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