diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2009-03-23 14:50:03 +0100 |
---|---|---|
committer | Thomas Gleixner <tglx@linutronix.de> | 2009-03-23 21:20:20 +0100 |
commit | 80c5520811d3805adcb15c570ea5e2d489fa5d0b (patch) | |
tree | ae797a7f4af39f80e77526533d06ac23b439f0ab /arch/x86/include/asm/spinlock.h | |
parent | b3e3b302cf6dc8d60b67f0e84d1fa5648889c038 (diff) | |
parent | 8c083f081d0014057901c68a0a3e0f8ca7ac8d23 (diff) |
Merge branch 'cpus4096' into irq/threaded
Conflicts:
arch/parisc/kernel/irq.c
kernel/irq/handle.c
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/include/asm/spinlock.h')
-rw-r--r-- | arch/x86/include/asm/spinlock.h | 69 |
1 files changed, 3 insertions, 66 deletions
diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h index 8247e94ac6b..3a569665668 100644 --- a/arch/x86/include/asm/spinlock.h +++ b/arch/x86/include/asm/spinlock.h @@ -172,70 +172,8 @@ static inline int __ticket_spin_is_contended(raw_spinlock_t *lock) return (((tmp >> TICKET_SHIFT) - tmp) & ((1 << TICKET_SHIFT) - 1)) > 1; } -#ifdef CONFIG_PARAVIRT -/* - * Define virtualization-friendly old-style lock byte lock, for use in - * pv_lock_ops if desired. - * - * This differs from the pre-2.6.24 spinlock by always using xchgb - * rather than decb to take the lock; this allows it to use a - * zero-initialized lock structure. It also maintains a 1-byte - * contention counter, so that we can implement - * __byte_spin_is_contended. - */ -struct __byte_spinlock { - s8 lock; - s8 spinners; -}; - -static inline int __byte_spin_is_locked(raw_spinlock_t *lock) -{ - struct __byte_spinlock *bl = (struct __byte_spinlock *)lock; - return bl->lock != 0; -} - -static inline int __byte_spin_is_contended(raw_spinlock_t *lock) -{ - struct __byte_spinlock *bl = (struct __byte_spinlock *)lock; - return bl->spinners != 0; -} - -static inline void __byte_spin_lock(raw_spinlock_t *lock) -{ - struct __byte_spinlock *bl = (struct __byte_spinlock *)lock; - s8 val = 1; - - asm("1: xchgb %1, %0\n" - " test %1,%1\n" - " jz 3f\n" - " " LOCK_PREFIX "incb %2\n" - "2: rep;nop\n" - " cmpb $1, %0\n" - " je 2b\n" - " " LOCK_PREFIX "decb %2\n" - " jmp 1b\n" - "3:" - : "+m" (bl->lock), "+q" (val), "+m" (bl->spinners): : "memory"); -} - -static inline int __byte_spin_trylock(raw_spinlock_t *lock) -{ - struct __byte_spinlock *bl = (struct __byte_spinlock *)lock; - u8 old = 1; - - asm("xchgb %1,%0" - : "+m" (bl->lock), "+q" (old) : : "memory"); +#ifndef CONFIG_PARAVIRT - return old == 0; -} - -static inline void __byte_spin_unlock(raw_spinlock_t *lock) -{ - struct __byte_spinlock *bl = (struct __byte_spinlock *)lock; - smp_wmb(); - bl->lock = 0; -} -#else /* !CONFIG_PARAVIRT */ static inline int __raw_spin_is_locked(raw_spinlock_t *lock) { return __ticket_spin_is_locked(lock); @@ -268,7 +206,7 @@ static __always_inline void __raw_spin_lock_flags(raw_spinlock_t *lock, __raw_spin_lock(lock); } -#endif /* CONFIG_PARAVIRT */ +#endif static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock) { @@ -330,8 +268,7 @@ static inline int __raw_read_trylock(raw_rwlock_t *lock) { atomic_t *count = (atomic_t *)lock; - atomic_dec(count); - if (atomic_read(count) >= 0) + if (atomic_dec_return(count) >= 0) return 1; atomic_inc(count); return 0; |