1.\" 2.\" Copyright (c) 1998 Kenneth D. Merry. 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 3. The name of the author may not be used to endorse or promote products 14.\" derived from this software without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" $FreeBSD: src/share/man/man4/xpt.4,v 1.3.2.7 2001/08/17 13:08:40 ru Exp $ 29.\" 30.Dd October 10, 1998 31.Dt XPT 4 32.Os 33.Sh NAME 34.Nm xpt 35.Nd CAM transport layer interface 36.Sh SYNOPSIS 37None. 38.Sh DESCRIPTION 39The 40.Nm 41driver provides a way for userland applications to issue certain CAM CCBs 42to the kernel. 43.Pp 44Since the 45.Nm 46driver allows direct access to the CAM subsystem, system administrators 47should exercise caution when granting access to this driver. If used 48improperly, this driver can allow userland applications to crash a machine 49or cause data loss. 50.Sh KERNEL CONFIGURATION 51There is no kernel configuration required for the 52.Nm 53driver. It is enabled when 54.Tn SCSI 55support is enabled in the kernel. There is one instance of the xpt driver 56per CAM transport layer instance. Since there is currently only one CAM 57transport layer, there will only be one instance of this driver. 58.Sh IOCTLS 59.Bl -tag -width 01234567890123 60.It Dv CAMIOCOMMAND 61This ioctl takes certain kinds of CAM CCBs and passes them through to the 62CAM transport layer for action. Only the following CCB types are 63supported: 64.Pp 65.Bl -tag -width XPT_DEV_MATCH -compact 66.It XPT_SCAN_BUS 67.It XPT_RESET_BUS 68.It XPT_SCAN_LUN 69.It XPT_ENG_INQ 70.It XPT_ENG_EXEC 71.It XPT_DEBUG 72.It XPT_DEV_MATCH 73.It XPT_PATH_INQ 74.El 75.Pp 76The above CCBs are the only ones supported since it makes more sense to 77send them through a generic passthrough device rather than a passthrough 78device tied to a particular underlying 79.Tn SCSI 80device. 81.It Dv CAMGETPASSTHRU 82This ioctl takes an XPT_GDEVLIST CCB, and returns the passthrough device 83corresponding to the device in question. 84.El 85.Sh FILES 86.Bl -tag -width /dev/xpt0 -compact 87.It Pa /dev/xpt0 88Character device node for the 89.Nm 90driver. 91.El 92.Sh DIAGNOSTICS 93None. 94.Sh SEE ALSO 95.Xr cam 3 , 96.Xr cam_cdbparse 3 , 97.Xr pass 4 , 98.Xr camcontrol 8 99.Sh HISTORY 100The CAM transport layer driver first appeared in 101.Fx 3.0 . 102.Sh AUTHORS 103.An Kenneth Merry Aq Mt ken@FreeBSD.org 104