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