Loading...
Note: File does not exist in v3.1.
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * CPPC (Collaborative Processor Performance Control) driver for
4 * interfacing with the CPUfreq layer and governors. See
5 * cppc_acpi.c for CPPC specific methods.
6 *
7 * (C) Copyright 2014, 2015 Linaro Ltd.
8 * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org>
9 */
10
11#define pr_fmt(fmt) "CPPC Cpufreq:" fmt
12
13#include <linux/arch_topology.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/delay.h>
17#include <linux/cpu.h>
18#include <linux/cpufreq.h>
19#include <linux/irq_work.h>
20#include <linux/kthread.h>
21#include <linux/time.h>
22#include <linux/vmalloc.h>
23#include <uapi/linux/sched/types.h>
24
25#include <linux/unaligned.h>
26
27#include <acpi/cppc_acpi.h>
28
29/*
30 * This list contains information parsed from per CPU ACPI _CPC and _PSD
31 * structures: e.g. the highest and lowest supported performance, capabilities,
32 * desired performance, level requested etc. Depending on the share_type, not
33 * all CPUs will have an entry in the list.
34 */
35static LIST_HEAD(cpu_data_list);
36
37static bool boost_supported;
38
39static struct cpufreq_driver cppc_cpufreq_driver;
40
41#ifdef CONFIG_ACPI_CPPC_CPUFREQ_FIE
42static enum {
43 FIE_UNSET = -1,
44 FIE_ENABLED,
45 FIE_DISABLED
46} fie_disabled = FIE_UNSET;
47
48module_param(fie_disabled, int, 0444);
49MODULE_PARM_DESC(fie_disabled, "Disable Frequency Invariance Engine (FIE)");
50
51/* Frequency invariance support */
52struct cppc_freq_invariance {
53 int cpu;
54 struct irq_work irq_work;
55 struct kthread_work work;
56 struct cppc_perf_fb_ctrs prev_perf_fb_ctrs;
57 struct cppc_cpudata *cpu_data;
58};
59
60static DEFINE_PER_CPU(struct cppc_freq_invariance, cppc_freq_inv);
61static struct kthread_worker *kworker_fie;
62
63static int cppc_perf_from_fbctrs(struct cppc_cpudata *cpu_data,
64 struct cppc_perf_fb_ctrs *fb_ctrs_t0,
65 struct cppc_perf_fb_ctrs *fb_ctrs_t1);
66
67/**
68 * cppc_scale_freq_workfn - CPPC arch_freq_scale updater for frequency invariance
69 * @work: The work item.
70 *
71 * The CPPC driver register itself with the topology core to provide its own
72 * implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which
73 * gets called by the scheduler on every tick.
74 *
75 * Note that the arch specific counters have higher priority than CPPC counters,
76 * if available, though the CPPC driver doesn't need to have any special
77 * handling for that.
78 *
79 * On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we
80 * reach here from hard-irq context), which then schedules a normal work item
81 * and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable
82 * based on the counter updates since the last tick.
83 */
84static void cppc_scale_freq_workfn(struct kthread_work *work)
85{
86 struct cppc_freq_invariance *cppc_fi;
87 struct cppc_perf_fb_ctrs fb_ctrs = {0};
88 struct cppc_cpudata *cpu_data;
89 unsigned long local_freq_scale;
90 u64 perf;
91
92 cppc_fi = container_of(work, struct cppc_freq_invariance, work);
93 cpu_data = cppc_fi->cpu_data;
94
95 if (cppc_get_perf_ctrs(cppc_fi->cpu, &fb_ctrs)) {
96 pr_warn("%s: failed to read perf counters\n", __func__);
97 return;
98 }
99
100 perf = cppc_perf_from_fbctrs(cpu_data, &cppc_fi->prev_perf_fb_ctrs,
101 &fb_ctrs);
102 if (!perf)
103 return;
104
105 cppc_fi->prev_perf_fb_ctrs = fb_ctrs;
106
107 perf <<= SCHED_CAPACITY_SHIFT;
108 local_freq_scale = div64_u64(perf, cpu_data->perf_caps.highest_perf);
109
110 /* This can happen due to counter's overflow */
111 if (unlikely(local_freq_scale > 1024))
112 local_freq_scale = 1024;
113
114 per_cpu(arch_freq_scale, cppc_fi->cpu) = local_freq_scale;
115}
116
117static void cppc_irq_work(struct irq_work *irq_work)
118{
119 struct cppc_freq_invariance *cppc_fi;
120
121 cppc_fi = container_of(irq_work, struct cppc_freq_invariance, irq_work);
122 kthread_queue_work(kworker_fie, &cppc_fi->work);
123}
124
125static void cppc_scale_freq_tick(void)
126{
127 struct cppc_freq_invariance *cppc_fi = &per_cpu(cppc_freq_inv, smp_processor_id());
128
129 /*
130 * cppc_get_perf_ctrs() can potentially sleep, call that from the right
131 * context.
132 */
133 irq_work_queue(&cppc_fi->irq_work);
134}
135
136static struct scale_freq_data cppc_sftd = {
137 .source = SCALE_FREQ_SOURCE_CPPC,
138 .set_freq_scale = cppc_scale_freq_tick,
139};
140
141static void cppc_cpufreq_cpu_fie_init(struct cpufreq_policy *policy)
142{
143 struct cppc_freq_invariance *cppc_fi;
144 int cpu, ret;
145
146 if (fie_disabled)
147 return;
148
149 for_each_cpu(cpu, policy->cpus) {
150 cppc_fi = &per_cpu(cppc_freq_inv, cpu);
151 cppc_fi->cpu = cpu;
152 cppc_fi->cpu_data = policy->driver_data;
153 kthread_init_work(&cppc_fi->work, cppc_scale_freq_workfn);
154 init_irq_work(&cppc_fi->irq_work, cppc_irq_work);
155
156 ret = cppc_get_perf_ctrs(cpu, &cppc_fi->prev_perf_fb_ctrs);
157 if (ret) {
158 pr_warn("%s: failed to read perf counters for cpu:%d: %d\n",
159 __func__, cpu, ret);
160
161 /*
162 * Don't abort if the CPU was offline while the driver
163 * was getting registered.
164 */
165 if (cpu_online(cpu))
166 return;
167 }
168 }
169
170 /* Register for freq-invariance */
171 topology_set_scale_freq_source(&cppc_sftd, policy->cpus);
172}
173
174/*
175 * We free all the resources on policy's removal and not on CPU removal as the
176 * irq-work are per-cpu and the hotplug core takes care of flushing the pending
177 * irq-works (hint: smpcfd_dying_cpu()) on CPU hotplug. Even if the kthread-work
178 * fires on another CPU after the concerned CPU is removed, it won't harm.
179 *
180 * We just need to make sure to remove them all on policy->exit().
181 */
182static void cppc_cpufreq_cpu_fie_exit(struct cpufreq_policy *policy)
183{
184 struct cppc_freq_invariance *cppc_fi;
185 int cpu;
186
187 if (fie_disabled)
188 return;
189
190 /* policy->cpus will be empty here, use related_cpus instead */
191 topology_clear_scale_freq_source(SCALE_FREQ_SOURCE_CPPC, policy->related_cpus);
192
193 for_each_cpu(cpu, policy->related_cpus) {
194 cppc_fi = &per_cpu(cppc_freq_inv, cpu);
195 irq_work_sync(&cppc_fi->irq_work);
196 kthread_cancel_work_sync(&cppc_fi->work);
197 }
198}
199
200static void __init cppc_freq_invariance_init(void)
201{
202 struct sched_attr attr = {
203 .size = sizeof(struct sched_attr),
204 .sched_policy = SCHED_DEADLINE,
205 .sched_nice = 0,
206 .sched_priority = 0,
207 /*
208 * Fake (unused) bandwidth; workaround to "fix"
209 * priority inheritance.
210 */
211 .sched_runtime = NSEC_PER_MSEC,
212 .sched_deadline = 10 * NSEC_PER_MSEC,
213 .sched_period = 10 * NSEC_PER_MSEC,
214 };
215 int ret;
216
217 if (fie_disabled != FIE_ENABLED && fie_disabled != FIE_DISABLED) {
218 fie_disabled = FIE_ENABLED;
219 if (cppc_perf_ctrs_in_pcc()) {
220 pr_info("FIE not enabled on systems with registers in PCC\n");
221 fie_disabled = FIE_DISABLED;
222 }
223 }
224
225 if (fie_disabled)
226 return;
227
228 kworker_fie = kthread_create_worker(0, "cppc_fie");
229 if (IS_ERR(kworker_fie)) {
230 pr_warn("%s: failed to create kworker_fie: %ld\n", __func__,
231 PTR_ERR(kworker_fie));
232 fie_disabled = FIE_DISABLED;
233 return;
234 }
235
236 ret = sched_setattr_nocheck(kworker_fie->task, &attr);
237 if (ret) {
238 pr_warn("%s: failed to set SCHED_DEADLINE: %d\n", __func__,
239 ret);
240 kthread_destroy_worker(kworker_fie);
241 fie_disabled = FIE_DISABLED;
242 }
243}
244
245static void cppc_freq_invariance_exit(void)
246{
247 if (fie_disabled)
248 return;
249
250 kthread_destroy_worker(kworker_fie);
251}
252
253#else
254static inline void cppc_cpufreq_cpu_fie_init(struct cpufreq_policy *policy)
255{
256}
257
258static inline void cppc_cpufreq_cpu_fie_exit(struct cpufreq_policy *policy)
259{
260}
261
262static inline void cppc_freq_invariance_init(void)
263{
264}
265
266static inline void cppc_freq_invariance_exit(void)
267{
268}
269#endif /* CONFIG_ACPI_CPPC_CPUFREQ_FIE */
270
271static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
272 unsigned int target_freq,
273 unsigned int relation)
274{
275 struct cppc_cpudata *cpu_data = policy->driver_data;
276 unsigned int cpu = policy->cpu;
277 struct cpufreq_freqs freqs;
278 int ret = 0;
279
280 cpu_data->perf_ctrls.desired_perf =
281 cppc_khz_to_perf(&cpu_data->perf_caps, target_freq);
282 freqs.old = policy->cur;
283 freqs.new = target_freq;
284
285 cpufreq_freq_transition_begin(policy, &freqs);
286 ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
287 cpufreq_freq_transition_end(policy, &freqs, ret != 0);
288
289 if (ret)
290 pr_debug("Failed to set target on CPU:%d. ret:%d\n",
291 cpu, ret);
292
293 return ret;
294}
295
296static unsigned int cppc_cpufreq_fast_switch(struct cpufreq_policy *policy,
297 unsigned int target_freq)
298{
299 struct cppc_cpudata *cpu_data = policy->driver_data;
300 unsigned int cpu = policy->cpu;
301 u32 desired_perf;
302 int ret;
303
304 desired_perf = cppc_khz_to_perf(&cpu_data->perf_caps, target_freq);
305 cpu_data->perf_ctrls.desired_perf = desired_perf;
306 ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
307
308 if (ret) {
309 pr_debug("Failed to set target on CPU:%d. ret:%d\n",
310 cpu, ret);
311 return 0;
312 }
313
314 return target_freq;
315}
316
317static int cppc_verify_policy(struct cpufreq_policy_data *policy)
318{
319 cpufreq_verify_within_cpu_limits(policy);
320 return 0;
321}
322
323/*
324 * The PCC subspace describes the rate at which platform can accept commands
325 * on the shared PCC channel (including READs which do not count towards freq
326 * transition requests), so ideally we need to use the PCC values as a fallback
327 * if we don't have a platform specific transition_delay_us
328 */
329#ifdef CONFIG_ARM64
330#include <asm/cputype.h>
331
332static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu)
333{
334 unsigned long implementor = read_cpuid_implementor();
335 unsigned long part_num = read_cpuid_part_number();
336
337 switch (implementor) {
338 case ARM_CPU_IMP_QCOM:
339 switch (part_num) {
340 case QCOM_CPU_PART_FALKOR_V1:
341 case QCOM_CPU_PART_FALKOR:
342 return 10000;
343 }
344 }
345 return cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
346}
347#else
348static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu)
349{
350 return cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
351}
352#endif
353
354#if defined(CONFIG_ARM64) && defined(CONFIG_ENERGY_MODEL)
355
356static DEFINE_PER_CPU(unsigned int, efficiency_class);
357static void cppc_cpufreq_register_em(struct cpufreq_policy *policy);
358
359/* Create an artificial performance state every CPPC_EM_CAP_STEP capacity unit. */
360#define CPPC_EM_CAP_STEP (20)
361/* Increase the cost value by CPPC_EM_COST_STEP every performance state. */
362#define CPPC_EM_COST_STEP (1)
363/* Add a cost gap correspnding to the energy of 4 CPUs. */
364#define CPPC_EM_COST_GAP (4 * SCHED_CAPACITY_SCALE * CPPC_EM_COST_STEP \
365 / CPPC_EM_CAP_STEP)
366
367static unsigned int get_perf_level_count(struct cpufreq_policy *policy)
368{
369 struct cppc_perf_caps *perf_caps;
370 unsigned int min_cap, max_cap;
371 struct cppc_cpudata *cpu_data;
372 int cpu = policy->cpu;
373
374 cpu_data = policy->driver_data;
375 perf_caps = &cpu_data->perf_caps;
376 max_cap = arch_scale_cpu_capacity(cpu);
377 min_cap = div_u64((u64)max_cap * perf_caps->lowest_perf,
378 perf_caps->highest_perf);
379 if ((min_cap == 0) || (max_cap < min_cap))
380 return 0;
381 return 1 + max_cap / CPPC_EM_CAP_STEP - min_cap / CPPC_EM_CAP_STEP;
382}
383
384/*
385 * The cost is defined as:
386 * cost = power * max_frequency / frequency
387 */
388static inline unsigned long compute_cost(int cpu, int step)
389{
390 return CPPC_EM_COST_GAP * per_cpu(efficiency_class, cpu) +
391 step * CPPC_EM_COST_STEP;
392}
393
394static int cppc_get_cpu_power(struct device *cpu_dev,
395 unsigned long *power, unsigned long *KHz)
396{
397 unsigned long perf_step, perf_prev, perf, perf_check;
398 unsigned int min_step, max_step, step, step_check;
399 unsigned long prev_freq = *KHz;
400 unsigned int min_cap, max_cap;
401 struct cpufreq_policy *policy;
402
403 struct cppc_perf_caps *perf_caps;
404 struct cppc_cpudata *cpu_data;
405
406 policy = cpufreq_cpu_get_raw(cpu_dev->id);
407 if (!policy)
408 return -EINVAL;
409
410 cpu_data = policy->driver_data;
411 perf_caps = &cpu_data->perf_caps;
412 max_cap = arch_scale_cpu_capacity(cpu_dev->id);
413 min_cap = div_u64((u64)max_cap * perf_caps->lowest_perf,
414 perf_caps->highest_perf);
415 perf_step = div_u64((u64)CPPC_EM_CAP_STEP * perf_caps->highest_perf,
416 max_cap);
417 min_step = min_cap / CPPC_EM_CAP_STEP;
418 max_step = max_cap / CPPC_EM_CAP_STEP;
419
420 perf_prev = cppc_khz_to_perf(perf_caps, *KHz);
421 step = perf_prev / perf_step;
422
423 if (step > max_step)
424 return -EINVAL;
425
426 if (min_step == max_step) {
427 step = max_step;
428 perf = perf_caps->highest_perf;
429 } else if (step < min_step) {
430 step = min_step;
431 perf = perf_caps->lowest_perf;
432 } else {
433 step++;
434 if (step == max_step)
435 perf = perf_caps->highest_perf;
436 else
437 perf = step * perf_step;
438 }
439
440 *KHz = cppc_perf_to_khz(perf_caps, perf);
441 perf_check = cppc_khz_to_perf(perf_caps, *KHz);
442 step_check = perf_check / perf_step;
443
444 /*
445 * To avoid bad integer approximation, check that new frequency value
446 * increased and that the new frequency will be converted to the
447 * desired step value.
448 */
449 while ((*KHz == prev_freq) || (step_check != step)) {
450 perf++;
451 *KHz = cppc_perf_to_khz(perf_caps, perf);
452 perf_check = cppc_khz_to_perf(perf_caps, *KHz);
453 step_check = perf_check / perf_step;
454 }
455
456 /*
457 * With an artificial EM, only the cost value is used. Still the power
458 * is populated such as 0 < power < EM_MAX_POWER. This allows to add
459 * more sense to the artificial performance states.
460 */
461 *power = compute_cost(cpu_dev->id, step);
462
463 return 0;
464}
465
466static int cppc_get_cpu_cost(struct device *cpu_dev, unsigned long KHz,
467 unsigned long *cost)
468{
469 unsigned long perf_step, perf_prev;
470 struct cppc_perf_caps *perf_caps;
471 struct cpufreq_policy *policy;
472 struct cppc_cpudata *cpu_data;
473 unsigned int max_cap;
474 int step;
475
476 policy = cpufreq_cpu_get_raw(cpu_dev->id);
477 if (!policy)
478 return -EINVAL;
479
480 cpu_data = policy->driver_data;
481 perf_caps = &cpu_data->perf_caps;
482 max_cap = arch_scale_cpu_capacity(cpu_dev->id);
483
484 perf_prev = cppc_khz_to_perf(perf_caps, KHz);
485 perf_step = CPPC_EM_CAP_STEP * perf_caps->highest_perf / max_cap;
486 step = perf_prev / perf_step;
487
488 *cost = compute_cost(cpu_dev->id, step);
489
490 return 0;
491}
492
493static int populate_efficiency_class(void)
494{
495 struct acpi_madt_generic_interrupt *gicc;
496 DECLARE_BITMAP(used_classes, 256) = {};
497 int class, cpu, index;
498
499 for_each_possible_cpu(cpu) {
500 gicc = acpi_cpu_get_madt_gicc(cpu);
501 class = gicc->efficiency_class;
502 bitmap_set(used_classes, class, 1);
503 }
504
505 if (bitmap_weight(used_classes, 256) <= 1) {
506 pr_debug("Efficiency classes are all equal (=%d). "
507 "No EM registered", class);
508 return -EINVAL;
509 }
510
511 /*
512 * Squeeze efficiency class values on [0:#efficiency_class-1].
513 * Values are per spec in [0:255].
514 */
515 index = 0;
516 for_each_set_bit(class, used_classes, 256) {
517 for_each_possible_cpu(cpu) {
518 gicc = acpi_cpu_get_madt_gicc(cpu);
519 if (gicc->efficiency_class == class)
520 per_cpu(efficiency_class, cpu) = index;
521 }
522 index++;
523 }
524 cppc_cpufreq_driver.register_em = cppc_cpufreq_register_em;
525
526 return 0;
527}
528
529static void cppc_cpufreq_register_em(struct cpufreq_policy *policy)
530{
531 struct cppc_cpudata *cpu_data;
532 struct em_data_callback em_cb =
533 EM_ADV_DATA_CB(cppc_get_cpu_power, cppc_get_cpu_cost);
534
535 cpu_data = policy->driver_data;
536 em_dev_register_perf_domain(get_cpu_device(policy->cpu),
537 get_perf_level_count(policy), &em_cb,
538 cpu_data->shared_cpu_map, 0);
539}
540
541#else
542static int populate_efficiency_class(void)
543{
544 return 0;
545}
546#endif
547
548static struct cppc_cpudata *cppc_cpufreq_get_cpu_data(unsigned int cpu)
549{
550 struct cppc_cpudata *cpu_data;
551 int ret;
552
553 cpu_data = kzalloc(sizeof(struct cppc_cpudata), GFP_KERNEL);
554 if (!cpu_data)
555 goto out;
556
557 if (!zalloc_cpumask_var(&cpu_data->shared_cpu_map, GFP_KERNEL))
558 goto free_cpu;
559
560 ret = acpi_get_psd_map(cpu, cpu_data);
561 if (ret) {
562 pr_debug("Err parsing CPU%d PSD data: ret:%d\n", cpu, ret);
563 goto free_mask;
564 }
565
566 ret = cppc_get_perf_caps(cpu, &cpu_data->perf_caps);
567 if (ret) {
568 pr_debug("Err reading CPU%d perf caps: ret:%d\n", cpu, ret);
569 goto free_mask;
570 }
571
572 list_add(&cpu_data->node, &cpu_data_list);
573
574 return cpu_data;
575
576free_mask:
577 free_cpumask_var(cpu_data->shared_cpu_map);
578free_cpu:
579 kfree(cpu_data);
580out:
581 return NULL;
582}
583
584static void cppc_cpufreq_put_cpu_data(struct cpufreq_policy *policy)
585{
586 struct cppc_cpudata *cpu_data = policy->driver_data;
587
588 list_del(&cpu_data->node);
589 free_cpumask_var(cpu_data->shared_cpu_map);
590 kfree(cpu_data);
591 policy->driver_data = NULL;
592}
593
594static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
595{
596 unsigned int cpu = policy->cpu;
597 struct cppc_cpudata *cpu_data;
598 struct cppc_perf_caps *caps;
599 int ret;
600
601 cpu_data = cppc_cpufreq_get_cpu_data(cpu);
602 if (!cpu_data) {
603 pr_err("Error in acquiring _CPC/_PSD data for CPU%d.\n", cpu);
604 return -ENODEV;
605 }
606 caps = &cpu_data->perf_caps;
607 policy->driver_data = cpu_data;
608
609 /*
610 * Set min to lowest nonlinear perf to avoid any efficiency penalty (see
611 * Section 8.4.7.1.1.5 of ACPI 6.1 spec)
612 */
613 policy->min = cppc_perf_to_khz(caps, caps->lowest_nonlinear_perf);
614 policy->max = cppc_perf_to_khz(caps, caps->nominal_perf);
615
616 /*
617 * Set cpuinfo.min_freq to Lowest to make the full range of performance
618 * available if userspace wants to use any perf between lowest & lowest
619 * nonlinear perf
620 */
621 policy->cpuinfo.min_freq = cppc_perf_to_khz(caps, caps->lowest_perf);
622 policy->cpuinfo.max_freq = cppc_perf_to_khz(caps, caps->nominal_perf);
623
624 policy->transition_delay_us = cppc_cpufreq_get_transition_delay_us(cpu);
625 policy->shared_type = cpu_data->shared_type;
626
627 switch (policy->shared_type) {
628 case CPUFREQ_SHARED_TYPE_HW:
629 case CPUFREQ_SHARED_TYPE_NONE:
630 /* Nothing to be done - we'll have a policy for each CPU */
631 break;
632 case CPUFREQ_SHARED_TYPE_ANY:
633 /*
634 * All CPUs in the domain will share a policy and all cpufreq
635 * operations will use a single cppc_cpudata structure stored
636 * in policy->driver_data.
637 */
638 cpumask_copy(policy->cpus, cpu_data->shared_cpu_map);
639 break;
640 default:
641 pr_debug("Unsupported CPU co-ord type: %d\n",
642 policy->shared_type);
643 ret = -EFAULT;
644 goto out;
645 }
646
647 policy->fast_switch_possible = cppc_allow_fast_switch();
648 policy->dvfs_possible_from_any_cpu = true;
649
650 /*
651 * If 'highest_perf' is greater than 'nominal_perf', we assume CPU Boost
652 * is supported.
653 */
654 if (caps->highest_perf > caps->nominal_perf)
655 boost_supported = true;
656
657 /* Set policy->cur to max now. The governors will adjust later. */
658 policy->cur = cppc_perf_to_khz(caps, caps->highest_perf);
659 cpu_data->perf_ctrls.desired_perf = caps->highest_perf;
660
661 ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
662 if (ret) {
663 pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
664 caps->highest_perf, cpu, ret);
665 goto out;
666 }
667
668 cppc_cpufreq_cpu_fie_init(policy);
669 return 0;
670
671out:
672 cppc_cpufreq_put_cpu_data(policy);
673 return ret;
674}
675
676static void cppc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
677{
678 struct cppc_cpudata *cpu_data = policy->driver_data;
679 struct cppc_perf_caps *caps = &cpu_data->perf_caps;
680 unsigned int cpu = policy->cpu;
681 int ret;
682
683 cppc_cpufreq_cpu_fie_exit(policy);
684
685 cpu_data->perf_ctrls.desired_perf = caps->lowest_perf;
686
687 ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
688 if (ret)
689 pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
690 caps->lowest_perf, cpu, ret);
691
692 cppc_cpufreq_put_cpu_data(policy);
693}
694
695static inline u64 get_delta(u64 t1, u64 t0)
696{
697 if (t1 > t0 || t0 > ~(u32)0)
698 return t1 - t0;
699
700 return (u32)t1 - (u32)t0;
701}
702
703static int cppc_perf_from_fbctrs(struct cppc_cpudata *cpu_data,
704 struct cppc_perf_fb_ctrs *fb_ctrs_t0,
705 struct cppc_perf_fb_ctrs *fb_ctrs_t1)
706{
707 u64 delta_reference, delta_delivered;
708 u64 reference_perf;
709
710 reference_perf = fb_ctrs_t0->reference_perf;
711
712 delta_reference = get_delta(fb_ctrs_t1->reference,
713 fb_ctrs_t0->reference);
714 delta_delivered = get_delta(fb_ctrs_t1->delivered,
715 fb_ctrs_t0->delivered);
716
717 /*
718 * Avoid divide-by zero and unchanged feedback counters.
719 * Leave it for callers to handle.
720 */
721 if (!delta_reference || !delta_delivered)
722 return 0;
723
724 return (reference_perf * delta_delivered) / delta_reference;
725}
726
727static int cppc_get_perf_ctrs_sample(int cpu,
728 struct cppc_perf_fb_ctrs *fb_ctrs_t0,
729 struct cppc_perf_fb_ctrs *fb_ctrs_t1)
730{
731 int ret;
732
733 ret = cppc_get_perf_ctrs(cpu, fb_ctrs_t0);
734 if (ret)
735 return ret;
736
737 udelay(2); /* 2usec delay between sampling */
738
739 return cppc_get_perf_ctrs(cpu, fb_ctrs_t1);
740}
741
742static unsigned int cppc_cpufreq_get_rate(unsigned int cpu)
743{
744 struct cppc_perf_fb_ctrs fb_ctrs_t0 = {0}, fb_ctrs_t1 = {0};
745 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
746 struct cppc_cpudata *cpu_data;
747 u64 delivered_perf;
748 int ret;
749
750 if (!policy)
751 return -ENODEV;
752
753 cpu_data = policy->driver_data;
754
755 cpufreq_cpu_put(policy);
756
757 ret = cppc_get_perf_ctrs_sample(cpu, &fb_ctrs_t0, &fb_ctrs_t1);
758 if (ret) {
759 if (ret == -EFAULT)
760 /* Any of the associated CPPC regs is 0. */
761 goto out_invalid_counters;
762 else
763 return 0;
764 }
765
766 delivered_perf = cppc_perf_from_fbctrs(cpu_data, &fb_ctrs_t0,
767 &fb_ctrs_t1);
768 if (!delivered_perf)
769 goto out_invalid_counters;
770
771 return cppc_perf_to_khz(&cpu_data->perf_caps, delivered_perf);
772
773out_invalid_counters:
774 /*
775 * Feedback counters could be unchanged or 0 when a cpu enters a
776 * low-power idle state, e.g. clock-gated or power-gated.
777 * Use desired perf for reflecting frequency. Get the latest register
778 * value first as some platforms may update the actual delivered perf
779 * there; if failed, resort to the cached desired perf.
780 */
781 if (cppc_get_desired_perf(cpu, &delivered_perf))
782 delivered_perf = cpu_data->perf_ctrls.desired_perf;
783
784 return cppc_perf_to_khz(&cpu_data->perf_caps, delivered_perf);
785}
786
787static int cppc_cpufreq_set_boost(struct cpufreq_policy *policy, int state)
788{
789 struct cppc_cpudata *cpu_data = policy->driver_data;
790 struct cppc_perf_caps *caps = &cpu_data->perf_caps;
791 int ret;
792
793 if (!boost_supported) {
794 pr_err("BOOST not supported by CPU or firmware\n");
795 return -EINVAL;
796 }
797
798 if (state)
799 policy->max = cppc_perf_to_khz(caps, caps->highest_perf);
800 else
801 policy->max = cppc_perf_to_khz(caps, caps->nominal_perf);
802 policy->cpuinfo.max_freq = policy->max;
803
804 ret = freq_qos_update_request(policy->max_freq_req, policy->max);
805 if (ret < 0)
806 return ret;
807
808 return 0;
809}
810
811static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
812{
813 struct cppc_cpudata *cpu_data = policy->driver_data;
814
815 return cpufreq_show_cpus(cpu_data->shared_cpu_map, buf);
816}
817cpufreq_freq_attr_ro(freqdomain_cpus);
818
819static struct freq_attr *cppc_cpufreq_attr[] = {
820 &freqdomain_cpus,
821 NULL,
822};
823
824static struct cpufreq_driver cppc_cpufreq_driver = {
825 .flags = CPUFREQ_CONST_LOOPS,
826 .verify = cppc_verify_policy,
827 .target = cppc_cpufreq_set_target,
828 .get = cppc_cpufreq_get_rate,
829 .fast_switch = cppc_cpufreq_fast_switch,
830 .init = cppc_cpufreq_cpu_init,
831 .exit = cppc_cpufreq_cpu_exit,
832 .set_boost = cppc_cpufreq_set_boost,
833 .attr = cppc_cpufreq_attr,
834 .name = "cppc_cpufreq",
835};
836
837static int __init cppc_cpufreq_init(void)
838{
839 int ret;
840
841 if (!acpi_cpc_valid())
842 return -ENODEV;
843
844 cppc_freq_invariance_init();
845 populate_efficiency_class();
846
847 ret = cpufreq_register_driver(&cppc_cpufreq_driver);
848 if (ret)
849 cppc_freq_invariance_exit();
850
851 return ret;
852}
853
854static inline void free_cpu_data(void)
855{
856 struct cppc_cpudata *iter, *tmp;
857
858 list_for_each_entry_safe(iter, tmp, &cpu_data_list, node) {
859 free_cpumask_var(iter->shared_cpu_map);
860 list_del(&iter->node);
861 kfree(iter);
862 }
863
864}
865
866static void __exit cppc_cpufreq_exit(void)
867{
868 cpufreq_unregister_driver(&cppc_cpufreq_driver);
869 cppc_freq_invariance_exit();
870
871 free_cpu_data();
872}
873
874module_exit(cppc_cpufreq_exit);
875MODULE_AUTHOR("Ashwin Chaugule");
876MODULE_DESCRIPTION("CPUFreq driver based on the ACPI CPPC v5.0+ spec");
877MODULE_LICENSE("GPL");
878
879late_initcall(cppc_cpufreq_init);
880
881static const struct acpi_device_id cppc_acpi_ids[] __used = {
882 {ACPI_PROCESSOR_DEVICE_HID, },
883 {}
884};
885
886MODULE_DEVICE_TABLE(acpi, cppc_acpi_ids);