acpi-cpufreq: fix printk typo and indentation
[sfrench/cifs-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 #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         if (cpu->x86_vendor != X86_VENDOR_INTEL ||
94             !cpu_has(cpu, X86_FEATURE_EST))
95                 return 0;
96
97         return 1;
98 }
99
100 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
101 {
102         struct acpi_processor_performance *perf;
103         int i;
104
105         perf = data->acpi_data;
106
107         for (i = 0; i < perf->state_count; i++) {
108                 if (value == perf->states[i].status)
109                         return data->freq_table[i].frequency;
110         }
111         return 0;
112 }
113
114 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
115 {
116         int i;
117         struct acpi_processor_performance *perf;
118
119         msr &= INTEL_MSR_RANGE;
120         perf = data->acpi_data;
121
122         for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
123                 if (msr == perf->states[data->freq_table[i].index].status)
124                         return data->freq_table[i].frequency;
125         }
126         return data->freq_table[0].frequency;
127 }
128
129 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
130 {
131         switch (data->cpu_feature) {
132         case SYSTEM_INTEL_MSR_CAPABLE:
133                 return extract_msr(val, data);
134         case SYSTEM_IO_CAPABLE:
135                 return extract_io(val, data);
136         default:
137                 return 0;
138         }
139 }
140
141 struct msr_addr {
142         u32 reg;
143 };
144
145 struct io_addr {
146         u16 port;
147         u8 bit_width;
148 };
149
150 struct drv_cmd {
151         unsigned int type;
152         const struct cpumask *mask;
153         union {
154                 struct msr_addr msr;
155                 struct io_addr io;
156         } addr;
157         u32 val;
158 };
159
160 /* Called via smp_call_function_single(), on the target CPU */
161 static void do_drv_read(void *_cmd)
162 {
163         struct drv_cmd *cmd = _cmd;
164         u32 h;
165
166         switch (cmd->type) {
167         case SYSTEM_INTEL_MSR_CAPABLE:
168                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
169                 break;
170         case SYSTEM_IO_CAPABLE:
171                 acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
172                                 &cmd->val,
173                                 (u32)cmd->addr.io.bit_width);
174                 break;
175         default:
176                 break;
177         }
178 }
179
180 /* Called via smp_call_function_many(), on the target CPUs */
181 static void do_drv_write(void *_cmd)
182 {
183         struct drv_cmd *cmd = _cmd;
184         u32 lo, hi;
185
186         switch (cmd->type) {
187         case SYSTEM_INTEL_MSR_CAPABLE:
188                 rdmsr(cmd->addr.msr.reg, lo, hi);
189                 lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
190                 wrmsr(cmd->addr.msr.reg, lo, hi);
191                 break;
192         case SYSTEM_IO_CAPABLE:
193                 acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
194                                 cmd->val,
195                                 (u32)cmd->addr.io.bit_width);
196                 break;
197         default:
198                 break;
199         }
200 }
201
202 static void drv_read(struct drv_cmd *cmd)
203 {
204         cmd->val = 0;
205
206         smp_call_function_single(cpumask_any(cmd->mask), do_drv_read, cmd, 1);
207 }
208
209 static void drv_write(struct drv_cmd *cmd)
210 {
211         int this_cpu;
212
213         this_cpu = get_cpu();
214         if (cpumask_test_cpu(this_cpu, cmd->mask))
215                 do_drv_write(cmd);
216         smp_call_function_many(cmd->mask, do_drv_write, cmd, 1);
217         put_cpu();
218 }
219
220 static u32 get_cur_val(const struct cpumask *mask)
221 {
222         struct acpi_processor_performance *perf;
223         struct drv_cmd cmd;
224
225         if (unlikely(cpumask_empty(mask)))
226                 return 0;
227
228         switch (per_cpu(drv_data, cpumask_first(mask))->cpu_feature) {
229         case SYSTEM_INTEL_MSR_CAPABLE:
230                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
231                 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
232                 break;
233         case SYSTEM_IO_CAPABLE:
234                 cmd.type = SYSTEM_IO_CAPABLE;
235                 perf = per_cpu(drv_data, cpumask_first(mask))->acpi_data;
236                 cmd.addr.io.port = perf->control_register.address;
237                 cmd.addr.io.bit_width = perf->control_register.bit_width;
238                 break;
239         default:
240                 return 0;
241         }
242
243         cmd.mask = mask;
244         drv_read(&cmd);
245
246         dprintk("get_cur_val = %u\n", cmd.val);
247
248         return cmd.val;
249 }
250
251 struct perf_pair {
252         union {
253                 struct {
254                         u32 lo;
255                         u32 hi;
256                 } split;
257                 u64 whole;
258         } aperf, mperf;
259 };
260
261 /* Called via smp_call_function_single(), on the target CPU */
262 static void read_measured_perf_ctrs(void *_cur)
263 {
264         struct perf_pair *cur = _cur;
265
266         rdmsr(MSR_IA32_APERF, cur->aperf.split.lo, cur->aperf.split.hi);
267         rdmsr(MSR_IA32_MPERF, cur->mperf.split.lo, cur->mperf.split.hi);
268 }
269
270 /*
271  * Return the measured active (C0) frequency on this CPU since last call
272  * to this function.
273  * Input: cpu number
274  * Return: Average CPU frequency in terms of max frequency (zero on error)
275  *
276  * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
277  * over a period of time, while CPU is in C0 state.
278  * IA32_MPERF counts at the rate of max advertised frequency
279  * IA32_APERF counts at the rate of actual CPU frequency
280  * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
281  * no meaning should be associated with absolute values of these MSRs.
282  */
283 static unsigned int get_measured_perf(struct cpufreq_policy *policy,
284                                       unsigned int cpu)
285 {
286         struct perf_pair readin, cur;
287         unsigned int perf_percent;
288         unsigned int retval;
289
290         if (smp_call_function_single(cpu, read_measured_perf_ctrs, &readin, 1))
291                 return 0;
292
293         cur.aperf.whole = readin.aperf.whole -
294                                 per_cpu(msr_data, cpu).saved_aperf;
295         cur.mperf.whole = readin.mperf.whole -
296                                 per_cpu(msr_data, cpu).saved_mperf;
297         per_cpu(msr_data, cpu).saved_aperf = readin.aperf.whole;
298         per_cpu(msr_data, cpu).saved_mperf = readin.mperf.whole;
299
300 #ifdef __i386__
301         /*
302          * We dont want to do 64 bit divide with 32 bit kernel
303          * Get an approximate value. Return failure in case we cannot get
304          * an approximate value.
305          */
306         if (unlikely(cur.aperf.split.hi || cur.mperf.split.hi)) {
307                 int shift_count;
308                 u32 h;
309
310                 h = max_t(u32, cur.aperf.split.hi, cur.mperf.split.hi);
311                 shift_count = fls(h);
312
313                 cur.aperf.whole >>= shift_count;
314                 cur.mperf.whole >>= shift_count;
315         }
316
317         if (((unsigned long)(-1) / 100) < cur.aperf.split.lo) {
318                 int shift_count = 7;
319                 cur.aperf.split.lo >>= shift_count;
320                 cur.mperf.split.lo >>= shift_count;
321         }
322
323         if (cur.aperf.split.lo && cur.mperf.split.lo)
324                 perf_percent = (cur.aperf.split.lo * 100) / cur.mperf.split.lo;
325         else
326                 perf_percent = 0;
327
328 #else
329         if (unlikely(((unsigned long)(-1) / 100) < cur.aperf.whole)) {
330                 int shift_count = 7;
331                 cur.aperf.whole >>= shift_count;
332                 cur.mperf.whole >>= shift_count;
333         }
334
335         if (cur.aperf.whole && cur.mperf.whole)
336                 perf_percent = (cur.aperf.whole * 100) / cur.mperf.whole;
337         else
338                 perf_percent = 0;
339
340 #endif
341
342         retval = (policy->cpuinfo.max_freq * perf_percent) / 100;
343
344         return retval;
345 }
346
347 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
348 {
349         struct acpi_cpufreq_data *data = per_cpu(drv_data, cpu);
350         unsigned int freq;
351         unsigned int cached_freq;
352
353         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
354
355         if (unlikely(data == NULL ||
356                      data->acpi_data == NULL || data->freq_table == NULL)) {
357                 return 0;
358         }
359
360         cached_freq = data->freq_table[data->acpi_data->state].frequency;
361         freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
362         if (freq != cached_freq) {
363                 /*
364                  * The dreaded BIOS frequency change behind our back.
365                  * Force set the frequency on next target call.
366                  */
367                 data->resume = 1;
368         }
369
370         dprintk("cur freq = %u\n", freq);
371
372         return freq;
373 }
374
375 static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
376                                 struct acpi_cpufreq_data *data)
377 {
378         unsigned int cur_freq;
379         unsigned int i;
380
381         for (i = 0; i < 100; i++) {
382                 cur_freq = extract_freq(get_cur_val(mask), data);
383                 if (cur_freq == freq)
384                         return 1;
385                 udelay(10);
386         }
387         return 0;
388 }
389
390 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
391                                unsigned int target_freq, unsigned int relation)
392 {
393         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
394         struct acpi_processor_performance *perf;
395         struct cpufreq_freqs freqs;
396         struct drv_cmd cmd;
397         unsigned int next_state = 0; /* Index into freq_table */
398         unsigned int next_perf_state = 0; /* Index into perf table */
399         unsigned int i;
400         int result = 0;
401         struct power_trace it;
402
403         dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
404
405         if (unlikely(data == NULL ||
406              data->acpi_data == NULL || data->freq_table == NULL)) {
407                 return -ENODEV;
408         }
409
410         perf = data->acpi_data;
411         result = cpufreq_frequency_table_target(policy,
412                                                 data->freq_table,
413                                                 target_freq,
414                                                 relation, &next_state);
415         if (unlikely(result)) {
416                 result = -ENODEV;
417                 goto out;
418         }
419
420         next_perf_state = data->freq_table[next_state].index;
421         if (perf->state == next_perf_state) {
422                 if (unlikely(data->resume)) {
423                         dprintk("Called after resume, resetting to P%d\n",
424                                 next_perf_state);
425                         data->resume = 0;
426                 } else {
427                         dprintk("Already at target state (P%d)\n",
428                                 next_perf_state);
429                         goto out;
430                 }
431         }
432
433         trace_power_mark(&it, POWER_PSTATE, next_perf_state);
434
435         switch (data->cpu_feature) {
436         case SYSTEM_INTEL_MSR_CAPABLE:
437                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
438                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
439                 cmd.val = (u32) perf->states[next_perf_state].control;
440                 break;
441         case SYSTEM_IO_CAPABLE:
442                 cmd.type = SYSTEM_IO_CAPABLE;
443                 cmd.addr.io.port = perf->control_register.address;
444                 cmd.addr.io.bit_width = perf->control_register.bit_width;
445                 cmd.val = (u32) perf->states[next_perf_state].control;
446                 break;
447         default:
448                 result = -ENODEV;
449                 goto out;
450         }
451
452         /* cpufreq holds the hotplug lock, so we are safe from here on */
453         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
454                 cmd.mask = policy->cpus;
455         else
456                 cmd.mask = cpumask_of(policy->cpu);
457
458         freqs.old = perf->states[perf->state].core_frequency * 1000;
459         freqs.new = data->freq_table[next_state].frequency;
460         for_each_cpu(i, cmd.mask) {
461                 freqs.cpu = i;
462                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
463         }
464
465         drv_write(&cmd);
466
467         if (acpi_pstate_strict) {
468                 if (!check_freqs(cmd.mask, freqs.new, data)) {
469                         dprintk("acpi_cpufreq_target failed (%d)\n",
470                                 policy->cpu);
471                         result = -EAGAIN;
472                         goto out;
473                 }
474         }
475
476         for_each_cpu(i, cmd.mask) {
477                 freqs.cpu = i;
478                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
479         }
480         perf->state = next_perf_state;
481
482 out:
483         return result;
484 }
485
486 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
487 {
488         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
489
490         dprintk("acpi_cpufreq_verify\n");
491
492         return cpufreq_frequency_table_verify(policy, data->freq_table);
493 }
494
495 static unsigned long
496 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
497 {
498         struct acpi_processor_performance *perf = data->acpi_data;
499
500         if (cpu_khz) {
501                 /* search the closest match to cpu_khz */
502                 unsigned int i;
503                 unsigned long freq;
504                 unsigned long freqn = perf->states[0].core_frequency * 1000;
505
506                 for (i = 0; i < (perf->state_count-1); i++) {
507                         freq = freqn;
508                         freqn = perf->states[i+1].core_frequency * 1000;
509                         if ((2 * cpu_khz) > (freqn + freq)) {
510                                 perf->state = i;
511                                 return freq;
512                         }
513                 }
514                 perf->state = perf->state_count-1;
515                 return freqn;
516         } else {
517                 /* assume CPU is at P0... */
518                 perf->state = 0;
519                 return perf->states[0].core_frequency * 1000;
520         }
521 }
522
523 static void free_acpi_perf_data(void)
524 {
525         unsigned int i;
526
527         /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
528         for_each_possible_cpu(i)
529                 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
530                                  ->shared_cpu_map);
531         free_percpu(acpi_perf_data);
532 }
533
534 /*
535  * acpi_cpufreq_early_init - initialize ACPI P-States library
536  *
537  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
538  * in order to determine correct frequency and voltage pairings. We can
539  * do _PDC and _PSD and find out the processor dependency for the
540  * actual init that will happen later...
541  */
542 static int __init acpi_cpufreq_early_init(void)
543 {
544         unsigned int i;
545         dprintk("acpi_cpufreq_early_init\n");
546
547         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
548         if (!acpi_perf_data) {
549                 dprintk("Memory allocation error for acpi_perf_data.\n");
550                 return -ENOMEM;
551         }
552         for_each_possible_cpu(i) {
553                 if (!alloc_cpumask_var_node(
554                         &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
555                         GFP_KERNEL, cpu_to_node(i))) {
556
557                         /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
558                         free_acpi_perf_data();
559                         return -ENOMEM;
560                 }
561         }
562
563         /* Do initialization in ACPI core */
564         acpi_processor_preregister_performance(acpi_perf_data);
565         return 0;
566 }
567
568 #ifdef CONFIG_SMP
569 /*
570  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
571  * or do it in BIOS firmware and won't inform about it to OS. If not
572  * detected, this has a side effect of making CPU run at a different speed
573  * than OS intended it to run at. Detect it and handle it cleanly.
574  */
575 static int bios_with_sw_any_bug;
576
577 static int sw_any_bug_found(const struct dmi_system_id *d)
578 {
579         bios_with_sw_any_bug = 1;
580         return 0;
581 }
582
583 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
584         {
585                 .callback = sw_any_bug_found,
586                 .ident = "Supermicro Server X6DLP",
587                 .matches = {
588                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
589                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
590                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
591                 },
592         },
593         { }
594 };
595 #endif
596
597 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
598 {
599         unsigned int i;
600         unsigned int valid_states = 0;
601         unsigned int cpu = policy->cpu;
602         struct acpi_cpufreq_data *data;
603         unsigned int result = 0;
604         struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
605         struct acpi_processor_performance *perf;
606
607         dprintk("acpi_cpufreq_cpu_init\n");
608
609         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
610         if (!data)
611                 return -ENOMEM;
612
613         data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
614         per_cpu(drv_data, cpu) = data;
615
616         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
617                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
618
619         result = acpi_processor_register_performance(data->acpi_data, cpu);
620         if (result)
621                 goto err_free;
622
623         perf = data->acpi_data;
624         policy->shared_type = perf->shared_type;
625
626         /*
627          * Will let policy->cpus know about dependency only when software
628          * coordination is required.
629          */
630         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
631             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
632                 cpumask_copy(policy->cpus, perf->shared_cpu_map);
633         }
634         cpumask_copy(policy->related_cpus, perf->shared_cpu_map);
635
636 #ifdef CONFIG_SMP
637         dmi_check_system(sw_any_bug_dmi_table);
638         if (bios_with_sw_any_bug && cpumask_weight(policy->cpus) == 1) {
639                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
640                 cpumask_copy(policy->cpus, cpu_core_mask(cpu));
641         }
642 #endif
643
644         /* capability check */
645         if (perf->state_count <= 1) {
646                 dprintk("No P-States\n");
647                 result = -ENODEV;
648                 goto err_unreg;
649         }
650
651         if (perf->control_register.space_id != perf->status_register.space_id) {
652                 result = -ENODEV;
653                 goto err_unreg;
654         }
655
656         switch (perf->control_register.space_id) {
657         case ACPI_ADR_SPACE_SYSTEM_IO:
658                 dprintk("SYSTEM IO addr space\n");
659                 data->cpu_feature = SYSTEM_IO_CAPABLE;
660                 break;
661         case ACPI_ADR_SPACE_FIXED_HARDWARE:
662                 dprintk("HARDWARE addr space\n");
663                 if (!check_est_cpu(cpu)) {
664                         result = -ENODEV;
665                         goto err_unreg;
666                 }
667                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
668                 break;
669         default:
670                 dprintk("Unknown addr space %d\n",
671                         (u32) (perf->control_register.space_id));
672                 result = -ENODEV;
673                 goto err_unreg;
674         }
675
676         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
677                     (perf->state_count+1), GFP_KERNEL);
678         if (!data->freq_table) {
679                 result = -ENOMEM;
680                 goto err_unreg;
681         }
682
683         /* detect transition latency */
684         policy->cpuinfo.transition_latency = 0;
685         for (i = 0; i < perf->state_count; i++) {
686                 if ((perf->states[i].transition_latency * 1000) >
687                     policy->cpuinfo.transition_latency)
688                         policy->cpuinfo.transition_latency =
689                             perf->states[i].transition_latency * 1000;
690         }
691
692         /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
693         if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
694             policy->cpuinfo.transition_latency > 20 * 1000) {
695                 policy->cpuinfo.transition_latency = 20 * 1000;
696                 printk_once(KERN_INFO
697                             "P-state transition latency capped at 20 uS\n");
698         }
699
700         /* table init */
701         for (i = 0; i < perf->state_count; i++) {
702                 if (i > 0 && perf->states[i].core_frequency >=
703                     data->freq_table[valid_states-1].frequency / 1000)
704                         continue;
705
706                 data->freq_table[valid_states].index = i;
707                 data->freq_table[valid_states].frequency =
708                     perf->states[i].core_frequency * 1000;
709                 valid_states++;
710         }
711         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
712         perf->state = 0;
713
714         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
715         if (result)
716                 goto err_freqfree;
717
718         if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
719                 printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
720
721         switch (perf->control_register.space_id) {
722         case ACPI_ADR_SPACE_SYSTEM_IO:
723                 /* Current speed is unknown and not detectable by IO port */
724                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
725                 break;
726         case ACPI_ADR_SPACE_FIXED_HARDWARE:
727                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
728                 policy->cur = get_cur_freq_on_cpu(cpu);
729                 break;
730         default:
731                 break;
732         }
733
734         /* notify BIOS that we exist */
735         acpi_processor_notify_smm(THIS_MODULE);
736
737         /* Check for APERF/MPERF support in hardware */
738         if (c->x86_vendor == X86_VENDOR_INTEL && c->cpuid_level >= 6) {
739                 unsigned int ecx;
740                 ecx = cpuid_ecx(6);
741                 if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY)
742                         acpi_cpufreq_driver.getavg = get_measured_perf;
743         }
744
745         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
746         for (i = 0; i < perf->state_count; i++)
747                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
748                         (i == perf->state ? '*' : ' '), i,
749                         (u32) perf->states[i].core_frequency,
750                         (u32) perf->states[i].power,
751                         (u32) perf->states[i].transition_latency);
752
753         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
754
755         /*
756          * the first call to ->target() should result in us actually
757          * writing something to the appropriate registers.
758          */
759         data->resume = 1;
760
761         return result;
762
763 err_freqfree:
764         kfree(data->freq_table);
765 err_unreg:
766         acpi_processor_unregister_performance(perf, cpu);
767 err_free:
768         kfree(data);
769         per_cpu(drv_data, cpu) = NULL;
770
771         return result;
772 }
773
774 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
775 {
776         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
777
778         dprintk("acpi_cpufreq_cpu_exit\n");
779
780         if (data) {
781                 cpufreq_frequency_table_put_attr(policy->cpu);
782                 per_cpu(drv_data, policy->cpu) = NULL;
783                 acpi_processor_unregister_performance(data->acpi_data,
784                                                       policy->cpu);
785                 kfree(data);
786         }
787
788         return 0;
789 }
790
791 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
792 {
793         struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
794
795         dprintk("acpi_cpufreq_resume\n");
796
797         data->resume = 1;
798
799         return 0;
800 }
801
802 static struct freq_attr *acpi_cpufreq_attr[] = {
803         &cpufreq_freq_attr_scaling_available_freqs,
804         NULL,
805 };
806
807 static struct cpufreq_driver acpi_cpufreq_driver = {
808         .verify = acpi_cpufreq_verify,
809         .target = acpi_cpufreq_target,
810         .init = acpi_cpufreq_cpu_init,
811         .exit = acpi_cpufreq_cpu_exit,
812         .resume = acpi_cpufreq_resume,
813         .name = "acpi-cpufreq",
814         .owner = THIS_MODULE,
815         .attr = acpi_cpufreq_attr,
816 };
817
818 static int __init acpi_cpufreq_init(void)
819 {
820         int ret;
821
822         if (acpi_disabled)
823                 return 0;
824
825         dprintk("acpi_cpufreq_init\n");
826
827         ret = acpi_cpufreq_early_init();
828         if (ret)
829                 return ret;
830
831         ret = cpufreq_register_driver(&acpi_cpufreq_driver);
832         if (ret)
833                 free_acpi_perf_data();
834
835         return ret;
836 }
837
838 static void __exit acpi_cpufreq_exit(void)
839 {
840         dprintk("acpi_cpufreq_exit\n");
841
842         cpufreq_unregister_driver(&acpi_cpufreq_driver);
843
844         free_percpu(acpi_perf_data);
845 }
846
847 module_param(acpi_pstate_strict, uint, 0644);
848 MODULE_PARM_DESC(acpi_pstate_strict,
849         "value 0 or non-zero. non-zero -> strict ACPI checks are "
850         "performed during frequency changes.");
851
852 late_initcall(acpi_cpufreq_init);
853 module_exit(acpi_cpufreq_exit);
854
855 MODULE_ALIAS("acpi");