xref: /linux/drivers/cpufreq/amd-pstate-ut.c (revision 3ab7ae8e07f888f223027f0ef84d33e43919ad55)
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/bitfield.h>
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/moduleparam.h>
29 #include <linux/fs.h>
30 #include <linux/cleanup.h>
31 
32 #include <acpi/cppc_acpi.h>
33 
34 #include "amd-pstate.h"
35 
36 
37 struct amd_pstate_ut_struct {
38 	const char *name;
39 	int (*func)(u32 index);
40 };
41 
42 /*
43  * Kernel module for testing the AMD P-State unit test
44  */
45 static int amd_pstate_ut_acpi_cpc_valid(u32 index);
46 static int amd_pstate_ut_check_enabled(u32 index);
47 static int amd_pstate_ut_check_perf(u32 index);
48 static int amd_pstate_ut_check_freq(u32 index);
49 static int amd_pstate_ut_check_driver(u32 index);
50 
51 static struct amd_pstate_ut_struct amd_pstate_ut_cases[] = {
52 	{"amd_pstate_ut_acpi_cpc_valid",   amd_pstate_ut_acpi_cpc_valid   },
53 	{"amd_pstate_ut_check_enabled",    amd_pstate_ut_check_enabled    },
54 	{"amd_pstate_ut_check_perf",       amd_pstate_ut_check_perf       },
55 	{"amd_pstate_ut_check_freq",       amd_pstate_ut_check_freq       },
56 	{"amd_pstate_ut_check_driver",	   amd_pstate_ut_check_driver     }
57 };
58 
59 static bool get_shared_mem(void)
60 {
61 	bool result = false;
62 
63 	if (!boot_cpu_has(X86_FEATURE_CPPC))
64 		result = true;
65 
66 	return result;
67 }
68 
69 /*
70  * check the _CPC object is present in SBIOS.
71  */
72 static int amd_pstate_ut_acpi_cpc_valid(u32 index)
73 {
74 	if (!acpi_cpc_valid()) {
75 		pr_err("%s the _CPC object is not present in SBIOS!\n", __func__);
76 		return -EINVAL;
77 	}
78 
79 	return 0;
80 }
81 
82 /*
83  * check if amd pstate is enabled
84  */
85 static int amd_pstate_ut_check_enabled(u32 index)
86 {
87 	u64 cppc_enable = 0;
88 	int ret;
89 
90 	if (get_shared_mem())
91 		return 0;
92 
93 	ret = rdmsrl_safe(MSR_AMD_CPPC_ENABLE, &cppc_enable);
94 	if (ret) {
95 		pr_err("%s rdmsrl_safe MSR_AMD_CPPC_ENABLE ret=%d error!\n", __func__, ret);
96 		return ret;
97 	}
98 
99 	if (!cppc_enable) {
100 		pr_err("%s amd pstate must be enabled!\n", __func__);
101 		return -EINVAL;
102 	}
103 
104 	return 0;
105 }
106 
107 /*
108  * check if performance values are reasonable.
109  * highest_perf >= nominal_perf > lowest_nonlinear_perf > lowest_perf > 0
110  */
111 static int amd_pstate_ut_check_perf(u32 index)
112 {
113 	int cpu = 0, ret = 0;
114 	u32 highest_perf = 0, nominal_perf = 0, lowest_nonlinear_perf = 0, lowest_perf = 0;
115 	u64 cap1 = 0;
116 	struct cppc_perf_caps cppc_perf;
117 	union perf_cached cur_perf;
118 
119 	for_each_online_cpu(cpu) {
120 		struct cpufreq_policy *policy __free(put_cpufreq_policy) = NULL;
121 		struct amd_cpudata *cpudata;
122 
123 		policy = cpufreq_cpu_get(cpu);
124 		if (!policy)
125 			continue;
126 		cpudata = policy->driver_data;
127 
128 		if (get_shared_mem()) {
129 			ret = cppc_get_perf_caps(cpu, &cppc_perf);
130 			if (ret) {
131 				pr_err("%s cppc_get_perf_caps ret=%d error!\n", __func__, ret);
132 				return ret;
133 			}
134 
135 			highest_perf = cppc_perf.highest_perf;
136 			nominal_perf = cppc_perf.nominal_perf;
137 			lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf;
138 			lowest_perf = cppc_perf.lowest_perf;
139 		} else {
140 			ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &cap1);
141 			if (ret) {
142 				pr_err("%s read CPPC_CAP1 ret=%d error!\n", __func__, ret);
143 				return ret;
144 			}
145 
146 			highest_perf = FIELD_GET(AMD_CPPC_HIGHEST_PERF_MASK, cap1);
147 			nominal_perf = FIELD_GET(AMD_CPPC_NOMINAL_PERF_MASK, cap1);
148 			lowest_nonlinear_perf = FIELD_GET(AMD_CPPC_LOWNONLIN_PERF_MASK, cap1);
149 			lowest_perf = FIELD_GET(AMD_CPPC_LOWEST_PERF_MASK, cap1);
150 		}
151 
152 		cur_perf = READ_ONCE(cpudata->perf);
153 		if (highest_perf != cur_perf.highest_perf && !cpudata->hw_prefcore) {
154 			pr_err("%s cpu%d highest=%d %d highest perf doesn't match\n",
155 				__func__, cpu, highest_perf, cur_perf.highest_perf);
156 			return -EINVAL;
157 		}
158 		if (nominal_perf != cur_perf.nominal_perf ||
159 		   (lowest_nonlinear_perf != cur_perf.lowest_nonlinear_perf) ||
160 		   (lowest_perf != cur_perf.lowest_perf)) {
161 			pr_err("%s cpu%d nominal=%d %d lowest_nonlinear=%d %d lowest=%d %d, they should be equal!\n",
162 				__func__, cpu, nominal_perf, cur_perf.nominal_perf,
163 				lowest_nonlinear_perf, cur_perf.lowest_nonlinear_perf,
164 				lowest_perf, cur_perf.lowest_perf);
165 			return -EINVAL;
166 		}
167 
168 		if (!((highest_perf >= nominal_perf) &&
169 			(nominal_perf > lowest_nonlinear_perf) &&
170 			(lowest_nonlinear_perf >= lowest_perf) &&
171 			(lowest_perf > 0))) {
172 			pr_err("%s cpu%d highest=%d >= nominal=%d > lowest_nonlinear=%d > lowest=%d > 0, the formula is incorrect!\n",
173 				__func__, cpu, highest_perf, nominal_perf,
174 				lowest_nonlinear_perf, lowest_perf);
175 			return -EINVAL;
176 		}
177 	}
178 
179 	return 0;
180 }
181 
182 /*
183  * Check if frequency values are reasonable.
184  * max_freq >= nominal_freq > lowest_nonlinear_freq > min_freq > 0
185  * check max freq when set support boost mode.
186  */
187 static int amd_pstate_ut_check_freq(u32 index)
188 {
189 	int cpu = 0;
190 
191 	for_each_online_cpu(cpu) {
192 		struct cpufreq_policy *policy __free(put_cpufreq_policy) = NULL;
193 		struct amd_cpudata *cpudata;
194 
195 		policy = cpufreq_cpu_get(cpu);
196 		if (!policy)
197 			continue;
198 		cpudata = policy->driver_data;
199 
200 		if (!((policy->cpuinfo.max_freq >= cpudata->nominal_freq) &&
201 			(cpudata->nominal_freq > cpudata->lowest_nonlinear_freq) &&
202 			(cpudata->lowest_nonlinear_freq >= policy->cpuinfo.min_freq) &&
203 			(policy->cpuinfo.min_freq > 0))) {
204 			pr_err("%s cpu%d max=%d >= nominal=%d > lowest_nonlinear=%d > min=%d > 0, the formula is incorrect!\n",
205 				__func__, cpu, policy->cpuinfo.max_freq, cpudata->nominal_freq,
206 				cpudata->lowest_nonlinear_freq, policy->cpuinfo.min_freq);
207 			return -EINVAL;
208 		}
209 
210 		if (cpudata->lowest_nonlinear_freq != policy->min) {
211 			pr_err("%s cpu%d cpudata_lowest_nonlinear_freq=%d policy_min=%d, they should be equal!\n",
212 				__func__, cpu, cpudata->lowest_nonlinear_freq, policy->min);
213 			return -EINVAL;
214 		}
215 
216 		if (cpudata->boost_supported) {
217 			if ((policy->max != policy->cpuinfo.max_freq) &&
218 			    (policy->max != cpudata->nominal_freq)) {
219 				pr_err("%s cpu%d policy_max=%d should be equal cpu_max=%d or cpu_nominal=%d !\n",
220 					__func__, cpu, policy->max, policy->cpuinfo.max_freq,
221 					cpudata->nominal_freq);
222 				return -EINVAL;
223 			}
224 		} else {
225 			pr_err("%s cpu%d must support boost!\n", __func__, cpu);
226 			return -EINVAL;
227 		}
228 	}
229 
230 	return 0;
231 }
232 
233 static int amd_pstate_set_mode(enum amd_pstate_mode mode)
234 {
235 	const char *mode_str = amd_pstate_get_mode_string(mode);
236 
237 	pr_debug("->setting mode to %s\n", mode_str);
238 
239 	return amd_pstate_update_status(mode_str, strlen(mode_str));
240 }
241 
242 static int amd_pstate_ut_check_driver(u32 index)
243 {
244 	enum amd_pstate_mode mode1, mode2 = AMD_PSTATE_DISABLE;
245 
246 	for (mode1 = AMD_PSTATE_DISABLE; mode1 < AMD_PSTATE_MAX; mode1++) {
247 		int ret = amd_pstate_set_mode(mode1);
248 		if (ret)
249 			return ret;
250 		for (mode2 = AMD_PSTATE_DISABLE; mode2 < AMD_PSTATE_MAX; mode2++) {
251 			if (mode1 == mode2)
252 				continue;
253 			ret = amd_pstate_set_mode(mode2);
254 			if (ret) {
255 				pr_err("%s: failed to update status for %s->%s\n", __func__,
256 					amd_pstate_get_mode_string(mode1),
257 					amd_pstate_get_mode_string(mode2));
258 				return ret;
259 			}
260 		}
261 	}
262 
263 	return 0;
264 }
265 
266 static int __init amd_pstate_ut_init(void)
267 {
268 	u32 i = 0, arr_size = ARRAY_SIZE(amd_pstate_ut_cases);
269 
270 	for (i = 0; i < arr_size; i++) {
271 		int ret = amd_pstate_ut_cases[i].func(i);
272 
273 		if (ret)
274 			pr_err("%-4d %-20s\t fail: %d!\n", i+1, amd_pstate_ut_cases[i].name, ret);
275 		else
276 			pr_info("%-4d %-20s\t success!\n", i+1, amd_pstate_ut_cases[i].name);
277 	}
278 
279 	return 0;
280 }
281 
282 static void __exit amd_pstate_ut_exit(void)
283 {
284 }
285 
286 module_init(amd_pstate_ut_init);
287 module_exit(amd_pstate_ut_exit);
288 
289 MODULE_AUTHOR("Meng Li <li.meng@amd.com>");
290 MODULE_DESCRIPTION("AMD P-state driver Test module");
291 MODULE_LICENSE("GPL");
292