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 <linux/smp.h>
  16 #include <linux/percpu.h>
  17 #include <asm/atomic.h>
  18 #include <asm/ptrace.h>
  19 #include <asm/system.h>
  20
  21 /*
  22  * These correspond to the IORESOURCE_IRQ_* defines in
  23  * linux/ioport.h to select the interrupt line behaviour.  When
  24  * requesting an interrupt without specifying a IRQF_TRIGGER, the
  25  * setting should be assumed to be "as already configured", which
  26  * may be as per machine or firmware initialisation.
  27  */
  28 #define IRQF_TRIGGER_NONE       0x00000000
  29 #define IRQF_TRIGGER_RISING     0x00000001
  30 #define IRQF_TRIGGER_FALLING    0x00000002
  31 #define IRQF_TRIGGER_HIGH       0x00000004
  32 #define IRQF_TRIGGER_LOW        0x00000008
  33 #define IRQF_TRIGGER_MASK       (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
  34                                  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
  35 #define IRQF_TRIGGER_PROBE      0x00000010
  36
  37 /*
  38  * These flags used only by the kernel as part of the
  39  * irq handling routines.
  40  *
  41  * IRQF_DISABLED - keep irqs disabled when calling the action handler
  42  * IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
  43  * IRQF_SHARED - allow sharing the irq among several devices
  44  * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
  45  * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
  46  * IRQF_PERCPU - Interrupt is per cpu
  47  * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
  48  * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
  49  *                registered first in an shared interrupt is considered for
  50  *                performance reasons)
  51  */
  52 #define IRQF_DISABLED           0x00000020
  53 #define IRQF_SAMPLE_RANDOM      0x00000040
  54 #define IRQF_SHARED             0x00000080
  55 #define IRQF_PROBE_SHARED       0x00000100
  56 #define IRQF_TIMER              0x00000200
  57 #define IRQF_PERCPU             0x00000400
  58 #define IRQF_NOBALANCING        0x00000800
  59 #define IRQF_IRQPOLL            0x00001000
  60
  61 typedef irqreturn_t (*irq_handler_t)(int, void *);
  62
  63 struct irqaction {
  64         irq_handler_t handler;
  65         unsigned long flags;
  66         cpumask_t mask;
  67         const char *name;
  68         void *dev_id;
  69         struct irqaction *next;
  70         int irq;
  71         struct proc_dir_entry *dir;
  72 };
  73
  74 extern irqreturn_t no_action(int cpl, void *dev_id);
  75 extern int __must_check request_irq(unsigned int, irq_handler_t handler,
  76                        unsigned long, const char *, void *);
  77 extern void free_irq(unsigned int, void *);
  78
  79 struct device;
  80
  81 extern int __must_check devm_request_irq(struct device *dev, unsigned int irq,
  82                             irq_handler_t handler, unsigned long irqflags,
  83                             const char *devname, void *dev_id);
  84 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
  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 extern void disable_irq_nosync(unsigned int irq);
 105 extern void disable_irq(unsigned int irq);
 106 extern void enable_irq(unsigned int irq);
 107
 108 #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
 109
 110 extern cpumask_t irq_default_affinity;
 111
 112 extern int irq_set_affinity(unsigned int irq, cpumask_t cpumask);
 113 extern int irq_can_set_affinity(unsigned int irq);
 114 extern int irq_select_affinity(unsigned int irq);
 115
 116 #else /* CONFIG_SMP */
 117
 118 static inline int irq_set_affinity(unsigned int irq, cpumask_t cpumask)
 119 {
 120         return -EINVAL;
 121 }
 122
 123 static inline int irq_can_set_affinity(unsigned int irq)
 124 {
 125         return 0;
 126 }
 127
 128 static inline int irq_select_affinity(unsigned int irq)  { return 0; }
 129
 130 #endif /* CONFIG_SMP && CONFIG_GENERIC_HARDIRQS */
 131
 132 #ifdef CONFIG_GENERIC_HARDIRQS
 133 /*
 134  * Special lockdep variants of irq disabling/enabling.
 135  * These should be used for locking constructs that
 136  * know that a particular irq context which is disabled,
 137  * and which is the only irq-context user of a lock,
 138  * that it's safe to take the lock in the irq-disabled
 139  * section without disabling hardirqs.
 140  *
 141  * On !CONFIG_LOCKDEP they are equivalent to the normal
 142  * irq disable/enable methods.
 143  */
 144 static inline void disable_irq_nosync_lockdep(unsigned int irq)
 145 {
 146         disable_irq_nosync(irq);
 147 #ifdef CONFIG_LOCKDEP
 148         local_irq_disable();
 149 #endif
 150 }
 151
 152 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 153 {
 154         disable_irq_nosync(irq);
 155 #ifdef CONFIG_LOCKDEP
 156         local_irq_save(*flags);
 157 #endif
 158 }
 159
 160 static inline void disable_irq_lockdep(unsigned int irq)
 161 {
 162         disable_irq(irq);
 163 #ifdef CONFIG_LOCKDEP
 164         local_irq_disable();
 165 #endif
 166 }
 167
 168 static inline void enable_irq_lockdep(unsigned int irq)
 169 {
 170 #ifdef CONFIG_LOCKDEP
 171         local_irq_enable();
 172 #endif
 173         enable_irq(irq);
 174 }
 175
 176 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 177 {
 178 #ifdef CONFIG_LOCKDEP
 179         local_irq_restore(*flags);
 180 #endif
 181         enable_irq(irq);
 182 }
 183
 184 /* IRQ wakeup (PM) control: */
 185 extern int set_irq_wake(unsigned int irq, unsigned int on);
 186
 187 static inline int enable_irq_wake(unsigned int irq)
 188 {
 189         return set_irq_wake(irq, 1);
 190 }
 191
 192 static inline int disable_irq_wake(unsigned int irq)
 193 {
 194         return set_irq_wake(irq, 0);
 195 }
 196
 197 #else /* !CONFIG_GENERIC_HARDIRQS */
 198 /*
 199  * NOTE: non-genirq architectures, if they want to support the lock
 200  * validator need to define the methods below in their asm/irq.h
 201  * files, under an #ifdef CONFIG_LOCKDEP section.
 202  */
 203 #ifndef CONFIG_LOCKDEP
 204 #  define disable_irq_nosync_lockdep(irq)       disable_irq_nosync(irq)
 205 #  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
 206                                                 disable_irq_nosync(irq)
 207 #  define disable_irq_lockdep(irq)              disable_irq(irq)
 208 #  define enable_irq_lockdep(irq)               enable_irq(irq)
 209 #  define enable_irq_lockdep_irqrestore(irq, flags) \
 210                                                 enable_irq(irq)
 211 # endif
 212
 213 static inline int enable_irq_wake(unsigned int irq)
 214 {
 215         return 0;
 216 }
 217
 218 static inline int disable_irq_wake(unsigned int irq)
 219 {
 220         return 0;
 221 }
 222 #endif /* CONFIG_GENERIC_HARDIRQS */
 223
 224 #ifndef __ARCH_SET_SOFTIRQ_PENDING
 225 #define set_softirq_pending(x) (local_softirq_pending() = (x))
 226 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 227 #endif
 228
 229 /* Some architectures might implement lazy enabling/disabling of
 230  * interrupts. In some cases, such as stop_machine, we might want
 231  * to ensure that after a local_irq_disable(), interrupts have
 232  * really been disabled in hardware. Such architectures need to
 233  * implement the following hook.
 234  */
 235 #ifndef hard_irq_disable
 236 #define hard_irq_disable()      do { } while(0)
 237 #endif
 238
 239 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 240    frequency threaded job scheduling. For almost all the purposes
 241    tasklets are more than enough. F.e. all serial device BHs et
 242    al. should be converted to tasklets, not to softirqs.
 243  */
 244
 245 enum
 246 {
 247         HI_SOFTIRQ=0,
 248         TIMER_SOFTIRQ,
 249         NET_TX_SOFTIRQ,
 250         NET_RX_SOFTIRQ,
 251         BLOCK_SOFTIRQ,
 252         TASKLET_SOFTIRQ,
 253         SCHED_SOFTIRQ,
 254 #ifdef CONFIG_HIGH_RES_TIMERS
 255         HRTIMER_SOFTIRQ,
 256 #endif
 257         RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
 258
 259         NR_SOFTIRQS
 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 };
 270
 271 asmlinkage void do_softirq(void);
 272 asmlinkage void __do_softirq(void);
 273 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
 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 /* This is the worklist that queues up per-cpu softirq work.
 280  *
 281  * send_remote_sendirq() adds work to these lists, and
 282  * the softirq handler itself dequeues from them.  The queues
 283  * are protected by disabling local cpu interrupts and they must
 284  * only be accessed by the local cpu that they are for.
 285  */
 286 DECLARE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
 287
 288 /* Try to send a softirq to a remote cpu.  If this cannot be done, the
 289  * work will be queued to the local cpu.
 290  */
 291 extern void send_remote_softirq(struct call_single_data *cp, int cpu, int softirq);
 292
 293 /* Like send_remote_softirq(), but the caller must disable local cpu interrupts
 294  * and compute the current cpu, passed in as 'this_cpu'.
 295  */
 296 extern void __send_remote_softirq(struct call_single_data *cp, int cpu,
 297                                   int this_cpu, int softirq);
 298
 299 /* Tasklets --- multithreaded analogue of BHs.
 300
 301    Main feature differing them of generic softirqs: tasklet
 302    is running only on one CPU simultaneously.
 303
 304    Main feature differing them of BHs: different tasklets
 305    may be run simultaneously on different CPUs.
 306
 307    Properties:
 308    * If tasklet_schedule() is called, then tasklet is guaranteed
 309      to be executed on some cpu at least once after this.
 310    * If the tasklet is already scheduled, but its excecution is still not
 311      started, it will be executed only once.
 312    * If this tasklet is already running on another CPU (or schedule is called
 313      from tasklet itself), it is rescheduled for later.
 314    * Tasklet is strictly serialized wrt itself, but not
 315      wrt another tasklets. If client needs some intertask synchronization,
 316      he makes it with spinlocks.
 317  */
 318
 319 struct tasklet_struct
 320 {
 321         struct tasklet_struct *next;
 322         unsigned long state;
 323         atomic_t count;
 324         void (*func)(unsigned long);
 325         unsigned long data;
 326 };
 327
 328 #define DECLARE_TASKLET(name, func, data) \
 329 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 330
 331 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 332 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 333
 334
 335 enum
 336 {
 337         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 338         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 339 };
 340
 341 #ifdef CONFIG_SMP
 342 static inline int tasklet_trylock(struct tasklet_struct *t)
 343 {
 344         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 345 }
 346
 347 static inline void tasklet_unlock(struct tasklet_struct *t)
 348 {
 349         smp_mb__before_clear_bit();
 350         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 351 }
 352
 353 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 354 {
 355         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 356 }
 357 #else
 358 #define tasklet_trylock(t) 1
 359 #define tasklet_unlock_wait(t) do { } while (0)
 360 #define tasklet_unlock(t) do { } while (0)
 361 #endif
 362
 363 extern void __tasklet_schedule(struct tasklet_struct *t);
 364
 365 static inline void tasklet_schedule(struct tasklet_struct *t)
 366 {
 367         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 368                 __tasklet_schedule(t);
 369 }
 370
 371 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
 372
 373 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 374 {
 375         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 376                 __tasklet_hi_schedule(t);
 377 }
 378
 379
 380 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 381 {
 382         atomic_inc(&t->count);
 383         smp_mb__after_atomic_inc();
 384 }
 385
 386 static inline void tasklet_disable(struct tasklet_struct *t)
 387 {
 388         tasklet_disable_nosync(t);
 389         tasklet_unlock_wait(t);
 390         smp_mb();
 391 }
 392
 393 static inline void tasklet_enable(struct tasklet_struct *t)
 394 {
 395         smp_mb__before_atomic_dec();
 396         atomic_dec(&t->count);
 397 }
 398
 399 static inline void tasklet_hi_enable(struct tasklet_struct *t)
 400 {
 401         smp_mb__before_atomic_dec();
 402         atomic_dec(&t->count);
 403 }
 404
 405 extern void tasklet_kill(struct tasklet_struct *t);
 406 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 407 extern void tasklet_init(struct tasklet_struct *t,
 408                          void (*func)(unsigned long), unsigned long data);
 409
 410 /*
 411  * Autoprobing for irqs:
 412  *
 413  * probe_irq_on() and probe_irq_off() provide robust primitives
 414  * for accurate IRQ probing during kernel initialization.  They are
 415  * reasonably simple to use, are not "fooled" by spurious interrupts,
 416  * and, unlike other attempts at IRQ probing, they do not get hung on
 417  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 418  *
 419  * For reasonably foolproof probing, use them as follows:
 420  *
 421  * 1. clear and/or mask the device's internal interrupt.
 422  * 2. sti();
 423  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 424  * 4. enable the device and cause it to trigger an interrupt.
 425  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 426  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 427  * 7. service the device to clear its pending interrupt.
 428  * 8. loop again if paranoia is required.
 429  *
 430  * probe_irq_on() returns a mask of allocated irq's.
 431  *
 432  * probe_irq_off() takes the mask as a parameter,
 433  * and returns the irq number which occurred,
 434  * or zero if none occurred, or a negative irq number
 435  * if more than one irq occurred.
 436  */
 437
 438 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 439 static inline unsigned long probe_irq_on(void)
 440 {
 441         return 0;
 442 }
 443 static inline int probe_irq_off(unsigned long val)
 444 {
 445         return 0;
 446 }
 447 static inline unsigned int probe_irq_mask(unsigned long val)
 448 {
 449         return 0;
 450 }
 451 #else
 452 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 453 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 454 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 455 #endif
 456
 457 #ifdef CONFIG_PROC_FS
 458 /* Initialize /proc/irq/ */
 459 extern void init_irq_proc(void);
 460 #else
 461 static inline void init_irq_proc(void)
 462 {
 463 }
 464 #endif
 465
 466 int show_interrupts(struct seq_file *p, void *v);
 467
 468 #endif