Manual Pages for UNIX Operating System command usage for man bp_mapout

Kernel Functions for Drivers                        bp_mapout(9F)



NAME
     bp_mapout - deallocate virtual address space

SYNOPSIS
     #include 
     #include 



     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  allo-
     cated 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


















SunOS 5.11          Last change: 15 Nov 1996                    1