diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-parisc/spinlock.h |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/asm-parisc/spinlock.h')
-rw-r--r-- | include/asm-parisc/spinlock.h | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/include/asm-parisc/spinlock.h b/include/asm-parisc/spinlock.h new file mode 100644 index 000000000000..679ea1c651ef --- /dev/null +++ b/include/asm-parisc/spinlock.h | |||
@@ -0,0 +1,258 @@ | |||
1 | #ifndef __ASM_SPINLOCK_H | ||
2 | #define __ASM_SPINLOCK_H | ||
3 | |||
4 | #include <asm/system.h> | ||
5 | |||
6 | /* Note that PA-RISC has to use `1' to mean unlocked and `0' to mean locked | ||
7 | * since it only has load-and-zero. Moreover, at least on some PA processors, | ||
8 | * the semaphore address has to be 16-byte aligned. | ||
9 | */ | ||
10 | |||
11 | #ifndef CONFIG_DEBUG_SPINLOCK | ||
12 | |||
13 | #define __SPIN_LOCK_UNLOCKED { { 1, 1, 1, 1 } } | ||
14 | #undef SPIN_LOCK_UNLOCKED | ||
15 | #define SPIN_LOCK_UNLOCKED (spinlock_t) __SPIN_LOCK_UNLOCKED | ||
16 | |||
17 | #define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while(0) | ||
18 | |||
19 | static inline int spin_is_locked(spinlock_t *x) | ||
20 | { | ||
21 | volatile unsigned int *a = __ldcw_align(x); | ||
22 | return *a == 0; | ||
23 | } | ||
24 | |||
25 | #define spin_unlock_wait(x) do { barrier(); } while(spin_is_locked(x)) | ||
26 | #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) | ||
27 | |||
28 | static inline void _raw_spin_lock(spinlock_t *x) | ||
29 | { | ||
30 | volatile unsigned int *a; | ||
31 | |||
32 | mb(); | ||
33 | a = __ldcw_align(x); | ||
34 | while (__ldcw(a) == 0) | ||
35 | while (*a == 0); | ||
36 | mb(); | ||
37 | } | ||
38 | |||
39 | static inline void _raw_spin_unlock(spinlock_t *x) | ||
40 | { | ||
41 | volatile unsigned int *a; | ||
42 | mb(); | ||
43 | a = __ldcw_align(x); | ||
44 | *a = 1; | ||
45 | mb(); | ||
46 | } | ||
47 | |||
48 | static inline int _raw_spin_trylock(spinlock_t *x) | ||
49 | { | ||
50 | volatile unsigned int *a; | ||
51 | int ret; | ||
52 | |||
53 | mb(); | ||
54 | a = __ldcw_align(x); | ||
55 | ret = __ldcw(a) != 0; | ||
56 | mb(); | ||
57 | |||
58 | return ret; | ||
59 | } | ||
60 | |||
61 | #define spin_lock_own(LOCK, LOCATION) ((void)0) | ||
62 | |||
63 | #else /* !(CONFIG_DEBUG_SPINLOCK) */ | ||
64 | |||
65 | #define SPINLOCK_MAGIC 0x1D244B3C | ||
66 | |||
67 | #define __SPIN_LOCK_UNLOCKED { { 1, 1, 1, 1 }, SPINLOCK_MAGIC, 10, __FILE__ , NULL, 0, -1, NULL, NULL } | ||
68 | #undef SPIN_LOCK_UNLOCKED | ||
69 | #define SPIN_LOCK_UNLOCKED (spinlock_t) __SPIN_LOCK_UNLOCKED | ||
70 | |||
71 | #define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while(0) | ||
72 | |||
73 | #define CHECK_LOCK(x) \ | ||
74 | do { \ | ||
75 | if (unlikely((x)->magic != SPINLOCK_MAGIC)) { \ | ||
76 | printk(KERN_ERR "%s:%d: spin_is_locked" \ | ||
77 | " on uninitialized spinlock %p.\n", \ | ||
78 | __FILE__, __LINE__, (x)); \ | ||
79 | } \ | ||
80 | } while(0) | ||
81 | |||
82 | #define spin_is_locked(x) \ | ||
83 | ({ \ | ||
84 | CHECK_LOCK(x); \ | ||
85 | volatile unsigned int *a = __ldcw_align(x); \ | ||
86 | if (unlikely((*a == 0) && (x)->babble)) { \ | ||
87 | (x)->babble--; \ | ||
88 | printk("KERN_WARNING \ | ||
89 | %s:%d: spin_is_locked(%s/%p) already" \ | ||
90 | " locked by %s:%d in %s at %p(%d)\n", \ | ||
91 | __FILE__,__LINE__, (x)->module, (x), \ | ||
92 | (x)->bfile, (x)->bline, (x)->task->comm,\ | ||
93 | (x)->previous, (x)->oncpu); \ | ||
94 | } \ | ||
95 | *a == 0; \ | ||
96 | }) | ||
97 | |||
98 | #define spin_unlock_wait(x) \ | ||
99 | do { \ | ||
100 | CHECK_LOCK(x); \ | ||
101 | volatile unsigned int *a = __ldcw_align(x); \ | ||
102 | if (unlikely((*a == 0) && (x)->babble)) { \ | ||
103 | (x)->babble--; \ | ||
104 | printk("KERN_WARNING \ | ||
105 | %s:%d: spin_unlock_wait(%s/%p)" \ | ||
106 | " owned by %s:%d in %s at %p(%d)\n", \ | ||
107 | __FILE__,__LINE__, (x)->module, (x), \ | ||
108 | (x)->bfile, (x)->bline, (x)->task->comm,\ | ||
109 | (x)->previous, (x)->oncpu); \ | ||
110 | } \ | ||
111 | barrier(); \ | ||
112 | } while (*((volatile unsigned char *)(__ldcw_align(x))) == 0) | ||
113 | |||
114 | extern void _dbg_spin_lock(spinlock_t *lock, const char *base_file, int line_no); | ||
115 | extern void _dbg_spin_unlock(spinlock_t *lock, const char *, int); | ||
116 | extern int _dbg_spin_trylock(spinlock_t * lock, const char *, int); | ||
117 | |||
118 | #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) | ||
119 | |||
120 | #define _raw_spin_unlock(lock) _dbg_spin_unlock(lock, __FILE__, __LINE__) | ||
121 | #define _raw_spin_lock(lock) _dbg_spin_lock(lock, __FILE__, __LINE__) | ||
122 | #define _raw_spin_trylock(lock) _dbg_spin_trylock(lock, __FILE__, __LINE__) | ||
123 | |||
124 | /* just in case we need it */ | ||
125 | #define spin_lock_own(LOCK, LOCATION) \ | ||
126 | do { \ | ||
127 | volatile unsigned int *a = __ldcw_align(LOCK); \ | ||
128 | if (!((*a == 0) && ((LOCK)->oncpu == smp_processor_id()))) \ | ||
129 | printk("KERN_WARNING \ | ||
130 | %s: called on %d from %p but lock %s on %d\n", \ | ||
131 | LOCATION, smp_processor_id(), \ | ||
132 | __builtin_return_address(0), \ | ||
133 | (*a == 0) ? "taken" : "freed", (LOCK)->on_cpu); \ | ||
134 | } while (0) | ||
135 | |||
136 | #endif /* !(CONFIG_DEBUG_SPINLOCK) */ | ||
137 | |||
138 | /* | ||
139 | * Read-write spinlocks, allowing multiple readers | ||
140 | * but only one writer. | ||
141 | */ | ||
142 | typedef struct { | ||
143 | spinlock_t lock; | ||
144 | volatile int counter; | ||
145 | #ifdef CONFIG_PREEMPT | ||
146 | unsigned int break_lock; | ||
147 | #endif | ||
148 | } rwlock_t; | ||
149 | |||
150 | #define RW_LOCK_UNLOCKED (rwlock_t) { __SPIN_LOCK_UNLOCKED, 0 } | ||
151 | |||
152 | #define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while (0) | ||
153 | |||
154 | #define _raw_read_trylock(lock) generic_raw_read_trylock(lock) | ||
155 | |||
156 | /* read_lock, read_unlock are pretty straightforward. Of course it somehow | ||
157 | * sucks we end up saving/restoring flags twice for read_lock_irqsave aso. */ | ||
158 | |||
159 | #ifdef CONFIG_DEBUG_RWLOCK | ||
160 | extern void _dbg_read_lock(rwlock_t * rw, const char *bfile, int bline); | ||
161 | #define _raw_read_lock(rw) _dbg_read_lock(rw, __FILE__, __LINE__) | ||
162 | #else | ||
163 | static __inline__ void _raw_read_lock(rwlock_t *rw) | ||
164 | { | ||
165 | unsigned long flags; | ||
166 | local_irq_save(flags); | ||
167 | _raw_spin_lock(&rw->lock); | ||
168 | |||
169 | rw->counter++; | ||
170 | |||
171 | _raw_spin_unlock(&rw->lock); | ||
172 | local_irq_restore(flags); | ||
173 | } | ||
174 | #endif /* CONFIG_DEBUG_RWLOCK */ | ||
175 | |||
176 | static __inline__ void _raw_read_unlock(rwlock_t *rw) | ||
177 | { | ||
178 | unsigned long flags; | ||
179 | local_irq_save(flags); | ||
180 | _raw_spin_lock(&rw->lock); | ||
181 | |||
182 | rw->counter--; | ||
183 | |||
184 | _raw_spin_unlock(&rw->lock); | ||
185 | local_irq_restore(flags); | ||
186 | } | ||
187 | |||
188 | /* write_lock is less trivial. We optimistically grab the lock and check | ||
189 | * if we surprised any readers. If so we release the lock and wait till | ||
190 | * they're all gone before trying again | ||
191 | * | ||
192 | * Also note that we don't use the _irqsave / _irqrestore suffixes here. | ||
193 | * If we're called with interrupts enabled and we've got readers (or other | ||
194 | * writers) in interrupt handlers someone fucked up and we'd dead-lock | ||
195 | * sooner or later anyway. prumpf */ | ||
196 | |||
197 | #ifdef CONFIG_DEBUG_RWLOCK | ||
198 | extern void _dbg_write_lock(rwlock_t * rw, const char *bfile, int bline); | ||
199 | #define _raw_write_lock(rw) _dbg_write_lock(rw, __FILE__, __LINE__) | ||
200 | #else | ||
201 | static __inline__ void _raw_write_lock(rwlock_t *rw) | ||
202 | { | ||
203 | retry: | ||
204 | _raw_spin_lock(&rw->lock); | ||
205 | |||
206 | if(rw->counter != 0) { | ||
207 | /* this basically never happens */ | ||
208 | _raw_spin_unlock(&rw->lock); | ||
209 | |||
210 | while(rw->counter != 0); | ||
211 | |||
212 | goto retry; | ||
213 | } | ||
214 | |||
215 | /* got it. now leave without unlocking */ | ||
216 | rw->counter = -1; /* remember we are locked */ | ||
217 | } | ||
218 | #endif /* CONFIG_DEBUG_RWLOCK */ | ||
219 | |||
220 | /* write_unlock is absolutely trivial - we don't have to wait for anything */ | ||
221 | |||
222 | static __inline__ void _raw_write_unlock(rwlock_t *rw) | ||
223 | { | ||
224 | rw->counter = 0; | ||
225 | _raw_spin_unlock(&rw->lock); | ||
226 | } | ||
227 | |||
228 | #ifdef CONFIG_DEBUG_RWLOCK | ||
229 | extern int _dbg_write_trylock(rwlock_t * rw, const char *bfile, int bline); | ||
230 | #define _raw_write_trylock(rw) _dbg_write_trylock(rw, __FILE__, __LINE__) | ||
231 | #else | ||
232 | static __inline__ int _raw_write_trylock(rwlock_t *rw) | ||
233 | { | ||
234 | _raw_spin_lock(&rw->lock); | ||
235 | if (rw->counter != 0) { | ||
236 | /* this basically never happens */ | ||
237 | _raw_spin_unlock(&rw->lock); | ||
238 | |||
239 | return 0; | ||
240 | } | ||
241 | |||
242 | /* got it. now leave without unlocking */ | ||
243 | rw->counter = -1; /* remember we are locked */ | ||
244 | return 1; | ||
245 | } | ||
246 | #endif /* CONFIG_DEBUG_RWLOCK */ | ||
247 | |||
248 | static __inline__ int is_read_locked(rwlock_t *rw) | ||
249 | { | ||
250 | return rw->counter > 0; | ||
251 | } | ||
252 | |||
253 | static __inline__ int is_write_locked(rwlock_t *rw) | ||
254 | { | ||
255 | return rw->counter < 0; | ||
256 | } | ||
257 | |||
258 | #endif /* __ASM_SPINLOCK_H */ | ||