a962dcb9c408518add7154ac9757ad2ed2c08f7c
[linux-2.6.git] / arch / x86 / kernel / cpu / cpufreq / acpi-cpufreq.c
1 /*
2  * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.4 $)
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
37 #include <linux/acpi.h>
38 #include <acpi/processor.h>
39
40 #include <asm/io.h>
41 #include <asm/msr.h>
42 #include <asm/processor.h>
43 #include <asm/cpufeature.h>
44 #include <asm/delay.h>
45 #include <asm/uaccess.h>
46
47 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
48
49 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
50 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
51 MODULE_LICENSE("GPL");
52
53 enum {
54         UNDEFINED_CAPABLE = 0,
55         SYSTEM_INTEL_MSR_CAPABLE,
56         SYSTEM_IO_CAPABLE,
57 };
58
59 #define INTEL_MSR_RANGE         (0xffff)
60 #define CPUID_6_ECX_APERFMPERF_CAPABILITY       (0x1)
61
62 struct acpi_cpufreq_data {
63         struct acpi_processor_performance *acpi_data;
64         struct cpufreq_frequency_table *freq_table;
65         unsigned int max_freq;
66         unsigned int resume;
67         unsigned int cpu_feature;
68 };
69
70 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data);
71
72 /* acpi_perf_data is a pointer to percpu data. */
73 static struct acpi_processor_performance *acpi_perf_data;
74
75 static struct cpufreq_driver acpi_cpufreq_driver;
76
77 static unsigned int acpi_pstate_strict;
78
79 static int check_est_cpu(unsigned int cpuid)
80 {
81         struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
82
83         if (cpu->x86_vendor != X86_VENDOR_INTEL ||
84             !cpu_has(cpu, X86_FEATURE_EST))
85                 return 0;
86
87         return 1;
88 }
89
90 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
91 {
92         struct acpi_processor_performance *perf;
93         int i;
94
95         perf = data->acpi_data;
96
97         for (i=0; i<perf->state_count; i++) {
98                 if (value == perf->states[i].status)
99                         return data->freq_table[i].frequency;
100         }
101         return 0;
102 }
103
104 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
105 {
106         int i;
107         struct acpi_processor_performance *perf;
108
109         msr &= INTEL_MSR_RANGE;
110         perf = data->acpi_data;
111
112         for (i=0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
113                 if (msr == perf->states[data->freq_table[i].index].status)
114                         return data->freq_table[i].frequency;
115         }
116         return data->freq_table[0].frequency;
117 }
118
119 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
120 {
121         switch (data->cpu_feature) {
122         case SYSTEM_INTEL_MSR_CAPABLE:
123                 return extract_msr(val, data);
124         case SYSTEM_IO_CAPABLE:
125                 return extract_io(val, data);
126         default:
127                 return 0;
128         }
129 }
130
131 struct msr_addr {
132         u32 reg;
133 };
134
135 struct io_addr {
136         u16 port;
137         u8 bit_width;
138 };
139
140 typedef union {
141         struct msr_addr msr;
142         struct io_addr io;
143 } drv_addr_union;
144
145 struct drv_cmd {
146         unsigned int type;
147         cpumask_t mask;
148         drv_addr_union addr;
149         u32 val;
150 };
151
152 static void do_drv_read(struct drv_cmd *cmd)
153 {
154         u32 h;
155
156         switch (cmd->type) {
157         case SYSTEM_INTEL_MSR_CAPABLE:
158                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
159                 break;
160         case SYSTEM_IO_CAPABLE:
161                 acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
162                                 &cmd->val,
163                                 (u32)cmd->addr.io.bit_width);
164                 break;
165         default:
166                 break;
167         }
168 }
169
170 static void do_drv_write(struct drv_cmd *cmd)
171 {
172         u32 lo, hi;
173
174         switch (cmd->type) {
175         case SYSTEM_INTEL_MSR_CAPABLE:
176                 rdmsr(cmd->addr.msr.reg, lo, hi);
177                 lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
178                 wrmsr(cmd->addr.msr.reg, lo, hi);
179                 break;
180         case SYSTEM_IO_CAPABLE:
181                 acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
182                                 cmd->val,
183                                 (u32)cmd->addr.io.bit_width);
184                 break;
185         default:
186                 break;
187         }
188 }
189
190 static void drv_read(struct drv_cmd *cmd)
191 {
192         cpumask_t saved_mask = current->cpus_allowed;
193         cmd->val = 0;
194
195         set_cpus_allowed(current, cmd->mask);
196         do_drv_read(cmd);
197         set_cpus_allowed(current, saved_mask);
198 }
199
200 static void drv_write(struct drv_cmd *cmd)
201 {
202         cpumask_t saved_mask = current->cpus_allowed;
203         unsigned int i;
204
205         for_each_cpu_mask(i, cmd->mask) {
206                 set_cpus_allowed(current, cpumask_of_cpu(i));
207                 do_drv_write(cmd);
208         }
209
210         set_cpus_allowed(current, saved_mask);
211         return;
212 }
213
214 static u32 get_cur_val(cpumask_t mask)
215 {
216         struct acpi_processor_performance *perf;
217         struct drv_cmd cmd;
218
219         if (unlikely(cpus_empty(mask)))
220                 return 0;
221
222         switch (per_cpu(drv_data, first_cpu(mask))->cpu_feature) {
223         case SYSTEM_INTEL_MSR_CAPABLE:
224                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
225                 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
226                 break;
227         case SYSTEM_IO_CAPABLE:
228                 cmd.type = SYSTEM_IO_CAPABLE;
229                 perf = per_cpu(drv_data, first_cpu(mask))->acpi_data;
230                 cmd.addr.io.port = perf->control_register.address;
231                 cmd.addr.io.bit_width = perf->control_register.bit_width;
232                 break;
233         default:
234                 return 0;
235         }
236
237         cmd.mask = mask;
238
239         drv_read(&cmd);
240
241         dprintk("get_cur_val = %u\n", cmd.val);
242
243         return cmd.val;
244 }
245
246 /*
247  * Return the measured active (C0) frequency on this CPU since last call
248  * to this function.
249  * Input: cpu number
250  * Return: Average CPU frequency in terms of max frequency (zero on error)
251  *
252  * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
253  * over a period of time, while CPU is in C0 state.
254  * IA32_MPERF counts at the rate of max advertised frequency
255  * IA32_APERF counts at the rate of actual CPU frequency
256  * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
257  * no meaning should be associated with absolute values of these MSRs.
258  */
259 static unsigned int get_measured_perf(unsigned int cpu)
260 {
261         union {
262                 struct {
263                         u32 lo;
264                         u32 hi;
265                 } split;
266                 u64 whole;
267         } aperf_cur, mperf_cur;
268
269         cpumask_t saved_mask;
270         unsigned int perf_percent;
271         unsigned int retval;
272
273         saved_mask = current->cpus_allowed;
274         set_cpus_allowed(current, cpumask_of_cpu(cpu));
275         if (get_cpu() != cpu) {
276                 /* We were not able to run on requested processor */
277                 put_cpu();
278                 return 0;
279         }
280
281         rdmsr(MSR_IA32_APERF, aperf_cur.split.lo, aperf_cur.split.hi);
282         rdmsr(MSR_IA32_MPERF, mperf_cur.split.lo, mperf_cur.split.hi);
283
284         wrmsr(MSR_IA32_APERF, 0,0);
285         wrmsr(MSR_IA32_MPERF, 0,0);
286
287 #ifdef __i386__
288         /*
289          * We dont want to do 64 bit divide with 32 bit kernel
290          * Get an approximate value. Return failure in case we cannot get
291          * an approximate value.
292          */
293         if (unlikely(aperf_cur.split.hi || mperf_cur.split.hi)) {
294                 int shift_count;
295                 u32 h;
296
297                 h = max_t(u32, aperf_cur.split.hi, mperf_cur.split.hi);
298                 shift_count = fls(h);
299
300                 aperf_cur.whole >>= shift_count;
301                 mperf_cur.whole >>= shift_count;
302         }
303
304         if (((unsigned long)(-1) / 100) < aperf_cur.split.lo) {
305                 int shift_count = 7;
306                 aperf_cur.split.lo >>= shift_count;
307                 mperf_cur.split.lo >>= shift_count;
308         }
309
310         if (aperf_cur.split.lo && mperf_cur.split.lo)
311                 perf_percent = (aperf_cur.split.lo * 100) / mperf_cur.split.lo;
312         else
313                 perf_percent = 0;
314
315 #else
316         if (unlikely(((unsigned long)(-1) / 100) < aperf_cur.whole)) {
317                 int shift_count = 7;
318                 aperf_cur.whole >>= shift_count;
319                 mperf_cur.whole >>= shift_count;
320         }
321
322         if (aperf_cur.whole && mperf_cur.whole)
323                 perf_percent = (aperf_cur.whole * 100) / mperf_cur.whole;
324         else
325                 perf_percent = 0;
326
327 #endif
328
329         retval = per_cpu(drv_data, cpu)->max_freq * perf_percent / 100;
330
331         put_cpu();
332         set_cpus_allowed(current, saved_mask);
333
334         dprintk("cpu %d: performance percent %d\n", cpu, perf_percent);
335         return retval;
336 }
337
338 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
339 {
340         struct acpi_cpufreq_data *data = per_cpu(drv_data, cpu);
341         unsigned int freq;
342
343         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
344
345         if (unlikely(data == NULL ||
346                      data->acpi_data == NULL || data->freq_table == NULL)) {
347                 return 0;
348         }
349
350         freq = extract_freq(get_cur_val(cpumask_of_cpu(cpu)), data);
351         dprintk("cur freq = %u\n", freq);
352
353         return freq;
354 }
355
356 static unsigned int check_freqs(cpumask_t mask, unsigned int freq,
357                                 struct acpi_cpufreq_data *data)
358 {
359         unsigned int cur_freq;
360         unsigned int i;
361
362         for (i=0; i<100; i++) {
363                 cur_freq = extract_freq(get_cur_val(mask), data);
364                 if (cur_freq == freq)
365                         return 1;
366                 udelay(10);
367         }
368         return 0;
369 }
370
371 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
372                                unsigned int target_freq, unsigned int relation)
373 {
374         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
375         struct acpi_processor_performance *perf;
376         struct cpufreq_freqs freqs;
377         cpumask_t online_policy_cpus;
378         struct drv_cmd cmd;
379         unsigned int next_state = 0; /* Index into freq_table */
380         unsigned int next_perf_state = 0; /* Index into perf table */
381         unsigned int i;
382         int result = 0;
383
384         dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
385
386         if (unlikely(data == NULL ||
387              data->acpi_data == NULL || data->freq_table == NULL)) {
388                 return -ENODEV;
389         }
390
391         perf = data->acpi_data;
392         result = cpufreq_frequency_table_target(policy,
393                                                 data->freq_table,
394                                                 target_freq,
395                                                 relation, &next_state);
396         if (unlikely(result))
397                 return -ENODEV;
398
399 #ifdef CONFIG_HOTPLUG_CPU
400         /* cpufreq holds the hotplug lock, so we are safe from here on */
401         cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
402 #else
403         online_policy_cpus = policy->cpus;
404 #endif
405
406         next_perf_state = data->freq_table[next_state].index;
407         if (perf->state == next_perf_state) {
408                 if (unlikely(data->resume)) {
409                         dprintk("Called after resume, resetting to P%d\n",
410                                 next_perf_state);
411                         data->resume = 0;
412                 } else {
413                         dprintk("Already at target state (P%d)\n",
414                                 next_perf_state);
415                         return 0;
416                 }
417         }
418
419         switch (data->cpu_feature) {
420         case SYSTEM_INTEL_MSR_CAPABLE:
421                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
422                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
423                 cmd.val = (u32) perf->states[next_perf_state].control;
424                 break;
425         case SYSTEM_IO_CAPABLE:
426                 cmd.type = SYSTEM_IO_CAPABLE;
427                 cmd.addr.io.port = perf->control_register.address;
428                 cmd.addr.io.bit_width = perf->control_register.bit_width;
429                 cmd.val = (u32) perf->states[next_perf_state].control;
430                 break;
431         default:
432                 return -ENODEV;
433         }
434
435         cpus_clear(cmd.mask);
436
437         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
438                 cmd.mask = online_policy_cpus;
439         else
440                 cpu_set(policy->cpu, cmd.mask);
441
442         freqs.old = perf->states[perf->state].core_frequency * 1000;
443         freqs.new = data->freq_table[next_state].frequency;
444         for_each_cpu_mask(i, cmd.mask) {
445                 freqs.cpu = i;
446                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
447         }
448
449         drv_write(&cmd);
450
451         if (acpi_pstate_strict) {
452                 if (!check_freqs(cmd.mask, freqs.new, data)) {
453                         dprintk("acpi_cpufreq_target failed (%d)\n",
454                                 policy->cpu);
455                         return -EAGAIN;
456                 }
457         }
458
459         for_each_cpu_mask(i, cmd.mask) {
460                 freqs.cpu = i;
461                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
462         }
463         perf->state = next_perf_state;
464
465         return result;
466 }
467
468 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
469 {
470         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
471
472         dprintk("acpi_cpufreq_verify\n");
473
474         return cpufreq_frequency_table_verify(policy, data->freq_table);
475 }
476
477 static unsigned long
478 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
479 {
480         struct acpi_processor_performance *perf = data->acpi_data;
481
482         if (cpu_khz) {
483                 /* search the closest match to cpu_khz */
484                 unsigned int i;
485                 unsigned long freq;
486                 unsigned long freqn = perf->states[0].core_frequency * 1000;
487
488                 for (i=0; i<(perf->state_count-1); i++) {
489                         freq = freqn;
490                         freqn = perf->states[i+1].core_frequency * 1000;
491                         if ((2 * cpu_khz) > (freqn + freq)) {
492                                 perf->state = i;
493                                 return freq;
494                         }
495                 }
496                 perf->state = perf->state_count-1;
497                 return freqn;
498         } else {
499                 /* assume CPU is at P0... */
500                 perf->state = 0;
501                 return perf->states[0].core_frequency * 1000;
502         }
503 }
504
505 /*
506  * acpi_cpufreq_early_init - initialize ACPI P-States library
507  *
508  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
509  * in order to determine correct frequency and voltage pairings. We can
510  * do _PDC and _PSD and find out the processor dependency for the
511  * actual init that will happen later...
512  */
513 static int __init acpi_cpufreq_early_init(void)
514 {
515         dprintk("acpi_cpufreq_early_init\n");
516
517         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
518         if (!acpi_perf_data) {
519                 dprintk("Memory allocation error for acpi_perf_data.\n");
520                 return -ENOMEM;
521         }
522
523         /* Do initialization in ACPI core */
524         acpi_processor_preregister_performance(acpi_perf_data);
525         return 0;
526 }
527
528 #ifdef CONFIG_SMP
529 /*
530  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
531  * or do it in BIOS firmware and won't inform about it to OS. If not
532  * detected, this has a side effect of making CPU run at a different speed
533  * than OS intended it to run at. Detect it and handle it cleanly.
534  */
535 static int bios_with_sw_any_bug;
536
537 static int sw_any_bug_found(const struct dmi_system_id *d)
538 {
539         bios_with_sw_any_bug = 1;
540         return 0;
541 }
542
543 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
544         {
545                 .callback = sw_any_bug_found,
546                 .ident = "Supermicro Server X6DLP",
547                 .matches = {
548                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
549                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
550                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
551                 },
552         },
553         { }
554 };
555 #endif
556
557 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
558 {
559         unsigned int i;
560         unsigned int valid_states = 0;
561         unsigned int cpu = policy->cpu;
562         struct acpi_cpufreq_data *data;
563         unsigned int result = 0;
564         struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
565         struct acpi_processor_performance *perf;
566
567         dprintk("acpi_cpufreq_cpu_init\n");
568
569         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
570         if (!data)
571                 return -ENOMEM;
572
573         data->acpi_data = percpu_ptr(acpi_perf_data, cpu);
574         per_cpu(drv_data, cpu) = data;
575
576         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
577                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
578
579         result = acpi_processor_register_performance(data->acpi_data, cpu);
580         if (result)
581                 goto err_free;
582
583         perf = data->acpi_data;
584         policy->shared_type = perf->shared_type;
585
586         /*
587          * Will let policy->cpus know about dependency only when software
588          * coordination is required.
589          */
590         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
591             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
592                 policy->cpus = perf->shared_cpu_map;
593         }
594
595 #ifdef CONFIG_SMP
596         dmi_check_system(sw_any_bug_dmi_table);
597         if (bios_with_sw_any_bug && cpus_weight(policy->cpus) == 1) {
598                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
599                 policy->cpus = per_cpu(cpu_core_map, cpu);
600         }
601 #endif
602
603         /* capability check */
604         if (perf->state_count <= 1) {
605                 dprintk("No P-States\n");
606                 result = -ENODEV;
607                 goto err_unreg;
608         }
609
610         if (perf->control_register.space_id != perf->status_register.space_id) {
611                 result = -ENODEV;
612                 goto err_unreg;
613         }
614
615         switch (perf->control_register.space_id) {
616         case ACPI_ADR_SPACE_SYSTEM_IO:
617                 dprintk("SYSTEM IO addr space\n");
618                 data->cpu_feature = SYSTEM_IO_CAPABLE;
619                 break;
620         case ACPI_ADR_SPACE_FIXED_HARDWARE:
621                 dprintk("HARDWARE addr space\n");
622                 if (!check_est_cpu(cpu)) {
623                         result = -ENODEV;
624                         goto err_unreg;
625                 }
626                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
627                 break;
628         default:
629                 dprintk("Unknown addr space %d\n",
630                         (u32) (perf->control_register.space_id));
631                 result = -ENODEV;
632                 goto err_unreg;
633         }
634
635         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
636                     (perf->state_count+1), GFP_KERNEL);
637         if (!data->freq_table) {
638                 result = -ENOMEM;
639                 goto err_unreg;
640         }
641
642         /* detect transition latency */
643         policy->cpuinfo.transition_latency = 0;
644         for (i=0; i<perf->state_count; i++) {
645                 if ((perf->states[i].transition_latency * 1000) >
646                     policy->cpuinfo.transition_latency)
647                         policy->cpuinfo.transition_latency =
648                             perf->states[i].transition_latency * 1000;
649         }
650
651         data->max_freq = perf->states[0].core_frequency * 1000;
652         /* table init */
653         for (i=0; i<perf->state_count; i++) {
654                 if (i>0 && perf->states[i].core_frequency >=
655                     data->freq_table[valid_states-1].frequency / 1000)
656                         continue;
657
658                 data->freq_table[valid_states].index = i;
659                 data->freq_table[valid_states].frequency =
660                     perf->states[i].core_frequency * 1000;
661                 valid_states++;
662         }
663         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
664         perf->state = 0;
665
666         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
667         if (result)
668                 goto err_freqfree;
669
670         switch (perf->control_register.space_id) {
671         case ACPI_ADR_SPACE_SYSTEM_IO:
672                 /* Current speed is unknown and not detectable by IO port */
673                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
674                 break;
675         case ACPI_ADR_SPACE_FIXED_HARDWARE:
676                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
677                 policy->cur = get_cur_freq_on_cpu(cpu);
678                 break;
679         default:
680                 break;
681         }
682
683         /* notify BIOS that we exist */
684         acpi_processor_notify_smm(THIS_MODULE);
685
686         /* Check for APERF/MPERF support in hardware */
687         if (c->x86_vendor == X86_VENDOR_INTEL && c->cpuid_level >= 6) {
688                 unsigned int ecx;
689                 ecx = cpuid_ecx(6);
690                 if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY)
691                         acpi_cpufreq_driver.getavg = get_measured_perf;
692         }
693
694         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
695         for (i = 0; i < perf->state_count; i++)
696                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
697                         (i == perf->state ? '*' : ' '), i,
698                         (u32) perf->states[i].core_frequency,
699                         (u32) perf->states[i].power,
700                         (u32) perf->states[i].transition_latency);
701
702         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
703
704         /*
705          * the first call to ->target() should result in us actually
706          * writing something to the appropriate registers.
707          */
708         data->resume = 1;
709
710         return result;
711
712 err_freqfree:
713         kfree(data->freq_table);
714 err_unreg:
715         acpi_processor_unregister_performance(perf, cpu);
716 err_free:
717         kfree(data);
718         per_cpu(drv_data, cpu) = NULL;
719
720         return result;
721 }
722
723 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
724 {
725         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
726
727         dprintk("acpi_cpufreq_cpu_exit\n");
728
729         if (data) {
730                 cpufreq_frequency_table_put_attr(policy->cpu);
731                 per_cpu(drv_data, policy->cpu) = NULL;
732                 acpi_processor_unregister_performance(data->acpi_data,
733                                                       policy->cpu);
734                 kfree(data);
735         }
736
737         return 0;
738 }
739
740 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
741 {
742         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
743
744         dprintk("acpi_cpufreq_resume\n");
745
746         data->resume = 1;
747
748         return 0;
749 }
750
751 static struct freq_attr *acpi_cpufreq_attr[] = {
752         &cpufreq_freq_attr_scaling_available_freqs,
753         NULL,
754 };
755
756 static struct cpufreq_driver acpi_cpufreq_driver = {
757         .verify = acpi_cpufreq_verify,
758         .target = acpi_cpufreq_target,
759         .init = acpi_cpufreq_cpu_init,
760         .exit = acpi_cpufreq_cpu_exit,
761         .resume = acpi_cpufreq_resume,
762         .name = "acpi-cpufreq",
763         .owner = THIS_MODULE,
764         .attr = acpi_cpufreq_attr,
765 };
766
767 static int __init acpi_cpufreq_init(void)
768 {
769         int ret;
770
771         dprintk("acpi_cpufreq_init\n");
772
773         ret = acpi_cpufreq_early_init();
774         if (ret)
775                 return ret;
776
777         return cpufreq_register_driver(&acpi_cpufreq_driver);
778 }
779
780 static void __exit acpi_cpufreq_exit(void)
781 {
782         dprintk("acpi_cpufreq_exit\n");
783
784         cpufreq_unregister_driver(&acpi_cpufreq_driver);
785
786         free_percpu(acpi_perf_data);
787
788         return;
789 }
790
791 module_param(acpi_pstate_strict, uint, 0644);
792 MODULE_PARM_DESC(acpi_pstate_strict,
793         "value 0 or non-zero. non-zero -> strict ACPI checks are "
794         "performed during frequency changes.");
795
796 late_initcall(acpi_cpufreq_init);
797 module_exit(acpi_cpufreq_exit);
798
799 MODULE_ALIAS("acpi");