include/linux/interrupt.h

   1 /* interrupt.h */
   2 #ifndef _LINUX_INTERRUPT_H
   3 #define _LINUX_INTERRUPT_H
   4
   5 #include <linux/kernel.h>
   6 #include <linux/linkage.h>
   7 #include <linux/bitops.h>
   8 #include <linux/preempt.h>
   9 #include <linux/cpumask.h>
  10 #include <linux/irqreturn.h>
  11 #include <linux/irqnr.h>
  12 #include <linux/hardirq.h>
  13 #include <linux/irqflags.h>
  14 #include <linux/smp.h>
  15 #include <linux/percpu.h>
  16 #include <linux/hrtimer.h>
  17
  18 #include <asm/atomic.h>
  19 #include <asm/ptrace.h>
  20 #include <asm/system.h>
  21 #include <trace/events/irq.h>
  22
  23 /*
  24  * These correspond to the IORESOURCE_IRQ_* defines in
  25  * linux/ioport.h to select the interrupt line behaviour.  When
  26  * requesting an interrupt without specifying a IRQF_TRIGGER, the
  27  * setting should be assumed to be "as already configured", which
  28  * may be as per machine or firmware initialisation.
  29  */
  30 #define IRQF_TRIGGER_NONE       0x00000000
  31 #define IRQF_TRIGGER_RISING     0x00000001
  32 #define IRQF_TRIGGER_FALLING    0x00000002
  33 #define IRQF_TRIGGER_HIGH       0x00000004
  34 #define IRQF_TRIGGER_LOW        0x00000008
  35 #define IRQF_TRIGGER_MASK       (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
  36                                  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
  37 #define IRQF_TRIGGER_PROBE      0x00000010
  38
  39 /*
  40  * These flags used only by the kernel as part of the
  41  * irq handling routines.
  42  *
  43  * IRQF_DISABLED - keep irqs disabled when calling the action handler.
  44  *                 DEPRECATED. This flag is a NOOP and scheduled to be removed
  45  * IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
  46  * IRQF_SHARED - allow sharing the irq among several devices
  47  * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
  48  * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
  49  * IRQF_PERCPU - Interrupt is per cpu
  50  * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
  51  * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
  52  *                registered first in an shared interrupt is considered for
  53  *                performance reasons)
  54  * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished.
  55  *                Used by threaded interrupts which need to keep the
  56  *                irq line disabled until the threaded handler has been run.
  57  * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend
  58  *
  59  */
  60 #define IRQF_DISABLED           0x00000020
  61 #define IRQF_SAMPLE_RANDOM      0x00000040
  62 #define IRQF_SHARED             0x00000080
  63 #define IRQF_PROBE_SHARED       0x00000100
  64 #define __IRQF_TIMER            0x00000200
  65 #define IRQF_PERCPU             0x00000400
  66 #define IRQF_NOBALANCING        0x00000800
  67 #define IRQF_IRQPOLL            0x00001000
  68 #define IRQF_ONESHOT            0x00002000
  69 #define IRQF_NO_SUSPEND         0x00004000
  70
  71 #define IRQF_TIMER              (__IRQF_TIMER | IRQF_NO_SUSPEND)
  72
  73 /*
  74  * Bits used by threaded handlers:
  75  * IRQTF_RUNTHREAD - signals that the interrupt handler thread should run
  76  * IRQTF_DIED      - handler thread died
  77  * IRQTF_WARNED    - warning "IRQ_WAKE_THREAD w/o thread_fn" has been printed
  78  * IRQTF_AFFINITY  - irq thread is requested to adjust affinity
  79  */
  80 enum {
  81         IRQTF_RUNTHREAD,
  82         IRQTF_DIED,
  83         IRQTF_WARNED,
  84         IRQTF_AFFINITY,
  85 };
  86
  87 /*
  88  * These values can be returned by request_any_context_irq() and
  89  * describe the context the interrupt will be run in.
  90  *
  91  * IRQC_IS_HARDIRQ - interrupt runs in hardirq context
  92  * IRQC_IS_NESTED - interrupt runs in a nested threaded context
  93  */
  94 enum {
  95         IRQC_IS_HARDIRQ = 0,
  96         IRQC_IS_NESTED,
  97 };
  98
  99 typedef irqreturn_t (*irq_handler_t)(int, void *);
 100
 101 /**
 102  * struct irqaction - per interrupt action descriptor
 103  * @handler:    interrupt handler function
 104  * @flags:      flags (see IRQF_* above)
 105  * @name:       name of the device
 106  * @dev_id:     cookie to identify the device
 107  * @next:       pointer to the next irqaction for shared interrupts
 108  * @irq:        interrupt number
 109  * @dir:        pointer to the proc/irq/NN/name entry
 110  * @thread_fn:  interupt handler function for threaded interrupts
 111  * @thread:     thread pointer for threaded interrupts
 112  * @thread_flags:       flags related to @thread
 113  */
 114 struct irqaction {
 115         irq_handler_t handler;
 116         unsigned long flags;
 117         const char *name;
 118         void *dev_id;
 119         struct irqaction *next;
 120         int irq;
 121         struct proc_dir_entry *dir;
 122         irq_handler_t thread_fn;
 123         struct task_struct *thread;
 124         unsigned long thread_flags;
 125 };
 126
 127 extern irqreturn_t no_action(int cpl, void *dev_id);
 128
 129 #ifdef CONFIG_GENERIC_HARDIRQS
 130 extern int __must_check
 131 request_threaded_irq(unsigned int irq, irq_handler_t handler,
 132                      irq_handler_t thread_fn,
 133                      unsigned long flags, const char *name, void *dev);
 134
 135 static inline int __must_check
 136 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
 137             const char *name, void *dev)
 138 {
 139         return request_threaded_irq(irq, handler, NULL, flags, name, dev);
 140 }
 141
 142 extern int __must_check
 143 request_any_context_irq(unsigned int irq, irq_handler_t handler,
 144                         unsigned long flags, const char *name, void *dev_id);
 145
 146 extern void exit_irq_thread(void);
 147 #else
 148
 149 extern int __must_check
 150 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
 151             const char *name, void *dev);
 152
 153 /*
 154  * Special function to avoid ifdeffery in kernel/irq/devres.c which
 155  * gets magically built by GENERIC_HARDIRQS=n architectures (sparc,
 156  * m68k). I really love these $@%#!* obvious Makefile references:
 157  * ../../../kernel/irq/devres.o
 158  */
 159 static inline int __must_check
 160 request_threaded_irq(unsigned int irq, irq_handler_t handler,
 161                      irq_handler_t thread_fn,
 162                      unsigned long flags, const char *name, void *dev)
 163 {
 164         return request_irq(irq, handler, flags, name, dev);
 165 }
 166
 167 static inline int __must_check
 168 request_any_context_irq(unsigned int irq, irq_handler_t handler,
 169                         unsigned long flags, const char *name, void *dev_id)
 170 {
 171         return request_irq(irq, handler, flags, name, dev_id);
 172 }
 173
 174 static inline void exit_irq_thread(void) { }
 175 #endif
 176
 177 extern void free_irq(unsigned int, void *);
 178
 179 struct device;
 180
 181 extern int __must_check
 182 devm_request_threaded_irq(struct device *dev, unsigned int irq,
 183                           irq_handler_t handler, irq_handler_t thread_fn,
 184                           unsigned long irqflags, const char *devname,
 185                           void *dev_id);
 186
 187 static inline int __must_check
 188 devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
 189                  unsigned long irqflags, const char *devname, void *dev_id)
 190 {
 191         return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
 192                                          devname, dev_id);
 193 }
 194
 195 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
 196
 197 /*
 198  * On lockdep we dont want to enable hardirqs in hardirq
 199  * context. Use local_irq_enable_in_hardirq() to annotate
 200  * kernel code that has to do this nevertheless (pretty much
 201  * the only valid case is for old/broken hardware that is
 202  * insanely slow).
 203  *
 204  * NOTE: in theory this might break fragile code that relies
 205  * on hardirq delivery - in practice we dont seem to have such
 206  * places left. So the only effect should be slightly increased
 207  * irqs-off latencies.
 208  */
 209 #ifdef CONFIG_LOCKDEP
 210 # define local_irq_enable_in_hardirq()  do { } while (0)
 211 #else
 212 # define local_irq_enable_in_hardirq()  local_irq_enable()
 213 #endif
 214
 215 extern void disable_irq_nosync(unsigned int irq);
 216 extern void disable_irq(unsigned int irq);
 217 extern void enable_irq(unsigned int irq);
 218
 219 /* The following three functions are for the core kernel use only. */
 220 #ifdef CONFIG_GENERIC_HARDIRQS
 221 extern void suspend_device_irqs(void);
 222 extern void resume_device_irqs(void);
 223 #ifdef CONFIG_PM_SLEEP
 224 extern int check_wakeup_irqs(void);
 225 #else
 226 static inline int check_wakeup_irqs(void) { return 0; }
 227 #endif
 228 #else
 229 static inline void suspend_device_irqs(void) { };
 230 static inline void resume_device_irqs(void) { };
 231 static inline int check_wakeup_irqs(void) { return 0; }
 232 #endif
 233
 234 #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
 235
 236 extern cpumask_var_t irq_default_affinity;
 237
 238 extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask);
 239 extern int irq_can_set_affinity(unsigned int irq);
 240 extern int irq_select_affinity(unsigned int irq);
 241
 242 extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
 243 #else /* CONFIG_SMP */
 244
 245 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
 246 {
 247         return -EINVAL;
 248 }
 249
 250 static inline int irq_can_set_affinity(unsigned int irq)
 251 {
 252         return 0;
 253 }
 254
 255 static inline int irq_select_affinity(unsigned int irq)  { return 0; }
 256
 257 static inline int irq_set_affinity_hint(unsigned int irq,
 258                                         const struct cpumask *m)
 259 {
 260         return -EINVAL;
 261 }
 262 #endif /* CONFIG_SMP && CONFIG_GENERIC_HARDIRQS */
 263
 264 #ifdef CONFIG_GENERIC_HARDIRQS
 265 /*
 266  * Special lockdep variants of irq disabling/enabling.
 267  * These should be used for locking constructs that
 268  * know that a particular irq context which is disabled,
 269  * and which is the only irq-context user of a lock,
 270  * that it's safe to take the lock in the irq-disabled
 271  * section without disabling hardirqs.
 272  *
 273  * On !CONFIG_LOCKDEP they are equivalent to the normal
 274  * irq disable/enable methods.
 275  */
 276 static inline void disable_irq_nosync_lockdep(unsigned int irq)
 277 {
 278         disable_irq_nosync(irq);
 279 #ifdef CONFIG_LOCKDEP
 280         local_irq_disable();
 281 #endif
 282 }
 283
 284 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 285 {
 286         disable_irq_nosync(irq);
 287 #ifdef CONFIG_LOCKDEP
 288         local_irq_save(*flags);
 289 #endif
 290 }
 291
 292 static inline void disable_irq_lockdep(unsigned int irq)
 293 {
 294         disable_irq(irq);
 295 #ifdef CONFIG_LOCKDEP
 296         local_irq_disable();
 297 #endif
 298 }
 299
 300 static inline void enable_irq_lockdep(unsigned int irq)
 301 {
 302 #ifdef CONFIG_LOCKDEP
 303         local_irq_enable();
 304 #endif
 305         enable_irq(irq);
 306 }
 307
 308 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 309 {
 310 #ifdef CONFIG_LOCKDEP
 311         local_irq_restore(*flags);
 312 #endif
 313         enable_irq(irq);
 314 }
 315
 316 /* IRQ wakeup (PM) control: */
 317 extern int set_irq_wake(unsigned int irq, unsigned int on);
 318
 319 static inline int enable_irq_wake(unsigned int irq)
 320 {
 321         return set_irq_wake(irq, 1);
 322 }
 323
 324 static inline int disable_irq_wake(unsigned int irq)
 325 {
 326         return set_irq_wake(irq, 0);
 327 }
 328
 329 #else /* !CONFIG_GENERIC_HARDIRQS */
 330 /*
 331  * NOTE: non-genirq architectures, if they want to support the lock
 332  * validator need to define the methods below in their asm/irq.h
 333  * files, under an #ifdef CONFIG_LOCKDEP section.
 334  */
 335 #ifndef CONFIG_LOCKDEP
 336 #  define disable_irq_nosync_lockdep(irq)       disable_irq_nosync(irq)
 337 #  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
 338                                                 disable_irq_nosync(irq)
 339 #  define disable_irq_lockdep(irq)              disable_irq(irq)
 340 #  define enable_irq_lockdep(irq)               enable_irq(irq)
 341 #  define enable_irq_lockdep_irqrestore(irq, flags) \
 342                                                 enable_irq(irq)
 343 # endif
 344
 345 static inline int enable_irq_wake(unsigned int irq)
 346 {
 347         return 0;
 348 }
 349
 350 static inline int disable_irq_wake(unsigned int irq)
 351 {
 352         return 0;
 353 }
 354 #endif /* CONFIG_GENERIC_HARDIRQS */
 355
 356 #ifndef __ARCH_SET_SOFTIRQ_PENDING
 357 #define set_softirq_pending(x) (local_softirq_pending() = (x))
 358 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 359 #endif
 360
 361 /* Some architectures might implement lazy enabling/disabling of
 362  * interrupts. In some cases, such as stop_machine, we might want
 363  * to ensure that after a local_irq_disable(), interrupts have
 364  * really been disabled in hardware. Such architectures need to
 365  * implement the following hook.
 366  */
 367 #ifndef hard_irq_disable
 368 #define hard_irq_disable()      do { } while(0)
 369 #endif
 370
 371 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 372    frequency threaded job scheduling. For almost all the purposes
 373    tasklets are more than enough. F.e. all serial device BHs et
 374    al. should be converted to tasklets, not to softirqs.
 375  */
 376
 377 enum
 378 {
 379         HI_SOFTIRQ=0,
 380         TIMER_SOFTIRQ,
 381         NET_TX_SOFTIRQ,
 382         NET_RX_SOFTIRQ,
 383         BLOCK_SOFTIRQ,
 384         BLOCK_IOPOLL_SOFTIRQ,
 385         TASKLET_SOFTIRQ,
 386         SCHED_SOFTIRQ,
 387         HRTIMER_SOFTIRQ,
 388         RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
 389
 390         NR_SOFTIRQS
 391 };
 392
 393 /* map softirq index to softirq name. update 'softirq_to_name' in
 394  * kernel/softirq.c when adding a new softirq.
 395  */
 396 extern char *softirq_to_name[NR_SOFTIRQS];
 397
 398 /* softirq mask and active fields moved to irq_cpustat_t in
 399  * asm/hardirq.h to get better cache usage.  KAO
 400  */
 401
 402 struct softirq_action
 403 {
 404         void    (*action)(struct softirq_action *);
 405 };
 406
 407 asmlinkage void do_softirq(void);
 408 asmlinkage void __do_softirq(void);
 409 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
 410 extern void softirq_init(void);
 411 static inline void __raise_softirq_irqoff(unsigned int nr)
 412 {
 413         trace_softirq_raise(nr);
 414         or_softirq_pending(1UL << nr);
 415 }
 416
 417 extern void raise_softirq_irqoff(unsigned int nr);
 418 extern void raise_softirq(unsigned int nr);
 419
 420 /* This is the worklist that queues up per-cpu softirq work.
 421  *
 422  * send_remote_sendirq() adds work to these lists, and
 423  * the softirq handler itself dequeues from them.  The queues
 424  * are protected by disabling local cpu interrupts and they must
 425  * only be accessed by the local cpu that they are for.
 426  */
 427 DECLARE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
 428
 429 /* Try to send a softirq to a remote cpu.  If this cannot be done, the
 430  * work will be queued to the local cpu.
 431  */
 432 extern void send_remote_softirq(struct call_single_data *cp, int cpu, int softirq);
 433
 434 /* Like send_remote_softirq(), but the caller must disable local cpu interrupts
 435  * and compute the current cpu, passed in as 'this_cpu'.
 436  */
 437 extern void __send_remote_softirq(struct call_single_data *cp, int cpu,
 438                                   int this_cpu, int softirq);
 439
 440 /* Tasklets --- multithreaded analogue of BHs.
 441
 442    Main feature differing them of generic softirqs: tasklet
 443    is running only on one CPU simultaneously.
 444
 445    Main feature differing them of BHs: different tasklets
 446    may be run simultaneously on different CPUs.
 447
 448    Properties:
 449    * If tasklet_schedule() is called, then tasklet is guaranteed
 450      to be executed on some cpu at least once after this.
 451    * If the tasklet is already scheduled, but its excecution is still not
 452      started, it will be executed only once.
 453    * If this tasklet is already running on another CPU (or schedule is called
 454      from tasklet itself), it is rescheduled for later.
 455    * Tasklet is strictly serialized wrt itself, but not
 456      wrt another tasklets. If client needs some intertask synchronization,
 457      he makes it with spinlocks.
 458  */
 459
 460 struct tasklet_struct
 461 {
 462         struct tasklet_struct *next;
 463         unsigned long state;
 464         atomic_t count;
 465         void (*func)(unsigned long);
 466         unsigned long data;
 467 };
 468
 469 #define DECLARE_TASKLET(name, func, data) \
 470 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 471
 472 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 473 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 474
 475
 476 enum
 477 {
 478         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 479         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 480 };
 481
 482 #ifdef CONFIG_SMP
 483 static inline int tasklet_trylock(struct tasklet_struct *t)
 484 {
 485         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 486 }
 487
 488 static inline void tasklet_unlock(struct tasklet_struct *t)
 489 {
 490         smp_mb__before_clear_bit();
 491         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 492 }
 493
 494 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 495 {
 496         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 497 }
 498 #else
 499 #define tasklet_trylock(t) 1
 500 #define tasklet_unlock_wait(t) do { } while (0)
 501 #define tasklet_unlock(t) do { } while (0)
 502 #endif
 503
 504 extern void __tasklet_schedule(struct tasklet_struct *t);
 505
 506 static inline void tasklet_schedule(struct tasklet_struct *t)
 507 {
 508         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 509                 __tasklet_schedule(t);
 510 }
 511
 512 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
 513
 514 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 515 {
 516         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 517                 __tasklet_hi_schedule(t);
 518 }
 519
 520 extern void __tasklet_hi_schedule_first(struct tasklet_struct *t);
 521
 522 /*
 523  * This version avoids touching any other tasklets. Needed for kmemcheck
 524  * in order not to take any page faults while enqueueing this tasklet;
 525  * consider VERY carefully whether you really need this or
 526  * tasklet_hi_schedule()...
 527  */
 528 static inline void tasklet_hi_schedule_first(struct tasklet_struct *t)
 529 {
 530         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 531                 __tasklet_hi_schedule_first(t);
 532 }
 533
 534
 535 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 536 {
 537         atomic_inc(&t->count);
 538         smp_mb__after_atomic_inc();
 539 }
 540
 541 static inline void tasklet_disable(struct tasklet_struct *t)
 542 {
 543         tasklet_disable_nosync(t);
 544         tasklet_unlock_wait(t);
 545         smp_mb();
 546 }
 547
 548 static inline void tasklet_enable(struct tasklet_struct *t)
 549 {
 550         smp_mb__before_atomic_dec();
 551         atomic_dec(&t->count);
 552 }
 553
 554 static inline void tasklet_hi_enable(struct tasklet_struct *t)
 555 {
 556         smp_mb__before_atomic_dec();
 557         atomic_dec(&t->count);
 558 }
 559
 560 extern void tasklet_kill(struct tasklet_struct *t);
 561 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 562 extern void tasklet_init(struct tasklet_struct *t,
 563                          void (*func)(unsigned long), unsigned long data);
 564
 565 struct tasklet_hrtimer {
 566         struct hrtimer          timer;
 567         struct tasklet_struct   tasklet;
 568         enum hrtimer_restart    (*function)(struct hrtimer *);
 569 };
 570
 571 extern void
 572 tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer,
 573                      enum hrtimer_restart (*function)(struct hrtimer *),
 574                      clockid_t which_clock, enum hrtimer_mode mode);
 575
 576 static inline
 577 int tasklet_hrtimer_start(struct tasklet_hrtimer *ttimer, ktime_t time,
 578                           const enum hrtimer_mode mode)
 579 {
 580         return hrtimer_start(&ttimer->timer, time, mode);
 581 }
 582
 583 static inline
 584 void tasklet_hrtimer_cancel(struct tasklet_hrtimer *ttimer)
 585 {
 586         hrtimer_cancel(&ttimer->timer);
 587         tasklet_kill(&ttimer->tasklet);
 588 }
 589
 590 /*
 591  * Autoprobing for irqs:
 592  *
 593  * probe_irq_on() and probe_irq_off() provide robust primitives
 594  * for accurate IRQ probing during kernel initialization.  They are
 595  * reasonably simple to use, are not "fooled" by spurious interrupts,
 596  * and, unlike other attempts at IRQ probing, they do not get hung on
 597  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 598  *
 599  * For reasonably foolproof probing, use them as follows:
 600  *
 601  * 1. clear and/or mask the device's internal interrupt.
 602  * 2. sti();
 603  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 604  * 4. enable the device and cause it to trigger an interrupt.
 605  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 606  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 607  * 7. service the device to clear its pending interrupt.
 608  * 8. loop again if paranoia is required.
 609  *
 610  * probe_irq_on() returns a mask of allocated irq's.
 611  *
 612  * probe_irq_off() takes the mask as a parameter,
 613  * and returns the irq number which occurred,
 614  * or zero if none occurred, or a negative irq number
 615  * if more than one irq occurred.
 616  */
 617
 618 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 619 static inline unsigned long probe_irq_on(void)
 620 {
 621         return 0;
 622 }
 623 static inline int probe_irq_off(unsigned long val)
 624 {
 625         return 0;
 626 }
 627 static inline unsigned int probe_irq_mask(unsigned long val)
 628 {
 629         return 0;
 630 }
 631 #else
 632 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 633 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 634 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 635 #endif
 636
 637 #ifdef CONFIG_PROC_FS
 638 /* Initialize /proc/irq/ */
 639 extern void init_irq_proc(void);
 640 #else
 641 static inline void init_irq_proc(void)
 642 {
 643 }
 644 #endif
 645
 646 struct seq_file;
 647 int show_interrupts(struct seq_file *p, void *v);
 648
 649 extern int early_irq_init(void);
 650 extern int arch_probe_nr_irqs(void);
 651 extern int arch_early_irq_init(void);
 652
 653 #endif