aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
blob: ff2fff56f0a8f2f1340a98a3305da24cd1dd3da1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
/*
 * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.4 $)
 *
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *  Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
 *  Copyright (C) 2006       Denis Sadykov <denis.m.sadykov@intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/sched.h>
#include <linux/cpufreq.h>
#include <linux/compiler.h>
#include <linux/dmi.h>

#include <linux/acpi.h>
#include <acpi/processor.h>

#include <asm/io.h>
#include <asm/msr.h>
#include <asm/processor.h>
#include <asm/cpufeature.h>
#include <asm/delay.h>
#include <asm/uaccess.h>

#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)

MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
MODULE_DESCRIPTION("ACPI Processor P-States Driver");
MODULE_LICENSE("GPL");

enum {
	UNDEFINED_CAPABLE = 0,
	SYSTEM_INTEL_MSR_CAPABLE,
	SYSTEM_IO_CAPABLE,
};

#define INTEL_MSR_RANGE		(0xffff)
#define CPUID_6_ECX_APERFMPERF_CAPABILITY	(0x1)

struct acpi_cpufreq_data {
	struct acpi_processor_performance *acpi_data;
	struct cpufreq_frequency_table *freq_table;
	unsigned int max_freq;
	unsigned int resume;
	unsigned int cpu_feature;
};

static DEFINE_PER_CPU(struct acpi_cpufreq_data *, drv_data);

/* acpi_perf_data is a pointer to percpu data. */
static struct acpi_processor_performance *acpi_perf_data;

static struct cpufreq_driver acpi_cpufreq_driver;

static unsigned int acpi_pstate_strict;

static int check_est_cpu(unsigned int cpuid)
{
	struct cpuinfo_x86 *cpu = &cpu_data(cpuid);

	if (cpu->x86_vendor != X86_VENDOR_INTEL ||
	    !cpu_has(cpu, X86_FEATURE_EST))
		return 0;

	return 1;
}

static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
{
	struct acpi_processor_performance *perf;
	int i;

	perf = data->acpi_data;

	for (i=0; i<perf->state_count; i++) {
		if (value == perf->states[i].status)
			return data->freq_table[i].frequency;
	}
	return 0;
}

static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
{
	int i;
	struct acpi_processor_performance *perf;

	msr &= INTEL_MSR_RANGE;
	perf = data->acpi_data;

	for (i=0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
		if (msr == perf->states[data->freq_table[i].index].status)
			return data->freq_table[i].frequency;
	}
	return data->freq_table[0].frequency;
}

static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
{
	switch (data->cpu_feature) {
	case SYSTEM_INTEL_MSR_CAPABLE:
		return extract_msr(val, data);
	case SYSTEM_IO_CAPABLE:
		return extract_io(val, data);
	default:
		return 0;
	}
}

struct msr_addr {
	u32 reg;
};

struct io_addr {
	u16 port;
	u8 bit_width;
};

typedef union {
	struct msr_addr msr;
	struct io_addr io;
} drv_addr_union;

struct drv_cmd {
	unsigned int type;
	cpumask_t mask;
	drv_addr_union addr;
	u32 val;
};

static void do_drv_read(struct drv_cmd *cmd)
{
	u32 h;

	switch (cmd->type) {
	case SYSTEM_INTEL_MSR_CAPABLE:
		rdmsr(cmd->addr.msr.reg, cmd->val, h);
		break;
	case SYSTEM_IO_CAPABLE:
		acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
				&cmd->val,
				(u32)cmd->addr.io.bit_width);
		break;
	default:
		break;
	}
}

static void do_drv_write(struct drv_cmd *cmd)
{
	u32 lo, hi;

	switch (cmd->type) {
	case SYSTEM_INTEL_MSR_CAPABLE:
		rdmsr(cmd->addr.msr.reg, lo, hi);
		lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
		wrmsr(cmd->addr.msr.reg, lo, hi);
		break;
	case SYSTEM_IO_CAPABLE:
		acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
				cmd->val,
				(u32)cmd->addr.io.bit_width);
		break;
	default:
		break;
	}
}

static void drv_read(struct drv_cmd *cmd)
{
	cpumask_t saved_mask = current->cpus_allowed;
	cmd->val = 0;

	set_cpus_allowed_ptr(current, &cmd->mask);
	do_drv_read(cmd);
	set_cpus_allowed_ptr(current, &saved_mask);
}

static void drv_write(struct drv_cmd *cmd)
{
	cpumask_t saved_mask = current->cpus_allowed;
	cpumask_of_cpu_ptr_declare(cpu_mask);
	unsigned int i;

	for_each_cpu_mask_nr(i, cmd->mask) {
		cpumask_of_cpu_ptr_next(cpu_mask, i);
		set_cpus_allowed_ptr(current, cpu_mask);
		do_drv_write(cmd);
	}

	set_cpus_allowed_ptr(current, &saved_mask);
	return;
}

static u32 get_cur_val(const cpumask_t *mask)
{
	struct acpi_processor_performance *perf;
	struct drv_cmd cmd;

	if (unlikely(cpus_empty(*mask)))
		return 0;

	switch (per_cpu(drv_data, first_cpu(*mask))->cpu_feature) {
	case SYSTEM_INTEL_MSR_CAPABLE:
		cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
		cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
		break;
	case SYSTEM_IO_CAPABLE:
		cmd.type = SYSTEM_IO_CAPABLE;
		perf = per_cpu(drv_data, first_cpu(*mask))->acpi_data;
		cmd.addr.io.port = perf->control_register.address;
		cmd.addr.io.bit_width = perf->control_register.bit_width;
		break;
	default:
		return 0;
	}

	cmd.mask = *mask;

	drv_read(&cmd);

	dprintk("get_cur_val = %u\n", cmd.val);

	return cmd.val;
}

/*
 * Return the measured active (C0) frequency on this CPU since last call
 * to this function.
 * Input: cpu number
 * Return: Average CPU frequency in terms of max frequency (zero on error)
 *
 * We use IA32_MPERF and IA32_APERF MSRs to get the measured performance
 * over a period of time, while CPU is in C0 state.
 * IA32_MPERF counts at the rate of max advertised frequency
 * IA32_APERF counts at the rate of actual CPU frequency
 * Only IA32_APERF/IA32_MPERF ratio is architecturally defined and
 * no meaning should be associated with absolute values of these MSRs.
 */
static unsigned int get_measured_perf(unsigned int cpu)
{
	union {
		struct {
			u32 lo;
			u32 hi;
		} split;
		u64 whole;
	} aperf_cur, mperf_cur;

	cpumask_t saved_mask;
	cpumask_of_cpu_ptr(cpu_mask, cpu);
	unsigned int perf_percent;
	unsigned int retval;

	saved_mask = current->cpus_allowed;
	set_cpus_allowed_ptr(current, cpu_mask);
	if (get_cpu() != cpu) {
		/* We were not able to run on requested processor */
		put_cpu();
		return 0;
	}

	rdmsr(MSR_IA32_APERF, aperf_cur.split.lo, aperf_cur.split.hi);
	rdmsr(MSR_IA32_MPERF, mperf_cur.split.lo, mperf_cur.split.hi);

	wrmsr(MSR_IA32_APERF, 0,0);
	wrmsr(MSR_IA32_MPERF, 0,0);

#ifdef __i386__
	/*
	 * We dont want to do 64 bit divide with 32 bit kernel
	 * Get an approximate value. Return failure in case we cannot get
	 * an approximate value.
	 */
	if (unlikely(aperf_cur.split.hi || mperf_cur.split.hi)) {
		int shift_count;
		u32 h;

		h = max_t(u32, aperf_cur.split.hi, mperf_cur.split.hi);
		shift_count = fls(h);

		aperf_cur.whole >>= shift_count;
		mperf_cur.whole >>= shift_count;
	}

	if (((unsigned long)(-1) / 100) < aperf_cur.split.lo) {
		int shift_count = 7;
		aperf_cur.split.lo >>= shift_count;
		mperf_cur.split.lo >>= shift_count;
	}

	if (aperf_cur.split.lo && mperf_cur.split.lo)
		perf_percent = (aperf_cur.split.lo * 100) / mperf_cur.split.lo;
	else
		perf_percent = 0;

#else
	if (unlikely(((unsigned long)(-1) / 100) < aperf_cur.whole)) {
		int shift_count = 7;
		aperf_cur.whole >>= shift_count;
		mperf_cur.whole >>= shift_count;
	}

	if (aperf_cur.whole && mperf_cur.whole)
		perf_percent = (aperf_cur.whole * 100) / mperf_cur.whole;
	else
		perf_percent = 0;

#endif

	retval = per_cpu(drv_data, cpu)->max_freq * perf_percent / 100;

	put_cpu();
	set_cpus_allowed_ptr(current, &saved_mask);

	dprintk("cpu %d: performance percent %d\n", cpu, perf_percent);
	return retval;
}

static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
{
	cpumask_of_cpu_ptr(cpu_mask, cpu);
	struct acpi_cpufreq_data *data = per_cpu(drv_data, cpu);
	unsigned int freq;
	unsigned int cached_freq;

	dprintk("get_cur_freq_on_cpu (%d)\n", cpu);

	if (unlikely(data == NULL ||
		     data->acpi_data == NULL || data->freq_table == NULL)) {
		return 0;
	}

	cached_freq = data->freq_table[data->acpi_data->state].frequency;
	freq = extract_freq(get_cur_val(cpu_mask), data);
	if (freq != cached_freq) {
		/*
		 * The dreaded BIOS frequency change behind our back.
		 * Force set the frequency on next target call.
		 */
		data->resume = 1;
	}

	dprintk("cur freq = %u\n", freq);

	return freq;
}

static unsigned int check_freqs(const cpumask_t *mask, unsigned int freq,
				struct acpi_cpufreq_data *data)
{
	unsigned int cur_freq;
	unsigned int i;

	for (i=0; i<100; i++) {
		cur_freq = extract_freq(get_cur_val(mask), data);
		if (cur_freq == freq)
			return 1;
		udelay(10);
	}
	return 0;
}

static int acpi_cpufreq_target(struct cpufreq_policy *policy,
			       unsigned int target_freq, unsigned int relation)
{
	struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);
	struct acpi_processor_performance *perf;
	struct cpufreq_freqs freqs;
	cpumask_t online_policy_cpus;
	struct drv_cmd cmd;
	unsigned int next_state = 0; /* Index into freq_table */
	unsigned int next_perf_state = 0; /* Index into perf table */
	unsigned int i;
	int result = 0;

	dprintk("acpi_cpufreq_target %d (%d)\n", target_freq, policy->cpu);

	if (unlikely(data == NULL ||
	     data->acpi_data == NULL || data->freq_table == NULL)) {
		return -ENODEV;
	}

	perf = data->acpi_data;
	result = cpufreq_frequency_table_target(policy,
						data->freq_table,
						target_freq,
						relation, &next_state);
	if (unlikely(result))
		return -ENODEV;

#ifdef CONFIG_HOTPLUG_CPU
	/* cpufreq holds the hotplug lock, so we are safe from here on */
	cpus_and(online_policy_cpus, cpu_online_map, policy->cpus);
#else
	online_policy_cpus = policy->cpus;
#endif

	next_perf_state = data->freq_table[next_state].index;
	if (perf->state == next_perf_state) {
		if (unlikely(data->resume)) {
			dprintk("Called after resume, resetting to P%d\n",
				next_perf_state);
			data->resume = 0;
		} else {
			dprintk("Already at target state (P%d)\n",
				next_perf_state);
			return 0;
		}
	}

	switch (data->cpu_feature) {
	case SYSTEM_INTEL_MSR_CAPABLE:
		cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
		cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
		cmd.val = (u32) perf->states[next_perf_state].control;
		break;
	case SYSTEM_IO_CAPABLE:
		cmd.type = SYSTEM_IO_CAPABLE;
		cmd.addr.io.port = perf->control_register.address;
		cmd.addr.io.bit_width = perf->control_register.bit_width;
		cmd.val = (u32) perf->states[next_perf_state].control;
		break;
	default:
		return -ENODEV;
	}

	cpus_clear(cmd.mask);

	if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
		cmd.mask = online_policy_cpus;
	else
		cpu_set(policy->cpu, cmd.mask);

	freqs.old = perf->states[perf->state].core_frequency * 1000;
	freqs.new = data->freq_table[next_state].frequency;
	for_each_cpu_mask_nr(i, cmd.mask) {
		freqs.cpu = i;
		cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
	}

	drv_write(&cmd);

	if (acpi_pstate_strict) {
		if (!check_freqs(&cmd.mask, freqs.new, data)) {
			dprintk("acpi_cpufreq_target failed (%d)\n",
				policy->cpu);
			return -EAGAIN;
		}
	}

	for_each_cpu_mask_nr(i, cmd.mask) {
		freqs.cpu = i;
		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	}
	perf->state = next_perf_state;

	return result;
}

static int acpi_cpufreq_verify(struct cpufreq_policy *policy)
{
	struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);

	dprintk("acpi_cpufreq_verify\n");

	return cpufreq_frequency_table_verify(policy, data->freq_table);
}

static unsigned long
acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
{
	struct acpi_processor_performance *perf = data->acpi_data;

	if (cpu_khz) {
		/* search the closest match to cpu_khz */
		unsigned int i;
		unsigned long freq;
		unsigned long freqn = perf->states[0].core_frequency * 1000;

		for (i=0; i<(perf->state_count-1); i++) {
			freq = freqn;
			freqn = perf->states[i+1].core_frequency * 1000;
			if ((2 * cpu_khz) > (freqn + freq)) {
				perf->state = i;
				return freq;
			}
		}
		perf->state = perf->state_count-1;
		return freqn;
	} else {
		/* assume CPU is at P0... */
		perf->state = 0;
		return perf->states[0].core_frequency * 1000;
	}
}

/*
 * acpi_cpufreq_early_init - initialize ACPI P-States library
 *
 * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
 * in order to determine correct frequency and voltage pairings. We can
 * do _PDC and _PSD and find out the processor dependency for the
 * actual init that will happen later...
 */
static int __init acpi_cpufreq_early_init(void)
{
	dprintk("acpi_cpufreq_early_init\n");

	acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
	if (!acpi_perf_data) {
		dprintk("Memory allocation error for acpi_perf_data.\n");
		return -ENOMEM;
	}

	/* Do initialization in ACPI core */
	acpi_processor_preregister_performance(acpi_perf_data);
	return 0;
}

#ifdef CONFIG_SMP
/*
 * Some BIOSes do SW_ANY coordination internally, either set it up in hw
 * or do it in BIOS firmware and won't inform about it to OS. If not
 * detected, this has a side effect of making CPU run at a different speed
 * than OS intended it to run at. Detect it and handle it cleanly.
 */
static int bios_with_sw_any_bug;

static int sw_any_bug_found(const struct dmi_system_id *d)
{
	bios_with_sw_any_bug = 1;
	return 0;
}

static const struct dmi_system_id sw_any_bug_dmi_table[] = {
	{
		.callback = sw_any_bug_found,
		.ident = "Supermicro Server X6DLP",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
			DMI_MATCH(DMI_BIOS_VERSION, "080010"),
			DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
		},
	},
	{ }
};
#endif

static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
	unsigned int i;
	unsigned int valid_states = 0;
	unsigned int cpu = policy->cpu;
	struct acpi_cpufreq_data *data;
	unsigned int result = 0;
	struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
	struct acpi_processor_performance *perf;

	dprintk("acpi_cpufreq_cpu_init\n");

	data = kzalloc(sizeof(struct acpi_cpufreq_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->acpi_data = percpu_ptr(acpi_perf_data, cpu);
	per_cpu(drv_data, cpu) = data;

	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
		acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;

	result = acpi_processor_register_performance(data->acpi_data, cpu);
	if (result)
		goto err_free;

	perf = data->acpi_data;
	policy->shared_type = perf->shared_type;

	/*
	 * Will let policy->cpus know about dependency only when software
	 * coordination is required.
	 */
	if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
	    policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
		policy->cpus = perf->shared_cpu_map;
	}
	policy->related_cpus = perf->shared_cpu_map;

#ifdef CONFIG_SMP
	dmi_check_system(sw_any_bug_dmi_table);
	if (bios_with_sw_any_bug && cpus_weight(policy->cpus) == 1) {
		policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
		policy->cpus = per_cpu(cpu_core_map, cpu);
	}
#endif

	/* capability check */
	if (perf->state_count <= 1) {
		dprintk("No P-States\n");
		result = -ENODEV;
		goto err_unreg;
	}

	if (perf->control_register.space_id != perf->status_register.space_id) {
		result = -ENODEV;
		goto err_unreg;
	}

	switch (perf->control_register.space_id) {
	case ACPI_ADR_SPACE_SYSTEM_IO:
		dprintk("SYSTEM IO addr space\n");
		data->cpu_feature = SYSTEM_IO_CAPABLE;
		break;
	case ACPI_ADR_SPACE_FIXED_HARDWARE:
		dprintk("HARDWARE addr space\n");
		if (!check_est_cpu(cpu)) {
			result = -ENODEV;
			goto err_unreg;
		}
		data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
		break;
	default:
		dprintk("Unknown addr space %d\n",
			(u32) (perf->control_register.space_id));
		result = -ENODEV;
		goto err_unreg;
	}

	data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
		    (perf->state_count+1), GFP_KERNEL);
	if (!data->freq_table) {
		result = -ENOMEM;
		goto err_unreg;
	}

	/* detect transition latency */
	policy->cpuinfo.transition_latency = 0;
	for (i=0; i<perf->state_count; i++) {
		if ((perf->states[i].transition_latency * 1000) >
		    policy->cpuinfo.transition_latency)
			policy->cpuinfo.transition_latency =
			    perf->states[i].transition_latency * 1000;
	}

	data->max_freq = perf->states[0].core_frequency * 1000;
	/* table init */
	for (i=0; i<perf->state_count; i++) {
		if (i>0 && perf->states[i].core_frequency >=
		    data->freq_table[valid_states-1].frequency / 1000)
			continue;

		data->freq_table[valid_states].index = i;
		data->freq_table[valid_states].frequency =
		    perf->states[i].core_frequency * 1000;
		valid_states++;
	}
	data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
	perf->state = 0;

	result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
	if (result)
		goto err_freqfree;

	switch (perf->control_register.space_id) {
	case ACPI_ADR_SPACE_SYSTEM_IO:
		/* Current speed is unknown and not detectable by IO port */
		policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
		break;
	case ACPI_ADR_SPACE_FIXED_HARDWARE:
		acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
		policy->cur = get_cur_freq_on_cpu(cpu);
		break;
	default:
		break;
	}

	/* notify BIOS that we exist */
	acpi_processor_notify_smm(THIS_MODULE);

	/* Check for APERF/MPERF support in hardware */
	if (c->x86_vendor == X86_VENDOR_INTEL && c->cpuid_level >= 6) {
		unsigned int ecx;
		ecx = cpuid_ecx(6);
		if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY)
			acpi_cpufreq_driver.getavg = get_measured_perf;
	}

	dprintk("CPU%u - ACPI performance management activated.\n", cpu);
	for (i = 0; i < perf->state_count; i++)
		dprintk("     %cP%d: %d MHz, %d mW, %d uS\n",
			(i == perf->state ? '*' : ' '), i,
			(u32) perf->states[i].core_frequency,
			(u32) perf->states[i].power,
			(u32) perf->states[i].transition_latency);

	cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);

	/*
	 * the first call to ->target() should result in us actually
	 * writing something to the appropriate registers.
	 */
	data->resume = 1;

	return result;

err_freqfree:
	kfree(data->freq_table);
err_unreg:
	acpi_processor_unregister_performance(perf, cpu);
err_free:
	kfree(data);
	per_cpu(drv_data, cpu) = NULL;

	return result;
}

static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
{
	struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);

	dprintk("acpi_cpufreq_cpu_exit\n");

	if (data) {
		cpufreq_frequency_table_put_attr(policy->cpu);
		per_cpu(drv_data, policy->cpu) = NULL;
		acpi_processor_unregister_performance(data->acpi_data,
						      policy->cpu);
		kfree(data);
	}

	return 0;
}

static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
{
	struct acpi_cpufreq_data *data = per_cpu(drv_data, policy->cpu);

	dprintk("acpi_cpufreq_resume\n");

	data->resume = 1;

	return 0;
}

static struct freq_attr *acpi_cpufreq_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	NULL,
};

static struct cpufreq_driver acpi_cpufreq_driver = {
	.verify = acpi_cpufreq_verify,
	.target = acpi_cpufreq_target,
	.init = acpi_cpufreq_cpu_init,
	.exit = acpi_cpufreq_cpu_exit,
	.resume = acpi_cpufreq_resume,
	.name = "acpi-cpufreq",
	.owner = THIS_MODULE,
	.attr = acpi_cpufreq_attr,
};

static int __init acpi_cpufreq_init(void)
{
	int ret;

	dprintk("acpi_cpufreq_init\n");

	ret = acpi_cpufreq_early_init();
	if (ret)
		return ret;

	return cpufreq_register_driver(&acpi_cpufreq_driver);
}

static void __exit acpi_cpufreq_exit(void)
{
	dprintk("acpi_cpufreq_exit\n");

	cpufreq_unregister_driver(&acpi_cpufreq_driver);

	free_percpu(acpi_perf_data);

	return;
}

module_param(acpi_pstate_strict, uint, 0644);
MODULE_PARM_DESC(acpi_pstate_strict,
	"value 0 or non-zero. non-zero -> strict ACPI checks are "
	"performed during frequency changes.");

late_initcall(acpi_cpufreq_init);
module_exit(acpi_cpufreq_exit);

MODULE_ALIAS("acpi");

Privacy Policy