/*
* Copyright (c) 1999
* HAYAKAWA Koichi. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* This file defines the rbus (pseudo) class
*
* What is rbus?
*
* The rbus is a recursive bus-space administrator. This means a
* parent bus-space administrator, which usually belongs to a bus
* bridge, makes some child bus-space administrators and gives
* (restricted) bus-space to the children. There is a root bus-space
* administrator which maintains the whole bus-space.
*
* Why recursive?
*
* The recursive bus-space administration has two virtues. The
* former is this modelling matches the actual memory and io space
* management of bridge devices well. The latter is that the rbus is a
* distributed management system, so it matches well with a
* multi-thread kernel.
*
* Abstraction
*
* The rbus models bus-to-bus bridges into three types: dedicated, shared,
* and slave. Dedicated means that the bridge has dedicated bus space.
* Shared means that the bridge has bus space, but this bus space is
* shared with other bus bridges. Slave means a bus bridge which
* does not have it own bus space and asks a parent bus bridge for bus
* space when a client requests bus space from the bridge.
*/
/*
* General rule
*
* 1) When a rbustag has no space for child (it means rb_extent is
* NULL), ask bus-space for parent through rb_parent.
*
* 2) When a rbustag has its own space (whether shared or dedicated),
* allocate from rb_ext.
*/
struct rbustag {
bus_space_tag_t rb_bt;
struct rbustag *rb_parent;
struct extent *rb_ext;
bus_addr_t rb_start;
bus_addr_t rb_end;
bus_addr_t rb_offset;
#if notyet
int (*rb_space_alloc)(struct rbustag *, bus_addr_t, bus_addr_t,
bus_addr_t, bus_size_t, bus_addr_t, bus_addr_t,
int, bus_addr_t *, bus_space_handle_t *);
int (*rbus_space_free)(struct rbustag *, bus_space_handle_t,
bus_size_t, bus_addr_t *);
#endif
int rb_flags;
#define RBUS_SPACE_INVALID 0x00
#define RBUS_SPACE_SHARE 0x01
#define RBUS_SPACE_DEDICATE 0x02
#define RBUS_SPACE_MASK 0x03
#define RBUS_SPACE_ASK_PARENT 0x04
/* your own data below */
void *rb_md;
};
typedef struct rbustag *rbus_tag_t;
/*
* These functions sugarcoat rbus interface to make rbus being used
* easier. These functions should be member functions of rbus
* `class'.
*/
int rbus_space_alloc(rbus_tag_t, bus_addr_t, bus_size_t, bus_addr_t,
bus_addr_t, int, bus_addr_t *, bus_space_handle_t *);
int rbus_space_free(rbus_tag_t, bus_space_handle_t, bus_size_t,
bus_addr_t *);
/*
* These functions create rbus instance. These functions are
* so-called-as a constructor of rbus.
*
* rbus_new is a constructor which make an rbus instance from a parent
* rbus.
*/
rbus_tag_t rbus_new(rbus_tag_t, bus_addr_t, bus_size_t, bus_addr_t, int);
