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