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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29 
30 #include <linux/kernel.h>
31 #include <linux/module.h>
32 #include <linux/init.h>
33 #include <linux/smp.h>
34 #include <linux/sched.h>
35 #include <linux/cpufreq.h>
36 #include <linux/compiler.h>
37 #include <linux/dmi.h>
38 #include <linux/slab.h>
39 
40 #include <linux/acpi.h>
41 #include <linux/io.h>
42 #include <linux/delay.h>
43 #include <linux/uaccess.h>
44 
45 #include <acpi/processor.h>
46 
47 #include <asm/msr.h>
48 #include <asm/processor.h>
49 #include <asm/cpufeature.h>
50 
51 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
52 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
53 MODULE_LICENSE("GPL");
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 	unsigned int resume;
69 	unsigned int cpu_feature;
70 	unsigned int acpi_perf_cpu;
71 	cpumask_var_t freqdomain_cpus;
72 	void (*cpu_freq_write)(struct acpi_pct_register *reg, u32 val);
73 	u32 (*cpu_freq_read)(struct acpi_pct_register *reg);
74 };
75 
76 /* acpi_perf_data is a pointer to percpu data. */
77 static struct acpi_processor_performance __percpu *acpi_perf_data;
78 
79 static inline struct acpi_processor_performance *to_perf_data(struct acpi_cpufreq_data *data)
80 {
81 	return per_cpu_ptr(acpi_perf_data, data->acpi_perf_cpu);
82 }
83 
84 static struct cpufreq_driver acpi_cpufreq_driver;
85 
86 static unsigned int acpi_pstate_strict;
87 static struct msr __percpu *msrs;
88 
89 static bool boost_state(unsigned int cpu)
90 {
91 	u32 lo, hi;
92 	u64 msr;
93 
94 	switch (boot_cpu_data.x86_vendor) {
95 	case X86_VENDOR_INTEL:
96 		rdmsr_on_cpu(cpu, MSR_IA32_MISC_ENABLE, &lo, &hi);
97 		msr = lo | ((u64)hi << 32);
98 		return !(msr & MSR_IA32_MISC_ENABLE_TURBO_DISABLE);
99 	case X86_VENDOR_AMD:
100 		rdmsr_on_cpu(cpu, MSR_K7_HWCR, &lo, &hi);
101 		msr = lo | ((u64)hi << 32);
102 		return !(msr & MSR_K7_HWCR_CPB_DIS);
103 	}
104 	return false;
105 }
106 
107 static void boost_set_msrs(bool enable, const struct cpumask *cpumask)
108 {
109 	u32 cpu;
110 	u32 msr_addr;
111 	u64 msr_mask;
112 
113 	switch (boot_cpu_data.x86_vendor) {
114 	case X86_VENDOR_INTEL:
115 		msr_addr = MSR_IA32_MISC_ENABLE;
116 		msr_mask = MSR_IA32_MISC_ENABLE_TURBO_DISABLE;
117 		break;
118 	case X86_VENDOR_AMD:
119 		msr_addr = MSR_K7_HWCR;
120 		msr_mask = MSR_K7_HWCR_CPB_DIS;
121 		break;
122 	default:
123 		return;
124 	}
125 
126 	rdmsr_on_cpus(cpumask, msr_addr, msrs);
127 
128 	for_each_cpu(cpu, cpumask) {
129 		struct msr *reg = per_cpu_ptr(msrs, cpu);
130 		if (enable)
131 			reg->q &= ~msr_mask;
132 		else
133 			reg->q |= msr_mask;
134 	}
135 
136 	wrmsr_on_cpus(cpumask, msr_addr, msrs);
137 }
138 
139 static int set_boost(int val)
140 {
141 	get_online_cpus();
142 	boost_set_msrs(val, cpu_online_mask);
143 	put_online_cpus();
144 	pr_debug("Core Boosting %sabled.\n", val ? "en" : "dis");
145 
146 	return 0;
147 }
148 
149 static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
150 {
151 	struct acpi_cpufreq_data *data = policy->driver_data;
152 
153 	if (unlikely(!data))
154 		return -ENODEV;
155 
156 	return cpufreq_show_cpus(data->freqdomain_cpus, buf);
157 }
158 
159 cpufreq_freq_attr_ro(freqdomain_cpus);
160 
161 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
162 static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
163 			 size_t count)
164 {
165 	int ret;
166 	unsigned int val = 0;
167 
168 	if (!acpi_cpufreq_driver.set_boost)
169 		return -EINVAL;
170 
171 	ret = kstrtouint(buf, 10, &val);
172 	if (ret || val > 1)
173 		return -EINVAL;
174 
175 	set_boost(val);
176 
177 	return count;
178 }
179 
180 static ssize_t show_cpb(struct cpufreq_policy *policy, char *buf)
181 {
182 	return sprintf(buf, "%u\n", acpi_cpufreq_driver.boost_enabled);
183 }
184 
185 cpufreq_freq_attr_rw(cpb);
186 #endif
187 
188 static int check_est_cpu(unsigned int cpuid)
189 {
190 	struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
191 
192 	return cpu_has(cpu, X86_FEATURE_EST);
193 }
194 
195 static int check_amd_hwpstate_cpu(unsigned int cpuid)
196 {
197 	struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
198 
199 	return cpu_has(cpu, X86_FEATURE_HW_PSTATE);
200 }
201 
202 static unsigned extract_io(struct cpufreq_policy *policy, u32 value)
203 {
204 	struct acpi_cpufreq_data *data = policy->driver_data;
205 	struct acpi_processor_performance *perf;
206 	int i;
207 
208 	perf = to_perf_data(data);
209 
210 	for (i = 0; i < perf->state_count; i++) {
211 		if (value == perf->states[i].status)
212 			return policy->freq_table[i].frequency;
213 	}
214 	return 0;
215 }
216 
217 static unsigned extract_msr(struct cpufreq_policy *policy, u32 msr)
218 {
219 	struct acpi_cpufreq_data *data = policy->driver_data;
220 	struct cpufreq_frequency_table *pos;
221 	struct acpi_processor_performance *perf;
222 
223 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
224 		msr &= AMD_MSR_RANGE;
225 	else
226 		msr &= INTEL_MSR_RANGE;
227 
228 	perf = to_perf_data(data);
229 
230 	cpufreq_for_each_entry(pos, policy->freq_table)
231 		if (msr == perf->states[pos->driver_data].status)
232 			return pos->frequency;
233 	return policy->freq_table[0].frequency;
234 }
235 
236 static unsigned extract_freq(struct cpufreq_policy *policy, u32 val)
237 {
238 	struct acpi_cpufreq_data *data = policy->driver_data;
239 
240 	switch (data->cpu_feature) {
241 	case SYSTEM_INTEL_MSR_CAPABLE:
242 	case SYSTEM_AMD_MSR_CAPABLE:
243 		return extract_msr(policy, val);
244 	case SYSTEM_IO_CAPABLE:
245 		return extract_io(policy, val);
246 	default:
247 		return 0;
248 	}
249 }
250 
251 static u32 cpu_freq_read_intel(struct acpi_pct_register *not_used)
252 {
253 	u32 val, dummy;
254 
255 	rdmsr(MSR_IA32_PERF_CTL, val, dummy);
256 	return val;
257 }
258 
259 static void cpu_freq_write_intel(struct acpi_pct_register *not_used, u32 val)
260 {
261 	u32 lo, hi;
262 
263 	rdmsr(MSR_IA32_PERF_CTL, lo, hi);
264 	lo = (lo & ~INTEL_MSR_RANGE) | (val & INTEL_MSR_RANGE);
265 	wrmsr(MSR_IA32_PERF_CTL, lo, hi);
266 }
267 
268 static u32 cpu_freq_read_amd(struct acpi_pct_register *not_used)
269 {
270 	u32 val, dummy;
271 
272 	rdmsr(MSR_AMD_PERF_CTL, val, dummy);
273 	return val;
274 }
275 
276 static void cpu_freq_write_amd(struct acpi_pct_register *not_used, u32 val)
277 {
278 	wrmsr(MSR_AMD_PERF_CTL, val, 0);
279 }
280 
281 static u32 cpu_freq_read_io(struct acpi_pct_register *reg)
282 {
283 	u32 val;
284 
285 	acpi_os_read_port(reg->address, &val, reg->bit_width);
286 	return val;
287 }
288 
289 static void cpu_freq_write_io(struct acpi_pct_register *reg, u32 val)
290 {
291 	acpi_os_write_port(reg->address, val, reg->bit_width);
292 }
293 
294 struct drv_cmd {
295 	struct acpi_pct_register *reg;
296 	u32 val;
297 	union {
298 		void (*write)(struct acpi_pct_register *reg, u32 val);
299 		u32 (*read)(struct acpi_pct_register *reg);
300 	} func;
301 };
302 
303 /* Called via smp_call_function_single(), on the target CPU */
304 static void do_drv_read(void *_cmd)
305 {
306 	struct drv_cmd *cmd = _cmd;
307 
308 	cmd->val = cmd->func.read(cmd->reg);
309 }
310 
311 static u32 drv_read(struct acpi_cpufreq_data *data, const struct cpumask *mask)
312 {
313 	struct acpi_processor_performance *perf = to_perf_data(data);
314 	struct drv_cmd cmd = {
315 		.reg = &perf->control_register,
316 		.func.read = data->cpu_freq_read,
317 	};
318 	int err;
319 
320 	err = smp_call_function_any(mask, do_drv_read, &cmd, 1);
321 	WARN_ON_ONCE(err);	/* smp_call_function_any() was buggy? */
322 	return cmd.val;
323 }
324 
325 /* Called via smp_call_function_many(), on the target CPUs */
326 static void do_drv_write(void *_cmd)
327 {
328 	struct drv_cmd *cmd = _cmd;
329 
330 	cmd->func.write(cmd->reg, cmd->val);
331 }
332 
333 static void drv_write(struct acpi_cpufreq_data *data,
334 		      const struct cpumask *mask, u32 val)
335 {
336 	struct acpi_processor_performance *perf = to_perf_data(data);
337 	struct drv_cmd cmd = {
338 		.reg = &perf->control_register,
339 		.val = val,
340 		.func.write = data->cpu_freq_write,
341 	};
342 	int this_cpu;
343 
344 	this_cpu = get_cpu();
345 	if (cpumask_test_cpu(this_cpu, mask))
346 		do_drv_write(&cmd);
347 
348 	smp_call_function_many(mask, do_drv_write, &cmd, 1);
349 	put_cpu();
350 }
351 
352 static u32 get_cur_val(const struct cpumask *mask, struct acpi_cpufreq_data *data)
353 {
354 	u32 val;
355 
356 	if (unlikely(cpumask_empty(mask)))
357 		return 0;
358 
359 	val = drv_read(data, mask);
360 
361 	pr_debug("get_cur_val = %u\n", val);
362 
363 	return val;
364 }
365 
366 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
367 {
368 	struct acpi_cpufreq_data *data;
369 	struct cpufreq_policy *policy;
370 	unsigned int freq;
371 	unsigned int cached_freq;
372 
373 	pr_debug("get_cur_freq_on_cpu (%d)\n", cpu);
374 
375 	policy = cpufreq_cpu_get_raw(cpu);
376 	if (unlikely(!policy))
377 		return 0;
378 
379 	data = policy->driver_data;
380 	if (unlikely(!data || !policy->freq_table))
381 		return 0;
382 
383 	cached_freq = policy->freq_table[to_perf_data(data)->state].frequency;
384 	freq = extract_freq(policy, get_cur_val(cpumask_of(cpu), data));
385 	if (freq != cached_freq) {
386 		/*
387 		 * The dreaded BIOS frequency change behind our back.
388 		 * Force set the frequency on next target call.
389 		 */
390 		data->resume = 1;
391 	}
392 
393 	pr_debug("cur freq = %u\n", freq);
394 
395 	return freq;
396 }
397 
398 static unsigned int check_freqs(struct cpufreq_policy *policy,
399 				const struct cpumask *mask, unsigned int freq)
400 {
401 	struct acpi_cpufreq_data *data = policy->driver_data;
402 	unsigned int cur_freq;
403 	unsigned int i;
404 
405 	for (i = 0; i < 100; i++) {
406 		cur_freq = extract_freq(policy, get_cur_val(mask, data));
407 		if (cur_freq == freq)
408 			return 1;
409 		udelay(10);
410 	}
411 	return 0;
412 }
413 
414 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
415 			       unsigned int index)
416 {
417 	struct acpi_cpufreq_data *data = policy->driver_data;
418 	struct acpi_processor_performance *perf;
419 	const struct cpumask *mask;
420 	unsigned int next_perf_state = 0; /* Index into perf table */
421 	int result = 0;
422 
423 	if (unlikely(!data)) {
424 		return -ENODEV;
425 	}
426 
427 	perf = to_perf_data(data);
428 	next_perf_state = policy->freq_table[index].driver_data;
429 	if (perf->state == next_perf_state) {
430 		if (unlikely(data->resume)) {
431 			pr_debug("Called after resume, resetting to P%d\n",
432 				next_perf_state);
433 			data->resume = 0;
434 		} else {
435 			pr_debug("Already at target state (P%d)\n",
436 				next_perf_state);
437 			return 0;
438 		}
439 	}
440 
441 	/*
442 	 * The core won't allow CPUs to go away until the governor has been
443 	 * stopped, so we can rely on the stability of policy->cpus.
444 	 */
445 	mask = policy->shared_type == CPUFREQ_SHARED_TYPE_ANY ?
446 		cpumask_of(policy->cpu) : policy->cpus;
447 
448 	drv_write(data, mask, perf->states[next_perf_state].control);
449 
450 	if (acpi_pstate_strict) {
451 		if (!check_freqs(policy, mask,
452 				 policy->freq_table[index].frequency)) {
453 			pr_debug("acpi_cpufreq_target failed (%d)\n",
454 				policy->cpu);
455 			result = -EAGAIN;
456 		}
457 	}
458 
459 	if (!result)
460 		perf->state = next_perf_state;
461 
462 	return result;
463 }
464 
465 unsigned int acpi_cpufreq_fast_switch(struct cpufreq_policy *policy,
466 				      unsigned int target_freq)
467 {
468 	struct acpi_cpufreq_data *data = policy->driver_data;
469 	struct acpi_processor_performance *perf;
470 	struct cpufreq_frequency_table *entry;
471 	unsigned int next_perf_state, next_freq, index;
472 
473 	/*
474 	 * Find the closest frequency above target_freq.
475 	 */
476 	if (policy->cached_target_freq == target_freq)
477 		index = policy->cached_resolved_idx;
478 	else
479 		index = cpufreq_table_find_index_dl(policy, target_freq);
480 
481 	entry = &policy->freq_table[index];
482 	next_freq = entry->frequency;
483 	next_perf_state = entry->driver_data;
484 
485 	perf = to_perf_data(data);
486 	if (perf->state == next_perf_state) {
487 		if (unlikely(data->resume))
488 			data->resume = 0;
489 		else
490 			return next_freq;
491 	}
492 
493 	data->cpu_freq_write(&perf->control_register,
494 			     perf->states[next_perf_state].control);
495 	perf->state = next_perf_state;
496 	return next_freq;
497 }
498 
499 static unsigned long
500 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
501 {
502 	struct acpi_processor_performance *perf;
503 
504 	perf = to_perf_data(data);
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_DOWN_FAILED:
556 	case CPU_DOWN_FAILED_FROZEN:
557 	case CPU_ONLINE:
558 	case CPU_ONLINE_FROZEN:
559 		boost_set_msrs(acpi_cpufreq_driver.boost_enabled, cpumask);
560 		break;
561 
562 	case CPU_DOWN_PREPARE:
563 	case CPU_DOWN_PREPARE_FROZEN:
564 		boost_set_msrs(1, cpumask);
565 		break;
566 
567 	default:
568 		break;
569 	}
570 
571 	return NOTIFY_OK;
572 }
573 
574 
575 static struct notifier_block boost_nb = {
576 	.notifier_call          = boost_notify,
577 };
578 
579 /*
580  * acpi_cpufreq_early_init - initialize ACPI P-States library
581  *
582  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
583  * in order to determine correct frequency and voltage pairings. We can
584  * do _PDC and _PSD and find out the processor dependency for the
585  * actual init that will happen later...
586  */
587 static int __init acpi_cpufreq_early_init(void)
588 {
589 	unsigned int i;
590 	pr_debug("acpi_cpufreq_early_init\n");
591 
592 	acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
593 	if (!acpi_perf_data) {
594 		pr_debug("Memory allocation error for acpi_perf_data.\n");
595 		return -ENOMEM;
596 	}
597 	for_each_possible_cpu(i) {
598 		if (!zalloc_cpumask_var_node(
599 			&per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
600 			GFP_KERNEL, cpu_to_node(i))) {
601 
602 			/* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
603 			free_acpi_perf_data();
604 			return -ENOMEM;
605 		}
606 	}
607 
608 	/* Do initialization in ACPI core */
609 	acpi_processor_preregister_performance(acpi_perf_data);
610 	return 0;
611 }
612 
613 #ifdef CONFIG_SMP
614 /*
615  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
616  * or do it in BIOS firmware and won't inform about it to OS. If not
617  * detected, this has a side effect of making CPU run at a different speed
618  * than OS intended it to run at. Detect it and handle it cleanly.
619  */
620 static int bios_with_sw_any_bug;
621 
622 static int sw_any_bug_found(const struct dmi_system_id *d)
623 {
624 	bios_with_sw_any_bug = 1;
625 	return 0;
626 }
627 
628 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
629 	{
630 		.callback = sw_any_bug_found,
631 		.ident = "Supermicro Server X6DLP",
632 		.matches = {
633 			DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
634 			DMI_MATCH(DMI_BIOS_VERSION, "080010"),
635 			DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
636 		},
637 	},
638 	{ }
639 };
640 
641 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
642 {
643 	/* Intel Xeon Processor 7100 Series Specification Update
644 	 * http://www.intel.com/Assets/PDF/specupdate/314554.pdf
645 	 * AL30: A Machine Check Exception (MCE) Occurring during an
646 	 * Enhanced Intel SpeedStep Technology Ratio Change May Cause
647 	 * Both Processor Cores to Lock Up. */
648 	if (c->x86_vendor == X86_VENDOR_INTEL) {
649 		if ((c->x86 == 15) &&
650 		    (c->x86_model == 6) &&
651 		    (c->x86_mask == 8)) {
652 			pr_info("Intel(R) Xeon(R) 7100 Errata AL30, processors may lock up on frequency changes: disabling acpi-cpufreq\n");
653 			return -ENODEV;
654 		    }
655 		}
656 	return 0;
657 }
658 #endif
659 
660 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
661 {
662 	unsigned int i;
663 	unsigned int valid_states = 0;
664 	unsigned int cpu = policy->cpu;
665 	struct acpi_cpufreq_data *data;
666 	unsigned int result = 0;
667 	struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
668 	struct acpi_processor_performance *perf;
669 	struct cpufreq_frequency_table *freq_table;
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 	perf = per_cpu_ptr(acpi_perf_data, cpu);
694 	data->acpi_perf_cpu = cpu;
695 	policy->driver_data = data;
696 
697 	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
698 		acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
699 
700 	result = acpi_processor_register_performance(perf, cpu);
701 	if (result)
702 		goto err_free_mask;
703 
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, topology_core_cpumask(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,
727 			     topology_sibling_cpumask(cpu));
728 		policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
729 		pr_info_once("overriding BIOS provided _PSD data\n");
730 	}
731 #endif
732 
733 	/* capability check */
734 	if (perf->state_count <= 1) {
735 		pr_debug("No P-States\n");
736 		result = -ENODEV;
737 		goto err_unreg;
738 	}
739 
740 	if (perf->control_register.space_id != perf->status_register.space_id) {
741 		result = -ENODEV;
742 		goto err_unreg;
743 	}
744 
745 	switch (perf->control_register.space_id) {
746 	case ACPI_ADR_SPACE_SYSTEM_IO:
747 		if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
748 		    boot_cpu_data.x86 == 0xf) {
749 			pr_debug("AMD K8 systems must use native drivers.\n");
750 			result = -ENODEV;
751 			goto err_unreg;
752 		}
753 		pr_debug("SYSTEM IO addr space\n");
754 		data->cpu_feature = SYSTEM_IO_CAPABLE;
755 		data->cpu_freq_read = cpu_freq_read_io;
756 		data->cpu_freq_write = cpu_freq_write_io;
757 		break;
758 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
759 		pr_debug("HARDWARE addr space\n");
760 		if (check_est_cpu(cpu)) {
761 			data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
762 			data->cpu_freq_read = cpu_freq_read_intel;
763 			data->cpu_freq_write = cpu_freq_write_intel;
764 			break;
765 		}
766 		if (check_amd_hwpstate_cpu(cpu)) {
767 			data->cpu_feature = SYSTEM_AMD_MSR_CAPABLE;
768 			data->cpu_freq_read = cpu_freq_read_amd;
769 			data->cpu_freq_write = cpu_freq_write_amd;
770 			break;
771 		}
772 		result = -ENODEV;
773 		goto err_unreg;
774 	default:
775 		pr_debug("Unknown addr space %d\n",
776 			(u32) (perf->control_register.space_id));
777 		result = -ENODEV;
778 		goto err_unreg;
779 	}
780 
781 	freq_table = kzalloc(sizeof(*freq_table) *
782 		    (perf->state_count+1), GFP_KERNEL);
783 	if (!freq_table) {
784 		result = -ENOMEM;
785 		goto err_unreg;
786 	}
787 
788 	/* detect transition latency */
789 	policy->cpuinfo.transition_latency = 0;
790 	for (i = 0; i < perf->state_count; i++) {
791 		if ((perf->states[i].transition_latency * 1000) >
792 		    policy->cpuinfo.transition_latency)
793 			policy->cpuinfo.transition_latency =
794 			    perf->states[i].transition_latency * 1000;
795 	}
796 
797 	/* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
798 	if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
799 	    policy->cpuinfo.transition_latency > 20 * 1000) {
800 		policy->cpuinfo.transition_latency = 20 * 1000;
801 		pr_info_once("P-state transition latency capped at 20 uS\n");
802 	}
803 
804 	/* table init */
805 	for (i = 0; i < perf->state_count; i++) {
806 		if (i > 0 && perf->states[i].core_frequency >=
807 		    freq_table[valid_states-1].frequency / 1000)
808 			continue;
809 
810 		freq_table[valid_states].driver_data = i;
811 		freq_table[valid_states].frequency =
812 		    perf->states[i].core_frequency * 1000;
813 		valid_states++;
814 	}
815 	freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
816 	perf->state = 0;
817 
818 	result = cpufreq_table_validate_and_show(policy, freq_table);
819 	if (result)
820 		goto err_freqfree;
821 
822 	if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
823 		pr_warn(FW_WARN "P-state 0 is not max freq\n");
824 
825 	switch (perf->control_register.space_id) {
826 	case ACPI_ADR_SPACE_SYSTEM_IO:
827 		/*
828 		 * The core will not set policy->cur, because
829 		 * cpufreq_driver->get is NULL, so we need to set it here.
830 		 * However, we have to guess it, because the current speed is
831 		 * unknown and not detectable via IO ports.
832 		 */
833 		policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
834 		break;
835 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
836 		acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
837 		break;
838 	default:
839 		break;
840 	}
841 
842 	/* notify BIOS that we exist */
843 	acpi_processor_notify_smm(THIS_MODULE);
844 
845 	pr_debug("CPU%u - ACPI performance management activated.\n", cpu);
846 	for (i = 0; i < perf->state_count; i++)
847 		pr_debug("     %cP%d: %d MHz, %d mW, %d uS\n",
848 			(i == perf->state ? '*' : ' '), i,
849 			(u32) perf->states[i].core_frequency,
850 			(u32) perf->states[i].power,
851 			(u32) perf->states[i].transition_latency);
852 
853 	/*
854 	 * the first call to ->target() should result in us actually
855 	 * writing something to the appropriate registers.
856 	 */
857 	data->resume = 1;
858 
859 	policy->fast_switch_possible = !acpi_pstate_strict &&
860 		!(policy_is_shared(policy) && policy->shared_type != CPUFREQ_SHARED_TYPE_ANY);
861 
862 	return result;
863 
864 err_freqfree:
865 	kfree(freq_table);
866 err_unreg:
867 	acpi_processor_unregister_performance(cpu);
868 err_free_mask:
869 	free_cpumask_var(data->freqdomain_cpus);
870 err_free:
871 	kfree(data);
872 	policy->driver_data = NULL;
873 
874 	return result;
875 }
876 
877 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
878 {
879 	struct acpi_cpufreq_data *data = policy->driver_data;
880 
881 	pr_debug("acpi_cpufreq_cpu_exit\n");
882 
883 	policy->fast_switch_possible = false;
884 	policy->driver_data = NULL;
885 	acpi_processor_unregister_performance(data->acpi_perf_cpu);
886 	free_cpumask_var(data->freqdomain_cpus);
887 	kfree(policy->freq_table);
888 	kfree(data);
889 
890 	return 0;
891 }
892 
893 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
894 {
895 	struct acpi_cpufreq_data *data = policy->driver_data;
896 
897 	pr_debug("acpi_cpufreq_resume\n");
898 
899 	data->resume = 1;
900 
901 	return 0;
902 }
903 
904 static struct freq_attr *acpi_cpufreq_attr[] = {
905 	&cpufreq_freq_attr_scaling_available_freqs,
906 	&freqdomain_cpus,
907 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
908 	&cpb,
909 #endif
910 	NULL,
911 };
912 
913 static struct cpufreq_driver acpi_cpufreq_driver = {
914 	.verify		= cpufreq_generic_frequency_table_verify,
915 	.target_index	= acpi_cpufreq_target,
916 	.fast_switch	= acpi_cpufreq_fast_switch,
917 	.bios_limit	= acpi_processor_get_bios_limit,
918 	.init		= acpi_cpufreq_cpu_init,
919 	.exit		= acpi_cpufreq_cpu_exit,
920 	.resume		= acpi_cpufreq_resume,
921 	.name		= "acpi-cpufreq",
922 	.attr		= acpi_cpufreq_attr,
923 };
924 
925 static void __init acpi_cpufreq_boost_init(void)
926 {
927 	if (boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA)) {
928 		msrs = msrs_alloc();
929 
930 		if (!msrs)
931 			return;
932 
933 		acpi_cpufreq_driver.set_boost = set_boost;
934 		acpi_cpufreq_driver.boost_enabled = boost_state(0);
935 
936 		cpu_notifier_register_begin();
937 
938 		/* Force all MSRs to the same value */
939 		boost_set_msrs(acpi_cpufreq_driver.boost_enabled,
940 			       cpu_online_mask);
941 
942 		__register_cpu_notifier(&boost_nb);
943 
944 		cpu_notifier_register_done();
945 	}
946 }
947 
948 static void acpi_cpufreq_boost_exit(void)
949 {
950 	if (msrs) {
951 		unregister_cpu_notifier(&boost_nb);
952 
953 		msrs_free(msrs);
954 		msrs = NULL;
955 	}
956 }
957 
958 static int __init acpi_cpufreq_init(void)
959 {
960 	int ret;
961 
962 	if (acpi_disabled)
963 		return -ENODEV;
964 
965 	/* don't keep reloading if cpufreq_driver exists */
966 	if (cpufreq_get_current_driver())
967 		return -EEXIST;
968 
969 	pr_debug("acpi_cpufreq_init\n");
970 
971 	ret = acpi_cpufreq_early_init();
972 	if (ret)
973 		return ret;
974 
975 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
976 	/* this is a sysfs file with a strange name and an even stranger
977 	 * semantic - per CPU instantiation, but system global effect.
978 	 * Lets enable it only on AMD CPUs for compatibility reasons and
979 	 * only if configured. This is considered legacy code, which
980 	 * will probably be removed at some point in the future.
981 	 */
982 	if (!check_amd_hwpstate_cpu(0)) {
983 		struct freq_attr **attr;
984 
985 		pr_debug("CPB unsupported, do not expose it\n");
986 
987 		for (attr = acpi_cpufreq_attr; *attr; attr++)
988 			if (*attr == &cpb) {
989 				*attr = NULL;
990 				break;
991 			}
992 	}
993 #endif
994 	acpi_cpufreq_boost_init();
995 
996 	ret = cpufreq_register_driver(&acpi_cpufreq_driver);
997 	if (ret) {
998 		free_acpi_perf_data();
999 		acpi_cpufreq_boost_exit();
1000 	}
1001 	return ret;
1002 }
1003 
1004 static void __exit acpi_cpufreq_exit(void)
1005 {
1006 	pr_debug("acpi_cpufreq_exit\n");
1007 
1008 	acpi_cpufreq_boost_exit();
1009 
1010 	cpufreq_unregister_driver(&acpi_cpufreq_driver);
1011 
1012 	free_acpi_perf_data();
1013 }
1014 
1015 module_param(acpi_pstate_strict, uint, 0644);
1016 MODULE_PARM_DESC(acpi_pstate_strict,
1017 	"value 0 or non-zero. non-zero -> strict ACPI checks are "
1018 	"performed during frequency changes.");
1019 
1020 late_initcall(acpi_cpufreq_init);
1021 module_exit(acpi_cpufreq_exit);
1022 
1023 static const struct x86_cpu_id acpi_cpufreq_ids[] = {
1024 	X86_FEATURE_MATCH(X86_FEATURE_ACPI),
1025 	X86_FEATURE_MATCH(X86_FEATURE_HW_PSTATE),
1026 	{}
1027 };
1028 MODULE_DEVICE_TABLE(x86cpu, acpi_cpufreq_ids);
1029 
1030 static const struct acpi_device_id processor_device_ids[] = {
1031 	{ACPI_PROCESSOR_OBJECT_HID, },
1032 	{ACPI_PROCESSOR_DEVICE_HID, },
1033 	{},
1034 };
1035 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
1036 
1037 MODULE_ALIAS("acpi");
1038