xref: /freebsd/share/man/man9/BUS_GET_CPUS.9 (revision 2e3507c25e42292b45a5482e116d278f5515d04d)
1.\" -*- nroff -*-
2.\"
3.\" Copyright (c) 2016 John H. Baldwin <jhb@FreeBSD.org>
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.Dd March 1, 2016
27.Dt BUS_GET_CPUS 9
28.Os
29.Sh NAME
30.Nm BUS_GET_CPUS ,
31.Nm bus_get_cpus
32.Nd "request a set of device-specific CPUs"
33.Sh SYNOPSIS
34.In sys/param.h
35.In sys/bus.h
36.In sys/cpuset.h
37.Ft int
38.Fo BUS_GET_CPUS
39.Fa "device_t dev" "device_t child" "enum cpu_sets op" "size_t setsize"
40.Fa "cpuset_t *cpuset"
41.Fc
42.Ft int
43.Fo bus_get_cpus
44.Fa "device_t dev" "enum cpu_sets op" "size_t setsize" "cpuset_t *cpuset"
45.Fc
46.Sh DESCRIPTION
47The
48.Fn BUS_GET_CPUS
49method queries the parent bus device for a set of device-specific CPUs.
50The
51.Fa op
52argument specifies which set of CPUs to retrieve.
53If successful,
54the requested set of CPUs are returned in
55.Fa cpuset .
56The
57.Fa setsize
58argument specifies the size in bytes of the set passed in
59.Fa cpuset .
60.Pp
61.Fn BUS_GET_CPUS
62supports querying different types of CPU sets via the
63.Fa op argument.
64Not all set types are supported for every device.
65If a set type is not supported,
66.Fn BUS_GET_CPUS
67fails with
68.Er EINVAL .
69These set types are supported:
70.Bl -tag -width ".Dv LOCAL_CPUS"
71.It Dv LOCAL_CPUS
72The set of CPUs that are local to the device.
73If a device is closer to a specific memory domain in a non-uniform memory
74architecture system
75.Pq NUMA ,
76this will return the set of CPUs in that memory domain.
77.It Dv INTR_CPUS
78The preferred set of CPUs that this device should use for device interrupts.
79This set type must be supported by all bus drivers.
80.El
81.Pp
82The
83.Fn bus_get_cpus
84function is a simple wrapper around
85.Fn BUS_GET_CPUS .
86.Sh RETURN VALUES
87Zero is returned on success, otherwise an appropriate error is returned.
88.Sh SEE ALSO
89.Xr cpuset 2 ,
90.Xr BUS_BIND_INTR 9 ,
91.Xr device 9
92.Sh HISTORY
93The
94.Fn BUS_GET_CPUS
95method and
96.Fn bus_get_cpus
97function first appeared in
98.Fx 11.0 .
99