Commit 14eb1c96 authored by Meng Li's avatar Meng Li Committed by Shuah Khan
Browse files

cpufreq: amd-pstate: Add test module for amd-pstate driver 



Add amd-pstate-ut test module, this module is used by kselftest
to unit test amd-pstate functionality. This module will be
expected by some of selftests to be present and loaded.

Signed-off-by: default avatarMeng Li <li.meng@amd.com>
Acked-by: default avatarHuang Rui <ray.huang@amd.com>
Reviewed-by: default avatarShuah Khan <skhan@linuxfoundation.org>
Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
parent f1375ec1

drivers/cpufreq/Kconfig.x86

+7 −0
Original line number Diff line number Diff line
@@ -51,6 +51,13 @@ config X86_AMD_PSTATE 


	  If in doubt, say N.



config X86_AMD_PSTATE_UT

	tristate "selftest for AMD Processor P-State driver"

	depends on X86 && ACPI_PROCESSOR

	default n

	help

	  This kernel module is used for testing. It's safe to say M here.



config X86_ACPI_CPUFREQ

	tristate "ACPI Processor P-States driver"

	depends on ACPI_PROCESSOR

drivers/cpufreq/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ amd_pstate-y := amd-pstate.o amd-pstate-trace.o 


obj-$(CONFIG_X86_ACPI_CPUFREQ)		+= acpi-cpufreq.o

obj-$(CONFIG_X86_AMD_PSTATE)		+= amd_pstate.o

obj-$(CONFIG_X86_AMD_PSTATE_UT)		+= amd-pstate-ut.o

obj-$(CONFIG_X86_POWERNOW_K8)		+= powernow-k8.o

obj-$(CONFIG_X86_PCC_CPUFREQ)		+= pcc-cpufreq.o

obj-$(CONFIG_X86_POWERNOW_K6)		+= powernow-k6.o

drivers/cpufreq/amd-pstate-ut.c

0 → 100644
+293 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-1.0-or-later

/*

 * AMD Processor P-state Frequency Driver Unit Test

 *

 * Copyright (C) 2022 Advanced Micro Devices, Inc. All Rights Reserved.

 *

 * Author: Meng Li <li.meng@amd.com>

 *

 * The AMD P-State Unit Test is a test module for testing the amd-pstate

 * driver. 1) It can help all users to verify their processor support

 * (SBIOS/Firmware or Hardware). 2) Kernel can have a basic function

 * test to avoid the kernel regression during the update. 3) We can

 * introduce more functional or performance tests to align the result

 * together, it will benefit power and performance scale optimization.

 *

 * This driver implements basic framework with plans to enhance it with

 * additional test cases to improve the depth and coverage of the test.

 *

 * See Documentation/admin-guide/pm/amd-pstate.rst Unit Tests for

 * amd-pstate to get more detail.

 */



#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt



#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/fs.h>

#include <linux/amd-pstate.h>



#include <acpi/cppc_acpi.h>



/*

 * Abbreviations:

 * amd_pstate_ut: used as a shortform for AMD P-State unit test.

 * It helps to keep variable names smaller, simpler

 */

enum amd_pstate_ut_result {

	AMD_PSTATE_UT_RESULT_PASS,

	AMD_PSTATE_UT_RESULT_FAIL,

};



struct amd_pstate_ut_struct {

	const char *name;

	void (*func)(u32 index);

	enum amd_pstate_ut_result result;

};



/*

 * Kernel module for testing the AMD P-State unit test

 */

static void amd_pstate_ut_acpi_cpc_valid(u32 index);

static void amd_pstate_ut_check_enabled(u32 index);

static void amd_pstate_ut_check_perf(u32 index);

static void amd_pstate_ut_check_freq(u32 index);



static struct amd_pstate_ut_struct amd_pstate_ut_cases[] = {

	{"amd_pstate_ut_acpi_cpc_valid",   amd_pstate_ut_acpi_cpc_valid   },

	{"amd_pstate_ut_check_enabled",    amd_pstate_ut_check_enabled    },

	{"amd_pstate_ut_check_perf",       amd_pstate_ut_check_perf       },

	{"amd_pstate_ut_check_freq",       amd_pstate_ut_check_freq       }

};



static bool get_shared_mem(void)

{

	bool result = false;

	char path[] = "/sys/module/amd_pstate/parameters/shared_mem";

	char buf[5] = {0};

	struct file *filp = NULL;

	loff_t pos = 0;

	ssize_t ret;



	if (!boot_cpu_has(X86_FEATURE_CPPC)) {

		filp = filp_open(path, FMODE_PREAD, 0);

		if (IS_ERR(filp))

			pr_err("%s unable to open %s file!\n", __func__, path);

		else {

			ret = kernel_read(filp, &buf, sizeof(buf), &pos);

			if (ret < 0)

				pr_err("%s read %s file fail ret=%ld!\n",

					__func__, path, (long)ret);

			filp_close(filp, NULL);

		}



		if ('Y' == *buf)

			result = true;

	}



	return result;

}



/*

 * check the _CPC object is present in SBIOS.

 */

static void amd_pstate_ut_acpi_cpc_valid(u32 index)

{

	if (acpi_cpc_valid())

		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;

	else {

		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;

		pr_err("%s the _CPC object is not present in SBIOS!\n", __func__);

	}

}



static void amd_pstate_ut_pstate_enable(u32 index)

{

	int ret = 0;

	u64 cppc_enable = 0;



	ret = rdmsrl_safe(MSR_AMD_CPPC_ENABLE, &cppc_enable);

	if (ret) {

		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;

		pr_err("%s rdmsrl_safe MSR_AMD_CPPC_ENABLE ret=%d error!\n", __func__, ret);

		return;

	}

	if (cppc_enable)

		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;

	else {

		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;

		pr_err("%s amd pstate must be enabled!\n", __func__);

	}

}



/*

 * check if amd pstate is enabled

 */

static void amd_pstate_ut_check_enabled(u32 index)

{

	if (get_shared_mem())

		amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;

	else

		amd_pstate_ut_pstate_enable(index);

}



/*

 * check if performance values are reasonable.

 * highest_perf >= nominal_perf > lowest_nonlinear_perf > lowest_perf > 0

 */

static void amd_pstate_ut_check_perf(u32 index)

{

	int cpu = 0, ret = 0;

	u32 highest_perf = 0, nominal_perf = 0, lowest_nonlinear_perf = 0, lowest_perf = 0;

	u64 cap1 = 0;

	struct cppc_perf_caps cppc_perf;

	struct cpufreq_policy *policy = NULL;

	struct amd_cpudata *cpudata = NULL;



	highest_perf = amd_get_highest_perf();



	for_each_possible_cpu(cpu) {

		policy = cpufreq_cpu_get(cpu);

		if (!policy)

			break;

		cpudata = policy->driver_data;



		if (get_shared_mem()) {

			ret = cppc_get_perf_caps(cpu, &cppc_perf);

			if (ret) {

				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;

				pr_err("%s cppc_get_perf_caps ret=%d error!\n", __func__, ret);

				return;

			}



			nominal_perf = cppc_perf.nominal_perf;

			lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf;

			lowest_perf = cppc_perf.lowest_perf;

		} else {

			ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &cap1);

			if (ret) {

				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;

				pr_err("%s read CPPC_CAP1 ret=%d error!\n", __func__, ret);

				return;

			}



			nominal_perf = AMD_CPPC_NOMINAL_PERF(cap1);

			lowest_nonlinear_perf = AMD_CPPC_LOWNONLIN_PERF(cap1);

			lowest_perf = AMD_CPPC_LOWEST_PERF(cap1);

		}



		if ((highest_perf != READ_ONCE(cpudata->highest_perf)) ||

			(nominal_perf != READ_ONCE(cpudata->nominal_perf)) ||

			(lowest_nonlinear_perf != READ_ONCE(cpudata->lowest_nonlinear_perf)) ||

			(lowest_perf != READ_ONCE(cpudata->lowest_perf))) {

			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;

			pr_err("%s cpu%d highest=%d %d nominal=%d %d lowest_nonlinear=%d %d lowest=%d %d, they should be equal!\n",

				__func__, cpu, highest_perf, cpudata->highest_perf,

				nominal_perf, cpudata->nominal_perf,

				lowest_nonlinear_perf, cpudata->lowest_nonlinear_perf,

				lowest_perf, cpudata->lowest_perf);

			return;

		}



		if (!((highest_perf >= nominal_perf) &&

			(nominal_perf > lowest_nonlinear_perf) &&

			(lowest_nonlinear_perf > lowest_perf) &&

			(lowest_perf > 0))) {

			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;

			pr_err("%s cpu%d highest=%d >= nominal=%d > lowest_nonlinear=%d > lowest=%d > 0, the formula is incorrect!\n",

				__func__, cpu, highest_perf, nominal_perf,

				lowest_nonlinear_perf, lowest_perf);

			return;

		}

	}



	amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;

}



/*

 * Check if frequency values are reasonable.

 * max_freq >= nominal_freq > lowest_nonlinear_freq > min_freq > 0

 * check max freq when set support boost mode.

 */

static void amd_pstate_ut_check_freq(u32 index)

{

	int cpu = 0;

	struct cpufreq_policy *policy = NULL;

	struct amd_cpudata *cpudata = NULL;



	for_each_possible_cpu(cpu) {

		policy = cpufreq_cpu_get(cpu);

		if (!policy)

			break;

		cpudata = policy->driver_data;



		if (!((cpudata->max_freq >= cpudata->nominal_freq) &&

			(cpudata->nominal_freq > cpudata->lowest_nonlinear_freq) &&

			(cpudata->lowest_nonlinear_freq > cpudata->min_freq) &&

			(cpudata->min_freq > 0))) {

			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;

			pr_err("%s cpu%d max=%d >= nominal=%d > lowest_nonlinear=%d > min=%d > 0, the formula is incorrect!\n",

				__func__, cpu, cpudata->max_freq, cpudata->nominal_freq,

				cpudata->lowest_nonlinear_freq, cpudata->min_freq);

			return;

		}



		if (cpudata->min_freq != policy->min) {

			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;

			pr_err("%s cpu%d cpudata_min_freq=%d policy_min=%d, they should be equal!\n",

				__func__, cpu, cpudata->min_freq, policy->min);

			return;

		}



		if (cpudata->boost_supported) {

			if ((policy->max == cpudata->max_freq) ||

					(policy->max == cpudata->nominal_freq))

				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;

			else {

				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;

				pr_err("%s cpu%d policy_max=%d should be equal cpu_max=%d or cpu_nominal=%d !\n",

					__func__, cpu, policy->max, cpudata->max_freq,

					cpudata->nominal_freq);

				return;

			}

		} else {

			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;

			pr_err("%s cpu%d must support boost!\n", __func__, cpu);

			return;

		}

	}



	amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;

}



static int __init amd_pstate_ut_init(void)

{

	u32 i = 0, arr_size = ARRAY_SIZE(amd_pstate_ut_cases);



	for (i = 0; i < arr_size; i++) {

		amd_pstate_ut_cases[i].func(i);

		switch (amd_pstate_ut_cases[i].result) {

		case AMD_PSTATE_UT_RESULT_PASS:

			pr_info("%-4d %-20s\t success!\n", i+1, amd_pstate_ut_cases[i].name);

			break;

		case AMD_PSTATE_UT_RESULT_FAIL:

		default:

			pr_info("%-4d %-20s\t fail!\n", i+1, amd_pstate_ut_cases[i].name);

			break;

		}

	}



	return 0;

}



static void __exit amd_pstate_ut_exit(void)

{

}



module_init(amd_pstate_ut_init);

module_exit(amd_pstate_ut_exit);



MODULE_AUTHOR("Meng Li <li.meng@amd.com>");

MODULE_DESCRIPTION("AMD P-state driver Test module");

MODULE_LICENSE("GPL");