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

6       bp_mapout - deallocate 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_mapout(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_mapout()  deallocates  system  virtual  address space allocated by a
26       previous call to  bp_mapin(9F).bp_mapout() should  only  be  called  on
27       buffers  which  have been allocated and are owned by the device driver.
28       It must not be called on buffers  passed  to  the  driver  through  the
29       strategy(9E)   entry   point   (for   example  a  filesystem).  Because
30       bp_mapin(9F) does not keep a reference count, bp_mapout() will wipe out
31       any kernel mapping that a layer above the device driver might rely on.
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CONTEXT

34       bp_mapout() can be called from user context only.
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SEE ALSO

37       strategy(9E), bp_mapin(9F), buf(9S)
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40       Writing Device Drivers
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44SunOS 5.11                        15 Nov 1996                    bp_mapout(9F)