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  */
  44 #define IRQF_DISABLED           0x00000020
  45 #define IRQF_SAMPLE_RANDOM      0x00000040
  46 #define IRQF_SHARED             0x00000080
  47 #define IRQF_PROBE_SHARED       0x00000100
  48 #define IRQF_TIMER              0x00000200
  49 #define IRQF_PERCPU             0x00000400
  50
  51 /*
  52  * Migration helpers. Scheduled for removal in 1/2007
  53  * Do not use for new code !
  54  */
  55 #define SA_INTERRUPT            IRQF_DISABLED
  56 #define SA_SAMPLE_RANDOM        IRQF_SAMPLE_RANDOM
  57 #define SA_SHIRQ                IRQF_SHARED
  58 #define SA_PROBEIRQ             IRQF_PROBE_SHARED
  59 #define SA_PERCPU               IRQF_PERCPU
  60
  61 #define SA_TRIGGER_LOW          IRQF_TRIGGER_LOW
  62 #define SA_TRIGGER_HIGH         IRQF_TRIGGER_HIGH
  63 #define SA_TRIGGER_FALLING      IRQF_TRIGGER_FALLING
  64 #define SA_TRIGGER_RISING       IRQF_TRIGGER_RISING
  65 #define SA_TRIGGER_MASK         IRQF_TRIGGER_MASK
  66
  67 typedef irqreturn_t (*irq_handler_t)(int, void *);
  68
  69 struct irqaction {
  70         irq_handler_t handler;
  71         unsigned long flags;
  72         cpumask_t mask;
  73         const char *name;
  74         void *dev_id;
  75         struct irqaction *next;
  76         int irq;
  77         struct proc_dir_entry *dir;
  78 };
  79
  80 extern irqreturn_t no_action(int cpl, void *dev_id);
  81 extern int request_irq(unsigned int, irq_handler_t handler,
  82                        unsigned long, const char *, void *);
  83 extern void free_irq(unsigned int, void *);
  84
  85 /*
  86  * On lockdep we dont want to enable hardirqs in hardirq
  87  * context. Use local_irq_enable_in_hardirq() to annotate
  88  * kernel code that has to do this nevertheless (pretty much
  89  * the only valid case is for old/broken hardware that is
  90  * insanely slow).
  91  *
  92  * NOTE: in theory this might break fragile code that relies
  93  * on hardirq delivery - in practice we dont seem to have such
  94  * places left. So the only effect should be slightly increased
  95  * irqs-off latencies.
  96  */
  97 #ifdef CONFIG_LOCKDEP
  98 # define local_irq_enable_in_hardirq()  do { } while (0)
  99 #else
 100 # define local_irq_enable_in_hardirq()  local_irq_enable()
 101 #endif
 102
 103 #ifdef CONFIG_GENERIC_HARDIRQS
 104 extern void disable_irq_nosync(unsigned int irq);
 105 extern void disable_irq(unsigned int irq);
 106 extern void enable_irq(unsigned int irq);
 107
 108 /*
 109  * Special lockdep variants of irq disabling/enabling.
 110  * These should be used for locking constructs that
 111  * know that a particular irq context which is disabled,
 112  * and which is the only irq-context user of a lock,
 113  * that it's safe to take the lock in the irq-disabled
 114  * section without disabling hardirqs.
 115  *
 116  * On !CONFIG_LOCKDEP they are equivalent to the normal
 117  * irq disable/enable methods.
 118  */
 119 static inline void disable_irq_nosync_lockdep(unsigned int irq)
 120 {
 121         disable_irq_nosync(irq);
 122 #ifdef CONFIG_LOCKDEP
 123         local_irq_disable();
 124 #endif
 125 }
 126
 127 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 128 {
 129         disable_irq_nosync(irq);
 130 #ifdef CONFIG_LOCKDEP
 131         local_irq_save(*flags);
 132 #endif
 133 }
 134
 135 static inline void disable_irq_lockdep(unsigned int irq)
 136 {
 137         disable_irq(irq);
 138 #ifdef CONFIG_LOCKDEP
 139         local_irq_disable();
 140 #endif
 141 }
 142
 143 static inline void enable_irq_lockdep(unsigned int irq)
 144 {
 145 #ifdef CONFIG_LOCKDEP
 146         local_irq_enable();
 147 #endif
 148         enable_irq(irq);
 149 }
 150
 151 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 152 {
 153 #ifdef CONFIG_LOCKDEP
 154         local_irq_restore(*flags);
 155 #endif
 156         enable_irq(irq);
 157 }
 158
 159 /* IRQ wakeup (PM) control: */
 160 extern int set_irq_wake(unsigned int irq, unsigned int on);
 161
 162 static inline int enable_irq_wake(unsigned int irq)
 163 {
 164         return set_irq_wake(irq, 1);
 165 }
 166
 167 static inline int disable_irq_wake(unsigned int irq)
 168 {
 169         return set_irq_wake(irq, 0);
 170 }
 171
 172 #else /* !CONFIG_GENERIC_HARDIRQS */
 173 /*
 174  * NOTE: non-genirq architectures, if they want to support the lock
 175  * validator need to define the methods below in their asm/irq.h
 176  * files, under an #ifdef CONFIG_LOCKDEP section.
 177  */
 178 # ifndef CONFIG_LOCKDEP
 179 #  define disable_irq_nosync_lockdep(irq)       disable_irq_nosync(irq)
 180 #  define disable_irq_lockdep(irq)              disable_irq(irq)
 181 #  define enable_irq_lockdep(irq)               enable_irq(irq)
 182 # endif
 183
 184 #endif /* CONFIG_GENERIC_HARDIRQS */
 185
 186 #ifndef __ARCH_SET_SOFTIRQ_PENDING
 187 #define set_softirq_pending(x) (local_softirq_pending() = (x))
 188 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 189 #endif
 190
 191 /*
 192  * Temporary defines for UP kernels, until all code gets fixed.
 193  */
 194 #ifndef CONFIG_SMP
 195 static inline void __deprecated cli(void)
 196 {
 197         local_irq_disable();
 198 }
 199 static inline void __deprecated sti(void)
 200 {
 201         local_irq_enable();
 202 }
 203 static inline void __deprecated save_flags(unsigned long *x)
 204 {
 205         local_save_flags(*x);
 206 }
 207 #define save_flags(x) save_flags(&x)
 208 static inline void __deprecated restore_flags(unsigned long x)
 209 {
 210         local_irq_restore(x);
 211 }
 212
 213 static inline void __deprecated save_and_cli(unsigned long *x)
 214 {
 215         local_irq_save(*x);
 216 }
 217 #define save_and_cli(x) save_and_cli(&x)
 218 #endif /* CONFIG_SMP */
 219
 220 extern void local_bh_disable(void);
 221 extern void __local_bh_enable(void);
 222 extern void _local_bh_enable(void);
 223 extern void local_bh_enable(void);
 224 extern void local_bh_enable_ip(unsigned long ip);
 225
 226 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 227    frequency threaded job scheduling. For almost all the purposes
 228    tasklets are more than enough. F.e. all serial device BHs et
 229    al. should be converted to tasklets, not to softirqs.
 230  */
 231
 232 enum
 233 {
 234         HI_SOFTIRQ=0,
 235         TIMER_SOFTIRQ,
 236         NET_TX_SOFTIRQ,
 237         NET_RX_SOFTIRQ,
 238         BLOCK_SOFTIRQ,
 239         TASKLET_SOFTIRQ
 240 };
 241
 242 /* softirq mask and active fields moved to irq_cpustat_t in
 243  * asm/hardirq.h to get better cache usage.  KAO
 244  */
 245
 246 struct softirq_action
 247 {
 248         void    (*action)(struct softirq_action *);
 249         void    *data;
 250 };
 251
 252 asmlinkage void do_softirq(void);
 253 extern void open_softirq(int nr, void (*action)(struct softirq_action*), void *data);
 254 extern void softirq_init(void);
 255 #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
 256 extern void FASTCALL(raise_softirq_irqoff(unsigned int nr));
 257 extern void FASTCALL(raise_softirq(unsigned int nr));
 258
 259
 260 /* Tasklets --- multithreaded analogue of BHs.
 261
 262    Main feature differing them of generic softirqs: tasklet
 263    is running only on one CPU simultaneously.
 264
 265    Main feature differing them of BHs: different tasklets
 266    may be run simultaneously on different CPUs.
 267
 268    Properties:
 269    * If tasklet_schedule() is called, then tasklet is guaranteed
 270      to be executed on some cpu at least once after this.
 271    * If the tasklet is already scheduled, but its excecution is still not
 272      started, it will be executed only once.
 273    * If this tasklet is already running on another CPU (or schedule is called
 274      from tasklet itself), it is rescheduled for later.
 275    * Tasklet is strictly serialized wrt itself, but not
 276      wrt another tasklets. If client needs some intertask synchronization,
 277      he makes it with spinlocks.
 278  */
 279
 280 struct tasklet_struct
 281 {
 282         struct tasklet_struct *next;
 283         unsigned long state;
 284         atomic_t count;
 285         void (*func)(unsigned long);
 286         unsigned long data;
 287 };
 288
 289 #define DECLARE_TASKLET(name, func, data) \
 290 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 291
 292 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 293 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 294
 295
 296 enum
 297 {
 298         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 299         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 300 };
 301
 302 #ifdef CONFIG_SMP
 303 static inline int tasklet_trylock(struct tasklet_struct *t)
 304 {
 305         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 306 }
 307
 308 static inline void tasklet_unlock(struct tasklet_struct *t)
 309 {
 310         smp_mb__before_clear_bit();
 311         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 312 }
 313
 314 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 315 {
 316         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 317 }
 318 #else
 319 #define tasklet_trylock(t) 1
 320 #define tasklet_unlock_wait(t) do { } while (0)
 321 #define tasklet_unlock(t) do { } while (0)
 322 #endif
 323
 324 extern void FASTCALL(__tasklet_schedule(struct tasklet_struct *t));
 325
 326 static inline void tasklet_schedule(struct tasklet_struct *t)
 327 {
 328         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 329                 __tasklet_schedule(t);
 330 }
 331
 332 extern void FASTCALL(__tasklet_hi_schedule(struct tasklet_struct *t));
 333
 334 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 335 {
 336         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 337                 __tasklet_hi_schedule(t);
 338 }
 339
 340
 341 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 342 {
 343         atomic_inc(&t->count);
 344         smp_mb__after_atomic_inc();
 345 }
 346
 347 static inline void tasklet_disable(struct tasklet_struct *t)
 348 {
 349         tasklet_disable_nosync(t);
 350         tasklet_unlock_wait(t);
 351         smp_mb();
 352 }
 353
 354 static inline void tasklet_enable(struct tasklet_struct *t)
 355 {
 356         smp_mb__before_atomic_dec();
 357         atomic_dec(&t->count);
 358 }
 359
 360 static inline void tasklet_hi_enable(struct tasklet_struct *t)
 361 {
 362         smp_mb__before_atomic_dec();
 363         atomic_dec(&t->count);
 364 }
 365
 366 extern void tasklet_kill(struct tasklet_struct *t);
 367 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 368 extern void tasklet_init(struct tasklet_struct *t,
 369                          void (*func)(unsigned long), unsigned long data);
 370
 371 /*
 372  * Autoprobing for irqs:
 373  *
 374  * probe_irq_on() and probe_irq_off() provide robust primitives
 375  * for accurate IRQ probing during kernel initialization.  They are
 376  * reasonably simple to use, are not "fooled" by spurious interrupts,
 377  * and, unlike other attempts at IRQ probing, they do not get hung on
 378  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 379  *
 380  * For reasonably foolproof probing, use them as follows:
 381  *
 382  * 1. clear and/or mask the device's internal interrupt.
 383  * 2. sti();
 384  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 385  * 4. enable the device and cause it to trigger an interrupt.
 386  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 387  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 388  * 7. service the device to clear its pending interrupt.
 389  * 8. loop again if paranoia is required.
 390  *
 391  * probe_irq_on() returns a mask of allocated irq's.
 392  *
 393  * probe_irq_off() takes the mask as a parameter,
 394  * and returns the irq number which occurred,
 395  * or zero if none occurred, or a negative irq number
 396  * if more than one irq occurred.
 397  */
 398
 399 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 400 static inline unsigned long probe_irq_on(void)
 401 {
 402         return 0;
 403 }
 404 static inline int probe_irq_off(unsigned long val)
 405 {
 406         return 0;
 407 }
 408 static inline unsigned int probe_irq_mask(unsigned long val)
 409 {
 410         return 0;
 411 }
 412 #else
 413 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 414 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 415 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 416 #endif
 417
 418 #endif