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freebsd-skq/share/man/man9/BUS_NEW_PASS.9

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Add support for multiple passes of the device tree during the boot-time probe. The current device order is unchanged. This commit just adds the infrastructure and ABI changes so that it is easier to merge later changes into 8.x. - Driver attachments now have an associated pass level. Attachments are not allowed to probe or attach to drivers until the system-wide pass level is >= the attachment's pass level. By default driver attachments use the "last" pass level (BUS_PASS_DEFAULT). Driver's that wish to probe during an earlier pass use EARLY_DRIVER_MODULE() instead of DRIVER_MODULE() which accepts the pass level as an additional parameter. - A new method BUS_NEW_PASS has been added to the bus interface. This method is invoked when the system-wide pass level is changed to kick off a rescan of the device tree so that drivers that have just been made "eligible" can probe and attach. - The bus_generic_new_pass() function provides a default implementation of BUS_NEW_PASS(). It first allows drivers that were just made eligible for this pass to identify new child devices. Then it propogates the rescan to child devices that already have an attached driver by invoking their BUS_NEW_PASS() method. It also reprobes devices without a driver. - BUS_PROBE_NOMATCH() is only invoked for devices that do not have an attached driver after being scanned during the final pass. - The bus_set_pass() function is used during boot to raise the pass level. Currently it is only called once during root_bus_configure() to raise the pass level to BUS_PASS_DEFAULT. This has the effect of probing all devices in a single pass identical to previous behavior. Reviewed by: imp Approved by: re (kib)
2009-06-09 14:26:23 +00:00
.\" -*- nroff -*-
.\"
.\" Copyright (c) 2009 Advanced Computing Technologies LLC
.\" Written by: John H. Baldwin <jhb@FreeBSD.org>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd June 8, 2009
.Dt BUS_NEW_PASS 9
.Os
.Sh NAME
.Nm BUS_NEW_PASS
.Nd "notify a bus that the pass level has been changed"
.Sh SYNOPSIS
.In sys/param.h
.In sys/bus.h
.Ft void
.Fn BUS_NEW_PASS "device_t dev"
.Sh DESCRIPTION
The
.Fn BUS_NEW_PASS
method is called on each bus device to rescan the device tree when the pass
level has been changed.
This method is responsible for invoking
.Xr BUS_NEW_PASS 9
Fix typos and spelling mistakes.
2010-08-06 14:33:42 +00:00
on child bus devices to propagate the rescan to child devices.
Add support for multiple passes of the device tree during the boot-time probe. The current device order is unchanged. This commit just adds the infrastructure and ABI changes so that it is easier to merge later changes into 8.x. - Driver attachments now have an associated pass level. Attachments are not allowed to probe or attach to drivers until the system-wide pass level is >= the attachment's pass level. By default driver attachments use the "last" pass level (BUS_PASS_DEFAULT). Driver's that wish to probe during an earlier pass use EARLY_DRIVER_MODULE() instead of DRIVER_MODULE() which accepts the pass level as an additional parameter. - A new method BUS_NEW_PASS has been added to the bus interface. This method is invoked when the system-wide pass level is changed to kick off a rescan of the device tree so that drivers that have just been made "eligible" can probe and attach. - The bus_generic_new_pass() function provides a default implementation of BUS_NEW_PASS(). It first allows drivers that were just made eligible for this pass to identify new child devices. Then it propogates the rescan to child devices that already have an attached driver by invoking their BUS_NEW_PASS() method. It also reprobes devices without a driver. - BUS_PROBE_NOMATCH() is only invoked for devices that do not have an attached driver after being scanned during the final pass. - The bus_set_pass() function is used during boot to raise the pass level. Currently it is only called once during root_bus_configure() to raise the pass level to BUS_PASS_DEFAULT. This has the effect of probing all devices in a single pass identical to previous behavior. Reviewed by: imp Approved by: re (kib)
2009-06-09 14:26:23 +00:00
It is also responsible for reprobing any unattached child devices and
allowing drivers for the current pass to identify new children.
A default implementation is provided by
.Xr bus_generic_new_pass 9 .
.Sh SEE ALSO
.Xr bus_generic_new_pass 9 ,
.Xr bus_set_pass 9 ,
.Xr device 9
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