1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2005-2007 Nate Lawson (SDG)
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31#ifndef _SYS_CPU_H_
32#define _SYS_CPU_H_
33
34#include <sys/_eventhandler.h>
35
36/*
37 * CPU device support.
38 */
39
40#define CPU_IVAR_PCPU		1
41#define CPU_IVAR_NOMINAL_MHZ	2
42#define CPU_IVAR_CPUID_SIZE	3
43#define CPU_IVAR_CPUID		4
44
45static __inline struct pcpu *cpu_get_pcpu(device_t dev)
46{
47	uintptr_t v = 0;
48	BUS_READ_IVAR(device_get_parent(dev), dev, CPU_IVAR_PCPU, &v);
49	return ((struct pcpu *)v);
50}
51
52static __inline int32_t cpu_get_nominal_mhz(device_t dev)
53{
54	uintptr_t v = 0;
55	if (BUS_READ_IVAR(device_get_parent(dev), dev,
56	    CPU_IVAR_NOMINAL_MHZ, &v) != 0)
57		return (-1);
58	return ((int32_t)v);
59}
60
61static __inline const uint32_t *cpu_get_cpuid(device_t dev, size_t *count)
62{
63	uintptr_t v = 0;
64	if (BUS_READ_IVAR(device_get_parent(dev), dev,
65	    CPU_IVAR_CPUID_SIZE, &v) != 0)
66		return (NULL);
67	*count = (size_t)v;
68
69	if (BUS_READ_IVAR(device_get_parent(dev), dev,
70	    CPU_IVAR_CPUID, &v) != 0)
71		return (NULL);
72	return ((const uint32_t *)v);
73}
74
75/*
76 * CPU frequency control interface.
77 */
78
79/* Each driver's CPU frequency setting is exported in this format. */
80struct cf_setting {
81	int	freq;	/* CPU clock in Mhz or 100ths of a percent. */
82	int	volts;	/* Voltage in mV. */
83	int	power;	/* Power consumed in mW. */
84	int	lat;	/* Transition latency in us. */
85	device_t dev;	/* Driver providing this setting. */
86	int	spec[4];/* Driver-specific storage for non-standard info. */
87};
88
89/* Maximum number of settings a given driver can have. */
90#define MAX_SETTINGS		256
91
92/* A combination of settings is a level. */
93struct cf_level {
94	struct cf_setting	total_set;
95	struct cf_setting	abs_set;
96	struct cf_setting	rel_set[MAX_SETTINGS];
97	int			rel_count;
98	TAILQ_ENTRY(cf_level)	link;
99};
100
101TAILQ_HEAD(cf_level_lst, cf_level);
102
103/* Drivers should set all unknown values to this. */
104#define CPUFREQ_VAL_UNKNOWN	(-1)
105
106/*
107 * Every driver offers a type of CPU control.  Absolute levels are mutually
108 * exclusive while relative levels modify the current absolute level.  There
109 * may be multiple absolute and relative drivers available on a given
110 * system.
111 *
112 * For example, consider a system with two absolute drivers that provide
113 * frequency settings of 100, 200 and 300, 400 and a relative driver that
114 * provides settings of 50%, 100%.  The cpufreq core would export frequency
115 * levels of 50, 100, 150, 200, 300, 400.
116 *
117 * The "info only" flag signifies that settings returned by
118 * CPUFREQ_DRV_SETTINGS cannot be passed to the CPUFREQ_DRV_SET method and
119 * are only informational.  This is for some drivers that can return
120 * information about settings but rely on another machine-dependent driver
121 * for actually performing the frequency transition (e.g., ACPI performance
122 * states of type "functional fixed hardware.")
123 *
124 * The "uncached" flag tells CPUFREQ_DRV_GET to try obtaining the real
125 * instantaneous frequency from the underlying hardware regardless of cached
126 * state. It is probably a bug to not combine this with "info only"
127 */
128#define CPUFREQ_TYPE_MASK	0xffff
129#define CPUFREQ_TYPE_RELATIVE	(1<<0)
130#define CPUFREQ_TYPE_ABSOLUTE	(1<<1)
131#define CPUFREQ_FLAG_INFO_ONLY	(1<<16)
132#define CPUFREQ_FLAG_UNCACHED	(1<<17)
133
134/*
135 * When setting a level, the caller indicates the priority of this request.
136 * Priorities determine, among other things, whether a level can be
137 * overridden by other callers.  For example, if the user sets a level but
138 * the system thermal driver needs to override it for emergency cooling,
139 * the driver would use a higher priority.  Once the event has passed, the
140 * driver would call cpufreq to resume any previous level.
141 */
142#define CPUFREQ_PRIO_HIGHEST	1000000
143#define CPUFREQ_PRIO_KERN	1000
144#define CPUFREQ_PRIO_USER	100
145#define CPUFREQ_PRIO_LOWEST	0
146
147/*
148 * Register and unregister a driver with the cpufreq core.  Once a driver
149 * is registered, it must support calls to its CPUFREQ_GET, CPUFREQ_GET_LEVEL,
150 * and CPUFREQ_SET methods.  It must also unregister before returning from
151 * its DEVICE_DETACH method.
152 */
153int	cpufreq_register(device_t dev);
154int	cpufreq_unregister(device_t dev);
155
156/*
157 * Notify the cpufreq core that the number of or values for settings have
158 * changed.
159 */
160int	cpufreq_settings_changed(device_t dev);
161
162/*
163 * Eventhandlers that are called before and after a change in frequency.
164 * The new level and the result of the change (0 is success) is passed in.
165 * If the driver wishes to revoke the change from cpufreq_pre_change, it
166 * stores a non-zero error code in the result parameter and the change will
167 * not be made.  If the post-change eventhandler gets a non-zero result,
168 * no change was made and the previous level remains in effect.  If a change
169 * is revoked, the post-change eventhandler is still called with the error
170 * value supplied by the revoking driver.  This gives listeners who cached
171 * some data in preparation for a level change a chance to clean up.
172 */
173typedef void (*cpufreq_pre_notify_fn)(void *, const struct cf_level *, int *);
174typedef void (*cpufreq_post_notify_fn)(void *, const struct cf_level *, int);
175EVENTHANDLER_DECLARE(cpufreq_pre_change, cpufreq_pre_notify_fn);
176EVENTHANDLER_DECLARE(cpufreq_post_change, cpufreq_post_notify_fn);
177
178/*
179 * Eventhandler called when the available list of levels changed.
180 * The unit number of the device (i.e. "cpufreq0") whose levels changed
181 * is provided so the listener can retrieve the new list of levels.
182 */
183typedef void (*cpufreq_levels_notify_fn)(void *, int);
184EVENTHANDLER_DECLARE(cpufreq_levels_changed, cpufreq_levels_notify_fn);
185
186/* Allow values to be +/- a bit since sometimes we have to estimate. */
187#define CPUFREQ_CMP(x, y)	(abs((x) - (y)) < 25)
188
189/*
190 * Machine-dependent functions.
191 */
192
193/* Estimate the current clock rate for the given CPU id. */
194int	cpu_est_clockrate(int cpu_id, uint64_t *rate);
195
196#endif /* !_SYS_CPU_H_ */
197