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_to_desc(irq)->irq_data.affinity, cpumask_of(cpu));
 340 #endif
 341
 342         xen_evtchn_port_bind_to_cpu(info, cpu);
 343
 344         info->cpu = cpu;
 345 }
 346
 347 static void xen_evtchn_mask_all(void)
 348 {
 349         unsigned int evtchn;
 350
 351         for (evtchn = 0; evtchn < xen_evtchn_nr_channels(); evtchn++)
 352                 mask_evtchn(evtchn);
 353 }
 354
 355 /**
 356  * notify_remote_via_irq - send event to remote end of event channel via irq
 357  * @irq: irq of event channel to send event to
 358  *
 359  * Unlike notify_remote_via_evtchn(), this is safe to use across
 360  * save/restore. Notifications on a broken connection are silently
 361  * dropped.
 362  */
 363 void notify_remote_via_irq(int irq)
 364 {
 365         int evtchn = evtchn_from_irq(irq);
 366
 367         if (VALID_EVTCHN(evtchn))
 368                 notify_remote_via_evtchn(evtchn);
 369 }
 370 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
 371
 372 static void xen_irq_init(unsigned irq)
 373 {
 374         struct irq_info *info;
 375 #ifdef CONFIG_SMP
 376         struct irq_desc *desc = irq_to_desc(irq);
 377
 378         /* By default all event channels notify CPU#0. */
 379         cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
 380 #endif
 381
 382         info = kzalloc(sizeof(*info), GFP_KERNEL);
 383         if (info == NULL)
 384                 panic("Unable to allocate metadata for IRQ%d\n", irq);
 385
 386         info->type = IRQT_UNBOUND;
 387         info->refcnt = -1;
 388
 389         irq_set_handler_data(irq, info);
 390
 391         list_add_tail(&info->list, &xen_irq_list_head);
 392 }
 393
 394 static int __must_check xen_allocate_irqs_dynamic(int nvec)
 395 {
 396         int first = 0;
 397         int i, irq;
 398
 399 #ifdef CONFIG_X86_IO_APIC
 400         /*
 401          * For an HVM guest or domain 0 which see "real" (emulated or
 402          * actual respectively) GSIs we allocate dynamic IRQs
 403          * e.g. those corresponding to event channels or MSIs
 404          * etc. from the range above those "real" GSIs to avoid
 405          * collisions.
 406          */
 407         if (xen_initial_domain() || xen_hvm_domain())
 408                 first = get_nr_irqs_gsi();
 409 #endif
 410
 411         irq = irq_alloc_descs_from(first, nvec, -1);
 412
 413         if (irq >= 0) {
 414                 for (i = 0; i < nvec; i++)
 415                         xen_irq_init(irq + i);
 416         }
 417
 418         return irq;
 419 }
 420
 421 static inline int __must_check xen_allocate_irq_dynamic(void)
 422 {
 423
 424         return xen_allocate_irqs_dynamic(1);
 425 }
 426
 427 static int __must_check xen_allocate_irq_gsi(unsigned gsi)
 428 {
 429         int irq;
 430
 431         /*
 432          * A PV guest has no concept of a GSI (since it has no ACPI
 433          * nor access to/knowledge of the physical APICs). Therefore
 434          * all IRQs are dynamically allocated from the entire IRQ
 435          * space.
 436          */
 437         if (xen_pv_domain() && !xen_initial_domain())
 438                 return xen_allocate_irq_dynamic();
 439
 440         /* Legacy IRQ descriptors are already allocated by the arch. */
 441         if (gsi < NR_IRQS_LEGACY)
 442                 irq = gsi;
 443         else
 444                 irq = irq_alloc_desc_at(gsi, -1);
 445
 446         xen_irq_init(irq);
 447
 448         return irq;
 449 }
 450
 451 static void xen_free_irq(unsigned irq)
 452 {
 453         struct irq_info *info = irq_get_handler_data(irq);
 454
 455         if (WARN_ON(!info))
 456                 return;
 457
 458         list_del(&info->list);
 459
 460         irq_set_handler_data(irq, NULL);
 461
 462         WARN_ON(info->refcnt > 0);
 463
 464         kfree(info);
 465
 466         /* Legacy IRQ descriptors are managed by the arch. */
 467         if (irq < NR_IRQS_LEGACY)
 468                 return;
 469
 470         irq_free_desc(irq);
 471 }
 472
 473 static void xen_evtchn_close(unsigned int port)
 474 {
 475         struct evtchn_close close;
 476
 477         close.port = port;
 478         if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 479                 BUG();
 480 }
 481
 482 static void pirq_query_unmask(int irq)
 483 {
 484         struct physdev_irq_status_query irq_status;
 485         struct irq_info *info = info_for_irq(irq);
 486
 487         BUG_ON(info->type != IRQT_PIRQ);
 488
 489         irq_status.irq = pirq_from_irq(irq);
 490         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
 491                 irq_status.flags = 0;
 492
 493         info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
 494         if (irq_status.flags & XENIRQSTAT_needs_eoi)
 495                 info->u.pirq.flags |= PIRQ_NEEDS_EOI;
 496 }
 497
 498 static bool probing_irq(int irq)
 499 {
 500         struct irq_desc *desc = irq_to_desc(irq);
 501
 502         return desc && desc->action == NULL;
 503 }
 504
 505 static void eoi_pirq(struct irq_data *data)
 506 {
 507         int evtchn = evtchn_from_irq(data->irq);
 508         struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
 509         int rc = 0;
 510
 511         irq_move_irq(data);
 512
 513         if (VALID_EVTCHN(evtchn))
 514                 clear_evtchn(evtchn);
 515
 516         if (pirq_needs_eoi(data->irq)) {
 517                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
 518                 WARN_ON(rc);
 519         }
 520 }
 521
 522 static void mask_ack_pirq(struct irq_data *data)
 523 {
 524         disable_dynirq(data);
 525         eoi_pirq(data);
 526 }
 527
 528 static unsigned int __startup_pirq(unsigned int irq)
 529 {
 530         struct evtchn_bind_pirq bind_pirq;
 531         struct irq_info *info = info_for_irq(irq);
 532         int evtchn = evtchn_from_irq(irq);
 533         int rc;
 534
 535         BUG_ON(info->type != IRQT_PIRQ);
 536
 537         if (VALID_EVTCHN(evtchn))
 538                 goto out;
 539
 540         bind_pirq.pirq = pirq_from_irq(irq);
 541         /* NB. We are happy to share unless we are probing. */
 542         bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
 543                                         BIND_PIRQ__WILL_SHARE : 0;
 544         rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
 545         if (rc != 0) {
 546                 if (!probing_irq(irq))
 547                         pr_info("Failed to obtain physical IRQ %d\n", irq);
 548                 return 0;
 549         }
 550         evtchn = bind_pirq.port;
 551
 552         pirq_query_unmask(irq);
 553
 554         rc = set_evtchn_to_irq(evtchn, irq);
 555         if (rc != 0) {
 556                 pr_err("irq%d: Failed to set port to irq mapping (%d)\n",
 557                        irq, rc);
 558                 xen_evtchn_close(evtchn);
 559                 return 0;
 560         }
 561         bind_evtchn_to_cpu(evtchn, 0);
 562         info->evtchn = evtchn;
 563
 564 out:
 565         unmask_evtchn(evtchn);
 566         eoi_pirq(irq_get_irq_data(irq));
 567
 568         return 0;
 569 }
 570
 571 static unsigned int startup_pirq(struct irq_data *data)
 572 {
 573         return __startup_pirq(data->irq);
 574 }
 575
 576 static void shutdown_pirq(struct irq_data *data)
 577 {
 578         unsigned int irq = data->irq;
 579         struct irq_info *info = info_for_irq(irq);
 580         unsigned evtchn = evtchn_from_irq(irq);
 581
 582         BUG_ON(info->type != IRQT_PIRQ);
 583
 584         if (!VALID_EVTCHN(evtchn))
 585                 return;
 586
 587         mask_evtchn(evtchn);
 588         xen_evtchn_close(evtchn);
 589         xen_irq_info_cleanup(info);
 590 }
 591
 592 static void enable_pirq(struct irq_data *data)
 593 {
 594         startup_pirq(data);
 595 }
 596
 597 static void disable_pirq(struct irq_data *data)
 598 {
 599         disable_dynirq(data);
 600 }
 601
 602 int xen_irq_from_gsi(unsigned gsi)
 603 {
 604         struct irq_info *info;
 605
 606         list_for_each_entry(info, &xen_irq_list_head, list) {
 607                 if (info->type != IRQT_PIRQ)
 608                         continue;
 609
 610                 if (info->u.pirq.gsi == gsi)
 611                         return info->irq;
 612         }
 613
 614         return -1;
 615 }
 616 EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
 617
 618 static void __unbind_from_irq(unsigned int irq)
 619 {
 620         int evtchn = evtchn_from_irq(irq);
 621         struct irq_info *info = irq_get_handler_data(irq);
 622
 623         if (info->refcnt > 0) {
 624                 info->refcnt--;
 625                 if (info->refcnt != 0)
 626                         return;
 627         }
 628
 629         if (VALID_EVTCHN(evtchn)) {
 630                 unsigned int cpu = cpu_from_irq(irq);
 631
 632                 xen_evtchn_close(evtchn);
 633
 634                 switch (type_from_irq(irq)) {
 635                 case IRQT_VIRQ:
 636                         per_cpu(virq_to_irq, cpu)[virq_from_irq(irq)] = -1;
 637                         break;
 638                 case IRQT_IPI:
 639                         per_cpu(ipi_to_irq, cpu)[ipi_from_irq(irq)] = -1;
 640                         break;
 641                 default:
 642                         break;
 643                 }
 644
 645                 xen_irq_info_cleanup(info);
 646         }
 647
 648         BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
 649
 650         xen_free_irq(irq);
 651 }
 652
 653 /*
 654  * Do not make any assumptions regarding the relationship between the
 655  * IRQ number returned here and the Xen pirq argument.
 656  *
 657  * Note: We don't assign an event channel until the irq actually started
 658  * up.  Return an existing irq if we've already got one for the gsi.
 659  *
 660  * Shareable implies level triggered, not shareable implies edge
 661  * triggered here.
 662  */
 663 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 664                              unsigned pirq, int shareable, char *name)
 665 {
 666         int irq = -1;
 667         struct physdev_irq irq_op;
 668         int ret;
 669
 670         mutex_lock(&irq_mapping_update_lock);
 671
 672         irq = xen_irq_from_gsi(gsi);
 673         if (irq != -1) {
 674                 pr_info("%s: returning irq %d for gsi %u\n",
 675                         __func__, irq, gsi);
 676                 goto out;
 677         }
 678
 679         irq = xen_allocate_irq_gsi(gsi);
 680         if (irq < 0)
 681                 goto out;
 682
 683         irq_op.irq = irq;
 684         irq_op.vector = 0;
 685
 686         /* Only the privileged domain can do this. For non-priv, the pcifront
 687          * driver provides a PCI bus that does the call to do exactly
 688          * this in the priv domain. */
 689         if (xen_initial_domain() &&
 690             HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
 691                 xen_free_irq(irq);
 692                 irq = -ENOSPC;
 693                 goto out;
 694         }
 695
 696         ret = xen_irq_info_pirq_setup(irq, 0, pirq, gsi, DOMID_SELF,
 697                                shareable ? PIRQ_SHAREABLE : 0);
 698         if (ret < 0) {
 699                 __unbind_from_irq(irq);
 700                 irq = ret;
 701                 goto out;
 702         }
 703
 704         pirq_query_unmask(irq);
 705         /* We try to use the handler with the appropriate semantic for the
 706          * type of interrupt: if the interrupt is an edge triggered
 707          * interrupt we use handle_edge_irq.
 708          *
 709          * On the other hand if the interrupt is level triggered we use
 710          * handle_fasteoi_irq like the native code does for this kind of
 711          * interrupts.
 712          *
 713          * Depending on the Xen version, pirq_needs_eoi might return true
 714          * not only for level triggered interrupts but for edge triggered
 715          * interrupts too. In any case Xen always honors the eoi mechanism,
 716          * not injecting any more pirqs of the same kind if the first one
 717          * hasn't received an eoi yet. Therefore using the fasteoi handler
 718          * is the right choice either way.
 719          */
 720         if (shareable)
 721                 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 722                                 handle_fasteoi_irq, name);
 723         else
 724                 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 725                                 handle_edge_irq, name);
 726
 727 out:
 728         mutex_unlock(&irq_mapping_update_lock);
 729
 730         return irq;
 731 }
 732
 733 #ifdef CONFIG_PCI_MSI
 734 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
 735 {
 736         int rc;
 737         struct physdev_get_free_pirq op_get_free_pirq;
 738
 739         op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
 740         rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
 741
 742         WARN_ONCE(rc == -ENOSYS,
 743                   "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
 744
 745         return rc ? -1 : op_get_free_pirq.pirq;
 746 }
 747
 748 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
 749                              int pirq, int nvec, const char *name, domid_t domid)
 750 {
 751         int i, irq, ret;
 752
 753         mutex_lock(&irq_mapping_update_lock);
 754
 755         irq = xen_allocate_irqs_dynamic(nvec);
 756         if (irq < 0)
 757                 goto out;
 758
 759         for (i = 0; i < nvec; i++) {
 760                 irq_set_chip_and_handler_name(irq + i, &xen_pirq_chip, handle_edge_irq, name);
 761
 762                 ret = xen_irq_info_pirq_setup(irq + i, 0, pirq + i, 0, domid,
 763                                               i == 0 ? 0 : PIRQ_MSI_GROUP);
 764                 if (ret < 0)
 765                         goto error_irq;
 766         }
 767
 768         ret = irq_set_msi_desc(irq, msidesc);
 769         if (ret < 0)
 770                 goto error_irq;
 771 out:
 772         mutex_unlock(&irq_mapping_update_lock);
 773         return irq;
 774 error_irq:
 775         for (; i >= 0; i--)
 776                 __unbind_from_irq(irq + i);
 777         mutex_unlock(&irq_mapping_update_lock);
 778         return ret;
 779 }
 780 #endif
 781
 782 int xen_destroy_irq(int irq)
 783 {
 784         struct irq_desc *desc;
 785         struct physdev_unmap_pirq unmap_irq;
 786         struct irq_info *info = info_for_irq(irq);
 787         int rc = -ENOENT;
 788
 789         mutex_lock(&irq_mapping_update_lock);
 790
 791         desc = irq_to_desc(irq);
 792         if (!desc)
 793                 goto out;
 794
 795         /*
 796          * If trying to remove a vector in a MSI group different
 797          * than the first one skip the PIRQ unmap unless this vector
 798          * is the first one in the group.
 799          */
 800         if (xen_initial_domain() && !(info->u.pirq.flags & PIRQ_MSI_GROUP)) {
 801                 unmap_irq.pirq = info->u.pirq.pirq;
 802                 unmap_irq.domid = info->u.pirq.domid;
 803                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
 804                 /* If another domain quits without making the pci_disable_msix
 805                  * call, the Xen hypervisor takes care of freeing the PIRQs
 806                  * (free_domain_pirqs).
 807                  */
 808                 if ((rc == -ESRCH && info->u.pirq.domid != DOMID_SELF))
 809                         pr_info("domain %d does not have %d anymore\n",
 810                                 info->u.pirq.domid, info->u.pirq.pirq);
 811                 else if (rc) {
 812                         pr_warn("unmap irq failed %d\n", rc);
 813                         goto out;
 814                 }
 815         }
 816
 817         xen_free_irq(irq);
 818
 819 out:
 820         mutex_unlock(&irq_mapping_update_lock);
 821         return rc;
 822 }
 823
 824 int xen_irq_from_pirq(unsigned pirq)
 825 {
 826         int irq;
 827
 828         struct irq_info *info;
 829
 830         mutex_lock(&irq_mapping_update_lock);
 831
 832         list_for_each_entry(info, &xen_irq_list_head, list) {
 833                 if (info->type != IRQT_PIRQ)
 834                         continue;
 835                 irq = info->irq;
 836                 if (info->u.pirq.pirq == pirq)
 837                         goto out;
 838         }
 839         irq = -1;
 840 out:
 841         mutex_unlock(&irq_mapping_update_lock);
 842
 843         return irq;
 844 }
 845
 846
 847 int xen_pirq_from_irq(unsigned irq)
 848 {
 849         return pirq_from_irq(irq);
 850 }
 851 EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
 852
 853 int bind_evtchn_to_irq(unsigned int evtchn)
 854 {
 855         int irq;
 856         int ret;
 857
 858         if (evtchn >= xen_evtchn_max_channels())
 859                 return -ENOMEM;
 860
 861         mutex_lock(&irq_mapping_update_lock);
 862
 863         irq = get_evtchn_to_irq(evtchn);
 864
 865         if (irq == -1) {
 866                 irq = xen_allocate_irq_dynamic();
 867                 if (irq < 0)
 868                         goto out;
 869
 870                 irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
 871                                               handle_edge_irq, "event");
 872
 873                 ret = xen_irq_info_evtchn_setup(irq, evtchn);
 874                 if (ret < 0) {
 875                         __unbind_from_irq(irq);
 876                         irq = ret;
 877                         goto out;
 878                 }
 879                 /* New interdomain events are bound to VCPU 0. */
 880                 bind_evtchn_to_cpu(evtchn, 0);
 881         } else {
 882                 struct irq_info *info = info_for_irq(irq);
 883                 WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
 884         }
 885
 886 out:
 887         mutex_unlock(&irq_mapping_update_lock);
 888
 889         return irq;
 890 }
 891 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
 892
 893 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 894 {
 895         struct evtchn_bind_ipi bind_ipi;
 896         int evtchn, irq;
 897         int ret;
 898
 899         mutex_lock(&irq_mapping_update_lock);
 900
 901         irq = per_cpu(ipi_to_irq, cpu)[ipi];
 902
 903         if (irq == -1) {
 904                 irq = xen_allocate_irq_dynamic();
 905                 if (irq < 0)
 906                         goto out;
 907
 908                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 909                                               handle_percpu_irq, "ipi");
 910
 911                 bind_ipi.vcpu = cpu;
 912                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
 913                                                 &bind_ipi) != 0)
 914                         BUG();
 915                 evtchn = bind_ipi.port;
 916
 917                 ret = xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
 918                 if (ret < 0) {
 919                         __unbind_from_irq(irq);
 920                         irq = ret;
 921                         goto out;
 922                 }
 923                 bind_evtchn_to_cpu(evtchn, cpu);
 924         } else {
 925                 struct irq_info *info = info_for_irq(irq);
 926                 WARN_ON(info == NULL || info->type != IRQT_IPI);
 927         }
 928
 929  out:
 930         mutex_unlock(&irq_mapping_update_lock);
 931         return irq;
 932 }
 933
 934 static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
 935                                           unsigned int remote_port)
 936 {
 937         struct evtchn_bind_interdomain bind_interdomain;
 938         int err;
 939
 940         bind_interdomain.remote_dom  = remote_domain;
 941         bind_interdomain.remote_port = remote_port;
 942
 943         err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
 944                                           &bind_interdomain);
 945
 946         return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
 947 }
 948
 949 static int find_virq(unsigned int virq, unsigned int cpu)
 950 {
 951         struct evtchn_status status;
 952         int port, rc = -ENOENT;
 953
 954         memset(&status, 0, sizeof(status));
 955         for (port = 0; port < xen_evtchn_max_channels(); port++) {
 956                 status.dom = DOMID_SELF;
 957                 status.port = port;
 958                 rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status);
 959                 if (rc < 0)
 960                         continue;
 961                 if (status.status != EVTCHNSTAT_virq)
 962                         continue;
 963                 if (status.u.virq == virq && status.vcpu == cpu) {
 964                         rc = port;
 965                         break;
 966                 }
 967         }
 968         return rc;
 969 }
 970
 971 /**
 972  * xen_evtchn_nr_channels - number of usable event channel ports
 973  *
 974  * This may be less than the maximum supported by the current
 975  * hypervisor ABI. Use xen_evtchn_max_channels() for the maximum
 976  * supported.
 977  */
 978 unsigned xen_evtchn_nr_channels(void)
 979 {
 980         return evtchn_ops->nr_channels();
 981 }
 982 EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
 983
 984 int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 985 {
 986         struct evtchn_bind_virq bind_virq;
 987         int evtchn, irq, ret;
 988
 989         mutex_lock(&irq_mapping_update_lock);
 990
 991         irq = per_cpu(virq_to_irq, cpu)[virq];
 992
 993         if (irq == -1) {
 994                 irq = xen_allocate_irq_dynamic();
 995                 if (irq < 0)
 996                         goto out;
 997
 998                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 999                                               handle_percpu_irq, "virq");
1000
1001                 bind_virq.virq = virq;
1002                 bind_virq.vcpu = cpu;
1003                 ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1004                                                 &bind_virq);
1005                 if (ret == 0)
1006                         evtchn = bind_virq.port;
1007                 else {
1008                         if (ret == -EEXIST)
1009                                 ret = find_virq(virq, cpu);
1010                         BUG_ON(ret < 0);
1011                         evtchn = ret;
1012                 }
1013
1014                 ret = xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
1015                 if (ret < 0) {
1016                         __unbind_from_irq(irq);
1017                         irq = ret;
1018                         goto out;
1019                 }
1020
1021                 bind_evtchn_to_cpu(evtchn, cpu);
1022         } else {
1023                 struct irq_info *info = info_for_irq(irq);
1024                 WARN_ON(info == NULL || info->type != IRQT_VIRQ);
1025         }
1026
1027 out:
1028         mutex_unlock(&irq_mapping_update_lock);
1029
1030         return irq;
1031 }
1032
1033 static void unbind_from_irq(unsigned int irq)
1034 {
1035         mutex_lock(&irq_mapping_update_lock);
1036         __unbind_from_irq(irq);
1037         mutex_unlock(&irq_mapping_update_lock);
1038 }
1039
1040 int bind_evtchn_to_irqhandler(unsigned int evtchn,
1041                               irq_handler_t handler,
1042                               unsigned long irqflags,
1043                               const char *devname, void *dev_id)
1044 {
1045         int irq, retval;
1046
1047         irq = bind_evtchn_to_irq(evtchn);
1048         if (irq < 0)
1049                 return irq;
1050         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1051         if (retval != 0) {
1052                 unbind_from_irq(irq);
1053                 return retval;
1054         }
1055
1056         return irq;
1057 }
1058 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
1059
1060 int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
1061                                           unsigned int remote_port,
1062                                           irq_handler_t handler,
1063                                           unsigned long irqflags,
1064                                           const char *devname,
1065                                           void *dev_id)
1066 {
1067         int irq, retval;
1068
1069         irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
1070         if (irq < 0)
1071                 return irq;
1072
1073         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1074         if (retval != 0) {
1075                 unbind_from_irq(irq);
1076                 return retval;
1077         }
1078
1079         return irq;
1080 }
1081 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
1082
1083 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
1084                             irq_handler_t handler,
1085                             unsigned long irqflags, const char *devname, void *dev_id)
1086 {
1087         int irq, retval;
1088
1089         irq = bind_virq_to_irq(virq, cpu);
1090         if (irq < 0)
1091                 return irq;
1092         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1093         if (retval != 0) {
1094                 unbind_from_irq(irq);
1095                 return retval;
1096         }
1097
1098         return irq;
1099 }
1100 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
1101
1102 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
1103                            unsigned int cpu,
1104                            irq_handler_t handler,
1105                            unsigned long irqflags,
1106                            const char *devname,
1107                            void *dev_id)
1108 {
1109         int irq, retval;
1110
1111         irq = bind_ipi_to_irq(ipi, cpu);
1112         if (irq < 0)
1113                 return irq;
1114
1115         irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME | IRQF_EARLY_RESUME;
1116         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1117         if (retval != 0) {
1118                 unbind_from_irq(irq);
1119                 return retval;
1120         }
1121
1122         return irq;
1123 }
1124
1125 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
1126 {
1127         struct irq_info *info = irq_get_handler_data(irq);
1128
1129         if (WARN_ON(!info))
1130                 return;
1131         free_irq(irq, dev_id);
1132         unbind_from_irq(irq);
1133 }
1134 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
1135
1136 /**
1137  * xen_set_irq_priority() - set an event channel priority.
1138  * @irq:irq bound to an event channel.
1139  * @priority: priority between XEN_IRQ_PRIORITY_MAX and XEN_IRQ_PRIORITY_MIN.
1140  */
1141 int xen_set_irq_priority(unsigned irq, unsigned priority)
1142 {
1143         struct evtchn_set_priority set_priority;
1144
1145         set_priority.port = evtchn_from_irq(irq);
1146         set_priority.priority = priority;
1147
1148         return HYPERVISOR_event_channel_op(EVTCHNOP_set_priority,
1149                                            &set_priority);
1150 }
1151 EXPORT_SYMBOL_GPL(xen_set_irq_priority);
1152
1153 int evtchn_make_refcounted(unsigned int evtchn)
1154 {
1155         int irq = get_evtchn_to_irq(evtchn);
1156         struct irq_info *info;
1157
1158         if (irq == -1)
1159                 return -ENOENT;
1160
1161         info = irq_get_handler_data(irq);
1162
1163         if (!info)
1164                 return -ENOENT;
1165
1166         WARN_ON(info->refcnt != -1);
1167
1168         info->refcnt = 1;
1169
1170         return 0;
1171 }
1172 EXPORT_SYMBOL_GPL(evtchn_make_refcounted);
1173
1174 int evtchn_get(unsigned int evtchn)
1175 {
1176         int irq;
1177         struct irq_info *info;
1178         int err = -ENOENT;
1179
1180         if (evtchn >= xen_evtchn_max_channels())
1181                 return -EINVAL;
1182
1183         mutex_lock(&irq_mapping_update_lock);
1184
1185         irq = get_evtchn_to_irq(evtchn);
1186         if (irq == -1)
1187                 goto done;
1188
1189         info = irq_get_handler_data(irq);
1190
1191         if (!info)
1192                 goto done;
1193
1194         err = -EINVAL;
1195         if (info->refcnt <= 0)
1196                 goto done;
1197
1198         info->refcnt++;
1199         err = 0;
1200  done:
1201         mutex_unlock(&irq_mapping_update_lock);
1202
1203         return err;
1204 }
1205 EXPORT_SYMBOL_GPL(evtchn_get);
1206
1207 void evtchn_put(unsigned int evtchn)
1208 {
1209         int irq = get_evtchn_to_irq(evtchn);
1210         if (WARN_ON(irq == -1))
1211                 return;
1212         unbind_from_irq(irq);
1213 }
1214 EXPORT_SYMBOL_GPL(evtchn_put);
1215
1216 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
1217 {
1218         int irq;
1219
1220 #ifdef CONFIG_X86
1221         if (unlikely(vector == XEN_NMI_VECTOR)) {
1222                 int rc =  HYPERVISOR_vcpu_op(VCPUOP_send_nmi, cpu, NULL);
1223                 if (rc < 0)
1224                         printk(KERN_WARNING "Sending nmi to CPU%d failed (rc:%d)\n", cpu, rc);
1225                 return;
1226         }
1227 #endif
1228         irq = per_cpu(ipi_to_irq, cpu)[vector];
1229         BUG_ON(irq < 0);
1230         notify_remote_via_irq(irq);
1231 }
1232
1233 static DEFINE_PER_CPU(unsigned, xed_nesting_count);
1234
1235 static void __xen_evtchn_do_upcall(void)
1236 {
1237         struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1238         int cpu = get_cpu();
1239         unsigned count;
1240
1241         do {
1242                 vcpu_info->evtchn_upcall_pending = 0;
1243
1244                 if (__this_cpu_inc_return(xed_nesting_count) - 1)
1245                         goto out;
1246
1247                 xen_evtchn_handle_events(cpu);
1248
1249                 BUG_ON(!irqs_disabled());
1250
1251                 count = __this_cpu_read(xed_nesting_count);
1252                 __this_cpu_write(xed_nesting_count, 0);
1253         } while (count != 1 || vcpu_info->evtchn_upcall_pending);
1254
1255 out:
1256
1257         put_cpu();
1258 }
1259
1260 void xen_evtchn_do_upcall(struct pt_regs *regs)
1261 {
1262         struct pt_regs *old_regs = set_irq_regs(regs);
1263
1264         irq_enter();
1265 #ifdef CONFIG_X86
1266         exit_idle();
1267 #endif
1268
1269         __xen_evtchn_do_upcall();
1270
1271         irq_exit();
1272         set_irq_regs(old_regs);
1273 }
1274
1275 void xen_hvm_evtchn_do_upcall(void)
1276 {
1277         __xen_evtchn_do_upcall();
1278 }
1279 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1280
1281 /* Rebind a new event channel to an existing irq. */
1282 void rebind_evtchn_irq(int evtchn, int irq)
1283 {
1284         struct irq_info *info = info_for_irq(irq);
1285
1286         if (WARN_ON(!info))
1287                 return;
1288
1289         /* Make sure the irq is masked, since the new event channel
1290            will also be masked. */
1291         disable_irq(irq);
1292
1293         mutex_lock(&irq_mapping_update_lock);
1294
1295         /* After resume the irq<->evtchn mappings are all cleared out */
1296         BUG_ON(get_evtchn_to_irq(evtchn) != -1);
1297         /* Expect irq to have been bound before,
1298            so there should be a proper type */
1299         BUG_ON(info->type == IRQT_UNBOUND);
1300
1301         (void)xen_irq_info_evtchn_setup(irq, evtchn);
1302
1303         mutex_unlock(&irq_mapping_update_lock);
1304
1305         /* new event channels are always bound to cpu 0 */
1306         irq_set_affinity(irq, cpumask_of(0));
1307
1308         /* Unmask the event channel. */
1309         enable_irq(irq);
1310 }
1311
1312 /* Rebind an evtchn so that it gets delivered to a specific cpu */
1313 static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
1314 {
1315         struct evtchn_bind_vcpu bind_vcpu;
1316         int evtchn = evtchn_from_irq(irq);
1317         int masked;
1318
1319         if (!VALID_EVTCHN(evtchn))
1320                 return -1;
1321
1322         /*
1323          * Events delivered via platform PCI interrupts are always
1324          * routed to vcpu 0 and hence cannot be rebound.
1325          */
1326         if (xen_hvm_domain() && !xen_have_vector_callback)
1327                 return -1;
1328
1329         /* Send future instances of this interrupt to other vcpu. */
1330         bind_vcpu.port = evtchn;
1331         bind_vcpu.vcpu = tcpu;
1332
1333         /*
1334          * Mask the event while changing the VCPU binding to prevent
1335          * it being delivered on an unexpected VCPU.
1336          */
1337         masked = test_and_set_mask(evtchn);
1338
1339         /*
1340          * If this fails, it usually just indicates that we're dealing with a
1341          * virq or IPI channel, which don't actually need to be rebound. Ignore
1342          * it, but don't do the xenlinux-level rebind in that case.
1343          */
1344         if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1345                 bind_evtchn_to_cpu(evtchn, tcpu);
1346
1347         if (!masked)
1348                 unmask_evtchn(evtchn);
1349
1350         return 0;
1351 }
1352
1353 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1354                             bool force)
1355 {
1356         unsigned tcpu = cpumask_first(dest);
1357
1358         return rebind_irq_to_cpu(data->irq, tcpu);
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         unsigned int evtchn = evtchn_from_irq(data->irq);
1396         int masked;
1397
1398         if (!VALID_EVTCHN(evtchn))
1399                 return 0;
1400
1401         masked = test_and_set_mask(evtchn);
1402         set_evtchn(evtchn);
1403         if (!masked)
1404                 unmask_evtchn(evtchn);
1405
1406         return 1;
1407 }
1408
1409 static void restore_pirqs(void)
1410 {
1411         int pirq, rc, irq, gsi;
1412         struct physdev_map_pirq map_irq;
1413         struct irq_info *info;
1414
1415         list_for_each_entry(info, &xen_irq_list_head, list) {
1416                 if (info->type != IRQT_PIRQ)
1417                         continue;
1418
1419                 pirq = info->u.pirq.pirq;
1420                 gsi = info->u.pirq.gsi;
1421                 irq = info->irq;
1422
1423                 /* save/restore of PT devices doesn't work, so at this point the
1424                  * only devices present are GSI based emulated devices */
1425                 if (!gsi)
1426                         continue;
1427
1428                 map_irq.domid = DOMID_SELF;
1429                 map_irq.type = MAP_PIRQ_TYPE_GSI;
1430                 map_irq.index = gsi;
1431                 map_irq.pirq = pirq;
1432
1433                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1434                 if (rc) {
1435                         pr_warn("xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1436                                 gsi, irq, pirq, rc);
1437                         xen_free_irq(irq);
1438                         continue;
1439                 }
1440
1441                 printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1442
1443                 __startup_pirq(irq);
1444         }
1445 }
1446
1447 static void restore_cpu_virqs(unsigned int cpu)
1448 {
1449         struct evtchn_bind_virq bind_virq;
1450         int virq, irq, evtchn;
1451
1452         for (virq = 0; virq < NR_VIRQS; virq++) {
1453                 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1454                         continue;
1455
1456                 BUG_ON(virq_from_irq(irq) != virq);
1457
1458                 /* Get a new binding from Xen. */
1459                 bind_virq.virq = virq;
1460                 bind_virq.vcpu = cpu;
1461                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1462                                                 &bind_virq) != 0)
1463                         BUG();
1464                 evtchn = bind_virq.port;
1465
1466                 /* Record the new mapping. */
1467                 (void)xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
1468                 bind_evtchn_to_cpu(evtchn, cpu);
1469         }
1470 }
1471
1472 static void restore_cpu_ipis(unsigned int cpu)
1473 {
1474         struct evtchn_bind_ipi bind_ipi;
1475         int ipi, irq, evtchn;
1476
1477         for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1478                 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1479                         continue;
1480
1481                 BUG_ON(ipi_from_irq(irq) != ipi);
1482
1483                 /* Get a new binding from Xen. */
1484                 bind_ipi.vcpu = cpu;
1485                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1486                                                 &bind_ipi) != 0)
1487                         BUG();
1488                 evtchn = bind_ipi.port;
1489
1490                 /* Record the new mapping. */
1491                 (void)xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
1492                 bind_evtchn_to_cpu(evtchn, cpu);
1493         }
1494 }
1495
1496 /* Clear an irq's pending state, in preparation for polling on it */
1497 void xen_clear_irq_pending(int irq)
1498 {
1499         int evtchn = evtchn_from_irq(irq);
1500
1501         if (VALID_EVTCHN(evtchn))
1502                 clear_evtchn(evtchn);
1503 }
1504 EXPORT_SYMBOL(xen_clear_irq_pending);
1505 void xen_set_irq_pending(int irq)
1506 {
1507         int evtchn = evtchn_from_irq(irq);
1508
1509         if (VALID_EVTCHN(evtchn))
1510                 set_evtchn(evtchn);
1511 }
1512
1513 bool xen_test_irq_pending(int irq)
1514 {
1515         int evtchn = evtchn_from_irq(irq);
1516         bool ret = false;
1517
1518         if (VALID_EVTCHN(evtchn))
1519                 ret = test_evtchn(evtchn);
1520
1521         return ret;
1522 }
1523
1524 /* Poll waiting for an irq to become pending with timeout.  In the usual case,
1525  * the irq will be disabled so it won't deliver an interrupt. */
1526 void xen_poll_irq_timeout(int irq, u64 timeout)
1527 {
1528         evtchn_port_t evtchn = evtchn_from_irq(irq);
1529
1530         if (VALID_EVTCHN(evtchn)) {
1531                 struct sched_poll poll;
1532
1533                 poll.nr_ports = 1;
1534                 poll.timeout = timeout;
1535                 set_xen_guest_handle(poll.ports, &evtchn);
1536
1537                 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1538                         BUG();
1539         }
1540 }
1541 EXPORT_SYMBOL(xen_poll_irq_timeout);
1542 /* Poll waiting for an irq to become pending.  In the usual case, the
1543  * irq will be disabled so it won't deliver an interrupt. */
1544 void xen_poll_irq(int irq)
1545 {
1546         xen_poll_irq_timeout(irq, 0 /* no timeout */);
1547 }
1548
1549 /* Check whether the IRQ line is shared with other guests. */
1550 int xen_test_irq_shared(int irq)
1551 {
1552         struct irq_info *info = info_for_irq(irq);
1553         struct physdev_irq_status_query irq_status;
1554
1555         if (WARN_ON(!info))
1556                 return -ENOENT;
1557
1558         irq_status.irq = info->u.pirq.pirq;
1559
1560         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
1561                 return 0;
1562         return !(irq_status.flags & XENIRQSTAT_shared);
1563 }
1564 EXPORT_SYMBOL_GPL(xen_test_irq_shared);
1565
1566 void xen_irq_resume(void)
1567 {
1568         unsigned int cpu;
1569         struct irq_info *info;
1570
1571         /* New event-channel space is not 'live' yet. */
1572         xen_evtchn_mask_all();
1573         xen_evtchn_resume();
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         clear_evtchn_to_irq_all();
1580
1581         for_each_possible_cpu(cpu) {
1582                 restore_cpu_virqs(cpu);
1583                 restore_cpu_ipis(cpu);
1584         }
1585
1586         restore_pirqs();
1587 }
1588
1589 static struct irq_chip xen_dynamic_chip __read_mostly = {
1590         .name                   = "xen-dyn",
1591
1592         .irq_disable            = disable_dynirq,
1593         .irq_mask               = disable_dynirq,
1594         .irq_unmask             = enable_dynirq,
1595
1596         .irq_ack                = ack_dynirq,
1597         .irq_mask_ack           = mask_ack_dynirq,
1598
1599         .irq_set_affinity       = set_affinity_irq,
1600         .irq_retrigger          = retrigger_dynirq,
1601 };
1602
1603 static struct irq_chip xen_pirq_chip __read_mostly = {
1604         .name                   = "xen-pirq",
1605
1606         .irq_startup            = startup_pirq,
1607         .irq_shutdown           = shutdown_pirq,
1608         .irq_enable             = enable_pirq,
1609         .irq_disable            = disable_pirq,
1610
1611         .irq_mask               = disable_dynirq,
1612         .irq_unmask             = enable_dynirq,
1613
1614         .irq_ack                = eoi_pirq,
1615         .irq_eoi                = eoi_pirq,
1616         .irq_mask_ack           = mask_ack_pirq,
1617
1618         .irq_set_affinity       = set_affinity_irq,
1619
1620         .irq_retrigger          = retrigger_dynirq,
1621 };
1622
1623 static struct irq_chip xen_percpu_chip __read_mostly = {
1624         .name                   = "xen-percpu",
1625
1626         .irq_disable            = disable_dynirq,
1627         .irq_mask               = disable_dynirq,
1628         .irq_unmask             = enable_dynirq,
1629
1630         .irq_ack                = ack_dynirq,
1631 };
1632
1633 int xen_set_callback_via(uint64_t via)
1634 {
1635         struct xen_hvm_param a;
1636         a.domid = DOMID_SELF;
1637         a.index = HVM_PARAM_CALLBACK_IRQ;
1638         a.value = via;
1639         return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1640 }
1641 EXPORT_SYMBOL_GPL(xen_set_callback_via);
1642
1643 #ifdef CONFIG_XEN_PVHVM
1644 /* Vector callbacks are better than PCI interrupts to receive event
1645  * channel notifications because we can receive vector callbacks on any
1646  * vcpu and we don't need PCI support or APIC interactions. */
1647 void xen_callback_vector(void)
1648 {
1649         int rc;
1650         uint64_t callback_via;
1651         if (xen_have_vector_callback) {
1652                 callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
1653                 rc = xen_set_callback_via(callback_via);
1654                 if (rc) {
1655                         pr_err("Request for Xen HVM callback vector failed\n");
1656                         xen_have_vector_callback = 0;
1657                         return;
1658                 }
1659                 pr_info("Xen HVM callback vector for event delivery is enabled\n");
1660                 /* in the restore case the vector has already been allocated */
1661                 if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
1662                         alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
1663                                         xen_hvm_callback_vector);
1664         }
1665 }
1666 #else
1667 void xen_callback_vector(void) {}
1668 #endif
1669
1670 #undef MODULE_PARAM_PREFIX
1671 #define MODULE_PARAM_PREFIX "xen."
1672
1673 static bool fifo_events = true;
1674 module_param(fifo_events, bool, 0);
1675
1676 void __init xen_init_IRQ(void)
1677 {
1678         int ret = -EINVAL;
1679
1680         if (fifo_events)
1681                 ret = xen_evtchn_fifo_init();
1682         if (ret < 0)
1683                 xen_evtchn_2l_init();
1684
1685         evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()),
1686                                 sizeof(*evtchn_to_irq), GFP_KERNEL);
1687         BUG_ON(!evtchn_to_irq);
1688
1689         /* No event channels are 'live' right now. */
1690         xen_evtchn_mask_all();
1691
1692         pirq_needs_eoi = pirq_needs_eoi_flag;
1693
1694 #ifdef CONFIG_X86
1695         if (xen_pv_domain()) {
1696                 irq_ctx_init(smp_processor_id());
1697                 if (xen_initial_domain())
1698                         pci_xen_initial_domain();
1699         }
1700         if (xen_feature(XENFEAT_hvm_callback_vector))
1701                 xen_callback_vector();
1702
1703         if (xen_hvm_domain()) {
1704                 native_init_IRQ();
1705                 /* pci_xen_hvm_init must be called after native_init_IRQ so that
1706                  * __acpi_register_gsi can point at the right function */
1707                 pci_xen_hvm_init();
1708         } else {
1709                 int rc;
1710                 struct physdev_pirq_eoi_gmfn eoi_gmfn;
1711
1712                 pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
1713                 eoi_gmfn.gmfn = virt_to_mfn(pirq_eoi_map);
1714                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn);
1715                 /* TODO: No PVH support for PIRQ EOI */
1716                 if (rc != 0) {
1717                         free_page((unsigned long) pirq_eoi_map);
1718                         pirq_eoi_map = NULL;
1719                 } else
1720                         pirq_needs_eoi = pirq_check_eoi_map;
1721         }
1722 #endif
1723 }