xref: /linux/drivers/cpufreq/amd-pstate.c (revision 71dfa617ea9f18e4585fe78364217cd32b1fc382)
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 AMD_PSTATE_PREFCORE_THRESHOLD	166
54 
55 /*
56  * TODO: We need more time to fine tune processors with shared memory solution
57  * with community together.
58  *
59  * There are some performance drops on the CPU benchmarks which reports from
60  * Suse. We are co-working with them to fine tune the shared memory solution. So
61  * we disable it by default to go acpi-cpufreq on these processors and add a
62  * module parameter to be able to enable it manually for debugging.
63  */
64 static struct cpufreq_driver *current_pstate_driver;
65 static struct cpufreq_driver amd_pstate_driver;
66 static struct cpufreq_driver amd_pstate_epp_driver;
67 static int cppc_state = AMD_PSTATE_UNDEFINED;
68 static bool cppc_enabled;
69 static bool amd_pstate_prefcore = true;
70 
71 /*
72  * AMD Energy Preference Performance (EPP)
73  * The EPP is used in the CCLK DPM controller to drive
74  * the frequency that a core is going to operate during
75  * short periods of activity. EPP values will be utilized for
76  * different OS profiles (balanced, performance, power savings)
77  * display strings corresponding to EPP index in the
78  * energy_perf_strings[]
79  *	index		String
80  *-------------------------------------
81  *	0		default
82  *	1		performance
83  *	2		balance_performance
84  *	3		balance_power
85  *	4		power
86  */
87 enum energy_perf_value_index {
88 	EPP_INDEX_DEFAULT = 0,
89 	EPP_INDEX_PERFORMANCE,
90 	EPP_INDEX_BALANCE_PERFORMANCE,
91 	EPP_INDEX_BALANCE_POWERSAVE,
92 	EPP_INDEX_POWERSAVE,
93 };
94 
95 static const char * const energy_perf_strings[] = {
96 	[EPP_INDEX_DEFAULT] = "default",
97 	[EPP_INDEX_PERFORMANCE] = "performance",
98 	[EPP_INDEX_BALANCE_PERFORMANCE] = "balance_performance",
99 	[EPP_INDEX_BALANCE_POWERSAVE] = "balance_power",
100 	[EPP_INDEX_POWERSAVE] = "power",
101 	NULL
102 };
103 
104 static unsigned int epp_values[] = {
105 	[EPP_INDEX_DEFAULT] = 0,
106 	[EPP_INDEX_PERFORMANCE] = AMD_CPPC_EPP_PERFORMANCE,
107 	[EPP_INDEX_BALANCE_PERFORMANCE] = AMD_CPPC_EPP_BALANCE_PERFORMANCE,
108 	[EPP_INDEX_BALANCE_POWERSAVE] = AMD_CPPC_EPP_BALANCE_POWERSAVE,
109 	[EPP_INDEX_POWERSAVE] = AMD_CPPC_EPP_POWERSAVE,
110  };
111 
112 typedef int (*cppc_mode_transition_fn)(int);
113 
114 static inline int get_mode_idx_from_str(const char *str, size_t size)
115 {
116 	int i;
117 
118 	for (i=0; i < AMD_PSTATE_MAX; i++) {
119 		if (!strncmp(str, amd_pstate_mode_string[i], size))
120 			return i;
121 	}
122 	return -EINVAL;
123 }
124 
125 static DEFINE_MUTEX(amd_pstate_limits_lock);
126 static DEFINE_MUTEX(amd_pstate_driver_lock);
127 
128 static s16 amd_pstate_get_epp(struct amd_cpudata *cpudata, u64 cppc_req_cached)
129 {
130 	u64 epp;
131 	int ret;
132 
133 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
134 		if (!cppc_req_cached) {
135 			epp = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
136 					&cppc_req_cached);
137 			if (epp)
138 				return epp;
139 		}
140 		epp = (cppc_req_cached >> 24) & 0xFF;
141 	} else {
142 		ret = cppc_get_epp_perf(cpudata->cpu, &epp);
143 		if (ret < 0) {
144 			pr_debug("Could not retrieve energy perf value (%d)\n", ret);
145 			return -EIO;
146 		}
147 	}
148 
149 	return (s16)(epp & 0xff);
150 }
151 
152 static int amd_pstate_get_energy_pref_index(struct amd_cpudata *cpudata)
153 {
154 	s16 epp;
155 	int index = -EINVAL;
156 
157 	epp = amd_pstate_get_epp(cpudata, 0);
158 	if (epp < 0)
159 		return epp;
160 
161 	switch (epp) {
162 	case AMD_CPPC_EPP_PERFORMANCE:
163 		index = EPP_INDEX_PERFORMANCE;
164 		break;
165 	case AMD_CPPC_EPP_BALANCE_PERFORMANCE:
166 		index = EPP_INDEX_BALANCE_PERFORMANCE;
167 		break;
168 	case AMD_CPPC_EPP_BALANCE_POWERSAVE:
169 		index = EPP_INDEX_BALANCE_POWERSAVE;
170 		break;
171 	case AMD_CPPC_EPP_POWERSAVE:
172 		index = EPP_INDEX_POWERSAVE;
173 		break;
174 	default:
175 		break;
176 	}
177 
178 	return index;
179 }
180 
181 static int amd_pstate_set_epp(struct amd_cpudata *cpudata, u32 epp)
182 {
183 	int ret;
184 	struct cppc_perf_ctrls perf_ctrls;
185 
186 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
187 		u64 value = READ_ONCE(cpudata->cppc_req_cached);
188 
189 		value &= ~GENMASK_ULL(31, 24);
190 		value |= (u64)epp << 24;
191 		WRITE_ONCE(cpudata->cppc_req_cached, value);
192 
193 		ret = wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
194 		if (!ret)
195 			cpudata->epp_cached = epp;
196 	} else {
197 		perf_ctrls.energy_perf = epp;
198 		ret = cppc_set_epp_perf(cpudata->cpu, &perf_ctrls, 1);
199 		if (ret) {
200 			pr_debug("failed to set energy perf value (%d)\n", ret);
201 			return ret;
202 		}
203 		cpudata->epp_cached = epp;
204 	}
205 
206 	return ret;
207 }
208 
209 static int amd_pstate_set_energy_pref_index(struct amd_cpudata *cpudata,
210 		int pref_index)
211 {
212 	int epp = -EINVAL;
213 	int ret;
214 
215 	if (!pref_index) {
216 		pr_debug("EPP pref_index is invalid\n");
217 		return -EINVAL;
218 	}
219 
220 	if (epp == -EINVAL)
221 		epp = epp_values[pref_index];
222 
223 	if (epp > 0 && cpudata->policy == CPUFREQ_POLICY_PERFORMANCE) {
224 		pr_debug("EPP cannot be set under performance policy\n");
225 		return -EBUSY;
226 	}
227 
228 	ret = amd_pstate_set_epp(cpudata, epp);
229 
230 	return ret;
231 }
232 
233 static inline int pstate_enable(bool enable)
234 {
235 	int ret, cpu;
236 	unsigned long logical_proc_id_mask = 0;
237 
238 	if (enable == cppc_enabled)
239 		return 0;
240 
241 	for_each_present_cpu(cpu) {
242 		unsigned long logical_id = topology_logical_die_id(cpu);
243 
244 		if (test_bit(logical_id, &logical_proc_id_mask))
245 			continue;
246 
247 		set_bit(logical_id, &logical_proc_id_mask);
248 
249 		ret = wrmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_ENABLE,
250 				enable);
251 		if (ret)
252 			return ret;
253 	}
254 
255 	cppc_enabled = enable;
256 	return 0;
257 }
258 
259 static int cppc_enable(bool enable)
260 {
261 	int cpu, ret = 0;
262 	struct cppc_perf_ctrls perf_ctrls;
263 
264 	if (enable == cppc_enabled)
265 		return 0;
266 
267 	for_each_present_cpu(cpu) {
268 		ret = cppc_set_enable(cpu, enable);
269 		if (ret)
270 			return ret;
271 
272 		/* Enable autonomous mode for EPP */
273 		if (cppc_state == AMD_PSTATE_ACTIVE) {
274 			/* Set desired perf as zero to allow EPP firmware control */
275 			perf_ctrls.desired_perf = 0;
276 			ret = cppc_set_perf(cpu, &perf_ctrls);
277 			if (ret)
278 				return ret;
279 		}
280 	}
281 
282 	cppc_enabled = enable;
283 	return ret;
284 }
285 
286 DEFINE_STATIC_CALL(amd_pstate_enable, pstate_enable);
287 
288 static inline int amd_pstate_enable(bool enable)
289 {
290 	return static_call(amd_pstate_enable)(enable);
291 }
292 
293 static int pstate_init_perf(struct amd_cpudata *cpudata)
294 {
295 	u64 cap1;
296 	u32 highest_perf;
297 
298 	int ret = rdmsrl_safe_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1,
299 				     &cap1);
300 	if (ret)
301 		return ret;
302 
303 	/* For platforms that do not support the preferred core feature, the
304 	 * highest_pef may be configured with 166 or 255, to avoid max frequency
305 	 * calculated wrongly. we take the AMD_CPPC_HIGHEST_PERF(cap1) value as
306 	 * the default max perf.
307 	 */
308 	if (cpudata->hw_prefcore)
309 		highest_perf = AMD_PSTATE_PREFCORE_THRESHOLD;
310 	else
311 		highest_perf = AMD_CPPC_HIGHEST_PERF(cap1);
312 
313 	WRITE_ONCE(cpudata->highest_perf, highest_perf);
314 	WRITE_ONCE(cpudata->max_limit_perf, highest_perf);
315 	WRITE_ONCE(cpudata->nominal_perf, AMD_CPPC_NOMINAL_PERF(cap1));
316 	WRITE_ONCE(cpudata->lowest_nonlinear_perf, AMD_CPPC_LOWNONLIN_PERF(cap1));
317 	WRITE_ONCE(cpudata->lowest_perf, AMD_CPPC_LOWEST_PERF(cap1));
318 	WRITE_ONCE(cpudata->prefcore_ranking, AMD_CPPC_HIGHEST_PERF(cap1));
319 	WRITE_ONCE(cpudata->min_limit_perf, AMD_CPPC_LOWEST_PERF(cap1));
320 	return 0;
321 }
322 
323 static int cppc_init_perf(struct amd_cpudata *cpudata)
324 {
325 	struct cppc_perf_caps cppc_perf;
326 	u32 highest_perf;
327 
328 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
329 	if (ret)
330 		return ret;
331 
332 	if (cpudata->hw_prefcore)
333 		highest_perf = AMD_PSTATE_PREFCORE_THRESHOLD;
334 	else
335 		highest_perf = cppc_perf.highest_perf;
336 
337 	WRITE_ONCE(cpudata->highest_perf, highest_perf);
338 	WRITE_ONCE(cpudata->max_limit_perf, highest_perf);
339 	WRITE_ONCE(cpudata->nominal_perf, cppc_perf.nominal_perf);
340 	WRITE_ONCE(cpudata->lowest_nonlinear_perf,
341 		   cppc_perf.lowest_nonlinear_perf);
342 	WRITE_ONCE(cpudata->lowest_perf, cppc_perf.lowest_perf);
343 	WRITE_ONCE(cpudata->prefcore_ranking, cppc_perf.highest_perf);
344 	WRITE_ONCE(cpudata->min_limit_perf, cppc_perf.lowest_perf);
345 
346 	if (cppc_state == AMD_PSTATE_ACTIVE)
347 		return 0;
348 
349 	ret = cppc_get_auto_sel_caps(cpudata->cpu, &cppc_perf);
350 	if (ret) {
351 		pr_warn("failed to get auto_sel, ret: %d\n", ret);
352 		return 0;
353 	}
354 
355 	ret = cppc_set_auto_sel(cpudata->cpu,
356 			(cppc_state == AMD_PSTATE_PASSIVE) ? 0 : 1);
357 
358 	if (ret)
359 		pr_warn("failed to set auto_sel, ret: %d\n", ret);
360 
361 	return ret;
362 }
363 
364 DEFINE_STATIC_CALL(amd_pstate_init_perf, pstate_init_perf);
365 
366 static inline int amd_pstate_init_perf(struct amd_cpudata *cpudata)
367 {
368 	return static_call(amd_pstate_init_perf)(cpudata);
369 }
370 
371 static void pstate_update_perf(struct amd_cpudata *cpudata, u32 min_perf,
372 			       u32 des_perf, u32 max_perf, bool fast_switch)
373 {
374 	if (fast_switch)
375 		wrmsrl(MSR_AMD_CPPC_REQ, READ_ONCE(cpudata->cppc_req_cached));
376 	else
377 		wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ,
378 			      READ_ONCE(cpudata->cppc_req_cached));
379 }
380 
381 static void cppc_update_perf(struct amd_cpudata *cpudata,
382 			     u32 min_perf, u32 des_perf,
383 			     u32 max_perf, bool fast_switch)
384 {
385 	struct cppc_perf_ctrls perf_ctrls;
386 
387 	perf_ctrls.max_perf = max_perf;
388 	perf_ctrls.min_perf = min_perf;
389 	perf_ctrls.desired_perf = des_perf;
390 
391 	cppc_set_perf(cpudata->cpu, &perf_ctrls);
392 }
393 
394 DEFINE_STATIC_CALL(amd_pstate_update_perf, pstate_update_perf);
395 
396 static inline void amd_pstate_update_perf(struct amd_cpudata *cpudata,
397 					  u32 min_perf, u32 des_perf,
398 					  u32 max_perf, bool fast_switch)
399 {
400 	static_call(amd_pstate_update_perf)(cpudata, min_perf, des_perf,
401 					    max_perf, fast_switch);
402 }
403 
404 static inline bool amd_pstate_sample(struct amd_cpudata *cpudata)
405 {
406 	u64 aperf, mperf, tsc;
407 	unsigned long flags;
408 
409 	local_irq_save(flags);
410 	rdmsrl(MSR_IA32_APERF, aperf);
411 	rdmsrl(MSR_IA32_MPERF, mperf);
412 	tsc = rdtsc();
413 
414 	if (cpudata->prev.mperf == mperf || cpudata->prev.tsc == tsc) {
415 		local_irq_restore(flags);
416 		return false;
417 	}
418 
419 	local_irq_restore(flags);
420 
421 	cpudata->cur.aperf = aperf;
422 	cpudata->cur.mperf = mperf;
423 	cpudata->cur.tsc =  tsc;
424 	cpudata->cur.aperf -= cpudata->prev.aperf;
425 	cpudata->cur.mperf -= cpudata->prev.mperf;
426 	cpudata->cur.tsc -= cpudata->prev.tsc;
427 
428 	cpudata->prev.aperf = aperf;
429 	cpudata->prev.mperf = mperf;
430 	cpudata->prev.tsc = tsc;
431 
432 	cpudata->freq = div64_u64((cpudata->cur.aperf * cpu_khz), cpudata->cur.mperf);
433 
434 	return true;
435 }
436 
437 static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
438 			      u32 des_perf, u32 max_perf, bool fast_switch, int gov_flags)
439 {
440 	u64 prev = READ_ONCE(cpudata->cppc_req_cached);
441 	u64 value = prev;
442 
443 	min_perf = clamp_t(unsigned long, min_perf, cpudata->min_limit_perf,
444 			cpudata->max_limit_perf);
445 	max_perf = clamp_t(unsigned long, max_perf, cpudata->min_limit_perf,
446 			cpudata->max_limit_perf);
447 	des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
448 
449 	if ((cppc_state == AMD_PSTATE_GUIDED) && (gov_flags & CPUFREQ_GOV_DYNAMIC_SWITCHING)) {
450 		min_perf = des_perf;
451 		des_perf = 0;
452 	}
453 
454 	value &= ~AMD_CPPC_MIN_PERF(~0L);
455 	value |= AMD_CPPC_MIN_PERF(min_perf);
456 
457 	value &= ~AMD_CPPC_DES_PERF(~0L);
458 	value |= AMD_CPPC_DES_PERF(des_perf);
459 
460 	value &= ~AMD_CPPC_MAX_PERF(~0L);
461 	value |= AMD_CPPC_MAX_PERF(max_perf);
462 
463 	if (trace_amd_pstate_perf_enabled() && amd_pstate_sample(cpudata)) {
464 		trace_amd_pstate_perf(min_perf, des_perf, max_perf, cpudata->freq,
465 			cpudata->cur.mperf, cpudata->cur.aperf, cpudata->cur.tsc,
466 				cpudata->cpu, (value != prev), fast_switch);
467 	}
468 
469 	if (value == prev)
470 		return;
471 
472 	WRITE_ONCE(cpudata->cppc_req_cached, value);
473 
474 	amd_pstate_update_perf(cpudata, min_perf, des_perf,
475 			       max_perf, fast_switch);
476 }
477 
478 static int amd_pstate_verify(struct cpufreq_policy_data *policy)
479 {
480 	cpufreq_verify_within_cpu_limits(policy);
481 
482 	return 0;
483 }
484 
485 static int amd_pstate_update_min_max_limit(struct cpufreq_policy *policy)
486 {
487 	u32 max_limit_perf, min_limit_perf, lowest_perf;
488 	struct amd_cpudata *cpudata = policy->driver_data;
489 
490 	max_limit_perf = div_u64(policy->max * cpudata->highest_perf, cpudata->max_freq);
491 	min_limit_perf = div_u64(policy->min * cpudata->highest_perf, cpudata->max_freq);
492 
493 	lowest_perf = READ_ONCE(cpudata->lowest_perf);
494 	if (min_limit_perf < lowest_perf)
495 		min_limit_perf = lowest_perf;
496 
497 	if (max_limit_perf < min_limit_perf)
498 		max_limit_perf = min_limit_perf;
499 
500 	WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
501 	WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
502 	WRITE_ONCE(cpudata->max_limit_freq, policy->max);
503 	WRITE_ONCE(cpudata->min_limit_freq, policy->min);
504 
505 	return 0;
506 }
507 
508 static int amd_pstate_update_freq(struct cpufreq_policy *policy,
509 				  unsigned int target_freq, bool fast_switch)
510 {
511 	struct cpufreq_freqs freqs;
512 	struct amd_cpudata *cpudata = policy->driver_data;
513 	unsigned long max_perf, min_perf, des_perf, cap_perf;
514 
515 	if (!cpudata->max_freq)
516 		return -ENODEV;
517 
518 	if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq)
519 		amd_pstate_update_min_max_limit(policy);
520 
521 	cap_perf = READ_ONCE(cpudata->highest_perf);
522 	min_perf = READ_ONCE(cpudata->lowest_perf);
523 	max_perf = cap_perf;
524 
525 	freqs.old = policy->cur;
526 	freqs.new = target_freq;
527 
528 	des_perf = DIV_ROUND_CLOSEST(target_freq * cap_perf,
529 				     cpudata->max_freq);
530 
531 	WARN_ON(fast_switch && !policy->fast_switch_enabled);
532 	/*
533 	 * If fast_switch is desired, then there aren't any registered
534 	 * transition notifiers. See comment for
535 	 * cpufreq_enable_fast_switch().
536 	 */
537 	if (!fast_switch)
538 		cpufreq_freq_transition_begin(policy, &freqs);
539 
540 	amd_pstate_update(cpudata, min_perf, des_perf,
541 			max_perf, fast_switch, policy->governor->flags);
542 
543 	if (!fast_switch)
544 		cpufreq_freq_transition_end(policy, &freqs, false);
545 
546 	return 0;
547 }
548 
549 static int amd_pstate_target(struct cpufreq_policy *policy,
550 			     unsigned int target_freq,
551 			     unsigned int relation)
552 {
553 	return amd_pstate_update_freq(policy, target_freq, false);
554 }
555 
556 static unsigned int amd_pstate_fast_switch(struct cpufreq_policy *policy,
557 				  unsigned int target_freq)
558 {
559 	if (!amd_pstate_update_freq(policy, target_freq, true))
560 		return target_freq;
561 	return policy->cur;
562 }
563 
564 static void amd_pstate_adjust_perf(unsigned int cpu,
565 				   unsigned long _min_perf,
566 				   unsigned long target_perf,
567 				   unsigned long capacity)
568 {
569 	unsigned long max_perf, min_perf, des_perf,
570 		      cap_perf, lowest_nonlinear_perf, max_freq;
571 	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
572 	struct amd_cpudata *cpudata = policy->driver_data;
573 	unsigned int target_freq;
574 
575 	if (policy->min != cpudata->min_limit_freq || policy->max != cpudata->max_limit_freq)
576 		amd_pstate_update_min_max_limit(policy);
577 
578 
579 	cap_perf = READ_ONCE(cpudata->highest_perf);
580 	lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf);
581 	max_freq = READ_ONCE(cpudata->max_freq);
582 
583 	des_perf = cap_perf;
584 	if (target_perf < capacity)
585 		des_perf = DIV_ROUND_UP(cap_perf * target_perf, capacity);
586 
587 	min_perf = READ_ONCE(cpudata->lowest_perf);
588 	if (_min_perf < capacity)
589 		min_perf = DIV_ROUND_UP(cap_perf * _min_perf, capacity);
590 
591 	if (min_perf < lowest_nonlinear_perf)
592 		min_perf = lowest_nonlinear_perf;
593 
594 	max_perf = cap_perf;
595 	if (max_perf < min_perf)
596 		max_perf = min_perf;
597 
598 	des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
599 	target_freq = div_u64(des_perf * max_freq, max_perf);
600 	policy->cur = target_freq;
601 
602 	amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true,
603 			policy->governor->flags);
604 	cpufreq_cpu_put(policy);
605 }
606 
607 static int amd_get_min_freq(struct amd_cpudata *cpudata)
608 {
609 	struct cppc_perf_caps cppc_perf;
610 
611 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
612 	if (ret)
613 		return ret;
614 
615 	/* Switch to khz */
616 	return cppc_perf.lowest_freq * 1000;
617 }
618 
619 static int amd_get_max_freq(struct amd_cpudata *cpudata)
620 {
621 	struct cppc_perf_caps cppc_perf;
622 	u32 max_perf, max_freq, nominal_freq, nominal_perf;
623 	u64 boost_ratio;
624 
625 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
626 	if (ret)
627 		return ret;
628 
629 	nominal_freq = cppc_perf.nominal_freq;
630 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
631 	max_perf = READ_ONCE(cpudata->highest_perf);
632 
633 	boost_ratio = div_u64(max_perf << SCHED_CAPACITY_SHIFT,
634 			      nominal_perf);
635 
636 	max_freq = nominal_freq * boost_ratio >> SCHED_CAPACITY_SHIFT;
637 
638 	/* Switch to khz */
639 	return max_freq * 1000;
640 }
641 
642 static int amd_get_nominal_freq(struct amd_cpudata *cpudata)
643 {
644 	struct cppc_perf_caps cppc_perf;
645 
646 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
647 	if (ret)
648 		return ret;
649 
650 	/* Switch to khz */
651 	return cppc_perf.nominal_freq * 1000;
652 }
653 
654 static int amd_get_lowest_nonlinear_freq(struct amd_cpudata *cpudata)
655 {
656 	struct cppc_perf_caps cppc_perf;
657 	u32 lowest_nonlinear_freq, lowest_nonlinear_perf,
658 	    nominal_freq, nominal_perf;
659 	u64 lowest_nonlinear_ratio;
660 
661 	int ret = cppc_get_perf_caps(cpudata->cpu, &cppc_perf);
662 	if (ret)
663 		return ret;
664 
665 	nominal_freq = cppc_perf.nominal_freq;
666 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
667 
668 	lowest_nonlinear_perf = cppc_perf.lowest_nonlinear_perf;
669 
670 	lowest_nonlinear_ratio = div_u64(lowest_nonlinear_perf << SCHED_CAPACITY_SHIFT,
671 					 nominal_perf);
672 
673 	lowest_nonlinear_freq = nominal_freq * lowest_nonlinear_ratio >> SCHED_CAPACITY_SHIFT;
674 
675 	/* Switch to khz */
676 	return lowest_nonlinear_freq * 1000;
677 }
678 
679 static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
680 {
681 	struct amd_cpudata *cpudata = policy->driver_data;
682 	int ret;
683 
684 	if (!cpudata->boost_supported) {
685 		pr_err("Boost mode is not supported by this processor or SBIOS\n");
686 		return -EINVAL;
687 	}
688 
689 	if (state)
690 		policy->cpuinfo.max_freq = cpudata->max_freq;
691 	else
692 		policy->cpuinfo.max_freq = cpudata->nominal_freq;
693 
694 	policy->max = policy->cpuinfo.max_freq;
695 
696 	ret = freq_qos_update_request(&cpudata->req[1],
697 				      policy->cpuinfo.max_freq);
698 	if (ret < 0)
699 		return ret;
700 
701 	return 0;
702 }
703 
704 static void amd_pstate_boost_init(struct amd_cpudata *cpudata)
705 {
706 	u32 highest_perf, nominal_perf;
707 
708 	highest_perf = READ_ONCE(cpudata->highest_perf);
709 	nominal_perf = READ_ONCE(cpudata->nominal_perf);
710 
711 	if (highest_perf <= nominal_perf)
712 		return;
713 
714 	cpudata->boost_supported = true;
715 	current_pstate_driver->boost_enabled = true;
716 }
717 
718 static void amd_perf_ctl_reset(unsigned int cpu)
719 {
720 	wrmsrl_on_cpu(cpu, MSR_AMD_PERF_CTL, 0);
721 }
722 
723 /*
724  * Set amd-pstate preferred core enable can't be done directly from cpufreq callbacks
725  * due to locking, so queue the work for later.
726  */
727 static void amd_pstste_sched_prefcore_workfn(struct work_struct *work)
728 {
729 	sched_set_itmt_support();
730 }
731 static DECLARE_WORK(sched_prefcore_work, amd_pstste_sched_prefcore_workfn);
732 
733 /*
734  * Get the highest performance register value.
735  * @cpu: CPU from which to get highest performance.
736  * @highest_perf: Return address.
737  *
738  * Return: 0 for success, -EIO otherwise.
739  */
740 static int amd_pstate_get_highest_perf(int cpu, u32 *highest_perf)
741 {
742 	int ret;
743 
744 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
745 		u64 cap1;
746 
747 		ret = rdmsrl_safe_on_cpu(cpu, MSR_AMD_CPPC_CAP1, &cap1);
748 		if (ret)
749 			return ret;
750 		WRITE_ONCE(*highest_perf, AMD_CPPC_HIGHEST_PERF(cap1));
751 	} else {
752 		u64 cppc_highest_perf;
753 
754 		ret = cppc_get_highest_perf(cpu, &cppc_highest_perf);
755 		if (ret)
756 			return ret;
757 		WRITE_ONCE(*highest_perf, cppc_highest_perf);
758 	}
759 
760 	return (ret);
761 }
762 
763 #define CPPC_MAX_PERF	U8_MAX
764 
765 static void amd_pstate_init_prefcore(struct amd_cpudata *cpudata)
766 {
767 	int ret, prio;
768 	u32 highest_perf;
769 
770 	ret = amd_pstate_get_highest_perf(cpudata->cpu, &highest_perf);
771 	if (ret)
772 		return;
773 
774 	cpudata->hw_prefcore = true;
775 	/* check if CPPC preferred core feature is enabled*/
776 	if (highest_perf < CPPC_MAX_PERF)
777 		prio = (int)highest_perf;
778 	else {
779 		pr_debug("AMD CPPC preferred core is unsupported!\n");
780 		cpudata->hw_prefcore = false;
781 		return;
782 	}
783 
784 	if (!amd_pstate_prefcore)
785 		return;
786 
787 	/*
788 	 * The priorities can be set regardless of whether or not
789 	 * sched_set_itmt_support(true) has been called and it is valid to
790 	 * update them at any time after it has been called.
791 	 */
792 	sched_set_itmt_core_prio(prio, cpudata->cpu);
793 
794 	schedule_work(&sched_prefcore_work);
795 }
796 
797 static void amd_pstate_update_limits(unsigned int cpu)
798 {
799 	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
800 	struct amd_cpudata *cpudata = policy->driver_data;
801 	u32 prev_high = 0, cur_high = 0;
802 	int ret;
803 	bool highest_perf_changed = false;
804 
805 	mutex_lock(&amd_pstate_driver_lock);
806 	if ((!amd_pstate_prefcore) || (!cpudata->hw_prefcore))
807 		goto free_cpufreq_put;
808 
809 	ret = amd_pstate_get_highest_perf(cpu, &cur_high);
810 	if (ret)
811 		goto free_cpufreq_put;
812 
813 	prev_high = READ_ONCE(cpudata->prefcore_ranking);
814 	if (prev_high != cur_high) {
815 		highest_perf_changed = true;
816 		WRITE_ONCE(cpudata->prefcore_ranking, cur_high);
817 
818 		if (cur_high < CPPC_MAX_PERF)
819 			sched_set_itmt_core_prio((int)cur_high, cpu);
820 	}
821 
822 free_cpufreq_put:
823 	cpufreq_cpu_put(policy);
824 
825 	if (!highest_perf_changed)
826 		cpufreq_update_policy(cpu);
827 
828 	mutex_unlock(&amd_pstate_driver_lock);
829 }
830 
831 static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
832 {
833 	int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret;
834 	struct device *dev;
835 	struct amd_cpudata *cpudata;
836 
837 	/*
838 	 * Resetting PERF_CTL_MSR will put the CPU in P0 frequency,
839 	 * which is ideal for initialization process.
840 	 */
841 	amd_perf_ctl_reset(policy->cpu);
842 	dev = get_cpu_device(policy->cpu);
843 	if (!dev)
844 		return -ENODEV;
845 
846 	cpudata = kzalloc(sizeof(*cpudata), GFP_KERNEL);
847 	if (!cpudata)
848 		return -ENOMEM;
849 
850 	cpudata->cpu = policy->cpu;
851 
852 	amd_pstate_init_prefcore(cpudata);
853 
854 	ret = amd_pstate_init_perf(cpudata);
855 	if (ret)
856 		goto free_cpudata1;
857 
858 	min_freq = amd_get_min_freq(cpudata);
859 	max_freq = amd_get_max_freq(cpudata);
860 	nominal_freq = amd_get_nominal_freq(cpudata);
861 	lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata);
862 
863 	if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) {
864 		dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n",
865 			min_freq, max_freq);
866 		ret = -EINVAL;
867 		goto free_cpudata1;
868 	}
869 
870 	policy->cpuinfo.transition_latency = AMD_PSTATE_TRANSITION_LATENCY;
871 	policy->transition_delay_us = AMD_PSTATE_TRANSITION_DELAY;
872 
873 	policy->min = min_freq;
874 	policy->max = max_freq;
875 
876 	policy->cpuinfo.min_freq = min_freq;
877 	policy->cpuinfo.max_freq = max_freq;
878 
879 	/* It will be updated by governor */
880 	policy->cur = policy->cpuinfo.min_freq;
881 
882 	if (boot_cpu_has(X86_FEATURE_CPPC))
883 		policy->fast_switch_possible = true;
884 
885 	ret = freq_qos_add_request(&policy->constraints, &cpudata->req[0],
886 				   FREQ_QOS_MIN, policy->cpuinfo.min_freq);
887 	if (ret < 0) {
888 		dev_err(dev, "Failed to add min-freq constraint (%d)\n", ret);
889 		goto free_cpudata1;
890 	}
891 
892 	ret = freq_qos_add_request(&policy->constraints, &cpudata->req[1],
893 				   FREQ_QOS_MAX, policy->cpuinfo.max_freq);
894 	if (ret < 0) {
895 		dev_err(dev, "Failed to add max-freq constraint (%d)\n", ret);
896 		goto free_cpudata2;
897 	}
898 
899 	/* Initial processor data capability frequencies */
900 	cpudata->max_freq = max_freq;
901 	cpudata->min_freq = min_freq;
902 	cpudata->max_limit_freq = max_freq;
903 	cpudata->min_limit_freq = min_freq;
904 	cpudata->nominal_freq = nominal_freq;
905 	cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
906 
907 	policy->driver_data = cpudata;
908 
909 	amd_pstate_boost_init(cpudata);
910 	if (!current_pstate_driver->adjust_perf)
911 		current_pstate_driver->adjust_perf = amd_pstate_adjust_perf;
912 
913 	return 0;
914 
915 free_cpudata2:
916 	freq_qos_remove_request(&cpudata->req[0]);
917 free_cpudata1:
918 	kfree(cpudata);
919 	return ret;
920 }
921 
922 static int amd_pstate_cpu_exit(struct cpufreq_policy *policy)
923 {
924 	struct amd_cpudata *cpudata = policy->driver_data;
925 
926 	freq_qos_remove_request(&cpudata->req[1]);
927 	freq_qos_remove_request(&cpudata->req[0]);
928 	policy->fast_switch_possible = false;
929 	kfree(cpudata);
930 
931 	return 0;
932 }
933 
934 static int amd_pstate_cpu_resume(struct cpufreq_policy *policy)
935 {
936 	int ret;
937 
938 	ret = amd_pstate_enable(true);
939 	if (ret)
940 		pr_err("failed to enable amd-pstate during resume, return %d\n", ret);
941 
942 	return ret;
943 }
944 
945 static int amd_pstate_cpu_suspend(struct cpufreq_policy *policy)
946 {
947 	int ret;
948 
949 	ret = amd_pstate_enable(false);
950 	if (ret)
951 		pr_err("failed to disable amd-pstate during suspend, return %d\n", ret);
952 
953 	return ret;
954 }
955 
956 /* Sysfs attributes */
957 
958 /*
959  * This frequency is to indicate the maximum hardware frequency.
960  * If boost is not active but supported, the frequency will be larger than the
961  * one in cpuinfo.
962  */
963 static ssize_t show_amd_pstate_max_freq(struct cpufreq_policy *policy,
964 					char *buf)
965 {
966 	int max_freq;
967 	struct amd_cpudata *cpudata = policy->driver_data;
968 
969 	max_freq = amd_get_max_freq(cpudata);
970 	if (max_freq < 0)
971 		return max_freq;
972 
973 	return sysfs_emit(buf, "%u\n", max_freq);
974 }
975 
976 static ssize_t show_amd_pstate_lowest_nonlinear_freq(struct cpufreq_policy *policy,
977 						     char *buf)
978 {
979 	int freq;
980 	struct amd_cpudata *cpudata = policy->driver_data;
981 
982 	freq = amd_get_lowest_nonlinear_freq(cpudata);
983 	if (freq < 0)
984 		return freq;
985 
986 	return sysfs_emit(buf, "%u\n", freq);
987 }
988 
989 /*
990  * In some of ASICs, the highest_perf is not the one in the _CPC table, so we
991  * need to expose it to sysfs.
992  */
993 static ssize_t show_amd_pstate_highest_perf(struct cpufreq_policy *policy,
994 					    char *buf)
995 {
996 	u32 perf;
997 	struct amd_cpudata *cpudata = policy->driver_data;
998 
999 	perf = READ_ONCE(cpudata->highest_perf);
1000 
1001 	return sysfs_emit(buf, "%u\n", perf);
1002 }
1003 
1004 static ssize_t show_amd_pstate_prefcore_ranking(struct cpufreq_policy *policy,
1005 						char *buf)
1006 {
1007 	u32 perf;
1008 	struct amd_cpudata *cpudata = policy->driver_data;
1009 
1010 	perf = READ_ONCE(cpudata->prefcore_ranking);
1011 
1012 	return sysfs_emit(buf, "%u\n", perf);
1013 }
1014 
1015 static ssize_t show_amd_pstate_hw_prefcore(struct cpufreq_policy *policy,
1016 					   char *buf)
1017 {
1018 	bool hw_prefcore;
1019 	struct amd_cpudata *cpudata = policy->driver_data;
1020 
1021 	hw_prefcore = READ_ONCE(cpudata->hw_prefcore);
1022 
1023 	return sysfs_emit(buf, "%s\n", str_enabled_disabled(hw_prefcore));
1024 }
1025 
1026 static ssize_t show_energy_performance_available_preferences(
1027 				struct cpufreq_policy *policy, char *buf)
1028 {
1029 	int i = 0;
1030 	int offset = 0;
1031 	struct amd_cpudata *cpudata = policy->driver_data;
1032 
1033 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
1034 		return sysfs_emit_at(buf, offset, "%s\n",
1035 				energy_perf_strings[EPP_INDEX_PERFORMANCE]);
1036 
1037 	while (energy_perf_strings[i] != NULL)
1038 		offset += sysfs_emit_at(buf, offset, "%s ", energy_perf_strings[i++]);
1039 
1040 	offset += sysfs_emit_at(buf, offset, "\n");
1041 
1042 	return offset;
1043 }
1044 
1045 static ssize_t store_energy_performance_preference(
1046 		struct cpufreq_policy *policy, const char *buf, size_t count)
1047 {
1048 	struct amd_cpudata *cpudata = policy->driver_data;
1049 	char str_preference[21];
1050 	ssize_t ret;
1051 
1052 	ret = sscanf(buf, "%20s", str_preference);
1053 	if (ret != 1)
1054 		return -EINVAL;
1055 
1056 	ret = match_string(energy_perf_strings, -1, str_preference);
1057 	if (ret < 0)
1058 		return -EINVAL;
1059 
1060 	mutex_lock(&amd_pstate_limits_lock);
1061 	ret = amd_pstate_set_energy_pref_index(cpudata, ret);
1062 	mutex_unlock(&amd_pstate_limits_lock);
1063 
1064 	return ret ?: count;
1065 }
1066 
1067 static ssize_t show_energy_performance_preference(
1068 				struct cpufreq_policy *policy, char *buf)
1069 {
1070 	struct amd_cpudata *cpudata = policy->driver_data;
1071 	int preference;
1072 
1073 	preference = amd_pstate_get_energy_pref_index(cpudata);
1074 	if (preference < 0)
1075 		return preference;
1076 
1077 	return sysfs_emit(buf, "%s\n", energy_perf_strings[preference]);
1078 }
1079 
1080 static void amd_pstate_driver_cleanup(void)
1081 {
1082 	amd_pstate_enable(false);
1083 	cppc_state = AMD_PSTATE_DISABLE;
1084 	current_pstate_driver = NULL;
1085 }
1086 
1087 static int amd_pstate_register_driver(int mode)
1088 {
1089 	int ret;
1090 
1091 	if (mode == AMD_PSTATE_PASSIVE || mode == AMD_PSTATE_GUIDED)
1092 		current_pstate_driver = &amd_pstate_driver;
1093 	else if (mode == AMD_PSTATE_ACTIVE)
1094 		current_pstate_driver = &amd_pstate_epp_driver;
1095 	else
1096 		return -EINVAL;
1097 
1098 	cppc_state = mode;
1099 	ret = cpufreq_register_driver(current_pstate_driver);
1100 	if (ret) {
1101 		amd_pstate_driver_cleanup();
1102 		return ret;
1103 	}
1104 	return 0;
1105 }
1106 
1107 static int amd_pstate_unregister_driver(int dummy)
1108 {
1109 	cpufreq_unregister_driver(current_pstate_driver);
1110 	amd_pstate_driver_cleanup();
1111 	return 0;
1112 }
1113 
1114 static int amd_pstate_change_mode_without_dvr_change(int mode)
1115 {
1116 	int cpu = 0;
1117 
1118 	cppc_state = mode;
1119 
1120 	if (boot_cpu_has(X86_FEATURE_CPPC) || cppc_state == AMD_PSTATE_ACTIVE)
1121 		return 0;
1122 
1123 	for_each_present_cpu(cpu) {
1124 		cppc_set_auto_sel(cpu, (cppc_state == AMD_PSTATE_PASSIVE) ? 0 : 1);
1125 	}
1126 
1127 	return 0;
1128 }
1129 
1130 static int amd_pstate_change_driver_mode(int mode)
1131 {
1132 	int ret;
1133 
1134 	ret = amd_pstate_unregister_driver(0);
1135 	if (ret)
1136 		return ret;
1137 
1138 	ret = amd_pstate_register_driver(mode);
1139 	if (ret)
1140 		return ret;
1141 
1142 	return 0;
1143 }
1144 
1145 static cppc_mode_transition_fn mode_state_machine[AMD_PSTATE_MAX][AMD_PSTATE_MAX] = {
1146 	[AMD_PSTATE_DISABLE]         = {
1147 		[AMD_PSTATE_DISABLE]     = NULL,
1148 		[AMD_PSTATE_PASSIVE]     = amd_pstate_register_driver,
1149 		[AMD_PSTATE_ACTIVE]      = amd_pstate_register_driver,
1150 		[AMD_PSTATE_GUIDED]      = amd_pstate_register_driver,
1151 	},
1152 	[AMD_PSTATE_PASSIVE]         = {
1153 		[AMD_PSTATE_DISABLE]     = amd_pstate_unregister_driver,
1154 		[AMD_PSTATE_PASSIVE]     = NULL,
1155 		[AMD_PSTATE_ACTIVE]      = amd_pstate_change_driver_mode,
1156 		[AMD_PSTATE_GUIDED]      = amd_pstate_change_mode_without_dvr_change,
1157 	},
1158 	[AMD_PSTATE_ACTIVE]          = {
1159 		[AMD_PSTATE_DISABLE]     = amd_pstate_unregister_driver,
1160 		[AMD_PSTATE_PASSIVE]     = amd_pstate_change_driver_mode,
1161 		[AMD_PSTATE_ACTIVE]      = NULL,
1162 		[AMD_PSTATE_GUIDED]      = amd_pstate_change_driver_mode,
1163 	},
1164 	[AMD_PSTATE_GUIDED]          = {
1165 		[AMD_PSTATE_DISABLE]     = amd_pstate_unregister_driver,
1166 		[AMD_PSTATE_PASSIVE]     = amd_pstate_change_mode_without_dvr_change,
1167 		[AMD_PSTATE_ACTIVE]      = amd_pstate_change_driver_mode,
1168 		[AMD_PSTATE_GUIDED]      = NULL,
1169 	},
1170 };
1171 
1172 static ssize_t amd_pstate_show_status(char *buf)
1173 {
1174 	if (!current_pstate_driver)
1175 		return sysfs_emit(buf, "disable\n");
1176 
1177 	return sysfs_emit(buf, "%s\n", amd_pstate_mode_string[cppc_state]);
1178 }
1179 
1180 static int amd_pstate_update_status(const char *buf, size_t size)
1181 {
1182 	int mode_idx;
1183 
1184 	if (size > strlen("passive") || size < strlen("active"))
1185 		return -EINVAL;
1186 
1187 	mode_idx = get_mode_idx_from_str(buf, size);
1188 
1189 	if (mode_idx < 0 || mode_idx >= AMD_PSTATE_MAX)
1190 		return -EINVAL;
1191 
1192 	if (mode_state_machine[cppc_state][mode_idx])
1193 		return mode_state_machine[cppc_state][mode_idx](mode_idx);
1194 
1195 	return 0;
1196 }
1197 
1198 static ssize_t status_show(struct device *dev,
1199 			   struct device_attribute *attr, char *buf)
1200 {
1201 	ssize_t ret;
1202 
1203 	mutex_lock(&amd_pstate_driver_lock);
1204 	ret = amd_pstate_show_status(buf);
1205 	mutex_unlock(&amd_pstate_driver_lock);
1206 
1207 	return ret;
1208 }
1209 
1210 static ssize_t status_store(struct device *a, struct device_attribute *b,
1211 			    const char *buf, size_t count)
1212 {
1213 	char *p = memchr(buf, '\n', count);
1214 	int ret;
1215 
1216 	mutex_lock(&amd_pstate_driver_lock);
1217 	ret = amd_pstate_update_status(buf, p ? p - buf : count);
1218 	mutex_unlock(&amd_pstate_driver_lock);
1219 
1220 	return ret < 0 ? ret : count;
1221 }
1222 
1223 static ssize_t prefcore_show(struct device *dev,
1224 			     struct device_attribute *attr, char *buf)
1225 {
1226 	return sysfs_emit(buf, "%s\n", str_enabled_disabled(amd_pstate_prefcore));
1227 }
1228 
1229 cpufreq_freq_attr_ro(amd_pstate_max_freq);
1230 cpufreq_freq_attr_ro(amd_pstate_lowest_nonlinear_freq);
1231 
1232 cpufreq_freq_attr_ro(amd_pstate_highest_perf);
1233 cpufreq_freq_attr_ro(amd_pstate_prefcore_ranking);
1234 cpufreq_freq_attr_ro(amd_pstate_hw_prefcore);
1235 cpufreq_freq_attr_rw(energy_performance_preference);
1236 cpufreq_freq_attr_ro(energy_performance_available_preferences);
1237 static DEVICE_ATTR_RW(status);
1238 static DEVICE_ATTR_RO(prefcore);
1239 
1240 static struct freq_attr *amd_pstate_attr[] = {
1241 	&amd_pstate_max_freq,
1242 	&amd_pstate_lowest_nonlinear_freq,
1243 	&amd_pstate_highest_perf,
1244 	&amd_pstate_prefcore_ranking,
1245 	&amd_pstate_hw_prefcore,
1246 	NULL,
1247 };
1248 
1249 static struct freq_attr *amd_pstate_epp_attr[] = {
1250 	&amd_pstate_max_freq,
1251 	&amd_pstate_lowest_nonlinear_freq,
1252 	&amd_pstate_highest_perf,
1253 	&amd_pstate_prefcore_ranking,
1254 	&amd_pstate_hw_prefcore,
1255 	&energy_performance_preference,
1256 	&energy_performance_available_preferences,
1257 	NULL,
1258 };
1259 
1260 static struct attribute *pstate_global_attributes[] = {
1261 	&dev_attr_status.attr,
1262 	&dev_attr_prefcore.attr,
1263 	NULL
1264 };
1265 
1266 static const struct attribute_group amd_pstate_global_attr_group = {
1267 	.name = "amd_pstate",
1268 	.attrs = pstate_global_attributes,
1269 };
1270 
1271 static bool amd_pstate_acpi_pm_profile_server(void)
1272 {
1273 	switch (acpi_gbl_FADT.preferred_profile) {
1274 	case PM_ENTERPRISE_SERVER:
1275 	case PM_SOHO_SERVER:
1276 	case PM_PERFORMANCE_SERVER:
1277 		return true;
1278 	}
1279 	return false;
1280 }
1281 
1282 static bool amd_pstate_acpi_pm_profile_undefined(void)
1283 {
1284 	if (acpi_gbl_FADT.preferred_profile == PM_UNSPECIFIED)
1285 		return true;
1286 	if (acpi_gbl_FADT.preferred_profile >= NR_PM_PROFILES)
1287 		return true;
1288 	return false;
1289 }
1290 
1291 static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
1292 {
1293 	int min_freq, max_freq, nominal_freq, lowest_nonlinear_freq, ret;
1294 	struct amd_cpudata *cpudata;
1295 	struct device *dev;
1296 	u64 value;
1297 
1298 	/*
1299 	 * Resetting PERF_CTL_MSR will put the CPU in P0 frequency,
1300 	 * which is ideal for initialization process.
1301 	 */
1302 	amd_perf_ctl_reset(policy->cpu);
1303 	dev = get_cpu_device(policy->cpu);
1304 	if (!dev)
1305 		return -ENODEV;
1306 
1307 	cpudata = kzalloc(sizeof(*cpudata), GFP_KERNEL);
1308 	if (!cpudata)
1309 		return -ENOMEM;
1310 
1311 	cpudata->cpu = policy->cpu;
1312 	cpudata->epp_policy = 0;
1313 
1314 	amd_pstate_init_prefcore(cpudata);
1315 
1316 	ret = amd_pstate_init_perf(cpudata);
1317 	if (ret)
1318 		goto free_cpudata1;
1319 
1320 	min_freq = amd_get_min_freq(cpudata);
1321 	max_freq = amd_get_max_freq(cpudata);
1322 	nominal_freq = amd_get_nominal_freq(cpudata);
1323 	lowest_nonlinear_freq = amd_get_lowest_nonlinear_freq(cpudata);
1324 	if (min_freq < 0 || max_freq < 0 || min_freq > max_freq) {
1325 		dev_err(dev, "min_freq(%d) or max_freq(%d) value is incorrect\n",
1326 				min_freq, max_freq);
1327 		ret = -EINVAL;
1328 		goto free_cpudata1;
1329 	}
1330 
1331 	policy->cpuinfo.min_freq = min_freq;
1332 	policy->cpuinfo.max_freq = max_freq;
1333 	/* It will be updated by governor */
1334 	policy->cur = policy->cpuinfo.min_freq;
1335 
1336 	/* Initial processor data capability frequencies */
1337 	cpudata->max_freq = max_freq;
1338 	cpudata->min_freq = min_freq;
1339 	cpudata->nominal_freq = nominal_freq;
1340 	cpudata->lowest_nonlinear_freq = lowest_nonlinear_freq;
1341 
1342 	policy->driver_data = cpudata;
1343 
1344 	cpudata->epp_cached = amd_pstate_get_epp(cpudata, 0);
1345 
1346 	policy->min = policy->cpuinfo.min_freq;
1347 	policy->max = policy->cpuinfo.max_freq;
1348 
1349 	/*
1350 	 * Set the policy to provide a valid fallback value in case
1351 	 * the default cpufreq governor is neither powersave nor performance.
1352 	 */
1353 	if (amd_pstate_acpi_pm_profile_server() ||
1354 	    amd_pstate_acpi_pm_profile_undefined())
1355 		policy->policy = CPUFREQ_POLICY_PERFORMANCE;
1356 	else
1357 		policy->policy = CPUFREQ_POLICY_POWERSAVE;
1358 
1359 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
1360 		ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, &value);
1361 		if (ret)
1362 			return ret;
1363 		WRITE_ONCE(cpudata->cppc_req_cached, value);
1364 
1365 		ret = rdmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_CAP1, &value);
1366 		if (ret)
1367 			return ret;
1368 		WRITE_ONCE(cpudata->cppc_cap1_cached, value);
1369 	}
1370 	amd_pstate_boost_init(cpudata);
1371 
1372 	return 0;
1373 
1374 free_cpudata1:
1375 	kfree(cpudata);
1376 	return ret;
1377 }
1378 
1379 static int amd_pstate_epp_cpu_exit(struct cpufreq_policy *policy)
1380 {
1381 	pr_debug("CPU %d exiting\n", policy->cpu);
1382 	return 0;
1383 }
1384 
1385 static void amd_pstate_epp_update_limit(struct cpufreq_policy *policy)
1386 {
1387 	struct amd_cpudata *cpudata = policy->driver_data;
1388 	u32 max_perf, min_perf, min_limit_perf, max_limit_perf;
1389 	u64 value;
1390 	s16 epp;
1391 
1392 	max_perf = READ_ONCE(cpudata->highest_perf);
1393 	min_perf = READ_ONCE(cpudata->lowest_perf);
1394 	max_limit_perf = div_u64(policy->max * cpudata->highest_perf, cpudata->max_freq);
1395 	min_limit_perf = div_u64(policy->min * cpudata->highest_perf, cpudata->max_freq);
1396 
1397 	if (min_limit_perf < min_perf)
1398 		min_limit_perf = min_perf;
1399 
1400 	if (max_limit_perf < min_limit_perf)
1401 		max_limit_perf = min_limit_perf;
1402 
1403 	WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
1404 	WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
1405 
1406 	max_perf = clamp_t(unsigned long, max_perf, cpudata->min_limit_perf,
1407 			cpudata->max_limit_perf);
1408 	min_perf = clamp_t(unsigned long, min_perf, cpudata->min_limit_perf,
1409 			cpudata->max_limit_perf);
1410 	value = READ_ONCE(cpudata->cppc_req_cached);
1411 
1412 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
1413 		min_perf = max_perf;
1414 
1415 	/* Initial min/max values for CPPC Performance Controls Register */
1416 	value &= ~AMD_CPPC_MIN_PERF(~0L);
1417 	value |= AMD_CPPC_MIN_PERF(min_perf);
1418 
1419 	value &= ~AMD_CPPC_MAX_PERF(~0L);
1420 	value |= AMD_CPPC_MAX_PERF(max_perf);
1421 
1422 	/* CPPC EPP feature require to set zero to the desire perf bit */
1423 	value &= ~AMD_CPPC_DES_PERF(~0L);
1424 	value |= AMD_CPPC_DES_PERF(0);
1425 
1426 	cpudata->epp_policy = cpudata->policy;
1427 
1428 	/* Get BIOS pre-defined epp value */
1429 	epp = amd_pstate_get_epp(cpudata, value);
1430 	if (epp < 0) {
1431 		/**
1432 		 * This return value can only be negative for shared_memory
1433 		 * systems where EPP register read/write not supported.
1434 		 */
1435 		return;
1436 	}
1437 
1438 	if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)
1439 		epp = 0;
1440 
1441 	/* Set initial EPP value */
1442 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
1443 		value &= ~GENMASK_ULL(31, 24);
1444 		value |= (u64)epp << 24;
1445 	}
1446 
1447 	WRITE_ONCE(cpudata->cppc_req_cached, value);
1448 	amd_pstate_set_epp(cpudata, epp);
1449 }
1450 
1451 static int amd_pstate_epp_set_policy(struct cpufreq_policy *policy)
1452 {
1453 	struct amd_cpudata *cpudata = policy->driver_data;
1454 
1455 	if (!policy->cpuinfo.max_freq)
1456 		return -ENODEV;
1457 
1458 	pr_debug("set_policy: cpuinfo.max %u policy->max %u\n",
1459 				policy->cpuinfo.max_freq, policy->max);
1460 
1461 	cpudata->policy = policy->policy;
1462 
1463 	amd_pstate_epp_update_limit(policy);
1464 
1465 	return 0;
1466 }
1467 
1468 static void amd_pstate_epp_reenable(struct amd_cpudata *cpudata)
1469 {
1470 	struct cppc_perf_ctrls perf_ctrls;
1471 	u64 value, max_perf;
1472 	int ret;
1473 
1474 	ret = amd_pstate_enable(true);
1475 	if (ret)
1476 		pr_err("failed to enable amd pstate during resume, return %d\n", ret);
1477 
1478 	value = READ_ONCE(cpudata->cppc_req_cached);
1479 	max_perf = READ_ONCE(cpudata->highest_perf);
1480 
1481 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
1482 		wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
1483 	} else {
1484 		perf_ctrls.max_perf = max_perf;
1485 		perf_ctrls.energy_perf = AMD_CPPC_ENERGY_PERF_PREF(cpudata->epp_cached);
1486 		cppc_set_perf(cpudata->cpu, &perf_ctrls);
1487 	}
1488 }
1489 
1490 static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
1491 {
1492 	struct amd_cpudata *cpudata = policy->driver_data;
1493 
1494 	pr_debug("AMD CPU Core %d going online\n", cpudata->cpu);
1495 
1496 	if (cppc_state == AMD_PSTATE_ACTIVE) {
1497 		amd_pstate_epp_reenable(cpudata);
1498 		cpudata->suspended = false;
1499 	}
1500 
1501 	return 0;
1502 }
1503 
1504 static void amd_pstate_epp_offline(struct cpufreq_policy *policy)
1505 {
1506 	struct amd_cpudata *cpudata = policy->driver_data;
1507 	struct cppc_perf_ctrls perf_ctrls;
1508 	int min_perf;
1509 	u64 value;
1510 
1511 	min_perf = READ_ONCE(cpudata->lowest_perf);
1512 	value = READ_ONCE(cpudata->cppc_req_cached);
1513 
1514 	mutex_lock(&amd_pstate_limits_lock);
1515 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
1516 		cpudata->epp_policy = CPUFREQ_POLICY_UNKNOWN;
1517 
1518 		/* Set max perf same as min perf */
1519 		value &= ~AMD_CPPC_MAX_PERF(~0L);
1520 		value |= AMD_CPPC_MAX_PERF(min_perf);
1521 		value &= ~AMD_CPPC_MIN_PERF(~0L);
1522 		value |= AMD_CPPC_MIN_PERF(min_perf);
1523 		wrmsrl_on_cpu(cpudata->cpu, MSR_AMD_CPPC_REQ, value);
1524 	} else {
1525 		perf_ctrls.desired_perf = 0;
1526 		perf_ctrls.max_perf = min_perf;
1527 		perf_ctrls.energy_perf = AMD_CPPC_ENERGY_PERF_PREF(HWP_EPP_BALANCE_POWERSAVE);
1528 		cppc_set_perf(cpudata->cpu, &perf_ctrls);
1529 	}
1530 	mutex_unlock(&amd_pstate_limits_lock);
1531 }
1532 
1533 static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
1534 {
1535 	struct amd_cpudata *cpudata = policy->driver_data;
1536 
1537 	pr_debug("AMD CPU Core %d going offline\n", cpudata->cpu);
1538 
1539 	if (cpudata->suspended)
1540 		return 0;
1541 
1542 	if (cppc_state == AMD_PSTATE_ACTIVE)
1543 		amd_pstate_epp_offline(policy);
1544 
1545 	return 0;
1546 }
1547 
1548 static int amd_pstate_epp_verify_policy(struct cpufreq_policy_data *policy)
1549 {
1550 	cpufreq_verify_within_cpu_limits(policy);
1551 	pr_debug("policy_max =%d, policy_min=%d\n", policy->max, policy->min);
1552 	return 0;
1553 }
1554 
1555 static int amd_pstate_epp_suspend(struct cpufreq_policy *policy)
1556 {
1557 	struct amd_cpudata *cpudata = policy->driver_data;
1558 	int ret;
1559 
1560 	/* avoid suspending when EPP is not enabled */
1561 	if (cppc_state != AMD_PSTATE_ACTIVE)
1562 		return 0;
1563 
1564 	/* set this flag to avoid setting core offline*/
1565 	cpudata->suspended = true;
1566 
1567 	/* disable CPPC in lowlevel firmware */
1568 	ret = amd_pstate_enable(false);
1569 	if (ret)
1570 		pr_err("failed to suspend, return %d\n", ret);
1571 
1572 	return 0;
1573 }
1574 
1575 static int amd_pstate_epp_resume(struct cpufreq_policy *policy)
1576 {
1577 	struct amd_cpudata *cpudata = policy->driver_data;
1578 
1579 	if (cpudata->suspended) {
1580 		mutex_lock(&amd_pstate_limits_lock);
1581 
1582 		/* enable amd pstate from suspend state*/
1583 		amd_pstate_epp_reenable(cpudata);
1584 
1585 		mutex_unlock(&amd_pstate_limits_lock);
1586 
1587 		cpudata->suspended = false;
1588 	}
1589 
1590 	return 0;
1591 }
1592 
1593 static struct cpufreq_driver amd_pstate_driver = {
1594 	.flags		= CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_UPDATE_LIMITS,
1595 	.verify		= amd_pstate_verify,
1596 	.target		= amd_pstate_target,
1597 	.fast_switch    = amd_pstate_fast_switch,
1598 	.init		= amd_pstate_cpu_init,
1599 	.exit		= amd_pstate_cpu_exit,
1600 	.suspend	= amd_pstate_cpu_suspend,
1601 	.resume		= amd_pstate_cpu_resume,
1602 	.set_boost	= amd_pstate_set_boost,
1603 	.update_limits	= amd_pstate_update_limits,
1604 	.name		= "amd-pstate",
1605 	.attr		= amd_pstate_attr,
1606 };
1607 
1608 static struct cpufreq_driver amd_pstate_epp_driver = {
1609 	.flags		= CPUFREQ_CONST_LOOPS,
1610 	.verify		= amd_pstate_epp_verify_policy,
1611 	.setpolicy	= amd_pstate_epp_set_policy,
1612 	.init		= amd_pstate_epp_cpu_init,
1613 	.exit		= amd_pstate_epp_cpu_exit,
1614 	.offline	= amd_pstate_epp_cpu_offline,
1615 	.online		= amd_pstate_epp_cpu_online,
1616 	.suspend	= amd_pstate_epp_suspend,
1617 	.resume		= amd_pstate_epp_resume,
1618 	.update_limits	= amd_pstate_update_limits,
1619 	.name		= "amd-pstate-epp",
1620 	.attr		= amd_pstate_epp_attr,
1621 };
1622 
1623 static int __init amd_pstate_set_driver(int mode_idx)
1624 {
1625 	if (mode_idx >= AMD_PSTATE_DISABLE && mode_idx < AMD_PSTATE_MAX) {
1626 		cppc_state = mode_idx;
1627 		if (cppc_state == AMD_PSTATE_DISABLE)
1628 			pr_info("driver is explicitly disabled\n");
1629 
1630 		if (cppc_state == AMD_PSTATE_ACTIVE)
1631 			current_pstate_driver = &amd_pstate_epp_driver;
1632 
1633 		if (cppc_state == AMD_PSTATE_PASSIVE || cppc_state == AMD_PSTATE_GUIDED)
1634 			current_pstate_driver = &amd_pstate_driver;
1635 
1636 		return 0;
1637 	}
1638 
1639 	return -EINVAL;
1640 }
1641 
1642 static int __init amd_pstate_init(void)
1643 {
1644 	struct device *dev_root;
1645 	int ret;
1646 
1647 	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
1648 		return -ENODEV;
1649 
1650 	if (!acpi_cpc_valid()) {
1651 		pr_warn_once("the _CPC object is not present in SBIOS or ACPI disabled\n");
1652 		return -ENODEV;
1653 	}
1654 
1655 	/* don't keep reloading if cpufreq_driver exists */
1656 	if (cpufreq_get_current_driver())
1657 		return -EEXIST;
1658 
1659 	switch (cppc_state) {
1660 	case AMD_PSTATE_UNDEFINED:
1661 		/* Disable on the following configs by default:
1662 		 * 1. Undefined platforms
1663 		 * 2. Server platforms
1664 		 * 3. Shared memory designs
1665 		 */
1666 		if (amd_pstate_acpi_pm_profile_undefined() ||
1667 		    amd_pstate_acpi_pm_profile_server() ||
1668 		    !boot_cpu_has(X86_FEATURE_CPPC)) {
1669 			pr_info("driver load is disabled, boot with specific mode to enable this\n");
1670 			return -ENODEV;
1671 		}
1672 		ret = amd_pstate_set_driver(CONFIG_X86_AMD_PSTATE_DEFAULT_MODE);
1673 		if (ret)
1674 			return ret;
1675 		break;
1676 	case AMD_PSTATE_DISABLE:
1677 		return -ENODEV;
1678 	case AMD_PSTATE_PASSIVE:
1679 	case AMD_PSTATE_ACTIVE:
1680 	case AMD_PSTATE_GUIDED:
1681 		break;
1682 	default:
1683 		return -EINVAL;
1684 	}
1685 
1686 	/* capability check */
1687 	if (boot_cpu_has(X86_FEATURE_CPPC)) {
1688 		pr_debug("AMD CPPC MSR based functionality is supported\n");
1689 		if (cppc_state != AMD_PSTATE_ACTIVE)
1690 			current_pstate_driver->adjust_perf = amd_pstate_adjust_perf;
1691 	} else {
1692 		pr_debug("AMD CPPC shared memory based functionality is supported\n");
1693 		static_call_update(amd_pstate_enable, cppc_enable);
1694 		static_call_update(amd_pstate_init_perf, cppc_init_perf);
1695 		static_call_update(amd_pstate_update_perf, cppc_update_perf);
1696 	}
1697 
1698 	/* enable amd pstate feature */
1699 	ret = amd_pstate_enable(true);
1700 	if (ret) {
1701 		pr_err("failed to enable with return %d\n", ret);
1702 		return ret;
1703 	}
1704 
1705 	ret = cpufreq_register_driver(current_pstate_driver);
1706 	if (ret)
1707 		pr_err("failed to register with return %d\n", ret);
1708 
1709 	dev_root = bus_get_dev_root(&cpu_subsys);
1710 	if (dev_root) {
1711 		ret = sysfs_create_group(&dev_root->kobj, &amd_pstate_global_attr_group);
1712 		put_device(dev_root);
1713 		if (ret) {
1714 			pr_err("sysfs attribute export failed with error %d.\n", ret);
1715 			goto global_attr_free;
1716 		}
1717 	}
1718 
1719 	return ret;
1720 
1721 global_attr_free:
1722 	cpufreq_unregister_driver(current_pstate_driver);
1723 	return ret;
1724 }
1725 device_initcall(amd_pstate_init);
1726 
1727 static int __init amd_pstate_param(char *str)
1728 {
1729 	size_t size;
1730 	int mode_idx;
1731 
1732 	if (!str)
1733 		return -EINVAL;
1734 
1735 	size = strlen(str);
1736 	mode_idx = get_mode_idx_from_str(str, size);
1737 
1738 	return amd_pstate_set_driver(mode_idx);
1739 }
1740 
1741 static int __init amd_prefcore_param(char *str)
1742 {
1743 	if (!strcmp(str, "disable"))
1744 		amd_pstate_prefcore = false;
1745 
1746 	return 0;
1747 }
1748 
1749 early_param("amd_pstate", amd_pstate_param);
1750 early_param("amd_prefcore", amd_prefcore_param);
1751 
1752 MODULE_AUTHOR("Huang Rui <ray.huang@amd.com>");
1753 MODULE_DESCRIPTION("AMD Processor P-state Frequency Driver");
1754