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authorLinus Torvalds <torvalds@linux-foundation.org>2010-03-07 15:52:38 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2010-03-07 15:52:38 -0500
commit08b8499bdd26822df16f962db88215d02e40850a (patch)
tree3a88a0f1a425637d0f5a8e68ec3419fc5f1bdb9b /arch
parent3ceb85ae35421c5bc560c7af8d0dd1c73d071ad0 (diff)
parentfb4635932a4e19c2f55383f968a0e9b64da37354 (diff)
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq: [CPUFREQ] Fix cast warning in pcc driver. [CPUFREQ] Processor Clocking Control interface driver
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/cpu/cpufreq/Kconfig14
-rw-r--r--arch/x86/kernel/cpu/cpufreq/Makefile1
-rw-r--r--arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c620
3 files changed, 635 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/cpufreq/Kconfig b/arch/x86/kernel/cpu/cpufreq/Kconfig
index f138c6c389b9..870e6cc6ad28 100644
--- a/arch/x86/kernel/cpu/cpufreq/Kconfig
+++ b/arch/x86/kernel/cpu/cpufreq/Kconfig
@@ -10,6 +10,20 @@ if CPU_FREQ
10 10
11comment "CPUFreq processor drivers" 11comment "CPUFreq processor drivers"
12 12
13config X86_PCC_CPUFREQ
14 tristate "Processor Clocking Control interface driver"
15 depends on ACPI && ACPI_PROCESSOR
16 help
17 This driver adds support for the PCC interface.
18
19 For details, take a look at:
20 <file:Documentation/cpu-freq/pcc-cpufreq.txt>.
21
22 To compile this driver as a module, choose M here: the
23 module will be called pcc-cpufreq.
24
25 If in doubt, say N.
26
13config X86_ACPI_CPUFREQ 27config X86_ACPI_CPUFREQ
14 tristate "ACPI Processor P-States driver" 28 tristate "ACPI Processor P-States driver"
15 select CPU_FREQ_TABLE 29 select CPU_FREQ_TABLE
diff --git a/arch/x86/kernel/cpu/cpufreq/Makefile b/arch/x86/kernel/cpu/cpufreq/Makefile
index 509296df294d..1840c0a5170b 100644
--- a/arch/x86/kernel/cpu/cpufreq/Makefile
+++ b/arch/x86/kernel/cpu/cpufreq/Makefile
@@ -4,6 +4,7 @@
4 4
5obj-$(CONFIG_X86_POWERNOW_K8) += powernow-k8.o 5obj-$(CONFIG_X86_POWERNOW_K8) += powernow-k8.o
6obj-$(CONFIG_X86_ACPI_CPUFREQ) += acpi-cpufreq.o 6obj-$(CONFIG_X86_ACPI_CPUFREQ) += acpi-cpufreq.o
7obj-$(CONFIG_X86_PCC_CPUFREQ) += pcc-cpufreq.o
7obj-$(CONFIG_X86_POWERNOW_K6) += powernow-k6.o 8obj-$(CONFIG_X86_POWERNOW_K6) += powernow-k6.o
8obj-$(CONFIG_X86_POWERNOW_K7) += powernow-k7.o 9obj-$(CONFIG_X86_POWERNOW_K7) += powernow-k7.o
9obj-$(CONFIG_X86_LONGHAUL) += longhaul.o 10obj-$(CONFIG_X86_LONGHAUL) += longhaul.o
diff --git a/arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c
new file mode 100644
index 000000000000..ff36d2979a90
--- /dev/null
+++ b/arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c
@@ -0,0 +1,620 @@
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
53struct 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
63struct 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
76static struct cpufreq_driver pcc_cpufreq_driver;
77
78struct 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
94static void __iomem *pcch_virt_addr;
95static struct pcc_header __iomem *pcch_hdr;
96
97static DEFINE_SPINLOCK(pcc_lock);
98
99static struct acpi_generic_address doorbell;
100
101static u64 doorbell_preserve;
102static u64 doorbell_write;
103
104static u8 OSC_UUID[16] = {0x63, 0x9B, 0x2C, 0x9F, 0x70, 0x91, 0x49, 0x1f,
105 0xBB, 0x4F, 0xA5, 0x98, 0x2F, 0xA1, 0xB5, 0x46};
106
107struct pcc_cpu {
108 u32 input_offset;
109 u32 output_offset;
110};
111
112static struct pcc_cpu *pcc_cpu_info;
113
114static 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
121static 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
136static inline void pcc_clear_mapping(void)
137{
138 if (pcch_virt_addr)
139 iounmap(pcch_virt_addr);
140 pcch_virt_addr = NULL;
141}
142
143static 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
194cmd_incomplete:
195 iowrite16(0, &pcch_hdr->status);
196 spin_unlock(&pcc_lock);
197 return -EINVAL;
198}
199
200static 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
248cmd_incomplete:
249 iowrite16(0, &pcch_hdr->status);
250 spin_unlock(&pcc_lock);
251 return -EINVAL;
252}
253
254static 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);
298out_free:
299 kfree(buffer.pointer);
300 return ret;
301}
302
303static 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
387out_free:
388 kfree(output.pointer);
389 return ret;
390}
391
392static 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;
531pcch_free:
532 pcc_clear_mapping();
533out_free:
534 kfree(output.pointer);
535 return ret;
536}
537
538static 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;
564free:
565 pcc_clear_mapping();
566 free_percpu(pcc_cpu_info);
567pcch_null:
568 return result;
569}
570
571static int pcc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
572{
573 return 0;
574}
575
576static 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
587static 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
605static 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
614MODULE_AUTHOR("Matthew Garrett, Naga Chumbalkar");
615MODULE_VERSION(PCC_VERSION);
616MODULE_DESCRIPTION("Processor Clocking Control interface driver");
617MODULE_LICENSE("GPL");
618
619late_initcall(pcc_cpufreq_init);
620module_exit(pcc_cpufreq_exit);