From b4a11fa3331e163e177e76098fe1d8b12b87cf6b Mon Sep 17 00:00:00 2001 From: Wyes Karny Date: Mon, 29 May 2023 14:25:51 +0000 Subject: cpufreq: Fail driver register if it has adjust_perf without fast_switch If fast_switch_possible flag is set by the scaling driver, the governor is free to select fast_switch function even if adjust_perf is set. Some scaling drivers which use adjust_perf don't set fast_switch thinking that the governor would never fall back to fast_switch. But the governor can fall back to fast_switch even in runtime if frequency invariance is disabled due to some reason. This could crash the kernel if the driver didn't set the fast_switch function pointer. Therefore, fail driver registration if it has adjust_perf without fast_switch. Suggested-by: Rafael J. Wysocki Suggested-by: Viresh Kumar Signed-off-by: Wyes Karny Signed-off-by: Rafael J. Wysocki --- include/linux/cpufreq.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 26e2eb399484..172ff51c1b2a 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -340,7 +340,10 @@ struct cpufreq_driver { /* * ->fast_switch() replacement for drivers that use an internal * representation of performance levels and can pass hints other than - * the target performance level to the hardware. + * the target performance level to the hardware. This can only be set + * if ->fast_switch is set too, because in those cases (under specific + * conditions) scale invariance can be disabled, which causes the + * schedutil governor to fall back to the latter. */ void (*adjust_perf)(unsigned int cpu, unsigned long min_perf, -- cgit v1.2.3 From 965262ef71c475857d0984a5eee57694b207a113 Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Tue, 20 Jun 2023 12:24:31 -0500 Subject: ACPI: CPPC: Add definition for undefined FADT preferred PM profile value In the event a new preferred PM profile value is introduced it's best for code to be able to defensively guard against it so that the wrong settings don't get applied on a new system that uses this profile but ancient kernels. Acked-by: Huang Rui Suggested-by: Gautham Ranjal Shenoy Link: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/05_ACPI_Software_Programming_Model/ACPI_Software_Programming_Model.html#fixed-acpi-description-table-fadt Signed-off-by: Mario Limonciello Reviewed-by: Perry Yuan Signed-off-by: Rafael J. Wysocki --- include/acpi/actbl.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/acpi/actbl.h b/include/acpi/actbl.h index e5dfb6f4de52..451f6276da49 100644 --- a/include/acpi/actbl.h +++ b/include/acpi/actbl.h @@ -307,7 +307,8 @@ enum acpi_preferred_pm_profiles { PM_SOHO_SERVER = 5, PM_APPLIANCE_PC = 6, PM_PERFORMANCE_SERVER = 7, - PM_TABLET = 8 + PM_TABLET = 8, + NR_PM_PROFILES = 9 }; /* Values for sleep_status and sleep_control registers (V5+ FADT) */ -- cgit v1.2.3 From c88ad30e3f861c7be4e3b4995554e2b0754059b7 Mon Sep 17 00:00:00 2001 From: Mario Limonciello Date: Tue, 20 Jun 2023 12:24:33 -0500 Subject: cpufreq: amd-pstate: Add a kernel config option to set default mode Users are having more success with amd-pstate since the introduction of EPP and Guided modes. To expose the driver to more users by default introduce a kernel configuration option for setting the default mode. Users can use an integer to map out which default mode they want to use in lieu of a kernel command line option. This will default to EPP, but only if: 1) The CPU supports an MSR. 2) The system profile is identified 3) The system profile is identified as a non-server by the FADT. Link: https://gitlab.freedesktop.org/hadess/power-profiles-daemon/-/merge_requests/121 Acked-by: Huang Rui Reviewed-by: Gautham R. Shenoy Co-developed-by: Perry Yuan Signed-off-by: Perry Yuan Signed-off-by: Mario Limonciello Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/Kconfig.x86 | 17 +++++++++++ drivers/cpufreq/amd-pstate.c | 73 +++++++++++++++++++++++++++++--------------- include/linux/amd-pstate.h | 4 ++- 3 files changed, 68 insertions(+), 26 deletions(-) (limited to 'include') diff --git a/drivers/cpufreq/Kconfig.x86 b/drivers/cpufreq/Kconfig.x86 index 00476e94db90..438c9e75a04d 100644 --- a/drivers/cpufreq/Kconfig.x86 +++ b/drivers/cpufreq/Kconfig.x86 @@ -51,6 +51,23 @@ config X86_AMD_PSTATE If in doubt, say N. +config X86_AMD_PSTATE_DEFAULT_MODE + int "AMD Processor P-State default mode" + depends on X86_AMD_PSTATE + default 3 if X86_AMD_PSTATE + range 1 4 + help + Select the default mode the amd-pstate driver will use on + supported hardware. + The value set has the following meanings: + 1 -> Disabled + 2 -> Passive + 3 -> Active (EPP) + 4 -> Guided + + For details, take a look at: + . + config X86_AMD_PSTATE_UT tristate "selftest for AMD Processor P-State driver" depends on X86 && ACPI_PROCESSOR diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c index 3546d7db614d..81fba0dcbee9 100644 --- a/drivers/cpufreq/amd-pstate.c +++ b/drivers/cpufreq/amd-pstate.c @@ -62,7 +62,7 @@ static struct cpufreq_driver *current_pstate_driver; static struct cpufreq_driver amd_pstate_driver; static struct cpufreq_driver amd_pstate_epp_driver; -static int cppc_state = AMD_PSTATE_DISABLE; +static int cppc_state = AMD_PSTATE_UNDEFINED; static bool cppc_enabled; /* @@ -1410,6 +1410,25 @@ static struct cpufreq_driver amd_pstate_epp_driver = { .attr = amd_pstate_epp_attr, }; +static int __init amd_pstate_set_driver(int mode_idx) +{ + if (mode_idx >= AMD_PSTATE_DISABLE && mode_idx < AMD_PSTATE_MAX) { + cppc_state = mode_idx; + if (cppc_state == AMD_PSTATE_DISABLE) + pr_info("driver is explicitly disabled\n"); + + if (cppc_state == AMD_PSTATE_ACTIVE) + current_pstate_driver = &amd_pstate_epp_driver; + + if (cppc_state == AMD_PSTATE_PASSIVE || cppc_state == AMD_PSTATE_GUIDED) + current_pstate_driver = &amd_pstate_driver; + + return 0; + } + + return -EINVAL; +} + static int __init amd_pstate_init(void) { struct device *dev_root; @@ -1417,15 +1436,6 @@ static int __init amd_pstate_init(void) if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD) return -ENODEV; - /* - * by default the pstate driver is disabled to load - * enable the amd_pstate passive mode driver explicitly - * with amd_pstate=passive or other modes in kernel command line - */ - if (cppc_state == AMD_PSTATE_DISABLE) { - pr_info("driver load is disabled, boot with specific mode to enable this\n"); - return -ENODEV; - } if (!acpi_cpc_valid()) { pr_warn_once("the _CPC object is not present in SBIOS or ACPI disabled\n"); @@ -1436,6 +1446,33 @@ static int __init amd_pstate_init(void) if (cpufreq_get_current_driver()) return -EEXIST; + switch (cppc_state) { + case AMD_PSTATE_UNDEFINED: + /* Disable on the following configs by default: + * 1. Undefined platforms + * 2. Server platforms + * 3. Shared memory designs + */ + if (amd_pstate_acpi_pm_profile_undefined() || + amd_pstate_acpi_pm_profile_server() || + !boot_cpu_has(X86_FEATURE_CPPC)) { + pr_info("driver load is disabled, boot with specific mode to enable this\n"); + return -ENODEV; + } + ret = amd_pstate_set_driver(CONFIG_X86_AMD_PSTATE_DEFAULT_MODE); + if (ret) + return ret; + break; + case AMD_PSTATE_DISABLE: + return -ENODEV; + case AMD_PSTATE_PASSIVE: + case AMD_PSTATE_ACTIVE: + case AMD_PSTATE_GUIDED: + break; + default: + return -EINVAL; + } + /* capability check */ if (boot_cpu_has(X86_FEATURE_CPPC)) { pr_debug("AMD CPPC MSR based functionality is supported\n"); @@ -1488,21 +1525,7 @@ static int __init amd_pstate_param(char *str) size = strlen(str); mode_idx = get_mode_idx_from_str(str, size); - if (mode_idx >= AMD_PSTATE_DISABLE && mode_idx < AMD_PSTATE_MAX) { - cppc_state = mode_idx; - if (cppc_state == AMD_PSTATE_DISABLE) - pr_info("driver is explicitly disabled\n"); - - if (cppc_state == AMD_PSTATE_ACTIVE) - current_pstate_driver = &amd_pstate_epp_driver; - - if (cppc_state == AMD_PSTATE_PASSIVE || cppc_state == AMD_PSTATE_GUIDED) - current_pstate_driver = &amd_pstate_driver; - - return 0; - } - - return -EINVAL; + return amd_pstate_set_driver(mode_idx); } early_param("amd_pstate", amd_pstate_param); diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h index c10ebf8c42e6..446394f84606 100644 --- a/include/linux/amd-pstate.h +++ b/include/linux/amd-pstate.h @@ -94,7 +94,8 @@ struct amd_cpudata { * enum amd_pstate_mode - driver working mode of amd pstate */ enum amd_pstate_mode { - AMD_PSTATE_DISABLE = 0, + AMD_PSTATE_UNDEFINED = 0, + AMD_PSTATE_DISABLE, AMD_PSTATE_PASSIVE, AMD_PSTATE_ACTIVE, AMD_PSTATE_GUIDED, @@ -102,6 +103,7 @@ enum amd_pstate_mode { }; static const char * const amd_pstate_mode_string[] = { + [AMD_PSTATE_UNDEFINED] = "undefined", [AMD_PSTATE_DISABLE] = "disable", [AMD_PSTATE_PASSIVE] = "passive", [AMD_PSTATE_ACTIVE] = "active", -- cgit v1.2.3