BP_MAPOUT(9F)BP_MAPOUT(9F)NAMEbp_mapout - deallocate virtual address space
void bp_mapout(struct buf *bp);
Architecture independent level 1 (DDI/DKI).
Pointer to the buffer header structure.
DESCRIPTIONbp_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.
CONTEXTbp_mapout() can be called from user context only.
SEE ALSOstrategy(9E), bp_mapin(9F), buf(9S)
Writing Device Drivers
Nov 15, 1996 BP_MAPOUT(9F)