Commit 4622ba92 authored by Arjan van de Ven's avatar Arjan van de Ven Committed by Rafael J. Wysocki
Browse files

intel_idle: refactor state->enter manipulation into its own function 



Since the 6.4 kernel, the logic for updating a state's enter method
based on "environmental conditions" (command line options, cpu sidechannel
workarounds etc etc) has gotten pretty complex.
This patch refactors this into a seperate small, self contained function
(no behavior changes) for improved readability and to make future
changes to this logic easier to do and understand.

Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 858fd168

drivers/idle/intel_idle.c

+28 −22
Original line number Diff line number Diff line
@@ -1839,6 +1839,32 @@ static bool __init intel_idle_verify_cstate(unsigned int mwait_hint) 
	return true;

}



static void state_update_enter_method(struct cpuidle_state *state, int cstate)

{

	if (state->flags & CPUIDLE_FLAG_INIT_XSTATE) {

		/*

		 * Combining with XSTATE with IBRS or IRQ_ENABLE flags

		 * is not currently supported but this driver.

		 */

		WARN_ON_ONCE(state->flags & CPUIDLE_FLAG_IBRS);

		WARN_ON_ONCE(state->flags & CPUIDLE_FLAG_IRQ_ENABLE);

		state->enter = intel_idle_xstate;

	} else if (cpu_feature_enabled(X86_FEATURE_KERNEL_IBRS) &&

			   state->flags & CPUIDLE_FLAG_IBRS) {

		/*

		 * IBRS mitigation requires that C-states are entered

		 * with interrupts disabled.

		 */

		WARN_ON_ONCE(state->flags & CPUIDLE_FLAG_IRQ_ENABLE);

		state->enter = intel_idle_ibrs;

	} else if (state->flags & CPUIDLE_FLAG_IRQ_ENABLE) {

		state->enter = intel_idle_irq;

	} else if (force_irq_on) {

		pr_info("forced intel_idle_irq for state %d\n", cstate);

		state->enter = intel_idle_irq;

	}

}



static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)

{

	int cstate;
@@ -1894,28 +1920,8 @@ static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv) 
		drv->states[drv->state_count] = cpuidle_state_table[cstate];

		state = &drv->states[drv->state_count];



		if (state->flags & CPUIDLE_FLAG_INIT_XSTATE) {

			/*

			 * Combining with XSTATE with IBRS or IRQ_ENABLE flags

			 * is not currently supported but this driver.

			 */

			WARN_ON_ONCE(state->flags & CPUIDLE_FLAG_IBRS);

			WARN_ON_ONCE(state->flags & CPUIDLE_FLAG_IRQ_ENABLE);

			state->enter = intel_idle_xstate;

		} else if (cpu_feature_enabled(X86_FEATURE_KERNEL_IBRS) &&

			   state->flags & CPUIDLE_FLAG_IBRS) {

			/*

			 * IBRS mitigation requires that C-states are entered

			 * with interrupts disabled.

			 */

			WARN_ON_ONCE(state->flags & CPUIDLE_FLAG_IRQ_ENABLE);

			state->enter = intel_idle_ibrs;

		} else if (state->flags & CPUIDLE_FLAG_IRQ_ENABLE) {

			state->enter = intel_idle_irq;

		} else if (force_irq_on) {

			pr_info("forced intel_idle_irq for state %d\n", cstate);

			state->enter = intel_idle_irq;

		}

		state_update_enter_method(state, cstate);





		if ((disabled_states_mask & BIT(drv->state_count)) ||

		    ((icpu->use_acpi || force_use_acpi) &&