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