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 <linux/bottom_half.h>
  15 #include <linux/device.h>
  16 #include <asm/atomic.h>
  17 #include <asm/ptrace.h>
  18 #include <asm/system.h>
  19
  20 /*
  21  * These correspond to the IORESOURCE_IRQ_* defines in
  22  * linux/ioport.h to select the interrupt line behaviour.  When
  23  * requesting an interrupt without specifying a IRQF_TRIGGER, the
  24  * setting should be assumed to be "as already configured", which
  25  * may be as per machine or firmware initialisation.
  26  */
  27 #define IRQF_TRIGGER_NONE       0x00000000
  28 #define IRQF_TRIGGER_RISING     0x00000001
  29 #define IRQF_TRIGGER_FALLING    0x00000002
  30 #define IRQF_TRIGGER_HIGH       0x00000004
  31 #define IRQF_TRIGGER_LOW        0x00000008
  32 #define IRQF_TRIGGER_MASK       (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
  33                                  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
  34 #define IRQF_TRIGGER_PROBE      0x00000010
  35
  36 /*
  37  * These flags used only by the kernel as part of the
  38  * irq handling routines.
  39  *
  40  * IRQF_DISABLED - keep irqs disabled when calling the action handler
  41  * IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
  42  * IRQF_SHARED - allow sharing the irq among several devices
  43  * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
  44  * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
  45  * IRQF_PERCPU - Interrupt is per cpu
  46  * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
  47  */
  48 #define IRQF_DISABLED           0x00000020
  49 #define IRQF_SAMPLE_RANDOM      0x00000040
  50 #define IRQF_SHARED             0x00000080
  51 #define IRQF_PROBE_SHARED       0x00000100
  52 #define IRQF_TIMER              0x00000200
  53 #define IRQF_PERCPU             0x00000400
  54 #define IRQF_NOBALANCING        0x00000800
  55
  56 /*
  57  * Migration helpers. Scheduled for removal in 1/2007
  58  * Do not use for new code !
  59  */
  60 #define SA_INTERRUPT            IRQF_DISABLED
  61 #define SA_SAMPLE_RANDOM        IRQF_SAMPLE_RANDOM
  62 #define SA_SHIRQ                IRQF_SHARED
  63 #define SA_PROBEIRQ             IRQF_PROBE_SHARED
  64 #define SA_PERCPU               IRQF_PERCPU
  65
  66 #define SA_TRIGGER_LOW          IRQF_TRIGGER_LOW
  67 #define SA_TRIGGER_HIGH         IRQF_TRIGGER_HIGH
  68 #define SA_TRIGGER_FALLING      IRQF_TRIGGER_FALLING
  69 #define SA_TRIGGER_RISING       IRQF_TRIGGER_RISING
  70 #define SA_TRIGGER_MASK         IRQF_TRIGGER_MASK
  71
  72 typedef irqreturn_t (*irq_handler_t)(int, void *);
  73
  74 struct irqaction {
  75         irq_handler_t handler;
  76         unsigned long flags;
  77         cpumask_t mask;
  78         const char *name;
  79         void *dev_id;
  80         struct irqaction *next;
  81         int irq;
  82         struct proc_dir_entry *dir;
  83 };
  84
  85 extern irqreturn_t no_action(int cpl, void *dev_id);
  86 extern int request_irq(unsigned int, irq_handler_t handler,
  87                        unsigned long, const char *, void *);
  88 extern void free_irq(unsigned int, void *);
  89
  90 extern int devm_request_irq(struct device *dev, unsigned int irq,
  91                             irq_handler_t handler, unsigned long irqflags,
  92                             const char *devname, void *dev_id);
  93 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
  94
  95 /*
  96  * On lockdep we dont want to enable hardirqs in hardirq
  97  * context. Use local_irq_enable_in_hardirq() to annotate
  98  * kernel code that has to do this nevertheless (pretty much
  99  * the only valid case is for old/broken hardware that is
 100  * insanely slow).
 101  *
 102  * NOTE: in theory this might break fragile code that relies
 103  * on hardirq delivery - in practice we dont seem to have such
 104  * places left. So the only effect should be slightly increased
 105  * irqs-off latencies.
 106  */
 107 #ifdef CONFIG_LOCKDEP
 108 # define local_irq_enable_in_hardirq()  do { } while (0)
 109 #else
 110 # define local_irq_enable_in_hardirq()  local_irq_enable()
 111 #endif
 112
 113 #ifdef CONFIG_GENERIC_HARDIRQS
 114 extern void disable_irq_nosync(unsigned int irq);
 115 extern void disable_irq(unsigned int irq);
 116 extern void enable_irq(unsigned int irq);
 117
 118 /*
 119  * Special lockdep variants of irq disabling/enabling.
 120  * These should be used for locking constructs that
 121  * know that a particular irq context which is disabled,
 122  * and which is the only irq-context user of a lock,
 123  * that it's safe to take the lock in the irq-disabled
 124  * section without disabling hardirqs.
 125  *
 126  * On !CONFIG_LOCKDEP they are equivalent to the normal
 127  * irq disable/enable methods.
 128  */
 129 static inline void disable_irq_nosync_lockdep(unsigned int irq)
 130 {
 131         disable_irq_nosync(irq);
 132 #ifdef CONFIG_LOCKDEP
 133         local_irq_disable();
 134 #endif
 135 }
 136
 137 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
 138 {
 139         disable_irq_nosync(irq);
 140 #ifdef CONFIG_LOCKDEP
 141         local_irq_save(*flags);
 142 #endif
 143 }
 144
 145 static inline void disable_irq_lockdep(unsigned int irq)
 146 {
 147         disable_irq(irq);
 148 #ifdef CONFIG_LOCKDEP
 149         local_irq_disable();
 150 #endif
 151 }
 152
 153 static inline void enable_irq_lockdep(unsigned int irq)
 154 {
 155 #ifdef CONFIG_LOCKDEP
 156         local_irq_enable();
 157 #endif
 158         enable_irq(irq);
 159 }
 160
 161 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
 162 {
 163 #ifdef CONFIG_LOCKDEP
 164         local_irq_restore(*flags);
 165 #endif
 166         enable_irq(irq);
 167 }
 168
 169 /* IRQ wakeup (PM) control: */
 170 extern int set_irq_wake(unsigned int irq, unsigned int on);
 171
 172 static inline int enable_irq_wake(unsigned int irq)
 173 {
 174         return set_irq_wake(irq, 1);
 175 }
 176
 177 static inline int disable_irq_wake(unsigned int irq)
 178 {
 179         return set_irq_wake(irq, 0);
 180 }
 181
 182 #else /* !CONFIG_GENERIC_HARDIRQS */
 183 /*
 184  * NOTE: non-genirq architectures, if they want to support the lock
 185  * validator need to define the methods below in their asm/irq.h
 186  * files, under an #ifdef CONFIG_LOCKDEP section.
 187  */
 188 # ifndef CONFIG_LOCKDEP
 189 #  define disable_irq_nosync_lockdep(irq)       disable_irq_nosync(irq)
 190 #  define disable_irq_lockdep(irq)              disable_irq(irq)
 191 #  define enable_irq_lockdep(irq)               enable_irq(irq)
 192 # endif
 193
 194 #endif /* CONFIG_GENERIC_HARDIRQS */
 195
 196 #ifndef __ARCH_SET_SOFTIRQ_PENDING
 197 #define set_softirq_pending(x) (local_softirq_pending() = (x))
 198 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 199 #endif
 200
 201 /*
 202  * Temporary defines for UP kernels, until all code gets fixed.
 203  */
 204 #ifndef CONFIG_SMP
 205 static inline void __deprecated cli(void)
 206 {
 207         local_irq_disable();
 208 }
 209 static inline void __deprecated sti(void)
 210 {
 211         local_irq_enable();
 212 }
 213 static inline void __deprecated save_flags(unsigned long *x)
 214 {
 215         local_save_flags(*x);
 216 }
 217 #define save_flags(x) save_flags(&x)
 218 static inline void __deprecated restore_flags(unsigned long x)
 219 {
 220         local_irq_restore(x);
 221 }
 222
 223 static inline void __deprecated save_and_cli(unsigned long *x)
 224 {
 225         local_irq_save(*x);
 226 }
 227 #define save_and_cli(x) save_and_cli(&x)
 228 #endif /* CONFIG_SMP */
 229
 230 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 231    frequency threaded job scheduling. For almost all the purposes
 232    tasklets are more than enough. F.e. all serial device BHs et
 233    al. should be converted to tasklets, not to softirqs.
 234  */
 235
 236 enum
 237 {
 238         HI_SOFTIRQ=0,
 239         TIMER_SOFTIRQ,
 240         NET_TX_SOFTIRQ,
 241         NET_RX_SOFTIRQ,
 242         BLOCK_SOFTIRQ,
 243         TASKLET_SOFTIRQ,
 244         SCHED_SOFTIRQ,
 245 #ifdef CONFIG_HIGH_RES_TIMERS
 246         HRTIMER_SOFTIRQ,
 247 #endif
 248 };
 249
 250 /* softirq mask and active fields moved to irq_cpustat_t in
 251  * asm/hardirq.h to get better cache usage.  KAO
 252  */
 253
 254 struct softirq_action
 255 {
 256         void    (*action)(struct softirq_action *);
 257         void    *data;
 258 };
 259
 260 asmlinkage void do_softirq(void);
 261 extern void open_softirq(int nr, void (*action)(struct softirq_action*), void *data);
 262 extern void softirq_init(void);
 263 #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
 264 extern void FASTCALL(raise_softirq_irqoff(unsigned int nr));
 265 extern void FASTCALL(raise_softirq(unsigned int nr));
 266
 267
 268 /* Tasklets --- multithreaded analogue of BHs.
 269
 270    Main feature differing them of generic softirqs: tasklet
 271    is running only on one CPU simultaneously.
 272
 273    Main feature differing them of BHs: different tasklets
 274    may be run simultaneously on different CPUs.
 275
 276    Properties:
 277    * If tasklet_schedule() is called, then tasklet is guaranteed
 278      to be executed on some cpu at least once after this.
 279    * If the tasklet is already scheduled, but its excecution is still not
 280      started, it will be executed only once.
 281    * If this tasklet is already running on another CPU (or schedule is called
 282      from tasklet itself), it is rescheduled for later.
 283    * Tasklet is strictly serialized wrt itself, but not
 284      wrt another tasklets. If client needs some intertask synchronization,
 285      he makes it with spinlocks.
 286  */
 287
 288 struct tasklet_struct
 289 {
 290         struct tasklet_struct *next;
 291         unsigned long state;
 292         atomic_t count;
 293         void (*func)(unsigned long);
 294         unsigned long data;
 295 };
 296
 297 #define DECLARE_TASKLET(name, func, data) \
 298 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 299
 300 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 301 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 302
 303
 304 enum
 305 {
 306         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 307         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 308 };
 309
 310 #ifdef CONFIG_SMP
 311 static inline int tasklet_trylock(struct tasklet_struct *t)
 312 {
 313         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 314 }
 315
 316 static inline void tasklet_unlock(struct tasklet_struct *t)
 317 {
 318         smp_mb__before_clear_bit();
 319         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 320 }
 321
 322 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 323 {
 324         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 325 }
 326 #else
 327 #define tasklet_trylock(t) 1
 328 #define tasklet_unlock_wait(t) do { } while (0)
 329 #define tasklet_unlock(t) do { } while (0)
 330 #endif
 331
 332 extern void FASTCALL(__tasklet_schedule(struct tasklet_struct *t));
 333
 334 static inline void tasklet_schedule(struct tasklet_struct *t)
 335 {
 336         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 337                 __tasklet_schedule(t);
 338 }
 339
 340 extern void FASTCALL(__tasklet_hi_schedule(struct tasklet_struct *t));
 341
 342 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 343 {
 344         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 345                 __tasklet_hi_schedule(t);
 346 }
 347
 348
 349 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 350 {
 351         atomic_inc(&t->count);
 352         smp_mb__after_atomic_inc();
 353 }
 354
 355 static inline void tasklet_disable(struct tasklet_struct *t)
 356 {
 357         tasklet_disable_nosync(t);
 358         tasklet_unlock_wait(t);
 359         smp_mb();
 360 }
 361
 362 static inline void tasklet_enable(struct tasklet_struct *t)
 363 {
 364         smp_mb__before_atomic_dec();
 365         atomic_dec(&t->count);
 366 }
 367
 368 static inline void tasklet_hi_enable(struct tasklet_struct *t)
 369 {
 370         smp_mb__before_atomic_dec();
 371         atomic_dec(&t->count);
 372 }
 373
 374 extern void tasklet_kill(struct tasklet_struct *t);
 375 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 376 extern void tasklet_init(struct tasklet_struct *t,
 377                          void (*func)(unsigned long), unsigned long data);
 378
 379 /*
 380  * Autoprobing for irqs:
 381  *
 382  * probe_irq_on() and probe_irq_off() provide robust primitives
 383  * for accurate IRQ probing during kernel initialization.  They are
 384  * reasonably simple to use, are not "fooled" by spurious interrupts,
 385  * and, unlike other attempts at IRQ probing, they do not get hung on
 386  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 387  *
 388  * For reasonably foolproof probing, use them as follows:
 389  *
 390  * 1. clear and/or mask the device's internal interrupt.
 391  * 2. sti();
 392  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 393  * 4. enable the device and cause it to trigger an interrupt.
 394  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 395  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 396  * 7. service the device to clear its pending interrupt.
 397  * 8. loop again if paranoia is required.
 398  *
 399  * probe_irq_on() returns a mask of allocated irq's.
 400  *
 401  * probe_irq_off() takes the mask as a parameter,
 402  * and returns the irq number which occurred,
 403  * or zero if none occurred, or a negative irq number
 404  * if more than one irq occurred.
 405  */
 406
 407 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 408 static inline unsigned long probe_irq_on(void)
 409 {
 410         return 0;
 411 }
 412 static inline int probe_irq_off(unsigned long val)
 413 {
 414         return 0;
 415 }
 416 static inline unsigned int probe_irq_mask(unsigned long val)
 417 {
 418         return 0;
 419 }
 420 #else
 421 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 422 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 423 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 424 #endif
 425
 426 #ifdef CONFIG_PROC_FS
 427 /* Initialize /proc/irq/ */
 428 extern void init_irq_proc(void);
 429 #else
 430 static inline void init_irq_proc(void)
 431 {
 432 }
 433 #endif
 434
 435 #endif