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/atomic.h |
Linux-2.6.12-rc2v2.6.12-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/atomic.h')
-rw-r--r-- | include/asm-parisc/atomic.h | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/include/asm-parisc/atomic.h b/include/asm-parisc/atomic.h new file mode 100644 index 000000000000..e24f7579adb0 --- /dev/null +++ b/include/asm-parisc/atomic.h | |||
@@ -0,0 +1,199 @@ | |||
1 | #ifndef _ASM_PARISC_ATOMIC_H_ | ||
2 | #define _ASM_PARISC_ATOMIC_H_ | ||
3 | |||
4 | #include <linux/config.h> | ||
5 | #include <asm/system.h> | ||
6 | /* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>. */ | ||
7 | |||
8 | /* | ||
9 | * Atomic operations that C can't guarantee us. Useful for | ||
10 | * resource counting etc.. | ||
11 | * | ||
12 | * And probably incredibly slow on parisc. OTOH, we don't | ||
13 | * have to write any serious assembly. prumpf | ||
14 | */ | ||
15 | |||
16 | #ifdef CONFIG_SMP | ||
17 | #include <asm/spinlock.h> | ||
18 | #include <asm/cache.h> /* we use L1_CACHE_BYTES */ | ||
19 | |||
20 | /* Use an array of spinlocks for our atomic_ts. | ||
21 | * Hash function to index into a different SPINLOCK. | ||
22 | * Since "a" is usually an address, use one spinlock per cacheline. | ||
23 | */ | ||
24 | # define ATOMIC_HASH_SIZE 4 | ||
25 | # define ATOMIC_HASH(a) (&(__atomic_hash[ (((unsigned long) a)/L1_CACHE_BYTES) & (ATOMIC_HASH_SIZE-1) ])) | ||
26 | |||
27 | extern spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned; | ||
28 | |||
29 | /* Can't use _raw_spin_lock_irq because of #include problems, so | ||
30 | * this is the substitute */ | ||
31 | #define _atomic_spin_lock_irqsave(l,f) do { \ | ||
32 | spinlock_t *s = ATOMIC_HASH(l); \ | ||
33 | local_irq_save(f); \ | ||
34 | _raw_spin_lock(s); \ | ||
35 | } while(0) | ||
36 | |||
37 | #define _atomic_spin_unlock_irqrestore(l,f) do { \ | ||
38 | spinlock_t *s = ATOMIC_HASH(l); \ | ||
39 | _raw_spin_unlock(s); \ | ||
40 | local_irq_restore(f); \ | ||
41 | } while(0) | ||
42 | |||
43 | |||
44 | #else | ||
45 | # define _atomic_spin_lock_irqsave(l,f) do { local_irq_save(f); } while (0) | ||
46 | # define _atomic_spin_unlock_irqrestore(l,f) do { local_irq_restore(f); } while (0) | ||
47 | #endif | ||
48 | |||
49 | /* Note that we need not lock read accesses - aligned word writes/reads | ||
50 | * are atomic, so a reader never sees unconsistent values. | ||
51 | * | ||
52 | * Cache-line alignment would conflict with, for example, linux/module.h | ||
53 | */ | ||
54 | |||
55 | typedef struct { volatile int counter; } atomic_t; | ||
56 | |||
57 | |||
58 | /* This should get optimized out since it's never called. | ||
59 | ** Or get a link error if xchg is used "wrong". | ||
60 | */ | ||
61 | extern void __xchg_called_with_bad_pointer(void); | ||
62 | |||
63 | |||
64 | /* __xchg32/64 defined in arch/parisc/lib/bitops.c */ | ||
65 | extern unsigned long __xchg8(char, char *); | ||
66 | extern unsigned long __xchg32(int, int *); | ||
67 | #ifdef __LP64__ | ||
68 | extern unsigned long __xchg64(unsigned long, unsigned long *); | ||
69 | #endif | ||
70 | |||
71 | /* optimizer better get rid of switch since size is a constant */ | ||
72 | static __inline__ unsigned long __xchg(unsigned long x, __volatile__ void * ptr, | ||
73 | int size) | ||
74 | { | ||
75 | |||
76 | switch(size) { | ||
77 | #ifdef __LP64__ | ||
78 | case 8: return __xchg64(x,(unsigned long *) ptr); | ||
79 | #endif | ||
80 | case 4: return __xchg32((int) x, (int *) ptr); | ||
81 | case 1: return __xchg8((char) x, (char *) ptr); | ||
82 | } | ||
83 | __xchg_called_with_bad_pointer(); | ||
84 | return x; | ||
85 | } | ||
86 | |||
87 | |||
88 | /* | ||
89 | ** REVISIT - Abandoned use of LDCW in xchg() for now: | ||
90 | ** o need to test sizeof(*ptr) to avoid clearing adjacent bytes | ||
91 | ** o and while we are at it, could __LP64__ code use LDCD too? | ||
92 | ** | ||
93 | ** if (__builtin_constant_p(x) && (x == NULL)) | ||
94 | ** if (((unsigned long)p & 0xf) == 0) | ||
95 | ** return __ldcw(p); | ||
96 | */ | ||
97 | #define xchg(ptr,x) \ | ||
98 | ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) | ||
99 | |||
100 | |||
101 | #define __HAVE_ARCH_CMPXCHG 1 | ||
102 | |||
103 | /* bug catcher for when unsupported size is used - won't link */ | ||
104 | extern void __cmpxchg_called_with_bad_pointer(void); | ||
105 | |||
106 | /* __cmpxchg_u32/u64 defined in arch/parisc/lib/bitops.c */ | ||
107 | extern unsigned long __cmpxchg_u32(volatile unsigned int *m, unsigned int old, unsigned int new_); | ||
108 | extern unsigned long __cmpxchg_u64(volatile unsigned long *ptr, unsigned long old, unsigned long new_); | ||
109 | |||
110 | /* don't worry...optimizer will get rid of most of this */ | ||
111 | static __inline__ unsigned long | ||
112 | __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size) | ||
113 | { | ||
114 | switch(size) { | ||
115 | #ifdef __LP64__ | ||
116 | case 8: return __cmpxchg_u64((unsigned long *)ptr, old, new_); | ||
117 | #endif | ||
118 | case 4: return __cmpxchg_u32((unsigned int *)ptr, (unsigned int) old, (unsigned int) new_); | ||
119 | } | ||
120 | __cmpxchg_called_with_bad_pointer(); | ||
121 | return old; | ||
122 | } | ||
123 | |||
124 | #define cmpxchg(ptr,o,n) \ | ||
125 | ({ \ | ||
126 | __typeof__(*(ptr)) _o_ = (o); \ | ||
127 | __typeof__(*(ptr)) _n_ = (n); \ | ||
128 | (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ | ||
129 | (unsigned long)_n_, sizeof(*(ptr))); \ | ||
130 | }) | ||
131 | |||
132 | |||
133 | |||
134 | /* It's possible to reduce all atomic operations to either | ||
135 | * __atomic_add_return, atomic_set and atomic_read (the latter | ||
136 | * is there only for consistency). | ||
137 | */ | ||
138 | |||
139 | static __inline__ int __atomic_add_return(int i, atomic_t *v) | ||
140 | { | ||
141 | int ret; | ||
142 | unsigned long flags; | ||
143 | _atomic_spin_lock_irqsave(v, flags); | ||
144 | |||
145 | ret = (v->counter += i); | ||
146 | |||
147 | _atomic_spin_unlock_irqrestore(v, flags); | ||
148 | return ret; | ||
149 | } | ||
150 | |||
151 | static __inline__ void atomic_set(atomic_t *v, int i) | ||
152 | { | ||
153 | unsigned long flags; | ||
154 | _atomic_spin_lock_irqsave(v, flags); | ||
155 | |||
156 | v->counter = i; | ||
157 | |||
158 | _atomic_spin_unlock_irqrestore(v, flags); | ||
159 | } | ||
160 | |||
161 | static __inline__ int atomic_read(const atomic_t *v) | ||
162 | { | ||
163 | return v->counter; | ||
164 | } | ||
165 | |||
166 | /* exported interface */ | ||
167 | |||
168 | #define atomic_add(i,v) ((void)(__atomic_add_return( ((int)i),(v)))) | ||
169 | #define atomic_sub(i,v) ((void)(__atomic_add_return(-((int)i),(v)))) | ||
170 | #define atomic_inc(v) ((void)(__atomic_add_return( 1,(v)))) | ||
171 | #define atomic_dec(v) ((void)(__atomic_add_return( -1,(v)))) | ||
172 | |||
173 | #define atomic_add_return(i,v) (__atomic_add_return( ((int)i),(v))) | ||
174 | #define atomic_sub_return(i,v) (__atomic_add_return(-((int)i),(v))) | ||
175 | #define atomic_inc_return(v) (__atomic_add_return( 1,(v))) | ||
176 | #define atomic_dec_return(v) (__atomic_add_return( -1,(v))) | ||
177 | |||
178 | #define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0) | ||
179 | |||
180 | /* | ||
181 | * atomic_inc_and_test - increment and test | ||
182 | * @v: pointer of type atomic_t | ||
183 | * | ||
184 | * Atomically increments @v by 1 | ||
185 | * and returns true if the result is zero, or false for all | ||
186 | * other cases. | ||
187 | */ | ||
188 | #define atomic_inc_and_test(v) (atomic_inc_return(v) == 0) | ||
189 | |||
190 | #define atomic_dec_and_test(v) (atomic_dec_return(v) == 0) | ||
191 | |||
192 | #define ATOMIC_INIT(i) { (i) } | ||
193 | |||
194 | #define smp_mb__before_atomic_dec() smp_mb() | ||
195 | #define smp_mb__after_atomic_dec() smp_mb() | ||
196 | #define smp_mb__before_atomic_inc() smp_mb() | ||
197 | #define smp_mb__after_atomic_inc() smp_mb() | ||
198 | |||
199 | #endif | ||