1.\" Copyright (c) 2006-2008 Stanislav Sedov <stas@FreeBSD.org> 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd May 31, 2008 28.Dt CPUCTL 4 29.Os 30.Sh NAME 31.Nm cpuctl 32.Nd cpuctl pseudo device 33.Sh SYNOPSIS 34To compile this driver into the kernel, 35place the following lines in your kernel 36configuration file: 37.Bd -ragged -offset indent 38.Cd "device cpuctl" 39.Ed 40.Pp 41Alternatively, to load the driver as a module 42at boot time, place the following in 43.Xr loader.conf 5 : 44.Bd -literal -offset indent 45cpuctl_load="YES" 46.Ed 47.Sh DESCRIPTION 48The special file 49.Pa /dev/cpuctl 50presents interace to the system CPU. It provides functionality to retrieve 51CPUID information, read/write machine specific registers (MSR) and perform 52cpu firmware updates. 53.Pp 54For each cpu present in the system, special file 55.Pa /dev/cpuctl%d 56with the appropriate index will be created. For multicore cpus the 57special file will be created for each core. 58.Pp 59Currently, only i386 and amd64 processors are 60supported. 61.Sh IOCTL INTERFACE 62All of the supported operations are invoked using the 63.Fr ioctl 2 64system call. Refer to that manpage for further information about 65this interface. Currently, the following ioctls are defined: 66.Bl -tag -width CPUCTL_UPDATE 67.It Dv CPUCTL_RDMSR Fa cpuctl_msr_args_t *args 68.It Dv CPUCTL_WRMSR Fa cpuctl_msr_args_t *args 69Read/write cpu machine specific register. The 70.Vt cpuctl_msr_args_t 71structure defined in 72.In sys/cpuctl.h 73as: 74.Pp 75.Bd -literal 76typedef struct { 77 int msr; /* MSR to read */ 78 uint64_t data; 79} cpuctl_msr_args_t; 80.Ed 81.It Dv CPUCTL_CPUID Fa cpuctl_cpuid_args_t *args 82Retrieve CPUID information. Arguments are supplied in 83the following struct: 84.Pp 85.Bd -literal 86typedef struct { 87 int level; /* CPUID level */ 88 uint32_t data[4]; 89} cpuctl_cpuid_args_t; 90.Ed 91.Pp 92The 93.Va level 94field indicates the CPUID level to retrieve information for, while the 95.Va data 96used to store CPUID data received. 97.It Dv CPUCTL_UPDATE cpuctl_update_args_t *args 98Update cpu firmware (microcode). The structure defined in 99.In sys/cpuctl.h 100as: 101.Pp 102.Bd -literal 103typedef struct { 104 void *data; 105 size_t size; 106} cpuctl_update_args_t; 107.Ed 108.Pp 109The 110.Va data 111field should point to the firmware image of size 112.Va size . 113.El 114.Pp 115For additional information refer to 116.Pa cpuctl.h . 117.Sh RETURN VALUES 118.Bl -tag -width Er 119.It Bq Er ENXIO 120The operation requested is not supported by device (e.g. unsupported 121architecture or cpu was disabled) 122.It Bq Er EINVAL 123Incorrect request was supplied, or microcode image is not correct. 124.It Bq Er ENOMEM 125No physical memory was available to complete the request. 126.It Bq Er EFAULT 127The firmware image address points outside process address space. 128.El 129.Sh FILES 130.Bl -tag -width /dev/cpuctl -compact 131.It Pa /dev/cpuctl 132.El 133.Sh SEE ALSO 134.Xr hwpmc 4 135.Sh HISTORY 136The 137.Nm 138driver first appeared in 139.Fx 8.0 140.Sh BUGS 141Yes, probably, report if any. 142.Sh AUTHORS 143The 144.Nm 145module and this manual page was written by 146.An Stanislav Sedov Aq stas@FreeBSD.org . 147