BP_MAPIN(9F)BP_MAPIN(9F)NAMEbp_mapin - allocate virtual address space
void bp_mapin(struct buf *bp);
Architecture independent level 1 (DDI/DKI).
Pointer to the buffer header structure.
DESCRIPTIONbp_mapin() is used to map virtual address space to a page list main‐
tained 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 allocat‐
ing space and no mapping is performed.
CONTEXTbp_mapin() can be called from user and kernel contexts.
SEE ALSObp_mapout(9F), buf(9S)
Writing Device Drivers
Sep 13, 1992 BP_MAPIN(9F)