         int evtchn = evtchn_from_irq(irq);
1272
1273         if (!VALID_EVTCHN(evtchn))
1274                 return -1;
1275
1276         /*
1277          * Events delivered via platform PCI interrupts are always
1278          * routed to vcpu 0 and hence cannot be rebound.
1279          */
1280         if (xen_hvm_domain() && !xen_have_vector_callback)
1281                 return -1;
1282
1283         /* Send future instances of this interrupt to other vcpu. */
1284         bind_vcpu.port = evtchn;
1285         bind_vcpu.vcpu = tcpu;
1286
1287         /*
1288          * If this fails, it usually just indicates that we're dealing with a
1289          * virq or IPI channel, which don't actually need to be rebound. Ignore
1290          * it, but don't do the xenlinux-level rebind in that case.
1291          */
1292         if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1293                 bind_evtchn_to_cpu(evtchn, tcpu);
1294
1295         return 0;
1296 }
1297
1298 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1299                             bool force)
1300 {
1301         unsigned tcpu = cpumask_first(dest);
1302
1303         return rebind_irq_to_cpu(data->irq, tcpu);
1304 }
1305
1306 int resend_irq_on_evtchn(unsigned int irq)
1307 {
1308         int masked, evtchn = evtchn_from_irq(irq);
1309         struct shared_info *s = HYPERVISOR_shared_info;
1310
1311         if (!VALID_EVTCHN(evtchn))
1312                 return 1;
1313
1314         masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
1315         sync_set_bit(evtchn, s->evtchn_pending);
1316         if (!masked)
1317                 unmask_evtchn(evtchn);
1318
1319         return 1;
1320 }
1321
1322 static void enable_dynirq(struct irq_data *data)
1323 {
1324         int evtchn = evtchn_from_irq(data->irq);
1325
1326         if (VALID_EVTCHN(evtchn))
1327                 unmask_evtchn(evtchn);
1328 }
1329
1330 static void disable_dynirq(struct irq_data *data)
1331 {
1332         int evtchn = evtchn_from_irq(data->irq);
1333
1334         if (VALID_EVTCHN(evtchn))
1335                 mask_evtchn(evtchn);
1336 }
1337
1338 static void ack_dynirq(struct irq_data *data)
1339 {
1340         int evtchn = evtchn_from_irq(data->irq);
1341
1342         irq_move_masked_irq(data);
1343
1344         if (VALID_EVTCHN(evtchn))
1345                 unmask_evtchn(evtchn);
1346 }
1347
1348 static int retrigger_dynirq(struct irq_data *data)
1349 {
1350         int evtchn = evtchn_from_irq(data->irq);
1351         struct shared_info *sh = HYPERVISOR_shared_info;
1352         int ret = 0;
1353
1354         if (VALID_EVTCHN(evtchn)) {
1355                 int masked;
1356
1357                 masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
1358                 sync_set_bit(evtchn, sh->evtchn_pending);
1359                 if (!masked)
1360                         unmask_evtchn(evtchn);
1361                 ret = 1;
1362         }
1363
1364         return ret;
1365 }
1366
1367 static void restore_pirqs(void)
1368 {
1369         int pirq, rc, irq, gsi;
1370         struct physdev_map_pirq map_irq;
1371         struct irq_info *info;
1372
1373         list_for_each_entry(info, &xen_irq_list_head, list) {
1374                 if (info->type != IRQT_PIRQ)
1375                         continue;
1376
1377                 pirq = info->u.pirq.pirq;
1378                 gsi = info->u.pirq.gsi;
1379                 irq = info->irq;
1380
1381                 /* save/restore of PT devices doesn't work, so at this point the
1382                  * only devices present are GSI based emulated devices */
1383                 if (!gsi)
1384                         continue;
1385
1386                 map_irq.domid = DOMID_SELF;
1387                 map_irq.type = MAP_PIRQ_TYPE_GSI;
1388                 map_irq.index = gsi;
1389                 map_irq.pirq = pirq;
1390
1391                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1392                 if (rc) {
1393                         printk(KERN_WARNING "xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1394                                         gsi, irq, pirq, rc);
1395                         xen_free_irq(irq);
1396                         continue;
1397                 }
1398
1399                 printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1400
1401                 __startup_pirq(irq);
1402         }
1403 }
1404
1405 static void restore_cpu_virqs(unsigned int cpu)
1406 {
1407         struct evtchn_bind_virq bind_virq;
1408         int virq, irq, evtchn;
1409
1410         for (virq = 0; virq < NR_VIRQS; virq++) {
1411                 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1412                         continue;
1413
1414                 BUG_ON(virq_from_irq(irq) != virq);
1415
1416                 /* Get a new binding from Xen. */
1417                 bind_virq.virq = virq;
1418                 bind_virq.vcpu = cpu;
1419                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1420                                                 &bind_virq) != 0)
1421                         BUG();
1422                 evtchn = bind_virq.port;
1423
1424                 /* Record the new mapping. */
1425                 xen_irq_info_virq_init(cpu, irq, evtchn, virq);
1426                 bind_evtchn_to_cpu(evtchn, cpu);
1427         }
1428 }
1429
1430 static void restore_cpu_ipis(unsigned int cpu)
1431 {
1432         struct evtchn_bind_ipi bind_ipi;
1433         int ipi, irq, evtchn;
1434
1435         for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1436                 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1437                         continue;
1438
1439                 BUG_ON(ipi_from_irq(irq) != ipi);
1440
1441                 /* Get a new binding from Xen. */
1442                 bind_ipi.vcpu = cpu;
1443                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1444                                                 &bind_ipi) != 0)
1445                         BUG();
1446                 evtchn = bind_ipi.port;
1447
1448                 /* Record the new mapping. */
1449                 xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
1450                 bind_evtchn_to_cpu(evtchn, cpu);
1451         }
1452 }
1453
1454 /* Clear an irq's pending state, in preparation for polling on it */
1455 void xen_clear_irq_pending(int irq)
1456 {
1457         int evtchn = evtchn_from_irq(irq);
1458
1459         if (VALID_EVTCHN(evtchn))
1460                 clear_evtchn(evtchn);
1461 }
1462 EXPORT_SYMBOL(xen_clear_irq_pending);
1463 void xen_set_irq_pending(int irq)
1464 {
1465         int evtchn = evtchn_from_irq(irq);
1466
1467         if (VALID_EVTCHN(evtchn))
1468                 set_evtchn(evtchn);
1469 }
1470
1471 bool xen_test_irq_pending(int irq)
1472 {
1473         int evtchn = evtchn_from_irq(irq);
1474         bool ret = false;
1475
1476         if (VALID_EVTCHN(evtchn))
1477                 ret = test_evtchn(evtchn);
1478
1479         return ret;
1480 }
1481
1482 /* Poll waiting for an irq to become pending with timeout.  In the usual case,
1483  * the irq will be disabled so it won't deliver an interrupt. */
1484 void xen_poll_irq_timeout(int irq, u64 timeout)
1485 {
1486         evtchn_port_t evtchn = evtchn_from_irq(irq);
1487
1488         if (VALID_EVTCHN(evtchn)) {
1489                 struct sched_poll poll;
1490
1491                 poll.nr_ports = 1;
1492                 poll.timeout = timeout;
1493                 set_xen_guest_handle(poll.ports, &evtchn);
1494
1495                 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1496                         BUG();
1497         }
1498 }
1499 EXPORT_SYMBOL(xen_poll_irq_timeout);
1500 /* Poll waiting for an irq to become pending.  In the usual case, the
1501  * irq will be disabled so it won't deliver an interrupt. */
1502 void xen_poll_irq(int irq)
1503 {
1504         xen_poll_irq_timeout(irq, 0 /* no timeout */);
1505 }
1506
1507 void xen_irq_resume(void)
1508 {
1509         unsigned int cpu, evtchn;
1510         struct irq_info *info;
1511
1512         init_evtchn_cpu_bindings();
1513
1514         /* New event-channel space is not 'live' yet. */
1515         for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1516                 mask_evtchn(evtchn);
1517
1518         /* No IRQ <-> event-channel mappings. */
1519         list_for_each_entry(info, &xen_irq_list_head, list)
1520                 info->evtchn = 0; /* zap event-channel binding */
1521
1522         for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1523                 evtchn_to_irq[evtchn] = -1;
1524
1525         for_each_possible_cpu(cpu) {
1526                 restore_cpu_virqs(cpu);
1527                 restore_cpu_ipis(cpu);
1528         }
1529
1530         restore_pirqs();
1531 }
1532
1533 static struct irq_chip xen_dynamic_chip __read_mostly = {
1534         .name                   = "xen-dyn",
1535
1536         .irq_disable            = disable_dynirq,
1537         .irq_mask               = disable_dynirq,
1538         .irq_unmask             = enable_dynirq,
1539
1540         .irq_eoi                = ack_dynirq,
1541         .irq_set_affinity       = set_affinity_irq,
1542         .irq_retrigger          = retrigger_dynirq,
1543 };
1544
1545 static struct irq_chip xen_pirq_chip __read_mostly = {
1546         .name                   = "xen-pirq",
1547
1548         .irq_startup            = startup_pirq,
1549         .irq_shutdown           = shutdown_pirq,
1550
1551         .irq_enable             = enable_pirq,
1552         .irq_unmask             = enable_pirq,
1553
1554         .irq_disable            = disable_pirq,
1555         .irq_mask               = disable_pirq,
1556
1557         .irq_ack                = ack_pirq,
1558
1559         .irq_set_affinity       = set_affinity_irq,
1560
1561         .irq_retrigger          = retrigger_dynirq,
1562 };
1563
1564 static struct irq_chip xen_percpu_chip __read_mostly = {
1565         .name                   = "xen-percpu",
1566
1567         .irq_disable            = disable_dynirq,
1568         .irq_mask               = disable_dynirq,
1569         .irq_unmask             = enable_dynirq,
1570
1571         .irq_ack                = ack_dynirq,
1572 };
1573
1574 int xen_set_callback_via(uint64_t via)
1575 {
1576         struct xen_hvm_param a;
1577         a.domid = DOMID_SELF;
1578         a.index = HVM_PARAM_CALLBACK_IRQ;
1579         a.value = via;
1580         return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1581 }
1582 EXPORT_SYMBOL_GPL(xen_set_callback_via);
1583
1584 #ifdef CONFIG_XEN_PVHVM
1585 /* Vector callbacks are better than PCI interrupts to receive event
1586  * channel notifications because we can receive vector callbacks on any
1587  * vcpu and we don't need PCI support or APIC interactions. */
1588 void xen_callback_vector(void)
1589 {
1590         int rc;
1591         uint64_t callback_via;
1592         if (xen_have_vector_callback) {
1593                 callback_via = HVM_CALLBACK_VECTOR(XEN_HVM_EVTCHN_CALLBACK);
1594                 rc = xen_set_callback_via(callback_via);
1595                 if (rc) {
1596                         printk(KERN_ERR "Request for Xen HVM callback vector"
1597                                         " failed.\n");
1598                         xen_have_vector_callback = 0;
1599                         return;
1600                 }
1601                 printk(KERN_INFO "Xen HVM callback vector for event delivery is "
1602                                 "enabled\n");
1603                 /* in the restore case the vector has already been allocated */
1604                 if (!test_bit(XEN_HVM_EVTCHN_CALLBACK, used_vectors))
1605                         alloc_intr_gate(XEN_HVM_EVTCHN_CALLBACK, xen_hvm_callback_vector);
1606         }
1607 }
1608 #else
1609 void xen_callback_vector(void) {}
1610 #endif
1611
1612 void __init xen_init_IRQ(void)
1613 {
1614         int i;
1615
1616         evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
1617                                     GFP_KERNEL);
1618         for (i = 0; i < NR_EVENT_CHANNELS; i++)
1619                 evtchn_to_irq[i] = -1;
1620
1621         init_evtchn_cpu_bindings();
1622
1623         /* No event channels are 'live' right now. */
1624         for (i = 0; i < NR_EVENT_CHANNELS; i++)
1625                 mask_evtchn(i);
1626
1627         if (xen_hvm_domain()) {
1628                 xen_callback_vector();
1629                 native_init_IRQ();
1630                 /* pci_xen_hvm_init must be called after native_init_IRQ so that
1631                  * __acpi_register_gsi can point at the right function */
1632                 pci_xen_hvm_init();
1633         } else {
1634                 irq_ctx_init(smp_processor_id());
1635                 if (xen_initial_domain())
1636                         xen_setup_pirqs();
1637         }
1638 }