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
particular, 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),
rmalloc_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,
rmallocmap() 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 November 20, 1996 RMALLOCMAP(9F)
