Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/agpgart
[linux-2.6.git] / arch / i386 / kernel / cpu / cpufreq / acpi-cpufreq.c
1 /*
2  * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.4 $)
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *  Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
7  *  Copyright (C) 2006       Denis Sadykov <denis.m.sadykov@intel.com>
8  *
9  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10  *
11  *  This program is free software; you can redistribute it and/or modify
12  *  it under the terms of the GNU General Public License as published by
13  *  the Free Software Foundation; either version 2 of the License, or (at
14  *  your option) any later version.
15  *
16  *  This program is distributed in the hope that it will be useful, but
17  *  WITHOUT ANY WARRANTY; without even the implied warranty of
18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  *  General Public License for more details.
20  *
21  *  You should have received a copy of the GNU General Public License along
22  *  with this program; if not, write to the Free Software Foundation, Inc.,
23  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
24  *
25  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
26  */
27
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/smp.h>
32 #include <linux/sched.h>
33 #include <linux/cpufreq.h>
34 #include <linux/compiler.h>
35 #include <linux/dmi.h>
36
37 #include <linux/acpi.h>
38 #include <acpi/processor.h>
39
40 #include <asm/io.h>
41 #include <asm/msr.h>
42 #include <asm/processor.h>
43 #include <asm/cpufeature.h>
44 #include <asm/delay.h>
45 #include <asm/uaccess.h>
46
47 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
48
49 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
50 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
51 MODULE_LICENSE("GPL");
52
53 enum {
54         UNDEFINED_CAPABLE = 0,
55         SYSTEM_INTEL_MSR_CAPABLE,
56         SYSTEM_IO_CAPABLE,
57 };
58
59 #define INTEL_MSR_RANGE         (0xffff)
60 #define CPUID_6_ECX_APERFMPERF_CAPABILITY       (0x1)
61
62 struct acpi_cpufreq_data {
63         struct acpi_processor_performance *acpi_data;
64         struct cpufreq_frequency_table *freq_table;
65         unsigned int max_freq;
66         unsigned int resume;
67         unsigned int cpu_feature;
68 };
69
70 static struct acpi_cpufreq_data *drv_data[NR_CPUS];
71 static struct acpi_processor_performance *acpi_perf_data[NR_CPUS];
72
73 static struct cpufreq_driver acpi_cpufreq_driver;
74
75 static unsigned int acpi_pstate_strict;
76
77 static int check_est_cpu(unsigned int cpuid)
78 {
79         struct cpuinfo_x86 *cpu = &cpu_data[cpuid];
80
81         if (cpu->x86_vendor != X86_VENDOR_INTEL ||
82             !cpu_has(cpu, X86_FEATURE_EST))
83                 return 0;
84
85         return 1;
86 }
87
88 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
89 {
90         struct acpi_processor_performance *perf;
91         int i;
92
93         perf = data->acpi_data;
94
95         for (i=0; i<perf->state_count; i++) {
96                 if (value == perf->states[i].status)
97                         return data->freq_table[i].frequency;
98         }
99         return 0;
100 }
101
102 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
103 {
104         int i;
105         struct acpi_processor_performance *perf;
106
107         msr &= INTEL_MSR_RANGE;
108         perf = data->acpi_data;
109
110         for (i=0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
111                 if (msr == perf->states[data->freq_table[i].index].status)
112                         return data->freq_table[i].frequency;
113         }
114         return data->freq_table[0].frequency;
115 }
116
117 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
118 {
119         switch (data->cpu_feature) {
120         case SYSTEM_INTEL_MSR_CAPABLE:
121                 return extract_msr(val, data);
122         case SYSTEM_IO_CAPABLE:
123                 return extract_io(val, data);
124         default:
125                 return 0;
126         }
127 }
128
129 struct msr_addr {
130         u32 reg;
131 };
132
133 struct io_addr {
134         u16 port;
135         u8 bit_width;
136 };
137
138 typedef union {
139         struct msr_addr msr;
140         struct io_addr io;
141 } drv_addr_union;
142
143 struct drv_cmd {
144         unsigned int type;
145         cpumask_t mask;
146         drv_addr_union addr;
147         u32 val;
148 };
149
150 static void do_drv_read(struct drv_cmd *cmd)
151 {
152         u32 h;
153
154         switch (cmd->type) {
155         case SYSTEM_INTEL_MSR_CAPABLE:
156                 rdmsr(cmd->addr.msr.reg, cmd->val, h);
157                 break;
158         case SYSTEM_IO_CAPABLE:
159                 acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
160                                 &cmd->val,
161                                 (u32)cmd->addr.io.bit_width);
162                 break;
163         default:
164                 break;
165         }
166 }
167
168 static void do_drv_write(struct drv_cmd *cmd)
169 {
170         u32 h = 0;
171
172         switch (cmd->type) {
173         case SYSTEM_INTEL_MSR_CAPABLE:
174                 wrmsr(cmd->addr.msr.reg, cmd->val, h);
175                 break;
176         case SYSTEM_IO_CAPABLE:
177                 acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
178                                 cmd->val,
179                                 (u32)cmd->addr.io.bit_width);
180                 break;
181         default:
182                 break;
183         }
184 }
185
186 static void drv_read(struct drv_cmd *cmd)
187 {
188         cpumask_t saved_mask = current->cpus_allowed;
189         cmd->val = 0;
190
191         set_cpus_allowed(current, cmd->mask);
192         do_drv_read(cmd);
193         set_cpus_allowed(current, saved_mask);
194 }
195
196 static void drv_write(struct drv_cmd *cmd)
197 {
198         cpumask_t saved_mask = current->cpus_allowed;
199         unsigned int i;
200
201         for_each_cpu_mask(i, cmd->mask) {
202                 set_cpus_allowed(current, cpumask_of_cpu(i));
203                 do_drv_write(cmd);
204         }
205
206         set_cpus_allowed(current, saved_mask);
207         return;
208 }
209
210 static u32 get_cur_val(cpumask_t mask)
211 {
212         struct acpi_processor_performance *perf;
213         struct drv_cmd cmd;
214
215         if (unlikely(cpus_empty(mask)))
216                 return 0;
217
218         switch (drv_data[first_cpu(mask)]->cpu_feature) {
219         case SYSTEM_INTEL_MSR_CAPABLE:
220                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
221                 cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
222                 break;
223         case SYSTEM_IO_CAPABLE:
224                 cmd.type = SYSTEM_IO_CAPABLE;
225                 perf = drv_data[first_cpu(mask)]->acpi_data;
226                 cmd.addr.io.port = perf->control_register.address;
227                 cmd.addr.io.bit_width = perf->control_register.bit_width;
228                 break;
229         default:
230                 return 0;
231         }
232
233         cmd.mask = mask;
234
235         drv_read(&cmd);
236
237         dprintk("get_cur_val = %u\n", cmd.val);
238
239         return cmd.val;
240 }
241
242 /*
243  * Return the measured active (C0) frequency on this CPU since last call
244  * to this function.
245  * Input: cpu number
246  * Return: Average CPU frequency in terms of max frequency (zero on error)
247  *
248  * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
249  * over a period of time, while CPU is in C0 state.
250  * IA32_MPERF counts at the rate of max advertised frequency
251  * IA32_APERF counts at the rate of actual CPU frequency
252  * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
253  * no meaning should be associated with absolute values of these MSRs.
254  */
255 static unsigned int get_measured_perf(unsigned int cpu)
256 {
257         union {
258                 struct {
259                         u32 lo;
260                         u32 hi;
261                 } split;
262                 u64 whole;
263         } aperf_cur, mperf_cur;
264
265         cpumask_t saved_mask;
266         unsigned int perf_percent;
267         unsigned int retval;
268
269         saved_mask = current->cpus_allowed;
270         set_cpus_allowed(current, cpumask_of_cpu(cpu));
271         if (get_cpu() != cpu) {
272                 /* We were not able to run on requested processor */
273                 put_cpu();
274                 return 0;
275         }
276
277         rdmsr(MSR_IA32_APERF, aperf_cur.split.lo, aperf_cur.split.hi);
278         rdmsr(MSR_IA32_MPERF, mperf_cur.split.lo, mperf_cur.split.hi);
279
280         wrmsr(MSR_IA32_APERF, 0,0);
281         wrmsr(MSR_IA32_MPERF, 0,0);
282
283 #ifdef __i386__
284         /*
285          * We dont want to do 64 bit divide with 32 bit kernel
286          * Get an approximate value. Return failure in case we cannot get
287          * an approximate value.
288          */
289         if (unlikely(aperf_cur.split.hi || mperf_cur.split.hi)) {
290                 int shift_count;
291                 u32 h;
292
293                 h = max_t(u32, aperf_cur.split.hi, mperf_cur.split.hi);
294                 shift_count = fls(h);
295
296                 aperf_cur.whole >>= shift_count;
297                 mperf_cur.whole >>= shift_count;
298         }
299
300         if (((unsigned long)(-1) / 100) < aperf_cur.split.lo) {
301                 int shift_count = 7;
302                 aperf_cur.split.lo >>= shift_count;
303                 mperf_cur.split.lo >>= shift_count;
304         }
305
306         if (aperf_cur.split.lo && mperf_cur.split.lo)
307                 perf_percent = (aperf_cur.split.lo * 100) / mperf_cur.split.lo;
308         else
309                 perf_percent = 0;
310
311 #else
312         if (unlikely(((unsigned long)(-1) / 100) < aperf_cur.whole)) {
313                 int shift_count = 7;
314                 aperf_cur.whole >>= shift_count;
315                 mperf_cur.whole >>= shift_count;
316         }
317
318         if (aperf_cur.whole && mperf_cur.whole)
319                 perf_percent = (aperf_cur.whole * 100) / mperf_cur.whole;
320         else
321                 perf_percent = 0;
322
323 #endif
324
325         retval = drv_data[cpu]->max_freq * perf_percent / 100;
326
327         put_cpu();
328         set_cpus_allowed(current, saved_mask);
329
330         dprintk("cpu %d: performance percent %d\n", cpu, perf_percent);
331         return retval;
332 }
333
334 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
335 {
336         struct acpi_cpufreq_data *data = drv_data[cpu];
337         unsigned int freq;
338
339         dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
340
341         if (unlikely(data == NULL ||
342                      data->acpi_data == NULL || data->freq_table == NULL)) {
343                 return 0;
344         }
345
346         freq = extract_freq(get_cur_val(cpumask_of_cpu(cpu)), data);
347         dprintk("cur freq = %u\n", freq);
348
349         return freq;
350 }
351
352 static unsigned int check_freqs(cpumask_t mask, unsigned int freq,
353                                 struct acpi_cpufreq_data *data)
354 {
355         unsigned int cur_freq;
356         unsigned int i;
357
358         for (i=0; i<100; i++) {
359                 cur_freq = extract_freq(get_cur_val(mask), data);
360                 if (cur_freq == freq)
361                         return 1;
362                 udelay(10);
363         }
364         return 0;
365 }
366
367 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
368                                unsigned int target_freq, unsigned int relation)
369 {
370         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
371         struct acpi_processor_performance *perf;
372         struct cpufreq_freqs freqs;
373         cpumask_t online_policy_cpus;
374         struct drv_cmd cmd;
375         unsigned int msr;
376         unsigned int next_state = 0; /* Index into freq_table */
377         unsigned int next_perf_state = 0; /* Index into perf table */
378         unsigned int i;
379         int result = 0;
380
381         dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);
382
383         if (unlikely(data == NULL ||
384              data->acpi_data == NULL || data->freq_table == NULL)) {
385                 return -ENODEV;
386         }
387
388         perf = data->acpi_data;
389         result = cpufreq_frequency_table_target(policy,
390                                                 data->freq_table,
391                                                 target_freq,
392                                                 relation, &next_state);
393         if (unlikely(result))
394                 return -ENODEV;
395
396 #ifdef CONFIG_HOTPLUG_CPU
397         /* cpufreq holds the hotplug lock, so we are safe from here on */
398         cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
399 #else
400         online_policy_cpus = policy->cpus;
401 #endif
402
403         next_perf_state = data->freq_table[next_state].index;
404         if (perf->state == next_perf_state) {
405                 if (unlikely(data->resume)) {
406                         dprintk("Called after resume, resetting to P%d\n",
407                                 next_perf_state);
408                         data->resume = 0;
409                 } else {
410                         dprintk("Already at target state (P%d)\n",
411                                 next_perf_state);
412                         return 0;
413                 }
414         }
415
416         switch (data->cpu_feature) {
417         case SYSTEM_INTEL_MSR_CAPABLE:
418                 cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
419                 cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
420                 msr =
421                     (u32) perf->states[next_perf_state].
422                     control & INTEL_MSR_RANGE;
423                 cmd.val = get_cur_val(online_policy_cpus);
424                 cmd.val = (cmd.val & ~INTEL_MSR_RANGE) | msr;
425                 break;
426         case SYSTEM_IO_CAPABLE:
427                 cmd.type = SYSTEM_IO_CAPABLE;
428                 cmd.addr.io.port = perf->control_register.address;
429                 cmd.addr.io.bit_width = perf->control_register.bit_width;
430                 cmd.val = (u32) perf->states[next_perf_state].control;
431                 break;
432         default:
433                 return -ENODEV;
434         }
435
436         cpus_clear(cmd.mask);
437
438         if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
439                 cmd.mask = online_policy_cpus;
440         else
441                 cpu_set(policy->cpu, cmd.mask);
442
443         freqs.old = perf->states[perf->state].core_frequency * 1000;
444         freqs.new = data->freq_table[next_state].frequency;
445         for_each_cpu_mask(i, cmd.mask) {
446                 freqs.cpu = i;
447                 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
448         }
449
450         drv_write(&cmd);
451
452         if (acpi_pstate_strict) {
453                 if (!check_freqs(cmd.mask, freqs.new, data)) {
454                         dprintk("acpi_cpufreq_target failed (%d)\n",
455                                 policy->cpu);
456                         return -EAGAIN;
457                 }
458         }
459
460         for_each_cpu_mask(i, cmd.mask) {
461                 freqs.cpu = i;
462                 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
463         }
464         perf->state = next_perf_state;
465
466         return result;
467 }
468
469 static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
470 {
471         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
472
473         dprintk("acpi_cpufreq_verify\n");
474
475         return cpufreq_frequency_table_verify(policy, data->freq_table);
476 }
477
478 static unsigned long
479 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
480 {
481         struct acpi_processor_performance *perf = data->acpi_data;
482
483         if (cpu_khz) {
484                 /* search the closest match to cpu_khz */
485                 unsigned int i;
486                 unsigned long freq;
487                 unsigned long freqn = perf->states[0].core_frequency * 1000;
488
489                 for (i=0; i<(perf->state_count-1); i++) {
490                         freq = freqn;
491                         freqn = perf->states[i+1].core_frequency * 1000;
492                         if ((2 * cpu_khz) > (freqn + freq)) {
493                                 perf->state = i;
494                                 return freq;
495                         }
496                 }
497                 perf->state = perf->state_count-1;
498                 return freqn;
499         } else {
500                 /* assume CPU is at P0... */
501                 perf->state = 0;
502                 return perf->states[0].core_frequency * 1000;
503         }
504 }
505
506 /*
507  * acpi_cpufreq_early_init - initialize ACPI P-States library
508  *
509  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
510  * in order to determine correct frequency and voltage pairings. We can
511  * do _PDC and _PSD and find out the processor dependency for the
512  * actual init that will happen later...
513  */
514 static int acpi_cpufreq_early_init(void)
515 {
516         struct acpi_processor_performance *data;
517         cpumask_t covered;
518         unsigned int i, j;
519
520         dprintk("acpi_cpufreq_early_init\n");
521
522         for_each_possible_cpu(i) {
523                 data = kzalloc(sizeof(struct acpi_processor_performance),
524                                GFP_KERNEL);
525                 if (!data) {
526                         for_each_cpu_mask(j, covered) {
527                                 kfree(acpi_perf_data[j]);
528                                 acpi_perf_data[j] = NULL;
529                         }
530                         return -ENOMEM;
531                 }
532                 acpi_perf_data[i] = data;
533                 cpu_set(i, covered);
534         }
535
536         /* Do initialization in ACPI core */
537         acpi_processor_preregister_performance(acpi_perf_data);
538         return 0;
539 }
540
541 #ifdef CONFIG_SMP
542 /*
543  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
544  * or do it in BIOS firmware and won't inform about it to OS. If not
545  * detected, this has a side effect of making CPU run at a different speed
546  * than OS intended it to run at. Detect it and handle it cleanly.
547  */
548 static int bios_with_sw_any_bug;
549
550 static int sw_any_bug_found(struct dmi_system_id *d)
551 {
552         bios_with_sw_any_bug = 1;
553         return 0;
554 }
555
556 static struct dmi_system_id sw_any_bug_dmi_table[] = {
557         {
558                 .callback = sw_any_bug_found,
559                 .ident = "Supermicro Server X6DLP",
560                 .matches = {
561                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
562                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
563                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
564                 },
565         },
566         { }
567 };
568 #endif
569
570 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
571 {
572         unsigned int i;
573         unsigned int valid_states = 0;
574         unsigned int cpu = policy->cpu;
575         struct acpi_cpufreq_data *data;
576         unsigned int result = 0;
577         struct cpuinfo_x86 *c = &cpu_data[policy->cpu];
578         struct acpi_processor_performance *perf;
579
580         dprintk("acpi_cpufreq_cpu_init\n");
581
582         if (!acpi_perf_data[cpu])
583                 return -ENODEV;
584
585         data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
586         if (!data)
587                 return -ENOMEM;
588
589         data->acpi_data = acpi_perf_data[cpu];
590         drv_data[cpu] = data;
591
592         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
593                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
594
595         result = acpi_processor_register_performance(data->acpi_data, cpu);
596         if (result)
597                 goto err_free;
598
599         perf = data->acpi_data;
600         policy->shared_type = perf->shared_type;
601
602         /*
603          * Will let policy->cpus know about dependency only when software
604          * coordination is required.
605          */
606         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
607             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
608                 policy->cpus = perf->shared_cpu_map;
609         }
610
611 #ifdef CONFIG_SMP
612         dmi_check_system(sw_any_bug_dmi_table);
613         if (bios_with_sw_any_bug && cpus_weight(policy->cpus) == 1) {
614                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
615                 policy->cpus = cpu_core_map[cpu];
616         }
617 #endif
618
619         /* capability check */
620         if (perf->state_count <= 1) {
621                 dprintk("No P-States\n");
622                 result = -ENODEV;
623                 goto err_unreg;
624         }
625
626         if (perf->control_register.space_id != perf->status_register.space_id) {
627                 result = -ENODEV;
628                 goto err_unreg;
629         }
630
631         switch (perf->control_register.space_id) {
632         case ACPI_ADR_SPACE_SYSTEM_IO:
633                 dprintk("SYSTEM IO addr space\n");
634                 data->cpu_feature = SYSTEM_IO_CAPABLE;
635                 break;
636         case ACPI_ADR_SPACE_FIXED_HARDWARE:
637                 dprintk("HARDWARE addr space\n");
638                 if (!check_est_cpu(cpu)) {
639                         result = -ENODEV;
640                         goto err_unreg;
641                 }
642                 data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
643                 break;
644         default:
645                 dprintk("Unknown addr space %d\n",
646                         (u32) (perf->control_register.space_id));
647                 result = -ENODEV;
648                 goto err_unreg;
649         }
650
651         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
652                     (perf->state_count+1), GFP_KERNEL);
653         if (!data->freq_table) {
654                 result = -ENOMEM;
655                 goto err_unreg;
656         }
657
658         /* detect transition latency */
659         policy->cpuinfo.transition_latency = 0;
660         for (i=0; i<perf->state_count; i++) {
661                 if ((perf->states[i].transition_latency * 1000) >
662                     policy->cpuinfo.transition_latency)
663                         policy->cpuinfo.transition_latency =
664                             perf->states[i].transition_latency * 1000;
665         }
666         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
667
668         data->max_freq = perf->states[0].core_frequency * 1000;
669         /* table init */
670         for (i=0; i<perf->state_count; i++) {
671                 if (i>0 && perf->states[i].core_frequency ==
672                     perf->states[i-1].core_frequency)
673                         continue;
674
675                 data->freq_table[valid_states].index = i;
676                 data->freq_table[valid_states].frequency =
677                     perf->states[i].core_frequency * 1000;
678                 valid_states++;
679         }
680         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
681         perf->state = 0;
682
683         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
684         if (result)
685                 goto err_freqfree;
686
687         switch (perf->control_register.space_id) {
688         case ACPI_ADR_SPACE_SYSTEM_IO:
689                 /* Current speed is unknown and not detectable by IO port */
690                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
691                 break;
692         case ACPI_ADR_SPACE_FIXED_HARDWARE:
693                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
694                 policy->cur = get_cur_freq_on_cpu(cpu);
695                 break;
696         default:
697                 break;
698         }
699
700         /* notify BIOS that we exist */
701         acpi_processor_notify_smm(THIS_MODULE);
702
703         /* Check for APERF/MPERF support in hardware */
704         if (c->x86_vendor == X86_VENDOR_INTEL && c->cpuid_level >= 6) {
705                 unsigned int ecx;
706                 ecx = cpuid_ecx(6);
707                 if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY)
708                         acpi_cpufreq_driver.getavg = get_measured_perf;
709         }
710
711         dprintk("CPU%u - ACPI performance management activated.\n", cpu);
712         for (i = 0; i < perf->state_count; i++)
713                 dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
714                         (i == perf->state ? '*' : ' '), i,
715                         (u32) perf->states[i].core_frequency,
716                         (u32) perf->states[i].power,
717                         (u32) perf->states[i].transition_latency);
718
719         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
720
721         /*
722          * the first call to ->target() should result in us actually
723          * writing something to the appropriate registers.
724          */
725         data->resume = 1;
726
727         return result;
728
729 err_freqfree:
730         kfree(data->freq_table);
731 err_unreg:
732         acpi_processor_unregister_performance(perf, cpu);
733 err_free:
734         kfree(data);
735         drv_data[cpu] = NULL;
736
737         return result;
738 }
739
740 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
741 {
742         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
743
744         dprintk("acpi_cpufreq_cpu_exit\n");
745
746         if (data) {
747                 cpufreq_frequency_table_put_attr(policy->cpu);
748                 drv_data[policy->cpu] = NULL;
749                 acpi_processor_unregister_performance(data->acpi_data,
750                                                       policy->cpu);
751                 kfree(data);
752         }
753
754         return 0;
755 }
756
757 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
758 {
759         struct acpi_cpufreq_data *data = drv_data[policy->cpu];
760
761         dprintk("acpi_cpufreq_resume\n");
762
763         data->resume = 1;
764
765         return 0;
766 }
767
768 static struct freq_attr *acpi_cpufreq_attr[] = {
769         &cpufreq_freq_attr_scaling_available_freqs,
770         NULL,
771 };
772
773 static struct cpufreq_driver acpi_cpufreq_driver = {
774         .verify = acpi_cpufreq_verify,
775         .target = acpi_cpufreq_target,
776         .init = acpi_cpufreq_cpu_init,
777         .exit = acpi_cpufreq_cpu_exit,
778         .resume = acpi_cpufreq_resume,
779         .name = "acpi-cpufreq",
780         .owner = THIS_MODULE,
781         .attr = acpi_cpufreq_attr,
782 };
783
784 static int __init acpi_cpufreq_init(void)
785 {
786         dprintk("acpi_cpufreq_init\n");
787
788         acpi_cpufreq_early_init();
789
790         return cpufreq_register_driver(&acpi_cpufreq_driver);
791 }
792
793 static void __exit acpi_cpufreq_exit(void)
794 {
795         unsigned int i;
796         dprintk("acpi_cpufreq_exit\n");
797
798         cpufreq_unregister_driver(&acpi_cpufreq_driver);
799
800         for_each_possible_cpu(i) {
801                 kfree(acpi_perf_data[i]);
802                 acpi_perf_data[i] = NULL;
803         }
804         return;
805 }
806
807 module_param(acpi_pstate_strict, uint, 0644);
808 MODULE_PARM_DESC(acpi_pstate_strict,
809         "value 0 or non-zero. non-zero -> strict ACPI checks are "
810         "performed during frequency changes.");
811
812 late_initcall(acpi_cpufreq_init);
813 module_exit(acpi_cpufreq_exit);
814
815 MODULE_ALIAS("acpi");