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