2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2005-2007 Nate Lawson (SDG)
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8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
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34 #include <sys/_eventhandler.h>
40 #define CPU_IVAR_PCPU 1
41 #define CPU_IVAR_NOMINAL_MHZ 2
42 #define CPU_IVAR_CPUID_SIZE 3
43 #define CPU_IVAR_CPUID 4
45 static __inline struct pcpu *cpu_get_pcpu(device_t dev)
48 BUS_READ_IVAR(device_get_parent(dev), dev, CPU_IVAR_PCPU, &v);
49 return ((struct pcpu *)v);
52 static __inline int32_t cpu_get_nominal_mhz(device_t dev)
55 if (BUS_READ_IVAR(device_get_parent(dev), dev,
56 CPU_IVAR_NOMINAL_MHZ, &v) != 0)
61 static __inline const uint32_t *cpu_get_cpuid(device_t dev, size_t *count)
64 if (BUS_READ_IVAR(device_get_parent(dev), dev,
65 CPU_IVAR_CPUID_SIZE, &v) != 0)
69 if (BUS_READ_IVAR(device_get_parent(dev), dev,
70 CPU_IVAR_CPUID, &v) != 0)
72 return ((const uint32_t *)v);
76 * CPU frequency control interface.
79 /* Each driver's CPU frequency setting is exported in this format. */
81 int freq; /* CPU clock in Mhz or 100ths of a percent. */
82 int volts; /* Voltage in mV. */
83 int power; /* Power consumed in mW. */
84 int lat; /* Transition latency in us. */
85 device_t dev; /* Driver providing this setting. */
86 int spec[4];/* Driver-specific storage for non-standard info. */
89 /* Maximum number of settings a given driver can have. */
90 #define MAX_SETTINGS 256
92 /* A combination of settings is a level. */
94 struct cf_setting total_set;
95 struct cf_setting abs_set;
96 struct cf_setting rel_set[MAX_SETTINGS];
98 TAILQ_ENTRY(cf_level) link;
101 TAILQ_HEAD(cf_level_lst, cf_level);
103 /* Drivers should set all unknown values to this. */
104 #define CPUFREQ_VAL_UNKNOWN (-1)
107 * Every driver offers a type of CPU control. Absolute levels are mutually
108 * exclusive while relative levels modify the current absolute level. There
109 * may be multiple absolute and relative drivers available on a given
112 * For example, consider a system with two absolute drivers that provide
113 * frequency settings of 100, 200 and 300, 400 and a relative driver that
114 * provides settings of 50%, 100%. The cpufreq core would export frequency
115 * levels of 50, 100, 150, 200, 300, 400.
117 * The "info only" flag signifies that settings returned by
118 * CPUFREQ_DRV_SETTINGS cannot be passed to the CPUFREQ_DRV_SET method and
119 * are only informational. This is for some drivers that can return
120 * information about settings but rely on another machine-dependent driver
121 * for actually performing the frequency transition (e.g., ACPI performance
122 * states of type "functional fixed hardware.")
124 * The "uncached" flag tells CPUFREQ_DRV_GET to try obtaining the real
125 * instantaneous frequency from the underlying hardware regardless of cached
126 * state. It is probably a bug to not combine this with "info only"
128 #define CPUFREQ_TYPE_MASK 0xffff
129 #define CPUFREQ_TYPE_RELATIVE (1<<0)
130 #define CPUFREQ_TYPE_ABSOLUTE (1<<1)
131 #define CPUFREQ_FLAG_INFO_ONLY (1<<16)
132 #define CPUFREQ_FLAG_UNCACHED (1<<17)
135 * When setting a level, the caller indicates the priority of this request.
136 * Priorities determine, among other things, whether a level can be
137 * overridden by other callers. For example, if the user sets a level but
138 * the system thermal driver needs to override it for emergency cooling,
139 * the driver would use a higher priority. Once the event has passed, the
140 * driver would call cpufreq to resume any previous level.
142 #define CPUFREQ_PRIO_HIGHEST 1000000
143 #define CPUFREQ_PRIO_KERN 1000
144 #define CPUFREQ_PRIO_USER 100
145 #define CPUFREQ_PRIO_LOWEST 0
148 * Register and unregister a driver with the cpufreq core. Once a driver
149 * is registered, it must support calls to its CPUFREQ_GET, CPUFREQ_GET_LEVEL,
150 * and CPUFREQ_SET methods. It must also unregister before returning from
151 * its DEVICE_DETACH method.
153 int cpufreq_register(device_t dev);
154 int cpufreq_unregister(device_t dev);
157 * Notify the cpufreq core that the number of or values for settings have
160 int cpufreq_settings_changed(device_t dev);
163 * Eventhandlers that are called before and after a change in frequency.
164 * The new level and the result of the change (0 is success) is passed in.
165 * If the driver wishes to revoke the change from cpufreq_pre_change, it
166 * stores a non-zero error code in the result parameter and the change will
167 * not be made. If the post-change eventhandler gets a non-zero result,
168 * no change was made and the previous level remains in effect. If a change
169 * is revoked, the post-change eventhandler is still called with the error
170 * value supplied by the revoking driver. This gives listeners who cached
171 * some data in preparation for a level change a chance to clean up.
173 typedef void (*cpufreq_pre_notify_fn)(void *, const struct cf_level *, int *);
174 typedef void (*cpufreq_post_notify_fn)(void *, const struct cf_level *, int);
175 EVENTHANDLER_DECLARE(cpufreq_pre_change, cpufreq_pre_notify_fn);
176 EVENTHANDLER_DECLARE(cpufreq_post_change, cpufreq_post_notify_fn);
179 * Eventhandler called when the available list of levels changed.
180 * The unit number of the device (i.e. "cpufreq0") whose levels changed
181 * is provided so the listener can retrieve the new list of levels.
183 typedef void (*cpufreq_levels_notify_fn)(void *, int);
184 EVENTHANDLER_DECLARE(cpufreq_levels_changed, cpufreq_levels_notify_fn);
186 /* Allow values to be +/- a bit since sometimes we have to estimate. */
187 #define CPUFREQ_CMP(x, y) (abs((x) - (y)) < 25)
190 * Machine-dependent functions.
193 /* Estimate the current clock rate for the given CPU id. */
194 int cpu_est_clockrate(int cpu_id, uint64_t *rate);
196 #endif /* !_SYS_CPU_H_ */