]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/blob - arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
4e4f2b04dac2451899d241145269328935cf02ca
[linux-2.6-omap-h63xx.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 #include <linux/ftrace.h>
37
38 #include <linux/acpi.h>
39 #include <acpi/processor.h>
40
41 #include <asm/io.h>
42 #include <asm/msr.h>
43 #include <asm/processor.h>
44 #include <asm/cpufeature.h>
45 #include <asm/delay.h>
46 #include <asm/uaccess.h>
47
48 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
49
50 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
51 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
52 MODULE_LICENSE("GPL");
53
54 enum {
55         UNDEFINED_CAPABLE = 0,
56         SYSTEM_INTEL_MSR_CAPABLE,
57         SYSTEM_IO_CAPABLE,
58 };
59
60 #define INTEL_MSR_RANGE         (0xffff)
61 #define CPUID_6_ECX_APERFMPERF_CAPABILITY       (0x1)
62
63 struct acpi_cpufreq_data {
64         struct acpi_processor_performance *acpi_data;
65         struct cpufreq_frequency_table *freq_table;
66         unsigned int max_freq;
67         unsigned int resume;
68         unsigned int cpu_feature;
69 };
70
71 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data);
72
73 /* acpi_perf_data is a pointer to percpu data. */
74 static struct acpi_processor_performance *acpi_perf_data;
75
76 static struct cpufreq_driver acpi_cpufreq_driver;
77
78 static unsigned int acpi_pstate_strict;
79
80 static int check_est_cpu(unsigned int cpuid)
81 {
82         struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
83
84         if (cpu->x86_vendor != X86_VENDOR_INTEL ||
85             !cpu_has(cpu, X86_FEATURE_EST))
86                 return 0;
87
88         return 1;
89 }
90
91 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
92 {
93         struct acpi_processor_performance *perf;
94         int i;
95
96         perf = data->acpi_data;
97
98         for (i=0; i<perf->state_count; i++) {
99                 if (value == perf->states[i].status)
100                         return data->freq_table[i].frequency;
101         }
102         return 0;
103 }
104
105 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
106 {
107         int i;
108         struct acpi_processor_performance *perf;
109
110         msr &= INTEL_MSR_RANGE;
111         perf = data->acpi_data;
112
113         for (i=0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
114                 if (msr == perf->states[data->freq_table[i].index].status)
115                         return data->freq_table[i].frequency;
116         }
117         return data->freq_table[0].frequency;
118 }
119
120 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
121 {
122         switch (data->cpu_feature) {
123         case SYSTEM_INTEL_MSR_CAPABLE:
124                 return extract_msr(val, data);
125         case SYSTEM_IO_CAPABLE:
126                 return extract_io(val, data);
127         default:
128                 return 0;
129         }
130 }
131
132 struct msr_addr {
133         u32 reg;
134 };
135
136 struct io_addr {
137         u16 port;
138         u8 bit_width;
139 };
140
141 typedef union {
142         struct msr_addr msr;
143         struct io_addr io;
144 } drv_addr_union;
145
146 struct drv_cmd {
147         unsigned int type;
148         cpumask_var_t mask;
149         drv_addr_union addr;
150         u32 val;
151 };
152
153 static long do_drv_read(void *_cmd)
154 {
155         struct drv_cmd *cmd = _cmd;
156         u32 h;
157
158         switch (cmd->type) {
159         case SYSTEM_INTEL_MSR_CAPABLE:
160                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
161                 break;
162         case SYSTEM_IO_CAPABLE:
163                 acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
164                                 &cmd->val,
165                                 (u32)cmd->addr.io.bit_width);
166                 break;
167         default:
168                 break;
169         }
170         return 0;
171 }
172
173 static long do_drv_write(void *_cmd)
174 {
175         struct drv_cmd *cmd = _cmd;
176         u32 lo, hi;
177
178         switch (cmd->type) {
179         case SYSTEM_INTEL_MSR_CAPABLE:
180                 rdmsr(cmd->addr.msr.reg, lo, hi);
181                 lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
182                 wrmsr(cmd->addr.msr.reg, lo, hi);
183                 break;
184         case SYSTEM_IO_CAPABLE:
185                 acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
186                                 cmd->val,
187                                 (u32)cmd->addr.io.bit_width);
188                 break;
189         default:
190                 break;
191         }
192         return 0;
193 }
194
195 static void drv_read(struct drv_cmd *cmd)
196 {
197         cmd->val = 0;
198
199         work_on_cpu(cpumask_any(cmd->mask), do_drv_read, cmd);
200 }
201
202 static void drv_write(struct drv_cmd *cmd)
203 {
204         unsigned int i;
205
206         for_each_cpu(i, cmd->mask) {
207                 work_on_cpu(i, do_drv_write, cmd);
208         }
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(drv_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(drv_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         if (unlikely(!alloc_cpumask_var(&cmd.mask, GFP_KERNEL)))
235                 return 0;
236
237         cpumask_copy(cmd.mask, mask);
238
239         drv_read(&cmd);
240
241         free_cpumask_var(cmd.mask);
242
243         dprintk("get_cur_val = %u\n", cmd.val);
244
245         return cmd.val;
246 }
247
248 /*
249  * Return the measured active (C0) frequency on this CPU since last call
250  * to this function.
251  * Input: cpu number
252  * Return: Average CPU frequency in terms of max frequency (zero on error)
253  *
254  * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
255  * over a period of time, while CPU is in C0 state.
256  * IA32_MPERF counts at the rate of max advertised frequency
257  * IA32_APERF counts at the rate of actual CPU frequency
258  * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
259  * no meaning should be associated with absolute values of these MSRs.
260  */
261 static unsigned int get_measured_perf(struct cpufreq_policy *policy,
262                                       unsigned int cpu)
263 {
264         union {
265                 struct {
266                         u32 lo;
267                         u32 hi;
268                 } split;
269                 u64 whole;
270         } aperf_cur, mperf_cur;
271
272         cpumask_t saved_mask;
273         unsigned int perf_percent;
274         unsigned int retval;
275
276         saved_mask = current->cpus_allowed;
277         set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
278         if (get_cpu() != cpu) {
279                 /* We were not able to run on requested processor */
280                 put_cpu();
281                 return 0;
282         }
283
284         rdmsr(MSR_IA32_APERF, aperf_cur.split.lo, aperf_cur.split.hi);
285         rdmsr(MSR_IA32_MPERF, mperf_cur.split.lo, mperf_cur.split.hi);
286
287         wrmsr(MSR_IA32_APERF, 0,0);
288         wrmsr(MSR_IA32_MPERF, 0,0);
289
290 #ifdef __i386__
291         /*
292          * We dont want to do 64 bit divide with 32 bit kernel
293          * Get an approximate value. Return failure in case we cannot get
294          * an approximate value.
295          */
296         if (unlikely(aperf_cur.split.hi || mperf_cur.split.hi)) {
297                 int shift_count;
298                 u32 h;
299
300                 h = max_t(u32, aperf_cur.split.hi, mperf_cur.split.hi);
301                 shift_count = fls(h);
302
303                 aperf_cur.whole >>= shift_count;
304                 mperf_cur.whole >>= shift_count;
305         }
306
307         if (((unsigned long)(-1) / 100) < aperf_cur.split.lo) {
308                 int shift_count = 7;
309                 aperf_cur.split.lo >>= shift_count;
310                 mperf_cur.split.lo >>= shift_count;
311         }
312
313         if (aperf_cur.split.lo && mperf_cur.split.lo)
314                 perf_percent = (aperf_cur.split.lo * 100) / mperf_cur.split.lo;
315         else
316                 perf_percent = 0;
317
318 #else
319         if (unlikely(((unsigned long)(-1) / 100) < aperf_cur.whole)) {
320                 int shift_count = 7;
321                 aperf_cur.whole >>= shift_count;
322                 mperf_cur.whole >>= shift_count;
323         }
324
325         if (aperf_cur.whole && mperf_cur.whole)
326                 perf_percent = (aperf_cur.whole * 100) / mperf_cur.whole;
327         else
328                 perf_percent = 0;
329
330 #endif
331
332         retval = per_cpu(drv_data, policy->cpu)->max_freq * perf_percent / 100;
333
334         put_cpu();
335         set_cpus_allowed_ptr(current, &saved_mask);
336
337         dprintk("cpu %d: performance percent %d\n", cpu, perf_percent);
338         return retval;
339 }
340
341 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
342 {
343         struct acpi_cpufreq_data *data = per_cpu(drv_data, cpu);
344         unsigned int freq;
345         unsigned int cached_freq;
346
347         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
348
349         if (unlikely(data == NULL ||
350                      data->acpi_data == NULL || data->freq_table == NULL)) {
351                 return 0;
352         }
353
354         cached_freq = data->freq_table[data->acpi_data->state].frequency;
355         freq = extract_freq(get_cur_val(&cpumask_of_cpu(cpu)), data);
356         if (freq != cached_freq) {
357                 /*
358                  * The dreaded BIOS frequency change behind our back.
359                  * Force set the frequency on next target call.
360                  */
361                 data->resume = 1;
362         }
363
364         dprintk("cur freq = %u\n", freq);
365
366         return freq;
367 }
368
369 static unsigned int check_freqs(const cpumask_t *mask, unsigned int freq,
370                                 struct acpi_cpufreq_data *data)
371 {
372         unsigned int cur_freq;
373         unsigned int i;
374
375         for (i=0; i<100; i++) {
376                 cur_freq = extract_freq(get_cur_val(mask), data);
377                 if (cur_freq == freq)
378                         return 1;
379                 udelay(10);
380         }
381         return 0;
382 }
383
384 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
385                                unsigned int target_freq, unsigned int relation)
386 {
387         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
388         struct acpi_processor_performance *perf;
389         struct cpufreq_freqs freqs;
390         struct drv_cmd cmd;
391         unsigned int next_state = 0; /* Index into freq_table */
392         unsigned int next_perf_state = 0; /* Index into perf table */
393         unsigned int i;
394         int result = 0;
395         struct power_trace it;
396
397         dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
398
399         if (unlikely(data == NULL ||
400              data->acpi_data == NULL || data->freq_table == NULL)) {
401                 return -ENODEV;
402         }
403
404         if (unlikely(!alloc_cpumask_var(&cmd.mask, GFP_KERNEL)))
405                 return -ENOMEM;
406
407         perf = data->acpi_data;
408         result = cpufreq_frequency_table_target(policy,
409                                                 data->freq_table,
410                                                 target_freq,
411                                                 relation, &next_state);
412         if (unlikely(result)) {
413                 result = -ENODEV;
414                 goto out;
415         }
416
417         next_perf_state = data->freq_table[next_state].index;
418         if (perf->state == next_perf_state) {
419                 if (unlikely(data->resume)) {
420                         dprintk("Called after resume, resetting to P%d\n",
421                                 next_perf_state);
422                         data->resume = 0;
423                 } else {
424                         dprintk("Already at target state (P%d)\n",
425                                 next_perf_state);
426                         goto out;
427                 }
428         }
429
430         trace_power_mark(&it, POWER_PSTATE, next_perf_state);
431
432         switch (data->cpu_feature) {
433         case SYSTEM_INTEL_MSR_CAPABLE:
434                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
435                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
436                 cmd.val = (u32) perf->states[next_perf_state].control;
437                 break;
438         case SYSTEM_IO_CAPABLE:
439                 cmd.type = SYSTEM_IO_CAPABLE;
440                 cmd.addr.io.port = perf->control_register.address;
441                 cmd.addr.io.bit_width = perf->control_register.bit_width;
442                 cmd.val = (u32) perf->states[next_perf_state].control;
443                 break;
444         default:
445                 result = -ENODEV;
446                 goto out;
447         }
448
449         /* cpufreq holds the hotplug lock, so we are safe from here on */
450         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
451                 cpumask_and(cmd.mask, cpu_online_mask, policy->cpus);
452         else
453                 cpumask_copy(cmd.mask, cpumask_of(policy->cpu));
454
455         freqs.old = perf->states[perf->state].core_frequency * 1000;
456         freqs.new = data->freq_table[next_state].frequency;
457         for_each_cpu(i, cmd.mask) {
458                 freqs.cpu = i;
459                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
460         }
461
462         drv_write(&cmd);
463
464         if (acpi_pstate_strict) {
465                 if (!check_freqs(cmd.mask, freqs.new, data)) {
466                         dprintk("acpi_cpufreq_target failed (%d)\n",
467                                 policy->cpu);
468                         result = -EAGAIN;
469                         goto out;
470                 }
471         }
472
473         for_each_cpu(i, cmd.mask) {
474                 freqs.cpu = i;
475                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
476         }
477         perf->state = next_perf_state;
478
479 out:
480         free_cpumask_var(cmd.mask);
481         return result;
482 }
483
484 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
485 {
486         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
487
488         dprintk("acpi_cpufreq_verify\n");
489
490         return cpufreq_frequency_table_verify(policy, data->freq_table);
491 }
492
493 static unsigned long
494 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
495 {
496         struct acpi_processor_performance *perf = data->acpi_data;
497
498         if (cpu_khz) {
499                 /* search the closest match to cpu_khz */
500                 unsigned int i;
501                 unsigned long freq;
502                 unsigned long freqn = perf->states[0].core_frequency * 1000;
503
504                 for (i=0; i<(perf->state_count-1); i++) {
505                         freq = freqn;
506                         freqn = perf->states[i+1].core_frequency * 1000;
507                         if ((2 * cpu_khz) > (freqn + freq)) {
508                                 perf->state = i;
509                                 return freq;
510                         }
511                 }
512                 perf->state = perf->state_count-1;
513                 return freqn;
514         } else {
515                 /* assume CPU is at P0... */
516                 perf->state = 0;
517                 return perf->states[0].core_frequency * 1000;
518         }
519 }
520
521 static void free_acpi_perf_data(void)
522 {
523         unsigned int i;
524
525         /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
526         for_each_possible_cpu(i)
527                 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
528                                  ->shared_cpu_map);
529         free_percpu(acpi_perf_data);
530 }
531
532 /*
533  * acpi_cpufreq_early_init - initialize ACPI P-States library
534  *
535  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
536  * in order to determine correct frequency and voltage pairings. We can
537  * do _PDC and _PSD and find out the processor dependency for the
538  * actual init that will happen later...
539  */
540 static int __init acpi_cpufreq_early_init(void)
541 {
542         unsigned int i;
543         dprintk("acpi_cpufreq_early_init\n");
544
545         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
546         if (!acpi_perf_data) {
547                 dprintk("Memory allocation error for acpi_perf_data.\n");
548                 return -ENOMEM;
549         }
550         for_each_possible_cpu(i) {
551                 if (!alloc_cpumask_var_node(
552                         &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
553                         GFP_KERNEL, cpu_to_node(i))) {
554
555                         /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
556                         free_acpi_perf_data();
557                         return -ENOMEM;
558                 }
559         }
560
561         /* Do initialization in ACPI core */
562         acpi_processor_preregister_performance(acpi_perf_data);
563         return 0;
564 }
565
566 #ifdef CONFIG_SMP
567 /*
568  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
569  * or do it in BIOS firmware and won't inform about it to OS. If not
570  * detected, this has a side effect of making CPU run at a different speed
571  * than OS intended it to run at. Detect it and handle it cleanly.
572  */
573 static int bios_with_sw_any_bug;
574
575 static int sw_any_bug_found(const struct dmi_system_id *d)
576 {
577         bios_with_sw_any_bug = 1;
578         return 0;
579 }
580
581 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
582         {
583                 .callback = sw_any_bug_found,
584                 .ident = "Supermicro Server X6DLP",
585                 .matches = {
586                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
587                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
588                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
589                 },
590         },
591         { }
592 };
593 #endif
594
595 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
596 {
597         unsigned int i;
598         unsigned int valid_states = 0;
599         unsigned int cpu = policy->cpu;
600         struct acpi_cpufreq_data *data;
601         unsigned int result = 0;
602         struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
603         struct acpi_processor_performance *perf;
604
605         dprintk("acpi_cpufreq_cpu_init\n");
606
607         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
608         if (!data)
609                 return -ENOMEM;
610
611         data->acpi_data = percpu_ptr(acpi_perf_data, cpu);
612         per_cpu(drv_data, cpu) = data;
613
614         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
615                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
616
617         result = acpi_processor_register_performance(data->acpi_data, cpu);
618         if (result)
619                 goto err_free;
620
621         perf = data->acpi_data;
622         policy->shared_type = perf->shared_type;
623
624         /*
625          * Will let policy->cpus know about dependency only when software
626          * coordination is required.
627          */
628         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
629             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
630                 cpumask_copy(policy->cpus, perf->shared_cpu_map);
631         }
632         cpumask_copy(policy->related_cpus, perf->shared_cpu_map);
633
634 #ifdef CONFIG_SMP
635         dmi_check_system(sw_any_bug_dmi_table);
636         if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) {
637                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
638                 cpumask_copy(policy->cpus, cpu_core_mask(cpu));
639         }
640 #endif
641
642         /* capability check */
643         if (perf->state_count <= 1) {
644                 dprintk("No P-States\n");
645                 result = -ENODEV;
646                 goto err_unreg;
647         }
648
649         if (perf->control_register.space_id != perf->status_register.space_id) {
650                 result = -ENODEV;
651                 goto err_unreg;
652         }
653
654         switch (perf->control_register.space_id) {
655         case ACPI_ADR_SPACE_SYSTEM_IO:
656                 dprintk("SYSTEM IO addr space\n");
657                 data->cpu_feature = SYSTEM_IO_CAPABLE;
658                 break;
659         case ACPI_ADR_SPACE_FIXED_HARDWARE:
660                 dprintk("HARDWARE addr space\n");
661                 if (!check_est_cpu(cpu)) {
662                         result = -ENODEV;
663                         goto err_unreg;
664                 }
665                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
666                 break;
667         default:
668                 dprintk("Unknown addr space %d\n",
669                         (u32) (perf->control_register.space_id));
670                 result = -ENODEV;
671                 goto err_unreg;
672         }
673
674         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
675                     (perf->state_count+1), GFP_KERNEL);
676         if (!data->freq_table) {
677                 result = -ENOMEM;
678                 goto err_unreg;
679         }
680
681         /* detect transition latency */
682         policy->cpuinfo.transition_latency = 0;
683         for (i=0; i<perf->state_count; i++) {
684                 if ((perf->states[i].transition_latency * 1000) >
685                     policy->cpuinfo.transition_latency)
686                         policy->cpuinfo.transition_latency =
687                             perf->states[i].transition_latency * 1000;
688         }
689
690         data->max_freq = perf->states[0].core_frequency * 1000;
691         /* table init */
692         for (i=0; i<perf->state_count; i++) {
693                 if (i>0 && perf->states[i].core_frequency >=
694                     data->freq_table[valid_states-1].frequency / 1000)
695                         continue;
696
697                 data->freq_table[valid_states].index = i;
698                 data->freq_table[valid_states].frequency =
699                     perf->states[i].core_frequency * 1000;
700                 valid_states++;
701         }
702         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
703         perf->state = 0;
704
705         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
706         if (result)
707                 goto err_freqfree;
708
709         switch (perf->control_register.space_id) {
710         case ACPI_ADR_SPACE_SYSTEM_IO:
711                 /* Current speed is unknown and not detectable by IO port */
712                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
713                 break;
714         case ACPI_ADR_SPACE_FIXED_HARDWARE:
715                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
716                 policy->cur = get_cur_freq_on_cpu(cpu);
717                 break;
718         default:
719                 break;
720         }
721
722         /* notify BIOS that we exist */
723         acpi_processor_notify_smm(THIS_MODULE);
724
725         /* Check for APERF/MPERF support in hardware */
726         if (c->x86_vendor == X86_VENDOR_INTEL && c->cpuid_level >= 6) {
727                 unsigned int ecx;
728                 ecx = cpuid_ecx(6);
729                 if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY)
730                         acpi_cpufreq_driver.getavg = get_measured_perf;
731         }
732
733         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
734         for (i = 0; i < perf->state_count; i++)
735                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
736                         (i == perf->state ? '*' : ' '), i,
737                         (u32) perf->states[i].core_frequency,
738                         (u32) perf->states[i].power,
739                         (u32) perf->states[i].transition_latency);
740
741         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
742
743         /*
744          * the first call to ->target() should result in us actually
745          * writing something to the appropriate registers.
746          */
747         data->resume = 1;
748
749         return result;
750
751 err_freqfree:
752         kfree(data->freq_table);
753 err_unreg:
754         acpi_processor_unregister_performance(perf, cpu);
755 err_free:
756         kfree(data);
757         per_cpu(drv_data, cpu) = NULL;
758
759         return result;
760 }
761
762 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
763 {
764         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
765
766         dprintk("acpi_cpufreq_cpu_exit\n");
767
768         if (data) {
769                 cpufreq_frequency_table_put_attr(policy->cpu);
770                 per_cpu(drv_data, policy->cpu) = NULL;
771                 acpi_processor_unregister_performance(data->acpi_data,
772                                                       policy->cpu);
773                 kfree(data);
774         }
775
776         return 0;
777 }
778
779 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
780 {
781         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
782
783         dprintk("acpi_cpufreq_resume\n");
784
785         data->resume = 1;
786
787         return 0;
788 }
789
790 static struct freq_attr *acpi_cpufreq_attr[] = {
791         &cpufreq_freq_attr_scaling_available_freqs,
792         NULL,
793 };
794
795 static struct cpufreq_driver acpi_cpufreq_driver = {
796         .verify = acpi_cpufreq_verify,
797         .target = acpi_cpufreq_target,
798         .init = acpi_cpufreq_cpu_init,
799         .exit = acpi_cpufreq_cpu_exit,
800         .resume = acpi_cpufreq_resume,
801         .name = "acpi-cpufreq",
802         .owner = THIS_MODULE,
803         .attr = acpi_cpufreq_attr,
804 };
805
806 static int __init acpi_cpufreq_init(void)
807 {
808         int ret;
809
810         if (acpi_disabled)
811                 return 0;
812
813         dprintk("acpi_cpufreq_init\n");
814
815         ret = acpi_cpufreq_early_init();
816         if (ret)
817                 return ret;
818
819         ret = cpufreq_register_driver(&acpi_cpufreq_driver);
820         if (ret)
821                 free_acpi_perf_data();
822
823         return ret;
824 }
825
826 static void __exit acpi_cpufreq_exit(void)
827 {
828         dprintk("acpi_cpufreq_exit\n");
829
830         cpufreq_unregister_driver(&acpi_cpufreq_driver);
831
832         free_percpu(acpi_perf_data);
833 }
834
835 module_param(acpi_pstate_strict, uint, 0644);
836 MODULE_PARM_DESC(acpi_pstate_strict,
837         "value 0 or non-zero. non-zero -> strict ACPI checks are "
838         "performed during frequency changes.");
839
840 late_initcall(acpi_cpufreq_init);
841 module_exit(acpi_cpufreq_exit);
842
843 MODULE_ALIAS("acpi");