BP_MAPOUT(9F) Kernel Functions for Drivers BP_MAPOUT(9F)
bp_mapout - deallocate virtual address space
#include <sys/types.h>
#include <sys/buf.h>
void bp_mapout(struct buf *bp);
Architecture independent level 1 (DDI/DKI).
bp
Pointer to the buffer header structure.
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.
bp_mapout() can be called from user context only.
strategy(9E), bp_mapin(9F), buf(9S)
Writing Device Drivers
November 15, 1996 BP_MAPOUT(9F)
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
November 15, 1996 BP_MAPOUT(9F)