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