include/linux/interrupt.h

   1 /* interrupt.h */
   2 #ifndef _LINUX_INTERRUPT_H
   3 #define _LINUX_INTERRUPT_H
   4
   5 #include <linux/config.h>
   6 #include <linux/kernel.h>
   7 #include <linux/linkage.h>
   8 #include <linux/bitops.h>
   9 #include <linux/preempt.h>
  10 #include <linux/cpumask.h>
  11 #include <linux/hardirq.h>
  12 #include <asm/atomic.h>
  13 #include <asm/ptrace.h>
  14 #include <asm/system.h>
  15
  16 /*
  17  * For 2.4.x compatibility, 2.4.x can use
  18  *
  19  *      typedef void irqreturn_t;
  20  *      #define IRQ_NONE
  21  *      #define IRQ_HANDLED
  22  *      #define IRQ_RETVAL(x)
  23  *
  24  * To mix old-style and new-style irq handler returns.
  25  *
  26  * IRQ_NONE means we didn't handle it.
  27  * IRQ_HANDLED means that we did have a valid interrupt and handled it.
  28  * IRQ_RETVAL(x) selects on the two depending on x being non-zero (for handled)
  29  */
  30 typedef int irqreturn_t;
  31
  32 #define IRQ_NONE        (0)
  33 #define IRQ_HANDLED     (1)
  34 #define IRQ_RETVAL(x)   ((x) != 0)
  35
  36 struct irqaction {
  37         irqreturn_t (*handler)(int, void *, struct pt_regs *);
  38         unsigned long flags;
  39         cpumask_t mask;
  40         const char *name;
  41         void *dev_id;
  42         struct irqaction *next;
  43         int irq;
  44         struct proc_dir_entry *dir;
  45 };
  46
  47 extern irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs);
  48 extern int request_irq(unsigned int,
  49                        irqreturn_t (*handler)(int, void *, struct pt_regs *),
  50                        unsigned long, const char *, void *);
  51 extern void free_irq(unsigned int, void *);
  52
  53
  54 #ifdef CONFIG_GENERIC_HARDIRQS
  55 extern void disable_irq_nosync(unsigned int irq);
  56 extern void disable_irq(unsigned int irq);
  57 extern void enable_irq(unsigned int irq);
  58 #endif
  59
  60 /*
  61  * Temporary defines for UP kernels, until all code gets fixed.
  62  */
  63 #ifndef CONFIG_SMP
  64 static inline void __deprecated cli(void)
  65 {
  66         local_irq_disable();
  67 }
  68 static inline void __deprecated sti(void)
  69 {
  70         local_irq_enable();
  71 }
  72 static inline void __deprecated save_flags(unsigned long *x)
  73 {
  74         local_save_flags(*x);
  75 }
  76 #define save_flags(x) save_flags(&x);
  77 static inline void __deprecated restore_flags(unsigned long x)
  78 {
  79         local_irq_restore(x);
  80 }
  81
  82 static inline void __deprecated save_and_cli(unsigned long *x)
  83 {
  84         local_irq_save(*x);
  85 }
  86 #define save_and_cli(x) save_and_cli(&x)
  87 #endif /* CONFIG_SMP */
  88
  89 /* SoftIRQ primitives.  */
  90 #define local_bh_disable() \
  91                 do { add_preempt_count(SOFTIRQ_OFFSET); barrier(); } while (0)
  92 #define __local_bh_enable() \
  93                 do { barrier(); sub_preempt_count(SOFTIRQ_OFFSET); } while (0)
  94
  95 extern void local_bh_enable(void);
  96
  97 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
  98    frequency threaded job scheduling. For almost all the purposes
  99    tasklets are more than enough. F.e. all serial device BHs et
 100    al. should be converted to tasklets, not to softirqs.
 101  */
 102
 103 enum
 104 {
 105         HI_SOFTIRQ=0,
 106         TIMER_SOFTIRQ,
 107         NET_TX_SOFTIRQ,
 108         NET_RX_SOFTIRQ,
 109         SCSI_SOFTIRQ,
 110         TASKLET_SOFTIRQ
 111 };
 112
 113 /* softirq mask and active fields moved to irq_cpustat_t in
 114  * asm/hardirq.h to get better cache usage.  KAO
 115  */
 116
 117 struct softirq_action
 118 {
 119         void    (*action)(struct softirq_action *);
 120         void    *data;
 121 };
 122
 123 asmlinkage void do_softirq(void);
 124 extern void open_softirq(int nr, void (*action)(struct softirq_action*), void *data);
 125 extern void softirq_init(void);
 126 #define __raise_softirq_irqoff(nr) do { local_softirq_pending() |= 1UL << (nr); } while (0)
 127 extern void FASTCALL(raise_softirq_irqoff(unsigned int nr));
 128 extern void FASTCALL(raise_softirq(unsigned int nr));
 129
 130
 131 /* Tasklets --- multithreaded analogue of BHs.
 132
 133    Main feature differing them of generic softirqs: tasklet
 134    is running only on one CPU simultaneously.
 135
 136    Main feature differing them of BHs: different tasklets
 137    may be run simultaneously on different CPUs.
 138
 139    Properties:
 140    * If tasklet_schedule() is called, then tasklet is guaranteed
 141      to be executed on some cpu at least once after this.
 142    * If the tasklet is already scheduled, but its excecution is still not
 143      started, it will be executed only once.
 144    * If this tasklet is already running on another CPU (or schedule is called
 145      from tasklet itself), it is rescheduled for later.
 146    * Tasklet is strictly serialized wrt itself, but not
 147      wrt another tasklets. If client needs some intertask synchronization,
 148      he makes it with spinlocks.
 149  */
 150
 151 struct tasklet_struct
 152 {
 153         struct tasklet_struct *next;
 154         unsigned long state;
 155         atomic_t count;
 156         void (*func)(unsigned long);
 157         unsigned long data;
 158 };
 159
 160 #define DECLARE_TASKLET(name, func, data) \
 161 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 162
 163 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 164 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 165
 166
 167 enum
 168 {
 169         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 170         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 171 };
 172
 173 #ifdef CONFIG_SMP
 174 static inline int tasklet_trylock(struct tasklet_struct *t)
 175 {
 176         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 177 }
 178
 179 static inline void tasklet_unlock(struct tasklet_struct *t)
 180 {
 181         smp_mb__before_clear_bit();
 182         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 183 }
 184
 185 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 186 {
 187         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 188 }
 189 #else
 190 #define tasklet_trylock(t) 1
 191 #define tasklet_unlock_wait(t) do { } while (0)
 192 #define tasklet_unlock(t) do { } while (0)
 193 #endif
 194
 195 extern void FASTCALL(__tasklet_schedule(struct tasklet_struct *t));
 196
 197 static inline void tasklet_schedule(struct tasklet_struct *t)
 198 {
 199         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 200                 __tasklet_schedule(t);
 201 }
 202
 203 extern void FASTCALL(__tasklet_hi_schedule(struct tasklet_struct *t));
 204
 205 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 206 {
 207         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 208                 __tasklet_hi_schedule(t);
 209 }
 210
 211
 212 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 213 {
 214         atomic_inc(&t->count);
 215         smp_mb__after_atomic_inc();
 216 }
 217
 218 static inline void tasklet_disable(struct tasklet_struct *t)
 219 {
 220         tasklet_disable_nosync(t);
 221         tasklet_unlock_wait(t);
 222         smp_mb();
 223 }
 224
 225 static inline void tasklet_enable(struct tasklet_struct *t)
 226 {
 227         smp_mb__before_atomic_dec();
 228         atomic_dec(&t->count);
 229 }
 230
 231 static inline void tasklet_hi_enable(struct tasklet_struct *t)
 232 {
 233         smp_mb__before_atomic_dec();
 234         atomic_dec(&t->count);
 235 }
 236
 237 extern void tasklet_kill(struct tasklet_struct *t);
 238 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 239 extern void tasklet_init(struct tasklet_struct *t,
 240                          void (*func)(unsigned long), unsigned long data);
 241
 242 /*
 243  * Autoprobing for irqs:
 244  *
 245  * probe_irq_on() and probe_irq_off() provide robust primitives
 246  * for accurate IRQ probing during kernel initialization.  They are
 247  * reasonably simple to use, are not "fooled" by spurious interrupts,
 248  * and, unlike other attempts at IRQ probing, they do not get hung on
 249  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 250  *
 251  * For reasonably foolproof probing, use them as follows:
 252  *
 253  * 1. clear and/or mask the device's internal interrupt.
 254  * 2. sti();
 255  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 256  * 4. enable the device and cause it to trigger an interrupt.
 257  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 258  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 259  * 7. service the device to clear its pending interrupt.
 260  * 8. loop again if paranoia is required.
 261  *
 262  * probe_irq_on() returns a mask of allocated irq's.
 263  *
 264  * probe_irq_off() takes the mask as a parameter,
 265  * and returns the irq number which occurred,
 266  * or zero if none occurred, or a negative irq number
 267  * if more than one irq occurred.
 268  */
 269
 270 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 271 static inline unsigned long probe_irq_on(void)
 272 {
 273         return 0;
 274 }
 275 static inline int probe_irq_off(unsigned long val)
 276 {
 277         return 0;
 278 }
 279 static inline unsigned int probe_irq_mask(unsigned long val)
 280 {
 281         return 0;
 282 }
 283 #else
 284 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 285 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 286 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 287 #endif
 288
 289 #endif