drivers/xen/events/events_base.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 #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
  25
  26 #include <linux/linkage.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/irq.h>
  29 #include <linux/module.h>
  30 #include <linux/string.h>
  31 #include <linux/bootmem.h>
  32 #include <linux/slab.h>
  33 #include <linux/irqnr.h>
  34 #include <linux/pci.h>
  35
  36 #ifdef CONFIG_X86
  37 #include <asm/desc.h>
  38 #include <asm/ptrace.h>
  39 #include <asm/irq.h>
  40 #include <asm/idle.h>
  41 #include <asm/io_apic.h>
  42 #include <asm/xen/page.h>
  43 #include <asm/xen/pci.h>
  44 #endif
  45 #include <asm/sync_bitops.h>
  46 #include <asm/xen/hypercall.h>
  47 #include <asm/xen/hypervisor.h>
  48
  49 #include <xen/xen.h>
  50 #include <xen/hvm.h>
  51 #include <xen/xen-ops.h>
  52 #include <xen/events.h>
  53 #include <xen/interface/xen.h>
  54 #include <xen/interface/event_channel.h>
  55 #include <xen/interface/hvm/hvm_op.h>
  56 #include <xen/interface/hvm/params.h>
  57 #include <xen/interface/physdev.h>
  58 #include <xen/interface/sched.h>
  59 #include <xen/interface/vcpu.h>
  60 #include <asm/hw_irq.h>
  61
  62 #include "events_internal.h"
  63
  64 const struct evtchn_ops *evtchn_ops;
  65
  66 /*
  67  * This lock protects updates to the following mapping and reference-count
  68  * arrays. The lock does not need to be acquired to read the mapping tables.
  69  */
  70 static DEFINE_MUTEX(irq_mapping_update_lock);
  71
  72 static LIST_HEAD(xen_irq_list_head);
  73
  74 /* IRQ <-> VIRQ mapping. */
  75 static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
  76
  77 /* IRQ <-> IPI mapping */
  78 static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
  79
  80 int **evtchn_to_irq;
  81 #ifdef CONFIG_X86
  82 static unsigned long *pirq_eoi_map;
  83 #endif
  84 static bool (*pirq_needs_eoi)(unsigned irq);
  85
  86 #define EVTCHN_ROW(e)  (e / (PAGE_SIZE/sizeof(**evtchn_to_irq)))
  87 #define EVTCHN_COL(e)  (e % (PAGE_SIZE/sizeof(**evtchn_to_irq)))
  88 #define EVTCHN_PER_ROW (PAGE_SIZE / sizeof(**evtchn_to_irq))
  89
  90 /* Xen will never allocate port zero for any purpose. */
  91 #define VALID_EVTCHN(chn)       ((chn) != 0)
  92
  93 static struct irq_chip xen_dynamic_chip;
  94 static struct irq_chip xen_percpu_chip;
  95 static struct irq_chip xen_pirq_chip;
  96 static void enable_dynirq(struct irq_data *data);
  97 static void disable_dynirq(struct irq_data *data);
  98
  99 static void clear_evtchn_to_irq_row(unsigned row)
 100 {
 101         unsigned col;
 102
 103         for (col = 0; col < EVTCHN_PER_ROW; col++)
 104                 evtchn_to_irq[row][col] = -1;
 105 }
 106
 107 static void clear_evtchn_to_irq_all(void)
 108 {
 109         unsigned row;
 110
 111         for (row = 0; row < EVTCHN_ROW(xen_evtchn_max_channels()); row++) {
 112                 if (evtchn_to_irq[row] == NULL)
 113                         continue;
 114                 clear_evtchn_to_irq_row(row);
 115         }
 116 }
 117
 118 static int set_evtchn_to_irq(unsigned evtchn, unsigned irq)
 119 {
 120         unsigned row;
 121         unsigned col;
 122
 123         if (evtchn >= xen_evtchn_max_channels())
 124                 return -EINVAL;
 125
 126         row = EVTCHN_ROW(evtchn);
 127         col = EVTCHN_COL(evtchn);
 128
 129         if (evtchn_to_irq[row] == NULL) {
 130                 /* Unallocated irq entries return -1 anyway */
 131                 if (irq == -1)
 132                         return 0;
 133
 134                 evtchn_to_irq[row] = (int *)get_zeroed_page(GFP_KERNEL);
 135                 if (evtchn_to_irq[row] == NULL)
 136                         return -ENOMEM;
 137
 138                 clear_evtchn_to_irq_row(row);
 139         }
 140
 141         evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)] = irq;
 142         return 0;
 143 }
 144
 145 int get_evtchn_to_irq(unsigned evtchn)
 146 {
 147         if (evtchn >= xen_evtchn_max_channels())
 148                 return -1;
 149         if (evtchn_to_irq[EVTCHN_ROW(evtchn)] == NULL)
 150                 return -1;
 151         return evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)];
 152 }
 153
 154 /* Get info for IRQ */
 155 struct irq_info *info_for_irq(unsigned irq)
 156 {
 157         return irq_get_handler_data(irq);
 158 }
 159
 160 /* Constructors for packed IRQ information. */
 161 static int xen_irq_info_common_setup(struct irq_info *info,
 162                                      unsigned irq,
 163                                      enum xen_irq_type type,
 164                                      unsigned evtchn,
 165                                      unsigned short cpu)
 166 {
 167         int ret;
 168
 169         BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
 170
 171         info->type = type;
 172         info->irq = irq;
 173         info->evtchn = evtchn;
 174         info->cpu = cpu;
 175
 176         ret = set_evtchn_to_irq(evtchn, irq);
 177         if (ret < 0)
 178                 return ret;
 179
 180         irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN);
 181
 182         return xen_evtchn_port_setup(info);
 183 }
 184
 185 static int xen_irq_info_evtchn_setup(unsigned irq,
 186                                      unsigned evtchn)
 187 {
 188         struct irq_info *info = info_for_irq(irq);
 189
 190         return xen_irq_info_common_setup(info, irq, IRQT_EVTCHN, evtchn, 0);
 191 }
 192
 193 static int xen_irq_info_ipi_setup(unsigned cpu,
 194                                   unsigned irq,
 195                                   unsigned evtchn,
 196                                   enum ipi_vector ipi)
 197 {
 198         struct irq_info *info = info_for_irq(irq);
 199
 200         info->u.ipi = ipi;
 201
 202         per_cpu(ipi_to_irq, cpu)[ipi] = irq;
 203
 204         return xen_irq_info_common_setup(info, irq, IRQT_IPI, evtchn, 0);
 205 }
 206
 207 static int xen_irq_info_virq_setup(unsigned cpu,
 208                                    unsigned irq,
 209                                    unsigned evtchn,
 210                                    unsigned virq)
 211 {
 212         struct irq_info *info = info_for_irq(irq);
 213
 214         info->u.virq = virq;
 215
 216         per_cpu(virq_to_irq, cpu)[virq] = irq;
 217
 218         return xen_irq_info_common_setup(info, irq, IRQT_VIRQ, evtchn, 0);
 219 }
 220
 221 static int xen_irq_info_pirq_setup(unsigned irq,
 222                                    unsigned evtchn,
 223                                    unsigned pirq,
 224                                    unsigned gsi,
 225                                    uint16_t domid,
 226                                    unsigned char flags)
 227 {
 228         struct irq_info *info = info_for_irq(irq);
 229
 230         info->u.pirq.pirq = pirq;
 231         info->u.pirq.gsi = gsi;
 232         info->u.pirq.domid = domid;
 233         info->u.pirq.flags = flags;
 234
 235         return xen_irq_info_common_setup(info, irq, IRQT_PIRQ, evtchn, 0);
 236 }
 237
 238 static void xen_irq_info_cleanup(struct irq_info *info)
 239 {
 240         set_evtchn_to_irq(info->evtchn, -1);
 241         info->evtchn = 0;
 242 }
 243
 244 /*
 245  * Accessors for packed IRQ information.
 246  */
 247 unsigned int evtchn_from_irq(unsigned irq)
 248 {
 249         if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))
 250                 return 0;
 251
 252         return info_for_irq(irq)->evtchn;
 253 }
 254
 255 unsigned irq_from_evtchn(unsigned int evtchn)
 256 {
 257         return get_evtchn_to_irq(evtchn);
 258 }
 259 EXPORT_SYMBOL_GPL(irq_from_evtchn);
 260
 261 int irq_from_virq(unsigned int cpu, unsigned int virq)
 262 {
 263         return per_cpu(virq_to_irq, cpu)[virq];
 264 }
 265
 266 static enum ipi_vector ipi_from_irq(unsigned irq)
 267 {
 268         struct irq_info *info = info_for_irq(irq);
 269
 270         BUG_ON(info == NULL);
 271         BUG_ON(info->type != IRQT_IPI);
 272
 273         return info->u.ipi;
 274 }
 275
 276 static unsigned virq_from_irq(unsigned irq)
 277 {
 278         struct irq_info *info = info_for_irq(irq);
 279
 280         BUG_ON(info == NULL);
 281         BUG_ON(info->type != IRQT_VIRQ);
 282
 283         return info->u.virq;
 284 }
 285
 286 static unsigned pirq_from_irq(unsigned irq)
 287 {
 288         struct irq_info *info = info_for_irq(irq);
 289
 290         BUG_ON(info == NULL);
 291         BUG_ON(info->type != IRQT_PIRQ);
 292
 293         return info->u.pirq.pirq;
 294 }
 295
 296 static enum xen_irq_type type_from_irq(unsigned irq)
 297 {
 298         return info_for_irq(irq)->type;
 299 }
 300
 301 unsigned cpu_from_irq(unsigned irq)
 302 {
 303         return info_for_irq(irq)->cpu;
 304 }
 305
 306 unsigned int cpu_from_evtchn(unsigned int evtchn)
 307 {
 308         int irq = get_evtchn_to_irq(evtchn);
 309         unsigned ret = 0;
 310
 311         if (irq != -1)
 312                 ret = cpu_from_irq(irq);
 313
 314         return ret;
 315 }
 316
 317 #ifdef CONFIG_X86
 318 static bool pirq_check_eoi_map(unsigned irq)
 319 {
 320         return test_bit(pirq_from_irq(irq), pirq_eoi_map);
 321 }
 322 #endif
 323
 324 static bool pirq_needs_eoi_flag(unsigned irq)
 325 {
 326         struct irq_info *info = info_for_irq(irq);
 327         BUG_ON(info->type != IRQT_PIRQ);
 328
 329         return info->u.pirq.flags & PIRQ_NEEDS_EOI;
 330 }
 331
 332 static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
 333 {
 334         int irq = get_evtchn_to_irq(chn);
 335         struct irq_info *info = info_for_irq(irq);
 336
 337         BUG_ON(irq == -1);
 338 #ifdef CONFIG_SMP
 339         cpumask_copy(irq_get_irq_data(irq)->affinity, cpumask_of(cpu));
 340 #endif
 341         xen_evtchn_port_bind_to_cpu(info, cpu);
 342
 343         info->cpu = cpu;
 344 }
 345
 346 static void xen_evtchn_mask_all(void)
 347 {
 348         unsigned int evtchn;
 349
 350         for (evtchn = 0; evtchn < xen_evtchn_nr_channels(); evtchn++)
 351                 mask_evtchn(evtchn);
 352 }
 353
 354 /**
 355  * notify_remote_via_irq - send event to remote end of event channel via irq
 356  * @irq: irq of event channel to send event to
 357  *
 358  * Unlike notify_remote_via_evtchn(), this is safe to use across
 359  * save/restore. Notifications on a broken connection are silently
 360  * dropped.
 361  */
 362 void notify_remote_via_irq(int irq)
 363 {
 364         int evtchn = evtchn_from_irq(irq);
 365
 366         if (VALID_EVTCHN(evtchn))
 367                 notify_remote_via_evtchn(evtchn);
 368 }
 369 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
 370
 371 static void xen_irq_init(unsigned irq)
 372 {
 373         struct irq_info *info;
 374 #ifdef CONFIG_SMP
 375         /* By default all event channels notify CPU#0. */
 376         cpumask_copy(irq_get_irq_data(irq)->affinity, cpumask_of(0));
 377 #endif
 378
 379         info = kzalloc(sizeof(*info), GFP_KERNEL);
 380         if (info == NULL)
 381                 panic("Unable to allocate metadata for IRQ%d\n", irq);
 382
 383         info->type = IRQT_UNBOUND;
 384         info->refcnt = -1;
 385
 386         irq_set_handler_data(irq, info);
 387
 388         list_add_tail(&info->list, &xen_irq_list_head);
 389 }
 390
 391 static int __must_check xen_allocate_irq_dynamic(void)
 392 {
 393         int first = 0;
 394         int irq;
 395
 396 #ifdef CONFIG_X86_IO_APIC
 397         /*
 398          * For an HVM guest or domain 0 which see "real" (emulated or
 399          * actual respectively) GSIs we allocate dynamic IRQs
 400          * e.g. those corresponding to event channels or MSIs
 401          * etc. from the range above those "real" GSIs to avoid
 402          * collisions.
 403          */
 404         if (xen_initial_domain() || xen_hvm_domain())
 405                 first = get_nr_irqs_gsi();
 406 #endif
 407
 408         irq = irq_alloc_desc_from(first, -1);
 409
 410         if (irq >= 0)
 411                 xen_irq_init(irq);
 412
 413         return irq;
 414 }
 415
 416 static int __must_check xen_allocate_irq_gsi(unsigned gsi)
 417 {
 418         int irq;
 419
 420         /*
 421          * A PV guest has no concept of a GSI (since it has no ACPI
 422          * nor access to/knowledge of the physical APICs). Therefore
 423          * all IRQs are dynamically allocated from the entire IRQ
 424          * space.
 425          */
 426         if (xen_pv_domain() && !xen_initial_domain())
 427                 return xen_allocate_irq_dynamic();
 428
 429         /* Legacy IRQ descriptors are already allocated by the arch. */
 430         if (gsi < NR_IRQS_LEGACY)
 431                 irq = gsi;
 432         else
 433                 irq = irq_alloc_desc_at(gsi, -1);
 434
 435         xen_irq_init(irq);
 436
 437         return irq;
 438 }
 439
 440 static void xen_free_irq(unsigned irq)
 441 {
 442         struct irq_info *info = irq_get_handler_data(irq);
 443
 444         if (WARN_ON(!info))
 445                 return;
 446
 447         list_del(&info->list);
 448
 449         irq_set_handler_data(irq, NULL);
 450
 451         WARN_ON(info->refcnt > 0);
 452
 453         kfree(info);
 454
 455         /* Legacy IRQ descriptors are managed by the arch. */
 456         if (irq < NR_IRQS_LEGACY)
 457                 return;
 458
 459         irq_free_desc(irq);
 460 }
 461
 462 static void xen_evtchn_close(unsigned int port)
 463 {
 464         struct evtchn_close close;
 465
 466         close.port = port;
 467         if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 468                 BUG();
 469
 470         /* Closed ports are implicitly re-bound to VCPU0. */
 471         bind_evtchn_to_cpu(port, 0);
 472 }
 473
 474 static void pirq_query_unmask(int irq)
 475 {
 476         struct physdev_irq_status_query irq_status;
 477         struct irq_info *info = info_for_irq(irq);
 478
 479         BUG_ON(info->type != IRQT_PIRQ);
 480
 481         irq_status.irq = pirq_from_irq(irq);
 482         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
 483                 irq_status.flags = 0;
 484
 485         info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
 486         if (irq_status.flags & XENIRQSTAT_needs_eoi)
 487                 info->u.pirq.flags |= PIRQ_NEEDS_EOI;
 488 }
 489
 490 static void eoi_pirq(struct irq_data *data)
 491 {
 492         int evtchn = evtchn_from_irq(data->irq);
 493         struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
 494         int rc = 0;
 495
 496         irq_move_irq(data);
 497
 498         if (VALID_EVTCHN(evtchn))
 499                 clear_evtchn(evtchn);
 500
 501         if (pirq_needs_eoi(data->irq)) {
 502                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
 503                 WARN_ON(rc);
 504         }
 505 }
 506
 507 static void mask_ack_pirq(struct irq_data *data)
 508 {
 509         disable_dynirq(data);
 510         eoi_pirq(data);
 511 }
 512
 513 static unsigned int __startup_pirq(unsigned int irq)
 514 {
 515         struct evtchn_bind_pirq bind_pirq;
 516         struct irq_info *info = info_for_irq(irq);
 517         int evtchn = evtchn_from_irq(irq);
 518         int rc;
 519
 520         BUG_ON(info->type != IRQT_PIRQ);
 521
 522         if (VALID_EVTCHN(evtchn))
 523                 goto out;
 524
 525         bind_pirq.pirq = pirq_from_irq(irq);
 526         /* NB. We are happy to share unless we are probing. */
 527         bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
 528                                         BIND_PIRQ__WILL_SHARE : 0;
 529         rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
 530         if (rc != 0) {
 531                 pr_warn("Failed to obtain physical IRQ %d\n", irq);
 532                 return 0;
 533         }
 534         evtchn = bind_pirq.port;
 535
 536         pirq_query_unmask(irq);
 537
 538         rc = set_evtchn_to_irq(evtchn, irq);
 539         if (rc != 0) {
 540                 pr_err("irq%d: Failed to set port to irq mapping (%d)\n",
 541                        irq, rc);
 542                 xen_evtchn_close(evtchn);
 543                 return 0;
 544         }
 545         bind_evtchn_to_cpu(evtchn, 0);
 546         info->evtchn = evtchn;
 547
 548 out:
 549         unmask_evtchn(evtchn);
 550         eoi_pirq(irq_get_irq_data(irq));
 551
 552         return 0;
 553 }
 554
 555 static unsigned int startup_pirq(struct irq_data *data)
 556 {
 557         return __startup_pirq(data->irq);
 558 }
 559
 560 static void shutdown_pirq(struct irq_data *data)
 561 {
 562         unsigned int irq = data->irq;
 563         struct irq_info *info = info_for_irq(irq);
 564         unsigned evtchn = evtchn_from_irq(irq);
 565
 566         BUG_ON(info->type != IRQT_PIRQ);
 567
 568         if (!VALID_EVTCHN(evtchn))
 569                 return;
 570
 571         mask_evtchn(evtchn);
 572         xen_evtchn_close(evtchn);
 573         xen_irq_info_cleanup(info);
 574 }
 575
 576 static void enable_pirq(struct irq_data *data)
 577 {
 578         startup_pirq(data);
 579 }
 580
 581 static void disable_pirq(struct irq_data *data)
 582 {
 583         disable_dynirq(data);
 584 }
 585
 586 int xen_irq_from_gsi(unsigned gsi)
 587 {
 588         struct irq_info *info;
 589
 590         list_for_each_entry(info, &xen_irq_list_head, list) {
 591                 if (info->type != IRQT_PIRQ)
 592                         continue;
 593
 594                 if (info->u.pirq.gsi == gsi)
 595                         return info->irq;
 596         }
 597
 598         return -1;
 599 }
 600 EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
 601
 602 static void __unbind_from_irq(unsigned int irq)
 603 {
 604         int evtchn = evtchn_from_irq(irq);
 605         struct irq_info *info = irq_get_handler_data(irq);
 606
 607         if (info->refcnt > 0) {
 608                 info->refcnt--;
 609                 if (info->refcnt != 0)
 610                         return;
 611         }
 612
 613         if (VALID_EVTCHN(evtchn)) {
 614                 unsigned int cpu = cpu_from_irq(irq);
 615
 616                 xen_evtchn_close(evtchn);
 617
 618                 switch (type_from_irq(irq)) {
 619                 case IRQT_VIRQ:
 620                         per_cpu(virq_to_irq, cpu)[virq_from_irq(irq)] = -1;
 621                         break;
 622                 case IRQT_IPI:
 623                         per_cpu(ipi_to_irq, cpu)[ipi_from_irq(irq)] = -1;
 624                         break;
 625                 default:
 626                         break;
 627                 }
 628
 629                 xen_irq_info_cleanup(info);
 630         }
 631
 632         BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
 633
 634         xen_free_irq(irq);
 635 }
 636
 637 /*
 638  * Do not make any assumptions regarding the relationship between the
 639  * IRQ number returned here and the Xen pirq argument.
 640  *
 641  * Note: We don't assign an event channel until the irq actually started
 642  * up.  Return an existing irq if we've already got one for the gsi.
 643  *
 644  * Shareable implies level triggered, not shareable implies edge
 645  * triggered here.
 646  */
 647 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 648                              unsigned pirq, int shareable, char *name)
 649 {
 650         int irq = -1;
 651         struct physdev_irq irq_op;
 652         int ret;
 653
 654         mutex_lock(&irq_mapping_update_lock);
 655
 656         irq = xen_irq_from_gsi(gsi);
 657         if (irq != -1) {
 658                 pr_info("%s: returning irq %d for gsi %u\n",
 659                         __func__, irq, gsi);
 660                 goto out;
 661         }
 662
 663         irq = xen_allocate_irq_gsi(gsi);
 664         if (irq < 0)
 665                 goto out;
 666
 667         irq_op.irq = irq;
 668         irq_op.vector = 0;
 669
 670         /* Only the privileged domain can do this. For non-priv, the pcifront
 671          * driver provides a PCI bus that does the call to do exactly
 672          * this in the priv domain. */
 673         if (xen_initial_domain() &&
 674             HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
 675                 xen_free_irq(irq);
 676                 irq = -ENOSPC;
 677                 goto out;
 678         }
 679
 680         ret = xen_irq_info_pirq_setup(irq, 0, pirq, gsi, DOMID_SELF,
 681                                shareable ? PIRQ_SHAREABLE : 0);
 682         if (ret < 0) {
 683                 __unbind_from_irq(irq);
 684                 irq = ret;
 685                 goto out;
 686         }
 687
 688         pirq_query_unmask(irq);
 689         /* We try to use the handler with the appropriate semantic for the
 690          * type of interrupt: if the interrupt is an edge triggered
 691          * interrupt we use handle_edge_irq.
 692          *
 693          * On the other hand if the interrupt is level triggered we use
 694          * handle_fasteoi_irq like the native code does for this kind of
 695          * interrupts.
 696          *
 697          * Depending on the Xen version, pirq_needs_eoi might return true
 698          * not only for level triggered interrupts but for edge triggered
 699          * interrupts too. In any case Xen always honors the eoi mechanism,
 700          * not injecting any more pirqs of the same kind if the first one
 701          * hasn't received an eoi yet. Therefore using the fasteoi handler
 702          * is the right choice either way.
 703          */
 704         if (shareable)
 705                 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 706                                 handle_fasteoi_irq, name);
 707         else
 708                 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 709                                 handle_edge_irq, name);
 710
 711 out:
 712         mutex_unlock(&irq_mapping_update_lock);
 713
 714         return irq;
 715 }
 716
 717 #ifdef CONFIG_PCI_MSI
 718 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
 719 {
 720         int rc;
 721         struct physdev_get_free_pirq op_get_free_pirq;
 722
 723         op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
 724         rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
 725
 726         WARN_ONCE(rc == -ENOSYS,
 727                   "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
 728
 729         return rc ? -1 : op_get_free_pirq.pirq;
 730 }
 731
 732 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
 733                              int pirq, const char *name, domid_t domid)
 734 {
 735         int irq, ret;
 736
 737         mutex_lock(&irq_mapping_update_lock);
 738
 739         irq = xen_allocate_irq_dynamic();
 740         if (irq < 0)
 741                 goto out;
 742
 743         irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_edge_irq,
 744                         name);
 745
 746         ret = xen_irq_info_pirq_setup(irq, 0, pirq, 0, domid, 0);
 747         if (ret < 0)
 748                 goto error_irq;
 749         ret = irq_set_msi_desc(irq, msidesc);
 750         if (ret < 0)
 751                 goto error_irq;
 752 out:
 753         mutex_unlock(&irq_mapping_update_lock);
 754         return irq;
 755 error_irq:
 756         __unbind_from_irq(irq);
 757         mutex_unlock(&irq_mapping_update_lock);
 758         return ret;
 759 }
 760 #endif
 761
 762 int xen_destroy_irq(int irq)
 763 {
 764         struct physdev_unmap_pirq unmap_irq;
 765         struct irq_info *info = info_for_irq(irq);
 766         int rc = -ENOENT;
 767
 768         mutex_lock(&irq_mapping_update_lock);
 769
 770         if (xen_initial_domain()) {
 771                 unmap_irq.pirq = info->u.pirq.pirq;
 772                 unmap_irq.domid = info->u.pirq.domid;
 773                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
 774                 /* If another domain quits without making the pci_disable_msix
 775                  * call, the Xen hypervisor takes care of freeing the PIRQs
 776                  * (free_domain_pirqs).
 777                  */
 778                 if ((rc == -ESRCH && info->u.pirq.domid != DOMID_SELF))
 779                         pr_info("domain %d does not have %d anymore\n",
 780                                 info->u.pirq.domid, info->u.pirq.pirq);
 781                 else if (rc) {
 782                         pr_warn("unmap irq failed %d\n", rc);
 783                         goto out;
 784                 }
 785         }
 786
 787         xen_free_irq(irq);
 788
 789 out:
 790         mutex_unlock(&irq_mapping_update_lock);
 791         return rc;
 792 }
 793
 794 int xen_irq_from_pirq(unsigned pirq)
 795 {
 796         int irq;
 797
 798         struct irq_info *info;
 799
 800         mutex_lock(&irq_mapping_update_lock);
 801
 802         list_for_each_entry(info, &xen_irq_list_head, list) {
 803                 if (info->type != IRQT_PIRQ)
 804                         continue;
 805                 irq = info->irq;
 806                 if (info->u.pirq.pirq == pirq)
 807                         goto out;
 808         }
 809         irq = -1;
 810 out:
 811         mutex_unlock(&irq_mapping_update_lock);
 812
 813         return irq;
 814 }
 815
 816
 817 int xen_pirq_from_irq(unsigned irq)
 818 {
 819         return pirq_from_irq(irq);
 820 }
 821 EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
 822
 823 int bind_evtchn_to_irq(unsigned int evtchn)
 824 {
 825         int irq;
 826         int ret;
 827
 828         if (evtchn >= xen_evtchn_max_channels())
 829                 return -ENOMEM;
 830
 831         mutex_lock(&irq_mapping_update_lock);
 832
 833         irq = get_evtchn_to_irq(evtchn);
 834
 835         if (irq == -1) {
 836                 irq = xen_allocate_irq_dynamic();
 837                 if (irq < 0)
 838                         goto out;
 839
 840                 irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
 841                                               handle_edge_irq, "event");
 842
 843                 ret = xen_irq_info_evtchn_setup(irq, evtchn);
 844                 if (ret < 0) {
 845                         __unbind_from_irq(irq);
 846                         irq = ret;
 847                         goto out;
 848                 }
 849                 /* New interdomain events are bound to VCPU 0. */
 850                 bind_evtchn_to_cpu(evtchn, 0);
 851         } else {
 852                 struct irq_info *info = info_for_irq(irq);
 853                 WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
 854         }
 855
 856 out:
 857         mutex_unlock(&irq_mapping_update_lock);
 858
 859         return irq;
 860 }
 861 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
 862
 863 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 864 {
 865         struct evtchn_bind_ipi bind_ipi;
 866         int evtchn, irq;
 867         int ret;
 868
 869         mutex_lock(&irq_mapping_update_lock);
 870
 871         irq = per_cpu(ipi_to_irq, cpu)[ipi];
 872
 873         if (irq == -1) {
 874                 irq = xen_allocate_irq_dynamic();
 875                 if (irq < 0)
 876                         goto out;
 877
 878                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 879                                               handle_percpu_irq, "ipi");
 880
 881                 bind_ipi.vcpu = cpu;
 882                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
 883                                                 &bind_ipi) != 0)
 884                         BUG();
 885                 evtchn = bind_ipi.port;
 886
 887                 ret = xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
 888                 if (ret < 0) {
 889                         __unbind_from_irq(irq);
 890                         irq = ret;
 891                         goto out;
 892                 }
 893                 bind_evtchn_to_cpu(evtchn, cpu);
 894         } else {
 895                 struct irq_info *info = info_for_irq(irq);
 896                 WARN_ON(info == NULL || info->type != IRQT_IPI);
 897         }
 898
 899  out:
 900         mutex_unlock(&irq_mapping_update_lock);
 901         return irq;
 902 }
 903
 904 static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
 905                                           unsigned int remote_port)
 906 {
 907         struct evtchn_bind_interdomain bind_interdomain;
 908         int err;
 909
 910         bind_interdomain.remote_dom  = remote_domain;
 911         bind_interdomain.remote_port = remote_port;
 912
 913         err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
 914                                           &bind_interdomain);
 915
 916         return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
 917 }
 918
 919 static int find_virq(unsigned int virq, unsigned int cpu)
 920 {
 921         struct evtchn_status status;
 922         int port, rc = -ENOENT;
 923
 924         memset(&status, 0, sizeof(status));
 925         for (port = 0; port < xen_evtchn_max_channels(); port++) {
 926                 status.dom = DOMID_SELF;
 927                 status.port = port;
 928                 rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status);
 929                 if (rc < 0)
 930                         continue;
 931                 if (status.status != EVTCHNSTAT_virq)
 932                         continue;
 933                 if (status.u.virq == virq && status.vcpu == cpu) {
 934                         rc = port;
 935                         break;
 936                 }
 937         }
 938         return rc;
 939 }
 940
 941 /**
 942  * xen_evtchn_nr_channels - number of usable event channel ports
 943  *
 944  * This may be less than the maximum supported by the current
 945  * hypervisor ABI. Use xen_evtchn_max_channels() for the maximum
 946  * supported.
 947  */
 948 unsigned xen_evtchn_nr_channels(void)
 949 {
 950         return evtchn_ops->nr_channels();
 951 }
 952 EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
 953
 954 int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 955 {
 956         struct evtchn_bind_virq bind_virq;
 957         int evtchn, irq, ret;
 958
 959         mutex_lock(&irq_mapping_update_lock);
 960
 961         irq = per_cpu(virq_to_irq, cpu)[virq];
 962
 963         if (irq == -1) {
 964                 irq = xen_allocate_irq_dynamic();
 965                 if (irq < 0)
 966                         goto out;
 967
 968                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 969                                               handle_percpu_irq, "virq");
 970
 971                 bind_virq.virq = virq;
 972                 bind_virq.vcpu = cpu;
 973                 ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
 974                                                 &bind_virq);
 975                 if (ret == 0)
 976                         evtchn = bind_virq.port;
 977                 else {
 978                         if (ret == -EEXIST)
 979                                 ret = find_virq(virq, cpu);
 980                         BUG_ON(ret < 0);
 981                         evtchn = ret;
 982                 }
 983
 984                 ret = xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
 985                 if (ret < 0) {
 986                         __unbind_from_irq(irq);
 987                         irq = ret;
 988                         goto out;
 989                 }
 990
 991                 bind_evtchn_to_cpu(evtchn, cpu);
 992         } else {
 993                 struct irq_info *info = info_for_irq(irq);
 994                 WARN_ON(info == NULL || info->type != IRQT_VIRQ);
 995         }
 996
 997 out:
 998         mutex_unlock(&irq_mapping_update_lock);
 999
1000         return irq;
1001 }
1002
1003 static void unbind_from_irq(unsigned int irq)
1004 {
1005         mutex_lock(&irq_mapping_update_lock);
1006         __unbind_from_irq(irq);
1007         mutex_unlock(&irq_mapping_update_lock);
1008 }
1009
1010 int bind_evtchn_to_irqhandler(unsigned int evtchn,
1011                               irq_handler_t handler,
1012                               unsigned long irqflags,
1013                               const char *devname, void *dev_id)
1014 {
1015         int irq, retval;
1016
1017         irq = bind_evtchn_to_irq(evtchn);
1018         if (irq < 0)
1019                 return irq;
1020         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1021         if (retval != 0) {
1022                 unbind_from_irq(irq);
1023                 return retval;
1024         }
1025
1026         return irq;
1027 }
1028 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
1029
1030 int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
1031                                           unsigned int remote_port,
1032                                           irq_handler_t handler,
1033                                           unsigned long irqflags,
1034                                           const char *devname,
1035                                           void *dev_id)
1036 {
1037         int irq, retval;
1038
1039         irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
1040         if (irq < 0)
1041                 return irq;
1042
1043         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1044         if (retval != 0) {
1045                 unbind_from_irq(irq);
1046                 return retval;
1047         }
1048
1049         return irq;
1050 }
1051 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
1052
1053 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
1054                             irq_handler_t handler,
1055                             unsigned long irqflags, const char *devname, void *dev_id)
1056 {
1057         int irq, retval;
1058
1059         irq = bind_virq_to_irq(virq, cpu);
1060         if (irq < 0)
1061                 return irq;
1062         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1063         if (retval != 0) {
1064                 unbind_from_irq(irq);
1065                 return retval;
1066         }
1067
1068         return irq;
1069 }
1070 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
1071
1072 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
1073                            unsigned int cpu,
1074                            irq_handler_t handler,
1075                            unsigned long irqflags,
1076                            const char *devname,
1077                            void *dev_id)
1078 {
1079         int irq, retval;
1080
1081         irq = bind_ipi_to_irq(ipi, cpu);
1082         if (irq < 0)
1083                 return irq;
1084
1085         irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME | IRQF_EARLY_RESUME;
1086         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1087         if (retval != 0) {
1088                 unbind_from_irq(irq);
1089                 return retval;
1090         }
1091
1092         return irq;
1093 }
1094
1095 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
1096 {
1097         struct irq_info *info = irq_get_handler_data(irq);
1098
1099         if (WARN_ON(!info))
1100                 return;
1101         free_irq(irq, dev_id);
1102         unbind_from_irq(irq);
1103 }
1104 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
1105
1106 /**
1107  * xen_set_irq_priority() - set an event channel priority.
1108  * @irq:irq bound to an event channel.
1109  * @priority: priority between XEN_IRQ_PRIORITY_MAX and XEN_IRQ_PRIORITY_MIN.
1110  */
1111 int xen_set_irq_priority(unsigned irq, unsigned priority)
1112 {
1113         struct evtchn_set_priority set_priority;
1114
1115         set_priority.port = evtchn_from_irq(irq);
1116         set_priority.priority = priority;
1117
1118         return HYPERVISOR_event_channel_op(EVTCHNOP_set_priority,
1119                                            &set_priority);
1120 }
1121 EXPORT_SYMBOL_GPL(xen_set_irq_priority);
1122
1123 int evtchn_make_refcounted(unsigned int evtchn)
1124 {
1125         int irq = get_evtchn_to_irq(evtchn);
1126         struct irq_info *info;
1127
1128         if (irq == -1)
1129                 return -ENOENT;
1130
1131         info = irq_get_handler_data(irq);
1132
1133         if (!info)
1134                 return -ENOENT;
1135
1136         WARN_ON(info->refcnt != -1);
1137
1138         info->refcnt = 1;
1139
1140         return 0;
1141 }
1142 EXPORT_SYMBOL_GPL(evtchn_make_refcounted);
1143
1144 int evtchn_get(unsigned int evtchn)
1145 {
1146         int irq;
1147         struct irq_info *info;
1148         int err = -ENOENT;
1149
1150         if (evtchn >= xen_evtchn_max_channels())
1151                 return -EINVAL;
1152
1153         mutex_lock(&irq_mapping_update_lock);
1154
1155         irq = get_evtchn_to_irq(evtchn);
1156         if (irq == -1)
1157                 goto done;
1158
1159         info = irq_get_handler_data(irq);
1160
1161         if (!info)
1162                 goto done;
1163
1164         err = -EINVAL;
1165         if (info->refcnt <= 0)
1166                 goto done;
1167
1168         info->refcnt++;
1169         err = 0;
1170  done:
1171         mutex_unlock(&irq_mapping_update_lock);
1172
1173         return err;
1174 }
1175 EXPORT_SYMBOL_GPL(evtchn_get);
1176
1177 void evtchn_put(unsigned int evtchn)
1178 {
1179         int irq = get_evtchn_to_irq(evtchn);
1180         if (WARN_ON(irq == -1))
1181                 return;
1182         unbind_from_irq(irq);
1183 }
1184 EXPORT_SYMBOL_GPL(evtchn_put);
1185
1186 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
1187 {
1188         int irq;
1189
1190 #ifdef CONFIG_X86
1191         if (unlikely(vector == XEN_NMI_VECTOR)) {
1192                 int rc =  HYPERVISOR_vcpu_op(VCPUOP_send_nmi, cpu, NULL);
1193                 if (rc < 0)
1194                         printk(KERN_WARNING "Sending nmi to CPU%d failed (rc:%d)\n", cpu, rc);
1195                 return;
1196         }
1197 #endif
1198         irq = per_cpu(ipi_to_irq, cpu)[vector];
1199         BUG_ON(irq < 0);
1200         notify_remote_via_irq(irq);
1201 }
1202
1203 static DEFINE_PER_CPU(unsigned, xed_nesting_count);
1204
1205 static void __xen_evtchn_do_upcall(void)
1206 {
1207         struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1208         int cpu = get_cpu();
1209         unsigned count;
1210
1211         do {
1212                 vcpu_info->evtchn_upcall_pending = 0;
1213
1214                 if (__this_cpu_inc_return(xed_nesting_count) - 1)
1215                         goto out;
1216
1217                 xen_evtchn_handle_events(cpu);
1218
1219                 BUG_ON(!irqs_disabled());
1220
1221                 count = __this_cpu_read(xed_nesting_count);
1222                 __this_cpu_write(xed_nesting_count, 0);
1223         } while (count != 1 || vcpu_info->evtchn_upcall_pending);
1224
1225 out:
1226
1227         put_cpu();
1228 }
1229
1230 void xen_evtchn_do_upcall(struct pt_regs *regs)
1231 {
1232         struct pt_regs *old_regs = set_irq_regs(regs);
1233
1234         irq_enter();
1235 #ifdef CONFIG_X86
1236         exit_idle();
1237 #endif
1238         inc_irq_stat(irq_hv_callback_count);
1239
1240         __xen_evtchn_do_upcall();
1241
1242         irq_exit();
1243         set_irq_regs(old_regs);
1244 }
1245
1246 void xen_hvm_evtchn_do_upcall(void)
1247 {
1248         __xen_evtchn_do_upcall();
1249 }
1250 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1251
1252 /* Rebind a new event channel to an existing irq. */
1253 void rebind_evtchn_irq(int evtchn, int irq)
1254 {
1255         struct irq_info *info = info_for_irq(irq);
1256
1257         if (WARN_ON(!info))
1258                 return;
1259
1260         /* Make sure the irq is masked, since the new event channel
1261            will also be masked. */
1262         disable_irq(irq);
1263
1264         mutex_lock(&irq_mapping_update_lock);
1265
1266         /* After resume the irq<->evtchn mappings are all cleared out */
1267         BUG_ON(get_evtchn_to_irq(evtchn) != -1);
1268         /* Expect irq to have been bound before,
1269            so there should be a proper type */
1270         BUG_ON(info->type == IRQT_UNBOUND);
1271
1272         (void)xen_irq_info_evtchn_setup(irq, evtchn);
1273
1274         mutex_unlock(&irq_mapping_update_lock);
1275
1276         /* new event channels are always bound to cpu 0 */
1277         irq_set_affinity(irq, cpumask_of(0));
1278
1279         /* Unmask the event channel. */
1280         enable_irq(irq);
1281 }
1282
1283 /* Rebind an evtchn so that it gets delivered to a specific cpu */
1284 static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
1285 {
1286         struct evtchn_bind_vcpu bind_vcpu;
1287         int evtchn = evtchn_from_irq(irq);
1288         int masked;
1289
1290         if (!VALID_EVTCHN(evtchn))
1291                 return -1;
1292
1293         /*
1294          * Events delivered via platform PCI interrupts are always
1295          * routed to vcpu 0 and hence cannot be rebound.
1296          */
1297         if (xen_hvm_domain() && !xen_have_vector_callback)
1298                 return -1;
1299
1300         /* Send future instances of this interrupt to other vcpu. */
1301         bind_vcpu.port = evtchn;
1302         bind_vcpu.vcpu = tcpu;
1303
1304         /*
1305          * Mask the event while changing the VCPU binding to prevent
1306          * it being delivered on an unexpected VCPU.
1307          */
1308         masked = test_and_set_mask(evtchn);
1309
1310         /*
1311          * If this fails, it usually just indicates that we're dealing with a
1312          * virq or IPI channel, which don't actually need to be rebound. Ignore
1313          * it, but don't do the xenlinux-level rebind in that case.
1314          */
1315         if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1316                 bind_evtchn_to_cpu(evtchn, tcpu);
1317
1318         if (!masked)
1319                 unmask_evtchn(evtchn);
1320
1321         return 0;
1322 }
1323
1324 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1325                             bool force)
1326 {
1327         unsigned tcpu = cpumask_first_and(dest, cpu_online_mask);
1328
1329         return rebind_irq_to_cpu(data->irq, tcpu);
1330 }
1331
1332 static int retrigger_evtchn(int evtchn)
1333 {
1334         int masked;
1335
1336         if (!VALID_EVTCHN(evtchn))
1337                 return 0;
1338
1339         masked = test_and_set_mask(evtchn);
1340         set_evtchn(evtchn);
1341         if (!masked)
1342                 unmask_evtchn(evtchn);
1343
1344         return 1;
1345 }
1346
1347 int resend_irq_on_evtchn(unsigned int irq)
1348 {
1349         return retrigger_evtchn(evtchn_from_irq(irq));
1350 }
1351
1352 static void enable_dynirq(struct irq_data *data)
1353 {
1354         int evtchn = evtchn_from_irq(data->irq);
1355
1356         if (VALID_EVTCHN(evtchn))
1357                 unmask_evtchn(evtchn);
1358 }
1359
1360 static void disable_dynirq(struct irq_data *data)
1361 {
1362         int evtchn = evtchn_from_irq(data->irq);
1363
1364         if (VALID_EVTCHN(evtchn))
1365                 mask_evtchn(evtchn);
1366 }
1367
1368 static void ack_dynirq(struct irq_data *data)
1369 {
1370         int evtchn = evtchn_from_irq(data->irq);
1371
1372         irq_move_irq(data);
1373
1374         if (VALID_EVTCHN(evtchn))
1375                 clear_evtchn(evtchn);
1376 }
1377
1378 static void mask_ack_dynirq(struct irq_data *data)
1379 {
1380         disable_dynirq(data);
1381         ack_dynirq(data);
1382 }
1383
1384 static int retrigger_dynirq(struct irq_data *data)
1385 {
1386         return retrigger_evtchn(evtchn_from_irq(data->irq));
1387 }
1388
1389 static void restore_pirqs(void)
1390 {
1391         int pirq, rc, irq, gsi;
1392         struct physdev_map_pirq map_irq;
1393         struct irq_info *info;
1394
1395         list_for_each_entry(info, &xen_irq_list_head, list) {
1396                 if (info->type != IRQT_PIRQ)
1397                         continue;
1398
1399                 pirq = info->u.pirq.pirq;
1400                 gsi = info->u.pirq.gsi;
1401                 irq = info->irq;
1402
1403                 /* save/restore of PT devices doesn't work, so at this point the
1404                  * only devices present are GSI based emulated devices */
1405                 if (!gsi)
1406                         continue;
1407
1408                 map_irq.domid = DOMID_SELF;
1409                 map_irq.type = MAP_PIRQ_TYPE_GSI;
1410                 map_irq.index = gsi;
1411                 map_irq.pirq = pirq;
1412
1413                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1414                 if (rc) {
1415                         pr_warn("xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1416                                 gsi, irq, pirq, rc);
1417                         xen_free_irq(irq);
1418                         continue;
1419                 }
1420
1421                 printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1422
1423                 __startup_pirq(irq);
1424         }
1425 }
1426
1427 static void restore_cpu_virqs(unsigned int cpu)
1428 {
1429         struct evtchn_bind_virq bind_virq;
1430         int virq, irq, evtchn;
1431
1432         for (virq = 0; virq < NR_VIRQS; virq++) {
1433                 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1434                         continue;
1435
1436                 BUG_ON(virq_from_irq(irq) != virq);
1437
1438                 /* Get a new binding from Xen. */
1439                 bind_virq.virq = virq;
1440                 bind_virq.vcpu = cpu;
1441                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1442                                                 &bind_virq) != 0)
1443                         BUG();
1444                 evtchn = bind_virq.port;
1445
1446                 /* Record the new mapping. */
1447                 (void)xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
1448                 bind_evtchn_to_cpu(evtchn, cpu);
1449         }
1450 }
1451
1452 static void restore_cpu_ipis(unsigned int cpu)
1453 {
1454         struct evtchn_bind_ipi bind_ipi;
1455         int ipi, irq, evtchn;
1456
1457         for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1458                 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1459                         continue;
1460
1461                 BUG_ON(ipi_from_irq(irq) != ipi);
1462
1463                 /* Get a new binding from Xen. */
1464                 bind_ipi.vcpu = cpu;
1465                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1466                                                 &bind_ipi) != 0)
1467                         BUG();
1468                 evtchn = bind_ipi.port;
1469
1470                 /* Record the new mapping. */
1471                 (void)xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
1472                 bind_evtchn_to_cpu(evtchn, cpu);
1473         }
1474 }
1475
1476 /* Clear an irq's pending state, in preparation for polling on it */
1477 void xen_clear_irq_pending(int irq)
1478 {
1479         int evtchn = evtchn_from_irq(irq);
1480
1481         if (VALID_EVTCHN(evtchn))
1482                 clear_evtchn(evtchn);
1483 }
1484 EXPORT_SYMBOL(xen_clear_irq_pending);
1485 void xen_set_irq_pending(int irq)
1486 {
1487         int evtchn = evtchn_from_irq(irq);
1488
1489         if (VALID_EVTCHN(evtchn))
1490                 set_evtchn(evtchn);
1491 }
1492
1493 bool xen_test_irq_pending(int irq)
1494 {
1495         int evtchn = evtchn_from_irq(irq);
1496         bool ret = false;
1497
1498         if (VALID_EVTCHN(evtchn))
1499                 ret = test_evtchn(evtchn);
1500
1501         return ret;
1502 }
1503
1504 /* Poll waiting for an irq to become pending with timeout.  In the usual case,
1505  * the irq will be disabled so it won't deliver an interrupt. */
1506 void xen_poll_irq_timeout(int irq, u64 timeout)
1507 {
1508         evtchn_port_t evtchn = evtchn_from_irq(irq);
1509
1510         if (VALID_EVTCHN(evtchn)) {
1511                 struct sched_poll poll;
1512
1513                 poll.nr_ports = 1;
1514                 poll.timeout = timeout;
1515                 set_xen_guest_handle(poll.ports, &evtchn);
1516
1517                 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1518                         BUG();
1519         }
1520 }
1521 EXPORT_SYMBOL(xen_poll_irq_timeout);
1522 /* Poll waiting for an irq to become pending.  In the usual case, the
1523  * irq will be disabled so it won't deliver an interrupt. */
1524 void xen_poll_irq(int irq)
1525 {
1526         xen_poll_irq_timeout(irq, 0 /* no timeout */);
1527 }
1528
1529 /* Check whether the IRQ line is shared with other guests. */
1530 int xen_test_irq_shared(int irq)
1531 {
1532         struct irq_info *info = info_for_irq(irq);
1533         struct physdev_irq_status_query irq_status;
1534
1535         if (WARN_ON(!info))
1536                 return -ENOENT;
1537
1538         irq_status.irq = info->u.pirq.pirq;
1539
1540         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
1541                 return 0;
1542         return !(irq_status.flags & XENIRQSTAT_shared);
1543 }
1544 EXPORT_SYMBOL_GPL(xen_test_irq_shared);
1545
1546 void xen_irq_resume(void)
1547 {
1548         unsigned int cpu;
1549         struct irq_info *info;
1550
1551         /* New event-channel space is not 'live' yet. */
1552         xen_evtchn_mask_all();
1553         xen_evtchn_resume();
1554
1555         /* No IRQ <-> event-channel mappings. */
1556         list_for_each_entry(info, &xen_irq_list_head, list)
1557                 info->evtchn = 0; /* zap event-channel binding */
1558
1559         clear_evtchn_to_irq_all();
1560
1561         for_each_possible_cpu(cpu) {
1562                 restore_cpu_virqs(cpu);
1563                 restore_cpu_ipis(cpu);
1564         }
1565
1566         restore_pirqs();
1567 }
1568
1569 static struct irq_chip xen_dynamic_chip __read_mostly = {
1570         .name                   = "xen-dyn",
1571
1572         .irq_disable            = disable_dynirq,
1573         .irq_mask               = disable_dynirq,
1574         .irq_unmask             = enable_dynirq,
1575
1576         .irq_ack                = ack_dynirq,
1577         .irq_mask_ack           = mask_ack_dynirq,
1578
1579         .irq_set_affinity       = set_affinity_irq,
1580         .irq_retrigger          = retrigger_dynirq,
1581 };
1582
1583 static struct irq_chip xen_pirq_chip __read_mostly = {
1584         .name                   = "xen-pirq",
1585
1586         .irq_startup            = startup_pirq,
1587         .irq_shutdown           = shutdown_pirq,
1588         .irq_enable             = enable_pirq,
1589         .irq_disable            = disable_pirq,
1590
1591         .irq_mask               = disable_dynirq,
1592         .irq_unmask             = enable_dynirq,
1593
1594         .irq_ack                = eoi_pirq,
1595         .irq_eoi                = eoi_pirq,
1596         .irq_mask_ack           = mask_ack_pirq,
1597
1598         .irq_set_affinity       = set_affinity_irq,
1599
1600         .irq_retrigger          = retrigger_dynirq,
1601 };
1602
1603 static struct irq_chip xen_percpu_chip __read_mostly = {
1604         .name                   = "xen-percpu",
1605
1606         .irq_disable            = disable_dynirq,
1607         .irq_mask               = disable_dynirq,
1608         .irq_unmask             = enable_dynirq,
1609
1610         .irq_ack                = ack_dynirq,
1611 };
1612
1613 int xen_set_callback_via(uint64_t via)
1614 {
1615         struct xen_hvm_param a;
1616         a.domid = DOMID_SELF;
1617         a.index = HVM_PARAM_CALLBACK_IRQ;
1618         a.value = via;
1619         return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1620 }
1621 EXPORT_SYMBOL_GPL(xen_set_callback_via);
1622
1623 #ifdef CONFIG_XEN_PVHVM
1624 /* Vector callbacks are better than PCI interrupts to receive event
1625  * channel notifications because we can receive vector callbacks on any
1626  * vcpu and we don't need PCI support or APIC interactions. */
1627 void xen_callback_vector(void)
1628 {
1629         int rc;
1630         uint64_t callback_via;
1631         if (xen_have_vector_callback) {
1632                 callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
1633                 rc = xen_set_callback_via(callback_via);
1634                 if (rc) {
1635                         pr_err("Request for Xen HVM callback vector failed\n");
1636                         xen_have_vector_callback = 0;
1637                         return;
1638                 }
1639                 pr_info("Xen HVM callback vector for event delivery is enabled\n");
1640                 /* in the restore case the vector has already been allocated */
1641                 if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
1642                         alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
1643                                         xen_hvm_callback_vector);
1644         }
1645 }
1646 #else
1647 void xen_callback_vector(void) {}
1648 #endif
1649
1650 #undef MODULE_PARAM_PREFIX
1651 #define MODULE_PARAM_PREFIX "xen."
1652
1653 static bool fifo_events = true;
1654 module_param(fifo_events, bool, 0);
1655
1656 void __init xen_init_IRQ(void)
1657 {
1658         int ret = -EINVAL;
1659
1660         if (fifo_events)
1661                 ret = xen_evtchn_fifo_init();
1662         if (ret < 0)
1663                 xen_evtchn_2l_init();
1664
1665         evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()),
1666                                 sizeof(*evtchn_to_irq), GFP_KERNEL);
1667         BUG_ON(!evtchn_to_irq);
1668
1669         /* No event channels are 'live' right now. */
1670         xen_evtchn_mask_all();
1671
1672         pirq_needs_eoi = pirq_needs_eoi_flag;
1673
1674 #ifdef CONFIG_X86
1675         if (xen_pv_domain()) {
1676                 irq_ctx_init(smp_processor_id());
1677                 if (xen_initial_domain())
1678                         pci_xen_initial_domain();
1679         }
1680         if (xen_feature(XENFEAT_hvm_callback_vector))
1681                 xen_callback_vector();
1682
1683         if (xen_hvm_domain()) {
1684                 native_init_IRQ();
1685                 /* pci_xen_hvm_init must be called after native_init_IRQ so that
1686                  * __acpi_register_gsi can point at the right function */
1687                 pci_xen_hvm_init();
1688         } else {
1689                 int rc;
1690                 struct physdev_pirq_eoi_gmfn eoi_gmfn;
1691
1692                 pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
1693                 eoi_gmfn.gmfn = virt_to_mfn(pirq_eoi_map);
1694                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn);
1695                 /* TODO: No PVH support for PIRQ EOI */
1696                 if (rc != 0) {
1697                         free_page((unsigned long) pirq_eoi_map);
1698                         pirq_eoi_map = NULL;
1699                 } else
1700                         pirq_needs_eoi = pirq_check_eoi_map;
1701         }
1702 #endif
1703 }