drivers/xen/events/events_base.c

   1 /*
   2  * Xen event channels
   3  *
   4  * Xen models interrupts with abstract event channels.  Because each
   5  * domain gets 1024 event channels, but NR_IRQ is not that large, we
   6  * must dynamically map irqs<->event channels.  The event channels
   7  * interface with the rest of the kernel by defining a xen interrupt
   8  * chip.  When an event is received, it is mapped to an irq and sent
   9  * through the normal interrupt processing path.
  10  *
  11  * There are four kinds of events which can be mapped to an event
  12  * channel:
  13  *
  14  * 1. Inter-domain notifications.  This includes all the virtual
  15  *    device events, since they're driven by front-ends in another domain
  16  *    (typically dom0).
  17  * 2. VIRQs, typically used for timers.  These are per-cpu events.
  18  * 3. IPIs.
  19  * 4. PIRQs - Hardware interrupts.
  20  *
  21  * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
  22  */
  23
  24 #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
  25
  26 #include <linux/linkage.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/irq.h>
  29 #include <linux/module.h>
  30 #include <linux/string.h>
  31 #include <linux/bootmem.h>
  32 #include <linux/slab.h>
  33 #include <linux/irqnr.h>
  34 #include <linux/pci.h>
  35
  36 #ifdef CONFIG_X86
  37 #include <asm/desc.h>
  38 #include <asm/ptrace.h>
  39 #include <asm/irq.h>
  40 #include <asm/idle.h>
  41 #include <asm/io_apic.h>
  42 #include <asm/xen/page.h>
  43 #include <asm/xen/pci.h>
  44 #endif
  45 #include <asm/sync_bitops.h>
  46 #include <asm/xen/hypercall.h>
  47 #include <asm/xen/hypervisor.h>
  48
  49 #include <xen/xen.h>
  50 #include <xen/hvm.h>
  51 #include <xen/xen-ops.h>
  52 #include <xen/events.h>
  53 #include <xen/interface/xen.h>
  54 #include <xen/interface/event_channel.h>
  55 #include <xen/interface/hvm/hvm_op.h>
  56 #include <xen/interface/hvm/params.h>
  57 #include <xen/interface/physdev.h>
  58 #include <xen/interface/sched.h>
  59 #include <xen/interface/vcpu.h>
  60 #include <asm/hw_irq.h>
  61
  62 #include "events_internal.h"
  63
  64 const struct evtchn_ops *evtchn_ops;
  65
  66 /*
  67  * This lock protects updates to the following mapping and reference-count
  68  * arrays. The lock does not need to be acquired to read the mapping tables.
  69  */
  70 static DEFINE_MUTEX(irq_mapping_update_lock);
  71
  72 static LIST_HEAD(xen_irq_list_head);
  73
  74 /* IRQ <-> VIRQ mapping. */
  75 static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
  76
  77 /* IRQ <-> IPI mapping */
  78 static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
  79
  80 int **evtchn_to_irq;
  81 #ifdef CONFIG_X86
  82 static unsigned long *pirq_eoi_map;
  83 #endif
  84 static bool (*pirq_needs_eoi)(unsigned irq);
  85
  86 #define EVTCHN_ROW(e)  (e / (PAGE_SIZE/sizeof(**evtchn_to_irq)))
  87 #define EVTCHN_COL(e)  (e % (PAGE_SIZE/sizeof(**evtchn_to_irq)))
  88 #define EVTCHN_PER_ROW (PAGE_SIZE / sizeof(**evtchn_to_irq))
  89
  90 /* Xen will never allocate port zero for any purpose. */
  91 #define VALID_EVTCHN(chn)       ((chn) != 0)
  92
  93 static struct irq_chip xen_dynamic_chip;
  94 static struct irq_chip xen_percpu_chip;
  95 static struct irq_chip xen_pirq_chip;
  96 static void enable_dynirq(struct irq_data *data);
  97 static void disable_dynirq(struct irq_data *data);
  98
  99 static void clear_evtchn_to_irq_row(unsigned row)
 100 {
 101         unsigned col;
 102
 103         for (col = 0; col < EVTCHN_PER_ROW; col++)
 104                 evtchn_to_irq[row][col] = -1;
 105 }
 106
 107 static void clear_evtchn_to_irq_all(void)
 108 {
 109         unsigned row;
 110
 111         for (row = 0; row < EVTCHN_ROW(xen_evtchn_max_channels()); row++) {
 112                 if (evtchn_to_irq[row] == NULL)
 113                         continue;
 114                 clear_evtchn_to_irq_row(row);
 115         }
 116 }
 117
 118 static int set_evtchn_to_irq(unsigned evtchn, unsigned irq)
 119 {
 120         unsigned row;
 121         unsigned col;
 122
 123         if (evtchn >= xen_evtchn_max_channels())
 124                 return -EINVAL;
 125
 126         row = EVTCHN_ROW(evtchn);
 127         col = EVTCHN_COL(evtchn);
 128
 129         if (evtchn_to_irq[row] == NULL) {
 130                 /* Unallocated irq entries return -1 anyway */
 131                 if (irq == -1)
 132                         return 0;
 133
 134                 evtchn_to_irq[row] = (int *)get_zeroed_page(GFP_KERNEL);
 135                 if (evtchn_to_irq[row] == NULL)
 136                         return -ENOMEM;
 137
 138                 clear_evtchn_to_irq_row(row);
 139         }
 140
 141         evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)] = irq;
 142         return 0;
 143 }
 144
 145 int get_evtchn_to_irq(unsigned evtchn)
 146 {
 147         if (evtchn >= xen_evtchn_max_channels())
 148                 return -1;
 149         if (evtchn_to_irq[EVTCHN_ROW(evtchn)] == NULL)
 150                 return -1;
 151         return evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)];
 152 }
 153
 154 /* Get info for IRQ */
 155 struct irq_info *info_for_irq(unsigned irq)
 156 {
 157         return irq_get_handler_data(irq);
 158 }
 159
 160 /* Constructors for packed IRQ information. */
 161 static int xen_irq_info_common_setup(struct irq_info *info,
 162                                      unsigned irq,
 163                                      enum xen_irq_type type,
 164                                      unsigned evtchn,
 165                                      unsigned short cpu)
 166 {
 167         int ret;
 168
 169         BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
 170
 171         info->type = type;
 172         info->irq = irq;
 173         info->evtchn = evtchn;
 174         info->cpu = cpu;
 175
 176         ret = set_evtchn_to_irq(evtchn, irq);
 177         if (ret < 0)
 178                 return ret;
 179
 180         irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN);
 181
 182         return xen_evtchn_port_setup(info);
 183 }
 184
 185 static int xen_irq_info_evtchn_setup(unsigned irq,
 186                                      unsigned evtchn)
 187 {
 188         struct irq_info *info = info_for_irq(irq);
 189
 190         return xen_irq_info_common_setup(info, irq, IRQT_EVTCHN, evtchn, 0);
 191 }
 192
 193 static int xen_irq_info_ipi_setup(unsigned cpu,
 194                                   unsigned irq,
 195                                   unsigned evtchn,
 196                                   enum ipi_vector ipi)
 197 {
 198         struct irq_info *info = info_for_irq(irq);
 199
 200         info->u.ipi = ipi;
 201
 202         per_cpu(ipi_to_irq, cpu)[ipi] = irq;
 203
 204         return xen_irq_info_common_setup(info, irq, IRQT_IPI, evtchn, 0);
 205 }
 206
 207 static int xen_irq_info_virq_setup(unsigned cpu,
 208                                    unsigned irq,
 209                                    unsigned evtchn,
 210                                    unsigned virq)
 211 {
 212         struct irq_info *info = info_for_irq(irq);
 213
 214         info->u.virq = virq;
 215
 216         per_cpu(virq_to_irq, cpu)[virq] = irq;
 217
 218         return xen_irq_info_common_setup(info, irq, IRQT_VIRQ, evtchn, 0);
 219 }
 220
 221 static int xen_irq_info_pirq_setup(unsigned irq,
 222                                    unsigned evtchn,
 223                                    unsigned pirq,
 224                                    unsigned gsi,
 225                                    uint16_t domid,
 226                                    unsigned char flags)
 227 {
 228         struct irq_info *info = info_for_irq(irq);
 229
 230         info->u.pirq.pirq = pirq;
 231         info->u.pirq.gsi = gsi;
 232         info->u.pirq.domid = domid;
 233         info->u.pirq.flags = flags;
 234
 235         return xen_irq_info_common_setup(info, irq, IRQT_PIRQ, evtchn, 0);
 236 }
 237
 238 static void xen_irq_info_cleanup(struct irq_info *info)
 239 {
 240         set_evtchn_to_irq(info->evtchn, -1);
 241         info->evtchn = 0;
 242 }
 243
 244 /*
 245  * Accessors for packed IRQ information.
 246  */
 247 unsigned int evtchn_from_irq(unsigned irq)
 248 {
 249         if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))
 250                 return 0;
 251
 252         return info_for_irq(irq)->evtchn;
 253 }
 254
 255 unsigned irq_from_evtchn(unsigned int evtchn)
 256 {
 257         return get_evtchn_to_irq(evtchn);
 258 }
 259 EXPORT_SYMBOL_GPL(irq_from_evtchn);
 260
 261 int irq_from_virq(unsigned int cpu, unsigned int virq)
 262 {
 263         return per_cpu(virq_to_irq, cpu)[virq];
 264 }
 265
 266 static enum ipi_vector ipi_from_irq(unsigned irq)
 267 {
 268         struct irq_info *info = info_for_irq(irq);
 269
 270         BUG_ON(info == NULL);
 271         BUG_ON(info->type != IRQT_IPI);
 272
 273         return info->u.ipi;
 274 }
 275
 276 static unsigned virq_from_irq(unsigned irq)
 277 {
 278         struct irq_info *info = info_for_irq(irq);
 279
 280         BUG_ON(info == NULL);
 281         BUG_ON(info->type != IRQT_VIRQ);
 282
 283         return info->u.virq;
 284 }
 285
 286 static unsigned pirq_from_irq(unsigned irq)
 287 {
 288         struct irq_info *info = info_for_irq(irq);
 289
 290         BUG_ON(info == NULL);
 291         BUG_ON(info->type != IRQT_PIRQ);
 292
 293         return info->u.pirq.pirq;
 294 }
 295
 296 static enum xen_irq_type type_from_irq(unsigned irq)
 297 {
 298         return info_for_irq(irq)->type;
 299 }
 300
 301 unsigned cpu_from_irq(unsigned irq)
 302 {
 303         return info_for_irq(irq)->cpu;
 304 }
 305
 306 unsigned int cpu_from_evtchn(unsigned int evtchn)
 307 {
 308         int irq = get_evtchn_to_irq(evtchn);
 309         unsigned ret = 0;
 310
 311         if (irq != -1)
 312                 ret = cpu_from_irq(irq);
 313
 314         return ret;
 315 }
 316
 317 #ifdef CONFIG_X86
 318 static bool pirq_check_eoi_map(unsigned irq)
 319 {
 320         return test_bit(pirq_from_irq(irq), pirq_eoi_map);
 321 }
 322 #endif
 323
 324 static bool pirq_needs_eoi_flag(unsigned irq)
 325 {
 326         struct irq_info *info = info_for_irq(irq);
 327         BUG_ON(info->type != IRQT_PIRQ);
 328
 329         return info->u.pirq.flags & PIRQ_NEEDS_EOI;
 330 }
 331
 332 static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
 333 {
 334         int irq = get_evtchn_to_irq(chn);
 335         struct irq_info *info = info_for_irq(irq);
 336
 337         BUG_ON(irq == -1);
 338 #ifdef CONFIG_SMP
 339         cpumask_copy(irq_get_irq_data(irq)->affinity, cpumask_of(cpu));
 340 #endif
 341         xen_evtchn_port_bind_to_cpu(info, cpu);
 342
 343         info->cpu = cpu;
 344 }
 345
 346 static void xen_evtchn_mask_all(void)
 347 {
 348         unsigned int evtchn;
 349
 350         for (evtchn = 0; evtchn < xen_evtchn_nr_channels(); evtchn++)
 351                 mask_evtchn(evtchn);
 352 }
 353
 354 /**
 355  * notify_remote_via_irq - send event to remote end of event channel via irq
 356  * @irq: irq of event channel to send event to
 357  *
 358  * Unlike notify_remote_via_evtchn(), this is safe to use across
 359  * save/restore. Notifications on a broken connection are silently
 360  * dropped.
 361  */
 362 void notify_remote_via_irq(int irq)
 363 {
 364         int evtchn = evtchn_from_irq(irq);
 365
 366         if (VALID_EVTCHN(evtchn))
 367                 notify_remote_via_evtchn(evtchn);
 368 }
 369 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
 370
 371 static void xen_irq_init(unsigned irq)
 372 {
 373         struct irq_info *info;
 374 #ifdef CONFIG_SMP
 375         /* By default all event channels notify CPU#0. */
 376         cpumask_copy(irq_get_irq_data(irq)->affinity, cpumask_of(0));
 377 #endif
 378
 379         info = kzalloc(sizeof(*info), GFP_KERNEL);
 380         if (info == NULL)
 381                 panic("Unable to allocate metadata for IRQ%d\n", irq);
 382
 383         info->type = IRQT_UNBOUND;
 384         info->refcnt = -1;
 385
 386         irq_set_handler_data(irq, info);
 387
 388         list_add_tail(&info->list, &xen_irq_list_head);
 389 }
 390
 391 static int __must_check xen_allocate_irqs_dynamic(int nvec)
 392 {
 393         int i, irq = irq_alloc_descs(-1, 0, nvec, -1);
 394
 395         if (irq >= 0) {
 396                 for (i = 0; i < nvec; i++)
 397                         xen_irq_init(irq + i);
 398         }
 399
 400         return irq;
 401 }
 402
 403 static inline int __must_check xen_allocate_irq_dynamic(void)
 404 {
 405
 406         return xen_allocate_irqs_dynamic(1);
 407 }
 408
 409 static int __must_check xen_allocate_irq_gsi(unsigned gsi)
 410 {
 411         int irq;
 412
 413         /*
 414          * A PV guest has no concept of a GSI (since it has no ACPI
 415          * nor access to/knowledge of the physical APICs). Therefore
 416          * all IRQs are dynamically allocated from the entire IRQ
 417          * space.
 418          */
 419         if (xen_pv_domain() && !xen_initial_domain())
 420                 return xen_allocate_irq_dynamic();
 421
 422         /* Legacy IRQ descriptors are already allocated by the arch. */
 423         if (gsi < NR_IRQS_LEGACY)
 424                 irq = gsi;
 425         else
 426                 irq = irq_alloc_desc_at(gsi, -1);
 427
 428         xen_irq_init(irq);
 429
 430         return irq;
 431 }
 432
 433 static void xen_free_irq(unsigned irq)
 434 {
 435         struct irq_info *info = irq_get_handler_data(irq);
 436
 437         if (WARN_ON(!info))
 438                 return;
 439
 440         list_del(&info->list);
 441
 442         irq_set_handler_data(irq, NULL);
 443
 444         WARN_ON(info->refcnt > 0);
 445
 446         kfree(info);
 447
 448         /* Legacy IRQ descriptors are managed by the arch. */
 449         if (irq < NR_IRQS_LEGACY)
 450                 return;
 451
 452         irq_free_desc(irq);
 453 }
 454
 455 static void xen_evtchn_close(unsigned int port)
 456 {
 457         struct evtchn_close close;
 458
 459         close.port = port;
 460         if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
 461                 BUG();
 462 }
 463
 464 static void pirq_query_unmask(int irq)
 465 {
 466         struct physdev_irq_status_query irq_status;
 467         struct irq_info *info = info_for_irq(irq);
 468
 469         BUG_ON(info->type != IRQT_PIRQ);
 470
 471         irq_status.irq = pirq_from_irq(irq);
 472         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
 473                 irq_status.flags = 0;
 474
 475         info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
 476         if (irq_status.flags & XENIRQSTAT_needs_eoi)
 477                 info->u.pirq.flags |= PIRQ_NEEDS_EOI;
 478 }
 479
 480 static void eoi_pirq(struct irq_data *data)
 481 {
 482         int evtchn = evtchn_from_irq(data->irq);
 483         struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
 484         int rc = 0;
 485
 486         irq_move_irq(data);
 487
 488         if (VALID_EVTCHN(evtchn))
 489                 clear_evtchn(evtchn);
 490
 491         if (pirq_needs_eoi(data->irq)) {
 492                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
 493                 WARN_ON(rc);
 494         }
 495 }
 496
 497 static void mask_ack_pirq(struct irq_data *data)
 498 {
 499         disable_dynirq(data);
 500         eoi_pirq(data);
 501 }
 502
 503 static unsigned int __startup_pirq(unsigned int irq)
 504 {
 505         struct evtchn_bind_pirq bind_pirq;
 506         struct irq_info *info = info_for_irq(irq);
 507         int evtchn = evtchn_from_irq(irq);
 508         int rc;
 509
 510         BUG_ON(info->type != IRQT_PIRQ);
 511
 512         if (VALID_EVTCHN(evtchn))
 513                 goto out;
 514
 515         bind_pirq.pirq = pirq_from_irq(irq);
 516         /* NB. We are happy to share unless we are probing. */
 517         bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
 518                                         BIND_PIRQ__WILL_SHARE : 0;
 519         rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
 520         if (rc != 0) {
 521                 pr_warn("Failed to obtain physical IRQ %d\n", irq);
 522                 return 0;
 523         }
 524         evtchn = bind_pirq.port;
 525
 526         pirq_query_unmask(irq);
 527
 528         rc = set_evtchn_to_irq(evtchn, irq);
 529         if (rc != 0) {
 530                 pr_err("irq%d: Failed to set port to irq mapping (%d)\n",
 531                        irq, rc);
 532                 xen_evtchn_close(evtchn);
 533                 return 0;
 534         }
 535         bind_evtchn_to_cpu(evtchn, 0);
 536         info->evtchn = evtchn;
 537
 538 out:
 539         unmask_evtchn(evtchn);
 540         eoi_pirq(irq_get_irq_data(irq));
 541
 542         return 0;
 543 }
 544
 545 static unsigned int startup_pirq(struct irq_data *data)
 546 {
 547         return __startup_pirq(data->irq);
 548 }
 549
 550 static void shutdown_pirq(struct irq_data *data)
 551 {
 552         unsigned int irq = data->irq;
 553         struct irq_info *info = info_for_irq(irq);
 554         unsigned evtchn = evtchn_from_irq(irq);
 555
 556         BUG_ON(info->type != IRQT_PIRQ);
 557
 558         if (!VALID_EVTCHN(evtchn))
 559                 return;
 560
 561         mask_evtchn(evtchn);
 562         xen_evtchn_close(evtchn);
 563         xen_irq_info_cleanup(info);
 564 }
 565
 566 static void enable_pirq(struct irq_data *data)
 567 {
 568         startup_pirq(data);
 569 }
 570
 571 static void disable_pirq(struct irq_data *data)
 572 {
 573         disable_dynirq(data);
 574 }
 575
 576 int xen_irq_from_gsi(unsigned gsi)
 577 {
 578         struct irq_info *info;
 579
 580         list_for_each_entry(info, &xen_irq_list_head, list) {
 581                 if (info->type != IRQT_PIRQ)
 582                         continue;
 583
 584                 if (info->u.pirq.gsi == gsi)
 585                         return info->irq;
 586         }
 587
 588         return -1;
 589 }
 590 EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
 591
 592 static void __unbind_from_irq(unsigned int irq)
 593 {
 594         int evtchn = evtchn_from_irq(irq);
 595         struct irq_info *info = irq_get_handler_data(irq);
 596
 597         if (info->refcnt > 0) {
 598                 info->refcnt--;
 599                 if (info->refcnt != 0)
 600                         return;
 601         }
 602
 603         if (VALID_EVTCHN(evtchn)) {
 604                 unsigned int cpu = cpu_from_irq(irq);
 605
 606                 xen_evtchn_close(evtchn);
 607
 608                 switch (type_from_irq(irq)) {
 609                 case IRQT_VIRQ:
 610                         per_cpu(virq_to_irq, cpu)[virq_from_irq(irq)] = -1;
 611                         break;
 612                 case IRQT_IPI:
 613                         per_cpu(ipi_to_irq, cpu)[ipi_from_irq(irq)] = -1;
 614                         break;
 615                 default:
 616                         break;
 617                 }
 618
 619                 xen_irq_info_cleanup(info);
 620         }
 621
 622         BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
 623
 624         xen_free_irq(irq);
 625 }
 626
 627 /*
 628  * Do not make any assumptions regarding the relationship between the
 629  * IRQ number returned here and the Xen pirq argument.
 630  *
 631  * Note: We don't assign an event channel until the irq actually started
 632  * up.  Return an existing irq if we've already got one for the gsi.
 633  *
 634  * Shareable implies level triggered, not shareable implies edge
 635  * triggered here.
 636  */
 637 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
 638                              unsigned pirq, int shareable, char *name)
 639 {
 640         int irq = -1;
 641         struct physdev_irq irq_op;
 642         int ret;
 643
 644         mutex_lock(&irq_mapping_update_lock);
 645
 646         irq = xen_irq_from_gsi(gsi);
 647         if (irq != -1) {
 648                 pr_info("%s: returning irq %d for gsi %u\n",
 649                         __func__, irq, gsi);
 650                 goto out;
 651         }
 652
 653         irq = xen_allocate_irq_gsi(gsi);
 654         if (irq < 0)
 655                 goto out;
 656
 657         irq_op.irq = irq;
 658         irq_op.vector = 0;
 659
 660         /* Only the privileged domain can do this. For non-priv, the pcifront
 661          * driver provides a PCI bus that does the call to do exactly
 662          * this in the priv domain. */
 663         if (xen_initial_domain() &&
 664             HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
 665                 xen_free_irq(irq);
 666                 irq = -ENOSPC;
 667                 goto out;
 668         }
 669
 670         ret = xen_irq_info_pirq_setup(irq, 0, pirq, gsi, DOMID_SELF,
 671                                shareable ? PIRQ_SHAREABLE : 0);
 672         if (ret < 0) {
 673                 __unbind_from_irq(irq);
 674                 irq = ret;
 675                 goto out;
 676         }
 677
 678         pirq_query_unmask(irq);
 679         /* We try to use the handler with the appropriate semantic for the
 680          * type of interrupt: if the interrupt is an edge triggered
 681          * interrupt we use handle_edge_irq.
 682          *
 683          * On the other hand if the interrupt is level triggered we use
 684          * handle_fasteoi_irq like the native code does for this kind of
 685          * interrupts.
 686          *
 687          * Depending on the Xen version, pirq_needs_eoi might return true
 688          * not only for level triggered interrupts but for edge triggered
 689          * interrupts too. In any case Xen always honors the eoi mechanism,
 690          * not injecting any more pirqs of the same kind if the first one
 691          * hasn't received an eoi yet. Therefore using the fasteoi handler
 692          * is the right choice either way.
 693          */
 694         if (shareable)
 695                 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 696                                 handle_fasteoi_irq, name);
 697         else
 698                 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
 699                                 handle_edge_irq, name);
 700
 701 out:
 702         mutex_unlock(&irq_mapping_update_lock);
 703
 704         return irq;
 705 }
 706
 707 #ifdef CONFIG_PCI_MSI
 708 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
 709 {
 710         int rc;
 711         struct physdev_get_free_pirq op_get_free_pirq;
 712
 713         op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
 714         rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
 715
 716         WARN_ONCE(rc == -ENOSYS,
 717                   "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
 718
 719         return rc ? -1 : op_get_free_pirq.pirq;
 720 }
 721
 722 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
 723                              int pirq, int nvec, const char *name, domid_t domid)
 724 {
 725         int i, irq, ret;
 726
 727         mutex_lock(&irq_mapping_update_lock);
 728
 729         irq = xen_allocate_irqs_dynamic(nvec);
 730         if (irq < 0)
 731                 goto out;
 732
 733         for (i = 0; i < nvec; i++) {
 734                 irq_set_chip_and_handler_name(irq + i, &xen_pirq_chip, handle_edge_irq, name);
 735
 736                 ret = xen_irq_info_pirq_setup(irq + i, 0, pirq + i, 0, domid,
 737                                               i == 0 ? 0 : PIRQ_MSI_GROUP);
 738                 if (ret < 0)
 739                         goto error_irq;
 740         }
 741
 742         ret = irq_set_msi_desc(irq, msidesc);
 743         if (ret < 0)
 744                 goto error_irq;
 745 out:
 746         mutex_unlock(&irq_mapping_update_lock);
 747         return irq;
 748 error_irq:
 749         for (; i >= 0; i--)
 750                 __unbind_from_irq(irq + i);
 751         mutex_unlock(&irq_mapping_update_lock);
 752         return ret;
 753 }
 754 #endif
 755
 756 int xen_destroy_irq(int irq)
 757 {
 758         struct physdev_unmap_pirq unmap_irq;
 759         struct irq_info *info = info_for_irq(irq);
 760         int rc = -ENOENT;
 761
 762         mutex_lock(&irq_mapping_update_lock);
 763
 764         /*
 765          * If trying to remove a vector in a MSI group different
 766          * than the first one skip the PIRQ unmap unless this vector
 767          * is the first one in the group.
 768          */
 769         if (xen_initial_domain() && !(info->u.pirq.flags & PIRQ_MSI_GROUP)) {
 770                 unmap_irq.pirq = info->u.pirq.pirq;
 771                 unmap_irq.domid = info->u.pirq.domid;
 772                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
 773                 /* If another domain quits without making the pci_disable_msix
 774                  * call, the Xen hypervisor takes care of freeing the PIRQs
 775                  * (free_domain_pirqs).
 776                  */
 777                 if ((rc == -ESRCH && info->u.pirq.domid != DOMID_SELF))
 778                         pr_info("domain %d does not have %d anymore\n",
 779                                 info->u.pirq.domid, info->u.pirq.pirq);
 780                 else if (rc) {
 781                         pr_warn("unmap irq failed %d\n", rc);
 782                         goto out;
 783                 }
 784         }
 785
 786         xen_free_irq(irq);
 787
 788 out:
 789         mutex_unlock(&irq_mapping_update_lock);
 790         return rc;
 791 }
 792
 793 int xen_irq_from_pirq(unsigned pirq)
 794 {
 795         int irq;
 796
 797         struct irq_info *info;
 798
 799         mutex_lock(&irq_mapping_update_lock);
 800
 801         list_for_each_entry(info, &xen_irq_list_head, list) {
 802                 if (info->type != IRQT_PIRQ)
 803                         continue;
 804                 irq = info->irq;
 805                 if (info->u.pirq.pirq == pirq)
 806                         goto out;
 807         }
 808         irq = -1;
 809 out:
 810         mutex_unlock(&irq_mapping_update_lock);
 811
 812         return irq;
 813 }
 814
 815
 816 int xen_pirq_from_irq(unsigned irq)
 817 {
 818         return pirq_from_irq(irq);
 819 }
 820 EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
 821
 822 int bind_evtchn_to_irq(unsigned int evtchn)
 823 {
 824         int irq;
 825         int ret;
 826
 827         if (evtchn >= xen_evtchn_max_channels())
 828                 return -ENOMEM;
 829
 830         mutex_lock(&irq_mapping_update_lock);
 831
 832         irq = get_evtchn_to_irq(evtchn);
 833
 834         if (irq == -1) {
 835                 irq = xen_allocate_irq_dynamic();
 836                 if (irq < 0)
 837                         goto out;
 838
 839                 irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
 840                                               handle_edge_irq, "event");
 841
 842                 ret = xen_irq_info_evtchn_setup(irq, evtchn);
 843                 if (ret < 0) {
 844                         __unbind_from_irq(irq);
 845                         irq = ret;
 846                         goto out;
 847                 }
 848                 /* New interdomain events are bound to VCPU 0. */
 849                 bind_evtchn_to_cpu(evtchn, 0);
 850         } else {
 851                 struct irq_info *info = info_for_irq(irq);
 852                 WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
 853         }
 854
 855 out:
 856         mutex_unlock(&irq_mapping_update_lock);
 857
 858         return irq;
 859 }
 860 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
 861
 862 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
 863 {
 864         struct evtchn_bind_ipi bind_ipi;
 865         int evtchn, irq;
 866         int ret;
 867
 868         mutex_lock(&irq_mapping_update_lock);
 869
 870         irq = per_cpu(ipi_to_irq, cpu)[ipi];
 871
 872         if (irq == -1) {
 873                 irq = xen_allocate_irq_dynamic();
 874                 if (irq < 0)
 875                         goto out;
 876
 877                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 878                                               handle_percpu_irq, "ipi");
 879
 880                 bind_ipi.vcpu = cpu;
 881                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
 882                                                 &bind_ipi) != 0)
 883                         BUG();
 884                 evtchn = bind_ipi.port;
 885
 886                 ret = xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
 887                 if (ret < 0) {
 888                         __unbind_from_irq(irq);
 889                         irq = ret;
 890                         goto out;
 891                 }
 892                 bind_evtchn_to_cpu(evtchn, cpu);
 893         } else {
 894                 struct irq_info *info = info_for_irq(irq);
 895                 WARN_ON(info == NULL || info->type != IRQT_IPI);
 896         }
 897
 898  out:
 899         mutex_unlock(&irq_mapping_update_lock);
 900         return irq;
 901 }
 902
 903 static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
 904                                           unsigned int remote_port)
 905 {
 906         struct evtchn_bind_interdomain bind_interdomain;
 907         int err;
 908
 909         bind_interdomain.remote_dom  = remote_domain;
 910         bind_interdomain.remote_port = remote_port;
 911
 912         err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
 913                                           &bind_interdomain);
 914
 915         return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
 916 }
 917
 918 static int find_virq(unsigned int virq, unsigned int cpu)
 919 {
 920         struct evtchn_status status;
 921         int port, rc = -ENOENT;
 922
 923         memset(&status, 0, sizeof(status));
 924         for (port = 0; port < xen_evtchn_max_channels(); port++) {
 925                 status.dom = DOMID_SELF;
 926                 status.port = port;
 927                 rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status);
 928                 if (rc < 0)
 929                         continue;
 930                 if (status.status != EVTCHNSTAT_virq)
 931                         continue;
 932                 if (status.u.virq == virq && status.vcpu == cpu) {
 933                         rc = port;
 934                         break;
 935                 }
 936         }
 937         return rc;
 938 }
 939
 940 /**
 941  * xen_evtchn_nr_channels - number of usable event channel ports
 942  *
 943  * This may be less than the maximum supported by the current
 944  * hypervisor ABI. Use xen_evtchn_max_channels() for the maximum
 945  * supported.
 946  */
 947 unsigned xen_evtchn_nr_channels(void)
 948 {
 949         return evtchn_ops->nr_channels();
 950 }
 951 EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
 952
 953 int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
 954 {
 955         struct evtchn_bind_virq bind_virq;
 956         int evtchn, irq, ret;
 957
 958         mutex_lock(&irq_mapping_update_lock);
 959
 960         irq = per_cpu(virq_to_irq, cpu)[virq];
 961
 962         if (irq == -1) {
 963                 irq = xen_allocate_irq_dynamic();
 964                 if (irq < 0)
 965                         goto out;
 966
 967                 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
 968                                               handle_percpu_irq, "virq");
 969
 970                 bind_virq.virq = virq;
 971                 bind_virq.vcpu = cpu;
 972                 ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
 973                                                 &bind_virq);
 974                 if (ret == 0)
 975                         evtchn = bind_virq.port;
 976                 else {
 977                         if (ret == -EEXIST)
 978                                 ret = find_virq(virq, cpu);
 979                         BUG_ON(ret < 0);
 980                         evtchn = ret;
 981                 }
 982
 983                 ret = xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
 984                 if (ret < 0) {
 985                         __unbind_from_irq(irq);
 986                         irq = ret;
 987                         goto out;
 988                 }
 989
 990                 bind_evtchn_to_cpu(evtchn, cpu);
 991         } else {
 992                 struct irq_info *info = info_for_irq(irq);
 993                 WARN_ON(info == NULL || info->type != IRQT_VIRQ);
 994         }
 995
 996 out:
 997         mutex_unlock(&irq_mapping_update_lock);
 998
 999         return irq;
1000 }
1001
1002 static void unbind_from_irq(unsigned int irq)
1003 {
1004         mutex_lock(&irq_mapping_update_lock);
1005         __unbind_from_irq(irq);
1006         mutex_unlock(&irq_mapping_update_lock);
1007 }
1008
1009 int bind_evtchn_to_irqhandler(unsigned int evtchn,
1010                               irq_handler_t handler,
1011                               unsigned long irqflags,
1012                               const char *devname, void *dev_id)
1013 {
1014         int irq, retval;
1015
1016         irq = bind_evtchn_to_irq(evtchn);
1017         if (irq < 0)
1018                 return irq;
1019         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1020         if (retval != 0) {
1021                 unbind_from_irq(irq);
1022                 return retval;
1023         }
1024
1025         return irq;
1026 }
1027 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
1028
1029 int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
1030                                           unsigned int remote_port,
1031                                           irq_handler_t handler,
1032                                           unsigned long irqflags,
1033                                           const char *devname,
1034                                           void *dev_id)
1035 {
1036         int irq, retval;
1037
1038         irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
1039         if (irq < 0)
1040                 return irq;
1041
1042         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1043         if (retval != 0) {
1044                 unbind_from_irq(irq);
1045                 return retval;
1046         }
1047
1048         return irq;
1049 }
1050 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
1051
1052 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
1053                             irq_handler_t handler,
1054                             unsigned long irqflags, const char *devname, void *dev_id)
1055 {
1056         int irq, retval;
1057
1058         irq = bind_virq_to_irq(virq, cpu);
1059         if (irq < 0)
1060                 return irq;
1061         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1062         if (retval != 0) {
1063                 unbind_from_irq(irq);
1064                 return retval;
1065         }
1066
1067         return irq;
1068 }
1069 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
1070
1071 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
1072                            unsigned int cpu,
1073                            irq_handler_t handler,
1074                            unsigned long irqflags,
1075                            const char *devname,
1076                            void *dev_id)
1077 {
1078         int irq, retval;
1079
1080         irq = bind_ipi_to_irq(ipi, cpu);
1081         if (irq < 0)
1082                 return irq;
1083
1084         irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME | IRQF_EARLY_RESUME;
1085         retval = request_irq(irq, handler, irqflags, devname, dev_id);
1086         if (retval != 0) {
1087                 unbind_from_irq(irq);
1088                 return retval;
1089         }
1090
1091         return irq;
1092 }
1093
1094 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
1095 {
1096         struct irq_info *info = irq_get_handler_data(irq);
1097
1098         if (WARN_ON(!info))
1099                 return;
1100         free_irq(irq, dev_id);
1101         unbind_from_irq(irq);
1102 }
1103 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
1104
1105 /**
1106  * xen_set_irq_priority() - set an event channel priority.
1107  * @irq:irq bound to an event channel.
1108  * @priority: priority between XEN_IRQ_PRIORITY_MAX and XEN_IRQ_PRIORITY_MIN.
1109  */
1110 int xen_set_irq_priority(unsigned irq, unsigned priority)
1111 {
1112         struct evtchn_set_priority set_priority;
1113
1114         set_priority.port = evtchn_from_irq(irq);
1115         set_priority.priority = priority;
1116
1117         return HYPERVISOR_event_channel_op(EVTCHNOP_set_priority,
1118                                            &set_priority);
1119 }
1120 EXPORT_SYMBOL_GPL(xen_set_irq_priority);
1121
1122 int evtchn_make_refcounted(unsigned int evtchn)
1123 {
1124         int irq = get_evtchn_to_irq(evtchn);
1125         struct irq_info *info;
1126
1127         if (irq == -1)
1128                 return -ENOENT;
1129
1130         info = irq_get_handler_data(irq);
1131
1132         if (!info)
1133                 return -ENOENT;
1134
1135         WARN_ON(info->refcnt != -1);
1136
1137         info->refcnt = 1;
1138
1139         return 0;
1140 }
1141 EXPORT_SYMBOL_GPL(evtchn_make_refcounted);
1142
1143 int evtchn_get(unsigned int evtchn)
1144 {
1145         int irq;
1146         struct irq_info *info;
1147         int err = -ENOENT;
1148
1149         if (evtchn >= xen_evtchn_max_channels())
1150                 return -EINVAL;
1151
1152         mutex_lock(&irq_mapping_update_lock);
1153
1154         irq = get_evtchn_to_irq(evtchn);
1155         if (irq == -1)
1156                 goto done;
1157
1158         info = irq_get_handler_data(irq);
1159
1160         if (!info)
1161                 goto done;
1162
1163         err = -EINVAL;
1164         if (info->refcnt <= 0)
1165                 goto done;
1166
1167         info->refcnt++;
1168         err = 0;
1169  done:
1170         mutex_unlock(&irq_mapping_update_lock);
1171
1172         return err;
1173 }
1174 EXPORT_SYMBOL_GPL(evtchn_get);
1175
1176 void evtchn_put(unsigned int evtchn)
1177 {
1178         int irq = get_evtchn_to_irq(evtchn);
1179         if (WARN_ON(irq == -1))
1180                 return;
1181         unbind_from_irq(irq);
1182 }
1183 EXPORT_SYMBOL_GPL(evtchn_put);
1184
1185 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
1186 {
1187         int irq;
1188
1189 #ifdef CONFIG_X86
1190         if (unlikely(vector == XEN_NMI_VECTOR)) {
1191                 int rc =  HYPERVISOR_vcpu_op(VCPUOP_send_nmi, cpu, NULL);
1192                 if (rc < 0)
1193                         printk(KERN_WARNING "Sending nmi to CPU%d failed (rc:%d)\n", cpu, rc);
1194                 return;
1195         }
1196 #endif
1197         irq = per_cpu(ipi_to_irq, cpu)[vector];
1198         BUG_ON(irq < 0);
1199         notify_remote_via_irq(irq);
1200 }
1201
1202 static DEFINE_PER_CPU(unsigned, xed_nesting_count);
1203
1204 static void __xen_evtchn_do_upcall(void)
1205 {
1206         struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1207         int cpu = get_cpu();
1208         unsigned count;
1209
1210         do {
1211                 vcpu_info->evtchn_upcall_pending = 0;
1212
1213                 if (__this_cpu_inc_return(xed_nesting_count) - 1)
1214                         goto out;
1215
1216                 xen_evtchn_handle_events(cpu);
1217
1218                 BUG_ON(!irqs_disabled());
1219
1220                 count = __this_cpu_read(xed_nesting_count);
1221                 __this_cpu_write(xed_nesting_count, 0);
1222         } while (count != 1 || vcpu_info->evtchn_upcall_pending);
1223
1224 out:
1225
1226         put_cpu();
1227 }
1228
1229 void xen_evtchn_do_upcall(struct pt_regs *regs)
1230 {
1231         struct pt_regs *old_regs = set_irq_regs(regs);
1232
1233         irq_enter();
1234 #ifdef CONFIG_X86
1235         exit_idle();
1236         inc_irq_stat(irq_hv_callback_count);
1237 #endif
1238
1239         __xen_evtchn_do_upcall();
1240
1241         irq_exit();
1242         set_irq_regs(old_regs);
1243 }
1244
1245 void xen_hvm_evtchn_do_upcall(void)
1246 {
1247         __xen_evtchn_do_upcall();
1248 }
1249 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1250
1251 /* Rebind a new event channel to an existing irq. */
1252 void rebind_evtchn_irq(int evtchn, int irq)
1253 {
1254         struct irq_info *info = info_for_irq(irq);
1255
1256         if (WARN_ON(!info))
1257                 return;
1258
1259         /* Make sure the irq is masked, since the new event channel
1260            will also be masked. */
1261         disable_irq(irq);
1262
1263         mutex_lock(&irq_mapping_update_lock);
1264
1265         /* After resume the irq<->evtchn mappings are all cleared out */
1266         BUG_ON(get_evtchn_to_irq(evtchn) != -1);
1267         /* Expect irq to have been bound before,
1268            so there should be a proper type */
1269         BUG_ON(info->type == IRQT_UNBOUND);
1270
1271         (void)xen_irq_info_evtchn_setup(irq, evtchn);
1272
1273         mutex_unlock(&irq_mapping_update_lock);
1274
1275         /* new event channels are always bound to cpu 0 */
1276         irq_set_affinity(irq, cpumask_of(0));
1277
1278         /* Unmask the event channel. */
1279         enable_irq(irq);
1280 }
1281
1282 /* Rebind an evtchn so that it gets delivered to a specific cpu */
1283 static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
1284 {
1285         struct evtchn_bind_vcpu bind_vcpu;
1286         int evtchn = evtchn_from_irq(irq);
1287         int masked;
1288
1289         if (!VALID_EVTCHN(evtchn))
1290                 return -1;
1291
1292         /*
1293          * Events delivered via platform PCI interrupts are always
1294          * routed to vcpu 0 and hence cannot be rebound.
1295          */
1296         if (xen_hvm_domain() && !xen_have_vector_callback)
1297                 return -1;
1298
1299         /* Send future instances of this interrupt to other vcpu. */
1300         bind_vcpu.port = evtchn;
1301         bind_vcpu.vcpu = tcpu;
1302
1303         /*
1304          * Mask the event while changing the VCPU binding to prevent
1305          * it being delivered on an unexpected VCPU.
1306          */
1307         masked = test_and_set_mask(evtchn);
1308
1309         /*
1310          * If this fails, it usually just indicates that we're dealing with a
1311          * virq or IPI channel, which don't actually need to be rebound. Ignore
1312          * it, but don't do the xenlinux-level rebind in that case.
1313          */
1314         if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1315                 bind_evtchn_to_cpu(evtchn, tcpu);
1316
1317         if (!masked)
1318                 unmask_evtchn(evtchn);
1319
1320         return 0;
1321 }
1322
1323 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1324                             bool force)
1325 {
1326         unsigned tcpu = cpumask_first_and(dest, cpu_online_mask);
1327
1328         return rebind_irq_to_cpu(data->irq, tcpu);
1329 }
1330
1331 static void enable_dynirq(struct irq_data *data)
1332 {
1333         int evtchn = evtchn_from_irq(data->irq);
1334
1335         if (VALID_EVTCHN(evtchn))
1336                 unmask_evtchn(evtchn);
1337 }
1338
1339 static void disable_dynirq(struct irq_data *data)
1340 {
1341         int evtchn = evtchn_from_irq(data->irq);
1342
1343         if (VALID_EVTCHN(evtchn))
1344                 mask_evtchn(evtchn);
1345 }
1346
1347 static void ack_dynirq(struct irq_data *data)
1348 {
1349         int evtchn = evtchn_from_irq(data->irq);
1350
1351         irq_move_irq(data);
1352
1353         if (VALID_EVTCHN(evtchn))
1354                 clear_evtchn(evtchn);
1355 }
1356
1357 static void mask_ack_dynirq(struct irq_data *data)
1358 {
1359         disable_dynirq(data);
1360         ack_dynirq(data);
1361 }
1362
1363 static int retrigger_dynirq(struct irq_data *data)
1364 {
1365         unsigned int evtchn = evtchn_from_irq(data->irq);
1366         int masked;
1367
1368         if (!VALID_EVTCHN(evtchn))
1369                 return 0;
1370
1371         masked = test_and_set_mask(evtchn);
1372         set_evtchn(evtchn);
1373         if (!masked)
1374                 unmask_evtchn(evtchn);
1375
1376         return 1;
1377 }
1378
1379 static void restore_pirqs(void)
1380 {
1381         int pirq, rc, irq, gsi;
1382         struct physdev_map_pirq map_irq;
1383         struct irq_info *info;
1384
1385         list_for_each_entry(info, &xen_irq_list_head, list) {
1386                 if (info->type != IRQT_PIRQ)
1387                         continue;
1388
1389                 pirq = info->u.pirq.pirq;
1390                 gsi = info->u.pirq.gsi;
1391                 irq = info->irq;
1392
1393                 /* save/restore of PT devices doesn't work, so at this point the
1394                  * only devices present are GSI based emulated devices */
1395                 if (!gsi)
1396                         continue;
1397
1398                 map_irq.domid = DOMID_SELF;
1399                 map_irq.type = MAP_PIRQ_TYPE_GSI;
1400                 map_irq.index = gsi;
1401                 map_irq.pirq = pirq;
1402
1403                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1404                 if (rc) {
1405                         pr_warn("xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1406                                 gsi, irq, pirq, rc);
1407                         xen_free_irq(irq);
1408                         continue;
1409                 }
1410
1411                 printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1412
1413                 __startup_pirq(irq);
1414         }
1415 }
1416
1417 static void restore_cpu_virqs(unsigned int cpu)
1418 {
1419         struct evtchn_bind_virq bind_virq;
1420         int virq, irq, evtchn;
1421
1422         for (virq = 0; virq < NR_VIRQS; virq++) {
1423                 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1424                         continue;
1425
1426                 BUG_ON(virq_from_irq(irq) != virq);
1427
1428                 /* Get a new binding from Xen. */
1429                 bind_virq.virq = virq;
1430                 bind_virq.vcpu = cpu;
1431                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1432                                                 &bind_virq) != 0)
1433                         BUG();
1434                 evtchn = bind_virq.port;
1435
1436                 /* Record the new mapping. */
1437                 (void)xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
1438                 bind_evtchn_to_cpu(evtchn, cpu);
1439         }
1440 }
1441
1442 static void restore_cpu_ipis(unsigned int cpu)
1443 {
1444         struct evtchn_bind_ipi bind_ipi;
1445         int ipi, irq, evtchn;
1446
1447         for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1448                 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1449                         continue;
1450
1451                 BUG_ON(ipi_from_irq(irq) != ipi);
1452
1453                 /* Get a new binding from Xen. */
1454                 bind_ipi.vcpu = cpu;
1455                 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1456                                                 &bind_ipi) != 0)
1457                         BUG();
1458                 evtchn = bind_ipi.port;
1459
1460                 /* Record the new mapping. */
1461                 (void)xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
1462                 bind_evtchn_to_cpu(evtchn, cpu);
1463         }
1464 }
1465
1466 /* Clear an irq's pending state, in preparation for polling on it */
1467 void xen_clear_irq_pending(int irq)
1468 {
1469         int evtchn = evtchn_from_irq(irq);
1470
1471         if (VALID_EVTCHN(evtchn))
1472                 clear_evtchn(evtchn);
1473 }
1474 EXPORT_SYMBOL(xen_clear_irq_pending);
1475 void xen_set_irq_pending(int irq)
1476 {
1477         int evtchn = evtchn_from_irq(irq);
1478
1479         if (VALID_EVTCHN(evtchn))
1480                 set_evtchn(evtchn);
1481 }
1482
1483 bool xen_test_irq_pending(int irq)
1484 {
1485         int evtchn = evtchn_from_irq(irq);
1486         bool ret = false;
1487
1488         if (VALID_EVTCHN(evtchn))
1489                 ret = test_evtchn(evtchn);
1490
1491         return ret;
1492 }
1493
1494 /* Poll waiting for an irq to become pending with timeout.  In the usual case,
1495  * the irq will be disabled so it won't deliver an interrupt. */
1496 void xen_poll_irq_timeout(int irq, u64 timeout)
1497 {
1498         evtchn_port_t evtchn = evtchn_from_irq(irq);
1499
1500         if (VALID_EVTCHN(evtchn)) {
1501                 struct sched_poll poll;
1502
1503                 poll.nr_ports = 1;
1504                 poll.timeout = timeout;
1505                 set_xen_guest_handle(poll.ports, &evtchn);
1506
1507                 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1508                         BUG();
1509         }
1510 }
1511 EXPORT_SYMBOL(xen_poll_irq_timeout);
1512 /* Poll waiting for an irq to become pending.  In the usual case, the
1513  * irq will be disabled so it won't deliver an interrupt. */
1514 void xen_poll_irq(int irq)
1515 {
1516         xen_poll_irq_timeout(irq, 0 /* no timeout */);
1517 }
1518
1519 /* Check whether the IRQ line is shared with other guests. */
1520 int xen_test_irq_shared(int irq)
1521 {
1522         struct irq_info *info = info_for_irq(irq);
1523         struct physdev_irq_status_query irq_status;
1524
1525         if (WARN_ON(!info))
1526                 return -ENOENT;
1527
1528         irq_status.irq = info->u.pirq.pirq;
1529
1530         if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
1531                 return 0;
1532         return !(irq_status.flags & XENIRQSTAT_shared);
1533 }
1534 EXPORT_SYMBOL_GPL(xen_test_irq_shared);
1535
1536 void xen_irq_resume(void)
1537 {
1538         unsigned int cpu;
1539         struct irq_info *info;
1540
1541         /* New event-channel space is not 'live' yet. */
1542         xen_evtchn_mask_all();
1543         xen_evtchn_resume();
1544
1545         /* No IRQ <-> event-channel mappings. */
1546         list_for_each_entry(info, &xen_irq_list_head, list)
1547                 info->evtchn = 0; /* zap event-channel binding */
1548
1549         clear_evtchn_to_irq_all();
1550
1551         for_each_possible_cpu(cpu) {
1552                 restore_cpu_virqs(cpu);
1553                 restore_cpu_ipis(cpu);
1554         }
1555
1556         restore_pirqs();
1557 }
1558
1559 static struct irq_chip xen_dynamic_chip __read_mostly = {
1560         .name                   = "xen-dyn",
1561
1562         .irq_disable            = disable_dynirq,
1563         .irq_mask               = disable_dynirq,
1564         .irq_unmask             = enable_dynirq,
1565
1566         .irq_ack                = ack_dynirq,
1567         .irq_mask_ack           = mask_ack_dynirq,
1568
1569         .irq_set_affinity       = set_affinity_irq,
1570         .irq_retrigger          = retrigger_dynirq,
1571 };
1572
1573 static struct irq_chip xen_pirq_chip __read_mostly = {
1574         .name                   = "xen-pirq",
1575
1576         .irq_startup            = startup_pirq,
1577         .irq_shutdown           = shutdown_pirq,
1578         .irq_enable             = enable_pirq,
1579         .irq_disable            = disable_pirq,
1580
1581         .irq_mask               = disable_dynirq,
1582         .irq_unmask             = enable_dynirq,
1583
1584         .irq_ack                = eoi_pirq,
1585         .irq_eoi                = eoi_pirq,
1586         .irq_mask_ack           = mask_ack_pirq,
1587
1588         .irq_set_affinity       = set_affinity_irq,
1589
1590         .irq_retrigger          = retrigger_dynirq,
1591 };
1592
1593 static struct irq_chip xen_percpu_chip __read_mostly = {
1594         .name                   = "xen-percpu",
1595
1596         .irq_disable            = disable_dynirq,
1597         .irq_mask               = disable_dynirq,
1598         .irq_unmask             = enable_dynirq,
1599
1600         .irq_ack                = ack_dynirq,
1601 };
1602
1603 int xen_set_callback_via(uint64_t via)
1604 {
1605         struct xen_hvm_param a;
1606         a.domid = DOMID_SELF;
1607         a.index = HVM_PARAM_CALLBACK_IRQ;
1608         a.value = via;
1609         return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1610 }
1611 EXPORT_SYMBOL_GPL(xen_set_callback_via);
1612
1613 #ifdef CONFIG_XEN_PVHVM
1614 /* Vector callbacks are better than PCI interrupts to receive event
1615  * channel notifications because we can receive vector callbacks on any
1616  * vcpu and we don't need PCI support or APIC interactions. */
1617 void xen_callback_vector(void)
1618 {
1619         int rc;
1620         uint64_t callback_via;
1621         if (xen_have_vector_callback) {
1622                 callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
1623                 rc = xen_set_callback_via(callback_via);
1624                 if (rc) {
1625                         pr_err("Request for Xen HVM callback vector failed\n");
1626                         xen_have_vector_callback = 0;
1627                         return;
1628                 }
1629                 pr_info("Xen HVM callback vector for event delivery is enabled\n");
1630                 /* in the restore case the vector has already been allocated */
1631                 if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors))
1632                         alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR,
1633                                         xen_hvm_callback_vector);
1634         }
1635 }
1636 #else
1637 void xen_callback_vector(void) {}
1638 #endif
1639
1640 #undef MODULE_PARAM_PREFIX
1641 #define MODULE_PARAM_PREFIX "xen."
1642
1643 static bool fifo_events = true;
1644 module_param(fifo_events, bool, 0);
1645
1646 void __init xen_init_IRQ(void)
1647 {
1648         int ret = -EINVAL;
1649
1650         if (fifo_events)
1651                 ret = xen_evtchn_fifo_init();
1652         if (ret < 0)
1653                 xen_evtchn_2l_init();
1654
1655         evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()),
1656                                 sizeof(*evtchn_to_irq), GFP_KERNEL);
1657         BUG_ON(!evtchn_to_irq);
1658
1659         /* No event channels are 'live' right now. */
1660         xen_evtchn_mask_all();
1661
1662         pirq_needs_eoi = pirq_needs_eoi_flag;
1663
1664 #ifdef CONFIG_X86
1665         if (xen_pv_domain()) {
1666                 irq_ctx_init(smp_processor_id());
1667                 if (xen_initial_domain())
1668                         pci_xen_initial_domain();
1669         }
1670         if (xen_feature(XENFEAT_hvm_callback_vector))
1671                 xen_callback_vector();
1672
1673         if (xen_hvm_domain()) {
1674                 native_init_IRQ();
1675                 /* pci_xen_hvm_init must be called after native_init_IRQ so that
1676                  * __acpi_register_gsi can point at the right function */
1677                 pci_xen_hvm_init();
1678         } else {
1679                 int rc;
1680                 struct physdev_pirq_eoi_gmfn eoi_gmfn;
1681
1682                 pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
1683                 eoi_gmfn.gmfn = virt_to_mfn(pirq_eoi_map);
1684                 rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn);
1685                 /* TODO: No PVH support for PIRQ EOI */
1686                 if (rc != 0) {
1687                         free_page((unsigned long) pirq_eoi_map);
1688                         pirq_eoi_map = NULL;
1689                 } else
1690                         pirq_needs_eoi = pirq_check_eoi_map;
1691         }
1692 #endif
1693 }