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 #define IRQF_NODELAY            0x00002000
  62 #define IRQF_TIMER              (__IRQF_TIMER | IRQF_NODELAY)
  63
  64 typedef irqreturn_t (*irq_handler_t)(int, void *);
  65
  66 /**
  67  * struct irqaction - per interrupt action descriptor
  68  * @handler:    interrupt handler function
  69  * @flags:      flags (see IRQF_* above)
  70  * @mask:       no comment as it is useless and about to be removed
  71  * @name:       name of the device
  72  * @dev_id:     cookie to identify the device
  73  * @next:       pointer to the next irqaction for shared interrupts
  74  * @irq:        interrupt number
  75  * @dir:        pointer to the proc/irq/NN/name entry
  76  */
  77 struct irqaction {
  78         irq_handler_t handler;
  79         unsigned long flags;
  80         cpumask_t mask;
  81         const char *name;
  82         void *dev_id;
  83         struct irqaction *next;
  84         int irq;
  85         struct proc_dir_entry *dir, *threaded;
  86 };
  87
  88 extern irqreturn_t no_action(int cpl, void *dev_id);
  89
  90 extern int __must_check
  91 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
  92             const char *name, void *dev);
  93
  94 extern void free_irq(unsigned int, void *);
  95
  96 struct device;
  97
  98 extern int __must_check
  99 devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
 100                  unsigned long irqflags, const char *devname, void *dev_id);
 101
 102 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
 103
 104 /*
 105  * On lockdep we dont want to enable hardirqs in hardirq
 106  * context. Use local_irq_enable_in_hardirq() to annotate
 107  * kernel code that has to do this nevertheless (pretty much
 108  * the only valid case is for old/broken hardware that is
 109  * insanely slow).
 110  *
 111  * NOTE: in theory this might break fragile code that relies
 112  * on hardirq delivery - in practice we dont seem to have such
 113  * places left. So the only effect should be slightly increased
 114  * irqs-off latencies.
 115  */
 116 #ifdef CONFIG_LOCKDEP
 117 # define local_irq_enable_in_hardirq()  do { } while (0)
 118 #else
 119 # define local_irq_enable_in_hardirq()  local_irq_enable_nort()
 120 #endif
 121
 122 extern void disable_irq_nosync(unsigned int irq);
 123 extern void disable_irq(unsigned int irq);
 124 extern void enable_irq(unsigned int irq);
 125
 126 #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
 127
 128 extern cpumask_var_t irq_default_affinity;
 129
 130 extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask);
 131 extern int irq_can_set_affinity(unsigned int irq);
 132 extern int irq_select_affinity(unsigned int irq);
 133
 134 #else /* CONFIG_SMP */
 135
 136 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
 137 {
 138         return -EINVAL;
 139 }
 140
 141 static inline int irq_can_set_affinity(unsigned int irq)
 142 {
 143         return 0;
 144 }
 145
 146 static inline int irq_select_affinity(unsigned int irq)  { return 0; }
 147
 148 #endif /* CONFIG_SMP && CONFIG_GENERIC_HARDIRQS */
 149
 150 #ifdef CONFIG_GENERIC_HARDIRQS
 151 /*
 152  * Special lockdep variants of irq disabling/enabling.
 153  * These should be used for locking constructs that
 154  * know that a particular irq context which is disabled,
 155  * and which is the only irq-context user of a lock,
 156  * that it's safe to take the lock in the irq-disabled
 157  * section without disabling hardirqs.
 158  *
 159  * On !CONFIG_LOCKDEP they are equivalent to the normal
 160  * irq disable/enable methods.
 161  */
 162 static inline void disable_irq_nosync_lockdep(unsigned int irq)
 163 {
 164         disable_irq_nosync(irq);
 165 #ifdef CONFIG_LOCKDEP
 166         local_irq_disable();
 167 #endif
 168 }
 169
 170 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 171 {
 172         disable_irq_nosync(irq);
 173 #ifdef CONFIG_LOCKDEP
 174         local_irq_save(*flags);
 175 #endif
 176 }
 177
 178 static inline void disable_irq_lockdep(unsigned int irq)
 179 {
 180         disable_irq(irq);
 181 #ifdef CONFIG_LOCKDEP
 182         local_irq_disable();
 183 #endif
 184 }
 185
 186 static inline void enable_irq_lockdep(unsigned int irq)
 187 {
 188 #ifdef CONFIG_LOCKDEP
 189         local_irq_enable();
 190 #endif
 191         enable_irq(irq);
 192 }
 193
 194 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 195 {
 196 #ifdef CONFIG_LOCKDEP
 197         local_irq_restore(*flags);
 198 #endif
 199         enable_irq(irq);
 200 }
 201
 202 /* IRQ wakeup (PM) control: */
 203 extern int set_irq_wake(unsigned int irq, unsigned int on);
 204
 205 static inline int enable_irq_wake(unsigned int irq)
 206 {
 207         return set_irq_wake(irq, 1);
 208 }
 209
 210 static inline int disable_irq_wake(unsigned int irq)
 211 {
 212         return set_irq_wake(irq, 0);
 213 }
 214
 215 #else /* !CONFIG_GENERIC_HARDIRQS */
 216 /*
 217  * NOTE: non-genirq architectures, if they want to support the lock
 218  * validator need to define the methods below in their asm/irq.h
 219  * files, under an #ifdef CONFIG_LOCKDEP section.
 220  */
 221 #ifndef CONFIG_LOCKDEP
 222 #  define disable_irq_nosync_lockdep(irq)       disable_irq_nosync(irq)
 223 #  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
 224                                                 disable_irq_nosync(irq)
 225 #  define disable_irq_lockdep(irq)              disable_irq(irq)
 226 #  define enable_irq_lockdep(irq)               enable_irq(irq)
 227 #  define enable_irq_lockdep_irqrestore(irq, flags) \
 228                                                 enable_irq(irq)
 229 # endif
 230
 231 static inline int enable_irq_wake(unsigned int irq)
 232 {
 233         return 0;
 234 }
 235
 236 static inline int disable_irq_wake(unsigned int irq)
 237 {
 238         return 0;
 239 }
 240 #endif /* CONFIG_GENERIC_HARDIRQS */
 241
 242 #ifndef __ARCH_SET_SOFTIRQ_PENDING
 243 #define set_softirq_pending(x) (local_softirq_pending() = (x))
 244 // FIXME: PREEMPT_RT: set_bit()?
 245 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 246 #endif
 247
 248 /* Some architectures might implement lazy enabling/disabling of
 249  * interrupts. In some cases, such as stop_machine, we might want
 250  * to ensure that after a local_irq_disable(), interrupts have
 251  * really been disabled in hardware. Such architectures need to
 252  * implement the following hook.
 253  */
 254 #ifndef hard_irq_disable
 255 #define hard_irq_disable()      do { } while(0)
 256 #endif
 257
 258 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 259    frequency threaded job scheduling. For almost all the purposes
 260    tasklets are more than enough. F.e. all serial device BHs et
 261    al. should be converted to tasklets, not to softirqs.
 262  */
 263
 264 enum
 265 {
 266         HI_SOFTIRQ=0,
 267         TIMER_SOFTIRQ,
 268         NET_TX_SOFTIRQ,
 269         NET_RX_SOFTIRQ,
 270         BLOCK_SOFTIRQ,
 271         TASKLET_SOFTIRQ,
 272         SCHED_SOFTIRQ,
 273         HRTIMER_SOFTIRQ,
 274         RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
 275         /* Entries after this are ignored in split softirq mode */
 276         MAX_SOFTIRQ,
 277
 278         NR_SOFTIRQS
 279 };
 280
 281 /* map softirq index to softirq name. update 'softirq_to_name' in
 282  * kernel/softirq.c when adding a new softirq.
 283  */
 284 extern char *softirq_to_name[NR_SOFTIRQS];
 285
 286 /* softirq mask and active fields moved to irq_cpustat_t in
 287  * asm/hardirq.h to get better cache usage.  KAO
 288  */
 289
 290 struct softirq_action
 291 {
 292         void    (*action)(struct softirq_action *);
 293 };
 294
 295 #ifdef CONFIG_PREEMPT_HARDIRQS
 296 # define __raise_softirq_irqoff(nr) raise_softirq_irqoff(nr)
 297 # define __do_raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
 298 #else
 299 # define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
 300 # define __do_raise_softirq_irqoff(nr) __raise_softirq_irqoff(nr)
 301 #endif
 302
 303 asmlinkage void do_softirq(void);
 304 asmlinkage void __do_softirq(void);
 305 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
 306 extern void softirq_init(void);
 307 extern void raise_softirq_irqoff(unsigned int nr);
 308 extern void raise_softirq(unsigned int nr);
 309
 310 /* This is the worklist that queues up per-cpu softirq work.
 311  *
 312  * send_remote_sendirq() adds work to these lists, and
 313  * the softirq handler itself dequeues from them.  The queues
 314  * are protected by disabling local cpu interrupts and they must
 315  * only be accessed by the local cpu that they are for.
 316  */
 317 DECLARE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
 318 #ifdef CONFIG_PREEMPT_SOFTIRQS
 319 extern void wait_for_softirq(int softirq);
 320 #else
 321 # define wait_for_softirq(x) do {} while(0)
 322 #endif
 323
 324 /* Try to send a softirq to a remote cpu.  If this cannot be done, the
 325  * work will be queued to the local cpu.
 326  */
 327 extern void send_remote_softirq(struct call_single_data *cp, int cpu, int softirq);
 328
 329 /* Like send_remote_softirq(), but the caller must disable local cpu interrupts
 330  * and compute the current cpu, passed in as 'this_cpu'.
 331  */
 332 extern void __send_remote_softirq(struct call_single_data *cp, int cpu,
 333                                   int this_cpu, int softirq);
 334
 335 /* Tasklets --- multithreaded analogue of BHs.
 336
 337    Main feature differing them of generic softirqs: tasklet
 338    is running only on one CPU simultaneously.
 339
 340    Main feature differing them of BHs: different tasklets
 341    may be run simultaneously on different CPUs.
 342
 343    Properties:
 344    * If tasklet_schedule() is called, then tasklet is guaranteed
 345      to be executed on some cpu at least once after this.
 346    * If the tasklet is already scheduled, but its excecution is still not
 347      started, it will be executed only once.
 348    * If this tasklet is already running on another CPU, it is rescheduled
 349      for later.
 350    * Schedule must not be called from the tasklet itself (a lockup occurs)
 351    * Tasklet is strictly serialized wrt itself, but not
 352      wrt another tasklets. If client needs some intertask synchronization,
 353      he makes it with spinlocks.
 354  */
 355
 356 struct tasklet_struct
 357 {
 358         struct tasklet_struct *next;
 359         unsigned long state;
 360         atomic_t count;
 361         void (*func)(unsigned long);
 362         unsigned long data;
 363 };
 364
 365 #define DECLARE_TASKLET(name, func, data) \
 366 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 367
 368 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 369 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 370
 371
 372 enum
 373 {
 374         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 375         TASKLET_STATE_RUN,      /* Tasklet is running (SMP only) */
 376         TASKLET_STATE_PENDING   /* Tasklet is pending */
 377 };
 378
 379 #define TASKLET_STATEF_SCHED    (1 << TASKLET_STATE_SCHED)
 380 #define TASKLET_STATEF_RUN      (1 << TASKLET_STATE_RUN)
 381 #define TASKLET_STATEF_PENDING  (1 << TASKLET_STATE_PENDING)
 382
 383 #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT_RT)
 384 static inline int tasklet_trylock(struct tasklet_struct *t)
 385 {
 386         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 387 }
 388
 389 static inline int tasklet_tryunlock(struct tasklet_struct *t)
 390 {
 391         return cmpxchg(&t->state, TASKLET_STATEF_RUN, 0) == TASKLET_STATEF_RUN;
 392 }
 393
 394 static inline void tasklet_unlock(struct tasklet_struct *t)
 395 {
 396         smp_mb__before_clear_bit();
 397         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 398 }
 399
 400 extern void tasklet_unlock_wait(struct tasklet_struct *t);
 401
 402 #else
 403 #define tasklet_trylock(t) 1
 404 #define tasklet_tryunlock(t)    1
 405 #define tasklet_unlock_wait(t) do { } while (0)
 406 #define tasklet_unlock(t) do { } while (0)
 407 #endif
 408
 409 extern void __tasklet_schedule(struct tasklet_struct *t);
 410
 411 static inline void tasklet_schedule(struct tasklet_struct *t)
 412 {
 413         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 414                 __tasklet_schedule(t);
 415 }
 416
 417 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
 418
 419 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 420 {
 421         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 422                 __tasklet_hi_schedule(t);
 423 }
 424
 425 extern void __tasklet_hi_schedule_first(struct tasklet_struct *t);
 426
 427 /*
 428  * This version avoids touching any other tasklets. Needed for kmemcheck
 429  * in order not to take any page faults while enqueueing this tasklet;
 430  * consider VERY carefully whether you really need this or
 431  * tasklet_hi_schedule()...
 432  */
 433 static inline void tasklet_hi_schedule_first(struct tasklet_struct *t)
 434 {
 435         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 436                 __tasklet_hi_schedule_first(t);
 437 }
 438
 439
 440 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 441 {
 442         atomic_inc(&t->count);
 443         smp_mb__after_atomic_inc();
 444 }
 445
 446 static inline void tasklet_disable(struct tasklet_struct *t)
 447 {
 448         tasklet_disable_nosync(t);
 449         tasklet_unlock_wait(t);
 450         smp_mb();
 451 }
 452
 453 extern  void tasklet_enable(struct tasklet_struct *t);
 454 extern  void tasklet_hi_enable(struct tasklet_struct *t);
 455
 456 extern void tasklet_kill(struct tasklet_struct *t);
 457 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 458 extern void tasklet_init(struct tasklet_struct *t,
 459                          void (*func)(unsigned long), unsigned long data);
 460 void takeover_tasklets(unsigned int cpu);
 461
 462 /*
 463  * Autoprobing for irqs:
 464  *
 465  * probe_irq_on() and probe_irq_off() provide robust primitives
 466  * for accurate IRQ probing during kernel initialization.  They are
 467  * reasonably simple to use, are not "fooled" by spurious interrupts,
 468  * and, unlike other attempts at IRQ probing, they do not get hung on
 469  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 470  *
 471  * For reasonably foolproof probing, use them as follows:
 472  *
 473  * 1. clear and/or mask the device's internal interrupt.
 474  * 2. sti();
 475  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 476  * 4. enable the device and cause it to trigger an interrupt.
 477  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 478  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 479  * 7. service the device to clear its pending interrupt.
 480  * 8. loop again if paranoia is required.
 481  *
 482  * probe_irq_on() returns a mask of allocated irq's.
 483  *
 484  * probe_irq_off() takes the mask as a parameter,
 485  * and returns the irq number which occurred,
 486  * or zero if none occurred, or a negative irq number
 487  * if more than one irq occurred.
 488  */
 489
 490 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 491 static inline unsigned long probe_irq_on(void)
 492 {
 493         return 0;
 494 }
 495 static inline int probe_irq_off(unsigned long val)
 496 {
 497         return 0;
 498 }
 499 static inline unsigned int probe_irq_mask(unsigned long val)
 500 {
 501         return 0;
 502 }
 503 #else
 504 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 505 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 506 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 507 #endif
 508
 509 #ifdef CONFIG_PROC_FS
 510 /* Initialize /proc/irq/ */
 511 extern void init_irq_proc(void);
 512 #else
 513 static inline void init_irq_proc(void)
 514 {
 515 }
 516 #endif
 517
 518 #if defined(CONFIG_GENERIC_HARDIRQS) && defined(CONFIG_DEBUG_SHIRQ)
 519 extern void debug_poll_all_shared_irqs(void);
 520 #else
 521 static inline void debug_poll_all_shared_irqs(void) { }
 522 #endif
 523
 524 int show_interrupts(struct seq_file *p, void *v);
 525
 526 struct irq_desc;
 527
 528 extern int early_irq_init(void);
 529 extern int arch_probe_nr_irqs(void);
 530 extern int arch_early_irq_init(void);
 531 extern int arch_init_chip_data(struct irq_desc *desc, int cpu);
 532
 533 #ifdef CONFIG_PREEMPT_RT
 534 # define local_irq_disable_nort()       do { } while (0)
 535 # define local_irq_enable_nort()        do { } while (0)
 536 # define local_irq_enable_rt()          local_irq_enable()
 537 # define local_irq_save_nort(flags)     do { local_save_flags(flags); } while (0)
 538 # define local_irq_restore_nort(flags)  do { (void)(flags); } while (0)
 539 # define spin_lock_nort(lock)           do { } while (0)
 540 # define spin_unlock_nort(lock)         do { } while (0)
 541 # define spin_lock_bh_nort(lock)        do { } while (0)
 542 # define spin_unlock_bh_nort(lock)      do { } while (0)
 543 # define spin_lock_rt(lock)             spin_lock(lock)
 544 # define spin_unlock_rt(lock)           spin_unlock(lock)
 545 # define smp_processor_id_rt(cpu)       (cpu)
 546 # define in_atomic_rt()                 (!oops_in_progress && \
 547                                           (in_atomic() || irqs_disabled()))
 548 # define read_trylock_rt(lock)          ({read_lock(lock); 1; })
 549 #else
 550 # define local_irq_disable_nort()       local_irq_disable()
 551 # define local_irq_enable_nort()        local_irq_enable()
 552 # define local_irq_enable_rt()          do { } while (0)
 553 # define local_irq_save_nort(flags)     local_irq_save(flags)
 554 # define local_irq_restore_nort(flags)  local_irq_restore(flags)
 555 # define spin_lock_rt(lock)             do { } while (0)
 556 # define spin_unlock_rt(lock)           do { } while (0)
 557 # define spin_lock_nort(lock)           spin_lock(lock)
 558 # define spin_unlock_nort(lock)         spin_unlock(lock)
 559 # define spin_lock_bh_nort(lock)        spin_lock_bh(lock)
 560 # define spin_unlock_bh_nort(lock)      spin_unlock_bh(lock)
 561 # define smp_processor_id_rt(cpu)       smp_processor_id()
 562 # define in_atomic_rt()                 0
 563 # define read_trylock_rt(lock)          read_trylock(lock)
 564 #endif
 565
 566 #endif