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authorAndi Kleen <ak@suse.de>2006-09-26 04:52:32 -0400
committerAndi Kleen <andi@basil.nowhere.org>2006-09-26 04:52:32 -0400
commitfb2e28485679418e459583605f9b19807a72ceca (patch)
treec3e6bf7f75fb9c6ed286ef09eebf281388761cfe /include/asm-i386
parent8b059d2373c16b6d32787a49daf8ccf72dc61b71 (diff)
[PATCH] i386: Clean up spin/rwlocks
- Inline spinlock strings into their inline functions - Convert macros to typesafe inlines - Replace some leftover __asm__ __volatile__s with asm volatile Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'include/asm-i386')
-rw-r--r--include/asm-i386/rwlock.h14
-rw-r--r--include/asm-i386/spinlock.h131
2 files changed, 68 insertions, 77 deletions
diff --git a/include/asm-i386/rwlock.h b/include/asm-i386/rwlock.h
index f40ccbd8cb7f..c3e5db32fa48 100644
--- a/include/asm-i386/rwlock.h
+++ b/include/asm-i386/rwlock.h
@@ -20,18 +20,6 @@
20#define RW_LOCK_BIAS 0x01000000 20#define RW_LOCK_BIAS 0x01000000
21#define RW_LOCK_BIAS_STR "0x01000000" 21#define RW_LOCK_BIAS_STR "0x01000000"
22 22
23#define __build_read_lock(rw, helper) \ 23/* Code is in asm-i386/spinlock.h */
24 asm volatile(LOCK_PREFIX " subl $1,(%0)\n\t" \
25 "jns 1f\n" \
26 "call " helper "\n\t" \
27 "1:\n" \
28 ::"a" (rw) : "memory")
29
30#define __build_write_lock(rw, helper) \
31 asm volatile(LOCK_PREFIX " subl $" RW_LOCK_BIAS_STR ",(%0)\n\t" \
32 "jz 1f\n" \
33 "call " helper "\n\t" \
34 "1:\n" \
35 ::"a" (rw) : "memory")
36 24
37#endif 25#endif
diff --git a/include/asm-i386/spinlock.h b/include/asm-i386/spinlock.h
index d1020363c41a..324329313af8 100644
--- a/include/asm-i386/spinlock.h
+++ b/include/asm-i386/spinlock.h
@@ -4,6 +4,7 @@
4#include <asm/atomic.h> 4#include <asm/atomic.h>
5#include <asm/rwlock.h> 5#include <asm/rwlock.h>
6#include <asm/page.h> 6#include <asm/page.h>
7#include <asm/processor.h>
7#include <linux/compiler.h> 8#include <linux/compiler.h>
8 9
9/* 10/*
@@ -17,67 +18,64 @@
17 * (the type definitions are in asm/spinlock_types.h) 18 * (the type definitions are in asm/spinlock_types.h)
18 */ 19 */
19 20
20#define __raw_spin_is_locked(x) \ 21static inline int __raw_spin_is_locked(raw_spinlock_t *x)
21 (*(volatile signed char *)(&(x)->slock) <= 0) 22{
22 23 return *(volatile signed char *)(&(x)->slock) <= 0;
23#define __raw_spin_lock_string \ 24}
24 "\n1:\t" \
25 LOCK_PREFIX " ; decb %0\n\t" \
26 "jns 3f\n" \
27 "2:\t" \
28 "rep;nop\n\t" \
29 "cmpb $0,%0\n\t" \
30 "jle 2b\n\t" \
31 "jmp 1b\n" \
32 "3:\n\t"
33
34/*
35 * NOTE: there's an irqs-on section here, which normally would have to be
36 * irq-traced, but on CONFIG_TRACE_IRQFLAGS we never use
37 * __raw_spin_lock_string_flags().
38 */
39#define __raw_spin_lock_string_flags \
40 "\n1:\t" \
41 LOCK_PREFIX " ; decb %0\n\t" \
42 "jns 5f\n" \
43 "2:\t" \
44 "testl $0x200, %1\n\t" \
45 "jz 4f\n\t" \
46 "sti\n" \
47 "3:\t" \
48 "rep;nop\n\t" \
49 "cmpb $0, %0\n\t" \
50 "jle 3b\n\t" \
51 "cli\n\t" \
52 "jmp 1b\n" \
53 "4:\t" \
54 "rep;nop\n\t" \
55 "cmpb $0, %0\n\t" \
56 "jg 1b\n\t" \
57 "jmp 4b\n" \
58 "5:\n\t"
59 25
60static inline void __raw_spin_lock(raw_spinlock_t *lock) 26static inline void __raw_spin_lock(raw_spinlock_t *lock)
61{ 27{
62 asm(__raw_spin_lock_string : "+m" (lock->slock) : : "memory"); 28 asm volatile("\n1:\t"
29 LOCK_PREFIX " ; decb %0\n\t"
30 "jns 3f\n"
31 "2:\t"
32 "rep;nop\n\t"
33 "cmpb $0,%0\n\t"
34 "jle 2b\n\t"
35 "jmp 1b\n"
36 "3:\n\t"
37 : "+m" (lock->slock) : : "memory");
63} 38}
64 39
65/* 40/*
66 * It is easier for the lock validator if interrupts are not re-enabled 41 * It is easier for the lock validator if interrupts are not re-enabled
67 * in the middle of a lock-acquire. This is a performance feature anyway 42 * in the middle of a lock-acquire. This is a performance feature anyway
68 * so we turn it off: 43 * so we turn it off:
44 *
45 * NOTE: there's an irqs-on section here, which normally would have to be
46 * irq-traced, but on CONFIG_TRACE_IRQFLAGS we never use this variant.
69 */ 47 */
70#ifndef CONFIG_PROVE_LOCKING 48#ifndef CONFIG_PROVE_LOCKING
71static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags) 49static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
72{ 50{
73 asm(__raw_spin_lock_string_flags : "+m" (lock->slock) : "r" (flags) : "memory"); 51 asm volatile(
52 "\n1:\t"
53 LOCK_PREFIX " ; decb %0\n\t"
54 "jns 5f\n"
55 "2:\t"
56 "testl $0x200, %1\n\t"
57 "jz 4f\n\t"
58 "sti\n"
59 "3:\t"
60 "rep;nop\n\t"
61 "cmpb $0, %0\n\t"
62 "jle 3b\n\t"
63 "cli\n\t"
64 "jmp 1b\n"
65 "4:\t"
66 "rep;nop\n\t"
67 "cmpb $0, %0\n\t"
68 "jg 1b\n\t"
69 "jmp 4b\n"
70 "5:\n\t"
71 : "+m" (lock->slock) : "r" (flags) : "memory");
74} 72}
75#endif 73#endif
76 74
77static inline int __raw_spin_trylock(raw_spinlock_t *lock) 75static inline int __raw_spin_trylock(raw_spinlock_t *lock)
78{ 76{
79 char oldval; 77 char oldval;
80 __asm__ __volatile__( 78 asm volatile(
81 "xchgb %b0,%1" 79 "xchgb %b0,%1"
82 :"=q" (oldval), "+m" (lock->slock) 80 :"=q" (oldval), "+m" (lock->slock)
83 :"0" (0) : "memory"); 81 :"0" (0) : "memory");
@@ -93,38 +91,29 @@ static inline int __raw_spin_trylock(raw_spinlock_t *lock)
93 91
94#if !defined(CONFIG_X86_OOSTORE) && !defined(CONFIG_X86_PPRO_FENCE) 92#if !defined(CONFIG_X86_OOSTORE) && !defined(CONFIG_X86_PPRO_FENCE)
95 93
96#define __raw_spin_unlock_string \
97 "movb $1,%0" \
98 :"+m" (lock->slock) : : "memory"
99
100
101static inline void __raw_spin_unlock(raw_spinlock_t *lock) 94static inline void __raw_spin_unlock(raw_spinlock_t *lock)
102{ 95{
103 __asm__ __volatile__( 96 asm volatile("movb $1,%0" : "+m" (lock->slock) :: "memory");
104 __raw_spin_unlock_string
105 );
106} 97}
107 98
108#else 99#else
109 100
110#define __raw_spin_unlock_string \
111 "xchgb %b0, %1" \
112 :"=q" (oldval), "+m" (lock->slock) \
113 :"0" (oldval) : "memory"
114
115static inline void __raw_spin_unlock(raw_spinlock_t *lock) 101static inline void __raw_spin_unlock(raw_spinlock_t *lock)
116{ 102{
117 char oldval = 1; 103 char oldval = 1;
118 104
119 __asm__ __volatile__( 105 asm volatile("xchgb %b0, %1"
120 __raw_spin_unlock_string 106 : "=q" (oldval), "+m" (lock->slock)
121 ); 107 : "0" (oldval) : "memory");
122} 108}
123 109
124#endif 110#endif
125 111
126#define __raw_spin_unlock_wait(lock) \ 112static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock)
127 do { while (__raw_spin_is_locked(lock)) cpu_relax(); } while (0) 113{
114 while (__raw_spin_is_locked(lock))
115 cpu_relax();
116}
128 117
129/* 118/*
130 * Read-write spinlocks, allowing multiple readers 119 * Read-write spinlocks, allowing multiple readers
@@ -151,22 +140,36 @@ static inline void __raw_spin_unlock(raw_spinlock_t *lock)
151 * read_can_lock - would read_trylock() succeed? 140 * read_can_lock - would read_trylock() succeed?
152 * @lock: the rwlock in question. 141 * @lock: the rwlock in question.
153 */ 142 */
154#define __raw_read_can_lock(x) ((int)(x)->lock > 0) 143static inline int __raw_read_can_lock(raw_rwlock_t *x)
144{
145 return (int)(x)->lock > 0;
146}
155 147
156/** 148/**
157 * write_can_lock - would write_trylock() succeed? 149 * write_can_lock - would write_trylock() succeed?
158 * @lock: the rwlock in question. 150 * @lock: the rwlock in question.
159 */ 151 */
160#define __raw_write_can_lock(x) ((x)->lock == RW_LOCK_BIAS) 152static inline int __raw_write_can_lock(raw_rwlock_t *x)
153{
154 return (x)->lock == RW_LOCK_BIAS;
155}
161 156
162static inline void __raw_read_lock(raw_rwlock_t *rw) 157static inline void __raw_read_lock(raw_rwlock_t *rw)
163{ 158{
164 __build_read_lock(rw, "__read_lock_failed"); 159 asm volatile(LOCK_PREFIX " subl $1,(%0)\n\t"
160 "jns 1f\n"
161 "call __read_lock_failed\n\t"
162 "1:\n"
163 ::"a" (rw) : "memory");
165} 164}
166 165
167static inline void __raw_write_lock(raw_rwlock_t *rw) 166static inline void __raw_write_lock(raw_rwlock_t *rw)
168{ 167{
169 __build_write_lock(rw, "__write_lock_failed"); 168 asm volatile(LOCK_PREFIX " subl $" RW_LOCK_BIAS_STR ",(%0)\n\t"
169 "jz 1f\n"
170 "call __write_lock_failed\n\t"
171 "1:\n"
172 ::"a" (rw) : "memory");
170} 173}
171 174
172static inline int __raw_read_trylock(raw_rwlock_t *lock) 175static inline int __raw_read_trylock(raw_rwlock_t *lock)