1 /*
2  * intel_pstate.c: Native P state management for Intel processors
3  *
4  * (C) Copyright 2012 Intel Corporation
5  * Author: Dirk Brandewie <dirk.j.brandewie@intel.com>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; version 2
10  * of the License.
11  */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/kernel.h>
16 #include <linux/kernel_stat.h>
17 #include <linux/module.h>
18 #include <linux/ktime.h>
19 #include <linux/hrtimer.h>
20 #include <linux/tick.h>
21 #include <linux/slab.h>
22 #include <linux/sched.h>
23 #include <linux/list.h>
24 #include <linux/cpu.h>
25 #include <linux/cpufreq.h>
26 #include <linux/sysfs.h>
27 #include <linux/types.h>
28 #include <linux/fs.h>
29 #include <linux/debugfs.h>
30 #include <linux/acpi.h>
31 #include <linux/vmalloc.h>
32 #include <trace/events/power.h>
33 
34 #include <asm/div64.h>
35 #include <asm/msr.h>
36 #include <asm/cpu_device_id.h>
37 #include <asm/cpufeature.h>
38 #include <asm/intel-family.h>
39 
40 #define ATOM_RATIOS		0x66a
41 #define ATOM_VIDS		0x66b
42 #define ATOM_TURBO_RATIOS	0x66c
43 #define ATOM_TURBO_VIDS		0x66d
44 
45 #ifdef CONFIG_ACPI
46 #include <acpi/processor.h>
47 #endif
48 
49 #define FRAC_BITS 8
50 #define int_tofp(X) ((int64_t)(X) << FRAC_BITS)
51 #define fp_toint(X) ((X) >> FRAC_BITS)
52 
53 #define EXT_BITS 6
54 #define EXT_FRAC_BITS (EXT_BITS + FRAC_BITS)
55 
56 static inline int32_t mul_fp(int32_t x, int32_t y)
57 {
58 	return ((int64_t)x * (int64_t)y) >> FRAC_BITS;
59 }
60 
61 static inline int32_t div_fp(s64 x, s64 y)
62 {
63 	return div64_s64((int64_t)x << FRAC_BITS, y);
64 }
65 
66 static inline int ceiling_fp(int32_t x)
67 {
68 	int mask, ret;
69 
70 	ret = fp_toint(x);
71 	mask = (1 << FRAC_BITS) - 1;
72 	if (x & mask)
73 		ret += 1;
74 	return ret;
75 }
76 
77 static inline u64 mul_ext_fp(u64 x, u64 y)
78 {
79 	return (x * y) >> EXT_FRAC_BITS;
80 }
81 
82 static inline u64 div_ext_fp(u64 x, u64 y)
83 {
84 	return div64_u64(x << EXT_FRAC_BITS, y);
85 }
86 
87 /**
88  * struct sample -	Store performance sample
89  * @core_avg_perf:	Ratio of APERF/MPERF which is the actual average
90  *			performance during last sample period
91  * @busy_scaled:	Scaled busy value which is used to calculate next
92  *			P state. This can be different than core_avg_perf
93  *			to account for cpu idle period
94  * @aperf:		Difference of actual performance frequency clock count
95  *			read from APERF MSR between last and current sample
96  * @mperf:		Difference of maximum performance frequency clock count
97  *			read from MPERF MSR between last and current sample
98  * @tsc:		Difference of time stamp counter between last and
99  *			current sample
100  * @time:		Current time from scheduler
101  *
102  * This structure is used in the cpudata structure to store performance sample
103  * data for choosing next P State.
104  */
105 struct sample {
106 	int32_t core_avg_perf;
107 	int32_t busy_scaled;
108 	u64 aperf;
109 	u64 mperf;
110 	u64 tsc;
111 	u64 time;
112 };
113 
114 /**
115  * struct pstate_data - Store P state data
116  * @current_pstate:	Current requested P state
117  * @min_pstate:		Min P state possible for this platform
118  * @max_pstate:		Max P state possible for this platform
119  * @max_pstate_physical:This is physical Max P state for a processor
120  *			This can be higher than the max_pstate which can
121  *			be limited by platform thermal design power limits
122  * @scaling:		Scaling factor to  convert frequency to cpufreq
123  *			frequency units
124  * @turbo_pstate:	Max Turbo P state possible for this platform
125  *
126  * Stores the per cpu model P state limits and current P state.
127  */
128 struct pstate_data {
129 	int	current_pstate;
130 	int	min_pstate;
131 	int	max_pstate;
132 	int	max_pstate_physical;
133 	int	scaling;
134 	int	turbo_pstate;
135 };
136 
137 /**
138  * struct vid_data -	Stores voltage information data
139  * @min:		VID data for this platform corresponding to
140  *			the lowest P state
141  * @max:		VID data corresponding to the highest P State.
142  * @turbo:		VID data for turbo P state
143  * @ratio:		Ratio of (vid max - vid min) /
144  *			(max P state - Min P State)
145  *
146  * Stores the voltage data for DVFS (Dynamic Voltage and Frequency Scaling)
147  * This data is used in Atom platforms, where in addition to target P state,
148  * the voltage data needs to be specified to select next P State.
149  */
150 struct vid_data {
151 	int min;
152 	int max;
153 	int turbo;
154 	int32_t ratio;
155 };
156 
157 /**
158  * struct _pid -	Stores PID data
159  * @setpoint:		Target set point for busyness or performance
160  * @integral:		Storage for accumulated error values
161  * @p_gain:		PID proportional gain
162  * @i_gain:		PID integral gain
163  * @d_gain:		PID derivative gain
164  * @deadband:		PID deadband
165  * @last_err:		Last error storage for integral part of PID calculation
166  *
167  * Stores PID coefficients and last error for PID controller.
168  */
169 struct _pid {
170 	int setpoint;
171 	int32_t integral;
172 	int32_t p_gain;
173 	int32_t i_gain;
174 	int32_t d_gain;
175 	int deadband;
176 	int32_t last_err;
177 };
178 
179 /**
180  * struct perf_limits - Store user and policy limits
181  * @no_turbo:		User requested turbo state from intel_pstate sysfs
182  * @turbo_disabled:	Platform turbo status either from msr
183  *			MSR_IA32_MISC_ENABLE or when maximum available pstate
184  *			matches the maximum turbo pstate
185  * @max_perf_pct:	Effective maximum performance limit in percentage, this
186  *			is minimum of either limits enforced by cpufreq policy
187  *			or limits from user set limits via intel_pstate sysfs
188  * @min_perf_pct:	Effective minimum performance limit in percentage, this
189  *			is maximum of either limits enforced by cpufreq policy
190  *			or limits from user set limits via intel_pstate sysfs
191  * @max_perf:		This is a scaled value between 0 to 255 for max_perf_pct
192  *			This value is used to limit max pstate
193  * @min_perf:		This is a scaled value between 0 to 255 for min_perf_pct
194  *			This value is used to limit min pstate
195  * @max_policy_pct:	The maximum performance in percentage enforced by
196  *			cpufreq setpolicy interface
197  * @max_sysfs_pct:	The maximum performance in percentage enforced by
198  *			intel pstate sysfs interface, unused when per cpu
199  *			controls are enforced
200  * @min_policy_pct:	The minimum performance in percentage enforced by
201  *			cpufreq setpolicy interface
202  * @min_sysfs_pct:	The minimum performance in percentage enforced by
203  *			intel pstate sysfs interface, unused when per cpu
204  *			controls are enforced
205  *
206  * Storage for user and policy defined limits.
207  */
208 struct perf_limits {
209 	int no_turbo;
210 	int turbo_disabled;
211 	int max_perf_pct;
212 	int min_perf_pct;
213 	int32_t max_perf;
214 	int32_t min_perf;
215 	int max_policy_pct;
216 	int max_sysfs_pct;
217 	int min_policy_pct;
218 	int min_sysfs_pct;
219 };
220 
221 /**
222  * struct cpudata -	Per CPU instance data storage
223  * @cpu:		CPU number for this instance data
224  * @policy:		CPUFreq policy value
225  * @update_util:	CPUFreq utility callback information
226  * @update_util_set:	CPUFreq utility callback is set
227  * @iowait_boost:	iowait-related boost fraction
228  * @last_update:	Time of the last update.
229  * @pstate:		Stores P state limits for this CPU
230  * @vid:		Stores VID limits for this CPU
231  * @pid:		Stores PID parameters for this CPU
232  * @last_sample_time:	Last Sample time
233  * @prev_aperf:		Last APERF value read from APERF MSR
234  * @prev_mperf:		Last MPERF value read from MPERF MSR
235  * @prev_tsc:		Last timestamp counter (TSC) value
236  * @prev_cummulative_iowait: IO Wait time difference from last and
237  *			current sample
238  * @sample:		Storage for storing last Sample data
239  * @perf_limits:	Pointer to perf_limit unique to this CPU
240  *			Not all field in the structure are applicable
241  *			when per cpu controls are enforced
242  * @acpi_perf_data:	Stores ACPI perf information read from _PSS
243  * @valid_pss_table:	Set to true for valid ACPI _PSS entries found
244  *
245  * This structure stores per CPU instance data for all CPUs.
246  */
247 struct cpudata {
248 	int cpu;
249 
250 	unsigned int policy;
251 	struct update_util_data update_util;
252 	bool   update_util_set;
253 
254 	struct pstate_data pstate;
255 	struct vid_data vid;
256 	struct _pid pid;
257 
258 	u64	last_update;
259 	u64	last_sample_time;
260 	u64	prev_aperf;
261 	u64	prev_mperf;
262 	u64	prev_tsc;
263 	u64	prev_cummulative_iowait;
264 	struct sample sample;
265 	struct perf_limits *perf_limits;
266 #ifdef CONFIG_ACPI
267 	struct acpi_processor_performance acpi_perf_data;
268 	bool valid_pss_table;
269 #endif
270 	unsigned int iowait_boost;
271 };
272 
273 static struct cpudata **all_cpu_data;
274 
275 /**
276  * struct pstate_adjust_policy - Stores static PID configuration data
277  * @sample_rate_ms:	PID calculation sample rate in ms
278  * @sample_rate_ns:	Sample rate calculation in ns
279  * @deadband:		PID deadband
280  * @setpoint:		PID Setpoint
281  * @p_gain_pct:		PID proportional gain
282  * @i_gain_pct:		PID integral gain
283  * @d_gain_pct:		PID derivative gain
284  *
285  * Stores per CPU model static PID configuration data.
286  */
287 struct pstate_adjust_policy {
288 	int sample_rate_ms;
289 	s64 sample_rate_ns;
290 	int deadband;
291 	int setpoint;
292 	int p_gain_pct;
293 	int d_gain_pct;
294 	int i_gain_pct;
295 };
296 
297 /**
298  * struct pstate_funcs - Per CPU model specific callbacks
299  * @get_max:		Callback to get maximum non turbo effective P state
300  * @get_max_physical:	Callback to get maximum non turbo physical P state
301  * @get_min:		Callback to get minimum P state
302  * @get_turbo:		Callback to get turbo P state
303  * @get_scaling:	Callback to get frequency scaling factor
304  * @get_val:		Callback to convert P state to actual MSR write value
305  * @get_vid:		Callback to get VID data for Atom platforms
306  * @get_target_pstate:	Callback to a function to calculate next P state to use
307  *
308  * Core and Atom CPU models have different way to get P State limits. This
309  * structure is used to store those callbacks.
310  */
311 struct pstate_funcs {
312 	int (*get_max)(void);
313 	int (*get_max_physical)(void);
314 	int (*get_min)(void);
315 	int (*get_turbo)(void);
316 	int (*get_scaling)(void);
317 	u64 (*get_val)(struct cpudata*, int pstate);
318 	void (*get_vid)(struct cpudata *);
319 	int32_t (*get_target_pstate)(struct cpudata *);
320 };
321 
322 /**
323  * struct cpu_defaults- Per CPU model default config data
324  * @pid_policy:	PID config data
325  * @funcs:		Callback function data
326  */
327 struct cpu_defaults {
328 	struct pstate_adjust_policy pid_policy;
329 	struct pstate_funcs funcs;
330 };
331 
332 static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu);
333 static inline int32_t get_target_pstate_use_cpu_load(struct cpudata *cpu);
334 
335 static struct pstate_adjust_policy pid_params __read_mostly;
336 static struct pstate_funcs pstate_funcs __read_mostly;
337 static int hwp_active __read_mostly;
338 static bool per_cpu_limits __read_mostly;
339 
340 #ifdef CONFIG_ACPI
341 static bool acpi_ppc;
342 #endif
343 
344 static struct perf_limits performance_limits = {
345 	.no_turbo = 0,
346 	.turbo_disabled = 0,
347 	.max_perf_pct = 100,
348 	.max_perf = int_tofp(1),
349 	.min_perf_pct = 100,
350 	.min_perf = int_tofp(1),
351 	.max_policy_pct = 100,
352 	.max_sysfs_pct = 100,
353 	.min_policy_pct = 0,
354 	.min_sysfs_pct = 0,
355 };
356 
357 static struct perf_limits powersave_limits = {
358 	.no_turbo = 0,
359 	.turbo_disabled = 0,
360 	.max_perf_pct = 100,
361 	.max_perf = int_tofp(1),
362 	.min_perf_pct = 0,
363 	.min_perf = 0,
364 	.max_policy_pct = 100,
365 	.max_sysfs_pct = 100,
366 	.min_policy_pct = 0,
367 	.min_sysfs_pct = 0,
368 };
369 
370 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE
371 static struct perf_limits *limits = &performance_limits;
372 #else
373 static struct perf_limits *limits = &powersave_limits;
374 #endif
375 
376 #ifdef CONFIG_ACPI
377 
378 static bool intel_pstate_get_ppc_enable_status(void)
379 {
380 	if (acpi_gbl_FADT.preferred_profile == PM_ENTERPRISE_SERVER ||
381 	    acpi_gbl_FADT.preferred_profile == PM_PERFORMANCE_SERVER)
382 		return true;
383 
384 	return acpi_ppc;
385 }
386 
387 static void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy)
388 {
389 	struct cpudata *cpu;
390 	int ret;
391 	int i;
392 
393 	if (hwp_active)
394 		return;
395 
396 	if (!intel_pstate_get_ppc_enable_status())
397 		return;
398 
399 	cpu = all_cpu_data[policy->cpu];
400 
401 	ret = acpi_processor_register_performance(&cpu->acpi_perf_data,
402 						  policy->cpu);
403 	if (ret)
404 		return;
405 
406 	/*
407 	 * Check if the control value in _PSS is for PERF_CTL MSR, which should
408 	 * guarantee that the states returned by it map to the states in our
409 	 * list directly.
410 	 */
411 	if (cpu->acpi_perf_data.control_register.space_id !=
412 						ACPI_ADR_SPACE_FIXED_HARDWARE)
413 		goto err;
414 
415 	/*
416 	 * If there is only one entry _PSS, simply ignore _PSS and continue as
417 	 * usual without taking _PSS into account
418 	 */
419 	if (cpu->acpi_perf_data.state_count < 2)
420 		goto err;
421 
422 	pr_debug("CPU%u - ACPI _PSS perf data\n", policy->cpu);
423 	for (i = 0; i < cpu->acpi_perf_data.state_count; i++) {
424 		pr_debug("     %cP%d: %u MHz, %u mW, 0x%x\n",
425 			 (i == cpu->acpi_perf_data.state ? '*' : ' '), i,
426 			 (u32) cpu->acpi_perf_data.states[i].core_frequency,
427 			 (u32) cpu->acpi_perf_data.states[i].power,
428 			 (u32) cpu->acpi_perf_data.states[i].control);
429 	}
430 
431 	/*
432 	 * The _PSS table doesn't contain whole turbo frequency range.
433 	 * This just contains +1 MHZ above the max non turbo frequency,
434 	 * with control value corresponding to max turbo ratio. But
435 	 * when cpufreq set policy is called, it will call with this
436 	 * max frequency, which will cause a reduced performance as
437 	 * this driver uses real max turbo frequency as the max
438 	 * frequency. So correct this frequency in _PSS table to
439 	 * correct max turbo frequency based on the turbo state.
440 	 * Also need to convert to MHz as _PSS freq is in MHz.
441 	 */
442 	if (!limits->turbo_disabled)
443 		cpu->acpi_perf_data.states[0].core_frequency =
444 					policy->cpuinfo.max_freq / 1000;
445 	cpu->valid_pss_table = true;
446 	pr_debug("_PPC limits will be enforced\n");
447 
448 	return;
449 
450  err:
451 	cpu->valid_pss_table = false;
452 	acpi_processor_unregister_performance(policy->cpu);
453 }
454 
455 static void intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
456 {
457 	struct cpudata *cpu;
458 
459 	cpu = all_cpu_data[policy->cpu];
460 	if (!cpu->valid_pss_table)
461 		return;
462 
463 	acpi_processor_unregister_performance(policy->cpu);
464 }
465 
466 #else
467 static void intel_pstate_init_acpi_perf_limits(struct cpufreq_policy *policy)
468 {
469 }
470 
471 static void intel_pstate_exit_perf_limits(struct cpufreq_policy *policy)
472 {
473 }
474 #endif
475 
476 static inline void pid_reset(struct _pid *pid, int setpoint, int busy,
477 			     int deadband, int integral) {
478 	pid->setpoint = int_tofp(setpoint);
479 	pid->deadband  = int_tofp(deadband);
480 	pid->integral  = int_tofp(integral);
481 	pid->last_err  = int_tofp(setpoint) - int_tofp(busy);
482 }
483 
484 static inline void pid_p_gain_set(struct _pid *pid, int percent)
485 {
486 	pid->p_gain = div_fp(percent, 100);
487 }
488 
489 static inline void pid_i_gain_set(struct _pid *pid, int percent)
490 {
491 	pid->i_gain = div_fp(percent, 100);
492 }
493 
494 static inline void pid_d_gain_set(struct _pid *pid, int percent)
495 {
496 	pid->d_gain = div_fp(percent, 100);
497 }
498 
499 static signed int pid_calc(struct _pid *pid, int32_t busy)
500 {
501 	signed int result;
502 	int32_t pterm, dterm, fp_error;
503 	int32_t integral_limit;
504 
505 	fp_error = pid->setpoint - busy;
506 
507 	if (abs(fp_error) <= pid->deadband)
508 		return 0;
509 
510 	pterm = mul_fp(pid->p_gain, fp_error);
511 
512 	pid->integral += fp_error;
513 
514 	/*
515 	 * We limit the integral here so that it will never
516 	 * get higher than 30.  This prevents it from becoming
517 	 * too large an input over long periods of time and allows
518 	 * it to get factored out sooner.
519 	 *
520 	 * The value of 30 was chosen through experimentation.
521 	 */
522 	integral_limit = int_tofp(30);
523 	if (pid->integral > integral_limit)
524 		pid->integral = integral_limit;
525 	if (pid->integral < -integral_limit)
526 		pid->integral = -integral_limit;
527 
528 	dterm = mul_fp(pid->d_gain, fp_error - pid->last_err);
529 	pid->last_err = fp_error;
530 
531 	result = pterm + mul_fp(pid->integral, pid->i_gain) + dterm;
532 	result = result + (1 << (FRAC_BITS-1));
533 	return (signed int)fp_toint(result);
534 }
535 
536 static inline void intel_pstate_busy_pid_reset(struct cpudata *cpu)
537 {
538 	pid_p_gain_set(&cpu->pid, pid_params.p_gain_pct);
539 	pid_d_gain_set(&cpu->pid, pid_params.d_gain_pct);
540 	pid_i_gain_set(&cpu->pid, pid_params.i_gain_pct);
541 
542 	pid_reset(&cpu->pid, pid_params.setpoint, 100, pid_params.deadband, 0);
543 }
544 
545 static inline void intel_pstate_reset_all_pid(void)
546 {
547 	unsigned int cpu;
548 
549 	for_each_online_cpu(cpu) {
550 		if (all_cpu_data[cpu])
551 			intel_pstate_busy_pid_reset(all_cpu_data[cpu]);
552 	}
553 }
554 
555 static inline void update_turbo_state(void)
556 {
557 	u64 misc_en;
558 	struct cpudata *cpu;
559 
560 	cpu = all_cpu_data[0];
561 	rdmsrl(MSR_IA32_MISC_ENABLE, misc_en);
562 	limits->turbo_disabled =
563 		(misc_en & MSR_IA32_MISC_ENABLE_TURBO_DISABLE ||
564 		 cpu->pstate.max_pstate == cpu->pstate.turbo_pstate);
565 }
566 
567 static void intel_pstate_hwp_set(const struct cpumask *cpumask)
568 {
569 	int min, hw_min, max, hw_max, cpu, range, adj_range;
570 	struct perf_limits *perf_limits = limits;
571 	u64 value, cap;
572 
573 	for_each_cpu(cpu, cpumask) {
574 		int max_perf_pct, min_perf_pct;
575 
576 		if (per_cpu_limits)
577 			perf_limits = all_cpu_data[cpu]->perf_limits;
578 
579 		rdmsrl_on_cpu(cpu, MSR_HWP_CAPABILITIES, &cap);
580 		hw_min = HWP_LOWEST_PERF(cap);
581 		hw_max = HWP_HIGHEST_PERF(cap);
582 		range = hw_max - hw_min;
583 
584 		max_perf_pct = perf_limits->max_perf_pct;
585 		min_perf_pct = perf_limits->min_perf_pct;
586 
587 		rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value);
588 		adj_range = min_perf_pct * range / 100;
589 		min = hw_min + adj_range;
590 		value &= ~HWP_MIN_PERF(~0L);
591 		value |= HWP_MIN_PERF(min);
592 
593 		adj_range = max_perf_pct * range / 100;
594 		max = hw_min + adj_range;
595 		if (limits->no_turbo) {
596 			hw_max = HWP_GUARANTEED_PERF(cap);
597 			if (hw_max < max)
598 				max = hw_max;
599 		}
600 
601 		value &= ~HWP_MAX_PERF(~0L);
602 		value |= HWP_MAX_PERF(max);
603 		wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value);
604 	}
605 }
606 
607 static int intel_pstate_hwp_set_policy(struct cpufreq_policy *policy)
608 {
609 	if (hwp_active)
610 		intel_pstate_hwp_set(policy->cpus);
611 
612 	return 0;
613 }
614 
615 static void intel_pstate_hwp_set_online_cpus(void)
616 {
617 	get_online_cpus();
618 	intel_pstate_hwp_set(cpu_online_mask);
619 	put_online_cpus();
620 }
621 
622 /************************** debugfs begin ************************/
623 static int pid_param_set(void *data, u64 val)
624 {
625 	*(u32 *)data = val;
626 	intel_pstate_reset_all_pid();
627 	return 0;
628 }
629 
630 static int pid_param_get(void *data, u64 *val)
631 {
632 	*val = *(u32 *)data;
633 	return 0;
634 }
635 DEFINE_SIMPLE_ATTRIBUTE(fops_pid_param, pid_param_get, pid_param_set, "%llu\n");
636 
637 struct pid_param {
638 	char *name;
639 	void *value;
640 };
641 
642 static struct pid_param pid_files[] = {
643 	{"sample_rate_ms", &pid_params.sample_rate_ms},
644 	{"d_gain_pct", &pid_params.d_gain_pct},
645 	{"i_gain_pct", &pid_params.i_gain_pct},
646 	{"deadband", &pid_params.deadband},
647 	{"setpoint", &pid_params.setpoint},
648 	{"p_gain_pct", &pid_params.p_gain_pct},
649 	{NULL, NULL}
650 };
651 
652 static void __init intel_pstate_debug_expose_params(void)
653 {
654 	struct dentry *debugfs_parent;
655 	int i = 0;
656 
657 	if (hwp_active ||
658 	    pstate_funcs.get_target_pstate == get_target_pstate_use_cpu_load)
659 		return;
660 
661 	debugfs_parent = debugfs_create_dir("pstate_snb", NULL);
662 	if (IS_ERR_OR_NULL(debugfs_parent))
663 		return;
664 	while (pid_files[i].name) {
665 		debugfs_create_file(pid_files[i].name, 0660,
666 				    debugfs_parent, pid_files[i].value,
667 				    &fops_pid_param);
668 		i++;
669 	}
670 }
671 
672 /************************** debugfs end ************************/
673 
674 /************************** sysfs begin ************************/
675 #define show_one(file_name, object)					\
676 	static ssize_t show_##file_name					\
677 	(struct kobject *kobj, struct attribute *attr, char *buf)	\
678 	{								\
679 		return sprintf(buf, "%u\n", limits->object);		\
680 	}
681 
682 static ssize_t show_turbo_pct(struct kobject *kobj,
683 				struct attribute *attr, char *buf)
684 {
685 	struct cpudata *cpu;
686 	int total, no_turbo, turbo_pct;
687 	uint32_t turbo_fp;
688 
689 	cpu = all_cpu_data[0];
690 
691 	total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1;
692 	no_turbo = cpu->pstate.max_pstate - cpu->pstate.min_pstate + 1;
693 	turbo_fp = div_fp(no_turbo, total);
694 	turbo_pct = 100 - fp_toint(mul_fp(turbo_fp, int_tofp(100)));
695 	return sprintf(buf, "%u\n", turbo_pct);
696 }
697 
698 static ssize_t show_num_pstates(struct kobject *kobj,
699 				struct attribute *attr, char *buf)
700 {
701 	struct cpudata *cpu;
702 	int total;
703 
704 	cpu = all_cpu_data[0];
705 	total = cpu->pstate.turbo_pstate - cpu->pstate.min_pstate + 1;
706 	return sprintf(buf, "%u\n", total);
707 }
708 
709 static ssize_t show_no_turbo(struct kobject *kobj,
710 			     struct attribute *attr, char *buf)
711 {
712 	ssize_t ret;
713 
714 	update_turbo_state();
715 	if (limits->turbo_disabled)
716 		ret = sprintf(buf, "%u\n", limits->turbo_disabled);
717 	else
718 		ret = sprintf(buf, "%u\n", limits->no_turbo);
719 
720 	return ret;
721 }
722 
723 static ssize_t store_no_turbo(struct kobject *a, struct attribute *b,
724 			      const char *buf, size_t count)
725 {
726 	unsigned int input;
727 	int ret;
728 
729 	ret = sscanf(buf, "%u", &input);
730 	if (ret != 1)
731 		return -EINVAL;
732 
733 	update_turbo_state();
734 	if (limits->turbo_disabled) {
735 		pr_warn("Turbo disabled by BIOS or unavailable on processor\n");
736 		return -EPERM;
737 	}
738 
739 	limits->no_turbo = clamp_t(int, input, 0, 1);
740 
741 	if (hwp_active)
742 		intel_pstate_hwp_set_online_cpus();
743 
744 	return count;
745 }
746 
747 static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b,
748 				  const char *buf, size_t count)
749 {
750 	unsigned int input;
751 	int ret;
752 
753 	ret = sscanf(buf, "%u", &input);
754 	if (ret != 1)
755 		return -EINVAL;
756 
757 	limits->max_sysfs_pct = clamp_t(int, input, 0 , 100);
758 	limits->max_perf_pct = min(limits->max_policy_pct,
759 				   limits->max_sysfs_pct);
760 	limits->max_perf_pct = max(limits->min_policy_pct,
761 				   limits->max_perf_pct);
762 	limits->max_perf_pct = max(limits->min_perf_pct,
763 				   limits->max_perf_pct);
764 	limits->max_perf = div_fp(limits->max_perf_pct, 100);
765 
766 	if (hwp_active)
767 		intel_pstate_hwp_set_online_cpus();
768 	return count;
769 }
770 
771 static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b,
772 				  const char *buf, size_t count)
773 {
774 	unsigned int input;
775 	int ret;
776 
777 	ret = sscanf(buf, "%u", &input);
778 	if (ret != 1)
779 		return -EINVAL;
780 
781 	limits->min_sysfs_pct = clamp_t(int, input, 0 , 100);
782 	limits->min_perf_pct = max(limits->min_policy_pct,
783 				   limits->min_sysfs_pct);
784 	limits->min_perf_pct = min(limits->max_policy_pct,
785 				   limits->min_perf_pct);
786 	limits->min_perf_pct = min(limits->max_perf_pct,
787 				   limits->min_perf_pct);
788 	limits->min_perf = div_fp(limits->min_perf_pct, 100);
789 
790 	if (hwp_active)
791 		intel_pstate_hwp_set_online_cpus();
792 	return count;
793 }
794 
795 show_one(max_perf_pct, max_perf_pct);
796 show_one(min_perf_pct, min_perf_pct);
797 
798 define_one_global_rw(no_turbo);
799 define_one_global_rw(max_perf_pct);
800 define_one_global_rw(min_perf_pct);
801 define_one_global_ro(turbo_pct);
802 define_one_global_ro(num_pstates);
803 
804 static struct attribute *intel_pstate_attributes[] = {
805 	&no_turbo.attr,
806 	&turbo_pct.attr,
807 	&num_pstates.attr,
808 	NULL
809 };
810 
811 static struct attribute_group intel_pstate_attr_group = {
812 	.attrs = intel_pstate_attributes,
813 };
814 
815 static void __init intel_pstate_sysfs_expose_params(void)
816 {
817 	struct kobject *intel_pstate_kobject;
818 	int rc;
819 
820 	intel_pstate_kobject = kobject_create_and_add("intel_pstate",
821 						&cpu_subsys.dev_root->kobj);
822 	if (WARN_ON(!intel_pstate_kobject))
823 		return;
824 
825 	rc = sysfs_create_group(intel_pstate_kobject, &intel_pstate_attr_group);
826 	if (WARN_ON(rc))
827 		return;
828 
829 	/*
830 	 * If per cpu limits are enforced there are no global limits, so
831 	 * return without creating max/min_perf_pct attributes
832 	 */
833 	if (per_cpu_limits)
834 		return;
835 
836 	rc = sysfs_create_file(intel_pstate_kobject, &max_perf_pct.attr);
837 	WARN_ON(rc);
838 
839 	rc = sysfs_create_file(intel_pstate_kobject, &min_perf_pct.attr);
840 	WARN_ON(rc);
841 
842 }
843 /************************** sysfs end ************************/
844 
845 static void intel_pstate_hwp_enable(struct cpudata *cpudata)
846 {
847 	/* First disable HWP notification interrupt as we don't process them */
848 	if (static_cpu_has(X86_FEATURE_HWP_NOTIFY))
849 		wrmsrl_on_cpu(cpudata->cpu, MSR_HWP_INTERRUPT, 0x00);
850 
851 	wrmsrl_on_cpu(cpudata->cpu, MSR_PM_ENABLE, 0x1);
852 }
853 
854 static int atom_get_min_pstate(void)
855 {
856 	u64 value;
857 
858 	rdmsrl(ATOM_RATIOS, value);
859 	return (value >> 8) & 0x7F;
860 }
861 
862 static int atom_get_max_pstate(void)
863 {
864 	u64 value;
865 
866 	rdmsrl(ATOM_RATIOS, value);
867 	return (value >> 16) & 0x7F;
868 }
869 
870 static int atom_get_turbo_pstate(void)
871 {
872 	u64 value;
873 
874 	rdmsrl(ATOM_TURBO_RATIOS, value);
875 	return value & 0x7F;
876 }
877 
878 static u64 atom_get_val(struct cpudata *cpudata, int pstate)
879 {
880 	u64 val;
881 	int32_t vid_fp;
882 	u32 vid;
883 
884 	val = (u64)pstate << 8;
885 	if (limits->no_turbo && !limits->turbo_disabled)
886 		val |= (u64)1 << 32;
887 
888 	vid_fp = cpudata->vid.min + mul_fp(
889 		int_tofp(pstate - cpudata->pstate.min_pstate),
890 		cpudata->vid.ratio);
891 
892 	vid_fp = clamp_t(int32_t, vid_fp, cpudata->vid.min, cpudata->vid.max);
893 	vid = ceiling_fp(vid_fp);
894 
895 	if (pstate > cpudata->pstate.max_pstate)
896 		vid = cpudata->vid.turbo;
897 
898 	return val | vid;
899 }
900 
901 static int silvermont_get_scaling(void)
902 {
903 	u64 value;
904 	int i;
905 	/* Defined in Table 35-6 from SDM (Sept 2015) */
906 	static int silvermont_freq_table[] = {
907 		83300, 100000, 133300, 116700, 80000};
908 
909 	rdmsrl(MSR_FSB_FREQ, value);
910 	i = value & 0x7;
911 	WARN_ON(i > 4);
912 
913 	return silvermont_freq_table[i];
914 }
915 
916 static int airmont_get_scaling(void)
917 {
918 	u64 value;
919 	int i;
920 	/* Defined in Table 35-10 from SDM (Sept 2015) */
921 	static int airmont_freq_table[] = {
922 		83300, 100000, 133300, 116700, 80000,
923 		93300, 90000, 88900, 87500};
924 
925 	rdmsrl(MSR_FSB_FREQ, value);
926 	i = value & 0xF;
927 	WARN_ON(i > 8);
928 
929 	return airmont_freq_table[i];
930 }
931 
932 static void atom_get_vid(struct cpudata *cpudata)
933 {
934 	u64 value;
935 
936 	rdmsrl(ATOM_VIDS, value);
937 	cpudata->vid.min = int_tofp((value >> 8) & 0x7f);
938 	cpudata->vid.max = int_tofp((value >> 16) & 0x7f);
939 	cpudata->vid.ratio = div_fp(
940 		cpudata->vid.max - cpudata->vid.min,
941 		int_tofp(cpudata->pstate.max_pstate -
942 			cpudata->pstate.min_pstate));
943 
944 	rdmsrl(ATOM_TURBO_VIDS, value);
945 	cpudata->vid.turbo = value & 0x7f;
946 }
947 
948 static int core_get_min_pstate(void)
949 {
950 	u64 value;
951 
952 	rdmsrl(MSR_PLATFORM_INFO, value);
953 	return (value >> 40) & 0xFF;
954 }
955 
956 static int core_get_max_pstate_physical(void)
957 {
958 	u64 value;
959 
960 	rdmsrl(MSR_PLATFORM_INFO, value);
961 	return (value >> 8) & 0xFF;
962 }
963 
964 static int core_get_max_pstate(void)
965 {
966 	u64 tar;
967 	u64 plat_info;
968 	int max_pstate;
969 	int err;
970 
971 	rdmsrl(MSR_PLATFORM_INFO, plat_info);
972 	max_pstate = (plat_info >> 8) & 0xFF;
973 
974 	err = rdmsrl_safe(MSR_TURBO_ACTIVATION_RATIO, &tar);
975 	if (!err) {
976 		/* Do some sanity checking for safety */
977 		if (plat_info & 0x600000000) {
978 			u64 tdp_ctrl;
979 			u64 tdp_ratio;
980 			int tdp_msr;
981 
982 			err = rdmsrl_safe(MSR_CONFIG_TDP_CONTROL, &tdp_ctrl);
983 			if (err)
984 				goto skip_tar;
985 
986 			tdp_msr = MSR_CONFIG_TDP_NOMINAL + (tdp_ctrl & 0x3);
987 			err = rdmsrl_safe(tdp_msr, &tdp_ratio);
988 			if (err)
989 				goto skip_tar;
990 
991 			/* For level 1 and 2, bits[23:16] contain the ratio */
992 			if (tdp_ctrl)
993 				tdp_ratio >>= 16;
994 
995 			tdp_ratio &= 0xff; /* ratios are only 8 bits long */
996 			if (tdp_ratio - 1 == tar) {
997 				max_pstate = tar;
998 				pr_debug("max_pstate=TAC %x\n", max_pstate);
999 			} else {
1000 				goto skip_tar;
1001 			}
1002 		}
1003 	}
1004 
1005 skip_tar:
1006 	return max_pstate;
1007 }
1008 
1009 static int core_get_turbo_pstate(void)
1010 {
1011 	u64 value;
1012 	int nont, ret;
1013 
1014 	rdmsrl(MSR_TURBO_RATIO_LIMIT, value);
1015 	nont = core_get_max_pstate();
1016 	ret = (value) & 255;
1017 	if (ret <= nont)
1018 		ret = nont;
1019 	return ret;
1020 }
1021 
1022 static inline int core_get_scaling(void)
1023 {
1024 	return 100000;
1025 }
1026 
1027 static u64 core_get_val(struct cpudata *cpudata, int pstate)
1028 {
1029 	u64 val;
1030 
1031 	val = (u64)pstate << 8;
1032 	if (limits->no_turbo && !limits->turbo_disabled)
1033 		val |= (u64)1 << 32;
1034 
1035 	return val;
1036 }
1037 
1038 static int knl_get_turbo_pstate(void)
1039 {
1040 	u64 value;
1041 	int nont, ret;
1042 
1043 	rdmsrl(MSR_TURBO_RATIO_LIMIT, value);
1044 	nont = core_get_max_pstate();
1045 	ret = (((value) >> 8) & 0xFF);
1046 	if (ret <= nont)
1047 		ret = nont;
1048 	return ret;
1049 }
1050 
1051 static struct cpu_defaults core_params = {
1052 	.pid_policy = {
1053 		.sample_rate_ms = 10,
1054 		.deadband = 0,
1055 		.setpoint = 97,
1056 		.p_gain_pct = 20,
1057 		.d_gain_pct = 0,
1058 		.i_gain_pct = 0,
1059 	},
1060 	.funcs = {
1061 		.get_max = core_get_max_pstate,
1062 		.get_max_physical = core_get_max_pstate_physical,
1063 		.get_min = core_get_min_pstate,
1064 		.get_turbo = core_get_turbo_pstate,
1065 		.get_scaling = core_get_scaling,
1066 		.get_val = core_get_val,
1067 		.get_target_pstate = get_target_pstate_use_performance,
1068 	},
1069 };
1070 
1071 static const struct cpu_defaults silvermont_params = {
1072 	.pid_policy = {
1073 		.sample_rate_ms = 10,
1074 		.deadband = 0,
1075 		.setpoint = 60,
1076 		.p_gain_pct = 14,
1077 		.d_gain_pct = 0,
1078 		.i_gain_pct = 4,
1079 	},
1080 	.funcs = {
1081 		.get_max = atom_get_max_pstate,
1082 		.get_max_physical = atom_get_max_pstate,
1083 		.get_min = atom_get_min_pstate,
1084 		.get_turbo = atom_get_turbo_pstate,
1085 		.get_val = atom_get_val,
1086 		.get_scaling = silvermont_get_scaling,
1087 		.get_vid = atom_get_vid,
1088 		.get_target_pstate = get_target_pstate_use_cpu_load,
1089 	},
1090 };
1091 
1092 static const struct cpu_defaults airmont_params = {
1093 	.pid_policy = {
1094 		.sample_rate_ms = 10,
1095 		.deadband = 0,
1096 		.setpoint = 60,
1097 		.p_gain_pct = 14,
1098 		.d_gain_pct = 0,
1099 		.i_gain_pct = 4,
1100 	},
1101 	.funcs = {
1102 		.get_max = atom_get_max_pstate,
1103 		.get_max_physical = atom_get_max_pstate,
1104 		.get_min = atom_get_min_pstate,
1105 		.get_turbo = atom_get_turbo_pstate,
1106 		.get_val = atom_get_val,
1107 		.get_scaling = airmont_get_scaling,
1108 		.get_vid = atom_get_vid,
1109 		.get_target_pstate = get_target_pstate_use_cpu_load,
1110 	},
1111 };
1112 
1113 static const struct cpu_defaults knl_params = {
1114 	.pid_policy = {
1115 		.sample_rate_ms = 10,
1116 		.deadband = 0,
1117 		.setpoint = 97,
1118 		.p_gain_pct = 20,
1119 		.d_gain_pct = 0,
1120 		.i_gain_pct = 0,
1121 	},
1122 	.funcs = {
1123 		.get_max = core_get_max_pstate,
1124 		.get_max_physical = core_get_max_pstate_physical,
1125 		.get_min = core_get_min_pstate,
1126 		.get_turbo = knl_get_turbo_pstate,
1127 		.get_scaling = core_get_scaling,
1128 		.get_val = core_get_val,
1129 		.get_target_pstate = get_target_pstate_use_performance,
1130 	},
1131 };
1132 
1133 static const struct cpu_defaults bxt_params = {
1134 	.pid_policy = {
1135 		.sample_rate_ms = 10,
1136 		.deadband = 0,
1137 		.setpoint = 60,
1138 		.p_gain_pct = 14,
1139 		.d_gain_pct = 0,
1140 		.i_gain_pct = 4,
1141 	},
1142 	.funcs = {
1143 		.get_max = core_get_max_pstate,
1144 		.get_max_physical = core_get_max_pstate_physical,
1145 		.get_min = core_get_min_pstate,
1146 		.get_turbo = core_get_turbo_pstate,
1147 		.get_scaling = core_get_scaling,
1148 		.get_val = core_get_val,
1149 		.get_target_pstate = get_target_pstate_use_cpu_load,
1150 	},
1151 };
1152 
1153 static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max)
1154 {
1155 	int max_perf = cpu->pstate.turbo_pstate;
1156 	int max_perf_adj;
1157 	int min_perf;
1158 	struct perf_limits *perf_limits = limits;
1159 
1160 	if (limits->no_turbo || limits->turbo_disabled)
1161 		max_perf = cpu->pstate.max_pstate;
1162 
1163 	if (per_cpu_limits)
1164 		perf_limits = cpu->perf_limits;
1165 
1166 	/*
1167 	 * performance can be limited by user through sysfs, by cpufreq
1168 	 * policy, or by cpu specific default values determined through
1169 	 * experimentation.
1170 	 */
1171 	max_perf_adj = fp_toint(max_perf * perf_limits->max_perf);
1172 	*max = clamp_t(int, max_perf_adj,
1173 			cpu->pstate.min_pstate, cpu->pstate.turbo_pstate);
1174 
1175 	min_perf = fp_toint(max_perf * perf_limits->min_perf);
1176 	*min = clamp_t(int, min_perf, cpu->pstate.min_pstate, max_perf);
1177 }
1178 
1179 static void intel_pstate_set_pstate(struct cpudata *cpu, int pstate)
1180 {
1181 	trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu);
1182 	cpu->pstate.current_pstate = pstate;
1183 	/*
1184 	 * Generally, there is no guarantee that this code will always run on
1185 	 * the CPU being updated, so force the register update to run on the
1186 	 * right CPU.
1187 	 */
1188 	wrmsrl_on_cpu(cpu->cpu, MSR_IA32_PERF_CTL,
1189 		      pstate_funcs.get_val(cpu, pstate));
1190 }
1191 
1192 static void intel_pstate_set_min_pstate(struct cpudata *cpu)
1193 {
1194 	intel_pstate_set_pstate(cpu, cpu->pstate.min_pstate);
1195 }
1196 
1197 static void intel_pstate_max_within_limits(struct cpudata *cpu)
1198 {
1199 	int min_pstate, max_pstate;
1200 
1201 	update_turbo_state();
1202 	intel_pstate_get_min_max(cpu, &min_pstate, &max_pstate);
1203 	intel_pstate_set_pstate(cpu, max_pstate);
1204 }
1205 
1206 static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
1207 {
1208 	cpu->pstate.min_pstate = pstate_funcs.get_min();
1209 	cpu->pstate.max_pstate = pstate_funcs.get_max();
1210 	cpu->pstate.max_pstate_physical = pstate_funcs.get_max_physical();
1211 	cpu->pstate.turbo_pstate = pstate_funcs.get_turbo();
1212 	cpu->pstate.scaling = pstate_funcs.get_scaling();
1213 
1214 	if (pstate_funcs.get_vid)
1215 		pstate_funcs.get_vid(cpu);
1216 
1217 	intel_pstate_set_min_pstate(cpu);
1218 }
1219 
1220 static inline void intel_pstate_calc_avg_perf(struct cpudata *cpu)
1221 {
1222 	struct sample *sample = &cpu->sample;
1223 
1224 	sample->core_avg_perf = div_ext_fp(sample->aperf, sample->mperf);
1225 }
1226 
1227 static inline bool intel_pstate_sample(struct cpudata *cpu, u64 time)
1228 {
1229 	u64 aperf, mperf;
1230 	unsigned long flags;
1231 	u64 tsc;
1232 
1233 	local_irq_save(flags);
1234 	rdmsrl(MSR_IA32_APERF, aperf);
1235 	rdmsrl(MSR_IA32_MPERF, mperf);
1236 	tsc = rdtsc();
1237 	if (cpu->prev_mperf == mperf || cpu->prev_tsc == tsc) {
1238 		local_irq_restore(flags);
1239 		return false;
1240 	}
1241 	local_irq_restore(flags);
1242 
1243 	cpu->last_sample_time = cpu->sample.time;
1244 	cpu->sample.time = time;
1245 	cpu->sample.aperf = aperf;
1246 	cpu->sample.mperf = mperf;
1247 	cpu->sample.tsc =  tsc;
1248 	cpu->sample.aperf -= cpu->prev_aperf;
1249 	cpu->sample.mperf -= cpu->prev_mperf;
1250 	cpu->sample.tsc -= cpu->prev_tsc;
1251 
1252 	cpu->prev_aperf = aperf;
1253 	cpu->prev_mperf = mperf;
1254 	cpu->prev_tsc = tsc;
1255 	/*
1256 	 * First time this function is invoked in a given cycle, all of the
1257 	 * previous sample data fields are equal to zero or stale and they must
1258 	 * be populated with meaningful numbers for things to work, so assume
1259 	 * that sample.time will always be reset before setting the utilization
1260 	 * update hook and make the caller skip the sample then.
1261 	 */
1262 	return !!cpu->last_sample_time;
1263 }
1264 
1265 static inline int32_t get_avg_frequency(struct cpudata *cpu)
1266 {
1267 	return mul_ext_fp(cpu->sample.core_avg_perf,
1268 			  cpu->pstate.max_pstate_physical * cpu->pstate.scaling);
1269 }
1270 
1271 static inline int32_t get_avg_pstate(struct cpudata *cpu)
1272 {
1273 	return mul_ext_fp(cpu->pstate.max_pstate_physical,
1274 			  cpu->sample.core_avg_perf);
1275 }
1276 
1277 static inline int32_t get_target_pstate_use_cpu_load(struct cpudata *cpu)
1278 {
1279 	struct sample *sample = &cpu->sample;
1280 	int32_t busy_frac, boost;
1281 	int target, avg_pstate;
1282 
1283 	busy_frac = div_fp(sample->mperf, sample->tsc);
1284 
1285 	boost = cpu->iowait_boost;
1286 	cpu->iowait_boost >>= 1;
1287 
1288 	if (busy_frac < boost)
1289 		busy_frac = boost;
1290 
1291 	sample->busy_scaled = busy_frac * 100;
1292 
1293 	target = limits->no_turbo || limits->turbo_disabled ?
1294 			cpu->pstate.max_pstate : cpu->pstate.turbo_pstate;
1295 	target += target >> 2;
1296 	target = mul_fp(target, busy_frac);
1297 	if (target < cpu->pstate.min_pstate)
1298 		target = cpu->pstate.min_pstate;
1299 
1300 	/*
1301 	 * If the average P-state during the previous cycle was higher than the
1302 	 * current target, add 50% of the difference to the target to reduce
1303 	 * possible performance oscillations and offset possible performance
1304 	 * loss related to moving the workload from one CPU to another within
1305 	 * a package/module.
1306 	 */
1307 	avg_pstate = get_avg_pstate(cpu);
1308 	if (avg_pstate > target)
1309 		target += (avg_pstate - target) >> 1;
1310 
1311 	return target;
1312 }
1313 
1314 static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu)
1315 {
1316 	int32_t perf_scaled, max_pstate, current_pstate, sample_ratio;
1317 	u64 duration_ns;
1318 
1319 	/*
1320 	 * perf_scaled is the ratio of the average P-state during the last
1321 	 * sampling period to the P-state requested last time (in percent).
1322 	 *
1323 	 * That measures the system's response to the previous P-state
1324 	 * selection.
1325 	 */
1326 	max_pstate = cpu->pstate.max_pstate_physical;
1327 	current_pstate = cpu->pstate.current_pstate;
1328 	perf_scaled = mul_ext_fp(cpu->sample.core_avg_perf,
1329 			       div_fp(100 * max_pstate, current_pstate));
1330 
1331 	/*
1332 	 * Since our utilization update callback will not run unless we are
1333 	 * in C0, check if the actual elapsed time is significantly greater (3x)
1334 	 * than our sample interval.  If it is, then we were idle for a long
1335 	 * enough period of time to adjust our performance metric.
1336 	 */
1337 	duration_ns = cpu->sample.time - cpu->last_sample_time;
1338 	if ((s64)duration_ns > pid_params.sample_rate_ns * 3) {
1339 		sample_ratio = div_fp(pid_params.sample_rate_ns, duration_ns);
1340 		perf_scaled = mul_fp(perf_scaled, sample_ratio);
1341 	} else {
1342 		sample_ratio = div_fp(100 * cpu->sample.mperf, cpu->sample.tsc);
1343 		if (sample_ratio < int_tofp(1))
1344 			perf_scaled = 0;
1345 	}
1346 
1347 	cpu->sample.busy_scaled = perf_scaled;
1348 	return cpu->pstate.current_pstate - pid_calc(&cpu->pid, perf_scaled);
1349 }
1350 
1351 static inline void intel_pstate_update_pstate(struct cpudata *cpu, int pstate)
1352 {
1353 	int max_perf, min_perf;
1354 
1355 	update_turbo_state();
1356 
1357 	intel_pstate_get_min_max(cpu, &min_perf, &max_perf);
1358 	pstate = clamp_t(int, pstate, min_perf, max_perf);
1359 	trace_cpu_frequency(pstate * cpu->pstate.scaling, cpu->cpu);
1360 	if (pstate == cpu->pstate.current_pstate)
1361 		return;
1362 
1363 	cpu->pstate.current_pstate = pstate;
1364 	wrmsrl(MSR_IA32_PERF_CTL, pstate_funcs.get_val(cpu, pstate));
1365 }
1366 
1367 static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
1368 {
1369 	int from, target_pstate;
1370 	struct sample *sample;
1371 
1372 	from = cpu->pstate.current_pstate;
1373 
1374 	target_pstate = cpu->policy == CPUFREQ_POLICY_PERFORMANCE ?
1375 		cpu->pstate.turbo_pstate : pstate_funcs.get_target_pstate(cpu);
1376 
1377 	intel_pstate_update_pstate(cpu, target_pstate);
1378 
1379 	sample = &cpu->sample;
1380 	trace_pstate_sample(mul_ext_fp(100, sample->core_avg_perf),
1381 		fp_toint(sample->busy_scaled),
1382 		from,
1383 		cpu->pstate.current_pstate,
1384 		sample->mperf,
1385 		sample->aperf,
1386 		sample->tsc,
1387 		get_avg_frequency(cpu),
1388 		fp_toint(cpu->iowait_boost * 100));
1389 }
1390 
1391 static void intel_pstate_update_util(struct update_util_data *data, u64 time,
1392 				     unsigned int flags)
1393 {
1394 	struct cpudata *cpu = container_of(data, struct cpudata, update_util);
1395 	u64 delta_ns;
1396 
1397 	if (pstate_funcs.get_target_pstate == get_target_pstate_use_cpu_load) {
1398 		if (flags & SCHED_CPUFREQ_IOWAIT) {
1399 			cpu->iowait_boost = int_tofp(1);
1400 		} else if (cpu->iowait_boost) {
1401 			/* Clear iowait_boost if the CPU may have been idle. */
1402 			delta_ns = time - cpu->last_update;
1403 			if (delta_ns > TICK_NSEC)
1404 				cpu->iowait_boost = 0;
1405 		}
1406 		cpu->last_update = time;
1407 	}
1408 
1409 	delta_ns = time - cpu->sample.time;
1410 	if ((s64)delta_ns >= pid_params.sample_rate_ns) {
1411 		bool sample_taken = intel_pstate_sample(cpu, time);
1412 
1413 		if (sample_taken) {
1414 			intel_pstate_calc_avg_perf(cpu);
1415 			if (!hwp_active)
1416 				intel_pstate_adjust_busy_pstate(cpu);
1417 		}
1418 	}
1419 }
1420 
1421 #define ICPU(model, policy) \
1422 	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_APERFMPERF,\
1423 			(unsigned long)&policy }
1424 
1425 static const struct x86_cpu_id intel_pstate_cpu_ids[] = {
1426 	ICPU(INTEL_FAM6_SANDYBRIDGE, 		core_params),
1427 	ICPU(INTEL_FAM6_SANDYBRIDGE_X,		core_params),
1428 	ICPU(INTEL_FAM6_ATOM_SILVERMONT1,	silvermont_params),
1429 	ICPU(INTEL_FAM6_IVYBRIDGE,		core_params),
1430 	ICPU(INTEL_FAM6_HASWELL_CORE,		core_params),
1431 	ICPU(INTEL_FAM6_BROADWELL_CORE,		core_params),
1432 	ICPU(INTEL_FAM6_IVYBRIDGE_X,		core_params),
1433 	ICPU(INTEL_FAM6_HASWELL_X,		core_params),
1434 	ICPU(INTEL_FAM6_HASWELL_ULT,		core_params),
1435 	ICPU(INTEL_FAM6_HASWELL_GT3E,		core_params),
1436 	ICPU(INTEL_FAM6_BROADWELL_GT3E,		core_params),
1437 	ICPU(INTEL_FAM6_ATOM_AIRMONT,		airmont_params),
1438 	ICPU(INTEL_FAM6_SKYLAKE_MOBILE,		core_params),
1439 	ICPU(INTEL_FAM6_BROADWELL_X,		core_params),
1440 	ICPU(INTEL_FAM6_SKYLAKE_DESKTOP,	core_params),
1441 	ICPU(INTEL_FAM6_BROADWELL_XEON_D,	core_params),
1442 	ICPU(INTEL_FAM6_XEON_PHI_KNL,		knl_params),
1443 	ICPU(INTEL_FAM6_ATOM_GOLDMONT,		bxt_params),
1444 	{}
1445 };
1446 MODULE_DEVICE_TABLE(x86cpu, intel_pstate_cpu_ids);
1447 
1448 static const struct x86_cpu_id intel_pstate_cpu_oob_ids[] __initconst = {
1449 	ICPU(INTEL_FAM6_BROADWELL_XEON_D, core_params),
1450 	ICPU(INTEL_FAM6_BROADWELL_X, core_params),
1451 	ICPU(INTEL_FAM6_SKYLAKE_X, core_params),
1452 	{}
1453 };
1454 
1455 static int intel_pstate_init_cpu(unsigned int cpunum)
1456 {
1457 	struct cpudata *cpu;
1458 
1459 	cpu = all_cpu_data[cpunum];
1460 
1461 	if (!cpu) {
1462 		unsigned int size = sizeof(struct cpudata);
1463 
1464 		if (per_cpu_limits)
1465 			size += sizeof(struct perf_limits);
1466 
1467 		cpu = kzalloc(size, GFP_KERNEL);
1468 		if (!cpu)
1469 			return -ENOMEM;
1470 
1471 		all_cpu_data[cpunum] = cpu;
1472 		if (per_cpu_limits)
1473 			cpu->perf_limits = (struct perf_limits *)(cpu + 1);
1474 
1475 	}
1476 
1477 	cpu = all_cpu_data[cpunum];
1478 
1479 	cpu->cpu = cpunum;
1480 
1481 	if (hwp_active) {
1482 		intel_pstate_hwp_enable(cpu);
1483 		pid_params.sample_rate_ms = 50;
1484 		pid_params.sample_rate_ns = 50 * NSEC_PER_MSEC;
1485 	}
1486 
1487 	intel_pstate_get_cpu_pstates(cpu);
1488 
1489 	intel_pstate_busy_pid_reset(cpu);
1490 
1491 	pr_debug("controlling: cpu %d\n", cpunum);
1492 
1493 	return 0;
1494 }
1495 
1496 static unsigned int intel_pstate_get(unsigned int cpu_num)
1497 {
1498 	struct cpudata *cpu = all_cpu_data[cpu_num];
1499 
1500 	return cpu ? get_avg_frequency(cpu) : 0;
1501 }
1502 
1503 static void intel_pstate_set_update_util_hook(unsigned int cpu_num)
1504 {
1505 	struct cpudata *cpu = all_cpu_data[cpu_num];
1506 
1507 	if (cpu->update_util_set)
1508 		return;
1509 
1510 	/* Prevent intel_pstate_update_util() from using stale data. */
1511 	cpu->sample.time = 0;
1512 	cpufreq_add_update_util_hook(cpu_num, &cpu->update_util,
1513 				     intel_pstate_update_util);
1514 	cpu->update_util_set = true;
1515 }
1516 
1517 static void intel_pstate_clear_update_util_hook(unsigned int cpu)
1518 {
1519 	struct cpudata *cpu_data = all_cpu_data[cpu];
1520 
1521 	if (!cpu_data->update_util_set)
1522 		return;
1523 
1524 	cpufreq_remove_update_util_hook(cpu);
1525 	cpu_data->update_util_set = false;
1526 	synchronize_sched();
1527 }
1528 
1529 static void intel_pstate_set_performance_limits(struct perf_limits *limits)
1530 {
1531 	limits->no_turbo = 0;
1532 	limits->turbo_disabled = 0;
1533 	limits->max_perf_pct = 100;
1534 	limits->max_perf = int_tofp(1);
1535 	limits->min_perf_pct = 100;
1536 	limits->min_perf = int_tofp(1);
1537 	limits->max_policy_pct = 100;
1538 	limits->max_sysfs_pct = 100;
1539 	limits->min_policy_pct = 0;
1540 	limits->min_sysfs_pct = 0;
1541 }
1542 
1543 static void intel_pstate_update_perf_limits(struct cpufreq_policy *policy,
1544 					    struct perf_limits *limits)
1545 {
1546 	limits->min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq;
1547 	limits->min_policy_pct = clamp_t(int, limits->min_policy_pct, 0, 100);
1548 	limits->max_policy_pct = DIV_ROUND_UP(policy->max * 100,
1549 					      policy->cpuinfo.max_freq);
1550 	limits->max_policy_pct = clamp_t(int, limits->max_policy_pct, 0, 100);
1551 
1552 	/* Normalize user input to [min_policy_pct, max_policy_pct] */
1553 	limits->min_perf_pct = max(limits->min_policy_pct,
1554 				   limits->min_sysfs_pct);
1555 	limits->min_perf_pct = min(limits->max_policy_pct,
1556 				   limits->min_perf_pct);
1557 	limits->max_perf_pct = min(limits->max_policy_pct,
1558 				   limits->max_sysfs_pct);
1559 	limits->max_perf_pct = max(limits->min_policy_pct,
1560 				   limits->max_perf_pct);
1561 
1562 	/* Make sure min_perf_pct <= max_perf_pct */
1563 	limits->min_perf_pct = min(limits->max_perf_pct, limits->min_perf_pct);
1564 
1565 	limits->min_perf = div_fp(limits->min_perf_pct, 100);
1566 	limits->max_perf = div_fp(limits->max_perf_pct, 100);
1567 	limits->max_perf = round_up(limits->max_perf, FRAC_BITS);
1568 
1569 	pr_debug("cpu:%d max_perf_pct:%d min_perf_pct:%d\n", policy->cpu,
1570 		 limits->max_perf_pct, limits->min_perf_pct);
1571 }
1572 
1573 static int intel_pstate_set_policy(struct cpufreq_policy *policy)
1574 {
1575 	struct cpudata *cpu;
1576 	struct perf_limits *perf_limits = NULL;
1577 
1578 	if (!policy->cpuinfo.max_freq)
1579 		return -ENODEV;
1580 
1581 	pr_debug("set_policy cpuinfo.max %u policy->max %u\n",
1582 		 policy->cpuinfo.max_freq, policy->max);
1583 
1584 	cpu = all_cpu_data[policy->cpu];
1585 	cpu->policy = policy->policy;
1586 
1587 	if (cpu->pstate.max_pstate_physical > cpu->pstate.max_pstate &&
1588 	    policy->max < policy->cpuinfo.max_freq &&
1589 	    policy->max > cpu->pstate.max_pstate * cpu->pstate.scaling) {
1590 		pr_debug("policy->max > max non turbo frequency\n");
1591 		policy->max = policy->cpuinfo.max_freq;
1592 	}
1593 
1594 	if (per_cpu_limits)
1595 		perf_limits = cpu->perf_limits;
1596 
1597 	if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
1598 		if (!perf_limits) {
1599 			limits = &performance_limits;
1600 			perf_limits = limits;
1601 		}
1602 		if (policy->max >= policy->cpuinfo.max_freq) {
1603 			pr_debug("set performance\n");
1604 			intel_pstate_set_performance_limits(perf_limits);
1605 			goto out;
1606 		}
1607 	} else {
1608 		pr_debug("set powersave\n");
1609 		if (!perf_limits) {
1610 			limits = &powersave_limits;
1611 			perf_limits = limits;
1612 		}
1613 
1614 	}
1615 
1616 	intel_pstate_update_perf_limits(policy, perf_limits);
1617  out:
1618 	if (cpu->policy == CPUFREQ_POLICY_PERFORMANCE) {
1619 		/*
1620 		 * NOHZ_FULL CPUs need this as the governor callback may not
1621 		 * be invoked on them.
1622 		 */
1623 		intel_pstate_clear_update_util_hook(policy->cpu);
1624 		intel_pstate_max_within_limits(cpu);
1625 	}
1626 
1627 	intel_pstate_set_update_util_hook(policy->cpu);
1628 
1629 	intel_pstate_hwp_set_policy(policy);
1630 
1631 	return 0;
1632 }
1633 
1634 static int intel_pstate_verify_policy(struct cpufreq_policy *policy)
1635 {
1636 	cpufreq_verify_within_cpu_limits(policy);
1637 
1638 	if (policy->policy != CPUFREQ_POLICY_POWERSAVE &&
1639 	    policy->policy != CPUFREQ_POLICY_PERFORMANCE)
1640 		return -EINVAL;
1641 
1642 	return 0;
1643 }
1644 
1645 static void intel_pstate_stop_cpu(struct cpufreq_policy *policy)
1646 {
1647 	int cpu_num = policy->cpu;
1648 	struct cpudata *cpu = all_cpu_data[cpu_num];
1649 
1650 	pr_debug("CPU %d exiting\n", cpu_num);
1651 
1652 	intel_pstate_clear_update_util_hook(cpu_num);
1653 
1654 	if (hwp_active)
1655 		return;
1656 
1657 	intel_pstate_set_min_pstate(cpu);
1658 }
1659 
1660 static int intel_pstate_cpu_init(struct cpufreq_policy *policy)
1661 {
1662 	struct cpudata *cpu;
1663 	int rc;
1664 
1665 	rc = intel_pstate_init_cpu(policy->cpu);
1666 	if (rc)
1667 		return rc;
1668 
1669 	cpu = all_cpu_data[policy->cpu];
1670 
1671 	if (limits->min_perf_pct == 100 && limits->max_perf_pct == 100)
1672 		policy->policy = CPUFREQ_POLICY_PERFORMANCE;
1673 	else
1674 		policy->policy = CPUFREQ_POLICY_POWERSAVE;
1675 
1676 	/*
1677 	 * We need sane value in the cpu->perf_limits, so inherit from global
1678 	 * perf_limits limits, which are seeded with values based on the
1679 	 * CONFIG_CPU_FREQ_DEFAULT_GOV_*, during boot up.
1680 	 */
1681 	if (per_cpu_limits)
1682 		memcpy(cpu->perf_limits, limits, sizeof(struct perf_limits));
1683 
1684 	policy->min = cpu->pstate.min_pstate * cpu->pstate.scaling;
1685 	policy->max = cpu->pstate.turbo_pstate * cpu->pstate.scaling;
1686 
1687 	/* cpuinfo and default policy values */
1688 	policy->cpuinfo.min_freq = cpu->pstate.min_pstate * cpu->pstate.scaling;
1689 	update_turbo_state();
1690 	policy->cpuinfo.max_freq = limits->turbo_disabled ?
1691 			cpu->pstate.max_pstate : cpu->pstate.turbo_pstate;
1692 	policy->cpuinfo.max_freq *= cpu->pstate.scaling;
1693 
1694 	intel_pstate_init_acpi_perf_limits(policy);
1695 	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
1696 	cpumask_set_cpu(policy->cpu, policy->cpus);
1697 
1698 	return 0;
1699 }
1700 
1701 static int intel_pstate_cpu_exit(struct cpufreq_policy *policy)
1702 {
1703 	intel_pstate_exit_perf_limits(policy);
1704 
1705 	return 0;
1706 }
1707 
1708 static struct cpufreq_driver intel_pstate_driver = {
1709 	.flags		= CPUFREQ_CONST_LOOPS,
1710 	.verify		= intel_pstate_verify_policy,
1711 	.setpolicy	= intel_pstate_set_policy,
1712 	.resume		= intel_pstate_hwp_set_policy,
1713 	.get		= intel_pstate_get,
1714 	.init		= intel_pstate_cpu_init,
1715 	.exit		= intel_pstate_cpu_exit,
1716 	.stop_cpu	= intel_pstate_stop_cpu,
1717 	.name		= "intel_pstate",
1718 };
1719 
1720 static int no_load __initdata;
1721 static int no_hwp __initdata;
1722 static int hwp_only __initdata;
1723 static unsigned int force_load __initdata;
1724 
1725 static int __init intel_pstate_msrs_not_valid(void)
1726 {
1727 	if (!pstate_funcs.get_max() ||
1728 	    !pstate_funcs.get_min() ||
1729 	    !pstate_funcs.get_turbo())
1730 		return -ENODEV;
1731 
1732 	return 0;
1733 }
1734 
1735 static void __init copy_pid_params(struct pstate_adjust_policy *policy)
1736 {
1737 	pid_params.sample_rate_ms = policy->sample_rate_ms;
1738 	pid_params.sample_rate_ns = pid_params.sample_rate_ms * NSEC_PER_MSEC;
1739 	pid_params.p_gain_pct = policy->p_gain_pct;
1740 	pid_params.i_gain_pct = policy->i_gain_pct;
1741 	pid_params.d_gain_pct = policy->d_gain_pct;
1742 	pid_params.deadband = policy->deadband;
1743 	pid_params.setpoint = policy->setpoint;
1744 }
1745 
1746 static void __init copy_cpu_funcs(struct pstate_funcs *funcs)
1747 {
1748 	pstate_funcs.get_max   = funcs->get_max;
1749 	pstate_funcs.get_max_physical = funcs->get_max_physical;
1750 	pstate_funcs.get_min   = funcs->get_min;
1751 	pstate_funcs.get_turbo = funcs->get_turbo;
1752 	pstate_funcs.get_scaling = funcs->get_scaling;
1753 	pstate_funcs.get_val   = funcs->get_val;
1754 	pstate_funcs.get_vid   = funcs->get_vid;
1755 	pstate_funcs.get_target_pstate = funcs->get_target_pstate;
1756 
1757 }
1758 
1759 #ifdef CONFIG_ACPI
1760 
1761 static bool __init intel_pstate_no_acpi_pss(void)
1762 {
1763 	int i;
1764 
1765 	for_each_possible_cpu(i) {
1766 		acpi_status status;
1767 		union acpi_object *pss;
1768 		struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1769 		struct acpi_processor *pr = per_cpu(processors, i);
1770 
1771 		if (!pr)
1772 			continue;
1773 
1774 		status = acpi_evaluate_object(pr->handle, "_PSS", NULL, &buffer);
1775 		if (ACPI_FAILURE(status))
1776 			continue;
1777 
1778 		pss = buffer.pointer;
1779 		if (pss && pss->type == ACPI_TYPE_PACKAGE) {
1780 			kfree(pss);
1781 			return false;
1782 		}
1783 
1784 		kfree(pss);
1785 	}
1786 
1787 	return true;
1788 }
1789 
1790 static bool __init intel_pstate_has_acpi_ppc(void)
1791 {
1792 	int i;
1793 
1794 	for_each_possible_cpu(i) {
1795 		struct acpi_processor *pr = per_cpu(processors, i);
1796 
1797 		if (!pr)
1798 			continue;
1799 		if (acpi_has_method(pr->handle, "_PPC"))
1800 			return true;
1801 	}
1802 	return false;
1803 }
1804 
1805 enum {
1806 	PSS,
1807 	PPC,
1808 };
1809 
1810 struct hw_vendor_info {
1811 	u16  valid;
1812 	char oem_id[ACPI_OEM_ID_SIZE];
1813 	char oem_table_id[ACPI_OEM_TABLE_ID_SIZE];
1814 	int  oem_pwr_table;
1815 };
1816 
1817 /* Hardware vendor-specific info that has its own power management modes */
1818 static struct hw_vendor_info vendor_info[] __initdata = {
1819 	{1, "HP    ", "ProLiant", PSS},
1820 	{1, "ORACLE", "X4-2    ", PPC},
1821 	{1, "ORACLE", "X4-2L   ", PPC},
1822 	{1, "ORACLE", "X4-2B   ", PPC},
1823 	{1, "ORACLE", "X3-2    ", PPC},
1824 	{1, "ORACLE", "X3-2L   ", PPC},
1825 	{1, "ORACLE", "X3-2B   ", PPC},
1826 	{1, "ORACLE", "X4470M2 ", PPC},
1827 	{1, "ORACLE", "X4270M3 ", PPC},
1828 	{1, "ORACLE", "X4270M2 ", PPC},
1829 	{1, "ORACLE", "X4170M2 ", PPC},
1830 	{1, "ORACLE", "X4170 M3", PPC},
1831 	{1, "ORACLE", "X4275 M3", PPC},
1832 	{1, "ORACLE", "X6-2    ", PPC},
1833 	{1, "ORACLE", "Sudbury ", PPC},
1834 	{0, "", ""},
1835 };
1836 
1837 static bool __init intel_pstate_platform_pwr_mgmt_exists(void)
1838 {
1839 	struct acpi_table_header hdr;
1840 	struct hw_vendor_info *v_info;
1841 	const struct x86_cpu_id *id;
1842 	u64 misc_pwr;
1843 
1844 	id = x86_match_cpu(intel_pstate_cpu_oob_ids);
1845 	if (id) {
1846 		rdmsrl(MSR_MISC_PWR_MGMT, misc_pwr);
1847 		if ( misc_pwr & (1 << 8))
1848 			return true;
1849 	}
1850 
1851 	if (acpi_disabled ||
1852 	    ACPI_FAILURE(acpi_get_table_header(ACPI_SIG_FADT, 0, &hdr)))
1853 		return false;
1854 
1855 	for (v_info = vendor_info; v_info->valid; v_info++) {
1856 		if (!strncmp(hdr.oem_id, v_info->oem_id, ACPI_OEM_ID_SIZE) &&
1857 			!strncmp(hdr.oem_table_id, v_info->oem_table_id,
1858 						ACPI_OEM_TABLE_ID_SIZE))
1859 			switch (v_info->oem_pwr_table) {
1860 			case PSS:
1861 				return intel_pstate_no_acpi_pss();
1862 			case PPC:
1863 				return intel_pstate_has_acpi_ppc() &&
1864 					(!force_load);
1865 			}
1866 	}
1867 
1868 	return false;
1869 }
1870 #else /* CONFIG_ACPI not enabled */
1871 static inline bool intel_pstate_platform_pwr_mgmt_exists(void) { return false; }
1872 static inline bool intel_pstate_has_acpi_ppc(void) { return false; }
1873 #endif /* CONFIG_ACPI */
1874 
1875 static const struct x86_cpu_id hwp_support_ids[] __initconst = {
1876 	{ X86_VENDOR_INTEL, 6, X86_MODEL_ANY, X86_FEATURE_HWP },
1877 	{}
1878 };
1879 
1880 static int __init intel_pstate_init(void)
1881 {
1882 	int cpu, rc = 0;
1883 	const struct x86_cpu_id *id;
1884 	struct cpu_defaults *cpu_def;
1885 
1886 	if (no_load)
1887 		return -ENODEV;
1888 
1889 	if (x86_match_cpu(hwp_support_ids) && !no_hwp) {
1890 		copy_cpu_funcs(&core_params.funcs);
1891 		hwp_active++;
1892 		goto hwp_cpu_matched;
1893 	}
1894 
1895 	id = x86_match_cpu(intel_pstate_cpu_ids);
1896 	if (!id)
1897 		return -ENODEV;
1898 
1899 	cpu_def = (struct cpu_defaults *)id->driver_data;
1900 
1901 	copy_pid_params(&cpu_def->pid_policy);
1902 	copy_cpu_funcs(&cpu_def->funcs);
1903 
1904 	if (intel_pstate_msrs_not_valid())
1905 		return -ENODEV;
1906 
1907 hwp_cpu_matched:
1908 	/*
1909 	 * The Intel pstate driver will be ignored if the platform
1910 	 * firmware has its own power management modes.
1911 	 */
1912 	if (intel_pstate_platform_pwr_mgmt_exists())
1913 		return -ENODEV;
1914 
1915 	pr_info("Intel P-state driver initializing\n");
1916 
1917 	all_cpu_data = vzalloc(sizeof(void *) * num_possible_cpus());
1918 	if (!all_cpu_data)
1919 		return -ENOMEM;
1920 
1921 	if (!hwp_active && hwp_only)
1922 		goto out;
1923 
1924 	rc = cpufreq_register_driver(&intel_pstate_driver);
1925 	if (rc)
1926 		goto out;
1927 
1928 	intel_pstate_debug_expose_params();
1929 	intel_pstate_sysfs_expose_params();
1930 
1931 	if (hwp_active)
1932 		pr_info("HWP enabled\n");
1933 
1934 	return rc;
1935 out:
1936 	get_online_cpus();
1937 	for_each_online_cpu(cpu) {
1938 		if (all_cpu_data[cpu]) {
1939 			intel_pstate_clear_update_util_hook(cpu);
1940 			kfree(all_cpu_data[cpu]);
1941 		}
1942 	}
1943 
1944 	put_online_cpus();
1945 	vfree(all_cpu_data);
1946 	return -ENODEV;
1947 }
1948 device_initcall(intel_pstate_init);
1949 
1950 static int __init intel_pstate_setup(char *str)
1951 {
1952 	if (!str)
1953 		return -EINVAL;
1954 
1955 	if (!strcmp(str, "disable"))
1956 		no_load = 1;
1957 	if (!strcmp(str, "no_hwp")) {
1958 		pr_info("HWP disabled\n");
1959 		no_hwp = 1;
1960 	}
1961 	if (!strcmp(str, "force"))
1962 		force_load = 1;
1963 	if (!strcmp(str, "hwp_only"))
1964 		hwp_only = 1;
1965 	if (!strcmp(str, "per_cpu_perf_limits"))
1966 		per_cpu_limits = true;
1967 
1968 #ifdef CONFIG_ACPI
1969 	if (!strcmp(str, "support_acpi_ppc"))
1970 		acpi_ppc = true;
1971 #endif
1972 
1973 	return 0;
1974 }
1975 early_param("intel_pstate", intel_pstate_setup);
1976 
1977 MODULE_AUTHOR("Dirk Brandewie <dirk.j.brandewie@intel.com>");
1978 MODULE_DESCRIPTION("'intel_pstate' - P state driver Intel Core processors");
1979 MODULE_LICENSE("GPL");
1980