--- /dev/null
+// 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");
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