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 device 49.Pa /dev/cpuctl 50presents interface to the system CPU. 51It provides functionality to retrieve 52CPUID information, read/write machine specific registers (MSR) and perform 53CPU firmware updates. 54.Pp 55For each CPU present in the system, the special device 56.Pa /dev/cpuctl%d 57with the appropriate index will be created. 58For multicore CPUs such a 59special device will be created for each core. 60.Pp 61Currently, only i386 and amd64 processors are 62supported. 63.Sh IOCTL INTERFACE 64All of the supported operations are invoked using the 65.Xr ioctl 2 66system call. 67Currently, the following ioctls are defined: 68.Bl -tag -width CPUCTL_UPDATE 69.It Dv CPUCTL_RDMSR Fa cpuctl_msr_args_t *args 70.It Dv CPUCTL_WRMSR Fa cpuctl_msr_args_t *args 71Read/write CPU machine specific register. 72The 73.Vt cpuctl_msr_args_t 74structure is defined in 75.In sys/cpuctl.h 76as: 77.Pp 78.Bd -literal 79typedef struct { 80 int msr; /* MSR to read */ 81 uint64_t data; 82} cpuctl_msr_args_t; 83.Ed 84.It Dv CPUCTL_CPUID Fa cpuctl_cpuid_args_t *args 85Retrieve CPUID information. 86Arguments are supplied in 87the following struct: 88.Pp 89.Bd -literal 90typedef struct { 91 int level; /* CPUID level */ 92 uint32_t data[4]; 93} cpuctl_cpuid_args_t; 94.Ed 95.Pp 96The 97.Va level 98field indicates the CPUID level to retrieve information for, while the 99.Va data 100field is used to store the received CPUID data. 101.It Dv CPUCTL_UPDATE cpuctl_update_args_t *args 102Update CPU firmware (microcode). 103The structure is defined in 104.In sys/cpuctl.h 105as: 106.Pp 107.Bd -literal 108typedef struct { 109 void *data; 110 size_t size; 111} cpuctl_update_args_t; 112.Ed 113.Pp 114The 115.Va data 116field should point to the firmware image of size 117.Va size . 118.El 119.Pp 120For additional information refer to 121.Pa cpuctl.h . 122.Sh RETURN VALUES 123.Bl -tag -width Er 124.It Bq Er ENXIO 125The operation requested is not supported by the device (e.g. unsupported 126architecture or the CPU is disabled) 127.It Bq Er EINVAL 128Incorrect request was supplied, or microcode image is not correct. 129.It Bq Er ENOMEM 130No physical memory was available to complete the request. 131.It Bq Er EFAULT 132The firmware image address points outside the process address space. 133.El 134.Sh FILES 135.Bl -tag -width /dev/cpuctl -compact 136.It Pa /dev/cpuctl 137.El 138.Sh SEE ALSO 139.Xr hwpmc 4 , 140.Xr cpucontrol 8 141.Sh HISTORY 142The 143.Nm 144driver first appeared in 145.Fx 8.0 . 146.Sh BUGS 147Yes, probably, report if any. 148.Sh AUTHORS 149The 150.Nm 151module and this manual page were written by 152.An Stanislav Sedov Aq stas@FreeBSD.org . 153