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/moduleparam.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/io_apic.h>
  41 #include <asm/i8259.h>
  42 #include <asm/xen/pci.h>
  43 #endif
  44 #include <asm/sync_bitops.h>
  45 #include <asm/xen/hypercall.h>
  46 #include <asm/xen/hypervisor.h>
  47 #include <xen/page.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 >= 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_affinity_mask(irq), cpumask_of(cpu));
 340 #endif
 341         xen_evtchn_port_bind_to_cpu(info, cpu);
 342
 343         info->cpu = cpu;
 344 }
 345
 346 /**
 347  * notify_remote_via_irq - send event to remote end of event channel via irq
 348  * @irq: irq of event channel to send event to
 349  *
 350  * Unlike notify_remote_via_evtchn(), this is safe to use across
 351  * save/restore. Notifications on a broken connection are silently
 352  * dropped.
 353  */
 354 void notify_remote_via_irq(int irq)
 355 {
 356         int evtchn = evtchn_from_irq(irq);
 357
 358         if (VALID_EVTCHN(evtchn))
 359                 notify_remote_via_evtchn(evtchn);
 360 }
 361 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
 362
 363 static void xen_irq_init(unsigned irq)
 364 {
 365         struct irq_info *info;
 366 #ifdef CONFIG_SMP
 367         /* By default all event channels notify CPU#0. */
 368         cpumask_copy(irq_get_affinity_mask(irq), cpumask_of(0));
 369 #endif
 370
 371         info = kzalloc(sizeof(*info), GFP_KERNEL);
 372         if (info == NULL)
 373                 panic("Unable to allocate metadata for IRQ%d\n", irq);
 374
 375         info->type = IRQT_UNBOUND;
 376         info->refcnt = -1;
 377
 378         irq_set_handler_data(irq, info);
 379
 380         list_add_tail(&info->list, &xen_irq_list_head);
 381 }
 382
 383 static int __must_check xen_allocate_irqs_dynamic(int nvec)
 384 {
 385         int i, irq = irq_alloc_descs(-1, 0, nvec, -1);
 386
 387         if (irq >= 0) {
 388                 for (i = 0; i < nvec; i++)
 389                         xen_irq_init(irq + i);
 390         }
 391
 392         return irq;
 393 }
 394
 395 static inline int __must_check xen_allocate_irq_dynamic(void)
 396 {
 397
 398         return xen_allocate_irqs_dynamic(1);
 399 }
 400
 401 static int __must_check xen_allocate_irq_gsi(unsigned gsi)
 402 {
 403         int irq;
 404
 405         /*
 406          * A PV guest has no concept of a GSI (since it has no ACPI
 407          * nor access to/knowledge of the physical APICs). Therefore
 408          * all IRQs are dynamically allocated from the entire IRQ
 409          * space.
 410          */
 411         if (xen_pv_domain() && !xen_initial_domain())
 412                 return xen_allocate_irq_dynamic();
 413
 414         /* Legacy IRQ descriptors are already allocated by the arch. */
 415         if (gsi < nr_legacy_irqs())
 416                 irq = gsi;
 417         else
 418                 irq = irq_alloc_desc_at(gsi, -1);
 419
 420         xen_irq_init(irq);
 421
 422         return irq;
 423 }
 424
 425 static void xen_free_irq(unsigned irq)
 426 {
 427         struct irq_info *info = irq_get_handler_data(irq);
 428
 429         if (WARN_ON(!info))
 430                 return;
 431
 432         list_del(&info->list);
 433
 434         irq_set_handler_data(irq, NULL);
 435
 436         WARN_ON(info->refcnt > 0);
 437
 438         kfree(info);
 439
 440         /* Legacy IRQ descriptors are managed by the arch. */
 441         if (irq < nr_legacy_irqs())
 442                 return;
 443
 444         irq_free_desc(irq);
 445 }
 446
 447 static void xen_evtchn_close(unsigned int port)
 448 {
 449         struct evtchn_close close;
 450
 451         close.port = port;
 452         if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 453                 BUG();
 454 }
 455
 456 static void pirq_query_unmask(int irq)
 457 {
 458         struct physdev_irq_status_query irq_status;
 459         struct irq_info *info = info_for_irq(irq);
 460
 461         BUG_ON(info->type != IRQT_PIRQ);
 462
 463         irq_status.irq = pirq_from_irq(irq);
 464         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
 465                 irq_status.flags = 0;
 466
 467         info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
 468         if (irq_status.flags & XENIRQSTAT_needs_eoi)
 469                 info->u.pirq.flags |= PIRQ_NEEDS_EOI;
 470 }
 471
 472 static void eoi_pirq(struct irq_data *data)
 473 {
 474         int evtchn = evtchn_from_irq(data->irq);
 475         struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
 476         int rc = 0;
 477
 478         if (!VALID_EVTCHN(evtchn))
 479                 return;
 480
 481         if (unlikely(irqd_is_setaffinity_pending(data)) &&
 482             likely(!irqd_irq_disabled(data))) {
 483                 int masked = test_and_set_mask(evtchn);
 484
 485                 clear_evtchn(evtchn);
 486
 487                 irq_move_masked_irq(data);
 488
 489                 if (!masked)
 490                         unmask_evtchn(evtchn);
 491         } else
 492                 clear_evtchn(evtchn);
 493
 494         if (pirq_needs_eoi(data->irq)) {
 495                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
 496                 WARN_ON(rc);
 497         }
 498 }
 499
 500 static void mask_ack_pirq(struct irq_data *data)
 501 {
 502         disable_dynirq(data);
 503         eoi_pirq(data);
 504 }
 505
 506 static unsigned int __startup_pirq(unsigned int irq)
 507 {
 508         struct evtchn_bind_pirq bind_pirq;
 509         struct irq_info *info = info_for_irq(irq);
 510         int evtchn = evtchn_from_irq(irq);
 511         int rc;
 512
 513         BUG_ON(info->type != IRQT_PIRQ);
 514
 515         if (VALID_EVTCHN(evtchn))
 516                 goto out;
 517
 518         bind_pirq.pirq = pirq_from_irq(irq);
 519         /* NB. We are happy to share unless we are probing. */
 520         bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
 521                                         BIND_PIRQ__WILL_SHARE : 0;
 522         rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
 523         if (rc != 0) {
 524                 pr_warn("Failed to obtain physical IRQ %d\n", irq);
 525                 return 0;
 526         }
 527         evtchn = bind_pirq.port;
 528
 529         pirq_query_unmask(irq);
 530
 531         rc = set_evtchn_to_irq(evtchn, irq);
 532         if (rc)
 533                 goto err;
 534
 535         info->evtchn = evtchn;
 536         bind_evtchn_to_cpu(evtchn, 0);
 537
 538         rc = xen_evtchn_port_setup(info);
 539         if (rc)
 540                 goto err;
 541
 542 out:
 543         unmask_evtchn(evtchn);
 544         eoi_pirq(irq_get_irq_data(irq));
 545
 546         return 0;
 547
 548 err:
 549         pr_err("irq%d: Failed to set port to irq mapping (%d)\n", irq, rc);
 550         xen_evtchn_close(evtchn);
 551         return 0;
 552 }
 553
 554 static unsigned int startup_pirq(struct irq_data *data)
 555 {
 556         return __startup_pirq(data->irq);
 557 }
 558
 559 static void shutdown_pirq(struct irq_data *data)
 560 {
 561         unsigned int irq = data->irq;
 562         struct irq_info *info = info_for_irq(irq);
 563         unsigned evtchn = evtchn_from_irq(irq);
 564
 565         BUG_ON(info->type != IRQT_PIRQ);
 566
 567         if (!VALID_EVTCHN(evtchn))
 568                 return;
 569
 570         mask_evtchn(evtchn);
 571         xen_evtchn_close(evtchn);
 572         xen_irq_info_cleanup(info);
 573 }
 574
 575 static void enable_pirq(struct irq_data *data)
 576 {
 577         enable_dynirq(data);
 578 }
 579
 580 static void disable_pirq(struct irq_data *data)
 581 {
 582         disable_dynirq(data);
 583 }
 584
 585 int xen_irq_from_gsi(unsigned gsi)
 586 {
 587         struct irq_info *info;
 588
 589         list_for_each_entry(info, &xen_irq_list_head, list) {
 590                 if (info->type != IRQT_PIRQ)
 591                         continue;
 592
 593                 if (info->u.pirq.gsi == gsi)
 594                         return info->irq;
 595         }
 596
 597         return -1;
 598 }
 599 EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
 600
 601 static void __unbind_from_irq(unsigned int irq)
 602 {
 603         int evtchn = evtchn_from_irq(irq);
 604         struct irq_info *info = irq_get_handler_data(irq);
 605
 606         if (info->refcnt > 0) {
 607                 info->refcnt--;
 608                 if (info->refcnt != 0)
 609                         return;
 610         }
 611
 612         if (VALID_EVTCHN(evtchn)) {
 613                 unsigned int cpu = cpu_from_irq(irq);
 614
 615                 xen_evtchn_close(evtchn);
 616
 617                 switch (type_from_irq(irq)) {
 618                 case IRQT_VIRQ:
 619                         per_cpu(virq_to_irq, cpu)[virq_from_irq(irq)] = -1;
 620                         break;
 621                 case IRQT_IPI:
 622                         per_cpu(ipi_to_irq, cpu)[ipi_from_irq(irq)] = -1;
 623                         break;
 624                 default:
 625                         break;
 626                 }
 627
 628                 xen_irq_info_cleanup(info);
 629         }
 630
 631         BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
 632
 633         xen_free_irq(irq);
 634 }
 635
 636 /*
 637  * Do not make any assumptions regarding the relationship between the
 638  * IRQ number returned here and the Xen pirq argument.
 639  *
 640  * Note: We don't assign an event channel until the irq actually started
 641  * up.  Return an existing irq if we've already got one for the gsi.
 642  *
 643  * Shareable implies level triggered, not shareable implies edge
 644  * triggered here.
 645  */
 646 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 647                              unsigned pirq, int shareable, char *name)
 648 {
 649         int irq = -1;
 650         struct physdev_irq irq_op;
 651         int ret;
 652
 653         mutex_lock(&irq_mapping_update_lock);
 654
 655         irq = xen_irq_from_gsi(gsi);
 656         if (irq != -1) {
 657                 pr_info("%s: returning irq %d for gsi %u\n",
 658                         __func__, irq, gsi);
 659                 goto out;
 660         }
 661
 662         irq = xen_allocate_irq_gsi(gsi);
 663         if (irq < 0)
 664                 goto out;
 665
 666         irq_op.irq = irq;
 667         irq_op.vector = 0;
 668
 669         /* Only the privileged domain can do this. For non-priv, the pcifront
 670          * driver provides a PCI bus that does the call to do exactly
 671          * this in the priv domain. */
 672         if (xen_initial_domain() &&
 673             HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
 674                 xen_free_irq(irq);
 675                 irq = -ENOSPC;
 676                 goto out;
 677         }
 678
 679         ret = xen_irq_info_pirq_setup(irq, 0, pirq, gsi, DOMID_SELF,
 680                                shareable ? PIRQ_SHAREABLE : 0);
 681         if (ret < 0) {
 682                 __unbind_from_irq(irq);
 683                 irq = ret;
 684                 goto out;
 685         }
 686
 687         pirq_query_unmask(irq);
 688         /* We try to use the handler with the appropriate semantic for the
 689          * type of interrupt: if the interrupt is an edge triggered
 690          * interrupt we use handle_edge_irq.
 691          *
 692          * On the other hand if the interrupt is level triggered we use
 693          * handle_fasteoi_irq like the native code does for this kind of
 694          * interrupts.
 695          *
 696          * Depending on the Xen version, pirq_needs_eoi might return true
 697          * not only for level triggered interrupts but for edge triggered
 698          * interrupts too. In any case Xen always honors the eoi mechanism,
 699          * not injecting any more pirqs of the same kind if the first one
 700          * hasn't received an eoi yet. Therefore using the fasteoi handler
 701          * is the right choice either way.
 702          */
 703         if (shareable)
 704                 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 705                                 handle_fasteoi_irq, name);
 706         else
 707                 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 708                                 handle_edge_irq, name);
 709
 710 out:
 711         mutex_unlock(&irq_mapping_update_lock);
 712
 713         return irq;
 714 }
 715
 716 #ifdef CONFIG_PCI_MSI
 717 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
 718 {
 719         int rc;
 720         struct physdev_get_free_pirq op_get_free_pirq;
 721
 722         op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
 723         rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
 724
 725         WARN_ONCE(rc == -ENOSYS,
 726                   "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
 727
 728         return rc ? -1 : op_get_free_pirq.pirq;
 729 }
 730
 731 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
 732                              int pirq, int nvec, const char *name, domid_t domid)
 733 {
 734         int i, irq, ret;
 735
 736         mutex_lock(&irq_mapping_update_lock);
 737
 738         irq = xen_allocate_irqs_dynamic(nvec);
 739         if (irq < 0)
 740                 goto out;
 741
 742         for (i = 0; i < nvec; i++) {
 743                 irq_set_chip_and_handler_name(irq + i, &xen_pirq_chip, handle_edge_irq, name);
 744
 745                 ret = xen_irq_info_pirq_setup(irq + i, 0, pirq + i, 0, domid,
 746                                               i == 0 ? 0 : PIRQ_MSI_GROUP);
 747                 if (ret < 0)
 748                         goto error_irq;
 749         }
 750
 751         ret = irq_set_msi_desc(irq, msidesc);
 752         if (ret < 0)
 753                 goto error_irq;
 754 out:
 755         mutex_unlock(&irq_mapping_update_lock);
 756         return irq;
 757 error_irq:
 758         for (; i >= 0; i--)
 759                 __unbind_from_irq(irq + i);
 760         mutex_unlock(&irq_mapping_update_lock);
 761         return ret;
 762 }
 763 #endif
 764
 765 int xen_destroy_irq(int irq)
 766 {
 767         struct physdev_unmap_pirq unmap_irq;
 768         struct irq_info *info = info_for_irq(irq);
 769         int rc = -ENOENT;
 770
 771         mutex_lock(&irq_mapping_update_lock);
 772
 773         /*
 774          * If trying to remove a vector in a MSI group different
 775          * than the first one skip the PIRQ unmap unless this vector
 776          * is the first one in the group.
 777          */
 778         if (xen_initial_domain() && !(info->u.pirq.flags & PIRQ_MSI_GROUP)) {
 779                 unmap_irq.pirq = info->u.pirq.pirq;
 780                 unmap_irq.domid = info->u.pirq.domid;
 781                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
 782                 /* If another domain quits without making the pci_disable_msix
 783                  * call, the Xen hypervisor takes care of freeing the PIRQs
 784                  * (free_domain_pirqs).
 785                  */
 786                 if ((rc == -ESRCH && info->u.pirq.domid != DOMID_SELF))
 787                         pr_info("domain %d does not have %d anymore\n",
 788                                 info->u.pirq.domid, info->u.pirq.pirq);
 789                 else if (rc) {
 790                         pr_warn("unmap irq failed %d\n", rc);
 791                         goto out;
 792                 }
 793         }
 794
 795         xen_free_irq(irq);
 796
 797 out:
 798         mutex_unlock(&irq_mapping_update_lock);
 799         return rc;
 800 }
 801
 802 int xen_irq_from_pirq(unsigned pirq)
 803 {
 804         int irq;
 805
 806         struct irq_info *info;
 807
 808         mutex_lock(&irq_mapping_update_lock);
 809
 810         list_for_each_entry(info, &xen_irq_list_head, list) {
 811                 if (info->type != IRQT_PIRQ)
 812                         continue;
 813                 irq = info->irq;
 814                 if (info->u.pirq.pirq == pirq)
 815                         goto out;
 816         }
 817         irq = -1;
 818 out:
 819         mutex_unlock(&irq_mapping_update_lock);
 820
 821         return irq;
 822 }
 823
 824
 825 int xen_pirq_from_irq(unsigned irq)
 826 {
 827         return pirq_from_irq(irq);
 828 }
 829 EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
 830
 831 int bind_evtchn_to_irq(unsigned int evtchn)
 832 {
 833         int irq;
 834         int ret;
 835
 836         if (evtchn >= xen_evtchn_max_channels())
 837                 return -ENOMEM;
 838
 839         mutex_lock(&irq_mapping_update_lock);
 840
 841         irq = get_evtchn_to_irq(evtchn);
 842
 843         if (irq == -1) {
 844                 irq = xen_allocate_irq_dynamic();
 845                 if (irq < 0)
 846                         goto out;
 847
 848                 irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
 849                                               handle_edge_irq, "event");
 850
 851                 ret = xen_irq_info_evtchn_setup(irq, evtchn);
 852                 if (ret < 0) {
 853                         __unbind_from_irq(irq);
 854                         irq = ret;
 855                         goto out;
 856                 }
 857                 /* New interdomain events are bound to VCPU 0. */
 858                 bind_evtchn_to_cpu(evtchn, 0);
 859         } else {
 860                 struct irq_info *info = info_for_irq(irq);
 861                 WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
 862         }
 863
 864 out:
 865         mutex_unlock(&irq_mapping_update_lock);
 866
 867         return irq;
 868 }
 869 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
 870
 871 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 872 {
 873         struct evtchn_bind_ipi bind_ipi;
 874         int evtchn, irq;
 875         int ret;
 876
 877         mutex_lock(&irq_mapping_update_lock);
 878
 879         irq = per_cpu(ipi_to_irq, cpu)[ipi];
 880
 881         if (irq == -1) {
 882                 irq = xen_allocate_irq_dynamic();
 883                 if (irq < 0)
 884                         goto out;
 885
 886                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 887                                               handle_percpu_irq, "ipi");
 888
 889                 bind_ipi.vcpu = xen_vcpu_nr(cpu);
 890                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
 891                                                 &bind_ipi) != 0)
 892                         BUG();
 893                 evtchn = bind_ipi.port;
 894
 895                 ret = xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
 896                 if (ret < 0) {
 897                         __unbind_from_irq(irq);
 898                         irq = ret;
 899                         goto out;
 900                 }
 901                 bind_evtchn_to_cpu(evtchn, cpu);
 902         } else {
 903                 struct irq_info *info = info_for_irq(irq);
 904                 WARN_ON(info == NULL || info->type != IRQT_IPI);
 905         }
 906
 907  out:
 908         mutex_unlock(&irq_mapping_update_lock);
 909         return irq;
 910 }
 911
 912 int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
 913                                    unsigned int remote_port)
 914 {
 915         struct evtchn_bind_interdomain bind_interdomain;
 916         int err;
 917
 918         bind_interdomain.remote_dom  = remote_domain;
 919         bind_interdomain.remote_port = remote_port;
 920
 921         err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
 922                                           &bind_interdomain);
 923
 924         return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
 925 }
 926 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq);
 927
 928 static int find_virq(unsigned int virq, unsigned int cpu)
 929 {
 930         struct evtchn_status status;
 931         int port, rc = -ENOENT;
 932
 933         memset(&status, 0, sizeof(status));
 934         for (port = 0; port < xen_evtchn_max_channels(); port++) {
 935                 status.dom = DOMID_SELF;
 936                 status.port = port;
 937                 rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status);
 938                 if (rc < 0)
 939                         continue;
 940                 if (status.status != EVTCHNSTAT_virq)
 941                         continue;
 942                 if (status.u.virq == virq && status.vcpu == xen_vcpu_nr(cpu)) {
 943                         rc = port;
 944                         break;
 945                 }
 946         }
 947         return rc;
 948 }
 949
 950 /**
 951  * xen_evtchn_nr_channels - number of usable event channel ports
 952  *
 953  * This may be less than the maximum supported by the current
 954  * hypervisor ABI. Use xen_evtchn_max_channels() for the maximum
 955  * supported.
 956  */
 957 unsigned xen_evtchn_nr_channels(void)
 958 {
 959         return evtchn_ops->nr_channels();
 960 }
 961 EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
 962
 963 int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
 964 {
 965         struct evtchn_bind_virq bind_virq;
 966         int evtchn, irq, ret;
 967
 968         mutex_lock(&irq_mapping_update_lock);
 969
 970         irq = per_cpu(virq_to_irq, cpu)[virq];
 971
 972         if (irq == -1) {
 973                 irq = xen_allocate_irq_dynamic();
 974                 if (irq < 0)
 975                         goto out;
 976
 977                 if (percpu)
 978                         irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 979                                                       handle_percpu_irq, "virq");
 980                 else
 981                         irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
 982                                                       handle_edge_irq, "virq");
 983
 984                 bind_virq.virq = virq;
 985                 bind_virq.vcpu = xen_vcpu_nr(cpu);
 986                 ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
 987                                                 &bind_virq);
 988                 if (ret == 0)
 989                         evtchn = bind_virq.port;
 990                 else {
 991                         if (ret == -EEXIST)
 992                                 ret = find_virq(virq, cpu);
 993                         BUG_ON(ret < 0);
 994                         evtchn = ret;
 995                 }
 996
 997                 ret = xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
 998                 if (ret < 0) {
 999                         __unbind_from_irq(irq);
1000                         irq = ret;
1001                         goto out;
1002                 }
1003
1004                 bind_evtchn_to_cpu(evtchn, cpu);
1005         } else {
1006                 struct irq_info *info = info_for_irq(irq);
1007                 WARN_ON(info == NULL || info->type != IRQT_VIRQ);
1008         }
1009
1010 out:
1011         mutex_unlock(&irq_mapping_update_lock);
1012
1013         return irq;
1014 }
1015
1016 static void unbind_from_irq(unsigned int irq)
1017 {
1018         mutex_lock(&irq_mapping_update_lock);
1019         __unbind_from_irq(irq);
1020         mutex_unlock(&irq_mapping_update_lock);
1021 }
1022
1023 int bind_evtchn_to_irqhandler(unsigned int evtchn,
1024                               irq_handler_t handler,
1025                               unsigned long irqflags,
1026                               const char *devname, void *dev_id)
1027 {
1028         int irq, retval;
1029
1030         irq = bind_evtchn_to_irq(evtchn);
1031         if (irq < 0)
1032                 return irq;
1033         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1034         if (retval != 0) {
1035                 unbind_from_irq(irq);
1036                 return retval;
1037         }
1038
1039         return irq;
1040 }
1041 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
1042
1043 int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
1044                                           unsigned int remote_port,
1045                                           irq_handler_t handler,
1046                                           unsigned long irqflags,
1047                                           const char *devname,
1048                                           void *dev_id)
1049 {
1050         int irq, retval;
1051
1052         irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
1053         if (irq < 0)
1054                 return irq;
1055
1056         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1057         if (retval != 0) {
1058                 unbind_from_irq(irq);
1059                 return retval;
1060         }
1061
1062         return irq;
1063 }
1064 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
1065
1066 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
1067                             irq_handler_t handler,
1068                             unsigned long irqflags, const char *devname, void *dev_id)
1069 {
1070         int irq, retval;
1071
1072         irq = bind_virq_to_irq(virq, cpu, irqflags & IRQF_PERCPU);
1073         if (irq < 0)
1074                 return irq;
1075         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1076         if (retval != 0) {
1077                 unbind_from_irq(irq);
1078                 return retval;
1079         }
1080
1081         return irq;
1082 }
1083 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
1084
1085 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
1086                            unsigned int cpu,
1087                            irq_handler_t handler,
1088                            unsigned long irqflags,
1089                            const char *devname,
1090                            void *dev_id)
1091 {
1092         int irq, retval;
1093
1094         irq = bind_ipi_to_irq(ipi, cpu);
1095         if (irq < 0)
1096                 return irq;
1097
1098         irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME | IRQF_EARLY_RESUME;
1099         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1100         if (retval != 0) {
1101                 unbind_from_irq(irq);
1102                 return retval;
1103         }
1104
1105         return irq;
1106 }
1107
1108 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
1109 {
1110         struct irq_info *info = irq_get_handler_data(irq);
1111
1112         if (WARN_ON(!info))
1113                 return;
1114         free_irq(irq, dev_id);
1115         unbind_from_irq(irq);
1116 }
1117 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
1118
1119 /**
1120  * xen_set_irq_priority() - set an event channel priority.
1121  * @irq:irq bound to an event channel.
1122  * @priority: priority between XEN_IRQ_PRIORITY_MAX and XEN_IRQ_PRIORITY_MIN.
1123  */
1124 int xen_set_irq_priority(unsigned irq, unsigned priority)
1125 {
1126         struct evtchn_set_priority set_priority;
1127
1128         set_priority.port = evtchn_from_irq(irq);
1129         set_priority.priority = priority;
1130
1131         return HYPERVISOR_event_channel_op(EVTCHNOP_set_priority,
1132                                            &set_priority);
1133 }
1134 EXPORT_SYMBOL_GPL(xen_set_irq_priority);
1135
1136 int evtchn_make_refcounted(unsigned int evtchn)
1137 {
1138         int irq = get_evtchn_to_irq(evtchn);
1139         struct irq_info *info;
1140
1141         if (irq == -1)
1142                 return -ENOENT;
1143
1144         info = irq_get_handler_data(irq);
1145
1146         if (!info)
1147                 return -ENOENT;
1148
1149         WARN_ON(info->refcnt != -1);
1150
1151         info->refcnt = 1;
1152
1153         return 0;
1154 }
1155 EXPORT_SYMBOL_GPL(evtchn_make_refcounted);
1156
1157 int evtchn_get(unsigned int evtchn)
1158 {
1159         int irq;
1160         struct irq_info *info;
1161         int err = -ENOENT;
1162
1163         if (evtchn >= xen_evtchn_max_channels())
1164                 return -EINVAL;
1165
1166         mutex_lock(&irq_mapping_update_lock);
1167
1168         irq = get_evtchn_to_irq(evtchn);
1169         if (irq == -1)
1170                 goto done;
1171
1172         info = irq_get_handler_data(irq);
1173
1174         if (!info)
1175                 goto done;
1176
1177         err = -EINVAL;
1178         if (info->refcnt <= 0)
1179                 goto done;
1180
1181         info->refcnt++;
1182         err = 0;
1183  done:
1184         mutex_unlock(&irq_mapping_update_lock);
1185
1186         return err;
1187 }
1188 EXPORT_SYMBOL_GPL(evtchn_get);
1189
1190 void evtchn_put(unsigned int evtchn)
1191 {
1192         int irq = get_evtchn_to_irq(evtchn);
1193         if (WARN_ON(irq == -1))
1194                 return;
1195         unbind_from_irq(irq);
1196 }
1197 EXPORT_SYMBOL_GPL(evtchn_put);
1198
1199 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
1200 {
1201         int irq;
1202
1203 #ifdef CONFIG_X86
1204         if (unlikely(vector == XEN_NMI_VECTOR)) {
1205                 int rc =  HYPERVISOR_vcpu_op(VCPUOP_send_nmi, xen_vcpu_nr(cpu),
1206                                              NULL);
1207                 if (rc < 0)
1208                         printk(KERN_WARNING "Sending nmi to CPU%d failed (rc:%d)\n", cpu, rc);
1209                 return;
1210         }
1211 #endif
1212         irq = per_cpu(ipi_to_irq, cpu)[vector];
1213         BUG_ON(irq < 0);
1214         notify_remote_via_irq(irq);
1215 }
1216
1217 static DEFINE_PER_CPU(unsigned, xed_nesting_count);
1218
1219 static void __xen_evtchn_do_upcall(void)
1220 {
1221         struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1222         int cpu = get_cpu();
1223         unsigned count;
1224
1225         do {
1226                 vcpu_info->evtchn_upcall_pending = 0;
1227
1228                 if (__this_cpu_inc_return(xed_nesting_count) - 1)
1229                         goto out;
1230
1231                 xen_evtchn_handle_events(cpu);
1232
1233                 BUG_ON(!irqs_disabled());
1234
1235                 count = __this_cpu_read(xed_nesting_count);
1236                 __this_cpu_write(xed_nesting_count, 0);
1237         } while (count != 1 || vcpu_info->evtchn_upcall_pending);
1238
1239 out:
1240
1241         put_cpu();
1242 }
1243
1244 void xen_evtchn_do_upcall(struct pt_regs *regs)
1245 {
1246         struct pt_regs *old_regs = set_irq_regs(regs);
1247
1248         irq_enter();
1249 #ifdef CONFIG_X86
1250         inc_irq_stat(irq_hv_callback_count);
1251 #endif
1252
1253         __xen_evtchn_do_upcall();
1254
1255         irq_exit();
1256         set_irq_regs(old_regs);
1257 }
1258
1259 void xen_hvm_evtchn_do_upcall(void)
1260 {
1261         __xen_evtchn_do_upcall();
1262 }
1263 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1264
1265 /* Rebind a new event channel to an existing irq. */
1266 void rebind_evtchn_irq(int evtchn, int irq)
1267 {
1268         struct irq_info *info = info_for_irq(irq);
1269
1270         if (WARN_ON(!info))
1271                 return;
1272
1273         /* Make sure the irq is masked, since the new event channel
1274            will also be masked. */
1275         disable_irq(irq);
1276
1277         mutex_lock(&irq_mapping_update_lock);
1278
1279         /* After resume the irq<->evtchn mappings are all cleared out */
1280         BUG_ON(get_evtchn_to_irq(evtchn) != -1);
1281         /* Expect irq to have been bound before,
1282            so there should be a proper type */
1283         BUG_ON(info->type == IRQT_UNBOUND);
1284
1285         (void)xen_irq_info_evtchn_setup(irq, evtchn);
1286
1287         mutex_unlock(&irq_mapping_update_lock);
1288
1289         bind_evtchn_to_cpu(evtchn, info->cpu);
1290         /* This will be deferred until interrupt is processed */
1291         irq_set_affinity(irq, cpumask_of(info->cpu));
1292
1293         /* Unmask the event channel. */
1294         enable_irq(irq);
1295 }
1296
1297 /* Rebind an evtchn so that it gets delivered to a specific cpu */
1298 int xen_rebind_evtchn_to_cpu(int evtchn, unsigned tcpu)
1299 {
1300         struct evtchn_bind_vcpu bind_vcpu;
1301         int masked;
1302
1303         if (!VALID_EVTCHN(evtchn))
1304                 return -1;
1305
1306         if (!xen_support_evtchn_rebind())
1307                 return -1;
1308
1309         /* Send future instances of this interrupt to other vcpu. */
1310         bind_vcpu.port = evtchn;
1311         bind_vcpu.vcpu = xen_vcpu_nr(tcpu);
1312
1313         /*
1314          * Mask the event while changing the VCPU binding to prevent
1315          * it being delivered on an unexpected VCPU.
1316          */
1317         masked = test_and_set_mask(evtchn);
1318
1319         /*
1320          * If this fails, it usually just indicates that we're dealing with a
1321          * virq or IPI channel, which don't actually need to be rebound. Ignore
1322          * it, but don't do the xenlinux-level rebind in that case.
1323          */
1324         if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1325                 bind_evtchn_to_cpu(evtchn, tcpu);
1326
1327         if (!masked)
1328                 unmask_evtchn(evtchn);
1329
1330         return 0;
1331 }
1332 EXPORT_SYMBOL_GPL(xen_rebind_evtchn_to_cpu);
1333
1334 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1335                             bool force)
1336 {
1337         unsigned tcpu = cpumask_first_and(dest, cpu_online_mask);
1338         int ret = xen_rebind_evtchn_to_cpu(evtchn_from_irq(data->irq), tcpu);
1339
1340         if (!ret)
1341                 irq_data_update_effective_affinity(data, cpumask_of(tcpu));
1342
1343         return ret;
1344 }
1345
1346 static void enable_dynirq(struct irq_data *data)
1347 {
1348         int evtchn = evtchn_from_irq(data->irq);
1349
1350         if (VALID_EVTCHN(evtchn))
1351                 unmask_evtchn(evtchn);
1352 }
1353
1354 static void disable_dynirq(struct irq_data *data)
1355 {
1356         int evtchn = evtchn_from_irq(data->irq);
1357
1358         if (VALID_EVTCHN(evtchn))
1359                 mask_evtchn(evtchn);
1360 }
1361
1362 static void ack_dynirq(struct irq_data *data)
1363 {
1364         int evtchn = evtchn_from_irq(data->irq);
1365
1366         if (!VALID_EVTCHN(evtchn))
1367                 return;
1368
1369         if (unlikely(irqd_is_setaffinity_pending(data)) &&
1370             likely(!irqd_irq_disabled(data))) {
1371                 int masked = test_and_set_mask(evtchn);
1372
1373                 clear_evtchn(evtchn);
1374
1375                 irq_move_masked_irq(data);
1376
1377                 if (!masked)
1378                         unmask_evtchn(evtchn);
1379         } else
1380                 clear_evtchn(evtchn);
1381 }
1382
1383 static void mask_ack_dynirq(struct irq_data *data)
1384 {
1385         disable_dynirq(data);
1386         ack_dynirq(data);
1387 }
1388
1389 static int retrigger_dynirq(struct irq_data *data)
1390 {
1391         unsigned int evtchn = evtchn_from_irq(data->irq);
1392         int masked;
1393
1394         if (!VALID_EVTCHN(evtchn))
1395                 return 0;
1396
1397         masked = test_and_set_mask(evtchn);
1398         set_evtchn(evtchn);
1399         if (!masked)
1400                 unmask_evtchn(evtchn);
1401
1402         return 1;
1403 }
1404
1405 static void restore_pirqs(void)
1406 {
1407         int pirq, rc, irq, gsi;
1408         struct physdev_map_pirq map_irq;
1409         struct irq_info *info;
1410
1411         list_for_each_entry(info, &xen_irq_list_head, list) {
1412                 if (info->type != IRQT_PIRQ)
1413                         continue;
1414
1415                 pirq = info->u.pirq.pirq;
1416                 gsi = info->u.pirq.gsi;
1417                 irq = info->irq;
1418
1419                 /* save/restore of PT devices doesn't work, so at this point the
1420                  * only devices present are GSI based emulated devices */
1421                 if (!gsi)
1422                         continue;
1423
1424                 map_irq.domid = DOMID_SELF;
1425                 map_irq.type = MAP_PIRQ_TYPE_GSI;
1426                 map_irq.index = gsi;
1427                 map_irq.pirq = pirq;
1428
1429                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1430                 if (rc) {
1431                         pr_warn("xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1432                                 gsi, irq, pirq, rc);
1433                         xen_free_irq(irq);
1434                         continue;
1435                 }
1436
1437                 printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1438
1439                 __startup_pirq(irq);
1440         }
1441 }
1442
1443 static void restore_cpu_virqs(unsigned int cpu)
1444 {
1445         struct evtchn_bind_virq bind_virq;
1446         int virq, irq, evtchn;
1447
1448         for (virq = 0; virq < NR_VIRQS; virq++) {
1449                 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1450                         continue;
1451
1452                 BUG_ON(virq_from_irq(irq) != virq);
1453
1454                 /* Get a new binding from Xen. */
1455                 bind_virq.virq = virq;
1456                 bind_virq.vcpu = xen_vcpu_nr(cpu);
1457                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1458                                                 &bind_virq) != 0)
1459                         BUG();
1460                 evtchn = bind_virq.port;
1461
1462                 /* Record the new mapping. */
1463                 (void)xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
1464                 bind_evtchn_to_cpu(evtchn, cpu);
1465         }
1466 }
1467
1468 static void restore_cpu_ipis(unsigned int cpu)
1469 {
1470         struct evtchn_bind_ipi bind_ipi;
1471         int ipi, irq, evtchn;
1472
1473         for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1474                 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1475                         continue;
1476
1477                 BUG_ON(ipi_from_irq(irq) != ipi);
1478
1479                 /* Get a new binding from Xen. */
1480                 bind_ipi.vcpu = xen_vcpu_nr(cpu);
1481                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1482                                                 &bind_ipi) != 0)
1483                         BUG();
1484                 evtchn = bind_ipi.port;
1485
1486                 /* Record the new mapping. */
1487                 (void)xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
1488                 bind_evtchn_to_cpu(evtchn, cpu);
1489         }
1490 }
1491
1492 /* Clear an irq's pending state, in preparation for polling on it */
1493 void xen_clear_irq_pending(int irq)
1494 {
1495         int evtchn = evtchn_from_irq(irq);
1496
1497         if (VALID_EVTCHN(evtchn))
1498                 clear_evtchn(evtchn);
1499 }
1500 EXPORT_SYMBOL(xen_clear_irq_pending);
1501 void xen_set_irq_pending(int irq)
1502 {
1503         int evtchn = evtchn_from_irq(irq);
1504
1505         if (VALID_EVTCHN(evtchn))
1506                 set_evtchn(evtchn);
1507 }
1508
1509 bool xen_test_irq_pending(int irq)
1510 {
1511         int evtchn = evtchn_from_irq(irq);
1512         bool ret = false;
1513
1514         if (VALID_EVTCHN(evtchn))
1515                 ret = test_evtchn(evtchn);
1516
1517         return ret;
1518 }
1519
1520 /* Poll waiting for an irq to become pending with timeout.  In the usual case,
1521  * the irq will be disabled so it won't deliver an interrupt. */
1522 void xen_poll_irq_timeout(int irq, u64 timeout)
1523 {
1524         evtchn_port_t evtchn = evtchn_from_irq(irq);
1525
1526         if (VALID_EVTCHN(evtchn)) {
1527                 struct sched_poll poll;
1528
1529                 poll.nr_ports = 1;
1530                 poll.timeout = timeout;
1531                 set_xen_guest_handle(poll.ports, &evtchn);
1532
1533                 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1534                         BUG();
1535         }
1536 }
1537 EXPORT_SYMBOL(xen_poll_irq_timeout);
1538 /* Poll waiting for an irq to become pending.  In the usual case, the
1539  * irq will be disabled so it won't deliver an interrupt. */
1540 void xen_poll_irq(int irq)
1541 {
1542         xen_poll_irq_timeout(irq, 0 /* no timeout */);
1543 }
1544
1545 /* Check whether the IRQ line is shared with other guests. */
1546 int xen_test_irq_shared(int irq)
1547 {
1548         struct irq_info *info = info_for_irq(irq);
1549         struct physdev_irq_status_query irq_status;
1550
1551         if (WARN_ON(!info))
1552                 return -ENOENT;
1553
1554         irq_status.irq = info->u.pirq.pirq;
1555
1556         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
1557                 return 0;
1558         return !(irq_status.flags & XENIRQSTAT_shared);
1559 }
1560 EXPORT_SYMBOL_GPL(xen_test_irq_shared);
1561
1562 void xen_irq_resume(void)
1563 {
1564         unsigned int cpu;
1565         struct irq_info *info;
1566
1567         /* New event-channel space is not 'live' yet. */
1568         xen_evtchn_resume();
1569
1570         /* No IRQ <-> event-channel mappings. */
1571         list_for_each_entry(info, &xen_irq_list_head, list)
1572                 info->evtchn = 0; /* zap event-channel binding */
1573
1574         clear_evtchn_to_irq_all();
1575
1576         for_each_possible_cpu(cpu) {
1577                 restore_cpu_virqs(cpu);
1578                 restore_cpu_ipis(cpu);
1579         }
1580
1581         restore_pirqs();
1582 }
1583
1584 static struct irq_chip xen_dynamic_chip __read_mostly = {
1585         .name                   = "xen-dyn",
1586
1587         .irq_disable            = disable_dynirq,
1588         .irq_mask               = disable_dynirq,
1589         .irq_unmask             = enable_dynirq,
1590
1591         .irq_ack                = ack_dynirq,
1592         .irq_mask_ack           = mask_ack_dynirq,
1593
1594         .irq_set_affinity       = set_affinity_irq,
1595         .irq_retrigger          = retrigger_dynirq,
1596 };
1597
1598 static struct irq_chip xen_pirq_chip __read_mostly = {
1599         .name                   = "xen-pirq",
1600
1601         .irq_startup            = startup_pirq,
1602         .irq_shutdown           = shutdown_pirq,
1603         .irq_enable             = enable_pirq,
1604         .irq_disable            = disable_pirq,
1605
1606         .irq_mask               = disable_dynirq,
1607         .irq_unmask             = enable_dynirq,
1608
1609         .irq_ack                = eoi_pirq,
1610         .irq_eoi                = eoi_pirq,
1611         .irq_mask_ack           = mask_ack_pirq,
1612
1613         .irq_set_affinity       = set_affinity_irq,
1614
1615         .irq_retrigger          = retrigger_dynirq,
1616 };
1617
1618 static struct irq_chip xen_percpu_chip __read_mostly = {
1619         .name                   = "xen-percpu",
1620
1621         .irq_disable            = disable_dynirq,
1622         .irq_mask               = disable_dynirq,
1623         .irq_unmask             = enable_dynirq,
1624
1625         .irq_ack                = ack_dynirq,
1626 };
1627
1628 int xen_set_callback_via(uint64_t via)
1629 {
1630         struct xen_hvm_param a;
1631         a.domid = DOMID_SELF;
1632         a.index = HVM_PARAM_CALLBACK_IRQ;
1633         a.value = via;
1634         return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1635 }
1636 EXPORT_SYMBOL_GPL(xen_set_callback_via);
1637
1638 #ifdef CONFIG_XEN_PVHVM
1639 /* Vector callbacks are better than PCI interrupts to receive event
1640  * channel notifications because we can receive vector callbacks on any
1641  * vcpu and we don't need PCI support or APIC interactions. */
1642 void xen_callback_vector(void)
1643 {
1644         int rc;
1645         uint64_t callback_via;
1646
1647         if (xen_have_vector_callback) {
1648                 callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
1649                 rc = xen_set_callback_via(callback_via);
1650                 if (rc) {
1651                         pr_err("Request for Xen HVM callback vector failed\n");
1652                         xen_have_vector_callback = 0;
1653                         return;
1654                 }
1655                 pr_info("Xen HVM callback vector for event delivery is enabled\n");
1656                 /* in the restore case the vector has already been allocated */
1657                 if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
1658                         alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
1659                                         xen_hvm_callback_vector);
1660         }
1661 }
1662 #else
1663 void xen_callback_vector(void) {}
1664 #endif
1665
1666 #undef MODULE_PARAM_PREFIX
1667 #define MODULE_PARAM_PREFIX "xen."
1668
1669 static bool fifo_events = true;
1670 module_param(fifo_events, bool, 0);
1671
1672 void __init xen_init_IRQ(void)
1673 {
1674         int ret = -EINVAL;
1675         unsigned int evtchn;
1676
1677         if (fifo_events)
1678                 ret = xen_evtchn_fifo_init();
1679         if (ret < 0)
1680                 xen_evtchn_2l_init();
1681
1682         evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()),
1683                                 sizeof(*evtchn_to_irq), GFP_KERNEL);
1684         BUG_ON(!evtchn_to_irq);
1685
1686         /* No event channels are 'live' right now. */
1687         for (evtchn = 0; evtchn < xen_evtchn_nr_channels(); evtchn++)
1688                 mask_evtchn(evtchn);
1689
1690         pirq_needs_eoi = pirq_needs_eoi_flag;
1691
1692 #ifdef CONFIG_X86
1693         if (xen_pv_domain()) {
1694                 irq_ctx_init(smp_processor_id());
1695                 if (xen_initial_domain())
1696                         pci_xen_initial_domain();
1697         }
1698         if (xen_feature(XENFEAT_hvm_callback_vector))
1699                 xen_callback_vector();
1700
1701         if (xen_hvm_domain()) {
1702                 native_init_IRQ();
1703                 /* pci_xen_hvm_init must be called after native_init_IRQ so that
1704                  * __acpi_register_gsi can point at the right function */
1705                 pci_xen_hvm_init();
1706         } else {
1707                 int rc;
1708                 struct physdev_pirq_eoi_gmfn eoi_gmfn;
1709
1710                 pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
1711                 eoi_gmfn.gmfn = virt_to_gfn(pirq_eoi_map);
1712                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn);
1713                 if (rc != 0) {
1714                         free_page((unsigned long) pirq_eoi_map);
1715                         pirq_eoi_map = NULL;
1716                 } else
1717                         pirq_needs_eoi = pirq_check_eoi_map;
1718         }
1719 #endif
1720 }