#ifndef _ASM_X86_QSPINLOCK_H #define _ASM_X86_QSPINLOCK_H #include <asm/cpufeature.h> #include <asm-generic/qspinlock_types.h> #include <asm/paravirt.h> #define queued_spin_unlock queued_spin_unlock /** * queued_spin_unlock - release a queued spinlock * @lock : Pointer to queued spinlock structure * * A smp_store_release() on the least-significant byte. */ static inline void native_queued_spin_unlock(struct qspinlock *lock) { smp_store_release((u8 *)lock, 0); } #ifdef CONFIG_PARAVIRT_SPINLOCKS extern void native_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val); extern void __pv_init_lock_hash(void); extern void __pv_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val); extern void __raw_callee_save___pv_queued_spin_unlock(struct qspinlock *lock); static inline void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val) { pv_queued_spin_lock_slowpath(lock, val); } static inline void queued_spin_unlock(struct qspinlock *lock) { pv_queued_spin_unlock(lock); } #else static inline void queued_spin_unlock(struct qspinlock *lock) { native_queued_spin_unlock(lock); } #endif #ifdef CONFIG_PARAVIRT #define virt_spin_lock virt_spin_lock static inline bool virt_spin_lock(struct qspinlock *lock) { if (!static_cpu_has(X86_FEATURE_HYPERVISOR)) return false; /* * On hypervisors without PARAVIRT_SPINLOCKS support we fall * back to a Test-and-Set spinlock, because fair locks have * horrible lock 'holder' preemption issues. */ do { while (atomic_read(&lock->val) != 0) cpu_relax(); } while (atomic_cmpxchg(&lock->val, 0, _Q_LOCKED_VAL) != 0); return true; } #endif /* CONFIG_PARAVIRT */ #include <asm-generic/qspinlock.h> #endif /* _ASM_X86_QSPINLOCK_H */