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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
commit7ca2b49b06a6d26e89e3535653889f1d7892b085 (patch)
tree99e460b4da18b0d841267082219d9b390c13a649 /include
parentadd659bf8aa92f8b3f01a8c0220557c959507fb1 (diff)
[PATCH] i386: Remove lock section support in semaphore.h
Lock sections don't work the new dwarf2 unwinder This generates slightly smaller code. It adds one more taken jump to the fast path. Cc: jbeulich@novell.com Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'include')
-rw-r--r--include/asm-i386/semaphore.h49
1 files changed, 17 insertions, 32 deletions
diff --git a/include/asm-i386/semaphore.h b/include/asm-i386/semaphore.h
index d51e800acf29..e63b6a68f04c 100644
--- a/include/asm-i386/semaphore.h
+++ b/include/asm-i386/semaphore.h
@@ -100,13 +100,10 @@ static inline void down(struct semaphore * sem)
100 __asm__ __volatile__( 100 __asm__ __volatile__(
101 "# atomic down operation\n\t" 101 "# atomic down operation\n\t"
102 LOCK_PREFIX "decl %0\n\t" /* --sem->count */ 102 LOCK_PREFIX "decl %0\n\t" /* --sem->count */
103 "js 2f\n" 103 "jns 2f\n"
104 "1:\n" 104 "\tlea %0,%%eax\n\t"
105 LOCK_SECTION_START("") 105 "call __down_failed\n"
106 "2:\tlea %0,%%eax\n\t" 106 "2:"
107 "call __down_failed\n\t"
108 "jmp 1b\n"
109 LOCK_SECTION_END
110 :"+m" (sem->count) 107 :"+m" (sem->count)
111 : 108 :
112 :"memory","ax"); 109 :"memory","ax");
@@ -123,15 +120,12 @@ static inline int down_interruptible(struct semaphore * sem)
123 might_sleep(); 120 might_sleep();
124 __asm__ __volatile__( 121 __asm__ __volatile__(
125 "# atomic interruptible down operation\n\t" 122 "# atomic interruptible down operation\n\t"
123 "xorl %0,%0\n\t"
126 LOCK_PREFIX "decl %1\n\t" /* --sem->count */ 124 LOCK_PREFIX "decl %1\n\t" /* --sem->count */
127 "js 2f\n\t" 125 "jns 2f\n\t"
128 "xorl %0,%0\n" 126 "lea %1,%%eax\n\t"
129 "1:\n" 127 "call __down_failed_interruptible\n"
130 LOCK_SECTION_START("") 128 "2:"
131 "2:\tlea %1,%%eax\n\t"
132 "call __down_failed_interruptible\n\t"
133 "jmp 1b\n"
134 LOCK_SECTION_END
135 :"=a" (result), "+m" (sem->count) 129 :"=a" (result), "+m" (sem->count)
136 : 130 :
137 :"memory"); 131 :"memory");
@@ -148,15 +142,12 @@ static inline int down_trylock(struct semaphore * sem)
148 142
149 __asm__ __volatile__( 143 __asm__ __volatile__(
150 "# atomic interruptible down operation\n\t" 144 "# atomic interruptible down operation\n\t"
145 "xorl %0,%0\n\t"
151 LOCK_PREFIX "decl %1\n\t" /* --sem->count */ 146 LOCK_PREFIX "decl %1\n\t" /* --sem->count */
152 "js 2f\n\t" 147 "jns 2f\n\t"
153 "xorl %0,%0\n" 148 "lea %1,%%eax\n\t"
154 "1:\n"
155 LOCK_SECTION_START("")
156 "2:\tlea %1,%%eax\n\t"
157 "call __down_failed_trylock\n\t" 149 "call __down_failed_trylock\n\t"
158 "jmp 1b\n" 150 "2:\n"
159 LOCK_SECTION_END
160 :"=a" (result), "+m" (sem->count) 151 :"=a" (result), "+m" (sem->count)
161 : 152 :
162 :"memory"); 153 :"memory");
@@ -166,22 +157,16 @@ static inline int down_trylock(struct semaphore * sem)
166/* 157/*
167 * Note! This is subtle. We jump to wake people up only if 158 * Note! This is subtle. We jump to wake people up only if
168 * the semaphore was negative (== somebody was waiting on it). 159 * the semaphore was negative (== somebody was waiting on it).
169 * The default case (no contention) will result in NO
170 * jumps for both down() and up().
171 */ 160 */
172static inline void up(struct semaphore * sem) 161static inline void up(struct semaphore * sem)
173{ 162{
174 __asm__ __volatile__( 163 __asm__ __volatile__(
175 "# atomic up operation\n\t" 164 "# atomic up operation\n\t"
176 LOCK_PREFIX "incl %0\n\t" /* ++sem->count */ 165 LOCK_PREFIX "incl %0\n\t" /* ++sem->count */
177 "jle 2f\n" 166 "jg 1f\n\t"
178 "1:\n" 167 "lea %0,%%eax\n\t"
179 LOCK_SECTION_START("") 168 "call __up_wakeup\n"
180 "2:\tlea %0,%%eax\n\t" 169 "1:"
181 "call __up_wakeup\n\t"
182 "jmp 1b\n"
183 LOCK_SECTION_END
184 ".subsection 0\n"
185 :"+m" (sem->count) 170 :"+m" (sem->count)
186 : 171 :
187 :"memory","ax"); 172 :"memory","ax");