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 <linux/sched.h>
  13 #include <asm/atomic.h>
  14 #include <asm/ptrace.h>
  15 #include <asm/system.h>
  16
  17 /*
  18  * For 2.4.x compatibility, 2.4.x can use
  19  *
  20  *      typedef void irqreturn_t;
  21  *      #define IRQ_NONE
  22  *      #define IRQ_HANDLED
  23  *      #define IRQ_RETVAL(x)
  24  *
  25  * To mix old-style and new-style irq handler returns.
  26  *
  27  * IRQ_NONE means we didn't handle it.
  28  * IRQ_HANDLED means that we did have a valid interrupt and handled it.
  29  * IRQ_RETVAL(x) selects on the two depending on x being non-zero (for handled)
  30  */
  31 typedef int irqreturn_t;
  32
  33 #define IRQ_NONE        (0)
  34 #define IRQ_HANDLED     (1)
  35 #define IRQ_RETVAL(x)   ((x) != 0)
  36
  37 struct irqaction {
  38         irqreturn_t (*handler)(int, void *, struct pt_regs *);
  39         unsigned long flags;
  40         cpumask_t mask;
  41         const char *name;
  42         void *dev_id;
  43         struct irqaction *next;
  44         int irq;
  45         struct proc_dir_entry *dir;
  46 };
  47
  48 extern irqreturn_t no_action(int cpl, void *dev_id, struct pt_regs *regs);
  49 extern int request_irq(unsigned int,
  50                        irqreturn_t (*handler)(int, void *, struct pt_regs *),
  51                        unsigned long, const char *, void *);
  52 extern void free_irq(unsigned int, void *);
  53
  54
  55 #ifdef CONFIG_GENERIC_HARDIRQS
  56 extern void disable_irq_nosync(unsigned int irq);
  57 extern void disable_irq(unsigned int irq);
  58 extern void enable_irq(unsigned int irq);
  59 #endif
  60
  61 #ifndef __ARCH_SET_SOFTIRQ_PENDING
  62 #define set_softirq_pending(x) (local_softirq_pending() = (x))
  63 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
  64 #endif
  65
  66 /*
  67  * Temporary defines for UP kernels, until all code gets fixed.
  68  */
  69 #ifndef CONFIG_SMP
  70 static inline void __deprecated cli(void)
  71 {
  72         local_irq_disable();
  73 }
  74 static inline void __deprecated sti(void)
  75 {
  76         local_irq_enable();
  77 }
  78 static inline void __deprecated save_flags(unsigned long *x)
  79 {
  80         local_save_flags(*x);
  81 }
  82 #define save_flags(x) save_flags(&x)
  83 static inline void __deprecated restore_flags(unsigned long x)
  84 {
  85         local_irq_restore(x);
  86 }
  87
  88 static inline void __deprecated save_and_cli(unsigned long *x)
  89 {
  90         local_irq_save(*x);
  91 }
  92 #define save_and_cli(x) save_and_cli(&x)
  93 #endif /* CONFIG_SMP */
  94
  95 /* SoftIRQ primitives.  */
  96 #define local_bh_disable() \
  97                 do { add_preempt_count(SOFTIRQ_OFFSET); barrier(); } while (0)
  98 #define __local_bh_enable() \
  99                 do { barrier(); sub_preempt_count(SOFTIRQ_OFFSET); } while (0)
 100
 101 extern void local_bh_enable(void);
 102
 103 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
 104    frequency threaded job scheduling. For almost all the purposes
 105    tasklets are more than enough. F.e. all serial device BHs et
 106    al. should be converted to tasklets, not to softirqs.
 107  */
 108
 109 enum
 110 {
 111         HI_SOFTIRQ=0,
 112         TIMER_SOFTIRQ,
 113         NET_TX_SOFTIRQ,
 114         NET_RX_SOFTIRQ,
 115         BLOCK_SOFTIRQ,
 116         TASKLET_SOFTIRQ
 117 };
 118
 119 /* softirq mask and active fields moved to irq_cpustat_t in
 120  * asm/hardirq.h to get better cache usage.  KAO
 121  */
 122
 123 struct softirq_action
 124 {
 125         void    (*action)(struct softirq_action *);
 126         void    *data;
 127 };
 128
 129 asmlinkage void do_softirq(void);
 130 extern void open_softirq(int nr, void (*action)(struct softirq_action*), void *data);
 131 extern void softirq_init(void);
 132 #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
 133 extern void FASTCALL(raise_softirq_irqoff(unsigned int nr));
 134 extern void FASTCALL(raise_softirq(unsigned int nr));
 135
 136
 137 /* Tasklets --- multithreaded analogue of BHs.
 138
 139    Main feature differing them of generic softirqs: tasklet
 140    is running only on one CPU simultaneously.
 141
 142    Main feature differing them of BHs: different tasklets
 143    may be run simultaneously on different CPUs.
 144
 145    Properties:
 146    * If tasklet_schedule() is called, then tasklet is guaranteed
 147      to be executed on some cpu at least once after this.
 148    * If the tasklet is already scheduled, but its excecution is still not
 149      started, it will be executed only once.
 150    * If this tasklet is already running on another CPU (or schedule is called
 151      from tasklet itself), it is rescheduled for later.
 152    * Tasklet is strictly serialized wrt itself, but not
 153      wrt another tasklets. If client needs some intertask synchronization,
 154      he makes it with spinlocks.
 155  */
 156
 157 struct tasklet_struct
 158 {
 159         struct tasklet_struct *next;
 160         unsigned long state;
 161         atomic_t count;
 162         void (*func)(unsigned long);
 163         unsigned long data;
 164 };
 165
 166 #define DECLARE_TASKLET(name, func, data) \
 167 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
 168
 169 #define DECLARE_TASKLET_DISABLED(name, func, data) \
 170 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
 171
 172
 173 enum
 174 {
 175         TASKLET_STATE_SCHED,    /* Tasklet is scheduled for execution */
 176         TASKLET_STATE_RUN       /* Tasklet is running (SMP only) */
 177 };
 178
 179 #ifdef CONFIG_SMP
 180 static inline int tasklet_trylock(struct tasklet_struct *t)
 181 {
 182         return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
 183 }
 184
 185 static inline void tasklet_unlock(struct tasklet_struct *t)
 186 {
 187         smp_mb__before_clear_bit();
 188         clear_bit(TASKLET_STATE_RUN, &(t)->state);
 189 }
 190
 191 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
 192 {
 193         while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
 194 }
 195 #else
 196 #define tasklet_trylock(t) 1
 197 #define tasklet_unlock_wait(t) do { } while (0)
 198 #define tasklet_unlock(t) do { } while (0)
 199 #endif
 200
 201 extern void FASTCALL(__tasklet_schedule(struct tasklet_struct *t));
 202
 203 static inline void tasklet_schedule(struct tasklet_struct *t)
 204 {
 205         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 206                 __tasklet_schedule(t);
 207 }
 208
 209 extern void FASTCALL(__tasklet_hi_schedule(struct tasklet_struct *t));
 210
 211 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
 212 {
 213         if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
 214                 __tasklet_hi_schedule(t);
 215 }
 216
 217
 218 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
 219 {
 220         atomic_inc(&t->count);
 221         smp_mb__after_atomic_inc();
 222 }
 223
 224 static inline void tasklet_disable(struct tasklet_struct *t)
 225 {
 226         tasklet_disable_nosync(t);
 227         tasklet_unlock_wait(t);
 228         smp_mb();
 229 }
 230
 231 static inline void tasklet_enable(struct tasklet_struct *t)
 232 {
 233         smp_mb__before_atomic_dec();
 234         atomic_dec(&t->count);
 235 }
 236
 237 static inline void tasklet_hi_enable(struct tasklet_struct *t)
 238 {
 239         smp_mb__before_atomic_dec();
 240         atomic_dec(&t->count);
 241 }
 242
 243 extern void tasklet_kill(struct tasklet_struct *t);
 244 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
 245 extern void tasklet_init(struct tasklet_struct *t,
 246                          void (*func)(unsigned long), unsigned long data);
 247
 248 /*
 249  * Autoprobing for irqs:
 250  *
 251  * probe_irq_on() and probe_irq_off() provide robust primitives
 252  * for accurate IRQ probing during kernel initialization.  They are
 253  * reasonably simple to use, are not "fooled" by spurious interrupts,
 254  * and, unlike other attempts at IRQ probing, they do not get hung on
 255  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
 256  *
 257  * For reasonably foolproof probing, use them as follows:
 258  *
 259  * 1. clear and/or mask the device's internal interrupt.
 260  * 2. sti();
 261  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
 262  * 4. enable the device and cause it to trigger an interrupt.
 263  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
 264  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
 265  * 7. service the device to clear its pending interrupt.
 266  * 8. loop again if paranoia is required.
 267  *
 268  * probe_irq_on() returns a mask of allocated irq's.
 269  *
 270  * probe_irq_off() takes the mask as a parameter,
 271  * and returns the irq number which occurred,
 272  * or zero if none occurred, or a negative irq number
 273  * if more than one irq occurred.
 274  */
 275
 276 #if defined(CONFIG_GENERIC_HARDIRQS) && !defined(CONFIG_GENERIC_IRQ_PROBE)
 277 static inline unsigned long probe_irq_on(void)
 278 {
 279         return 0;
 280 }
 281 static inline int probe_irq_off(unsigned long val)
 282 {
 283         return 0;
 284 }
 285 static inline unsigned int probe_irq_mask(unsigned long val)
 286 {
 287         return 0;
 288 }
 289 #else
 290 extern unsigned long probe_irq_on(void);        /* returns 0 on failure */
 291 extern int probe_irq_off(unsigned long);        /* returns 0 or negative on failure */
 292 extern unsigned int probe_irq_mask(unsigned long);      /* returns mask of ISA interrupts */
 293 #endif
 294
 295 #endif