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

     rman, rman_activate_resource, rman_adjust_resource,
     rman_deactivate_resource, rman_fini, rman_init, rman_init_from_resource,
     rman_is_region_manager, rman_manage_region, rman_first_free_region,
     rman_last_free_region, rman_release_resource, rman_reserve_resource,
     rman_reserve_resource_bound, rman_make_alignment_flags, rman_get_start,
     rman_get_end, rman_get_device, rman_get_size, rman_get_flags,
     rman_set_mapping, rman_get_mapping, rman_set_virtual, rman_get_virtual,
     rman_set_bustag, rman_get_bustag, rman_set_bushandle, rman_get_bushandle,
     rman_set_rid, rman_get_rid	-- resource management functions

     #include <sys/types.h>
     #include <sys/rman.h>

     rman_activate_resource(struct resource *r);

     rman_adjust_resource(struct resource *r, rman_res_t start,
	 rman_res_t end);

     rman_deactivate_resource(struct resource *r);

     rman_fini(struct rman *rm);

     rman_init(struct rman *rm);

     rman_init_from_resource(struct rman *rm, struct resource *r);

     rman_is_region_manager(struct resource *r,	struct rman *rm);

     rman_manage_region(struct rman *rm, rman_res_t start, rman_res_t end);

     rman_first_free_region(struct rman	*rm, rman_res_t	*start,
	 rman_res_t *end);

     rman_last_free_region(struct rman *rm, rman_res_t *start,
	 rman_res_t *end);

     rman_release_resource(struct resource *r);

     struct resource *
     rman_reserve_resource(struct rman *rm, rman_res_t start, rman_res_t end,
	 rman_res_t count, u_int flags,	struct device *dev);

     struct resource *
     rman_reserve_resource_bound(struct	rman *rm, rman_res_t start,
	 rman_res_t end, rman_res_t count, rman_res_t bound, u_int flags,
	 struct	device *dev);

     rman_make_alignment_flags(uint32_t	size);

     rman_get_start(struct resource *r);

     rman_get_end(struct resource *r);

     struct device *
     rman_get_device(struct resource *r);

     rman_get_size(struct resource *r);

     rman_get_flags(struct resource *r);

     rman_set_mapping(struct resource *r, struct resource_map *map);

     rman_get_mapping(struct resource *r, struct resource_map *map);

     rman_set_virtual(struct resource *r, void *v);

     void *
     rman_get_virtual(struct resource *r);

     rman_set_bustag(struct resource *r, bus_space_tag_t t);

     rman_get_bustag(struct resource *r);

     rman_set_bushandle(struct resource	*r, bus_space_handle_t h);

     rman_get_bushandle(struct resource	*r);

     rman_set_rid(struct resource *r, int rid);

     rman_get_rid(struct resource *r);

     The rman set of functions provides	a flexible resource management ab-
     straction.	 It is used extensively	by the bus management code.  It	imple-
     ments the abstractions of region and resource.  A region descriptor is
     used to manage a region; this could be memory or some other form of bus

     Each region has a set of bounds.  Within these bounds, allocated segments
     may reside.  Each segment,	termed a resource, has several properties
     which are represented by a	16-bit flag register, as follows.

     #define RF_ALLOCATED    0x0001 /* resource	has been reserved */
     #define RF_ACTIVE	     0x0002 /* resource	allocation has been activated */
     #define RF_SHAREABLE    0x0004 /* resource	permits	contemporaneous	sharing	*/
     #define RF_FIRSTSHARE   0x0020 /* first in	sharing	list */
     #define RF_PREFETCHABLE 0x0040 /* resource	is prefetchable	*/
     #define RF_UNMAPPED     0x0100 /* don't map resource when activating */

     Bits 15:10	 of the	flag register are used to represent the	desired	align-
     ment of the resource within the region.

     The rman_init() function initializes the region descriptor, pointed to by
     the rm argument, for use with the resource	management functions.  It is
     required that the fields rm_type and rm_descr of struct rman be set be-
     fore calling rman_init().	The field rm_type shall	be set to RMAN_ARRAY.
     The field rm_descr	shall be set to	a string that describes	the resource
     to	be managed.  The rm_start and rm_end fields may	be set to limit	the
     range of acceptable resource addresses.  If these fields are not set,
     rman_init() will initialize them to allow the entire range	of resource
     addresses.	 It also initializes any mutexes associated with the struc-
     ture.  If rman_init() fails to initialize the mutex, it will return
     ENOMEM; otherwise it will return 0	and rm will be initialized.

     The rman_fini() function frees any	structures associated with the struc-
     ture pointed to by	the rm argument.  If any of the	resources within the
     managed region have the RF_ALLOCATED flag set, it will return EBUSY; oth-
     erwise, any mutexes associated with the structure will be released	and
     destroyed,	and the	function will return 0.

     The rman_manage_region() function establishes the concept of a region
     which is under rman control.  The rman argument points to the region de-
     scriptor.	The start and end arguments specify the	bounds of the region.
     If	successful, rman_manage_region() will return 0.	 If the	region over-
     laps with an existing region, it will return EBUSY.  If any part of the
     region falls outside of the valid address range for rm, it	will return
     EINVAL.  ENOMEM will be returned when rman_manage_region()	failed to al-
     locate memory for the region.

     The rman_init_from_resource() function is a wrapper routine to create a
     resource manager backed by	an existing resource.  It initializes rm using
     rman_init() and then adds a region	to rm corresponding to the address
     range allocated to	r via rman_manage_region().

     The rman_first_free_region() and rman_last_free_region() functions	can be
     used to query a resource manager for its first (or	last) unallocated re-
     gion.  If rm contains no free region, these functions will	return ENOENT.
     Otherwise,	*start and *end	are set	to the bounds of the free region and
     zero is returned.

     The rman_reserve_resource_bound() function	is where the bulk of the rman
     logic is located.	It attempts to reserve a contiguous range in the spec-
     ified region rm for the use of the	device dev.  The caller	can specify
     the start and end of an acceptable	range, as well as a boundary restric-
     tion and required aligment, and the code will attempt to find a free seg-
     ment which	fits.  The start argument is the lowest	acceptable starting
     value of the resource.  The end argument is the highest acceptable	ending
     value of the resource.  Therefore,	start +	count -	1 must be <= end for
     any allocation to happen.	The aligment requirement (if any) is specified
     in	flags.	The bound argument may be set to specify a boundary restric-
     tion such that an allocated region	may cross an address that is a multi-
     ple of the	boundary.  The bound argument must be a	power of two.  It may
     be	set to zero to specify no boundary restriction.	 A shared segment will
     be	allocated if the RF_SHAREABLE flag is set, otherwise an	exclusive seg-
     ment will be allocated.  If this shared segment already exists, the
     caller has	its device added to the	list of	consumers.

     The rman_reserve_resource() function is used to reserve resources within
     a previously established region.  It is a simplified interface to
     rman_reserve_resource_bound() which passes	0 for the bound	argument.

     The rman_make_alignment_flags() function returns the flag mask corre-
     sponding to the desired alignment size.  This should be used when calling

     The rman_is_region_manager() function returns true	if the allocated re-
     source r was allocated from rm.  Otherwise, it returns false.

     The rman_adjust_resource()	function is used to adjust the reserved	ad-
     dress range of an allocated resource to reserve start through end.	 It
     can be used to grow or shrink one or both ends of the resource range.
     The current implementation	does not support entirely relocating the re-
     source and	will fail with EINVAL if the new resource range	does not over-
     lap the old resource range.  If either end	of the resource	range grows
     and the new resource range	would conflict with another allocated re-
     source, the function will fail with EBUSY.	 The rman_adjust_resource()
     function does not support adjusting the resource range for	shared re-
     sources and will fail such	attempts with EINVAL.  Upon success, the re-
     source r will have	a start	address	of start and an	end address of end and
     the function will return zero.  Note that none of the constraints of the
     original allocation request such as alignment or boundary restrictions
     are checked by rman_adjust_resource().  It	is the caller's	responsibility
     to	enforce	any such requirements.

     The rman_release_resource() function releases the reserved	resource r.
     It	may attempt to merge adjacent free resources.

     The rman_activate_resource() function marks a resource as active, by set-
     ting the RF_ACTIVE	flag.  If this is a time shared	resource, and the
     caller has	not yet	acquired the resource, the function returns EBUSY.

     The rman_deactivate_resource() function marks a resource r	as inactive,
     by	clearing the RF_ACTIVE flag.  If other consumers are waiting for this
     range, it will wakeup their threads.

     The rman_get_start(), rman_get_end(), rman_get_size(), and
     rman_get_flags() functions	return the bounds, size	and flags of the pre-
     viously reserved resource r.

     The rman_set_bustag() function associates a bus_space_tag_t t with	the
     resource r.  The rman_get_bustag()	function is used to retrieve this tag
     once set.

     The rman_set_bushandle() function associates a bus_space_handle_t h with
     the resource r.  The rman_get_bushandle() function	is used	to retrieve
     this handle once set.

     The rman_set_virtual() function is	used to	associate a kernel virtual ad-
     dress with	a resource r.  The rman_get_virtual() function can be used to
     retrieve the KVA once set.

     The rman_set_mapping() function is	used to	associate a resource mapping
     with a resource r.	 The mapping must cover	the entire resource.  Setting
     a mapping sets the	associated bus_space(9)	handle and tag for r as	well
     as	the kernel virtual address if the mapping contains one.	 These indi-
     vidual values can be retrieved via	rman_get_bushandle(),
     rman_get_bustag(),	and rman_get_virtual().

     The rman_get_mapping() function can be used to retrieve the associated
     resource mapping once set.

     The rman_set_rid()	function associates a resource identifier with a re-
     source r.	The rman_get_rid() function retrieves this RID.

     The rman_get_device() function returns a pointer to the device which re-
     served the	resource r.

     bus_activate_resource(9), bus_adjust_resource(9), bus_alloc_resource(9),
     bus_map_resource(9), bus_release_resource(9), bus_set_resource(9),
     bus_space(9), mutex(9)

     This manual page was written by Bruce M Simpson <>.

BSD				 May 20, 2016				   BSD


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