kernel26-2.6.12-alx-r9/kernel/spinlock.c

/*
 * Copyright (2004) Linus Torvalds
 *
 * Author: Zwane Mwaikambo <zwane@fsmlabs.com>
 *
 * Copyright (2004) Ingo Molnar
 */

#include <linux/config.h>
#include <linux/linkage.h>
#include <linux/preempt.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/module.h>

/*
 * Generic declaration of the raw read_trylock() function,
 * architectures are supposed to optimize this:
 */
int __lockfunc generic_raw_read_trylock(rwlock_t *lock)
{
	_raw_read_lock(lock);
	return 1;
}
EXPORT_SYMBOL(generic_raw_read_trylock);

int __lockfunc _spin_trylock(spinlock_t *lock)
{
	preempt_disable();
	if (_raw_spin_trylock(lock))
		return 1;
	
	preempt_enable();
	return 0;
}
EXPORT_SYMBOL(_spin_trylock);

int __lockfunc _read_trylock(rwlock_t *lock)
{
	preempt_disable();
	if (_raw_read_trylock(lock))
		return 1;

	preempt_enable();
	return 0;
}
EXPORT_SYMBOL(_read_trylock);

int __lockfunc _write_trylock(rwlock_t *lock)
{
	preempt_disable();
	if (_raw_write_trylock(lock))
		return 1;

	preempt_enable();
	return 0;
}
EXPORT_SYMBOL(_write_trylock);

#ifndef CONFIG_PREEMPT

void __lockfunc _read_lock(rwlock_t *lock)
{
	preempt_disable();
	_raw_read_lock(lock);
}
EXPORT_SYMBOL(_read_lock);

unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
{
	unsigned long flags;

	local_irq_save(flags);
	preempt_disable();
	_raw_spin_lock_flags(lock, flags);
	return flags;
}
EXPORT_SYMBOL(_spin_lock_irqsave);

void __lockfunc _spin_lock_irq(spinlock_t *lock)
{
	local_irq_disable();
	preempt_disable();
	_raw_spin_lock(lock);
}
EXPORT_SYMBOL(_spin_lock_irq);

void __lockfunc _spin_lock_bh(spinlock_t *lock)
{
	local_bh_disable();
	preempt_disable();
	_raw_spin_lock(lock);
}
EXPORT_SYMBOL(_spin_lock_bh);

unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
{
	unsigned long flags;

	local_irq_save(flags);
	preempt_disable();
	_raw_read_lock(lock);
	return flags;
}
EXPORT_SYMBOL(_read_lock_irqsave);

void __lockfunc _read_lock_irq(rwlock_t *lock)
{
	local_irq_disable();
	preempt_disable();
	_raw_read_lock(lock);
}
EXPORT_SYMBOL(_read_lock_irq);

void __lockfunc _read_lock_bh(rwlock_t *lock)
{
	local_bh_disable();
	preempt_disable();
	_raw_read_lock(lock);
}
EXPORT_SYMBOL(_read_lock_bh);

unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)
{
	unsigned long flags;

	local_irq_save(flags);
	preempt_disable();
	_raw_write_lock(lock);
	return flags;
}
EXPORT_SYMBOL(_write_lock_irqsave);

void __lockfunc _write_lock_irq(rwlock_t *lock)
{
	local_irq_disable();
	preempt_disable();
	_raw_write_lock(lock);
}
EXPORT_SYMBOL(_write_lock_irq);

void __lockfunc _write_lock_bh(rwlock_t *lock)
{
	local_bh_disable();
	preempt_disable();
	_raw_write_lock(lock);
}
EXPORT_SYMBOL(_write_lock_bh);

void __lockfunc _spin_lock(spinlock_t *lock)
{
	preempt_disable();
	_raw_spin_lock(lock);
}

EXPORT_SYMBOL(_spin_lock);

void __lockfunc _write_lock(rwlock_t *lock)
{
	preempt_disable();
	_raw_write_lock(lock);
}

EXPORT_SYMBOL(_write_lock);

#else /* CONFIG_PREEMPT: */

/*
 * This could be a long-held lock. We both prepare to spin for a long
 * time (making _this_ CPU preemptable if possible), and we also signal
 * towards that other CPU that it should break the lock ASAP.
 *
 * (We do this in a function because inlining it would be excessive.)
 */

#define BUILD_LOCK_OPS(op, locktype)					\
void __lockfunc _##op##_lock(locktype##_t *lock)			\
{									\
	preempt_disable();						\
	for (;;) {							\
		if (likely(_raw_##op##_trylock(lock)))			\
			break;						\
		preempt_enable();					\
		if (!(lock)->break_lock)				\
			(lock)->break_lock = 1;				\
		while (!op##_can_lock(lock) && (lock)->break_lock)	\
			cpu_relax();					\
		preempt_disable();					\
	}								\
	(lock)->break_lock = 0;						\
}									\
									\
EXPORT_SYMBOL(_##op##_lock);						\
									\
unsigned long __lockfunc _##op##_lock_irqsave(locktype##_t *lock)	\
{									\
	unsigned long flags;						\
									\
	preempt_disable();						\
	for (;;) {							\
		local_irq_save(flags);					\
		if (likely(_raw_##op##_trylock(lock)))			\
			break;						\
		local_irq_restore(flags);				\
									\
		preempt_enable();					\
		if (!(lock)->break_lock)				\
			(lock)->break_lock = 1;				\
		while (!op##_can_lock(lock) && (lock)->break_lock)	\
			cpu_relax();					\
		preempt_disable();					\
	}								\
	(lock)->break_lock = 0;						\
	return flags;							\
}									\
									\
EXPORT_SYMBOL(_##op##_lock_irqsave);					\
									\
void __lockfunc _##op##_lock_irq(locktype##_t *lock)			\
{									\
	_##op##_lock_irqsave(lock);					\
}									\
									\
EXPORT_SYMBOL(_##op##_lock_irq);					\
									\
void __lockfunc _##op##_lock_bh(locktype##_t *lock)			\
{									\
	unsigned long flags;						\
									\
	/*							*/	\
	/* Careful: we must exclude softirqs too, hence the	*/	\
	/* irq-disabling. We use the generic preemption-aware	*/	\
	/* function:						*/	\
	/**/								\
	flags = _##op##_lock_irqsave(lock);				\
	local_bh_disable();						\
	local_irq_restore(flags);					\
}									\
									\
EXPORT_SYMBOL(_##op##_lock_bh)

/*
 * Build preemption-friendly versions of the following
 * lock-spinning functions:
 *
 *         _[spin|read|write]_lock()
 *         _[spin|read|write]_lock_irq()
 *         _[spin|read|write]_lock_irqsave()
 *         _[spin|read|write]_lock_bh()
 */
BUILD_LOCK_OPS(spin, spinlock);
BUILD_LOCK_OPS(read, rwlock);
BUILD_LOCK_OPS(write, rwlock);

#endif /* CONFIG_PREEMPT */

void __lockfunc _spin_unlock(spinlock_t *lock)
{
	_raw_spin_unlock(lock);
	preempt_enable();
}
EXPORT_SYMBOL(_spin_unlock);

void __lockfunc _write_unlock(rwlock_t *lock)
{
	_raw_write_unlock(lock);
	preempt_enable();
}
EXPORT_SYMBOL(_write_unlock);

void __lockfunc _read_unlock(rwlock_t *lock)
{
	_raw_read_unlock(lock);
	preempt_enable();
}
EXPORT_SYMBOL(_read_unlock);

void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
{
	_raw_spin_unlock(lock);
	local_irq_restore(flags);
	preempt_enable();
}
EXPORT_SYMBOL(_spin_unlock_irqrestore);

void __lockfunc _spin_unlock_irq(spinlock_t *lock)
{
	_raw_spin_unlock(lock);
	local_irq_enable();
	preempt_enable();
}
EXPORT_SYMBOL(_spin_unlock_irq);

void __lockfunc _spin_unlock_bh(spinlock_t *lock)
{
	_raw_spin_unlock(lock);
	preempt_enable_no_resched();
	local_bh_enable();
}
EXPORT_SYMBOL(_spin_unlock_bh);

void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
	_raw_read_unlock(lock);
	local_irq_restore(flags);
	preempt_enable();
}
EXPORT_SYMBOL(_read_unlock_irqrestore);

void __lockfunc _read_unlock_irq(rwlock_t *lock)
{
	_raw_read_unlock(lock);
	local_irq_enable();
	preempt_enable();
}
EXPORT_SYMBOL(_read_unlock_irq);

void __lockfunc _read_unlock_bh(rwlock_t *lock)
{
	_raw_read_unlock(lock);
	preempt_enable_no_resched();
	local_bh_enable();
}
EXPORT_SYMBOL(_read_unlock_bh);

void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
{
	_raw_write_unlock(lock);
	local_irq_restore(flags);
	preempt_enable();
}
EXPORT_SYMBOL(_write_unlock_irqrestore);

void __lockfunc _write_unlock_irq(rwlock_t *lock)
{
	_raw_write_unlock(lock);
	local_irq_enable();
	preempt_enable();
}
EXPORT_SYMBOL(_write_unlock_irq);

void __lockfunc _write_unlock_bh(rwlock_t *lock)
{
	_raw_write_unlock(lock);
	preempt_enable_no_resched();
	local_bh_enable();
}
EXPORT_SYMBOL(_write_unlock_bh);

int __lockfunc _spin_trylock_bh(spinlock_t *lock)
{
	local_bh_disable();
	preempt_disable();
	if (_raw_spin_trylock(lock))
		return 1;

	preempt_enable_no_resched();
	local_bh_enable();
	return 0;
}
EXPORT_SYMBOL(_spin_trylock_bh);

int in_lock_functions(unsigned long addr)
{
	/* Linker adds these: start and end of __lockfunc functions */
	extern char __lock_text_start[], __lock_text_end[];

	return addr >= (unsigned long)__lock_text_start
	&& addr < (unsigned long)__lock_text_end;
}
EXPORT_SYMBOL(in_lock_functions);
1	/*
2	* Copyright (2004) Linus Torvalds
3	*
4	* Author: Zwane Mwaikambo <zwane@fsmlabs.com>
5	*
6	* Copyright (2004) Ingo Molnar
7	*/
8
9	#include <linux/config.h>
10	#include <linux/linkage.h>
11	#include <linux/preempt.h>
12	#include <linux/spinlock.h>
13	#include <linux/interrupt.h>
14	#include <linux/module.h>
15
16	/*
17	* Generic declaration of the raw read_trylock() function,
18	* architectures are supposed to optimize this:
19	*/
20	int __lockfunc generic_raw_read_trylock(rwlock_t *lock)
21	{
22	_raw_read_lock(lock);
23	return 1;
24	}
25	EXPORT_SYMBOL(generic_raw_read_trylock);
26
27	int __lockfunc _spin_trylock(spinlock_t *lock)
28	{
29	preempt_disable();
30	if (_raw_spin_trylock(lock))
31	return 1;
32
33	preempt_enable();
34	return 0;
35	}
36	EXPORT_SYMBOL(_spin_trylock);
37
38	int __lockfunc _read_trylock(rwlock_t *lock)
39	{
40	preempt_disable();
41	if (_raw_read_trylock(lock))
42	return 1;
43
44	preempt_enable();
45	return 0;
46	}
47	EXPORT_SYMBOL(_read_trylock);
48
49	int __lockfunc _write_trylock(rwlock_t *lock)
50	{
51	preempt_disable();
52	if (_raw_write_trylock(lock))
53	return 1;
54
55	preempt_enable();
56	return 0;
57	}
58	EXPORT_SYMBOL(_write_trylock);
59
60	#ifndef CONFIG_PREEMPT
61
62	void __lockfunc _read_lock(rwlock_t *lock)
63	{
64	preempt_disable();
65	_raw_read_lock(lock);
66	}
67	EXPORT_SYMBOL(_read_lock);
68
69	unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
70	{
71	unsigned long flags;
72
73	local_irq_save(flags);
74	preempt_disable();
75	_raw_spin_lock_flags(lock, flags);
76	return flags;
77	}
78	EXPORT_SYMBOL(_spin_lock_irqsave);
79
80	void __lockfunc _spin_lock_irq(spinlock_t *lock)
81	{
82	local_irq_disable();
83	preempt_disable();
84	_raw_spin_lock(lock);
85	}
86	EXPORT_SYMBOL(_spin_lock_irq);
87
88	void __lockfunc _spin_lock_bh(spinlock_t *lock)
89	{
90	local_bh_disable();
91	preempt_disable();
92	_raw_spin_lock(lock);
93	}
94	EXPORT_SYMBOL(_spin_lock_bh);
95
96	unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
97	{
98	unsigned long flags;
99
100	local_irq_save(flags);
101	preempt_disable();
102	_raw_read_lock(lock);
103	return flags;
104	}
105	EXPORT_SYMBOL(_read_lock_irqsave);
106
107	void __lockfunc _read_lock_irq(rwlock_t *lock)
108	{
109	local_irq_disable();
110	preempt_disable();
111	_raw_read_lock(lock);
112	}
113	EXPORT_SYMBOL(_read_lock_irq);
114
115	void __lockfunc _read_lock_bh(rwlock_t *lock)
116	{
117	local_bh_disable();
118	preempt_disable();
119	_raw_read_lock(lock);
120	}
121	EXPORT_SYMBOL(_read_lock_bh);
122
123	unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)
124	{
125	unsigned long flags;
126
127	local_irq_save(flags);
128	preempt_disable();
129	_raw_write_lock(lock);
130	return flags;
131	}
132	EXPORT_SYMBOL(_write_lock_irqsave);
133
134	void __lockfunc _write_lock_irq(rwlock_t *lock)
135	{
136	local_irq_disable();
137	preempt_disable();
138	_raw_write_lock(lock);
139	}
140	EXPORT_SYMBOL(_write_lock_irq);
141
142	void __lockfunc _write_lock_bh(rwlock_t *lock)
143	{
144	local_bh_disable();
145	preempt_disable();
146	_raw_write_lock(lock);
147	}
148	EXPORT_SYMBOL(_write_lock_bh);
149
150	void __lockfunc _spin_lock(spinlock_t *lock)
151	{
152	preempt_disable();
153	_raw_spin_lock(lock);
154	}
155
156	EXPORT_SYMBOL(_spin_lock);
157
158	void __lockfunc _write_lock(rwlock_t *lock)
159	{
160	preempt_disable();
161	_raw_write_lock(lock);
162	}
163
164	EXPORT_SYMBOL(_write_lock);
165
166	#else /* CONFIG_PREEMPT: */
167
168	/*
169	* This could be a long-held lock. We both prepare to spin for a long
170	* time (making _this_ CPU preemptable if possible), and we also signal
171	* towards that other CPU that it should break the lock ASAP.
172	*
173	* (We do this in a function because inlining it would be excessive.)
174	*/
175
176	#define BUILD_LOCK_OPS(op, locktype) \
177	void __lockfunc _##op##_lock(locktype##_t *lock) \
178	{ \
179	preempt_disable(); \
180	for (;;) { \
181	if (likely(_raw_##op##_trylock(lock))) \
182	break; \
183	preempt_enable(); \
184	if (!(lock)->break_lock) \
185	(lock)->break_lock = 1; \
186	while (!op##_can_lock(lock) && (lock)->break_lock) \
187	cpu_relax(); \
188	preempt_disable(); \
189	} \
190	(lock)->break_lock = 0; \
191	} \
192	\
193	EXPORT_SYMBOL(_##op##_lock); \
194	\
195	unsigned long __lockfunc _##op##_lock_irqsave(locktype##_t *lock) \
196	{ \
197	unsigned long flags; \
198	\
199	preempt_disable(); \
200	for (;;) { \
201	local_irq_save(flags); \
202	if (likely(_raw_##op##_trylock(lock))) \
203	break; \
204	local_irq_restore(flags); \
205	\
206	preempt_enable(); \
207	if (!(lock)->break_lock) \
208	(lock)->break_lock = 1; \
209	while (!op##_can_lock(lock) && (lock)->break_lock) \
210	cpu_relax(); \
211	preempt_disable(); \
212	} \
213	(lock)->break_lock = 0; \
214	return flags; \
215	} \
216	\
217	EXPORT_SYMBOL(_##op##_lock_irqsave); \
218	\
219	void __lockfunc _##op##_lock_irq(locktype##_t *lock) \
220	{ \
221	_##op##_lock_irqsave(lock); \
222	} \
223	\
224	EXPORT_SYMBOL(_##op##_lock_irq); \
225	\
226	void __lockfunc _##op##_lock_bh(locktype##_t *lock) \
227	{ \
228	unsigned long flags; \
229	\
230	/* */ \
231	/* Careful: we must exclude softirqs too, hence the */ \
232	/* irq-disabling. We use the generic preemption-aware */ \
233	/* function: */ \
234	/**/ \
235	flags = _##op##_lock_irqsave(lock); \
236	local_bh_disable(); \
237	local_irq_restore(flags); \
238	} \
239	\
240	EXPORT_SYMBOL(_##op##_lock_bh)
241
242	/*
243	* Build preemption-friendly versions of the following
244	* lock-spinning functions:
245	*
246	* _[spin\|read\|write]_lock()
247	* _[spin\|read\|write]_lock_irq()
248	* _[spin\|read\|write]_lock_irqsave()
249	* _[spin\|read\|write]_lock_bh()
250	*/
251	BUILD_LOCK_OPS(spin, spinlock);
252	BUILD_LOCK_OPS(read, rwlock);
253	BUILD_LOCK_OPS(write, rwlock);
254
255	#endif /* CONFIG_PREEMPT */
256
257	void __lockfunc _spin_unlock(spinlock_t *lock)
258	{
259	_raw_spin_unlock(lock);
260	preempt_enable();
261	}
262	EXPORT_SYMBOL(_spin_unlock);
263
264	void __lockfunc _write_unlock(rwlock_t *lock)
265	{
266	_raw_write_unlock(lock);
267	preempt_enable();
268	}
269	EXPORT_SYMBOL(_write_unlock);
270
271	void __lockfunc _read_unlock(rwlock_t *lock)
272	{
273	_raw_read_unlock(lock);
274	preempt_enable();
275	}
276	EXPORT_SYMBOL(_read_unlock);
277
278	void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
279	{
280	_raw_spin_unlock(lock);
281	local_irq_restore(flags);
282	preempt_enable();
283	}
284	EXPORT_SYMBOL(_spin_unlock_irqrestore);
285
286	void __lockfunc _spin_unlock_irq(spinlock_t *lock)
287	{
288	_raw_spin_unlock(lock);
289	local_irq_enable();
290	preempt_enable();
291	}
292	EXPORT_SYMBOL(_spin_unlock_irq);
293
294	void __lockfunc _spin_unlock_bh(spinlock_t *lock)
295	{
296	_raw_spin_unlock(lock);
297	preempt_enable_no_resched();
298	local_bh_enable();
299	}
300	EXPORT_SYMBOL(_spin_unlock_bh);
301
302	void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
303	{
304	_raw_read_unlock(lock);
305	local_irq_restore(flags);
306	preempt_enable();
307	}
308	EXPORT_SYMBOL(_read_unlock_irqrestore);
309
310	void __lockfunc _read_unlock_irq(rwlock_t *lock)
311	{
312	_raw_read_unlock(lock);
313	local_irq_enable();
314	preempt_enable();
315	}
316	EXPORT_SYMBOL(_read_unlock_irq);
317
318	void __lockfunc _read_unlock_bh(rwlock_t *lock)
319	{
320	_raw_read_unlock(lock);
321	preempt_enable_no_resched();
322	local_bh_enable();
323	}
324	EXPORT_SYMBOL(_read_unlock_bh);
325
326	void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
327	{
328	_raw_write_unlock(lock);
329	local_irq_restore(flags);
330	preempt_enable();
331	}
332	EXPORT_SYMBOL(_write_unlock_irqrestore);
333
334	void __lockfunc _write_unlock_irq(rwlock_t *lock)
335	{
336	_raw_write_unlock(lock);
337	local_irq_enable();
338	preempt_enable();
339	}
340	EXPORT_SYMBOL(_write_unlock_irq);
341
342	void __lockfunc _write_unlock_bh(rwlock_t *lock)
343	{
344	_raw_write_unlock(lock);
345	preempt_enable_no_resched();
346	local_bh_enable();
347	}
348	EXPORT_SYMBOL(_write_unlock_bh);
349
350	int __lockfunc _spin_trylock_bh(spinlock_t *lock)
351	{
352	local_bh_disable();
353	preempt_disable();
354	if (_raw_spin_trylock(lock))
355	return 1;
356
357	preempt_enable_no_resched();
358	local_bh_enable();
359	return 0;
360	}
361	EXPORT_SYMBOL(_spin_trylock_bh);
362
363	int in_lock_functions(unsigned long addr)
364	{
365	/* Linker adds these: start and end of __lockfunc functions */
366	extern char __lock_text_start[], __lock_text_end[];
367
368	return addr >= (unsigned long)__lock_text_start
369	&& addr < (unsigned long)__lock_text_end;
370	}
371	EXPORT_SYMBOL(in_lock_functions);