Merge branch 'perfcounters-core-for-linus' of git://git.kernel.org/pub/scm/linux...
[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/events/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 /* 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         cmd->val = 0;
194
195         smp_call_function_single(cpumask_any(cmd->mask), do_drv_read, cmd, 1);
196 }
197
198 static void drv_write(struct drv_cmd *cmd)
199 {
200         int this_cpu;
201
202         this_cpu = get_cpu();
203         if (cpumask_test_cpu(this_cpu, cmd->mask))
204                 do_drv_write(cmd);
205         smp_call_function_many(cmd->mask, do_drv_write, cmd, 1);
206         put_cpu();
207 }
208
209 static u32 get_cur_val(const struct cpumask *mask)
210 {
211         struct acpi_processor_performance *perf;
212         struct drv_cmd cmd;
213
214         if (unlikely(cpumask_empty(mask)))
215                 return 0;
216
217         switch (per_cpu(drv_data, cpumask_first(mask))->cpu_feature) {
218         case SYSTEM_INTEL_MSR_CAPABLE:
219                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
220                 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
221                 break;
222         case SYSTEM_IO_CAPABLE:
223                 cmd.type = SYSTEM_IO_CAPABLE;
224                 perf = per_cpu(drv_data, cpumask_first(mask))->acpi_data;
225                 cmd.addr.io.port = perf->control_register.address;
226                 cmd.addr.io.bit_width = perf->control_register.bit_width;
227                 break;
228         default:
229                 return 0;
230         }
231
232         cmd.mask = mask;
233         drv_read(&cmd);
234
235         dprintk("get_cur_val = %u\n", cmd.val);
236
237         return cmd.val;
238 }
239
240 /* Called via smp_call_function_single(), on the target CPU */
241 static void read_measured_perf_ctrs(void *_cur)
242 {
243         struct aperfmperf *am = _cur;
244
245         get_aperfmperf(am);
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         struct aperfmperf perf;
265         unsigned long ratio;
266         unsigned int retval;
267
268         if (smp_call_function_single(cpu, read_measured_perf_ctrs, &perf, 1))
269                 return 0;
270
271         ratio = calc_aperfmperf_ratio(&per_cpu(old_perf, cpu), &perf);
272         per_cpu(old_perf, cpu) = perf;
273
274         retval = (policy->cpuinfo.max_freq * ratio) >> APERFMPERF_SHIFT;
275
276         return retval;
277 }
278
279 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
280 {
281         struct acpi_cpufreq_data *data = per_cpu(drv_data, cpu);
282         unsigned int freq;
283         unsigned int cached_freq;
284
285         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
286
287         if (unlikely(data == NULL ||
288                      data->acpi_data == NULL || data->freq_table == NULL)) {
289                 return 0;
290         }
291
292         cached_freq = data->freq_table[data->acpi_data->state].frequency;
293         freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
294         if (freq != cached_freq) {
295                 /*
296                  * The dreaded BIOS frequency change behind our back.
297                  * Force set the frequency on next target call.
298                  */
299                 data->resume = 1;
300         }
301
302         dprintk("cur freq = %u\n", freq);
303
304         return freq;
305 }
306
307 static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
308                                 struct acpi_cpufreq_data *data)
309 {
310         unsigned int cur_freq;
311         unsigned int i;
312
313         for (i = 0; i < 100; i++) {
314                 cur_freq = extract_freq(get_cur_val(mask), data);
315                 if (cur_freq == freq)
316                         return 1;
317                 udelay(10);
318         }
319         return 0;
320 }
321
322 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
323                                unsigned int target_freq, unsigned int relation)
324 {
325         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
326         struct acpi_processor_performance *perf;
327         struct cpufreq_freqs freqs;
328         struct drv_cmd cmd;
329         unsigned int next_state = 0; /* Index into freq_table */
330         unsigned int next_perf_state = 0; /* Index into perf table */
331         unsigned int i;
332         int result = 0;
333
334         dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
335
336         if (unlikely(data == NULL ||
337              data->acpi_data == NULL || data->freq_table == NULL)) {
338                 return -ENODEV;
339         }
340
341         perf = data->acpi_data;
342         result = cpufreq_frequency_table_target(policy,
343                                                 data->freq_table,
344                                                 target_freq,
345                                                 relation, &next_state);
346         if (unlikely(result)) {
347                 result = -ENODEV;
348                 goto out;
349         }
350
351         next_perf_state = data->freq_table[next_state].index;
352         if (perf->state == next_perf_state) {
353                 if (unlikely(data->resume)) {
354                         dprintk("Called after resume, resetting to P%d\n",
355                                 next_perf_state);
356                         data->resume = 0;
357                 } else {
358                         dprintk("Already at target state (P%d)\n",
359                                 next_perf_state);
360                         goto out;
361                 }
362         }
363
364         trace_power_frequency(POWER_PSTATE, data->freq_table[next_state].frequency);
365
366         switch (data->cpu_feature) {
367         case SYSTEM_INTEL_MSR_CAPABLE:
368                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
369                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
370                 cmd.val = (u32) perf->states[next_perf_state].control;
371                 break;
372         case SYSTEM_IO_CAPABLE:
373                 cmd.type = SYSTEM_IO_CAPABLE;
374                 cmd.addr.io.port = perf->control_register.address;
375                 cmd.addr.io.bit_width = perf->control_register.bit_width;
376                 cmd.val = (u32) perf->states[next_perf_state].control;
377                 break;
378         default:
379                 result = -ENODEV;
380                 goto out;
381         }
382
383         /* cpufreq holds the hotplug lock, so we are safe from here on */
384         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
385                 cmd.mask = policy->cpus;
386         else
387                 cmd.mask = cpumask_of(policy->cpu);
388
389         freqs.old = perf->states[perf->state].core_frequency * 1000;
390         freqs.new = data->freq_table[next_state].frequency;
391         for_each_cpu(i, cmd.mask) {
392                 freqs.cpu = i;
393                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
394         }
395
396         drv_write(&cmd);
397
398         if (acpi_pstate_strict) {
399                 if (!check_freqs(cmd.mask, freqs.new, data)) {
400                         dprintk("acpi_cpufreq_target failed (%d)\n",
401                                 policy->cpu);
402                         result = -EAGAIN;
403                         goto out;
404                 }
405         }
406
407         for_each_cpu(i, cmd.mask) {
408                 freqs.cpu = i;
409                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
410         }
411         perf->state = next_perf_state;
412
413 out:
414         return result;
415 }
416
417 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
418 {
419         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
420
421         dprintk("acpi_cpufreq_verify\n");
422
423         return cpufreq_frequency_table_verify(policy, data->freq_table);
424 }
425
426 static unsigned long
427 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
428 {
429         struct acpi_processor_performance *perf = data->acpi_data;
430
431         if (cpu_khz) {
432                 /* search the closest match to cpu_khz */
433                 unsigned int i;
434                 unsigned long freq;
435                 unsigned long freqn = perf->states[0].core_frequency * 1000;
436
437                 for (i = 0; i < (perf->state_count-1); i++) {
438                         freq = freqn;
439                         freqn = perf->states[i+1].core_frequency * 1000;
440                         if ((2 * cpu_khz) > (freqn + freq)) {
441                                 perf->state = i;
442                                 return freq;
443                         }
444                 }
445                 perf->state = perf->state_count-1;
446                 return freqn;
447         } else {
448                 /* assume CPU is at P0... */
449                 perf->state = 0;
450                 return perf->states[0].core_frequency * 1000;
451         }
452 }
453
454 static void free_acpi_perf_data(void)
455 {
456         unsigned int i;
457
458         /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
459         for_each_possible_cpu(i)
460                 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
461                                  ->shared_cpu_map);
462         free_percpu(acpi_perf_data);
463 }
464
465 /*
466  * acpi_cpufreq_early_init - initialize ACPI P-States library
467  *
468  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
469  * in order to determine correct frequency and voltage pairings. We can
470  * do _PDC and _PSD and find out the processor dependency for the
471  * actual init that will happen later...
472  */
473 static int __init acpi_cpufreq_early_init(void)
474 {
475         unsigned int i;
476         dprintk("acpi_cpufreq_early_init\n");
477
478         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
479         if (!acpi_perf_data) {
480                 dprintk("Memory allocation error for acpi_perf_data.\n");
481                 return -ENOMEM;
482         }
483         for_each_possible_cpu(i) {
484                 if (!zalloc_cpumask_var_node(
485                         &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
486                         GFP_KERNEL, cpu_to_node(i))) {
487
488                         /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
489                         free_acpi_perf_data();
490                         return -ENOMEM;
491                 }
492         }
493
494         /* Do initialization in ACPI core */
495         acpi_processor_preregister_performance(acpi_perf_data);
496         return 0;
497 }
498
499 #ifdef CONFIG_SMP
500 /*
501  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
502  * or do it in BIOS firmware and won't inform about it to OS. If not
503  * detected, this has a side effect of making CPU run at a different speed
504  * than OS intended it to run at. Detect it and handle it cleanly.
505  */
506 static int bios_with_sw_any_bug;
507
508 static int sw_any_bug_found(const struct dmi_system_id *d)
509 {
510         bios_with_sw_any_bug = 1;
511         return 0;
512 }
513
514 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
515         {
516                 .callback = sw_any_bug_found,
517                 .ident = "Supermicro Server X6DLP",
518                 .matches = {
519                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
520                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
521                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
522                 },
523         },
524         { }
525 };
526
527 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
528 {
529         /* http://www.intel.com/Assets/PDF/specupdate/314554.pdf
530          * AL30: A Machine Check Exception (MCE) Occurring during an
531          * Enhanced Intel SpeedStep Technology Ratio Change May Cause
532          * Both Processor Cores to Lock Up when HT is enabled*/
533         if (c->x86_vendor == X86_VENDOR_INTEL) {
534                 if ((c->x86 == 15) &&
535                     (c->x86_model == 6) &&
536                     (c->x86_mask == 8) && smt_capable())
537                         return -ENODEV;
538                 }
539         return 0;
540 }
541 #endif
542
543 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
544 {
545         unsigned int i;
546         unsigned int valid_states = 0;
547         unsigned int cpu = policy->cpu;
548         struct acpi_cpufreq_data *data;
549         unsigned int result = 0;
550         struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
551         struct acpi_processor_performance *perf;
552
553         dprintk("acpi_cpufreq_cpu_init\n");
554
555 #ifdef CONFIG_SMP
556         result = acpi_cpufreq_blacklist(c);
557         if (result)
558                 return result;
559 #endif
560
561         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
562         if (!data)
563                 return -ENOMEM;
564
565         data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
566         per_cpu(drv_data, cpu) = data;
567
568         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
569                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
570
571         result = acpi_processor_register_performance(data->acpi_data, cpu);
572         if (result)
573                 goto err_free;
574
575         perf = data->acpi_data;
576         policy->shared_type = perf->shared_type;
577
578         /*
579          * Will let policy->cpus know about dependency only when software
580          * coordination is required.
581          */
582         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
583             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
584                 cpumask_copy(policy->cpus, perf->shared_cpu_map);
585         }
586         cpumask_copy(policy->related_cpus, perf->shared_cpu_map);
587
588 #ifdef CONFIG_SMP
589         dmi_check_system(sw_any_bug_dmi_table);
590         if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) {
591                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
592                 cpumask_copy(policy->cpus, cpu_core_mask(cpu));
593         }
594 #endif
595
596         /* capability check */
597         if (perf->state_count <= 1) {
598                 dprintk("No P-States\n");
599                 result = -ENODEV;
600                 goto err_unreg;
601         }
602
603         if (perf->control_register.space_id != perf->status_register.space_id) {
604                 result = -ENODEV;
605                 goto err_unreg;
606         }
607
608         switch (perf->control_register.space_id) {
609         case ACPI_ADR_SPACE_SYSTEM_IO:
610                 dprintk("SYSTEM IO addr space\n");
611                 data->cpu_feature = SYSTEM_IO_CAPABLE;
612                 break;
613         case ACPI_ADR_SPACE_FIXED_HARDWARE:
614                 dprintk("HARDWARE addr space\n");
615                 if (!check_est_cpu(cpu)) {
616                         result = -ENODEV;
617                         goto err_unreg;
618                 }
619                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
620                 break;
621         default:
622                 dprintk("Unknown addr space %d\n",
623                         (u32) (perf->control_register.space_id));
624                 result = -ENODEV;
625                 goto err_unreg;
626         }
627
628         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
629                     (perf->state_count+1), GFP_KERNEL);
630         if (!data->freq_table) {
631                 result = -ENOMEM;
632                 goto err_unreg;
633         }
634
635         /* detect transition latency */
636         policy->cpuinfo.transition_latency = 0;
637         for (i = 0; i < perf->state_count; i++) {
638                 if ((perf->states[i].transition_latency * 1000) >
639                     policy->cpuinfo.transition_latency)
640                         policy->cpuinfo.transition_latency =
641                             perf->states[i].transition_latency * 1000;
642         }
643
644         /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
645         if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
646             policy->cpuinfo.transition_latency > 20 * 1000) {
647                 policy->cpuinfo.transition_latency = 20 * 1000;
648                 printk_once(KERN_INFO
649                             "P-state transition latency capped at 20 uS\n");
650         }
651
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         if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
671                 printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
672
673         switch (perf->control_register.space_id) {
674         case ACPI_ADR_SPACE_SYSTEM_IO:
675                 /* Current speed is unknown and not detectable by IO port */
676                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
677                 break;
678         case ACPI_ADR_SPACE_FIXED_HARDWARE:
679                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
680                 policy->cur = get_cur_freq_on_cpu(cpu);
681                 break;
682         default:
683                 break;
684         }
685
686         /* notify BIOS that we exist */
687         acpi_processor_notify_smm(THIS_MODULE);
688
689         /* Check for APERF/MPERF support in hardware */
690         if (cpu_has(c, X86_FEATURE_APERFMPERF))
691                 acpi_cpufreq_driver.getavg = get_measured_perf;
692
693         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
694         for (i = 0; i < perf->state_count; i++)
695                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
696                         (i == perf->state ? '*' : ' '), i,
697                         (u32) perf->states[i].core_frequency,
698                         (u32) perf->states[i].power,
699                         (u32) perf->states[i].transition_latency);
700
701         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
702
703         /*
704          * the first call to ->target() should result in us actually
705          * writing something to the appropriate registers.
706          */
707         data->resume = 1;
708
709         return result;
710
711 err_freqfree:
712         kfree(data->freq_table);
713 err_unreg:
714         acpi_processor_unregister_performance(perf, cpu);
715 err_free:
716         kfree(data);
717         per_cpu(drv_data, cpu) = NULL;
718
719         return result;
720 }
721
722 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
723 {
724         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
725
726         dprintk("acpi_cpufreq_cpu_exit\n");
727
728         if (data) {
729                 cpufreq_frequency_table_put_attr(policy->cpu);
730                 per_cpu(drv_data, policy->cpu) = NULL;
731                 acpi_processor_unregister_performance(data->acpi_data,
732                                                       policy->cpu);
733                 kfree(data);
734         }
735
736         return 0;
737 }
738
739 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
740 {
741         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
742
743         dprintk("acpi_cpufreq_resume\n");
744
745         data->resume = 1;
746
747         return 0;
748 }
749
750 static struct freq_attr *acpi_cpufreq_attr[] = {
751         &cpufreq_freq_attr_scaling_available_freqs,
752         NULL,
753 };
754
755 static struct cpufreq_driver acpi_cpufreq_driver = {
756         .verify = acpi_cpufreq_verify,
757         .target = acpi_cpufreq_target,
758         .init = acpi_cpufreq_cpu_init,
759         .exit = acpi_cpufreq_cpu_exit,
760         .resume = acpi_cpufreq_resume,
761         .name = "acpi-cpufreq",
762         .owner = THIS_MODULE,
763         .attr = acpi_cpufreq_attr,
764 };
765
766 static int __init acpi_cpufreq_init(void)
767 {
768         int ret;
769
770         if (acpi_disabled)
771                 return 0;
772
773         dprintk("acpi_cpufreq_init\n");
774
775         ret = acpi_cpufreq_early_init();
776         if (ret)
777                 return ret;
778
779         ret = cpufreq_register_driver(&acpi_cpufreq_driver);
780         if (ret)
781                 free_acpi_perf_data();
782
783         return ret;
784 }
785
786 static void __exit acpi_cpufreq_exit(void)
787 {
788         dprintk("acpi_cpufreq_exit\n");
789
790         cpufreq_unregister_driver(&acpi_cpufreq_driver);
791
792         free_percpu(acpi_perf_data);
793 }
794
795 module_param(acpi_pstate_strict, uint, 0644);
796 MODULE_PARM_DESC(acpi_pstate_strict,
797         "value 0 or non-zero. non-zero -> strict ACPI checks are "
798         "performed during frequency changes.");
799
800 late_initcall(acpi_cpufreq_init);
801 module_exit(acpi_cpufreq_exit);
802
803 MODULE_ALIAS("acpi");