1.\" Copyright (c) 2007 Joseph Koshy. All rights reserved. 2.\" 3.\" Redistribution and use in source and binary forms, with or without 4.\" modification, are permitted provided that the following conditions 5.\" are met: 6.\" 1. Redistributions of source code must retain the above copyright 7.\" notice, this list of conditions and the following disclaimer. 8.\" 2. Redistributions in binary form must reproduce the above copyright 9.\" notice, this list of conditions and the following disclaimer in the 10.\" documentation and/or other materials provided with the distribution. 11.\" 12.\" This software is provided by Joseph Koshy ``as is'' and 13.\" any express or implied warranties, including, but not limited to, the 14.\" implied warranties of merchantability and fitness for a particular purpose 15.\" are disclaimed. in no event shall Joseph Koshy be liable 16.\" for any direct, indirect, incidental, special, exemplary, or consequential 17.\" damages (including, but not limited to, procurement of substitute goods 18.\" or services; loss of use, data, or profits; or business interruption) 19.\" however caused and on any theory of liability, whether in contract, strict 20.\" liability, or tort (including negligence or otherwise) arising in any way 21.\" out of the use of this software, even if advised of the possibility of 22.\" such damage. 23.\" 24.\" $FreeBSD$ 25.\" 26.Dd November 25, 2007 27.Os 28.Dt PMC_GET_MSR 3 29.Sh NAME 30.Nm pmc_get_msr 31.Nd x86 architecture-specific PMC operations 32.Sh LIBRARY 33.Lb libpmc 34.Sh SYNOPSIS 35.In pmc.h 36.Ft int 37.Fn pmc_get_msr "pmc_id_t pmc" "uint32_t *msr" 38.Sh DESCRIPTION 39The function 40.Fn pmc_get_msr 41returns the processor model specific register number associated with 42a PMC for subsequent use with RDPMC instructions. 43Argument 44.Fa pmc 45specifies a process scope counting PMC. 46The function will write the model specific register number associated 47with the PMC to the location pointed to by argument 48.Fa msr . 49.Pp 50After successful completion of this function, applications 51can directly read the contents of PMC hardware using 52RDPMC instructions. 53.Sh RETURN VALUES 54.Rv -std pmc_get_msr 55.Sh ERRORS 56A call to 57.Fn pmc_get_msr 58may fail with the following errors: 59.Bl -tag -width Er 60.It Bq Er EINVAL 61The PMC handle specified was invalid. 62.It Bq Er EINVAL 63The PMC specified did not have process scope or counting mode. 64.It Bq Er EINVAL 65The PMC specified was allocated with the 66.Dv PMC_F_DESCENDANTS 67flag. 68.It Bq Er EINVAL 69The specified PMC is already attached to target processes other 70than the owner. 71.It Bq Er ENOSYS 72The underlying hardware does not support an RDPMC instruction. 73.El 74.Sh SEE ALSO 75.Xr pmc 3 , 76.Xr hwpmc 4 77