1/*
2 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
3 *
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27 */
28/*
29 * @OSF_COPYRIGHT@
30 */
31/*
32 * Mach Operating System
33 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
34 * All Rights Reserved.
35 *
36 * Permission to use, copy, modify and distribute this software and its
37 * documentation is hereby granted, provided that both the copyright
38 * notice and this permission notice appear in all copies of the
39 * software, derivative works or modified versions, and any portions
40 * thereof, and that both notices appear in supporting documentation.
41 *
42 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
43 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
44 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
45 *
46 * Carnegie Mellon requests users of this software to return to
47 *
48 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
49 *  School of Computer Science
50 *  Carnegie Mellon University
51 *  Pittsburgh PA 15213-3890
52 *
53 * any improvements or extensions that they make and grant Carnegie Mellon
54 * the rights to redistribute these changes.
55 */
56/*
57 */
58/*
59 *	File:	ipc/ipc_table.h
60 *	Author:	Rich Draves
61 *	Date:	1989
62 *
63 *	Definitions for tables, used for IPC capabilities (ipc_entry_t)
64 *	and dead-name requests (ipc_port_request_t).
65 */
66
67#ifndef	_IPC_IPC_TABLE_H_
68#define	_IPC_IPC_TABLE_H_
69
70#include <mach/mach_types.h>
71#include <mach/boolean.h>
72#include <mach/vm_param.h>
73
74#include <ipc/ipc_types.h>
75
76/*
77 *	The is_table_next field of an ipc_space_t points to
78 *	an ipc_table_size structure.  These structures must
79 *	be elements of an array, ipc_table_entries.
80 *
81 *	The array must end with two elements with the same its_size value.
82 *	Except for the terminating element, the its_size values must
83 *	be strictly increasing.  The largest (last) its_size value
84 *	must be less than or equal to MACH_PORT_INDEX(MACH_PORT_DEAD).
85 *	This ensures that
86 *		1) MACH_PORT_INDEX(MACH_PORT_DEAD) isn't a valid index
87 *		in the table, so ipc_entry_get won't allocate it.
88 *		2) MACH_PORT_MAKE(index+1, 0) and MAKE_PORT_MAKE(size, 0)
89 *		won't ever overflow.
90 *
91 *
92 *	The ipr_size field of the first element in a table of
93 *	dead-name requests (ipc_port_request_t) points to the
94 *	ipc_table_size structure.  The structures must be elements
95 *	of ipc_table_dnrequests.  ipc_table_dnrequests must end
96 *	with an element with zero its_size, and except for this last
97 *	element, the its_size values must be strictly increasing.
98 *
99 *	The is_table_next field points to the ipc_table_size structure
100 *	for the next larger size of table, not the one currently in use.
101 *	The ipr_size field points to the currently used ipc_table_size.
102 */
103
104struct ipc_table_size {
105	ipc_table_elems_t its_size;	/* number of elements in table */
106};
107
108extern ipc_table_size_t ipc_table_entries;
109extern ipc_table_size_t ipc_table_dnrequests;
110
111/* Initialize IPC capabilities table storage */
112extern void ipc_table_init(void) __attribute__((section("__TEXT, initcode")));
113
114/*
115 *	Note that ipc_table_alloc, ipc_table_realloc, and ipc_table_free
116 *	all potentially use the VM system.  Hence simple locks can't
117 *	be held across them.
118 *
119 *	We can't use a copying realloc, because the realloc happens
120 *	with the data unlocked.  ipc_table_realloc remaps the data,
121 *	so it is OK.
122 */
123
124/* Allocate a table */
125extern void * ipc_table_alloc(
126	vm_size_t	size);
127
128/* Reallocate a big table */
129extern void * ipc_table_realloc(
130	vm_size_t	old_size,
131	void *		old_table,
132	vm_size_t	new_size);
133
134/* Free a table */
135extern void ipc_table_free(
136	vm_size_t	size,
137	void *		table);
138
139#define it_entries_reallocable(its)					\
140	((its)->its_size * sizeof(struct ipc_entry) >= PAGE_SIZE)
141
142#define	it_entries_alloc(its)						\
143	((ipc_entry_t)							\
144	ipc_table_alloc(it_entries_reallocable(its) ?			\
145	    round_page((its)->its_size * sizeof(struct ipc_entry)) :	\
146	    (its)->its_size * sizeof(struct ipc_entry)			\
147	))
148
149#define	it_entries_realloc(its, table, nits)				\
150	((ipc_entry_t)							\
151	ipc_table_realloc(						\
152	    round_page((its)->its_size * sizeof(struct ipc_entry)),	\
153	    (void *)(table),					\
154	    round_page((nits)->its_size * sizeof(struct ipc_entry))	\
155	))
156
157#define	it_entries_free(its, table)					\
158	ipc_table_free(it_entries_reallocable(its) ?			\
159	    round_page((its)->its_size * sizeof(struct ipc_entry)) :	\
160	    (its)->its_size * sizeof(struct ipc_entry),			\
161	    (void *)(table)					\
162	)
163
164#define	it_dnrequests_alloc(its)					\
165	((ipc_port_request_t)						\
166	 ipc_table_alloc((its)->its_size *				\
167			 sizeof(struct ipc_port_request)))
168
169#define	it_dnrequests_free(its, table)					\
170	ipc_table_free((its)->its_size *				\
171		       sizeof(struct ipc_port_request),			\
172		       (void *)(table))
173
174#endif	/* _IPC_IPC_TABLE_H_ */
175