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 <linux/slab.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 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
50 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
51 MODULE_LICENSE("GPL");
52 
53 #define PFX "acpi-cpufreq: "
54 
55 enum {
56 	UNDEFINED_CAPABLE = 0,
57 	SYSTEM_INTEL_MSR_CAPABLE,
58 	SYSTEM_AMD_MSR_CAPABLE,
59 	SYSTEM_IO_CAPABLE,
60 };
61 
62 #define INTEL_MSR_RANGE		(0xffff)
63 #define AMD_MSR_RANGE		(0x7)
64 
65 #define MSR_K7_HWCR_CPB_DIS	(1ULL << 25)
66 
67 struct acpi_cpufreq_data {
68 	struct acpi_processor_performance *acpi_data;
69 	struct cpufreq_frequency_table *freq_table;
70 	unsigned int resume;
71 	unsigned int cpu_feature;
72 	cpumask_var_t freqdomain_cpus;
73 };
74 
75 static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);
76 
77 /* acpi_perf_data is a pointer to percpu data. */
78 static struct acpi_processor_performance __percpu *acpi_perf_data;
79 
80 static struct cpufreq_driver acpi_cpufreq_driver;
81 
82 static unsigned int acpi_pstate_strict;
83 static bool boost_enabled, boost_supported;
84 static struct msr __percpu *msrs;
85 
86 static bool boost_state(unsigned int cpu)
87 {
88 	u32 lo, hi;
89 	u64 msr;
90 
91 	switch (boot_cpu_data.x86_vendor) {
92 	case X86_VENDOR_INTEL:
93 		rdmsr_on_cpu(cpu, MSR_IA32_MISC_ENABLE, &lo, &hi);
94 		msr = lo | ((u64)hi << 32);
95 		return !(msr & MSR_IA32_MISC_ENABLE_TURBO_DISABLE);
96 	case X86_VENDOR_AMD:
97 		rdmsr_on_cpu(cpu, MSR_K7_HWCR, &lo, &hi);
98 		msr = lo | ((u64)hi << 32);
99 		return !(msr & MSR_K7_HWCR_CPB_DIS);
100 	}
101 	return false;
102 }
103 
104 static void boost_set_msrs(bool enable, const struct cpumask *cpumask)
105 {
106 	u32 cpu;
107 	u32 msr_addr;
108 	u64 msr_mask;
109 
110 	switch (boot_cpu_data.x86_vendor) {
111 	case X86_VENDOR_INTEL:
112 		msr_addr = MSR_IA32_MISC_ENABLE;
113 		msr_mask = MSR_IA32_MISC_ENABLE_TURBO_DISABLE;
114 		break;
115 	case X86_VENDOR_AMD:
116 		msr_addr = MSR_K7_HWCR;
117 		msr_mask = MSR_K7_HWCR_CPB_DIS;
118 		break;
119 	default:
120 		return;
121 	}
122 
123 	rdmsr_on_cpus(cpumask, msr_addr, msrs);
124 
125 	for_each_cpu(cpu, cpumask) {
126 		struct msr *reg = per_cpu_ptr(msrs, cpu);
127 		if (enable)
128 			reg->q &= ~msr_mask;
129 		else
130 			reg->q |= msr_mask;
131 	}
132 
133 	wrmsr_on_cpus(cpumask, msr_addr, msrs);
134 }
135 
136 static ssize_t _store_boost(const char *buf, size_t count)
137 {
138 	int ret;
139 	unsigned long val = 0;
140 
141 	if (!boost_supported)
142 		return -EINVAL;
143 
144 	ret = kstrtoul(buf, 10, &val);
145 	if (ret || (val > 1))
146 		return -EINVAL;
147 
148 	if ((val && boost_enabled) || (!val && !boost_enabled))
149 		return count;
150 
151 	get_online_cpus();
152 
153 	boost_set_msrs(val, cpu_online_mask);
154 
155 	put_online_cpus();
156 
157 	boost_enabled = val;
158 	pr_debug("Core Boosting %sabled.\n", val ? "en" : "dis");
159 
160 	return count;
161 }
162 
163 static ssize_t store_global_boost(struct kobject *kobj, struct attribute *attr,
164 				  const char *buf, size_t count)
165 {
166 	return _store_boost(buf, count);
167 }
168 
169 static ssize_t show_global_boost(struct kobject *kobj,
170 				 struct attribute *attr, char *buf)
171 {
172 	return sprintf(buf, "%u\n", boost_enabled);
173 }
174 
175 static struct global_attr global_boost = __ATTR(boost, 0644,
176 						show_global_boost,
177 						store_global_boost);
178 
179 static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
180 {
181 	struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
182 
183 	return cpufreq_show_cpus(data->freqdomain_cpus, buf);
184 }
185 
186 cpufreq_freq_attr_ro(freqdomain_cpus);
187 
188 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
189 static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
190 			 size_t count)
191 {
192 	return _store_boost(buf, count);
193 }
194 
195 static ssize_t show_cpb(struct cpufreq_policy *policy, char *buf)
196 {
197 	return sprintf(buf, "%u\n", boost_enabled);
198 }
199 
200 cpufreq_freq_attr_rw(cpb);
201 #endif
202 
203 static int check_est_cpu(unsigned int cpuid)
204 {
205 	struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
206 
207 	return cpu_has(cpu, X86_FEATURE_EST);
208 }
209 
210 static int check_amd_hwpstate_cpu(unsigned int cpuid)
211 {
212 	struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
213 
214 	return cpu_has(cpu, X86_FEATURE_HW_PSTATE);
215 }
216 
217 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
218 {
219 	struct acpi_processor_performance *perf;
220 	int i;
221 
222 	perf = data->acpi_data;
223 
224 	for (i = 0; i < perf->state_count; i++) {
225 		if (value == perf->states[i].status)
226 			return data->freq_table[i].frequency;
227 	}
228 	return 0;
229 }
230 
231 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
232 {
233 	int i;
234 	struct acpi_processor_performance *perf;
235 
236 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
237 		msr &= AMD_MSR_RANGE;
238 	else
239 		msr &= INTEL_MSR_RANGE;
240 
241 	perf = data->acpi_data;
242 
243 	for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
244 		if (msr == perf->states[data->freq_table[i].driver_data].status)
245 			return data->freq_table[i].frequency;
246 	}
247 	return data->freq_table[0].frequency;
248 }
249 
250 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
251 {
252 	switch (data->cpu_feature) {
253 	case SYSTEM_INTEL_MSR_CAPABLE:
254 	case SYSTEM_AMD_MSR_CAPABLE:
255 		return extract_msr(val, data);
256 	case SYSTEM_IO_CAPABLE:
257 		return extract_io(val, data);
258 	default:
259 		return 0;
260 	}
261 }
262 
263 struct msr_addr {
264 	u32 reg;
265 };
266 
267 struct io_addr {
268 	u16 port;
269 	u8 bit_width;
270 };
271 
272 struct drv_cmd {
273 	unsigned int type;
274 	const struct cpumask *mask;
275 	union {
276 		struct msr_addr msr;
277 		struct io_addr io;
278 	} addr;
279 	u32 val;
280 };
281 
282 /* Called via smp_call_function_single(), on the target CPU */
283 static void do_drv_read(void *_cmd)
284 {
285 	struct drv_cmd *cmd = _cmd;
286 	u32 h;
287 
288 	switch (cmd->type) {
289 	case SYSTEM_INTEL_MSR_CAPABLE:
290 	case SYSTEM_AMD_MSR_CAPABLE:
291 		rdmsr(cmd->addr.msr.reg, cmd->val, h);
292 		break;
293 	case SYSTEM_IO_CAPABLE:
294 		acpi_os_read_port((acpi_io_address)cmd->addr.io.port,
295 				&cmd->val,
296 				(u32)cmd->addr.io.bit_width);
297 		break;
298 	default:
299 		break;
300 	}
301 }
302 
303 /* Called via smp_call_function_many(), on the target CPUs */
304 static void do_drv_write(void *_cmd)
305 {
306 	struct drv_cmd *cmd = _cmd;
307 	u32 lo, hi;
308 
309 	switch (cmd->type) {
310 	case SYSTEM_INTEL_MSR_CAPABLE:
311 		rdmsr(cmd->addr.msr.reg, lo, hi);
312 		lo = (lo & ~INTEL_MSR_RANGE) | (cmd->val & INTEL_MSR_RANGE);
313 		wrmsr(cmd->addr.msr.reg, lo, hi);
314 		break;
315 	case SYSTEM_AMD_MSR_CAPABLE:
316 		wrmsr(cmd->addr.msr.reg, cmd->val, 0);
317 		break;
318 	case SYSTEM_IO_CAPABLE:
319 		acpi_os_write_port((acpi_io_address)cmd->addr.io.port,
320 				cmd->val,
321 				(u32)cmd->addr.io.bit_width);
322 		break;
323 	default:
324 		break;
325 	}
326 }
327 
328 static void drv_read(struct drv_cmd *cmd)
329 {
330 	int err;
331 	cmd->val = 0;
332 
333 	err = smp_call_function_any(cmd->mask, do_drv_read, cmd, 1);
334 	WARN_ON_ONCE(err);	/* smp_call_function_any() was buggy? */
335 }
336 
337 static void drv_write(struct drv_cmd *cmd)
338 {
339 	int this_cpu;
340 
341 	this_cpu = get_cpu();
342 	if (cpumask_test_cpu(this_cpu, cmd->mask))
343 		do_drv_write(cmd);
344 	smp_call_function_many(cmd->mask, do_drv_write, cmd, 1);
345 	put_cpu();
346 }
347 
348 static u32 get_cur_val(const struct cpumask *mask)
349 {
350 	struct acpi_processor_performance *perf;
351 	struct drv_cmd cmd;
352 
353 	if (unlikely(cpumask_empty(mask)))
354 		return 0;
355 
356 	switch (per_cpu(acfreq_data, cpumask_first(mask))->cpu_feature) {
357 	case SYSTEM_INTEL_MSR_CAPABLE:
358 		cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
359 		cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
360 		break;
361 	case SYSTEM_AMD_MSR_CAPABLE:
362 		cmd.type = SYSTEM_AMD_MSR_CAPABLE;
363 		cmd.addr.msr.reg = MSR_AMD_PERF_CTL;
364 		break;
365 	case SYSTEM_IO_CAPABLE:
366 		cmd.type = SYSTEM_IO_CAPABLE;
367 		perf = per_cpu(acfreq_data, cpumask_first(mask))->acpi_data;
368 		cmd.addr.io.port = perf->control_register.address;
369 		cmd.addr.io.bit_width = perf->control_register.bit_width;
370 		break;
371 	default:
372 		return 0;
373 	}
374 
375 	cmd.mask = mask;
376 	drv_read(&cmd);
377 
378 	pr_debug("get_cur_val = %u\n", cmd.val);
379 
380 	return cmd.val;
381 }
382 
383 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
384 {
385 	struct acpi_cpufreq_data *data = per_cpu(acfreq_data, cpu);
386 	unsigned int freq;
387 	unsigned int cached_freq;
388 
389 	pr_debug("get_cur_freq_on_cpu (%d)\n", cpu);
390 
391 	if (unlikely(data == NULL ||
392 		     data->acpi_data == NULL || data->freq_table == NULL)) {
393 		return 0;
394 	}
395 
396 	cached_freq = data->freq_table[data->acpi_data->state].frequency;
397 	freq = extract_freq(get_cur_val(cpumask_of(cpu)), data);
398 	if (freq != cached_freq) {
399 		/*
400 		 * The dreaded BIOS frequency change behind our back.
401 		 * Force set the frequency on next target call.
402 		 */
403 		data->resume = 1;
404 	}
405 
406 	pr_debug("cur freq = %u\n", freq);
407 
408 	return freq;
409 }
410 
411 static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
412 				struct acpi_cpufreq_data *data)
413 {
414 	unsigned int cur_freq;
415 	unsigned int i;
416 
417 	for (i = 0; i < 100; i++) {
418 		cur_freq = extract_freq(get_cur_val(mask), data);
419 		if (cur_freq == freq)
420 			return 1;
421 		udelay(10);
422 	}
423 	return 0;
424 }
425 
426 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
427 			       unsigned int index)
428 {
429 	struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
430 	struct acpi_processor_performance *perf;
431 	struct drv_cmd cmd;
432 	unsigned int next_perf_state = 0; /* Index into perf table */
433 	int result = 0;
434 
435 	if (unlikely(data == NULL ||
436 	     data->acpi_data == NULL || data->freq_table == NULL)) {
437 		return -ENODEV;
438 	}
439 
440 	perf = data->acpi_data;
441 	next_perf_state = data->freq_table[index].driver_data;
442 	if (perf->state == next_perf_state) {
443 		if (unlikely(data->resume)) {
444 			pr_debug("Called after resume, resetting to P%d\n",
445 				next_perf_state);
446 			data->resume = 0;
447 		} else {
448 			pr_debug("Already at target state (P%d)\n",
449 				next_perf_state);
450 			goto out;
451 		}
452 	}
453 
454 	switch (data->cpu_feature) {
455 	case SYSTEM_INTEL_MSR_CAPABLE:
456 		cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
457 		cmd.addr.msr.reg = MSR_IA32_PERF_CTL;
458 		cmd.val = (u32) perf->states[next_perf_state].control;
459 		break;
460 	case SYSTEM_AMD_MSR_CAPABLE:
461 		cmd.type = SYSTEM_AMD_MSR_CAPABLE;
462 		cmd.addr.msr.reg = MSR_AMD_PERF_CTL;
463 		cmd.val = (u32) perf->states[next_perf_state].control;
464 		break;
465 	case SYSTEM_IO_CAPABLE:
466 		cmd.type = SYSTEM_IO_CAPABLE;
467 		cmd.addr.io.port = perf->control_register.address;
468 		cmd.addr.io.bit_width = perf->control_register.bit_width;
469 		cmd.val = (u32) perf->states[next_perf_state].control;
470 		break;
471 	default:
472 		result = -ENODEV;
473 		goto out;
474 	}
475 
476 	/* cpufreq holds the hotplug lock, so we are safe from here on */
477 	if (policy->shared_type != CPUFREQ_SHARED_TYPE_ANY)
478 		cmd.mask = policy->cpus;
479 	else
480 		cmd.mask = cpumask_of(policy->cpu);
481 
482 	drv_write(&cmd);
483 
484 	if (acpi_pstate_strict) {
485 		if (!check_freqs(cmd.mask, data->freq_table[index].frequency,
486 					data)) {
487 			pr_debug("acpi_cpufreq_target failed (%d)\n",
488 				policy->cpu);
489 			result = -EAGAIN;
490 		}
491 	}
492 
493 	if (!result)
494 		perf->state = next_perf_state;
495 
496 out:
497 	return result;
498 }
499 
500 static unsigned long
501 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
502 {
503 	struct acpi_processor_performance *perf = data->acpi_data;
504 
505 	if (cpu_khz) {
506 		/* search the closest match to cpu_khz */
507 		unsigned int i;
508 		unsigned long freq;
509 		unsigned long freqn = perf->states[0].core_frequency * 1000;
510 
511 		for (i = 0; i < (perf->state_count-1); i++) {
512 			freq = freqn;
513 			freqn = perf->states[i+1].core_frequency * 1000;
514 			if ((2 * cpu_khz) > (freqn + freq)) {
515 				perf->state = i;
516 				return freq;
517 			}
518 		}
519 		perf->state = perf->state_count-1;
520 		return freqn;
521 	} else {
522 		/* assume CPU is at P0... */
523 		perf->state = 0;
524 		return perf->states[0].core_frequency * 1000;
525 	}
526 }
527 
528 static void free_acpi_perf_data(void)
529 {
530 	unsigned int i;
531 
532 	/* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
533 	for_each_possible_cpu(i)
534 		free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
535 				 ->shared_cpu_map);
536 	free_percpu(acpi_perf_data);
537 }
538 
539 static int boost_notify(struct notifier_block *nb, unsigned long action,
540 		      void *hcpu)
541 {
542 	unsigned cpu = (long)hcpu;
543 	const struct cpumask *cpumask;
544 
545 	cpumask = get_cpu_mask(cpu);
546 
547 	/*
548 	 * Clear the boost-disable bit on the CPU_DOWN path so that
549 	 * this cpu cannot block the remaining ones from boosting. On
550 	 * the CPU_UP path we simply keep the boost-disable flag in
551 	 * sync with the current global state.
552 	 */
553 
554 	switch (action) {
555 	case CPU_UP_PREPARE:
556 	case CPU_UP_PREPARE_FROZEN:
557 		boost_set_msrs(boost_enabled, cpumask);
558 		break;
559 
560 	case CPU_DOWN_PREPARE:
561 	case CPU_DOWN_PREPARE_FROZEN:
562 		boost_set_msrs(1, cpumask);
563 		break;
564 
565 	default:
566 		break;
567 	}
568 
569 	return NOTIFY_OK;
570 }
571 
572 
573 static struct notifier_block boost_nb = {
574 	.notifier_call          = boost_notify,
575 };
576 
577 /*
578  * acpi_cpufreq_early_init - initialize ACPI P-States library
579  *
580  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
581  * in order to determine correct frequency and voltage pairings. We can
582  * do _PDC and _PSD and find out the processor dependency for the
583  * actual init that will happen later...
584  */
585 static int __init acpi_cpufreq_early_init(void)
586 {
587 	unsigned int i;
588 	pr_debug("acpi_cpufreq_early_init\n");
589 
590 	acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
591 	if (!acpi_perf_data) {
592 		pr_debug("Memory allocation error for acpi_perf_data.\n");
593 		return -ENOMEM;
594 	}
595 	for_each_possible_cpu(i) {
596 		if (!zalloc_cpumask_var_node(
597 			&per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
598 			GFP_KERNEL, cpu_to_node(i))) {
599 
600 			/* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
601 			free_acpi_perf_data();
602 			return -ENOMEM;
603 		}
604 	}
605 
606 	/* Do initialization in ACPI core */
607 	acpi_processor_preregister_performance(acpi_perf_data);
608 	return 0;
609 }
610 
611 #ifdef CONFIG_SMP
612 /*
613  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
614  * or do it in BIOS firmware and won't inform about it to OS. If not
615  * detected, this has a side effect of making CPU run at a different speed
616  * than OS intended it to run at. Detect it and handle it cleanly.
617  */
618 static int bios_with_sw_any_bug;
619 
620 static int sw_any_bug_found(const struct dmi_system_id *d)
621 {
622 	bios_with_sw_any_bug = 1;
623 	return 0;
624 }
625 
626 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
627 	{
628 		.callback = sw_any_bug_found,
629 		.ident = "Supermicro Server X6DLP",
630 		.matches = {
631 			DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
632 			DMI_MATCH(DMI_BIOS_VERSION, "080010"),
633 			DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
634 		},
635 	},
636 	{ }
637 };
638 
639 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
640 {
641 	/* Intel Xeon Processor 7100 Series Specification Update
642 	 * http://www.intel.com/Assets/PDF/specupdate/314554.pdf
643 	 * AL30: A Machine Check Exception (MCE) Occurring during an
644 	 * Enhanced Intel SpeedStep Technology Ratio Change May Cause
645 	 * Both Processor Cores to Lock Up. */
646 	if (c->x86_vendor == X86_VENDOR_INTEL) {
647 		if ((c->x86 == 15) &&
648 		    (c->x86_model == 6) &&
649 		    (c->x86_mask == 8)) {
650 			printk(KERN_INFO "acpi-cpufreq: Intel(R) "
651 			    "Xeon(R) 7100 Errata AL30, processors may "
652 			    "lock up on frequency changes: disabling "
653 			    "acpi-cpufreq.\n");
654 			return -ENODEV;
655 		    }
656 		}
657 	return 0;
658 }
659 #endif
660 
661 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
662 {
663 	unsigned int i;
664 	unsigned int valid_states = 0;
665 	unsigned int cpu = policy->cpu;
666 	struct acpi_cpufreq_data *data;
667 	unsigned int result = 0;
668 	struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
669 	struct acpi_processor_performance *perf;
670 #ifdef CONFIG_SMP
671 	static int blacklisted;
672 #endif
673 
674 	pr_debug("acpi_cpufreq_cpu_init\n");
675 
676 #ifdef CONFIG_SMP
677 	if (blacklisted)
678 		return blacklisted;
679 	blacklisted = acpi_cpufreq_blacklist(c);
680 	if (blacklisted)
681 		return blacklisted;
682 #endif
683 
684 	data = kzalloc(sizeof(*data), GFP_KERNEL);
685 	if (!data)
686 		return -ENOMEM;
687 
688 	if (!zalloc_cpumask_var(&data->freqdomain_cpus, GFP_KERNEL)) {
689 		result = -ENOMEM;
690 		goto err_free;
691 	}
692 
693 	data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
694 	per_cpu(acfreq_data, cpu) = data;
695 
696 	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
697 		acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
698 
699 	result = acpi_processor_register_performance(data->acpi_data, cpu);
700 	if (result)
701 		goto err_free_mask;
702 
703 	perf = data->acpi_data;
704 	policy->shared_type = perf->shared_type;
705 
706 	/*
707 	 * Will let policy->cpus know about dependency only when software
708 	 * coordination is required.
709 	 */
710 	if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
711 	    policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
712 		cpumask_copy(policy->cpus, perf->shared_cpu_map);
713 	}
714 	cpumask_copy(data->freqdomain_cpus, perf->shared_cpu_map);
715 
716 #ifdef CONFIG_SMP
717 	dmi_check_system(sw_any_bug_dmi_table);
718 	if (bios_with_sw_any_bug && !policy_is_shared(policy)) {
719 		policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
720 		cpumask_copy(policy->cpus, cpu_core_mask(cpu));
721 	}
722 
723 	if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
724 		cpumask_clear(policy->cpus);
725 		cpumask_set_cpu(cpu, policy->cpus);
726 		cpumask_copy(data->freqdomain_cpus, cpu_sibling_mask(cpu));
727 		policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
728 		pr_info_once(PFX "overriding BIOS provided _PSD data\n");
729 	}
730 #endif
731 
732 	/* capability check */
733 	if (perf->state_count <= 1) {
734 		pr_debug("No P-States\n");
735 		result = -ENODEV;
736 		goto err_unreg;
737 	}
738 
739 	if (perf->control_register.space_id != perf->status_register.space_id) {
740 		result = -ENODEV;
741 		goto err_unreg;
742 	}
743 
744 	switch (perf->control_register.space_id) {
745 	case ACPI_ADR_SPACE_SYSTEM_IO:
746 		if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
747 		    boot_cpu_data.x86 == 0xf) {
748 			pr_debug("AMD K8 systems must use native drivers.\n");
749 			result = -ENODEV;
750 			goto err_unreg;
751 		}
752 		pr_debug("SYSTEM IO addr space\n");
753 		data->cpu_feature = SYSTEM_IO_CAPABLE;
754 		break;
755 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
756 		pr_debug("HARDWARE addr space\n");
757 		if (check_est_cpu(cpu)) {
758 			data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
759 			break;
760 		}
761 		if (check_amd_hwpstate_cpu(cpu)) {
762 			data->cpu_feature = SYSTEM_AMD_MSR_CAPABLE;
763 			break;
764 		}
765 		result = -ENODEV;
766 		goto err_unreg;
767 	default:
768 		pr_debug("Unknown addr space %d\n",
769 			(u32) (perf->control_register.space_id));
770 		result = -ENODEV;
771 		goto err_unreg;
772 	}
773 
774 	data->freq_table = kmalloc(sizeof(*data->freq_table) *
775 		    (perf->state_count+1), GFP_KERNEL);
776 	if (!data->freq_table) {
777 		result = -ENOMEM;
778 		goto err_unreg;
779 	}
780 
781 	/* detect transition latency */
782 	policy->cpuinfo.transition_latency = 0;
783 	for (i = 0; i < perf->state_count; i++) {
784 		if ((perf->states[i].transition_latency * 1000) >
785 		    policy->cpuinfo.transition_latency)
786 			policy->cpuinfo.transition_latency =
787 			    perf->states[i].transition_latency * 1000;
788 	}
789 
790 	/* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
791 	if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
792 	    policy->cpuinfo.transition_latency > 20 * 1000) {
793 		policy->cpuinfo.transition_latency = 20 * 1000;
794 		printk_once(KERN_INFO
795 			    "P-state transition latency capped at 20 uS\n");
796 	}
797 
798 	/* table init */
799 	for (i = 0; i < perf->state_count; i++) {
800 		if (i > 0 && perf->states[i].core_frequency >=
801 		    data->freq_table[valid_states-1].frequency / 1000)
802 			continue;
803 
804 		data->freq_table[valid_states].driver_data = i;
805 		data->freq_table[valid_states].frequency =
806 		    perf->states[i].core_frequency * 1000;
807 		valid_states++;
808 	}
809 	data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
810 	perf->state = 0;
811 
812 	result = cpufreq_table_validate_and_show(policy, data->freq_table);
813 	if (result)
814 		goto err_freqfree;
815 
816 	if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
817 		printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
818 
819 	switch (perf->control_register.space_id) {
820 	case ACPI_ADR_SPACE_SYSTEM_IO:
821 		/*
822 		 * The core will not set policy->cur, because
823 		 * cpufreq_driver->get is NULL, so we need to set it here.
824 		 * However, we have to guess it, because the current speed is
825 		 * unknown and not detectable via IO ports.
826 		 */
827 		policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
828 		break;
829 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
830 		acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
831 		break;
832 	default:
833 		break;
834 	}
835 
836 	/* notify BIOS that we exist */
837 	acpi_processor_notify_smm(THIS_MODULE);
838 
839 	pr_debug("CPU%u - ACPI performance management activated.\n", cpu);
840 	for (i = 0; i < perf->state_count; i++)
841 		pr_debug("     %cP%d: %d MHz, %d mW, %d uS\n",
842 			(i == perf->state ? '*' : ' '), i,
843 			(u32) perf->states[i].core_frequency,
844 			(u32) perf->states[i].power,
845 			(u32) perf->states[i].transition_latency);
846 
847 	/*
848 	 * the first call to ->target() should result in us actually
849 	 * writing something to the appropriate registers.
850 	 */
851 	data->resume = 1;
852 
853 	return result;
854 
855 err_freqfree:
856 	kfree(data->freq_table);
857 err_unreg:
858 	acpi_processor_unregister_performance(perf, cpu);
859 err_free_mask:
860 	free_cpumask_var(data->freqdomain_cpus);
861 err_free:
862 	kfree(data);
863 	per_cpu(acfreq_data, cpu) = NULL;
864 
865 	return result;
866 }
867 
868 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
869 {
870 	struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
871 
872 	pr_debug("acpi_cpufreq_cpu_exit\n");
873 
874 	if (data) {
875 		cpufreq_frequency_table_put_attr(policy->cpu);
876 		per_cpu(acfreq_data, policy->cpu) = NULL;
877 		acpi_processor_unregister_performance(data->acpi_data,
878 						      policy->cpu);
879 		free_cpumask_var(data->freqdomain_cpus);
880 		kfree(data->freq_table);
881 		kfree(data);
882 	}
883 
884 	return 0;
885 }
886 
887 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
888 {
889 	struct acpi_cpufreq_data *data = per_cpu(acfreq_data, policy->cpu);
890 
891 	pr_debug("acpi_cpufreq_resume\n");
892 
893 	data->resume = 1;
894 
895 	return 0;
896 }
897 
898 static struct freq_attr *acpi_cpufreq_attr[] = {
899 	&cpufreq_freq_attr_scaling_available_freqs,
900 	&freqdomain_cpus,
901 	NULL,	/* this is a placeholder for cpb, do not remove */
902 	NULL,
903 };
904 
905 static struct cpufreq_driver acpi_cpufreq_driver = {
906 	.verify		= cpufreq_generic_frequency_table_verify,
907 	.target_index	= acpi_cpufreq_target,
908 	.bios_limit	= acpi_processor_get_bios_limit,
909 	.init		= acpi_cpufreq_cpu_init,
910 	.exit		= acpi_cpufreq_cpu_exit,
911 	.resume		= acpi_cpufreq_resume,
912 	.name		= "acpi-cpufreq",
913 	.attr		= acpi_cpufreq_attr,
914 };
915 
916 static void __init acpi_cpufreq_boost_init(void)
917 {
918 	if (boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA)) {
919 		msrs = msrs_alloc();
920 
921 		if (!msrs)
922 			return;
923 
924 		boost_supported = true;
925 		boost_enabled = boost_state(0);
926 
927 		get_online_cpus();
928 
929 		/* Force all MSRs to the same value */
930 		boost_set_msrs(boost_enabled, cpu_online_mask);
931 
932 		register_cpu_notifier(&boost_nb);
933 
934 		put_online_cpus();
935 	} else
936 		global_boost.attr.mode = 0444;
937 
938 	/* We create the boost file in any case, though for systems without
939 	 * hardware support it will be read-only and hardwired to return 0.
940 	 */
941 	if (cpufreq_sysfs_create_file(&(global_boost.attr)))
942 		pr_warn(PFX "could not register global boost sysfs file\n");
943 	else
944 		pr_debug("registered global boost sysfs file\n");
945 }
946 
947 static void __exit acpi_cpufreq_boost_exit(void)
948 {
949 	cpufreq_sysfs_remove_file(&(global_boost.attr));
950 
951 	if (msrs) {
952 		unregister_cpu_notifier(&boost_nb);
953 
954 		msrs_free(msrs);
955 		msrs = NULL;
956 	}
957 }
958 
959 static int __init acpi_cpufreq_init(void)
960 {
961 	int ret;
962 
963 	if (acpi_disabled)
964 		return -ENODEV;
965 
966 	/* don't keep reloading if cpufreq_driver exists */
967 	if (cpufreq_get_current_driver())
968 		return -EEXIST;
969 
970 	pr_debug("acpi_cpufreq_init\n");
971 
972 	ret = acpi_cpufreq_early_init();
973 	if (ret)
974 		return ret;
975 
976 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
977 	/* this is a sysfs file with a strange name and an even stranger
978 	 * semantic - per CPU instantiation, but system global effect.
979 	 * Lets enable it only on AMD CPUs for compatibility reasons and
980 	 * only if configured. This is considered legacy code, which
981 	 * will probably be removed at some point in the future.
982 	 */
983 	if (check_amd_hwpstate_cpu(0)) {
984 		struct freq_attr **iter;
985 
986 		pr_debug("adding sysfs entry for cpb\n");
987 
988 		for (iter = acpi_cpufreq_attr; *iter != NULL; iter++)
989 			;
990 
991 		/* make sure there is a terminator behind it */
992 		if (iter[1] == NULL)
993 			*iter = &cpb;
994 	}
995 #endif
996 
997 	ret = cpufreq_register_driver(&acpi_cpufreq_driver);
998 	if (ret)
999 		free_acpi_perf_data();
1000 	else
1001 		acpi_cpufreq_boost_init();
1002 
1003 	return ret;
1004 }
1005 
1006 static void __exit acpi_cpufreq_exit(void)
1007 {
1008 	pr_debug("acpi_cpufreq_exit\n");
1009 
1010 	acpi_cpufreq_boost_exit();
1011 
1012 	cpufreq_unregister_driver(&acpi_cpufreq_driver);
1013 
1014 	free_acpi_perf_data();
1015 }
1016 
1017 module_param(acpi_pstate_strict, uint, 0644);
1018 MODULE_PARM_DESC(acpi_pstate_strict,
1019 	"value 0 or non-zero. non-zero -> strict ACPI checks are "
1020 	"performed during frequency changes.");
1021 
1022 late_initcall(acpi_cpufreq_init);
1023 module_exit(acpi_cpufreq_exit);
1024 
1025 static const struct x86_cpu_id acpi_cpufreq_ids[] = {
1026 	X86_FEATURE_MATCH(X86_FEATURE_ACPI),
1027 	X86_FEATURE_MATCH(X86_FEATURE_HW_PSTATE),
1028 	{}
1029 };
1030 MODULE_DEVICE_TABLE(x86cpu, acpi_cpufreq_ids);
1031 
1032 static const struct acpi_device_id processor_device_ids[] = {
1033 	{ACPI_PROCESSOR_OBJECT_HID, },
1034 	{ACPI_PROCESSOR_DEVICE_HID, },
1035 	{},
1036 };
1037 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
1038 
1039 MODULE_ALIAS("acpi");
1040