Commit 9f3d6daf authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

intel_idle: Refactor intel_idle_cpuidle_driver_init() 



Move the C-state verification and checks from
intel_idle_cpuidle_driver_init() to a separate function,
intel_idle_verify_cstate(), and make the former call it after
checking the CPUIDLE_FLAG_UNUSABLE state flag.

Also combine the drv->states[] updates with the incrementation of
drv->state_count.

No intentional functional impact.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 77fb4e0a

drivers/idle/intel_idle.c

+25 −24
Original line number Diff line number Diff line
@@ -944,6 +944,22 @@ static void intel_idle_s2idle(struct cpuidle_device *dev, 
	mwait_idle_with_hints(eax, ecx);

}



static bool intel_idle_verify_cstate(unsigned int mwait_hint)

{

	unsigned int mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint) + 1;

	unsigned int num_substates = (mwait_substates >> mwait_cstate * 4) &

					MWAIT_SUBSTATE_MASK;



	/* Ignore the C-state if there are NO sub-states in CPUID for it. */

	if (num_substates == 0)

		return false;



	if (mwait_cstate > 2 && !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))

		mark_tsc_unstable("TSC halts in idle states deeper than C2");



	return true;

}



static void __setup_broadcast_timer(bool on)

{

	if (on)
@@ -1332,10 +1348,10 @@ static void __init intel_idle_cpuidle_driver_init(void) 
	drv->state_count = 1;



	for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {

		int num_substates, mwait_hint, mwait_cstate;

		unsigned int mwait_hint;



		if ((cpuidle_state_table[cstate].enter == NULL) &&

		    (cpuidle_state_table[cstate].enter_s2idle == NULL))

		if (!cpuidle_state_table[cstate].enter &&

		    !cpuidle_state_table[cstate].enter_s2idle)

			break;



		if (cstate + 1 > max_cstate) {
@@ -1343,34 +1359,19 @@ static void __init intel_idle_cpuidle_driver_init(void) 
			break;

		}



		mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);

		mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint);



		/* number of sub-states for this state in CPUID.MWAIT */

		num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4))

					& MWAIT_SUBSTATE_MASK;



		/* if NO sub-states for this state in CPUID, skip it */

		if (num_substates == 0)

			continue;



		/* if state marked as disabled, skip it */

		/* If marked as unusable, skip this state. */

		if (cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_UNUSABLE) {

			pr_debug("state %s is disabled\n",

				 cpuidle_state_table[cstate].name);

			continue;

		}



		mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);

		if (!intel_idle_verify_cstate(mwait_hint))

			continue;



		if (((mwait_cstate + 1) > 2) &&

			!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))

			mark_tsc_unstable("TSC halts in idle"

					" states deeper than C2");



		drv->states[drv->state_count] =	/* structure copy */

			cpuidle_state_table[cstate];



		drv->state_count += 1;

		/* Structure copy. */

		drv->states[drv->state_count++] = cpuidle_state_table[cstate];

	}



	if (icpu->byt_auto_demotion_disable_flag) {

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