drivers/cpufreq/amd-pstate-ut.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * AMD Processor P-state Frequency Driver Unit Test
   4  *
   5  * Copyright (C) 2022 Advanced Micro Devices, Inc. All Rights Reserved.
   6  *
   7  * Author: Meng Li <li.meng@amd.com>
   8  *
   9  * The AMD P-State Unit Test is a test module for testing the amd-pstate
  10  * driver. 1) It can help all users to verify their processor support
  11  * (SBIOS/Firmware or Hardware). 2) Kernel can have a basic function
  12  * test to avoid the kernel regression during the update. 3) We can
  13  * introduce more functional or performance tests to align the result
  14  * together, it will benefit power and performance scale optimization.
  15  *
  16  * This driver implements basic framework with plans to enhance it with
  17  * additional test cases to improve the depth and coverage of the test.
  18  *
  19  * See Documentation/admin-guide/pm/amd-pstate.rst Unit Tests for
  20  * amd-pstate to get more detail.
  21  */
  22
  23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  24
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/moduleparam.h>
  28 #include <linux/fs.h>
  29
  30 #include <acpi/cppc_acpi.h>
  31
  32 #include "amd-pstate.h"
  33
  34 /*
  35  * Abbreviations:
  36  * amd_pstate_ut: used as a shortform for AMD P-State unit test.
  37  * It helps to keep variable names smaller, simpler
  38  */
  39 enum amd_pstate_ut_result {
  40         AMD_PSTATE_UT_RESULT_PASS,
  41         AMD_PSTATE_UT_RESULT_FAIL,
  42 };
  43
  44 struct amd_pstate_ut_struct {
  45         const char *name;
  46         void (*func)(u32 index);
  47         enum amd_pstate_ut_result result;
  48 };
  49
  50 /*
  51  * Kernel module for testing the AMD P-State unit test
  52  */
  53 static void amd_pstate_ut_acpi_cpc_valid(u32 index);
  54 static void amd_pstate_ut_check_enabled(u32 index);
  55 static void amd_pstate_ut_check_perf(u32 index);
  56 static void amd_pstate_ut_check_freq(u32 index);
  57 static void amd_pstate_ut_check_driver(u32 index);
  58
  59 static struct amd_pstate_ut_struct amd_pstate_ut_cases[] = {
  60         {"amd_pstate_ut_acpi_cpc_valid",   amd_pstate_ut_acpi_cpc_valid   },
  61         {"amd_pstate_ut_check_enabled",    amd_pstate_ut_check_enabled    },
  62         {"amd_pstate_ut_check_perf",       amd_pstate_ut_check_perf       },
  63         {"amd_pstate_ut_check_freq",       amd_pstate_ut_check_freq       },
  64         {"amd_pstate_ut_check_driver",     amd_pstate_ut_check_driver     }
  65 };
  66
  67 static bool get_shared_mem(void)
  68 {
  69         bool result = false;
  70
  71         if (!boot_cpu_has(X86_FEATURE_CPPC))
  72                 result = true;
  73
  74         return result;
  75 }
  76
  77 /*
  78  * check the _CPC object is present in SBIOS.
  79  */
  80 static void amd_pstate_ut_acpi_cpc_valid(u32 index)
  81 {
  82         if (acpi_cpc_valid())
  83                 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
  84         else {
  85                 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
  86                 pr_err("%s the _CPC object is not present in SBIOS!\n", __func__);
  87         }
  88 }
  89
  90 static void amd_pstate_ut_pstate_enable(u32 index)
  91 {
  92         int ret = 0;
  93         u64 cppc_enable = 0;
  94
  95         ret = rdmsrl_safe(MSR_AMD_CPPC_ENABLE, &cppc_enable);
  96         if (ret) {
  97                 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
  98                 pr_err("%s rdmsrl_safe MSR_AMD_CPPC_ENABLE ret=%d error!\n", __func__, ret);
  99                 return;
 100         }
 101         if (cppc_enable)
 102                 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
 103         else {
 104                 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 105                 pr_err("%s amd pstate must be enabled!\n", __func__);
 106         }
 107 }
 108
 109 /*
 110  * check if amd pstate is enabled
 111  */
 112 static void amd_pstate_ut_check_enabled(u32 index)
 113 {
 114         if (get_shared_mem())
 115                 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
 116         else
 117                 amd_pstate_ut_pstate_enable(index);
 118 }
 119
 120 /*
 121  * check if performance values are reasonable.
 122  * highest_perf >= nominal_perf > lowest_nonlinear_perf > lowest_perf > 0
 123  */
 124 static void amd_pstate_ut_check_perf(u32 index)
 125 {
 126         int cpu = 0, ret = 0;
 127         u32 highest_perf = 0, nominal_perf = 0, lowest_nonlinear_perf = 0, lowest_perf = 0;
 128         u64 cap1 = 0;
 129         struct cppc_perf_caps cppc_perf;
 130         struct cpufreq_policy *policy = NULL;
 131         struct amd_cpudata *cpudata = NULL;
 132
 133         for_each_possible_cpu(cpu) {
 134                 policy = cpufreq_cpu_get(cpu);
 135                 if (!policy)
 136                         break;
 137                 cpudata = policy->driver_data;
 138
 139                 if (get_shared_mem()) {
 140                         ret = cppc_get_perf_caps(cpu, &cppc_perf);
 141                         if (ret) {
 142                                 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 143                                 pr_err("%s cppc_get_perf_caps ret=%d error!\n", __func__, ret);
 144                                 goto skip_test;
 145                         }
 146
 147                         highest_perf = cppc_perf.highest_perf;
 148                         nominal_perf = cppc_perf.nominal_perf;
 149                         lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf;
 150                         lowest_perf = cppc_perf.lowest_perf;
 151                 } else {
 152                         ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &cap1);
 153                         if (ret) {
 154                                 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 155                                 pr_err("%s read CPPC_CAP1 ret=%d error!\n", __func__, ret);
 156                                 goto skip_test;
 157                         }
 158
 159                         highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
 160                         nominal_perf = AMD_CPPC_NOMINAL_PERF(cap1);
 161                         lowest_nonlinear_perf = AMD_CPPC_LOWNONLIN_PERF(cap1);
 162                         lowest_perf = AMD_CPPC_LOWEST_PERF(cap1);
 163                 }
 164
 165                 if (highest_perf != READ_ONCE(cpudata->highest_perf) && !cpudata->hw_prefcore) {
 166                         pr_err("%s cpu%d highest=%d %d highest perf doesn't match\n",
 167                                 __func__, cpu, highest_perf, cpudata->highest_perf);
 168                         goto skip_test;
 169                 }
 170                 if ((nominal_perf != READ_ONCE(cpudata->nominal_perf)) ||
 171                         (lowest_nonlinear_perf != READ_ONCE(cpudata->lowest_nonlinear_perf)) ||
 172                         (lowest_perf != READ_ONCE(cpudata->lowest_perf))) {
 173                         amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 174                         pr_err("%s cpu%d nominal=%d %d lowest_nonlinear=%d %d lowest=%d %d, they should be equal!\n",
 175                                 __func__, cpu, nominal_perf, cpudata->nominal_perf,
 176                                 lowest_nonlinear_perf, cpudata->lowest_nonlinear_perf,
 177                                 lowest_perf, cpudata->lowest_perf);
 178                         goto skip_test;
 179                 }
 180
 181                 if (!((highest_perf >= nominal_perf) &&
 182                         (nominal_perf > lowest_nonlinear_perf) &&
 183                         (lowest_nonlinear_perf > lowest_perf) &&
 184                         (lowest_perf > 0))) {
 185                         amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 186                         pr_err("%s cpu%d highest=%d >= nominal=%d > lowest_nonlinear=%d > lowest=%d > 0, the formula is incorrect!\n",
 187                                 __func__, cpu, highest_perf, nominal_perf,
 188                                 lowest_nonlinear_perf, lowest_perf);
 189                         goto skip_test;
 190                 }
 191                 cpufreq_cpu_put(policy);
 192         }
 193
 194         amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
 195         return;
 196 skip_test:
 197         cpufreq_cpu_put(policy);
 198 }
 199
 200 /*
 201  * Check if frequency values are reasonable.
 202  * max_freq >= nominal_freq > lowest_nonlinear_freq > min_freq > 0
 203  * check max freq when set support boost mode.
 204  */
 205 static void amd_pstate_ut_check_freq(u32 index)
 206 {
 207         int cpu = 0;
 208         struct cpufreq_policy *policy = NULL;
 209         struct amd_cpudata *cpudata = NULL;
 210         u32 nominal_freq_khz;
 211
 212         for_each_possible_cpu(cpu) {
 213                 policy = cpufreq_cpu_get(cpu);
 214                 if (!policy)
 215                         break;
 216                 cpudata = policy->driver_data;
 217
 218                 nominal_freq_khz = cpudata->nominal_freq*1000;
 219                 if (!((cpudata->max_freq >= nominal_freq_khz) &&
 220                         (nominal_freq_khz > cpudata->lowest_nonlinear_freq) &&
 221                         (cpudata->lowest_nonlinear_freq > cpudata->min_freq) &&
 222                         (cpudata->min_freq > 0))) {
 223                         amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 224                         pr_err("%s cpu%d max=%d >= nominal=%d > lowest_nonlinear=%d > min=%d > 0, the formula is incorrect!\n",
 225                                 __func__, cpu, cpudata->max_freq, nominal_freq_khz,
 226                                 cpudata->lowest_nonlinear_freq, cpudata->min_freq);
 227                         goto skip_test;
 228                 }
 229
 230                 if (cpudata->lowest_nonlinear_freq != policy->min) {
 231                         amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 232                         pr_err("%s cpu%d cpudata_lowest_nonlinear_freq=%d policy_min=%d, they should be equal!\n",
 233                                 __func__, cpu, cpudata->lowest_nonlinear_freq, policy->min);
 234                         goto skip_test;
 235                 }
 236
 237                 if (cpudata->boost_supported) {
 238                         if ((policy->max == cpudata->max_freq) ||
 239                                         (policy->max == nominal_freq_khz))
 240                                 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
 241                         else {
 242                                 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 243                                 pr_err("%s cpu%d policy_max=%d should be equal cpu_max=%d or cpu_nominal=%d !\n",
 244                                         __func__, cpu, policy->max, cpudata->max_freq,
 245                                         nominal_freq_khz);
 246                                 goto skip_test;
 247                         }
 248                 } else {
 249                         amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
 250                         pr_err("%s cpu%d must support boost!\n", __func__, cpu);
 251                         goto skip_test;
 252                 }
 253                 cpufreq_cpu_put(policy);
 254         }
 255
 256         amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
 257         return;
 258 skip_test:
 259         cpufreq_cpu_put(policy);
 260 }
 261
 262 static int amd_pstate_set_mode(enum amd_pstate_mode mode)
 263 {
 264         const char *mode_str = amd_pstate_get_mode_string(mode);
 265
 266         pr_debug("->setting mode to %s\n", mode_str);
 267
 268         return amd_pstate_update_status(mode_str, strlen(mode_str));
 269 }
 270
 271 static void amd_pstate_ut_check_driver(u32 index)
 272 {
 273         enum amd_pstate_mode mode1, mode2 = AMD_PSTATE_DISABLE;
 274         int ret;
 275
 276         for (mode1 = AMD_PSTATE_DISABLE; mode1 < AMD_PSTATE_MAX; mode1++) {
 277                 ret = amd_pstate_set_mode(mode1);
 278                 if (ret)
 279                         goto out;
 280                 for (mode2 = AMD_PSTATE_DISABLE; mode2 < AMD_PSTATE_MAX; mode2++) {
 281                         if (mode1 == mode2)
 282                                 continue;
 283                         ret = amd_pstate_set_mode(mode2);
 284                         if (ret)
 285                                 goto out;
 286                 }
 287         }
 288 out:
 289         if (ret)
 290                 pr_warn("%s: failed to update status for %s->%s: %d\n", __func__,
 291                         amd_pstate_get_mode_string(mode1),
 292                         amd_pstate_get_mode_string(mode2), ret);
 293
 294         amd_pstate_ut_cases[index].result = ret ?
 295                                             AMD_PSTATE_UT_RESULT_FAIL :
 296                                             AMD_PSTATE_UT_RESULT_PASS;
 297 }
 298
 299 static int __init amd_pstate_ut_init(void)
 300 {
 301         u32 i = 0, arr_size = ARRAY_SIZE(amd_pstate_ut_cases);
 302
 303         for (i = 0; i < arr_size; i++) {
 304                 amd_pstate_ut_cases[i].func(i);
 305                 switch (amd_pstate_ut_cases[i].result) {
 306                 case AMD_PSTATE_UT_RESULT_PASS:
 307                         pr_info("%-4d %-20s\t success!\n", i+1, amd_pstate_ut_cases[i].name);
 308                         break;
 309                 case AMD_PSTATE_UT_RESULT_FAIL:
 310                 default:
 311                         pr_info("%-4d %-20s\t fail!\n", i+1, amd_pstate_ut_cases[i].name);
 312                         break;
 313                 }
 314         }
 315
 316         return 0;
 317 }
 318
 319 static void __exit amd_pstate_ut_exit(void)
 320 {
 321 }
 322
 323 module_init(amd_pstate_ut_init);
 324 module_exit(amd_pstate_ut_exit);
 325
 326 MODULE_AUTHOR("Meng Li <li.meng@amd.com>");
 327 MODULE_DESCRIPTION("AMD P-state driver Test module");
 328 MODULE_LICENSE("GPL");