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-sparc/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-sparc/spinlock.h')
-rw-r--r-- | include/asm-sparc/spinlock.h | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/include/asm-sparc/spinlock.h b/include/asm-sparc/spinlock.h new file mode 100644 index 00000000000..0cbd87ad491 --- /dev/null +++ b/include/asm-sparc/spinlock.h | |||
@@ -0,0 +1,238 @@ | |||
1 | /* spinlock.h: 32-bit Sparc spinlock support. | ||
2 | * | ||
3 | * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu) | ||
4 | */ | ||
5 | |||
6 | #ifndef __SPARC_SPINLOCK_H | ||
7 | #define __SPARC_SPINLOCK_H | ||
8 | |||
9 | #include <linux/threads.h> /* For NR_CPUS */ | ||
10 | |||
11 | #ifndef __ASSEMBLY__ | ||
12 | |||
13 | #include <asm/psr.h> | ||
14 | |||
15 | #ifdef CONFIG_DEBUG_SPINLOCK | ||
16 | struct _spinlock_debug { | ||
17 | unsigned char lock; | ||
18 | unsigned long owner_pc; | ||
19 | #ifdef CONFIG_PREEMPT | ||
20 | unsigned int break_lock; | ||
21 | #endif | ||
22 | }; | ||
23 | typedef struct _spinlock_debug spinlock_t; | ||
24 | |||
25 | #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0, 0 } | ||
26 | #define spin_lock_init(lp) do { *(lp)= SPIN_LOCK_UNLOCKED; } while(0) | ||
27 | #define spin_is_locked(lp) (*((volatile unsigned char *)(&((lp)->lock))) != 0) | ||
28 | #define spin_unlock_wait(lp) do { barrier(); } while(*(volatile unsigned char *)(&(lp)->lock)) | ||
29 | |||
30 | extern void _do_spin_lock(spinlock_t *lock, char *str); | ||
31 | extern int _spin_trylock(spinlock_t *lock); | ||
32 | extern void _do_spin_unlock(spinlock_t *lock); | ||
33 | |||
34 | #define _raw_spin_trylock(lp) _spin_trylock(lp) | ||
35 | #define _raw_spin_lock(lock) _do_spin_lock(lock, "spin_lock") | ||
36 | #define _raw_spin_unlock(lock) _do_spin_unlock(lock) | ||
37 | |||
38 | struct _rwlock_debug { | ||
39 | volatile unsigned int lock; | ||
40 | unsigned long owner_pc; | ||
41 | unsigned long reader_pc[NR_CPUS]; | ||
42 | #ifdef CONFIG_PREEMPT | ||
43 | unsigned int break_lock; | ||
44 | #endif | ||
45 | }; | ||
46 | typedef struct _rwlock_debug rwlock_t; | ||
47 | |||
48 | #define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0, {0} } | ||
49 | |||
50 | #define rwlock_init(lp) do { *(lp)= RW_LOCK_UNLOCKED; } while(0) | ||
51 | |||
52 | extern void _do_read_lock(rwlock_t *rw, char *str); | ||
53 | extern void _do_read_unlock(rwlock_t *rw, char *str); | ||
54 | extern void _do_write_lock(rwlock_t *rw, char *str); | ||
55 | extern void _do_write_unlock(rwlock_t *rw); | ||
56 | |||
57 | #define _raw_read_lock(lock) \ | ||
58 | do { unsigned long flags; \ | ||
59 | local_irq_save(flags); \ | ||
60 | _do_read_lock(lock, "read_lock"); \ | ||
61 | local_irq_restore(flags); \ | ||
62 | } while(0) | ||
63 | |||
64 | #define _raw_read_unlock(lock) \ | ||
65 | do { unsigned long flags; \ | ||
66 | local_irq_save(flags); \ | ||
67 | _do_read_unlock(lock, "read_unlock"); \ | ||
68 | local_irq_restore(flags); \ | ||
69 | } while(0) | ||
70 | |||
71 | #define _raw_write_lock(lock) \ | ||
72 | do { unsigned long flags; \ | ||
73 | local_irq_save(flags); \ | ||
74 | _do_write_lock(lock, "write_lock"); \ | ||
75 | local_irq_restore(flags); \ | ||
76 | } while(0) | ||
77 | |||
78 | #define _raw_write_unlock(lock) \ | ||
79 | do { unsigned long flags; \ | ||
80 | local_irq_save(flags); \ | ||
81 | _do_write_unlock(lock); \ | ||
82 | local_irq_restore(flags); \ | ||
83 | } while(0) | ||
84 | |||
85 | #else /* !CONFIG_DEBUG_SPINLOCK */ | ||
86 | |||
87 | typedef struct { | ||
88 | unsigned char lock; | ||
89 | #ifdef CONFIG_PREEMPT | ||
90 | unsigned int break_lock; | ||
91 | #endif | ||
92 | } spinlock_t; | ||
93 | |||
94 | #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } | ||
95 | |||
96 | #define spin_lock_init(lock) (*((unsigned char *)(lock)) = 0) | ||
97 | #define spin_is_locked(lock) (*((volatile unsigned char *)(lock)) != 0) | ||
98 | |||
99 | #define spin_unlock_wait(lock) \ | ||
100 | do { \ | ||
101 | barrier(); \ | ||
102 | } while(*((volatile unsigned char *)lock)) | ||
103 | |||
104 | extern __inline__ void _raw_spin_lock(spinlock_t *lock) | ||
105 | { | ||
106 | __asm__ __volatile__( | ||
107 | "\n1:\n\t" | ||
108 | "ldstub [%0], %%g2\n\t" | ||
109 | "orcc %%g2, 0x0, %%g0\n\t" | ||
110 | "bne,a 2f\n\t" | ||
111 | " ldub [%0], %%g2\n\t" | ||
112 | ".subsection 2\n" | ||
113 | "2:\n\t" | ||
114 | "orcc %%g2, 0x0, %%g0\n\t" | ||
115 | "bne,a 2b\n\t" | ||
116 | " ldub [%0], %%g2\n\t" | ||
117 | "b,a 1b\n\t" | ||
118 | ".previous\n" | ||
119 | : /* no outputs */ | ||
120 | : "r" (lock) | ||
121 | : "g2", "memory", "cc"); | ||
122 | } | ||
123 | |||
124 | extern __inline__ int _raw_spin_trylock(spinlock_t *lock) | ||
125 | { | ||
126 | unsigned int result; | ||
127 | __asm__ __volatile__("ldstub [%1], %0" | ||
128 | : "=r" (result) | ||
129 | : "r" (lock) | ||
130 | : "memory"); | ||
131 | return (result == 0); | ||
132 | } | ||
133 | |||
134 | extern __inline__ void _raw_spin_unlock(spinlock_t *lock) | ||
135 | { | ||
136 | __asm__ __volatile__("stb %%g0, [%0]" : : "r" (lock) : "memory"); | ||
137 | } | ||
138 | |||
139 | /* Read-write spinlocks, allowing multiple readers | ||
140 | * but only one writer. | ||
141 | * | ||
142 | * NOTE! it is quite common to have readers in interrupts | ||
143 | * but no interrupt writers. For those circumstances we | ||
144 | * can "mix" irq-safe locks - any writer needs to get a | ||
145 | * irq-safe write-lock, but readers can get non-irqsafe | ||
146 | * read-locks. | ||
147 | * | ||
148 | * XXX This might create some problems with my dual spinlock | ||
149 | * XXX scheme, deadlocks etc. -DaveM | ||
150 | */ | ||
151 | typedef struct { | ||
152 | volatile unsigned int lock; | ||
153 | #ifdef CONFIG_PREEMPT | ||
154 | unsigned int break_lock; | ||
155 | #endif | ||
156 | } rwlock_t; | ||
157 | |||
158 | #define RW_LOCK_UNLOCKED (rwlock_t) { 0 } | ||
159 | |||
160 | #define rwlock_init(lp) do { *(lp)= RW_LOCK_UNLOCKED; } while(0) | ||
161 | |||
162 | |||
163 | /* Sort of like atomic_t's on Sparc, but even more clever. | ||
164 | * | ||
165 | * ------------------------------------ | ||
166 | * | 24-bit counter | wlock | rwlock_t | ||
167 | * ------------------------------------ | ||
168 | * 31 8 7 0 | ||
169 | * | ||
170 | * wlock signifies the one writer is in or somebody is updating | ||
171 | * counter. For a writer, if he successfully acquires the wlock, | ||
172 | * but counter is non-zero, he has to release the lock and wait, | ||
173 | * till both counter and wlock are zero. | ||
174 | * | ||
175 | * Unfortunately this scheme limits us to ~16,000,000 cpus. | ||
176 | */ | ||
177 | extern __inline__ void _read_lock(rwlock_t *rw) | ||
178 | { | ||
179 | register rwlock_t *lp asm("g1"); | ||
180 | lp = rw; | ||
181 | __asm__ __volatile__( | ||
182 | "mov %%o7, %%g4\n\t" | ||
183 | "call ___rw_read_enter\n\t" | ||
184 | " ldstub [%%g1 + 3], %%g2\n" | ||
185 | : /* no outputs */ | ||
186 | : "r" (lp) | ||
187 | : "g2", "g4", "memory", "cc"); | ||
188 | } | ||
189 | |||
190 | #define _raw_read_lock(lock) \ | ||
191 | do { unsigned long flags; \ | ||
192 | local_irq_save(flags); \ | ||
193 | _read_lock(lock); \ | ||
194 | local_irq_restore(flags); \ | ||
195 | } while(0) | ||
196 | |||
197 | extern __inline__ void _read_unlock(rwlock_t *rw) | ||
198 | { | ||
199 | register rwlock_t *lp asm("g1"); | ||
200 | lp = rw; | ||
201 | __asm__ __volatile__( | ||
202 | "mov %%o7, %%g4\n\t" | ||
203 | "call ___rw_read_exit\n\t" | ||
204 | " ldstub [%%g1 + 3], %%g2\n" | ||
205 | : /* no outputs */ | ||
206 | : "r" (lp) | ||
207 | : "g2", "g4", "memory", "cc"); | ||
208 | } | ||
209 | |||
210 | #define _raw_read_unlock(lock) \ | ||
211 | do { unsigned long flags; \ | ||
212 | local_irq_save(flags); \ | ||
213 | _read_unlock(lock); \ | ||
214 | local_irq_restore(flags); \ | ||
215 | } while(0) | ||
216 | |||
217 | extern __inline__ void _raw_write_lock(rwlock_t *rw) | ||
218 | { | ||
219 | register rwlock_t *lp asm("g1"); | ||
220 | lp = rw; | ||
221 | __asm__ __volatile__( | ||
222 | "mov %%o7, %%g4\n\t" | ||
223 | "call ___rw_write_enter\n\t" | ||
224 | " ldstub [%%g1 + 3], %%g2\n" | ||
225 | : /* no outputs */ | ||
226 | : "r" (lp) | ||
227 | : "g2", "g4", "memory", "cc"); | ||
228 | } | ||
229 | |||
230 | #define _raw_write_unlock(rw) do { (rw)->lock = 0; } while(0) | ||
231 | |||
232 | #endif /* CONFIG_DEBUG_SPINLOCK */ | ||
233 | |||
234 | #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) | ||
235 | |||
236 | #endif /* !(__ASSEMBLY__) */ | ||
237 | |||
238 | #endif /* __SPARC_SPINLOCK_H */ | ||