release_mem_region_adjustable(9) [centos man page]

RELEASE_MEM_REGION_A(9) 					Hardware Interfaces					   RELEASE_MEM_REGION_A(9)

NAME

       release_mem_region_adjustable - release a previously reserved memory region

SYNOPSIS

       int release_mem_region_adjustable(struct resource * parent, resource_size_t start, resource_size_t size);

ARGUMENTS

       parent
	   parent resource descriptor

       start
	   resource start address

       size
	   resource region size

DESCRIPTION

       This interface is intended for memory hot-delete. The requested region is released from a currently busy memory resource. The requested
       region must either match exactly or fit into a single busy resource entry. In the latter case, the remaining resource is adjusted
       accordingly. Existing children of the busy memory resource must be immutable in the request.

NOTE

       - Additional release conditions, such as overlapping region, can be supported after they are confirmed as valid cases. - When a busy memory
       resource gets split into two entries, the code assumes that all children remain in the lower address entry for simplicity. Enhance this
       logic when necessary.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						   RELEASE_MEM_REGION_A(9)

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