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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/dmi.h>
20#include <linux/irq_work.h>
21#include <linux/kthread.h>
22#include <linux/time.h>
23#include <linux/vmalloc.h>
24#include <uapi/linux/sched/types.h>
25
26#include <asm/unaligned.h>
27
28#include <acpi/cppc_acpi.h>
29
30/* Minimum struct length needed for the DMI processor entry we want */
31#define DMI_ENTRY_PROCESSOR_MIN_LENGTH 48
32
33/* Offset in the DMI processor structure for the max frequency */
34#define DMI_PROCESSOR_MAX_SPEED 0x14
35
36/*
37 * This list contains information parsed from per CPU ACPI _CPC and _PSD
38 * structures: e.g. the highest and lowest supported performance, capabilities,
39 * desired performance, level requested etc. Depending on the share_type, not
40 * all CPUs will have an entry in the list.
41 */
42static LIST_HEAD(cpu_data_list);
43
44static bool boost_supported;
45
46struct cppc_workaround_oem_info {
47 char oem_id[ACPI_OEM_ID_SIZE + 1];
48 char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
49 u32 oem_revision;
50};
51
52static struct cppc_workaround_oem_info wa_info[] = {
53 {
54 .oem_id = "HISI ",
55 .oem_table_id = "HIP07 ",
56 .oem_revision = 0,
57 }, {
58 .oem_id = "HISI ",
59 .oem_table_id = "HIP08 ",
60 .oem_revision = 0,
61 }
62};
63
64#ifdef CONFIG_ACPI_CPPC_CPUFREQ_FIE
65
66/* Frequency invariance support */
67struct cppc_freq_invariance {
68 int cpu;
69 struct irq_work irq_work;
70 struct kthread_work work;
71 struct cppc_perf_fb_ctrs prev_perf_fb_ctrs;
72 struct cppc_cpudata *cpu_data;
73};
74
75static DEFINE_PER_CPU(struct cppc_freq_invariance, cppc_freq_inv);
76static struct kthread_worker *kworker_fie;
77
78static struct cpufreq_driver cppc_cpufreq_driver;
79static unsigned int hisi_cppc_cpufreq_get_rate(unsigned int cpu);
80static int cppc_perf_from_fbctrs(struct cppc_cpudata *cpu_data,
81 struct cppc_perf_fb_ctrs *fb_ctrs_t0,
82 struct cppc_perf_fb_ctrs *fb_ctrs_t1);
83
84/**
85 * cppc_scale_freq_workfn - CPPC arch_freq_scale updater for frequency invariance
86 * @work: The work item.
87 *
88 * The CPPC driver register itself with the topology core to provide its own
89 * implementation (cppc_scale_freq_tick()) of topology_scale_freq_tick() which
90 * gets called by the scheduler on every tick.
91 *
92 * Note that the arch specific counters have higher priority than CPPC counters,
93 * if available, though the CPPC driver doesn't need to have any special
94 * handling for that.
95 *
96 * On an invocation of cppc_scale_freq_tick(), we schedule an irq work (since we
97 * reach here from hard-irq context), which then schedules a normal work item
98 * and cppc_scale_freq_workfn() updates the per_cpu arch_freq_scale variable
99 * based on the counter updates since the last tick.
100 */
101static void cppc_scale_freq_workfn(struct kthread_work *work)
102{
103 struct cppc_freq_invariance *cppc_fi;
104 struct cppc_perf_fb_ctrs fb_ctrs = {0};
105 struct cppc_cpudata *cpu_data;
106 unsigned long local_freq_scale;
107 u64 perf;
108
109 cppc_fi = container_of(work, struct cppc_freq_invariance, work);
110 cpu_data = cppc_fi->cpu_data;
111
112 if (cppc_get_perf_ctrs(cppc_fi->cpu, &fb_ctrs)) {
113 pr_warn("%s: failed to read perf counters\n", __func__);
114 return;
115 }
116
117 perf = cppc_perf_from_fbctrs(cpu_data, &cppc_fi->prev_perf_fb_ctrs,
118 &fb_ctrs);
119 cppc_fi->prev_perf_fb_ctrs = fb_ctrs;
120
121 perf <<= SCHED_CAPACITY_SHIFT;
122 local_freq_scale = div64_u64(perf, cpu_data->perf_caps.highest_perf);
123
124 /* This can happen due to counter's overflow */
125 if (unlikely(local_freq_scale > 1024))
126 local_freq_scale = 1024;
127
128 per_cpu(arch_freq_scale, cppc_fi->cpu) = local_freq_scale;
129}
130
131static void cppc_irq_work(struct irq_work *irq_work)
132{
133 struct cppc_freq_invariance *cppc_fi;
134
135 cppc_fi = container_of(irq_work, struct cppc_freq_invariance, irq_work);
136 kthread_queue_work(kworker_fie, &cppc_fi->work);
137}
138
139static void cppc_scale_freq_tick(void)
140{
141 struct cppc_freq_invariance *cppc_fi = &per_cpu(cppc_freq_inv, smp_processor_id());
142
143 /*
144 * cppc_get_perf_ctrs() can potentially sleep, call that from the right
145 * context.
146 */
147 irq_work_queue(&cppc_fi->irq_work);
148}
149
150static struct scale_freq_data cppc_sftd = {
151 .source = SCALE_FREQ_SOURCE_CPPC,
152 .set_freq_scale = cppc_scale_freq_tick,
153};
154
155static void cppc_cpufreq_cpu_fie_init(struct cpufreq_policy *policy)
156{
157 struct cppc_freq_invariance *cppc_fi;
158 int cpu, ret;
159
160 if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate)
161 return;
162
163 for_each_cpu(cpu, policy->cpus) {
164 cppc_fi = &per_cpu(cppc_freq_inv, cpu);
165 cppc_fi->cpu = cpu;
166 cppc_fi->cpu_data = policy->driver_data;
167 kthread_init_work(&cppc_fi->work, cppc_scale_freq_workfn);
168 init_irq_work(&cppc_fi->irq_work, cppc_irq_work);
169
170 ret = cppc_get_perf_ctrs(cpu, &cppc_fi->prev_perf_fb_ctrs);
171 if (ret) {
172 pr_warn("%s: failed to read perf counters for cpu:%d: %d\n",
173 __func__, cpu, ret);
174
175 /*
176 * Don't abort if the CPU was offline while the driver
177 * was getting registered.
178 */
179 if (cpu_online(cpu))
180 return;
181 }
182 }
183
184 /* Register for freq-invariance */
185 topology_set_scale_freq_source(&cppc_sftd, policy->cpus);
186}
187
188/*
189 * We free all the resources on policy's removal and not on CPU removal as the
190 * irq-work are per-cpu and the hotplug core takes care of flushing the pending
191 * irq-works (hint: smpcfd_dying_cpu()) on CPU hotplug. Even if the kthread-work
192 * fires on another CPU after the concerned CPU is removed, it won't harm.
193 *
194 * We just need to make sure to remove them all on policy->exit().
195 */
196static void cppc_cpufreq_cpu_fie_exit(struct cpufreq_policy *policy)
197{
198 struct cppc_freq_invariance *cppc_fi;
199 int cpu;
200
201 if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate)
202 return;
203
204 /* policy->cpus will be empty here, use related_cpus instead */
205 topology_clear_scale_freq_source(SCALE_FREQ_SOURCE_CPPC, policy->related_cpus);
206
207 for_each_cpu(cpu, policy->related_cpus) {
208 cppc_fi = &per_cpu(cppc_freq_inv, cpu);
209 irq_work_sync(&cppc_fi->irq_work);
210 kthread_cancel_work_sync(&cppc_fi->work);
211 }
212}
213
214static void __init cppc_freq_invariance_init(void)
215{
216 struct sched_attr attr = {
217 .size = sizeof(struct sched_attr),
218 .sched_policy = SCHED_DEADLINE,
219 .sched_nice = 0,
220 .sched_priority = 0,
221 /*
222 * Fake (unused) bandwidth; workaround to "fix"
223 * priority inheritance.
224 */
225 .sched_runtime = 1000000,
226 .sched_deadline = 10000000,
227 .sched_period = 10000000,
228 };
229 int ret;
230
231 if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate)
232 return;
233
234 kworker_fie = kthread_create_worker(0, "cppc_fie");
235 if (IS_ERR(kworker_fie))
236 return;
237
238 ret = sched_setattr_nocheck(kworker_fie->task, &attr);
239 if (ret) {
240 pr_warn("%s: failed to set SCHED_DEADLINE: %d\n", __func__,
241 ret);
242 kthread_destroy_worker(kworker_fie);
243 return;
244 }
245}
246
247static void cppc_freq_invariance_exit(void)
248{
249 if (cppc_cpufreq_driver.get == hisi_cppc_cpufreq_get_rate)
250 return;
251
252 kthread_destroy_worker(kworker_fie);
253 kworker_fie = NULL;
254}
255
256#else
257static inline void cppc_cpufreq_cpu_fie_init(struct cpufreq_policy *policy)
258{
259}
260
261static inline void cppc_cpufreq_cpu_fie_exit(struct cpufreq_policy *policy)
262{
263}
264
265static inline void cppc_freq_invariance_init(void)
266{
267}
268
269static inline void cppc_freq_invariance_exit(void)
270{
271}
272#endif /* CONFIG_ACPI_CPPC_CPUFREQ_FIE */
273
274/* Callback function used to retrieve the max frequency from DMI */
275static void cppc_find_dmi_mhz(const struct dmi_header *dm, void *private)
276{
277 const u8 *dmi_data = (const u8 *)dm;
278 u16 *mhz = (u16 *)private;
279
280 if (dm->type == DMI_ENTRY_PROCESSOR &&
281 dm->length >= DMI_ENTRY_PROCESSOR_MIN_LENGTH) {
282 u16 val = (u16)get_unaligned((const u16 *)
283 (dmi_data + DMI_PROCESSOR_MAX_SPEED));
284 *mhz = val > *mhz ? val : *mhz;
285 }
286}
287
288/* Look up the max frequency in DMI */
289static u64 cppc_get_dmi_max_khz(void)
290{
291 u16 mhz = 0;
292
293 dmi_walk(cppc_find_dmi_mhz, &mhz);
294
295 /*
296 * Real stupid fallback value, just in case there is no
297 * actual value set.
298 */
299 mhz = mhz ? mhz : 1;
300
301 return (1000 * mhz);
302}
303
304/*
305 * If CPPC lowest_freq and nominal_freq registers are exposed then we can
306 * use them to convert perf to freq and vice versa
307 *
308 * If the perf/freq point lies between Nominal and Lowest, we can treat
309 * (Low perf, Low freq) and (Nom Perf, Nom freq) as 2D co-ordinates of a line
310 * and extrapolate the rest
311 * For perf/freq > Nominal, we use the ratio perf:freq at Nominal for conversion
312 */
313static unsigned int cppc_cpufreq_perf_to_khz(struct cppc_cpudata *cpu_data,
314 unsigned int perf)
315{
316 struct cppc_perf_caps *caps = &cpu_data->perf_caps;
317 static u64 max_khz;
318 u64 mul, div;
319
320 if (caps->lowest_freq && caps->nominal_freq) {
321 if (perf >= caps->nominal_perf) {
322 mul = caps->nominal_freq;
323 div = caps->nominal_perf;
324 } else {
325 mul = caps->nominal_freq - caps->lowest_freq;
326 div = caps->nominal_perf - caps->lowest_perf;
327 }
328 } else {
329 if (!max_khz)
330 max_khz = cppc_get_dmi_max_khz();
331 mul = max_khz;
332 div = caps->highest_perf;
333 }
334 return (u64)perf * mul / div;
335}
336
337static unsigned int cppc_cpufreq_khz_to_perf(struct cppc_cpudata *cpu_data,
338 unsigned int freq)
339{
340 struct cppc_perf_caps *caps = &cpu_data->perf_caps;
341 static u64 max_khz;
342 u64 mul, div;
343
344 if (caps->lowest_freq && caps->nominal_freq) {
345 if (freq >= caps->nominal_freq) {
346 mul = caps->nominal_perf;
347 div = caps->nominal_freq;
348 } else {
349 mul = caps->lowest_perf;
350 div = caps->lowest_freq;
351 }
352 } else {
353 if (!max_khz)
354 max_khz = cppc_get_dmi_max_khz();
355 mul = caps->highest_perf;
356 div = max_khz;
357 }
358
359 return (u64)freq * mul / div;
360}
361
362static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
363 unsigned int target_freq,
364 unsigned int relation)
365
366{
367 struct cppc_cpudata *cpu_data = policy->driver_data;
368 unsigned int cpu = policy->cpu;
369 struct cpufreq_freqs freqs;
370 u32 desired_perf;
371 int ret = 0;
372
373 desired_perf = cppc_cpufreq_khz_to_perf(cpu_data, target_freq);
374 /* Return if it is exactly the same perf */
375 if (desired_perf == cpu_data->perf_ctrls.desired_perf)
376 return ret;
377
378 cpu_data->perf_ctrls.desired_perf = desired_perf;
379 freqs.old = policy->cur;
380 freqs.new = target_freq;
381
382 cpufreq_freq_transition_begin(policy, &freqs);
383 ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
384 cpufreq_freq_transition_end(policy, &freqs, ret != 0);
385
386 if (ret)
387 pr_debug("Failed to set target on CPU:%d. ret:%d\n",
388 cpu, ret);
389
390 return ret;
391}
392
393static int cppc_verify_policy(struct cpufreq_policy_data *policy)
394{
395 cpufreq_verify_within_cpu_limits(policy);
396 return 0;
397}
398
399/*
400 * The PCC subspace describes the rate at which platform can accept commands
401 * on the shared PCC channel (including READs which do not count towards freq
402 * transition requests), so ideally we need to use the PCC values as a fallback
403 * if we don't have a platform specific transition_delay_us
404 */
405#ifdef CONFIG_ARM64
406#include <asm/cputype.h>
407
408static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu)
409{
410 unsigned long implementor = read_cpuid_implementor();
411 unsigned long part_num = read_cpuid_part_number();
412
413 switch (implementor) {
414 case ARM_CPU_IMP_QCOM:
415 switch (part_num) {
416 case QCOM_CPU_PART_FALKOR_V1:
417 case QCOM_CPU_PART_FALKOR:
418 return 10000;
419 }
420 }
421 return cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
422}
423
424#else
425
426static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu)
427{
428 return cppc_get_transition_latency(cpu) / NSEC_PER_USEC;
429}
430#endif
431
432
433static struct cppc_cpudata *cppc_cpufreq_get_cpu_data(unsigned int cpu)
434{
435 struct cppc_cpudata *cpu_data;
436 int ret;
437
438 cpu_data = kzalloc(sizeof(struct cppc_cpudata), GFP_KERNEL);
439 if (!cpu_data)
440 goto out;
441
442 if (!zalloc_cpumask_var(&cpu_data->shared_cpu_map, GFP_KERNEL))
443 goto free_cpu;
444
445 ret = acpi_get_psd_map(cpu, cpu_data);
446 if (ret) {
447 pr_debug("Err parsing CPU%d PSD data: ret:%d\n", cpu, ret);
448 goto free_mask;
449 }
450
451 ret = cppc_get_perf_caps(cpu, &cpu_data->perf_caps);
452 if (ret) {
453 pr_debug("Err reading CPU%d perf caps: ret:%d\n", cpu, ret);
454 goto free_mask;
455 }
456
457 /* Convert the lowest and nominal freq from MHz to KHz */
458 cpu_data->perf_caps.lowest_freq *= 1000;
459 cpu_data->perf_caps.nominal_freq *= 1000;
460
461 list_add(&cpu_data->node, &cpu_data_list);
462
463 return cpu_data;
464
465free_mask:
466 free_cpumask_var(cpu_data->shared_cpu_map);
467free_cpu:
468 kfree(cpu_data);
469out:
470 return NULL;
471}
472
473static void cppc_cpufreq_put_cpu_data(struct cpufreq_policy *policy)
474{
475 struct cppc_cpudata *cpu_data = policy->driver_data;
476
477 list_del(&cpu_data->node);
478 free_cpumask_var(cpu_data->shared_cpu_map);
479 kfree(cpu_data);
480 policy->driver_data = NULL;
481}
482
483static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
484{
485 unsigned int cpu = policy->cpu;
486 struct cppc_cpudata *cpu_data;
487 struct cppc_perf_caps *caps;
488 int ret;
489
490 cpu_data = cppc_cpufreq_get_cpu_data(cpu);
491 if (!cpu_data) {
492 pr_err("Error in acquiring _CPC/_PSD data for CPU%d.\n", cpu);
493 return -ENODEV;
494 }
495 caps = &cpu_data->perf_caps;
496 policy->driver_data = cpu_data;
497
498 /*
499 * Set min to lowest nonlinear perf to avoid any efficiency penalty (see
500 * Section 8.4.7.1.1.5 of ACPI 6.1 spec)
501 */
502 policy->min = cppc_cpufreq_perf_to_khz(cpu_data,
503 caps->lowest_nonlinear_perf);
504 policy->max = cppc_cpufreq_perf_to_khz(cpu_data,
505 caps->nominal_perf);
506
507 /*
508 * Set cpuinfo.min_freq to Lowest to make the full range of performance
509 * available if userspace wants to use any perf between lowest & lowest
510 * nonlinear perf
511 */
512 policy->cpuinfo.min_freq = cppc_cpufreq_perf_to_khz(cpu_data,
513 caps->lowest_perf);
514 policy->cpuinfo.max_freq = cppc_cpufreq_perf_to_khz(cpu_data,
515 caps->nominal_perf);
516
517 policy->transition_delay_us = cppc_cpufreq_get_transition_delay_us(cpu);
518 policy->shared_type = cpu_data->shared_type;
519
520 switch (policy->shared_type) {
521 case CPUFREQ_SHARED_TYPE_HW:
522 case CPUFREQ_SHARED_TYPE_NONE:
523 /* Nothing to be done - we'll have a policy for each CPU */
524 break;
525 case CPUFREQ_SHARED_TYPE_ANY:
526 /*
527 * All CPUs in the domain will share a policy and all cpufreq
528 * operations will use a single cppc_cpudata structure stored
529 * in policy->driver_data.
530 */
531 cpumask_copy(policy->cpus, cpu_data->shared_cpu_map);
532 break;
533 default:
534 pr_debug("Unsupported CPU co-ord type: %d\n",
535 policy->shared_type);
536 ret = -EFAULT;
537 goto out;
538 }
539
540 /*
541 * If 'highest_perf' is greater than 'nominal_perf', we assume CPU Boost
542 * is supported.
543 */
544 if (caps->highest_perf > caps->nominal_perf)
545 boost_supported = true;
546
547 /* Set policy->cur to max now. The governors will adjust later. */
548 policy->cur = cppc_cpufreq_perf_to_khz(cpu_data, caps->highest_perf);
549 cpu_data->perf_ctrls.desired_perf = caps->highest_perf;
550
551 ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
552 if (ret) {
553 pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
554 caps->highest_perf, cpu, ret);
555 goto out;
556 }
557
558 cppc_cpufreq_cpu_fie_init(policy);
559 return 0;
560
561out:
562 cppc_cpufreq_put_cpu_data(policy);
563 return ret;
564}
565
566static int cppc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
567{
568 struct cppc_cpudata *cpu_data = policy->driver_data;
569 struct cppc_perf_caps *caps = &cpu_data->perf_caps;
570 unsigned int cpu = policy->cpu;
571 int ret;
572
573 cppc_cpufreq_cpu_fie_exit(policy);
574
575 cpu_data->perf_ctrls.desired_perf = caps->lowest_perf;
576
577 ret = cppc_set_perf(cpu, &cpu_data->perf_ctrls);
578 if (ret)
579 pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
580 caps->lowest_perf, cpu, ret);
581
582 cppc_cpufreq_put_cpu_data(policy);
583 return 0;
584}
585
586static inline u64 get_delta(u64 t1, u64 t0)
587{
588 if (t1 > t0 || t0 > ~(u32)0)
589 return t1 - t0;
590
591 return (u32)t1 - (u32)t0;
592}
593
594static int cppc_perf_from_fbctrs(struct cppc_cpudata *cpu_data,
595 struct cppc_perf_fb_ctrs *fb_ctrs_t0,
596 struct cppc_perf_fb_ctrs *fb_ctrs_t1)
597{
598 u64 delta_reference, delta_delivered;
599 u64 reference_perf;
600
601 reference_perf = fb_ctrs_t0->reference_perf;
602
603 delta_reference = get_delta(fb_ctrs_t1->reference,
604 fb_ctrs_t0->reference);
605 delta_delivered = get_delta(fb_ctrs_t1->delivered,
606 fb_ctrs_t0->delivered);
607
608 /* Check to avoid divide-by zero and invalid delivered_perf */
609 if (!delta_reference || !delta_delivered)
610 return cpu_data->perf_ctrls.desired_perf;
611
612 return (reference_perf * delta_delivered) / delta_reference;
613}
614
615static unsigned int cppc_cpufreq_get_rate(unsigned int cpu)
616{
617 struct cppc_perf_fb_ctrs fb_ctrs_t0 = {0}, fb_ctrs_t1 = {0};
618 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
619 struct cppc_cpudata *cpu_data = policy->driver_data;
620 u64 delivered_perf;
621 int ret;
622
623 cpufreq_cpu_put(policy);
624
625 ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t0);
626 if (ret)
627 return ret;
628
629 udelay(2); /* 2usec delay between sampling */
630
631 ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t1);
632 if (ret)
633 return ret;
634
635 delivered_perf = cppc_perf_from_fbctrs(cpu_data, &fb_ctrs_t0,
636 &fb_ctrs_t1);
637
638 return cppc_cpufreq_perf_to_khz(cpu_data, delivered_perf);
639}
640
641static int cppc_cpufreq_set_boost(struct cpufreq_policy *policy, int state)
642{
643 struct cppc_cpudata *cpu_data = policy->driver_data;
644 struct cppc_perf_caps *caps = &cpu_data->perf_caps;
645 int ret;
646
647 if (!boost_supported) {
648 pr_err("BOOST not supported by CPU or firmware\n");
649 return -EINVAL;
650 }
651
652 if (state)
653 policy->max = cppc_cpufreq_perf_to_khz(cpu_data,
654 caps->highest_perf);
655 else
656 policy->max = cppc_cpufreq_perf_to_khz(cpu_data,
657 caps->nominal_perf);
658 policy->cpuinfo.max_freq = policy->max;
659
660 ret = freq_qos_update_request(policy->max_freq_req, policy->max);
661 if (ret < 0)
662 return ret;
663
664 return 0;
665}
666
667static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
668{
669 struct cppc_cpudata *cpu_data = policy->driver_data;
670
671 return cpufreq_show_cpus(cpu_data->shared_cpu_map, buf);
672}
673cpufreq_freq_attr_ro(freqdomain_cpus);
674
675static struct freq_attr *cppc_cpufreq_attr[] = {
676 &freqdomain_cpus,
677 NULL,
678};
679
680static struct cpufreq_driver cppc_cpufreq_driver = {
681 .flags = CPUFREQ_CONST_LOOPS,
682 .verify = cppc_verify_policy,
683 .target = cppc_cpufreq_set_target,
684 .get = cppc_cpufreq_get_rate,
685 .init = cppc_cpufreq_cpu_init,
686 .exit = cppc_cpufreq_cpu_exit,
687 .set_boost = cppc_cpufreq_set_boost,
688 .attr = cppc_cpufreq_attr,
689 .name = "cppc_cpufreq",
690};
691
692/*
693 * HISI platform does not support delivered performance counter and
694 * reference performance counter. It can calculate the performance using the
695 * platform specific mechanism. We reuse the desired performance register to
696 * store the real performance calculated by the platform.
697 */
698static unsigned int hisi_cppc_cpufreq_get_rate(unsigned int cpu)
699{
700 struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
701 struct cppc_cpudata *cpu_data = policy->driver_data;
702 u64 desired_perf;
703 int ret;
704
705 cpufreq_cpu_put(policy);
706
707 ret = cppc_get_desired_perf(cpu, &desired_perf);
708 if (ret < 0)
709 return -EIO;
710
711 return cppc_cpufreq_perf_to_khz(cpu_data, desired_perf);
712}
713
714static void cppc_check_hisi_workaround(void)
715{
716 struct acpi_table_header *tbl;
717 acpi_status status = AE_OK;
718 int i;
719
720 status = acpi_get_table(ACPI_SIG_PCCT, 0, &tbl);
721 if (ACPI_FAILURE(status) || !tbl)
722 return;
723
724 for (i = 0; i < ARRAY_SIZE(wa_info); i++) {
725 if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE) &&
726 !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) &&
727 wa_info[i].oem_revision == tbl->oem_revision) {
728 /* Overwrite the get() callback */
729 cppc_cpufreq_driver.get = hisi_cppc_cpufreq_get_rate;
730 break;
731 }
732 }
733
734 acpi_put_table(tbl);
735}
736
737static int __init cppc_cpufreq_init(void)
738{
739 int ret;
740
741 if ((acpi_disabled) || !acpi_cpc_valid())
742 return -ENODEV;
743
744 INIT_LIST_HEAD(&cpu_data_list);
745
746 cppc_check_hisi_workaround();
747 cppc_freq_invariance_init();
748
749 ret = cpufreq_register_driver(&cppc_cpufreq_driver);
750 if (ret)
751 cppc_freq_invariance_exit();
752
753 return ret;
754}
755
756static inline void free_cpu_data(void)
757{
758 struct cppc_cpudata *iter, *tmp;
759
760 list_for_each_entry_safe(iter, tmp, &cpu_data_list, node) {
761 free_cpumask_var(iter->shared_cpu_map);
762 list_del(&iter->node);
763 kfree(iter);
764 }
765
766}
767
768static void __exit cppc_cpufreq_exit(void)
769{
770 cpufreq_unregister_driver(&cppc_cpufreq_driver);
771 cppc_freq_invariance_exit();
772
773 free_cpu_data();
774}
775
776module_exit(cppc_cpufreq_exit);
777MODULE_AUTHOR("Ashwin Chaugule");
778MODULE_DESCRIPTION("CPUFreq driver based on the ACPI CPPC v5.0+ spec");
779MODULE_LICENSE("GPL");
780
781late_initcall(cppc_cpufreq_init);
782
783static const struct acpi_device_id cppc_acpi_ids[] __used = {
784 {ACPI_PROCESSOR_DEVICE_HID, },
785 {}
786};
787
788MODULE_DEVICE_TABLE(acpi, cppc_acpi_ids);