[PATCH 5.18 1032/1095] intel_idle: Add AlderLake support
From: Greg Kroah-Hartman
Date: Mon Aug 15 2022 - 19:30:14 EST
From: Zhang Rui <rui.zhang@xxxxxxxxx>
[ Upstream commit d1cf8bbfed1edc5108220342ab39e4544d55fbc3 ]
Similar to SPR, the C1 and C1E states on ADL are mutually exclusive.
Only one of them can be enabled at a time.
But contrast to SPR, which usually has a strong latency requirement
as a Xeon processor, C1E is preferred on ADL for better energy
efficiency.
Add custom C-state tables for ADL with both C1 and C1E, and
1. Enable the "C1E promotion" bit in MSR_IA32_POWER_CTL and mark C1
with the CPUIDLE_FLAG_UNUSABLE flag, so C1 is not available by
default.
2. Add support for the "preferred_cstates" module parameter, so that
users can choose to use C1 instead of C1E by booting with
"intel_idle.preferred_cstates=2".
Separate custom C-state tables are introduced for the ADL mobile and
desktop processors, because of the exit latency differences between
these two variants, especially with respect to PC10.
Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
[ rjw: Changelog edits, code rearrangement ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/idle/intel_idle.c | 133 ++++++++++++++++++++++++++++++++++++++
1 file changed, 133 insertions(+)
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index 47b68c6071be..907700d1e78e 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -811,6 +811,106 @@ static struct cpuidle_state icx_cstates[] __initdata = {
.enter = NULL }
};
+/*
+ * On AlderLake C1 has to be disabled if C1E is enabled, and vice versa.
+ * C1E is enabled only if "C1E promotion" bit is set in MSR_IA32_POWER_CTL.
+ * But in this case there is effectively no C1, because C1 requests are
+ * promoted to C1E. If the "C1E promotion" bit is cleared, then both C1
+ * and C1E requests end up with C1, so there is effectively no C1E.
+ *
+ * By default we enable C1E and disable C1 by marking it with
+ * 'CPUIDLE_FLAG_UNUSABLE'.
+ */
+static struct cpuidle_state adl_cstates[] __initdata = {
+ {
+ .name = "C1",
+ .desc = "MWAIT 0x00",
+ .flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_UNUSABLE,
+ .exit_latency = 1,
+ .target_residency = 1,
+ .enter = &intel_idle,
+ .enter_s2idle = intel_idle_s2idle, },
+ {
+ .name = "C1E",
+ .desc = "MWAIT 0x01",
+ .flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
+ .exit_latency = 2,
+ .target_residency = 4,
+ .enter = &intel_idle,
+ .enter_s2idle = intel_idle_s2idle, },
+ {
+ .name = "C6",
+ .desc = "MWAIT 0x20",
+ .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .exit_latency = 220,
+ .target_residency = 600,
+ .enter = &intel_idle,
+ .enter_s2idle = intel_idle_s2idle, },
+ {
+ .name = "C8",
+ .desc = "MWAIT 0x40",
+ .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .exit_latency = 280,
+ .target_residency = 800,
+ .enter = &intel_idle,
+ .enter_s2idle = intel_idle_s2idle, },
+ {
+ .name = "C10",
+ .desc = "MWAIT 0x60",
+ .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .exit_latency = 680,
+ .target_residency = 2000,
+ .enter = &intel_idle,
+ .enter_s2idle = intel_idle_s2idle, },
+ {
+ .enter = NULL }
+};
+
+static struct cpuidle_state adl_l_cstates[] __initdata = {
+ {
+ .name = "C1",
+ .desc = "MWAIT 0x00",
+ .flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_UNUSABLE,
+ .exit_latency = 1,
+ .target_residency = 1,
+ .enter = &intel_idle,
+ .enter_s2idle = intel_idle_s2idle, },
+ {
+ .name = "C1E",
+ .desc = "MWAIT 0x01",
+ .flags = MWAIT2flg(0x01) | CPUIDLE_FLAG_ALWAYS_ENABLE,
+ .exit_latency = 2,
+ .target_residency = 4,
+ .enter = &intel_idle,
+ .enter_s2idle = intel_idle_s2idle, },
+ {
+ .name = "C6",
+ .desc = "MWAIT 0x20",
+ .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .exit_latency = 170,
+ .target_residency = 500,
+ .enter = &intel_idle,
+ .enter_s2idle = intel_idle_s2idle, },
+ {
+ .name = "C8",
+ .desc = "MWAIT 0x40",
+ .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .exit_latency = 200,
+ .target_residency = 600,
+ .enter = &intel_idle,
+ .enter_s2idle = intel_idle_s2idle, },
+ {
+ .name = "C10",
+ .desc = "MWAIT 0x60",
+ .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .exit_latency = 230,
+ .target_residency = 700,
+ .enter = &intel_idle,
+ .enter_s2idle = intel_idle_s2idle, },
+ {
+ .enter = NULL }
+};
+
/*
* On Sapphire Rapids Xeon C1 has to be disabled if C1E is enabled, and vice
* versa. On SPR C1E is enabled only if "C1E promotion" bit is set in
@@ -1194,6 +1294,14 @@ static const struct idle_cpu idle_cpu_icx __initconst = {
.use_acpi = true,
};
+static const struct idle_cpu idle_cpu_adl __initconst = {
+ .state_table = adl_cstates,
+};
+
+static const struct idle_cpu idle_cpu_adl_l __initconst = {
+ .state_table = adl_l_cstates,
+};
+
static const struct idle_cpu idle_cpu_spr __initconst = {
.state_table = spr_cstates,
.disable_promotion_to_c1e = true,
@@ -1262,6 +1370,8 @@ static const struct x86_cpu_id intel_idle_ids[] __initconst = {
X86_MATCH_INTEL_FAM6_MODEL(SKYLAKE_X, &idle_cpu_skx),
X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_X, &idle_cpu_icx),
X86_MATCH_INTEL_FAM6_MODEL(ICELAKE_D, &idle_cpu_icx),
+ X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE, &idle_cpu_adl),
+ X86_MATCH_INTEL_FAM6_MODEL(ALDERLAKE_L, &idle_cpu_adl_l),
X86_MATCH_INTEL_FAM6_MODEL(SAPPHIRERAPIDS_X, &idle_cpu_spr),
X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNL, &idle_cpu_knl),
X86_MATCH_INTEL_FAM6_MODEL(XEON_PHI_KNM, &idle_cpu_knl),
@@ -1620,6 +1730,25 @@ static void __init skx_idle_state_table_update(void)
}
}
+/**
+ * adl_idle_state_table_update - Adjust AlderLake idle states table.
+ */
+static void __init adl_idle_state_table_update(void)
+{
+ /* Check if user prefers C1 over C1E. */
+ if (preferred_states_mask & BIT(1) && !(preferred_states_mask & BIT(2))) {
+ cpuidle_state_table[0].flags &= ~CPUIDLE_FLAG_UNUSABLE;
+ cpuidle_state_table[1].flags |= CPUIDLE_FLAG_UNUSABLE;
+
+ /* Disable C1E by clearing the "C1E promotion" bit. */
+ c1e_promotion = C1E_PROMOTION_DISABLE;
+ return;
+ }
+
+ /* Make sure C1E is enabled by default */
+ c1e_promotion = C1E_PROMOTION_ENABLE;
+}
+
/**
* spr_idle_state_table_update - Adjust Sapphire Rapids idle states table.
*/
@@ -1689,6 +1818,10 @@ static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
case INTEL_FAM6_SAPPHIRERAPIDS_X:
spr_idle_state_table_update();
break;
+ case INTEL_FAM6_ALDERLAKE:
+ case INTEL_FAM6_ALDERLAKE_L:
+ adl_idle_state_table_update();
+ break;
}
for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
--
2.35.1