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path: root/drivers/idle/intel_idle.c
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Diffstat (limited to 'drivers/idle/intel_idle.c')
-rw-r--r--drivers/idle/intel_idle.c46
1 files changed, 46 insertions, 0 deletions
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index 1c7c25909e54..b2688c326522 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -64,6 +64,7 @@ static struct cpuidle_driver intel_idle_driver = {
/* intel_idle.max_cstate=0 disables driver */
static int max_cstate = CPUIDLE_STATE_MAX - 1;
static unsigned int disabled_states_mask;
+static unsigned int preferred_states_mask;
static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
@@ -1400,6 +1401,8 @@ static inline void intel_idle_init_cstates_acpi(struct cpuidle_driver *drv) { }
static inline bool intel_idle_off_by_default(u32 mwait_hint) { return false; }
#endif /* !CONFIG_ACPI_PROCESSOR_CSTATE */
+static void c1e_promotion_enable(void);
+
/**
* ivt_idle_state_table_update - Tune the idle states table for Ivy Town.
*
@@ -1570,6 +1573,26 @@ static void __init skx_idle_state_table_update(void)
}
}
+/**
+ * spr_idle_state_table_update - Adjust Sapphire Rapids idle states table.
+ */
+static void __init spr_idle_state_table_update(void)
+{
+ /* Check if user prefers C1E over C1. */
+ if (preferred_states_mask & BIT(2)) {
+ if (preferred_states_mask & BIT(1))
+ /* Both can't be enabled, stick to the defaults. */
+ return;
+
+ spr_cstates[0].flags |= CPUIDLE_FLAG_UNUSABLE;
+ spr_cstates[1].flags &= ~CPUIDLE_FLAG_UNUSABLE;
+
+ /* Enable C1E using the "C1E promotion" bit. */
+ c1e_promotion_enable();
+ disable_promotion_to_c1e = false;
+ }
+}
+
static bool __init intel_idle_verify_cstate(unsigned int mwait_hint)
{
unsigned int mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint) + 1;
@@ -1604,6 +1627,9 @@ static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
case INTEL_FAM6_SKYLAKE_X:
skx_idle_state_table_update();
break;
+ case INTEL_FAM6_SAPPHIRERAPIDS_X:
+ spr_idle_state_table_update();
+ break;
}
for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
@@ -1676,6 +1702,15 @@ static void auto_demotion_disable(void)
wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
}
+static void c1e_promotion_enable(void)
+{
+ unsigned long long msr_bits;
+
+ rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
+ msr_bits |= 0x2;
+ wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
+}
+
static void c1e_promotion_disable(void)
{
unsigned long long msr_bits;
@@ -1845,3 +1880,14 @@ module_param(max_cstate, int, 0444);
*/
module_param_named(states_off, disabled_states_mask, uint, 0444);
MODULE_PARM_DESC(states_off, "Mask of disabled idle states");
+/*
+ * Some platforms come with mutually exclusive C-states, so that if one is
+ * enabled, the other C-states must not be used. Example: C1 and C1E on
+ * Sapphire Rapids platform. This parameter allows for selecting the
+ * preferred C-states among the groups of mutually exclusive C-states - the
+ * selected C-states will be registered, the other C-states from the mutually
+ * exclusive group won't be registered. If the platform has no mutually
+ * exclusive C-states, this parameter has no effect.
+ */
+module_param_named(preferred_cstates, preferred_states_mask, uint, 0444);
+MODULE_PARM_DESC(preferred_cstates, "Mask of preferred idle states");