1bp_mapin(9F)             Kernel Functions for Drivers             bp_mapin(9F)
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NAME

6       bp_mapin - allocate virtual address space
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SYNOPSIS

9       #include <sys/types.h>
10       #include <sys/buf.h>
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14       void bp_mapin(struct buf *bp);
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INTERFACE LEVEL

18       Architecture independent level 1 (DDI/DKI).
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PARAMETERS

21       bp     Pointer to the buffer header structure.
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DESCRIPTION

25       bp_mapin()  is  used  to map virtual address space to a page list main‐
26       tained by the buffer header during a  paged-  I/O  request.  bp_mapin()
27       allocates  system  virtual  address  space, maps that space to the page
28       list,  and  returns  the  starting  address  of  the   space   in   the
29       bp->b_un.b_addr  field  of the buf(9S) structure. Virtual address space
30       is then deallocated using the bp_mapout(9F) function.
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33       If a null page list is encountered, bp_mapin() returns without allocat‐
34       ing space and no mapping is performed.
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CONTEXT

37       bp_mapin() can be called from user and kernel contexts.
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SEE ALSO

40       bp_mapout(9F), buf(9S)
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43       Writing Device Drivers
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47SunOS 5.11                        13 Sep 1992                     bp_mapin(9F)