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: head/share/man/man4/cpuctl.4 267938 2014-06-26 21:46:14Z bapt $ 26.\" 27.Dd April 12, 2016 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 x86_64 processors are supported. 62.Sh IOCTL INTERFACE 63All of the supported operations are invoked using the 64.Xr ioctl 2 65system call. 66Currently, the following ioctls are defined: 67.Bl -tag -width ".Dv CPUCTL_CPUID_COUNT" 68.It Dv CPUCTL_RDMSR Fa cpuctl_msr_args_t *args 69.It Dv CPUCTL_WRMSR Fa cpuctl_msr_args_t *args 70Read/write CPU machine specific register. 71The 72.Vt cpuctl_msr_args_t 73structure is defined in 74.In sys/cpuctl.h 75as: 76.Bd -literal 77typedef struct { 78 int msr; /* MSR to read */ 79 uint64_t data; 80} cpuctl_msr_args_t; 81.Ed 82.It Dv CPUCTL_MSRSBIT Fa cpuctl_msr_args_t *args 83.It Dv CPUCTL_MSRCBIT Fa cpuctl_msr_args_t *args 84Set/clear MSR bits according to the mask given in the 85.Va data 86field. 87.It Dv CPUCTL_CPUID Fa cpuctl_cpuid_args_t *args 88Retrieve CPUID information. 89Arguments are supplied in the following structure: 90.Bd -literal 91typedef struct { 92 int level; /* CPUID level */ 93 uint32_t data[4]; 94} cpuctl_cpuid_args_t; 95.Ed 96It is equivalent to the 97.Dv CPUCTL_CPUID_COUNT 98request with 99.Va level_type 100set to 0. 101.It Dv CPUCTL_CPUID_COUNT Fa cpuctl_cpuid_count_args_t *args 102Retrieve CPUID information. 103Arguments are supplied in the following structure: 104.Bd -literal 105typedef struct { 106 int level; /* CPUID level */ 107 int level_type; /* CPUID level type */ 108 uint32_t data[4]; 109} cpuctl_cpuid_count_args_t; 110.Ed 111The 112.Va level 113field indicates the CPUID level to retrieve, 114it is loaded into the 115.Va %eax 116register before the CPUID instruction is executed, 117The 118.Va level_type 119field indicates the CPUID level type to retrieve, 120it is loaded into the 121.Va %ecx 122register. 123.Pp 124The 125.Va data 126field is used to store the received CPUID data. 127That is, 128.Va data[0] 129contains the value of 130.Va %eax 131register after the CPUID instruction is executed, 132.Va data[1] 133is for 134.Va %ebx , 135.Va data[2] 136for 137.Va %ecx , 138and 139.Va data[3] 140for 141.Va %edx . 142.It Dv CPUCTL_UPDATE cpuctl_update_args_t *args 143Update CPU firmware (microcode). 144The structure is defined in 145.In sys/cpuctl.h 146as: 147.Bd -literal 148typedef struct { 149 void *data; 150 size_t size; 151} cpuctl_update_args_t; 152.Ed 153.Pp 154The 155.Va data 156field should point to the firmware image of size 157.Va size . 158.El 159.Pp 160For additional information refer to 161.Pa cpuctl.h . 162.Sh FILES 163.Bl -tag -width /dev/cpuctl -compact 164.It Pa /dev/cpuctl 165.El 166.Sh ERRORS 167.Bl -tag -width Er 168.It Bq Er ENXIO 169The operation requested is not supported by the device (e.g., unsupported 170architecture or the CPU is disabled). 171.It Bq Er EINVAL 172Incorrect request was supplied, or microcode image is not correct. 173.It Bq Er ENOMEM 174No physical memory was available to complete the request. 175.It Bq Er EFAULT 176The firmware image address points outside the process address space. 177.El 178.Sh SEE ALSO 179.\".Xr hwpmc 4 , 180.Xr cpucontrol 8 181.Sh HISTORY 182The 183.Nm 184driver first appeared in 185.Fx 7.2 . 186.Sh AUTHORS 187The 188.Nm 189module and this manual page were written by 190.An Stanislav Sedov Aq Mt stas@FreeBSD.org . 191.Sh BUGS 192Yes, probably, report if any. 193