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: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index aa2d19db2b1d93cdff3638421b07126d33012907..c351b21c08751c6f20fe877aac0576b43950344f 100644 (file)
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -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) &&