blob: 2e5c741c41ca03467074b615dee8dcc65c9b2deb [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* intel_tcc.c - Library for Intel TCC (thermal control circuitry) MSR access
* Copyright (c) 2022, Intel Corporation.
*/
#include <linux/errno.h>
#include <linux/intel_tcc.h>
#include <asm/msr.h>
/**
* intel_tcc_get_tjmax() - returns the default TCC activation Temperature
* @cpu: cpu that the MSR should be run on, nagative value means any cpu.
*
* Get the TjMax value, which is the default thermal throttling or TCC
* activation temperature in degrees C.
*
* Return: Tjmax value in degrees C on success, negative error code otherwise.
*/
int intel_tcc_get_tjmax(int cpu)
{
u32 low, high;
int val, err;
if (cpu < 0)
err = rdmsr_safe(MSR_IA32_TEMPERATURE_TARGET, &low, &high);
else
err = rdmsr_safe_on_cpu(cpu, MSR_IA32_TEMPERATURE_TARGET, &low, &high);
if (err)
return err;
val = (low >> 16) & 0xff;
return val ? val : -ENODATA;
}
EXPORT_SYMBOL_NS_GPL(intel_tcc_get_tjmax, INTEL_TCC);
/**
* intel_tcc_get_offset() - returns the TCC Offset value to Tjmax
* @cpu: cpu that the MSR should be run on, nagative value means any cpu.
*
* Get the TCC offset value to Tjmax. The effective thermal throttling or TCC
* activation temperature equals "Tjmax" - "TCC Offset", in degrees C.
*
* Return: Tcc offset value in degrees C on success, negative error code otherwise.
*/
int intel_tcc_get_offset(int cpu)
{
u32 low, high;
int err;
if (cpu < 0)
err = rdmsr_safe(MSR_IA32_TEMPERATURE_TARGET, &low, &high);
else
err = rdmsr_safe_on_cpu(cpu, MSR_IA32_TEMPERATURE_TARGET, &low, &high);
if (err)
return err;
return (low >> 24) & 0x3f;
}
EXPORT_SYMBOL_NS_GPL(intel_tcc_get_offset, INTEL_TCC);
/**
* intel_tcc_set_offset() - set the TCC offset value to Tjmax
* @cpu: cpu that the MSR should be run on, nagative value means any cpu.
* @offset: TCC offset value in degree C
*
* Set the TCC Offset value to Tjmax. The effective thermal throttling or TCC
* activation temperature equals "Tjmax" - "TCC Offset", in degree C.
*
* Return: On success returns 0, negative error code otherwise.
*/
int intel_tcc_set_offset(int cpu, int offset)
{
u32 low, high;
int err;
if (offset < 0 || offset > 0x3f)
return -EINVAL;
if (cpu < 0)
err = rdmsr_safe(MSR_IA32_TEMPERATURE_TARGET, &low, &high);
else
err = rdmsr_safe_on_cpu(cpu, MSR_IA32_TEMPERATURE_TARGET, &low, &high);
if (err)
return err;
/* MSR Locked */
if (low & BIT(31))
return -EPERM;
low &= ~(0x3f << 24);
low |= offset << 24;
if (cpu < 0)
return wrmsr_safe(MSR_IA32_TEMPERATURE_TARGET, low, high);
else
return wrmsr_safe_on_cpu(cpu, MSR_IA32_TEMPERATURE_TARGET, low, high);
}
EXPORT_SYMBOL_NS_GPL(intel_tcc_set_offset, INTEL_TCC);
/**
* intel_tcc_get_temp() - returns the current temperature
* @cpu: cpu that the MSR should be run on, nagative value means any cpu.
* @pkg: true: Package Thermal Sensor. false: Core Thermal Sensor.
*
* Get the current temperature returned by the CPU core/package level
* thermal sensor, in degrees C.
*
* Return: Temperature in degrees C on success, negative error code otherwise.
*/
int intel_tcc_get_temp(int cpu, bool pkg)
{
u32 low, high;
u32 msr = pkg ? MSR_IA32_PACKAGE_THERM_STATUS : MSR_IA32_THERM_STATUS;
int tjmax, temp, err;
tjmax = intel_tcc_get_tjmax(cpu);
if (tjmax < 0)
return tjmax;
if (cpu < 0)
err = rdmsr_safe(msr, &low, &high);
else
err = rdmsr_safe_on_cpu(cpu, msr, &low, &high);
if (err)
return err;
/* Temperature is beyond the valid thermal sensor range */
if (!(low & BIT(31)))
return -ENODATA;
temp = tjmax - ((low >> 16) & 0x7f);
/* Do not allow negative CPU temperature */
return temp >= 0 ? temp : -ENODATA;
}
EXPORT_SYMBOL_NS_GPL(intel_tcc_get_temp, INTEL_TCC);