diff options
| -rw-r--r-- | arch/x86/include/asm/qspinlock.h | 15 | ||||
| -rw-r--r-- | kernel/locking/qspinlock.c | 16 |
2 files changed, 30 insertions, 1 deletions
diff --git a/arch/x86/include/asm/qspinlock.h b/arch/x86/include/asm/qspinlock.h index 3e70bed8a978..87623c6b13db 100644 --- a/arch/x86/include/asm/qspinlock.h +++ b/arch/x86/include/asm/qspinlock.h @@ -6,9 +6,24 @@ #include <asm/cpufeature.h> #include <asm-generic/qspinlock_types.h> #include <asm/paravirt.h> +#include <asm/rmwcc.h> #define _Q_PENDING_LOOPS (1 << 9) +#define queued_fetch_set_pending_acquire queued_fetch_set_pending_acquire +static __always_inline u32 queued_fetch_set_pending_acquire(struct qspinlock *lock) +{ + u32 val = 0; + + if (GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c, + "I", _Q_PENDING_OFFSET)) + val |= _Q_PENDING_VAL; + + val |= atomic_read(&lock->val) & ~_Q_PENDING_MASK; + + return val; +} + #ifdef CONFIG_PARAVIRT_SPINLOCKS extern void native_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val); extern void __pv_init_lock_hash(void); diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c index 47cb99787e4d..341ca666bc60 100644 --- a/kernel/locking/qspinlock.c +++ b/kernel/locking/qspinlock.c @@ -232,6 +232,20 @@ static __always_inline u32 xchg_tail(struct qspinlock *lock, u32 tail) #endif /* _Q_PENDING_BITS == 8 */ /** + * queued_fetch_set_pending_acquire - fetch the whole lock value and set pending + * @lock : Pointer to queued spinlock structure + * Return: The previous lock value + * + * *,*,* -> *,1,* + */ +#ifndef queued_fetch_set_pending_acquire +static __always_inline u32 queued_fetch_set_pending_acquire(struct qspinlock *lock) +{ + return atomic_fetch_or_acquire(_Q_PENDING_VAL, &lock->val); +} +#endif + +/** * set_locked - Set the lock bit and own the lock * @lock: Pointer to queued spinlock structure * @@ -328,7 +342,7 @@ void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val) * * 0,0,* -> 0,1,* -> 0,0,1 pending, trylock */ - val = atomic_fetch_or_acquire(_Q_PENDING_VAL, &lock->val); + val = queued_fetch_set_pending_acquire(lock); /* * If we observe contention, there is a concurrent locker. |