1 /* 2 * linux/kernel/irq/manage.c 3 * 4 * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar 5 * Copyright (C) 2005-2006 Thomas Gleixner 6 * 7 * This file contains driver APIs to the irq subsystem. 8 */ 9 10 #define pr_fmt(fmt) "genirq: " fmt 11 12 #include <linux/irq.h> 13 #include <linux/kthread.h> 14 #include <linux/module.h> 15 #include <linux/random.h> 16 #include <linux/interrupt.h> 17 #include <linux/slab.h> 18 #include <linux/sched.h> 19 #include <linux/sched/rt.h> 20 #include <linux/task_work.h> 21 22 #include "internals.h" 23 24 #ifdef CONFIG_IRQ_FORCED_THREADING 25 __read_mostly bool force_irqthreads; 26 27 static int __init setup_forced_irqthreads(char *arg) 28 { 29 force_irqthreads = true; 30 return 0; 31 } 32 early_param("threadirqs", setup_forced_irqthreads); 33 #endif 34 35 static void __synchronize_hardirq(struct irq_desc *desc) 36 { 37 bool inprogress; 38 39 do { 40 unsigned long flags; 41 42 /* 43 * Wait until we're out of the critical section. This might 44 * give the wrong answer due to the lack of memory barriers. 45 */ 46 while (irqd_irq_inprogress(&desc->irq_data)) 47 cpu_relax(); 48 49 /* Ok, that indicated we're done: double-check carefully. */ 50 raw_spin_lock_irqsave(&desc->lock, flags); 51 inprogress = irqd_irq_inprogress(&desc->irq_data); 52 raw_spin_unlock_irqrestore(&desc->lock, flags); 53 54 /* Oops, that failed? */ 55 } while (inprogress); 56 } 57 58 /** 59 * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs) 60 * @irq: interrupt number to wait for 61 * 62 * This function waits for any pending hard IRQ handlers for this 63 * interrupt to complete before returning. If you use this 64 * function while holding a resource the IRQ handler may need you 65 * will deadlock. It does not take associated threaded handlers 66 * into account. 67 * 68 * Do not use this for shutdown scenarios where you must be sure 69 * that all parts (hardirq and threaded handler) have completed. 70 * 71 * Returns: false if a threaded handler is active. 72 * 73 * This function may be called - with care - from IRQ context. 74 */ 75 bool synchronize_hardirq(unsigned int irq) 76 { 77 struct irq_desc *desc = irq_to_desc(irq); 78 79 if (desc) { 80 __synchronize_hardirq(desc); 81 return !atomic_read(&desc->threads_active); 82 } 83 84 return true; 85 } 86 EXPORT_SYMBOL(synchronize_hardirq); 87 88 /** 89 * synchronize_irq - wait for pending IRQ handlers (on other CPUs) 90 * @irq: interrupt number to wait for 91 * 92 * This function waits for any pending IRQ handlers for this interrupt 93 * to complete before returning. If you use this function while 94 * holding a resource the IRQ handler may need you will deadlock. 95 * 96 * This function may be called - with care - from IRQ context. 97 */ 98 void synchronize_irq(unsigned int irq) 99 { 100 struct irq_desc *desc = irq_to_desc(irq); 101 102 if (desc) { 103 __synchronize_hardirq(desc); 104 /* 105 * We made sure that no hardirq handler is 106 * running. Now verify that no threaded handlers are 107 * active. 108 */ 109 wait_event(desc->wait_for_threads, 110 !atomic_read(&desc->threads_active)); 111 } 112 } 113 EXPORT_SYMBOL(synchronize_irq); 114 115 #ifdef CONFIG_SMP 116 cpumask_var_t irq_default_affinity; 117 118 static bool __irq_can_set_affinity(struct irq_desc *desc) 119 { 120 if (!desc || !irqd_can_balance(&desc->irq_data) || 121 !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity) 122 return false; 123 return true; 124 } 125 126 /** 127 * irq_can_set_affinity - Check if the affinity of a given irq can be set 128 * @irq: Interrupt to check 129 * 130 */ 131 int irq_can_set_affinity(unsigned int irq) 132 { 133 return __irq_can_set_affinity(irq_to_desc(irq)); 134 } 135 136 /** 137 * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space 138 * @irq: Interrupt to check 139 * 140 * Like irq_can_set_affinity() above, but additionally checks for the 141 * AFFINITY_MANAGED flag. 142 */ 143 bool irq_can_set_affinity_usr(unsigned int irq) 144 { 145 struct irq_desc *desc = irq_to_desc(irq); 146 147 return __irq_can_set_affinity(desc) && 148 !irqd_affinity_is_managed(&desc->irq_data); 149 } 150 151 /** 152 * irq_set_thread_affinity - Notify irq threads to adjust affinity 153 * @desc: irq descriptor which has affitnity changed 154 * 155 * We just set IRQTF_AFFINITY and delegate the affinity setting 156 * to the interrupt thread itself. We can not call 157 * set_cpus_allowed_ptr() here as we hold desc->lock and this 158 * code can be called from hard interrupt context. 159 */ 160 void irq_set_thread_affinity(struct irq_desc *desc) 161 { 162 struct irqaction *action; 163 164 for_each_action_of_desc(desc, action) 165 if (action->thread) 166 set_bit(IRQTF_AFFINITY, &action->thread_flags); 167 } 168 169 #ifdef CONFIG_GENERIC_PENDING_IRQ 170 static inline bool irq_can_move_pcntxt(struct irq_data *data) 171 { 172 return irqd_can_move_in_process_context(data); 173 } 174 static inline bool irq_move_pending(struct irq_data *data) 175 { 176 return irqd_is_setaffinity_pending(data); 177 } 178 static inline void 179 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) 180 { 181 cpumask_copy(desc->pending_mask, mask); 182 } 183 static inline void 184 irq_get_pending(struct cpumask *mask, struct irq_desc *desc) 185 { 186 cpumask_copy(mask, desc->pending_mask); 187 } 188 #else 189 static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; } 190 static inline bool irq_move_pending(struct irq_data *data) { return false; } 191 static inline void 192 irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { } 193 static inline void 194 irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { } 195 #endif 196 197 int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask, 198 bool force) 199 { 200 struct irq_desc *desc = irq_data_to_desc(data); 201 struct irq_chip *chip = irq_data_get_irq_chip(data); 202 int ret; 203 204 ret = chip->irq_set_affinity(data, mask, force); 205 switch (ret) { 206 case IRQ_SET_MASK_OK: 207 case IRQ_SET_MASK_OK_DONE: 208 cpumask_copy(desc->irq_common_data.affinity, mask); 209 case IRQ_SET_MASK_OK_NOCOPY: 210 irq_set_thread_affinity(desc); 211 ret = 0; 212 } 213 214 return ret; 215 } 216 217 int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask, 218 bool force) 219 { 220 struct irq_chip *chip = irq_data_get_irq_chip(data); 221 struct irq_desc *desc = irq_data_to_desc(data); 222 int ret = 0; 223 224 if (!chip || !chip->irq_set_affinity) 225 return -EINVAL; 226 227 if (irq_can_move_pcntxt(data)) { 228 ret = irq_do_set_affinity(data, mask, force); 229 } else { 230 irqd_set_move_pending(data); 231 irq_copy_pending(desc, mask); 232 } 233 234 if (desc->affinity_notify) { 235 kref_get(&desc->affinity_notify->kref); 236 schedule_work(&desc->affinity_notify->work); 237 } 238 irqd_set(data, IRQD_AFFINITY_SET); 239 240 return ret; 241 } 242 243 int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force) 244 { 245 struct irq_desc *desc = irq_to_desc(irq); 246 unsigned long flags; 247 int ret; 248 249 if (!desc) 250 return -EINVAL; 251 252 raw_spin_lock_irqsave(&desc->lock, flags); 253 ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force); 254 raw_spin_unlock_irqrestore(&desc->lock, flags); 255 return ret; 256 } 257 258 int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m) 259 { 260 unsigned long flags; 261 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); 262 263 if (!desc) 264 return -EINVAL; 265 desc->affinity_hint = m; 266 irq_put_desc_unlock(desc, flags); 267 /* set the initial affinity to prevent every interrupt being on CPU0 */ 268 if (m) 269 __irq_set_affinity(irq, m, false); 270 return 0; 271 } 272 EXPORT_SYMBOL_GPL(irq_set_affinity_hint); 273 274 static void irq_affinity_notify(struct work_struct *work) 275 { 276 struct irq_affinity_notify *notify = 277 container_of(work, struct irq_affinity_notify, work); 278 struct irq_desc *desc = irq_to_desc(notify->irq); 279 cpumask_var_t cpumask; 280 unsigned long flags; 281 282 if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL)) 283 goto out; 284 285 raw_spin_lock_irqsave(&desc->lock, flags); 286 if (irq_move_pending(&desc->irq_data)) 287 irq_get_pending(cpumask, desc); 288 else 289 cpumask_copy(cpumask, desc->irq_common_data.affinity); 290 raw_spin_unlock_irqrestore(&desc->lock, flags); 291 292 notify->notify(notify, cpumask); 293 294 free_cpumask_var(cpumask); 295 out: 296 kref_put(¬ify->kref, notify->release); 297 } 298 299 /** 300 * irq_set_affinity_notifier - control notification of IRQ affinity changes 301 * @irq: Interrupt for which to enable/disable notification 302 * @notify: Context for notification, or %NULL to disable 303 * notification. Function pointers must be initialised; 304 * the other fields will be initialised by this function. 305 * 306 * Must be called in process context. Notification may only be enabled 307 * after the IRQ is allocated and must be disabled before the IRQ is 308 * freed using free_irq(). 309 */ 310 int 311 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify) 312 { 313 struct irq_desc *desc = irq_to_desc(irq); 314 struct irq_affinity_notify *old_notify; 315 unsigned long flags; 316 317 /* The release function is promised process context */ 318 might_sleep(); 319 320 if (!desc) 321 return -EINVAL; 322 323 /* Complete initialisation of *notify */ 324 if (notify) { 325 notify->irq = irq; 326 kref_init(¬ify->kref); 327 INIT_WORK(¬ify->work, irq_affinity_notify); 328 } 329 330 raw_spin_lock_irqsave(&desc->lock, flags); 331 old_notify = desc->affinity_notify; 332 desc->affinity_notify = notify; 333 raw_spin_unlock_irqrestore(&desc->lock, flags); 334 335 if (old_notify) 336 kref_put(&old_notify->kref, old_notify->release); 337 338 return 0; 339 } 340 EXPORT_SYMBOL_GPL(irq_set_affinity_notifier); 341 342 #ifndef CONFIG_AUTO_IRQ_AFFINITY 343 /* 344 * Generic version of the affinity autoselector. 345 */ 346 static int setup_affinity(struct irq_desc *desc, struct cpumask *mask) 347 { 348 struct cpumask *set = irq_default_affinity; 349 int node = irq_desc_get_node(desc); 350 351 /* Excludes PER_CPU and NO_BALANCE interrupts */ 352 if (!__irq_can_set_affinity(desc)) 353 return 0; 354 355 /* 356 * Preserve the managed affinity setting and an userspace affinity 357 * setup, but make sure that one of the targets is online. 358 */ 359 if (irqd_affinity_is_managed(&desc->irq_data) || 360 irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) { 361 if (cpumask_intersects(desc->irq_common_data.affinity, 362 cpu_online_mask)) 363 set = desc->irq_common_data.affinity; 364 else 365 irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET); 366 } 367 368 cpumask_and(mask, cpu_online_mask, set); 369 if (node != NUMA_NO_NODE) { 370 const struct cpumask *nodemask = cpumask_of_node(node); 371 372 /* make sure at least one of the cpus in nodemask is online */ 373 if (cpumask_intersects(mask, nodemask)) 374 cpumask_and(mask, mask, nodemask); 375 } 376 irq_do_set_affinity(&desc->irq_data, mask, false); 377 return 0; 378 } 379 #else 380 /* Wrapper for ALPHA specific affinity selector magic */ 381 static inline int setup_affinity(struct irq_desc *d, struct cpumask *mask) 382 { 383 return irq_select_affinity(irq_desc_get_irq(d)); 384 } 385 #endif 386 387 /* 388 * Called when affinity is set via /proc/irq 389 */ 390 int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask) 391 { 392 struct irq_desc *desc = irq_to_desc(irq); 393 unsigned long flags; 394 int ret; 395 396 raw_spin_lock_irqsave(&desc->lock, flags); 397 ret = setup_affinity(desc, mask); 398 raw_spin_unlock_irqrestore(&desc->lock, flags); 399 return ret; 400 } 401 402 #else 403 static inline int 404 setup_affinity(struct irq_desc *desc, struct cpumask *mask) 405 { 406 return 0; 407 } 408 #endif 409 410 /** 411 * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt 412 * @irq: interrupt number to set affinity 413 * @vcpu_info: vCPU specific data 414 * 415 * This function uses the vCPU specific data to set the vCPU 416 * affinity for an irq. The vCPU specific data is passed from 417 * outside, such as KVM. One example code path is as below: 418 * KVM -> IOMMU -> irq_set_vcpu_affinity(). 419 */ 420 int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info) 421 { 422 unsigned long flags; 423 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0); 424 struct irq_data *data; 425 struct irq_chip *chip; 426 int ret = -ENOSYS; 427 428 if (!desc) 429 return -EINVAL; 430 431 data = irq_desc_get_irq_data(desc); 432 chip = irq_data_get_irq_chip(data); 433 if (chip && chip->irq_set_vcpu_affinity) 434 ret = chip->irq_set_vcpu_affinity(data, vcpu_info); 435 irq_put_desc_unlock(desc, flags); 436 437 return ret; 438 } 439 EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity); 440 441 void __disable_irq(struct irq_desc *desc) 442 { 443 if (!desc->depth++) 444 irq_disable(desc); 445 } 446 447 static int __disable_irq_nosync(unsigned int irq) 448 { 449 unsigned long flags; 450 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); 451 452 if (!desc) 453 return -EINVAL; 454 __disable_irq(desc); 455 irq_put_desc_busunlock(desc, flags); 456 return 0; 457 } 458 459 /** 460 * disable_irq_nosync - disable an irq without waiting 461 * @irq: Interrupt to disable 462 * 463 * Disable the selected interrupt line. Disables and Enables are 464 * nested. 465 * Unlike disable_irq(), this function does not ensure existing 466 * instances of the IRQ handler have completed before returning. 467 * 468 * This function may be called from IRQ context. 469 */ 470 void disable_irq_nosync(unsigned int irq) 471 { 472 __disable_irq_nosync(irq); 473 } 474 EXPORT_SYMBOL(disable_irq_nosync); 475 476 /** 477 * disable_irq - disable an irq and wait for completion 478 * @irq: Interrupt to disable 479 * 480 * Disable the selected interrupt line. Enables and Disables are 481 * nested. 482 * This function waits for any pending IRQ handlers for this interrupt 483 * to complete before returning. If you use this function while 484 * holding a resource the IRQ handler may need you will deadlock. 485 * 486 * This function may be called - with care - from IRQ context. 487 */ 488 void disable_irq(unsigned int irq) 489 { 490 if (!__disable_irq_nosync(irq)) 491 synchronize_irq(irq); 492 } 493 EXPORT_SYMBOL(disable_irq); 494 495 /** 496 * disable_hardirq - disables an irq and waits for hardirq completion 497 * @irq: Interrupt to disable 498 * 499 * Disable the selected interrupt line. Enables and Disables are 500 * nested. 501 * This function waits for any pending hard IRQ handlers for this 502 * interrupt to complete before returning. If you use this function while 503 * holding a resource the hard IRQ handler may need you will deadlock. 504 * 505 * When used to optimistically disable an interrupt from atomic context 506 * the return value must be checked. 507 * 508 * Returns: false if a threaded handler is active. 509 * 510 * This function may be called - with care - from IRQ context. 511 */ 512 bool disable_hardirq(unsigned int irq) 513 { 514 if (!__disable_irq_nosync(irq)) 515 return synchronize_hardirq(irq); 516 517 return false; 518 } 519 EXPORT_SYMBOL_GPL(disable_hardirq); 520 521 void __enable_irq(struct irq_desc *desc) 522 { 523 switch (desc->depth) { 524 case 0: 525 err_out: 526 WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", 527 irq_desc_get_irq(desc)); 528 break; 529 case 1: { 530 if (desc->istate & IRQS_SUSPENDED) 531 goto err_out; 532 /* Prevent probing on this irq: */ 533 irq_settings_set_noprobe(desc); 534 irq_enable(desc); 535 check_irq_resend(desc); 536 /* fall-through */ 537 } 538 default: 539 desc->depth--; 540 } 541 } 542 543 /** 544 * enable_irq - enable handling of an irq 545 * @irq: Interrupt to enable 546 * 547 * Undoes the effect of one call to disable_irq(). If this 548 * matches the last disable, processing of interrupts on this 549 * IRQ line is re-enabled. 550 * 551 * This function may be called from IRQ context only when 552 * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL ! 553 */ 554 void enable_irq(unsigned int irq) 555 { 556 unsigned long flags; 557 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); 558 559 if (!desc) 560 return; 561 if (WARN(!desc->irq_data.chip, 562 KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq)) 563 goto out; 564 565 __enable_irq(desc); 566 out: 567 irq_put_desc_busunlock(desc, flags); 568 } 569 EXPORT_SYMBOL(enable_irq); 570 571 static int set_irq_wake_real(unsigned int irq, unsigned int on) 572 { 573 struct irq_desc *desc = irq_to_desc(irq); 574 int ret = -ENXIO; 575 576 if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE) 577 return 0; 578 579 if (desc->irq_data.chip->irq_set_wake) 580 ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on); 581 582 return ret; 583 } 584 585 /** 586 * irq_set_irq_wake - control irq power management wakeup 587 * @irq: interrupt to control 588 * @on: enable/disable power management wakeup 589 * 590 * Enable/disable power management wakeup mode, which is 591 * disabled by default. Enables and disables must match, 592 * just as they match for non-wakeup mode support. 593 * 594 * Wakeup mode lets this IRQ wake the system from sleep 595 * states like "suspend to RAM". 596 */ 597 int irq_set_irq_wake(unsigned int irq, unsigned int on) 598 { 599 unsigned long flags; 600 struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); 601 int ret = 0; 602 603 if (!desc) 604 return -EINVAL; 605 606 /* wakeup-capable irqs can be shared between drivers that 607 * don't need to have the same sleep mode behaviors. 608 */ 609 if (on) { 610 if (desc->wake_depth++ == 0) { 611 ret = set_irq_wake_real(irq, on); 612 if (ret) 613 desc->wake_depth = 0; 614 else 615 irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE); 616 } 617 } else { 618 if (desc->wake_depth == 0) { 619 WARN(1, "Unbalanced IRQ %d wake disable\n", irq); 620 } else if (--desc->wake_depth == 0) { 621 ret = set_irq_wake_real(irq, on); 622 if (ret) 623 desc->wake_depth = 1; 624 else 625 irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE); 626 } 627 } 628 irq_put_desc_busunlock(desc, flags); 629 return ret; 630 } 631 EXPORT_SYMBOL(irq_set_irq_wake); 632 633 /* 634 * Internal function that tells the architecture code whether a 635 * particular irq has been exclusively allocated or is available 636 * for driver use. 637 */ 638 int can_request_irq(unsigned int irq, unsigned long irqflags) 639 { 640 unsigned long flags; 641 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0); 642 int canrequest = 0; 643 644 if (!desc) 645 return 0; 646 647 if (irq_settings_can_request(desc)) { 648 if (!desc->action || 649 irqflags & desc->action->flags & IRQF_SHARED) 650 canrequest = 1; 651 } 652 irq_put_desc_unlock(desc, flags); 653 return canrequest; 654 } 655 656 int __irq_set_trigger(struct irq_desc *desc, unsigned long flags) 657 { 658 struct irq_chip *chip = desc->irq_data.chip; 659 int ret, unmask = 0; 660 661 if (!chip || !chip->irq_set_type) { 662 /* 663 * IRQF_TRIGGER_* but the PIC does not support multiple 664 * flow-types? 665 */ 666 pr_debug("No set_type function for IRQ %d (%s)\n", 667 irq_desc_get_irq(desc), 668 chip ? (chip->name ? : "unknown") : "unknown"); 669 return 0; 670 } 671 672 if (chip->flags & IRQCHIP_SET_TYPE_MASKED) { 673 if (!irqd_irq_masked(&desc->irq_data)) 674 mask_irq(desc); 675 if (!irqd_irq_disabled(&desc->irq_data)) 676 unmask = 1; 677 } 678 679 /* Mask all flags except trigger mode */ 680 flags &= IRQ_TYPE_SENSE_MASK; 681 ret = chip->irq_set_type(&desc->irq_data, flags); 682 683 switch (ret) { 684 case IRQ_SET_MASK_OK: 685 case IRQ_SET_MASK_OK_DONE: 686 irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK); 687 irqd_set(&desc->irq_data, flags); 688 689 case IRQ_SET_MASK_OK_NOCOPY: 690 flags = irqd_get_trigger_type(&desc->irq_data); 691 irq_settings_set_trigger_mask(desc, flags); 692 irqd_clear(&desc->irq_data, IRQD_LEVEL); 693 irq_settings_clr_level(desc); 694 if (flags & IRQ_TYPE_LEVEL_MASK) { 695 irq_settings_set_level(desc); 696 irqd_set(&desc->irq_data, IRQD_LEVEL); 697 } 698 699 ret = 0; 700 break; 701 default: 702 pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n", 703 flags, irq_desc_get_irq(desc), chip->irq_set_type); 704 } 705 if (unmask) 706 unmask_irq(desc); 707 return ret; 708 } 709 710 #ifdef CONFIG_HARDIRQS_SW_RESEND 711 int irq_set_parent(int irq, int parent_irq) 712 { 713 unsigned long flags; 714 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0); 715 716 if (!desc) 717 return -EINVAL; 718 719 desc->parent_irq = parent_irq; 720 721 irq_put_desc_unlock(desc, flags); 722 return 0; 723 } 724 #endif 725 726 /* 727 * Default primary interrupt handler for threaded interrupts. Is 728 * assigned as primary handler when request_threaded_irq is called 729 * with handler == NULL. Useful for oneshot interrupts. 730 */ 731 static irqreturn_t irq_default_primary_handler(int irq, void *dev_id) 732 { 733 return IRQ_WAKE_THREAD; 734 } 735 736 /* 737 * Primary handler for nested threaded interrupts. Should never be 738 * called. 739 */ 740 static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id) 741 { 742 WARN(1, "Primary handler called for nested irq %d\n", irq); 743 return IRQ_NONE; 744 } 745 746 static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id) 747 { 748 WARN(1, "Secondary action handler called for irq %d\n", irq); 749 return IRQ_NONE; 750 } 751 752 static int irq_wait_for_interrupt(struct irqaction *action) 753 { 754 set_current_state(TASK_INTERRUPTIBLE); 755 756 while (!kthread_should_stop()) { 757 758 if (test_and_clear_bit(IRQTF_RUNTHREAD, 759 &action->thread_flags)) { 760 __set_current_state(TASK_RUNNING); 761 return 0; 762 } 763 schedule(); 764 set_current_state(TASK_INTERRUPTIBLE); 765 } 766 __set_current_state(TASK_RUNNING); 767 return -1; 768 } 769 770 /* 771 * Oneshot interrupts keep the irq line masked until the threaded 772 * handler finished. unmask if the interrupt has not been disabled and 773 * is marked MASKED. 774 */ 775 static void irq_finalize_oneshot(struct irq_desc *desc, 776 struct irqaction *action) 777 { 778 if (!(desc->istate & IRQS_ONESHOT) || 779 action->handler == irq_forced_secondary_handler) 780 return; 781 again: 782 chip_bus_lock(desc); 783 raw_spin_lock_irq(&desc->lock); 784 785 /* 786 * Implausible though it may be we need to protect us against 787 * the following scenario: 788 * 789 * The thread is faster done than the hard interrupt handler 790 * on the other CPU. If we unmask the irq line then the 791 * interrupt can come in again and masks the line, leaves due 792 * to IRQS_INPROGRESS and the irq line is masked forever. 793 * 794 * This also serializes the state of shared oneshot handlers 795 * versus "desc->threads_onehsot |= action->thread_mask;" in 796 * irq_wake_thread(). See the comment there which explains the 797 * serialization. 798 */ 799 if (unlikely(irqd_irq_inprogress(&desc->irq_data))) { 800 raw_spin_unlock_irq(&desc->lock); 801 chip_bus_sync_unlock(desc); 802 cpu_relax(); 803 goto again; 804 } 805 806 /* 807 * Now check again, whether the thread should run. Otherwise 808 * we would clear the threads_oneshot bit of this thread which 809 * was just set. 810 */ 811 if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags)) 812 goto out_unlock; 813 814 desc->threads_oneshot &= ~action->thread_mask; 815 816 if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) && 817 irqd_irq_masked(&desc->irq_data)) 818 unmask_threaded_irq(desc); 819 820 out_unlock: 821 raw_spin_unlock_irq(&desc->lock); 822 chip_bus_sync_unlock(desc); 823 } 824 825 #ifdef CONFIG_SMP 826 /* 827 * Check whether we need to change the affinity of the interrupt thread. 828 */ 829 static void 830 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) 831 { 832 cpumask_var_t mask; 833 bool valid = true; 834 835 if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags)) 836 return; 837 838 /* 839 * In case we are out of memory we set IRQTF_AFFINITY again and 840 * try again next time 841 */ 842 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) { 843 set_bit(IRQTF_AFFINITY, &action->thread_flags); 844 return; 845 } 846 847 raw_spin_lock_irq(&desc->lock); 848 /* 849 * This code is triggered unconditionally. Check the affinity 850 * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out. 851 */ 852 if (desc->irq_common_data.affinity) 853 cpumask_copy(mask, desc->irq_common_data.affinity); 854 else 855 valid = false; 856 raw_spin_unlock_irq(&desc->lock); 857 858 if (valid) 859 set_cpus_allowed_ptr(current, mask); 860 free_cpumask_var(mask); 861 } 862 #else 863 static inline void 864 irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { } 865 #endif 866 867 /* 868 * Interrupts which are not explicitely requested as threaded 869 * interrupts rely on the implicit bh/preempt disable of the hard irq 870 * context. So we need to disable bh here to avoid deadlocks and other 871 * side effects. 872 */ 873 static irqreturn_t 874 irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action) 875 { 876 irqreturn_t ret; 877 878 local_bh_disable(); 879 ret = action->thread_fn(action->irq, action->dev_id); 880 irq_finalize_oneshot(desc, action); 881 local_bh_enable(); 882 return ret; 883 } 884 885 /* 886 * Interrupts explicitly requested as threaded interrupts want to be 887 * preemtible - many of them need to sleep and wait for slow busses to 888 * complete. 889 */ 890 static irqreturn_t irq_thread_fn(struct irq_desc *desc, 891 struct irqaction *action) 892 { 893 irqreturn_t ret; 894 895 ret = action->thread_fn(action->irq, action->dev_id); 896 irq_finalize_oneshot(desc, action); 897 return ret; 898 } 899 900 static void wake_threads_waitq(struct irq_desc *desc) 901 { 902 if (atomic_dec_and_test(&desc->threads_active)) 903 wake_up(&desc->wait_for_threads); 904 } 905 906 static void irq_thread_dtor(struct callback_head *unused) 907 { 908 struct task_struct *tsk = current; 909 struct irq_desc *desc; 910 struct irqaction *action; 911 912 if (WARN_ON_ONCE(!(current->flags & PF_EXITING))) 913 return; 914 915 action = kthread_data(tsk); 916 917 pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n", 918 tsk->comm, tsk->pid, action->irq); 919 920 921 desc = irq_to_desc(action->irq); 922 /* 923 * If IRQTF_RUNTHREAD is set, we need to decrement 924 * desc->threads_active and wake possible waiters. 925 */ 926 if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags)) 927 wake_threads_waitq(desc); 928 929 /* Prevent a stale desc->threads_oneshot */ 930 irq_finalize_oneshot(desc, action); 931 } 932 933 static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action) 934 { 935 struct irqaction *secondary = action->secondary; 936 937 if (WARN_ON_ONCE(!secondary)) 938 return; 939 940 raw_spin_lock_irq(&desc->lock); 941 __irq_wake_thread(desc, secondary); 942 raw_spin_unlock_irq(&desc->lock); 943 } 944 945 /* 946 * Interrupt handler thread 947 */ 948 static int irq_thread(void *data) 949 { 950 struct callback_head on_exit_work; 951 struct irqaction *action = data; 952 struct irq_desc *desc = irq_to_desc(action->irq); 953 irqreturn_t (*handler_fn)(struct irq_desc *desc, 954 struct irqaction *action); 955 956 if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD, 957 &action->thread_flags)) 958 handler_fn = irq_forced_thread_fn; 959 else 960 handler_fn = irq_thread_fn; 961 962 init_task_work(&on_exit_work, irq_thread_dtor); 963 task_work_add(current, &on_exit_work, false); 964 965 irq_thread_check_affinity(desc, action); 966 967 while (!irq_wait_for_interrupt(action)) { 968 irqreturn_t action_ret; 969 970 irq_thread_check_affinity(desc, action); 971 972 action_ret = handler_fn(desc, action); 973 if (action_ret == IRQ_HANDLED) 974 atomic_inc(&desc->threads_handled); 975 if (action_ret == IRQ_WAKE_THREAD) 976 irq_wake_secondary(desc, action); 977 978 wake_threads_waitq(desc); 979 } 980 981 /* 982 * This is the regular exit path. __free_irq() is stopping the 983 * thread via kthread_stop() after calling 984 * synchronize_irq(). So neither IRQTF_RUNTHREAD nor the 985 * oneshot mask bit can be set. We cannot verify that as we 986 * cannot touch the oneshot mask at this point anymore as 987 * __setup_irq() might have given out currents thread_mask 988 * again. 989 */ 990 task_work_cancel(current, irq_thread_dtor); 991 return 0; 992 } 993 994 /** 995 * irq_wake_thread - wake the irq thread for the action identified by dev_id 996 * @irq: Interrupt line 997 * @dev_id: Device identity for which the thread should be woken 998 * 999 */ 1000 void irq_wake_thread(unsigned int irq, void *dev_id) 1001 { 1002 struct irq_desc *desc = irq_to_desc(irq); 1003 struct irqaction *action; 1004 unsigned long flags; 1005 1006 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc))) 1007 return; 1008 1009 raw_spin_lock_irqsave(&desc->lock, flags); 1010 for_each_action_of_desc(desc, action) { 1011 if (action->dev_id == dev_id) { 1012 if (action->thread) 1013 __irq_wake_thread(desc, action); 1014 break; 1015 } 1016 } 1017 raw_spin_unlock_irqrestore(&desc->lock, flags); 1018 } 1019 EXPORT_SYMBOL_GPL(irq_wake_thread); 1020 1021 static int irq_setup_forced_threading(struct irqaction *new) 1022 { 1023 if (!force_irqthreads) 1024 return 0; 1025 if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT)) 1026 return 0; 1027 1028 new->flags |= IRQF_ONESHOT; 1029 1030 /* 1031 * Handle the case where we have a real primary handler and a 1032 * thread handler. We force thread them as well by creating a 1033 * secondary action. 1034 */ 1035 if (new->handler != irq_default_primary_handler && new->thread_fn) { 1036 /* Allocate the secondary action */ 1037 new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL); 1038 if (!new->secondary) 1039 return -ENOMEM; 1040 new->secondary->handler = irq_forced_secondary_handler; 1041 new->secondary->thread_fn = new->thread_fn; 1042 new->secondary->dev_id = new->dev_id; 1043 new->secondary->irq = new->irq; 1044 new->secondary->name = new->name; 1045 } 1046 /* Deal with the primary handler */ 1047 set_bit(IRQTF_FORCED_THREAD, &new->thread_flags); 1048 new->thread_fn = new->handler; 1049 new->handler = irq_default_primary_handler; 1050 return 0; 1051 } 1052 1053 static int irq_request_resources(struct irq_desc *desc) 1054 { 1055 struct irq_data *d = &desc->irq_data; 1056 struct irq_chip *c = d->chip; 1057 1058 return c->irq_request_resources ? c->irq_request_resources(d) : 0; 1059 } 1060 1061 static void irq_release_resources(struct irq_desc *desc) 1062 { 1063 struct irq_data *d = &desc->irq_data; 1064 struct irq_chip *c = d->chip; 1065 1066 if (c->irq_release_resources) 1067 c->irq_release_resources(d); 1068 } 1069 1070 static int 1071 setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary) 1072 { 1073 struct task_struct *t; 1074 struct sched_param param = { 1075 .sched_priority = MAX_USER_RT_PRIO/2, 1076 }; 1077 1078 if (!secondary) { 1079 t = kthread_create(irq_thread, new, "irq/%d-%s", irq, 1080 new->name); 1081 } else { 1082 t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq, 1083 new->name); 1084 param.sched_priority -= 1; 1085 } 1086 1087 if (IS_ERR(t)) 1088 return PTR_ERR(t); 1089 1090 sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m); 1091 1092 /* 1093 * We keep the reference to the task struct even if 1094 * the thread dies to avoid that the interrupt code 1095 * references an already freed task_struct. 1096 */ 1097 get_task_struct(t); 1098 new->thread = t; 1099 /* 1100 * Tell the thread to set its affinity. This is 1101 * important for shared interrupt handlers as we do 1102 * not invoke setup_affinity() for the secondary 1103 * handlers as everything is already set up. Even for 1104 * interrupts marked with IRQF_NO_BALANCE this is 1105 * correct as we want the thread to move to the cpu(s) 1106 * on which the requesting code placed the interrupt. 1107 */ 1108 set_bit(IRQTF_AFFINITY, &new->thread_flags); 1109 return 0; 1110 } 1111 1112 /* 1113 * Internal function to register an irqaction - typically used to 1114 * allocate special interrupts that are part of the architecture. 1115 */ 1116 static int 1117 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) 1118 { 1119 struct irqaction *old, **old_ptr; 1120 unsigned long flags, thread_mask = 0; 1121 int ret, nested, shared = 0; 1122 cpumask_var_t mask; 1123 1124 if (!desc) 1125 return -EINVAL; 1126 1127 if (desc->irq_data.chip == &no_irq_chip) 1128 return -ENOSYS; 1129 if (!try_module_get(desc->owner)) 1130 return -ENODEV; 1131 1132 new->irq = irq; 1133 1134 /* 1135 * If the trigger type is not specified by the caller, 1136 * then use the default for this interrupt. 1137 */ 1138 if (!(new->flags & IRQF_TRIGGER_MASK)) 1139 new->flags |= irqd_get_trigger_type(&desc->irq_data); 1140 1141 /* 1142 * Check whether the interrupt nests into another interrupt 1143 * thread. 1144 */ 1145 nested = irq_settings_is_nested_thread(desc); 1146 if (nested) { 1147 if (!new->thread_fn) { 1148 ret = -EINVAL; 1149 goto out_mput; 1150 } 1151 /* 1152 * Replace the primary handler which was provided from 1153 * the driver for non nested interrupt handling by the 1154 * dummy function which warns when called. 1155 */ 1156 new->handler = irq_nested_primary_handler; 1157 } else { 1158 if (irq_settings_can_thread(desc)) { 1159 ret = irq_setup_forced_threading(new); 1160 if (ret) 1161 goto out_mput; 1162 } 1163 } 1164 1165 /* 1166 * Create a handler thread when a thread function is supplied 1167 * and the interrupt does not nest into another interrupt 1168 * thread. 1169 */ 1170 if (new->thread_fn && !nested) { 1171 ret = setup_irq_thread(new, irq, false); 1172 if (ret) 1173 goto out_mput; 1174 if (new->secondary) { 1175 ret = setup_irq_thread(new->secondary, irq, true); 1176 if (ret) 1177 goto out_thread; 1178 } 1179 } 1180 1181 if (!alloc_cpumask_var(&mask, GFP_KERNEL)) { 1182 ret = -ENOMEM; 1183 goto out_thread; 1184 } 1185 1186 /* 1187 * Drivers are often written to work w/o knowledge about the 1188 * underlying irq chip implementation, so a request for a 1189 * threaded irq without a primary hard irq context handler 1190 * requires the ONESHOT flag to be set. Some irq chips like 1191 * MSI based interrupts are per se one shot safe. Check the 1192 * chip flags, so we can avoid the unmask dance at the end of 1193 * the threaded handler for those. 1194 */ 1195 if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE) 1196 new->flags &= ~IRQF_ONESHOT; 1197 1198 /* 1199 * The following block of code has to be executed atomically 1200 */ 1201 raw_spin_lock_irqsave(&desc->lock, flags); 1202 old_ptr = &desc->action; 1203 old = *old_ptr; 1204 if (old) { 1205 /* 1206 * Can't share interrupts unless both agree to and are 1207 * the same type (level, edge, polarity). So both flag 1208 * fields must have IRQF_SHARED set and the bits which 1209 * set the trigger type must match. Also all must 1210 * agree on ONESHOT. 1211 */ 1212 if (!((old->flags & new->flags) & IRQF_SHARED) || 1213 ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) || 1214 ((old->flags ^ new->flags) & IRQF_ONESHOT)) 1215 goto mismatch; 1216 1217 /* All handlers must agree on per-cpuness */ 1218 if ((old->flags & IRQF_PERCPU) != 1219 (new->flags & IRQF_PERCPU)) 1220 goto mismatch; 1221 1222 /* add new interrupt at end of irq queue */ 1223 do { 1224 /* 1225 * Or all existing action->thread_mask bits, 1226 * so we can find the next zero bit for this 1227 * new action. 1228 */ 1229 thread_mask |= old->thread_mask; 1230 old_ptr = &old->next; 1231 old = *old_ptr; 1232 } while (old); 1233 shared = 1; 1234 } 1235 1236 /* 1237 * Setup the thread mask for this irqaction for ONESHOT. For 1238 * !ONESHOT irqs the thread mask is 0 so we can avoid a 1239 * conditional in irq_wake_thread(). 1240 */ 1241 if (new->flags & IRQF_ONESHOT) { 1242 /* 1243 * Unlikely to have 32 resp 64 irqs sharing one line, 1244 * but who knows. 1245 */ 1246 if (thread_mask == ~0UL) { 1247 ret = -EBUSY; 1248 goto out_mask; 1249 } 1250 /* 1251 * The thread_mask for the action is or'ed to 1252 * desc->thread_active to indicate that the 1253 * IRQF_ONESHOT thread handler has been woken, but not 1254 * yet finished. The bit is cleared when a thread 1255 * completes. When all threads of a shared interrupt 1256 * line have completed desc->threads_active becomes 1257 * zero and the interrupt line is unmasked. See 1258 * handle.c:irq_wake_thread() for further information. 1259 * 1260 * If no thread is woken by primary (hard irq context) 1261 * interrupt handlers, then desc->threads_active is 1262 * also checked for zero to unmask the irq line in the 1263 * affected hard irq flow handlers 1264 * (handle_[fasteoi|level]_irq). 1265 * 1266 * The new action gets the first zero bit of 1267 * thread_mask assigned. See the loop above which or's 1268 * all existing action->thread_mask bits. 1269 */ 1270 new->thread_mask = 1 << ffz(thread_mask); 1271 1272 } else if (new->handler == irq_default_primary_handler && 1273 !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) { 1274 /* 1275 * The interrupt was requested with handler = NULL, so 1276 * we use the default primary handler for it. But it 1277 * does not have the oneshot flag set. In combination 1278 * with level interrupts this is deadly, because the 1279 * default primary handler just wakes the thread, then 1280 * the irq lines is reenabled, but the device still 1281 * has the level irq asserted. Rinse and repeat.... 1282 * 1283 * While this works for edge type interrupts, we play 1284 * it safe and reject unconditionally because we can't 1285 * say for sure which type this interrupt really 1286 * has. The type flags are unreliable as the 1287 * underlying chip implementation can override them. 1288 */ 1289 pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n", 1290 irq); 1291 ret = -EINVAL; 1292 goto out_mask; 1293 } 1294 1295 if (!shared) { 1296 ret = irq_request_resources(desc); 1297 if (ret) { 1298 pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n", 1299 new->name, irq, desc->irq_data.chip->name); 1300 goto out_mask; 1301 } 1302 1303 init_waitqueue_head(&desc->wait_for_threads); 1304 1305 /* Setup the type (level, edge polarity) if configured: */ 1306 if (new->flags & IRQF_TRIGGER_MASK) { 1307 ret = __irq_set_trigger(desc, 1308 new->flags & IRQF_TRIGGER_MASK); 1309 1310 if (ret) 1311 goto out_mask; 1312 } 1313 1314 desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \ 1315 IRQS_ONESHOT | IRQS_WAITING); 1316 irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS); 1317 1318 if (new->flags & IRQF_PERCPU) { 1319 irqd_set(&desc->irq_data, IRQD_PER_CPU); 1320 irq_settings_set_per_cpu(desc); 1321 } 1322 1323 if (new->flags & IRQF_ONESHOT) 1324 desc->istate |= IRQS_ONESHOT; 1325 1326 if (irq_settings_can_autoenable(desc)) 1327 irq_startup(desc, true); 1328 else 1329 /* Undo nested disables: */ 1330 desc->depth = 1; 1331 1332 /* Exclude IRQ from balancing if requested */ 1333 if (new->flags & IRQF_NOBALANCING) { 1334 irq_settings_set_no_balancing(desc); 1335 irqd_set(&desc->irq_data, IRQD_NO_BALANCING); 1336 } 1337 1338 /* Set default affinity mask once everything is setup */ 1339 setup_affinity(desc, mask); 1340 1341 } else if (new->flags & IRQF_TRIGGER_MASK) { 1342 unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK; 1343 unsigned int omsk = irq_settings_get_trigger_mask(desc); 1344 1345 if (nmsk != omsk) 1346 /* hope the handler works with current trigger mode */ 1347 pr_warn("irq %d uses trigger mode %u; requested %u\n", 1348 irq, nmsk, omsk); 1349 } 1350 1351 *old_ptr = new; 1352 1353 irq_pm_install_action(desc, new); 1354 1355 /* Reset broken irq detection when installing new handler */ 1356 desc->irq_count = 0; 1357 desc->irqs_unhandled = 0; 1358 1359 /* 1360 * Check whether we disabled the irq via the spurious handler 1361 * before. Reenable it and give it another chance. 1362 */ 1363 if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) { 1364 desc->istate &= ~IRQS_SPURIOUS_DISABLED; 1365 __enable_irq(desc); 1366 } 1367 1368 raw_spin_unlock_irqrestore(&desc->lock, flags); 1369 1370 /* 1371 * Strictly no need to wake it up, but hung_task complains 1372 * when no hard interrupt wakes the thread up. 1373 */ 1374 if (new->thread) 1375 wake_up_process(new->thread); 1376 if (new->secondary) 1377 wake_up_process(new->secondary->thread); 1378 1379 register_irq_proc(irq, desc); 1380 new->dir = NULL; 1381 register_handler_proc(irq, new); 1382 free_cpumask_var(mask); 1383 1384 return 0; 1385 1386 mismatch: 1387 if (!(new->flags & IRQF_PROBE_SHARED)) { 1388 pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n", 1389 irq, new->flags, new->name, old->flags, old->name); 1390 #ifdef CONFIG_DEBUG_SHIRQ 1391 dump_stack(); 1392 #endif 1393 } 1394 ret = -EBUSY; 1395 1396 out_mask: 1397 raw_spin_unlock_irqrestore(&desc->lock, flags); 1398 free_cpumask_var(mask); 1399 1400 out_thread: 1401 if (new->thread) { 1402 struct task_struct *t = new->thread; 1403 1404 new->thread = NULL; 1405 kthread_stop(t); 1406 put_task_struct(t); 1407 } 1408 if (new->secondary && new->secondary->thread) { 1409 struct task_struct *t = new->secondary->thread; 1410 1411 new->secondary->thread = NULL; 1412 kthread_stop(t); 1413 put_task_struct(t); 1414 } 1415 out_mput: 1416 module_put(desc->owner); 1417 return ret; 1418 } 1419 1420 /** 1421 * setup_irq - setup an interrupt 1422 * @irq: Interrupt line to setup 1423 * @act: irqaction for the interrupt 1424 * 1425 * Used to statically setup interrupts in the early boot process. 1426 */ 1427 int setup_irq(unsigned int irq, struct irqaction *act) 1428 { 1429 int retval; 1430 struct irq_desc *desc = irq_to_desc(irq); 1431 1432 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc))) 1433 return -EINVAL; 1434 1435 retval = irq_chip_pm_get(&desc->irq_data); 1436 if (retval < 0) 1437 return retval; 1438 1439 chip_bus_lock(desc); 1440 retval = __setup_irq(irq, desc, act); 1441 chip_bus_sync_unlock(desc); 1442 1443 if (retval) 1444 irq_chip_pm_put(&desc->irq_data); 1445 1446 return retval; 1447 } 1448 EXPORT_SYMBOL_GPL(setup_irq); 1449 1450 /* 1451 * Internal function to unregister an irqaction - used to free 1452 * regular and special interrupts that are part of the architecture. 1453 */ 1454 static struct irqaction *__free_irq(unsigned int irq, void *dev_id) 1455 { 1456 struct irq_desc *desc = irq_to_desc(irq); 1457 struct irqaction *action, **action_ptr; 1458 unsigned long flags; 1459 1460 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq); 1461 1462 if (!desc) 1463 return NULL; 1464 1465 chip_bus_lock(desc); 1466 raw_spin_lock_irqsave(&desc->lock, flags); 1467 1468 /* 1469 * There can be multiple actions per IRQ descriptor, find the right 1470 * one based on the dev_id: 1471 */ 1472 action_ptr = &desc->action; 1473 for (;;) { 1474 action = *action_ptr; 1475 1476 if (!action) { 1477 WARN(1, "Trying to free already-free IRQ %d\n", irq); 1478 raw_spin_unlock_irqrestore(&desc->lock, flags); 1479 chip_bus_sync_unlock(desc); 1480 return NULL; 1481 } 1482 1483 if (action->dev_id == dev_id) 1484 break; 1485 action_ptr = &action->next; 1486 } 1487 1488 /* Found it - now remove it from the list of entries: */ 1489 *action_ptr = action->next; 1490 1491 irq_pm_remove_action(desc, action); 1492 1493 /* If this was the last handler, shut down the IRQ line: */ 1494 if (!desc->action) { 1495 irq_settings_clr_disable_unlazy(desc); 1496 irq_shutdown(desc); 1497 irq_release_resources(desc); 1498 } 1499 1500 #ifdef CONFIG_SMP 1501 /* make sure affinity_hint is cleaned up */ 1502 if (WARN_ON_ONCE(desc->affinity_hint)) 1503 desc->affinity_hint = NULL; 1504 #endif 1505 1506 raw_spin_unlock_irqrestore(&desc->lock, flags); 1507 chip_bus_sync_unlock(desc); 1508 1509 unregister_handler_proc(irq, action); 1510 1511 /* Make sure it's not being used on another CPU: */ 1512 synchronize_irq(irq); 1513 1514 #ifdef CONFIG_DEBUG_SHIRQ 1515 /* 1516 * It's a shared IRQ -- the driver ought to be prepared for an IRQ 1517 * event to happen even now it's being freed, so let's make sure that 1518 * is so by doing an extra call to the handler .... 1519 * 1520 * ( We do this after actually deregistering it, to make sure that a 1521 * 'real' IRQ doesn't run in * parallel with our fake. ) 1522 */ 1523 if (action->flags & IRQF_SHARED) { 1524 local_irq_save(flags); 1525 action->handler(irq, dev_id); 1526 local_irq_restore(flags); 1527 } 1528 #endif 1529 1530 if (action->thread) { 1531 kthread_stop(action->thread); 1532 put_task_struct(action->thread); 1533 if (action->secondary && action->secondary->thread) { 1534 kthread_stop(action->secondary->thread); 1535 put_task_struct(action->secondary->thread); 1536 } 1537 } 1538 1539 irq_chip_pm_put(&desc->irq_data); 1540 module_put(desc->owner); 1541 kfree(action->secondary); 1542 return action; 1543 } 1544 1545 /** 1546 * remove_irq - free an interrupt 1547 * @irq: Interrupt line to free 1548 * @act: irqaction for the interrupt 1549 * 1550 * Used to remove interrupts statically setup by the early boot process. 1551 */ 1552 void remove_irq(unsigned int irq, struct irqaction *act) 1553 { 1554 struct irq_desc *desc = irq_to_desc(irq); 1555 1556 if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc))) 1557 __free_irq(irq, act->dev_id); 1558 } 1559 EXPORT_SYMBOL_GPL(remove_irq); 1560 1561 /** 1562 * free_irq - free an interrupt allocated with request_irq 1563 * @irq: Interrupt line to free 1564 * @dev_id: Device identity to free 1565 * 1566 * Remove an interrupt handler. The handler is removed and if the 1567 * interrupt line is no longer in use by any driver it is disabled. 1568 * On a shared IRQ the caller must ensure the interrupt is disabled 1569 * on the card it drives before calling this function. The function 1570 * does not return until any executing interrupts for this IRQ 1571 * have completed. 1572 * 1573 * This function must not be called from interrupt context. 1574 */ 1575 void free_irq(unsigned int irq, void *dev_id) 1576 { 1577 struct irq_desc *desc = irq_to_desc(irq); 1578 1579 if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc))) 1580 return; 1581 1582 #ifdef CONFIG_SMP 1583 if (WARN_ON(desc->affinity_notify)) 1584 desc->affinity_notify = NULL; 1585 #endif 1586 1587 kfree(__free_irq(irq, dev_id)); 1588 } 1589 EXPORT_SYMBOL(free_irq); 1590 1591 /** 1592 * request_threaded_irq - allocate an interrupt line 1593 * @irq: Interrupt line to allocate 1594 * @handler: Function to be called when the IRQ occurs. 1595 * Primary handler for threaded interrupts 1596 * If NULL and thread_fn != NULL the default 1597 * primary handler is installed 1598 * @thread_fn: Function called from the irq handler thread 1599 * If NULL, no irq thread is created 1600 * @irqflags: Interrupt type flags 1601 * @devname: An ascii name for the claiming device 1602 * @dev_id: A cookie passed back to the handler function 1603 * 1604 * This call allocates interrupt resources and enables the 1605 * interrupt line and IRQ handling. From the point this 1606 * call is made your handler function may be invoked. Since 1607 * your handler function must clear any interrupt the board 1608 * raises, you must take care both to initialise your hardware 1609 * and to set up the interrupt handler in the right order. 1610 * 1611 * If you want to set up a threaded irq handler for your device 1612 * then you need to supply @handler and @thread_fn. @handler is 1613 * still called in hard interrupt context and has to check 1614 * whether the interrupt originates from the device. If yes it 1615 * needs to disable the interrupt on the device and return 1616 * IRQ_WAKE_THREAD which will wake up the handler thread and run 1617 * @thread_fn. This split handler design is necessary to support 1618 * shared interrupts. 1619 * 1620 * Dev_id must be globally unique. Normally the address of the 1621 * device data structure is used as the cookie. Since the handler 1622 * receives this value it makes sense to use it. 1623 * 1624 * If your interrupt is shared you must pass a non NULL dev_id 1625 * as this is required when freeing the interrupt. 1626 * 1627 * Flags: 1628 * 1629 * IRQF_SHARED Interrupt is shared 1630 * IRQF_TRIGGER_* Specify active edge(s) or level 1631 * 1632 */ 1633 int request_threaded_irq(unsigned int irq, irq_handler_t handler, 1634 irq_handler_t thread_fn, unsigned long irqflags, 1635 const char *devname, void *dev_id) 1636 { 1637 struct irqaction *action; 1638 struct irq_desc *desc; 1639 int retval; 1640 1641 if (irq == IRQ_NOTCONNECTED) 1642 return -ENOTCONN; 1643 1644 /* 1645 * Sanity-check: shared interrupts must pass in a real dev-ID, 1646 * otherwise we'll have trouble later trying to figure out 1647 * which interrupt is which (messes up the interrupt freeing 1648 * logic etc). 1649 * 1650 * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and 1651 * it cannot be set along with IRQF_NO_SUSPEND. 1652 */ 1653 if (((irqflags & IRQF_SHARED) && !dev_id) || 1654 (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) || 1655 ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND))) 1656 return -EINVAL; 1657 1658 desc = irq_to_desc(irq); 1659 if (!desc) 1660 return -EINVAL; 1661 1662 if (!irq_settings_can_request(desc) || 1663 WARN_ON(irq_settings_is_per_cpu_devid(desc))) 1664 return -EINVAL; 1665 1666 if (!handler) { 1667 if (!thread_fn) 1668 return -EINVAL; 1669 handler = irq_default_primary_handler; 1670 } 1671 1672 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); 1673 if (!action) 1674 return -ENOMEM; 1675 1676 action->handler = handler; 1677 action->thread_fn = thread_fn; 1678 action->flags = irqflags; 1679 action->name = devname; 1680 action->dev_id = dev_id; 1681 1682 retval = irq_chip_pm_get(&desc->irq_data); 1683 if (retval < 0) { 1684 kfree(action); 1685 return retval; 1686 } 1687 1688 chip_bus_lock(desc); 1689 retval = __setup_irq(irq, desc, action); 1690 chip_bus_sync_unlock(desc); 1691 1692 if (retval) { 1693 irq_chip_pm_put(&desc->irq_data); 1694 kfree(action->secondary); 1695 kfree(action); 1696 } 1697 1698 #ifdef CONFIG_DEBUG_SHIRQ_FIXME 1699 if (!retval && (irqflags & IRQF_SHARED)) { 1700 /* 1701 * It's a shared IRQ -- the driver ought to be prepared for it 1702 * to happen immediately, so let's make sure.... 1703 * We disable the irq to make sure that a 'real' IRQ doesn't 1704 * run in parallel with our fake. 1705 */ 1706 unsigned long flags; 1707 1708 disable_irq(irq); 1709 local_irq_save(flags); 1710 1711 handler(irq, dev_id); 1712 1713 local_irq_restore(flags); 1714 enable_irq(irq); 1715 } 1716 #endif 1717 return retval; 1718 } 1719 EXPORT_SYMBOL(request_threaded_irq); 1720 1721 /** 1722 * request_any_context_irq - allocate an interrupt line 1723 * @irq: Interrupt line to allocate 1724 * @handler: Function to be called when the IRQ occurs. 1725 * Threaded handler for threaded interrupts. 1726 * @flags: Interrupt type flags 1727 * @name: An ascii name for the claiming device 1728 * @dev_id: A cookie passed back to the handler function 1729 * 1730 * This call allocates interrupt resources and enables the 1731 * interrupt line and IRQ handling. It selects either a 1732 * hardirq or threaded handling method depending on the 1733 * context. 1734 * 1735 * On failure, it returns a negative value. On success, 1736 * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED. 1737 */ 1738 int request_any_context_irq(unsigned int irq, irq_handler_t handler, 1739 unsigned long flags, const char *name, void *dev_id) 1740 { 1741 struct irq_desc *desc; 1742 int ret; 1743 1744 if (irq == IRQ_NOTCONNECTED) 1745 return -ENOTCONN; 1746 1747 desc = irq_to_desc(irq); 1748 if (!desc) 1749 return -EINVAL; 1750 1751 if (irq_settings_is_nested_thread(desc)) { 1752 ret = request_threaded_irq(irq, NULL, handler, 1753 flags, name, dev_id); 1754 return !ret ? IRQC_IS_NESTED : ret; 1755 } 1756 1757 ret = request_irq(irq, handler, flags, name, dev_id); 1758 return !ret ? IRQC_IS_HARDIRQ : ret; 1759 } 1760 EXPORT_SYMBOL_GPL(request_any_context_irq); 1761 1762 void enable_percpu_irq(unsigned int irq, unsigned int type) 1763 { 1764 unsigned int cpu = smp_processor_id(); 1765 unsigned long flags; 1766 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU); 1767 1768 if (!desc) 1769 return; 1770 1771 /* 1772 * If the trigger type is not specified by the caller, then 1773 * use the default for this interrupt. 1774 */ 1775 type &= IRQ_TYPE_SENSE_MASK; 1776 if (type == IRQ_TYPE_NONE) 1777 type = irqd_get_trigger_type(&desc->irq_data); 1778 1779 if (type != IRQ_TYPE_NONE) { 1780 int ret; 1781 1782 ret = __irq_set_trigger(desc, type); 1783 1784 if (ret) { 1785 WARN(1, "failed to set type for IRQ%d\n", irq); 1786 goto out; 1787 } 1788 } 1789 1790 irq_percpu_enable(desc, cpu); 1791 out: 1792 irq_put_desc_unlock(desc, flags); 1793 } 1794 EXPORT_SYMBOL_GPL(enable_percpu_irq); 1795 1796 /** 1797 * irq_percpu_is_enabled - Check whether the per cpu irq is enabled 1798 * @irq: Linux irq number to check for 1799 * 1800 * Must be called from a non migratable context. Returns the enable 1801 * state of a per cpu interrupt on the current cpu. 1802 */ 1803 bool irq_percpu_is_enabled(unsigned int irq) 1804 { 1805 unsigned int cpu = smp_processor_id(); 1806 struct irq_desc *desc; 1807 unsigned long flags; 1808 bool is_enabled; 1809 1810 desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU); 1811 if (!desc) 1812 return false; 1813 1814 is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled); 1815 irq_put_desc_unlock(desc, flags); 1816 1817 return is_enabled; 1818 } 1819 EXPORT_SYMBOL_GPL(irq_percpu_is_enabled); 1820 1821 void disable_percpu_irq(unsigned int irq) 1822 { 1823 unsigned int cpu = smp_processor_id(); 1824 unsigned long flags; 1825 struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU); 1826 1827 if (!desc) 1828 return; 1829 1830 irq_percpu_disable(desc, cpu); 1831 irq_put_desc_unlock(desc, flags); 1832 } 1833 EXPORT_SYMBOL_GPL(disable_percpu_irq); 1834 1835 /* 1836 * Internal function to unregister a percpu irqaction. 1837 */ 1838 static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id) 1839 { 1840 struct irq_desc *desc = irq_to_desc(irq); 1841 struct irqaction *action; 1842 unsigned long flags; 1843 1844 WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq); 1845 1846 if (!desc) 1847 return NULL; 1848 1849 raw_spin_lock_irqsave(&desc->lock, flags); 1850 1851 action = desc->action; 1852 if (!action || action->percpu_dev_id != dev_id) { 1853 WARN(1, "Trying to free already-free IRQ %d\n", irq); 1854 goto bad; 1855 } 1856 1857 if (!cpumask_empty(desc->percpu_enabled)) { 1858 WARN(1, "percpu IRQ %d still enabled on CPU%d!\n", 1859 irq, cpumask_first(desc->percpu_enabled)); 1860 goto bad; 1861 } 1862 1863 /* Found it - now remove it from the list of entries: */ 1864 desc->action = NULL; 1865 1866 raw_spin_unlock_irqrestore(&desc->lock, flags); 1867 1868 unregister_handler_proc(irq, action); 1869 1870 irq_chip_pm_put(&desc->irq_data); 1871 module_put(desc->owner); 1872 return action; 1873 1874 bad: 1875 raw_spin_unlock_irqrestore(&desc->lock, flags); 1876 return NULL; 1877 } 1878 1879 /** 1880 * remove_percpu_irq - free a per-cpu interrupt 1881 * @irq: Interrupt line to free 1882 * @act: irqaction for the interrupt 1883 * 1884 * Used to remove interrupts statically setup by the early boot process. 1885 */ 1886 void remove_percpu_irq(unsigned int irq, struct irqaction *act) 1887 { 1888 struct irq_desc *desc = irq_to_desc(irq); 1889 1890 if (desc && irq_settings_is_per_cpu_devid(desc)) 1891 __free_percpu_irq(irq, act->percpu_dev_id); 1892 } 1893 1894 /** 1895 * free_percpu_irq - free an interrupt allocated with request_percpu_irq 1896 * @irq: Interrupt line to free 1897 * @dev_id: Device identity to free 1898 * 1899 * Remove a percpu interrupt handler. The handler is removed, but 1900 * the interrupt line is not disabled. This must be done on each 1901 * CPU before calling this function. The function does not return 1902 * until any executing interrupts for this IRQ have completed. 1903 * 1904 * This function must not be called from interrupt context. 1905 */ 1906 void free_percpu_irq(unsigned int irq, void __percpu *dev_id) 1907 { 1908 struct irq_desc *desc = irq_to_desc(irq); 1909 1910 if (!desc || !irq_settings_is_per_cpu_devid(desc)) 1911 return; 1912 1913 chip_bus_lock(desc); 1914 kfree(__free_percpu_irq(irq, dev_id)); 1915 chip_bus_sync_unlock(desc); 1916 } 1917 EXPORT_SYMBOL_GPL(free_percpu_irq); 1918 1919 /** 1920 * setup_percpu_irq - setup a per-cpu interrupt 1921 * @irq: Interrupt line to setup 1922 * @act: irqaction for the interrupt 1923 * 1924 * Used to statically setup per-cpu interrupts in the early boot process. 1925 */ 1926 int setup_percpu_irq(unsigned int irq, struct irqaction *act) 1927 { 1928 struct irq_desc *desc = irq_to_desc(irq); 1929 int retval; 1930 1931 if (!desc || !irq_settings_is_per_cpu_devid(desc)) 1932 return -EINVAL; 1933 1934 retval = irq_chip_pm_get(&desc->irq_data); 1935 if (retval < 0) 1936 return retval; 1937 1938 chip_bus_lock(desc); 1939 retval = __setup_irq(irq, desc, act); 1940 chip_bus_sync_unlock(desc); 1941 1942 if (retval) 1943 irq_chip_pm_put(&desc->irq_data); 1944 1945 return retval; 1946 } 1947 1948 /** 1949 * request_percpu_irq - allocate a percpu interrupt line 1950 * @irq: Interrupt line to allocate 1951 * @handler: Function to be called when the IRQ occurs. 1952 * @devname: An ascii name for the claiming device 1953 * @dev_id: A percpu cookie passed back to the handler function 1954 * 1955 * This call allocates interrupt resources and enables the 1956 * interrupt on the local CPU. If the interrupt is supposed to be 1957 * enabled on other CPUs, it has to be done on each CPU using 1958 * enable_percpu_irq(). 1959 * 1960 * Dev_id must be globally unique. It is a per-cpu variable, and 1961 * the handler gets called with the interrupted CPU's instance of 1962 * that variable. 1963 */ 1964 int request_percpu_irq(unsigned int irq, irq_handler_t handler, 1965 const char *devname, void __percpu *dev_id) 1966 { 1967 struct irqaction *action; 1968 struct irq_desc *desc; 1969 int retval; 1970 1971 if (!dev_id) 1972 return -EINVAL; 1973 1974 desc = irq_to_desc(irq); 1975 if (!desc || !irq_settings_can_request(desc) || 1976 !irq_settings_is_per_cpu_devid(desc)) 1977 return -EINVAL; 1978 1979 action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); 1980 if (!action) 1981 return -ENOMEM; 1982 1983 action->handler = handler; 1984 action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND; 1985 action->name = devname; 1986 action->percpu_dev_id = dev_id; 1987 1988 retval = irq_chip_pm_get(&desc->irq_data); 1989 if (retval < 0) { 1990 kfree(action); 1991 return retval; 1992 } 1993 1994 chip_bus_lock(desc); 1995 retval = __setup_irq(irq, desc, action); 1996 chip_bus_sync_unlock(desc); 1997 1998 if (retval) { 1999 irq_chip_pm_put(&desc->irq_data); 2000 kfree(action); 2001 } 2002 2003 return retval; 2004 } 2005 EXPORT_SYMBOL_GPL(request_percpu_irq); 2006 2007 /** 2008 * irq_get_irqchip_state - returns the irqchip state of a interrupt. 2009 * @irq: Interrupt line that is forwarded to a VM 2010 * @which: One of IRQCHIP_STATE_* the caller wants to know about 2011 * @state: a pointer to a boolean where the state is to be storeed 2012 * 2013 * This call snapshots the internal irqchip state of an 2014 * interrupt, returning into @state the bit corresponding to 2015 * stage @which 2016 * 2017 * This function should be called with preemption disabled if the 2018 * interrupt controller has per-cpu registers. 2019 */ 2020 int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which, 2021 bool *state) 2022 { 2023 struct irq_desc *desc; 2024 struct irq_data *data; 2025 struct irq_chip *chip; 2026 unsigned long flags; 2027 int err = -EINVAL; 2028 2029 desc = irq_get_desc_buslock(irq, &flags, 0); 2030 if (!desc) 2031 return err; 2032 2033 data = irq_desc_get_irq_data(desc); 2034 2035 do { 2036 chip = irq_data_get_irq_chip(data); 2037 if (chip->irq_get_irqchip_state) 2038 break; 2039 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY 2040 data = data->parent_data; 2041 #else 2042 data = NULL; 2043 #endif 2044 } while (data); 2045 2046 if (data) 2047 err = chip->irq_get_irqchip_state(data, which, state); 2048 2049 irq_put_desc_busunlock(desc, flags); 2050 return err; 2051 } 2052 EXPORT_SYMBOL_GPL(irq_get_irqchip_state); 2053 2054 /** 2055 * irq_set_irqchip_state - set the state of a forwarded interrupt. 2056 * @irq: Interrupt line that is forwarded to a VM 2057 * @which: State to be restored (one of IRQCHIP_STATE_*) 2058 * @val: Value corresponding to @which 2059 * 2060 * This call sets the internal irqchip state of an interrupt, 2061 * depending on the value of @which. 2062 * 2063 * This function should be called with preemption disabled if the 2064 * interrupt controller has per-cpu registers. 2065 */ 2066 int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which, 2067 bool val) 2068 { 2069 struct irq_desc *desc; 2070 struct irq_data *data; 2071 struct irq_chip *chip; 2072 unsigned long flags; 2073 int err = -EINVAL; 2074 2075 desc = irq_get_desc_buslock(irq, &flags, 0); 2076 if (!desc) 2077 return err; 2078 2079 data = irq_desc_get_irq_data(desc); 2080 2081 do { 2082 chip = irq_data_get_irq_chip(data); 2083 if (chip->irq_set_irqchip_state) 2084 break; 2085 #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY 2086 data = data->parent_data; 2087 #else 2088 data = NULL; 2089 #endif 2090 } while (data); 2091 2092 if (data) 2093 err = chip->irq_set_irqchip_state(data, which, val); 2094 2095 irq_put_desc_busunlock(desc, flags); 2096 return err; 2097 } 2098 EXPORT_SYMBOL_GPL(irq_set_irqchip_state); 2099