freebsd-nq/sys/sys/cpu.h
Nate Lawson 0d4ac62a35 Add an interface for drivers to be notified of changes to CPU frequency.
cpufreq_pre_change is called before the change, giving each driver a chance
to revoke the change.  cpufreq_post_change provides the results of the
change (success or failure).  cpufreq_levels_changed gives the unit number
of the cpufreq device whose number of available levels has changed.  Hook
in all the drivers I could find that needed it.

* TSC: update TSC frequency value.  When the available levels change, take the
highest possible level and notify the timecounter set_cputicker() of that
freq.  This gets rid of the "calcru: runtime went backwards" messages.
* identcpu: updates the sysctl hw.clockrate value
* Profiling: if profiling is active when the clock changes, let the user
know the results may be inaccurate.

Reviewed by:	bde, phk
MFC after:	1 month
2007-03-26 18:03:29 +00:00

164 lines
6.1 KiB
C

/*-
* Copyright (c) 2005-2007 Nate Lawson (SDG)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _SYS_CPU_H_
#define _SYS_CPU_H_
#include <sys/eventhandler.h>
/*
* CPU device support.
*/
#define CPU_IVAR_PCPU 1
static __inline struct pcpu *cpu_get_pcpu(device_t dev)
{
uintptr_t v = 0;
BUS_READ_IVAR(device_get_parent(dev), dev, CPU_IVAR_PCPU, &v);
return ((struct pcpu *)v);
}
/*
* CPU frequency control interface.
*/
/* Each driver's CPU frequency setting is exported in this format. */
struct cf_setting {
int freq; /* CPU clock in Mhz or 100ths of a percent. */
int volts; /* Voltage in mV. */
int power; /* Power consumed in mW. */
int lat; /* Transition latency in us. */
device_t dev; /* Driver providing this setting. */
int spec[4];/* Driver-specific storage for non-standard info. */
};
/* Maximum number of settings a given driver can have. */
#define MAX_SETTINGS 24
/* A combination of settings is a level. */
struct cf_level {
struct cf_setting total_set;
struct cf_setting abs_set;
struct cf_setting rel_set[MAX_SETTINGS];
int rel_count;
TAILQ_ENTRY(cf_level) link;
};
TAILQ_HEAD(cf_level_lst, cf_level);
/* Drivers should set all unknown values to this. */
#define CPUFREQ_VAL_UNKNOWN (-1)
/*
* Every driver offers a type of CPU control. Absolute levels are mutually
* exclusive while relative levels modify the current absolute level. There
* may be multiple absolute and relative drivers available on a given
* system.
*
* For example, consider a system with two absolute drivers that provide
* frequency settings of 100, 200 and 300, 400 and a relative driver that
* provides settings of 50%, 100%. The cpufreq core would export frequency
* levels of 50, 100, 150, 200, 300, 400.
*
* The "info only" flag signifies that settings returned by
* CPUFREQ_DRV_SETTINGS cannot be passed to the CPUFREQ_DRV_SET method and
* are only informational. This is for some drivers that can return
* information about settings but rely on another machine-dependent driver
* for actually performing the frequency transition (e.g., ACPI performance
* states of type "functional fixed hardware.")
*/
#define CPUFREQ_TYPE_MASK 0xffff
#define CPUFREQ_TYPE_RELATIVE (1<<0)
#define CPUFREQ_TYPE_ABSOLUTE (1<<1)
#define CPUFREQ_FLAG_INFO_ONLY (1<<16)
/*
* When setting a level, the caller indicates the priority of this request.
* Priorities determine, among other things, whether a level can be
* overridden by other callers. For example, if the user sets a level but
* the system thermal driver needs to override it for emergency cooling,
* the driver would use a higher priority. Once the event has passed, the
* driver would call cpufreq to resume any previous level.
*/
#define CPUFREQ_PRIO_HIGHEST 1000000
#define CPUFREQ_PRIO_KERN 1000
#define CPUFREQ_PRIO_USER 100
#define CPUFREQ_PRIO_LOWEST 0
/*
* Register and unregister a driver with the cpufreq core. Once a driver
* is registered, it must support calls to its CPUFREQ_GET, CPUFREQ_GET_LEVEL,
* and CPUFREQ_SET methods. It must also unregister before returning from
* its DEVICE_DETACH method.
*/
int cpufreq_register(device_t dev);
int cpufreq_unregister(device_t dev);
/*
* Notify the cpufreq core that the number of or values for settings have
* changed.
*/
int cpufreq_settings_changed(device_t dev);
/*
* Eventhandlers that are called before and after a change in frequency.
* The new level and the result of the change (0 is success) is passed in.
* If the driver wishes to revoke the change from cpufreq_pre_change, it
* stores a non-zero error code in the result parameter and the change will
* not be made. If the post-change eventhandler gets a non-zero result,
* no change was made and the previous level remains in effect. If a change
* is revoked, the post-change eventhandler is still called with the error
* value supplied by the revoking driver. This gives listeners who cached
* some data in preparation for a level change a chance to clean up.
*/
typedef void (*cpufreq_pre_notify_fn)(void *, const struct cf_level *, int *);
typedef void (*cpufreq_post_notify_fn)(void *, const struct cf_level *, int);
EVENTHANDLER_DECLARE(cpufreq_pre_change, cpufreq_pre_notify_fn);
EVENTHANDLER_DECLARE(cpufreq_post_change, cpufreq_post_notify_fn);
/*
* Eventhandler called when the available list of levels changed.
* The unit number of the device (i.e. "cpufreq0") whose levels changed
* is provided so the listener can retrieve the new list of levels.
*/
typedef void (*cpufreq_levels_notify_fn)(void *, int);
EVENTHANDLER_DECLARE(cpufreq_levels_changed, cpufreq_levels_notify_fn);
/* Allow values to be +/- a bit since sometimes we have to estimate. */
#define CPUFREQ_CMP(x, y) (abs((x) - (y)) < 25)
/*
* Machine-dependent functions.
*/
/* Estimate the current clock rate for the given CPU id. */
int cpu_est_clockrate(int cpu_id, uint64_t *rate);
#endif /* !_SYS_CPU_H_ */