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 /*
55 * Assumes the parent bus sets the CPU_IVAR_PCPU instance variable, which most
56 * CPU buses do. A panic will ensue if not the case. Calling devices should
57 * check for that condition (most probably in their attach function).
58 */
59 static __inline u_int
cpu_get_pcpuid(device_t dev)60 cpu_get_pcpuid(device_t dev)
61 {
62 return (cpu_get_pcpu(dev)->pc_cpuid);
63 }
64
65 static __inline int32_t
cpu_get_nominal_mhz(device_t dev)66 cpu_get_nominal_mhz(device_t dev)
67 {
68 uintptr_t v = 0;
69
70 if (BUS_READ_IVAR(device_get_parent(dev), dev,
71 CPU_IVAR_NOMINAL_MHZ, &v) != 0)
72 return (-1);
73 return ((int32_t)v);
74 }
75
76 static __inline const uint32_t *
cpu_get_cpuid(device_t dev,size_t * count)77 cpu_get_cpuid(device_t dev, size_t *count)
78 {
79 uintptr_t v = 0;
80
81 if (BUS_READ_IVAR(device_get_parent(dev), dev,
82 CPU_IVAR_CPUID_SIZE, &v) != 0)
83 return (NULL);
84 *count = (size_t)v;
85
86 if (BUS_READ_IVAR(device_get_parent(dev), dev,
87 CPU_IVAR_CPUID, &v) != 0)
88 return (NULL);
89 return ((const uint32_t *)v);
90 }
91
92 /*
93 * CPU frequency control interface.
94 */
95
96 /* Each driver's CPU frequency setting is exported in this format. */
97 struct cf_setting {
98 int freq; /* CPU clock in Mhz or 100ths of a percent. */
99 int volts; /* Voltage in mV. */
100 int power; /* Power consumed in mW. */
101 int lat; /* Transition latency in us. */
102 device_t dev; /* Driver providing this setting. */
103 int spec[4];/* Driver-specific storage for non-standard info. */
104 };
105
106 /* Maximum number of settings a given driver can have. */
107 #define MAX_SETTINGS 256
108
109 /* A combination of settings is a level. */
110 struct cf_level {
111 struct cf_setting total_set;
112 struct cf_setting abs_set;
113 struct cf_setting rel_set[MAX_SETTINGS];
114 int rel_count;
115 TAILQ_ENTRY(cf_level) link;
116 };
117
118 TAILQ_HEAD(cf_level_lst, cf_level);
119
120 /* Drivers should set all unknown values to this. */
121 #define CPUFREQ_VAL_UNKNOWN (-1)
122
123 /*
124 * Every driver offers a type of CPU control. Absolute levels are mutually
125 * exclusive while relative levels modify the current absolute level. There
126 * may be multiple absolute and relative drivers available on a given
127 * system.
128 *
129 * For example, consider a system with two absolute drivers that provide
130 * frequency settings of 100, 200 and 300, 400 and a relative driver that
131 * provides settings of 50%, 100%. The cpufreq core would export frequency
132 * levels of 50, 100, 150, 200, 300, 400.
133 *
134 * The "info only" flag signifies that settings returned by
135 * CPUFREQ_DRV_SETTINGS cannot be passed to the CPUFREQ_DRV_SET method and
136 * are only informational. This is for some drivers that can return
137 * information about settings but rely on another machine-dependent driver
138 * for actually performing the frequency transition (e.g., ACPI performance
139 * states of type "functional fixed hardware.")
140 *
141 * The "uncached" flag tells CPUFREQ_DRV_GET to try obtaining the real
142 * instantaneous frequency from the underlying hardware regardless of cached
143 * state. It is probably a bug to not combine this with "info only"
144 */
145 #define CPUFREQ_TYPE_MASK 0xffff
146 #define CPUFREQ_TYPE_RELATIVE (1 << 0)
147 #define CPUFREQ_TYPE_ABSOLUTE (1 << 1)
148 #define CPUFREQ_FLAG_INFO_ONLY (1 << 16)
149 #define CPUFREQ_FLAG_UNCACHED (1 << 17)
150
151 /*
152 * When setting a level, the caller indicates the priority of this request.
153 * Priorities determine, among other things, whether a level can be
154 * overridden by other callers. For example, if the user sets a level but
155 * the system thermal driver needs to override it for emergency cooling,
156 * the driver would use a higher priority. Once the event has passed, the
157 * driver would call cpufreq to resume any previous level.
158 */
159 #define CPUFREQ_PRIO_HIGHEST 1000000
160 #define CPUFREQ_PRIO_KERN 1000
161 #define CPUFREQ_PRIO_USER 100
162 #define CPUFREQ_PRIO_LOWEST 0
163
164 /*
165 * Register and unregister a driver with the cpufreq core. Once a driver
166 * is registered, it must support calls to its CPUFREQ_GET, CPUFREQ_GET_LEVEL,
167 * and CPUFREQ_SET methods. It must also unregister before returning from
168 * its DEVICE_DETACH method.
169 */
170 int cpufreq_register(device_t dev);
171 int cpufreq_unregister(device_t dev);
172
173 /*
174 * Notify the cpufreq core that the number of or values for settings have
175 * changed.
176 */
177 int cpufreq_settings_changed(device_t dev);
178
179 /*
180 * Eventhandlers that are called before and after a change in frequency.
181 * The new level and the result of the change (0 is success) is passed in.
182 * If the driver wishes to revoke the change from cpufreq_pre_change, it
183 * stores a non-zero error code in the result parameter and the change will
184 * not be made. If the post-change eventhandler gets a non-zero result,
185 * no change was made and the previous level remains in effect. If a change
186 * is revoked, the post-change eventhandler is still called with the error
187 * value supplied by the revoking driver. This gives listeners who cached
188 * some data in preparation for a level change a chance to clean up.
189 */
190 typedef void (*cpufreq_pre_notify_fn)(void *, const struct cf_level *, int *);
191 typedef void (*cpufreq_post_notify_fn)(void *, const struct cf_level *, int);
192 EVENTHANDLER_DECLARE(cpufreq_pre_change, cpufreq_pre_notify_fn);
193 EVENTHANDLER_DECLARE(cpufreq_post_change, cpufreq_post_notify_fn);
194
195 /*
196 * Eventhandler called when the available list of levels changed.
197 * The unit number of the device (i.e. "cpufreq0") whose levels changed
198 * is provided so the listener can retrieve the new list of levels.
199 */
200 typedef void (*cpufreq_levels_notify_fn)(void *, int);
201 EVENTHANDLER_DECLARE(cpufreq_levels_changed, cpufreq_levels_notify_fn);
202
203 /* Allow values to be +/- a bit since sometimes we have to estimate. */
204 #define CPUFREQ_CMP(x, y) (abs((x) - (y)) < 25)
205
206 /*
207 * Machine-dependent functions.
208 */
209
210 /* Estimate the current clock rate for the given CPU id. */
211 int cpu_est_clockrate(int cpu_id, uint64_t *rate);
212
213 #endif /* !_SYS_CPU_H_ */
214