From 3a9cf77b60dc9839b6674943bb7c9dcd524b6294 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Wed, 2 Mar 2022 10:16:00 +0200 Subject: [PATCH] intel_idle: add core C6 optimization for SPR Add a Sapphire Rapids Xeon C6 optimization, similar to what we have for Sky Lake Xeon: if package C6 is disabled, adjust C6 exit latency and target residency to match core C6 values, instead of using the default package C6 values. Signed-off-by: Artem Bityutskiy Signed-off-by: Rafael J. Wysocki --- drivers/idle/intel_idle.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index b2688c326522..e385ddf15b32 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -1578,6 +1578,8 @@ static void __init skx_idle_state_table_update(void) */ static void __init spr_idle_state_table_update(void) { + unsigned long long msr; + /* Check if user prefers C1E over C1. */ if (preferred_states_mask & BIT(2)) { if (preferred_states_mask & BIT(1)) @@ -1591,6 +1593,19 @@ static void __init spr_idle_state_table_update(void) c1e_promotion_enable(); disable_promotion_to_c1e = false; } + + /* + * By default, the C6 state assumes the worst-case scenario of package + * C6. However, if PC6 is disabled, we update the numbers to match + * core C6. + */ + rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr); + + /* Limit value 2 and above allow for PC6. */ + if ((msr & 0x7) < 2) { + spr_cstates[2].exit_latency = 190; + spr_cstates[2].target_residency = 600; + } } static bool __init intel_idle_verify_cstate(unsigned int mwait_hint)