1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * acpi-cpufreq.c - ACPI Processor P-States Driver
4  *
5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
7  *  Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
8  *  Copyright (C) 2006       Denis Sadykov <denis.m.sadykov@intel.com>
9  */
10 
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/smp.h>
17 #include <linux/sched.h>
18 #include <linux/cpufreq.h>
19 #include <linux/compiler.h>
20 #include <linux/dmi.h>
21 #include <linux/slab.h>
22 
23 #include <linux/acpi.h>
24 #include <linux/io.h>
25 #include <linux/delay.h>
26 #include <linux/uaccess.h>
27 
28 #include <acpi/processor.h>
29 
30 #include <asm/msr.h>
31 #include <asm/processor.h>
32 #include <asm/cpufeature.h>
33 #include <asm/cpu_device_id.h>
34 
35 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
36 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
37 MODULE_LICENSE("GPL");
38 
39 enum {
40 	UNDEFINED_CAPABLE = 0,
41 	SYSTEM_INTEL_MSR_CAPABLE,
42 	SYSTEM_AMD_MSR_CAPABLE,
43 	SYSTEM_IO_CAPABLE,
44 };
45 
46 #define INTEL_MSR_RANGE		(0xffff)
47 #define AMD_MSR_RANGE		(0x7)
48 #define HYGON_MSR_RANGE		(0x7)
49 
50 #define MSR_K7_HWCR_CPB_DIS	(1ULL << 25)
51 
52 struct acpi_cpufreq_data {
53 	unsigned int resume;
54 	unsigned int cpu_feature;
55 	unsigned int acpi_perf_cpu;
56 	cpumask_var_t freqdomain_cpus;
57 	void (*cpu_freq_write)(struct acpi_pct_register *reg, u32 val);
58 	u32 (*cpu_freq_read)(struct acpi_pct_register *reg);
59 };
60 
61 /* acpi_perf_data is a pointer to percpu data. */
62 static struct acpi_processor_performance __percpu *acpi_perf_data;
63 
64 static inline struct acpi_processor_performance *to_perf_data(struct acpi_cpufreq_data *data)
65 {
66 	return per_cpu_ptr(acpi_perf_data, data->acpi_perf_cpu);
67 }
68 
69 static struct cpufreq_driver acpi_cpufreq_driver;
70 
71 static unsigned int acpi_pstate_strict;
72 
73 static bool boost_state(unsigned int cpu)
74 {
75 	u32 lo, hi;
76 	u64 msr;
77 
78 	switch (boot_cpu_data.x86_vendor) {
79 	case X86_VENDOR_INTEL:
80 		rdmsr_on_cpu(cpu, MSR_IA32_MISC_ENABLE, &lo, &hi);
81 		msr = lo | ((u64)hi << 32);
82 		return !(msr & MSR_IA32_MISC_ENABLE_TURBO_DISABLE);
83 	case X86_VENDOR_HYGON:
84 	case X86_VENDOR_AMD:
85 		rdmsr_on_cpu(cpu, MSR_K7_HWCR, &lo, &hi);
86 		msr = lo | ((u64)hi << 32);
87 		return !(msr & MSR_K7_HWCR_CPB_DIS);
88 	}
89 	return false;
90 }
91 
92 static int boost_set_msr(bool enable)
93 {
94 	u32 msr_addr;
95 	u64 msr_mask, val;
96 
97 	switch (boot_cpu_data.x86_vendor) {
98 	case X86_VENDOR_INTEL:
99 		msr_addr = MSR_IA32_MISC_ENABLE;
100 		msr_mask = MSR_IA32_MISC_ENABLE_TURBO_DISABLE;
101 		break;
102 	case X86_VENDOR_HYGON:
103 	case X86_VENDOR_AMD:
104 		msr_addr = MSR_K7_HWCR;
105 		msr_mask = MSR_K7_HWCR_CPB_DIS;
106 		break;
107 	default:
108 		return -EINVAL;
109 	}
110 
111 	rdmsrl(msr_addr, val);
112 
113 	if (enable)
114 		val &= ~msr_mask;
115 	else
116 		val |= msr_mask;
117 
118 	wrmsrl(msr_addr, val);
119 	return 0;
120 }
121 
122 static void boost_set_msr_each(void *p_en)
123 {
124 	bool enable = (bool) p_en;
125 
126 	boost_set_msr(enable);
127 }
128 
129 static int set_boost(struct cpufreq_policy *policy, int val)
130 {
131 	on_each_cpu_mask(policy->cpus, boost_set_msr_each,
132 			 (void *)(long)val, 1);
133 	pr_debug("CPU %*pbl: Core Boosting %sabled.\n",
134 		 cpumask_pr_args(policy->cpus), val ? "en" : "dis");
135 
136 	return 0;
137 }
138 
139 static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
140 {
141 	struct acpi_cpufreq_data *data = policy->driver_data;
142 
143 	if (unlikely(!data))
144 		return -ENODEV;
145 
146 	return cpufreq_show_cpus(data->freqdomain_cpus, buf);
147 }
148 
149 cpufreq_freq_attr_ro(freqdomain_cpus);
150 
151 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
152 static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
153 			 size_t count)
154 {
155 	int ret;
156 	unsigned int val = 0;
157 
158 	if (!acpi_cpufreq_driver.set_boost)
159 		return -EINVAL;
160 
161 	ret = kstrtouint(buf, 10, &val);
162 	if (ret || val > 1)
163 		return -EINVAL;
164 
165 	get_online_cpus();
166 	set_boost(policy, val);
167 	put_online_cpus();
168 
169 	return count;
170 }
171 
172 static ssize_t show_cpb(struct cpufreq_policy *policy, char *buf)
173 {
174 	return sprintf(buf, "%u\n", acpi_cpufreq_driver.boost_enabled);
175 }
176 
177 cpufreq_freq_attr_rw(cpb);
178 #endif
179 
180 static int check_est_cpu(unsigned int cpuid)
181 {
182 	struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
183 
184 	return cpu_has(cpu, X86_FEATURE_EST);
185 }
186 
187 static int check_amd_hwpstate_cpu(unsigned int cpuid)
188 {
189 	struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
190 
191 	return cpu_has(cpu, X86_FEATURE_HW_PSTATE);
192 }
193 
194 static unsigned extract_io(struct cpufreq_policy *policy, u32 value)
195 {
196 	struct acpi_cpufreq_data *data = policy->driver_data;
197 	struct acpi_processor_performance *perf;
198 	int i;
199 
200 	perf = to_perf_data(data);
201 
202 	for (i = 0; i < perf->state_count; i++) {
203 		if (value == perf->states[i].status)
204 			return policy->freq_table[i].frequency;
205 	}
206 	return 0;
207 }
208 
209 static unsigned extract_msr(struct cpufreq_policy *policy, u32 msr)
210 {
211 	struct acpi_cpufreq_data *data = policy->driver_data;
212 	struct cpufreq_frequency_table *pos;
213 	struct acpi_processor_performance *perf;
214 
215 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
216 		msr &= AMD_MSR_RANGE;
217 	else if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
218 		msr &= HYGON_MSR_RANGE;
219 	else
220 		msr &= INTEL_MSR_RANGE;
221 
222 	perf = to_perf_data(data);
223 
224 	cpufreq_for_each_entry(pos, policy->freq_table)
225 		if (msr == perf->states[pos->driver_data].status)
226 			return pos->frequency;
227 	return policy->freq_table[0].frequency;
228 }
229 
230 static unsigned extract_freq(struct cpufreq_policy *policy, u32 val)
231 {
232 	struct acpi_cpufreq_data *data = policy->driver_data;
233 
234 	switch (data->cpu_feature) {
235 	case SYSTEM_INTEL_MSR_CAPABLE:
236 	case SYSTEM_AMD_MSR_CAPABLE:
237 		return extract_msr(policy, val);
238 	case SYSTEM_IO_CAPABLE:
239 		return extract_io(policy, val);
240 	default:
241 		return 0;
242 	}
243 }
244 
245 static u32 cpu_freq_read_intel(struct acpi_pct_register *not_used)
246 {
247 	u32 val, dummy;
248 
249 	rdmsr(MSR_IA32_PERF_CTL, val, dummy);
250 	return val;
251 }
252 
253 static void cpu_freq_write_intel(struct acpi_pct_register *not_used, u32 val)
254 {
255 	u32 lo, hi;
256 
257 	rdmsr(MSR_IA32_PERF_CTL, lo, hi);
258 	lo = (lo & ~INTEL_MSR_RANGE) | (val & INTEL_MSR_RANGE);
259 	wrmsr(MSR_IA32_PERF_CTL, lo, hi);
260 }
261 
262 static u32 cpu_freq_read_amd(struct acpi_pct_register *not_used)
263 {
264 	u32 val, dummy;
265 
266 	rdmsr(MSR_AMD_PERF_CTL, val, dummy);
267 	return val;
268 }
269 
270 static void cpu_freq_write_amd(struct acpi_pct_register *not_used, u32 val)
271 {
272 	wrmsr(MSR_AMD_PERF_CTL, val, 0);
273 }
274 
275 static u32 cpu_freq_read_io(struct acpi_pct_register *reg)
276 {
277 	u32 val;
278 
279 	acpi_os_read_port(reg->address, &val, reg->bit_width);
280 	return val;
281 }
282 
283 static void cpu_freq_write_io(struct acpi_pct_register *reg, u32 val)
284 {
285 	acpi_os_write_port(reg->address, val, reg->bit_width);
286 }
287 
288 struct drv_cmd {
289 	struct acpi_pct_register *reg;
290 	u32 val;
291 	union {
292 		void (*write)(struct acpi_pct_register *reg, u32 val);
293 		u32 (*read)(struct acpi_pct_register *reg);
294 	} func;
295 };
296 
297 /* Called via smp_call_function_single(), on the target CPU */
298 static void do_drv_read(void *_cmd)
299 {
300 	struct drv_cmd *cmd = _cmd;
301 
302 	cmd->val = cmd->func.read(cmd->reg);
303 }
304 
305 static u32 drv_read(struct acpi_cpufreq_data *data, const struct cpumask *mask)
306 {
307 	struct acpi_processor_performance *perf = to_perf_data(data);
308 	struct drv_cmd cmd = {
309 		.reg = &perf->control_register,
310 		.func.read = data->cpu_freq_read,
311 	};
312 	int err;
313 
314 	err = smp_call_function_any(mask, do_drv_read, &cmd, 1);
315 	WARN_ON_ONCE(err);	/* smp_call_function_any() was buggy? */
316 	return cmd.val;
317 }
318 
319 /* Called via smp_call_function_many(), on the target CPUs */
320 static void do_drv_write(void *_cmd)
321 {
322 	struct drv_cmd *cmd = _cmd;
323 
324 	cmd->func.write(cmd->reg, cmd->val);
325 }
326 
327 static void drv_write(struct acpi_cpufreq_data *data,
328 		      const struct cpumask *mask, u32 val)
329 {
330 	struct acpi_processor_performance *perf = to_perf_data(data);
331 	struct drv_cmd cmd = {
332 		.reg = &perf->control_register,
333 		.val = val,
334 		.func.write = data->cpu_freq_write,
335 	};
336 	int this_cpu;
337 
338 	this_cpu = get_cpu();
339 	if (cpumask_test_cpu(this_cpu, mask))
340 		do_drv_write(&cmd);
341 
342 	smp_call_function_many(mask, do_drv_write, &cmd, 1);
343 	put_cpu();
344 }
345 
346 static u32 get_cur_val(const struct cpumask *mask, struct acpi_cpufreq_data *data)
347 {
348 	u32 val;
349 
350 	if (unlikely(cpumask_empty(mask)))
351 		return 0;
352 
353 	val = drv_read(data, mask);
354 
355 	pr_debug("%s = %u\n", __func__, val);
356 
357 	return val;
358 }
359 
360 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
361 {
362 	struct acpi_cpufreq_data *data;
363 	struct cpufreq_policy *policy;
364 	unsigned int freq;
365 	unsigned int cached_freq;
366 
367 	pr_debug("%s (%d)\n", __func__, cpu);
368 
369 	policy = cpufreq_cpu_get_raw(cpu);
370 	if (unlikely(!policy))
371 		return 0;
372 
373 	data = policy->driver_data;
374 	if (unlikely(!data || !policy->freq_table))
375 		return 0;
376 
377 	cached_freq = policy->freq_table[to_perf_data(data)->state].frequency;
378 	freq = extract_freq(policy, get_cur_val(cpumask_of(cpu), data));
379 	if (freq != cached_freq) {
380 		/*
381 		 * The dreaded BIOS frequency change behind our back.
382 		 * Force set the frequency on next target call.
383 		 */
384 		data->resume = 1;
385 	}
386 
387 	pr_debug("cur freq = %u\n", freq);
388 
389 	return freq;
390 }
391 
392 static unsigned int check_freqs(struct cpufreq_policy *policy,
393 				const struct cpumask *mask, unsigned int freq)
394 {
395 	struct acpi_cpufreq_data *data = policy->driver_data;
396 	unsigned int cur_freq;
397 	unsigned int i;
398 
399 	for (i = 0; i < 100; i++) {
400 		cur_freq = extract_freq(policy, get_cur_val(mask, data));
401 		if (cur_freq == freq)
402 			return 1;
403 		udelay(10);
404 	}
405 	return 0;
406 }
407 
408 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
409 			       unsigned int index)
410 {
411 	struct acpi_cpufreq_data *data = policy->driver_data;
412 	struct acpi_processor_performance *perf;
413 	const struct cpumask *mask;
414 	unsigned int next_perf_state = 0; /* Index into perf table */
415 	int result = 0;
416 
417 	if (unlikely(!data)) {
418 		return -ENODEV;
419 	}
420 
421 	perf = to_perf_data(data);
422 	next_perf_state = policy->freq_table[index].driver_data;
423 	if (perf->state == next_perf_state) {
424 		if (unlikely(data->resume)) {
425 			pr_debug("Called after resume, resetting to P%d\n",
426 				next_perf_state);
427 			data->resume = 0;
428 		} else {
429 			pr_debug("Already at target state (P%d)\n",
430 				next_perf_state);
431 			return 0;
432 		}
433 	}
434 
435 	/*
436 	 * The core won't allow CPUs to go away until the governor has been
437 	 * stopped, so we can rely on the stability of policy->cpus.
438 	 */
439 	mask = policy->shared_type == CPUFREQ_SHARED_TYPE_ANY ?
440 		cpumask_of(policy->cpu) : policy->cpus;
441 
442 	drv_write(data, mask, perf->states[next_perf_state].control);
443 
444 	if (acpi_pstate_strict) {
445 		if (!check_freqs(policy, mask,
446 				 policy->freq_table[index].frequency)) {
447 			pr_debug("%s (%d)\n", __func__, policy->cpu);
448 			result = -EAGAIN;
449 		}
450 	}
451 
452 	if (!result)
453 		perf->state = next_perf_state;
454 
455 	return result;
456 }
457 
458 static unsigned int acpi_cpufreq_fast_switch(struct cpufreq_policy *policy,
459 					     unsigned int target_freq)
460 {
461 	struct acpi_cpufreq_data *data = policy->driver_data;
462 	struct acpi_processor_performance *perf;
463 	struct cpufreq_frequency_table *entry;
464 	unsigned int next_perf_state, next_freq, index;
465 
466 	/*
467 	 * Find the closest frequency above target_freq.
468 	 */
469 	if (policy->cached_target_freq == target_freq)
470 		index = policy->cached_resolved_idx;
471 	else
472 		index = cpufreq_table_find_index_dl(policy, target_freq);
473 
474 	entry = &policy->freq_table[index];
475 	next_freq = entry->frequency;
476 	next_perf_state = entry->driver_data;
477 
478 	perf = to_perf_data(data);
479 	if (perf->state == next_perf_state) {
480 		if (unlikely(data->resume))
481 			data->resume = 0;
482 		else
483 			return next_freq;
484 	}
485 
486 	data->cpu_freq_write(&perf->control_register,
487 			     perf->states[next_perf_state].control);
488 	perf->state = next_perf_state;
489 	return next_freq;
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 cpufreq_boost_online(unsigned int cpu)
533 {
534 	/*
535 	 * On the CPU_UP path we simply keep the boost-disable flag
536 	 * in sync with the current global state.
537 	 */
538 	return boost_set_msr(acpi_cpufreq_driver.boost_enabled);
539 }
540 
541 static int cpufreq_boost_down_prep(unsigned int cpu)
542 {
543 	/*
544 	 * Clear the boost-disable bit on the CPU_DOWN path so that
545 	 * this cpu cannot block the remaining ones from boosting.
546 	 */
547 	return boost_set_msr(1);
548 }
549 
550 /*
551  * acpi_cpufreq_early_init - initialize ACPI P-States library
552  *
553  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
554  * in order to determine correct frequency and voltage pairings. We can
555  * do _PDC and _PSD and find out the processor dependency for the
556  * actual init that will happen later...
557  */
558 static int __init acpi_cpufreq_early_init(void)
559 {
560 	unsigned int i;
561 	pr_debug("%s\n", __func__);
562 
563 	acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
564 	if (!acpi_perf_data) {
565 		pr_debug("Memory allocation error for acpi_perf_data.\n");
566 		return -ENOMEM;
567 	}
568 	for_each_possible_cpu(i) {
569 		if (!zalloc_cpumask_var_node(
570 			&per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
571 			GFP_KERNEL, cpu_to_node(i))) {
572 
573 			/* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
574 			free_acpi_perf_data();
575 			return -ENOMEM;
576 		}
577 	}
578 
579 	/* Do initialization in ACPI core */
580 	acpi_processor_preregister_performance(acpi_perf_data);
581 	return 0;
582 }
583 
584 #ifdef CONFIG_SMP
585 /*
586  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
587  * or do it in BIOS firmware and won't inform about it to OS. If not
588  * detected, this has a side effect of making CPU run at a different speed
589  * than OS intended it to run at. Detect it and handle it cleanly.
590  */
591 static int bios_with_sw_any_bug;
592 
593 static int sw_any_bug_found(const struct dmi_system_id *d)
594 {
595 	bios_with_sw_any_bug = 1;
596 	return 0;
597 }
598 
599 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
600 	{
601 		.callback = sw_any_bug_found,
602 		.ident = "Supermicro Server X6DLP",
603 		.matches = {
604 			DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
605 			DMI_MATCH(DMI_BIOS_VERSION, "080010"),
606 			DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
607 		},
608 	},
609 	{ }
610 };
611 
612 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
613 {
614 	/* Intel Xeon Processor 7100 Series Specification Update
615 	 * http://www.intel.com/Assets/PDF/specupdate/314554.pdf
616 	 * AL30: A Machine Check Exception (MCE) Occurring during an
617 	 * Enhanced Intel SpeedStep Technology Ratio Change May Cause
618 	 * Both Processor Cores to Lock Up. */
619 	if (c->x86_vendor == X86_VENDOR_INTEL) {
620 		if ((c->x86 == 15) &&
621 		    (c->x86_model == 6) &&
622 		    (c->x86_stepping == 8)) {
623 			pr_info("Intel(R) Xeon(R) 7100 Errata AL30, processors may lock up on frequency changes: disabling acpi-cpufreq\n");
624 			return -ENODEV;
625 		    }
626 		}
627 	return 0;
628 }
629 #endif
630 
631 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
632 {
633 	unsigned int i;
634 	unsigned int valid_states = 0;
635 	unsigned int cpu = policy->cpu;
636 	struct acpi_cpufreq_data *data;
637 	unsigned int result = 0;
638 	struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
639 	struct acpi_processor_performance *perf;
640 	struct cpufreq_frequency_table *freq_table;
641 #ifdef CONFIG_SMP
642 	static int blacklisted;
643 #endif
644 
645 	pr_debug("%s\n", __func__);
646 
647 #ifdef CONFIG_SMP
648 	if (blacklisted)
649 		return blacklisted;
650 	blacklisted = acpi_cpufreq_blacklist(c);
651 	if (blacklisted)
652 		return blacklisted;
653 #endif
654 
655 	data = kzalloc(sizeof(*data), GFP_KERNEL);
656 	if (!data)
657 		return -ENOMEM;
658 
659 	if (!zalloc_cpumask_var(&data->freqdomain_cpus, GFP_KERNEL)) {
660 		result = -ENOMEM;
661 		goto err_free;
662 	}
663 
664 	perf = per_cpu_ptr(acpi_perf_data, cpu);
665 	data->acpi_perf_cpu = cpu;
666 	policy->driver_data = data;
667 
668 	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
669 		acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
670 
671 	result = acpi_processor_register_performance(perf, cpu);
672 	if (result)
673 		goto err_free_mask;
674 
675 	policy->shared_type = perf->shared_type;
676 
677 	/*
678 	 * Will let policy->cpus know about dependency only when software
679 	 * coordination is required.
680 	 */
681 	if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
682 	    policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
683 		cpumask_copy(policy->cpus, perf->shared_cpu_map);
684 	}
685 	cpumask_copy(data->freqdomain_cpus, perf->shared_cpu_map);
686 
687 #ifdef CONFIG_SMP
688 	dmi_check_system(sw_any_bug_dmi_table);
689 	if (bios_with_sw_any_bug && !policy_is_shared(policy)) {
690 		policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
691 		cpumask_copy(policy->cpus, topology_core_cpumask(cpu));
692 	}
693 
694 	if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
695 		cpumask_clear(policy->cpus);
696 		cpumask_set_cpu(cpu, policy->cpus);
697 		cpumask_copy(data->freqdomain_cpus,
698 			     topology_sibling_cpumask(cpu));
699 		policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
700 		pr_info_once("overriding BIOS provided _PSD data\n");
701 	}
702 #endif
703 
704 	/* capability check */
705 	if (perf->state_count <= 1) {
706 		pr_debug("No P-States\n");
707 		result = -ENODEV;
708 		goto err_unreg;
709 	}
710 
711 	if (perf->control_register.space_id != perf->status_register.space_id) {
712 		result = -ENODEV;
713 		goto err_unreg;
714 	}
715 
716 	switch (perf->control_register.space_id) {
717 	case ACPI_ADR_SPACE_SYSTEM_IO:
718 		if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
719 		    boot_cpu_data.x86 == 0xf) {
720 			pr_debug("AMD K8 systems must use native drivers.\n");
721 			result = -ENODEV;
722 			goto err_unreg;
723 		}
724 		pr_debug("SYSTEM IO addr space\n");
725 		data->cpu_feature = SYSTEM_IO_CAPABLE;
726 		data->cpu_freq_read = cpu_freq_read_io;
727 		data->cpu_freq_write = cpu_freq_write_io;
728 		break;
729 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
730 		pr_debug("HARDWARE addr space\n");
731 		if (check_est_cpu(cpu)) {
732 			data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
733 			data->cpu_freq_read = cpu_freq_read_intel;
734 			data->cpu_freq_write = cpu_freq_write_intel;
735 			break;
736 		}
737 		if (check_amd_hwpstate_cpu(cpu)) {
738 			data->cpu_feature = SYSTEM_AMD_MSR_CAPABLE;
739 			data->cpu_freq_read = cpu_freq_read_amd;
740 			data->cpu_freq_write = cpu_freq_write_amd;
741 			break;
742 		}
743 		result = -ENODEV;
744 		goto err_unreg;
745 	default:
746 		pr_debug("Unknown addr space %d\n",
747 			(u32) (perf->control_register.space_id));
748 		result = -ENODEV;
749 		goto err_unreg;
750 	}
751 
752 	freq_table = kcalloc(perf->state_count + 1, sizeof(*freq_table),
753 			     GFP_KERNEL);
754 	if (!freq_table) {
755 		result = -ENOMEM;
756 		goto err_unreg;
757 	}
758 
759 	/* detect transition latency */
760 	policy->cpuinfo.transition_latency = 0;
761 	for (i = 0; i < perf->state_count; i++) {
762 		if ((perf->states[i].transition_latency * 1000) >
763 		    policy->cpuinfo.transition_latency)
764 			policy->cpuinfo.transition_latency =
765 			    perf->states[i].transition_latency * 1000;
766 	}
767 
768 	/* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
769 	if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
770 	    policy->cpuinfo.transition_latency > 20 * 1000) {
771 		policy->cpuinfo.transition_latency = 20 * 1000;
772 		pr_info_once("P-state transition latency capped at 20 uS\n");
773 	}
774 
775 	/* table init */
776 	for (i = 0; i < perf->state_count; i++) {
777 		if (i > 0 && perf->states[i].core_frequency >=
778 		    freq_table[valid_states-1].frequency / 1000)
779 			continue;
780 
781 		freq_table[valid_states].driver_data = i;
782 		freq_table[valid_states].frequency =
783 		    perf->states[i].core_frequency * 1000;
784 		valid_states++;
785 	}
786 	freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
787 	policy->freq_table = freq_table;
788 	perf->state = 0;
789 
790 	switch (perf->control_register.space_id) {
791 	case ACPI_ADR_SPACE_SYSTEM_IO:
792 		/*
793 		 * The core will not set policy->cur, because
794 		 * cpufreq_driver->get is NULL, so we need to set it here.
795 		 * However, we have to guess it, because the current speed is
796 		 * unknown and not detectable via IO ports.
797 		 */
798 		policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
799 		break;
800 	case ACPI_ADR_SPACE_FIXED_HARDWARE:
801 		acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
802 		break;
803 	default:
804 		break;
805 	}
806 
807 	/* notify BIOS that we exist */
808 	acpi_processor_notify_smm(THIS_MODULE);
809 
810 	pr_debug("CPU%u - ACPI performance management activated.\n", cpu);
811 	for (i = 0; i < perf->state_count; i++)
812 		pr_debug("     %cP%d: %d MHz, %d mW, %d uS\n",
813 			(i == perf->state ? '*' : ' '), i,
814 			(u32) perf->states[i].core_frequency,
815 			(u32) perf->states[i].power,
816 			(u32) perf->states[i].transition_latency);
817 
818 	/*
819 	 * the first call to ->target() should result in us actually
820 	 * writing something to the appropriate registers.
821 	 */
822 	data->resume = 1;
823 
824 	policy->fast_switch_possible = !acpi_pstate_strict &&
825 		!(policy_is_shared(policy) && policy->shared_type != CPUFREQ_SHARED_TYPE_ANY);
826 
827 	return result;
828 
829 err_unreg:
830 	acpi_processor_unregister_performance(cpu);
831 err_free_mask:
832 	free_cpumask_var(data->freqdomain_cpus);
833 err_free:
834 	kfree(data);
835 	policy->driver_data = NULL;
836 
837 	return result;
838 }
839 
840 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
841 {
842 	struct acpi_cpufreq_data *data = policy->driver_data;
843 
844 	pr_debug("%s\n", __func__);
845 
846 	policy->fast_switch_possible = false;
847 	policy->driver_data = NULL;
848 	acpi_processor_unregister_performance(data->acpi_perf_cpu);
849 	free_cpumask_var(data->freqdomain_cpus);
850 	kfree(policy->freq_table);
851 	kfree(data);
852 
853 	return 0;
854 }
855 
856 static void acpi_cpufreq_cpu_ready(struct cpufreq_policy *policy)
857 {
858 	struct acpi_processor_performance *perf = per_cpu_ptr(acpi_perf_data,
859 							      policy->cpu);
860 
861 	if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
862 		pr_warn(FW_WARN "P-state 0 is not max freq\n");
863 }
864 
865 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
866 {
867 	struct acpi_cpufreq_data *data = policy->driver_data;
868 
869 	pr_debug("%s\n", __func__);
870 
871 	data->resume = 1;
872 
873 	return 0;
874 }
875 
876 static struct freq_attr *acpi_cpufreq_attr[] = {
877 	&cpufreq_freq_attr_scaling_available_freqs,
878 	&freqdomain_cpus,
879 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
880 	&cpb,
881 #endif
882 	NULL,
883 };
884 
885 static struct cpufreq_driver acpi_cpufreq_driver = {
886 	.verify		= cpufreq_generic_frequency_table_verify,
887 	.target_index	= acpi_cpufreq_target,
888 	.fast_switch	= acpi_cpufreq_fast_switch,
889 	.bios_limit	= acpi_processor_get_bios_limit,
890 	.init		= acpi_cpufreq_cpu_init,
891 	.exit		= acpi_cpufreq_cpu_exit,
892 	.ready		= acpi_cpufreq_cpu_ready,
893 	.resume		= acpi_cpufreq_resume,
894 	.name		= "acpi-cpufreq",
895 	.attr		= acpi_cpufreq_attr,
896 };
897 
898 static enum cpuhp_state acpi_cpufreq_online;
899 
900 static void __init acpi_cpufreq_boost_init(void)
901 {
902 	int ret;
903 
904 	if (!(boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA))) {
905 		pr_debug("Boost capabilities not present in the processor\n");
906 		return;
907 	}
908 
909 	acpi_cpufreq_driver.set_boost = set_boost;
910 	acpi_cpufreq_driver.boost_enabled = boost_state(0);
911 
912 	/*
913 	 * This calls the online callback on all online cpu and forces all
914 	 * MSRs to the same value.
915 	 */
916 	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "cpufreq/acpi:online",
917 				cpufreq_boost_online, cpufreq_boost_down_prep);
918 	if (ret < 0) {
919 		pr_err("acpi_cpufreq: failed to register hotplug callbacks\n");
920 		return;
921 	}
922 	acpi_cpufreq_online = ret;
923 }
924 
925 static void acpi_cpufreq_boost_exit(void)
926 {
927 	if (acpi_cpufreq_online > 0)
928 		cpuhp_remove_state_nocalls(acpi_cpufreq_online);
929 }
930 
931 static int __init acpi_cpufreq_init(void)
932 {
933 	int ret;
934 
935 	if (acpi_disabled)
936 		return -ENODEV;
937 
938 	/* don't keep reloading if cpufreq_driver exists */
939 	if (cpufreq_get_current_driver())
940 		return -EEXIST;
941 
942 	pr_debug("%s\n", __func__);
943 
944 	ret = acpi_cpufreq_early_init();
945 	if (ret)
946 		return ret;
947 
948 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
949 	/* this is a sysfs file with a strange name and an even stranger
950 	 * semantic - per CPU instantiation, but system global effect.
951 	 * Lets enable it only on AMD CPUs for compatibility reasons and
952 	 * only if configured. This is considered legacy code, which
953 	 * will probably be removed at some point in the future.
954 	 */
955 	if (!check_amd_hwpstate_cpu(0)) {
956 		struct freq_attr **attr;
957 
958 		pr_debug("CPB unsupported, do not expose it\n");
959 
960 		for (attr = acpi_cpufreq_attr; *attr; attr++)
961 			if (*attr == &cpb) {
962 				*attr = NULL;
963 				break;
964 			}
965 	}
966 #endif
967 	acpi_cpufreq_boost_init();
968 
969 	ret = cpufreq_register_driver(&acpi_cpufreq_driver);
970 	if (ret) {
971 		free_acpi_perf_data();
972 		acpi_cpufreq_boost_exit();
973 	}
974 	return ret;
975 }
976 
977 static void __exit acpi_cpufreq_exit(void)
978 {
979 	pr_debug("%s\n", __func__);
980 
981 	acpi_cpufreq_boost_exit();
982 
983 	cpufreq_unregister_driver(&acpi_cpufreq_driver);
984 
985 	free_acpi_perf_data();
986 }
987 
988 module_param(acpi_pstate_strict, uint, 0644);
989 MODULE_PARM_DESC(acpi_pstate_strict,
990 	"value 0 or non-zero. non-zero -> strict ACPI checks are "
991 	"performed during frequency changes.");
992 
993 late_initcall(acpi_cpufreq_init);
994 module_exit(acpi_cpufreq_exit);
995 
996 static const struct x86_cpu_id acpi_cpufreq_ids[] = {
997 	X86_MATCH_FEATURE(X86_FEATURE_ACPI, NULL),
998 	X86_MATCH_FEATURE(X86_FEATURE_HW_PSTATE, NULL),
999 	{}
1000 };
1001 MODULE_DEVICE_TABLE(x86cpu, acpi_cpufreq_ids);
1002 
1003 static const struct acpi_device_id processor_device_ids[] = {
1004 	{ACPI_PROCESSOR_OBJECT_HID, },
1005 	{ACPI_PROCESSOR_DEVICE_HID, },
1006 	{},
1007 };
1008 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
1009 
1010 MODULE_ALIAS("acpi");
1011