include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[linux-2.6.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 #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     "1.00.00"
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 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER,      \
52                                              "pcc-cpufreq", msg)
53
54 struct pcc_register_resource {
55         u8 descriptor;
56         u16 length;
57         u8 space_id;
58         u8 bit_width;
59         u8 bit_offset;
60         u8 access_size;
61         u64 address;
62 } __attribute__ ((packed));
63
64 struct pcc_memory_resource {
65         u8 descriptor;
66         u16 length;
67         u8 space_id;
68         u8 resource_usage;
69         u8 type_specific;
70         u64 granularity;
71         u64 minimum;
72         u64 maximum;
73         u64 translation_offset;
74         u64 address_length;
75 } __attribute__ ((packed));
76
77 static struct cpufreq_driver pcc_cpufreq_driver;
78
79 struct pcc_header {
80         u32 signature;
81         u16 length;
82         u8 major;
83         u8 minor;
84         u32 features;
85         u16 command;
86         u16 status;
87         u32 latency;
88         u32 minimum_time;
89         u32 maximum_time;
90         u32 nominal;
91         u32 throttled_frequency;
92         u32 minimum_frequency;
93 };
94
95 static void __iomem *pcch_virt_addr;
96 static struct pcc_header __iomem *pcch_hdr;
97
98 static DEFINE_SPINLOCK(pcc_lock);
99
100 static struct acpi_generic_address doorbell;
101
102 static u64 doorbell_preserve;
103 static u64 doorbell_write;
104
105 static u8 OSC_UUID[16] = {0x63, 0x9B, 0x2C, 0x9F, 0x70, 0x91, 0x49, 0x1f,
106                           0xBB, 0x4F, 0xA5, 0x98, 0x2F, 0xA1, 0xB5, 0x46};
107
108 struct pcc_cpu {
109         u32 input_offset;
110         u32 output_offset;
111 };
112
113 static struct pcc_cpu *pcc_cpu_info;
114
115 static int pcc_cpufreq_verify(struct cpufreq_policy *policy)
116 {
117         cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
118                                      policy->cpuinfo.max_freq);
119         return 0;
120 }
121
122 static inline void pcc_cmd(void)
123 {
124         u64 doorbell_value;
125         int i;
126
127         acpi_read(&doorbell_value, &doorbell);
128         acpi_write((doorbell_value & doorbell_preserve) | doorbell_write,
129                    &doorbell);
130
131         for (i = 0; i < POLL_LOOPS; i++) {
132                 if (ioread16(&pcch_hdr->status) & CMD_COMPLETE)
133                         break;
134         }
135 }
136
137 static inline void pcc_clear_mapping(void)
138 {
139         if (pcch_virt_addr)
140                 iounmap(pcch_virt_addr);
141         pcch_virt_addr = NULL;
142 }
143
144 static unsigned int pcc_get_freq(unsigned int cpu)
145 {
146         struct pcc_cpu *pcc_cpu_data;
147         unsigned int curr_freq;
148         unsigned int freq_limit;
149         u16 status;
150         u32 input_buffer;
151         u32 output_buffer;
152
153         spin_lock(&pcc_lock);
154
155         dprintk("get: get_freq for CPU %d\n", cpu);
156         pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
157
158         input_buffer = 0x1;
159         iowrite32(input_buffer,
160                         (pcch_virt_addr + pcc_cpu_data->input_offset));
161         iowrite16(CMD_GET_FREQ, &pcch_hdr->command);
162
163         pcc_cmd();
164
165         output_buffer =
166                 ioread32(pcch_virt_addr + pcc_cpu_data->output_offset);
167
168         /* Clear the input buffer - we are done with the current command */
169         memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
170
171         status = ioread16(&pcch_hdr->status);
172         if (status != CMD_COMPLETE) {
173                 dprintk("get: FAILED: for CPU %d, status is %d\n",
174                         cpu, status);
175                 goto cmd_incomplete;
176         }
177         iowrite16(0, &pcch_hdr->status);
178         curr_freq = (((ioread32(&pcch_hdr->nominal) * (output_buffer & 0xff))
179                         / 100) * 1000);
180
181         dprintk("get: SUCCESS: (virtual) output_offset for cpu %d is "
182                 "0x%x, contains a value of: 0x%x. Speed is: %d MHz\n",
183                 cpu, (pcch_virt_addr + pcc_cpu_data->output_offset),
184                 output_buffer, curr_freq);
185
186         freq_limit = (output_buffer >> 8) & 0xff;
187         if (freq_limit != 0xff) {
188                 dprintk("get: frequency for cpu %d is being temporarily"
189                         " capped at %d\n", cpu, curr_freq);
190         }
191
192         spin_unlock(&pcc_lock);
193         return curr_freq;
194
195 cmd_incomplete:
196         iowrite16(0, &pcch_hdr->status);
197         spin_unlock(&pcc_lock);
198         return -EINVAL;
199 }
200
201 static int pcc_cpufreq_target(struct cpufreq_policy *policy,
202                               unsigned int target_freq,
203                               unsigned int relation)
204 {
205         struct pcc_cpu *pcc_cpu_data;
206         struct cpufreq_freqs freqs;
207         u16 status;
208         u32 input_buffer;
209         int cpu;
210
211         spin_lock(&pcc_lock);
212         cpu = policy->cpu;
213         pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
214
215         dprintk("target: CPU %d should go to target freq: %d "
216                 "(virtual) input_offset is 0x%x\n",
217                 cpu, target_freq,
218                 (pcch_virt_addr + pcc_cpu_data->input_offset));
219
220         freqs.new = target_freq;
221         freqs.cpu = cpu;
222         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
223
224         input_buffer = 0x1 | (((target_freq * 100)
225                                / (ioread32(&pcch_hdr->nominal) * 1000)) << 8);
226         iowrite32(input_buffer,
227                         (pcch_virt_addr + pcc_cpu_data->input_offset));
228         iowrite16(CMD_SET_FREQ, &pcch_hdr->command);
229
230         pcc_cmd();
231
232         /* Clear the input buffer - we are done with the current command */
233         memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
234
235         status = ioread16(&pcch_hdr->status);
236         if (status != CMD_COMPLETE) {
237                 dprintk("target: FAILED for cpu %d, with status: 0x%x\n",
238                         cpu, status);
239                 goto cmd_incomplete;
240         }
241         iowrite16(0, &pcch_hdr->status);
242
243         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
244         dprintk("target: was SUCCESSFUL for cpu %d\n", cpu);
245         spin_unlock(&pcc_lock);
246
247         return 0;
248
249 cmd_incomplete:
250         iowrite16(0, &pcch_hdr->status);
251         spin_unlock(&pcc_lock);
252         return -EINVAL;
253 }
254
255 static int pcc_get_offset(int cpu)
256 {
257         acpi_status status;
258         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
259         union acpi_object *pccp, *offset;
260         struct pcc_cpu *pcc_cpu_data;
261         struct acpi_processor *pr;
262         int ret = 0;
263
264         pr = per_cpu(processors, cpu);
265         pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
266
267         status = acpi_evaluate_object(pr->handle, "PCCP", NULL, &buffer);
268         if (ACPI_FAILURE(status))
269                 return -ENODEV;
270
271         pccp = buffer.pointer;
272         if (!pccp || pccp->type != ACPI_TYPE_PACKAGE) {
273                 ret = -ENODEV;
274                 goto out_free;
275         };
276
277         offset = &(pccp->package.elements[0]);
278         if (!offset || offset->type != ACPI_TYPE_INTEGER) {
279                 ret = -ENODEV;
280                 goto out_free;
281         }
282
283         pcc_cpu_data->input_offset = offset->integer.value;
284
285         offset = &(pccp->package.elements[1]);
286         if (!offset || offset->type != ACPI_TYPE_INTEGER) {
287                 ret = -ENODEV;
288                 goto out_free;
289         }
290
291         pcc_cpu_data->output_offset = offset->integer.value;
292
293         memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
294         memset_io((pcch_virt_addr + pcc_cpu_data->output_offset), 0, BUF_SZ);
295
296         dprintk("pcc_get_offset: for CPU %d: pcc_cpu_data "
297                 "input_offset: 0x%x, pcc_cpu_data output_offset: 0x%x\n",
298                 cpu, pcc_cpu_data->input_offset, pcc_cpu_data->output_offset);
299 out_free:
300         kfree(buffer.pointer);
301         return ret;
302 }
303
304 static int __init pcc_cpufreq_do_osc(acpi_handle *handle)
305 {
306         acpi_status status;
307         struct acpi_object_list input;
308         struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
309         union acpi_object in_params[4];
310         union acpi_object *out_obj;
311         u32 capabilities[2];
312         u32 errors;
313         u32 supported;
314         int ret = 0;
315
316         input.count = 4;
317         input.pointer = in_params;
318         input.count = 4;
319         input.pointer = in_params;
320         in_params[0].type               = ACPI_TYPE_BUFFER;
321         in_params[0].buffer.length      = 16;
322         in_params[0].buffer.pointer     = OSC_UUID;
323         in_params[1].type               = ACPI_TYPE_INTEGER;
324         in_params[1].integer.value      = 1;
325         in_params[2].type               = ACPI_TYPE_INTEGER;
326         in_params[2].integer.value      = 2;
327         in_params[3].type               = ACPI_TYPE_BUFFER;
328         in_params[3].buffer.length      = 8;
329         in_params[3].buffer.pointer     = (u8 *)&capabilities;
330
331         capabilities[0] = OSC_QUERY_ENABLE;
332         capabilities[1] = 0x1;
333
334         status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
335         if (ACPI_FAILURE(status))
336                 return -ENODEV;
337
338         if (!output.length)
339                 return -ENODEV;
340
341         out_obj = output.pointer;
342         if (out_obj->type != ACPI_TYPE_BUFFER) {
343                 ret = -ENODEV;
344                 goto out_free;
345         }
346
347         errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
348         if (errors) {
349                 ret = -ENODEV;
350                 goto out_free;
351         }
352
353         supported = *((u32 *)(out_obj->buffer.pointer + 4));
354         if (!(supported & 0x1)) {
355                 ret = -ENODEV;
356                 goto out_free;
357         }
358
359         kfree(output.pointer);
360         capabilities[0] = 0x0;
361         capabilities[1] = 0x1;
362
363         status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
364         if (ACPI_FAILURE(status))
365                 return -ENODEV;
366
367         if (!output.length)
368                 return -ENODEV;
369
370         out_obj = output.pointer;
371         if (out_obj->type != ACPI_TYPE_BUFFER) {
372                 ret = -ENODEV;
373                 goto out_free;
374         }
375
376         errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
377         if (errors) {
378                 ret = -ENODEV;
379                 goto out_free;
380         }
381
382         supported = *((u32 *)(out_obj->buffer.pointer + 4));
383         if (!(supported & 0x1)) {
384                 ret = -ENODEV;
385                 goto out_free;
386         }
387
388 out_free:
389         kfree(output.pointer);
390         return ret;
391 }
392
393 static int __init pcc_cpufreq_probe(void)
394 {
395         acpi_status status;
396         struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
397         struct pcc_memory_resource *mem_resource;
398         struct pcc_register_resource *reg_resource;
399         union acpi_object *out_obj, *member;
400         acpi_handle handle, osc_handle;
401         int ret = 0;
402
403         status = acpi_get_handle(NULL, "\\_SB", &handle);
404         if (ACPI_FAILURE(status))
405                 return -ENODEV;
406
407         status = acpi_get_handle(handle, "_OSC", &osc_handle);
408         if (ACPI_SUCCESS(status)) {
409                 ret = pcc_cpufreq_do_osc(&osc_handle);
410                 if (ret)
411                         dprintk("probe: _OSC evaluation did not succeed\n");
412                 /* Firmware's use of _OSC is optional */
413                 ret = 0;
414         }
415
416         status = acpi_evaluate_object(handle, "PCCH", NULL, &output);
417         if (ACPI_FAILURE(status))
418                 return -ENODEV;
419
420         out_obj = output.pointer;
421         if (out_obj->type != ACPI_TYPE_PACKAGE) {
422                 ret = -ENODEV;
423                 goto out_free;
424         }
425
426         member = &out_obj->package.elements[0];
427         if (member->type != ACPI_TYPE_BUFFER) {
428                 ret = -ENODEV;
429                 goto out_free;
430         }
431
432         mem_resource = (struct pcc_memory_resource *)member->buffer.pointer;
433
434         dprintk("probe: mem_resource descriptor: 0x%x,"
435                 " length: %d, space_id: %d, resource_usage: %d,"
436                 " type_specific: %d, granularity: 0x%llx,"
437                 " minimum: 0x%llx, maximum: 0x%llx,"
438                 " translation_offset: 0x%llx, address_length: 0x%llx\n",
439                 mem_resource->descriptor, mem_resource->length,
440                 mem_resource->space_id, mem_resource->resource_usage,
441                 mem_resource->type_specific, mem_resource->granularity,
442                 mem_resource->minimum, mem_resource->maximum,
443                 mem_resource->translation_offset,
444                 mem_resource->address_length);
445
446         if (mem_resource->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
447                 ret = -ENODEV;
448                 goto out_free;
449         }
450
451         pcch_virt_addr = ioremap_nocache(mem_resource->minimum,
452                                         mem_resource->address_length);
453         if (pcch_virt_addr == NULL) {
454                 dprintk("probe: could not map shared mem region\n");
455                 goto out_free;
456         }
457         pcch_hdr = pcch_virt_addr;
458
459         dprintk("probe: PCCH header (virtual) addr: 0x%p\n", pcch_hdr);
460         dprintk("probe: PCCH header is at physical address: 0x%llx,"
461                 " signature: 0x%x, length: %d bytes, major: %d, minor: %d,"
462                 " supported features: 0x%x, command field: 0x%x,"
463                 " status field: 0x%x, nominal latency: %d us\n",
464                 mem_resource->minimum, ioread32(&pcch_hdr->signature),
465                 ioread16(&pcch_hdr->length), ioread8(&pcch_hdr->major),
466                 ioread8(&pcch_hdr->minor), ioread32(&pcch_hdr->features),
467                 ioread16(&pcch_hdr->command), ioread16(&pcch_hdr->status),
468                 ioread32(&pcch_hdr->latency));
469
470         dprintk("probe: min time between commands: %d us,"
471                 " max time between commands: %d us,"
472                 " nominal CPU frequency: %d MHz,"
473                 " minimum CPU frequency: %d MHz,"
474                 " minimum CPU frequency without throttling: %d MHz\n",
475                 ioread32(&pcch_hdr->minimum_time),
476                 ioread32(&pcch_hdr->maximum_time),
477                 ioread32(&pcch_hdr->nominal),
478                 ioread32(&pcch_hdr->throttled_frequency),
479                 ioread32(&pcch_hdr->minimum_frequency));
480
481         member = &out_obj->package.elements[1];
482         if (member->type != ACPI_TYPE_BUFFER) {
483                 ret = -ENODEV;
484                 goto pcch_free;
485         }
486
487         reg_resource = (struct pcc_register_resource *)member->buffer.pointer;
488
489         doorbell.space_id = reg_resource->space_id;
490         doorbell.bit_width = reg_resource->bit_width;
491         doorbell.bit_offset = reg_resource->bit_offset;
492         doorbell.access_width = 64;
493         doorbell.address = reg_resource->address;
494
495         dprintk("probe: doorbell: space_id is %d, bit_width is %d, "
496                 "bit_offset is %d, access_width is %d, address is 0x%llx\n",
497                 doorbell.space_id, doorbell.bit_width, doorbell.bit_offset,
498                 doorbell.access_width, reg_resource->address);
499
500         member = &out_obj->package.elements[2];
501         if (member->type != ACPI_TYPE_INTEGER) {
502                 ret = -ENODEV;
503                 goto pcch_free;
504         }
505
506         doorbell_preserve = member->integer.value;
507
508         member = &out_obj->package.elements[3];
509         if (member->type != ACPI_TYPE_INTEGER) {
510                 ret = -ENODEV;
511                 goto pcch_free;
512         }
513
514         doorbell_write = member->integer.value;
515
516         dprintk("probe: doorbell_preserve: 0x%llx,"
517                 " doorbell_write: 0x%llx\n",
518                 doorbell_preserve, doorbell_write);
519
520         pcc_cpu_info = alloc_percpu(struct pcc_cpu);
521         if (!pcc_cpu_info) {
522                 ret = -ENOMEM;
523                 goto pcch_free;
524         }
525
526         printk(KERN_DEBUG "pcc-cpufreq: (v%s) driver loaded with frequency"
527                " limits: %d MHz, %d MHz\n", PCC_VERSION,
528                ioread32(&pcch_hdr->minimum_frequency),
529                ioread32(&pcch_hdr->nominal));
530         kfree(output.pointer);
531         return ret;
532 pcch_free:
533         pcc_clear_mapping();
534 out_free:
535         kfree(output.pointer);
536         return ret;
537 }
538
539 static int pcc_cpufreq_cpu_init(struct cpufreq_policy *policy)
540 {
541         unsigned int cpu = policy->cpu;
542         unsigned int result = 0;
543
544         if (!pcch_virt_addr) {
545                 result = -1;
546                 goto pcch_null;
547         }
548
549         result = pcc_get_offset(cpu);
550         if (result) {
551                 dprintk("init: PCCP evaluation failed\n");
552                 goto free;
553         }
554
555         policy->max = policy->cpuinfo.max_freq =
556                 ioread32(&pcch_hdr->nominal) * 1000;
557         policy->min = policy->cpuinfo.min_freq =
558                 ioread32(&pcch_hdr->minimum_frequency) * 1000;
559         policy->cur = pcc_get_freq(cpu);
560
561         dprintk("init: policy->max is %d, policy->min is %d\n",
562                 policy->max, policy->min);
563
564         return 0;
565 free:
566         pcc_clear_mapping();
567         free_percpu(pcc_cpu_info);
568 pcch_null:
569         return result;
570 }
571
572 static int pcc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
573 {
574         return 0;
575 }
576
577 static struct cpufreq_driver pcc_cpufreq_driver = {
578         .flags = CPUFREQ_CONST_LOOPS,
579         .get = pcc_get_freq,
580         .verify = pcc_cpufreq_verify,
581         .target = pcc_cpufreq_target,
582         .init = pcc_cpufreq_cpu_init,
583         .exit = pcc_cpufreq_cpu_exit,
584         .name = "pcc-cpufreq",
585         .owner = THIS_MODULE,
586 };
587
588 static int __init pcc_cpufreq_init(void)
589 {
590         int ret;
591
592         if (acpi_disabled)
593                 return 0;
594
595         ret = pcc_cpufreq_probe();
596         if (ret) {
597                 dprintk("pcc_cpufreq_init: PCCH evaluation failed\n");
598                 return ret;
599         }
600
601         ret = cpufreq_register_driver(&pcc_cpufreq_driver);
602
603         return ret;
604 }
605
606 static void __exit pcc_cpufreq_exit(void)
607 {
608         cpufreq_unregister_driver(&pcc_cpufreq_driver);
609
610         pcc_clear_mapping();
611
612         free_percpu(pcc_cpu_info);
613 }
614
615 MODULE_AUTHOR("Matthew Garrett, Naga Chumbalkar");
616 MODULE_VERSION(PCC_VERSION);
617 MODULE_DESCRIPTION("Processor Clocking Control interface driver");
618 MODULE_LICENSE("GPL");
619
620 late_initcall(pcc_cpufreq_init);
621 module_exit(pcc_cpufreq_exit);