Merge commit 'v2.6.34-rc1' into perf/urgent
[pandora-kernel.git] / arch / x86 / kernel / cpu / 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
34 #include <linux/acpi.h>
35 #include <linux/io.h>
36 #include <linux/spinlock.h>
37 #include <linux/uaccess.h>
38
39 #include <acpi/processor.h>
40
41 #define PCC_VERSION     "1.00.00"
42 #define POLL_LOOPS      300
43
44 #define CMD_COMPLETE    0x1
45 #define CMD_GET_FREQ    0x0
46 #define CMD_SET_FREQ    0x1
47
48 #define BUF_SZ          4
49
50 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER,      \
51                                              "pcc-cpufreq", msg)
52
53 struct pcc_register_resource {
54         u8 descriptor;
55         u16 length;
56         u8 space_id;
57         u8 bit_width;
58         u8 bit_offset;
59         u8 access_size;
60         u64 address;
61 } __attribute__ ((packed));
62
63 struct pcc_memory_resource {
64         u8 descriptor;
65         u16 length;
66         u8 space_id;
67         u8 resource_usage;
68         u8 type_specific;
69         u64 granularity;
70         u64 minimum;
71         u64 maximum;
72         u64 translation_offset;
73         u64 address_length;
74 } __attribute__ ((packed));
75
76 static struct cpufreq_driver pcc_cpufreq_driver;
77
78 struct pcc_header {
79         u32 signature;
80         u16 length;
81         u8 major;
82         u8 minor;
83         u32 features;
84         u16 command;
85         u16 status;
86         u32 latency;
87         u32 minimum_time;
88         u32 maximum_time;
89         u32 nominal;
90         u32 throttled_frequency;
91         u32 minimum_frequency;
92 };
93
94 static void __iomem *pcch_virt_addr;
95 static struct pcc_header __iomem *pcch_hdr;
96
97 static DEFINE_SPINLOCK(pcc_lock);
98
99 static struct acpi_generic_address doorbell;
100
101 static u64 doorbell_preserve;
102 static u64 doorbell_write;
103
104 static u8 OSC_UUID[16] = {0x63, 0x9B, 0x2C, 0x9F, 0x70, 0x91, 0x49, 0x1f,
105                           0xBB, 0x4F, 0xA5, 0x98, 0x2F, 0xA1, 0xB5, 0x46};
106
107 struct pcc_cpu {
108         u32 input_offset;
109         u32 output_offset;
110 };
111
112 static struct pcc_cpu *pcc_cpu_info;
113
114 static int pcc_cpufreq_verify(struct cpufreq_policy *policy)
115 {
116         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
117                                      policy->cpuinfo.max_freq);
118         return 0;
119 }
120
121 static inline void pcc_cmd(void)
122 {
123         u64 doorbell_value;
124         int i;
125
126         acpi_read(&doorbell_value, &doorbell);
127         acpi_write((doorbell_value & doorbell_preserve) | doorbell_write,
128                    &doorbell);
129
130         for (i = 0; i < POLL_LOOPS; i++) {
131                 if (ioread16(&pcch_hdr->status) & CMD_COMPLETE)
132                         break;
133         }
134 }
135
136 static inline void pcc_clear_mapping(void)
137 {
138         if (pcch_virt_addr)
139                 iounmap(pcch_virt_addr);
140         pcch_virt_addr = NULL;
141 }
142
143 static unsigned int pcc_get_freq(unsigned int cpu)
144 {
145         struct pcc_cpu *pcc_cpu_data;
146         unsigned int curr_freq;
147         unsigned int freq_limit;
148         u16 status;
149         u32 input_buffer;
150         u32 output_buffer;
151
152         spin_lock(&pcc_lock);
153
154         dprintk("get: get_freq for CPU %d\n", cpu);
155         pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
156
157         input_buffer = 0x1;
158         iowrite32(input_buffer,
159                         (pcch_virt_addr + pcc_cpu_data->input_offset));
160         iowrite16(CMD_GET_FREQ, &pcch_hdr->command);
161
162         pcc_cmd();
163
164         output_buffer =
165                 ioread32(pcch_virt_addr + pcc_cpu_data->output_offset);
166
167         /* Clear the input buffer - we are done with the current command */
168         memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
169
170         status = ioread16(&pcch_hdr->status);
171         if (status != CMD_COMPLETE) {
172                 dprintk("get: FAILED: for CPU %d, status is %d\n",
173                         cpu, status);
174                 goto cmd_incomplete;
175         }
176         iowrite16(0, &pcch_hdr->status);
177         curr_freq = (((ioread32(&pcch_hdr->nominal) * (output_buffer & 0xff))
178                         / 100) * 1000);
179
180         dprintk("get: SUCCESS: (virtual) output_offset for cpu %d is "
181                 "0x%x, contains a value of: 0x%x. Speed is: %d MHz\n",
182                 cpu, (pcch_virt_addr + pcc_cpu_data->output_offset),
183                 output_buffer, curr_freq);
184
185         freq_limit = (output_buffer >> 8) & 0xff;
186         if (freq_limit != 0xff) {
187                 dprintk("get: frequency for cpu %d is being temporarily"
188                         " capped at %d\n", cpu, curr_freq);
189         }
190
191         spin_unlock(&pcc_lock);
192         return curr_freq;
193
194 cmd_incomplete:
195         iowrite16(0, &pcch_hdr->status);
196         spin_unlock(&pcc_lock);
197         return -EINVAL;
198 }
199
200 static int pcc_cpufreq_target(struct cpufreq_policy *policy,
201                               unsigned int target_freq,
202                               unsigned int relation)
203 {
204         struct pcc_cpu *pcc_cpu_data;
205         struct cpufreq_freqs freqs;
206         u16 status;
207         u32 input_buffer;
208         int cpu;
209
210         spin_lock(&pcc_lock);
211         cpu = policy->cpu;
212         pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
213
214         dprintk("target: CPU %d should go to target freq: %d "
215                 "(virtual) input_offset is 0x%x\n",
216                 cpu, target_freq,
217                 (pcch_virt_addr + pcc_cpu_data->input_offset));
218
219         freqs.new = target_freq;
220         freqs.cpu = cpu;
221         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
222
223         input_buffer = 0x1 | (((target_freq * 100)
224                                / (ioread32(&pcch_hdr->nominal) * 1000)) << 8);
225         iowrite32(input_buffer,
226                         (pcch_virt_addr + pcc_cpu_data->input_offset));
227         iowrite16(CMD_SET_FREQ, &pcch_hdr->command);
228
229         pcc_cmd();
230
231         /* Clear the input buffer - we are done with the current command */
232         memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
233
234         status = ioread16(&pcch_hdr->status);
235         if (status != CMD_COMPLETE) {
236                 dprintk("target: FAILED for cpu %d, with status: 0x%x\n",
237                         cpu, status);
238                 goto cmd_incomplete;
239         }
240         iowrite16(0, &pcch_hdr->status);
241
242         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
243         dprintk("target: was SUCCESSFUL for cpu %d\n", cpu);
244         spin_unlock(&pcc_lock);
245
246         return 0;
247
248 cmd_incomplete:
249         iowrite16(0, &pcch_hdr->status);
250         spin_unlock(&pcc_lock);
251         return -EINVAL;
252 }
253
254 static int pcc_get_offset(int cpu)
255 {
256         acpi_status status;
257         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
258         union acpi_object *pccp, *offset;
259         struct pcc_cpu *pcc_cpu_data;
260         struct acpi_processor *pr;
261         int ret = 0;
262
263         pr = per_cpu(processors, cpu);
264         pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
265
266         status = acpi_evaluate_object(pr->handle, "PCCP", NULL, &buffer);
267         if (ACPI_FAILURE(status))
268                 return -ENODEV;
269
270         pccp = buffer.pointer;
271         if (!pccp || pccp->type != ACPI_TYPE_PACKAGE) {
272                 ret = -ENODEV;
273                 goto out_free;
274         };
275
276         offset = &(pccp->package.elements[0]);
277         if (!offset || offset->type != ACPI_TYPE_INTEGER) {
278                 ret = -ENODEV;
279                 goto out_free;
280         }
281
282         pcc_cpu_data->input_offset = offset->integer.value;
283
284         offset = &(pccp->package.elements[1]);
285         if (!offset || offset->type != ACPI_TYPE_INTEGER) {
286                 ret = -ENODEV;
287                 goto out_free;
288         }
289
290         pcc_cpu_data->output_offset = offset->integer.value;
291
292         memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
293         memset_io((pcch_virt_addr + pcc_cpu_data->output_offset), 0, BUF_SZ);
294
295         dprintk("pcc_get_offset: for CPU %d: pcc_cpu_data "
296                 "input_offset: 0x%x, pcc_cpu_data output_offset: 0x%x\n",
297                 cpu, pcc_cpu_data->input_offset, pcc_cpu_data->output_offset);
298 out_free:
299         kfree(buffer.pointer);
300         return ret;
301 }
302
303 static int __init pcc_cpufreq_do_osc(acpi_handle *handle)
304 {
305         acpi_status status;
306         struct acpi_object_list input;
307         struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
308         union acpi_object in_params[4];
309         union acpi_object *out_obj;
310         u32 capabilities[2];
311         u32 errors;
312         u32 supported;
313         int ret = 0;
314
315         input.count = 4;
316         input.pointer = in_params;
317         input.count = 4;
318         input.pointer = in_params;
319         in_params[0].type               = ACPI_TYPE_BUFFER;
320         in_params[0].buffer.length      = 16;
321         in_params[0].buffer.pointer     = OSC_UUID;
322         in_params[1].type               = ACPI_TYPE_INTEGER;
323         in_params[1].integer.value      = 1;
324         in_params[2].type               = ACPI_TYPE_INTEGER;
325         in_params[2].integer.value      = 2;
326         in_params[3].type               = ACPI_TYPE_BUFFER;
327         in_params[3].buffer.length      = 8;
328         in_params[3].buffer.pointer     = (u8 *)&capabilities;
329
330         capabilities[0] = OSC_QUERY_ENABLE;
331         capabilities[1] = 0x1;
332
333         status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
334         if (ACPI_FAILURE(status))
335                 return -ENODEV;
336
337         if (!output.length)
338                 return -ENODEV;
339
340         out_obj = output.pointer;
341         if (out_obj->type != ACPI_TYPE_BUFFER) {
342                 ret = -ENODEV;
343                 goto out_free;
344         }
345
346         errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
347         if (errors) {
348                 ret = -ENODEV;
349                 goto out_free;
350         }
351
352         supported = *((u32 *)(out_obj->buffer.pointer + 4));
353         if (!(supported & 0x1)) {
354                 ret = -ENODEV;
355                 goto out_free;
356         }
357
358         kfree(output.pointer);
359         capabilities[0] = 0x0;
360         capabilities[1] = 0x1;
361
362         status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
363         if (ACPI_FAILURE(status))
364                 return -ENODEV;
365
366         if (!output.length)
367                 return -ENODEV;
368
369         out_obj = output.pointer;
370         if (out_obj->type != ACPI_TYPE_BUFFER) {
371                 ret = -ENODEV;
372                 goto out_free;
373         }
374
375         errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
376         if (errors) {
377                 ret = -ENODEV;
378                 goto out_free;
379         }
380
381         supported = *((u32 *)(out_obj->buffer.pointer + 4));
382         if (!(supported & 0x1)) {
383                 ret = -ENODEV;
384                 goto out_free;
385         }
386
387 out_free:
388         kfree(output.pointer);
389         return ret;
390 }
391
392 static int __init pcc_cpufreq_probe(void)
393 {
394         acpi_status status;
395         struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
396         struct pcc_memory_resource *mem_resource;
397         struct pcc_register_resource *reg_resource;
398         union acpi_object *out_obj, *member;
399         acpi_handle handle, osc_handle;
400         int ret = 0;
401
402         status = acpi_get_handle(NULL, "\\_SB", &handle);
403         if (ACPI_FAILURE(status))
404                 return -ENODEV;
405
406         status = acpi_get_handle(handle, "_OSC", &osc_handle);
407         if (ACPI_SUCCESS(status)) {
408                 ret = pcc_cpufreq_do_osc(&osc_handle);
409                 if (ret)
410                         dprintk("probe: _OSC evaluation did not succeed\n");
411                 /* Firmware's use of _OSC is optional */
412                 ret = 0;
413         }
414
415         status = acpi_evaluate_object(handle, "PCCH", NULL, &output);
416         if (ACPI_FAILURE(status))
417                 return -ENODEV;
418
419         out_obj = output.pointer;
420         if (out_obj->type != ACPI_TYPE_PACKAGE) {
421                 ret = -ENODEV;
422                 goto out_free;
423         }
424
425         member = &out_obj->package.elements[0];
426         if (member->type != ACPI_TYPE_BUFFER) {
427                 ret = -ENODEV;
428                 goto out_free;
429         }
430
431         mem_resource = (struct pcc_memory_resource *)member->buffer.pointer;
432
433         dprintk("probe: mem_resource descriptor: 0x%x,"
434                 " length: %d, space_id: %d, resource_usage: %d,"
435                 " type_specific: %d, granularity: 0x%llx,"
436                 " minimum: 0x%llx, maximum: 0x%llx,"
437                 " translation_offset: 0x%llx, address_length: 0x%llx\n",
438                 mem_resource->descriptor, mem_resource->length,
439                 mem_resource->space_id, mem_resource->resource_usage,
440                 mem_resource->type_specific, mem_resource->granularity,
441                 mem_resource->minimum, mem_resource->maximum,
442                 mem_resource->translation_offset,
443                 mem_resource->address_length);
444
445         if (mem_resource->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
446                 ret = -ENODEV;
447                 goto out_free;
448         }
449
450         pcch_virt_addr = ioremap_nocache(mem_resource->minimum,
451                                         mem_resource->address_length);
452         if (pcch_virt_addr == NULL) {
453                 dprintk("probe: could not map shared mem region\n");
454                 goto out_free;
455         }
456         pcch_hdr = pcch_virt_addr;
457
458         dprintk("probe: PCCH header (virtual) addr: 0x%p\n", pcch_hdr);
459         dprintk("probe: PCCH header is at physical address: 0x%llx,"
460                 " signature: 0x%x, length: %d bytes, major: %d, minor: %d,"
461                 " supported features: 0x%x, command field: 0x%x,"
462                 " status field: 0x%x, nominal latency: %d us\n",
463                 mem_resource->minimum, ioread32(&pcch_hdr->signature),
464                 ioread16(&pcch_hdr->length), ioread8(&pcch_hdr->major),
465                 ioread8(&pcch_hdr->minor), ioread32(&pcch_hdr->features),
466                 ioread16(&pcch_hdr->command), ioread16(&pcch_hdr->status),
467                 ioread32(&pcch_hdr->latency));
468
469         dprintk("probe: min time between commands: %d us,"
470                 " max time between commands: %d us,"
471                 " nominal CPU frequency: %d MHz,"
472                 " minimum CPU frequency: %d MHz,"
473                 " minimum CPU frequency without throttling: %d MHz\n",
474                 ioread32(&pcch_hdr->minimum_time),
475                 ioread32(&pcch_hdr->maximum_time),
476                 ioread32(&pcch_hdr->nominal),
477                 ioread32(&pcch_hdr->throttled_frequency),
478                 ioread32(&pcch_hdr->minimum_frequency));
479
480         member = &out_obj->package.elements[1];
481         if (member->type != ACPI_TYPE_BUFFER) {
482                 ret = -ENODEV;
483                 goto pcch_free;
484         }
485
486         reg_resource = (struct pcc_register_resource *)member->buffer.pointer;
487
488         doorbell.space_id = reg_resource->space_id;
489         doorbell.bit_width = reg_resource->bit_width;
490         doorbell.bit_offset = reg_resource->bit_offset;
491         doorbell.access_width = 64;
492         doorbell.address = reg_resource->address;
493
494         dprintk("probe: doorbell: space_id is %d, bit_width is %d, "
495                 "bit_offset is %d, access_width is %d, address is 0x%llx\n",
496                 doorbell.space_id, doorbell.bit_width, doorbell.bit_offset,
497                 doorbell.access_width, reg_resource->address);
498
499         member = &out_obj->package.elements[2];
500         if (member->type != ACPI_TYPE_INTEGER) {
501                 ret = -ENODEV;
502                 goto pcch_free;
503         }
504
505         doorbell_preserve = member->integer.value;
506
507         member = &out_obj->package.elements[3];
508         if (member->type != ACPI_TYPE_INTEGER) {
509                 ret = -ENODEV;
510                 goto pcch_free;
511         }
512
513         doorbell_write = member->integer.value;
514
515         dprintk("probe: doorbell_preserve: 0x%llx,"
516                 " doorbell_write: 0x%llx\n",
517                 doorbell_preserve, doorbell_write);
518
519         pcc_cpu_info = alloc_percpu(struct pcc_cpu);
520         if (!pcc_cpu_info) {
521                 ret = -ENOMEM;
522                 goto pcch_free;
523         }
524
525         printk(KERN_DEBUG "pcc-cpufreq: (v%s) driver loaded with frequency"
526                " limits: %d MHz, %d MHz\n", PCC_VERSION,
527                ioread32(&pcch_hdr->minimum_frequency),
528                ioread32(&pcch_hdr->nominal));
529         kfree(output.pointer);
530         return ret;
531 pcch_free:
532         pcc_clear_mapping();
533 out_free:
534         kfree(output.pointer);
535         return ret;
536 }
537
538 static int pcc_cpufreq_cpu_init(struct cpufreq_policy *policy)
539 {
540         unsigned int cpu = policy->cpu;
541         unsigned int result = 0;
542
543         if (!pcch_virt_addr) {
544                 result = -1;
545                 goto pcch_null;
546         }
547
548         result = pcc_get_offset(cpu);
549         if (result) {
550                 dprintk("init: PCCP evaluation failed\n");
551                 goto free;
552         }
553
554         policy->max = policy->cpuinfo.max_freq =
555                 ioread32(&pcch_hdr->nominal) * 1000;
556         policy->min = policy->cpuinfo.min_freq =
557                 ioread32(&pcch_hdr->minimum_frequency) * 1000;
558         policy->cur = pcc_get_freq(cpu);
559
560         dprintk("init: policy->max is %d, policy->min is %d\n",
561                 policy->max, policy->min);
562
563         return 0;
564 free:
565         pcc_clear_mapping();
566         free_percpu(pcc_cpu_info);
567 pcch_null:
568         return result;
569 }
570
571 static int pcc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
572 {
573         return 0;
574 }
575
576 static struct cpufreq_driver pcc_cpufreq_driver = {
577         .flags = CPUFREQ_CONST_LOOPS,
578         .get = pcc_get_freq,
579         .verify = pcc_cpufreq_verify,
580         .target = pcc_cpufreq_target,
581         .init = pcc_cpufreq_cpu_init,
582         .exit = pcc_cpufreq_cpu_exit,
583         .name = "pcc-cpufreq",
584         .owner = THIS_MODULE,
585 };
586
587 static int __init pcc_cpufreq_init(void)
588 {
589         int ret;
590
591         if (acpi_disabled)
592                 return 0;
593
594         ret = pcc_cpufreq_probe();
595         if (ret) {
596                 dprintk("pcc_cpufreq_init: PCCH evaluation failed\n");
597                 return ret;
598         }
599
600         ret = cpufreq_register_driver(&pcc_cpufreq_driver);
601
602         return ret;
603 }
604
605 static void __exit pcc_cpufreq_exit(void)
606 {
607         cpufreq_unregister_driver(&pcc_cpufreq_driver);
608
609         pcc_clear_mapping();
610
611         free_percpu(pcc_cpu_info);
612 }
613
614 MODULE_AUTHOR("Matthew Garrett, Naga Chumbalkar");
615 MODULE_VERSION(PCC_VERSION);
616 MODULE_DESCRIPTION("Processor Clocking Control interface driver");
617 MODULE_LICENSE("GPL");
618
619 late_initcall(pcc_cpufreq_init);
620 module_exit(pcc_cpufreq_exit);