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