linux-stable/include/linux/amd-pstate.h
Perry Yuan ffa5096a7c 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 <ray.huang@amd.com>
Reviewed-by: Mario Limonciello <Mario.Limonciello@amd.com>
Reviewed-by: Wyes Karny <wyes.karny@amd.com>
Tested-by: Wyes Karny <wyes.karny@amd.com>
Signed-off-by: Perry Yuan <Perry.Yuan@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-02-03 21:59:41 +01:00

108 lines
3.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/include/linux/amd-pstate.h
*
* Copyright (C) 2022 Advanced Micro Devices, Inc.
*
* Author: Meng Li <li.meng@amd.com>
*/
#ifndef _LINUX_AMD_PSTATE_H
#define _LINUX_AMD_PSTATE_H
#include <linux/pm_qos.h>
#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 *
*********************************************************************/
/**
* struct amd_aperf_mperf
* @aperf: actual performance frequency clock count
* @mperf: maximum performance frequency clock count
* @tsc: time stamp counter
*/
struct amd_aperf_mperf {
u64 aperf;
u64 mperf;
u64 tsc;
};
/**
* struct amd_cpudata - private CPU data for AMD P-State
* @cpu: CPU number
* @req: constraint request to apply
* @cppc_req_cached: cached performance request hints
* @highest_perf: the maximum performance an individual processor may reach,
* assuming ideal conditions
* @nominal_perf: the maximum sustained performance level of the processor,
* assuming ideal operating conditions
* @lowest_nonlinear_perf: the lowest performance level at which nonlinear power
* savings are achieved
* @lowest_perf: the absolute lowest performance level of the processor
* @max_freq: the frequency that mapped to highest_perf
* @min_freq: the frequency that mapped to lowest_perf
* @nominal_freq: the frequency that mapped to nominal_perf
* @lowest_nonlinear_freq: the frequency that mapped to lowest_nonlinear_perf
* @cur: Difference of Aperf/Mperf/tsc count between last and current sample
* @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.
*/
struct amd_cpudata {
int cpu;
struct freq_qos_request req[2];
u64 cppc_req_cached;
u32 highest_perf;
u32 nominal_perf;
u32 lowest_nonlinear_perf;
u32 lowest_perf;
u32 max_freq;
u32 min_freq;
u32 nominal_freq;
u32 lowest_nonlinear_freq;
struct amd_aperf_mperf cur;
struct amd_aperf_mperf prev;
u64 freq;
bool boost_supported;
/* EPP feature related attributes*/
s16 epp_policy;
s16 epp_cached;
u32 policy;
u64 cppc_cap1_cached;
};
/*
* enum amd_pstate_mode - driver working mode of amd pstate
*/
enum amd_pstate_mode {
AMD_PSTATE_DISABLE = 0,
AMD_PSTATE_PASSIVE,
AMD_PSTATE_ACTIVE,
AMD_PSTATE_MAX,
};
static const char * const amd_pstate_mode_string[] = {
[AMD_PSTATE_DISABLE] = "disable",
[AMD_PSTATE_PASSIVE] = "passive",
[AMD_PSTATE_ACTIVE] = "active",
NULL,
};
#endif /* _LINUX_AMD_PSTATE_H */