From 08f5fcbe6e0ea029c7e9b1b1c338700ab7809daf Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 5 Sep 2008 13:26:39 +0100 Subject: [PATCH] x86: ticket spin locks: factor out more common code Signed-off-by: Jan Beulich Signed-off-by: Ingo Molnar --- include/asm-x86/spinlock.h | 42 +++++++++++++++----------------------- 1 file changed, 16 insertions(+), 26 deletions(-) diff --git a/include/asm-x86/spinlock.h b/include/asm-x86/spinlock.h index acd9bdda55c..63d3b610a5e 100644 --- a/include/asm-x86/spinlock.h +++ b/include/asm-x86/spinlock.h @@ -54,19 +54,7 @@ * 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) { @@ -116,19 +104,7 @@ 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) { @@ -182,6 +158,20 @@ static __always_inline void __ticket_spin_unlock(raw_spinlock_t *lock) } #endif +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; +} + #define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock) #ifdef CONFIG_PARAVIRT -- 2.41.1