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