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 #include <linux/kref.h>
  18 #include <linux/workqueue.h>
  19
  20 #include <linux/atomic.h>
  21 #include <asm/ptrace.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_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  * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend
  57  * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set
  58  * IRQF_NO_THREAD - Interrupt cannot be threaded
  59  * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device
  60  *                resume time.
  61  */
  62 #define IRQF_DISABLED           0x00000020
  63 #define IRQF_SHARED             0x00000080
  64 #define IRQF_PROBE_SHARED       0x00000100
  65 #define __IRQF_TIMER            0x00000200
  66 #define IRQF_PERCPU             0x00000400
  67 #define IRQF_NOBALANCING        0x00000800
  68 #define IRQF_IRQPOLL            0x00001000
  69 #define IRQF_ONESHOT            0x00002000
  70 #define IRQF_NO_SUSPEND         0x00004000
  71 #define IRQF_FORCE_RESUME       0x00008000
  72 #define IRQF_NO_THREAD          0x00010000
  73 #define IRQF_EARLY_RESUME       0x00020000
  74
  75 #define IRQF_TIMER              (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
  76
  77 /*
  78  * These values can be returned by request_any_context_irq() and
  79  * describe the context the interrupt will be run in.
  80  *
  81  * IRQC_IS_HARDIRQ - interrupt runs in hardirq context
  82  * IRQC_IS_NESTED - interrupt runs in a nested threaded context
  83  */
  84 enum {
  85         IRQC_IS_HARDIRQ = 0,
  86         IRQC_IS_NESTED,
  87 };
  88
  89 typedef irqreturn_t (*irq_handler_t)(int, void *);
  90
  91 /**
  92  * struct irqaction - per interrupt action descriptor
  93  * @handler:    interrupt handler function
  94  * @name:       name of the device
  95  * @dev_id:     cookie to identify the device
  96  * @percpu_dev_id:      cookie to identify the device
  97  * @next:       pointer to the next irqaction for shared interrupts
  98  * @irq:        interrupt number
  99  * @flags:      flags (see IRQF_* above)
 100  * @thread_fn:  interrupt handler function for threaded interrupts
 101  * @thread:     thread pointer for threaded interrupts
 102  * @thread_flags:       flags related to @thread
 103  * @thread_mask:        bitmask for keeping track of @thread activity
 104  * @dir:        pointer to the proc/irq/NN/name entry
 105  */
 106 struct irqaction {
 107         irq_handler_t           handler;
 108         void                    *dev_id;
 109         void __percpu           *percpu_dev_id;
 110         struct irqaction        *next;
 111         irq_handler_t           thread_fn;
 112         struct task_struct      *thread;
 113         unsigned int            irq;
 114         unsigned int            flags;
 115         unsigned long           thread_flags;
 116         unsigned long           thread_mask;
 117         const char              *name;
 118         struct proc_dir_entry   *dir;
 119 } ____cacheline_internodealigned_in_smp;
 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 int __must_check
 141 request_percpu_irq(unsigned int irq, irq_handler_t handler,
 142                    const char *devname, void __percpu *percpu_dev_id);
 143 #else
 144
 145 extern int __must_check
 146 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
 147             const char *name, void *dev);
 148
 149 /*
 150  * Special function to avoid ifdeffery in kernel/irq/devres.c which
 151  * gets magically built by GENERIC_HARDIRQS=n architectures (sparc,
 152  * m68k). I really love these $@%#!* obvious Makefile references:
 153  * ../../../kernel/irq/devres.o
 154  */
 155 static inline int __must_check
 156 request_threaded_irq(unsigned int irq, irq_handler_t handler,
 157                      irq_handler_t thread_fn,
 158                      unsigned long flags, const char *name, void *dev)
 159 {
 160         return request_irq(irq, handler, flags, name, dev);
 161 }
 162
 163 static inline int __must_check
 164 request_any_context_irq(unsigned int irq, irq_handler_t handler,
 165                         unsigned long flags, const char *name, void *dev_id)
 166 {
 167         return request_irq(irq, handler, flags, name, dev_id);
 168 }
 169
 170 static inline int __must_check
 171 request_percpu_irq(unsigned int irq, irq_handler_t handler,
 172                    const char *devname, void __percpu *percpu_dev_id)
 173 {
 174         return request_irq(irq, handler, 0, devname, percpu_dev_id);
 175 }
 176 #endif
 177
 178 extern void free_irq(unsigned int, void *);
 179 extern void free_percpu_irq(unsigned int, void __percpu *);
 180
 181 struct device;
 182
 183 extern int __must_check
 184 devm_request_threaded_irq(struct device *dev, unsigned int irq,
 185                           irq_handler_t handler, irq_handler_t thread_fn,
 186                           unsigned long irqflags, const char *devname,
 187                           void *dev_id);
 188
 189 static inline int __must_check
 190 devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
 191                  unsigned long irqflags, const char *devname, void *dev_id)
 192 {
 193         return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
 194                                          devname, dev_id);
 195 }
 196
 197 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
 198
 199 /*
 200  * On lockdep we dont want to enable hardirqs in hardirq
 201  * context. Use local_irq_enable_in_hardirq() to annotate
 202  * kernel code that has to do this nevertheless (pretty much
 203  * the only valid case is for old/broken hardware that is
 204  * insanely slow).
 205  *
 206  * NOTE: in theory this might break fragile code that relies
 207  * on hardirq delivery - in practice we dont seem to have such
 208  * places left. So the only effect should be slightly increased
 209  * irqs-off latencies.
 210  */
 211 #ifdef CONFIG_LOCKDEP
 212 # define local_irq_enable_in_hardirq()  do { } while (0)
 213 #else
 214 # define local_irq_enable_in_hardirq()  local_irq_enable()
 215 #endif
 216
 217 extern void disable_irq_nosync(unsigned int irq);
 218 extern void disable_irq(unsigned int irq);
 219 extern void disable_percpu_irq(unsigned int irq);
 220 extern void enable_irq(unsigned int irq);
 221 extern void enable_percpu_irq(unsigned int irq, unsigned int type);
 222
 223 /* The following three functions are for the core kernel use only. */
 224 #ifdef CONFIG_GENERIC_HARDIRQS
 225 extern void suspend_device_irqs(void);
 226 extern void resume_device_irqs(void);
 227 #ifdef CONFIG_PM_SLEEP
 228 extern int check_wakeup_irqs(void);
 229 #else
 230 static inline int check_wakeup_irqs(void) { return 0; }
 231 #endif
 232 #else
 233 static inline void suspend_device_irqs(void) { };
 234 static inline void resume_device_irqs(void) { };
 235 static inline int check_wakeup_irqs(void) { return 0; }
 236 #endif
 237
 238 #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
 239
 240 extern cpumask_var_t irq_default_affinity;
 241
 242 extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask);
 243 extern int irq_can_set_affinity(unsigned int irq);
 244 extern int irq_select_affinity(unsigned int irq);
 245
 246 extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
 247
 248 /**
 249  * struct irq_affinity_notify - context for notification of IRQ affinity changes
 250  * @irq:                Interrupt to which notification applies
 251  * @kref:               Reference count, for internal use
 252  * @work:               Work item, for internal use
 253  * @notify:             Function to be called on change.  This will be
 254  *                      called in process context.
 255  * @release:            Function to be called on release.  This will be
 256  *                      called in process context.  Once registered, the
 257  *                      structure must only be freed when this function is
 258  *                      called or later.
 259  */
 260 struct irq_affinity_notify {
 261         unsigned int irq;
 262         struct kref kref;
 263         struct work_struct work;
 264         void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
 265         void (*release)(struct kref *ref);
 266 };
 267
 268 extern int
 269 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
 270
 271 #else /* CONFIG_SMP */
 272
 273 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
 274 {
 275         return -EINVAL;
 276 }
 277
 278 static inline int irq_can_set_affinity(unsigned int irq)
 279 {
 280         return 0;
 281 }
 282
 283 static inline int irq_select_affinity(unsigned int irq)  { return 0; }
 284
 285 static inline int irq_set_affinity_hint(unsigned int irq,
 286                                         const struct cpumask *m)
 287 {
 288         return -EINVAL;
 289 }
 290 #endif /* CONFIG_SMP && CONFIG_GENERIC_HARDIRQS */
 291
 292 #ifdef CONFIG_GENERIC_HARDIRQS
 293 /*
 294  * Special lockdep variants of irq disabling/enabling.
 295  * These should be used for locking constructs that
 296  * know that a particular irq context which is disabled,
 297  * and which is the only irq-context user of a lock,
 298  * that it's safe to take the lock in the irq-disabled
 299  * section without disabling hardirqs.
 300  *
 301  * On !CONFIG_LOCKDEP they are equivalent to the normal
 302  * irq disable/enable methods.
 303  */
 304 static inline void disable_irq_nosync_lockdep(unsigned int irq)
 305 {
 306         disable_irq_nosync(irq);
 307 #ifdef CONFIG_LOCKDEP
 308         local_irq_disable();
 309 #endif
 310 }
 311
 312 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 313 {
 314         disable_irq_nosync(irq);
 315 #ifdef CONFIG_LOCKDEP
 316         local_irq_save(*flags);
 317 #endif
 318 }
 319
 320 static inline void disable_irq_lockdep(unsigned int irq)
 321 {
 322         disable_irq(irq);
 323 #ifdef CONFIG_LOCKDEP
 324         local_irq_disable();
 325 #endif
 326 }
 327
 328 static inline void enable_irq_lockdep(unsigned int irq)
 329 {
 330 #ifdef CONFIG_LOCKDEP
 331         local_irq_enable();
 332 #endif
 333         enable_irq(irq);
 334 }
 335
 336 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 337 {
 338 #ifdef CONFIG_LOCKDEP
 339         local_irq_restore(*flags);
 340 #endif
 341         enable_irq(irq);
 342 }
 343
 344 /* IRQ wakeup (PM) control: */
 345 extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
 346
 347 static inline int enable_irq_wake(unsigned int irq)
 348 {
 349         return irq_set_irq_wake(irq, 1);
 350 }
 351
 352 static inline int disable_irq_wake(unsigned int irq)
 353 {
 354         return irq_set_irq_wake(irq, 0);
 355 }
 356
 357 #else /* !CONFIG_GENERIC_HARDIRQS */
 358 /*
 359  * NOTE: non-genirq architectures, if they want to support the lock
 360  * validator need to define the methods below in their asm/irq.h
 361  * files, under an #ifdef CONFIG_LOCKDEP section.
 362  */
 363 #ifndef CONFIG_LOCKDEP
 364 #  define disable_irq_nosync_lockdep(irq)       disable_irq_nosync(irq)
 365 #  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
 366                                                 disable_irq_nosync(irq)
 367 #  define disable_irq_lockdep(irq)              disable_irq(irq)
 368 #  define enable_irq_lockdep(irq)               enable_irq(irq)
 369 #  define enable_irq_lockdep_irqrestore(irq, flags) \
 370                                                 enable_irq(irq)
 371 # endif
 372
 373 static inline int enable_irq_wake(unsigned int irq)
 374 {
 375         return 0;
 376 }
 377
 378 static inline int disable_irq_wake(unsigned int irq)
 379 {
 380         return 0;
 381 }
 382 #endif /* CONFIG_GENERIC_HARDIRQS */
 383
 384
 385 #ifdef CONFIG_IRQ_FORCED_THREADING
 386 extern bool force_irqthreads;
 387 #else
 388 #define force_irqthreads        (0)
 389 #endif
 390
 391 #ifndef __ARCH_SET_SOFTIRQ_PENDING
 392 #define set_softirq_pending(x) (local_softirq_pending() = (x))
 393 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 394 #endif
 395
 396 /* Some architectures might implement lazy enabling/disabling of
 397  * interrupts. In some cases, such as stop_machine, we might want
 398  * to ensure that after a local_irq_disable(), interrupts have
 399  * really been disabled in hardware. Such architectures need to
 400  * implement the following hook.
 401  */
 402 #ifndef hard_irq_disable
 403 #define hard_irq_disable()      do { } while(0)
 404 #endif
 405
 406 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 407    frequency threaded job scheduling. For almost all the purposes
 408    tasklets are more than enough. F.e. all serial device BHs et
 409    al. should be converted to tasklets, not to softirqs.
 410  */
 411
 412 enum
 413 {
 414         HI_SOFTIRQ=0,
 415         TIMER_SOFTIRQ,
 416         NET_TX_SOFTIRQ,
 417         NET_RX_SOFTIRQ,
 418         BLOCK_SOFTIRQ,
 419         BLOCK_IOPOLL_SOFTIRQ,
 420         TASKLET_SOFTIRQ,
 421         SCHED_SOFTIRQ,
 422         HRTIMER_SOFTIRQ,
 423         RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
 424
 425         NR_SOFTIRQS
 426 };
 427
 428 #define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
 429
 430 /* map softirq index to softirq name. update 'softirq_to_name' in
 431  * kernel/softirq.c when adding a new softirq.
 432  */
 433 extern char *softirq_to_name[NR_SOFTIRQS];
 434
 435 /* softirq mask and active fields moved to irq_cpustat_t in
 436  * asm/hardirq.h to get better cache usage.  KAO
 437  */
 438
 439 struct softirq_action
 440 {
 441         void    (*action)(struct softirq_action *);
 442 };
 443
 444 asmlinkage void do_softirq(void);
 445 asmlinkage void __do_softirq(void);
 446 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
 447 extern void softirq_init(void);
 448 extern void __raise_softirq_irqoff(unsigned int nr);
 449
 450 extern void raise_softirq_irqoff(unsigned int nr);
 451 extern void raise_softirq(unsigned int nr);
 452
 453 /* This is the worklist that queues up per-cpu softirq work.
 454  *
 455  * send_remote_sendirq() adds work to these lists, and
 456  * the softirq handler itself dequeues from them.  The queues
 457  * are protected by disabling local cpu interrupts and they must
 458  * only be accessed by the local cpu that they are for.
 459  */
 460 DECLARE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
 461
 462 DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
 463
 464 static inline struct task_struct *this_cpu_ksoftirqd(void)
 465 {
 466         return this_cpu_read(ksoftirqd);
 467 }
 468
 469 /* Try to send a softirq to a remote cpu.  If this cannot be done, the
 470  * work will be queued to the local cpu.
 471  */
 472 extern void send_remote_softirq(struct call_single_data *cp, int cpu, int softirq);
 473
 474 /* Like send_remote_softirq(), but the caller must disable local cpu interrupts
 475  * and compute the current cpu, passed in as 'this_cpu'.
 476  */
 477 extern void __send_remote_softirq(struct call_single_data *cp, int cpu,
 478                                   int this_cpu, int softirq);
 479
 480 /* Tasklets --- multithreaded analogue of BHs.
 481
 482    Main feature differing them of generic softirqs: tasklet
 483    is running only on one CPU simultaneously.
 484
 485    Main feature differing them of BHs: different tasklets
 486    may be run simultaneously on different CPUs.
 487
 488    Properties:
 489    * If tasklet_schedule() is called, then tasklet is guaranteed
 490      to be executed on some cpu at least once after this.
 491    * If the tasklet is already scheduled, but its execution is still not
 492      started, it will be executed only once.
 493    * If this tasklet is already running on another CPU (or schedule is called
 494      from tasklet itself), it is rescheduled for later.
 495    * Tasklet is strictly serialized wrt itself, but not
 496      wrt another tasklets. If client needs some intertask synchronization,
 497      he makes it with spinlocks.
 498  */
 499
 500 struct tasklet_struct
 501 {
 502         struct tasklet_struct *next;
 503         unsigned long state;
 504         atomic_t count;
 505         void (*func)(unsigned long);
 506         unsigned long data;
 507 };
 508
 509 #define DECLARE_TASKLET(name, func, data) \
 510 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 511
 512 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 513 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 514
 515
 516 enum
 517 {
 518         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 519         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 520 };
 521
 522 #ifdef CONFIG_SMP
 523 static inline int tasklet_trylock(struct tasklet_struct *t)
 524 {
 525         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 526 }
 527
 528 static inline void tasklet_unlock(struct tasklet_struct *t)
 529 {
 530         smp_mb__before_clear_bit();
 531         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 532 }
 533
 534 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 535 {
 536         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 537 }
 538 #else
 539 #define tasklet_trylock(t) 1
 540 #define tasklet_unlock_wait(t) do { } while (0)
 541 #define tasklet_unlock(t) do { } while (0)
 542 #endif
 543
 544 extern void __tasklet_schedule(struct tasklet_struct *t);
 545
 546 static inline void tasklet_schedule(struct tasklet_struct *t)
 547 {
 548         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 549                 __tasklet_schedule(t);
 550 }
 551
 552 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
 553
 554 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 555 {
 556         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 557                 __tasklet_hi_schedule(t);
 558 }
 559
 560 extern void __tasklet_hi_schedule_first(struct tasklet_struct *t);
 561
 562 /*
 563  * This version avoids touching any other tasklets. Needed for kmemcheck
 564  * in order not to take any page faults while enqueueing this tasklet;
 565  * consider VERY carefully whether you really need this or
 566  * tasklet_hi_schedule()...
 567  */
 568 static inline void tasklet_hi_schedule_first(struct tasklet_struct *t)
 569 {
 570         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 571                 __tasklet_hi_schedule_first(t);
 572 }
 573
 574
 575 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 576 {
 577         atomic_inc(&t->count);
 578         smp_mb__after_atomic_inc();
 579 }
 580
 581 static inline void tasklet_disable(struct tasklet_struct *t)
 582 {
 583         tasklet_disable_nosync(t);
 584         tasklet_unlock_wait(t);
 585         smp_mb();
 586 }
 587
 588 static inline void tasklet_enable(struct tasklet_struct *t)
 589 {
 590         smp_mb__before_atomic_dec();
 591         atomic_dec(&t->count);
 592 }
 593
 594 static inline void tasklet_hi_enable(struct tasklet_struct *t)
 595 {
 596         smp_mb__before_atomic_dec();
 597         atomic_dec(&t->count);
 598 }
 599
 600 extern void tasklet_kill(struct tasklet_struct *t);
 601 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 602 extern void tasklet_init(struct tasklet_struct *t,
 603                          void (*func)(unsigned long), unsigned long data);
 604
 605 struct tasklet_hrtimer {
 606         struct hrtimer          timer;
 607         struct tasklet_struct   tasklet;
 608         enum hrtimer_restart    (*function)(struct hrtimer *);
 609 };
 610
 611 extern void
 612 tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer,
 613                      enum hrtimer_restart (*function)(struct hrtimer *),
 614                      clockid_t which_clock, enum hrtimer_mode mode);
 615
 616 static inline
 617 int tasklet_hrtimer_start(struct tasklet_hrtimer *ttimer, ktime_t time,
 618                           const enum hrtimer_mode mode)
 619 {
 620         return hrtimer_start(&ttimer->timer, time, mode);
 621 }
 622
 623 static inline
 624 void tasklet_hrtimer_cancel(struct tasklet_hrtimer *ttimer)
 625 {
 626         hrtimer_cancel(&ttimer->timer);
 627         tasklet_kill(&ttimer->tasklet);
 628 }
 629
 630 /*
 631  * Autoprobing for irqs:
 632  *
 633  * probe_irq_on() and probe_irq_off() provide robust primitives
 634  * for accurate IRQ probing during kernel initialization.  They are
 635  * reasonably simple to use, are not "fooled" by spurious interrupts,
 636  * and, unlike other attempts at IRQ probing, they do not get hung on
 637  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 638  *
 639  * For reasonably foolproof probing, use them as follows:
 640  *
 641  * 1. clear and/or mask the device's internal interrupt.
 642  * 2. sti();
 643  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 644  * 4. enable the device and cause it to trigger an interrupt.
 645  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 646  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 647  * 7. service the device to clear its pending interrupt.
 648  * 8. loop again if paranoia is required.
 649  *
 650  * probe_irq_on() returns a mask of allocated irq's.
 651  *
 652  * probe_irq_off() takes the mask as a parameter,
 653  * and returns the irq number which occurred,
 654  * or zero if none occurred, or a negative irq number
 655  * if more than one irq occurred.
 656  */
 657
 658 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 659 static inline unsigned long probe_irq_on(void)
 660 {
 661         return 0;
 662 }
 663 static inline int probe_irq_off(unsigned long val)
 664 {
 665         return 0;
 666 }
 667 static inline unsigned int probe_irq_mask(unsigned long val)
 668 {
 669         return 0;
 670 }
 671 #else
 672 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 673 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 674 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 675 #endif
 676
 677 #ifdef CONFIG_PROC_FS
 678 /* Initialize /proc/irq/ */
 679 extern void init_irq_proc(void);
 680 #else
 681 static inline void init_irq_proc(void)
 682 {
 683 }
 684 #endif
 685
 686 struct seq_file;
 687 int show_interrupts(struct seq_file *p, void *v);
 688 int arch_show_interrupts(struct seq_file *p, int prec);
 689
 690 extern int early_irq_init(void);
 691 extern int arch_probe_nr_irqs(void);
 692 extern int arch_early_irq_init(void);
 693
 694 #endif