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20#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21
22#include <linux/clk.h>
23#include <linux/cpu.h>
24#include <linux/cpufreq.h>
25#include <linux/cpumask.h>
26#include <linux/cpu_cooling.h>
27#include <linux/export.h>
28#include <linux/module.h>
29#include <linux/mutex.h>
30#include <linux/of_platform.h>
31#include <linux/pm_opp.h>
32#include <linux/slab.h>
33#include <linux/topology.h>
34#include <linux/types.h>
35
36#include "arm_big_little.h"
37
38
39#define A15_CLUSTER 0
40#define A7_CLUSTER 1
41#define MAX_CLUSTERS 2
42
43#ifdef CONFIG_BL_SWITCHER
44#include <asm/bL_switcher.h>
45static bool bL_switching_enabled;
46#define is_bL_switching_enabled() bL_switching_enabled
47#define set_switching_enabled(x) (bL_switching_enabled = (x))
48#else
49#define is_bL_switching_enabled() false
50#define set_switching_enabled(x) do { } while (0)
51#define bL_switch_request(...) do { } while (0)
52#define bL_switcher_put_enabled() do { } while (0)
53#define bL_switcher_get_enabled() do { } while (0)
54#endif
55
56#define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq)
57#define VIRT_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
58
59static struct thermal_cooling_device *cdev[MAX_CLUSTERS];
60static const struct cpufreq_arm_bL_ops *arm_bL_ops;
61static struct clk *clk[MAX_CLUSTERS];
62static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
63static atomic_t cluster_usage[MAX_CLUSTERS + 1];
64
65static unsigned int clk_big_min;
66static unsigned int clk_little_max;
67
68static DEFINE_PER_CPU(unsigned int, physical_cluster);
69static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);
70
71static struct mutex cluster_lock[MAX_CLUSTERS];
72
73static inline int raw_cpu_to_cluster(int cpu)
74{
75 return topology_physical_package_id(cpu);
76}
77
78static inline int cpu_to_cluster(int cpu)
79{
80 return is_bL_switching_enabled() ?
81 MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
82}
83
84static unsigned int find_cluster_maxfreq(int cluster)
85{
86 int j;
87 u32 max_freq = 0, cpu_freq;
88
89 for_each_online_cpu(j) {
90 cpu_freq = per_cpu(cpu_last_req_freq, j);
91
92 if ((cluster == per_cpu(physical_cluster, j)) &&
93 (max_freq < cpu_freq))
94 max_freq = cpu_freq;
95 }
96
97 pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
98 max_freq);
99
100 return max_freq;
101}
102
103static unsigned int clk_get_cpu_rate(unsigned int cpu)
104{
105 u32 cur_cluster = per_cpu(physical_cluster, cpu);
106 u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;
107
108
109 if (is_bL_switching_enabled())
110 rate = VIRT_FREQ(cur_cluster, rate);
111
112 pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
113 cur_cluster, rate);
114
115 return rate;
116}
117
118static unsigned int bL_cpufreq_get_rate(unsigned int cpu)
119{
120 if (is_bL_switching_enabled()) {
121 pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
122 cpu));
123
124 return per_cpu(cpu_last_req_freq, cpu);
125 } else {
126 return clk_get_cpu_rate(cpu);
127 }
128}
129
130static unsigned int
131bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
132{
133 u32 new_rate, prev_rate;
134 int ret;
135 bool bLs = is_bL_switching_enabled();
136
137 mutex_lock(&cluster_lock[new_cluster]);
138
139 if (bLs) {
140 prev_rate = per_cpu(cpu_last_req_freq, cpu);
141 per_cpu(cpu_last_req_freq, cpu) = rate;
142 per_cpu(physical_cluster, cpu) = new_cluster;
143
144 new_rate = find_cluster_maxfreq(new_cluster);
145 new_rate = ACTUAL_FREQ(new_cluster, new_rate);
146 } else {
147 new_rate = rate;
148 }
149
150 pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
151 __func__, cpu, old_cluster, new_cluster, new_rate);
152
153 ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
154 if (!ret) {
155
156
157
158
159
160
161
162
163 if (clk_get_rate(clk[new_cluster]) != new_rate * 1000)
164 ret = -EIO;
165 }
166
167 if (WARN_ON(ret)) {
168 pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
169 new_cluster);
170 if (bLs) {
171 per_cpu(cpu_last_req_freq, cpu) = prev_rate;
172 per_cpu(physical_cluster, cpu) = old_cluster;
173 }
174
175 mutex_unlock(&cluster_lock[new_cluster]);
176
177 return ret;
178 }
179
180 mutex_unlock(&cluster_lock[new_cluster]);
181
182
183 if (old_cluster != new_cluster) {
184 pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
185 __func__, cpu, old_cluster, new_cluster);
186
187
188 bL_switch_request(cpu, new_cluster);
189
190 mutex_lock(&cluster_lock[old_cluster]);
191
192
193 new_rate = find_cluster_maxfreq(old_cluster);
194 new_rate = ACTUAL_FREQ(old_cluster, new_rate);
195
196 if (new_rate) {
197 pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
198 __func__, old_cluster, new_rate);
199
200 if (clk_set_rate(clk[old_cluster], new_rate * 1000))
201 pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
202 __func__, ret, old_cluster);
203 }
204 mutex_unlock(&cluster_lock[old_cluster]);
205 }
206
207 return 0;
208}
209
210
211static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
212 unsigned int index)
213{
214 u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
215 unsigned int freqs_new;
216 int ret;
217
218 cur_cluster = cpu_to_cluster(cpu);
219 new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
220
221 freqs_new = freq_table[cur_cluster][index].frequency;
222
223 if (is_bL_switching_enabled()) {
224 if ((actual_cluster == A15_CLUSTER) &&
225 (freqs_new < clk_big_min)) {
226 new_cluster = A7_CLUSTER;
227 } else if ((actual_cluster == A7_CLUSTER) &&
228 (freqs_new > clk_little_max)) {
229 new_cluster = A15_CLUSTER;
230 }
231 }
232
233 ret = bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
234
235 if (!ret) {
236 arch_set_freq_scale(policy->related_cpus, freqs_new,
237 policy->cpuinfo.max_freq);
238 }
239
240 return ret;
241}
242
243static inline u32 get_table_count(struct cpufreq_frequency_table *table)
244{
245 int count;
246
247 for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
248 ;
249
250 return count;
251}
252
253
254static inline u32 get_table_min(struct cpufreq_frequency_table *table)
255{
256 struct cpufreq_frequency_table *pos;
257 uint32_t min_freq = ~0;
258 cpufreq_for_each_entry(pos, table)
259 if (pos->frequency < min_freq)
260 min_freq = pos->frequency;
261 return min_freq;
262}
263
264
265static inline u32 get_table_max(struct cpufreq_frequency_table *table)
266{
267 struct cpufreq_frequency_table *pos;
268 uint32_t max_freq = 0;
269 cpufreq_for_each_entry(pos, table)
270 if (pos->frequency > max_freq)
271 max_freq = pos->frequency;
272 return max_freq;
273}
274
275static int merge_cluster_tables(void)
276{
277 int i, j, k = 0, count = 1;
278 struct cpufreq_frequency_table *table;
279
280 for (i = 0; i < MAX_CLUSTERS; i++)
281 count += get_table_count(freq_table[i]);
282
283 table = kcalloc(count, sizeof(*table), GFP_KERNEL);
284 if (!table)
285 return -ENOMEM;
286
287 freq_table[MAX_CLUSTERS] = table;
288
289
290 for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
291 for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
292 j++) {
293 table[k].frequency = VIRT_FREQ(i,
294 freq_table[i][j].frequency);
295 pr_debug("%s: index: %d, freq: %d\n", __func__, k,
296 table[k].frequency);
297 k++;
298 }
299 }
300
301 table[k].driver_data = k;
302 table[k].frequency = CPUFREQ_TABLE_END;
303
304 pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
305
306 return 0;
307}
308
309static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
310 const struct cpumask *cpumask)
311{
312 u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
313
314 if (!freq_table[cluster])
315 return;
316
317 clk_put(clk[cluster]);
318 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
319 if (arm_bL_ops->free_opp_table)
320 arm_bL_ops->free_opp_table(cpumask);
321 dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
322}
323
324static void put_cluster_clk_and_freq_table(struct device *cpu_dev,
325 const struct cpumask *cpumask)
326{
327 u32 cluster = cpu_to_cluster(cpu_dev->id);
328 int i;
329
330 if (atomic_dec_return(&cluster_usage[cluster]))
331 return;
332
333 if (cluster < MAX_CLUSTERS)
334 return _put_cluster_clk_and_freq_table(cpu_dev, cpumask);
335
336 for_each_present_cpu(i) {
337 struct device *cdev = get_cpu_device(i);
338 if (!cdev) {
339 pr_err("%s: failed to get cpu%d device\n", __func__, i);
340 return;
341 }
342
343 _put_cluster_clk_and_freq_table(cdev, cpumask);
344 }
345
346
347 kfree(freq_table[cluster]);
348}
349
350static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
351 const struct cpumask *cpumask)
352{
353 u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
354 int ret;
355
356 if (freq_table[cluster])
357 return 0;
358
359 ret = arm_bL_ops->init_opp_table(cpumask);
360 if (ret) {
361 dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
362 __func__, cpu_dev->id, ret);
363 goto out;
364 }
365
366 ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
367 if (ret) {
368 dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
369 __func__, cpu_dev->id, ret);
370 goto free_opp_table;
371 }
372
373 clk[cluster] = clk_get(cpu_dev, NULL);
374 if (!IS_ERR(clk[cluster])) {
375 dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
376 __func__, clk[cluster], freq_table[cluster],
377 cluster);
378 return 0;
379 }
380
381 dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
382 __func__, cpu_dev->id, cluster);
383 ret = PTR_ERR(clk[cluster]);
384 dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
385
386free_opp_table:
387 if (arm_bL_ops->free_opp_table)
388 arm_bL_ops->free_opp_table(cpumask);
389out:
390 dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
391 cluster);
392 return ret;
393}
394
395static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
396 const struct cpumask *cpumask)
397{
398 u32 cluster = cpu_to_cluster(cpu_dev->id);
399 int i, ret;
400
401 if (atomic_inc_return(&cluster_usage[cluster]) != 1)
402 return 0;
403
404 if (cluster < MAX_CLUSTERS) {
405 ret = _get_cluster_clk_and_freq_table(cpu_dev, cpumask);
406 if (ret)
407 atomic_dec(&cluster_usage[cluster]);
408 return ret;
409 }
410
411
412
413
414
415 for_each_present_cpu(i) {
416 struct device *cdev = get_cpu_device(i);
417 if (!cdev) {
418 pr_err("%s: failed to get cpu%d device\n", __func__, i);
419 return -ENODEV;
420 }
421
422 ret = _get_cluster_clk_and_freq_table(cdev, cpumask);
423 if (ret)
424 goto put_clusters;
425 }
426
427 ret = merge_cluster_tables();
428 if (ret)
429 goto put_clusters;
430
431
432 clk_big_min = get_table_min(freq_table[0]);
433 clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
434
435 pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
436 __func__, cluster, clk_big_min, clk_little_max);
437
438 return 0;
439
440put_clusters:
441 for_each_present_cpu(i) {
442 struct device *cdev = get_cpu_device(i);
443 if (!cdev) {
444 pr_err("%s: failed to get cpu%d device\n", __func__, i);
445 return -ENODEV;
446 }
447
448 _put_cluster_clk_and_freq_table(cdev, cpumask);
449 }
450
451 atomic_dec(&cluster_usage[cluster]);
452
453 return ret;
454}
455
456
457static int bL_cpufreq_init(struct cpufreq_policy *policy)
458{
459 u32 cur_cluster = cpu_to_cluster(policy->cpu);
460 struct device *cpu_dev;
461 int ret;
462
463 cpu_dev = get_cpu_device(policy->cpu);
464 if (!cpu_dev) {
465 pr_err("%s: failed to get cpu%d device\n", __func__,
466 policy->cpu);
467 return -ENODEV;
468 }
469
470 if (cur_cluster < MAX_CLUSTERS) {
471 int cpu;
472
473 cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
474
475 for_each_cpu(cpu, policy->cpus)
476 per_cpu(physical_cluster, cpu) = cur_cluster;
477 } else {
478
479 per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
480 }
481
482 ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
483 if (ret)
484 return ret;
485
486 policy->freq_table = freq_table[cur_cluster];
487 policy->cpuinfo.transition_latency =
488 arm_bL_ops->get_transition_latency(cpu_dev);
489
490 if (is_bL_switching_enabled())
491 per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
492
493 dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
494 return 0;
495}
496
497static int bL_cpufreq_exit(struct cpufreq_policy *policy)
498{
499 struct device *cpu_dev;
500 int cur_cluster = cpu_to_cluster(policy->cpu);
501
502 if (cur_cluster < MAX_CLUSTERS) {
503 cpufreq_cooling_unregister(cdev[cur_cluster]);
504 cdev[cur_cluster] = NULL;
505 }
506
507 cpu_dev = get_cpu_device(policy->cpu);
508 if (!cpu_dev) {
509 pr_err("%s: failed to get cpu%d device\n", __func__,
510 policy->cpu);
511 return -ENODEV;
512 }
513
514 put_cluster_clk_and_freq_table(cpu_dev, policy->related_cpus);
515 dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
516
517 return 0;
518}
519
520static void bL_cpufreq_ready(struct cpufreq_policy *policy)
521{
522 int cur_cluster = cpu_to_cluster(policy->cpu);
523
524
525 if (cur_cluster >= MAX_CLUSTERS)
526 return;
527
528 cdev[cur_cluster] = of_cpufreq_cooling_register(policy);
529}
530
531static struct cpufreq_driver bL_cpufreq_driver = {
532 .name = "arm-big-little",
533 .flags = CPUFREQ_STICKY |
534 CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
535 CPUFREQ_NEED_INITIAL_FREQ_CHECK,
536 .verify = cpufreq_generic_frequency_table_verify,
537 .target_index = bL_cpufreq_set_target,
538 .get = bL_cpufreq_get_rate,
539 .init = bL_cpufreq_init,
540 .exit = bL_cpufreq_exit,
541 .ready = bL_cpufreq_ready,
542 .attr = cpufreq_generic_attr,
543};
544
545#ifdef CONFIG_BL_SWITCHER
546static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
547 unsigned long action, void *_arg)
548{
549 pr_debug("%s: action: %ld\n", __func__, action);
550
551 switch (action) {
552 case BL_NOTIFY_PRE_ENABLE:
553 case BL_NOTIFY_PRE_DISABLE:
554 cpufreq_unregister_driver(&bL_cpufreq_driver);
555 break;
556
557 case BL_NOTIFY_POST_ENABLE:
558 set_switching_enabled(true);
559 cpufreq_register_driver(&bL_cpufreq_driver);
560 break;
561
562 case BL_NOTIFY_POST_DISABLE:
563 set_switching_enabled(false);
564 cpufreq_register_driver(&bL_cpufreq_driver);
565 break;
566
567 default:
568 return NOTIFY_DONE;
569 }
570
571 return NOTIFY_OK;
572}
573
574static struct notifier_block bL_switcher_notifier = {
575 .notifier_call = bL_cpufreq_switcher_notifier,
576};
577
578static int __bLs_register_notifier(void)
579{
580 return bL_switcher_register_notifier(&bL_switcher_notifier);
581}
582
583static int __bLs_unregister_notifier(void)
584{
585 return bL_switcher_unregister_notifier(&bL_switcher_notifier);
586}
587#else
588static int __bLs_register_notifier(void) { return 0; }
589static int __bLs_unregister_notifier(void) { return 0; }
590#endif
591
592int bL_cpufreq_register(const struct cpufreq_arm_bL_ops *ops)
593{
594 int ret, i;
595
596 if (arm_bL_ops) {
597 pr_debug("%s: Already registered: %s, exiting\n", __func__,
598 arm_bL_ops->name);
599 return -EBUSY;
600 }
601
602 if (!ops || !strlen(ops->name) || !ops->init_opp_table ||
603 !ops->get_transition_latency) {
604 pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
605 return -ENODEV;
606 }
607
608 arm_bL_ops = ops;
609
610 set_switching_enabled(bL_switcher_get_enabled());
611
612 for (i = 0; i < MAX_CLUSTERS; i++)
613 mutex_init(&cluster_lock[i]);
614
615 ret = cpufreq_register_driver(&bL_cpufreq_driver);
616 if (ret) {
617 pr_info("%s: Failed registering platform driver: %s, err: %d\n",
618 __func__, ops->name, ret);
619 arm_bL_ops = NULL;
620 } else {
621 ret = __bLs_register_notifier();
622 if (ret) {
623 cpufreq_unregister_driver(&bL_cpufreq_driver);
624 arm_bL_ops = NULL;
625 } else {
626 pr_info("%s: Registered platform driver: %s\n",
627 __func__, ops->name);
628 }
629 }
630
631 bL_switcher_put_enabled();
632 return ret;
633}
634EXPORT_SYMBOL_GPL(bL_cpufreq_register);
635
636void bL_cpufreq_unregister(const struct cpufreq_arm_bL_ops *ops)
637{
638 if (arm_bL_ops != ops) {
639 pr_err("%s: Registered with: %s, can't unregister, exiting\n",
640 __func__, arm_bL_ops->name);
641 return;
642 }
643
644 bL_switcher_get_enabled();
645 __bLs_unregister_notifier();
646 cpufreq_unregister_driver(&bL_cpufreq_driver);
647 bL_switcher_put_enabled();
648 pr_info("%s: Un-registered platform driver: %s\n", __func__,
649 arm_bL_ops->name);
650 arm_bL_ops = NULL;
651}
652EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);
653
654MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
655MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver");
656MODULE_LICENSE("GPL v2");
657
