rmfree(9F) Kernel Functions for Drivers rmfree(9F)NAMErmfree - 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 ALSOrmalloc(9F), rmalloc_wait(9F), rmallocmap(9F), rmfreemap(9F)
Writing Device Drivers
SunOS 5.10 16 Jan 2006 rmfree(9F)
