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Commit 0563bb7b authored by Jason Baron's avatar Jason Baron Committed by Rafael J. Wysocki
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intel_idle: replace conditionals with static_cpu_has(X86_FEATURE_ARAT) 



If the 'arat' cpu flag is set, then the conditionals in intel_idle() that
guard calling tick_broadcast_enter()/exit() will never be true. Use
static_cpu_has(X86_FEATURE_ARAT) to create a fast path to replace
the conditional.

Signed-off-by: default avatarJason Baron <jbaron@akamai.com>
Acked-by: default avatarJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent f187851b

drivers/idle/intel_idle.c

+11 −5
Original line number Diff line number Diff line
@@ -913,8 +913,7 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev, 
	struct cpuidle_state *state = &drv->states[index];

	unsigned long eax = flg2MWAIT(state->flags);

	unsigned int cstate;



	cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) + 1;

	bool uninitialized_var(tick);



	/*

	 * NB: if CPUIDLE_FLAG_TLB_FLUSHED is set, this idle transition
@@ -923,12 +922,19 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev, 
	 * useful with this knowledge.

	 */



	if (!(lapic_timer_reliable_states & (1 << (cstate))))

	if (!static_cpu_has(X86_FEATURE_ARAT)) {

		cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) &

				MWAIT_CSTATE_MASK) + 1;

		tick = false;

		if (!(lapic_timer_reliable_states & (1 << (cstate)))) {

			tick = true;

			tick_broadcast_enter();

		}

	}



	mwait_idle_with_hints(eax, ecx);



	if (!(lapic_timer_reliable_states & (1 << (cstate))))

	if (!static_cpu_has(X86_FEATURE_ARAT) && tick)

		tick_broadcast_exit();



	return index;