1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* interrupt.h */ 3 #ifndef _LINUX_INTERRUPT_H 4 #define _LINUX_INTERRUPT_H 5 6 #include <linux/kernel.h> 7 #include <linux/linkage.h> 8 #include <linux/bitops.h> 9 #include <linux/preempt.h> 10 #include <linux/cpumask.h> 11 #include <linux/irqreturn.h> 12 #include <linux/irqnr.h> 13 #include <linux/hardirq.h> 14 #include <linux/irqflags.h> 15 #include <linux/hrtimer.h> 16 #include <linux/kref.h> 17 #include <linux/workqueue.h> 18 19 #include <linux/atomic.h> 20 #include <asm/ptrace.h> 21 #include <asm/irq.h> 22 #include <asm/sections.h> 23 24 /* 25 * These correspond to the IORESOURCE_IRQ_* defines in 26 * linux/ioport.h to select the interrupt line behaviour. When 27 * requesting an interrupt without specifying a IRQF_TRIGGER, the 28 * setting should be assumed to be "as already configured", which 29 * may be as per machine or firmware initialisation. 30 */ 31 #define IRQF_TRIGGER_NONE 0x00000000 32 #define IRQF_TRIGGER_RISING 0x00000001 33 #define IRQF_TRIGGER_FALLING 0x00000002 34 #define IRQF_TRIGGER_HIGH 0x00000004 35 #define IRQF_TRIGGER_LOW 0x00000008 36 #define IRQF_TRIGGER_MASK (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \ 37 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING) 38 #define IRQF_TRIGGER_PROBE 0x00000010 39 40 /* 41 * These flags used only by the kernel as part of the 42 * irq handling routines. 43 * 44 * IRQF_SHARED - allow sharing the irq among several devices 45 * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur 46 * IRQF_TIMER - Flag to mark this interrupt as timer interrupt 47 * IRQF_PERCPU - Interrupt is per cpu 48 * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing 49 * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is 50 * registered first in an shared interrupt is considered for 51 * performance reasons) 52 * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished. 53 * Used by threaded interrupts which need to keep the 54 * irq line disabled until the threaded handler has been run. 55 * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend. Does not guarantee 56 * that this interrupt will wake the system from a suspended 57 * state. See Documentation/power/suspend-and-interrupts.txt 58 * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set 59 * IRQF_NO_THREAD - Interrupt cannot be threaded 60 * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device 61 * resume time. 62 * IRQF_COND_SUSPEND - If the IRQ is shared with a NO_SUSPEND user, execute this 63 * interrupt handler after suspending interrupts. For system 64 * wakeup devices users need to implement wakeup detection in 65 * their interrupt handlers. 66 */ 67 #define IRQF_SHARED 0x00000080 68 #define IRQF_PROBE_SHARED 0x00000100 69 #define __IRQF_TIMER 0x00000200 70 #define IRQF_PERCPU 0x00000400 71 #define IRQF_NOBALANCING 0x00000800 72 #define IRQF_IRQPOLL 0x00001000 73 #define IRQF_ONESHOT 0x00002000 74 #define IRQF_NO_SUSPEND 0x00004000 75 #define IRQF_FORCE_RESUME 0x00008000 76 #define IRQF_NO_THREAD 0x00010000 77 #define IRQF_EARLY_RESUME 0x00020000 78 #define IRQF_COND_SUSPEND 0x00040000 79 80 #define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD) 81 82 /* 83 * These values can be returned by request_any_context_irq() and 84 * describe the context the interrupt will be run in. 85 * 86 * IRQC_IS_HARDIRQ - interrupt runs in hardirq context 87 * IRQC_IS_NESTED - interrupt runs in a nested threaded context 88 */ 89 enum { 90 IRQC_IS_HARDIRQ = 0, 91 IRQC_IS_NESTED, 92 }; 93 94 typedef irqreturn_t (*irq_handler_t)(int, void *); 95 96 /** 97 * struct irqaction - per interrupt action descriptor 98 * @handler: interrupt handler function 99 * @name: name of the device 100 * @dev_id: cookie to identify the device 101 * @percpu_dev_id: cookie to identify the device 102 * @next: pointer to the next irqaction for shared interrupts 103 * @irq: interrupt number 104 * @flags: flags (see IRQF_* above) 105 * @thread_fn: interrupt handler function for threaded interrupts 106 * @thread: thread pointer for threaded interrupts 107 * @secondary: pointer to secondary irqaction (force threading) 108 * @thread_flags: flags related to @thread 109 * @thread_mask: bitmask for keeping track of @thread activity 110 * @dir: pointer to the proc/irq/NN/name entry 111 */ 112 struct irqaction { 113 irq_handler_t handler; 114 void *dev_id; 115 void __percpu *percpu_dev_id; 116 struct irqaction *next; 117 irq_handler_t thread_fn; 118 struct task_struct *thread; 119 struct irqaction *secondary; 120 unsigned int irq; 121 unsigned int flags; 122 unsigned long thread_flags; 123 unsigned long thread_mask; 124 const char *name; 125 struct proc_dir_entry *dir; 126 } ____cacheline_internodealigned_in_smp; 127 128 extern irqreturn_t no_action(int cpl, void *dev_id); 129 130 /* 131 * If a (PCI) device interrupt is not connected we set dev->irq to 132 * IRQ_NOTCONNECTED. This causes request_irq() to fail with -ENOTCONN, so we 133 * can distingiush that case from other error returns. 134 * 135 * 0x80000000 is guaranteed to be outside the available range of interrupts 136 * and easy to distinguish from other possible incorrect values. 137 */ 138 #define IRQ_NOTCONNECTED (1U << 31) 139 140 extern int __must_check 141 request_threaded_irq(unsigned int irq, irq_handler_t handler, 142 irq_handler_t thread_fn, 143 unsigned long flags, const char *name, void *dev); 144 145 static inline int __must_check 146 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, 147 const char *name, void *dev) 148 { 149 return request_threaded_irq(irq, handler, NULL, flags, name, dev); 150 } 151 152 extern int __must_check 153 request_any_context_irq(unsigned int irq, irq_handler_t handler, 154 unsigned long flags, const char *name, void *dev_id); 155 156 extern int __must_check 157 __request_percpu_irq(unsigned int irq, irq_handler_t handler, 158 unsigned long flags, const char *devname, 159 void __percpu *percpu_dev_id); 160 161 static inline int __must_check 162 request_percpu_irq(unsigned int irq, irq_handler_t handler, 163 const char *devname, void __percpu *percpu_dev_id) 164 { 165 return __request_percpu_irq(irq, handler, 0, 166 devname, percpu_dev_id); 167 } 168 169 extern const void *free_irq(unsigned int, void *); 170 extern void free_percpu_irq(unsigned int, void __percpu *); 171 172 struct device; 173 174 extern int __must_check 175 devm_request_threaded_irq(struct device *dev, unsigned int irq, 176 irq_handler_t handler, irq_handler_t thread_fn, 177 unsigned long irqflags, const char *devname, 178 void *dev_id); 179 180 static inline int __must_check 181 devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler, 182 unsigned long irqflags, const char *devname, void *dev_id) 183 { 184 return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags, 185 devname, dev_id); 186 } 187 188 extern int __must_check 189 devm_request_any_context_irq(struct device *dev, unsigned int irq, 190 irq_handler_t handler, unsigned long irqflags, 191 const char *devname, void *dev_id); 192 193 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id); 194 195 /* 196 * On lockdep we dont want to enable hardirqs in hardirq 197 * context. Use local_irq_enable_in_hardirq() to annotate 198 * kernel code that has to do this nevertheless (pretty much 199 * the only valid case is for old/broken hardware that is 200 * insanely slow). 201 * 202 * NOTE: in theory this might break fragile code that relies 203 * on hardirq delivery - in practice we dont seem to have such 204 * places left. So the only effect should be slightly increased 205 * irqs-off latencies. 206 */ 207 #ifdef CONFIG_LOCKDEP 208 # define local_irq_enable_in_hardirq() do { } while (0) 209 #else 210 # define local_irq_enable_in_hardirq() local_irq_enable() 211 #endif 212 213 extern void disable_irq_nosync(unsigned int irq); 214 extern bool disable_hardirq(unsigned int irq); 215 extern void disable_irq(unsigned int irq); 216 extern void disable_percpu_irq(unsigned int irq); 217 extern void enable_irq(unsigned int irq); 218 extern void enable_percpu_irq(unsigned int irq, unsigned int type); 219 extern bool irq_percpu_is_enabled(unsigned int irq); 220 extern void irq_wake_thread(unsigned int irq, void *dev_id); 221 222 /* The following three functions are for the core kernel use only. */ 223 extern void suspend_device_irqs(void); 224 extern void resume_device_irqs(void); 225 226 /** 227 * struct irq_affinity_notify - context for notification of IRQ affinity changes 228 * @irq: Interrupt to which notification applies 229 * @kref: Reference count, for internal use 230 * @work: Work item, for internal use 231 * @notify: Function to be called on change. This will be 232 * called in process context. 233 * @release: Function to be called on release. This will be 234 * called in process context. Once registered, the 235 * structure must only be freed when this function is 236 * called or later. 237 */ 238 struct irq_affinity_notify { 239 unsigned int irq; 240 struct kref kref; 241 struct work_struct work; 242 void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask); 243 void (*release)(struct kref *ref); 244 }; 245 246 /** 247 * struct irq_affinity - Description for automatic irq affinity assignements 248 * @pre_vectors: Don't apply affinity to @pre_vectors at beginning of 249 * the MSI(-X) vector space 250 * @post_vectors: Don't apply affinity to @post_vectors at end of 251 * the MSI(-X) vector space 252 */ 253 struct irq_affinity { 254 int pre_vectors; 255 int post_vectors; 256 }; 257 258 #if defined(CONFIG_SMP) 259 260 extern cpumask_var_t irq_default_affinity; 261 262 /* Internal implementation. Use the helpers below */ 263 extern int __irq_set_affinity(unsigned int irq, const struct cpumask *cpumask, 264 bool force); 265 266 /** 267 * irq_set_affinity - Set the irq affinity of a given irq 268 * @irq: Interrupt to set affinity 269 * @cpumask: cpumask 270 * 271 * Fails if cpumask does not contain an online CPU 272 */ 273 static inline int 274 irq_set_affinity(unsigned int irq, const struct cpumask *cpumask) 275 { 276 return __irq_set_affinity(irq, cpumask, false); 277 } 278 279 /** 280 * irq_force_affinity - Force the irq affinity of a given irq 281 * @irq: Interrupt to set affinity 282 * @cpumask: cpumask 283 * 284 * Same as irq_set_affinity, but without checking the mask against 285 * online cpus. 286 * 287 * Solely for low level cpu hotplug code, where we need to make per 288 * cpu interrupts affine before the cpu becomes online. 289 */ 290 static inline int 291 irq_force_affinity(unsigned int irq, const struct cpumask *cpumask) 292 { 293 return __irq_set_affinity(irq, cpumask, true); 294 } 295 296 extern int irq_can_set_affinity(unsigned int irq); 297 extern int irq_select_affinity(unsigned int irq); 298 299 extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m); 300 301 extern int 302 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify); 303 304 struct cpumask *irq_create_affinity_masks(int nvec, const struct irq_affinity *affd); 305 int irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity *affd); 306 307 #else /* CONFIG_SMP */ 308 309 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m) 310 { 311 return -EINVAL; 312 } 313 314 static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask) 315 { 316 return 0; 317 } 318 319 static inline int irq_can_set_affinity(unsigned int irq) 320 { 321 return 0; 322 } 323 324 static inline int irq_select_affinity(unsigned int irq) { return 0; } 325 326 static inline int irq_set_affinity_hint(unsigned int irq, 327 const struct cpumask *m) 328 { 329 return -EINVAL; 330 } 331 332 static inline int 333 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify) 334 { 335 return 0; 336 } 337 338 static inline struct cpumask * 339 irq_create_affinity_masks(int nvec, const struct irq_affinity *affd) 340 { 341 return NULL; 342 } 343 344 static inline int 345 irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity *affd) 346 { 347 return maxvec; 348 } 349 350 #endif /* CONFIG_SMP */ 351 352 /* 353 * Special lockdep variants of irq disabling/enabling. 354 * These should be used for locking constructs that 355 * know that a particular irq context which is disabled, 356 * and which is the only irq-context user of a lock, 357 * that it's safe to take the lock in the irq-disabled 358 * section without disabling hardirqs. 359 * 360 * On !CONFIG_LOCKDEP they are equivalent to the normal 361 * irq disable/enable methods. 362 */ 363 static inline void disable_irq_nosync_lockdep(unsigned int irq) 364 { 365 disable_irq_nosync(irq); 366 #ifdef CONFIG_LOCKDEP 367 local_irq_disable(); 368 #endif 369 } 370 371 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags) 372 { 373 disable_irq_nosync(irq); 374 #ifdef CONFIG_LOCKDEP 375 local_irq_save(*flags); 376 #endif 377 } 378 379 static inline void disable_irq_lockdep(unsigned int irq) 380 { 381 disable_irq(irq); 382 #ifdef CONFIG_LOCKDEP 383 local_irq_disable(); 384 #endif 385 } 386 387 static inline void enable_irq_lockdep(unsigned int irq) 388 { 389 #ifdef CONFIG_LOCKDEP 390 local_irq_enable(); 391 #endif 392 enable_irq(irq); 393 } 394 395 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags) 396 { 397 #ifdef CONFIG_LOCKDEP 398 local_irq_restore(*flags); 399 #endif 400 enable_irq(irq); 401 } 402 403 /* IRQ wakeup (PM) control: */ 404 extern int irq_set_irq_wake(unsigned int irq, unsigned int on); 405 406 static inline int enable_irq_wake(unsigned int irq) 407 { 408 return irq_set_irq_wake(irq, 1); 409 } 410 411 static inline int disable_irq_wake(unsigned int irq) 412 { 413 return irq_set_irq_wake(irq, 0); 414 } 415 416 /* 417 * irq_get_irqchip_state/irq_set_irqchip_state specific flags 418 */ 419 enum irqchip_irq_state { 420 IRQCHIP_STATE_PENDING, /* Is interrupt pending? */ 421 IRQCHIP_STATE_ACTIVE, /* Is interrupt in progress? */ 422 IRQCHIP_STATE_MASKED, /* Is interrupt masked? */ 423 IRQCHIP_STATE_LINE_LEVEL, /* Is IRQ line high? */ 424 }; 425 426 extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which, 427 bool *state); 428 extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which, 429 bool state); 430 431 #ifdef CONFIG_IRQ_FORCED_THREADING 432 extern bool force_irqthreads; 433 #else 434 #define force_irqthreads (0) 435 #endif 436 437 #ifndef __ARCH_SET_SOFTIRQ_PENDING 438 #define set_softirq_pending(x) (local_softirq_pending() = (x)) 439 #define or_softirq_pending(x) (local_softirq_pending() |= (x)) 440 #endif 441 442 /* Some architectures might implement lazy enabling/disabling of 443 * interrupts. In some cases, such as stop_machine, we might want 444 * to ensure that after a local_irq_disable(), interrupts have 445 * really been disabled in hardware. Such architectures need to 446 * implement the following hook. 447 */ 448 #ifndef hard_irq_disable 449 #define hard_irq_disable() do { } while(0) 450 #endif 451 452 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high 453 frequency threaded job scheduling. For almost all the purposes 454 tasklets are more than enough. F.e. all serial device BHs et 455 al. should be converted to tasklets, not to softirqs. 456 */ 457 458 enum 459 { 460 HI_SOFTIRQ=0, 461 TIMER_SOFTIRQ, 462 NET_TX_SOFTIRQ, 463 NET_RX_SOFTIRQ, 464 BLOCK_SOFTIRQ, 465 IRQ_POLL_SOFTIRQ, 466 TASKLET_SOFTIRQ, 467 SCHED_SOFTIRQ, 468 HRTIMER_SOFTIRQ, /* Unused, but kept as tools rely on the 469 numbering. Sigh! */ 470 RCU_SOFTIRQ, /* Preferable RCU should always be the last softirq */ 471 472 NR_SOFTIRQS 473 }; 474 475 #define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ)) 476 477 /* map softirq index to softirq name. update 'softirq_to_name' in 478 * kernel/softirq.c when adding a new softirq. 479 */ 480 extern const char * const softirq_to_name[NR_SOFTIRQS]; 481 482 /* softirq mask and active fields moved to irq_cpustat_t in 483 * asm/hardirq.h to get better cache usage. KAO 484 */ 485 486 struct softirq_action 487 { 488 void (*action)(struct softirq_action *); 489 }; 490 491 asmlinkage void do_softirq(void); 492 asmlinkage void __do_softirq(void); 493 494 #ifdef __ARCH_HAS_DO_SOFTIRQ 495 void do_softirq_own_stack(void); 496 #else 497 static inline void do_softirq_own_stack(void) 498 { 499 __do_softirq(); 500 } 501 #endif 502 503 extern void open_softirq(int nr, void (*action)(struct softirq_action *)); 504 extern void softirq_init(void); 505 extern void __raise_softirq_irqoff(unsigned int nr); 506 507 extern void raise_softirq_irqoff(unsigned int nr); 508 extern void raise_softirq(unsigned int nr); 509 510 DECLARE_PER_CPU(struct task_struct *, ksoftirqd); 511 512 static inline struct task_struct *this_cpu_ksoftirqd(void) 513 { 514 return this_cpu_read(ksoftirqd); 515 } 516 517 /* Tasklets --- multithreaded analogue of BHs. 518 519 Main feature differing them of generic softirqs: tasklet 520 is running only on one CPU simultaneously. 521 522 Main feature differing them of BHs: different tasklets 523 may be run simultaneously on different CPUs. 524 525 Properties: 526 * If tasklet_schedule() is called, then tasklet is guaranteed 527 to be executed on some cpu at least once after this. 528 * If the tasklet is already scheduled, but its execution is still not 529 started, it will be executed only once. 530 * If this tasklet is already running on another CPU (or schedule is called 531 from tasklet itself), it is rescheduled for later. 532 * Tasklet is strictly serialized wrt itself, but not 533 wrt another tasklets. If client needs some intertask synchronization, 534 he makes it with spinlocks. 535 */ 536 537 struct tasklet_struct 538 { 539 struct tasklet_struct *next; 540 unsigned long state; 541 atomic_t count; 542 void (*func)(unsigned long); 543 unsigned long data; 544 }; 545 546 #define DECLARE_TASKLET(name, func, data) \ 547 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data } 548 549 #define DECLARE_TASKLET_DISABLED(name, func, data) \ 550 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data } 551 552 553 enum 554 { 555 TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */ 556 TASKLET_STATE_RUN /* Tasklet is running (SMP only) */ 557 }; 558 559 #ifdef CONFIG_SMP 560 static inline int tasklet_trylock(struct tasklet_struct *t) 561 { 562 return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state); 563 } 564 565 static inline void tasklet_unlock(struct tasklet_struct *t) 566 { 567 smp_mb__before_atomic(); 568 clear_bit(TASKLET_STATE_RUN, &(t)->state); 569 } 570 571 static inline void tasklet_unlock_wait(struct tasklet_struct *t) 572 { 573 while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); } 574 } 575 #else 576 #define tasklet_trylock(t) 1 577 #define tasklet_unlock_wait(t) do { } while (0) 578 #define tasklet_unlock(t) do { } while (0) 579 #endif 580 581 extern void __tasklet_schedule(struct tasklet_struct *t); 582 583 static inline void tasklet_schedule(struct tasklet_struct *t) 584 { 585 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) 586 __tasklet_schedule(t); 587 } 588 589 extern void __tasklet_hi_schedule(struct tasklet_struct *t); 590 591 static inline void tasklet_hi_schedule(struct tasklet_struct *t) 592 { 593 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state)) 594 __tasklet_hi_schedule(t); 595 } 596 597 static inline void tasklet_disable_nosync(struct tasklet_struct *t) 598 { 599 atomic_inc(&t->count); 600 smp_mb__after_atomic(); 601 } 602 603 static inline void tasklet_disable(struct tasklet_struct *t) 604 { 605 tasklet_disable_nosync(t); 606 tasklet_unlock_wait(t); 607 smp_mb(); 608 } 609 610 static inline void tasklet_enable(struct tasklet_struct *t) 611 { 612 smp_mb__before_atomic(); 613 atomic_dec(&t->count); 614 } 615 616 extern void tasklet_kill(struct tasklet_struct *t); 617 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu); 618 extern void tasklet_init(struct tasklet_struct *t, 619 void (*func)(unsigned long), unsigned long data); 620 621 struct tasklet_hrtimer { 622 struct hrtimer timer; 623 struct tasklet_struct tasklet; 624 enum hrtimer_restart (*function)(struct hrtimer *); 625 }; 626 627 extern void 628 tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer, 629 enum hrtimer_restart (*function)(struct hrtimer *), 630 clockid_t which_clock, enum hrtimer_mode mode); 631 632 static inline 633 void tasklet_hrtimer_start(struct tasklet_hrtimer *ttimer, ktime_t time, 634 const enum hrtimer_mode mode) 635 { 636 hrtimer_start(&ttimer->timer, time, mode); 637 } 638 639 static inline 640 void tasklet_hrtimer_cancel(struct tasklet_hrtimer *ttimer) 641 { 642 hrtimer_cancel(&ttimer->timer); 643 tasklet_kill(&ttimer->tasklet); 644 } 645 646 /* 647 * Autoprobing for irqs: 648 * 649 * probe_irq_on() and probe_irq_off() provide robust primitives 650 * for accurate IRQ probing during kernel initialization. They are 651 * reasonably simple to use, are not "fooled" by spurious interrupts, 652 * and, unlike other attempts at IRQ probing, they do not get hung on 653 * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards). 654 * 655 * For reasonably foolproof probing, use them as follows: 656 * 657 * 1. clear and/or mask the device's internal interrupt. 658 * 2. sti(); 659 * 3. irqs = probe_irq_on(); // "take over" all unassigned idle IRQs 660 * 4. enable the device and cause it to trigger an interrupt. 661 * 5. wait for the device to interrupt, using non-intrusive polling or a delay. 662 * 6. irq = probe_irq_off(irqs); // get IRQ number, 0=none, negative=multiple 663 * 7. service the device to clear its pending interrupt. 664 * 8. loop again if paranoia is required. 665 * 666 * probe_irq_on() returns a mask of allocated irq's. 667 * 668 * probe_irq_off() takes the mask as a parameter, 669 * and returns the irq number which occurred, 670 * or zero if none occurred, or a negative irq number 671 * if more than one irq occurred. 672 */ 673 674 #if !defined(CONFIG_GENERIC_IRQ_PROBE) 675 static inline unsigned long probe_irq_on(void) 676 { 677 return 0; 678 } 679 static inline int probe_irq_off(unsigned long val) 680 { 681 return 0; 682 } 683 static inline unsigned int probe_irq_mask(unsigned long val) 684 { 685 return 0; 686 } 687 #else 688 extern unsigned long probe_irq_on(void); /* returns 0 on failure */ 689 extern int probe_irq_off(unsigned long); /* returns 0 or negative on failure */ 690 extern unsigned int probe_irq_mask(unsigned long); /* returns mask of ISA interrupts */ 691 #endif 692 693 #ifdef CONFIG_PROC_FS 694 /* Initialize /proc/irq/ */ 695 extern void init_irq_proc(void); 696 #else 697 static inline void init_irq_proc(void) 698 { 699 } 700 #endif 701 702 #ifdef CONFIG_IRQ_TIMINGS 703 void irq_timings_enable(void); 704 void irq_timings_disable(void); 705 u64 irq_timings_next_event(u64 now); 706 #endif 707 708 struct seq_file; 709 int show_interrupts(struct seq_file *p, void *v); 710 int arch_show_interrupts(struct seq_file *p, int prec); 711 712 extern int early_irq_init(void); 713 extern int arch_probe_nr_irqs(void); 714 extern int arch_early_irq_init(void); 715 716 /* 717 * We want to know which function is an entrypoint of a hardirq or a softirq. 718 */ 719 #define __irq_entry __attribute__((__section__(".irqentry.text"))) 720 #define __softirq_entry \ 721 __attribute__((__section__(".softirqentry.text"))) 722 723 #endif 724
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.