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

#include <asm/kvm_para.h>
#include <asm/paravirt.h>

#ifdef CONFIG_PARAVIRT

#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;
}

/*
 * Macro is better than inline function here
 * With macro, parameter cpu is parsed only when it is used.
 * With inline function, parameter cpu is parsed even though it is not used.
 * This may cause cache line thrashing across NUMA nodes.
 */
#define vcpu_is_preempted(cpu)                                                  \
({                                                                              \
        bool __val;                                                             \
                                                                                \
        if (!static_branch_unlikely(&virt_preempt_key))                         \
                __val = false;                                                  \
        else {                                                                  \
                struct kvm_steal_time *src;                                     \
                src = &per_cpu(steal_time, cpu);                                \
                __val = !!(READ_ONCE(src->preempted) & KVM_VCPU_PREEMPTED);     \
        }                                                                       \
        __val;                                                                  \
})

#endif /* CONFIG_PARAVIRT */

#include <asm-generic/qspinlock.h>

#endif // _ASM_LOONGARCH_QSPINLOCK_H