1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
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
29#ifndef _SYS_CPU_H_
30#define _SYS_CPU_H_
31
32#include <sys/_eventhandler.h>
33
34/*
35 * CPU device support.
36 */
37
38#define CPU_IVAR_PCPU 1
39#define CPU_IVAR_NOMINAL_MHZ 2
40#define CPU_IVAR_CPUID_SIZE 3
41#define CPU_IVAR_CPUID 4
42
43static __inline struct pcpu *cpu_get_pcpu(device_t dev)
44{
45 uintptr_t v = 0;
46 BUS_READ_IVAR(device_get_parent(dev), dev, CPU_IVAR_PCPU, &v);
47 return ((struct pcpu *)v);
48}
49
50static __inline int32_t cpu_get_nominal_mhz(device_t dev)
51{
52 uintptr_t v = 0;
53 if (BUS_READ_IVAR(device_get_parent(dev), dev,
54 CPU_IVAR_NOMINAL_MHZ, &v) != 0)
55 return (-1);
56 return ((int32_t)v);
57}
58
59static __inline const uint32_t *cpu_get_cpuid(device_t dev, size_t *count)
60{
61 uintptr_t v = 0;
62 if (BUS_READ_IVAR(device_get_parent(dev), dev,
63 CPU_IVAR_CPUID_SIZE, &v) != 0)
64 return (NULL);
65 *count = (size_t)v;
66
67 if (BUS_READ_IVAR(device_get_parent(dev), dev,
68 CPU_IVAR_CPUID, &v) != 0)
69 return (NULL);
70 return ((const uint32_t *)v);
71}
72
73/*
74 * CPU frequency control interface.
75 */
76
77/* Each driver's CPU frequency setting is exported in this format. */
78struct cf_setting {
79 int freq; /* CPU clock in Mhz or 100ths of a percent. */
80 int volts; /* Voltage in mV. */
81 int power; /* Power consumed in mW. */
82 int lat; /* Transition latency in us. */
83 device_t dev; /* Driver providing this setting. */
84 int spec[4];/* Driver-specific storage for non-standard info. */
85};
86
87/* Maximum number of settings a given driver can have. */
88#define MAX_SETTINGS 256
89
90/* A combination of settings is a level. */
91struct cf_level {
92 struct cf_setting total_set;
93 struct cf_setting abs_set;
94 struct cf_setting rel_set[MAX_SETTINGS];
95 int rel_count;
96 TAILQ_ENTRY(cf_level) link;
97};
98
99TAILQ_HEAD(cf_level_lst, cf_level);
100
101/* Drivers should set all unknown values to this. */
102#define CPUFREQ_VAL_UNKNOWN (-1)
103
104/*
105 * Every driver offers a type of CPU control. Absolute levels are mutually
106 * exclusive while relative levels modify the current absolute level. There
107 * may be multiple absolute and relative drivers available on a given
108 * system.
109 *
110 * For example, consider a system with two absolute drivers that provide
111 * frequency settings of 100, 200 and 300, 400 and a relative driver that
112 * provides settings of 50%, 100%. The cpufreq core would export frequency
113 * levels of 50, 100, 150, 200, 300, 400.
114 *
115 * The "info only" flag signifies that settings returned by
116 * CPUFREQ_DRV_SETTINGS cannot be passed to the CPUFREQ_DRV_SET method and
117 * are only informational. This is for some drivers that can return
118 * information about settings but rely on another machine-dependent driver
119 * for actually performing the frequency transition (e.g., ACPI performance
120 * states of type "functional fixed hardware.")
121 *
122 * The "uncached" flag tells CPUFREQ_DRV_GET to try obtaining the real
123 * instantaneous frequency from the underlying hardware regardless of cached
124 * state. It is probably a bug to not combine this with "info only"
125 */
126#define CPUFREQ_TYPE_MASK 0xffff
127#define CPUFREQ_TYPE_RELATIVE (1<<0)
128#define CPUFREQ_TYPE_ABSOLUTE (1<<1)
129#define CPUFREQ_FLAG_INFO_ONLY (1<<16)
130#define CPUFREQ_FLAG_UNCACHED (1<<17)
131
132/*
133 * When setting a level, the caller indicates the priority of this request.
134 * Priorities determine, among other things, whether a level can be
135 * overridden by other callers. For example, if the user sets a level but
136 * the system thermal driver needs to override it for emergency cooling,
137 * the driver would use a higher priority. Once the event has passed, the
138 * driver would call cpufreq to resume any previous level.
139 */
140#define CPUFREQ_PRIO_HIGHEST 1000000
141#define CPUFREQ_PRIO_KERN 1000
142#define CPUFREQ_PRIO_USER 100
143#define CPUFREQ_PRIO_LOWEST 0
144
145/*
146 * Register and unregister a driver with the cpufreq core. Once a driver
147 * is registered, it must support calls to its CPUFREQ_GET, CPUFREQ_GET_LEVEL,
148 * and CPUFREQ_SET methods. It must also unregister before returning from
149 * its DEVICE_DETACH method.
150 */
151int cpufreq_register(device_t dev);
152int cpufreq_unregister(device_t dev);
153
154/*
155 * Notify the cpufreq core that the number of or values for settings have
156 * changed.
157 */
158int cpufreq_settings_changed(device_t dev);
159
160/*
161 * Eventhandlers that are called before and after a change in frequency.
162 * The new level and the result of the change (0 is success) is passed in.
163 * If the driver wishes to revoke the change from cpufreq_pre_change, it
164 * stores a non-zero error code in the result parameter and the change will
165 * not be made. If the post-change eventhandler gets a non-zero result,
166 * no change was made and the previous level remains in effect. If a change
167 * is revoked, the post-change eventhandler is still called with the error
168 * value supplied by the revoking driver. This gives listeners who cached
169 * some data in preparation for a level change a chance to clean up.
170 */
171typedef void (*cpufreq_pre_notify_fn)(void *, const struct cf_level *, int *);
172typedef void (*cpufreq_post_notify_fn)(void *, const struct cf_level *, int);
173EVENTHANDLER_DECLARE(cpufreq_pre_change, cpufreq_pre_notify_fn);
174EVENTHANDLER_DECLARE(cpufreq_post_change, cpufreq_post_notify_fn);
175
176/*
177 * Eventhandler called when the available list of levels changed.
178 * The unit number of the device (i.e. "cpufreq0") whose levels changed
179 * is provided so the listener can retrieve the new list of levels.
180 */
181typedef void (*cpufreq_levels_notify_fn)(void *, int);
182EVENTHANDLER_DECLARE(cpufreq_levels_changed, cpufreq_levels_notify_fn);
183
184/* Allow values to be +/- a bit since sometimes we have to estimate. */
185#define CPUFREQ_CMP(x, y) (abs((x) - (y)) < 25)
186
187/*
188 * Machine-dependent functions.
189 */
190
191/* Estimate the current clock rate for the given CPU id. */
192int cpu_est_clockrate(int cpu_id, uint64_t *rate);
193
194#endif /* !_SYS_CPU_H_ */