• Home
  • History
  • Annotate
  • Line#
  • Navigate
  • Raw
  • Download
  • only in /netgear-WNDR4500-V1.0.1.40_1.0.68/src/linux/linux-2.6/arch/i386/kernel/cpu/cpufreq/
1/*
2 * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.1.1.1 $)
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
49MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
50MODULE_DESCRIPTION("ACPI Processor P-States Driver");
51MODULE_LICENSE("GPL");
52
53enum {
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
62struct 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
70static struct acpi_cpufreq_data *drv_data[NR_CPUS];
71static struct acpi_processor_performance *acpi_perf_data[NR_CPUS];
72
73static struct cpufreq_driver acpi_cpufreq_driver;
74
75static unsigned int acpi_pstate_strict;
76
77static 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
88static 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
102static 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
117static 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
129struct msr_addr {
130	u32 reg;
131};
132
133struct io_addr {
134	u16 port;
135	u8 bit_width;
136};
137
138typedef union {
139	struct msr_addr msr;
140	struct io_addr io;
141} drv_addr_union;
142
143struct drv_cmd {
144	unsigned int type;
145	cpumask_t mask;
146	drv_addr_union addr;
147	u32 val;
148};
149
150static 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
168static 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
186static 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
196static 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
210static 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 */
255static 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
334static 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
352static 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
367static 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
469static 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
478static unsigned long
479acpi_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 */
514static 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 */
548static int bios_with_sw_any_bug;
549
550static int sw_any_bug_found(struct dmi_system_id *d)
551{
552	bios_with_sw_any_bug = 1;
553	return 0;
554}
555
556static 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
570static 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
729err_freqfree:
730	kfree(data->freq_table);
731err_unreg:
732	acpi_processor_unregister_performance(perf, cpu);
733err_free:
734	kfree(data);
735	drv_data[cpu] = NULL;
736
737	return result;
738}
739
740static 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
757static 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
768static struct freq_attr *acpi_cpufreq_attr[] = {
769	&cpufreq_freq_attr_scaling_available_freqs,
770	NULL,
771};
772
773static 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
784static 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
793static 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
807module_param(acpi_pstate_strict, uint, 0644);
808MODULE_PARM_DESC(acpi_pstate_strict,
809	"value 0 or non-zero. non-zero -> strict ACPI checks are "
810	"performed during frequency changes.");
811
812late_initcall(acpi_cpufreq_init);
813module_exit(acpi_cpufreq_exit);
814
815MODULE_ALIAS("acpi");
816