1234567891011121314151617181920212223242526272829303132333435363738394041
/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_LOONGARCH_QSPINLOCK_H #define _ASM_LOONGARCH_QSPINLOCK_H #include <linux/jump_label.h> #ifdef CONFIG_PARAVIRT DECLARE_STATIC_KEY_FALSE(virt_spin_lock_key); #define virt_spin_lock virt_spin_lock static inline bool virt_spin_lock(struct qspinlock *lock) { int val; if (!static_branch_unlikely(&virt_spin_lock_key)) return false; /* * On hypervisors without PARAVIRT_SPINLOCKS support we fall * back to a Test-and-Set spinlock, because fair locks have * horrible lock 'holder' preemption issues. */ __retry: val = atomic_read(&lock->val); if (val || !atomic_try_cmpxchg(&lock->val, &val, _Q_LOCKED_VAL)) { cpu_relax(); goto __retry; } return true; } #endif /* CONFIG_PARAVIRT */ #include <asm-generic/qspinlock.h> #endif // _ASM_LOONGARCH_QSPINLOCK_H