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