GNU Linux-libre 5.19-rc6-gnu
[releases.git] / drivers / cpufreq / pcc-cpufreq.c
1 /*
2  *  pcc-cpufreq.c - Processor Clocking Control firmware cpufreq interface
3  *
4  *  Copyright (C) 2009 Red Hat, Matthew Garrett <mjg@redhat.com>
5  *  Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
6  *      Nagananda Chumbalkar <nagananda.chumbalkar@hp.com>
7  *
8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9  *
10  *  This program is free software; you can redistribute it and/or modify
11  *  it under the terms of the GNU General Public License as published by
12  *  the Free Software Foundation; version 2 of the License.
13  *
14  *  This program is distributed in the hope that it will be useful, but
15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or NON
17  *  INFRINGEMENT. See the GNU General Public License for more details.
18  *
19  *  You should have received a copy of the GNU General Public License along
20  *  with this program; if not, write to the Free Software Foundation, Inc.,
21  *  675 Mass Ave, Cambridge, MA 02139, USA.
22  *
23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
24  */
25
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <linux/smp.h>
30 #include <linux/sched.h>
31 #include <linux/cpufreq.h>
32 #include <linux/compiler.h>
33 #include <linux/slab.h>
34
35 #include <linux/acpi.h>
36 #include <linux/io.h>
37 #include <linux/spinlock.h>
38 #include <linux/uaccess.h>
39
40 #include <acpi/processor.h>
41
42 #define PCC_VERSION     "1.10.00"
43 #define POLL_LOOPS      300
44
45 #define CMD_COMPLETE    0x1
46 #define CMD_GET_FREQ    0x0
47 #define CMD_SET_FREQ    0x1
48
49 #define BUF_SZ          4
50
51 struct pcc_register_resource {
52         u8 descriptor;
53         u16 length;
54         u8 space_id;
55         u8 bit_width;
56         u8 bit_offset;
57         u8 access_size;
58         u64 address;
59 } __attribute__ ((packed));
60
61 struct pcc_memory_resource {
62         u8 descriptor;
63         u16 length;
64         u8 space_id;
65         u8 resource_usage;
66         u8 type_specific;
67         u64 granularity;
68         u64 minimum;
69         u64 maximum;
70         u64 translation_offset;
71         u64 address_length;
72 } __attribute__ ((packed));
73
74 static struct cpufreq_driver pcc_cpufreq_driver;
75
76 struct pcc_header {
77         u32 signature;
78         u16 length;
79         u8 major;
80         u8 minor;
81         u32 features;
82         u16 command;
83         u16 status;
84         u32 latency;
85         u32 minimum_time;
86         u32 maximum_time;
87         u32 nominal;
88         u32 throttled_frequency;
89         u32 minimum_frequency;
90 };
91
92 static void __iomem *pcch_virt_addr;
93 static struct pcc_header __iomem *pcch_hdr;
94
95 static DEFINE_SPINLOCK(pcc_lock);
96
97 static struct acpi_generic_address doorbell;
98
99 static u64 doorbell_preserve;
100 static u64 doorbell_write;
101
102 static u8 OSC_UUID[16] = {0x9F, 0x2C, 0x9B, 0x63, 0x91, 0x70, 0x1f, 0x49,
103                           0xBB, 0x4F, 0xA5, 0x98, 0x2F, 0xA1, 0xB5, 0x46};
104
105 struct pcc_cpu {
106         u32 input_offset;
107         u32 output_offset;
108 };
109
110 static struct pcc_cpu __percpu *pcc_cpu_info;
111
112 static int pcc_cpufreq_verify(struct cpufreq_policy_data *policy)
113 {
114         cpufreq_verify_within_cpu_limits(policy);
115         return 0;
116 }
117
118 static inline void pcc_cmd(void)
119 {
120         u64 doorbell_value;
121         int i;
122
123         acpi_read(&doorbell_value, &doorbell);
124         acpi_write((doorbell_value & doorbell_preserve) | doorbell_write,
125                    &doorbell);
126
127         for (i = 0; i < POLL_LOOPS; i++) {
128                 if (ioread16(&pcch_hdr->status) & CMD_COMPLETE)
129                         break;
130         }
131 }
132
133 static inline void pcc_clear_mapping(void)
134 {
135         if (pcch_virt_addr)
136                 iounmap(pcch_virt_addr);
137         pcch_virt_addr = NULL;
138 }
139
140 static unsigned int pcc_get_freq(unsigned int cpu)
141 {
142         struct pcc_cpu *pcc_cpu_data;
143         unsigned int curr_freq;
144         unsigned int freq_limit;
145         u16 status;
146         u32 input_buffer;
147         u32 output_buffer;
148
149         spin_lock(&pcc_lock);
150
151         pr_debug("get: get_freq for CPU %d\n", cpu);
152         pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
153
154         input_buffer = 0x1;
155         iowrite32(input_buffer,
156                         (pcch_virt_addr + pcc_cpu_data->input_offset));
157         iowrite16(CMD_GET_FREQ, &pcch_hdr->command);
158
159         pcc_cmd();
160
161         output_buffer =
162                 ioread32(pcch_virt_addr + pcc_cpu_data->output_offset);
163
164         /* Clear the input buffer - we are done with the current command */
165         memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
166
167         status = ioread16(&pcch_hdr->status);
168         if (status != CMD_COMPLETE) {
169                 pr_debug("get: FAILED: for CPU %d, status is %d\n",
170                         cpu, status);
171                 goto cmd_incomplete;
172         }
173         iowrite16(0, &pcch_hdr->status);
174         curr_freq = (((ioread32(&pcch_hdr->nominal) * (output_buffer & 0xff))
175                         / 100) * 1000);
176
177         pr_debug("get: SUCCESS: (virtual) output_offset for cpu %d is "
178                 "0x%p, contains a value of: 0x%x. Speed is: %d MHz\n",
179                 cpu, (pcch_virt_addr + pcc_cpu_data->output_offset),
180                 output_buffer, curr_freq);
181
182         freq_limit = (output_buffer >> 8) & 0xff;
183         if (freq_limit != 0xff) {
184                 pr_debug("get: frequency for cpu %d is being temporarily"
185                         " capped at %d\n", cpu, curr_freq);
186         }
187
188         spin_unlock(&pcc_lock);
189         return curr_freq;
190
191 cmd_incomplete:
192         iowrite16(0, &pcch_hdr->status);
193         spin_unlock(&pcc_lock);
194         return 0;
195 }
196
197 static int pcc_cpufreq_target(struct cpufreq_policy *policy,
198                               unsigned int target_freq,
199                               unsigned int relation)
200 {
201         struct pcc_cpu *pcc_cpu_data;
202         struct cpufreq_freqs freqs;
203         u16 status;
204         u32 input_buffer;
205         int cpu;
206
207         cpu = policy->cpu;
208         pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
209
210         pr_debug("target: CPU %d should go to target freq: %d "
211                 "(virtual) input_offset is 0x%p\n",
212                 cpu, target_freq,
213                 (pcch_virt_addr + pcc_cpu_data->input_offset));
214
215         freqs.old = policy->cur;
216         freqs.new = target_freq;
217         cpufreq_freq_transition_begin(policy, &freqs);
218         spin_lock(&pcc_lock);
219
220         input_buffer = 0x1 | (((target_freq * 100)
221                                / (ioread32(&pcch_hdr->nominal) * 1000)) << 8);
222         iowrite32(input_buffer,
223                         (pcch_virt_addr + pcc_cpu_data->input_offset));
224         iowrite16(CMD_SET_FREQ, &pcch_hdr->command);
225
226         pcc_cmd();
227
228         /* Clear the input buffer - we are done with the current command */
229         memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
230
231         status = ioread16(&pcch_hdr->status);
232         iowrite16(0, &pcch_hdr->status);
233
234         cpufreq_freq_transition_end(policy, &freqs, status != CMD_COMPLETE);
235         spin_unlock(&pcc_lock);
236
237         if (status != CMD_COMPLETE) {
238                 pr_debug("target: FAILED for cpu %d, with status: 0x%x\n",
239                         cpu, status);
240                 return -EINVAL;
241         }
242
243         pr_debug("target: was SUCCESSFUL for cpu %d\n", cpu);
244
245         return 0;
246 }
247
248 static int pcc_get_offset(int cpu)
249 {
250         acpi_status status;
251         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
252         union acpi_object *pccp, *offset;
253         struct pcc_cpu *pcc_cpu_data;
254         struct acpi_processor *pr;
255         int ret = 0;
256
257         pr = per_cpu(processors, cpu);
258         pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
259
260         if (!pr)
261                 return -ENODEV;
262
263         status = acpi_evaluate_object(pr->handle, "PCCP", NULL, &buffer);
264         if (ACPI_FAILURE(status))
265                 return -ENODEV;
266
267         pccp = buffer.pointer;
268         if (!pccp || pccp->type != ACPI_TYPE_PACKAGE) {
269                 ret = -ENODEV;
270                 goto out_free;
271         }
272
273         offset = &(pccp->package.elements[0]);
274         if (!offset || offset->type != ACPI_TYPE_INTEGER) {
275                 ret = -ENODEV;
276                 goto out_free;
277         }
278
279         pcc_cpu_data->input_offset = offset->integer.value;
280
281         offset = &(pccp->package.elements[1]);
282         if (!offset || offset->type != ACPI_TYPE_INTEGER) {
283                 ret = -ENODEV;
284                 goto out_free;
285         }
286
287         pcc_cpu_data->output_offset = offset->integer.value;
288
289         memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
290         memset_io((pcch_virt_addr + pcc_cpu_data->output_offset), 0, BUF_SZ);
291
292         pr_debug("pcc_get_offset: for CPU %d: pcc_cpu_data "
293                 "input_offset: 0x%x, pcc_cpu_data output_offset: 0x%x\n",
294                 cpu, pcc_cpu_data->input_offset, pcc_cpu_data->output_offset);
295 out_free:
296         kfree(buffer.pointer);
297         return ret;
298 }
299
300 static int __init pcc_cpufreq_do_osc(acpi_handle *handle)
301 {
302         acpi_status status;
303         struct acpi_object_list input;
304         struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
305         union acpi_object in_params[4];
306         union acpi_object *out_obj;
307         u32 capabilities[2];
308         u32 errors;
309         u32 supported;
310         int ret = 0;
311
312         input.count = 4;
313         input.pointer = in_params;
314         in_params[0].type               = ACPI_TYPE_BUFFER;
315         in_params[0].buffer.length      = 16;
316         in_params[0].buffer.pointer     = OSC_UUID;
317         in_params[1].type               = ACPI_TYPE_INTEGER;
318         in_params[1].integer.value      = 1;
319         in_params[2].type               = ACPI_TYPE_INTEGER;
320         in_params[2].integer.value      = 2;
321         in_params[3].type               = ACPI_TYPE_BUFFER;
322         in_params[3].buffer.length      = 8;
323         in_params[3].buffer.pointer     = (u8 *)&capabilities;
324
325         capabilities[0] = OSC_QUERY_ENABLE;
326         capabilities[1] = 0x1;
327
328         status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
329         if (ACPI_FAILURE(status))
330                 return -ENODEV;
331
332         if (!output.length)
333                 return -ENODEV;
334
335         out_obj = output.pointer;
336         if (out_obj->type != ACPI_TYPE_BUFFER) {
337                 ret = -ENODEV;
338                 goto out_free;
339         }
340
341         errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
342         if (errors) {
343                 ret = -ENODEV;
344                 goto out_free;
345         }
346
347         supported = *((u32 *)(out_obj->buffer.pointer + 4));
348         if (!(supported & 0x1)) {
349                 ret = -ENODEV;
350                 goto out_free;
351         }
352
353         kfree(output.pointer);
354         capabilities[0] = 0x0;
355         capabilities[1] = 0x1;
356
357         status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
358         if (ACPI_FAILURE(status))
359                 return -ENODEV;
360
361         if (!output.length)
362                 return -ENODEV;
363
364         out_obj = output.pointer;
365         if (out_obj->type != ACPI_TYPE_BUFFER) {
366                 ret = -ENODEV;
367                 goto out_free;
368         }
369
370         errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
371         if (errors) {
372                 ret = -ENODEV;
373                 goto out_free;
374         }
375
376         supported = *((u32 *)(out_obj->buffer.pointer + 4));
377         if (!(supported & 0x1)) {
378                 ret = -ENODEV;
379                 goto out_free;
380         }
381
382 out_free:
383         kfree(output.pointer);
384         return ret;
385 }
386
387 static int __init pcc_cpufreq_probe(void)
388 {
389         acpi_status status;
390         struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
391         struct pcc_memory_resource *mem_resource;
392         struct pcc_register_resource *reg_resource;
393         union acpi_object *out_obj, *member;
394         acpi_handle handle, osc_handle;
395         int ret = 0;
396
397         status = acpi_get_handle(NULL, "\\_SB", &handle);
398         if (ACPI_FAILURE(status))
399                 return -ENODEV;
400
401         if (!acpi_has_method(handle, "PCCH"))
402                 return -ENODEV;
403
404         status = acpi_get_handle(handle, "_OSC", &osc_handle);
405         if (ACPI_SUCCESS(status)) {
406                 ret = pcc_cpufreq_do_osc(&osc_handle);
407                 if (ret)
408                         pr_debug("probe: _OSC evaluation did not succeed\n");
409                 /* Firmware's use of _OSC is optional */
410                 ret = 0;
411         }
412
413         status = acpi_evaluate_object(handle, "PCCH", NULL, &output);
414         if (ACPI_FAILURE(status))
415                 return -ENODEV;
416
417         out_obj = output.pointer;
418         if (out_obj->type != ACPI_TYPE_PACKAGE) {
419                 ret = -ENODEV;
420                 goto out_free;
421         }
422
423         member = &out_obj->package.elements[0];
424         if (member->type != ACPI_TYPE_BUFFER) {
425                 ret = -ENODEV;
426                 goto out_free;
427         }
428
429         mem_resource = (struct pcc_memory_resource *)member->buffer.pointer;
430
431         pr_debug("probe: mem_resource descriptor: 0x%x,"
432                 " length: %d, space_id: %d, resource_usage: %d,"
433                 " type_specific: %d, granularity: 0x%llx,"
434                 " minimum: 0x%llx, maximum: 0x%llx,"
435                 " translation_offset: 0x%llx, address_length: 0x%llx\n",
436                 mem_resource->descriptor, mem_resource->length,
437                 mem_resource->space_id, mem_resource->resource_usage,
438                 mem_resource->type_specific, mem_resource->granularity,
439                 mem_resource->minimum, mem_resource->maximum,
440                 mem_resource->translation_offset,
441                 mem_resource->address_length);
442
443         if (mem_resource->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
444                 ret = -ENODEV;
445                 goto out_free;
446         }
447
448         pcch_virt_addr = ioremap(mem_resource->minimum,
449                                         mem_resource->address_length);
450         if (pcch_virt_addr == NULL) {
451                 pr_debug("probe: could not map shared mem region\n");
452                 ret = -ENOMEM;
453                 goto out_free;
454         }
455         pcch_hdr = pcch_virt_addr;
456
457         pr_debug("probe: PCCH header (virtual) addr: 0x%p\n", pcch_hdr);
458         pr_debug("probe: PCCH header is at physical address: 0x%llx,"
459                 " signature: 0x%x, length: %d bytes, major: %d, minor: %d,"
460                 " supported features: 0x%x, command field: 0x%x,"
461                 " status field: 0x%x, nominal latency: %d us\n",
462                 mem_resource->minimum, ioread32(&pcch_hdr->signature),
463                 ioread16(&pcch_hdr->length), ioread8(&pcch_hdr->major),
464                 ioread8(&pcch_hdr->minor), ioread32(&pcch_hdr->features),
465                 ioread16(&pcch_hdr->command), ioread16(&pcch_hdr->status),
466                 ioread32(&pcch_hdr->latency));
467
468         pr_debug("probe: min time between commands: %d us,"
469                 " max time between commands: %d us,"
470                 " nominal CPU frequency: %d MHz,"
471                 " minimum CPU frequency: %d MHz,"
472                 " minimum CPU frequency without throttling: %d MHz\n",
473                 ioread32(&pcch_hdr->minimum_time),
474                 ioread32(&pcch_hdr->maximum_time),
475                 ioread32(&pcch_hdr->nominal),
476                 ioread32(&pcch_hdr->throttled_frequency),
477                 ioread32(&pcch_hdr->minimum_frequency));
478
479         member = &out_obj->package.elements[1];
480         if (member->type != ACPI_TYPE_BUFFER) {
481                 ret = -ENODEV;
482                 goto pcch_free;
483         }
484
485         reg_resource = (struct pcc_register_resource *)member->buffer.pointer;
486
487         doorbell.space_id = reg_resource->space_id;
488         doorbell.bit_width = reg_resource->bit_width;
489         doorbell.bit_offset = reg_resource->bit_offset;
490         doorbell.access_width = 4;
491         doorbell.address = reg_resource->address;
492
493         pr_debug("probe: doorbell: space_id is %d, bit_width is %d, "
494                 "bit_offset is %d, access_width is %d, address is 0x%llx\n",
495                 doorbell.space_id, doorbell.bit_width, doorbell.bit_offset,
496                 doorbell.access_width, reg_resource->address);
497
498         member = &out_obj->package.elements[2];
499         if (member->type != ACPI_TYPE_INTEGER) {
500                 ret = -ENODEV;
501                 goto pcch_free;
502         }
503
504         doorbell_preserve = member->integer.value;
505
506         member = &out_obj->package.elements[3];
507         if (member->type != ACPI_TYPE_INTEGER) {
508                 ret = -ENODEV;
509                 goto pcch_free;
510         }
511
512         doorbell_write = member->integer.value;
513
514         pr_debug("probe: doorbell_preserve: 0x%llx,"
515                 " doorbell_write: 0x%llx\n",
516                 doorbell_preserve, doorbell_write);
517
518         pcc_cpu_info = alloc_percpu(struct pcc_cpu);
519         if (!pcc_cpu_info) {
520                 ret = -ENOMEM;
521                 goto pcch_free;
522         }
523
524         printk(KERN_DEBUG "pcc-cpufreq: (v%s) driver loaded with frequency"
525                " limits: %d MHz, %d MHz\n", PCC_VERSION,
526                ioread32(&pcch_hdr->minimum_frequency),
527                ioread32(&pcch_hdr->nominal));
528         kfree(output.pointer);
529         return ret;
530 pcch_free:
531         pcc_clear_mapping();
532 out_free:
533         kfree(output.pointer);
534         return ret;
535 }
536
537 static int pcc_cpufreq_cpu_init(struct cpufreq_policy *policy)
538 {
539         unsigned int cpu = policy->cpu;
540         unsigned int result = 0;
541
542         if (!pcch_virt_addr) {
543                 result = -1;
544                 goto out;
545         }
546
547         result = pcc_get_offset(cpu);
548         if (result) {
549                 pr_debug("init: PCCP evaluation failed\n");
550                 goto out;
551         }
552
553         policy->max = policy->cpuinfo.max_freq =
554                 ioread32(&pcch_hdr->nominal) * 1000;
555         policy->min = policy->cpuinfo.min_freq =
556                 ioread32(&pcch_hdr->minimum_frequency) * 1000;
557
558         pr_debug("init: policy->max is %d, policy->min is %d\n",
559                 policy->max, policy->min);
560 out:
561         return result;
562 }
563
564 static int pcc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
565 {
566         return 0;
567 }
568
569 static struct cpufreq_driver pcc_cpufreq_driver = {
570         .flags = CPUFREQ_CONST_LOOPS,
571         .get = pcc_get_freq,
572         .verify = pcc_cpufreq_verify,
573         .target = pcc_cpufreq_target,
574         .init = pcc_cpufreq_cpu_init,
575         .exit = pcc_cpufreq_cpu_exit,
576         .name = "pcc-cpufreq",
577 };
578
579 static int __init pcc_cpufreq_init(void)
580 {
581         int ret;
582
583         /* Skip initialization if another cpufreq driver is there. */
584         if (cpufreq_get_current_driver())
585                 return -EEXIST;
586
587         if (acpi_disabled)
588                 return -ENODEV;
589
590         ret = pcc_cpufreq_probe();
591         if (ret) {
592                 pr_debug("pcc_cpufreq_init: PCCH evaluation failed\n");
593                 return ret;
594         }
595
596         if (num_present_cpus() > 4) {
597                 pcc_cpufreq_driver.flags |= CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING;
598                 pr_err("%s: Too many CPUs, dynamic performance scaling disabled\n",
599                        __func__);
600                 pr_err("%s: Try to enable another scaling driver through BIOS settings\n",
601                        __func__);
602                 pr_err("%s: and complain to the system vendor\n", __func__);
603         }
604
605         ret = cpufreq_register_driver(&pcc_cpufreq_driver);
606
607         return ret;
608 }
609
610 static void __exit pcc_cpufreq_exit(void)
611 {
612         cpufreq_unregister_driver(&pcc_cpufreq_driver);
613
614         pcc_clear_mapping();
615
616         free_percpu(pcc_cpu_info);
617 }
618
619 static const struct acpi_device_id __maybe_unused processor_device_ids[] = {
620         {ACPI_PROCESSOR_OBJECT_HID, },
621         {ACPI_PROCESSOR_DEVICE_HID, },
622         {},
623 };
624 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
625
626 MODULE_AUTHOR("Matthew Garrett, Naga Chumbalkar");
627 MODULE_VERSION(PCC_VERSION);
628 MODULE_DESCRIPTION("Processor Clocking Control interface driver");
629 MODULE_LICENSE("GPL");
630
631 late_initcall(pcc_cpufreq_init);
632 module_exit(pcc_cpufreq_exit);