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 <linux/bottom_half.h>
  15 #include <asm/atomic.h>
  16 #include <asm/ptrace.h>
  17 #include <asm/system.h>
  18
  19 /*
  20  * These correspond to the IORESOURCE_IRQ_* defines in
  21  * linux/ioport.h to select the interrupt line behaviour.  When
  22  * requesting an interrupt without specifying a IRQF_TRIGGER, the
  23  * setting should be assumed to be "as already configured", which
  24  * may be as per machine or firmware initialisation.
  25  */
  26 #define IRQF_TRIGGER_NONE       0x00000000
  27 #define IRQF_TRIGGER_RISING     0x00000001
  28 #define IRQF_TRIGGER_FALLING    0x00000002
  29 #define IRQF_TRIGGER_HIGH       0x00000004
  30 #define IRQF_TRIGGER_LOW        0x00000008
  31 #define IRQF_TRIGGER_MASK       (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
  32                                  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
  33 #define IRQF_TRIGGER_PROBE      0x00000010
  34
  35 /*
  36  * These flags used only by the kernel as part of the
  37  * irq handling routines.
  38  *
  39  * IRQF_DISABLED - keep irqs disabled when calling the action handler
  40  * IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
  41  * IRQF_SHARED - allow sharing the irq among several devices
  42  * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
  43  * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
  44  */
  45 #define IRQF_DISABLED           0x00000020
  46 #define IRQF_SAMPLE_RANDOM      0x00000040
  47 #define IRQF_SHARED             0x00000080
  48 #define IRQF_PROBE_SHARED       0x00000100
  49 #define IRQF_TIMER              0x00000200
  50 #define IRQF_PERCPU             0x00000400
  51
  52 /*
  53  * Migration helpers. Scheduled for removal in 1/2007
  54  * Do not use for new code !
  55  */
  56 #define SA_INTERRUPT            IRQF_DISABLED
  57 #define SA_SAMPLE_RANDOM        IRQF_SAMPLE_RANDOM
  58 #define SA_SHIRQ                IRQF_SHARED
  59 #define SA_PROBEIRQ             IRQF_PROBE_SHARED
  60 #define SA_PERCPU               IRQF_PERCPU
  61
  62 #define SA_TRIGGER_LOW          IRQF_TRIGGER_LOW
  63 #define SA_TRIGGER_HIGH         IRQF_TRIGGER_HIGH
  64 #define SA_TRIGGER_FALLING      IRQF_TRIGGER_FALLING
  65 #define SA_TRIGGER_RISING       IRQF_TRIGGER_RISING
  66 #define SA_TRIGGER_MASK         IRQF_TRIGGER_MASK
  67
  68 typedef irqreturn_t (*irq_handler_t)(int, void *);
  69
  70 struct irqaction {
  71         irq_handler_t handler;
  72         unsigned long flags;
  73         cpumask_t mask;
  74         const char *name;
  75         void *dev_id;
  76         struct irqaction *next;
  77         int irq;
  78         struct proc_dir_entry *dir;
  79 };
  80
  81 extern irqreturn_t no_action(int cpl, void *dev_id);
  82 extern int request_irq(unsigned int, irq_handler_t handler,
  83                        unsigned long, const char *, void *);
  84 extern void free_irq(unsigned int, void *);
  85
  86 /*
  87  * On lockdep we dont want to enable hardirqs in hardirq
  88  * context. Use local_irq_enable_in_hardirq() to annotate
  89  * kernel code that has to do this nevertheless (pretty much
  90  * the only valid case is for old/broken hardware that is
  91  * insanely slow).
  92  *
  93  * NOTE: in theory this might break fragile code that relies
  94  * on hardirq delivery - in practice we dont seem to have such
  95  * places left. So the only effect should be slightly increased
  96  * irqs-off latencies.
  97  */
  98 #ifdef CONFIG_LOCKDEP
  99 # define local_irq_enable_in_hardirq()  do { } while (0)
 100 #else
 101 # define local_irq_enable_in_hardirq()  local_irq_enable()
 102 #endif
 103
 104 #ifdef CONFIG_GENERIC_HARDIRQS
 105 extern void disable_irq_nosync(unsigned int irq);
 106 extern void disable_irq(unsigned int irq);
 107 extern void enable_irq(unsigned int irq);
 108
 109 /*
 110  * Special lockdep variants of irq disabling/enabling.
 111  * These should be used for locking constructs that
 112  * know that a particular irq context which is disabled,
 113  * and which is the only irq-context user of a lock,
 114  * that it's safe to take the lock in the irq-disabled
 115  * section without disabling hardirqs.
 116  *
 117  * On !CONFIG_LOCKDEP they are equivalent to the normal
 118  * irq disable/enable methods.
 119  */
 120 static inline void disable_irq_nosync_lockdep(unsigned int irq)
 121 {
 122         disable_irq_nosync(irq);
 123 #ifdef CONFIG_LOCKDEP
 124         local_irq_disable();
 125 #endif
 126 }
 127
 128 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 129 {
 130         disable_irq_nosync(irq);
 131 #ifdef CONFIG_LOCKDEP
 132         local_irq_save(*flags);
 133 #endif
 134 }
 135
 136 static inline void disable_irq_lockdep(unsigned int irq)
 137 {
 138         disable_irq(irq);
 139 #ifdef CONFIG_LOCKDEP
 140         local_irq_disable();
 141 #endif
 142 }
 143
 144 static inline void enable_irq_lockdep(unsigned int irq)
 145 {
 146 #ifdef CONFIG_LOCKDEP
 147         local_irq_enable();
 148 #endif
 149         enable_irq(irq);
 150 }
 151
 152 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 153 {
 154 #ifdef CONFIG_LOCKDEP
 155         local_irq_restore(*flags);
 156 #endif
 157         enable_irq(irq);
 158 }
 159
 160 /* IRQ wakeup (PM) control: */
 161 extern int set_irq_wake(unsigned int irq, unsigned int on);
 162
 163 static inline int enable_irq_wake(unsigned int irq)
 164 {
 165         return set_irq_wake(irq, 1);
 166 }
 167
 168 static inline int disable_irq_wake(unsigned int irq)
 169 {
 170         return set_irq_wake(irq, 0);
 171 }
 172
 173 #else /* !CONFIG_GENERIC_HARDIRQS */
 174 /*
 175  * NOTE: non-genirq architectures, if they want to support the lock
 176  * validator need to define the methods below in their asm/irq.h
 177  * files, under an #ifdef CONFIG_LOCKDEP section.
 178  */
 179 # ifndef CONFIG_LOCKDEP
 180 #  define disable_irq_nosync_lockdep(irq)       disable_irq_nosync(irq)
 181 #  define disable_irq_lockdep(irq)              disable_irq(irq)
 182 #  define enable_irq_lockdep(irq)               enable_irq(irq)
 183 # endif
 184
 185 #endif /* CONFIG_GENERIC_HARDIRQS */
 186
 187 #ifndef __ARCH_SET_SOFTIRQ_PENDING
 188 #define set_softirq_pending(x) (local_softirq_pending() = (x))
 189 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 190 #endif
 191
 192 /*
 193  * Temporary defines for UP kernels, until all code gets fixed.
 194  */
 195 #ifndef CONFIG_SMP
 196 static inline void __deprecated cli(void)
 197 {
 198         local_irq_disable();
 199 }
 200 static inline void __deprecated sti(void)
 201 {
 202         local_irq_enable();
 203 }
 204 static inline void __deprecated save_flags(unsigned long *x)
 205 {
 206         local_save_flags(*x);
 207 }
 208 #define save_flags(x) save_flags(&x)
 209 static inline void __deprecated restore_flags(unsigned long x)
 210 {
 211         local_irq_restore(x);
 212 }
 213
 214 static inline void __deprecated save_and_cli(unsigned long *x)
 215 {
 216         local_irq_save(*x);
 217 }
 218 #define save_and_cli(x) save_and_cli(&x)
 219 #endif /* CONFIG_SMP */
 220
 221 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 222    frequency threaded job scheduling. For almost all the purposes
 223    tasklets are more than enough. F.e. all serial device BHs et
 224    al. should be converted to tasklets, not to softirqs.
 225  */
 226
 227 enum
 228 {
 229         HI_SOFTIRQ=0,
 230         TIMER_SOFTIRQ,
 231         NET_TX_SOFTIRQ,
 232         NET_RX_SOFTIRQ,
 233         BLOCK_SOFTIRQ,
 234         TASKLET_SOFTIRQ
 235 };
 236
 237 /* softirq mask and active fields moved to irq_cpustat_t in
 238  * asm/hardirq.h to get better cache usage.  KAO
 239  */
 240
 241 struct softirq_action
 242 {
 243         void    (*action)(struct softirq_action *);
 244         void    *data;
 245 };
 246
 247 asmlinkage void do_softirq(void);
 248 extern void open_softirq(int nr, void (*action)(struct softirq_action*), void *data);
 249 extern void softirq_init(void);
 250 #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
 251 extern void FASTCALL(raise_softirq_irqoff(unsigned int nr));
 252 extern void FASTCALL(raise_softirq(unsigned int nr));
 253
 254
 255 /* Tasklets --- multithreaded analogue of BHs.
 256
 257    Main feature differing them of generic softirqs: tasklet
 258    is running only on one CPU simultaneously.
 259
 260    Main feature differing them of BHs: different tasklets
 261    may be run simultaneously on different CPUs.
 262
 263    Properties:
 264    * If tasklet_schedule() is called, then tasklet is guaranteed
 265      to be executed on some cpu at least once after this.
 266    * If the tasklet is already scheduled, but its excecution is still not
 267      started, it will be executed only once.
 268    * If this tasklet is already running on another CPU (or schedule is called
 269      from tasklet itself), it is rescheduled for later.
 270    * Tasklet is strictly serialized wrt itself, but not
 271      wrt another tasklets. If client needs some intertask synchronization,
 272      he makes it with spinlocks.
 273  */
 274
 275 struct tasklet_struct
 276 {
 277         struct tasklet_struct *next;
 278         unsigned long state;
 279         atomic_t count;
 280         void (*func)(unsigned long);
 281         unsigned long data;
 282 };
 283
 284 #define DECLARE_TASKLET(name, func, data) \
 285 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 286
 287 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 288 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 289
 290
 291 enum
 292 {
 293         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 294         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 295 };
 296
 297 #ifdef CONFIG_SMP
 298 static inline int tasklet_trylock(struct tasklet_struct *t)
 299 {
 300         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 301 }
 302
 303 static inline void tasklet_unlock(struct tasklet_struct *t)
 304 {
 305         smp_mb__before_clear_bit();
 306         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 307 }
 308
 309 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 310 {
 311         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 312 }
 313 #else
 314 #define tasklet_trylock(t) 1
 315 #define tasklet_unlock_wait(t) do { } while (0)
 316 #define tasklet_unlock(t) do { } while (0)
 317 #endif
 318
 319 extern void FASTCALL(__tasklet_schedule(struct tasklet_struct *t));
 320
 321 static inline void tasklet_schedule(struct tasklet_struct *t)
 322 {
 323         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 324                 __tasklet_schedule(t);
 325 }
 326
 327 extern void FASTCALL(__tasklet_hi_schedule(struct tasklet_struct *t));
 328
 329 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 330 {
 331         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 332                 __tasklet_hi_schedule(t);
 333 }
 334
 335
 336 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 337 {
 338         atomic_inc(&t->count);
 339         smp_mb__after_atomic_inc();
 340 }
 341
 342 static inline void tasklet_disable(struct tasklet_struct *t)
 343 {
 344         tasklet_disable_nosync(t);
 345         tasklet_unlock_wait(t);
 346         smp_mb();
 347 }
 348
 349 static inline void tasklet_enable(struct tasklet_struct *t)
 350 {
 351         smp_mb__before_atomic_dec();
 352         atomic_dec(&t->count);
 353 }
 354
 355 static inline void tasklet_hi_enable(struct tasklet_struct *t)
 356 {
 357         smp_mb__before_atomic_dec();
 358         atomic_dec(&t->count);
 359 }
 360
 361 extern void tasklet_kill(struct tasklet_struct *t);
 362 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 363 extern void tasklet_init(struct tasklet_struct *t,
 364                          void (*func)(unsigned long), unsigned long data);
 365
 366 /*
 367  * Autoprobing for irqs:
 368  *
 369  * probe_irq_on() and probe_irq_off() provide robust primitives
 370  * for accurate IRQ probing during kernel initialization.  They are
 371  * reasonably simple to use, are not "fooled" by spurious interrupts,
 372  * and, unlike other attempts at IRQ probing, they do not get hung on
 373  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 374  *
 375  * For reasonably foolproof probing, use them as follows:
 376  *
 377  * 1. clear and/or mask the device's internal interrupt.
 378  * 2. sti();
 379  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 380  * 4. enable the device and cause it to trigger an interrupt.
 381  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 382  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 383  * 7. service the device to clear its pending interrupt.
 384  * 8. loop again if paranoia is required.
 385  *
 386  * probe_irq_on() returns a mask of allocated irq's.
 387  *
 388  * probe_irq_off() takes the mask as a parameter,
 389  * and returns the irq number which occurred,
 390  * or zero if none occurred, or a negative irq number
 391  * if more than one irq occurred.
 392  */
 393
 394 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 395 static inline unsigned long probe_irq_on(void)
 396 {
 397         return 0;
 398 }
 399 static inline int probe_irq_off(unsigned long val)
 400 {
 401         return 0;
 402 }
 403 static inline unsigned int probe_irq_mask(unsigned long val)
 404 {
 405         return 0;
 406 }
 407 #else
 408 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 409 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 410 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 411 #endif
 412
 413 #endif