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