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 enum {
39 CPU_IVAR_PCPU = BUS_IVARS_PRIVATE,
40 CPU_IVAR_NOMINAL_MHZ,
41 CPU_IVAR_CPUID_SIZE,
42 CPU_IVAR_CPUID
43 };
44
45 static __inline struct pcpu *
cpu_get_pcpu(device_t dev)46 cpu_get_pcpu(device_t dev)
47 {
48 uintptr_t v = 0;
49
50 BUS_READ_IVAR(device_get_parent(dev), dev, CPU_IVAR_PCPU, &v);
51 return ((struct pcpu *)v);
52 }
53
54 static __inline int32_t
cpu_get_nominal_mhz(device_t dev)55 cpu_get_nominal_mhz(device_t dev)
56 {
57 uintptr_t v = 0;
58
59 if (BUS_READ_IVAR(device_get_parent(dev), dev,
60 CPU_IVAR_NOMINAL_MHZ, &v) != 0)
61 return (-1);
62 return ((int32_t)v);
63 }
64
65 static __inline const uint32_t *
cpu_get_cpuid(device_t dev,size_t * count)66 cpu_get_cpuid(device_t dev, size_t *count)
67 {
68 uintptr_t v = 0;
69
70 if (BUS_READ_IVAR(device_get_parent(dev), dev,
71 CPU_IVAR_CPUID_SIZE, &v) != 0)
72 return (NULL);
73 *count = (size_t)v;
74
75 if (BUS_READ_IVAR(device_get_parent(dev), dev,
76 CPU_IVAR_CPUID, &v) != 0)
77 return (NULL);
78 return ((const uint32_t *)v);
79 }
80
81 /*
82 * CPU frequency control interface.
83 */
84
85 /* Each driver's CPU frequency setting is exported in this format. */
86 struct cf_setting {
87 int freq; /* CPU clock in Mhz or 100ths of a percent. */
88 int volts; /* Voltage in mV. */
89 int power; /* Power consumed in mW. */
90 int lat; /* Transition latency in us. */
91 device_t dev; /* Driver providing this setting. */
92 int spec[4];/* Driver-specific storage for non-standard info. */
93 };
94
95 /* Maximum number of settings a given driver can have. */
96 #define MAX_SETTINGS 256
97
98 /* A combination of settings is a level. */
99 struct cf_level {
100 struct cf_setting total_set;
101 struct cf_setting abs_set;
102 struct cf_setting rel_set[MAX_SETTINGS];
103 int rel_count;
104 TAILQ_ENTRY(cf_level) link;
105 };
106
107 TAILQ_HEAD(cf_level_lst, cf_level);
108
109 /* Drivers should set all unknown values to this. */
110 #define CPUFREQ_VAL_UNKNOWN (-1)
111
112 /*
113 * Every driver offers a type of CPU control. Absolute levels are mutually
114 * exclusive while relative levels modify the current absolute level. There
115 * may be multiple absolute and relative drivers available on a given
116 * system.
117 *
118 * For example, consider a system with two absolute drivers that provide
119 * frequency settings of 100, 200 and 300, 400 and a relative driver that
120 * provides settings of 50%, 100%. The cpufreq core would export frequency
121 * levels of 50, 100, 150, 200, 300, 400.
122 *
123 * The "info only" flag signifies that settings returned by
124 * CPUFREQ_DRV_SETTINGS cannot be passed to the CPUFREQ_DRV_SET method and
125 * are only informational. This is for some drivers that can return
126 * information about settings but rely on another machine-dependent driver
127 * for actually performing the frequency transition (e.g., ACPI performance
128 * states of type "functional fixed hardware.")
129 *
130 * The "uncached" flag tells CPUFREQ_DRV_GET to try obtaining the real
131 * instantaneous frequency from the underlying hardware regardless of cached
132 * state. It is probably a bug to not combine this with "info only"
133 */
134 #define CPUFREQ_TYPE_MASK 0xffff
135 #define CPUFREQ_TYPE_RELATIVE (1 << 0)
136 #define CPUFREQ_TYPE_ABSOLUTE (1 << 1)
137 #define CPUFREQ_FLAG_INFO_ONLY (1 << 16)
138 #define CPUFREQ_FLAG_UNCACHED (1 << 17)
139
140 /*
141 * When setting a level, the caller indicates the priority of this request.
142 * Priorities determine, among other things, whether a level can be
143 * overridden by other callers. For example, if the user sets a level but
144 * the system thermal driver needs to override it for emergency cooling,
145 * the driver would use a higher priority. Once the event has passed, the
146 * driver would call cpufreq to resume any previous level.
147 */
148 #define CPUFREQ_PRIO_HIGHEST 1000000
149 #define CPUFREQ_PRIO_KERN 1000
150 #define CPUFREQ_PRIO_USER 100
151 #define CPUFREQ_PRIO_LOWEST 0
152
153 /*
154 * Register and unregister a driver with the cpufreq core. Once a driver
155 * is registered, it must support calls to its CPUFREQ_GET, CPUFREQ_GET_LEVEL,
156 * and CPUFREQ_SET methods. It must also unregister before returning from
157 * its DEVICE_DETACH method.
158 */
159 int cpufreq_register(device_t dev);
160 int cpufreq_unregister(device_t dev);
161
162 /*
163 * Notify the cpufreq core that the number of or values for settings have
164 * changed.
165 */
166 int cpufreq_settings_changed(device_t dev);
167
168 /*
169 * Eventhandlers that are called before and after a change in frequency.
170 * The new level and the result of the change (0 is success) is passed in.
171 * If the driver wishes to revoke the change from cpufreq_pre_change, it
172 * stores a non-zero error code in the result parameter and the change will
173 * not be made. If the post-change eventhandler gets a non-zero result,
174 * no change was made and the previous level remains in effect. If a change
175 * is revoked, the post-change eventhandler is still called with the error
176 * value supplied by the revoking driver. This gives listeners who cached
177 * some data in preparation for a level change a chance to clean up.
178 */
179 typedef void (*cpufreq_pre_notify_fn)(void *, const struct cf_level *, int *);
180 typedef void (*cpufreq_post_notify_fn)(void *, const struct cf_level *, int);
181 EVENTHANDLER_DECLARE(cpufreq_pre_change, cpufreq_pre_notify_fn);
182 EVENTHANDLER_DECLARE(cpufreq_post_change, cpufreq_post_notify_fn);
183
184 /*
185 * Eventhandler called when the available list of levels changed.
186 * The unit number of the device (i.e. "cpufreq0") whose levels changed
187 * is provided so the listener can retrieve the new list of levels.
188 */
189 typedef void (*cpufreq_levels_notify_fn)(void *, int);
190 EVENTHANDLER_DECLARE(cpufreq_levels_changed, cpufreq_levels_notify_fn);
191
192 /* Allow values to be +/- a bit since sometimes we have to estimate. */
193 #define CPUFREQ_CMP(x, y) (abs((x) - (y)) < 25)
194
195 /*
196 * Machine-dependent functions.
197 */
198
199 /* Estimate the current clock rate for the given CPU id. */
200 int cpu_est_clockrate(int cpu_id, uint64_t *rate);
201
202 #endif /* !_SYS_CPU_H_ */
203