freebsd man page for bus_adjust_resource

BUS_ADJUST_RESOURCE(9)					   BSD Kernel Developer's Manual				    BUS_ADJUST_RESOURCE(9)

NAME
     bus_adjust_resource -- adjust resource allocated from a parent bus

SYNOPSIS
     #include <sys/param.h>
     #include <sys/bus.h>

     #include <machine/bus.h>
     #include <sys/rman.h>
     #include <machine/resource.h>

     int
     bus_adjust_resource(device_t dev, int type, struct resource *r, u_long start, u_long end);

DESCRIPTION
     This function is used to ask the parent bus to adjust the resource range assigned to an allocated resource.  The resource r should have been
     allocated by a previous call to bus_alloc_resource(9).  The new resource range must overlap the existing range of r.  The type argument
     should match the type argument passed to bus_alloc_resource(9) when the resource was initially allocated.

     Note that none of the constraints of the original allocation request such as alignment or boundary restrictions are checked by
     bus_adjust_resource().  It is the caller's responsibility to enforce any such requirements.

RETURN VALUES
     The bus_adjust_resource() method returns zero on success or an error code on failure.

EXAMPLES
     Grow an existing memory resource by 4096 bytes.

	     struct resource *res;
	     int error;

	     error = bus_adjust_resource(dev, SYS_RES_MEMORY, res,
		 rman_get_start(res), rman_get_end(res) + 0x1000);

ERRORS
     bus_adjust_resource() will fail if:

     [EINVAL]		The dev device does not have a parent device.

     [EINVAL]		The r resource is a shared resource.

     [EINVAL]		The new address range does not overlap with the existing address range of r.

     [EBUSY]		The new address range conflicts with another allocated resource.

SEE ALSO
     bus_alloc_resource(9), bus_release_resource(9), device(9), driver(9)

BSD
								  April 29, 2011							       BSD