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authorAndi Kleen <ak@suse.de>2006-08-30 19:37:13 +0200
committerLinus Torvalds <torvalds@g5.osdl.org>2006-08-30 16:05:15 -0700
commit841be8ddf92578e5b481ed9f9abb85649fc13238 (patch)
tree55d2d25350eb15b6822d91b38a7cddd9c697b58f
parentceee88223047749ad683d397b19904c3dfb6adeb (diff)
downloadop-kernel-dev-841be8ddf92578e5b481ed9f9abb85649fc13238.zip
op-kernel-dev-841be8ddf92578e5b481ed9f9abb85649fc13238.tar.gz
[PATCH] x86_64: Remove alternative_smp
The .fill causes miscompilations with some binutils version. Instead just patch the lock prefix in the lock constructs. That is the majority of the cost and should be good enough. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--include/asm-x86_64/alternative.h20
-rw-r--r--include/asm-x86_64/spinlock.h11
2 files changed, 4 insertions, 27 deletions
diff --git a/include/asm-x86_64/alternative.h b/include/asm-x86_64/alternative.h
index 709ad3f..a584826 100644
--- a/include/asm-x86_64/alternative.h
+++ b/include/asm-x86_64/alternative.h
@@ -103,9 +103,6 @@ static inline void alternatives_smp_switch(int smp) {}
/*
* Alternative inline assembly for SMP.
*
- * alternative_smp() takes two versions (SMP first, UP second) and is
- * for more complex stuff such as spinlocks.
- *
* The LOCK_PREFIX macro defined here replaces the LOCK and
* LOCK_PREFIX macros used everywhere in the source tree.
*
@@ -125,21 +122,6 @@ static inline void alternatives_smp_switch(int smp) {}
*/
#ifdef CONFIG_SMP
-#define alternative_smp(smpinstr, upinstr, args...) \
- asm volatile ("661:\n\t" smpinstr "\n662:\n" \
- ".section .smp_altinstructions,\"a\"\n" \
- " .align 8\n" \
- " .quad 661b\n" /* label */ \
- " .quad 663f\n" /* new instruction */ \
- " .byte " __stringify(X86_FEATURE_UP) "\n" \
- " .byte 662b-661b\n" /* sourcelen */ \
- " .byte 664f-663f\n" /* replacementlen */ \
- ".previous\n" \
- ".section .smp_altinstr_replacement,\"awx\"\n" \
- "663:\n\t" upinstr "\n" /* replacement */ \
- "664:\n\t.fill 662b-661b,1,0x42\n" /* space for original */ \
- ".previous" : args)
-
#define LOCK_PREFIX \
".section .smp_locks,\"a\"\n" \
" .align 8\n" \
@@ -148,8 +130,6 @@ static inline void alternatives_smp_switch(int smp) {}
"661:\n\tlock; "
#else /* ! CONFIG_SMP */
-#define alternative_smp(smpinstr, upinstr, args...) \
- asm volatile (upinstr : args)
#define LOCK_PREFIX ""
#endif
diff --git a/include/asm-x86_64/spinlock.h b/include/asm-x86_64/spinlock.h
index 8d34219..248a79f 100644
--- a/include/asm-x86_64/spinlock.h
+++ b/include/asm-x86_64/spinlock.h
@@ -21,7 +21,7 @@
#define __raw_spin_lock_string \
"\n1:\t" \
- "lock ; decl %0\n\t" \
+ LOCK_PREFIX " ; decl %0\n\t" \
"js 2f\n" \
LOCK_SECTION_START("") \
"2:\t" \
@@ -40,10 +40,7 @@
static inline void __raw_spin_lock(raw_spinlock_t *lock)
{
- alternative_smp(
- __raw_spin_lock_string,
- __raw_spin_lock_string_up,
- "=m" (lock->slock) : : "memory");
+ asm volatile(__raw_spin_lock_string : "=m" (lock->slock) : : "memory");
}
#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
@@ -125,12 +122,12 @@ static inline int __raw_write_trylock(raw_rwlock_t *lock)
static inline void __raw_read_unlock(raw_rwlock_t *rw)
{
- asm volatile("lock ; incl %0" :"=m" (rw->lock) : : "memory");
+ asm volatile(LOCK_PREFIX " ; incl %0" :"=m" (rw->lock) : : "memory");
}
static inline void __raw_write_unlock(raw_rwlock_t *rw)
{
- asm volatile("lock ; addl $" RW_LOCK_BIAS_STR ",%0"
+ asm volatile(LOCK_PREFIX " ; addl $" RW_LOCK_BIAS_STR ",%0"
: "=m" (rw->lock) : : "memory");
}
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