xref: /illumos-gate/usr/src/man/man9f/bp_mapout.9f (revision bbf21555)
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Copyright 1989 AT&T
Copyright (c) 1996, Sun Microsystems, Inc. All Rights Reserved
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When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
BP_MAPOUT 9F "Nov 15, 1996"
NAME
bp_mapout - deallocate virtual address space
SYNOPSIS

#include <sys/types.h>
#include <sys/buf.h>



void bp_mapout(struct buf *bp);
INTERFACE LEVEL

Architecture independent level 1 (DDI/DKI).

PARAMETERS
bp

Pointer to the buffer header structure.

DESCRIPTION

bp_mapout() deallocates system virtual address space allocated by a previous call to bp_mapin(9F).bp_mapout() should only be called on buffers which have been allocated and are owned by the device driver. It must not be called on buffers passed to the driver through the strategy(9E) entry point (for example a filesystem). Because bp_mapin(9F) does not keep a reference count, bp_mapout() will wipe out any kernel mapping that a layer above the device driver might rely on.

CONTEXT

bp_mapout() can be called from user context only.

SEE ALSO

strategy (9E), bp_mapin (9F), buf (9S)

Writing Device Drivers