File: /usr/src/linux/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/smp.h>
8 #include <linux/cache.h>
9
10 #include <asm/bitops.h>
11 #include <asm/atomic.h>
12 #include <asm/ptrace.h>
13
14 struct irqaction {
15 void (*handler)(int, void *, struct pt_regs *);
16 unsigned long flags;
17 unsigned long mask;
18 const char *name;
19 void *dev_id;
20 struct irqaction *next;
21 };
22
23
24 /* Who gets which entry in bh_base. Things which will occur most often
25 should come first */
26
27 enum {
28 TIMER_BH = 0,
29 TQUEUE_BH,
30 DIGI_BH,
31 SERIAL_BH,
32 RISCOM8_BH,
33 SPECIALIX_BH,
34 AURORA_BH,
35 ESP_BH,
36 SCSI_BH,
37 IMMEDIATE_BH,
38 CYCLADES_BH,
39 CM206_BH,
40 JS_BH,
41 MACSERIAL_BH,
42 ISICOM_BH
43 };
44
45 #include <asm/hardirq.h>
46 #include <asm/softirq.h>
47
48
49
50 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
51 frequency threaded job scheduling. For almost all the purposes
52 tasklets are more than enough. F.e. all serial device BHs et
53 al. should be converted to tasklets, not to softirqs.
54 */
55
56 enum
57 {
58 HI_SOFTIRQ=0,
59 NET_TX_SOFTIRQ,
60 NET_RX_SOFTIRQ,
61 TASKLET_SOFTIRQ
62 };
63
64 /* softirq mask and active fields moved to irq_cpustat_t in
65 * asm/hardirq.h to get better cache usage. KAO
66 */
67
68 struct softirq_action
69 {
70 void (*action)(struct softirq_action *);
71 void *data;
72 };
73
74 asmlinkage void do_softirq(void);
75 extern void open_softirq(int nr, void (*action)(struct softirq_action*), void *data);
76 extern void softirq_init(void);
77 #define __cpu_raise_softirq(cpu, nr) do { softirq_pending(cpu) |= 1UL << (nr); } while (0)
78 extern void FASTCALL(cpu_raise_softirq(unsigned int cpu, unsigned int nr));
79 extern void FASTCALL(raise_softirq(unsigned int nr));
80
81
82
83 /* Tasklets --- multithreaded analogue of BHs.
84
85 Main feature differing them of generic softirqs: tasklet
86 is running only on one CPU simultaneously.
87
88 Main feature differing them of BHs: different tasklets
89 may be run simultaneously on different CPUs.
90
91 Properties:
92 * If tasklet_schedule() is called, then tasklet is guaranteed
93 to be executed on some cpu at least once after this.
94 * If the tasklet is already scheduled, but its excecution is still not
95 started, it will be executed only once.
96 * If this tasklet is already running on another CPU (or schedule is called
97 from tasklet itself), it is rescheduled for later.
98 * Tasklet is strictly serialized wrt itself, but not
99 wrt another tasklets. If client needs some intertask synchronization,
100 he makes it with spinlocks.
101 */
102
103 struct tasklet_struct
104 {
105 struct tasklet_struct *next;
106 unsigned long state;
107 atomic_t count;
108 void (*func)(unsigned long);
109 unsigned long data;
110 };
111
112 #define DECLARE_TASKLET(name, func, data) \
113 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
114
115 #define DECLARE_TASKLET_DISABLED(name, func, data) \
116 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
117
118
119 enum
120 {
121 TASKLET_STATE_SCHED, /* Tasklet is scheduled for execution */
122 TASKLET_STATE_RUN /* Tasklet is running (SMP only) */
123 };
124
125 struct tasklet_head
126 {
127 struct tasklet_struct *list;
128 } __attribute__ ((__aligned__(SMP_CACHE_BYTES)));
129
130 extern struct tasklet_head tasklet_vec[NR_CPUS];
131 extern struct tasklet_head tasklet_hi_vec[NR_CPUS];
132
133 #ifdef CONFIG_SMP
134 static inline int tasklet_trylock(struct tasklet_struct *t)
135 {
136 return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
137 }
138
139 static inline void tasklet_unlock(struct tasklet_struct *t)
140 {
141 smp_mb__before_clear_bit();
142 clear_bit(TASKLET_STATE_RUN, &(t)->state);
143 }
144
145 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
146 {
147 while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
148 }
149 #else
150 #define tasklet_trylock(t) 1
151 #define tasklet_unlock_wait(t) do { } while (0)
152 #define tasklet_unlock(t) do { } while (0)
153 #endif
154
155 extern void FASTCALL(__tasklet_schedule(struct tasklet_struct *t));
156
157 static inline void tasklet_schedule(struct tasklet_struct *t)
158 {
159 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
160 __tasklet_schedule(t);
161 }
162
163 extern void FASTCALL(__tasklet_hi_schedule(struct tasklet_struct *t));
164
165 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
166 {
167 if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
168 __tasklet_hi_schedule(t);
169 }
170
171
172 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
173 {
174 atomic_inc(&t->count);
175 smp_mb__after_atomic_inc();
176 }
177
178 static inline void tasklet_disable(struct tasklet_struct *t)
179 {
180 tasklet_disable_nosync(t);
181 tasklet_unlock_wait(t);
182 smp_mb();
183 }
184
185 static inline void tasklet_enable(struct tasklet_struct *t)
186 {
187 smp_mb__before_atomic_dec();
188 atomic_dec(&t->count);
189 }
190
191 static inline void tasklet_hi_enable(struct tasklet_struct *t)
192 {
193 smp_mb__before_atomic_dec();
194 atomic_dec(&t->count);
195 }
196
197 extern void tasklet_kill(struct tasklet_struct *t);
198 extern void tasklet_init(struct tasklet_struct *t,
199 void (*func)(unsigned long), unsigned long data);
200
201 #ifdef CONFIG_SMP
202
203 #define SMP_TIMER_NAME(name) name##__thr
204
205 #define SMP_TIMER_DEFINE(name, task) \
206 DECLARE_TASKLET(task, name##__thr, 0); \
207 static void name (unsigned long dummy) \
208 { \
209 tasklet_schedule(&(task)); \
210 }
211
212 #else /* CONFIG_SMP */
213
214 #define SMP_TIMER_NAME(name) name
215 #define SMP_TIMER_DEFINE(name, task)
216
217 #endif /* CONFIG_SMP */
218
219
220 /* Old BH definitions */
221
222 extern struct tasklet_struct bh_task_vec[];
223
224 /* It is exported _ONLY_ for wait_on_irq(). */
225 extern spinlock_t global_bh_lock;
226
227 static inline void mark_bh(int nr)
228 {
229 tasklet_hi_schedule(bh_task_vec+nr);
230 }
231
232 extern void init_bh(int nr, void (*routine)(void));
233 extern void remove_bh(int nr);
234
235
236 /*
237 * Autoprobing for irqs:
238 *
239 * probe_irq_on() and probe_irq_off() provide robust primitives
240 * for accurate IRQ probing during kernel initialization. They are
241 * reasonably simple to use, are not "fooled" by spurious interrupts,
242 * and, unlike other attempts at IRQ probing, they do not get hung on
243 * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
244 *
245 * For reasonably foolproof probing, use them as follows:
246 *
247 * 1. clear and/or mask the device's internal interrupt.
248 * 2. sti();
249 * 3. irqs = probe_irq_on(); // "take over" all unassigned idle IRQs
250 * 4. enable the device and cause it to trigger an interrupt.
251 * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
252 * 6. irq = probe_irq_off(irqs); // get IRQ number, 0=none, negative=multiple
253 * 7. service the device to clear its pending interrupt.
254 * 8. loop again if paranoia is required.
255 *
256 * probe_irq_on() returns a mask of allocated irq's.
257 *
258 * probe_irq_off() takes the mask as a parameter,
259 * and returns the irq number which occurred,
260 * or zero if none occurred, or a negative irq number
261 * if more than one irq occurred.
262 */
263 extern unsigned long probe_irq_on(void); /* returns 0 on failure */
264 extern int probe_irq_off(unsigned long); /* returns 0 or negative on failure */
265 extern unsigned int probe_irq_mask(unsigned long); /* returns mask of ISA interrupts */
266
267 #endif
268