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 #include <linux/amd-pstate.h>
30
31 #include <acpi/cppc_acpi.h>
32
33 /*
34 * Abbreviations:
35 * amd_pstate_ut: used as a shortform for AMD P-State unit test.
36 * It helps to keep variable names smaller, simpler
37 */
38 enum amd_pstate_ut_result {
39 AMD_PSTATE_UT_RESULT_PASS,
40 AMD_PSTATE_UT_RESULT_FAIL,
41 };
42
43 struct amd_pstate_ut_struct {
44 const char *name;
45 void (*func)(u32 index);
46 enum amd_pstate_ut_result result;
47 };
48
49 /*
50 * Kernel module for testing the AMD P-State unit test
51 */
52 static void amd_pstate_ut_acpi_cpc_valid(u32 index);
53 static void amd_pstate_ut_check_enabled(u32 index);
54 static void amd_pstate_ut_check_perf(u32 index);
55 static void amd_pstate_ut_check_freq(u32 index);
56
57 static struct amd_pstate_ut_struct amd_pstate_ut_cases[] = {
58 {"amd_pstate_ut_acpi_cpc_valid", amd_pstate_ut_acpi_cpc_valid },
59 {"amd_pstate_ut_check_enabled", amd_pstate_ut_check_enabled },
60 {"amd_pstate_ut_check_perf", amd_pstate_ut_check_perf },
61 {"amd_pstate_ut_check_freq", amd_pstate_ut_check_freq }
62 };
63
get_shared_mem(void)64 static bool get_shared_mem(void)
65 {
66 bool result = false;
67
68 if (!boot_cpu_has(X86_FEATURE_CPPC))
69 result = true;
70
71 return result;
72 }
73
74 /*
75 * check the _CPC object is present in SBIOS.
76 */
amd_pstate_ut_acpi_cpc_valid(u32 index)77 static void amd_pstate_ut_acpi_cpc_valid(u32 index)
78 {
79 if (acpi_cpc_valid())
80 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
81 else {
82 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
83 pr_err("%s the _CPC object is not present in SBIOS!\n", __func__);
84 }
85 }
86
amd_pstate_ut_pstate_enable(u32 index)87 static void amd_pstate_ut_pstate_enable(u32 index)
88 {
89 int ret = 0;
90 u64 cppc_enable = 0;
91
92 ret = rdmsrl_safe(MSR_AMD_CPPC_ENABLE, &cppc_enable);
93 if (ret) {
94 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
95 pr_err("%s rdmsrl_safe MSR_AMD_CPPC_ENABLE ret=%d error!\n", __func__, ret);
96 return;
97 }
98 if (cppc_enable)
99 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
100 else {
101 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
102 pr_err("%s amd pstate must be enabled!\n", __func__);
103 }
104 }
105
106 /*
107 * check if amd pstate is enabled
108 */
amd_pstate_ut_check_enabled(u32 index)109 static void amd_pstate_ut_check_enabled(u32 index)
110 {
111 if (get_shared_mem())
112 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
113 else
114 amd_pstate_ut_pstate_enable(index);
115 }
116
117 /*
118 * check if performance values are reasonable.
119 * highest_perf >= nominal_perf > lowest_nonlinear_perf > lowest_perf > 0
120 */
amd_pstate_ut_check_perf(u32 index)121 static void amd_pstate_ut_check_perf(u32 index)
122 {
123 int cpu = 0, ret = 0;
124 u32 highest_perf = 0, nominal_perf = 0, lowest_nonlinear_perf = 0, lowest_perf = 0;
125 u64 cap1 = 0;
126 struct cppc_perf_caps cppc_perf;
127 struct cpufreq_policy *policy = NULL;
128 struct amd_cpudata *cpudata = NULL;
129
130 for_each_possible_cpu(cpu) {
131 policy = cpufreq_cpu_get(cpu);
132 if (!policy)
133 break;
134 cpudata = policy->driver_data;
135
136 if (get_shared_mem()) {
137 ret = cppc_get_perf_caps(cpu, &cppc_perf);
138 if (ret) {
139 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
140 pr_err("%s cppc_get_perf_caps ret=%d error!\n", __func__, ret);
141 goto skip_test;
142 }
143
144 highest_perf = cppc_perf.highest_perf;
145 nominal_perf = cppc_perf.nominal_perf;
146 lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf;
147 lowest_perf = cppc_perf.lowest_perf;
148 } else {
149 ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &cap1);
150 if (ret) {
151 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
152 pr_err("%s read CPPC_CAP1 ret=%d error!\n", __func__, ret);
153 goto skip_test;
154 }
155
156 highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
157 nominal_perf = AMD_CPPC_NOMINAL_PERF(cap1);
158 lowest_nonlinear_perf = AMD_CPPC_LOWNONLIN_PERF(cap1);
159 lowest_perf = AMD_CPPC_LOWEST_PERF(cap1);
160 }
161
162 if ((highest_perf != READ_ONCE(cpudata->highest_perf)) ||
163 (nominal_perf != READ_ONCE(cpudata->nominal_perf)) ||
164 (lowest_nonlinear_perf != READ_ONCE(cpudata->lowest_nonlinear_perf)) ||
165 (lowest_perf != READ_ONCE(cpudata->lowest_perf))) {
166 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
167 pr_err("%s cpu%d highest=%d %d nominal=%d %d lowest_nonlinear=%d %d lowest=%d %d, they should be equal!\n",
168 __func__, cpu, highest_perf, cpudata->highest_perf,
169 nominal_perf, cpudata->nominal_perf,
170 lowest_nonlinear_perf, cpudata->lowest_nonlinear_perf,
171 lowest_perf, cpudata->lowest_perf);
172 goto skip_test;
173 }
174
175 if (!((highest_perf >= nominal_perf) &&
176 (nominal_perf > lowest_nonlinear_perf) &&
177 (lowest_nonlinear_perf > lowest_perf) &&
178 (lowest_perf > 0))) {
179 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
180 pr_err("%s cpu%d highest=%d >= nominal=%d > lowest_nonlinear=%d > lowest=%d > 0, the formula is incorrect!\n",
181 __func__, cpu, highest_perf, nominal_perf,
182 lowest_nonlinear_perf, lowest_perf);
183 goto skip_test;
184 }
185 cpufreq_cpu_put(policy);
186 }
187
188 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
189 return;
190 skip_test:
191 cpufreq_cpu_put(policy);
192 }
193
194 /*
195 * Check if frequency values are reasonable.
196 * max_freq >= nominal_freq > lowest_nonlinear_freq > min_freq > 0
197 * check max freq when set support boost mode.
198 */
amd_pstate_ut_check_freq(u32 index)199 static void amd_pstate_ut_check_freq(u32 index)
200 {
201 int cpu = 0;
202 struct cpufreq_policy *policy = NULL;
203 struct amd_cpudata *cpudata = NULL;
204
205 for_each_possible_cpu(cpu) {
206 policy = cpufreq_cpu_get(cpu);
207 if (!policy)
208 break;
209 cpudata = policy->driver_data;
210
211 if (!((cpudata->max_freq >= cpudata->nominal_freq) &&
212 (cpudata->nominal_freq > cpudata->lowest_nonlinear_freq) &&
213 (cpudata->lowest_nonlinear_freq > cpudata->min_freq) &&
214 (cpudata->min_freq > 0))) {
215 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
216 pr_err("%s cpu%d max=%d >= nominal=%d > lowest_nonlinear=%d > min=%d > 0, the formula is incorrect!\n",
217 __func__, cpu, cpudata->max_freq, cpudata->nominal_freq,
218 cpudata->lowest_nonlinear_freq, cpudata->min_freq);
219 goto skip_test;
220 }
221
222 if (cpudata->min_freq != policy->min) {
223 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
224 pr_err("%s cpu%d cpudata_min_freq=%d policy_min=%d, they should be equal!\n",
225 __func__, cpu, cpudata->min_freq, policy->min);
226 goto skip_test;
227 }
228
229 if (cpudata->boost_supported) {
230 if ((policy->max == cpudata->max_freq) ||
231 (policy->max == cpudata->nominal_freq))
232 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
233 else {
234 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
235 pr_err("%s cpu%d policy_max=%d should be equal cpu_max=%d or cpu_nominal=%d !\n",
236 __func__, cpu, policy->max, cpudata->max_freq,
237 cpudata->nominal_freq);
238 goto skip_test;
239 }
240 } else {
241 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
242 pr_err("%s cpu%d must support boost!\n", __func__, cpu);
243 goto skip_test;
244 }
245 cpufreq_cpu_put(policy);
246 }
247
248 amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
249 return;
250 skip_test:
251 cpufreq_cpu_put(policy);
252 }
253
amd_pstate_ut_init(void)254 static int __init amd_pstate_ut_init(void)
255 {
256 u32 i = 0, arr_size = ARRAY_SIZE(amd_pstate_ut_cases);
257
258 for (i = 0; i < arr_size; i++) {
259 amd_pstate_ut_cases[i].func(i);
260 switch (amd_pstate_ut_cases[i].result) {
261 case AMD_PSTATE_UT_RESULT_PASS:
262 pr_info("%-4d %-20s\t success!\n", i+1, amd_pstate_ut_cases[i].name);
263 break;
264 case AMD_PSTATE_UT_RESULT_FAIL:
265 default:
266 pr_info("%-4d %-20s\t fail!\n", i+1, amd_pstate_ut_cases[i].name);
267 break;
268 }
269 }
270
271 return 0;
272 }
273
amd_pstate_ut_exit(void)274 static void __exit amd_pstate_ut_exit(void)
275 {
276 }
277
278 module_init(amd_pstate_ut_init);
279 module_exit(amd_pstate_ut_exit);
280
281 MODULE_AUTHOR("Meng Li <li.meng@amd.com>");
282 MODULE_DESCRIPTION("AMD P-state driver Test module");
283 MODULE_LICENSE("GPL");
284