summaryrefslogtreecommitdiff
path: root/drivers/cpufreq/cppc_cpufreq.c
blob: 64420d9cfd1ed3cbec1c6a25a7640c4afa875466 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
// SPDX-License-Identifier: GPL-2.0-only
/*
 * CPPC (Collaborative Processor Performance Control) driver for
 * interfacing with the CPUfreq layer and governors. See
 * cppc_acpi.c for CPPC specific methods.
 *
 * (C) Copyright 2014, 2015 Linaro Ltd.
 * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org>
 */

#define pr_fmt(fmt)	"CPPC Cpufreq:"	fmt

#include <linux/arch_topology.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/irq_work.h>
#include <linux/kthread.h>
#include <linux/time.h>
#include <linux/vmalloc.h>
#include <uapi/linux/sched/types.h>

#include <asm/unaligned.h>

#include <acpi/cppc_acpi.h>

/*
 * This list contains information parsed from per CPU ACPI _CPC and _PSD
 * structures: e.g. the highest and lowest supported performance, capabilities,
 * desired performance, level requested etc. Depending on the share_type, not
 * all CPUs will have an entry in the list.
 */
static LIST_HEAD(cpu_data_list);

static bool boost_supported;

struct cppc_workaround_oem_info {
	char oem_id[ACPI_OEM_ID_SIZE + 1];
	char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
	u32 oem_revision;
};

static struct cppc_workaround_oem_info wa_info[] = {
	{
		.oem_id		= "HISI  ",
		.oem_table_id	= "HIP07   ",
		.oem_revision	= 0,
	}, {
		.oem_id		= "HISI  ",
		.oem_table_id	= "HIP08   ",
		.oem_revision	= 0,
	}
};

static struct cpufreq_driver cppc_cpufreq_driver;

static enum {
	FIE_UNSET = -1,
	FIE_ENABLED,
	FIE_DISABLED
} fie_disabled = FIE_UNSET;

#ifdef CONFIG_ACPI_CPPC_CPUFREQ_FIE
module_param(fie_disabled, int, 0444);
MODULE_PARM_DESC(fie_disabled, "Disable Frequency Invariance Engine (FIE)");

/* Frequency invariance support */
struct cppc_freq_invariance {
	int cpu;
	struct irq_work irq_work;
	struct kthread_work work;
	struct cppc_perf_fb_ctrs prev_perf_fb_ctrs;
	struct cppc_cpudata *cpu_data;
};

static DEFINE_PER_CPU(struct cppc_freq_invariance, cppc_freq_inv);
static struct kthread_worker *kworker_fie;

static unsigned int hisi_cppc_cpufreq_get_rate(unsigned int cpu);
static int cppc_perf_from_fbctrs(struct cppc_cpudata *cpu_data,
				 struct cppc_perf_fb_ctrs *fb_ctrs_t0,
				 struct cppc_perf_fb_ctrs *fb_ctrs_t1);

/**
 * cppc_scale_freq_workfn - CPPC arch_freq_scale updater for frequency invariance
 * @work: The work item.
 *
 * The CPPC driver register itself with the topology core to provide its own
 * implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which
 * gets called by the scheduler on every tick.
 *
 * Note that the arch specific counters have higher priority than CPPC counters,
 * if available, though the CPPC driver doesn't need to have any special
 * handling for that.
 *
 * On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we
 * reach here from hard-irq context), which then schedules a normal work item
 * and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable
 * based on the counter updates since the last tick.
 */
static void cppc_scale_freq_workfn(struct kthread_work *work)
{
	struct cppc_freq_invariance *cppc_fi;
	struct cppc_perf_fb_ctrs fb_ctrs = {0};
	struct cppc_cpudata *cpu_data;
	unsigned long local_freq_scale;
	u64 perf;

	cppc_fi = container_of(work, struct cppc_freq_invariance, work);
	cpu_data = cppc_fi->cpu_data;

	if (cppc_get_perf_ctrs(cppc_fi->cpu, &fb_ctrs)) {
		pr_warn("%s: failed to read perf counters\n", __func__);
		return;
	}

	perf = cppc_perf_from_fbctrs(cpu_data, &cppc_fi->prev_perf_fb_ctrs,
				     &fb_ctrs);
	cppc_fi->prev_perf_fb_ctrs = fb_ctrs;

	perf <<= SCHED_CAPACITY_SHIFT;
	local_freq_scale = div64_u64(perf, cpu_data->perf_caps.highest_perf);

	/* This can happen due to counter's overflow */
	if (unlikely(local_freq_scale > 1024))
		local_freq_scale = 1024;

	per_cpu(arch_freq_scale, cppc_fi->cpu) = local_freq_scale;
}

static void cppc_irq_work(struct irq_work *irq_work)
{
	struct cppc_freq_invariance *cppc_fi;

	cppc_fi = container_of(irq_work, struct cppc_freq_invariance, irq_work);
	kthread_queue_work(kworker_fie, &cppc_fi->work);
}

static void cppc_scale_freq_tick(void)
{
	struct cppc_freq_invariance *cppc_fi = &per_cpu(cppc_freq_inv, smp_processor_id());

	/*
	 * cppc_get_perf_ctrs() can potentially sleep, call that from the right
	 * context.
	 */
	irq_work_queue(&cppc_fi->irq_work);
}

static struct scale_freq_data cppc_sftd = {
	.source = SCALE_FREQ_SOURCE_CPPC,
	.set_freq_scale = cppc_scale_freq_tick,
};

static void cppc_cpufreq_cpu_fie_init(struct cpufreq_policy *policy)
{
	struct cppc_freq_invariance *cppc_fi;
	int cpu, ret;

	if (fie_disabled)
		return;

	for_each_cpu(cpu, policy->cpus) {
		cppc_fi = &per_cpu(cppc_freq_inv, cpu);
		cppc_fi->cpu = cpu;
		cppc_fi->cpu_data = policy->driver_data;
		kthread_init_work(&cppc_fi->work, cppc_scale_freq_workfn);
		init_irq_work(&cppc_fi->irq_work, cppc_irq_work);

		ret = cppc_get_perf_ctrs(cpu, &cppc_fi->prev_perf_fb_ctrs);
		if (ret) {
			pr_warn("%s: failed to read perf counters for cpu:%d: %d\n",
				__func__, cpu, ret);

			/*
			 * Don't abort if the CPU was offline while the driver
			 * was getting registered.
			 */
			if (cpu_online(cpu))
				return;
		}
	}

	/* Register for freq-invariance */
	topology_set_scale_freq_source(&cppc_sftd, policy->cpus);
}

/*
 * We free all the resources on policy's removal and not on CPU removal as the
 * irq-work are per-cpu and the hotplug core takes care of flushing the pending
 * irq-works (hint: smpcfd_dying_cpu()) on CPU hotplug. Even if the kthread-work
 * fires on another CPU after the concerned CPU is removed, it won't harm.
 *
 * We just need to make sure to remove them all on policy->exit().
 */
static void cppc_cpufreq_cpu_fie_exit(struct cpufreq_policy *policy)
{
	struct cppc_freq_invariance *cppc_fi;
	int cpu;

	if (fie_disabled)
		return;

	/* policy->cpus will be empty here, use related_cpus instead */
	topology_clear_scale_freq_source(SCALE_FREQ_SOURCE_CPPC, policy->related_cpus);

	for_each_cpu(cpu, policy->related_cpus) {
		cppc_fi = &per_cpu(cppc_freq_inv, cpu);
		irq_work_sync(&cppc_fi->irq_work);
		kthread_cancel_work_sync(&cppc_fi->work);
	}
}

static void __init cppc_freq_invariance_init(void)
{
	struct sched_attr attr = {
		.size		= sizeof(struct sched_attr),
		.sched_policy	= SCHED_DEADLINE,
		.sched_nice	= 0,
		.sched_priority	= 0,
		/*
		 * Fake (unused) bandwidth; workaround to "fix"
		 * priority inheritance.
		 */
		.sched_runtime	= 1000000,
		.sched_deadline = 10000000,
		.sched_period	= 10000000,
	};
	int ret;

	if (fie_disabled != FIE_ENABLED && fie_disabled != FIE_DISABLED) {
		fie_disabled = FIE_ENABLED;
		if (cppc_perf_ctrs_in_pcc()) {
			pr_info("FIE not enabled on systems with registers in PCC\n");
			fie_disabled = FIE_DISABLED;
		}
	}

	if (fie_disabled)
		return;

	kworker_fie = kthread_create_worker(0, "cppc_fie");
	if (IS_ERR(kworker_fie)) {
		pr_warn("%s: failed to create kworker_fie: %ld\n", __func__,
			PTR_ERR(kworker_fie));
		fie_disabled = FIE_DISABLED;
		return;
	}

	ret = sched_setattr_nocheck(kworker_fie->task, &attr);
	if (ret) {
		pr_warn("%s: failed to set SCHED_DEADLINE: %d\n", __func__,
			ret);
		kthread_destroy_worker(kworker_fie);
		fie_disabled = FIE_DISABLED;
	}
}

static void cppc_freq_invariance_exit(void)
{
	if (fie_disabled)
		return;

	kthread_destroy_worker(kworker_fie);
}

#else
static inline void cppc_cpufreq_cpu_fie_init(struct cpufreq_policy *policy)
{
}

static inline void cppc_cpufreq_cpu_fie_exit(struct cpufreq_policy *policy)
{
}

static inline void cppc_freq_invariance_init(void)
{
}

static inline void cppc_freq_invariance_exit(void)
{
}
#endif /* CONFIG_ACPI_CPPC_CPUFREQ_FIE */

static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
				   unsigned int target_freq,
				   unsigned int relation)
{
	struct cppc_cpudata *cpu_data = policy->driver_data;
	unsigned int cpu = policy->cpu;
	struct cpufreq_freqs freqs;
	u32 desired_perf;
	int ret = 0;

	desired_perf = cppc_khz_to_perf(&cpu_data->perf_caps, target_freq);
	/* Return if it is exactly the same perf */
	if (desired_perf == cpu_data->perf_ctrls.desired_perf)
		return ret;

	cpu_data->perf_ctrls.desired_perf = desired_perf;
	freqs.old = policy->cur;
	freqs.new = target_freq;

	cpufreq_freq_transition_begin(policy, &freqs);
	ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
	cpufreq_freq_transition_end(policy, &freqs, ret != 0);

	if (ret)
		pr_debug("Failed to set target on CPU:%d. ret:%d\n",
			 cpu, ret);

	return ret;
}

static unsigned int cppc_cpufreq_fast_switch(struct cpufreq_policy *policy,
					      unsigned int target_freq)
{
	struct cppc_cpudata *cpu_data = policy->driver_data;
	unsigned int cpu = policy->cpu;
	u32 desired_perf;
	int ret;

	desired_perf = cppc_khz_to_perf(&cpu_data->perf_caps, target_freq);
	cpu_data->perf_ctrls.desired_perf = desired_perf;
	ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);

	if (ret) {
		pr_debug("Failed to set target on CPU:%d. ret:%d\n",
			 cpu, ret);
		return 0;
	}

	return target_freq;
}

static int cppc_verify_policy(struct cpufreq_policy_data *policy)
{
	cpufreq_verify_within_cpu_limits(policy);
	return 0;
}

/*
 * The PCC subspace describes the rate at which platform can accept commands
 * on the shared PCC channel (including READs which do not count towards freq
 * transition requests), so ideally we need to use the PCC values as a fallback
 * if we don't have a platform specific transition_delay_us
 */
#ifdef CONFIG_ARM64
#include <asm/cputype.h>

static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu)
{
	unsigned long implementor = read_cpuid_implementor();
	unsigned long part_num = read_cpuid_part_number();

	switch (implementor) {
	case ARM_CPU_IMP_QCOM:
		switch (part_num) {
		case QCOM_CPU_PART_FALKOR_V1:
		case QCOM_CPU_PART_FALKOR:
			return 10000;
		}
	}
	return cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
}
#else
static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu)
{
	return cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
}
#endif

#if defined(CONFIG_ARM64) && defined(CONFIG_ENERGY_MODEL)

static DEFINE_PER_CPU(unsigned int, efficiency_class);
static void cppc_cpufreq_register_em(struct cpufreq_policy *policy);

/* Create an artificial performance state every CPPC_EM_CAP_STEP capacity unit. */
#define CPPC_EM_CAP_STEP	(20)
/* Increase the cost value by CPPC_EM_COST_STEP every performance state. */
#define CPPC_EM_COST_STEP	(1)
/* Add a cost gap correspnding to the energy of 4 CPUs. */
#define CPPC_EM_COST_GAP	(4 * SCHED_CAPACITY_SCALE * CPPC_EM_COST_STEP \
				/ CPPC_EM_CAP_STEP)

static unsigned int get_perf_level_count(struct cpufreq_policy *policy)
{
	struct cppc_perf_caps *perf_caps;
	unsigned int min_cap, max_cap;
	struct cppc_cpudata *cpu_data;
	int cpu = policy->cpu;

	cpu_data = policy->driver_data;
	perf_caps = &cpu_data->perf_caps;
	max_cap = arch_scale_cpu_capacity(cpu);
	min_cap = div_u64((u64)max_cap * perf_caps->lowest_perf,
			  perf_caps->highest_perf);
	if ((min_cap == 0) || (max_cap < min_cap))
		return 0;
	return 1 + max_cap / CPPC_EM_CAP_STEP - min_cap / CPPC_EM_CAP_STEP;
}

/*
 * The cost is defined as:
 *   cost = power * max_frequency / frequency
 */
static inline unsigned long compute_cost(int cpu, int step)
{
	return CPPC_EM_COST_GAP * per_cpu(efficiency_class, cpu) +
			step * CPPC_EM_COST_STEP;
}

static int cppc_get_cpu_power(struct device *cpu_dev,
		unsigned long *power, unsigned long *KHz)
{
	unsigned long perf_step, perf_prev, perf, perf_check;
	unsigned int min_step, max_step, step, step_check;
	unsigned long prev_freq = *KHz;
	unsigned int min_cap, max_cap;
	struct cpufreq_policy *policy;

	struct cppc_perf_caps *perf_caps;
	struct cppc_cpudata *cpu_data;

	policy = cpufreq_cpu_get_raw(cpu_dev->id);
	cpu_data = policy->driver_data;
	perf_caps = &cpu_data->perf_caps;
	max_cap = arch_scale_cpu_capacity(cpu_dev->id);
	min_cap = div_u64((u64)max_cap * perf_caps->lowest_perf,
			  perf_caps->highest_perf);
	perf_step = div_u64((u64)CPPC_EM_CAP_STEP * perf_caps->highest_perf,
			    max_cap);
	min_step = min_cap / CPPC_EM_CAP_STEP;
	max_step = max_cap / CPPC_EM_CAP_STEP;

	perf_prev = cppc_khz_to_perf(perf_caps, *KHz);
	step = perf_prev / perf_step;

	if (step > max_step)
		return -EINVAL;

	if (min_step == max_step) {
		step = max_step;
		perf = perf_caps->highest_perf;
	} else if (step < min_step) {
		step = min_step;
		perf = perf_caps->lowest_perf;
	} else {
		step++;
		if (step == max_step)
			perf = perf_caps->highest_perf;
		else
			perf = step * perf_step;
	}

	*KHz = cppc_perf_to_khz(perf_caps, perf);
	perf_check = cppc_khz_to_perf(perf_caps, *KHz);
	step_check = perf_check / perf_step;

	/*
	 * To avoid bad integer approximation, check that new frequency value
	 * increased and that the new frequency will be converted to the
	 * desired step value.
	 */
	while ((*KHz == prev_freq) || (step_check != step)) {
		perf++;
		*KHz = cppc_perf_to_khz(perf_caps, perf);
		perf_check = cppc_khz_to_perf(perf_caps, *KHz);
		step_check = perf_check / perf_step;
	}

	/*
	 * With an artificial EM, only the cost value is used. Still the power
	 * is populated such as 0 < power < EM_MAX_POWER. This allows to add
	 * more sense to the artificial performance states.
	 */
	*power = compute_cost(cpu_dev->id, step);

	return 0;
}

static int cppc_get_cpu_cost(struct device *cpu_dev, unsigned long KHz,
		unsigned long *cost)
{
	unsigned long perf_step, perf_prev;
	struct cppc_perf_caps *perf_caps;
	struct cpufreq_policy *policy;
	struct cppc_cpudata *cpu_data;
	unsigned int max_cap;
	int step;

	policy = cpufreq_cpu_get_raw(cpu_dev->id);
	cpu_data = policy->driver_data;
	perf_caps = &cpu_data->perf_caps;
	max_cap = arch_scale_cpu_capacity(cpu_dev->id);

	perf_prev = cppc_khz_to_perf(perf_caps, KHz);
	perf_step = CPPC_EM_CAP_STEP * perf_caps->highest_perf / max_cap;
	step = perf_prev / perf_step;

	*cost = compute_cost(cpu_dev->id, step);

	return 0;
}

static int populate_efficiency_class(void)
{
	struct acpi_madt_generic_interrupt *gicc;
	DECLARE_BITMAP(used_classes, 256) = {};
	int class, cpu, index;

	for_each_possible_cpu(cpu) {
		gicc = acpi_cpu_get_madt_gicc(cpu);
		class = gicc->efficiency_class;
		bitmap_set(used_classes, class, 1);
	}

	if (bitmap_weight(used_classes, 256) <= 1) {
		pr_debug("Efficiency classes are all equal (=%d). "
			"No EM registered", class);
		return -EINVAL;
	}

	/*
	 * Squeeze efficiency class values on [0:#efficiency_class-1].
	 * Values are per spec in [0:255].
	 */
	index = 0;
	for_each_set_bit(class, used_classes, 256) {
		for_each_possible_cpu(cpu) {
			gicc = acpi_cpu_get_madt_gicc(cpu);
			if (gicc->efficiency_class == class)
				per_cpu(efficiency_class, cpu) = index;
		}
		index++;
	}
	cppc_cpufreq_driver.register_em = cppc_cpufreq_register_em;

	return 0;
}

static void cppc_cpufreq_register_em(struct cpufreq_policy *policy)
{
	struct cppc_cpudata *cpu_data;
	struct em_data_callback em_cb =
		EM_ADV_DATA_CB(cppc_get_cpu_power, cppc_get_cpu_cost);

	cpu_data = policy->driver_data;
	em_dev_register_perf_domain(get_cpu_device(policy->cpu),
			get_perf_level_count(policy), &em_cb,
			cpu_data->shared_cpu_map, 0);
}

#else
static int populate_efficiency_class(void)
{
	return 0;
}
#endif

static struct cppc_cpudata *cppc_cpufreq_get_cpu_data(unsigned int cpu)
{
	struct cppc_cpudata *cpu_data;
	int ret;

	cpu_data = kzalloc(sizeof(struct cppc_cpudata), GFP_KERNEL);
	if (!cpu_data)
		goto out;

	if (!zalloc_cpumask_var(&cpu_data->shared_cpu_map, GFP_KERNEL))
		goto free_cpu;

	ret = acpi_get_psd_map(cpu, cpu_data);
	if (ret) {
		pr_debug("Err parsing CPU%d PSD data: ret:%d\n", cpu, ret);
		goto free_mask;
	}

	ret = cppc_get_perf_caps(cpu, &cpu_data->perf_caps);
	if (ret) {
		pr_debug("Err reading CPU%d perf caps: ret:%d\n", cpu, ret);
		goto free_mask;
	}

	list_add(&cpu_data->node, &cpu_data_list);

	return cpu_data;

free_mask:
	free_cpumask_var(cpu_data->shared_cpu_map);
free_cpu:
	kfree(cpu_data);
out:
	return NULL;
}

static void cppc_cpufreq_put_cpu_data(struct cpufreq_policy *policy)
{
	struct cppc_cpudata *cpu_data = policy->driver_data;

	list_del(&cpu_data->node);
	free_cpumask_var(cpu_data->shared_cpu_map);
	kfree(cpu_data);
	policy->driver_data = NULL;
}

static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
	unsigned int cpu = policy->cpu;
	struct cppc_cpudata *cpu_data;
	struct cppc_perf_caps *caps;
	int ret;

	cpu_data = cppc_cpufreq_get_cpu_data(cpu);
	if (!cpu_data) {
		pr_err("Error in acquiring _CPC/_PSD data for CPU%d.\n", cpu);
		return -ENODEV;
	}
	caps = &cpu_data->perf_caps;
	policy->driver_data = cpu_data;

	/*
	 * Set min to lowest nonlinear perf to avoid any efficiency penalty (see
	 * Section 8.4.7.1.1.5 of ACPI 6.1 spec)
	 */
	policy->min = cppc_perf_to_khz(caps, caps->lowest_nonlinear_perf);
	policy->max = cppc_perf_to_khz(caps, caps->nominal_perf);

	/*
	 * Set cpuinfo.min_freq to Lowest to make the full range of performance
	 * available if userspace wants to use any perf between lowest & lowest
	 * nonlinear perf
	 */
	policy->cpuinfo.min_freq = cppc_perf_to_khz(caps, caps->lowest_perf);
	policy->cpuinfo.max_freq = cppc_perf_to_khz(caps, caps->nominal_perf);

	policy->transition_delay_us = cppc_cpufreq_get_transition_delay_us(cpu);
	policy->shared_type = cpu_data->shared_type;

	switch (policy->shared_type) {
	case CPUFREQ_SHARED_TYPE_HW:
	case CPUFREQ_SHARED_TYPE_NONE:
		/* Nothing to be done - we'll have a policy for each CPU */
		break;
	case CPUFREQ_SHARED_TYPE_ANY:
		/*
		 * All CPUs in the domain will share a policy and all cpufreq
		 * operations will use a single cppc_cpudata structure stored
		 * in policy->driver_data.
		 */
		cpumask_copy(policy->cpus, cpu_data->shared_cpu_map);
		break;
	default:
		pr_debug("Unsupported CPU co-ord type: %d\n",
			 policy->shared_type);
		ret = -EFAULT;
		goto out;
	}

	policy->fast_switch_possible = cppc_allow_fast_switch();
	policy->dvfs_possible_from_any_cpu = true;

	/*
	 * If 'highest_perf' is greater than 'nominal_perf', we assume CPU Boost
	 * is supported.
	 */
	if (caps->highest_perf > caps->nominal_perf)
		boost_supported = true;

	/* Set policy->cur to max now. The governors will adjust later. */
	policy->cur = cppc_perf_to_khz(caps, caps->highest_perf);
	cpu_data->perf_ctrls.desired_perf =  caps->highest_perf;

	ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
	if (ret) {
		pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
			 caps->highest_perf, cpu, ret);
		goto out;
	}

	cppc_cpufreq_cpu_fie_init(policy);
	return 0;

out:
	cppc_cpufreq_put_cpu_data(policy);
	return ret;
}

static int cppc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
{
	struct cppc_cpudata *cpu_data = policy->driver_data;
	struct cppc_perf_caps *caps = &cpu_data->perf_caps;
	unsigned int cpu = policy->cpu;
	int ret;

	cppc_cpufreq_cpu_fie_exit(policy);

	cpu_data->perf_ctrls.desired_perf = caps->lowest_perf;

	ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
	if (ret)
		pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
			 caps->lowest_perf, cpu, ret);

	cppc_cpufreq_put_cpu_data(policy);
	return 0;
}

static inline u64 get_delta(u64 t1, u64 t0)
{
	if (t1 > t0 || t0 > ~(u32)0)
		return t1 - t0;

	return (u32)t1 - (u32)t0;
}

static int cppc_perf_from_fbctrs(struct cppc_cpudata *cpu_data,
				 struct cppc_perf_fb_ctrs *fb_ctrs_t0,
				 struct cppc_perf_fb_ctrs *fb_ctrs_t1)
{
	u64 delta_reference, delta_delivered;
	u64 reference_perf;

	reference_perf = fb_ctrs_t0->reference_perf;

	delta_reference = get_delta(fb_ctrs_t1->reference,
				    fb_ctrs_t0->reference);
	delta_delivered = get_delta(fb_ctrs_t1->delivered,
				    fb_ctrs_t0->delivered);

	/* Check to avoid divide-by zero and invalid delivered_perf */
	if (!delta_reference || !delta_delivered)
		return cpu_data->perf_ctrls.desired_perf;

	return (reference_perf * delta_delivered) / delta_reference;
}

static unsigned int cppc_cpufreq_get_rate(unsigned int cpu)
{
	struct cppc_perf_fb_ctrs fb_ctrs_t0 = {0}, fb_ctrs_t1 = {0};
	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
	struct cppc_cpudata *cpu_data = policy->driver_data;
	u64 delivered_perf;
	int ret;

	cpufreq_cpu_put(policy);

	ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t0);
	if (ret)
		return 0;

	udelay(2); /* 2usec delay between sampling */

	ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t1);
	if (ret)
		return 0;

	delivered_perf = cppc_perf_from_fbctrs(cpu_data, &fb_ctrs_t0,
					       &fb_ctrs_t1);

	return cppc_perf_to_khz(&cpu_data->perf_caps, delivered_perf);
}

static int cppc_cpufreq_set_boost(struct cpufreq_policy *policy, int state)
{
	struct cppc_cpudata *cpu_data = policy->driver_data;
	struct cppc_perf_caps *caps = &cpu_data->perf_caps;
	int ret;

	if (!boost_supported) {
		pr_err("BOOST not supported by CPU or firmware\n");
		return -EINVAL;
	}

	if (state)
		policy->max = cppc_perf_to_khz(caps, caps->highest_perf);
	else
		policy->max = cppc_perf_to_khz(caps, caps->nominal_perf);
	policy->cpuinfo.max_freq = policy->max;

	ret = freq_qos_update_request(policy->max_freq_req, policy->max);
	if (ret < 0)
		return ret;

	return 0;
}

static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
{
	struct cppc_cpudata *cpu_data = policy->driver_data;

	return cpufreq_show_cpus(cpu_data->shared_cpu_map, buf);
}
cpufreq_freq_attr_ro(freqdomain_cpus);

static struct freq_attr *cppc_cpufreq_attr[] = {
	&freqdomain_cpus,
	NULL,
};

static struct cpufreq_driver cppc_cpufreq_driver = {
	.flags = CPUFREQ_CONST_LOOPS,
	.verify = cppc_verify_policy,
	.target = cppc_cpufreq_set_target,
	.get = cppc_cpufreq_get_rate,
	.fast_switch = cppc_cpufreq_fast_switch,
	.init = cppc_cpufreq_cpu_init,
	.exit = cppc_cpufreq_cpu_exit,
	.set_boost = cppc_cpufreq_set_boost,
	.attr = cppc_cpufreq_attr,
	.name = "cppc_cpufreq",
};

/*
 * HISI platform does not support delivered performance counter and
 * reference performance counter. It can calculate the performance using the
 * platform specific mechanism. We reuse the desired performance register to
 * store the real performance calculated by the platform.
 */
static unsigned int hisi_cppc_cpufreq_get_rate(unsigned int cpu)
{
	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
	struct cppc_cpudata *cpu_data = policy->driver_data;
	u64 desired_perf;
	int ret;

	cpufreq_cpu_put(policy);

	ret = cppc_get_desired_perf(cpu, &desired_perf);
	if (ret < 0)
		return -EIO;

	return cppc_perf_to_khz(&cpu_data->perf_caps, desired_perf);
}

static void cppc_check_hisi_workaround(void)
{
	struct acpi_table_header *tbl;
	acpi_status status = AE_OK;
	int i;

	status = acpi_get_table(ACPI_SIG_PCCT, 0, &tbl);
	if (ACPI_FAILURE(status) || !tbl)
		return;

	for (i = 0; i < ARRAY_SIZE(wa_info); i++) {
		if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE) &&
		    !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) &&
		    wa_info[i].oem_revision == tbl->oem_revision) {
			/* Overwrite the get() callback */
			cppc_cpufreq_driver.get = hisi_cppc_cpufreq_get_rate;
			fie_disabled = FIE_DISABLED;
			break;
		}
	}

	acpi_put_table(tbl);
}

static int __init cppc_cpufreq_init(void)
{
	int ret;

	if (!acpi_cpc_valid())
		return -ENODEV;

	cppc_check_hisi_workaround();
	cppc_freq_invariance_init();
	populate_efficiency_class();

	ret = cpufreq_register_driver(&cppc_cpufreq_driver);
	if (ret)
		cppc_freq_invariance_exit();

	return ret;
}

static inline void free_cpu_data(void)
{
	struct cppc_cpudata *iter, *tmp;

	list_for_each_entry_safe(iter, tmp, &cpu_data_list, node) {
		free_cpumask_var(iter->shared_cpu_map);
		list_del(&iter->node);
		kfree(iter);
	}

}

static void __exit cppc_cpufreq_exit(void)
{
	cpufreq_unregister_driver(&cppc_cpufreq_driver);
	cppc_freq_invariance_exit();

	free_cpu_data();
}

module_exit(cppc_cpufreq_exit);
MODULE_AUTHOR("Ashwin Chaugule");
MODULE_DESCRIPTION("CPUFreq driver based on the ACPI CPPC v5.0+ spec");
MODULE_LICENSE("GPL");

late_initcall(cppc_cpufreq_init);

static const struct acpi_device_id cppc_acpi_ids[] __used = {
	{ACPI_PROCESSOR_DEVICE_HID, },
	{}
};

MODULE_DEVICE_TABLE(acpi, cppc_acpi_ids);