From ffa5096a7c338641f70fb06d4778e8cf400181a8 Mon Sep 17 00:00:00 2001 From: Perry Yuan Date: Tue, 31 Jan 2023 17:00:09 +0800 Subject: cpufreq: amd-pstate: implement Pstate EPP support for the AMD processors Add EPP driver support for AMD SoCs which support a dedicated MSR for CPPC. EPP is used by the DPM controller to configure the frequency that a core operates at during short periods of activity. The SoC EPP targets are configured on a scale from 0 to 255 where 0 represents maximum performance and 255 represents maximum efficiency. The amd-pstate driver exports profile string names to userspace that are tied to specific EPP values. The balance_performance string (0x80) provides the best balance for efficiency versus power on most systems, but users can choose other strings to meet their needs as well. $ cat /sys/devices/system/cpu/cpufreq/policy0/energy_performance_available_preferences default performance balance_performance balance_power power $ cat /sys/devices/system/cpu/cpufreq/policy0/energy_performance_preference balance_performance To enable the driver,it needs to add `amd_pstate=active` to kernel command line and kernel will load the active mode epp driver Acked-by: Huang Rui Reviewed-by: Mario Limonciello Reviewed-by: Wyes Karny Tested-by: Wyes Karny Signed-off-by: Perry Yuan Signed-off-by: Rafael J. Wysocki --- include/linux/amd-pstate.h | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/amd-pstate.h b/include/linux/amd-pstate.h index dae2ce0f6735..72ea7cf85ca3 100644 --- a/include/linux/amd-pstate.h +++ b/include/linux/amd-pstate.h @@ -12,6 +12,11 @@ #include +#define AMD_CPPC_EPP_PERFORMANCE 0x00 +#define AMD_CPPC_EPP_BALANCE_PERFORMANCE 0x80 +#define AMD_CPPC_EPP_BALANCE_POWERSAVE 0xBF +#define AMD_CPPC_EPP_POWERSAVE 0xFF + /********************************************************************* * AMD P-state INTERFACE * *********************************************************************/ @@ -47,6 +52,10 @@ struct amd_aperf_mperf { * @prev: Last Aperf/Mperf/tsc count value read from register * @freq: current cpu frequency value * @boost_supported: check whether the Processor or SBIOS supports boost mode + * @epp_policy: Last saved policy used to set energy-performance preference + * @epp_cached: Cached CPPC energy-performance preference value + * @policy: Cpufreq policy value + * @cppc_cap1_cached Cached MSR_AMD_CPPC_CAP1 register value * * The amd_cpudata is key private data for each CPU thread in AMD P-State, and * represents all the attributes and goals that AMD P-State requests at runtime. @@ -72,6 +81,12 @@ struct amd_cpudata { u64 freq; bool boost_supported; + + /* EPP feature related attributes*/ + s16 epp_policy; + s16 epp_cached; + u32 policy; + u64 cppc_cap1_cached; }; /* @@ -90,5 +105,4 @@ static const char * const amd_pstate_mode_string[] = { [AMD_PSTATE_ACTIVE] = "active", NULL, }; - #endif /* _LINUX_AMD_PSTATE_H */ -- cgit v1.2.3