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1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* | |
3 | * Copyright 2020 Linaro Limited | |
4 | * | |
5 | * Author: Daniel Lezcano <daniel.lezcano@linaro.org> | |
6 | * | |
7 | * The DTPM CPU is based on the energy model. It hooks the CPU in the | |
8 | * DTPM tree which in turns update the power number by propagating the | |
9 | * power number from the CPU energy model information to the parents. | |
10 | * | |
11 | * The association between the power and the performance state, allows | |
12 | * to set the power of the CPU at the OPP granularity. | |
13 | * | |
14 | * The CPU hotplug is supported and the power numbers will be updated | |
15 | * if a CPU is hot plugged / unplugged. | |
16 | */ | |
17 | #include <linux/cpumask.h> | |
18 | #include <linux/cpufreq.h> | |
19 | #include <linux/cpuhotplug.h> | |
20 | #include <linux/dtpm.h> | |
21 | #include <linux/energy_model.h> | |
22 | #include <linux/pm_qos.h> | |
23 | #include <linux/slab.h> | |
24 | #include <linux/units.h> | |
25 | ||
26 | static struct dtpm *__parent; | |
27 | ||
28 | static DEFINE_PER_CPU(struct dtpm *, dtpm_per_cpu); | |
29 | ||
30 | struct dtpm_cpu { | |
31 | struct freq_qos_request qos_req; | |
32 | int cpu; | |
33 | }; | |
34 | ||
35 | /* | |
36 | * When a new CPU is inserted at hotplug or boot time, add the power | |
37 | * contribution and update the dtpm tree. | |
38 | */ | |
39 | static int power_add(struct dtpm *dtpm, struct em_perf_domain *em) | |
40 | { | |
41 | u64 power_min, power_max; | |
42 | ||
43 | power_min = em->table[0].power; | |
44 | power_min *= MICROWATT_PER_MILLIWATT; | |
45 | power_min += dtpm->power_min; | |
46 | ||
47 | power_max = em->table[em->nr_perf_states - 1].power; | |
48 | power_max *= MICROWATT_PER_MILLIWATT; | |
49 | power_max += dtpm->power_max; | |
50 | ||
51 | return dtpm_update_power(dtpm, power_min, power_max); | |
52 | } | |
53 | ||
54 | /* | |
55 | * When a CPU is unplugged, remove its power contribution from the | |
56 | * dtpm tree. | |
57 | */ | |
58 | static int power_sub(struct dtpm *dtpm, struct em_perf_domain *em) | |
59 | { | |
60 | u64 power_min, power_max; | |
61 | ||
62 | power_min = em->table[0].power; | |
63 | power_min *= MICROWATT_PER_MILLIWATT; | |
64 | power_min = dtpm->power_min - power_min; | |
65 | ||
66 | power_max = em->table[em->nr_perf_states - 1].power; | |
67 | power_max *= MICROWATT_PER_MILLIWATT; | |
68 | power_max = dtpm->power_max - power_max; | |
69 | ||
70 | return dtpm_update_power(dtpm, power_min, power_max); | |
71 | } | |
72 | ||
73 | static u64 set_pd_power_limit(struct dtpm *dtpm, u64 power_limit) | |
74 | { | |
75 | struct dtpm_cpu *dtpm_cpu = dtpm->private; | |
76 | struct em_perf_domain *pd; | |
77 | struct cpumask cpus; | |
78 | unsigned long freq; | |
79 | u64 power; | |
80 | int i, nr_cpus; | |
81 | ||
82 | pd = em_cpu_get(dtpm_cpu->cpu); | |
83 | ||
84 | cpumask_and(&cpus, cpu_online_mask, to_cpumask(pd->cpus)); | |
85 | ||
86 | nr_cpus = cpumask_weight(&cpus); | |
87 | ||
88 | for (i = 0; i < pd->nr_perf_states; i++) { | |
89 | ||
90 | power = pd->table[i].power * MICROWATT_PER_MILLIWATT * nr_cpus; | |
91 | ||
92 | if (power > power_limit) | |
93 | break; | |
94 | } | |
95 | ||
96 | freq = pd->table[i - 1].frequency; | |
97 | ||
98 | freq_qos_update_request(&dtpm_cpu->qos_req, freq); | |
99 | ||
100 | power_limit = pd->table[i - 1].power * | |
101 | MICROWATT_PER_MILLIWATT * nr_cpus; | |
102 | ||
103 | return power_limit; | |
104 | } | |
105 | ||
106 | static u64 get_pd_power_uw(struct dtpm *dtpm) | |
107 | { | |
108 | struct dtpm_cpu *dtpm_cpu = dtpm->private; | |
109 | struct em_perf_domain *pd; | |
110 | struct cpumask cpus; | |
111 | unsigned long freq; | |
112 | int i, nr_cpus; | |
113 | ||
114 | pd = em_cpu_get(dtpm_cpu->cpu); | |
115 | freq = cpufreq_quick_get(dtpm_cpu->cpu); | |
116 | cpumask_and(&cpus, cpu_online_mask, to_cpumask(pd->cpus)); | |
117 | nr_cpus = cpumask_weight(&cpus); | |
118 | ||
119 | for (i = 0; i < pd->nr_perf_states; i++) { | |
120 | ||
121 | if (pd->table[i].frequency < freq) | |
122 | continue; | |
123 | ||
124 | return pd->table[i].power * | |
125 | MICROWATT_PER_MILLIWATT * nr_cpus; | |
126 | } | |
127 | ||
128 | return 0; | |
129 | } | |
130 | ||
131 | static void pd_release(struct dtpm *dtpm) | |
132 | { | |
133 | struct dtpm_cpu *dtpm_cpu = dtpm->private; | |
134 | ||
135 | if (freq_qos_request_active(&dtpm_cpu->qos_req)) | |
136 | freq_qos_remove_request(&dtpm_cpu->qos_req); | |
137 | ||
138 | kfree(dtpm_cpu); | |
139 | } | |
140 | ||
141 | static struct dtpm_ops dtpm_ops = { | |
142 | .set_power_uw = set_pd_power_limit, | |
143 | .get_power_uw = get_pd_power_uw, | |
144 | .release = pd_release, | |
145 | }; | |
146 | ||
147 | static int cpuhp_dtpm_cpu_offline(unsigned int cpu) | |
148 | { | |
149 | struct cpufreq_policy *policy; | |
150 | struct em_perf_domain *pd; | |
151 | struct dtpm *dtpm; | |
152 | ||
153 | policy = cpufreq_cpu_get(cpu); | |
154 | ||
155 | if (!policy) | |
156 | return 0; | |
157 | ||
158 | pd = em_cpu_get(cpu); | |
159 | if (!pd) | |
160 | return -EINVAL; | |
161 | ||
162 | dtpm = per_cpu(dtpm_per_cpu, cpu); | |
163 | ||
164 | power_sub(dtpm, pd); | |
165 | ||
166 | if (cpumask_weight(policy->cpus) != 1) | |
167 | return 0; | |
168 | ||
169 | for_each_cpu(cpu, policy->related_cpus) | |
170 | per_cpu(dtpm_per_cpu, cpu) = NULL; | |
171 | ||
172 | dtpm_unregister(dtpm); | |
173 | ||
174 | return 0; | |
175 | } | |
176 | ||
177 | static int cpuhp_dtpm_cpu_online(unsigned int cpu) | |
178 | { | |
179 | struct dtpm *dtpm; | |
180 | struct dtpm_cpu *dtpm_cpu; | |
181 | struct cpufreq_policy *policy; | |
182 | struct em_perf_domain *pd; | |
183 | char name[CPUFREQ_NAME_LEN]; | |
184 | int ret = -ENOMEM; | |
185 | ||
186 | policy = cpufreq_cpu_get(cpu); | |
187 | ||
188 | if (!policy) | |
189 | return 0; | |
190 | ||
191 | pd = em_cpu_get(cpu); | |
192 | if (!pd) | |
193 | return -EINVAL; | |
194 | ||
195 | dtpm = per_cpu(dtpm_per_cpu, cpu); | |
196 | if (dtpm) | |
197 | return power_add(dtpm, pd); | |
198 | ||
199 | dtpm = dtpm_alloc(&dtpm_ops); | |
200 | if (!dtpm) | |
201 | return -EINVAL; | |
202 | ||
66e713fb | 203 | dtpm_cpu = kzalloc(sizeof(*dtpm_cpu), GFP_KERNEL); |
0e8f68d7 DL |
204 | if (!dtpm_cpu) |
205 | goto out_kfree_dtpm; | |
206 | ||
207 | dtpm->private = dtpm_cpu; | |
208 | dtpm_cpu->cpu = cpu; | |
209 | ||
210 | for_each_cpu(cpu, policy->related_cpus) | |
211 | per_cpu(dtpm_per_cpu, cpu) = dtpm; | |
212 | ||
213 | sprintf(name, "cpu%d", dtpm_cpu->cpu); | |
214 | ||
215 | ret = dtpm_register(name, dtpm, __parent); | |
216 | if (ret) | |
217 | goto out_kfree_dtpm_cpu; | |
218 | ||
219 | ret = power_add(dtpm, pd); | |
220 | if (ret) | |
221 | goto out_dtpm_unregister; | |
222 | ||
223 | ret = freq_qos_add_request(&policy->constraints, | |
224 | &dtpm_cpu->qos_req, FREQ_QOS_MAX, | |
225 | pd->table[pd->nr_perf_states - 1].frequency); | |
226 | if (ret) | |
227 | goto out_power_sub; | |
228 | ||
229 | return 0; | |
230 | ||
231 | out_power_sub: | |
232 | power_sub(dtpm, pd); | |
233 | ||
234 | out_dtpm_unregister: | |
235 | dtpm_unregister(dtpm); | |
236 | dtpm_cpu = NULL; | |
237 | dtpm = NULL; | |
238 | ||
239 | out_kfree_dtpm_cpu: | |
240 | for_each_cpu(cpu, policy->related_cpus) | |
241 | per_cpu(dtpm_per_cpu, cpu) = NULL; | |
242 | kfree(dtpm_cpu); | |
243 | ||
244 | out_kfree_dtpm: | |
245 | kfree(dtpm); | |
246 | return ret; | |
247 | } | |
248 | ||
249 | int dtpm_register_cpu(struct dtpm *parent) | |
250 | { | |
251 | __parent = parent; | |
252 | ||
253 | return cpuhp_setup_state(CPUHP_AP_DTPM_CPU_ONLINE, | |
254 | "dtpm_cpu:online", | |
255 | cpuhp_dtpm_cpu_online, | |
256 | cpuhp_dtpm_cpu_offline); | |
257 | } |