Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
[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 <trace/power.h>
37
38 #include <linux/acpi.h>
39 #include <linux/io.h>
40 #include <linux/delay.h>
41 #include <linux/uaccess.h>
42
43 #include <acpi/processor.h>
44
45 #include <asm/msr.h>
46 #include <asm/processor.h>
47 #include <asm/cpufeature.h>
48
49 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, \
50                 "acpi-cpufreq", msg)
51
52 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
53 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
54 MODULE_LICENSE("GPL");
55
56 enum {
57         UNDEFINED_CAPABLE = 0,
58         SYSTEM_INTEL_MSR_CAPABLE,
59         SYSTEM_IO_CAPABLE,
60 };
61
62 #define INTEL_MSR_RANGE         (0xffff)
63
64 struct acpi_cpufreq_data {
65         struct acpi_processor_performance *acpi_data;
66         struct cpufreq_frequency_table *freq_table;
67         unsigned int resume;
68         unsigned int cpu_feature;
69 };
70
71 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data);
72
73 static DEFINE_PER_CPU(struct aperfmperf, old_perf);
74
75 DEFINE_TRACE(power_mark);
76
77 /* acpi_perf_data is a pointer to percpu data. */
78 static struct acpi_processor_performance *acpi_perf_data;
79
80 static struct cpufreq_driver acpi_cpufreq_driver;
81
82 static unsigned int acpi_pstate_strict;
83
84 static int check_est_cpu(unsigned int cpuid)
85 {
86         struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
87
88         return cpu_has(cpu, X86_FEATURE_EST);
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 struct drv_cmd {
142         unsigned int type;
143         const struct cpumask *mask;
144         union {
145                 struct msr_addr msr;
146                 struct io_addr io;
147         } addr;
148         u32 val;
149 };
150
151 /* Called via smp_call_function_single(), on the target CPU */
152 static void do_drv_read(void *_cmd)
153 {
154         struct drv_cmd *cmd = _cmd;
155         u32 h;
156
157         switch (cmd->type) {
158         case SYSTEM_INTEL_MSR_CAPABLE:
159                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
160                 break;
161         case SYSTEM_IO_CAPABLE:
162                 acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
163                                 &cmd->val,
164                                 (u32)cmd->addr.io.bit_width);
165                 break;
166         default:
167                 break;
168         }
169 }
170
171 /* Called via smp_call_function_many(), on the target CPUs */
172 static void do_drv_write(void *_cmd)
173 {
174         struct drv_cmd *cmd = _cmd;
175         u32 lo, hi;
176
177         switch (cmd->type) {
178         case SYSTEM_INTEL_MSR_CAPABLE:
179                 rdmsr(cmd->addr.msr.reg, lo, hi);
180                 lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
181                 wrmsr(cmd->addr.msr.reg, lo, hi);
182                 break;
183         case SYSTEM_IO_CAPABLE:
184                 acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
185                                 cmd->val,
186                                 (u32)cmd->addr.io.bit_width);
187                 break;
188         default:
189                 break;
190         }
191 }
192
193 static void drv_read(struct drv_cmd *cmd)
194 {
195         cmd->val = 0;
196
197         smp_call_function_single(cpumask_any(cmd->mask), do_drv_read, cmd, 1);
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(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         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 /* Called via smp_call_function_single(), on the target CPU */
243 static void read_measured_perf_ctrs(void *_cur)
244 {
245         struct aperfmperf *am = _cur;
246
247         get_aperfmperf(am);
248 }
249
250 /*
251  * Return the measured active (C0) frequency on this CPU since last call
252  * to this function.
253  * Input: cpu number
254  * Return: Average CPU frequency in terms of max frequency (zero on error)
255  *
256  * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
257  * over a period of time, while CPU is in C0 state.
258  * IA32_MPERF counts at the rate of max advertised frequency
259  * IA32_APERF counts at the rate of actual CPU frequency
260  * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
261  * no meaning should be associated with absolute values of these MSRs.
262  */
263 static unsigned int get_measured_perf(struct cpufreq_policy *policy,
264                                       unsigned int cpu)
265 {
266         struct aperfmperf perf;
267         unsigned long ratio;
268         unsigned int retval;
269
270         if (smp_call_function_single(cpu, read_measured_perf_ctrs, &perf, 1))
271                 return 0;
272
273         ratio = calc_aperfmperf_ratio(&per_cpu(old_perf, cpu), &perf);
274         per_cpu(old_perf, cpu) = perf;
275
276         retval = (policy->cpuinfo.max_freq * ratio) >> APERFMPERF_SHIFT;
277
278         return retval;
279 }
280
281 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
282 {
283         struct acpi_cpufreq_data *data = per_cpu(drv_data, cpu);
284         unsigned int freq;
285         unsigned int cached_freq;
286
287         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
288
289         if (unlikely(data == NULL ||
290                      data->acpi_data == NULL || data->freq_table == NULL)) {
291                 return 0;
292         }
293
294         cached_freq = data->freq_table[data->acpi_data->state].frequency;
295         freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
296         if (freq != cached_freq) {
297                 /*
298                  * The dreaded BIOS frequency change behind our back.
299                  * Force set the frequency on next target call.
300                  */
301                 data->resume = 1;
302         }
303
304         dprintk("cur freq = %u\n", freq);
305
306         return freq;
307 }
308
309 static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
310                                 struct acpi_cpufreq_data *data)
311 {
312         unsigned int cur_freq;
313         unsigned int i;
314
315         for (i = 0; i < 100; i++) {
316                 cur_freq = extract_freq(get_cur_val(mask), data);
317                 if (cur_freq == freq)
318                         return 1;
319                 udelay(10);
320         }
321         return 0;
322 }
323
324 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
325                                unsigned int target_freq, unsigned int relation)
326 {
327         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
328         struct acpi_processor_performance *perf;
329         struct cpufreq_freqs freqs;
330         struct drv_cmd cmd;
331         unsigned int next_state = 0; /* Index into freq_table */
332         unsigned int next_perf_state = 0; /* Index into perf table */
333         unsigned int i;
334         int result = 0;
335         struct power_trace it;
336
337         dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
338
339         if (unlikely(data == NULL ||
340              data->acpi_data == NULL || data->freq_table == NULL)) {
341                 return -ENODEV;
342         }
343
344         perf = data->acpi_data;
345         result = cpufreq_frequency_table_target(policy,
346                                                 data->freq_table,
347                                                 target_freq,
348                                                 relation, &next_state);
349         if (unlikely(result)) {
350                 result = -ENODEV;
351                 goto out;
352         }
353
354         next_perf_state = data->freq_table[next_state].index;
355         if (perf->state == next_perf_state) {
356                 if (unlikely(data->resume)) {
357                         dprintk("Called after resume, resetting to P%d\n",
358                                 next_perf_state);
359                         data->resume = 0;
360                 } else {
361                         dprintk("Already at target state (P%d)\n",
362                                 next_perf_state);
363                         goto out;
364                 }
365         }
366
367         trace_power_mark(&it, POWER_PSTATE, next_perf_state);
368
369         switch (data->cpu_feature) {
370         case SYSTEM_INTEL_MSR_CAPABLE:
371                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
372                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
373                 cmd.val = (u32) perf->states[next_perf_state].control;
374                 break;
375         case SYSTEM_IO_CAPABLE:
376                 cmd.type = SYSTEM_IO_CAPABLE;
377                 cmd.addr.io.port = perf->control_register.address;
378                 cmd.addr.io.bit_width = perf->control_register.bit_width;
379                 cmd.val = (u32) perf->states[next_perf_state].control;
380                 break;
381         default:
382                 result = -ENODEV;
383                 goto out;
384         }
385
386         /* cpufreq holds the hotplug lock, so we are safe from here on */
387         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
388                 cmd.mask = policy->cpus;
389         else
390                 cmd.mask = cpumask_of(policy->cpu);
391
392         freqs.old = perf->states[perf->state].core_frequency * 1000;
393         freqs.new = data->freq_table[next_state].frequency;
394         for_each_cpu(i, cmd.mask) {
395                 freqs.cpu = i;
396                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
397         }
398
399         drv_write(&cmd);
400
401         if (acpi_pstate_strict) {
402                 if (!check_freqs(cmd.mask, freqs.new, data)) {
403                         dprintk("acpi_cpufreq_target failed (%d)\n",
404                                 policy->cpu);
405                         result = -EAGAIN;
406                         goto out;
407                 }
408         }
409
410         for_each_cpu(i, cmd.mask) {
411                 freqs.cpu = i;
412                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
413         }
414         perf->state = next_perf_state;
415
416 out:
417         return result;
418 }
419
420 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
421 {
422         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
423
424         dprintk("acpi_cpufreq_verify\n");
425
426         return cpufreq_frequency_table_verify(policy, data->freq_table);
427 }
428
429 static unsigned long
430 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
431 {
432         struct acpi_processor_performance *perf = data->acpi_data;
433
434         if (cpu_khz) {
435                 /* search the closest match to cpu_khz */
436                 unsigned int i;
437                 unsigned long freq;
438                 unsigned long freqn = perf->states[0].core_frequency * 1000;
439
440                 for (i = 0; i < (perf->state_count-1); i++) {
441                         freq = freqn;
442                         freqn = perf->states[i+1].core_frequency * 1000;
443                         if ((2 * cpu_khz) > (freqn + freq)) {
444                                 perf->state = i;
445                                 return freq;
446                         }
447                 }
448                 perf->state = perf->state_count-1;
449                 return freqn;
450         } else {
451                 /* assume CPU is at P0... */
452                 perf->state = 0;
453                 return perf->states[0].core_frequency * 1000;
454         }
455 }
456
457 static void free_acpi_perf_data(void)
458 {
459         unsigned int i;
460
461         /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
462         for_each_possible_cpu(i)
463                 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
464                                  ->shared_cpu_map);
465         free_percpu(acpi_perf_data);
466 }
467
468 /*
469  * acpi_cpufreq_early_init - initialize ACPI P-States library
470  *
471  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
472  * in order to determine correct frequency and voltage pairings. We can
473  * do _PDC and _PSD and find out the processor dependency for the
474  * actual init that will happen later...
475  */
476 static int __init acpi_cpufreq_early_init(void)
477 {
478         unsigned int i;
479         dprintk("acpi_cpufreq_early_init\n");
480
481         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
482         if (!acpi_perf_data) {
483                 dprintk("Memory allocation error for acpi_perf_data.\n");
484                 return -ENOMEM;
485         }
486         for_each_possible_cpu(i) {
487                 if (!zalloc_cpumask_var_node(
488                         &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
489                         GFP_KERNEL, cpu_to_node(i))) {
490
491                         /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
492                         free_acpi_perf_data();
493                         return -ENOMEM;
494                 }
495         }
496
497         /* Do initialization in ACPI core */
498         acpi_processor_preregister_performance(acpi_perf_data);
499         return 0;
500 }
501
502 #ifdef CONFIG_SMP
503 /*
504  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
505  * or do it in BIOS firmware and won't inform about it to OS. If not
506  * detected, this has a side effect of making CPU run at a different speed
507  * than OS intended it to run at. Detect it and handle it cleanly.
508  */
509 static int bios_with_sw_any_bug;
510
511 static int sw_any_bug_found(const struct dmi_system_id *d)
512 {
513         bios_with_sw_any_bug = 1;
514         return 0;
515 }
516
517 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
518         {
519                 .callback = sw_any_bug_found,
520                 .ident = "Supermicro Server X6DLP",
521                 .matches = {
522                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
523                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
524                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
525                 },
526         },
527         { }
528 };
529
530 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
531 {
532         /* http://www.intel.com/Assets/PDF/specupdate/314554.pdf
533          * AL30: A Machine Check Exception (MCE) Occurring during an
534          * Enhanced Intel SpeedStep Technology Ratio Change May Cause
535          * Both Processor Cores to Lock Up when HT is enabled*/
536         if (c->x86_vendor == X86_VENDOR_INTEL) {
537                 if ((c->x86 == 15) &&
538                     (c->x86_model == 6) &&
539                     (c->x86_mask == 8) && smt_capable())
540                         return -ENODEV;
541                 }
542         return 0;
543 }
544 #endif
545
546 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
547 {
548         unsigned int i;
549         unsigned int valid_states = 0;
550         unsigned int cpu = policy->cpu;
551         struct acpi_cpufreq_data *data;
552         unsigned int result = 0;
553         struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
554         struct acpi_processor_performance *perf;
555
556         dprintk("acpi_cpufreq_cpu_init\n");
557
558 #ifdef CONFIG_SMP
559         result = acpi_cpufreq_blacklist(c);
560         if (result)
561                 return result;
562 #endif
563
564         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
565         if (!data)
566                 return -ENOMEM;
567
568         data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
569         per_cpu(drv_data, cpu) = data;
570
571         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
572                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
573
574         result = acpi_processor_register_performance(data->acpi_data, cpu);
575         if (result)
576                 goto err_free;
577
578         perf = data->acpi_data;
579         policy->shared_type = perf->shared_type;
580
581         /*
582          * Will let policy->cpus know about dependency only when software
583          * coordination is required.
584          */
585         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
586             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
587                 cpumask_copy(policy->cpus, perf->shared_cpu_map);
588         }
589         cpumask_copy(policy->related_cpus, perf->shared_cpu_map);
590
591 #ifdef CONFIG_SMP
592         dmi_check_system(sw_any_bug_dmi_table);
593         if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) {
594                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
595                 cpumask_copy(policy->cpus, cpu_core_mask(cpu));
596         }
597 #endif
598
599         /* capability check */
600         if (perf->state_count <= 1) {
601                 dprintk("No P-States\n");
602                 result = -ENODEV;
603                 goto err_unreg;
604         }
605
606         if (perf->control_register.space_id != perf->status_register.space_id) {
607                 result = -ENODEV;
608                 goto err_unreg;
609         }
610
611         switch (perf->control_register.space_id) {
612         case ACPI_ADR_SPACE_SYSTEM_IO:
613                 dprintk("SYSTEM IO addr space\n");
614                 data->cpu_feature = SYSTEM_IO_CAPABLE;
615                 break;
616         case ACPI_ADR_SPACE_FIXED_HARDWARE:
617                 dprintk("HARDWARE addr space\n");
618                 if (!check_est_cpu(cpu)) {
619                         result = -ENODEV;
620                         goto err_unreg;
621                 }
622                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
623                 break;
624         default:
625                 dprintk("Unknown addr space %d\n",
626                         (u32) (perf->control_register.space_id));
627                 result = -ENODEV;
628                 goto err_unreg;
629         }
630
631         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
632                     (perf->state_count+1), GFP_KERNEL);
633         if (!data->freq_table) {
634                 result = -ENOMEM;
635                 goto err_unreg;
636         }
637
638         /* detect transition latency */
639         policy->cpuinfo.transition_latency = 0;
640         for (i = 0; i < perf->state_count; i++) {
641                 if ((perf->states[i].transition_latency * 1000) >
642                     policy->cpuinfo.transition_latency)
643                         policy->cpuinfo.transition_latency =
644                             perf->states[i].transition_latency * 1000;
645         }
646
647         /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
648         if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
649             policy->cpuinfo.transition_latency > 20 * 1000) {
650                 policy->cpuinfo.transition_latency = 20 * 1000;
651                 printk_once(KERN_INFO
652                             "P-state transition latency capped at 20 uS\n");
653         }
654
655         /* table init */
656         for (i = 0; i < perf->state_count; i++) {
657                 if (i > 0 && perf->states[i].core_frequency >=
658                     data->freq_table[valid_states-1].frequency / 1000)
659                         continue;
660
661                 data->freq_table[valid_states].index = i;
662                 data->freq_table[valid_states].frequency =
663                     perf->states[i].core_frequency * 1000;
664                 valid_states++;
665         }
666         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
667         perf->state = 0;
668
669         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
670         if (result)
671                 goto err_freqfree;
672
673         if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
674                 printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
675
676         switch (perf->control_register.space_id) {
677         case ACPI_ADR_SPACE_SYSTEM_IO:
678                 /* Current speed is unknown and not detectable by IO port */
679                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
680                 break;
681         case ACPI_ADR_SPACE_FIXED_HARDWARE:
682                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
683                 policy->cur = get_cur_freq_on_cpu(cpu);
684                 break;
685         default:
686                 break;
687         }
688
689         /* notify BIOS that we exist */
690         acpi_processor_notify_smm(THIS_MODULE);
691
692         /* Check for APERF/MPERF support in hardware */
693         if (cpu_has(c, X86_FEATURE_APERFMPERF))
694                 acpi_cpufreq_driver.getavg = get_measured_perf;
695
696         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
697         for (i = 0; i < perf->state_count; i++)
698                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
699                         (i == perf->state ? '*' : ' '), i,
700                         (u32) perf->states[i].core_frequency,
701                         (u32) perf->states[i].power,
702                         (u32) perf->states[i].transition_latency);
703
704         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
705
706         /*
707          * the first call to ->target() should result in us actually
708          * writing something to the appropriate registers.
709          */
710         data->resume = 1;
711
712         return result;
713
714 err_freqfree:
715         kfree(data->freq_table);
716 err_unreg:
717         acpi_processor_unregister_performance(perf, cpu);
718 err_free:
719         kfree(data);
720         per_cpu(drv_data, cpu) = NULL;
721
722         return result;
723 }
724
725 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
726 {
727         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
728
729         dprintk("acpi_cpufreq_cpu_exit\n");
730
731         if (data) {
732                 cpufreq_frequency_table_put_attr(policy->cpu);
733                 per_cpu(drv_data, policy->cpu) = NULL;
734                 acpi_processor_unregister_performance(data->acpi_data,
735                                                       policy->cpu);
736                 kfree(data);
737         }
738
739         return 0;
740 }
741
742 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
743 {
744         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
745
746         dprintk("acpi_cpufreq_resume\n");
747
748         data->resume = 1;
749
750         return 0;
751 }
752
753 static struct freq_attr *acpi_cpufreq_attr[] = {
754         &cpufreq_freq_attr_scaling_available_freqs,
755         NULL,
756 };
757
758 static struct cpufreq_driver acpi_cpufreq_driver = {
759         .verify = acpi_cpufreq_verify,
760         .target = acpi_cpufreq_target,
761         .init = acpi_cpufreq_cpu_init,
762         .exit = acpi_cpufreq_cpu_exit,
763         .resume = acpi_cpufreq_resume,
764         .name = "acpi-cpufreq",
765         .owner = THIS_MODULE,
766         .attr = acpi_cpufreq_attr,
767 };
768
769 static int __init acpi_cpufreq_init(void)
770 {
771         int ret;
772
773         if (acpi_disabled)
774                 return 0;
775
776         dprintk("acpi_cpufreq_init\n");
777
778         ret = acpi_cpufreq_early_init();
779         if (ret)
780                 return ret;
781
782         ret = cpufreq_register_driver(&acpi_cpufreq_driver);
783         if (ret)
784                 free_acpi_perf_data();
785
786         return ret;
787 }
788
789 static void __exit acpi_cpufreq_exit(void)
790 {
791         dprintk("acpi_cpufreq_exit\n");
792
793         cpufreq_unregister_driver(&acpi_cpufreq_driver);
794
795         free_percpu(acpi_perf_data);
796 }
797
798 module_param(acpi_pstate_strict, uint, 0644);
799 MODULE_PARM_DESC(acpi_pstate_strict,
800         "value 0 or non-zero. non-zero -> strict ACPI checks are "
801         "performed during frequency changes.");
802
803 late_initcall(acpi_cpufreq_init);
804 module_exit(acpi_cpufreq_exit);
805
806 MODULE_ALIAS("acpi");