Re: [PATCH V4 2/3] selftests: amd-pstate: Add test module for amd-pstate driver

[Huang Rui <ray.huang@amd.com>]

On Wed, Apr 27, 2022 at 09:53:14PM +0800, Meng, Li (Jassmine) wrote:
> Add amd-pstate-ut module, which is conceptually out-of-tree module
> and provides ways for selftests/amd-pstate driver to test various
> kernel module-related functionality. This module will be expected by
> some of selftests to be present and loaded.
> 
> Signed-off-by: Meng Li <li.meng@amd.com>
> ---
>  tools/testing/selftests/Makefile              |   1 +
>  tools/testing/selftests/amd-pstate/Makefile   |   9 +
>  .../selftests/amd-pstate/amd-pstate-ut.sh     |  27 ++
>  .../amd-pstate/amd-pstate-ut/Makefile         |  20 ++
>  .../amd-pstate/amd-pstate-ut/amd-pstate-ut.c  | 275 ++++++++++++++++++
>  tools/testing/selftests/amd-pstate/config     |   1 +
>  6 files changed, 333 insertions(+)
>  create mode 100644 tools/testing/selftests/amd-pstate/Makefile
>  create mode 100755 tools/testing/selftests/amd-pstate/amd-pstate-ut.sh
>  create mode 100644 tools/testing/selftests/amd-pstate/amd-pstate-ut/Makefile
>  create mode 100644 tools/testing/selftests/amd-pstate/amd-pstate-ut/amd-pstate-ut.c
>  create mode 100644 tools/testing/selftests/amd-pstate/config
> 
> diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
> index 2319ec87f53d..975c13368286 100644
> --- a/tools/testing/selftests/Makefile
> +++ b/tools/testing/selftests/Makefile
> @@ -1,5 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
>  TARGETS += alsa
> +TARGETS += amd-pstate
>  TARGETS += arm64
>  TARGETS += bpf
>  TARGETS += breakpoints
> diff --git a/tools/testing/selftests/amd-pstate/Makefile b/tools/testing/selftests/amd-pstate/Makefile
> new file mode 100644
> index 000000000000..199867f44b32
> --- /dev/null
> +++ b/tools/testing/selftests/amd-pstate/Makefile
> @@ -0,0 +1,9 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +# Makefile for amd-pstate/ function selftests
> +
> +# No binaries, but make sure arg-less "make" doesn't trigger "run_tests"
> +all:
> +
> +TEST_PROGS := amd-pstate-ut.sh
> +
> +include ../lib.mk
> diff --git a/tools/testing/selftests/amd-pstate/amd-pstate-ut.sh b/tools/testing/selftests/amd-pstate/amd-pstate-ut.sh
> new file mode 100755
> index 000000000000..9e787ead6b14
> --- /dev/null
> +++ b/tools/testing/selftests/amd-pstate/amd-pstate-ut.sh
> @@ -0,0 +1,27 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0
> +
> +# amd-pstate-ut 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.
> +
> +# Kselftest framework requirement - SKIP code is 4.
> +ksft_skip=4
> +
> +if ! uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/ | grep -q x86; then
> +	echo "$0 # Skipped: Test can only run on x86 architectures."
> +	exit $ksft_skip
> +fi
> +
> +scaling_driver=$(cat /sys/devices/system/cpu/cpufreq/policy0/scaling_driver)
> +
> +if [ "$scaling_driver" != "amd-pstate" ]; then
> +	echo "$0 # Skipped: Test can only run on amd-pstate driver."

Maybe it's better to print the current scaling_driver which is running
here.

> +	exit $ksft_skip
> +fi
> +

Can we add load the amd-pstate-ut test module in the script?

> +$(dirname $0)/../kselftest/module.sh "amd-pstate-ut" amd-pstate-ut
> diff --git a/tools/testing/selftests/amd-pstate/amd-pstate-ut/Makefile b/tools/testing/selftests/amd-pstate/amd-pstate-ut/Makefile
> new file mode 100644
> index 000000000000..16e09c64369a
> --- /dev/null
> +++ b/tools/testing/selftests/amd-pstate/amd-pstate-ut/Makefile
> @@ -0,0 +1,20 @@
> +AMD_PSTATE_UT_DIR := $(realpath $(dir $(abspath $(lastword $(MAKEFILE_LIST)))))
> +KDIR ?= $(abspath $(AMD_PSATE_UT_DIR)/../../../../..)
> +
> +ifeq ($(V),1)
> +Q =
> +else
> +Q = @
> +endif
> +
> +MODULES = amd-pstate-ut.ko
> +
> +obj-m += amd-pstate-ut.o
> +CFLAGS_amd-pstate-ut.o = -I$(src)
> +
> +all:
> +	+$(Q)make -C $(KDIR) M=$(AMD_PSTATE_UT_DIR) modules
> +
> +clean:
> +	+$(Q)make -C $(KDIR) M=$(AMD_PSTATE_UT_DIR) clean
> +
> diff --git a/tools/testing/selftests/amd-pstate/amd-pstate-ut/amd-pstate-ut.c b/tools/testing/selftests/amd-pstate/amd-pstate-ut/amd-pstate-ut.c
> new file mode 100644
> index 000000000000..ec7b5c984879
> --- /dev/null
> +++ b/tools/testing/selftests/amd-pstate/amd-pstate-ut/amd-pstate-ut.c
> @@ -0,0 +1,275 @@
> +// 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.
> + *
> + * At present, it only implements the basic framework and some simple
> + * test cases. Next, 1) we will add a rst document. 2) we will add more
> + * test cases to improve the depth and coverage of the test.
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include "../../kselftest_module.h"
> +
> +#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:
> + * aput: used as a shortform for AMD P-State unit test.
> + * It helps to keep variable names smaller, simpler
> + */
> +
> +KSTM_MODULE_GLOBALS();
> +
> +/*
> + * Kernel module for testing the AMD P-State unit test
> + */
> +enum aput_result {
> +	APUT_RESULT_PASS,
> +	APUT_RESULT_FAIL,
> +	MAX_APUT_RESULT,
> +};
> +
> +struct aput_struct {
> +	const char *name;
> +	void (*func)(u32 index);
> +	enum aput_result result;
> +};
> +
> +static void aput_acpi_cpc(u32 index);
> +static void aput_check_enabled(u32 index);
> +static void aput_check_perf(u32 index);
> +static void aput_check_freq(u32 index);
> +
> +static struct aput_struct aput_cases[] = {
> +	{"acpi_cpc_valid",   aput_acpi_cpc         },
> +	{"check_enabled",    aput_check_enabled    },
> +	{"check_perf",       aput_check_perf       },
> +	{"check_freq",       aput_check_freq       }
> +};
> +
> +static bool get_shared_mem(void)
> +{
> +	bool result = false;
> +	char buf[5] = {0};
> +	struct file *filp = NULL;
> +	loff_t pos = 0;
> +	ssize_t ret;
> +
> +	filp = filp_open("/sys/module/amd_pstate/parameters/shared_mem", FMODE_PREAD, 0);

We need to add a check of read back from X86_FEATURE_CPPC in case somebody
set the "shared_mem" parameter on full MSR processors.

Others look good for me, thanks Li!

Thanks,
Ray

> +	if (IS_ERR(filp))
> +		pr_err("%s Open param file fail!\n", __func__);
> +	else {
> +		ret = kernel_read(filp, &buf, sizeof(buf), &pos);
> +		if (ret < 0)
> +			pr_err("%s ret=%ld unable to read from param file!\n", __func__, ret);
> +		filp_close(filp, NULL);
> +	}
> +
> +	if ('Y' == *buf)
> +		result = true;
> +
> +	return result;
> +}
> +
> +static void aput_acpi_cpc(u32 index)
> +{
> +	if (acpi_cpc_valid())
> +		aput_cases[index].result = APUT_RESULT_PASS;
> +	else
> +		aput_cases[index].result = APUT_RESULT_FAIL;
> +}
> +
> +static void aput_pstate_enable(u32 index)
> +{
> +	int ret = 0;
> +	u64 cppc_enable = 0;
> +
> +	ret = rdmsrl_safe(MSR_AMD_CPPC_ENABLE, &cppc_enable);
> +	if (ret) {
> +		aput_cases[index].result = APUT_RESULT_FAIL;
> +		pr_err("%s rdmsrl_safe MSR_AMD_CPPC_ENABLE ret=%d is error!\n", __func__, ret);
> +		return;
> +	}
> +	if (cppc_enable)
> +		aput_cases[index].result = APUT_RESULT_PASS;
> +	else
> +		aput_cases[index].result = APUT_RESULT_FAIL;
> +}
> +
> +/*
> + *Check if enabled amd pstate
> + */
> +static void aput_check_enabled(u32 index)
> +{
> +	if (get_shared_mem())
> +		aput_cases[index].result = APUT_RESULT_PASS;
> +	else
> +		aput_pstate_enable(index);
> +}
> +
> +/*
> + * Check if the each performance values are reasonable.
> + * highest_perf >= nominal_perf > lowest_nonlinear_perf > lowest_perf > 0
> + */
> +static void aput_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) {
> +				aput_cases[index].result = APUT_RESULT_FAIL;
> +				pr_err("%s cppc_get_perf_caps ret=%d is 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) {
> +				aput_cases[index].result = APUT_RESULT_FAIL;
> +				pr_err("%s read CPPC_CAP1 ret=%d is 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))) {
> +			aput_cases[index].result = APUT_RESULT_FAIL;
> +			pr_err("%s cpu%d highest=%d %d nominal=%d %d lowest_nonlinear=%d %d lowest=%d %d are not 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))) {
> +			aput_cases[index].result = APUT_RESULT_FAIL;
> +			pr_err("%s cpu%d highest=%d nominal=%d lowest_nonlinear=%d lowest=%d have error!\n",
> +				__func__, cpu, highest_perf, nominal_perf,
> +				lowest_nonlinear_perf, lowest_perf);
> +			return;
> +		}
> +	}
> +
> +	aput_cases[index].result = APUT_RESULT_PASS;
> +}
> +
> +/*
> + * Check if the each frequency values are reasonable.
> + * max_freq >= nominal_freq > lowest_nonlinear_freq > min_freq > 0
> + * check max freq when set support boost mode.
> + */
> +static void aput_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))) {
> +			aput_cases[index].result = APUT_RESULT_FAIL;
> +			pr_err("%s cpu%d max=%d nominal=%d lowest_nonlinear=%d min=%d have error!\n",
> +				__func__, cpu, cpudata->max_freq, cpudata->nominal_freq,
> +				cpudata->lowest_nonlinear_freq, cpudata->min_freq);
> +			return;
> +		}
> +
> +		if (cpudata->min_freq != policy->min) {
> +			aput_cases[index].result = APUT_RESULT_FAIL;
> +			pr_err("%s cpu%d cpudata_min_freq=%d policy_min=%d have error!\n",
> +				__func__, cpu, cpudata->min_freq, policy->min);
> +			return;
> +		}
> +
> +		if (cpudata->boost_supported) {
> +			if ((policy->max == cpudata->max_freq) ||
> +					(policy->max == cpudata->nominal_freq))
> +				aput_cases[index].result = APUT_RESULT_PASS;
> +			else {
> +				aput_cases[index].result = APUT_RESULT_FAIL;
> +				pr_err("%s cpu%d policy_max=%d cpu_max=%d cpu_nominal=%d have error!\n",
> +					__func__, cpu, policy->max, cpudata->max_freq,
> +					cpudata->nominal_freq);
> +				return;
> +			}
> +		} else {
> +			aput_cases[index].result = APUT_RESULT_FAIL;
> +			pr_err("%s cpu%d not support boost!\n", __func__, cpu);
> +			return;
> +		}
> +	}
> +}
> +
> +static void aput_do_test_case(void)
> +{
> +	u32 i = 0, arr_size = ARRAY_SIZE(aput_cases);
> +
> +	for (i = 0; i < arr_size; i++) {
> +		pr_info("****** Begin %-5d\t %-20s\t ******\n", i+1, aput_cases[i].name);
> +		aput_cases[i].func(i);
> +		KSTM_CHECK_ZERO(aput_cases[i].result);
> +		pr_info("****** End   %-5d\t %-20s\t ******\n", i+1, aput_cases[i].name);
> +	}
> +}
> +
> +static void __init selftest(void)
> +{
> +	aput_do_test_case();
> +}
> +
> +KSTM_MODULE_LOADERS(amd_pstate_ut);
> +MODULE_AUTHOR("Meng Li <li.meng@amd.com>");
> +MODULE_DESCRIPTION("Unit test for AMD P-state driver");
> +MODULE_LICENSE("GPL");
> diff --git a/tools/testing/selftests/amd-pstate/config b/tools/testing/selftests/amd-pstate/config
> new file mode 100644
> index 000000000000..f43103c9adc4
> --- /dev/null
> +++ b/tools/testing/selftests/amd-pstate/config
> @@ -0,0 +1 @@
> +CONFIG_X86_AMD_PSTATE_UT=m
> -- 
> 2.25.1
>