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 #ifdef CONFIG_MTPROF_IRQ_DURATION
 119         unsigned long long duration;
 120         unsigned long count;
 121         unsigned long long dur_max;
 122         unsigned long long dur_min;
 123 #endif
 124         struct proc_dir_entry   *dir;
 125 } ____cacheline_internodealigned_in_smp;
 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 int __must_check
 147 request_percpu_irq(unsigned int irq, irq_handler_t handler,
 148                    const char *devname, void __percpu *percpu_dev_id);
 149 #else
 150
 151 extern int __must_check
 152 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
 153             const char *name, void *dev);
 154
 155 /*
 156  * Special function to avoid ifdeffery in kernel/irq/devres.c which
 157  * gets magically built by GENERIC_HARDIRQS=n architectures (sparc,
 158  * m68k). I really love these $@%#!* obvious Makefile references:
 159  * ../../../kernel/irq/devres.o
 160  */
 161 static inline int __must_check
 162 request_threaded_irq(unsigned int irq, irq_handler_t handler,
 163                      irq_handler_t thread_fn,
 164                      unsigned long flags, const char *name, void *dev)
 165 {
 166         return request_irq(irq, handler, flags, name, dev);
 167 }
 168
 169 static inline int __must_check
 170 request_any_context_irq(unsigned int irq, irq_handler_t handler,
 171                         unsigned long flags, const char *name, void *dev_id)
 172 {
 173         return request_irq(irq, handler, flags, name, dev_id);
 174 }
 175
 176 static inline int __must_check
 177 request_percpu_irq(unsigned int irq, irq_handler_t handler,
 178                    const char *devname, void __percpu *percpu_dev_id)
 179 {
 180         return request_irq(irq, handler, 0, devname, percpu_dev_id);
 181 }
 182 #endif
 183
 184 extern void free_irq(unsigned int, void *);
 185 extern void free_percpu_irq(unsigned int, void __percpu *);
 186
 187 struct device;
 188
 189 extern int __must_check
 190 devm_request_threaded_irq(struct device *dev, unsigned int irq,
 191                           irq_handler_t handler, irq_handler_t thread_fn,
 192                           unsigned long irqflags, const char *devname,
 193                           void *dev_id);
 194
 195 static inline int __must_check
 196 devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
 197                  unsigned long irqflags, const char *devname, void *dev_id)
 198 {
 199         return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
 200                                          devname, dev_id);
 201 }
 202
 203 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
 204
 205 /*
 206  * On lockdep we dont want to enable hardirqs in hardirq
 207  * context. Use local_irq_enable_in_hardirq() to annotate
 208  * kernel code that has to do this nevertheless (pretty much
 209  * the only valid case is for old/broken hardware that is
 210  * insanely slow).
 211  *
 212  * NOTE: in theory this might break fragile code that relies
 213  * on hardirq delivery - in practice we dont seem to have such
 214  * places left. So the only effect should be slightly increased
 215  * irqs-off latencies.
 216  */
 217 #ifdef CONFIG_LOCKDEP
 218 # define local_irq_enable_in_hardirq()  do { } while (0)
 219 #else
 220 # define local_irq_enable_in_hardirq()  local_irq_enable()
 221 #endif
 222
 223 extern void disable_irq_nosync(unsigned int irq);
 224 extern void disable_irq(unsigned int irq);
 225 extern void disable_percpu_irq(unsigned int irq);
 226 extern void enable_irq(unsigned int irq);
 227 extern void enable_percpu_irq(unsigned int irq, unsigned int type);
 228
 229 /* The following three functions are for the core kernel use only. */
 230 #ifdef CONFIG_GENERIC_HARDIRQS
 231 extern void suspend_device_irqs(void);
 232 extern void resume_device_irqs(void);
 233 #ifdef CONFIG_PM_SLEEP
 234 extern int check_wakeup_irqs(void);
 235 #else
 236 static inline int check_wakeup_irqs(void) { return 0; }
 237 #endif
 238 #else
 239 static inline void suspend_device_irqs(void) { };
 240 static inline void resume_device_irqs(void) { };
 241 static inline int check_wakeup_irqs(void) { return 0; }
 242 #endif
 243
 244 #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
 245
 246 extern cpumask_var_t irq_default_affinity;
 247
 248 /* Internal implementation. Use the helpers below */
 249 extern int __irq_set_affinity(unsigned int irq, const struct cpumask *cpumask,
 250                               bool force);
 251
 252 /**
 253  * irq_set_affinity - Set the irq affinity of a given irq
 254  * @irq:        Interrupt to set affinity
 255  * @mask:       cpumask
 256  *
 257  * Fails if cpumask does not contain an online CPU
 258  */
 259 static inline int
 260 irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
 261 {
 262         return __irq_set_affinity(irq, cpumask, false);
 263 }
 264
 265 /**
 266  * irq_force_affinity - Force the irq affinity of a given irq
 267  * @irq:        Interrupt to set affinity
 268  * @mask:       cpumask
 269  *
 270  * Same as irq_set_affinity, but without checking the mask against
 271  * online cpus.
 272  *
 273  * Solely for low level cpu hotplug code, where we need to make per
 274  * cpu interrupts affine before the cpu becomes online.
 275  */
 276 static inline int
 277 irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
 278 {
 279         return __irq_set_affinity(irq, cpumask, true);
 280 }
 281
 282 extern int irq_can_set_affinity(unsigned int irq);
 283 extern int irq_select_affinity(unsigned int irq);
 284
 285 extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
 286
 287 /**
 288  * struct irq_affinity_notify - context for notification of IRQ affinity changes
 289  * @irq:                Interrupt to which notification applies
 290  * @kref:               Reference count, for internal use
 291  * @work:               Work item, for internal use
 292  * @notify:             Function to be called on change.  This will be
 293  *                      called in process context.
 294  * @release:            Function to be called on release.  This will be
 295  *                      called in process context.  Once registered, the
 296  *                      structure must only be freed when this function is
 297  *                      called or later.
 298  */
 299 struct irq_affinity_notify {
 300         unsigned int irq;
 301         struct kref kref;
 302         struct work_struct work;
 303         void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
 304         void (*release)(struct kref *ref);
 305 };
 306
 307 extern int
 308 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
 309
 310 #else /* CONFIG_SMP */
 311
 312 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
 313 {
 314         return -EINVAL;
 315 }
 316
 317 static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
 318 {
 319         return 0;
 320 }
 321
 322 static inline int irq_can_set_affinity(unsigned int irq)
 323 {
 324         return 0;
 325 }
 326
 327 static inline int irq_select_affinity(unsigned int irq)  { return 0; }
 328
 329 static inline int irq_set_affinity_hint(unsigned int irq,
 330                                         const struct cpumask *m)
 331 {
 332         return -EINVAL;
 333 }
 334 #endif /* CONFIG_SMP && CONFIG_GENERIC_HARDIRQS */
 335
 336 #ifdef CONFIG_GENERIC_HARDIRQS
 337 /*
 338  * Special lockdep variants of irq disabling/enabling.
 339  * These should be used for locking constructs that
 340  * know that a particular irq context which is disabled,
 341  * and which is the only irq-context user of a lock,
 342  * that it's safe to take the lock in the irq-disabled
 343  * section without disabling hardirqs.
 344  *
 345  * On !CONFIG_LOCKDEP they are equivalent to the normal
 346  * irq disable/enable methods.
 347  */
 348 static inline void disable_irq_nosync_lockdep(unsigned int irq)
 349 {
 350         disable_irq_nosync(irq);
 351 #ifdef CONFIG_LOCKDEP
 352         local_irq_disable();
 353 #endif
 354 }
 355
 356 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 357 {
 358         disable_irq_nosync(irq);
 359 #ifdef CONFIG_LOCKDEP
 360         local_irq_save(*flags);
 361 #endif
 362 }
 363
 364 static inline void disable_irq_lockdep(unsigned int irq)
 365 {
 366         disable_irq(irq);
 367 #ifdef CONFIG_LOCKDEP
 368         local_irq_disable();
 369 #endif
 370 }
 371
 372 static inline void enable_irq_lockdep(unsigned int irq)
 373 {
 374 #ifdef CONFIG_LOCKDEP
 375         local_irq_enable();
 376 #endif
 377         enable_irq(irq);
 378 }
 379
 380 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 381 {
 382 #ifdef CONFIG_LOCKDEP
 383         local_irq_restore(*flags);
 384 #endif
 385         enable_irq(irq);
 386 }
 387
 388 /* IRQ wakeup (PM) control: */
 389 extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
 390
 391 static inline int enable_irq_wake(unsigned int irq)
 392 {
 393         return irq_set_irq_wake(irq, 1);
 394 }
 395
 396 static inline int disable_irq_wake(unsigned int irq)
 397 {
 398         return irq_set_irq_wake(irq, 0);
 399 }
 400
 401 #else /* !CONFIG_GENERIC_HARDIRQS */
 402 /*
 403  * NOTE: non-genirq architectures, if they want to support the lock
 404  * validator need to define the methods below in their asm/irq.h
 405  * files, under an #ifdef CONFIG_LOCKDEP section.
 406  */
 407 #ifndef CONFIG_LOCKDEP
 408 #  define disable_irq_nosync_lockdep(irq)       disable_irq_nosync(irq)
 409 #  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
 410                                                 disable_irq_nosync(irq)
 411 #  define disable_irq_lockdep(irq)              disable_irq(irq)
 412 #  define enable_irq_lockdep(irq)               enable_irq(irq)
 413 #  define enable_irq_lockdep_irqrestore(irq, flags) \
 414                                                 enable_irq(irq)
 415 # endif
 416
 417 static inline int enable_irq_wake(unsigned int irq)
 418 {
 419         return 0;
 420 }
 421
 422 static inline int disable_irq_wake(unsigned int irq)
 423 {
 424         return 0;
 425 }
 426 #endif /* CONFIG_GENERIC_HARDIRQS */
 427
 428
 429 #ifdef CONFIG_IRQ_FORCED_THREADING
 430 extern bool force_irqthreads;
 431 #else
 432 #define force_irqthreads        (0)
 433 #endif
 434
 435 #ifndef __ARCH_SET_SOFTIRQ_PENDING
 436 #define set_softirq_pending(x) (local_softirq_pending() = (x))
 437 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 438 #endif
 439
 440 /* Some architectures might implement lazy enabling/disabling of
 441  * interrupts. In some cases, such as stop_machine, we might want
 442  * to ensure that after a local_irq_disable(), interrupts have
 443  * really been disabled in hardware. Such architectures need to
 444  * implement the following hook.
 445  */
 446 #ifndef hard_irq_disable
 447 #define hard_irq_disable()      do { } while(0)
 448 #endif
 449
 450 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 451    frequency threaded job scheduling. For almost all the purposes
 452    tasklets are more than enough. F.e. all serial device BHs et
 453    al. should be converted to tasklets, not to softirqs.
 454  */
 455
 456 enum
 457 {
 458         HI_SOFTIRQ=0,
 459         TIMER_SOFTIRQ,
 460         NET_TX_SOFTIRQ,
 461         NET_RX_SOFTIRQ,
 462         BLOCK_SOFTIRQ,
 463         BLOCK_IOPOLL_SOFTIRQ,
 464         TASKLET_SOFTIRQ,
 465         SCHED_SOFTIRQ,
 466         HRTIMER_SOFTIRQ,
 467         RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
 468
 469         NR_SOFTIRQS
 470 };
 471
 472 #define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
 473
 474 /* map softirq index to softirq name. update 'softirq_to_name' in
 475  * kernel/softirq.c when adding a new softirq.
 476  */
 477 extern char *softirq_to_name[NR_SOFTIRQS];
 478
 479 /* softirq mask and active fields moved to irq_cpustat_t in
 480  * asm/hardirq.h to get better cache usage.  KAO
 481  */
 482
 483 struct softirq_action
 484 {
 485         void    (*action)(struct softirq_action *);
 486 };
 487
 488 asmlinkage void do_softirq(void);
 489 asmlinkage void __do_softirq(void);
 490 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
 491 extern void softirq_init(void);
 492 extern void __raise_softirq_irqoff(unsigned int nr);
 493
 494 extern void raise_softirq_irqoff(unsigned int nr);
 495 extern void raise_softirq(unsigned int nr);
 496
 497 /* This is the worklist that queues up per-cpu softirq work.
 498  *
 499  * send_remote_sendirq() adds work to these lists, and
 500  * the softirq handler itself dequeues from them.  The queues
 501  * are protected by disabling local cpu interrupts and they must
 502  * only be accessed by the local cpu that they are for.
 503  */
 504 DECLARE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
 505
 506 DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
 507
 508 static inline struct task_struct *this_cpu_ksoftirqd(void)
 509 {
 510         return this_cpu_read(ksoftirqd);
 511 }
 512
 513 /* Try to send a softirq to a remote cpu.  If this cannot be done, the
 514  * work will be queued to the local cpu.
 515  */
 516 extern void send_remote_softirq(struct call_single_data *cp, int cpu, int softirq);
 517
 518 /* Like send_remote_softirq(), but the caller must disable local cpu interrupts
 519  * and compute the current cpu, passed in as 'this_cpu'.
 520  */
 521 extern void __send_remote_softirq(struct call_single_data *cp, int cpu,
 522                                   int this_cpu, int softirq);
 523
 524 /* Tasklets --- multithreaded analogue of BHs.
 525
 526    Main feature differing them of generic softirqs: tasklet
 527    is running only on one CPU simultaneously.
 528
 529    Main feature differing them of BHs: different tasklets
 530    may be run simultaneously on different CPUs.
 531
 532    Properties:
 533    * If tasklet_schedule() is called, then tasklet is guaranteed
 534      to be executed on some cpu at least once after this.
 535    * If the tasklet is already scheduled, but its execution is still not
 536      started, it will be executed only once.
 537    * If this tasklet is already running on another CPU (or schedule is called
 538      from tasklet itself), it is rescheduled for later.
 539    * Tasklet is strictly serialized wrt itself, but not
 540      wrt another tasklets. If client needs some intertask synchronization,
 541      he makes it with spinlocks.
 542  */
 543
 544 struct tasklet_struct
 545 {
 546         struct tasklet_struct *next;
 547         unsigned long state;
 548         atomic_t count;
 549         void (*func)(unsigned long);
 550         unsigned long data;
 551 };
 552
 553 #define DECLARE_TASKLET(name, func, data) \
 554 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 555
 556 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 557 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 558
 559
 560 enum
 561 {
 562         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 563         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 564 };
 565
 566 #ifdef CONFIG_SMP
 567 static inline int tasklet_trylock(struct tasklet_struct *t)
 568 {
 569         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 570 }
 571
 572 static inline void tasklet_unlock(struct tasklet_struct *t)
 573 {
 574         smp_mb__before_clear_bit();
 575         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 576 }
 577
 578 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 579 {
 580         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 581 }
 582 #else
 583 #define tasklet_trylock(t) 1
 584 #define tasklet_unlock_wait(t) do { } while (0)
 585 #define tasklet_unlock(t) do { } while (0)
 586 #endif
 587
 588 extern void __tasklet_schedule(struct tasklet_struct *t);
 589
 590 static inline void tasklet_schedule(struct tasklet_struct *t)
 591 {
 592         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 593                 __tasklet_schedule(t);
 594 }
 595
 596 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
 597
 598 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 599 {
 600         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 601                 __tasklet_hi_schedule(t);
 602 }
 603
 604 extern void __tasklet_hi_schedule_first(struct tasklet_struct *t);
 605
 606 /*
 607  * This version avoids touching any other tasklets. Needed for kmemcheck
 608  * in order not to take any page faults while enqueueing this tasklet;
 609  * consider VERY carefully whether you really need this or
 610  * tasklet_hi_schedule()...
 611  */
 612 static inline void tasklet_hi_schedule_first(struct tasklet_struct *t)
 613 {
 614         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 615                 __tasklet_hi_schedule_first(t);
 616 }
 617
 618
 619 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 620 {
 621         atomic_inc(&t->count);
 622         smp_mb__after_atomic_inc();
 623 }
 624
 625 static inline void tasklet_disable(struct tasklet_struct *t)
 626 {
 627         tasklet_disable_nosync(t);
 628         tasklet_unlock_wait(t);
 629         smp_mb();
 630 }
 631
 632 static inline void tasklet_enable(struct tasklet_struct *t)
 633 {
 634         smp_mb__before_atomic_dec();
 635         atomic_dec(&t->count);
 636 }
 637
 638 static inline void tasklet_hi_enable(struct tasklet_struct *t)
 639 {
 640         smp_mb__before_atomic_dec();
 641         atomic_dec(&t->count);
 642 }
 643
 644 extern void tasklet_kill(struct tasklet_struct *t);
 645 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 646 extern void tasklet_init(struct tasklet_struct *t,
 647                          void (*func)(unsigned long), unsigned long data);
 648
 649 struct tasklet_hrtimer {
 650         struct hrtimer          timer;
 651         struct tasklet_struct   tasklet;
 652         enum hrtimer_restart    (*function)(struct hrtimer *);
 653 };
 654
 655 extern void
 656 tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer,
 657                      enum hrtimer_restart (*function)(struct hrtimer *),
 658                      clockid_t which_clock, enum hrtimer_mode mode);
 659
 660 static inline
 661 int tasklet_hrtimer_start(struct tasklet_hrtimer *ttimer, ktime_t time,
 662                           const enum hrtimer_mode mode)
 663 {
 664         return hrtimer_start(&ttimer->timer, time, mode);
 665 }
 666
 667 static inline
 668 void tasklet_hrtimer_cancel(struct tasklet_hrtimer *ttimer)
 669 {
 670         hrtimer_cancel(&ttimer->timer);
 671         tasklet_kill(&ttimer->tasklet);
 672 }
 673
 674 /*
 675  * Autoprobing for irqs:
 676  *
 677  * probe_irq_on() and probe_irq_off() provide robust primitives
 678  * for accurate IRQ probing during kernel initialization.  They are
 679  * reasonably simple to use, are not "fooled" by spurious interrupts,
 680  * and, unlike other attempts at IRQ probing, they do not get hung on
 681  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 682  *
 683  * For reasonably foolproof probing, use them as follows:
 684  *
 685  * 1. clear and/or mask the device's internal interrupt.
 686  * 2. sti();
 687  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 688  * 4. enable the device and cause it to trigger an interrupt.
 689  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 690  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 691  * 7. service the device to clear its pending interrupt.
 692  * 8. loop again if paranoia is required.
 693  *
 694  * probe_irq_on() returns a mask of allocated irq's.
 695  *
 696  * probe_irq_off() takes the mask as a parameter,
 697  * and returns the irq number which occurred,
 698  * or zero if none occurred, or a negative irq number
 699  * if more than one irq occurred.
 700  */
 701
 702 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 703 static inline unsigned long probe_irq_on(void)
 704 {
 705         return 0;
 706 }
 707 static inline int probe_irq_off(unsigned long val)
 708 {
 709         return 0;
 710 }
 711 static inline unsigned int probe_irq_mask(unsigned long val)
 712 {
 713         return 0;
 714 }
 715 #else
 716 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 717 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 718 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 719 #endif
 720
 721 #ifdef CONFIG_PROC_FS
 722 /* Initialize /proc/irq/ */
 723 extern void init_irq_proc(void);
 724 #else
 725 static inline void init_irq_proc(void)
 726 {
 727 }
 728 #endif
 729
 730 struct seq_file;
 731 int show_interrupts(struct seq_file *p, void *v);
 732 int arch_show_interrupts(struct seq_file *p, int prec);
 733
 734 extern int early_irq_init(void);
 735 extern int arch_probe_nr_irqs(void);
 736 extern int arch_early_irq_init(void);
 737
 738 #endif