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/irqnr.h>
  12 #include <linux/hardirq.h>
  13 #include <linux/sched.h>
  14 #include <linux/irqflags.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  * IRQF_PERCPU - Interrupt is per cpu
  45  * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
  46  * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
  47  *                registered first in an shared interrupt is considered for
  48  *                performance reasons)
  49  */
  50 #define IRQF_DISABLED           0x00000020
  51 #define IRQF_SAMPLE_RANDOM      0x00000040
  52 #define IRQF_SHARED             0x00000080
  53 #define IRQF_PROBE_SHARED       0x00000100
  54 #define IRQF_TIMER              0x00000200
  55 #define IRQF_PERCPU             0x00000400
  56 #define IRQF_NOBALANCING        0x00000800
  57 #define IRQF_IRQPOLL            0x00001000
  58
  59 typedef irqreturn_t (*irq_handler_t)(int, void *);
  60
  61 struct irqaction {
  62         irq_handler_t handler;
  63         unsigned long flags;
  64         cpumask_t mask;
  65         const char *name;
  66         void *dev_id;
  67         struct irqaction *next;
  68         int irq;
  69         struct proc_dir_entry *dir;
  70 };
  71
  72 extern irqreturn_t no_action(int cpl, void *dev_id);
  73 extern int __must_check request_irq(unsigned int, irq_handler_t handler,
  74                        unsigned long, const char *, void *);
  75 extern void free_irq(unsigned int, void *);
  76
  77 struct device;
  78
  79 extern int __must_check devm_request_irq(struct device *dev, unsigned int irq,
  80                             irq_handler_t handler, unsigned long irqflags,
  81                             const char *devname, void *dev_id);
  82 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
  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 extern void disable_irq_nosync(unsigned int irq);
 103 extern void disable_irq(unsigned int irq);
 104 extern void enable_irq(unsigned int irq);
 105
 106 #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
 107
 108 extern cpumask_t irq_default_affinity;
 109
 110 extern int irq_set_affinity(unsigned int irq, cpumask_t cpumask);
 111 extern int irq_can_set_affinity(unsigned int irq);
 112 extern int irq_select_affinity(unsigned int irq);
 113
 114 #else /* CONFIG_SMP */
 115
 116 static inline int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
 117 {
 118         return -EINVAL;
 119 }
 120
 121 static inline int irq_can_set_affinity(unsigned int irq)
 122 {
 123         return 0;
 124 }
 125
 126 static inline int irq_select_affinity(unsigned int irq)  { return 0; }
 127
 128 #endif /* CONFIG_SMP && CONFIG_GENERIC_HARDIRQS */
 129
 130 #ifdef CONFIG_GENERIC_HARDIRQS
 131 /*
 132  * Special lockdep variants of irq disabling/enabling.
 133  * These should be used for locking constructs that
 134  * know that a particular irq context which is disabled,
 135  * and which is the only irq-context user of a lock,
 136  * that it's safe to take the lock in the irq-disabled
 137  * section without disabling hardirqs.
 138  *
 139  * On !CONFIG_LOCKDEP they are equivalent to the normal
 140  * irq disable/enable methods.
 141  */
 142 static inline void disable_irq_nosync_lockdep(unsigned int irq)
 143 {
 144         disable_irq_nosync(irq);
 145 #ifdef CONFIG_LOCKDEP
 146         local_irq_disable();
 147 #endif
 148 }
 149
 150 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 151 {
 152         disable_irq_nosync(irq);
 153 #ifdef CONFIG_LOCKDEP
 154         local_irq_save(*flags);
 155 #endif
 156 }
 157
 158 static inline void disable_irq_lockdep(unsigned int irq)
 159 {
 160         disable_irq(irq);
 161 #ifdef CONFIG_LOCKDEP
 162         local_irq_disable();
 163 #endif
 164 }
 165
 166 static inline void enable_irq_lockdep(unsigned int irq)
 167 {
 168 #ifdef CONFIG_LOCKDEP
 169         local_irq_enable();
 170 #endif
 171         enable_irq(irq);
 172 }
 173
 174 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 175 {
 176 #ifdef CONFIG_LOCKDEP
 177         local_irq_restore(*flags);
 178 #endif
 179         enable_irq(irq);
 180 }
 181
 182 /* IRQ wakeup (PM) control: */
 183 extern int set_irq_wake(unsigned int irq, unsigned int on);
 184
 185 static inline int enable_irq_wake(unsigned int irq)
 186 {
 187         return set_irq_wake(irq, 1);
 188 }
 189
 190 static inline int disable_irq_wake(unsigned int irq)
 191 {
 192         return set_irq_wake(irq, 0);
 193 }
 194
 195 #else /* !CONFIG_GENERIC_HARDIRQS */
 196 /*
 197  * NOTE: non-genirq architectures, if they want to support the lock
 198  * validator need to define the methods below in their asm/irq.h
 199  * files, under an #ifdef CONFIG_LOCKDEP section.
 200  */
 201 #ifndef CONFIG_LOCKDEP
 202 #  define disable_irq_nosync_lockdep(irq)       disable_irq_nosync(irq)
 203 #  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
 204                                                 disable_irq_nosync(irq)
 205 #  define disable_irq_lockdep(irq)              disable_irq(irq)
 206 #  define enable_irq_lockdep(irq)               enable_irq(irq)
 207 #  define enable_irq_lockdep_irqrestore(irq, flags) \
 208                                                 enable_irq(irq)
 209 # endif
 210
 211 static inline int enable_irq_wake(unsigned int irq)
 212 {
 213         return 0;
 214 }
 215
 216 static inline int disable_irq_wake(unsigned int irq)
 217 {
 218         return 0;
 219 }
 220 #endif /* CONFIG_GENERIC_HARDIRQS */
 221
 222 #ifndef __ARCH_SET_SOFTIRQ_PENDING
 223 #define set_softirq_pending(x) (local_softirq_pending() = (x))
 224 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 225 #endif
 226
 227 /* Some architectures might implement lazy enabling/disabling of
 228  * interrupts. In some cases, such as stop_machine, we might want
 229  * to ensure that after a local_irq_disable(), interrupts have
 230  * really been disabled in hardware. Such architectures need to
 231  * implement the following hook.
 232  */
 233 #ifndef hard_irq_disable
 234 #define hard_irq_disable()      do { } while(0)
 235 #endif
 236
 237 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 238    frequency threaded job scheduling. For almost all the purposes
 239    tasklets are more than enough. F.e. all serial device BHs et
 240    al. should be converted to tasklets, not to softirqs.
 241  */
 242
 243 enum
 244 {
 245         HI_SOFTIRQ=0,
 246         TIMER_SOFTIRQ,
 247         NET_TX_SOFTIRQ,
 248         NET_RX_SOFTIRQ,
 249         BLOCK_SOFTIRQ,
 250         TASKLET_SOFTIRQ,
 251         SCHED_SOFTIRQ,
 252 #ifdef CONFIG_HIGH_RES_TIMERS
 253         HRTIMER_SOFTIRQ,
 254 #endif
 255         RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
 256 };
 257
 258 /* softirq mask and active fields moved to irq_cpustat_t in
 259  * asm/hardirq.h to get better cache usage.  KAO
 260  */
 261
 262 struct softirq_action
 263 {
 264         void    (*action)(struct softirq_action *);
 265 };
 266
 267 asmlinkage void do_softirq(void);
 268 asmlinkage void __do_softirq(void);
 269 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
 270 extern void softirq_init(void);
 271 #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
 272 extern void raise_softirq_irqoff(unsigned int nr);
 273 extern void raise_softirq(unsigned int nr);
 274
 275
 276 /* Tasklets --- multithreaded analogue of BHs.
 277
 278    Main feature differing them of generic softirqs: tasklet
 279    is running only on one CPU simultaneously.
 280
 281    Main feature differing them of BHs: different tasklets
 282    may be run simultaneously on different CPUs.
 283
 284    Properties:
 285    * If tasklet_schedule() is called, then tasklet is guaranteed
 286      to be executed on some cpu at least once after this.
 287    * If the tasklet is already scheduled, but its excecution is still not
 288      started, it will be executed only once.
 289    * If this tasklet is already running on another CPU (or schedule is called
 290      from tasklet itself), it is rescheduled for later.
 291    * Tasklet is strictly serialized wrt itself, but not
 292      wrt another tasklets. If client needs some intertask synchronization,
 293      he makes it with spinlocks.
 294  */
 295
 296 struct tasklet_struct
 297 {
 298         struct tasklet_struct *next;
 299         unsigned long state;
 300         atomic_t count;
 301         void (*func)(unsigned long);
 302         unsigned long data;
 303 };
 304
 305 #define DECLARE_TASKLET(name, func, data) \
 306 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 307
 308 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 309 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 310
 311
 312 enum
 313 {
 314         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 315         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 316 };
 317
 318 #ifdef CONFIG_SMP
 319 static inline int tasklet_trylock(struct tasklet_struct *t)
 320 {
 321         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 322 }
 323
 324 static inline void tasklet_unlock(struct tasklet_struct *t)
 325 {
 326         smp_mb__before_clear_bit();
 327         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 328 }
 329
 330 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 331 {
 332         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 333 }
 334 #else
 335 #define tasklet_trylock(t) 1
 336 #define tasklet_unlock_wait(t) do { } while (0)
 337 #define tasklet_unlock(t) do { } while (0)
 338 #endif
 339
 340 extern void __tasklet_schedule(struct tasklet_struct *t);
 341
 342 static inline void tasklet_schedule(struct tasklet_struct *t)
 343 {
 344         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 345                 __tasklet_schedule(t);
 346 }
 347
 348 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
 349
 350 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 351 {
 352         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 353                 __tasklet_hi_schedule(t);
 354 }
 355
 356
 357 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 358 {
 359         atomic_inc(&t->count);
 360         smp_mb__after_atomic_inc();
 361 }
 362
 363 static inline void tasklet_disable(struct tasklet_struct *t)
 364 {
 365         tasklet_disable_nosync(t);
 366         tasklet_unlock_wait(t);
 367         smp_mb();
 368 }
 369
 370 static inline void tasklet_enable(struct tasklet_struct *t)
 371 {
 372         smp_mb__before_atomic_dec();
 373         atomic_dec(&t->count);
 374 }
 375
 376 static inline void tasklet_hi_enable(struct tasklet_struct *t)
 377 {
 378         smp_mb__before_atomic_dec();
 379         atomic_dec(&t->count);
 380 }
 381
 382 extern void tasklet_kill(struct tasklet_struct *t);
 383 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 384 extern void tasklet_init(struct tasklet_struct *t,
 385                          void (*func)(unsigned long), unsigned long data);
 386
 387 /*
 388  * Autoprobing for irqs:
 389  *
 390  * probe_irq_on() and probe_irq_off() provide robust primitives
 391  * for accurate IRQ probing during kernel initialization.  They are
 392  * reasonably simple to use, are not "fooled" by spurious interrupts,
 393  * and, unlike other attempts at IRQ probing, they do not get hung on
 394  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 395  *
 396  * For reasonably foolproof probing, use them as follows:
 397  *
 398  * 1. clear and/or mask the device's internal interrupt.
 399  * 2. sti();
 400  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 401  * 4. enable the device and cause it to trigger an interrupt.
 402  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 403  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 404  * 7. service the device to clear its pending interrupt.
 405  * 8. loop again if paranoia is required.
 406  *
 407  * probe_irq_on() returns a mask of allocated irq's.
 408  *
 409  * probe_irq_off() takes the mask as a parameter,
 410  * and returns the irq number which occurred,
 411  * or zero if none occurred, or a negative irq number
 412  * if more than one irq occurred.
 413  */
 414
 415 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 416 static inline unsigned long probe_irq_on(void)
 417 {
 418         return 0;
 419 }
 420 static inline int probe_irq_off(unsigned long val)
 421 {
 422         return 0;
 423 }
 424 static inline unsigned int probe_irq_mask(unsigned long val)
 425 {
 426         return 0;
 427 }
 428 #else
 429 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 430 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 431 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 432 #endif
 433
 434 #ifdef CONFIG_PROC_FS
 435 /* Initialize /proc/irq/ */
 436 extern void init_irq_proc(void);
 437 #else
 438 static inline void init_irq_proc(void)
 439 {
 440 }
 441 #endif
 442
 443 int show_interrupts(struct seq_file *p, void *v);
 444
 445 #endif