summaryrefslogtreecommitdiff
path: root/ipc/ipc_table.c
blob: d5b790452cd00c9ae1cfbea76337ecb9c29105af (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990,1989 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 */
/*
 *	File:	ipc/ipc_table.c
 *	Author:	Rich Draves
 *	Date:	1989
 *
 *	Functions to manipulate tables of IPC capabilities.
 */

#include <mach/kern_return.h>
#include <mach/vm_param.h>
#include <ipc/ipc_table.h>
#include <ipc/ipc_port.h>
#include <ipc/ipc_entry.h>
#include <kern/kalloc.h>
#include <vm/vm_kern.h>

/*
 * Forward declarations
 */
void ipc_table_fill(
	ipc_table_size_t	its,
	unsigned int		num,
	unsigned int		min,
	vm_size_t		elemsize);

ipc_table_size_t ipc_table_entries;
unsigned int ipc_table_entries_size = 512;

ipc_table_size_t ipc_table_dnrequests;
unsigned int ipc_table_dnrequests_size = 64;

void
ipc_table_fill(
	ipc_table_size_t	its,	     /* array to fill */
	unsigned int		num,	     /* size of array */
	unsigned int		min,	     /* at least this many elements */
	vm_size_t		elemsize)    /* size of elements */
{
	unsigned int index;
	vm_size_t minsize = min * elemsize;
	vm_size_t size;
	vm_size_t incrsize;

	/* first use powers of two, up to the page size */

	for (index = 0, size = 1;
	     (index < num) && (size < PAGE_SIZE);
	     size <<= 1) {
		if (size >= minsize) {
			its[index].its_size = size / elemsize;
			index++;
		}
	}

	/* then increments of a page, then two pages, etc. */

	for (incrsize = PAGE_SIZE; index < num;) {
		unsigned int period;

		for (period = 0;
		     (period < 15) && (index < num);
		     period++, size += incrsize) {
			if (size >= minsize) {
				its[index].its_size = size / elemsize;
				index++;
			}
		}
		if (incrsize < (PAGE_SIZE << 3))
			incrsize <<= 1;
	}
}

void
ipc_table_init(void)
{
	ipc_table_entries = (ipc_table_size_t)
		kalloc(sizeof(struct ipc_table_size) *
		       ipc_table_entries_size);
	assert(ipc_table_entries != ITS_NULL);

	ipc_table_fill(ipc_table_entries, ipc_table_entries_size - 1,
		       4, sizeof(struct ipc_entry));

	/* the last two elements should have the same size */

	ipc_table_entries[ipc_table_entries_size - 1].its_size =
		ipc_table_entries[ipc_table_entries_size - 2].its_size;


	ipc_table_dnrequests = (ipc_table_size_t)
		kalloc(sizeof(struct ipc_table_size) *
		       ipc_table_dnrequests_size);
	assert(ipc_table_dnrequests != ITS_NULL);

	ipc_table_fill(ipc_table_dnrequests, ipc_table_dnrequests_size - 1,
		       2, sizeof(struct ipc_port_request));

	/* the last element should have zero size */

	ipc_table_dnrequests[ipc_table_dnrequests_size - 1].its_size = 0;
}

/*
 *	Routine:	ipc_table_alloc
 *	Purpose:
 *		Allocate a table.
 *	Conditions:
 *		May block.
 */

vm_offset_t
ipc_table_alloc(
	vm_size_t	size)
{
	vm_offset_t table;

	if (size < PAGE_SIZE)
		table = kalloc(size);
	else
		if (kmem_alloc(kalloc_map, &table, size) != KERN_SUCCESS)
			table = 0;

	return table;
}

/*
 *	Routine:	ipc_table_realloc
 *	Purpose:
 *		Reallocate a big table.
 *
 *		The new table remaps the old table,
 *		so copying is not necessary.
 *	Conditions:
 *		Only works for page-size or bigger tables.
 *		May block.
 */

vm_offset_t
ipc_table_realloc(
	vm_size_t	old_size,
	vm_offset_t	old_table,
	vm_size_t	new_size)
{
	vm_offset_t new_table;

	if (kmem_realloc(kalloc_map, old_table, old_size,
			 &new_table, new_size) != KERN_SUCCESS)
		new_table = 0;

	return new_table;
}

/*
 *	Routine:	ipc_table_free
 *	Purpose:
 *		Free a table allocated with ipc_table_alloc or
 *		ipc_table_realloc.
 *	Conditions:
 *		May block.
 */

void
ipc_table_free(
	vm_size_t	size,
	vm_offset_t	table)
{
	if (size < PAGE_SIZE)
		kfree(table, size);
	else
		kmem_free(kalloc_map, table, size);
}