opensolaris man page for rmfree

rmfree(9F)						   Kernel Functions for Drivers 						rmfree(9F)

NAME
       rmfree - free space back into a resource map

SYNOPSIS
       #include <sys/map.h>
       #include <sys/ddi.h>

       void rmfree(struct map *mp, size_t size, ulong_t index);

INTERFACE LEVEL
       Architecture independent level 1 (DDI/DKI).

PARAMETERS
       mp	Pointer to the map structure.

       size	Number of units being freed.

       index	Index of the first unit of the allocated resource.

DESCRIPTION
       The  rmfree() function releases space back into a resource map. It is the opposite of rmalloc(9F), which allocates space that is controlled
       by a resource map structure.

       When releasing resources using rmfree() the size and index passed to rmfree() must exactly match the size and index values  passed  to  and
       returned from a previous call to rmalloc(). Resources cannot be returned piecemeal.

       Drivers	may define resource maps for resource allocation, in terms of arbitrary units, using the rmallocmap(9F) function. The system main-
       tains the resource map structure by size and index, computed in units appropriate  for  the  resource.  For  example,  units  may  be  byte
       addresses, pages of memory, or blocks. rmfree() frees up unallocated space for re-use.

       The  rmfree()  function	can  also  be used to initialize a resource map, in which case the size and index should cover the entire resource
       area.

CONTEXT
       The rmfree() function can be called from user, interrupt, or kernel context.

SEE ALSO
       rmalloc(9F), rmalloc_wait(9F), rmallocmap(9F), rmfreemap(9F)

       Writing Device Drivers

SunOS 5.11							    16 Jan 2006 							rmfree(9F)