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 <[email protected]>
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 
get_shared_mem(void)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  */
amd_pstate_ut_acpi_cpc_valid(u32 index)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 
amd_pstate_ut_pstate_enable(u32 index)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  */
amd_pstate_ut_check_enabled(u32 index)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  */
amd_pstate_ut_check_perf(u32 index)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  */
amd_pstate_ut_check_freq(u32 index)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 
211 	for_each_possible_cpu(cpu) {
212 		policy = cpufreq_cpu_get(cpu);
213 		if (!policy)
214 			break;
215 		cpudata = policy->driver_data;
216 
217 		if (!((cpudata->max_freq >= cpudata->nominal_freq) &&
218 			(cpudata->nominal_freq > cpudata->lowest_nonlinear_freq) &&
219 			(cpudata->lowest_nonlinear_freq > cpudata->min_freq) &&
220 			(cpudata->min_freq > 0))) {
221 			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
222 			pr_err("%s cpu%d max=%d >= nominal=%d > lowest_nonlinear=%d > min=%d > 0, the formula is incorrect!\n",
223 				__func__, cpu, cpudata->max_freq, cpudata->nominal_freq,
224 				cpudata->lowest_nonlinear_freq, cpudata->min_freq);
225 			goto skip_test;
226 		}
227 
228 		if (cpudata->lowest_nonlinear_freq != policy->min) {
229 			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
230 			pr_err("%s cpu%d cpudata_lowest_nonlinear_freq=%d policy_min=%d, they should be equal!\n",
231 				__func__, cpu, cpudata->lowest_nonlinear_freq, policy->min);
232 			goto skip_test;
233 		}
234 
235 		if (cpudata->boost_supported) {
236 			if ((policy->max == cpudata->max_freq) ||
237 					(policy->max == cpudata->nominal_freq))
238 				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
239 			else {
240 				amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
241 				pr_err("%s cpu%d policy_max=%d should be equal cpu_max=%d or cpu_nominal=%d !\n",
242 					__func__, cpu, policy->max, cpudata->max_freq,
243 					cpudata->nominal_freq);
244 				goto skip_test;
245 			}
246 		} else {
247 			amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_FAIL;
248 			pr_err("%s cpu%d must support boost!\n", __func__, cpu);
249 			goto skip_test;
250 		}
251 		cpufreq_cpu_put(policy);
252 	}
253 
254 	amd_pstate_ut_cases[index].result = AMD_PSTATE_UT_RESULT_PASS;
255 	return;
256 skip_test:
257 	cpufreq_cpu_put(policy);
258 }
259 
amd_pstate_set_mode(enum amd_pstate_mode mode)260 static int amd_pstate_set_mode(enum amd_pstate_mode mode)
261 {
262 	const char *mode_str = amd_pstate_get_mode_string(mode);
263 
264 	pr_debug("->setting mode to %s\n", mode_str);
265 
266 	return amd_pstate_update_status(mode_str, strlen(mode_str));
267 }
268 
amd_pstate_ut_check_driver(u32 index)269 static void amd_pstate_ut_check_driver(u32 index)
270 {
271 	enum amd_pstate_mode mode1, mode2 = AMD_PSTATE_DISABLE;
272 	int ret;
273 
274 	for (mode1 = AMD_PSTATE_DISABLE; mode1 < AMD_PSTATE_MAX; mode1++) {
275 		ret = amd_pstate_set_mode(mode1);
276 		if (ret)
277 			goto out;
278 		for (mode2 = AMD_PSTATE_DISABLE; mode2 < AMD_PSTATE_MAX; mode2++) {
279 			if (mode1 == mode2)
280 				continue;
281 			ret = amd_pstate_set_mode(mode2);
282 			if (ret)
283 				goto out;
284 		}
285 	}
286 out:
287 	if (ret)
288 		pr_warn("%s: failed to update status for %s->%s: %d\n", __func__,
289 			amd_pstate_get_mode_string(mode1),
290 			amd_pstate_get_mode_string(mode2), ret);
291 
292 	amd_pstate_ut_cases[index].result = ret ?
293 					    AMD_PSTATE_UT_RESULT_FAIL :
294 					    AMD_PSTATE_UT_RESULT_PASS;
295 }
296 
amd_pstate_ut_init(void)297 static int __init amd_pstate_ut_init(void)
298 {
299 	u32 i = 0, arr_size = ARRAY_SIZE(amd_pstate_ut_cases);
300 
301 	for (i = 0; i < arr_size; i++) {
302 		amd_pstate_ut_cases[i].func(i);
303 		switch (amd_pstate_ut_cases[i].result) {
304 		case AMD_PSTATE_UT_RESULT_PASS:
305 			pr_info("%-4d %-20s\t success!\n", i+1, amd_pstate_ut_cases[i].name);
306 			break;
307 		case AMD_PSTATE_UT_RESULT_FAIL:
308 		default:
309 			pr_info("%-4d %-20s\t fail!\n", i+1, amd_pstate_ut_cases[i].name);
310 			break;
311 		}
312 	}
313 
314 	return 0;
315 }
316 
amd_pstate_ut_exit(void)317 static void __exit amd_pstate_ut_exit(void)
318 {
319 }
320 
321 module_init(amd_pstate_ut_init);
322 module_exit(amd_pstate_ut_exit);
323 
324 MODULE_AUTHOR("Meng Li <[email protected]>");
325 MODULE_DESCRIPTION("AMD P-state driver Test module");
326 MODULE_LICENSE("GPL");
327