NAME

bp_mapin − allocate virtual address space

SYNOPSIS

#include <sys/types.h>
#include <sys/buf.h>
void bp_mapin(struct buf ∗bp);

ARGUMENTS

bp Pointer to the buffer header structure. 

INTERFACE LEVEL

Architecture independent level 1 (DDI/DKI). 

DESCRIPTION

bp_mapin() is used to map virtual address space to a page list maintained by the buffer header during a paged- I/O request.  bp_mapin() allocates system virtual address space, maps that space to the page list, and returns the starting address of the space in the bp->b_un.b_addr field of the buf(9S) structure.  Virtual address space is then deallocated using the bp_mapout(9F) function. 

If a null page list is encountered, bp_mapin() returns without allocating space and no mapping is performed.

CONTEXT

bp_mapin() can be called from user context only.

SEE ALSO

bp_mapout(9F), buf(9S)

Writing Device Drivers

SunOS 5.4  —  Last change: 13 Sep 1992