Commit 841be8dd authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds

[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: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent ceee8822
...@@ -103,9 +103,6 @@ static inline void alternatives_smp_switch(int smp) {} ...@@ -103,9 +103,6 @@ static inline void alternatives_smp_switch(int smp) {}
/* /*
* Alternative inline assembly for 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 * The LOCK_PREFIX macro defined here replaces the LOCK and
* LOCK_PREFIX macros used everywhere in the source tree. * LOCK_PREFIX macros used everywhere in the source tree.
* *
...@@ -125,21 +122,6 @@ static inline void alternatives_smp_switch(int smp) {} ...@@ -125,21 +122,6 @@ static inline void alternatives_smp_switch(int smp) {}
*/ */
#ifdef CONFIG_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 \ #define LOCK_PREFIX \
".section .smp_locks,\"a\"\n" \ ".section .smp_locks,\"a\"\n" \
" .align 8\n" \ " .align 8\n" \
...@@ -148,8 +130,6 @@ static inline void alternatives_smp_switch(int smp) {} ...@@ -148,8 +130,6 @@ static inline void alternatives_smp_switch(int smp) {}
"661:\n\tlock; " "661:\n\tlock; "
#else /* ! CONFIG_SMP */ #else /* ! CONFIG_SMP */
#define alternative_smp(smpinstr, upinstr, args...) \
asm volatile (upinstr : args)
#define LOCK_PREFIX "" #define LOCK_PREFIX ""
#endif #endif
......
...@@ -21,7 +21,7 @@ ...@@ -21,7 +21,7 @@
#define __raw_spin_lock_string \ #define __raw_spin_lock_string \
"\n1:\t" \ "\n1:\t" \
"lock ; decl %0\n\t" \ LOCK_PREFIX " ; decl %0\n\t" \
"js 2f\n" \ "js 2f\n" \
LOCK_SECTION_START("") \ LOCK_SECTION_START("") \
"2:\t" \ "2:\t" \
...@@ -40,10 +40,7 @@ ...@@ -40,10 +40,7 @@
static inline void __raw_spin_lock(raw_spinlock_t *lock) static inline void __raw_spin_lock(raw_spinlock_t *lock)
{ {
alternative_smp( asm volatile(__raw_spin_lock_string : "=m" (lock->slock) : : "memory");
__raw_spin_lock_string,
__raw_spin_lock_string_up,
"=m" (lock->slock) : : "memory");
} }
#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock) #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) ...@@ -125,12 +122,12 @@ static inline int __raw_write_trylock(raw_rwlock_t *lock)
static inline void __raw_read_unlock(raw_rwlock_t *rw) 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) 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"); : "=m" (rw->lock) : : "memory");
} }
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment