linux/arch/x86/include/asm/qspinlock.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_QSPINLOCK_H
#define _ASM_X86_QSPINLOCK_H

#include <linux/jump_label.h>
#include <asm/cpufeature.h>
#include <asm-generic/qspinlock_types.h>
#include <asm/paravirt.h>
#include <asm/rmwcc.h>

#define _Q_PENDING_LOOPS …

#define queued_fetch_set_pending_acquire …
static __always_inline u32 queued_fetch_set_pending_acquire(struct qspinlock *lock)
{ … }

#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);
extern bool nopvspin;

#define 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)
{ … }

static inline void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
{ … }

static inline void queued_spin_unlock(struct qspinlock *lock)
{ … }

#define vcpu_is_preempted …
static inline bool vcpu_is_preempted(long cpu)
{ … }
#endif

#ifdef CONFIG_PARAVIRT
/*
 * virt_spin_lock_key - disables by default the virt_spin_lock() hijack.
 *
 * Native (and PV wanting native due to vCPU pinning) should keep this key
 * disabled. Native does not touch the key.
 *
 * When in a guest then native_pv_lock_init() enables the key first and
 * KVM/XEN might conditionally disable it later in the boot process again.
 */
DECLARE_STATIC_KEY_FALSE(virt_spin_lock_key);

/*
 * Shortcut for the queued_spin_lock_slowpath() function that allows
 * virt to hijack it.
 *
 * Returns:
 *   true - lock has been negotiated, all done;
 *   false - queued_spin_lock_slowpath() will do its thing.
 */
#define virt_spin_lock …
static inline bool virt_spin_lock(struct qspinlock *lock)
{ … }

#endif /* CONFIG_PARAVIRT */

#include <asm-generic/qspinlock.h>

#endif /* _ASM_X86_QSPINLOCK_H */