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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * drivers/cpufreq/cpufreq_ondemand.c
4 *
5 * Copyright (C) 2001 Russell King
6 * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
7 * Jun Nakajima <jun.nakajima@intel.com>
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/cpu.h>
13#include <linux/percpu-defs.h>
14#include <linux/slab.h>
15#include <linux/tick.h>
16#include <linux/sched/cpufreq.h>
17
18#include "cpufreq_ondemand.h"
19
20/* On-demand governor macros */
21#define DEF_FREQUENCY_UP_THRESHOLD (80)
22#define DEF_SAMPLING_DOWN_FACTOR (1)
23#define MAX_SAMPLING_DOWN_FACTOR (100000)
24#define MICRO_FREQUENCY_UP_THRESHOLD (95)
25#define MICRO_FREQUENCY_MIN_SAMPLE_RATE (10000)
26#define MIN_FREQUENCY_UP_THRESHOLD (1)
27#define MAX_FREQUENCY_UP_THRESHOLD (100)
28
29static struct od_ops od_ops;
30
31static unsigned int default_powersave_bias;
32
33/*
34 * Not all CPUs want IO time to be accounted as busy; this depends on how
35 * efficient idling at a higher frequency/voltage is.
36 * Pavel Machek says this is not so for various generations of AMD and old
37 * Intel systems.
38 * Mike Chan (android.com) claims this is also not true for ARM.
39 * Because of this, whitelist specific known (series) of CPUs by default, and
40 * leave all others up to the user.
41 */
42static int should_io_be_busy(void)
43{
44#if defined(CONFIG_X86)
45 /*
46 * For Intel, Core 2 (model 15) and later have an efficient idle.
47 */
48 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
49 boot_cpu_data.x86 == 6 &&
50 boot_cpu_data.x86_model >= 15)
51 return 1;
52#endif
53 return 0;
54}
55
56/*
57 * Find right freq to be set now with powersave_bias on.
58 * Returns the freq_hi to be used right now and will set freq_hi_delay_us,
59 * freq_lo, and freq_lo_delay_us in percpu area for averaging freqs.
60 */
61static unsigned int generic_powersave_bias_target(struct cpufreq_policy *policy,
62 unsigned int freq_next, unsigned int relation)
63{
64 unsigned int freq_req, freq_reduc, freq_avg;
65 unsigned int freq_hi, freq_lo;
66 unsigned int index;
67 unsigned int delay_hi_us;
68 struct policy_dbs_info *policy_dbs = policy->governor_data;
69 struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
70 struct dbs_data *dbs_data = policy_dbs->dbs_data;
71 struct od_dbs_tuners *od_tuners = dbs_data->tuners;
72 struct cpufreq_frequency_table *freq_table = policy->freq_table;
73
74 if (!freq_table) {
75 dbs_info->freq_lo = 0;
76 dbs_info->freq_lo_delay_us = 0;
77 return freq_next;
78 }
79
80 index = cpufreq_frequency_table_target(policy, freq_next, relation);
81 freq_req = freq_table[index].frequency;
82 freq_reduc = freq_req * od_tuners->powersave_bias / 1000;
83 freq_avg = freq_req - freq_reduc;
84
85 /* Find freq bounds for freq_avg in freq_table */
86 index = cpufreq_table_find_index_h(policy, freq_avg);
87 freq_lo = freq_table[index].frequency;
88 index = cpufreq_table_find_index_l(policy, freq_avg);
89 freq_hi = freq_table[index].frequency;
90
91 /* Find out how long we have to be in hi and lo freqs */
92 if (freq_hi == freq_lo) {
93 dbs_info->freq_lo = 0;
94 dbs_info->freq_lo_delay_us = 0;
95 return freq_lo;
96 }
97 delay_hi_us = (freq_avg - freq_lo) * dbs_data->sampling_rate;
98 delay_hi_us += (freq_hi - freq_lo) / 2;
99 delay_hi_us /= freq_hi - freq_lo;
100 dbs_info->freq_hi_delay_us = delay_hi_us;
101 dbs_info->freq_lo = freq_lo;
102 dbs_info->freq_lo_delay_us = dbs_data->sampling_rate - delay_hi_us;
103 return freq_hi;
104}
105
106static void ondemand_powersave_bias_init(struct cpufreq_policy *policy)
107{
108 struct od_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);
109
110 dbs_info->freq_lo = 0;
111}
112
113static void dbs_freq_increase(struct cpufreq_policy *policy, unsigned int freq)
114{
115 struct policy_dbs_info *policy_dbs = policy->governor_data;
116 struct dbs_data *dbs_data = policy_dbs->dbs_data;
117 struct od_dbs_tuners *od_tuners = dbs_data->tuners;
118
119 if (od_tuners->powersave_bias)
120 freq = od_ops.powersave_bias_target(policy, freq,
121 CPUFREQ_RELATION_H);
122 else if (policy->cur == policy->max)
123 return;
124
125 __cpufreq_driver_target(policy, freq, od_tuners->powersave_bias ?
126 CPUFREQ_RELATION_L : CPUFREQ_RELATION_H);
127}
128
129/*
130 * Every sampling_rate, we check, if current idle time is less than 20%
131 * (default), then we try to increase frequency. Else, we adjust the frequency
132 * proportional to load.
133 */
134static void od_update(struct cpufreq_policy *policy)
135{
136 struct policy_dbs_info *policy_dbs = policy->governor_data;
137 struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
138 struct dbs_data *dbs_data = policy_dbs->dbs_data;
139 struct od_dbs_tuners *od_tuners = dbs_data->tuners;
140 unsigned int load = dbs_update(policy);
141
142 dbs_info->freq_lo = 0;
143
144 /* Check for frequency increase */
145 if (load > dbs_data->up_threshold) {
146 /* If switching to max speed, apply sampling_down_factor */
147 if (policy->cur < policy->max)
148 policy_dbs->rate_mult = dbs_data->sampling_down_factor;
149 dbs_freq_increase(policy, policy->max);
150 } else {
151 /* Calculate the next frequency proportional to load */
152 unsigned int freq_next, min_f, max_f;
153
154 min_f = policy->cpuinfo.min_freq;
155 max_f = policy->cpuinfo.max_freq;
156 freq_next = min_f + load * (max_f - min_f) / 100;
157
158 /* No longer fully busy, reset rate_mult */
159 policy_dbs->rate_mult = 1;
160
161 if (od_tuners->powersave_bias)
162 freq_next = od_ops.powersave_bias_target(policy,
163 freq_next,
164 CPUFREQ_RELATION_L);
165
166 __cpufreq_driver_target(policy, freq_next, CPUFREQ_RELATION_C);
167 }
168}
169
170static unsigned int od_dbs_update(struct cpufreq_policy *policy)
171{
172 struct policy_dbs_info *policy_dbs = policy->governor_data;
173 struct dbs_data *dbs_data = policy_dbs->dbs_data;
174 struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
175 int sample_type = dbs_info->sample_type;
176
177 /* Common NORMAL_SAMPLE setup */
178 dbs_info->sample_type = OD_NORMAL_SAMPLE;
179 /*
180 * OD_SUB_SAMPLE doesn't make sense if sample_delay_ns is 0, so ignore
181 * it then.
182 */
183 if (sample_type == OD_SUB_SAMPLE && policy_dbs->sample_delay_ns > 0) {
184 __cpufreq_driver_target(policy, dbs_info->freq_lo,
185 CPUFREQ_RELATION_H);
186 return dbs_info->freq_lo_delay_us;
187 }
188
189 od_update(policy);
190
191 if (dbs_info->freq_lo) {
192 /* Setup SUB_SAMPLE */
193 dbs_info->sample_type = OD_SUB_SAMPLE;
194 return dbs_info->freq_hi_delay_us;
195 }
196
197 return dbs_data->sampling_rate * policy_dbs->rate_mult;
198}
199
200/************************** sysfs interface ************************/
201static struct dbs_governor od_dbs_gov;
202
203static ssize_t store_io_is_busy(struct gov_attr_set *attr_set, const char *buf,
204 size_t count)
205{
206 struct dbs_data *dbs_data = to_dbs_data(attr_set);
207 unsigned int input;
208 int ret;
209
210 ret = sscanf(buf, "%u", &input);
211 if (ret != 1)
212 return -EINVAL;
213 dbs_data->io_is_busy = !!input;
214
215 /* we need to re-evaluate prev_cpu_idle */
216 gov_update_cpu_data(dbs_data);
217
218 return count;
219}
220
221static ssize_t store_up_threshold(struct gov_attr_set *attr_set,
222 const char *buf, size_t count)
223{
224 struct dbs_data *dbs_data = to_dbs_data(attr_set);
225 unsigned int input;
226 int ret;
227 ret = sscanf(buf, "%u", &input);
228
229 if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD ||
230 input < MIN_FREQUENCY_UP_THRESHOLD) {
231 return -EINVAL;
232 }
233
234 dbs_data->up_threshold = input;
235 return count;
236}
237
238static ssize_t store_sampling_down_factor(struct gov_attr_set *attr_set,
239 const char *buf, size_t count)
240{
241 struct dbs_data *dbs_data = to_dbs_data(attr_set);
242 struct policy_dbs_info *policy_dbs;
243 unsigned int input;
244 int ret;
245 ret = sscanf(buf, "%u", &input);
246
247 if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
248 return -EINVAL;
249
250 dbs_data->sampling_down_factor = input;
251
252 /* Reset down sampling multiplier in case it was active */
253 list_for_each_entry(policy_dbs, &attr_set->policy_list, list) {
254 /*
255 * Doing this without locking might lead to using different
256 * rate_mult values in od_update() and od_dbs_update().
257 */
258 mutex_lock(&policy_dbs->update_mutex);
259 policy_dbs->rate_mult = 1;
260 mutex_unlock(&policy_dbs->update_mutex);
261 }
262
263 return count;
264}
265
266static ssize_t store_ignore_nice_load(struct gov_attr_set *attr_set,
267 const char *buf, size_t count)
268{
269 struct dbs_data *dbs_data = to_dbs_data(attr_set);
270 unsigned int input;
271 int ret;
272
273 ret = sscanf(buf, "%u", &input);
274 if (ret != 1)
275 return -EINVAL;
276
277 if (input > 1)
278 input = 1;
279
280 if (input == dbs_data->ignore_nice_load) { /* nothing to do */
281 return count;
282 }
283 dbs_data->ignore_nice_load = input;
284
285 /* we need to re-evaluate prev_cpu_idle */
286 gov_update_cpu_data(dbs_data);
287
288 return count;
289}
290
291static ssize_t store_powersave_bias(struct gov_attr_set *attr_set,
292 const char *buf, size_t count)
293{
294 struct dbs_data *dbs_data = to_dbs_data(attr_set);
295 struct od_dbs_tuners *od_tuners = dbs_data->tuners;
296 struct policy_dbs_info *policy_dbs;
297 unsigned int input;
298 int ret;
299 ret = sscanf(buf, "%u", &input);
300
301 if (ret != 1)
302 return -EINVAL;
303
304 if (input > 1000)
305 input = 1000;
306
307 od_tuners->powersave_bias = input;
308
309 list_for_each_entry(policy_dbs, &attr_set->policy_list, list)
310 ondemand_powersave_bias_init(policy_dbs->policy);
311
312 return count;
313}
314
315gov_show_one_common(sampling_rate);
316gov_show_one_common(up_threshold);
317gov_show_one_common(sampling_down_factor);
318gov_show_one_common(ignore_nice_load);
319gov_show_one_common(io_is_busy);
320gov_show_one(od, powersave_bias);
321
322gov_attr_rw(sampling_rate);
323gov_attr_rw(io_is_busy);
324gov_attr_rw(up_threshold);
325gov_attr_rw(sampling_down_factor);
326gov_attr_rw(ignore_nice_load);
327gov_attr_rw(powersave_bias);
328
329static struct attribute *od_attributes[] = {
330 &sampling_rate.attr,
331 &up_threshold.attr,
332 &sampling_down_factor.attr,
333 &ignore_nice_load.attr,
334 &powersave_bias.attr,
335 &io_is_busy.attr,
336 NULL
337};
338
339/************************** sysfs end ************************/
340
341static struct policy_dbs_info *od_alloc(void)
342{
343 struct od_policy_dbs_info *dbs_info;
344
345 dbs_info = kzalloc(sizeof(*dbs_info), GFP_KERNEL);
346 return dbs_info ? &dbs_info->policy_dbs : NULL;
347}
348
349static void od_free(struct policy_dbs_info *policy_dbs)
350{
351 kfree(to_dbs_info(policy_dbs));
352}
353
354static int od_init(struct dbs_data *dbs_data)
355{
356 struct od_dbs_tuners *tuners;
357 u64 idle_time;
358 int cpu;
359
360 tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
361 if (!tuners)
362 return -ENOMEM;
363
364 cpu = get_cpu();
365 idle_time = get_cpu_idle_time_us(cpu, NULL);
366 put_cpu();
367 if (idle_time != -1ULL) {
368 /* Idle micro accounting is supported. Use finer thresholds */
369 dbs_data->up_threshold = MICRO_FREQUENCY_UP_THRESHOLD;
370 } else {
371 dbs_data->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
372 }
373
374 dbs_data->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
375 dbs_data->ignore_nice_load = 0;
376 tuners->powersave_bias = default_powersave_bias;
377 dbs_data->io_is_busy = should_io_be_busy();
378
379 dbs_data->tuners = tuners;
380 return 0;
381}
382
383static void od_exit(struct dbs_data *dbs_data)
384{
385 kfree(dbs_data->tuners);
386}
387
388static void od_start(struct cpufreq_policy *policy)
389{
390 struct od_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);
391
392 dbs_info->sample_type = OD_NORMAL_SAMPLE;
393 ondemand_powersave_bias_init(policy);
394}
395
396static struct od_ops od_ops = {
397 .powersave_bias_target = generic_powersave_bias_target,
398};
399
400static struct dbs_governor od_dbs_gov = {
401 .gov = CPUFREQ_DBS_GOVERNOR_INITIALIZER("ondemand"),
402 .kobj_type = { .default_attrs = od_attributes },
403 .gov_dbs_update = od_dbs_update,
404 .alloc = od_alloc,
405 .free = od_free,
406 .init = od_init,
407 .exit = od_exit,
408 .start = od_start,
409};
410
411#define CPU_FREQ_GOV_ONDEMAND (od_dbs_gov.gov)
412
413static void od_set_powersave_bias(unsigned int powersave_bias)
414{
415 unsigned int cpu;
416 cpumask_t done;
417
418 default_powersave_bias = powersave_bias;
419 cpumask_clear(&done);
420
421 get_online_cpus();
422 for_each_online_cpu(cpu) {
423 struct cpufreq_policy *policy;
424 struct policy_dbs_info *policy_dbs;
425 struct dbs_data *dbs_data;
426 struct od_dbs_tuners *od_tuners;
427
428 if (cpumask_test_cpu(cpu, &done))
429 continue;
430
431 policy = cpufreq_cpu_get_raw(cpu);
432 if (!policy || policy->governor != &CPU_FREQ_GOV_ONDEMAND)
433 continue;
434
435 policy_dbs = policy->governor_data;
436 if (!policy_dbs)
437 continue;
438
439 cpumask_or(&done, &done, policy->cpus);
440
441 dbs_data = policy_dbs->dbs_data;
442 od_tuners = dbs_data->tuners;
443 od_tuners->powersave_bias = default_powersave_bias;
444 }
445 put_online_cpus();
446}
447
448void od_register_powersave_bias_handler(unsigned int (*f)
449 (struct cpufreq_policy *, unsigned int, unsigned int),
450 unsigned int powersave_bias)
451{
452 od_ops.powersave_bias_target = f;
453 od_set_powersave_bias(powersave_bias);
454}
455EXPORT_SYMBOL_GPL(od_register_powersave_bias_handler);
456
457void od_unregister_powersave_bias_handler(void)
458{
459 od_ops.powersave_bias_target = generic_powersave_bias_target;
460 od_set_powersave_bias(0);
461}
462EXPORT_SYMBOL_GPL(od_unregister_powersave_bias_handler);
463
464MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>");
465MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>");
466MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for "
467 "Low Latency Frequency Transition capable processors");
468MODULE_LICENSE("GPL");
469
470#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
471struct cpufreq_governor *cpufreq_default_governor(void)
472{
473 return &CPU_FREQ_GOV_ONDEMAND;
474}
475#endif
476
477cpufreq_governor_init(CPU_FREQ_GOV_ONDEMAND);
478cpufreq_governor_exit(CPU_FREQ_GOV_ONDEMAND);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * drivers/cpufreq/cpufreq_ondemand.c
4 *
5 * Copyright (C) 2001 Russell King
6 * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
7 * Jun Nakajima <jun.nakajima@intel.com>
8 */
9
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/cpu.h>
13#include <linux/percpu-defs.h>
14#include <linux/slab.h>
15#include <linux/tick.h>
16#include <linux/sched/cpufreq.h>
17
18#include "cpufreq_ondemand.h"
19
20/* On-demand governor macros */
21#define DEF_FREQUENCY_UP_THRESHOLD (80)
22#define DEF_SAMPLING_DOWN_FACTOR (1)
23#define MAX_SAMPLING_DOWN_FACTOR (100000)
24#define MICRO_FREQUENCY_UP_THRESHOLD (95)
25#define MICRO_FREQUENCY_MIN_SAMPLE_RATE (10000)
26#define MIN_FREQUENCY_UP_THRESHOLD (1)
27#define MAX_FREQUENCY_UP_THRESHOLD (100)
28
29static struct od_ops od_ops;
30
31static unsigned int default_powersave_bias;
32
33/*
34 * Not all CPUs want IO time to be accounted as busy; this depends on how
35 * efficient idling at a higher frequency/voltage is.
36 * Pavel Machek says this is not so for various generations of AMD and old
37 * Intel systems.
38 * Mike Chan (android.com) claims this is also not true for ARM.
39 * Because of this, whitelist specific known (series) of CPUs by default, and
40 * leave all others up to the user.
41 */
42static int should_io_be_busy(void)
43{
44#if defined(CONFIG_X86)
45 /*
46 * For Intel, Core 2 (model 15) and later have an efficient idle.
47 */
48 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
49 boot_cpu_data.x86 == 6 &&
50 boot_cpu_data.x86_model >= 15)
51 return 1;
52#endif
53 return 0;
54}
55
56/*
57 * Find right freq to be set now with powersave_bias on.
58 * Returns the freq_hi to be used right now and will set freq_hi_delay_us,
59 * freq_lo, and freq_lo_delay_us in percpu area for averaging freqs.
60 */
61static unsigned int generic_powersave_bias_target(struct cpufreq_policy *policy,
62 unsigned int freq_next, unsigned int relation)
63{
64 unsigned int freq_req, freq_reduc, freq_avg;
65 unsigned int freq_hi, freq_lo;
66 unsigned int index;
67 unsigned int delay_hi_us;
68 struct policy_dbs_info *policy_dbs = policy->governor_data;
69 struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
70 struct dbs_data *dbs_data = policy_dbs->dbs_data;
71 struct od_dbs_tuners *od_tuners = dbs_data->tuners;
72 struct cpufreq_frequency_table *freq_table = policy->freq_table;
73
74 if (!freq_table) {
75 dbs_info->freq_lo = 0;
76 dbs_info->freq_lo_delay_us = 0;
77 return freq_next;
78 }
79
80 index = cpufreq_frequency_table_target(policy, freq_next, relation);
81 freq_req = freq_table[index].frequency;
82 freq_reduc = freq_req * od_tuners->powersave_bias / 1000;
83 freq_avg = freq_req - freq_reduc;
84
85 /* Find freq bounds for freq_avg in freq_table */
86 index = cpufreq_table_find_index_h(policy, freq_avg);
87 freq_lo = freq_table[index].frequency;
88 index = cpufreq_table_find_index_l(policy, freq_avg);
89 freq_hi = freq_table[index].frequency;
90
91 /* Find out how long we have to be in hi and lo freqs */
92 if (freq_hi == freq_lo) {
93 dbs_info->freq_lo = 0;
94 dbs_info->freq_lo_delay_us = 0;
95 return freq_lo;
96 }
97 delay_hi_us = (freq_avg - freq_lo) * dbs_data->sampling_rate;
98 delay_hi_us += (freq_hi - freq_lo) / 2;
99 delay_hi_us /= freq_hi - freq_lo;
100 dbs_info->freq_hi_delay_us = delay_hi_us;
101 dbs_info->freq_lo = freq_lo;
102 dbs_info->freq_lo_delay_us = dbs_data->sampling_rate - delay_hi_us;
103 return freq_hi;
104}
105
106static void ondemand_powersave_bias_init(struct cpufreq_policy *policy)
107{
108 struct od_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);
109
110 dbs_info->freq_lo = 0;
111}
112
113static void dbs_freq_increase(struct cpufreq_policy *policy, unsigned int freq)
114{
115 struct policy_dbs_info *policy_dbs = policy->governor_data;
116 struct dbs_data *dbs_data = policy_dbs->dbs_data;
117 struct od_dbs_tuners *od_tuners = dbs_data->tuners;
118
119 if (od_tuners->powersave_bias)
120 freq = od_ops.powersave_bias_target(policy, freq,
121 CPUFREQ_RELATION_H);
122 else if (policy->cur == policy->max)
123 return;
124
125 __cpufreq_driver_target(policy, freq, od_tuners->powersave_bias ?
126 CPUFREQ_RELATION_L : CPUFREQ_RELATION_H);
127}
128
129/*
130 * Every sampling_rate, we check, if current idle time is less than 20%
131 * (default), then we try to increase frequency. Else, we adjust the frequency
132 * proportional to load.
133 */
134static void od_update(struct cpufreq_policy *policy)
135{
136 struct policy_dbs_info *policy_dbs = policy->governor_data;
137 struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
138 struct dbs_data *dbs_data = policy_dbs->dbs_data;
139 struct od_dbs_tuners *od_tuners = dbs_data->tuners;
140 unsigned int load = dbs_update(policy);
141
142 dbs_info->freq_lo = 0;
143
144 /* Check for frequency increase */
145 if (load > dbs_data->up_threshold) {
146 /* If switching to max speed, apply sampling_down_factor */
147 if (policy->cur < policy->max)
148 policy_dbs->rate_mult = dbs_data->sampling_down_factor;
149 dbs_freq_increase(policy, policy->max);
150 } else {
151 /* Calculate the next frequency proportional to load */
152 unsigned int freq_next, min_f, max_f;
153
154 min_f = policy->cpuinfo.min_freq;
155 max_f = policy->cpuinfo.max_freq;
156 freq_next = min_f + load * (max_f - min_f) / 100;
157
158 /* No longer fully busy, reset rate_mult */
159 policy_dbs->rate_mult = 1;
160
161 if (od_tuners->powersave_bias)
162 freq_next = od_ops.powersave_bias_target(policy,
163 freq_next,
164 CPUFREQ_RELATION_L);
165
166 __cpufreq_driver_target(policy, freq_next, CPUFREQ_RELATION_C);
167 }
168}
169
170static unsigned int od_dbs_update(struct cpufreq_policy *policy)
171{
172 struct policy_dbs_info *policy_dbs = policy->governor_data;
173 struct dbs_data *dbs_data = policy_dbs->dbs_data;
174 struct od_policy_dbs_info *dbs_info = to_dbs_info(policy_dbs);
175 int sample_type = dbs_info->sample_type;
176
177 /* Common NORMAL_SAMPLE setup */
178 dbs_info->sample_type = OD_NORMAL_SAMPLE;
179 /*
180 * OD_SUB_SAMPLE doesn't make sense if sample_delay_ns is 0, so ignore
181 * it then.
182 */
183 if (sample_type == OD_SUB_SAMPLE && policy_dbs->sample_delay_ns > 0) {
184 __cpufreq_driver_target(policy, dbs_info->freq_lo,
185 CPUFREQ_RELATION_H);
186 return dbs_info->freq_lo_delay_us;
187 }
188
189 od_update(policy);
190
191 if (dbs_info->freq_lo) {
192 /* Setup SUB_SAMPLE */
193 dbs_info->sample_type = OD_SUB_SAMPLE;
194 return dbs_info->freq_hi_delay_us;
195 }
196
197 return dbs_data->sampling_rate * policy_dbs->rate_mult;
198}
199
200/************************** sysfs interface ************************/
201static struct dbs_governor od_dbs_gov;
202
203static ssize_t store_io_is_busy(struct gov_attr_set *attr_set, const char *buf,
204 size_t count)
205{
206 struct dbs_data *dbs_data = to_dbs_data(attr_set);
207 unsigned int input;
208 int ret;
209
210 ret = sscanf(buf, "%u", &input);
211 if (ret != 1)
212 return -EINVAL;
213 dbs_data->io_is_busy = !!input;
214
215 /* we need to re-evaluate prev_cpu_idle */
216 gov_update_cpu_data(dbs_data);
217
218 return count;
219}
220
221static ssize_t store_up_threshold(struct gov_attr_set *attr_set,
222 const char *buf, size_t count)
223{
224 struct dbs_data *dbs_data = to_dbs_data(attr_set);
225 unsigned int input;
226 int ret;
227 ret = sscanf(buf, "%u", &input);
228
229 if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD ||
230 input < MIN_FREQUENCY_UP_THRESHOLD) {
231 return -EINVAL;
232 }
233
234 dbs_data->up_threshold = input;
235 return count;
236}
237
238static ssize_t store_sampling_down_factor(struct gov_attr_set *attr_set,
239 const char *buf, size_t count)
240{
241 struct dbs_data *dbs_data = to_dbs_data(attr_set);
242 struct policy_dbs_info *policy_dbs;
243 unsigned int input;
244 int ret;
245 ret = sscanf(buf, "%u", &input);
246
247 if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
248 return -EINVAL;
249
250 dbs_data->sampling_down_factor = input;
251
252 /* Reset down sampling multiplier in case it was active */
253 list_for_each_entry(policy_dbs, &attr_set->policy_list, list) {
254 /*
255 * Doing this without locking might lead to using different
256 * rate_mult values in od_update() and od_dbs_update().
257 */
258 mutex_lock(&policy_dbs->update_mutex);
259 policy_dbs->rate_mult = 1;
260 mutex_unlock(&policy_dbs->update_mutex);
261 }
262
263 return count;
264}
265
266static ssize_t store_ignore_nice_load(struct gov_attr_set *attr_set,
267 const char *buf, size_t count)
268{
269 struct dbs_data *dbs_data = to_dbs_data(attr_set);
270 unsigned int input;
271 int ret;
272
273 ret = sscanf(buf, "%u", &input);
274 if (ret != 1)
275 return -EINVAL;
276
277 if (input > 1)
278 input = 1;
279
280 if (input == dbs_data->ignore_nice_load) { /* nothing to do */
281 return count;
282 }
283 dbs_data->ignore_nice_load = input;
284
285 /* we need to re-evaluate prev_cpu_idle */
286 gov_update_cpu_data(dbs_data);
287
288 return count;
289}
290
291static ssize_t store_powersave_bias(struct gov_attr_set *attr_set,
292 const char *buf, size_t count)
293{
294 struct dbs_data *dbs_data = to_dbs_data(attr_set);
295 struct od_dbs_tuners *od_tuners = dbs_data->tuners;
296 struct policy_dbs_info *policy_dbs;
297 unsigned int input;
298 int ret;
299 ret = sscanf(buf, "%u", &input);
300
301 if (ret != 1)
302 return -EINVAL;
303
304 if (input > 1000)
305 input = 1000;
306
307 od_tuners->powersave_bias = input;
308
309 list_for_each_entry(policy_dbs, &attr_set->policy_list, list)
310 ondemand_powersave_bias_init(policy_dbs->policy);
311
312 return count;
313}
314
315gov_show_one_common(sampling_rate);
316gov_show_one_common(up_threshold);
317gov_show_one_common(sampling_down_factor);
318gov_show_one_common(ignore_nice_load);
319gov_show_one_common(io_is_busy);
320gov_show_one(od, powersave_bias);
321
322gov_attr_rw(sampling_rate);
323gov_attr_rw(io_is_busy);
324gov_attr_rw(up_threshold);
325gov_attr_rw(sampling_down_factor);
326gov_attr_rw(ignore_nice_load);
327gov_attr_rw(powersave_bias);
328
329static struct attribute *od_attributes[] = {
330 &sampling_rate.attr,
331 &up_threshold.attr,
332 &sampling_down_factor.attr,
333 &ignore_nice_load.attr,
334 &powersave_bias.attr,
335 &io_is_busy.attr,
336 NULL
337};
338
339/************************** sysfs end ************************/
340
341static struct policy_dbs_info *od_alloc(void)
342{
343 struct od_policy_dbs_info *dbs_info;
344
345 dbs_info = kzalloc(sizeof(*dbs_info), GFP_KERNEL);
346 return dbs_info ? &dbs_info->policy_dbs : NULL;
347}
348
349static void od_free(struct policy_dbs_info *policy_dbs)
350{
351 kfree(to_dbs_info(policy_dbs));
352}
353
354static int od_init(struct dbs_data *dbs_data)
355{
356 struct od_dbs_tuners *tuners;
357 u64 idle_time;
358 int cpu;
359
360 tuners = kzalloc(sizeof(*tuners), GFP_KERNEL);
361 if (!tuners)
362 return -ENOMEM;
363
364 cpu = get_cpu();
365 idle_time = get_cpu_idle_time_us(cpu, NULL);
366 put_cpu();
367 if (idle_time != -1ULL) {
368 /* Idle micro accounting is supported. Use finer thresholds */
369 dbs_data->up_threshold = MICRO_FREQUENCY_UP_THRESHOLD;
370 } else {
371 dbs_data->up_threshold = DEF_FREQUENCY_UP_THRESHOLD;
372 }
373
374 dbs_data->sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR;
375 dbs_data->ignore_nice_load = 0;
376 tuners->powersave_bias = default_powersave_bias;
377 dbs_data->io_is_busy = should_io_be_busy();
378
379 dbs_data->tuners = tuners;
380 return 0;
381}
382
383static void od_exit(struct dbs_data *dbs_data)
384{
385 kfree(dbs_data->tuners);
386}
387
388static void od_start(struct cpufreq_policy *policy)
389{
390 struct od_policy_dbs_info *dbs_info = to_dbs_info(policy->governor_data);
391
392 dbs_info->sample_type = OD_NORMAL_SAMPLE;
393 ondemand_powersave_bias_init(policy);
394}
395
396static struct od_ops od_ops = {
397 .powersave_bias_target = generic_powersave_bias_target,
398};
399
400static struct dbs_governor od_dbs_gov = {
401 .gov = CPUFREQ_DBS_GOVERNOR_INITIALIZER("ondemand"),
402 .kobj_type = { .default_attrs = od_attributes },
403 .gov_dbs_update = od_dbs_update,
404 .alloc = od_alloc,
405 .free = od_free,
406 .init = od_init,
407 .exit = od_exit,
408 .start = od_start,
409};
410
411#define CPU_FREQ_GOV_ONDEMAND (&od_dbs_gov.gov)
412
413static void od_set_powersave_bias(unsigned int powersave_bias)
414{
415 unsigned int cpu;
416 cpumask_t done;
417
418 default_powersave_bias = powersave_bias;
419 cpumask_clear(&done);
420
421 get_online_cpus();
422 for_each_online_cpu(cpu) {
423 struct cpufreq_policy *policy;
424 struct policy_dbs_info *policy_dbs;
425 struct dbs_data *dbs_data;
426 struct od_dbs_tuners *od_tuners;
427
428 if (cpumask_test_cpu(cpu, &done))
429 continue;
430
431 policy = cpufreq_cpu_get_raw(cpu);
432 if (!policy || policy->governor != CPU_FREQ_GOV_ONDEMAND)
433 continue;
434
435 policy_dbs = policy->governor_data;
436 if (!policy_dbs)
437 continue;
438
439 cpumask_or(&done, &done, policy->cpus);
440
441 dbs_data = policy_dbs->dbs_data;
442 od_tuners = dbs_data->tuners;
443 od_tuners->powersave_bias = default_powersave_bias;
444 }
445 put_online_cpus();
446}
447
448void od_register_powersave_bias_handler(unsigned int (*f)
449 (struct cpufreq_policy *, unsigned int, unsigned int),
450 unsigned int powersave_bias)
451{
452 od_ops.powersave_bias_target = f;
453 od_set_powersave_bias(powersave_bias);
454}
455EXPORT_SYMBOL_GPL(od_register_powersave_bias_handler);
456
457void od_unregister_powersave_bias_handler(void)
458{
459 od_ops.powersave_bias_target = generic_powersave_bias_target;
460 od_set_powersave_bias(0);
461}
462EXPORT_SYMBOL_GPL(od_unregister_powersave_bias_handler);
463
464static int __init cpufreq_gov_dbs_init(void)
465{
466 return cpufreq_register_governor(CPU_FREQ_GOV_ONDEMAND);
467}
468
469static void __exit cpufreq_gov_dbs_exit(void)
470{
471 cpufreq_unregister_governor(CPU_FREQ_GOV_ONDEMAND);
472}
473
474MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>");
475MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>");
476MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for "
477 "Low Latency Frequency Transition capable processors");
478MODULE_LICENSE("GPL");
479
480#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
481struct cpufreq_governor *cpufreq_default_governor(void)
482{
483 return CPU_FREQ_GOV_ONDEMAND;
484}
485
486fs_initcall(cpufreq_gov_dbs_init);
487#else
488module_init(cpufreq_gov_dbs_init);
489#endif
490module_exit(cpufreq_gov_dbs_exit);