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

NAME

       rmallocmap, rmallocmap_wait, rmfreemap - allocate and free resource maps

SYNOPSIS

       #include <sys/ddi.h>
       #include <sys/sunddi.h>

       struct map *rmallocmap(size_t mapsize);

       struct map *rmallocmap_wait(size_t mapsize);

       void rmfreemap(struct map *mp);

INTERFACE LEVEL

       Architecture independent level 1 (DDI/DKI).

PARAMETERS

       mapsize	   Number of entries for the map.

       mp	   A pointer to the map structure to be deallocated.

DESCRIPTION

       rmallocmap() dynamically allocates a resource map structure. The argument mapsize defines the total number of entries in the map.  In  par-
       ticular, it is the total number of allocations that can be outstanding at any one time.

       rmallocmap() initializes the map but does not associate it with the actual resource. In	order  to  associate   the  map  with  the  actual
       resource,  a call to rmfree(9F) is used to make the entirety of the actual resource available for allocation, starting from the first index
       into the resource. Typically, the call to rmallocmap() is followed by a call to rmfree(9F), passing the address of the  map  returned  from
       rmallocmap(), the total size of the resource, and the first index into the actual resource.

       The resource map allocated by rmallocmap() can be used to describe an arbitrary resource in whatever allocation units are appropriate, such
       as blocks, pages, or data structures. This resource can then  be  managed  by  the  system  by  subsequent  calls  to   rmalloc(9F),  rmal-
       loc_wait(9F), and rmfree(9F).

       rmallocmap_wait() is similar to	rmallocmap(), with the exception that it will wait for space to become available if necessary.

       rmfreemap() deallocates a resource map structure previously allocated by rmallocmap() or rmallocmap_wait(). The argument mp is a pointer to
       the map structure to be deallocated.

RETURN VALUES

       Upon successful completion, rmallocmap() and  rmallocmap_wait() return a pointer to the newly allocated map structure. Upon failure,  rmal-
       locmap() returns a  NULL pointer.

CONTEXT

       rmallocmap() and rmfreemap() can be called from user, kernel, or interrupt context.

       rmallocmap_wait() can only be called from user or kernel context.

SEE ALSO

       rmalloc(9F), rmalloc_wait(9F), rmfree(9F)

       Writing Device Drivers

SunOS 5.11							    20 Nov 1996 						    rmallocmap(9F)