Manpage for read_msr and write_msr libx86info.so library functions

From: Thomas Renninger <trenn@suse.de>

Index: x86info-1.24/x86info.3
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+.\" Copyright 2009 Thomas Renninger, SuSE Products GmbH, Novell
+.\"
+.\" Permission is granted to make and distribute verbatim copies of this
+.\" manual provided the copyright notice and this permission notice are
+.\" preserved on all copies.
+.\"
+.\" Permission is granted to copy and distribute modified versions of this
+.\" manual under the conditions for verbatim copying, provided that the
+.\" entire resulting derived work is distributed under the terms of a
+.\" permission notice identical to this one.
+.\"
+.\" Since the Linux kernel and libraries are constantly changing, this
+.\" manual page may be incorrect or out-of-date.  The author(s) assume no
+.\" responsibility for errors or omissions, or for damages resulting from
+.\" the use of the information contained herein.
+.\"
+.\" Formatted or processed versions of this manual, if unaccompanied by
+.\" the source, must acknowledge the copyright and authors of this work.
+.\"
+.\" The numa.3 manpage from Andi Kleen has been used as a template for
+.\" this manpage.
+.TH X86INFO 3 "April 2009" "Linux" "Linux Programmer's Manual"
+.SH NAME
+x86info \- X86 processor information library
+.SH SYNOPSIS
+.B #include <x86_info.h>
+.sp
+.B cc ... -lx86info
+.sp
+.B int read_msr(int cpu, unsigned int index, unsigned long long *value)
+.sp
+.B int write_msr(int cpu, unsigned int index, unsigned long long value)
+.SH DESCRIPTION
+.B libx86info
+Offers a simple programming interface to read out from and modify system
+information on x86 processors.
+Currently only reading and writing to a CPU's MSRs (Machine Specific Register)
+is supported via the library.
+
+.B read_msr()
+reads the MSR address
+.I index
+from the CPU core
+.I cpu
+and stores the result in
+.I value.
+On success zero is returned, -1 if an error occured.
+
+.B write_msr()
+writes
+.I value
+to the MSR address
+.I index
+on CPU core
+.I cpu.
+On success zero is returned, -1 if an error occured.
+
+.SH NOTES
+To be able to read or write MSRs you have to
+have the msr kernel driver loaded and the appropriate devices
+under /dev/cpu/X/msr created.
+
+.SH ERRORS
+If
+.B read_msr
+or
+.B write_msr
+does not succeed, -1 is returned and errno is set by the underlying file
+accessing calls. Also look at
+.B open(2)
+what errors you generally could expect.
+
+.SH SEE ALSO
+.I x86info(1)
+.I lsmsr(8)