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 
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  */
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 
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  */
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  */
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  */
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 
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 
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