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