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 <asm/atomic.h>
  14 #include <asm/ptrace.h>
  15 #include <asm/system.h>
  16
  17 /*
  18  * These correspond to the IORESOURCE_IRQ_* defines in
  19  * linux/ioport.h to select the interrupt line behaviour.  When
  20  * requesting an interrupt without specifying a IRQF_TRIGGER, the
  21  * setting should be assumed to be "as already configured", which
  22  * may be as per machine or firmware initialisation.
  23  */
  24 #define IRQF_TRIGGER_NONE       0x00000000
  25 #define IRQF_TRIGGER_RISING     0x00000001
  26 #define IRQF_TRIGGER_FALLING    0x00000002
  27 #define IRQF_TRIGGER_HIGH       0x00000004
  28 #define IRQF_TRIGGER_LOW        0x00000008
  29 #define IRQF_TRIGGER_MASK       (IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
  30                                  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
  31 #define IRQF_TRIGGER_PROBE      0x00000010
  32
  33 /*
  34  * These flags used only by the kernel as part of the
  35  * irq handling routines.
  36  *
  37  * IRQF_DISABLED - keep irqs disabled when calling the action handler
  38  * IRQF_SAMPLE_RANDOM - irq is used to feed the random generator
  39  * IRQF_SHARED - allow sharing the irq among several devices
  40  * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
  41  * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
  42  */
  43 #define IRQF_DISABLED           0x00000020
  44 #define IRQF_SAMPLE_RANDOM      0x00000040
  45 #define IRQF_SHARED             0x00000080
  46 #define IRQF_PROBE_SHARED       0x00000100
  47 #define IRQF_TIMER              0x00000200
  48 #define IRQF_PERCPU             0x00000400
  49
  50 /*
  51  * Migration helpers. Scheduled for removal in 1/2007
  52  * Do not use for new code !
  53  */
  54 #define SA_INTERRUPT            IRQF_DISABLED
  55 #define SA_SAMPLE_RANDOM        IRQF_SAMPLE_RANDOM
  56 #define SA_SHIRQ                IRQF_SHARED
  57 #define SA_PROBEIRQ             IRQF_PROBE_SHARED
  58 #define SA_PERCPU               IRQF_PERCPU
  59
  60 #define SA_TRIGGER_LOW          IRQF_TRIGGER_LOW
  61 #define SA_TRIGGER_HIGH         IRQF_TRIGGER_HIGH
  62 #define SA_TRIGGER_FALLING      IRQF_TRIGGER_FALLING
  63 #define SA_TRIGGER_RISING       IRQF_TRIGGER_RISING
  64 #define SA_TRIGGER_MASK         IRQF_TRIGGER_MASK
  65
  66 struct irqaction {
  67         irqreturn_t (*handler)(int, void *, struct pt_regs *);
  68         unsigned long flags;
  69         cpumask_t mask;
  70         const char *name;
  71         void *dev_id;
  72         struct irqaction *next;
  73         int irq;
  74         struct proc_dir_entry *dir;
  75 };
  76
  77 extern irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs);
  78 extern int request_irq(unsigned int,
  79                        irqreturn_t (*handler)(int, void *, struct pt_regs *),
  80                        unsigned long, const char *, void *);
  81 extern void free_irq(unsigned int, void *);
  82
  83
  84 #ifdef CONFIG_GENERIC_HARDIRQS
  85 extern void disable_irq_nosync(unsigned int irq);
  86 extern void disable_irq(unsigned int irq);
  87 extern void enable_irq(unsigned int irq);
  88
  89 /* IRQ wakeup (PM) control: */
  90 extern int set_irq_wake(unsigned int irq, unsigned int on);
  91
  92 static inline int enable_irq_wake(unsigned int irq)
  93 {
  94         return set_irq_wake(irq, 1);
  95 }
  96
  97 static inline int disable_irq_wake(unsigned int irq)
  98 {
  99         return set_irq_wake(irq, 0);
 100 }
 101
 102 #endif
 103
 104 #ifndef __ARCH_SET_SOFTIRQ_PENDING
 105 #define set_softirq_pending(x) (local_softirq_pending() = (x))
 106 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
 107 #endif
 108
 109 /*
 110  * Temporary defines for UP kernels, until all code gets fixed.
 111  */
 112 #ifndef CONFIG_SMP
 113 static inline void __deprecated cli(void)
 114 {
 115         local_irq_disable();
 116 }
 117 static inline void __deprecated sti(void)
 118 {
 119         local_irq_enable();
 120 }
 121 static inline void __deprecated save_flags(unsigned long *x)
 122 {
 123         local_save_flags(*x);
 124 }
 125 #define save_flags(x) save_flags(&x)
 126 static inline void __deprecated restore_flags(unsigned long x)
 127 {
 128         local_irq_restore(x);
 129 }
 130
 131 static inline void __deprecated save_and_cli(unsigned long *x)
 132 {
 133         local_irq_save(*x);
 134 }
 135 #define save_and_cli(x) save_and_cli(&x)
 136 #endif /* CONFIG_SMP */
 137
 138 /* SoftIRQ primitives.  */
 139 #define local_bh_disable() \
 140                 do { add_preempt_count(SOFTIRQ_OFFSET); barrier(); } while (0)
 141 #define __local_bh_enable() \
 142                 do { barrier(); sub_preempt_count(SOFTIRQ_OFFSET); } while (0)
 143
 144 extern void local_bh_enable(void);
 145
 146 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 147    frequency threaded job scheduling. For almost all the purposes
 148    tasklets are more than enough. F.e. all serial device BHs et
 149    al. should be converted to tasklets, not to softirqs.
 150  */
 151
 152 enum
 153 {
 154         HI_SOFTIRQ=0,
 155         TIMER_SOFTIRQ,
 156         NET_TX_SOFTIRQ,
 157         NET_RX_SOFTIRQ,
 158         BLOCK_SOFTIRQ,
 159         TASKLET_SOFTIRQ
 160 };
 161
 162 /* softirq mask and active fields moved to irq_cpustat_t in
 163  * asm/hardirq.h to get better cache usage.  KAO
 164  */
 165
 166 struct softirq_action
 167 {
 168         void    (*action)(struct softirq_action *);
 169         void    *data;
 170 };
 171
 172 asmlinkage void do_softirq(void);
 173 extern void open_softirq(int nr, void (*action)(struct softirq_action*), void *data);
 174 extern void softirq_init(void);
 175 #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
 176 extern void FASTCALL(raise_softirq_irqoff(unsigned int nr));
 177 extern void FASTCALL(raise_softirq(unsigned int nr));
 178
 179
 180 /* Tasklets --- multithreaded analogue of BHs.
 181
 182    Main feature differing them of generic softirqs: tasklet
 183    is running only on one CPU simultaneously.
 184
 185    Main feature differing them of BHs: different tasklets
 186    may be run simultaneously on different CPUs.
 187
 188    Properties:
 189    * If tasklet_schedule() is called, then tasklet is guaranteed
 190      to be executed on some cpu at least once after this.
 191    * If the tasklet is already scheduled, but its excecution is still not
 192      started, it will be executed only once.
 193    * If this tasklet is already running on another CPU (or schedule is called
 194      from tasklet itself), it is rescheduled for later.
 195    * Tasklet is strictly serialized wrt itself, but not
 196      wrt another tasklets. If client needs some intertask synchronization,
 197      he makes it with spinlocks.
 198  */
 199
 200 struct tasklet_struct
 201 {
 202         struct tasklet_struct *next;
 203         unsigned long state;
 204         atomic_t count;
 205         void (*func)(unsigned long);
 206         unsigned long data;
 207 };
 208
 209 #define DECLARE_TASKLET(name, func, data) \
 210 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 211
 212 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 213 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 214
 215
 216 enum
 217 {
 218         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 219         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 220 };
 221
 222 #ifdef CONFIG_SMP
 223 static inline int tasklet_trylock(struct tasklet_struct *t)
 224 {
 225         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 226 }
 227
 228 static inline void tasklet_unlock(struct tasklet_struct *t)
 229 {
 230         smp_mb__before_clear_bit();
 231         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 232 }
 233
 234 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 235 {
 236         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 237 }
 238 #else
 239 #define tasklet_trylock(t) 1
 240 #define tasklet_unlock_wait(t) do { } while (0)
 241 #define tasklet_unlock(t) do { } while (0)
 242 #endif
 243
 244 extern void FASTCALL(__tasklet_schedule(struct tasklet_struct *t));
 245
 246 static inline void tasklet_schedule(struct tasklet_struct *t)
 247 {
 248         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 249                 __tasklet_schedule(t);
 250 }
 251
 252 extern void FASTCALL(__tasklet_hi_schedule(struct tasklet_struct *t));
 253
 254 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 255 {
 256         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 257                 __tasklet_hi_schedule(t);
 258 }
 259
 260
 261 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 262 {
 263         atomic_inc(&t->count);
 264         smp_mb__after_atomic_inc();
 265 }
 266
 267 static inline void tasklet_disable(struct tasklet_struct *t)
 268 {
 269         tasklet_disable_nosync(t);
 270         tasklet_unlock_wait(t);
 271         smp_mb();
 272 }
 273
 274 static inline void tasklet_enable(struct tasklet_struct *t)
 275 {
 276         smp_mb__before_atomic_dec();
 277         atomic_dec(&t->count);
 278 }
 279
 280 static inline void tasklet_hi_enable(struct tasklet_struct *t)
 281 {
 282         smp_mb__before_atomic_dec();
 283         atomic_dec(&t->count);
 284 }
 285
 286 extern void tasklet_kill(struct tasklet_struct *t);
 287 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 288 extern void tasklet_init(struct tasklet_struct *t,
 289                          void (*func)(unsigned long), unsigned long data);
 290
 291 /*
 292  * Autoprobing for irqs:
 293  *
 294  * probe_irq_on() and probe_irq_off() provide robust primitives
 295  * for accurate IRQ probing during kernel initialization.  They are
 296  * reasonably simple to use, are not "fooled" by spurious interrupts,
 297  * and, unlike other attempts at IRQ probing, they do not get hung on
 298  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 299  *
 300  * For reasonably foolproof probing, use them as follows:
 301  *
 302  * 1. clear and/or mask the device's internal interrupt.
 303  * 2. sti();
 304  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 305  * 4. enable the device and cause it to trigger an interrupt.
 306  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 307  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 308  * 7. service the device to clear its pending interrupt.
 309  * 8. loop again if paranoia is required.
 310  *
 311  * probe_irq_on() returns a mask of allocated irq's.
 312  *
 313  * probe_irq_off() takes the mask as a parameter,
 314  * and returns the irq number which occurred,
 315  * or zero if none occurred, or a negative irq number
 316  * if more than one irq occurred.
 317  */
 318
 319 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 320 static inline unsigned long probe_irq_on(void)
 321 {
 322         return 0;
 323 }
 324 static inline int probe_irq_off(unsigned long val)
 325 {
 326         return 0;
 327 }
 328 static inline unsigned int probe_irq_mask(unsigned long val)
 329 {
 330         return 0;
 331 }
 332 #else
 333 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 334 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 335 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 336 #endif
 337
 338 #endif