1 #ifndef _ASM_X86_QSPINLOCK_H
2 #define _ASM_X86_QSPINLOCK_H
4 #include <asm/cpufeature.h>
5 #include <asm-generic/qspinlock_types.h>
6 #include <asm/paravirt.h>
9 #define _Q_PENDING_LOOPS (1 << 9)
11 #define queued_fetch_set_pending_acquire queued_fetch_set_pending_acquire
13 static __always_inline bool __queued_RMW_btsl(struct qspinlock *lock)
15 GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter,
16 "I", _Q_PENDING_OFFSET, "%0", c);
19 static __always_inline u32 queued_fetch_set_pending_acquire(struct qspinlock *lock)
23 if (__queued_RMW_btsl(lock))
24 val |= _Q_PENDING_VAL;
26 val |= atomic_read(&lock->val) & ~_Q_PENDING_MASK;
31 #define queued_spin_unlock queued_spin_unlock
33 * queued_spin_unlock - release a queued spinlock
34 * @lock : Pointer to queued spinlock structure
36 * A smp_store_release() on the least-significant byte.
38 static inline void native_queued_spin_unlock(struct qspinlock *lock)
40 smp_store_release(&lock->locked, 0);
43 #ifdef CONFIG_PARAVIRT_SPINLOCKS
44 extern void native_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
45 extern void __pv_init_lock_hash(void);
46 extern void __pv_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
47 extern void __raw_callee_save___pv_queued_spin_unlock(struct qspinlock *lock);
49 static inline void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
51 pv_queued_spin_lock_slowpath(lock, val);
54 static inline void queued_spin_unlock(struct qspinlock *lock)
56 pv_queued_spin_unlock(lock);
59 static inline void queued_spin_unlock(struct qspinlock *lock)
61 native_queued_spin_unlock(lock);
65 #ifdef CONFIG_PARAVIRT
66 #define virt_spin_lock virt_spin_lock
67 static inline bool virt_spin_lock(struct qspinlock *lock)
69 if (!static_cpu_has(X86_FEATURE_HYPERVISOR))
73 * On hypervisors without PARAVIRT_SPINLOCKS support we fall
74 * back to a Test-and-Set spinlock, because fair locks have
75 * horrible lock 'holder' preemption issues.
79 while (atomic_read(&lock->val) != 0)
81 } while (atomic_cmpxchg(&lock->val, 0, _Q_LOCKED_VAL) != 0);
85 #endif /* CONFIG_PARAVIRT */
87 #include <asm-generic/qspinlock.h>
89 #endif /* _ASM_X86_QSPINLOCK_H */