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cpufreq: amd-pstate: Add a kernel config option to set default mode

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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 <ray.huang@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Co-developed-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Mario Limonciello 2023-06-20 12:24:33 -05:00 committed by Rafael J. Wysocki
parent 32f80b9adf
commit c88ad30e3f
3 changed files with 68 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
drivers/cpufreq/Kconfig.x86
View File

@ -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:
<file:Documentation/admin-guide/pm/amd-pstate.rst>.
config X86_AMD_PSTATE_UT
tristate "selftest for AMD Processor P-State driver"
depends on X86 && ACPI_PROCESSOR

73
drivers/cpufreq/amd-pstate.c
View File

@ -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);

4
include/linux/amd-pstate.h
View File

@ -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",