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