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Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_POWERPC_QSPINLOCK_H
3#define _ASM_POWERPC_QSPINLOCK_H
4
5#include <asm-generic/qspinlock_types.h>
6#include <asm/paravirt.h>
7
8#define _Q_PENDING_LOOPS (1 << 9) /* not tuned */
9
10#ifdef CONFIG_PARAVIRT_SPINLOCKS
11extern void native_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
12extern void __pv_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
13extern void __pv_queued_spin_unlock(struct qspinlock *lock);
14
15static __always_inline void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
16{
17 if (!is_shared_processor())
18 native_queued_spin_lock_slowpath(lock, val);
19 else
20 __pv_queued_spin_lock_slowpath(lock, val);
21}
22
23#define queued_spin_unlock queued_spin_unlock
24static inline void queued_spin_unlock(struct qspinlock *lock)
25{
26 if (!is_shared_processor())
27 smp_store_release(&lock->locked, 0);
28 else
29 __pv_queued_spin_unlock(lock);
30}
31
32#else
33extern void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
34#endif
35
36static __always_inline void queued_spin_lock(struct qspinlock *lock)
37{
38 u32 val = 0;
39
40 if (likely(atomic_try_cmpxchg_lock(&lock->val, &val, _Q_LOCKED_VAL)))
41 return;
42
43 queued_spin_lock_slowpath(lock, val);
44}
45#define queued_spin_lock queued_spin_lock
46
47#define smp_mb__after_spinlock() smp_mb()
48
49static __always_inline int queued_spin_is_locked(struct qspinlock *lock)
50{
51 /*
52 * This barrier was added to simple spinlocks by commit 51d7d5205d338,
53 * but it should now be possible to remove it, asm arm64 has done with
54 * commit c6f5d02b6a0f.
55 */
56 smp_mb();
57 return atomic_read(&lock->val);
58}
59#define queued_spin_is_locked queued_spin_is_locked
60
61#ifdef CONFIG_PARAVIRT_SPINLOCKS
62#define SPIN_THRESHOLD (1<<15) /* not tuned */
63
64static __always_inline void pv_wait(u8 *ptr, u8 val)
65{
66 if (*ptr != val)
67 return;
68 yield_to_any();
69 /*
70 * We could pass in a CPU here if waiting in the queue and yield to
71 * the previous CPU in the queue.
72 */
73}
74
75static __always_inline void pv_kick(int cpu)
76{
77 prod_cpu(cpu);
78}
79
80extern void __pv_init_lock_hash(void);
81
82static inline void pv_spinlocks_init(void)
83{
84 __pv_init_lock_hash();
85}
86
87#endif
88
89#include <asm-generic/qspinlock.h>
90
91#endif /* _ASM_POWERPC_QSPINLOCK_H */