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