xref: /openbmc/linux/drivers/cpufreq/amd-pstate.c (revision 3b843046)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * amd-pstate.c - AMD Processor P-state Frequency Driver
4  *
5  * Copyright (C) 2021 Advanced Micro Devices, Inc. All Rights Reserved.
6  *
7  * Author: Huang Rui <ray.huang@amd.com>
8  *
9  * AMD P-State introduces a new CPU performance scaling design for AMD
10  * processors using the ACPI Collaborative Performance and Power Control (CPPC)
11  * feature which works with the AMD SMU firmware providing a finer grained
12  * frequency control range. It is to replace the legacy ACPI P-States control,
13  * allows a flexible, low-latency interface for the Linux kernel to directly
14  * communicate the performance hints to hardware.
15  *
16  * AMD P-State is supported on recent AMD Zen base CPU series include some of
17  * Zen2 and Zen3 processors. _CPC needs to be present in the ACPI tables of AMD
18  * P-State supported system. And there are two types of hardware implementations
19  * for AMD P-State: 1) Full MSR Solution and 2) Shared Memory Solution.
20  * X86_FEATURE_CPPC CPU feature flag is used to distinguish the different types.
21  */
22 
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24 
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/init.h>
28 #include <linux/smp.h>
29 #include <linux/sched.h>
30 #include <linux/cpufreq.h>
31 #include <linux/compiler.h>
32 #include <linux/dmi.h>
33 #include <linux/slab.h>
34 #include <linux/acpi.h>
35 #include <linux/io.h>
36 #include <linux/delay.h>
37 #include <linux/uaccess.h>
38 #include <linux/static_call.h>
39 #include <linux/amd-pstate.h>
40 #include <linux/topology.h>
41 
42 #include <acpi/processor.h>
43 #include <acpi/cppc_acpi.h>
44 
45 #include <asm/msr.h>
46 #include <asm/processor.h>
47 #include <asm/cpufeature.h>
48 #include <asm/cpu_device_id.h>
49 #include "amd-pstate-trace.h"
50 
51 #define AMD_PSTATE_TRANSITION_LATENCY	20000
52 #define AMD_PSTATE_TRANSITION_DELAY	1000
53 #define CPPC_HIGHEST_PERF_PERFORMANCE	196
54 #define CPPC_HIGHEST_PERF_DEFAULT	166
55 
56 /*
57  * TODO: We need more time to fine tune processors with shared memory solution
58  * with community together.
59  *
60  * There are some performance drops on the CPU benchmarks which reports from
61  * Suse. We are co-working with them to fine tune the shared memory solution. So
62  * we disable it by default to go acpi-cpufreq on these processors and add a
63  * module parameter to be able to enable it manually for debugging.
64  */
65 static struct cpufreq_driver *current_pstate_driver;
66 static struct cpufreq_driver amd_pstate_driver;
67 static struct cpufreq_driver amd_pstate_epp_driver;
68 static int cppc_state = AMD_PSTATE_UNDEFINED;
69 static bool cppc_enabled;
70 static bool amd_pstate_prefcore = true;
71 
72 /*
73  * AMD Energy Preference Performance (EPP)
74  * The EPP is used in the CCLK DPM controller to drive
75  * the frequency that a core is going to operate during
76  * short periods of activity. EPP values will be utilized for
77  * different OS profiles (balanced, performance, power savings)
78  * display strings corresponding to EPP index in the
79  * energy_perf_strings[]
80  *	index		String
81  *-------------------------------------
82  *	0		default
83  *	1		performance
84  *	2		balance_performance
85  *	3		balance_power
86  *	4		power
87  */
88 enum energy_perf_value_index {
89 	EPP_INDEX_DEFAULT = 0,
90 	EPP_INDEX_PERFORMANCE,
91 	EPP_INDEX_BALANCE_PERFORMANCE,
92 	EPP_INDEX_BALANCE_POWERSAVE,
93 	EPP_INDEX_POWERSAVE,
94 };
95 
96 static const char * const energy_perf_strings[] = {
97 	[EPP_INDEX_DEFAULT] = "default",
98 	[EPP_INDEX_PERFORMANCE] = "performance",
99 	[EPP_INDEX_BALANCE_PERFORMANCE] = "balance_performance",
100 	[EPP_INDEX_BALANCE_POWERSAVE] = "balance_power",
101 	[EPP_INDEX_POWERSAVE] = "power",
102 	NULL
103 };
104 
105 static unsigned int epp_values[] = {
106 	[EPP_INDEX_DEFAULT] = 0,
107 	[EPP_INDEX_PERFORMANCE] = AMD_CPPC_EPP_PERFORMANCE,
108 	[EPP_INDEX_BALANCE_PERFORMANCE] = AMD_CPPC_EPP_BALANCE_PERFORMANCE,
109 	[EPP_INDEX_BALANCE_POWERSAVE] = AMD_CPPC_EPP_BALANCE_POWERSAVE,
110 	[EPP_INDEX_POWERSAVE] = AMD_CPPC_EPP_POWERSAVE,
111  };
112 
113 typedef int (*cppc_mode_transition_fn)(int);
114 
115 static inline int get_mode_idx_from_str(const char *str, size_t size)
116 {
117 	int i;
118 
119 	for (i=0; i < AMD_PSTATE_MAX; i++) {
120 		if (!strncmp(str, amd_pstate_mode_string[i], size))
121 			return i;
122 	}
123 	return -EINVAL;
124 }
125 
126 static DEFINE_MUTEX(amd_pstate_limits_lock);
127 static DEFINE_MUTEX(amd_pstate_driver_lock);
128 
129 static s16 amd_pstate_get_epp(struct amd_cpudata *cpudata, u64 cppc_req_cached)
130 {
131 	u64 epp;
132 	int ret;
133 
134 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
135 		if (!cppc_req_cached) {
136 			epp = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
137 					&cppc_req_cached);
138 			if (epp)
139 				return epp;
140 		}
141 		epp = (cppc_req_cached >> 24) & 0xFF;
142 	} else {
143 		ret = cppc_get_epp_perf(cpudata->cpu, &epp);
144 		if (ret < 0) {
145 			pr_debug("Could not retrieve energy perf value (%d)\n", ret);
146 			return -EIO;
147 		}
148 	}
149 
150 	return (s16)(epp & 0xff);
151 }
152 
153 static int amd_pstate_get_energy_pref_index(struct amd_cpudata *cpudata)
154 {
155 	s16 epp;
156 	int index = -EINVAL;
157 
158 	epp = amd_pstate_get_epp(cpudata, 0);
159 	if (epp < 0)
160 		return epp;
161 
162 	switch (epp) {
163 	case AMD_CPPC_EPP_PERFORMANCE:
164 		index = EPP_INDEX_PERFORMANCE;
165 		break;
166 	case AMD_CPPC_EPP_BALANCE_PERFORMANCE:
167 		index = EPP_INDEX_BALANCE_PERFORMANCE;
168 		break;
169 	case AMD_CPPC_EPP_BALANCE_POWERSAVE:
170 		index = EPP_INDEX_BALANCE_POWERSAVE;
171 		break;
172 	case AMD_CPPC_EPP_POWERSAVE:
173 		index = EPP_INDEX_POWERSAVE;
174 		break;
175 	default:
176 		break;
177 	}
178 
179 	return index;
180 }
181 
182 static void pstate_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
183 			       u32 des_perf, u32 max_perf, bool fast_switch)
184 {
185 	if (fast_switch)
186 		wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached));
187 	else
188 		wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
189 			      READ_ONCE(cpudata->cppc_req_cached));
190 }
191 
192 DEFINE_STATIC_CALL(amd_pstate_update_perf, pstate_update_perf);
193 
194 static inline void amd_pstate_update_perf(struct amd_cpudata *cpudata,
195 					  u32 min_perf, u32 des_perf,
196 					  u32 max_perf, bool fast_switch)
197 {
198 	static_call(amd_pstate_update_perf)(cpudata, min_perf, des_perf,
199 					    max_perf, fast_switch);
200 }
201 
202 static int amd_pstate_set_epp(struct amd_cpudata *cpudata, u32 epp)
203 {
204 	int ret;
205 	struct cppc_perf_ctrls perf_ctrls;
206 
207 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
208 		u64 value = READ_ONCE(cpudata->cppc_req_cached);
209 
210 		value &= ~GENMASK_ULL(31, 24);
211 		value |= (u64)epp << 24;
212 		WRITE_ONCE(cpudata->cppc_req_cached, value);
213 
214 		ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
215 		if (!ret)
216 			cpudata->epp_cached = epp;
217 	} else {
218 		amd_pstate_update_perf(cpudata, cpudata->min_limit_perf, 0U,
219 					     cpudata->max_limit_perf, false);
220 
221 		perf_ctrls.energy_perf = epp;
222 		ret = cppc_set_epp_perf(cpudata->cpu, &perf_ctrls, 1);
223 		if (ret) {
224 			pr_debug("failed to set energy perf value (%d)\n", ret);
225 			return ret;
226 		}
227 		cpudata->epp_cached = epp;
228 	}
229 
230 	return ret;
231 }
232 
233 static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
234 		int pref_index)
235 {
236 	int epp = -EINVAL;
237 	int ret;
238 
239 	if (!pref_index) {
240 		pr_debug("EPP pref_index is invalid\n");
241 		return -EINVAL;
242 	}
243 
244 	if (epp == -EINVAL)
245 		epp = epp_values[pref_index];
246 
247 	if (epp > 0 && cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) {
248 		pr_debug("EPP cannot be set under performance policy\n");
249 		return -EBUSY;
250 	}
251 
252 	ret = amd_pstate_set_epp(cpudata, epp);
253 
254 	return ret;
255 }
256 
257 static inline int pstate_enable(bool enable)
258 {
259 	int ret, cpu;
260 	unsigned long logical_proc_id_mask = 0;
261 
262 	if (enable == cppc_enabled)
263 		return 0;
264 
265 	for_each_present_cpu(cpu) {
266 		unsigned long logical_id = topology_logical_die_id(cpu);
267 
268 		if (test_bit(logical_id, &logical_proc_id_mask))
269 			continue;
270 
271 		set_bit(logical_id, &logical_proc_id_mask);
272 
273 		ret = wrmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_ENABLE,
274 				enable);
275 		if (ret)
276 			return ret;
277 	}
278 
279 	cppc_enabled = enable;
280 	return 0;
281 }
282 
283 static int cppc_enable(bool enable)
284 {
285 	int cpu, ret = 0;
286 	struct cppc_perf_ctrls perf_ctrls;
287 
288 	if (enable == cppc_enabled)
289 		return 0;
290 
291 	for_each_present_cpu(cpu) {
292 		ret = cppc_set_enable(cpu, enable);
293 		if (ret)
294 			return ret;
295 
296 		/* Enable autonomous mode for EPP */
297 		if (cppc_state == AMD_PSTATE_ACTIVE) {
298 			/* Set desired perf as zero to allow EPP firmware control */
299 			perf_ctrls.desired_perf = 0;
300 			ret = cppc_set_perf(cpu, &perf_ctrls);
301 			if (ret)
302 				return ret;
303 		}
304 	}
305 
306 	cppc_enabled = enable;
307 	return ret;
308 }
309 
310 DEFINE_STATIC_CALL(amd_pstate_enable, pstate_enable);
311 
312 static inline int amd_pstate_enable(bool enable)
313 {
314 	return static_call(amd_pstate_enable)(enable);
315 }
316 
317 static u32 amd_pstate_highest_perf_set(struct amd_cpudata *cpudata)
318 {
319 	struct cpuinfo_x86 *c = &cpu_data(0);
320 
321 	/*
322 	 * For AMD CPUs with Family ID 19H and Model ID range 0x70 to 0x7f,
323 	 * the highest performance level is set to 196.
324 	 * https://bugzilla.kernel.org/show_bug.cgi?id=218759
325 	 */
326 	if (c->x86 == 0x19 && (c->x86_model >= 0x70 && c->x86_model <= 0x7f))
327 		return CPPC_HIGHEST_PERF_PERFORMANCE;
328 
329 	return CPPC_HIGHEST_PERF_DEFAULT;
330 }
331 
332 static int pstate_init_perf(struct amd_cpudata *cpudata)
333 {
334 	u64 cap1;
335 	u32 highest_perf;
336 
337 	int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1,
338 				     &cap1);
339 	if (ret)
340 		return ret;
341 
342 	/* For platforms that do not support the preferred core feature, the
343 	 * highest_pef may be configured with 166 or 255, to avoid max frequency
344 	 * calculated wrongly. we take the AMD_CPPC_HIGHEST_PERF(cap1) value as
345 	 * the default max perf.
346 	 */
347 	if (cpudata->hw_prefcore)
348 		highest_perf = amd_pstate_highest_perf_set(cpudata);
349 	else
350 		highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
351 
352 	WRITE_ONCE(cpudata->highest_perf, highest_perf);
353 	WRITE_ONCE(cpudata->max_limit_perf, highest_perf);
354 	WRITE_ONCE(cpudata->nominal_perf, AMD_CPPC_NOMINAL_PERF(cap1));
355 	WRITE_ONCE(cpudata->lowest_nonlinear_perf, AMD_CPPC_LOWNONLIN_PERF(cap1));
356 	WRITE_ONCE(cpudata->lowest_perf, AMD_CPPC_LOWEST_PERF(cap1));
357 	WRITE_ONCE(cpudata->min_limit_perf, AMD_CPPC_LOWEST_PERF(cap1));
358 	return 0;
359 }
360 
361 static int cppc_init_perf(struct amd_cpudata *cpudata)
362 {
363 	struct cppc_perf_caps cppc_perf;
364 	u32 highest_perf;
365 
366 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
367 	if (ret)
368 		return ret;
369 
370 	if (cpudata->hw_prefcore)
371 		highest_perf = amd_pstate_highest_perf_set(cpudata);
372 	else
373 		highest_perf = cppc_perf.highest_perf;
374 
375 	WRITE_ONCE(cpudata->highest_perf, highest_perf);
376 	WRITE_ONCE(cpudata->max_limit_perf, highest_perf);
377 	WRITE_ONCE(cpudata->nominal_perf, cppc_perf.nominal_perf);
378 	WRITE_ONCE(cpudata->lowest_nonlinear_perf,
379 		   cppc_perf.lowest_nonlinear_perf);
380 	WRITE_ONCE(cpudata->lowest_perf, cppc_perf.lowest_perf);
381 	WRITE_ONCE(cpudata->min_limit_perf, cppc_perf.lowest_perf);
382 
383 	if (cppc_state == AMD_PSTATE_ACTIVE)
384 		return 0;
385 
386 	ret = cppc_get_auto_sel_caps(cpudata->cpu, &cppc_perf);
387 	if (ret) {
388 		pr_warn("failed to get auto_sel, ret: %d\n", ret);
389 		return 0;
390 	}
391 
392 	ret = cppc_set_auto_sel(cpudata->cpu,
393 			(cppc_state == AMD_PSTATE_PASSIVE) ? 0 : 1);
394 
395 	if (ret)
396 		pr_warn("failed to set auto_sel, ret: %d\n", ret);
397 
398 	return ret;
399 }
400 
401 DEFINE_STATIC_CALL(amd_pstate_init_perf, pstate_init_perf);
402 
403 static inline int amd_pstate_init_perf(struct amd_cpudata *cpudata)
404 {
405 	return static_call(amd_pstate_init_perf)(cpudata);
406 }
407 
408 static void cppc_update_perf(struct amd_cpudata *cpudata,
409 			     u32 min_perf, u32 des_perf,
410 			     u32 max_perf, bool fast_switch)
411 {
412 	struct cppc_perf_ctrls perf_ctrls;
413 
414 	perf_ctrls.max_perf = max_perf;
415 	perf_ctrls.min_perf = min_perf;
416 	perf_ctrls.desired_perf = des_perf;
417 
418 	cppc_set_perf(cpudata->cpu, &perf_ctrls);
419 }
420 
421 static inline bool amd_pstate_sample(struct amd_cpudata *cpudata)
422 {
423 	u64 aperf, mperf, tsc;
424 	unsigned long flags;
425 
426 	local_irq_save(flags);
427 	rdmsrl(MSR_IA32_APERF, aperf);
428 	rdmsrl(MSR_IA32_MPERF, mperf);
429 	tsc = rdtsc();
430 
431 	if (cpudata->prev.mperf == mperf || cpudata->prev.tsc == tsc) {
432 		local_irq_restore(flags);
433 		return false;
434 	}
435 
436 	local_irq_restore(flags);
437 
438 	cpudata->cur.aperf = aperf;
439 	cpudata->cur.mperf = mperf;
440 	cpudata->cur.tsc =  tsc;
441 	cpudata->cur.aperf -= cpudata->prev.aperf;
442 	cpudata->cur.mperf -= cpudata->prev.mperf;
443 	cpudata->cur.tsc -= cpudata->prev.tsc;
444 
445 	cpudata->prev.aperf = aperf;
446 	cpudata->prev.mperf = mperf;
447 	cpudata->prev.tsc = tsc;
448 
449 	cpudata->freq = div64_u64((cpudata->cur.aperf * cpu_khz), cpudata->cur.mperf);
450 
451 	return true;
452 }
453 
454 static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
455 			      u32 des_perf, u32 max_perf, bool fast_switch, int gov_flags)
456 {
457 	u64 prev = READ_ONCE(cpudata->cppc_req_cached);
458 	u64 value = prev;
459 
460 	min_perf = clamp_t(unsigned long, min_perf, cpudata->min_limit_perf,
461 			cpudata->max_limit_perf);
462 	max_perf = clamp_t(unsigned long, max_perf, cpudata->min_limit_perf,
463 			cpudata->max_limit_perf);
464 	des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
465 
466 	if ((cppc_state == AMD_PSTATE_GUIDED) && (gov_flags & CPUFREQ_GOV_DYNAMIC_SWITCHING)) {
467 		min_perf = des_perf;
468 		des_perf = 0;
469 	}
470 
471 	value &= ~AMD_CPPC_MIN_PERF(~0L);
472 	value |= AMD_CPPC_MIN_PERF(min_perf);
473 
474 	value &= ~AMD_CPPC_DES_PERF(~0L);
475 	value |= AMD_CPPC_DES_PERF(des_perf);
476 
477 	value &= ~AMD_CPPC_MAX_PERF(~0L);
478 	value |= AMD_CPPC_MAX_PERF(max_perf);
479 
480 	if (trace_amd_pstate_perf_enabled() && amd_pstate_sample(cpudata)) {
481 		trace_amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq,
482 			cpudata->cur.mperf, cpudata->cur.aperf, cpudata->cur.tsc,
483 				cpudata->cpu, (value != prev), fast_switch);
484 	}
485 
486 	if (value == prev)
487 		return;
488 
489 	WRITE_ONCE(cpudata->cppc_req_cached, value);
490 
491 	amd_pstate_update_perf(cpudata, min_perf, des_perf,
492 			       max_perf, fast_switch);
493 }
494 
495 static int amd_pstate_verify(struct cpufreq_policy_data *policy)
496 {
497 	cpufreq_verify_within_cpu_limits(policy);
498 
499 	return 0;
500 }
501 
502 static int amd_pstate_update_min_max_limit(struct cpufreq_policy *policy)
503 {
504 	u32 max_limit_perf, min_limit_perf;
505 	struct amd_cpudata *cpudata = policy->driver_data;
506 
507 	max_limit_perf = div_u64(policy->max * cpudata->highest_perf, cpudata->max_freq);
508 	min_limit_perf = div_u64(policy->min * cpudata->highest_perf, cpudata->max_freq);
509 
510 	WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
511 	WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
512 	WRITE_ONCE(cpudata->max_limit_freq, policy->max);
513 	WRITE_ONCE(cpudata->min_limit_freq, policy->min);
514 
515 	return 0;
516 }
517 
518 static int amd_pstate_update_freq(struct cpufreq_policy *policy,
519 				  unsigned int target_freq, bool fast_switch)
520 {
521 	struct cpufreq_freqs freqs;
522 	struct amd_cpudata *cpudata = policy->driver_data;
523 	unsigned long max_perf, min_perf, des_perf, cap_perf;
524 
525 	if (!cpudata->max_freq)
526 		return -ENODEV;
527 
528 	if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq)
529 		amd_pstate_update_min_max_limit(policy);
530 
531 	cap_perf = READ_ONCE(cpudata->highest_perf);
532 	min_perf = READ_ONCE(cpudata->lowest_perf);
533 	max_perf = cap_perf;
534 
535 	freqs.old = policy->cur;
536 	freqs.new = target_freq;
537 
538 	des_perf = DIV_ROUND_CLOSEST(target_freq * cap_perf,
539 				     cpudata->max_freq);
540 
541 	WARN_ON(fast_switch && !policy->fast_switch_enabled);
542 	/*
543 	 * If fast_switch is desired, then there aren't any registered
544 	 * transition notifiers. See comment for
545 	 * cpufreq_enable_fast_switch().
546 	 */
547 	if (!fast_switch)
548 		cpufreq_freq_transition_begin(policy, &freqs);
549 
550 	amd_pstate_update(cpudata, min_perf, des_perf,
551 			max_perf, fast_switch, policy->governor->flags);
552 
553 	if (!fast_switch)
554 		cpufreq_freq_transition_end(policy, &freqs, false);
555 
556 	return 0;
557 }
558 
559 static int amd_pstate_target(struct cpufreq_policy *policy,
560 			     unsigned int target_freq,
561 			     unsigned int relation)
562 {
563 	return amd_pstate_update_freq(policy, target_freq, false);
564 }
565 
566 static unsigned int amd_pstate_fast_switch(struct cpufreq_policy *policy,
567 				  unsigned int target_freq)
568 {
569 	if (!amd_pstate_update_freq(policy, target_freq, true))
570 		return target_freq;
571 	return policy->cur;
572 }
573 
574 static void amd_pstate_adjust_perf(unsigned int cpu,
575 				   unsigned long _min_perf,
576 				   unsigned long target_perf,
577 				   unsigned long capacity)
578 {
579 	unsigned long max_perf, min_perf, des_perf,
580 		      cap_perf, lowest_nonlinear_perf, max_freq;
581 	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
582 	struct amd_cpudata *cpudata = policy->driver_data;
583 	unsigned int target_freq;
584 
585 	if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq)
586 		amd_pstate_update_min_max_limit(policy);
587 
588 
589 	cap_perf = READ_ONCE(cpudata->highest_perf);
590 	lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf);
591 	max_freq = READ_ONCE(cpudata->max_freq);
592 
593 	des_perf = cap_perf;
594 	if (target_perf < capacity)
595 		des_perf = DIV_ROUND_UP(cap_perf * target_perf, capacity);
596 
597 	min_perf = READ_ONCE(cpudata->lowest_perf);
598 	if (_min_perf < capacity)
599 		min_perf = DIV_ROUND_UP(cap_perf * _min_perf, capacity);
600 
601 	if (min_perf < lowest_nonlinear_perf)
602 		min_perf = lowest_nonlinear_perf;
603 
604 	max_perf = cap_perf;
605 	if (max_perf < min_perf)
606 		max_perf = min_perf;
607 
608 	des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
609 	target_freq = div_u64(des_perf * max_freq, max_perf);
610 	policy->cur = target_freq;
611 
612 	amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true,
613 			policy->governor->flags);
614 	cpufreq_cpu_put(policy);
615 }
616 
617 static int amd_get_min_freq(struct amd_cpudata *cpudata)
618 {
619 	struct cppc_perf_caps cppc_perf;
620 
621 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
622 	if (ret)
623 		return ret;
624 
625 	/* Switch to khz */
626 	return cppc_perf.lowest_freq * 1000;
627 }
628 
629 static int amd_get_max_freq(struct amd_cpudata *cpudata)
630 {
631 	struct cppc_perf_caps cppc_perf;
632 	u32 max_perf, max_freq, nominal_freq, nominal_perf;
633 	u64 boost_ratio;
634 
635 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
636 	if (ret)
637 		return ret;
638 
639 	nominal_freq = cppc_perf.nominal_freq;
640 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
641 	max_perf = READ_ONCE(cpudata->highest_perf);
642 
643 	boost_ratio = div_u64(max_perf << SCHED_CAPACITY_SHIFT,
644 			      nominal_perf);
645 
646 	max_freq = nominal_freq * boost_ratio >> SCHED_CAPACITY_SHIFT;
647 
648 	/* Switch to khz */
649 	return max_freq * 1000;
650 }
651 
652 static int amd_get_nominal_freq(struct amd_cpudata *cpudata)
653 {
654 	struct cppc_perf_caps cppc_perf;
655 
656 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
657 	if (ret)
658 		return ret;
659 
660 	/* Switch to khz */
661 	return cppc_perf.nominal_freq * 1000;
662 }
663 
664 static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata)
665 {
666 	struct cppc_perf_caps cppc_perf;
667 	u32 lowest_nonlinear_freq, lowest_nonlinear_perf,
668 	    nominal_freq, nominal_perf;
669 	u64 lowest_nonlinear_ratio;
670 
671 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
672 	if (ret)
673 		return ret;
674 
675 	nominal_freq = cppc_perf.nominal_freq;
676 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
677 
678 	lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf;
679 
680 	lowest_nonlinear_ratio = div_u64(lowest_nonlinear_perf << SCHED_CAPACITY_SHIFT,
681 					 nominal_perf);
682 
683 	lowest_nonlinear_freq = nominal_freq * lowest_nonlinear_ratio >> SCHED_CAPACITY_SHIFT;
684 
685 	/* Switch to khz */
686 	return lowest_nonlinear_freq * 1000;
687 }
688 
689 static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
690 {
691 	struct amd_cpudata *cpudata = policy->driver_data;
692 	int ret;
693 
694 	if (!cpudata->boost_supported) {
695 		pr_err("Boost mode is not supported by this processor or SBIOS\n");
696 		return -EINVAL;
697 	}
698 
699 	if (state)
700 		policy->cpuinfo.max_freq = cpudata->max_freq;
701 	else
702 		policy->cpuinfo.max_freq = cpudata->nominal_freq;
703 
704 	policy->max = policy->cpuinfo.max_freq;
705 
706 	ret = freq_qos_update_request(&cpudata->req[1],
707 				      policy->cpuinfo.max_freq);
708 	if (ret < 0)
709 		return ret;
710 
711 	return 0;
712 }
713 
714 static void amd_pstate_boost_init(struct amd_cpudata *cpudata)
715 {
716 	u32 highest_perf, nominal_perf;
717 
718 	highest_perf = READ_ONCE(cpudata->highest_perf);
719 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
720 
721 	if (highest_perf <= nominal_perf)
722 		return;
723 
724 	cpudata->boost_supported = true;
725 	current_pstate_driver->boost_enabled = true;
726 }
727 
728 static void amd_perf_ctl_reset(unsigned int cpu)
729 {
730 	wrmsrl_on_cpu(cpu, MSR_AMD_PERF_CTL, 0);
731 }
732 
733 /*
734  * Set amd-pstate preferred core enable can't be done directly from cpufreq callbacks
735  * due to locking, so queue the work for later.
736  */
737 static void amd_pstste_sched_prefcore_workfn(struct work_struct *work)
738 {
739 	sched_set_itmt_support();
740 }
741 static DECLARE_WORK(sched_prefcore_work, amd_pstste_sched_prefcore_workfn);
742 
743 /*
744  * Get the highest performance register value.
745  * @cpu: CPU from which to get highest performance.
746  * @highest_perf: Return address.
747  *
748  * Return: 0 for success, -EIO otherwise.
749  */
750 static int amd_pstate_get_highest_perf(int cpu, u32 *highest_perf)
751 {
752 	int ret;
753 
754 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
755 		u64 cap1;
756 
757 		ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &cap1);
758 		if (ret)
759 			return ret;
760 		WRITE_ONCE(*highest_perf, AMD_CPPC_HIGHEST_PERF(cap1));
761 	} else {
762 		u64 cppc_highest_perf;
763 
764 		ret = cppc_get_highest_perf(cpu, &cppc_highest_perf);
765 		if (ret)
766 			return ret;
767 		WRITE_ONCE(*highest_perf, cppc_highest_perf);
768 	}
769 
770 	return (ret);
771 }
772 
773 #define CPPC_MAX_PERF	U8_MAX
774 
775 static void amd_pstate_init_prefcore(struct amd_cpudata *cpudata)
776 {
777 	int ret, prio;
778 	u32 highest_perf;
779 
780 	ret = amd_pstate_get_highest_perf(cpudata->cpu, &highest_perf);
781 	if (ret)
782 		return;
783 
784 	cpudata->hw_prefcore = true;
785 	/* check if CPPC preferred core feature is enabled*/
786 	if (highest_perf < CPPC_MAX_PERF)
787 		prio = (int)highest_perf;
788 	else {
789 		pr_debug("AMD CPPC preferred core is unsupported!\n");
790 		cpudata->hw_prefcore = false;
791 		return;
792 	}
793 
794 	if (!amd_pstate_prefcore)
795 		return;
796 
797 	/*
798 	 * The priorities can be set regardless of whether or not
799 	 * sched_set_itmt_support(true) has been called and it is valid to
800 	 * update them at any time after it has been called.
801 	 */
802 	sched_set_itmt_core_prio(prio, cpudata->cpu);
803 
804 	schedule_work(&sched_prefcore_work);
805 }
806 
807 static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
808 {
809 	int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret;
810 	struct device *dev;
811 	struct amd_cpudata *cpudata;
812 
813 	/*
814 	 * Resetting PERF_CTL_MSR will put the CPU in P0 frequency,
815 	 * which is ideal for initialization process.
816 	 */
817 	amd_perf_ctl_reset(policy->cpu);
818 	dev = get_cpu_device(policy->cpu);
819 	if (!dev)
820 		return -ENODEV;
821 
822 	cpudata = kzalloc(sizeof(*cpudata), GFP_KERNEL);
823 	if (!cpudata)
824 		return -ENOMEM;
825 
826 	cpudata->cpu = policy->cpu;
827 
828 	amd_pstate_init_prefcore(cpudata);
829 
830 	ret = amd_pstate_init_perf(cpudata);
831 	if (ret)
832 		goto free_cpudata1;
833 
834 	min_freq = amd_get_min_freq(cpudata);
835 	max_freq = amd_get_max_freq(cpudata);
836 	nominal_freq = amd_get_nominal_freq(cpudata);
837 	lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata);
838 
839 	if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) {
840 		dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n",
841 			min_freq, max_freq);
842 		ret = -EINVAL;
843 		goto free_cpudata1;
844 	}
845 
846 	policy->cpuinfo.transition_latency = AMD_PSTATE_TRANSITION_LATENCY;
847 	policy->transition_delay_us = AMD_PSTATE_TRANSITION_DELAY;
848 
849 	policy->min = min_freq;
850 	policy->max = max_freq;
851 
852 	policy->cpuinfo.min_freq = min_freq;
853 	policy->cpuinfo.max_freq = max_freq;
854 
855 	/* It will be updated by governor */
856 	policy->cur = policy->cpuinfo.min_freq;
857 
858 	if (boot_cpu_has(X86_FEATURE_CPPC))
859 		policy->fast_switch_possible = true;
860 
861 	ret = freq_qos_add_request(&policy->constraints, &cpudata->req[0],
862 				   FREQ_QOS_MIN, policy->cpuinfo.min_freq);
863 	if (ret < 0) {
864 		dev_err(dev, "Failed to add min-freq constraint (%d)\n", ret);
865 		goto free_cpudata1;
866 	}
867 
868 	ret = freq_qos_add_request(&policy->constraints, &cpudata->req[1],
869 				   FREQ_QOS_MAX, policy->cpuinfo.max_freq);
870 	if (ret < 0) {
871 		dev_err(dev, "Failed to add max-freq constraint (%d)\n", ret);
872 		goto free_cpudata2;
873 	}
874 
875 	/* Initial processor data capability frequencies */
876 	cpudata->max_freq = max_freq;
877 	cpudata->min_freq = min_freq;
878 	cpudata->max_limit_freq = max_freq;
879 	cpudata->min_limit_freq = min_freq;
880 	cpudata->nominal_freq = nominal_freq;
881 	cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
882 
883 	policy->driver_data = cpudata;
884 
885 	amd_pstate_boost_init(cpudata);
886 	if (!current_pstate_driver->adjust_perf)
887 		current_pstate_driver->adjust_perf = amd_pstate_adjust_perf;
888 
889 	return 0;
890 
891 free_cpudata2:
892 	freq_qos_remove_request(&cpudata->req[0]);
893 free_cpudata1:
894 	kfree(cpudata);
895 	return ret;
896 }
897 
898 static int amd_pstate_cpu_exit(struct cpufreq_policy *policy)
899 {
900 	struct amd_cpudata *cpudata = policy->driver_data;
901 
902 	freq_qos_remove_request(&cpudata->req[1]);
903 	freq_qos_remove_request(&cpudata->req[0]);
904 	policy->fast_switch_possible = false;
905 	kfree(cpudata);
906 
907 	return 0;
908 }
909 
910 static int amd_pstate_cpu_resume(struct cpufreq_policy *policy)
911 {
912 	int ret;
913 
914 	ret = amd_pstate_enable(true);
915 	if (ret)
916 		pr_err("failed to enable amd-pstate during resume, return %d\n", ret);
917 
918 	return ret;
919 }
920 
921 static int amd_pstate_cpu_suspend(struct cpufreq_policy *policy)
922 {
923 	int ret;
924 
925 	ret = amd_pstate_enable(false);
926 	if (ret)
927 		pr_err("failed to disable amd-pstate during suspend, return %d\n", ret);
928 
929 	return ret;
930 }
931 
932 /* Sysfs attributes */
933 
934 /*
935  * This frequency is to indicate the maximum hardware frequency.
936  * If boost is not active but supported, the frequency will be larger than the
937  * one in cpuinfo.
938  */
939 static ssize_t show_amd_pstate_max_freq(struct cpufreq_policy *policy,
940 					char *buf)
941 {
942 	int max_freq;
943 	struct amd_cpudata *cpudata = policy->driver_data;
944 
945 	max_freq = amd_get_max_freq(cpudata);
946 	if (max_freq < 0)
947 		return max_freq;
948 
949 	return sysfs_emit(buf, "%u\n", max_freq);
950 }
951 
952 static ssize_t show_amd_pstate_lowest_nonlinear_freq(struct cpufreq_policy *policy,
953 						     char *buf)
954 {
955 	int freq;
956 	struct amd_cpudata *cpudata = policy->driver_data;
957 
958 	freq = amd_get_lowest_nonlinear_freq(cpudata);
959 	if (freq < 0)
960 		return freq;
961 
962 	return sysfs_emit(buf, "%u\n", freq);
963 }
964 
965 /*
966  * In some of ASICs, the highest_perf is not the one in the _CPC table, so we
967  * need to expose it to sysfs.
968  */
969 static ssize_t show_amd_pstate_highest_perf(struct cpufreq_policy *policy,
970 					    char *buf)
971 {
972 	u32 perf;
973 	struct amd_cpudata *cpudata = policy->driver_data;
974 
975 	perf = READ_ONCE(cpudata->highest_perf);
976 
977 	return sysfs_emit(buf, "%u\n", perf);
978 }
979 
980 static ssize_t show_amd_pstate_hw_prefcore(struct cpufreq_policy *policy,
981 					   char *buf)
982 {
983 	bool hw_prefcore;
984 	struct amd_cpudata *cpudata = policy->driver_data;
985 
986 	hw_prefcore = READ_ONCE(cpudata->hw_prefcore);
987 
988 	return sysfs_emit(buf, "%s\n", str_enabled_disabled(hw_prefcore));
989 }
990 
991 static ssize_t show_energy_performance_available_preferences(
992 				struct cpufreq_policy *policy, char *buf)
993 {
994 	int i = 0;
995 	int offset = 0;
996 	struct amd_cpudata *cpudata = policy->driver_data;
997 
998 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
999 		return sysfs_emit_at(buf, offset, "%s\n",
1000 				energy_perf_strings[EPP_INDEX_PERFORMANCE]);
1001 
1002 	while (energy_perf_strings[i] != NULL)
1003 		offset += sysfs_emit_at(buf, offset, "%s ", energy_perf_strings[i++]);
1004 
1005 	offset += sysfs_emit_at(buf, offset, "\n");
1006 
1007 	return offset;
1008 }
1009 
1010 static ssize_t store_energy_performance_preference(
1011 		struct cpufreq_policy *policy, const char *buf, size_t count)
1012 {
1013 	struct amd_cpudata *cpudata = policy->driver_data;
1014 	char str_preference[21];
1015 	ssize_t ret;
1016 
1017 	ret = sscanf(buf, "%20s", str_preference);
1018 	if (ret != 1)
1019 		return -EINVAL;
1020 
1021 	ret = match_string(energy_perf_strings, -1, str_preference);
1022 	if (ret < 0)
1023 		return -EINVAL;
1024 
1025 	mutex_lock(&amd_pstate_limits_lock);
1026 	ret = amd_pstate_set_energy_pref_index(cpudata, ret);
1027 	mutex_unlock(&amd_pstate_limits_lock);
1028 
1029 	return ret ?: count;
1030 }
1031 
1032 static ssize_t show_energy_performance_preference(
1033 				struct cpufreq_policy *policy, char *buf)
1034 {
1035 	struct amd_cpudata *cpudata = policy->driver_data;
1036 	int preference;
1037 
1038 	preference = amd_pstate_get_energy_pref_index(cpudata);
1039 	if (preference < 0)
1040 		return preference;
1041 
1042 	return sysfs_emit(buf, "%s\n", energy_perf_strings[preference]);
1043 }
1044 
1045 static void amd_pstate_driver_cleanup(void)
1046 {
1047 	amd_pstate_enable(false);
1048 	cppc_state = AMD_PSTATE_DISABLE;
1049 	current_pstate_driver = NULL;
1050 }
1051 
1052 static int amd_pstate_register_driver(int mode)
1053 {
1054 	int ret;
1055 
1056 	if (mode == AMD_PSTATE_PASSIVE || mode == AMD_PSTATE_GUIDED)
1057 		current_pstate_driver = &amd_pstate_driver;
1058 	else if (mode == AMD_PSTATE_ACTIVE)
1059 		current_pstate_driver = &amd_pstate_epp_driver;
1060 	else
1061 		return -EINVAL;
1062 
1063 	cppc_state = mode;
1064 	ret = cpufreq_register_driver(current_pstate_driver);
1065 	if (ret) {
1066 		amd_pstate_driver_cleanup();
1067 		return ret;
1068 	}
1069 	return 0;
1070 }
1071 
1072 static int amd_pstate_unregister_driver(int dummy)
1073 {
1074 	cpufreq_unregister_driver(current_pstate_driver);
1075 	amd_pstate_driver_cleanup();
1076 	return 0;
1077 }
1078 
1079 static int amd_pstate_change_mode_without_dvr_change(int mode)
1080 {
1081 	int cpu = 0;
1082 
1083 	cppc_state = mode;
1084 
1085 	if (boot_cpu_has(X86_FEATURE_CPPC) || cppc_state == AMD_PSTATE_ACTIVE)
1086 		return 0;
1087 
1088 	for_each_present_cpu(cpu) {
1089 		cppc_set_auto_sel(cpu, (cppc_state == AMD_PSTATE_PASSIVE) ? 0 : 1);
1090 	}
1091 
1092 	return 0;
1093 }
1094 
1095 static int amd_pstate_change_driver_mode(int mode)
1096 {
1097 	int ret;
1098 
1099 	ret = amd_pstate_unregister_driver(0);
1100 	if (ret)
1101 		return ret;
1102 
1103 	ret = amd_pstate_register_driver(mode);
1104 	if (ret)
1105 		return ret;
1106 
1107 	return 0;
1108 }
1109 
1110 static cppc_mode_transition_fn mode_state_machine[AMD_PSTATE_MAX][AMD_PSTATE_MAX] = {
1111 	[AMD_PSTATE_DISABLE]         = {
1112 		[AMD_PSTATE_DISABLE]     = NULL,
1113 		[AMD_PSTATE_PASSIVE]     = amd_pstate_register_driver,
1114 		[AMD_PSTATE_ACTIVE]      = amd_pstate_register_driver,
1115 		[AMD_PSTATE_GUIDED]      = amd_pstate_register_driver,
1116 	},
1117 	[AMD_PSTATE_PASSIVE]         = {
1118 		[AMD_PSTATE_DISABLE]     = amd_pstate_unregister_driver,
1119 		[AMD_PSTATE_PASSIVE]     = NULL,
1120 		[AMD_PSTATE_ACTIVE]      = amd_pstate_change_driver_mode,
1121 		[AMD_PSTATE_GUIDED]      = amd_pstate_change_mode_without_dvr_change,
1122 	},
1123 	[AMD_PSTATE_ACTIVE]          = {
1124 		[AMD_PSTATE_DISABLE]     = amd_pstate_unregister_driver,
1125 		[AMD_PSTATE_PASSIVE]     = amd_pstate_change_driver_mode,
1126 		[AMD_PSTATE_ACTIVE]      = NULL,
1127 		[AMD_PSTATE_GUIDED]      = amd_pstate_change_driver_mode,
1128 	},
1129 	[AMD_PSTATE_GUIDED]          = {
1130 		[AMD_PSTATE_DISABLE]     = amd_pstate_unregister_driver,
1131 		[AMD_PSTATE_PASSIVE]     = amd_pstate_change_mode_without_dvr_change,
1132 		[AMD_PSTATE_ACTIVE]      = amd_pstate_change_driver_mode,
1133 		[AMD_PSTATE_GUIDED]      = NULL,
1134 	},
1135 };
1136 
1137 static ssize_t amd_pstate_show_status(char *buf)
1138 {
1139 	if (!current_pstate_driver)
1140 		return sysfs_emit(buf, "disable\n");
1141 
1142 	return sysfs_emit(buf, "%s\n", amd_pstate_mode_string[cppc_state]);
1143 }
1144 
1145 static int amd_pstate_update_status(const char *buf, size_t size)
1146 {
1147 	int mode_idx;
1148 
1149 	if (size > strlen("passive") || size < strlen("active"))
1150 		return -EINVAL;
1151 
1152 	mode_idx = get_mode_idx_from_str(buf, size);
1153 
1154 	if (mode_idx < 0 || mode_idx >= AMD_PSTATE_MAX)
1155 		return -EINVAL;
1156 
1157 	if (mode_state_machine[cppc_state][mode_idx])
1158 		return mode_state_machine[cppc_state][mode_idx](mode_idx);
1159 
1160 	return 0;
1161 }
1162 
1163 static ssize_t status_show(struct device *dev,
1164 			   struct device_attribute *attr, char *buf)
1165 {
1166 	ssize_t ret;
1167 
1168 	mutex_lock(&amd_pstate_driver_lock);
1169 	ret = amd_pstate_show_status(buf);
1170 	mutex_unlock(&amd_pstate_driver_lock);
1171 
1172 	return ret;
1173 }
1174 
1175 static ssize_t status_store(struct device *a, struct device_attribute *b,
1176 			    const char *buf, size_t count)
1177 {
1178 	char *p = memchr(buf, '\n', count);
1179 	int ret;
1180 
1181 	mutex_lock(&amd_pstate_driver_lock);
1182 	ret = amd_pstate_update_status(buf, p ? p - buf : count);
1183 	mutex_unlock(&amd_pstate_driver_lock);
1184 
1185 	return ret < 0 ? ret : count;
1186 }
1187 
1188 static ssize_t prefcore_show(struct device *dev,
1189 			     struct device_attribute *attr, char *buf)
1190 {
1191 	return sysfs_emit(buf, "%s\n", str_enabled_disabled(amd_pstate_prefcore));
1192 }
1193 
1194 cpufreq_freq_attr_ro(amd_pstate_max_freq);
1195 cpufreq_freq_attr_ro(amd_pstate_lowest_nonlinear_freq);
1196 
1197 cpufreq_freq_attr_ro(amd_pstate_highest_perf);
1198 cpufreq_freq_attr_ro(amd_pstate_hw_prefcore);
1199 cpufreq_freq_attr_rw(energy_performance_preference);
1200 cpufreq_freq_attr_ro(energy_performance_available_preferences);
1201 static DEVICE_ATTR_RW(status);
1202 static DEVICE_ATTR_RO(prefcore);
1203 
1204 static struct freq_attr *amd_pstate_attr[] = {
1205 	&amd_pstate_max_freq,
1206 	&amd_pstate_lowest_nonlinear_freq,
1207 	&amd_pstate_highest_perf,
1208 	&amd_pstate_hw_prefcore,
1209 	NULL,
1210 };
1211 
1212 static struct freq_attr *amd_pstate_epp_attr[] = {
1213 	&amd_pstate_max_freq,
1214 	&amd_pstate_lowest_nonlinear_freq,
1215 	&amd_pstate_highest_perf,
1216 	&amd_pstate_hw_prefcore,
1217 	&energy_performance_preference,
1218 	&energy_performance_available_preferences,
1219 	NULL,
1220 };
1221 
1222 static struct attribute *pstate_global_attributes[] = {
1223 	&dev_attr_status.attr,
1224 	&dev_attr_prefcore.attr,
1225 	NULL
1226 };
1227 
1228 static const struct attribute_group amd_pstate_global_attr_group = {
1229 	.name = "amd_pstate",
1230 	.attrs = pstate_global_attributes,
1231 };
1232 
1233 static bool amd_pstate_acpi_pm_profile_server(void)
1234 {
1235 	switch (acpi_gbl_FADT.preferred_profile) {
1236 	case PM_ENTERPRISE_SERVER:
1237 	case PM_SOHO_SERVER:
1238 	case PM_PERFORMANCE_SERVER:
1239 		return true;
1240 	}
1241 	return false;
1242 }
1243 
1244 static bool amd_pstate_acpi_pm_profile_undefined(void)
1245 {
1246 	if (acpi_gbl_FADT.preferred_profile == PM_UNSPECIFIED)
1247 		return true;
1248 	if (acpi_gbl_FADT.preferred_profile >= NR_PM_PROFILES)
1249 		return true;
1250 	return false;
1251 }
1252 
1253 static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
1254 {
1255 	int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret;
1256 	struct amd_cpudata *cpudata;
1257 	struct device *dev;
1258 	u64 value;
1259 
1260 	/*
1261 	 * Resetting PERF_CTL_MSR will put the CPU in P0 frequency,
1262 	 * which is ideal for initialization process.
1263 	 */
1264 	amd_perf_ctl_reset(policy->cpu);
1265 	dev = get_cpu_device(policy->cpu);
1266 	if (!dev)
1267 		return -ENODEV;
1268 
1269 	cpudata = kzalloc(sizeof(*cpudata), GFP_KERNEL);
1270 	if (!cpudata)
1271 		return -ENOMEM;
1272 
1273 	cpudata->cpu = policy->cpu;
1274 	cpudata->epp_policy = 0;
1275 
1276 	amd_pstate_init_prefcore(cpudata);
1277 
1278 	ret = amd_pstate_init_perf(cpudata);
1279 	if (ret)
1280 		goto free_cpudata1;
1281 
1282 	min_freq = amd_get_min_freq(cpudata);
1283 	max_freq = amd_get_max_freq(cpudata);
1284 	nominal_freq = amd_get_nominal_freq(cpudata);
1285 	lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata);
1286 	if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) {
1287 		dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n",
1288 				min_freq, max_freq);
1289 		ret = -EINVAL;
1290 		goto free_cpudata1;
1291 	}
1292 
1293 	policy->cpuinfo.min_freq = min_freq;
1294 	policy->cpuinfo.max_freq = max_freq;
1295 	/* It will be updated by governor */
1296 	policy->cur = policy->cpuinfo.min_freq;
1297 
1298 	/* Initial processor data capability frequencies */
1299 	cpudata->max_freq = max_freq;
1300 	cpudata->min_freq = min_freq;
1301 	cpudata->nominal_freq = nominal_freq;
1302 	cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
1303 
1304 	policy->driver_data = cpudata;
1305 
1306 	cpudata->epp_cached = amd_pstate_get_epp(cpudata, 0);
1307 
1308 	policy->min = policy->cpuinfo.min_freq;
1309 	policy->max = policy->cpuinfo.max_freq;
1310 
1311 	/*
1312 	 * Set the policy to provide a valid fallback value in case
1313 	 * the default cpufreq governor is neither powersave nor performance.
1314 	 */
1315 	if (amd_pstate_acpi_pm_profile_server() ||
1316 	    amd_pstate_acpi_pm_profile_undefined())
1317 		policy->policy = CPUFREQ_POLICY_PERFORMANCE;
1318 	else
1319 		policy->policy = CPUFREQ_POLICY_POWERSAVE;
1320 
1321 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
1322 		ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &value);
1323 		if (ret)
1324 			return ret;
1325 		WRITE_ONCE(cpudata->cppc_req_cached, value);
1326 
1327 		ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1, &value);
1328 		if (ret)
1329 			return ret;
1330 		WRITE_ONCE(cpudata->cppc_cap1_cached, value);
1331 	}
1332 	amd_pstate_boost_init(cpudata);
1333 
1334 	return 0;
1335 
1336 free_cpudata1:
1337 	kfree(cpudata);
1338 	return ret;
1339 }
1340 
1341 static int amd_pstate_epp_cpu_exit(struct cpufreq_policy *policy)
1342 {
1343 	struct amd_cpudata *cpudata = policy->driver_data;
1344 
1345 	if (cpudata) {
1346 		kfree(cpudata);
1347 		policy->driver_data = NULL;
1348 	}
1349 
1350 	pr_debug("CPU %d exiting\n", policy->cpu);
1351 	return 0;
1352 }
1353 
1354 static void amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
1355 {
1356 	struct amd_cpudata *cpudata = policy->driver_data;
1357 	u32 max_perf, min_perf, min_limit_perf, max_limit_perf;
1358 	u64 value;
1359 	s16 epp;
1360 
1361 	max_perf = READ_ONCE(cpudata->highest_perf);
1362 	min_perf = READ_ONCE(cpudata->lowest_perf);
1363 	max_limit_perf = div_u64(policy->max * cpudata->highest_perf, cpudata->max_freq);
1364 	min_limit_perf = div_u64(policy->min * cpudata->highest_perf, cpudata->max_freq);
1365 
1366 	WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
1367 	WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
1368 
1369 	max_perf = clamp_t(unsigned long, max_perf, cpudata->min_limit_perf,
1370 			cpudata->max_limit_perf);
1371 	min_perf = clamp_t(unsigned long, min_perf, cpudata->min_limit_perf,
1372 			cpudata->max_limit_perf);
1373 	value = READ_ONCE(cpudata->cppc_req_cached);
1374 
1375 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
1376 		min_perf = max_perf;
1377 
1378 	/* Initial min/max values for CPPC Performance Controls Register */
1379 	value &= ~AMD_CPPC_MIN_PERF(~0L);
1380 	value |= AMD_CPPC_MIN_PERF(min_perf);
1381 
1382 	value &= ~AMD_CPPC_MAX_PERF(~0L);
1383 	value |= AMD_CPPC_MAX_PERF(max_perf);
1384 
1385 	/* CPPC EPP feature require to set zero to the desire perf bit */
1386 	value &= ~AMD_CPPC_DES_PERF(~0L);
1387 	value |= AMD_CPPC_DES_PERF(0);
1388 
1389 	cpudata->epp_policy = cpudata->policy;
1390 
1391 	/* Get BIOS pre-defined epp value */
1392 	epp = amd_pstate_get_epp(cpudata, value);
1393 	if (epp < 0) {
1394 		/**
1395 		 * This return value can only be negative for shared_memory
1396 		 * systems where EPP register read/write not supported.
1397 		 */
1398 		return;
1399 	}
1400 
1401 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
1402 		epp = 0;
1403 
1404 	/* Set initial EPP value */
1405 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
1406 		value &= ~GENMASK_ULL(31, 24);
1407 		value |= (u64)epp << 24;
1408 	}
1409 
1410 	WRITE_ONCE(cpudata->cppc_req_cached, value);
1411 	amd_pstate_set_epp(cpudata, epp);
1412 }
1413 
1414 static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
1415 {
1416 	struct amd_cpudata *cpudata = policy->driver_data;
1417 
1418 	if (!policy->cpuinfo.max_freq)
1419 		return -ENODEV;
1420 
1421 	pr_debug("set_policy: cpuinfo.max %u policy->max %u\n",
1422 				policy->cpuinfo.max_freq, policy->max);
1423 
1424 	cpudata->policy = policy->policy;
1425 
1426 	amd_pstate_epp_update_limit(policy);
1427 
1428 	return 0;
1429 }
1430 
1431 static void amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
1432 {
1433 	struct cppc_perf_ctrls perf_ctrls;
1434 	u64 value, max_perf;
1435 	int ret;
1436 
1437 	ret = amd_pstate_enable(true);
1438 	if (ret)
1439 		pr_err("failed to enable amd pstate during resume, return %d\n", ret);
1440 
1441 	value = READ_ONCE(cpudata->cppc_req_cached);
1442 	max_perf = READ_ONCE(cpudata->highest_perf);
1443 
1444 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
1445 		wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
1446 	} else {
1447 		perf_ctrls.max_perf = max_perf;
1448 		perf_ctrls.energy_perf = AMD_CPPC_ENERGY_PERF_PREF(cpudata->epp_cached);
1449 		cppc_set_perf(cpudata->cpu, &perf_ctrls);
1450 	}
1451 }
1452 
1453 static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
1454 {
1455 	struct amd_cpudata *cpudata = policy->driver_data;
1456 
1457 	pr_debug("AMD CPU Core %d going online\n", cpudata->cpu);
1458 
1459 	if (cppc_state == AMD_PSTATE_ACTIVE) {
1460 		amd_pstate_epp_reenable(cpudata);
1461 		cpudata->suspended = false;
1462 	}
1463 
1464 	return 0;
1465 }
1466 
1467 static void amd_pstate_epp_offline(struct cpufreq_policy *policy)
1468 {
1469 	struct amd_cpudata *cpudata = policy->driver_data;
1470 	struct cppc_perf_ctrls perf_ctrls;
1471 	int min_perf;
1472 	u64 value;
1473 
1474 	min_perf = READ_ONCE(cpudata->lowest_perf);
1475 	value = READ_ONCE(cpudata->cppc_req_cached);
1476 
1477 	mutex_lock(&amd_pstate_limits_lock);
1478 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
1479 		cpudata->epp_policy = CPUFREQ_POLICY_UNKNOWN;
1480 
1481 		/* Set max perf same as min perf */
1482 		value &= ~AMD_CPPC_MAX_PERF(~0L);
1483 		value |= AMD_CPPC_MAX_PERF(min_perf);
1484 		value &= ~AMD_CPPC_MIN_PERF(~0L);
1485 		value |= AMD_CPPC_MIN_PERF(min_perf);
1486 		wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
1487 	} else {
1488 		perf_ctrls.desired_perf = 0;
1489 		perf_ctrls.max_perf = min_perf;
1490 		perf_ctrls.energy_perf = AMD_CPPC_ENERGY_PERF_PREF(HWP_EPP_BALANCE_POWERSAVE);
1491 		cppc_set_perf(cpudata->cpu, &perf_ctrls);
1492 	}
1493 	mutex_unlock(&amd_pstate_limits_lock);
1494 }
1495 
1496 static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
1497 {
1498 	struct amd_cpudata *cpudata = policy->driver_data;
1499 
1500 	pr_debug("AMD CPU Core %d going offline\n", cpudata->cpu);
1501 
1502 	if (cpudata->suspended)
1503 		return 0;
1504 
1505 	if (cppc_state == AMD_PSTATE_ACTIVE)
1506 		amd_pstate_epp_offline(policy);
1507 
1508 	return 0;
1509 }
1510 
1511 static int amd_pstate_epp_verify_policy(struct cpufreq_policy_data *policy)
1512 {
1513 	cpufreq_verify_within_cpu_limits(policy);
1514 	pr_debug("policy_max =%d, policy_min=%d\n", policy->max, policy->min);
1515 	return 0;
1516 }
1517 
1518 static int amd_pstate_epp_suspend(struct cpufreq_policy *policy)
1519 {
1520 	struct amd_cpudata *cpudata = policy->driver_data;
1521 	int ret;
1522 
1523 	/* avoid suspending when EPP is not enabled */
1524 	if (cppc_state != AMD_PSTATE_ACTIVE)
1525 		return 0;
1526 
1527 	/* set this flag to avoid setting core offline*/
1528 	cpudata->suspended = true;
1529 
1530 	/* disable CPPC in lowlevel firmware */
1531 	ret = amd_pstate_enable(false);
1532 	if (ret)
1533 		pr_err("failed to suspend, return %d\n", ret);
1534 
1535 	return 0;
1536 }
1537 
1538 static int amd_pstate_epp_resume(struct cpufreq_policy *policy)
1539 {
1540 	struct amd_cpudata *cpudata = policy->driver_data;
1541 
1542 	if (cpudata->suspended) {
1543 		mutex_lock(&amd_pstate_limits_lock);
1544 
1545 		/* enable amd pstate from suspend state*/
1546 		amd_pstate_epp_reenable(cpudata);
1547 
1548 		mutex_unlock(&amd_pstate_limits_lock);
1549 
1550 		cpudata->suspended = false;
1551 	}
1552 
1553 	return 0;
1554 }
1555 
1556 static struct cpufreq_driver amd_pstate_driver = {
1557 	.flags		= CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS,
1558 	.verify		= amd_pstate_verify,
1559 	.target		= amd_pstate_target,
1560 	.fast_switch    = amd_pstate_fast_switch,
1561 	.init		= amd_pstate_cpu_init,
1562 	.exit		= amd_pstate_cpu_exit,
1563 	.suspend	= amd_pstate_cpu_suspend,
1564 	.resume		= amd_pstate_cpu_resume,
1565 	.set_boost	= amd_pstate_set_boost,
1566 	.name		= "amd-pstate",
1567 	.attr		= amd_pstate_attr,
1568 };
1569 
1570 static struct cpufreq_driver amd_pstate_epp_driver = {
1571 	.flags		= CPUFREQ_CONST_LOOPS,
1572 	.verify		= amd_pstate_epp_verify_policy,
1573 	.setpolicy	= amd_pstate_epp_set_policy,
1574 	.init		= amd_pstate_epp_cpu_init,
1575 	.exit		= amd_pstate_epp_cpu_exit,
1576 	.offline	= amd_pstate_epp_cpu_offline,
1577 	.online		= amd_pstate_epp_cpu_online,
1578 	.suspend	= amd_pstate_epp_suspend,
1579 	.resume		= amd_pstate_epp_resume,
1580 	.name		= "amd-pstate-epp",
1581 	.attr		= amd_pstate_epp_attr,
1582 };
1583 
1584 static int __init amd_pstate_set_driver(int mode_idx)
1585 {
1586 	if (mode_idx >= AMD_PSTATE_DISABLE && mode_idx < AMD_PSTATE_MAX) {
1587 		cppc_state = mode_idx;
1588 		if (cppc_state == AMD_PSTATE_DISABLE)
1589 			pr_info("driver is explicitly disabled\n");
1590 
1591 		if (cppc_state == AMD_PSTATE_ACTIVE)
1592 			current_pstate_driver = &amd_pstate_epp_driver;
1593 
1594 		if (cppc_state == AMD_PSTATE_PASSIVE || cppc_state == AMD_PSTATE_GUIDED)
1595 			current_pstate_driver = &amd_pstate_driver;
1596 
1597 		return 0;
1598 	}
1599 
1600 	return -EINVAL;
1601 }
1602 
1603 static int __init amd_pstate_init(void)
1604 {
1605 	struct device *dev_root;
1606 	int ret;
1607 
1608 	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
1609 		return -ENODEV;
1610 
1611 	if (!acpi_cpc_valid()) {
1612 		pr_warn_once("the _CPC object is not present in SBIOS or ACPI disabled\n");
1613 		return -ENODEV;
1614 	}
1615 
1616 	/* don't keep reloading if cpufreq_driver exists */
1617 	if (cpufreq_get_current_driver())
1618 		return -EEXIST;
1619 
1620 	switch (cppc_state) {
1621 	case AMD_PSTATE_UNDEFINED:
1622 		/* Disable on the following configs by default:
1623 		 * 1. Undefined platforms
1624 		 * 2. Server platforms
1625 		 * 3. Shared memory designs
1626 		 */
1627 		if (amd_pstate_acpi_pm_profile_undefined() ||
1628 		    amd_pstate_acpi_pm_profile_server() ||
1629 		    !boot_cpu_has(X86_FEATURE_CPPC)) {
1630 			pr_info("driver load is disabled, boot with specific mode to enable this\n");
1631 			return -ENODEV;
1632 		}
1633 		ret = amd_pstate_set_driver(CONFIG_X86_AMD_PSTATE_DEFAULT_MODE);
1634 		if (ret)
1635 			return ret;
1636 		break;
1637 	case AMD_PSTATE_DISABLE:
1638 		return -ENODEV;
1639 	case AMD_PSTATE_PASSIVE:
1640 	case AMD_PSTATE_ACTIVE:
1641 	case AMD_PSTATE_GUIDED:
1642 		break;
1643 	default:
1644 		return -EINVAL;
1645 	}
1646 
1647 	/* capability check */
1648 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
1649 		pr_debug("AMD CPPC MSR based functionality is supported\n");
1650 		if (cppc_state != AMD_PSTATE_ACTIVE)
1651 			current_pstate_driver->adjust_perf = amd_pstate_adjust_perf;
1652 	} else {
1653 		pr_debug("AMD CPPC shared memory based functionality is supported\n");
1654 		static_call_update(amd_pstate_enable, cppc_enable);
1655 		static_call_update(amd_pstate_init_perf, cppc_init_perf);
1656 		static_call_update(amd_pstate_update_perf, cppc_update_perf);
1657 	}
1658 
1659 	/* enable amd pstate feature */
1660 	ret = amd_pstate_enable(true);
1661 	if (ret) {
1662 		pr_err("failed to enable with return %d\n", ret);
1663 		return ret;
1664 	}
1665 
1666 	ret = cpufreq_register_driver(current_pstate_driver);
1667 	if (ret)
1668 		pr_err("failed to register with return %d\n", ret);
1669 
1670 	dev_root = bus_get_dev_root(&cpu_subsys);
1671 	if (dev_root) {
1672 		ret = sysfs_create_group(&dev_root->kobj, &amd_pstate_global_attr_group);
1673 		put_device(dev_root);
1674 		if (ret) {
1675 			pr_err("sysfs attribute export failed with error %d.\n", ret);
1676 			goto global_attr_free;
1677 		}
1678 	}
1679 
1680 	return ret;
1681 
1682 global_attr_free:
1683 	cpufreq_unregister_driver(current_pstate_driver);
1684 	return ret;
1685 }
1686 device_initcall(amd_pstate_init);
1687 
1688 static int __init amd_pstate_param(char *str)
1689 {
1690 	size_t size;
1691 	int mode_idx;
1692 
1693 	if (!str)
1694 		return -EINVAL;
1695 
1696 	size = strlen(str);
1697 	mode_idx = get_mode_idx_from_str(str, size);
1698 
1699 	return amd_pstate_set_driver(mode_idx);
1700 }
1701 
1702 static int __init amd_prefcore_param(char *str)
1703 {
1704 	if (!strcmp(str, "disable"))
1705 		amd_pstate_prefcore = false;
1706 
1707 	return 0;
1708 }
1709 
1710 early_param("amd_pstate", amd_pstate_param);
1711 early_param("amd_prefcore", amd_prefcore_param);
1712 
1713 MODULE_AUTHOR("Huang Rui <ray.huang@amd.com>");
1714 MODULE_DESCRIPTION("AMD Processor P-state Frequency Driver");
1715