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Diffstat (limited to 'static/netbsd/man9/devsw_attach.9')
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diff --git a/static/netbsd/man9/devsw_attach.9 b/static/netbsd/man9/devsw_attach.9 new file mode 100644 index 00000000..48ccbbce --- /dev/null +++ b/static/netbsd/man9/devsw_attach.9 @@ -0,0 +1,185 @@ +.\" $NetBSD: devsw_attach.9,v 1.6 2023/02/02 14:09:52 uwe Exp $ +.\" +.\" Copyright (c) 2015 The NetBSD Foundation, Inc. +.\" All rights reserved. +.\" +.\" This code is derived from software contributed to The NetBSD Foundation +.\" by Kamil Rytarowski. +.\" +.\" 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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. +.\" +.Dd February 2, 2023 +.Dt DEVSW 9 +.Os +.Sh NAME +.Nm devsw , +.Nm devsw_attach , +.Nm devsw_detach , +.Nm bdevsw_lookup , +.Nm cdevsw_lookup , +.Nm bdevsw_lookup_major , +.Nm cdevsw_lookup_major +.Nd character and block device switch functions +.Sh SYNOPSIS +.In sys/conf.h +.Ft int +.Fo devsw_attach +.Fa "const char *devname" +.Fa "const struct bdevsw *bev" +.Fa "devmajor_t *bmajor" +.Fa "const struct cdevsw *cdev" +.Fa "devmajor_t *cmajor" +.Fc +.Ft void +.Fo devsw_detach +.Fa "const struct bdevsw *bdev" +.Fa "const struct cdevsw *cdev" +.Fc +.Ft "const struct bdevsw *" +.Fo bdevsw_lookup +.Fa "dev_t dev" +.Fc +.Ft "const struct cdevsw *" +.Fo cdevsw_lookup +.Fa "dev_t dev" +.Fc +.Ft devmajor_t +.Fo bdevsw_lookup_major +.Fa "const struct bdevsw *bdev" +.Fc +.Ft devmajor_t +.Fo cdevsw_lookup_major +.Fa "const struct cdevsw *cdev" +.Fc +.Sh DESCRIPTION +If a device driver has character device interfaces accessed from +userland, the driver must define a +.Vt cdevsw +structure. +If the driver also has block device interfaces, the driver must +additionally define a +.Vt bdevsw +structure. +These structures are constant, and are defined within the +.Xr driver 9 . +.Pp +For drivers which are included in the kernel via +.Xr config 1 , +the +.Vt cdevsw +and +.Vt bdevsw +structures are automatically linked into the configuration database. +For drivers which are separately loaded, the +.Fn devsw_attach +function creates the necessary linkage and associates the +.Fa cdev +and optional +.Fa bdev +with the +.Xr driver 9 . +If there is no block device interface needed, +.Fa bdev +should be set to +.Dv NULL +and +.Fa bmajor +to +.Dv NODEVMAJOR . +The +.Fa devname , +major number, and device type +(character or block) +must correspond to the device file which will be opened by user programs. +By passing +.Dv NODEVMAJOR +to the function for the +.Fa cmajor +or +.Fa bmajor , +the major number can be automatically generated. +It can then be returned to userspace +.Po +for example, using +.Xr sysctl 8 +.Pc +for creation of the device node. +.Pp +The +.Fn devsw_detach +function is used to detach the +.Fa bdev +and +.Fa cdev +structures. +.Fn devsw_detach +should be called before a loaded device driver is unloaded. +The caller must ensure that there are no open instances of the device, +and that the device's +.Fa d_open +function will fail, before calling +.Fn devsw_detach . +.Pp +The +.Fn bdevsw_lookup +and +.Fn cdevsw_lookup +functions return +.Vt "const struct bdevsw *" +and +.Vt "const struct cdevsw *" +for the given +.Fa dev . +.Pp +The +.Fn bdevsw_lookup_major +and +.Fn cdevsw_lookup_major +functions return +.Vt "devmajor_t" +for the given +.Vt "const struct bdevsw *" +or +.Vt "const struct cdevsw *" . +.Sh RETURN VALUES +Upon successful completion, +.Fn devsw_attach +returns 0. +Otherwise it returns an error value. +.Pp +In case of failure, +.Fn bdevsw_lookup +and +.Fn cdevsw_lookup +return the +.Dv NULL +value. +.Pp +The +.Fn bdevsw_lookup_major +and +.Fn cdevsw_lookup_major +functions return +.Dv NODEVMAJOR +for an unsuccessful completion. +.Sh SEE ALSO +.Xr driver 9 |