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authorAndi Kleen <ak@suse.de>2006-09-26 04:52:31 -0400
committerAndi Kleen <andi@basil.nowhere.org>2006-09-26 04:52:31 -0400
commitadd659bf8aa92f8b3f01a8c0220557c959507fb1 (patch)
treeef140ba27d91ee45ee0a01ab7d92de5138a681ca /include/asm-i386/rwsem.h
parent01215ad8d83e18321d99e9b5750a6f21cac243a2 (diff)
[PATCH] i386: Remove lock section support in rwsem.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. Also move the trampolines into semaphore.S and add proper CFI annotations. Cc: jbeulich@novell.com Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'include/asm-i386/rwsem.h')
-rw-r--r--include/asm-i386/rwsem.h62
1 files changed, 12 insertions, 50 deletions
diff --git a/include/asm-i386/rwsem.h b/include/asm-i386/rwsem.h
index 43113f5608eb..bc598d6388e3 100644
--- a/include/asm-i386/rwsem.h
+++ b/include/asm-i386/rwsem.h
@@ -99,17 +99,9 @@ static inline void __down_read(struct rw_semaphore *sem)
99 __asm__ __volatile__( 99 __asm__ __volatile__(
100 "# beginning down_read\n\t" 100 "# beginning down_read\n\t"
101LOCK_PREFIX " incl (%%eax)\n\t" /* adds 0x00000001, returns the old value */ 101LOCK_PREFIX " incl (%%eax)\n\t" /* adds 0x00000001, returns the old value */
102 " js 2f\n\t" /* jump if we weren't granted the lock */ 102 " jns 1f\n"
103 " call call_rwsem_down_read_failed\n"
103 "1:\n\t" 104 "1:\n\t"
104 LOCK_SECTION_START("")
105 "2:\n\t"
106 " pushl %%ecx\n\t"
107 " pushl %%edx\n\t"
108 " call rwsem_down_read_failed\n\t"
109 " popl %%edx\n\t"
110 " popl %%ecx\n\t"
111 " jmp 1b\n"
112 LOCK_SECTION_END
113 "# ending down_read\n\t" 105 "# ending down_read\n\t"
114 : "+m" (sem->count) 106 : "+m" (sem->count)
115 : "a" (sem) 107 : "a" (sem)
@@ -151,15 +143,9 @@ static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
151 "# beginning down_write\n\t" 143 "# beginning down_write\n\t"
152LOCK_PREFIX " xadd %%edx,(%%eax)\n\t" /* subtract 0x0000ffff, returns the old value */ 144LOCK_PREFIX " xadd %%edx,(%%eax)\n\t" /* subtract 0x0000ffff, returns the old value */
153 " testl %%edx,%%edx\n\t" /* was the count 0 before? */ 145 " testl %%edx,%%edx\n\t" /* was the count 0 before? */
154 " jnz 2f\n\t" /* jump if we weren't granted the lock */ 146 " jz 1f\n"
155 "1:\n\t" 147 " call call_rwsem_down_write_failed\n"
156 LOCK_SECTION_START("") 148 "1:\n"
157 "2:\n\t"
158 " pushl %%ecx\n\t"
159 " call rwsem_down_write_failed\n\t"
160 " popl %%ecx\n\t"
161 " jmp 1b\n"
162 LOCK_SECTION_END
163 "# ending down_write" 149 "# ending down_write"
164 : "+m" (sem->count), "=d" (tmp) 150 : "+m" (sem->count), "=d" (tmp)
165 : "a" (sem), "1" (tmp) 151 : "a" (sem), "1" (tmp)
@@ -193,17 +179,9 @@ static inline void __up_read(struct rw_semaphore *sem)
193 __asm__ __volatile__( 179 __asm__ __volatile__(
194 "# beginning __up_read\n\t" 180 "# beginning __up_read\n\t"
195LOCK_PREFIX " xadd %%edx,(%%eax)\n\t" /* subtracts 1, returns the old value */ 181LOCK_PREFIX " xadd %%edx,(%%eax)\n\t" /* subtracts 1, returns the old value */
196 " js 2f\n\t" /* jump if the lock is being waited upon */ 182 " jns 1f\n\t"
197 "1:\n\t" 183 " call call_rwsem_wake\n"
198 LOCK_SECTION_START("") 184 "1:\n"
199 "2:\n\t"
200 " decw %%dx\n\t" /* do nothing if still outstanding active readers */
201 " jnz 1b\n\t"
202 " pushl %%ecx\n\t"
203 " call rwsem_wake\n\t"
204 " popl %%ecx\n\t"
205 " jmp 1b\n"
206 LOCK_SECTION_END
207 "# ending __up_read\n" 185 "# ending __up_read\n"
208 : "+m" (sem->count), "=d" (tmp) 186 : "+m" (sem->count), "=d" (tmp)
209 : "a" (sem), "1" (tmp) 187 : "a" (sem), "1" (tmp)
@@ -219,17 +197,9 @@ static inline void __up_write(struct rw_semaphore *sem)
219 "# beginning __up_write\n\t" 197 "# beginning __up_write\n\t"
220 " movl %2,%%edx\n\t" 198 " movl %2,%%edx\n\t"
221LOCK_PREFIX " xaddl %%edx,(%%eax)\n\t" /* tries to transition 0xffff0001 -> 0x00000000 */ 199LOCK_PREFIX " xaddl %%edx,(%%eax)\n\t" /* tries to transition 0xffff0001 -> 0x00000000 */
222 " jnz 2f\n\t" /* jump if the lock is being waited upon */ 200 " jz 1f\n"
201 " call call_rwsem_wake\n"
223 "1:\n\t" 202 "1:\n\t"
224 LOCK_SECTION_START("")
225 "2:\n\t"
226 " decw %%dx\n\t" /* did the active count reduce to 0? */
227 " jnz 1b\n\t" /* jump back if not */
228 " pushl %%ecx\n\t"
229 " call rwsem_wake\n\t"
230 " popl %%ecx\n\t"
231 " jmp 1b\n"
232 LOCK_SECTION_END
233 "# ending __up_write\n" 203 "# ending __up_write\n"
234 : "+m" (sem->count) 204 : "+m" (sem->count)
235 : "a" (sem), "i" (-RWSEM_ACTIVE_WRITE_BIAS) 205 : "a" (sem), "i" (-RWSEM_ACTIVE_WRITE_BIAS)
@@ -244,17 +214,9 @@ static inline void __downgrade_write(struct rw_semaphore *sem)
244 __asm__ __volatile__( 214 __asm__ __volatile__(
245 "# beginning __downgrade_write\n\t" 215 "# beginning __downgrade_write\n\t"
246LOCK_PREFIX " addl %2,(%%eax)\n\t" /* transitions 0xZZZZ0001 -> 0xYYYY0001 */ 216LOCK_PREFIX " addl %2,(%%eax)\n\t" /* transitions 0xZZZZ0001 -> 0xYYYY0001 */
247 " js 2f\n\t" /* jump if the lock is being waited upon */ 217 " jns 1f\n\t"
218 " call call_rwsem_downgrade_wake\n"
248 "1:\n\t" 219 "1:\n\t"
249 LOCK_SECTION_START("")
250 "2:\n\t"
251 " pushl %%ecx\n\t"
252 " pushl %%edx\n\t"
253 " call rwsem_downgrade_wake\n\t"
254 " popl %%edx\n\t"
255 " popl %%ecx\n\t"
256 " jmp 1b\n"
257 LOCK_SECTION_END
258 "# ending __downgrade_write\n" 220 "# ending __downgrade_write\n"
259 : "+m" (sem->count) 221 : "+m" (sem->count)
260 : "a" (sem), "i" (-RWSEM_WAITING_BIAS) 222 : "a" (sem), "i" (-RWSEM_WAITING_BIAS)
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-18 15:04:40 -0500