diff options
Diffstat (limited to 'include/asm-x86/spinlock.h')
| -rw-r--r-- | include/asm-x86/spinlock.h | 79 |
1 files changed, 37 insertions, 42 deletions
diff --git a/include/asm-x86/spinlock.h b/include/asm-x86/spinlock.h index e39c790dbfd..157ff7fab97 100644 --- a/include/asm-x86/spinlock.h +++ b/include/asm-x86/spinlock.h @@ -1,5 +1,5 @@ -#ifndef _X86_SPINLOCK_H_ -#define _X86_SPINLOCK_H_ +#ifndef ASM_X86__SPINLOCK_H +#define ASM_X86__SPINLOCK_H #include <asm/atomic.h> #include <asm/rwlock.h> @@ -21,8 +21,10 @@ #ifdef CONFIG_X86_32 # define LOCK_PTR_REG "a" +# define REG_PTR_MODE "k" #else # define LOCK_PTR_REG "D" +# define REG_PTR_MODE "q" #endif #if defined(CONFIG_X86_32) && \ @@ -54,19 +56,7 @@ * much between them in performance though, especially as locks are out of line. */ #if (NR_CPUS < 256) -static inline int __ticket_spin_is_locked(raw_spinlock_t *lock) -{ - int tmp = ACCESS_ONCE(lock->slock); - - return (((tmp >> 8) & 0xff) != (tmp & 0xff)); -} - -static inline int __ticket_spin_is_contended(raw_spinlock_t *lock) -{ - int tmp = ACCESS_ONCE(lock->slock); - - return (((tmp >> 8) - tmp) & 0xff) > 1; -} +#define TICKET_SHIFT 8 static __always_inline void __ticket_spin_lock(raw_spinlock_t *lock) { @@ -89,19 +79,17 @@ static __always_inline void __ticket_spin_lock(raw_spinlock_t *lock) static __always_inline int __ticket_spin_trylock(raw_spinlock_t *lock) { - int tmp; - short new; + int tmp, new; - asm volatile("movw %2,%w0\n\t" + asm volatile("movzwl %2, %0\n\t" "cmpb %h0,%b0\n\t" + "leal 0x100(%" REG_PTR_MODE "0), %1\n\t" "jne 1f\n\t" - "movw %w0,%w1\n\t" - "incb %h1\n\t" - "lock ; cmpxchgw %w1,%2\n\t" + LOCK_PREFIX "cmpxchgw %w1,%2\n\t" "1:" "sete %b1\n\t" "movzbl %b1,%0\n\t" - : "=&a" (tmp), "=Q" (new), "+m" (lock->slock) + : "=&a" (tmp), "=&q" (new), "+m" (lock->slock) : : "memory", "cc"); @@ -116,26 +104,14 @@ static __always_inline void __ticket_spin_unlock(raw_spinlock_t *lock) : "memory", "cc"); } #else -static inline int __ticket_spin_is_locked(raw_spinlock_t *lock) -{ - int tmp = ACCESS_ONCE(lock->slock); - - return (((tmp >> 16) & 0xffff) != (tmp & 0xffff)); -} - -static inline int __ticket_spin_is_contended(raw_spinlock_t *lock) -{ - int tmp = ACCESS_ONCE(lock->slock); - - return (((tmp >> 16) - tmp) & 0xffff) > 1; -} +#define TICKET_SHIFT 16 static __always_inline void __ticket_spin_lock(raw_spinlock_t *lock) { int inc = 0x00010000; int tmp; - asm volatile("lock ; xaddl %0, %1\n" + asm volatile(LOCK_PREFIX "xaddl %0, %1\n" "movzwl %w0, %2\n\t" "shrl $16, %0\n\t" "1:\t" @@ -146,7 +122,7 @@ static __always_inline void __ticket_spin_lock(raw_spinlock_t *lock) /* don't need lfence here, because loads are in-order */ "jmp 1b\n" "2:" - : "+Q" (inc), "+m" (lock->slock), "=r" (tmp) + : "+r" (inc), "+m" (lock->slock), "=&r" (tmp) : : "memory", "cc"); } @@ -160,13 +136,13 @@ static __always_inline int __ticket_spin_trylock(raw_spinlock_t *lock) "movl %0,%1\n\t" "roll $16, %0\n\t" "cmpl %0,%1\n\t" + "leal 0x00010000(%" REG_PTR_MODE "0), %1\n\t" "jne 1f\n\t" - "addl $0x00010000, %1\n\t" - "lock ; cmpxchgl %1,%2\n\t" + LOCK_PREFIX "cmpxchgl %1,%2\n\t" "1:" "sete %b1\n\t" "movzbl %b1,%0\n\t" - : "=&a" (tmp), "=r" (new), "+m" (lock->slock) + : "=&a" (tmp), "=&q" (new), "+m" (lock->slock) : : "memory", "cc"); @@ -182,7 +158,19 @@ static __always_inline void __ticket_spin_unlock(raw_spinlock_t *lock) } #endif -#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock) +static inline int __ticket_spin_is_locked(raw_spinlock_t *lock) +{ + int tmp = ACCESS_ONCE(lock->slock); + + return !!(((tmp >> TICKET_SHIFT) ^ tmp) & ((1 << TICKET_SHIFT) - 1)); +} + +static inline int __ticket_spin_is_contended(raw_spinlock_t *lock) +{ + int tmp = ACCESS_ONCE(lock->slock); + + return (((tmp >> TICKET_SHIFT) - tmp) & ((1 << TICKET_SHIFT) - 1)) > 1; +} #ifdef CONFIG_PARAVIRT /* @@ -272,6 +260,13 @@ static __always_inline void __raw_spin_unlock(raw_spinlock_t *lock) { __ticket_spin_unlock(lock); } + +static __always_inline void __raw_spin_lock_flags(raw_spinlock_t *lock, + unsigned long flags) +{ + __raw_spin_lock(lock); +} + #endif /* CONFIG_PARAVIRT */ static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock) @@ -366,4 +361,4 @@ static inline void __raw_write_unlock(raw_rwlock_t *rw) #define _raw_read_relax(lock) cpu_relax() #define _raw_write_relax(lock) cpu_relax() -#endif +#endif /* ASM_X86__SPINLOCK_H */ |