Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6.git] / arch / x86 / kernel / cpu / cpufreq / acpi-cpufreq.c
1 /*
2  * acpi-cpufreq.c - ACPI Processor P-States Driver
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *  Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
7  *  Copyright (C) 2006       Denis Sadykov <denis.m.sadykov@intel.com>
8  *
9  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10  *
11  *  This program is free software; you can redistribute it and/or modify
12  *  it under the terms of the GNU General Public License as published by
13  *  the Free Software Foundation; either version 2 of the License, or (at
14  *  your option) any later version.
15  *
16  *  This program is distributed in the hope that it will be useful, but
17  *  WITHOUT ANY WARRANTY; without even the implied warranty of
18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  *  General Public License for more details.
20  *
21  *  You should have received a copy of the GNU General Public License along
22  *  with this program; if not, write to the Free Software Foundation, Inc.,
23  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
24  *
25  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
26  */
27
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/smp.h>
32 #include <linux/sched.h>
33 #include <linux/cpufreq.h>
34 #include <linux/compiler.h>
35 #include <linux/dmi.h>
36 #include <linux/slab.h>
37 #include <trace/events/power.h>
38
39 #include <linux/acpi.h>
40 #include <linux/io.h>
41 #include <linux/delay.h>
42 #include <linux/uaccess.h>
43
44 #include <acpi/processor.h>
45
46 #include <asm/msr.h>
47 #include <asm/processor.h>
48 #include <asm/cpufeature.h>
49 #include "mperf.h"
50
51 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, \
52                 "acpi-cpufreq", msg)
53
54 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
55 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
56 MODULE_LICENSE("GPL");
57
58 enum {
59         UNDEFINED_CAPABLE = 0,
60         SYSTEM_INTEL_MSR_CAPABLE,
61         SYSTEM_IO_CAPABLE,
62 };
63
64 #define INTEL_MSR_RANGE         (0xffff)
65
66 struct acpi_cpufreq_data {
67         struct acpi_processor_performance *acpi_data;
68         struct cpufreq_frequency_table *freq_table;
69         unsigned int resume;
70         unsigned int cpu_feature;
71 };
72
73 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);
74
75 /* acpi_perf_data is a pointer to percpu data. */
76 static struct acpi_processor_performance *acpi_perf_data;
77
78 static struct cpufreq_driver acpi_cpufreq_driver;
79
80 static unsigned int acpi_pstate_strict;
81
82 static int check_est_cpu(unsigned int cpuid)
83 {
84         struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
85
86         return cpu_has(cpu, X86_FEATURE_EST);
87 }
88
89 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
90 {
91         struct acpi_processor_performance *perf;
92         int i;
93
94         perf = data->acpi_data;
95
96         for (i = 0; i < perf->state_count; i++) {
97                 if (value == perf->states[i].status)
98                         return data->freq_table[i].frequency;
99         }
100         return 0;
101 }
102
103 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
104 {
105         int i;
106         struct acpi_processor_performance *perf;
107
108         msr &= INTEL_MSR_RANGE;
109         perf = data->acpi_data;
110
111         for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
112                 if (msr == perf->states[data->freq_table[i].index].status)
113                         return data->freq_table[i].frequency;
114         }
115         return data->freq_table[0].frequency;
116 }
117
118 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
119 {
120         switch (data->cpu_feature) {
121         case SYSTEM_INTEL_MSR_CAPABLE:
122                 return extract_msr(val, data);
123         case SYSTEM_IO_CAPABLE:
124                 return extract_io(val, data);
125         default:
126                 return 0;
127         }
128 }
129
130 struct msr_addr {
131         u32 reg;
132 };
133
134 struct io_addr {
135         u16 port;
136         u8 bit_width;
137 };
138
139 struct drv_cmd {
140         unsigned int type;
141         const struct cpumask *mask;
142         union {
143                 struct msr_addr msr;
144                 struct io_addr io;
145         } addr;
146         u32 val;
147 };
148
149 /* Called via smp_call_function_single(), on the target CPU */
150 static void do_drv_read(void *_cmd)
151 {
152         struct drv_cmd *cmd = _cmd;
153         u32 h;
154
155         switch (cmd->type) {
156         case SYSTEM_INTEL_MSR_CAPABLE:
157                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
158                 break;
159         case SYSTEM_IO_CAPABLE:
160                 acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
161                                 &cmd->val,
162                                 (u32)cmd->addr.io.bit_width);
163                 break;
164         default:
165                 break;
166         }
167 }
168
169 /* Called via smp_call_function_many(), on the target CPUs */
170 static void do_drv_write(void *_cmd)
171 {
172         struct drv_cmd *cmd = _cmd;
173         u32 lo, hi;
174
175         switch (cmd->type) {
176         case SYSTEM_INTEL_MSR_CAPABLE:
177                 rdmsr(cmd->addr.msr.reg, lo, hi);
178                 lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
179                 wrmsr(cmd->addr.msr.reg, lo, hi);
180                 break;
181         case SYSTEM_IO_CAPABLE:
182                 acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
183                                 cmd->val,
184                                 (u32)cmd->addr.io.bit_width);
185                 break;
186         default:
187                 break;
188         }
189 }
190
191 static void drv_read(struct drv_cmd *cmd)
192 {
193         int err;
194         cmd->val = 0;
195
196         err = smp_call_function_any(cmd->mask, do_drv_read, cmd, 1);
197         WARN_ON_ONCE(err);      /* smp_call_function_any() was buggy? */
198 }
199
200 static void drv_write(struct drv_cmd *cmd)
201 {
202         int this_cpu;
203
204         this_cpu = get_cpu();
205         if (cpumask_test_cpu(this_cpu, cmd->mask))
206                 do_drv_write(cmd);
207         smp_call_function_many(cmd->mask, do_drv_write, cmd, 1);
208         put_cpu();
209 }
210
211 static u32 get_cur_val(const struct cpumask *mask)
212 {
213         struct acpi_processor_performance *perf;
214         struct drv_cmd cmd;
215
216         if (unlikely(cpumask_empty(mask)))
217                 return 0;
218
219         switch (per_cpu(acfreq_data, cpumask_first(mask))->cpu_feature) {
220         case SYSTEM_INTEL_MSR_CAPABLE:
221                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
222                 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
223                 break;
224         case SYSTEM_IO_CAPABLE:
225                 cmd.type = SYSTEM_IO_CAPABLE;
226                 perf = per_cpu(acfreq_data, cpumask_first(mask))->acpi_data;
227                 cmd.addr.io.port = perf->control_register.address;
228                 cmd.addr.io.bit_width = perf->control_register.bit_width;
229                 break;
230         default:
231                 return 0;
232         }
233
234         cmd.mask = mask;
235         drv_read(&cmd);
236
237         dprintk("get_cur_val = %u\n", cmd.val);
238
239         return cmd.val;
240 }
241
242 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
243 {
244         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, cpu);
245         unsigned int freq;
246         unsigned int cached_freq;
247
248         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
249
250         if (unlikely(data == NULL ||
251                      data->acpi_data == NULL || data->freq_table == NULL)) {
252                 return 0;
253         }
254
255         cached_freq = data->freq_table[data->acpi_data->state].frequency;
256         freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
257         if (freq != cached_freq) {
258                 /*
259                  * The dreaded BIOS frequency change behind our back.
260                  * Force set the frequency on next target call.
261                  */
262                 data->resume = 1;
263         }
264
265         dprintk("cur freq = %u\n", freq);
266
267         return freq;
268 }
269
270 static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
271                                 struct acpi_cpufreq_data *data)
272 {
273         unsigned int cur_freq;
274         unsigned int i;
275
276         for (i = 0; i < 100; i++) {
277                 cur_freq = extract_freq(get_cur_val(mask), data);
278                 if (cur_freq == freq)
279                         return 1;
280                 udelay(10);
281         }
282         return 0;
283 }
284
285 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
286                                unsigned int target_freq, unsigned int relation)
287 {
288         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
289         struct acpi_processor_performance *perf;
290         struct cpufreq_freqs freqs;
291         struct drv_cmd cmd;
292         unsigned int next_state = 0; /* Index into freq_table */
293         unsigned int next_perf_state = 0; /* Index into perf table */
294         unsigned int i;
295         int result = 0;
296
297         dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
298
299         if (unlikely(data == NULL ||
300              data->acpi_data == NULL || data->freq_table == NULL)) {
301                 return -ENODEV;
302         }
303
304         perf = data->acpi_data;
305         result = cpufreq_frequency_table_target(policy,
306                                                 data->freq_table,
307                                                 target_freq,
308                                                 relation, &next_state);
309         if (unlikely(result)) {
310                 result = -ENODEV;
311                 goto out;
312         }
313
314         next_perf_state = data->freq_table[next_state].index;
315         if (perf->state == next_perf_state) {
316                 if (unlikely(data->resume)) {
317                         dprintk("Called after resume, resetting to P%d\n",
318                                 next_perf_state);
319                         data->resume = 0;
320                 } else {
321                         dprintk("Already at target state (P%d)\n",
322                                 next_perf_state);
323                         goto out;
324                 }
325         }
326
327         trace_power_frequency(POWER_PSTATE, data->freq_table[next_state].frequency);
328
329         switch (data->cpu_feature) {
330         case SYSTEM_INTEL_MSR_CAPABLE:
331                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
332                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
333                 cmd.val = (u32) perf->states[next_perf_state].control;
334                 break;
335         case SYSTEM_IO_CAPABLE:
336                 cmd.type = SYSTEM_IO_CAPABLE;
337                 cmd.addr.io.port = perf->control_register.address;
338                 cmd.addr.io.bit_width = perf->control_register.bit_width;
339                 cmd.val = (u32) perf->states[next_perf_state].control;
340                 break;
341         default:
342                 result = -ENODEV;
343                 goto out;
344         }
345
346         /* cpufreq holds the hotplug lock, so we are safe from here on */
347         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
348                 cmd.mask = policy->cpus;
349         else
350                 cmd.mask = cpumask_of(policy->cpu);
351
352         freqs.old = perf->states[perf->state].core_frequency * 1000;
353         freqs.new = data->freq_table[next_state].frequency;
354         for_each_cpu(i, cmd.mask) {
355                 freqs.cpu = i;
356                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
357         }
358
359         drv_write(&cmd);
360
361         if (acpi_pstate_strict) {
362                 if (!check_freqs(cmd.mask, freqs.new, data)) {
363                         dprintk("acpi_cpufreq_target failed (%d)\n",
364                                 policy->cpu);
365                         result = -EAGAIN;
366                         goto out;
367                 }
368         }
369
370         for_each_cpu(i, cmd.mask) {
371                 freqs.cpu = i;
372                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
373         }
374         perf->state = next_perf_state;
375
376 out:
377         return result;
378 }
379
380 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
381 {
382         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
383
384         dprintk("acpi_cpufreq_verify\n");
385
386         return cpufreq_frequency_table_verify(policy, data->freq_table);
387 }
388
389 static unsigned long
390 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
391 {
392         struct acpi_processor_performance *perf = data->acpi_data;
393
394         if (cpu_khz) {
395                 /* search the closest match to cpu_khz */
396                 unsigned int i;
397                 unsigned long freq;
398                 unsigned long freqn = perf->states[0].core_frequency * 1000;
399
400                 for (i = 0; i < (perf->state_count-1); i++) {
401                         freq = freqn;
402                         freqn = perf->states[i+1].core_frequency * 1000;
403                         if ((2 * cpu_khz) > (freqn + freq)) {
404                                 perf->state = i;
405                                 return freq;
406                         }
407                 }
408                 perf->state = perf->state_count-1;
409                 return freqn;
410         } else {
411                 /* assume CPU is at P0... */
412                 perf->state = 0;
413                 return perf->states[0].core_frequency * 1000;
414         }
415 }
416
417 static void free_acpi_perf_data(void)
418 {
419         unsigned int i;
420
421         /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
422         for_each_possible_cpu(i)
423                 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
424                                  ->shared_cpu_map);
425         free_percpu(acpi_perf_data);
426 }
427
428 /*
429  * acpi_cpufreq_early_init - initialize ACPI P-States library
430  *
431  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
432  * in order to determine correct frequency and voltage pairings. We can
433  * do _PDC and _PSD and find out the processor dependency for the
434  * actual init that will happen later...
435  */
436 static int __init acpi_cpufreq_early_init(void)
437 {
438         unsigned int i;
439         dprintk("acpi_cpufreq_early_init\n");
440
441         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
442         if (!acpi_perf_data) {
443                 dprintk("Memory allocation error for acpi_perf_data.\n");
444                 return -ENOMEM;
445         }
446         for_each_possible_cpu(i) {
447                 if (!zalloc_cpumask_var_node(
448                         &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
449                         GFP_KERNEL, cpu_to_node(i))) {
450
451                         /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
452                         free_acpi_perf_data();
453                         return -ENOMEM;
454                 }
455         }
456
457         /* Do initialization in ACPI core */
458         acpi_processor_preregister_performance(acpi_perf_data);
459         return 0;
460 }
461
462 #ifdef CONFIG_SMP
463 /*
464  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
465  * or do it in BIOS firmware and won't inform about it to OS. If not
466  * detected, this has a side effect of making CPU run at a different speed
467  * than OS intended it to run at. Detect it and handle it cleanly.
468  */
469 static int bios_with_sw_any_bug;
470
471 static int sw_any_bug_found(const struct dmi_system_id *d)
472 {
473         bios_with_sw_any_bug = 1;
474         return 0;
475 }
476
477 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
478         {
479                 .callback = sw_any_bug_found,
480                 .ident = "Supermicro Server X6DLP",
481                 .matches = {
482                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
483                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
484                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
485                 },
486         },
487         { }
488 };
489
490 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
491 {
492         /* Intel Xeon Processor 7100 Series Specification Update
493          * http://www.intel.com/Assets/PDF/specupdate/314554.pdf
494          * AL30: A Machine Check Exception (MCE) Occurring during an
495          * Enhanced Intel SpeedStep Technology Ratio Change May Cause
496          * Both Processor Cores to Lock Up. */
497         if (c->x86_vendor == X86_VENDOR_INTEL) {
498                 if ((c->x86 == 15) &&
499                     (c->x86_model == 6) &&
500                     (c->x86_mask == 8)) {
501                         printk(KERN_INFO "acpi-cpufreq: Intel(R) "
502                             "Xeon(R) 7100 Errata AL30, processors may "
503                             "lock up on frequency changes: disabling "
504                             "acpi-cpufreq.\n");
505                         return -ENODEV;
506                     }
507                 }
508         return 0;
509 }
510 #endif
511
512 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
513 {
514         unsigned int i;
515         unsigned int valid_states = 0;
516         unsigned int cpu = policy->cpu;
517         struct acpi_cpufreq_data *data;
518         unsigned int result = 0;
519         struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
520         struct acpi_processor_performance *perf;
521 #ifdef CONFIG_SMP
522         static int blacklisted;
523 #endif
524
525         dprintk("acpi_cpufreq_cpu_init\n");
526
527 #ifdef CONFIG_SMP
528         if (blacklisted)
529                 return blacklisted;
530         blacklisted = acpi_cpufreq_blacklist(c);
531         if (blacklisted)
532                 return blacklisted;
533 #endif
534
535         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
536         if (!data)
537                 return -ENOMEM;
538
539         data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
540         per_cpu(acfreq_data, cpu) = data;
541
542         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
543                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
544
545         result = acpi_processor_register_performance(data->acpi_data, cpu);
546         if (result)
547                 goto err_free;
548
549         perf = data->acpi_data;
550         policy->shared_type = perf->shared_type;
551
552         /*
553          * Will let policy->cpus know about dependency only when software
554          * coordination is required.
555          */
556         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
557             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
558                 cpumask_copy(policy->cpus, perf->shared_cpu_map);
559         }
560         cpumask_copy(policy->related_cpus, perf->shared_cpu_map);
561
562 #ifdef CONFIG_SMP
563         dmi_check_system(sw_any_bug_dmi_table);
564         if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) {
565                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
566                 cpumask_copy(policy->cpus, cpu_core_mask(cpu));
567         }
568 #endif
569
570         /* capability check */
571         if (perf->state_count <= 1) {
572                 dprintk("No P-States\n");
573                 result = -ENODEV;
574                 goto err_unreg;
575         }
576
577         if (perf->control_register.space_id != perf->status_register.space_id) {
578                 result = -ENODEV;
579                 goto err_unreg;
580         }
581
582         switch (perf->control_register.space_id) {
583         case ACPI_ADR_SPACE_SYSTEM_IO:
584                 dprintk("SYSTEM IO addr space\n");
585                 data->cpu_feature = SYSTEM_IO_CAPABLE;
586                 break;
587         case ACPI_ADR_SPACE_FIXED_HARDWARE:
588                 dprintk("HARDWARE addr space\n");
589                 if (!check_est_cpu(cpu)) {
590                         result = -ENODEV;
591                         goto err_unreg;
592                 }
593                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
594                 break;
595         default:
596                 dprintk("Unknown addr space %d\n",
597                         (u32) (perf->control_register.space_id));
598                 result = -ENODEV;
599                 goto err_unreg;
600         }
601
602         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
603                     (perf->state_count+1), GFP_KERNEL);
604         if (!data->freq_table) {
605                 result = -ENOMEM;
606                 goto err_unreg;
607         }
608
609         /* detect transition latency */
610         policy->cpuinfo.transition_latency = 0;
611         for (i = 0; i < perf->state_count; i++) {
612                 if ((perf->states[i].transition_latency * 1000) >
613                     policy->cpuinfo.transition_latency)
614                         policy->cpuinfo.transition_latency =
615                             perf->states[i].transition_latency * 1000;
616         }
617
618         /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
619         if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
620             policy->cpuinfo.transition_latency > 20 * 1000) {
621                 policy->cpuinfo.transition_latency = 20 * 1000;
622                 printk_once(KERN_INFO
623                             "P-state transition latency capped at 20 uS\n");
624         }
625
626         /* table init */
627         for (i = 0; i < perf->state_count; i++) {
628                 if (i > 0 && perf->states[i].core_frequency >=
629                     data->freq_table[valid_states-1].frequency / 1000)
630                         continue;
631
632                 data->freq_table[valid_states].index = i;
633                 data->freq_table[valid_states].frequency =
634                     perf->states[i].core_frequency * 1000;
635                 valid_states++;
636         }
637         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
638         perf->state = 0;
639
640         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
641         if (result)
642                 goto err_freqfree;
643
644         if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
645                 printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
646
647         switch (perf->control_register.space_id) {
648         case ACPI_ADR_SPACE_SYSTEM_IO:
649                 /* Current speed is unknown and not detectable by IO port */
650                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
651                 break;
652         case ACPI_ADR_SPACE_FIXED_HARDWARE:
653                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
654                 policy->cur = get_cur_freq_on_cpu(cpu);
655                 break;
656         default:
657                 break;
658         }
659
660         /* notify BIOS that we exist */
661         acpi_processor_notify_smm(THIS_MODULE);
662
663         /* Check for APERF/MPERF support in hardware */
664         if (cpu_has(c, X86_FEATURE_APERFMPERF))
665                 acpi_cpufreq_driver.getavg = cpufreq_get_measured_perf;
666
667         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
668         for (i = 0; i < perf->state_count; i++)
669                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
670                         (i == perf->state ? '*' : ' '), i,
671                         (u32) perf->states[i].core_frequency,
672                         (u32) perf->states[i].power,
673                         (u32) perf->states[i].transition_latency);
674
675         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
676
677         /*
678          * the first call to ->target() should result in us actually
679          * writing something to the appropriate registers.
680          */
681         data->resume = 1;
682
683         return result;
684
685 err_freqfree:
686         kfree(data->freq_table);
687 err_unreg:
688         acpi_processor_unregister_performance(perf, cpu);
689 err_free:
690         kfree(data);
691         per_cpu(acfreq_data, cpu) = NULL;
692
693         return result;
694 }
695
696 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
697 {
698         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
699
700         dprintk("acpi_cpufreq_cpu_exit\n");
701
702         if (data) {
703                 cpufreq_frequency_table_put_attr(policy->cpu);
704                 per_cpu(acfreq_data, policy->cpu) = NULL;
705                 acpi_processor_unregister_performance(data->acpi_data,
706                                                       policy->cpu);
707                 kfree(data);
708         }
709
710         return 0;
711 }
712
713 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
714 {
715         struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
716
717         dprintk("acpi_cpufreq_resume\n");
718
719         data->resume = 1;
720
721         return 0;
722 }
723
724 static struct freq_attr *acpi_cpufreq_attr[] = {
725         &cpufreq_freq_attr_scaling_available_freqs,
726         NULL,
727 };
728
729 static struct cpufreq_driver acpi_cpufreq_driver = {
730         .verify         = acpi_cpufreq_verify,
731         .target         = acpi_cpufreq_target,
732         .bios_limit     = acpi_processor_get_bios_limit,
733         .init           = acpi_cpufreq_cpu_init,
734         .exit           = acpi_cpufreq_cpu_exit,
735         .resume         = acpi_cpufreq_resume,
736         .name           = "acpi-cpufreq",
737         .owner          = THIS_MODULE,
738         .attr           = acpi_cpufreq_attr,
739 };
740
741 static int __init acpi_cpufreq_init(void)
742 {
743         int ret;
744
745         if (acpi_disabled)
746                 return 0;
747
748         dprintk("acpi_cpufreq_init\n");
749
750         ret = acpi_cpufreq_early_init();
751         if (ret)
752                 return ret;
753
754         ret = cpufreq_register_driver(&acpi_cpufreq_driver);
755         if (ret)
756                 free_acpi_perf_data();
757
758         return ret;
759 }
760
761 static void __exit acpi_cpufreq_exit(void)
762 {
763         dprintk("acpi_cpufreq_exit\n");
764
765         cpufreq_unregister_driver(&acpi_cpufreq_driver);
766
767         free_percpu(acpi_perf_data);
768 }
769
770 module_param(acpi_pstate_strict, uint, 0644);
771 MODULE_PARM_DESC(acpi_pstate_strict,
772         "value 0 or non-zero. non-zero -> strict ACPI checks are "
773         "performed during frequency changes.");
774
775 late_initcall(acpi_cpufreq_init);
776 module_exit(acpi_cpufreq_exit);
777
778 MODULE_ALIAS("acpi");