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 /*
  59  * Migration helpers. Scheduled for removal in 9/2007
  60  * Do not use for new code !
  61  */
  62 static inline
  63 unsigned long __deprecated deprecated_irq_flag(unsigned long flag)
  64 {
  65         return flag;
  66 }
  67
  68 #define SA_INTERRUPT            deprecated_irq_flag(IRQF_DISABLED)
  69 #define SA_SAMPLE_RANDOM        deprecated_irq_flag(IRQF_SAMPLE_RANDOM)
  70 #define SA_SHIRQ                deprecated_irq_flag(IRQF_SHARED)
  71 #define SA_PROBEIRQ             deprecated_irq_flag(IRQF_PROBE_SHARED)
  72 #define SA_PERCPU               deprecated_irq_flag(IRQF_PERCPU)
  73
  74 #define SA_TRIGGER_LOW          deprecated_irq_flag(IRQF_TRIGGER_LOW)
  75 #define SA_TRIGGER_HIGH         deprecated_irq_flag(IRQF_TRIGGER_HIGH)
  76 #define SA_TRIGGER_FALLING      deprecated_irq_flag(IRQF_TRIGGER_FALLING)
  77 #define SA_TRIGGER_RISING       deprecated_irq_flag(IRQF_TRIGGER_RISING)
  78 #define SA_TRIGGER_MASK         deprecated_irq_flag(IRQF_TRIGGER_MASK)
  79
  80 typedef irqreturn_t (*irq_handler_t)(int, void *);
  81
  82 struct irqaction {
  83         irq_handler_t handler;
  84         unsigned long flags;
  85         cpumask_t mask;
  86         const char *name;
  87         void *dev_id;
  88         struct irqaction *next;
  89         int irq;
  90         struct proc_dir_entry *dir;
  91 };
  92
  93 extern irqreturn_t no_action(int cpl, void *dev_id);
  94 extern int __must_check request_irq(unsigned int, irq_handler_t handler,
  95                        unsigned long, const char *, void *);
  96 extern void free_irq(unsigned int, void *);
  97
  98 struct device;
  99
 100 extern int __must_check devm_request_irq(struct device *dev, unsigned int irq,
 101                             irq_handler_t handler, unsigned long irqflags,
 102                             const char *devname, void *dev_id);
 103 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
 104
 105 /*
 106  * On lockdep we dont want to enable hardirqs in hardirq
 107  * context. Use local_irq_enable_in_hardirq() to annotate
 108  * kernel code that has to do this nevertheless (pretty much
 109  * the only valid case is for old/broken hardware that is
 110  * insanely slow).
 111  *
 112  * NOTE: in theory this might break fragile code that relies
 113  * on hardirq delivery - in practice we dont seem to have such
 114  * places left. So the only effect should be slightly increased
 115  * irqs-off latencies.
 116  */
 117 #ifdef CONFIG_LOCKDEP
 118 # define local_irq_enable_in_hardirq()  do { } while (0)
 119 #else
 120 # define local_irq_enable_in_hardirq()  local_irq_enable()
 121 #endif
 122
 123 extern void disable_irq_nosync(unsigned int irq);
 124 extern void disable_irq(unsigned int irq);
 125 extern void enable_irq(unsigned int irq);
 126
 127 #ifdef CONFIG_GENERIC_HARDIRQS
 128 /*
 129  * Special lockdep variants of irq disabling/enabling.
 130  * These should be used for locking constructs that
 131  * know that a particular irq context which is disabled,
 132  * and which is the only irq-context user of a lock,
 133  * that it's safe to take the lock in the irq-disabled
 134  * section without disabling hardirqs.
 135  *
 136  * On !CONFIG_LOCKDEP they are equivalent to the normal
 137  * irq disable/enable methods.
 138  */
 139 static inline void disable_irq_nosync_lockdep(unsigned int irq)
 140 {
 141         disable_irq_nosync(irq);
 142 #ifdef CONFIG_LOCKDEP
 143         local_irq_disable();
 144 #endif
 145 }
 146
 147 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 148 {
 149         disable_irq_nosync(irq);
 150 #ifdef CONFIG_LOCKDEP
 151         local_irq_save(*flags);
 152 #endif
 153 }
 154
 155 static inline void disable_irq_lockdep(unsigned int irq)
 156 {
 157         disable_irq(irq);
 158 #ifdef CONFIG_LOCKDEP
 159         local_irq_disable();
 160 #endif
 161 }
 162
 163 static inline void enable_irq_lockdep(unsigned int irq)
 164 {
 165 #ifdef CONFIG_LOCKDEP
 166         local_irq_enable();
 167 #endif
 168         enable_irq(irq);
 169 }
 170
 171 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 172 {
 173 #ifdef CONFIG_LOCKDEP
 174         local_irq_restore(*flags);
 175 #endif
 176         enable_irq(irq);
 177 }
 178
 179 /* IRQ wakeup (PM) control: */
 180 extern int set_irq_wake(unsigned int irq, unsigned int on);
 181
 182 static inline int enable_irq_wake(unsigned int irq)
 183 {
 184         return set_irq_wake(irq, 1);
 185 }
 186
 187 static inline int disable_irq_wake(unsigned int irq)
 188 {
 189         return set_irq_wake(irq, 0);
 190 }
 191
 192 #else /* !CONFIG_GENERIC_HARDIRQS */
 193 /*
 194  * NOTE: non-genirq architectures, if they want to support the lock
 195  * validator need to define the methods below in their asm/irq.h
 196  * files, under an #ifdef CONFIG_LOCKDEP section.
 197  */
 198 #ifndef CONFIG_LOCKDEP
 199 #  define disable_irq_nosync_lockdep(irq)       disable_irq_nosync(irq)
 200 #  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
 201                                                 disable_irq_nosync(irq)
 202 #  define disable_irq_lockdep(irq)              disable_irq(irq)
 203 #  define enable_irq_lockdep(irq)               enable_irq(irq)
 204 #  define enable_irq_lockdep_irqrestore(irq, flags) \
 205                                                 enable_irq(irq)
 206 # endif
 207
 208 #endif /* CONFIG_GENERIC_HARDIRQS */
 209
 210 #ifndef __ARCH_SET_SOFTIRQ_PENDING
 211 #define set_softirq_pending(x) (local_softirq_pending() = (x))
 212 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 213 #endif
 214
 215 /*
 216  * Temporary defines for UP kernels, until all code gets fixed.
 217  */
 218 #ifndef CONFIG_SMP
 219 static inline void __deprecated cli(void)
 220 {
 221         local_irq_disable();
 222 }
 223 static inline void __deprecated sti(void)
 224 {
 225         local_irq_enable();
 226 }
 227 static inline void __deprecated save_flags(unsigned long *x)
 228 {
 229         local_save_flags(*x);
 230 }
 231 #define save_flags(x) save_flags(&x)
 232 static inline void __deprecated restore_flags(unsigned long x)
 233 {
 234         local_irq_restore(x);
 235 }
 236
 237 static inline void __deprecated save_and_cli(unsigned long *x)
 238 {
 239         local_irq_save(*x);
 240 }
 241 #define save_and_cli(x) save_and_cli(&x)
 242 #endif /* CONFIG_SMP */
 243
 244 /* Some architectures might implement lazy enabling/disabling of
 245  * interrupts. In some cases, such as stop_machine, we might want
 246  * to ensure that after a local_irq_disable(), interrupts have
 247  * really been disabled in hardware. Such architectures need to
 248  * implement the following hook.
 249  */
 250 #ifndef hard_irq_disable
 251 #define hard_irq_disable()      do { } while(0)
 252 #endif
 253
 254 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 255    frequency threaded job scheduling. For almost all the purposes
 256    tasklets are more than enough. F.e. all serial device BHs et
 257    al. should be converted to tasklets, not to softirqs.
 258  */
 259
 260 enum
 261 {
 262         HI_SOFTIRQ=0,
 263         TIMER_SOFTIRQ,
 264         NET_TX_SOFTIRQ,
 265         NET_RX_SOFTIRQ,
 266         BLOCK_SOFTIRQ,
 267         TASKLET_SOFTIRQ,
 268         SCHED_SOFTIRQ,
 269 #ifdef CONFIG_HIGH_RES_TIMERS
 270         HRTIMER_SOFTIRQ,
 271 #endif
 272 };
 273
 274 /* softirq mask and active fields moved to irq_cpustat_t in
 275  * asm/hardirq.h to get better cache usage.  KAO
 276  */
 277
 278 struct softirq_action
 279 {
 280         void    (*action)(struct softirq_action *);
 281         void    *data;
 282 };
 283
 284 asmlinkage void do_softirq(void);
 285 extern void open_softirq(int nr, void (*action)(struct softirq_action*), void *data);
 286 extern void softirq_init(void);
 287 #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
 288 extern void FASTCALL(raise_softirq_irqoff(unsigned int nr));
 289 extern void FASTCALL(raise_softirq(unsigned int nr));
 290
 291
 292 /* Tasklets --- multithreaded analogue of BHs.
 293
 294    Main feature differing them of generic softirqs: tasklet
 295    is running only on one CPU simultaneously.
 296
 297    Main feature differing them of BHs: different tasklets
 298    may be run simultaneously on different CPUs.
 299
 300    Properties:
 301    * If tasklet_schedule() is called, then tasklet is guaranteed
 302      to be executed on some cpu at least once after this.
 303    * If the tasklet is already scheduled, but its excecution is still not
 304      started, it will be executed only once.
 305    * If this tasklet is already running on another CPU (or schedule is called
 306      from tasklet itself), it is rescheduled for later.
 307    * Tasklet is strictly serialized wrt itself, but not
 308      wrt another tasklets. If client needs some intertask synchronization,
 309      he makes it with spinlocks.
 310  */
 311
 312 struct tasklet_struct
 313 {
 314         struct tasklet_struct *next;
 315         unsigned long state;
 316         atomic_t count;
 317         void (*func)(unsigned long);
 318         unsigned long data;
 319 };
 320
 321 #define DECLARE_TASKLET(name, func, data) \
 322 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 323
 324 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 325 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 326
 327
 328 enum
 329 {
 330         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 331         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 332 };
 333
 334 #ifdef CONFIG_SMP
 335 static inline int tasklet_trylock(struct tasklet_struct *t)
 336 {
 337         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 338 }
 339
 340 static inline void tasklet_unlock(struct tasklet_struct *t)
 341 {
 342         smp_mb__before_clear_bit();
 343         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 344 }
 345
 346 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 347 {
 348         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 349 }
 350 #else
 351 #define tasklet_trylock(t) 1
 352 #define tasklet_unlock_wait(t) do { } while (0)
 353 #define tasklet_unlock(t) do { } while (0)
 354 #endif
 355
 356 extern void FASTCALL(__tasklet_schedule(struct tasklet_struct *t));
 357
 358 static inline void tasklet_schedule(struct tasklet_struct *t)
 359 {
 360         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 361                 __tasklet_schedule(t);
 362 }
 363
 364 extern void FASTCALL(__tasklet_hi_schedule(struct tasklet_struct *t));
 365
 366 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 367 {
 368         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 369                 __tasklet_hi_schedule(t);
 370 }
 371
 372
 373 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 374 {
 375         atomic_inc(&t->count);
 376         smp_mb__after_atomic_inc();
 377 }
 378
 379 static inline void tasklet_disable(struct tasklet_struct *t)
 380 {
 381         tasklet_disable_nosync(t);
 382         tasklet_unlock_wait(t);
 383         smp_mb();
 384 }
 385
 386 static inline void tasklet_enable(struct tasklet_struct *t)
 387 {
 388         smp_mb__before_atomic_dec();
 389         atomic_dec(&t->count);
 390 }
 391
 392 static inline void tasklet_hi_enable(struct tasklet_struct *t)
 393 {
 394         smp_mb__before_atomic_dec();
 395         atomic_dec(&t->count);
 396 }
 397
 398 extern void tasklet_kill(struct tasklet_struct *t);
 399 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 400 extern void tasklet_init(struct tasklet_struct *t,
 401                          void (*func)(unsigned long), unsigned long data);
 402
 403 /*
 404  * Autoprobing for irqs:
 405  *
 406  * probe_irq_on() and probe_irq_off() provide robust primitives
 407  * for accurate IRQ probing during kernel initialization.  They are
 408  * reasonably simple to use, are not "fooled" by spurious interrupts,
 409  * and, unlike other attempts at IRQ probing, they do not get hung on
 410  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 411  *
 412  * For reasonably foolproof probing, use them as follows:
 413  *
 414  * 1. clear and/or mask the device's internal interrupt.
 415  * 2. sti();
 416  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 417  * 4. enable the device and cause it to trigger an interrupt.
 418  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 419  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 420  * 7. service the device to clear its pending interrupt.
 421  * 8. loop again if paranoia is required.
 422  *
 423  * probe_irq_on() returns a mask of allocated irq's.
 424  *
 425  * probe_irq_off() takes the mask as a parameter,
 426  * and returns the irq number which occurred,
 427  * or zero if none occurred, or a negative irq number
 428  * if more than one irq occurred.
 429  */
 430
 431 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 432 static inline unsigned long probe_irq_on(void)
 433 {
 434         return 0;
 435 }
 436 static inline int probe_irq_off(unsigned long val)
 437 {
 438         return 0;
 439 }
 440 static inline unsigned int probe_irq_mask(unsigned long val)
 441 {
 442         return 0;
 443 }
 444 #else
 445 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 446 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 447 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 448 #endif
 449
 450 #ifdef CONFIG_PROC_FS
 451 /* Initialize /proc/irq/ */
 452 extern void init_irq_proc(void);
 453 #else
 454 static inline void init_irq_proc(void)
 455 {
 456 }
 457 #endif
 458
 459 #endif