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/hardirq.h>
  12 #include <linux/sched.h>
  13 #include <linux/irqflags.h>
  14 #include <asm/atomic.h>
  15 #include <asm/ptrace.h>
  16 #include <asm/system.h>
  17
  18 /*
  19  * These correspond to the IORESOURCE_IRQ_* defines in
  20  * linux/ioport.h to select the interrupt line behaviour.  When
  21  * requesting an interrupt without specifying a IRQF_TRIGGER, the
  22  * setting should be assumed to be "as already configured", which
  23  * may be as per machine or firmware initialisation.
  24  */
  25 #define IRQF_TRIGGER_NONE       0x00000000
  26 #define IRQF_TRIGGER_RISING     0x00000001
  27 #define IRQF_TRIGGER_FALLING    0x00000002
  28 #define IRQF_TRIGGER_HIGH       0x00000004
  29 #define IRQF_TRIGGER_LOW        0x00000008
  30 #define IRQF_TRIGGER_MASK       (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
  31                                  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
  32 #define IRQF_TRIGGER_PROBE      0x00000010
  33
  34 /*
  35  * These flags used only by the kernel as part of the
  36  * irq handling routines.
  37  *
  38  * IRQF_DISABLED - keep irqs disabled when calling the action handler
  39  * IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
  40  * IRQF_SHARED - allow sharing the irq among several devices
  41  * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
  42  * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
  43  * IRQF_PERCPU - Interrupt is per cpu
  44  * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
  45  * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
  46  *                registered first in an shared interrupt is considered for
  47  *                performance reasons)
  48  */
  49 #define IRQF_DISABLED           0x00000020
  50 #define IRQF_SAMPLE_RANDOM      0x00000040
  51 #define IRQF_SHARED             0x00000080
  52 #define IRQF_PROBE_SHARED       0x00000100
  53 #define IRQF_TIMER              0x00000200
  54 #define IRQF_PERCPU             0x00000400
  55 #define IRQF_NOBALANCING        0x00000800
  56 #define IRQF_IRQPOLL            0x00001000
  57
  58 typedef irqreturn_t (*irq_handler_t)(int, void *);
  59
  60 struct irqaction {
  61         irq_handler_t handler;
  62         unsigned long flags;
  63         cpumask_t mask;
  64         const char *name;
  65         void *dev_id;
  66         struct irqaction *next;
  67         int irq;
  68         struct proc_dir_entry *dir;
  69 };
  70
  71 extern irqreturn_t no_action(int cpl, void *dev_id);
  72 extern int __must_check request_irq(unsigned int, irq_handler_t handler,
  73                        unsigned long, const char *, void *);
  74 extern void free_irq(unsigned int, void *);
  75
  76 struct device;
  77
  78 extern int __must_check devm_request_irq(struct device *dev, unsigned int irq,
  79                             irq_handler_t handler, unsigned long irqflags,
  80                             const char *devname, void *dev_id);
  81 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
  82
  83 /*
  84  * On lockdep we dont want to enable hardirqs in hardirq
  85  * context. Use local_irq_enable_in_hardirq() to annotate
  86  * kernel code that has to do this nevertheless (pretty much
  87  * the only valid case is for old/broken hardware that is
  88  * insanely slow).
  89  *
  90  * NOTE: in theory this might break fragile code that relies
  91  * on hardirq delivery - in practice we dont seem to have such
  92  * places left. So the only effect should be slightly increased
  93  * irqs-off latencies.
  94  */
  95 #ifdef CONFIG_LOCKDEP
  96 # define local_irq_enable_in_hardirq()  do { } while (0)
  97 #else
  98 # define local_irq_enable_in_hardirq()  local_irq_enable()
  99 #endif
 100
 101 extern void disable_irq_nosync(unsigned int irq);
 102 extern void disable_irq(unsigned int irq);
 103 extern void enable_irq(unsigned int irq);
 104
 105 #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
 106
 107 extern int irq_set_affinity(unsigned int irq, cpumask_t cpumask);
 108 extern int irq_can_set_affinity(unsigned int irq);
 109
 110 #else /* CONFIG_SMP */
 111
 112 static inline int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
 113 {
 114         return -EINVAL;
 115 }
 116
 117 static inline int irq_can_set_affinity(unsigned int irq)
 118 {
 119         return 0;
 120 }
 121
 122 #endif /* CONFIG_SMP && CONFIG_GENERIC_HARDIRQS */
 123
 124 #ifdef CONFIG_GENERIC_HARDIRQS
 125 /*
 126  * Special lockdep variants of irq disabling/enabling.
 127  * These should be used for locking constructs that
 128  * know that a particular irq context which is disabled,
 129  * and which is the only irq-context user of a lock,
 130  * that it's safe to take the lock in the irq-disabled
 131  * section without disabling hardirqs.
 132  *
 133  * On !CONFIG_LOCKDEP they are equivalent to the normal
 134  * irq disable/enable methods.
 135  */
 136 static inline void disable_irq_nosync_lockdep(unsigned int irq)
 137 {
 138         disable_irq_nosync(irq);
 139 #ifdef CONFIG_LOCKDEP
 140         local_irq_disable();
 141 #endif
 142 }
 143
 144 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 145 {
 146         disable_irq_nosync(irq);
 147 #ifdef CONFIG_LOCKDEP
 148         local_irq_save(*flags);
 149 #endif
 150 }
 151
 152 static inline void disable_irq_lockdep(unsigned int irq)
 153 {
 154         disable_irq(irq);
 155 #ifdef CONFIG_LOCKDEP
 156         local_irq_disable();
 157 #endif
 158 }
 159
 160 static inline void enable_irq_lockdep(unsigned int irq)
 161 {
 162 #ifdef CONFIG_LOCKDEP
 163         local_irq_enable();
 164 #endif
 165         enable_irq(irq);
 166 }
 167
 168 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 169 {
 170 #ifdef CONFIG_LOCKDEP
 171         local_irq_restore(*flags);
 172 #endif
 173         enable_irq(irq);
 174 }
 175
 176 /* IRQ wakeup (PM) control: */
 177 extern int set_irq_wake(unsigned int irq, unsigned int on);
 178
 179 static inline int enable_irq_wake(unsigned int irq)
 180 {
 181         return set_irq_wake(irq, 1);
 182 }
 183
 184 static inline int disable_irq_wake(unsigned int irq)
 185 {
 186         return set_irq_wake(irq, 0);
 187 }
 188
 189 #else /* !CONFIG_GENERIC_HARDIRQS */
 190 /*
 191  * NOTE: non-genirq architectures, if they want to support the lock
 192  * validator need to define the methods below in their asm/irq.h
 193  * files, under an #ifdef CONFIG_LOCKDEP section.
 194  */
 195 #ifndef CONFIG_LOCKDEP
 196 #  define disable_irq_nosync_lockdep(irq)       disable_irq_nosync(irq)
 197 #  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
 198                                                 disable_irq_nosync(irq)
 199 #  define disable_irq_lockdep(irq)              disable_irq(irq)
 200 #  define enable_irq_lockdep(irq)               enable_irq(irq)
 201 #  define enable_irq_lockdep_irqrestore(irq, flags) \
 202                                                 enable_irq(irq)
 203 # endif
 204
 205 static inline int enable_irq_wake(unsigned int irq)
 206 {
 207         return 0;
 208 }
 209
 210 static inline int disable_irq_wake(unsigned int irq)
 211 {
 212         return 0;
 213 }
 214 #endif /* CONFIG_GENERIC_HARDIRQS */
 215
 216 #ifndef __ARCH_SET_SOFTIRQ_PENDING
 217 #define set_softirq_pending(x) (local_softirq_pending() = (x))
 218 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 219 #endif
 220
 221 /*
 222  * Temporary defines for UP kernels, until all code gets fixed.
 223  */
 224 #ifndef CONFIG_SMP
 225 static inline void __deprecated cli(void)
 226 {
 227         local_irq_disable();
 228 }
 229 static inline void __deprecated sti(void)
 230 {
 231         local_irq_enable();
 232 }
 233 static inline void __deprecated save_flags(unsigned long *x)
 234 {
 235         local_save_flags(*x);
 236 }
 237 #define save_flags(x) save_flags(&x)
 238 static inline void __deprecated restore_flags(unsigned long x)
 239 {
 240         local_irq_restore(x);
 241 }
 242
 243 static inline void __deprecated save_and_cli(unsigned long *x)
 244 {
 245         local_irq_save(*x);
 246 }
 247 #define save_and_cli(x) save_and_cli(&x)
 248 #endif /* CONFIG_SMP */
 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 #ifdef CONFIG_HIGH_RES_TIMERS
 276         HRTIMER_SOFTIRQ,
 277 #endif
 278         RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
 279 };
 280
 281 /* softirq mask and active fields moved to irq_cpustat_t in
 282  * asm/hardirq.h to get better cache usage.  KAO
 283  */
 284
 285 struct softirq_action
 286 {
 287         void    (*action)(struct softirq_action *);
 288         void    *data;
 289 };
 290
 291 asmlinkage void do_softirq(void);
 292 asmlinkage void __do_softirq(void);
 293 extern void open_softirq(int nr, void (*action)(struct softirq_action*), void *data);
 294 extern void softirq_init(void);
 295 #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
 296 extern void raise_softirq_irqoff(unsigned int nr);
 297 extern void raise_softirq(unsigned int nr);
 298
 299
 300 /* Tasklets --- multithreaded analogue of BHs.
 301
 302    Main feature differing them of generic softirqs: tasklet
 303    is running only on one CPU simultaneously.
 304
 305    Main feature differing them of BHs: different tasklets
 306    may be run simultaneously on different CPUs.
 307
 308    Properties:
 309    * If tasklet_schedule() is called, then tasklet is guaranteed
 310      to be executed on some cpu at least once after this.
 311    * If the tasklet is already scheduled, but its excecution is still not
 312      started, it will be executed only once.
 313    * If this tasklet is already running on another CPU (or schedule is called
 314      from tasklet itself), it is rescheduled for later.
 315    * Tasklet is strictly serialized wrt itself, but not
 316      wrt another tasklets. If client needs some intertask synchronization,
 317      he makes it with spinlocks.
 318  */
 319
 320 struct tasklet_struct
 321 {
 322         struct tasklet_struct *next;
 323         unsigned long state;
 324         atomic_t count;
 325         void (*func)(unsigned long);
 326         unsigned long data;
 327 };
 328
 329 #define DECLARE_TASKLET(name, func, data) \
 330 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 331
 332 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 333 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 334
 335
 336 enum
 337 {
 338         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 339         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 340 };
 341
 342 #ifdef CONFIG_SMP
 343 static inline int tasklet_trylock(struct tasklet_struct *t)
 344 {
 345         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 346 }
 347
 348 static inline void tasklet_unlock(struct tasklet_struct *t)
 349 {
 350         smp_mb__before_clear_bit();
 351         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 352 }
 353
 354 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 355 {
 356         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 357 }
 358 #else
 359 #define tasklet_trylock(t) 1
 360 #define tasklet_unlock_wait(t) do { } while (0)
 361 #define tasklet_unlock(t) do { } while (0)
 362 #endif
 363
 364 extern void __tasklet_schedule(struct tasklet_struct *t);
 365
 366 static inline void tasklet_schedule(struct tasklet_struct *t)
 367 {
 368         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 369                 __tasklet_schedule(t);
 370 }
 371
 372 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
 373
 374 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 375 {
 376         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 377                 __tasklet_hi_schedule(t);
 378 }
 379
 380
 381 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 382 {
 383         atomic_inc(&t->count);
 384         smp_mb__after_atomic_inc();
 385 }
 386
 387 static inline void tasklet_disable(struct tasklet_struct *t)
 388 {
 389         tasklet_disable_nosync(t);
 390         tasklet_unlock_wait(t);
 391         smp_mb();
 392 }
 393
 394 static inline void tasklet_enable(struct tasklet_struct *t)
 395 {
 396         smp_mb__before_atomic_dec();
 397         atomic_dec(&t->count);
 398 }
 399
 400 static inline void tasklet_hi_enable(struct tasklet_struct *t)
 401 {
 402         smp_mb__before_atomic_dec();
 403         atomic_dec(&t->count);
 404 }
 405
 406 extern void tasklet_kill(struct tasklet_struct *t);
 407 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 408 extern void tasklet_init(struct tasklet_struct *t,
 409                          void (*func)(unsigned long), unsigned long data);
 410
 411 /*
 412  * Autoprobing for irqs:
 413  *
 414  * probe_irq_on() and probe_irq_off() provide robust primitives
 415  * for accurate IRQ probing during kernel initialization.  They are
 416  * reasonably simple to use, are not "fooled" by spurious interrupts,
 417  * and, unlike other attempts at IRQ probing, they do not get hung on
 418  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 419  *
 420  * For reasonably foolproof probing, use them as follows:
 421  *
 422  * 1. clear and/or mask the device's internal interrupt.
 423  * 2. sti();
 424  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 425  * 4. enable the device and cause it to trigger an interrupt.
 426  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 427  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 428  * 7. service the device to clear its pending interrupt.
 429  * 8. loop again if paranoia is required.
 430  *
 431  * probe_irq_on() returns a mask of allocated irq's.
 432  *
 433  * probe_irq_off() takes the mask as a parameter,
 434  * and returns the irq number which occurred,
 435  * or zero if none occurred, or a negative irq number
 436  * if more than one irq occurred.
 437  */
 438
 439 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 440 static inline unsigned long probe_irq_on(void)
 441 {
 442         return 0;
 443 }
 444 static inline int probe_irq_off(unsigned long val)
 445 {
 446         return 0;
 447 }
 448 static inline unsigned int probe_irq_mask(unsigned long val)
 449 {
 450         return 0;
 451 }
 452 #else
 453 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 454 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 455 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 456 #endif
 457
 458 #ifdef CONFIG_PROC_FS
 459 /* Initialize /proc/irq/ */
 460 extern void init_irq_proc(void);
 461 #else
 462 static inline void init_irq_proc(void)
 463 {
 464 }
 465 #endif
 466
 467 int show_interrupts(struct seq_file *p, void *v);
 468
 469 #endif