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