85 lines
2.0 KiB
C
85 lines
2.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _ASM_POWERPC_QSPINLOCK_H
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#define _ASM_POWERPC_QSPINLOCK_H
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#include <asm-generic/qspinlock_types.h>
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#include <asm/paravirt.h>
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#define _Q_PENDING_LOOPS (1 << 9) /* not tuned */
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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_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
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extern void __pv_queued_spin_unlock(struct qspinlock *lock);
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static __always_inline void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
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{
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if (!is_shared_processor())
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native_queued_spin_lock_slowpath(lock, val);
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else
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__pv_queued_spin_lock_slowpath(lock, val);
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}
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#define queued_spin_unlock queued_spin_unlock
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static inline void queued_spin_unlock(struct qspinlock *lock)
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{
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if (!is_shared_processor())
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smp_store_release(&lock->locked, 0);
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else
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__pv_queued_spin_unlock(lock);
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}
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#else
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extern void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
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#endif
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static __always_inline void queued_spin_lock(struct qspinlock *lock)
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{
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u32 val = 0;
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if (likely(arch_atomic_try_cmpxchg_lock(&lock->val, &val, _Q_LOCKED_VAL)))
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return;
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queued_spin_lock_slowpath(lock, val);
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}
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#define queued_spin_lock queued_spin_lock
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#ifdef CONFIG_PARAVIRT_SPINLOCKS
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#define SPIN_THRESHOLD (1<<15) /* not tuned */
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static __always_inline void pv_wait(u8 *ptr, u8 val)
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{
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if (*ptr != val)
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return;
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yield_to_any();
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/*
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* We could pass in a CPU here if waiting in the queue and yield to
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* the previous CPU in the queue.
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*/
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}
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static __always_inline void pv_kick(int cpu)
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{
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prod_cpu(cpu);
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}
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extern void __pv_init_lock_hash(void);
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static inline void pv_spinlocks_init(void)
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{
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__pv_init_lock_hash();
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}
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#endif
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/*
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* Queued spinlocks rely heavily on smp_cond_load_relaxed() to busy-wait,
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* which was found to have performance problems if implemented with
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* the preferred spin_begin()/spin_end() SMT priority pattern. Use the
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* generic version instead.
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*/
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#include <asm-generic/qspinlock.h>
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#endif /* _ASM_POWERPC_QSPINLOCK_H */
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