Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec...
[linux-2.6] / 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 #define CPUID_6_ECX_APERFMPERF_CAPABILITY       (0x1)
64
65 struct acpi_cpufreq_data {
66         struct acpi_processor_performance *acpi_data;
67         struct cpufreq_frequency_table *freq_table;
68         unsigned int resume;
69         unsigned int cpu_feature;
70 };
71
72 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data);
73
74 struct acpi_msr_data {
75         u64 saved_aperf, saved_mperf;
76 };
77
78 static DEFINE_PER_CPU(struct acpi_msr_data, msr_data);
79
80 DEFINE_TRACE(power_mark);
81
82 /* acpi_perf_data is a pointer to percpu data. */
83 static struct acpi_processor_performance *acpi_perf_data;
84
85 static struct cpufreq_driver acpi_cpufreq_driver;
86
87 static unsigned int acpi_pstate_strict;
88
89 static int check_est_cpu(unsigned int cpuid)
90 {
91         struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
92
93         return cpu_has(cpu, X86_FEATURE_EST);
94 }
95
96 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
97 {
98         struct acpi_processor_performance *perf;
99         int i;
100
101         perf = data->acpi_data;
102
103         for (i = 0; i < perf->state_count; i++) {
104                 if (value == perf->states[i].status)
105                         return data->freq_table[i].frequency;
106         }
107         return 0;
108 }
109
110 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
111 {
112         int i;
113         struct acpi_processor_performance *perf;
114
115         msr &= INTEL_MSR_RANGE;
116         perf = data->acpi_data;
117
118         for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
119                 if (msr == perf->states[data->freq_table[i].index].status)
120                         return data->freq_table[i].frequency;
121         }
122         return data->freq_table[0].frequency;
123 }
124
125 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
126 {
127         switch (data->cpu_feature) {
128         case SYSTEM_INTEL_MSR_CAPABLE:
129                 return extract_msr(val, data);
130         case SYSTEM_IO_CAPABLE:
131                 return extract_io(val, data);
132         default:
133                 return 0;
134         }
135 }
136
137 struct msr_addr {
138         u32 reg;
139 };
140
141 struct io_addr {
142         u16 port;
143         u8 bit_width;
144 };
145
146 struct drv_cmd {
147         unsigned int type;
148         const struct cpumask *mask;
149         union {
150                 struct msr_addr msr;
151                 struct io_addr io;
152         } addr;
153         u32 val;
154 };
155
156 /* Called via smp_call_function_single(), on the target CPU */
157 static void do_drv_read(void *_cmd)
158 {
159         struct drv_cmd *cmd = _cmd;
160         u32 h;
161
162         switch (cmd->type) {
163         case SYSTEM_INTEL_MSR_CAPABLE:
164                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
165                 break;
166         case SYSTEM_IO_CAPABLE:
167                 acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
168                                 &cmd->val,
169                                 (u32)cmd->addr.io.bit_width);
170                 break;
171         default:
172                 break;
173         }
174 }
175
176 /* Called via smp_call_function_many(), on the target CPUs */
177 static void do_drv_write(void *_cmd)
178 {
179         struct drv_cmd *cmd = _cmd;
180         u32 lo, hi;
181
182         switch (cmd->type) {
183         case SYSTEM_INTEL_MSR_CAPABLE:
184                 rdmsr(cmd->addr.msr.reg, lo, hi);
185                 lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
186                 wrmsr(cmd->addr.msr.reg, lo, hi);
187                 break;
188         case SYSTEM_IO_CAPABLE:
189                 acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
190                                 cmd->val,
191                                 (u32)cmd->addr.io.bit_width);
192                 break;
193         default:
194                 break;
195         }
196 }
197
198 static void drv_read(struct drv_cmd *cmd)
199 {
200         cmd->val = 0;
201
202         smp_call_function_single(cpumask_any(cmd->mask), do_drv_read, cmd, 1);
203 }
204
205 static void drv_write(struct drv_cmd *cmd)
206 {
207         int this_cpu;
208
209         this_cpu = get_cpu();
210         if (cpumask_test_cpu(this_cpu, cmd->mask))
211                 do_drv_write(cmd);
212         smp_call_function_many(cmd->mask, do_drv_write, cmd, 1);
213         put_cpu();
214 }
215
216 static u32 get_cur_val(const struct cpumask *mask)
217 {
218         struct acpi_processor_performance *perf;
219         struct drv_cmd cmd;
220
221         if (unlikely(cpumask_empty(mask)))
222                 return 0;
223
224         switch (per_cpu(drv_data, cpumask_first(mask))->cpu_feature) {
225         case SYSTEM_INTEL_MSR_CAPABLE:
226                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
227                 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
228                 break;
229         case SYSTEM_IO_CAPABLE:
230                 cmd.type = SYSTEM_IO_CAPABLE;
231                 perf = per_cpu(drv_data, cpumask_first(mask))->acpi_data;
232                 cmd.addr.io.port = perf->control_register.address;
233                 cmd.addr.io.bit_width = perf->control_register.bit_width;
234                 break;
235         default:
236                 return 0;
237         }
238
239         cmd.mask = mask;
240         drv_read(&cmd);
241
242         dprintk("get_cur_val = %u\n", cmd.val);
243
244         return cmd.val;
245 }
246
247 struct perf_pair {
248         union {
249                 struct {
250                         u32 lo;
251                         u32 hi;
252                 } split;
253                 u64 whole;
254         } aperf, mperf;
255 };
256
257 /* Called via smp_call_function_single(), on the target CPU */
258 static void read_measured_perf_ctrs(void *_cur)
259 {
260         struct perf_pair *cur = _cur;
261
262         rdmsr(MSR_IA32_APERF, cur->aperf.split.lo, cur->aperf.split.hi);
263         rdmsr(MSR_IA32_MPERF, cur->mperf.split.lo, cur->mperf.split.hi);
264 }
265
266 /*
267  * Return the measured active (C0) frequency on this CPU since last call
268  * to this function.
269  * Input: cpu number
270  * Return: Average CPU frequency in terms of max frequency (zero on error)
271  *
272  * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
273  * over a period of time, while CPU is in C0 state.
274  * IA32_MPERF counts at the rate of max advertised frequency
275  * IA32_APERF counts at the rate of actual CPU frequency
276  * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
277  * no meaning should be associated with absolute values of these MSRs.
278  */
279 static unsigned int get_measured_perf(struct cpufreq_policy *policy,
280                                       unsigned int cpu)
281 {
282         struct perf_pair readin, cur;
283         unsigned int perf_percent;
284         unsigned int retval;
285
286         if (smp_call_function_single(cpu, read_measured_perf_ctrs, &readin, 1))
287                 return 0;
288
289         cur.aperf.whole = readin.aperf.whole -
290                                 per_cpu(msr_data, cpu).saved_aperf;
291         cur.mperf.whole = readin.mperf.whole -
292                                 per_cpu(msr_data, cpu).saved_mperf;
293         per_cpu(msr_data, cpu).saved_aperf = readin.aperf.whole;
294         per_cpu(msr_data, cpu).saved_mperf = readin.mperf.whole;
295
296 #ifdef __i386__
297         /*
298          * We dont want to do 64 bit divide with 32 bit kernel
299          * Get an approximate value. Return failure in case we cannot get
300          * an approximate value.
301          */
302         if (unlikely(cur.aperf.split.hi || cur.mperf.split.hi)) {
303                 int shift_count;
304                 u32 h;
305
306                 h = max_t(u32, cur.aperf.split.hi, cur.mperf.split.hi);
307                 shift_count = fls(h);
308
309                 cur.aperf.whole >>= shift_count;
310                 cur.mperf.whole >>= shift_count;
311         }
312
313         if (((unsigned long)(-1) / 100) < cur.aperf.split.lo) {
314                 int shift_count = 7;
315                 cur.aperf.split.lo >>= shift_count;
316                 cur.mperf.split.lo >>= shift_count;
317         }
318
319         if (cur.aperf.split.lo && cur.mperf.split.lo)
320                 perf_percent = (cur.aperf.split.lo * 100) / cur.mperf.split.lo;
321         else
322                 perf_percent = 0;
323
324 #else
325         if (unlikely(((unsigned long)(-1) / 100) < cur.aperf.whole)) {
326                 int shift_count = 7;
327                 cur.aperf.whole >>= shift_count;
328                 cur.mperf.whole >>= shift_count;
329         }
330
331         if (cur.aperf.whole && cur.mperf.whole)
332                 perf_percent = (cur.aperf.whole * 100) / cur.mperf.whole;
333         else
334                 perf_percent = 0;
335
336 #endif
337
338         retval = (policy->cpuinfo.max_freq * perf_percent) / 100;
339
340         return retval;
341 }
342
343 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
344 {
345         struct acpi_cpufreq_data *data = per_cpu(drv_data, cpu);
346         unsigned int freq;
347         unsigned int cached_freq;
348
349         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
350
351         if (unlikely(data == NULL ||
352                      data->acpi_data == NULL || data->freq_table == NULL)) {
353                 return 0;
354         }
355
356         cached_freq = data->freq_table[data->acpi_data->state].frequency;
357         freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
358         if (freq != cached_freq) {
359                 /*
360                  * The dreaded BIOS frequency change behind our back.
361                  * Force set the frequency on next target call.
362                  */
363                 data->resume = 1;
364         }
365
366         dprintk("cur freq = %u\n", freq);
367
368         return freq;
369 }
370
371 static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
372                                 struct acpi_cpufreq_data *data)
373 {
374         unsigned int cur_freq;
375         unsigned int i;
376
377         for (i = 0; i < 100; i++) {
378                 cur_freq = extract_freq(get_cur_val(mask), data);
379                 if (cur_freq == freq)
380                         return 1;
381                 udelay(10);
382         }
383         return 0;
384 }
385
386 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
387                                unsigned int target_freq, unsigned int relation)
388 {
389         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
390         struct acpi_processor_performance *perf;
391         struct cpufreq_freqs freqs;
392         struct drv_cmd cmd;
393         unsigned int next_state = 0; /* Index into freq_table */
394         unsigned int next_perf_state = 0; /* Index into perf table */
395         unsigned int i;
396         int result = 0;
397         struct power_trace it;
398
399         dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
400
401         if (unlikely(data == NULL ||
402              data->acpi_data == NULL || data->freq_table == NULL)) {
403                 return -ENODEV;
404         }
405
406         perf = data->acpi_data;
407         result = cpufreq_frequency_table_target(policy,
408                                                 data->freq_table,
409                                                 target_freq,
410                                                 relation, &next_state);
411         if (unlikely(result)) {
412                 result = -ENODEV;
413                 goto out;
414         }
415
416         next_perf_state = data->freq_table[next_state].index;
417         if (perf->state == next_perf_state) {
418                 if (unlikely(data->resume)) {
419                         dprintk("Called after resume, resetting to P%d\n",
420                                 next_perf_state);
421                         data->resume = 0;
422                 } else {
423                         dprintk("Already at target state (P%d)\n",
424                                 next_perf_state);
425                         goto out;
426                 }
427         }
428
429         trace_power_mark(&it, POWER_PSTATE, next_perf_state);
430
431         switch (data->cpu_feature) {
432         case SYSTEM_INTEL_MSR_CAPABLE:
433                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
434                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
435                 cmd.val = (u32) perf->states[next_perf_state].control;
436                 break;
437         case SYSTEM_IO_CAPABLE:
438                 cmd.type = SYSTEM_IO_CAPABLE;
439                 cmd.addr.io.port = perf->control_register.address;
440                 cmd.addr.io.bit_width = perf->control_register.bit_width;
441                 cmd.val = (u32) perf->states[next_perf_state].control;
442                 break;
443         default:
444                 result = -ENODEV;
445                 goto out;
446         }
447
448         /* cpufreq holds the hotplug lock, so we are safe from here on */
449         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
450                 cmd.mask = policy->cpus;
451         else
452                 cmd.mask = cpumask_of(policy->cpu);
453
454         freqs.old = perf->states[perf->state].core_frequency * 1000;
455         freqs.new = data->freq_table[next_state].frequency;
456         for_each_cpu(i, cmd.mask) {
457                 freqs.cpu = i;
458                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
459         }
460
461         drv_write(&cmd);
462
463         if (acpi_pstate_strict) {
464                 if (!check_freqs(cmd.mask, freqs.new, data)) {
465                         dprintk("acpi_cpufreq_target failed (%d)\n",
466                                 policy->cpu);
467                         result = -EAGAIN;
468                         goto out;
469                 }
470         }
471
472         for_each_cpu(i, cmd.mask) {
473                 freqs.cpu = i;
474                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
475         }
476         perf->state = next_perf_state;
477
478 out:
479         return result;
480 }
481
482 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
483 {
484         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
485
486         dprintk("acpi_cpufreq_verify\n");
487
488         return cpufreq_frequency_table_verify(policy, data->freq_table);
489 }
490
491 static unsigned long
492 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
493 {
494         struct acpi_processor_performance *perf = data->acpi_data;
495
496         if (cpu_khz) {
497                 /* search the closest match to cpu_khz */
498                 unsigned int i;
499                 unsigned long freq;
500                 unsigned long freqn = perf->states[0].core_frequency * 1000;
501
502                 for (i = 0; i < (perf->state_count-1); i++) {
503                         freq = freqn;
504                         freqn = perf->states[i+1].core_frequency * 1000;
505                         if ((2 * cpu_khz) > (freqn + freq)) {
506                                 perf->state = i;
507                                 return freq;
508                         }
509                 }
510                 perf->state = perf->state_count-1;
511                 return freqn;
512         } else {
513                 /* assume CPU is at P0... */
514                 perf->state = 0;
515                 return perf->states[0].core_frequency * 1000;
516         }
517 }
518
519 static void free_acpi_perf_data(void)
520 {
521         unsigned int i;
522
523         /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
524         for_each_possible_cpu(i)
525                 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
526                                  ->shared_cpu_map);
527         free_percpu(acpi_perf_data);
528 }
529
530 /*
531  * acpi_cpufreq_early_init - initialize ACPI P-States library
532  *
533  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
534  * in order to determine correct frequency and voltage pairings. We can
535  * do _PDC and _PSD and find out the processor dependency for the
536  * actual init that will happen later...
537  */
538 static int __init acpi_cpufreq_early_init(void)
539 {
540         unsigned int i;
541         dprintk("acpi_cpufreq_early_init\n");
542
543         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
544         if (!acpi_perf_data) {
545                 dprintk("Memory allocation error for acpi_perf_data.\n");
546                 return -ENOMEM;
547         }
548         for_each_possible_cpu(i) {
549                 if (!zalloc_cpumask_var_node(
550                         &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
551                         GFP_KERNEL, cpu_to_node(i))) {
552
553                         /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
554                         free_acpi_perf_data();
555                         return -ENOMEM;
556                 }
557         }
558
559         /* Do initialization in ACPI core */
560         acpi_processor_preregister_performance(acpi_perf_data);
561         return 0;
562 }
563
564 #ifdef CONFIG_SMP
565 /*
566  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
567  * or do it in BIOS firmware and won't inform about it to OS. If not
568  * detected, this has a side effect of making CPU run at a different speed
569  * than OS intended it to run at. Detect it and handle it cleanly.
570  */
571 static int bios_with_sw_any_bug;
572
573 static int sw_any_bug_found(const struct dmi_system_id *d)
574 {
575         bios_with_sw_any_bug = 1;
576         return 0;
577 }
578
579 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
580         {
581                 .callback = sw_any_bug_found,
582                 .ident = "Supermicro Server X6DLP",
583                 .matches = {
584                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
585                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
586                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
587                 },
588         },
589         { }
590 };
591 #endif
592
593 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
594 {
595         unsigned int i;
596         unsigned int valid_states = 0;
597         unsigned int cpu = policy->cpu;
598         struct acpi_cpufreq_data *data;
599         unsigned int result = 0;
600         struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
601         struct acpi_processor_performance *perf;
602
603         dprintk("acpi_cpufreq_cpu_init\n");
604
605         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
606         if (!data)
607                 return -ENOMEM;
608
609         data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
610         per_cpu(drv_data, cpu) = data;
611
612         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
613                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
614
615         result = acpi_processor_register_performance(data->acpi_data, cpu);
616         if (result)
617                 goto err_free;
618
619         perf = data->acpi_data;
620         policy->shared_type = perf->shared_type;
621
622         /*
623          * Will let policy->cpus know about dependency only when software
624          * coordination is required.
625          */
626         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
627             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
628                 cpumask_copy(policy->cpus, perf->shared_cpu_map);
629         }
630         cpumask_copy(policy->related_cpus, perf->shared_cpu_map);
631
632 #ifdef CONFIG_SMP
633         dmi_check_system(sw_any_bug_dmi_table);
634         if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) {
635                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
636                 cpumask_copy(policy->cpus, cpu_core_mask(cpu));
637         }
638 #endif
639
640         /* capability check */
641         if (perf->state_count <= 1) {
642                 dprintk("No P-States\n");
643                 result = -ENODEV;
644                 goto err_unreg;
645         }
646
647         if (perf->control_register.space_id != perf->status_register.space_id) {
648                 result = -ENODEV;
649                 goto err_unreg;
650         }
651
652         switch (perf->control_register.space_id) {
653         case ACPI_ADR_SPACE_SYSTEM_IO:
654                 dprintk("SYSTEM IO addr space\n");
655                 data->cpu_feature = SYSTEM_IO_CAPABLE;
656                 break;
657         case ACPI_ADR_SPACE_FIXED_HARDWARE:
658                 dprintk("HARDWARE addr space\n");
659                 if (!check_est_cpu(cpu)) {
660                         result = -ENODEV;
661                         goto err_unreg;
662                 }
663                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
664                 break;
665         default:
666                 dprintk("Unknown addr space %d\n",
667                         (u32) (perf->control_register.space_id));
668                 result = -ENODEV;
669                 goto err_unreg;
670         }
671
672         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
673                     (perf->state_count+1), GFP_KERNEL);
674         if (!data->freq_table) {
675                 result = -ENOMEM;
676                 goto err_unreg;
677         }
678
679         /* detect transition latency */
680         policy->cpuinfo.transition_latency = 0;
681         for (i = 0; i < perf->state_count; i++) {
682                 if ((perf->states[i].transition_latency * 1000) >
683                     policy->cpuinfo.transition_latency)
684                         policy->cpuinfo.transition_latency =
685                             perf->states[i].transition_latency * 1000;
686         }
687
688         /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
689         if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
690             policy->cpuinfo.transition_latency > 20 * 1000) {
691                 policy->cpuinfo.transition_latency = 20 * 1000;
692                 printk_once(KERN_INFO
693                             "P-state transition latency capped at 20 uS\n");
694         }
695
696         /* table init */
697         for (i = 0; i < perf->state_count; i++) {
698                 if (i > 0 && perf->states[i].core_frequency >=
699                     data->freq_table[valid_states-1].frequency / 1000)
700                         continue;
701
702                 data->freq_table[valid_states].index = i;
703                 data->freq_table[valid_states].frequency =
704                     perf->states[i].core_frequency * 1000;
705                 valid_states++;
706         }
707         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
708         perf->state = 0;
709
710         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
711         if (result)
712                 goto err_freqfree;
713
714         if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
715                 printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
716
717         switch (perf->control_register.space_id) {
718         case ACPI_ADR_SPACE_SYSTEM_IO:
719                 /* Current speed is unknown and not detectable by IO port */
720                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
721                 break;
722         case ACPI_ADR_SPACE_FIXED_HARDWARE:
723                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
724                 policy->cur = get_cur_freq_on_cpu(cpu);
725                 break;
726         default:
727                 break;
728         }
729
730         /* notify BIOS that we exist */
731         acpi_processor_notify_smm(THIS_MODULE);
732
733         /* Check for APERF/MPERF support in hardware */
734         if (c->x86_vendor == X86_VENDOR_INTEL && c->cpuid_level >= 6) {
735                 unsigned int ecx;
736                 ecx = cpuid_ecx(6);
737                 if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY)
738                         acpi_cpufreq_driver.getavg = get_measured_perf;
739         }
740
741         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
742         for (i = 0; i < perf->state_count; i++)
743                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
744                         (i == perf->state ? '*' : ' '), i,
745                         (u32) perf->states[i].core_frequency,
746                         (u32) perf->states[i].power,
747                         (u32) perf->states[i].transition_latency);
748
749         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
750
751         /*
752          * the first call to ->target() should result in us actually
753          * writing something to the appropriate registers.
754          */
755         data->resume = 1;
756
757         return result;
758
759 err_freqfree:
760         kfree(data->freq_table);
761 err_unreg:
762         acpi_processor_unregister_performance(perf, cpu);
763 err_free:
764         kfree(data);
765         per_cpu(drv_data, cpu) = NULL;
766
767         return result;
768 }
769
770 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
771 {
772         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
773
774         dprintk("acpi_cpufreq_cpu_exit\n");
775
776         if (data) {
777                 cpufreq_frequency_table_put_attr(policy->cpu);
778                 per_cpu(drv_data, policy->cpu) = NULL;
779                 acpi_processor_unregister_performance(data->acpi_data,
780                                                       policy->cpu);
781                 kfree(data);
782         }
783
784         return 0;
785 }
786
787 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
788 {
789         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
790
791         dprintk("acpi_cpufreq_resume\n");
792
793         data->resume = 1;
794
795         return 0;
796 }
797
798 static struct freq_attr *acpi_cpufreq_attr[] = {
799         &cpufreq_freq_attr_scaling_available_freqs,
800         NULL,
801 };
802
803 static struct cpufreq_driver acpi_cpufreq_driver = {
804         .verify = acpi_cpufreq_verify,
805         .target = acpi_cpufreq_target,
806         .init = acpi_cpufreq_cpu_init,
807         .exit = acpi_cpufreq_cpu_exit,
808         .resume = acpi_cpufreq_resume,
809         .name = "acpi-cpufreq",
810         .owner = THIS_MODULE,
811         .attr = acpi_cpufreq_attr,
812 };
813
814 static int __init acpi_cpufreq_init(void)
815 {
816         int ret;
817
818         if (acpi_disabled)
819                 return 0;
820
821         dprintk("acpi_cpufreq_init\n");
822
823         ret = acpi_cpufreq_early_init();
824         if (ret)
825                 return ret;
826
827         ret = cpufreq_register_driver(&acpi_cpufreq_driver);
828         if (ret)
829                 free_acpi_perf_data();
830
831         return ret;
832 }
833
834 static void __exit acpi_cpufreq_exit(void)
835 {
836         dprintk("acpi_cpufreq_exit\n");
837
838         cpufreq_unregister_driver(&acpi_cpufreq_driver);
839
840         free_percpu(acpi_perf_data);
841 }
842
843 module_param(acpi_pstate_strict, uint, 0644);
844 MODULE_PARM_DESC(acpi_pstate_strict,
845         "value 0 or non-zero. non-zero -> strict ACPI checks are "
846         "performed during frequency changes.");
847
848 late_initcall(acpi_cpufreq_init);
849 module_exit(acpi_cpufreq_exit);
850
851 MODULE_ALIAS("acpi");