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
  18 #include <asm/atomic.h>
  19 #include <asm/ptrace.h>
  20 #include <asm/system.h>
  21
  22 /*
  23  * These correspond to the IORESOURCE_IRQ_* defines in
  24  * linux/ioport.h to select the interrupt line behaviour.  When
  25  * requesting an interrupt without specifying a IRQF_TRIGGER, the
  26  * setting should be assumed to be "as already configured", which
  27  * may be as per machine or firmware initialisation.
  28  */
  29 #define IRQF_TRIGGER_NONE       0x00000000
  30 #define IRQF_TRIGGER_RISING     0x00000001
  31 #define IRQF_TRIGGER_FALLING    0x00000002
  32 #define IRQF_TRIGGER_HIGH       0x00000004
  33 #define IRQF_TRIGGER_LOW        0x00000008
  34 #define IRQF_TRIGGER_MASK       (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
  35                                  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
  36 #define IRQF_TRIGGER_PROBE      0x00000010
  37
  38 /*
  39  * These flags used only by the kernel as part of the
  40  * irq handling routines.
  41  *
  42  * IRQF_DISABLED - keep irqs disabled when calling the action handler
  43  * IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
  44  * IRQF_SHARED - allow sharing the irq among several devices
  45  * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
  46  * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
  47  * IRQF_PERCPU - Interrupt is per cpu
  48  * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
  49  * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
  50  *                registered first in an shared interrupt is considered for
  51  *                performance reasons)
  52  */
  53 #define IRQF_DISABLED           0x00000020
  54 #define IRQF_SAMPLE_RANDOM      0x00000040
  55 #define IRQF_SHARED             0x00000080
  56 #define IRQF_PROBE_SHARED       0x00000100
  57 #define IRQF_TIMER              0x00000200
  58 #define IRQF_PERCPU             0x00000400
  59 #define IRQF_NOBALANCING        0x00000800
  60 #define IRQF_IRQPOLL            0x00001000
  61
  62 typedef irqreturn_t (*irq_handler_t)(int, void *);
  63
  64 struct irqaction {
  65         irq_handler_t handler;
  66         unsigned long flags;
  67         cpumask_t mask;
  68         const char *name;
  69         void *dev_id;
  70         struct irqaction *next;
  71         int irq;
  72         struct proc_dir_entry *dir;
  73 };
  74
  75 extern irqreturn_t no_action(int cpl, void *dev_id);
  76 extern int __must_check request_irq(unsigned int, irq_handler_t handler,
  77                        unsigned long, const char *, void *);
  78 extern void free_irq(unsigned int, void *);
  79
  80 struct device;
  81
  82 extern int __must_check devm_request_irq(struct device *dev, unsigned int irq,
  83                             irq_handler_t handler, unsigned long irqflags,
  84                             const char *devname, void *dev_id);
  85 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
  86
  87 /*
  88  * On lockdep we dont want to enable hardirqs in hardirq
  89  * context. Use local_irq_enable_in_hardirq() to annotate
  90  * kernel code that has to do this nevertheless (pretty much
  91  * the only valid case is for old/broken hardware that is
  92  * insanely slow).
  93  *
  94  * NOTE: in theory this might break fragile code that relies
  95  * on hardirq delivery - in practice we dont seem to have such
  96  * places left. So the only effect should be slightly increased
  97  * irqs-off latencies.
  98  */
  99 #ifdef CONFIG_LOCKDEP
 100 # define local_irq_enable_in_hardirq()  do { } while (0)
 101 #else
 102 # define local_irq_enable_in_hardirq()  local_irq_enable()
 103 #endif
 104
 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 #if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
 110
 111 extern cpumask_var_t irq_default_affinity;
 112
 113 extern int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask);
 114 extern int irq_can_set_affinity(unsigned int irq);
 115 extern int irq_select_affinity(unsigned int irq);
 116
 117 #else /* CONFIG_SMP */
 118
 119 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
 120 {
 121         return -EINVAL;
 122 }
 123
 124 static inline int irq_can_set_affinity(unsigned int irq)
 125 {
 126         return 0;
 127 }
 128
 129 static inline int irq_select_affinity(unsigned int irq)  { return 0; }
 130
 131 #endif /* CONFIG_SMP && CONFIG_GENERIC_HARDIRQS */
 132
 133 #ifdef CONFIG_GENERIC_HARDIRQS
 134 /*
 135  * Special lockdep variants of irq disabling/enabling.
 136  * These should be used for locking constructs that
 137  * know that a particular irq context which is disabled,
 138  * and which is the only irq-context user of a lock,
 139  * that it's safe to take the lock in the irq-disabled
 140  * section without disabling hardirqs.
 141  *
 142  * On !CONFIG_LOCKDEP they are equivalent to the normal
 143  * irq disable/enable methods.
 144  */
 145 static inline void disable_irq_nosync_lockdep(unsigned int irq)
 146 {
 147         disable_irq_nosync(irq);
 148 #ifdef CONFIG_LOCKDEP
 149         local_irq_disable();
 150 #endif
 151 }
 152
 153 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 154 {
 155         disable_irq_nosync(irq);
 156 #ifdef CONFIG_LOCKDEP
 157         local_irq_save(*flags);
 158 #endif
 159 }
 160
 161 static inline void disable_irq_lockdep(unsigned int irq)
 162 {
 163         disable_irq(irq);
 164 #ifdef CONFIG_LOCKDEP
 165         local_irq_disable();
 166 #endif
 167 }
 168
 169 static inline void enable_irq_lockdep(unsigned int irq)
 170 {
 171 #ifdef CONFIG_LOCKDEP
 172         local_irq_enable();
 173 #endif
 174         enable_irq(irq);
 175 }
 176
 177 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 178 {
 179 #ifdef CONFIG_LOCKDEP
 180         local_irq_restore(*flags);
 181 #endif
 182         enable_irq(irq);
 183 }
 184
 185 /* IRQ wakeup (PM) control: */
 186 extern int set_irq_wake(unsigned int irq, unsigned int on);
 187
 188 static inline int enable_irq_wake(unsigned int irq)
 189 {
 190         return set_irq_wake(irq, 1);
 191 }
 192
 193 static inline int disable_irq_wake(unsigned int irq)
 194 {
 195         return set_irq_wake(irq, 0);
 196 }
 197
 198 #else /* !CONFIG_GENERIC_HARDIRQS */
 199 /*
 200  * NOTE: non-genirq architectures, if they want to support the lock
 201  * validator need to define the methods below in their asm/irq.h
 202  * files, under an #ifdef CONFIG_LOCKDEP section.
 203  */
 204 #ifndef CONFIG_LOCKDEP
 205 #  define disable_irq_nosync_lockdep(irq)       disable_irq_nosync(irq)
 206 #  define disable_irq_nosync_lockdep_irqsave(irq, flags) \
 207                                                 disable_irq_nosync(irq)
 208 #  define disable_irq_lockdep(irq)              disable_irq(irq)
 209 #  define enable_irq_lockdep(irq)               enable_irq(irq)
 210 #  define enable_irq_lockdep_irqrestore(irq, flags) \
 211                                                 enable_irq(irq)
 212 # endif
 213
 214 static inline int enable_irq_wake(unsigned int irq)
 215 {
 216         return 0;
 217 }
 218
 219 static inline int disable_irq_wake(unsigned int irq)
 220 {
 221         return 0;
 222 }
 223 #endif /* CONFIG_GENERIC_HARDIRQS */
 224
 225 #ifndef __ARCH_SET_SOFTIRQ_PENDING
 226 #define set_softirq_pending(x) (local_softirq_pending() = (x))
 227 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 228 #endif
 229
 230 /* Some architectures might implement lazy enabling/disabling of
 231  * interrupts. In some cases, such as stop_machine, we might want
 232  * to ensure that after a local_irq_disable(), interrupts have
 233  * really been disabled in hardware. Such architectures need to
 234  * implement the following hook.
 235  */
 236 #ifndef hard_irq_disable
 237 #define hard_irq_disable()      do { } while(0)
 238 #endif
 239
 240 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 241    frequency threaded job scheduling. For almost all the purposes
 242    tasklets are more than enough. F.e. all serial device BHs et
 243    al. should be converted to tasklets, not to softirqs.
 244  */
 245
 246 enum
 247 {
 248         HI_SOFTIRQ=0,
 249         TIMER_SOFTIRQ,
 250         NET_TX_SOFTIRQ,
 251         NET_RX_SOFTIRQ,
 252         BLOCK_SOFTIRQ,
 253         TASKLET_SOFTIRQ,
 254         SCHED_SOFTIRQ,
 255         HRTIMER_SOFTIRQ,
 256         RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
 257
 258         NR_SOFTIRQS
 259 };
 260
 261 /* softirq mask and active fields moved to irq_cpustat_t in
 262  * asm/hardirq.h to get better cache usage.  KAO
 263  */
 264
 265 struct softirq_action
 266 {
 267         void    (*action)(struct softirq_action *);
 268 };
 269
 270 asmlinkage void do_softirq(void);
 271 asmlinkage void __do_softirq(void);
 272 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
 273 extern void softirq_init(void);
 274 #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
 275 extern void raise_softirq_irqoff(unsigned int nr);
 276 extern void raise_softirq(unsigned int nr);
 277
 278 /* This is the worklist that queues up per-cpu softirq work.
 279  *
 280  * send_remote_sendirq() adds work to these lists, and
 281  * the softirq handler itself dequeues from them.  The queues
 282  * are protected by disabling local cpu interrupts and they must
 283  * only be accessed by the local cpu that they are for.
 284  */
 285 DECLARE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
 286
 287 /* Try to send a softirq to a remote cpu.  If this cannot be done, the
 288  * work will be queued to the local cpu.
 289  */
 290 extern void send_remote_softirq(struct call_single_data *cp, int cpu, int softirq);
 291
 292 /* Like send_remote_softirq(), but the caller must disable local cpu interrupts
 293  * and compute the current cpu, passed in as 'this_cpu'.
 294  */
 295 extern void __send_remote_softirq(struct call_single_data *cp, int cpu,
 296                                   int this_cpu, int softirq);
 297
 298 /* Tasklets --- multithreaded analogue of BHs.
 299
 300    Main feature differing them of generic softirqs: tasklet
 301    is running only on one CPU simultaneously.
 302
 303    Main feature differing them of BHs: different tasklets
 304    may be run simultaneously on different CPUs.
 305
 306    Properties:
 307    * If tasklet_schedule() is called, then tasklet is guaranteed
 308      to be executed on some cpu at least once after this.
 309    * If the tasklet is already scheduled, but its excecution is still not
 310      started, it will be executed only once.
 311    * If this tasklet is already running on another CPU (or schedule is called
 312      from tasklet itself), it is rescheduled for later.
 313    * Tasklet is strictly serialized wrt itself, but not
 314      wrt another tasklets. If client needs some intertask synchronization,
 315      he makes it with spinlocks.
 316  */
 317
 318 struct tasklet_struct
 319 {
 320         struct tasklet_struct *next;
 321         unsigned long state;
 322         atomic_t count;
 323         void (*func)(unsigned long);
 324         unsigned long data;
 325 };
 326
 327 #define DECLARE_TASKLET(name, func, data) \
 328 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 329
 330 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 331 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 332
 333
 334 enum
 335 {
 336         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 337         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 338 };
 339
 340 #ifdef CONFIG_SMP
 341 static inline int tasklet_trylock(struct tasklet_struct *t)
 342 {
 343         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 344 }
 345
 346 static inline void tasklet_unlock(struct tasklet_struct *t)
 347 {
 348         smp_mb__before_clear_bit();
 349         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 350 }
 351
 352 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 353 {
 354         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 355 }
 356 #else
 357 #define tasklet_trylock(t) 1
 358 #define tasklet_unlock_wait(t) do { } while (0)
 359 #define tasklet_unlock(t) do { } while (0)
 360 #endif
 361
 362 extern void __tasklet_schedule(struct tasklet_struct *t);
 363
 364 static inline void tasklet_schedule(struct tasklet_struct *t)
 365 {
 366         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 367                 __tasklet_schedule(t);
 368 }
 369
 370 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
 371
 372 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 373 {
 374         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 375                 __tasklet_hi_schedule(t);
 376 }
 377
 378
 379 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 380 {
 381         atomic_inc(&t->count);
 382         smp_mb__after_atomic_inc();
 383 }
 384
 385 static inline void tasklet_disable(struct tasklet_struct *t)
 386 {
 387         tasklet_disable_nosync(t);
 388         tasklet_unlock_wait(t);
 389         smp_mb();
 390 }
 391
 392 static inline void tasklet_enable(struct tasklet_struct *t)
 393 {
 394         smp_mb__before_atomic_dec();
 395         atomic_dec(&t->count);
 396 }
 397
 398 static inline void tasklet_hi_enable(struct tasklet_struct *t)
 399 {
 400         smp_mb__before_atomic_dec();
 401         atomic_dec(&t->count);
 402 }
 403
 404 extern void tasklet_kill(struct tasklet_struct *t);
 405 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 406 extern void tasklet_init(struct tasklet_struct *t,
 407                          void (*func)(unsigned long), unsigned long data);
 408
 409 /*
 410  * Autoprobing for irqs:
 411  *
 412  * probe_irq_on() and probe_irq_off() provide robust primitives
 413  * for accurate IRQ probing during kernel initialization.  They are
 414  * reasonably simple to use, are not "fooled" by spurious interrupts,
 415  * and, unlike other attempts at IRQ probing, they do not get hung on
 416  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 417  *
 418  * For reasonably foolproof probing, use them as follows:
 419  *
 420  * 1. clear and/or mask the device's internal interrupt.
 421  * 2. sti();
 422  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 423  * 4. enable the device and cause it to trigger an interrupt.
 424  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 425  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 426  * 7. service the device to clear its pending interrupt.
 427  * 8. loop again if paranoia is required.
 428  *
 429  * probe_irq_on() returns a mask of allocated irq's.
 430  *
 431  * probe_irq_off() takes the mask as a parameter,
 432  * and returns the irq number which occurred,
 433  * or zero if none occurred, or a negative irq number
 434  * if more than one irq occurred.
 435  */
 436
 437 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 438 static inline unsigned long probe_irq_on(void)
 439 {
 440         return 0;
 441 }
 442 static inline int probe_irq_off(unsigned long val)
 443 {
 444         return 0;
 445 }
 446 static inline unsigned int probe_irq_mask(unsigned long val)
 447 {
 448         return 0;
 449 }
 450 #else
 451 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 452 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 453 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 454 #endif
 455
 456 #ifdef CONFIG_PROC_FS
 457 /* Initialize /proc/irq/ */
 458 extern void init_irq_proc(void);
 459 #else
 460 static inline void init_irq_proc(void)
 461 {
 462 }
 463 #endif
 464
 465 int show_interrupts(struct seq_file *p, void *v);
 466
 467 struct irq_desc;
 468
 469 extern int early_irq_init(void);
 470 extern int arch_probe_nr_irqs(void);
 471 extern int arch_early_irq_init(void);
 472 extern int arch_init_chip_data(struct irq_desc *desc, int cpu);
 473
 474 #endif