1/*
2 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
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8 * Version 2.0 (the 'License'). You may not use this file except in
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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.c
60 *	Author:	Rich Draves
61 *	Date:	1989
62 *
63 *	Functions to manipulate tables of IPC capabilities.
64 */
65
66#include <mach/kern_return.h>
67#include <mach/vm_param.h>
68#include <ipc/ipc_table.h>
69#include <ipc/ipc_port.h>
70#include <ipc/ipc_entry.h>
71#include <kern/kalloc.h>
72#include <vm/vm_kern.h>
73
74/*
75 * Forward declarations
76 */
77void ipc_table_fill(
78	ipc_table_size_t	its,
79	unsigned int		num,
80	unsigned int		min,
81	vm_size_t		elemsize);
82
83/*
84 *	We borrow the kalloc map, rather than creating
85 *	yet another submap of the kernel map.
86 */
87
88extern vm_map_t kalloc_map;
89
90ipc_table_size_t ipc_table_entries;
91unsigned int ipc_table_entries_size = 512;
92
93ipc_table_size_t ipc_table_requests;
94unsigned int ipc_table_requests_size = 64;
95
96void
97ipc_table_fill(
98	ipc_table_size_t	its,	     /* array to fill */
99	unsigned int		num,	     /* size of array */
100	unsigned int		min,	     /* at least this many elements */
101	vm_size_t		elemsize)    /* size of elements */
102{
103	unsigned int index;
104	vm_size_t minsize = min * elemsize;
105	vm_size_t size;
106	vm_size_t incrsize;
107
108	/* first use powers of two, up to the page size */
109
110	for (index = 0, size = 1;
111	     (index < num) && (size < PAGE_SIZE);
112	     size <<= 1) {
113		if (size >= minsize) {
114			its[index].its_size = (ipc_table_elems_t)(size / elemsize);
115			index++;
116		}
117	}
118
119	/* then increments of a page, then two pages, etc. */
120
121	for (incrsize = PAGE_SIZE; index < num;) {
122		unsigned int period;
123
124		for (period = 0;
125		     (period < 15) && (index < num);
126		     period++, size += incrsize) {
127			if (size >= minsize) {
128				its[index].its_size = (ipc_table_elems_t)(size / elemsize);
129				index++;
130			}
131		}
132		if (incrsize < (PAGE_SIZE << 3))
133			incrsize <<= 1;
134	}
135}
136
137void
138ipc_table_init(void)
139{
140	ipc_table_entries = (ipc_table_size_t)
141		kalloc(sizeof(struct ipc_table_size) *
142		       ipc_table_entries_size);
143	assert(ipc_table_entries != ITS_NULL);
144
145	ipc_table_fill(ipc_table_entries, ipc_table_entries_size - 1,
146		       16, sizeof(struct ipc_entry));
147
148	/* the last two elements should have the same size */
149
150	ipc_table_entries[ipc_table_entries_size - 1].its_size =
151		ipc_table_entries[ipc_table_entries_size - 2].its_size;
152
153
154	ipc_table_requests = (ipc_table_size_t)
155		kalloc(sizeof(struct ipc_table_size) *
156		       ipc_table_requests_size);
157	assert(ipc_table_requests != ITS_NULL);
158
159	ipc_table_fill(ipc_table_requests, ipc_table_requests_size - 1,
160		       2, sizeof(struct ipc_port_request));
161
162	/* the last element should have zero size */
163
164	ipc_table_requests[ipc_table_requests_size - 1].its_size = 0;
165}
166
167/*
168 *	Routine:	ipc_table_alloc
169 *	Purpose:
170 *		Allocate a table.
171 *	Conditions:
172 *		May block.
173 */
174
175void *
176ipc_table_alloc(
177	vm_size_t	size)
178{
179	vm_offset_t table;
180
181	if (size < PAGE_SIZE)
182		return kalloc(size);
183
184	if (kmem_alloc(kalloc_map, &table, size) != KERN_SUCCESS)
185		table = 0;
186
187	return (void *)table;
188}
189
190
191/*
192 *	Routine:	ipc_table_free
193 *	Purpose:
194 *		Free a table allocated with ipc_table_alloc or
195 *		ipc_table_realloc.
196 *	Conditions:
197 *		May block.
198 */
199
200void
201ipc_table_free(
202	vm_size_t	size,
203	void *		table)
204{
205	if (size < PAGE_SIZE)
206		kfree(table, size);
207	else
208		kmem_free(kalloc_map, (vm_offset_t)table, size);
209}
210