xref: /openbmc/qemu/include/system/cpu-throttle.h (revision 65cb7129f4160c7e07a0da107f888ec73ae96776)
1*32cad1ffSPhilippe Mathieu-Daudé /*
2*32cad1ffSPhilippe Mathieu-Daudé  * Copyright (c) 2012 SUSE LINUX Products GmbH
3*32cad1ffSPhilippe Mathieu-Daudé  *
4*32cad1ffSPhilippe Mathieu-Daudé  * This program is free software; you can redistribute it and/or
5*32cad1ffSPhilippe Mathieu-Daudé  * modify it under the terms of the GNU General Public License
6*32cad1ffSPhilippe Mathieu-Daudé  * as published by the Free Software Foundation; either version 2
7*32cad1ffSPhilippe Mathieu-Daudé  * of the License, or (at your option) any later version.
8*32cad1ffSPhilippe Mathieu-Daudé  *
9*32cad1ffSPhilippe Mathieu-Daudé  * This program is distributed in the hope that it will be useful,
10*32cad1ffSPhilippe Mathieu-Daudé  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11*32cad1ffSPhilippe Mathieu-Daudé  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12*32cad1ffSPhilippe Mathieu-Daudé  * GNU General Public License for more details.
13*32cad1ffSPhilippe Mathieu-Daudé  *
14*32cad1ffSPhilippe Mathieu-Daudé  * You should have received a copy of the GNU General Public License
15*32cad1ffSPhilippe Mathieu-Daudé  * along with this program; if not, see
16*32cad1ffSPhilippe Mathieu-Daudé  * <http://www.gnu.org/licenses/gpl-2.0.html>
17*32cad1ffSPhilippe Mathieu-Daudé  */
18*32cad1ffSPhilippe Mathieu-Daudé 
19*32cad1ffSPhilippe Mathieu-Daudé #ifndef SYSTEM_CPU_THROTTLE_H
20*32cad1ffSPhilippe Mathieu-Daudé #define SYSTEM_CPU_THROTTLE_H
21*32cad1ffSPhilippe Mathieu-Daudé 
22*32cad1ffSPhilippe Mathieu-Daudé #include "qemu/timer.h"
23*32cad1ffSPhilippe Mathieu-Daudé 
24*32cad1ffSPhilippe Mathieu-Daudé /**
25*32cad1ffSPhilippe Mathieu-Daudé  * cpu_throttle_init:
26*32cad1ffSPhilippe Mathieu-Daudé  *
27*32cad1ffSPhilippe Mathieu-Daudé  * Initialize the CPU throttling API.
28*32cad1ffSPhilippe Mathieu-Daudé  */
29*32cad1ffSPhilippe Mathieu-Daudé void cpu_throttle_init(void);
30*32cad1ffSPhilippe Mathieu-Daudé 
31*32cad1ffSPhilippe Mathieu-Daudé /**
32*32cad1ffSPhilippe Mathieu-Daudé  * cpu_throttle_set:
33*32cad1ffSPhilippe Mathieu-Daudé  * @new_throttle_pct: Percent of sleep time. Valid range is 1 to 99.
34*32cad1ffSPhilippe Mathieu-Daudé  *
35*32cad1ffSPhilippe Mathieu-Daudé  * Throttles all vcpus by forcing them to sleep for the given percentage of
36*32cad1ffSPhilippe Mathieu-Daudé  * time. A throttle_percentage of 25 corresponds to a 75% duty cycle roughly.
37*32cad1ffSPhilippe Mathieu-Daudé  * (example: 10ms sleep for every 30ms awake).
38*32cad1ffSPhilippe Mathieu-Daudé  *
39*32cad1ffSPhilippe Mathieu-Daudé  * cpu_throttle_set can be called as needed to adjust new_throttle_pct.
40*32cad1ffSPhilippe Mathieu-Daudé  * Once the throttling starts, it will remain in effect until cpu_throttle_stop
41*32cad1ffSPhilippe Mathieu-Daudé  * is called.
42*32cad1ffSPhilippe Mathieu-Daudé  */
43*32cad1ffSPhilippe Mathieu-Daudé void cpu_throttle_set(int new_throttle_pct);
44*32cad1ffSPhilippe Mathieu-Daudé 
45*32cad1ffSPhilippe Mathieu-Daudé /**
46*32cad1ffSPhilippe Mathieu-Daudé  * cpu_throttle_stop:
47*32cad1ffSPhilippe Mathieu-Daudé  *
48*32cad1ffSPhilippe Mathieu-Daudé  * Stops the vcpu throttling started by cpu_throttle_set.
49*32cad1ffSPhilippe Mathieu-Daudé  */
50*32cad1ffSPhilippe Mathieu-Daudé void cpu_throttle_stop(void);
51*32cad1ffSPhilippe Mathieu-Daudé 
52*32cad1ffSPhilippe Mathieu-Daudé /**
53*32cad1ffSPhilippe Mathieu-Daudé  * cpu_throttle_active:
54*32cad1ffSPhilippe Mathieu-Daudé  *
55*32cad1ffSPhilippe Mathieu-Daudé  * Returns: %true if the vcpus are currently being throttled, %false otherwise.
56*32cad1ffSPhilippe Mathieu-Daudé  */
57*32cad1ffSPhilippe Mathieu-Daudé bool cpu_throttle_active(void);
58*32cad1ffSPhilippe Mathieu-Daudé 
59*32cad1ffSPhilippe Mathieu-Daudé /**
60*32cad1ffSPhilippe Mathieu-Daudé  * cpu_throttle_get_percentage:
61*32cad1ffSPhilippe Mathieu-Daudé  *
62*32cad1ffSPhilippe Mathieu-Daudé  * Returns the vcpu throttle percentage. See cpu_throttle_set for details.
63*32cad1ffSPhilippe Mathieu-Daudé  *
64*32cad1ffSPhilippe Mathieu-Daudé  * Returns: The throttle percentage in range 1 to 99.
65*32cad1ffSPhilippe Mathieu-Daudé  */
66*32cad1ffSPhilippe Mathieu-Daudé int cpu_throttle_get_percentage(void);
67*32cad1ffSPhilippe Mathieu-Daudé 
68*32cad1ffSPhilippe Mathieu-Daudé /**
69*32cad1ffSPhilippe Mathieu-Daudé  * cpu_throttle_dirty_sync_timer_tick:
70*32cad1ffSPhilippe Mathieu-Daudé  *
71*32cad1ffSPhilippe Mathieu-Daudé  * Dirty sync timer hook.
72*32cad1ffSPhilippe Mathieu-Daudé  */
73*32cad1ffSPhilippe Mathieu-Daudé void cpu_throttle_dirty_sync_timer_tick(void *opaque);
74*32cad1ffSPhilippe Mathieu-Daudé 
75*32cad1ffSPhilippe Mathieu-Daudé /**
76*32cad1ffSPhilippe Mathieu-Daudé  * cpu_throttle_dirty_sync_timer:
77*32cad1ffSPhilippe Mathieu-Daudé  *
78*32cad1ffSPhilippe Mathieu-Daudé  * Start or stop the dirty sync timer.
79*32cad1ffSPhilippe Mathieu-Daudé  */
80*32cad1ffSPhilippe Mathieu-Daudé void cpu_throttle_dirty_sync_timer(bool enable);
81*32cad1ffSPhilippe Mathieu-Daudé 
82*32cad1ffSPhilippe Mathieu-Daudé #endif /* SYSTEM_CPU_THROTTLE_H */
83