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// SPDX-License-Identifier: GPL-2.0
/*
* Split spinlock implementation out into its own file, so it can be
* compiled in a FTRACE-compatible way.
*/
#include <linux/static_call.h>
#include <linux/spinlock.h>
#include <linux/export.h>
#include <linux/jump_label.h>
#include <trace/events/lock.h>
DEFINE_STATIC_KEY_FALSE(virt_spin_lock_key);
#ifdef CONFIG_SMP
void __init native_pv_lock_init(void)
{
if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
static_branch_enable(&virt_spin_lock_key);
}
#endif
#ifdef CONFIG_PARAVIRT_SPINLOCKS
__visible void __native_queued_spin_unlock(struct qspinlock *lock)
{
native_queued_spin_unlock(lock);
}
PV_CALLEE_SAVE_REGS_THUNK(__native_queued_spin_unlock);
DEFINE_STATIC_CALL(queued_spin_lock_slowpath, native_queued_spin_lock_slowpath);
EXPORT_STATIC_CALL_TRAMP(queued_spin_lock_slowpath);
DEFINE_STATIC_CALL(queued_spin_unlock, __raw_callee_save___native_queued_spin_unlock);
EXPORT_STATIC_CALL_TRAMP(queued_spin_unlock);
/*
* Traced unlock variants, swapped in via static_call while the
* contended_release tracepoint is enabled. Two of them, so each tail calls its
* own base directly.
*/
__visible void native_queued_spin_unlock_traced(struct qspinlock *lock)
{
if (queued_spin_is_contended(lock))
trace_call__contended_release(lock);
native_queued_spin_unlock(lock);
}
PV_CALLEE_SAVE_REGS_THUNK(native_queued_spin_unlock_traced);
__visible void pv_queued_spin_unlock_traced(struct qspinlock *lock)
{
if (queued_spin_is_contended(lock))
trace_call__contended_release(lock);
__raw_callee_save___pv_queued_spin_unlock(lock);
}
PV_CALLEE_SAVE_REGS_THUNK(pv_queued_spin_unlock_traced);
bool pv_is_native_spin_unlock(void)
{
void *unlock = static_call_query(queued_spin_unlock);
return unlock == __raw_callee_save___native_queued_spin_unlock ||
unlock == __raw_callee_save_native_queued_spin_unlock_traced;
}
int arch_contended_release_trace_reg(void)
{
void *cur = static_call_query(queued_spin_unlock);
if (cur == __raw_callee_save___native_queued_spin_unlock)
static_call_update(queued_spin_unlock,
__raw_callee_save_native_queued_spin_unlock_traced);
else if (cur == __raw_callee_save___pv_queued_spin_unlock)
static_call_update(queued_spin_unlock,
__raw_callee_save_pv_queued_spin_unlock_traced);
return 0;
}
void arch_contended_release_trace_unreg(void)
{
void *cur = static_call_query(queued_spin_unlock);
if (cur == __raw_callee_save_native_queued_spin_unlock_traced)
static_call_update(queued_spin_unlock,
__raw_callee_save___native_queued_spin_unlock);
else if (cur == __raw_callee_save_pv_queued_spin_unlock_traced)
static_call_update(queued_spin_unlock,
__raw_callee_save___pv_queued_spin_unlock);
}
__visible bool __native_vcpu_is_preempted(long cpu)
{
return false;
}
PV_CALLEE_SAVE_REGS_THUNK(__native_vcpu_is_preempted);
bool pv_is_native_vcpu_is_preempted(void)
{
return pv_ops_lock.vcpu_is_preempted.func ==
__raw_callee_save___native_vcpu_is_preempted;
}
void __init paravirt_set_cap(void)
{
if (!pv_is_native_vcpu_is_preempted())
setup_force_cpu_cap(X86_FEATURE_VCPUPREEMPT);
}
struct pv_lock_ops pv_ops_lock = {
.wait = paravirt_nop,
.kick = paravirt_nop,
.vcpu_is_preempted = PV_CALLEE_SAVE(__native_vcpu_is_preempted),
};
EXPORT_SYMBOL(pv_ops_lock);
#endif
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