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intel_idle: Add AlderLake support

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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@intel.com>
[ rjw: Changelog edits, code rearrangement ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Zhang Rui 2022-04-15 17:39:51 +08:00 committed by Rafael J. Wysocki
parent 7eac3bd38d
commit d1cf8bbfed
1 changed files with 133 additions and 0 deletions
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133
drivers/idle/intel_idle.c
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@ -764,6 +764,106 @@ 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
@ -1147,6 +1247,14 @@ 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,
@ -1215,6 +1323,8 @@ 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),
@ -1573,6 +1683,25 @@ 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.
*/
@ -1642,6 +1771,10 @@ 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) {