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