freebsd-skq/share/man/man9/store.9
Konstantin Belousov 2361c6d135 Add type qualifier volatile to the base (userspace) address argument
of fuword(9) and suword(9).  This makes the functions type-compatible
with volatile objects and does not require devolatile force, e.g. in
kern_umtx.c.

Requested by:	bde
Reviewed by:	jhb
Sponsored by:	The FreeBSD Foundation
MFC after:	3 weeks
2014-10-31 17:43:21 +00:00

101 lines
3.2 KiB
Groff

.\" $NetBSD: store.9,v 1.2 1996/01/09 21:59:27 perry Exp $
.\"
.\" Copyright (c) 1996 Jason R. Thorpe.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed by Kenneth Stailey.
.\"
.\" 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.
.\" 3. All advertising materials mentioning features or use of this software
.\" must display the following acknowledgement:
.\" This product includes software developed for the NetBSD Project
.\" by Jason R. Thorpe.
.\" 4. The name of the author may not be used to endorse or promote products
.\" derived from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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 October 29, 2014
.Dt STORE 9
.Os
.Sh NAME
.Nm store ,
.Nm subyte ,
.Nm suswintr ,
.Nm suword
.Nd store data to user-space
.Sh SYNOPSIS
.In sys/types.h
.In sys/time.h
.In sys/systm.h
.Ft int
.Fn subyte "volatile void *base" "int byte"
.Ft int
.Fn suword "volatile void *base" "long word"
.Ft int
.Fn suword16 "volatile void *base" "int word"
.Ft int
.Fn suword32 "volatile void *base" "int32_t word"
.Ft int
.Fn suword64 "volatile void *base" "int64_t word"
.In sys/resourcevar.h
.Ft int
.Fn suswintr "void *base" "int word"
.Sh DESCRIPTION
The
.Nm
functions are designed to copy small amounts of data to user-space.
If write is successful, it is performed atomically.
The data written must be naturally aligned.
.Pp
The
.Nm
routines provide the following functionality:
.Bl -tag -width "suswintr()"
.It Fn subyte
Stores a byte of data to the user-space address
.Pa base .
.It Fn suword
Stores a word of data to the user-space address
.Pa base .
.It Fn suword16
Stores 16 bits of data to the user-space address
.Pa base .
.It Fn suword32
Stores 32 bits of data to the user-space address
.Pa base .
.It Fn suword64
Stores 64 bits of data to the user-space address
.Pa base .
.It Fn suswintr
Stores a short word of data to the user-space address
.Pa base .
This function is safe to call during an interrupt context.
.El
.Sh RETURN VALUES
The
.Nm
functions return 0 on success or -1 on failure.
.Sh SEE ALSO
.Xr copy 9 ,
.Xr fetch 9