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.
DESCRIPTIONrmallocmap() dynamically allocates a resource map structure. The argu‐
ment 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 rmal‐
locmap(), 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 man‐
aged 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.
CONTEXTrmallocmap() and rmfreemap() can be called from user, kernel, or inter‐
rupt context.
rmallocmap_wait() can only be called from user or kernel context.
SEE ALSOrmalloc(9F), rmalloc_wait(9F), rmfree(9F)
Writing Device Drivers
SunOS 5.10 20 Nov 1996 rmallocmap(9F)
