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                         uint16_t domid;
 105                 } pirq;
 106         } u;
 107 };
 108 #define PIRQ_NEEDS_EOI  (1 << 0)
 109 #define PIRQ_SHAREABLE  (1 << 1)
 110
 111 static int *evtchn_to_irq;
 112
 113 static DEFINE_PER_CPU(unsigned long [NR_EVENT_CHANNELS/BITS_PER_LONG],
 114                       cpu_evtchn_mask);
 115
 116 /* Xen will never allocate port zero for any purpose. */
 117 #define VALID_EVTCHN(chn)       ((chn) != 0)
 118
 119 static struct irq_chip xen_dynamic_chip;
 120 static struct irq_chip xen_percpu_chip;
 121 static struct irq_chip xen_pirq_chip;
 122 static void enable_dynirq(struct irq_data *data);
 123 static void disable_dynirq(struct irq_data *data);
 124
 125 /* Get info for IRQ */
 126 static struct irq_info *info_for_irq(unsigned irq)
 127 {
 128         return irq_get_handler_data(irq);
 129 }
 130
 131 /* Constructors for packed IRQ information. */
 132 static void xen_irq_info_common_init(struct irq_info *info,
 133                                      unsigned irq,
 134                                      enum xen_irq_type type,
 135                                      unsigned short evtchn,
 136                                      unsigned short cpu)
 137 {
 138
 139         BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
 140
 141         info->type = type;
 142         info->irq = irq;
 143         info->evtchn = evtchn;
 144         info->cpu = cpu;
 145
 146         evtchn_to_irq[evtchn] = irq;
 147 }
 148
 149 static void xen_irq_info_evtchn_init(unsigned irq,
 150                                      unsigned short evtchn)
 151 {
 152         struct irq_info *info = info_for_irq(irq);
 153
 154         xen_irq_info_common_init(info, irq, IRQT_EVTCHN, evtchn, 0);
 155 }
 156
 157 static void xen_irq_info_ipi_init(unsigned cpu,
 158                                   unsigned irq,
 159                                   unsigned short evtchn,
 160                                   enum ipi_vector ipi)
 161 {
 162         struct irq_info *info = info_for_irq(irq);
 163
 164         xen_irq_info_common_init(info, irq, IRQT_IPI, evtchn, 0);
 165
 166         info->u.ipi = ipi;
 167
 168         per_cpu(ipi_to_irq, cpu)[ipi] = irq;
 169 }
 170
 171 static void xen_irq_info_virq_init(unsigned cpu,
 172                                    unsigned irq,
 173                                    unsigned short evtchn,
 174                                    unsigned short virq)
 175 {
 176         struct irq_info *info = info_for_irq(irq);
 177
 178         xen_irq_info_common_init(info, irq, IRQT_VIRQ, evtchn, 0);
 179
 180         info->u.virq = virq;
 181
 182         per_cpu(virq_to_irq, cpu)[virq] = irq;
 183 }
 184
 185 static void xen_irq_info_pirq_init(unsigned irq,
 186                                    unsigned short evtchn,
 187                                    unsigned short pirq,
 188                                    unsigned short gsi,
 189                                    unsigned short vector,
 190                                    uint16_t domid,
 191                                    unsigned char flags)
 192 {
 193         struct irq_info *info = info_for_irq(irq);
 194
 195         xen_irq_info_common_init(info, irq, IRQT_PIRQ, evtchn, 0);
 196
 197         info->u.pirq.pirq = pirq;
 198         info->u.pirq.gsi = gsi;
 199         info->u.pirq.vector = vector;
 200         info->u.pirq.domid = domid;
 201         info->u.pirq.flags = flags;
 202 }
 203
 204 /*
 205  * Accessors for packed IRQ information.
 206  */
 207 static unsigned int evtchn_from_irq(unsigned irq)
 208 {
 209         if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))
 210                 return 0;
 211
 212         return info_for_irq(irq)->evtchn;
 213 }
 214
 215 unsigned irq_from_evtchn(unsigned int evtchn)
 216 {
 217         return evtchn_to_irq[evtchn];
 218 }
 219 EXPORT_SYMBOL_GPL(irq_from_evtchn);
 220
 221 static enum ipi_vector ipi_from_irq(unsigned irq)
 222 {
 223         struct irq_info *info = info_for_irq(irq);
 224
 225         BUG_ON(info == NULL);
 226         BUG_ON(info->type != IRQT_IPI);
 227
 228         return info->u.ipi;
 229 }
 230
 231 static unsigned virq_from_irq(unsigned irq)
 232 {
 233         struct irq_info *info = info_for_irq(irq);
 234
 235         BUG_ON(info == NULL);
 236         BUG_ON(info->type != IRQT_VIRQ);
 237
 238         return info->u.virq;
 239 }
 240
 241 static unsigned pirq_from_irq(unsigned irq)
 242 {
 243         struct irq_info *info = info_for_irq(irq);
 244
 245         BUG_ON(info == NULL);
 246         BUG_ON(info->type != IRQT_PIRQ);
 247
 248         return info->u.pirq.pirq;
 249 }
 250
 251 static enum xen_irq_type type_from_irq(unsigned irq)
 252 {
 253         return info_for_irq(irq)->type;
 254 }
 255
 256 static unsigned cpu_from_irq(unsigned irq)
 257 {
 258         return info_for_irq(irq)->cpu;
 259 }
 260
 261 static unsigned int cpu_from_evtchn(unsigned int evtchn)
 262 {
 263         int irq = evtchn_to_irq[evtchn];
 264         unsigned ret = 0;
 265
 266         if (irq != -1)
 267                 ret = cpu_from_irq(irq);
 268
 269         return ret;
 270 }
 271
 272 static bool pirq_needs_eoi(unsigned irq)
 273 {
 274         struct irq_info *info = info_for_irq(irq);
 275
 276         BUG_ON(info->type != IRQT_PIRQ);
 277
 278         return info->u.pirq.flags & PIRQ_NEEDS_EOI;
 279 }
 280
 281 static inline unsigned long active_evtchns(unsigned int cpu,
 282                                            struct shared_info *sh,
 283                                            unsigned int idx)
 284 {
 285         return (sh->evtchn_pending[idx] &
 286                 per_cpu(cpu_evtchn_mask, cpu)[idx] &
 287                 ~sh->evtchn_mask[idx]);
 288 }
 289
 290 static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
 291 {
 292         int irq = evtchn_to_irq[chn];
 293
 294         BUG_ON(irq == -1);
 295 #ifdef CONFIG_SMP
 296         cpumask_copy(irq_to_desc(irq)->irq_data.affinity, cpumask_of(cpu));
 297 #endif
 298
 299         clear_bit(chn, per_cpu(cpu_evtchn_mask, cpu_from_irq(irq)));
 300         set_bit(chn, per_cpu(cpu_evtchn_mask, cpu));
 301
 302         info_for_irq(irq)->cpu = cpu;
 303 }
 304
 305 static void init_evtchn_cpu_bindings(void)
 306 {
 307         int i;
 308 #ifdef CONFIG_SMP
 309         struct irq_info *info;
 310
 311         /* By default all event channels notify CPU#0. */
 312         list_for_each_entry(info, &xen_irq_list_head, list) {
 313                 struct irq_desc *desc = irq_to_desc(info->irq);
 314                 cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
 315         }
 316 #endif
 317
 318         for_each_possible_cpu(i)
 319                 memset(per_cpu(cpu_evtchn_mask, i),
 320                        (i == 0) ? ~0 : 0, sizeof(*per_cpu(cpu_evtchn_mask, i)));
 321 }
 322
 323 static inline void clear_evtchn(int port)
 324 {
 325         struct shared_info *s = HYPERVISOR_shared_info;
 326         sync_clear_bit(port, &s->evtchn_pending[0]);
 327 }
 328
 329 static inline void set_evtchn(int port)
 330 {
 331         struct shared_info *s = HYPERVISOR_shared_info;
 332         sync_set_bit(port, &s->evtchn_pending[0]);
 333 }
 334
 335 static inline int test_evtchn(int port)
 336 {
 337         struct shared_info *s = HYPERVISOR_shared_info;
 338         return sync_test_bit(port, &s->evtchn_pending[0]);
 339 }
 340
 341
 342 /**
 343  * notify_remote_via_irq - send event to remote end of event channel via irq
 344  * @irq: irq of event channel to send event to
 345  *
 346  * Unlike notify_remote_via_evtchn(), this is safe to use across
 347  * save/restore. Notifications on a broken connection are silently
 348  * dropped.
 349  */
 350 void notify_remote_via_irq(int irq)
 351 {
 352         int evtchn = evtchn_from_irq(irq);
 353
 354         if (VALID_EVTCHN(evtchn))
 355                 notify_remote_via_evtchn(evtchn);
 356 }
 357 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
 358
 359 static void mask_evtchn(int port)
 360 {
 361         struct shared_info *s = HYPERVISOR_shared_info;
 362         sync_set_bit(port, &s->evtchn_mask[0]);
 363 }
 364
 365 static void unmask_evtchn(int port)
 366 {
 367         struct shared_info *s = HYPERVISOR_shared_info;
 368         unsigned int cpu = get_cpu();
 369
 370         BUG_ON(!irqs_disabled());
 371
 372         /* Slow path (hypercall) if this is a non-local port. */
 373         if (unlikely(cpu != cpu_from_evtchn(port))) {
 374                 struct evtchn_unmask unmask = { .port = port };
 375                 (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
 376         } else {
 377                 struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
 378
 379                 sync_clear_bit(port, &s->evtchn_mask[0]);
 380
 381                 /*
 382                  * The following is basically the equivalent of
 383                  * 'hw_resend_irq'. Just like a real IO-APIC we 'lose
 384                  * the interrupt edge' if the channel is masked.
 385                  */
 386                 if (sync_test_bit(port, &s->evtchn_pending[0]) &&
 387                     !sync_test_and_set_bit(port / BITS_PER_LONG,
 388                                            &vcpu_info->evtchn_pending_sel))
 389                         vcpu_info->evtchn_upcall_pending = 1;
 390         }
 391
 392         put_cpu();
 393 }
 394
 395 static void xen_irq_init(unsigned irq)
 396 {
 397         struct irq_info *info;
 398 #ifdef CONFIG_SMP
 399         struct irq_desc *desc = irq_to_desc(irq);
 400
 401         /* By default all event channels notify CPU#0. */
 402         cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
 403 #endif
 404
 405         info = kzalloc(sizeof(*info), GFP_KERNEL);
 406         if (info == NULL)
 407                 panic("Unable to allocate metadata for IRQ%d\n", irq);
 408
 409         info->type = IRQT_UNBOUND;
 410
 411         irq_set_handler_data(irq, info);
 412
 413         list_add_tail(&info->list, &xen_irq_list_head);
 414 }
 415
 416 static int __must_check xen_allocate_irq_dynamic(void)
 417 {
 418         int first = 0;
 419         int irq;
 420
 421 #ifdef CONFIG_X86_IO_APIC
 422         /*
 423          * For an HVM guest or domain 0 which see "real" (emulated or
 424          * actual respectively) GSIs we allocate dynamic IRQs
 425          * e.g. those corresponding to event channels or MSIs
 426          * etc. from the range above those "real" GSIs to avoid
 427          * collisions.
 428          */
 429         if (xen_initial_domain() || xen_hvm_domain())
 430                 first = get_nr_irqs_gsi();
 431 #endif
 432
 433         irq = irq_alloc_desc_from(first, -1);
 434
 435         xen_irq_init(irq);
 436
 437         return irq;
 438 }
 439
 440 static int __must_check xen_allocate_irq_gsi(unsigned gsi)
 441 {
 442         int irq;
 443
 444         /*
 445          * A PV guest has no concept of a GSI (since it has no ACPI
 446          * nor access to/knowledge of the physical APICs). Therefore
 447          * all IRQs are dynamically allocated from the entire IRQ
 448          * space.
 449          */
 450         if (xen_pv_domain() && !xen_initial_domain())
 451                 return xen_allocate_irq_dynamic();
 452
 453         /* Legacy IRQ descriptors are already allocated by the arch. */
 454         if (gsi < NR_IRQS_LEGACY)
 455                 irq = gsi;
 456         else
 457                 irq = irq_alloc_desc_at(gsi, -1);
 458
 459         xen_irq_init(irq);
 460
 461         return irq;
 462 }
 463
 464 static void xen_free_irq(unsigned irq)
 465 {
 466         struct irq_info *info = irq_get_handler_data(irq);
 467
 468         list_del(&info->list);
 469
 470         irq_set_handler_data(irq, NULL);
 471
 472         kfree(info);
 473
 474         /* Legacy IRQ descriptors are managed by the arch. */
 475         if (irq < NR_IRQS_LEGACY)
 476                 return;
 477
 478         irq_free_desc(irq);
 479 }
 480
 481 static void pirq_query_unmask(int irq)
 482 {
 483         struct physdev_irq_status_query irq_status;
 484         struct irq_info *info = info_for_irq(irq);
 485
 486         BUG_ON(info->type != IRQT_PIRQ);
 487
 488         irq_status.irq = pirq_from_irq(irq);
 489         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
 490                 irq_status.flags = 0;
 491
 492         info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
 493         if (irq_status.flags & XENIRQSTAT_needs_eoi)
 494                 info->u.pirq.flags |= PIRQ_NEEDS_EOI;
 495 }
 496
 497 static bool probing_irq(int irq)
 498 {
 499         struct irq_desc *desc = irq_to_desc(irq);
 500
 501         return desc && desc->action == NULL;
 502 }
 503
 504 static void eoi_pirq(struct irq_data *data)
 505 {
 506         int evtchn = evtchn_from_irq(data->irq);
 507         struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
 508         int rc = 0;
 509
 510         irq_move_irq(data);
 511
 512         if (VALID_EVTCHN(evtchn))
 513                 clear_evtchn(evtchn);
 514
 515         if (pirq_needs_eoi(data->irq)) {
 516                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
 517                 WARN_ON(rc);
 518         }
 519 }
 520
 521 static void mask_ack_pirq(struct irq_data *data)
 522 {
 523         disable_dynirq(data);
 524         eoi_pirq(data);
 525 }
 526
 527 static unsigned int __startup_pirq(unsigned int irq)
 528 {
 529         struct evtchn_bind_pirq bind_pirq;
 530         struct irq_info *info = info_for_irq(irq);
 531         int evtchn = evtchn_from_irq(irq);
 532         int rc;
 533
 534         BUG_ON(info->type != IRQT_PIRQ);
 535
 536         if (VALID_EVTCHN(evtchn))
 537                 goto out;
 538
 539         bind_pirq.pirq = pirq_from_irq(irq);
 540         /* NB. We are happy to share unless we are probing. */
 541         bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
 542                                         BIND_PIRQ__WILL_SHARE : 0;
 543         rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
 544         if (rc != 0) {
 545                 if (!probing_irq(irq))
 546                         printk(KERN_INFO "Failed to obtain physical IRQ %d\n",
 547                                irq);
 548                 return 0;
 549         }
 550         evtchn = bind_pirq.port;
 551
 552         pirq_query_unmask(irq);
 553
 554         evtchn_to_irq[evtchn] = irq;
 555         bind_evtchn_to_cpu(evtchn, 0);
 556         info->evtchn = evtchn;
 557
 558 out:
 559         unmask_evtchn(evtchn);
 560         eoi_pirq(irq_get_irq_data(irq));
 561
 562         return 0;
 563 }
 564
 565 static unsigned int startup_pirq(struct irq_data *data)
 566 {
 567         return __startup_pirq(data->irq);
 568 }
 569
 570 static void shutdown_pirq(struct irq_data *data)
 571 {
 572         struct evtchn_close close;
 573         unsigned int irq = data->irq;
 574         struct irq_info *info = info_for_irq(irq);
 575         int evtchn = evtchn_from_irq(irq);
 576
 577         BUG_ON(info->type != IRQT_PIRQ);
 578
 579         if (!VALID_EVTCHN(evtchn))
 580                 return;
 581
 582         mask_evtchn(evtchn);
 583
 584         close.port = evtchn;
 585         if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 586                 BUG();
 587
 588         bind_evtchn_to_cpu(evtchn, 0);
 589         evtchn_to_irq[evtchn] = -1;
 590         info->evtchn = 0;
 591 }
 592
 593 static void enable_pirq(struct irq_data *data)
 594 {
 595         startup_pirq(data);
 596 }
 597
 598 static void disable_pirq(struct irq_data *data)
 599 {
 600         disable_dynirq(data);
 601 }
 602
 603 static int find_irq_by_gsi(unsigned gsi)
 604 {
 605         struct irq_info *info;
 606
 607         list_for_each_entry(info, &xen_irq_list_head, list) {
 608                 if (info->type != IRQT_PIRQ)
 609                         continue;
 610
 611                 if (info->u.pirq.gsi == gsi)
 612                         return info->irq;
 613         }
 614
 615         return -1;
 616 }
 617
 618 int xen_allocate_pirq_gsi(unsigned gsi)
 619 {
 620         return gsi;
 621 }
 622
 623 /*
 624  * Do not make any assumptions regarding the relationship between the
 625  * IRQ number returned here and the Xen pirq argument.
 626  *
 627  * Note: We don't assign an event channel until the irq actually started
 628  * up.  Return an existing irq if we've already got one for the gsi.
 629  *
 630  * Shareable implies level triggered, not shareable implies edge
 631  * triggered here.
 632  */
 633 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 634                              unsigned pirq, int shareable, char *name)
 635 {
 636         int irq = -1;
 637         struct physdev_irq irq_op;
 638
 639         spin_lock(&irq_mapping_update_lock);
 640
 641         irq = find_irq_by_gsi(gsi);
 642         if (irq != -1) {
 643                 printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n",
 644                        irq, gsi);
 645                 goto out;       /* XXX need refcount? */
 646         }
 647
 648         irq = xen_allocate_irq_gsi(gsi);
 649         if (irq < 0)
 650                 goto out;
 651
 652         irq_op.irq = irq;
 653         irq_op.vector = 0;
 654
 655         /* Only the privileged domain can do this. For non-priv, the pcifront
 656          * driver provides a PCI bus that does the call to do exactly
 657          * this in the priv domain. */
 658         if (xen_initial_domain() &&
 659             HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
 660                 xen_free_irq(irq);
 661                 irq = -ENOSPC;
 662                 goto out;
 663         }
 664
 665         xen_irq_info_pirq_init(irq, 0, pirq, gsi, irq_op.vector, DOMID_SELF,
 666                                shareable ? PIRQ_SHAREABLE : 0);
 667
 668         pirq_query_unmask(irq);
 669         /* We try to use the handler with the appropriate semantic for the
 670          * type of interrupt: if the interrupt is an edge triggered
 671          * interrupt we use handle_edge_irq.
 672          *
 673          * On the other hand if the interrupt is level triggered we use
 674          * handle_fasteoi_irq like the native code does for this kind of
 675          * interrupts.
 676          *
 677          * Depending on the Xen version, pirq_needs_eoi might return true
 678          * not only for level triggered interrupts but for edge triggered
 679          * interrupts too. In any case Xen always honors the eoi mechanism,
 680          * not injecting any more pirqs of the same kind if the first one
 681          * hasn't received an eoi yet. Therefore using the fasteoi handler
 682          * is the right choice either way.
 683          */
 684         if (shareable)
 685                 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 686                                 handle_fasteoi_irq, name);
 687         else
 688                 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 689                                 handle_edge_irq, name);
 690
 691 out:
 692         spin_unlock(&irq_mapping_update_lock);
 693
 694         return irq;
 695 }
 696
 697 #ifdef CONFIG_PCI_MSI
 698 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
 699 {
 700         int rc;
 701         struct physdev_get_free_pirq op_get_free_pirq;
 702
 703         op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
 704         rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
 705
 706         WARN_ONCE(rc == -ENOSYS,
 707                   "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
 708
 709         return rc ? -1 : op_get_free_pirq.pirq;
 710 }
 711
 712 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
 713                              int pirq, int vector, const char *name,
 714                              domid_t domid)
 715 {
 716         int irq, ret;
 717
 718         spin_lock(&irq_mapping_update_lock);
 719
 720         irq = xen_allocate_irq_dynamic();
 721         if (irq == -1)
 722                 goto out;
 723
 724         irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_edge_irq,
 725                         name);
 726
 727         xen_irq_info_pirq_init(irq, 0, pirq, 0, vector, domid, 0);
 728         ret = irq_set_msi_desc(irq, msidesc);
 729         if (ret < 0)
 730                 goto error_irq;
 731 out:
 732         spin_unlock(&irq_mapping_update_lock);
 733         return irq;
 734 error_irq:
 735         spin_unlock(&irq_mapping_update_lock);
 736         xen_free_irq(irq);
 737         return -1;
 738 }
 739 #endif
 740
 741 int xen_destroy_irq(int irq)
 742 {
 743         struct irq_desc *desc;
 744         struct physdev_unmap_pirq unmap_irq;
 745         struct irq_info *info = info_for_irq(irq);
 746         int rc = -ENOENT;
 747
 748         spin_lock(&irq_mapping_update_lock);
 749
 750         desc = irq_to_desc(irq);
 751         if (!desc)
 752                 goto out;
 753
 754         if (xen_initial_domain()) {
 755                 unmap_irq.pirq = info->u.pirq.pirq;
 756                 unmap_irq.domid = info->u.pirq.domid;
 757                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
 758                 /* If another domain quits without making the pci_disable_msix
 759                  * call, the Xen hypervisor takes care of freeing the PIRQs
 760                  * (free_domain_pirqs).
 761                  */
 762                 if ((rc == -ESRCH && info->u.pirq.domid != DOMID_SELF))
 763                         printk(KERN_INFO "domain %d does not have %d anymore\n",
 764                                 info->u.pirq.domid, info->u.pirq.pirq);
 765                 else if (rc) {
 766                         printk(KERN_WARNING "unmap irq failed %d\n", rc);
 767                         goto out;
 768                 }
 769         }
 770
 771         xen_free_irq(irq);
 772
 773 out:
 774         spin_unlock(&irq_mapping_update_lock);
 775         return rc;
 776 }
 777
 778 int xen_irq_from_pirq(unsigned pirq)
 779 {
 780         int irq;
 781
 782         struct irq_info *info;
 783
 784         spin_lock(&irq_mapping_update_lock);
 785
 786         list_for_each_entry(info, &xen_irq_list_head, list) {
 787                 if (info == NULL || info->type != IRQT_PIRQ)
 788                         continue;
 789                 irq = info->irq;
 790                 if (info->u.pirq.pirq == pirq)
 791                         goto out;
 792         }
 793         irq = -1;
 794 out:
 795         spin_unlock(&irq_mapping_update_lock);
 796
 797         return irq;
 798 }
 799
 800
 801 int xen_pirq_from_irq(unsigned irq)
 802 {
 803         return pirq_from_irq(irq);
 804 }
 805 EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
 806 int bind_evtchn_to_irq(unsigned int evtchn)
 807 {
 808         int irq;
 809
 810         spin_lock(&irq_mapping_update_lock);
 811
 812         irq = evtchn_to_irq[evtchn];
 813
 814         if (irq == -1) {
 815                 irq = xen_allocate_irq_dynamic();
 816                 if (irq == -1)
 817                         goto out;
 818
 819                 irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
 820                                               handle_edge_irq, "event");
 821
 822                 xen_irq_info_evtchn_init(irq, evtchn);
 823         }
 824
 825 out:
 826         spin_unlock(&irq_mapping_update_lock);
 827
 828         return irq;
 829 }
 830 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
 831
 832 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 833 {
 834         struct evtchn_bind_ipi bind_ipi;
 835         int evtchn, irq;
 836
 837         spin_lock(&irq_mapping_update_lock);
 838
 839         irq = per_cpu(ipi_to_irq, cpu)[ipi];
 840
 841         if (irq == -1) {
 842                 irq = xen_allocate_irq_dynamic();
 843                 if (irq < 0)
 844                         goto out;
 845
 846                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 847                                               handle_percpu_irq, "ipi");
 848
 849                 bind_ipi.vcpu = cpu;
 850                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
 851                                                 &bind_ipi) != 0)
 852                         BUG();
 853                 evtchn = bind_ipi.port;
 854
 855                 xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
 856
 857                 bind_evtchn_to_cpu(evtchn, cpu);
 858         }
 859
 860  out:
 861         spin_unlock(&irq_mapping_update_lock);
 862         return irq;
 863 }
 864
 865 static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
 866                                           unsigned int remote_port)
 867 {
 868         struct evtchn_bind_interdomain bind_interdomain;
 869         int err;
 870
 871         bind_interdomain.remote_dom  = remote_domain;
 872         bind_interdomain.remote_port = remote_port;
 873
 874         err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
 875                                           &bind_interdomain);
 876
 877         return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
 878 }
 879
 880
 881 int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 882 {
 883         struct evtchn_bind_virq bind_virq;
 884         int evtchn, irq;
 885
 886         spin_lock(&irq_mapping_update_lock);
 887
 888         irq = per_cpu(virq_to_irq, cpu)[virq];
 889
 890         if (irq == -1) {
 891                 irq = xen_allocate_irq_dynamic();
 892                 if (irq == -1)
 893                         goto out;
 894
 895                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 896                                               handle_percpu_irq, "virq");
 897
 898                 bind_virq.virq = virq;
 899                 bind_virq.vcpu = cpu;
 900                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
 901                                                 &bind_virq) != 0)
 902                         BUG();
 903                 evtchn = bind_virq.port;
 904
 905                 xen_irq_info_virq_init(cpu, irq, evtchn, virq);
 906
 907                 bind_evtchn_to_cpu(evtchn, cpu);
 908         }
 909
 910 out:
 911         spin_unlock(&irq_mapping_update_lock);
 912
 913         return irq;
 914 }
 915
 916 static void unbind_from_irq(unsigned int irq)
 917 {
 918         struct evtchn_close close;
 919         int evtchn = evtchn_from_irq(irq);
 920
 921         spin_lock(&irq_mapping_update_lock);
 922
 923         if (VALID_EVTCHN(evtchn)) {
 924                 close.port = evtchn;
 925                 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 926                         BUG();
 927
 928                 switch (type_from_irq(irq)) {
 929                 case IRQT_VIRQ:
 930                         per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
 931                                 [virq_from_irq(irq)] = -1;
 932                         break;
 933                 case IRQT_IPI:
 934                         per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn))
 935                                 [ipi_from_irq(irq)] = -1;
 936                         break;
 937                 default:
 938                         break;
 939                 }
 940
 941                 /* Closed ports are implicitly re-bound to VCPU0. */
 942                 bind_evtchn_to_cpu(evtchn, 0);
 943
 944                 evtchn_to_irq[evtchn] = -1;
 945         }
 946
 947         BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
 948
 949         xen_free_irq(irq);
 950
 951         spin_unlock(&irq_mapping_update_lock);
 952 }
 953
 954 int bind_evtchn_to_irqhandler(unsigned int evtchn,
 955                               irq_handler_t handler,
 956                               unsigned long irqflags,
 957                               const char *devname, void *dev_id)
 958 {
 959         int irq, retval;
 960
 961         irq = bind_evtchn_to_irq(evtchn);
 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_evtchn_to_irqhandler);
 973
 974 int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
 975                                           unsigned int remote_port,
 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_interdomain_evtchn_to_irq(remote_domain, remote_port);
 984         if (irq < 0)
 985                 return irq;
 986
 987         retval = request_irq(irq, handler, irqflags, devname, dev_id);
 988         if (retval != 0) {
 989                 unbind_from_irq(irq);
 990                 return retval;
 991         }
 992
 993         return irq;
 994 }
 995 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
 996
 997 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
 998                             irq_handler_t handler,
 999                             unsigned long irqflags, const char *devname, void *dev_id)
1000 {
1001         int irq, retval;
1002
1003         irq = bind_virq_to_irq(virq, cpu);
1004         if (irq < 0)
1005                 return irq;
1006         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1007         if (retval != 0) {
1008                 unbind_from_irq(irq);
1009                 return retval;
1010         }
1011
1012         return irq;
1013 }
1014 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
1015
1016 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
1017                            unsigned int cpu,
1018                            irq_handler_t handler,
1019                            unsigned long irqflags,
1020                            const char *devname,
1021                            void *dev_id)
1022 {
1023         int irq, retval;
1024
1025         irq = bind_ipi_to_irq(ipi, cpu);
1026         if (irq < 0)
1027                 return irq;
1028
1029         irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME;
1030         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1031         if (retval != 0) {
1032                 unbind_from_irq(irq);
1033                 return retval;
1034         }
1035
1036         return irq;
1037 }
1038
1039 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
1040 {
1041         free_irq(irq, dev_id);
1042         unbind_from_irq(irq);
1043 }
1044 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
1045
1046 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
1047 {
1048         int irq = per_cpu(ipi_to_irq, cpu)[vector];
1049         BUG_ON(irq < 0);
1050         notify_remote_via_irq(irq);
1051 }
1052
1053 irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
1054 {
1055         struct shared_info *sh = HYPERVISOR_shared_info;
1056         int cpu = smp_processor_id();
1057         unsigned long *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu);
1058         int i;
1059         unsigned long flags;
1060         static DEFINE_SPINLOCK(debug_lock);
1061         struct vcpu_info *v;
1062
1063         spin_lock_irqsave(&debug_lock, flags);
1064
1065         printk("\nvcpu %d\n  ", cpu);
1066
1067         for_each_online_cpu(i) {
1068                 int pending;
1069                 v = per_cpu(xen_vcpu, i);
1070                 pending = (get_irq_regs() && i == cpu)
1071                         ? xen_irqs_disabled(get_irq_regs())
1072                         : v->evtchn_upcall_mask;
1073                 printk("%d: masked=%d pending=%d event_sel %0*lx\n  ", i,
1074                        pending, v->evtchn_upcall_pending,
1075                        (int)(sizeof(v->evtchn_pending_sel)*2),
1076                        v->evtchn_pending_sel);
1077         }
1078         v = per_cpu(xen_vcpu, cpu);
1079
1080         printk("\npending:\n   ");
1081         for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
1082                 printk("%0*lx%s", (int)sizeof(sh->evtchn_pending[0])*2,
1083                        sh->evtchn_pending[i],
1084                        i % 8 == 0 ? "\n   " : " ");
1085         printk("\nglobal mask:\n   ");
1086         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
1087                 printk("%0*lx%s",
1088                        (int)(sizeof(sh->evtchn_mask[0])*2),
1089                        sh->evtchn_mask[i],
1090                        i % 8 == 0 ? "\n   " : " ");
1091
1092         printk("\nglobally unmasked:\n   ");
1093         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
1094                 printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
1095                        sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
1096                        i % 8 == 0 ? "\n   " : " ");
1097
1098         printk("\nlocal cpu%d mask:\n   ", cpu);
1099         for (i = (NR_EVENT_CHANNELS/BITS_PER_LONG)-1; i >= 0; i--)
1100                 printk("%0*lx%s", (int)(sizeof(cpu_evtchn[0])*2),
1101                        cpu_evtchn[i],
1102                        i % 8 == 0 ? "\n   " : " ");
1103
1104         printk("\nlocally unmasked:\n   ");
1105         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) {
1106                 unsigned long pending = sh->evtchn_pending[i]
1107                         & ~sh->evtchn_mask[i]
1108                         & cpu_evtchn[i];
1109                 printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
1110                        pending, i % 8 == 0 ? "\n   " : " ");
1111         }
1112
1113         printk("\npending list:\n");
1114         for (i = 0; i < NR_EVENT_CHANNELS; i++) {
1115                 if (sync_test_bit(i, sh->evtchn_pending)) {
1116                         int word_idx = i / BITS_PER_LONG;
1117                         printk("  %d: event %d -> irq %d%s%s%s\n",
1118                                cpu_from_evtchn(i), i,
1119                                evtchn_to_irq[i],
1120                                sync_test_bit(word_idx, &v->evtchn_pending_sel)
1121                                              ? "" : " l2-clear",
1122                                !sync_test_bit(i, sh->evtchn_mask)
1123                                              ? "" : " globally-masked",
1124                                sync_test_bit(i, cpu_evtchn)
1125                                              ? "" : " locally-masked");
1126                 }
1127         }
1128
1129         spin_unlock_irqrestore(&debug_lock, flags);
1130
1131         return IRQ_HANDLED;
1132 }
1133
1134 static DEFINE_PER_CPU(unsigned, xed_nesting_count);
1135 static DEFINE_PER_CPU(unsigned int, current_word_idx);
1136 static DEFINE_PER_CPU(unsigned int, current_bit_idx);
1137
1138 /*
1139  * Mask out the i least significant bits of w
1140  */
1141 #define MASK_LSBS(w, i) (w & ((~0UL) << i))
1142
1143 /*
1144  * Search the CPUs pending events bitmasks.  For each one found, map
1145  * the event number to an irq, and feed it into do_IRQ() for
1146  * handling.
1147  *
1148  * Xen uses a two-level bitmap to speed searching.  The first level is
1149  * a bitset of words which contain pending event bits.  The second
1150  * level is a bitset of pending events themselves.
1151  */
1152 static void __xen_evtchn_do_upcall(void)
1153 {
1154         int start_word_idx, start_bit_idx;
1155         int word_idx, bit_idx;
1156         int i;
1157         int cpu = get_cpu();
1158         struct shared_info *s = HYPERVISOR_shared_info;
1159         struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1160         unsigned count;
1161
1162         do {
1163                 unsigned long pending_words;
1164
1165                 vcpu_info->evtchn_upcall_pending = 0;
1166
1167                 if (__this_cpu_inc_return(xed_nesting_count) - 1)
1168                         goto out;
1169
1170 #ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
1171                 /* Clear master flag /before/ clearing selector flag. */
1172                 wmb();
1173 #endif
1174                 pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
1175
1176                 start_word_idx = __this_cpu_read(current_word_idx);
1177                 start_bit_idx = __this_cpu_read(current_bit_idx);
1178
1179                 word_idx = start_word_idx;
1180
1181                 for (i = 0; pending_words != 0; i++) {
1182                         unsigned long pending_bits;
1183                         unsigned long words;
1184
1185                         words = MASK_LSBS(pending_words, word_idx);
1186
1187                         /*
1188                          * If we masked out all events, wrap to beginning.
1189                          */
1190                         if (words == 0) {
1191                                 word_idx = 0;
1192                                 bit_idx = 0;
1193                                 continue;
1194                         }
1195                         word_idx = __ffs(words);
1196
1197                         pending_bits = active_evtchns(cpu, s, word_idx);
1198                         bit_idx = 0; /* usually scan entire word from start */
1199                         if (word_idx == start_word_idx) {
1200                                 /* We scan the starting word in two parts */
1201                                 if (i == 0)
1202                                         /* 1st time: start in the middle */
1203                                         bit_idx = start_bit_idx;
1204                                 else
1205                                         /* 2nd time: mask bits done already */
1206                                         bit_idx &= (1UL << start_bit_idx) - 1;
1207                         }
1208
1209                         do {
1210                                 unsigned long bits;
1211                                 int port, irq;
1212                                 struct irq_desc *desc;
1213
1214                                 bits = MASK_LSBS(pending_bits, bit_idx);
1215
1216                                 /* If we masked out all events, move on. */
1217                                 if (bits == 0)
1218                                         break;
1219
1220                                 bit_idx = __ffs(bits);
1221
1222                                 /* Process port. */
1223                                 port = (word_idx * BITS_PER_LONG) + bit_idx;
1224                                 irq = evtchn_to_irq[port];
1225
1226                                 if (irq != -1) {
1227                                         desc = irq_to_desc(irq);
1228                                         if (desc)
1229                                                 generic_handle_irq_desc(irq, desc);
1230                                 }
1231
1232                                 bit_idx = (bit_idx + 1) % BITS_PER_LONG;
1233
1234                                 /* Next caller starts at last processed + 1 */
1235                                 __this_cpu_write(current_word_idx,
1236                                                  bit_idx ? word_idx :
1237                                                  (word_idx+1) % BITS_PER_LONG);
1238                                 __this_cpu_write(current_bit_idx, bit_idx);
1239                         } while (bit_idx != 0);
1240
1241                         /* Scan start_l1i twice; all others once. */
1242                         if ((word_idx != start_word_idx) || (i != 0))
1243                                 pending_words &= ~(1UL << word_idx);
1244
1245                         word_idx = (word_idx + 1) % BITS_PER_LONG;
1246                 }
1247
1248                 BUG_ON(!irqs_disabled());
1249
1250                 count = __this_cpu_read(xed_nesting_count);
1251                 __this_cpu_write(xed_nesting_count, 0);
1252         } while (count != 1 || vcpu_info->evtchn_upcall_pending);
1253
1254 out:
1255
1256         put_cpu();
1257 }
1258
1259 void xen_evtchn_do_upcall(struct pt_regs *regs)
1260 {
1261         struct pt_regs *old_regs = set_irq_regs(regs);
1262
1263         exit_idle();
1264         irq_enter();
1265
1266         __xen_evtchn_do_upcall();
1267
1268         irq_exit();
1269         set_irq_regs(old_regs);
1270 }
1271
1272 void xen_hvm_evtchn_do_upcall(void)
1273 {
1274         __xen_evtchn_do_upcall();
1275 }
1276 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1277
1278 /* Rebind a new event channel to an existing irq. */
1279 void rebind_evtchn_irq(int evtchn, int irq)
1280 {
1281         struct irq_info *info = info_for_irq(irq);
1282
1283         /* Make sure the irq is masked, since the new event channel
1284            will also be masked. */
1285         disable_irq(irq);
1286
1287         spin_lock(&irq_mapping_update_lock);
1288
1289         /* After resume the irq<->evtchn mappings are all cleared out */
1290         BUG_ON(evtchn_to_irq[evtchn] != -1);
1291         /* Expect irq to have been bound before,
1292            so there should be a proper type */
1293         BUG_ON(info->type == IRQT_UNBOUND);
1294
1295         xen_irq_info_evtchn_init(irq, evtchn);
1296
1297         spin_unlock(&irq_mapping_update_lock);
1298
1299         /* new event channels are always bound to cpu 0 */
1300         irq_set_affinity(irq, cpumask_of(0));
1301
1302         /* Unmask the event channel. */
1303         enable_irq(irq);
1304 }
1305
1306 /* Rebind an evtchn so that it gets delivered to a specific cpu */
1307 static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
1308 {
1309         struct evtchn_bind_vcpu bind_vcpu;
1310         int evtchn = evtchn_from_irq(irq);
1311
1312         if (!VALID_EVTCHN(evtchn))
1313                 return -1;
1314
1315         /*
1316          * Events delivered via platform PCI interrupts are always
1317          * routed to vcpu 0 and hence cannot be rebound.
1318          */
1319         if (xen_hvm_domain() && !xen_have_vector_callback)
1320                 return -1;
1321
1322         /* Send future instances of this interrupt to other vcpu. */
1323         bind_vcpu.port = evtchn;
1324         bind_vcpu.vcpu = tcpu;
1325
1326         /*
1327          * If this fails, it usually just indicates that we're dealing with a
1328          * virq or IPI channel, which don't actually need to be rebound. Ignore
1329          * it, but don't do the xenlinux-level rebind in that case.
1330          */
1331         if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1332                 bind_evtchn_to_cpu(evtchn, tcpu);
1333
1334         return 0;
1335 }
1336
1337 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1338                             bool force)
1339 {
1340         unsigned tcpu = cpumask_first(dest);
1341
1342         return rebind_irq_to_cpu(data->irq, tcpu);
1343 }
1344
1345 int resend_irq_on_evtchn(unsigned int irq)
1346 {
1347         int masked, evtchn = evtchn_from_irq(irq);
1348         struct shared_info *s = HYPERVISOR_shared_info;
1349
1350         if (!VALID_EVTCHN(evtchn))
1351                 return 1;
1352
1353         masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
1354         sync_set_bit(evtchn, s->evtchn_pending);
1355         if (!masked)
1356                 unmask_evtchn(evtchn);
1357
1358         return 1;
1359 }
1360
1361 static void enable_dynirq(struct irq_data *data)
1362 {
1363         int evtchn = evtchn_from_irq(data->irq);
1364
1365         if (VALID_EVTCHN(evtchn))
1366                 unmask_evtchn(evtchn);
1367 }
1368
1369 static void disable_dynirq(struct irq_data *data)
1370 {
1371         int evtchn = evtchn_from_irq(data->irq);
1372
1373         if (VALID_EVTCHN(evtchn))
1374                 mask_evtchn(evtchn);
1375 }
1376
1377 static void ack_dynirq(struct irq_data *data)
1378 {
1379         int evtchn = evtchn_from_irq(data->irq);
1380
1381         irq_move_irq(data);
1382
1383         if (VALID_EVTCHN(evtchn))
1384                 clear_evtchn(evtchn);
1385 }
1386
1387 static void mask_ack_dynirq(struct irq_data *data)
1388 {
1389         disable_dynirq(data);
1390         ack_dynirq(data);
1391 }
1392
1393 static int retrigger_dynirq(struct irq_data *data)
1394 {
1395         int evtchn = evtchn_from_irq(data->irq);
1396         struct shared_info *sh = HYPERVISOR_shared_info;
1397         int ret = 0;
1398
1399         if (VALID_EVTCHN(evtchn)) {
1400                 int masked;
1401
1402                 masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
1403                 sync_set_bit(evtchn, sh->evtchn_pending);
1404                 if (!masked)
1405                         unmask_evtchn(evtchn);
1406                 ret = 1;
1407         }
1408
1409         return ret;
1410 }
1411
1412 static void restore_pirqs(void)
1413 {
1414         int pirq, rc, irq, gsi;
1415         struct physdev_map_pirq map_irq;
1416         struct irq_info *info;
1417
1418         list_for_each_entry(info, &xen_irq_list_head, list) {
1419                 if (info->type != IRQT_PIRQ)
1420                         continue;
1421
1422                 pirq = info->u.pirq.pirq;
1423                 gsi = info->u.pirq.gsi;
1424                 irq = info->irq;
1425
1426                 /* save/restore of PT devices doesn't work, so at this point the
1427                  * only devices present are GSI based emulated devices */
1428                 if (!gsi)
1429                         continue;
1430
1431                 map_irq.domid = DOMID_SELF;
1432                 map_irq.type = MAP_PIRQ_TYPE_GSI;
1433                 map_irq.index = gsi;
1434                 map_irq.pirq = pirq;
1435
1436                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1437                 if (rc) {
1438                         printk(KERN_WARNING "xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1439                                         gsi, irq, pirq, rc);
1440                         xen_free_irq(irq);
1441                         continue;
1442                 }
1443
1444                 printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1445
1446                 __startup_pirq(irq);
1447         }
1448 }
1449
1450 static void restore_cpu_virqs(unsigned int cpu)
1451 {
1452         struct evtchn_bind_virq bind_virq;
1453         int virq, irq, evtchn;
1454
1455         for (virq = 0; virq < NR_VIRQS; virq++) {
1456                 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1457                         continue;
1458
1459                 BUG_ON(virq_from_irq(irq) != virq);
1460
1461                 /* Get a new binding from Xen. */
1462                 bind_virq.virq = virq;
1463                 bind_virq.vcpu = cpu;
1464                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1465                                                 &bind_virq) != 0)
1466                         BUG();
1467                 evtchn = bind_virq.port;
1468
1469                 /* Record the new mapping. */
1470                 xen_irq_info_virq_init(cpu, irq, evtchn, virq);
1471                 bind_evtchn_to_cpu(evtchn, cpu);
1472         }
1473 }
1474
1475 static void restore_cpu_ipis(unsigned int cpu)
1476 {
1477         struct evtchn_bind_ipi bind_ipi;
1478         int ipi, irq, evtchn;
1479
1480         for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1481                 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1482                         continue;
1483
1484                 BUG_ON(ipi_from_irq(irq) != ipi);
1485
1486                 /* Get a new binding from Xen. */
1487                 bind_ipi.vcpu = cpu;
1488                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1489                                                 &bind_ipi) != 0)
1490                         BUG();
1491                 evtchn = bind_ipi.port;
1492
1493                 /* Record the new mapping. */
1494                 xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
1495                 bind_evtchn_to_cpu(evtchn, cpu);
1496         }
1497 }
1498
1499 /* Clear an irq's pending state, in preparation for polling on it */
1500 void xen_clear_irq_pending(int irq)
1501 {
1502         int evtchn = evtchn_from_irq(irq);
1503
1504         if (VALID_EVTCHN(evtchn))
1505                 clear_evtchn(evtchn);
1506 }
1507 EXPORT_SYMBOL(xen_clear_irq_pending);
1508 void xen_set_irq_pending(int irq)
1509 {
1510         int evtchn = evtchn_from_irq(irq);
1511
1512         if (VALID_EVTCHN(evtchn))
1513                 set_evtchn(evtchn);
1514 }
1515
1516 bool xen_test_irq_pending(int irq)
1517 {
1518         int evtchn = evtchn_from_irq(irq);
1519         bool ret = false;
1520
1521         if (VALID_EVTCHN(evtchn))
1522                 ret = test_evtchn(evtchn);
1523
1524         return ret;
1525 }
1526
1527 /* Poll waiting for an irq to become pending with timeout.  In the usual case,
1528  * the irq will be disabled so it won't deliver an interrupt. */
1529 void xen_poll_irq_timeout(int irq, u64 timeout)
1530 {
1531         evtchn_port_t evtchn = evtchn_from_irq(irq);
1532
1533         if (VALID_EVTCHN(evtchn)) {
1534                 struct sched_poll poll;
1535
1536                 poll.nr_ports = 1;
1537                 poll.timeout = timeout;
1538                 set_xen_guest_handle(poll.ports, &evtchn);
1539
1540                 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1541                         BUG();
1542         }
1543 }
1544 EXPORT_SYMBOL(xen_poll_irq_timeout);
1545 /* Poll waiting for an irq to become pending.  In the usual case, the
1546  * irq will be disabled so it won't deliver an interrupt. */
1547 void xen_poll_irq(int irq)
1548 {
1549         xen_poll_irq_timeout(irq, 0 /* no timeout */);
1550 }
1551
1552 /* Check whether the IRQ line is shared with other guests. */
1553 int xen_test_irq_shared(int irq)
1554 {
1555         struct irq_info *info = info_for_irq(irq);
1556         struct physdev_irq_status_query irq_status = { .irq = info->u.pirq.pirq };
1557
1558         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
1559                 return 0;
1560         return !(irq_status.flags & XENIRQSTAT_shared);
1561 }
1562 EXPORT_SYMBOL_GPL(xen_test_irq_shared);
1563
1564 void xen_irq_resume(void)
1565 {
1566         unsigned int cpu, evtchn;
1567         struct irq_info *info;
1568
1569         init_evtchn_cpu_bindings();
1570
1571         /* New event-channel space is not 'live' yet. */
1572         for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1573                 mask_evtchn(evtchn);
1574
1575         /* No IRQ <-> event-channel mappings. */
1576         list_for_each_entry(info, &xen_irq_list_head, list)
1577                 info->evtchn = 0; /* zap event-channel binding */
1578
1579         for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1580                 evtchn_to_irq[evtchn] = -1;
1581
1582         for_each_possible_cpu(cpu) {
1583                 restore_cpu_virqs(cpu);
1584                 restore_cpu_ipis(cpu);
1585         }
1586
1587         restore_pirqs();
1588 }
1589
1590 static struct irq_chip xen_dynamic_chip __read_mostly = {
1591         .name                   = "xen-dyn",
1592
1593         .irq_disable            = disable_dynirq,
1594         .irq_mask               = disable_dynirq,
1595         .irq_unmask             = enable_dynirq,
1596
1597         .irq_ack                = ack_dynirq,
1598         .irq_mask_ack           = mask_ack_dynirq,
1599
1600         .irq_set_affinity       = set_affinity_irq,
1601         .irq_retrigger          = retrigger_dynirq,
1602 };
1603
1604 static struct irq_chip xen_pirq_chip __read_mostly = {
1605         .name                   = "xen-pirq",
1606
1607         .irq_startup            = startup_pirq,
1608         .irq_shutdown           = shutdown_pirq,
1609         .irq_enable             = enable_pirq,
1610         .irq_disable            = disable_pirq,
1611
1612         .irq_mask               = disable_dynirq,
1613         .irq_unmask             = enable_dynirq,
1614
1615         .irq_ack                = eoi_pirq,
1616         .irq_eoi                = eoi_pirq,
1617         .irq_mask_ack           = mask_ack_pirq,
1618
1619         .irq_set_affinity       = set_affinity_irq,
1620
1621         .irq_retrigger          = retrigger_dynirq,
1622 };
1623
1624 static struct irq_chip xen_percpu_chip __read_mostly = {
1625         .name                   = "xen-percpu",
1626
1627         .irq_disable            = disable_dynirq,
1628         .irq_mask               = disable_dynirq,
1629         .irq_unmask             = enable_dynirq,
1630
1631         .irq_ack                = ack_dynirq,
1632 };
1633
1634 int xen_set_callback_via(uint64_t via)
1635 {
1636         struct xen_hvm_param a;
1637         a.domid = DOMID_SELF;
1638         a.index = HVM_PARAM_CALLBACK_IRQ;
1639         a.value = via;
1640         return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1641 }
1642 EXPORT_SYMBOL_GPL(xen_set_callback_via);
1643
1644 #ifdef CONFIG_XEN_PVHVM
1645 /* Vector callbacks are better than PCI interrupts to receive event
1646  * channel notifications because we can receive vector callbacks on any
1647  * vcpu and we don't need PCI support or APIC interactions. */
1648 void xen_callback_vector(void)
1649 {
1650         int rc;
1651         uint64_t callback_via;
1652         if (xen_have_vector_callback) {
1653                 callback_via = HVM_CALLBACK_VECTOR(XEN_HVM_EVTCHN_CALLBACK);
1654                 rc = xen_set_callback_via(callback_via);
1655                 if (rc) {
1656                         printk(KERN_ERR "Request for Xen HVM callback vector"
1657                                         " failed.\n");
1658                         xen_have_vector_callback = 0;
1659                         return;
1660                 }
1661                 printk(KERN_INFO "Xen HVM callback vector for event delivery is "
1662                                 "enabled\n");
1663                 /* in the restore case the vector has already been allocated */
1664                 if (!test_bit(XEN_HVM_EVTCHN_CALLBACK, used_vectors))
1665                         alloc_intr_gate(XEN_HVM_EVTCHN_CALLBACK, xen_hvm_callback_vector);
1666         }
1667 }
1668 #else
1669 void xen_callback_vector(void) {}
1670 #endif
1671
1672 void __init xen_init_IRQ(void)
1673 {
1674         int i;
1675
1676         evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
1677                                     GFP_KERNEL);
1678         for (i = 0; i < NR_EVENT_CHANNELS; i++)
1679                 evtchn_to_irq[i] = -1;
1680
1681         init_evtchn_cpu_bindings();
1682
1683         /* No event channels are 'live' right now. */
1684         for (i = 0; i < NR_EVENT_CHANNELS; i++)
1685                 mask_evtchn(i);
1686
1687         if (xen_hvm_domain()) {
1688                 xen_callback_vector();
1689                 native_init_IRQ();
1690                 /* pci_xen_hvm_init must be called after native_init_IRQ so that
1691                  * __acpi_register_gsi can point at the right function */
1692                 pci_xen_hvm_init();
1693         } else {
1694                 irq_ctx_init(smp_processor_id());
1695                 if (xen_initial_domain())
1696                         xen_setup_pirqs();
1697         }
1698 }