xref: /freebsd/sys/sys/cpu.h (revision 5b9c547c)
1 /*-
2  * Copyright (c) 2005-2007 Nate Lawson (SDG)
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
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 {
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 
50 static __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 
59 static __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. */
78 struct 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		24
89 
90 /* A combination of settings is a level. */
91 struct 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 
99 TAILQ_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 #define CPUFREQ_TYPE_MASK	0xffff
123 #define CPUFREQ_TYPE_RELATIVE	(1<<0)
124 #define CPUFREQ_TYPE_ABSOLUTE	(1<<1)
125 #define CPUFREQ_FLAG_INFO_ONLY	(1<<16)
126 
127 /*
128  * When setting a level, the caller indicates the priority of this request.
129  * Priorities determine, among other things, whether a level can be
130  * overridden by other callers.  For example, if the user sets a level but
131  * the system thermal driver needs to override it for emergency cooling,
132  * the driver would use a higher priority.  Once the event has passed, the
133  * driver would call cpufreq to resume any previous level.
134  */
135 #define CPUFREQ_PRIO_HIGHEST	1000000
136 #define CPUFREQ_PRIO_KERN	1000
137 #define CPUFREQ_PRIO_USER	100
138 #define CPUFREQ_PRIO_LOWEST	0
139 
140 /*
141  * Register and unregister a driver with the cpufreq core.  Once a driver
142  * is registered, it must support calls to its CPUFREQ_GET, CPUFREQ_GET_LEVEL,
143  * and CPUFREQ_SET methods.  It must also unregister before returning from
144  * its DEVICE_DETACH method.
145  */
146 int	cpufreq_register(device_t dev);
147 int	cpufreq_unregister(device_t dev);
148 
149 /*
150  * Notify the cpufreq core that the number of or values for settings have
151  * changed.
152  */
153 int	cpufreq_settings_changed(device_t dev);
154 
155 /*
156  * Eventhandlers that are called before and after a change in frequency.
157  * The new level and the result of the change (0 is success) is passed in.
158  * If the driver wishes to revoke the change from cpufreq_pre_change, it
159  * stores a non-zero error code in the result parameter and the change will
160  * not be made.  If the post-change eventhandler gets a non-zero result,
161  * no change was made and the previous level remains in effect.  If a change
162  * is revoked, the post-change eventhandler is still called with the error
163  * value supplied by the revoking driver.  This gives listeners who cached
164  * some data in preparation for a level change a chance to clean up.
165  */
166 typedef void (*cpufreq_pre_notify_fn)(void *, const struct cf_level *, int *);
167 typedef void (*cpufreq_post_notify_fn)(void *, const struct cf_level *, int);
168 EVENTHANDLER_DECLARE(cpufreq_pre_change, cpufreq_pre_notify_fn);
169 EVENTHANDLER_DECLARE(cpufreq_post_change, cpufreq_post_notify_fn);
170 
171 /*
172  * Eventhandler called when the available list of levels changed.
173  * The unit number of the device (i.e. "cpufreq0") whose levels changed
174  * is provided so the listener can retrieve the new list of levels.
175  */
176 typedef void (*cpufreq_levels_notify_fn)(void *, int);
177 EVENTHANDLER_DECLARE(cpufreq_levels_changed, cpufreq_levels_notify_fn);
178 
179 /* Allow values to be +/- a bit since sometimes we have to estimate. */
180 #define CPUFREQ_CMP(x, y)	(abs((x) - (y)) < 25)
181 
182 /*
183  * Machine-dependent functions.
184  */
185 
186 /* Estimate the current clock rate for the given CPU id. */
187 int	cpu_est_clockrate(int cpu_id, uint64_t *rate);
188 
189 #endif /* !_SYS_CPU_H_ */
190