Commit 7ca2b49b authored by Andi Kleen's avatar Andi Kleen Committed by Andi Kleen
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[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: default avatarAndi Kleen <ak@suse.de>
parent add659bf
......@@ -100,13 +100,10 @@ static inline void down(struct semaphore * sem)
__asm__ __volatile__(
"# atomic down operation\n\t"
LOCK_PREFIX "decl %0\n\t" /* --sem->count */
"js 2f\n"
"1:\n"
LOCK_SECTION_START("")
"2:\tlea %0,%%eax\n\t"
"call __down_failed\n\t"
"jmp 1b\n"
LOCK_SECTION_END
"jns 2f\n"
"\tlea %0,%%eax\n\t"
"call __down_failed\n"
"2:"
:"+m" (sem->count)
:
:"memory","ax");
......@@ -123,15 +120,12 @@ static inline int down_interruptible(struct semaphore * sem)
might_sleep();
__asm__ __volatile__(
"# atomic interruptible down operation\n\t"
"xorl %0,%0\n\t"
LOCK_PREFIX "decl %1\n\t" /* --sem->count */
"js 2f\n\t"
"xorl %0,%0\n"
"1:\n"
LOCK_SECTION_START("")
"2:\tlea %1,%%eax\n\t"
"call __down_failed_interruptible\n\t"
"jmp 1b\n"
LOCK_SECTION_END
"jns 2f\n\t"
"lea %1,%%eax\n\t"
"call __down_failed_interruptible\n"
"2:"
:"=a" (result), "+m" (sem->count)
:
:"memory");
......@@ -148,15 +142,12 @@ static inline int down_trylock(struct semaphore * sem)
__asm__ __volatile__(
"# atomic interruptible down operation\n\t"
"xorl %0,%0\n\t"
LOCK_PREFIX "decl %1\n\t" /* --sem->count */
"js 2f\n\t"
"xorl %0,%0\n"
"1:\n"
LOCK_SECTION_START("")
"2:\tlea %1,%%eax\n\t"
"jns 2f\n\t"
"lea %1,%%eax\n\t"
"call __down_failed_trylock\n\t"
"jmp 1b\n"
LOCK_SECTION_END
"2:\n"
:"=a" (result), "+m" (sem->count)
:
:"memory");
......@@ -166,22 +157,16 @@ static inline int down_trylock(struct semaphore * sem)
/*
* Note! This is subtle. We jump to wake people up only if
* the semaphore was negative (== somebody was waiting on it).
* The default case (no contention) will result in NO
* jumps for both down() and up().
*/
static inline void up(struct semaphore * sem)
{
__asm__ __volatile__(
"# atomic up operation\n\t"
LOCK_PREFIX "incl %0\n\t" /* ++sem->count */
"jle 2f\n"
"1:\n"
LOCK_SECTION_START("")
"2:\tlea %0,%%eax\n\t"
"call __up_wakeup\n\t"
"jmp 1b\n"
LOCK_SECTION_END
".subsection 0\n"
"jg 1f\n\t"
"lea %0,%%eax\n\t"
"call __up_wakeup\n"
"1:"
:"+m" (sem->count)
:
:"memory","ax");
......
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