1 /* $NetBSD: alloc.c,v 1.5 2011/05/19 03:09:47 christos Exp $ */
2
3 /*-
4 * Copyright (c) 1997 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 /*
33 * Copyright (c) 1997 Christopher G. Demetriou. All rights reserved.
34 * Copyright (c) 1996
35 * Matthias Drochner. All rights reserved.
36 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
37 * Copyright (C) 1995, 1996 TooLs GmbH.
38 * All rights reserved.
39 *
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
42 * are met:
43 * 1. Redistributions of source code must retain the above copyright
44 * notice, this list of conditions and the following disclaimer.
45 * 2. Redistributions in binary form must reproduce the above copyright
46 * notice, this list of conditions and the following disclaimer in the
47 * documentation and/or other materials provided with the distribution.
48 * 3. All advertising materials mentioning features or use of this software
49 * must display the following acknowledgement:
50 * This product includes software developed by TooLs GmbH.
51 * 4. The name of TooLs GmbH may not be used to endorse or promote products
52 * derived from this software without specific prior written permission.
53 *
54 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
55 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
56 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
57 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
58 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
59 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
60 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
61 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
62 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
63 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
64 */
65
66 /*
67 * Dynamic memory allocator suitable for use with OpenFirmware.
68 *
69 * Compile options:
70 *
71 * ALLOC_TRACE enable tracing of allocations/deallocations
72 *
73 * ALLOC_FIRST_FIT use a first-fit allocation algorithm, rather than
74 * the default best-fit algorithm.
75 *
76 * DEBUG enable debugging sanity checks.
77 */
78
79 #include <sys/param.h>
80 #include <sys/queue.h>
81
82 #include <lib/libsa/stand.h>
83
84 #include "openfirm.h"
85 #include "boot.h"
86
87 /*
88 * Each block actually has ALIGN(struct ml) + ALIGN(size) bytes allocated
89 * to it, as follows:
90 *
91 * 0 ... (sizeof(struct ml) - 1)
92 * allocated or unallocated: holds size of user-data part of block.
93 *
94 * sizeof(struct ml) ... (ALIGN(sizeof(struct ml)) - 1)
95 * allocated: unused
96 * unallocated: depends on packing of struct fl
97 *
98 * ALIGN(sizeof(struct ml)) ... (ALIGN(sizeof(struct ml)) +
99 * ALIGN(data size) - 1)
100 * allocated: user data
101 * unallocated: depends on packing of struct fl
102 *
103 * 'next' is only used when the block is unallocated (i.e. on the free list).
104 * However, note that ALIGN(sizeof(struct ml)) + ALIGN(data size) must
105 * be at least 'sizeof(struct fl)', so that blocks can be used as structures
106 * when on the free list.
107 */
108
109 /*
110 * Memory lists.
111 */
112 struct ml {
113 unsigned size;
114 LIST_ENTRY(ml) list;
115 };
116
117 LIST_HEAD(, ml) freelist = LIST_HEAD_INITIALIZER(freelist);
118 LIST_HEAD(, ml) allocatedlist = LIST_HEAD_INITIALIZER(allocatedlist);
119
120 #define OVERHEAD ALIGN(sizeof (struct ml)) /* shorthand */
121
122 void *
alloc(size_t size)123 alloc(size_t size)
124 {
125 struct ml *f, *bestf;
126 #ifndef ALLOC_FIRST_FIT
127 unsigned bestsize = 0xffffffff; /* greater than any real size */
128 #endif
129 char *help;
130 int failed;
131
132 #ifdef ALLOC_TRACE
133 printf("alloc(%zu)", size);
134 #endif
135
136 /*
137 * Account for overhead now, so that we don't get an
138 * "exact fit" which doesn't have enough space.
139 */
140 size = ALIGN(size) + OVERHEAD;
141
142 #ifdef ALLOC_FIRST_FIT
143 /* scan freelist */
144 for (f = freelist.lh_first; f != NULL && (size_t)f->size < size;
145 f = f->list.le_next)
146 /* noop */ ;
147 bestf = f;
148 failed = (bestf == NULL);
149 #else
150 /* scan freelist */
151 bestf = NULL; /* XXXGCC: -Wuninitialized */
152 f = freelist.lh_first;
153 while (f != NULL) {
154 if ((size_t)f->size >= size) {
155 if ((size_t)f->size == size) /* exact match */
156 goto found;
157
158 if (f->size < bestsize) {
159 /* keep best fit */
160 bestf = f;
161 bestsize = f->size;
162 }
163 }
164 f = f->list.le_next;
165 }
166
167 /* no match in freelist if bestsize unchanged */
168 failed = (bestsize == 0xffffffff);
169 #endif
170
171 if (failed) { /* nothing found */
172 /*
173 * Allocate memory from the OpenFirmware, rounded
174 * to page size, and record the chunk size.
175 */
176 size = roundup(size, NBPG);
177 help = OF_claim(NULL, (unsigned)size, NBPG);
178 if (help == (char *)-1)
179 panic("alloc: out of memory");
180
181 f = (struct ml *)help;
182 f->size = (unsigned)size;
183 #ifdef ALLOC_TRACE
184 printf("=%lx (new chunk size %u)\n",
185 (u_long)(help + OVERHEAD), f->size);
186 #endif
187 goto out;
188 }
189
190 /* we take the best fit */
191 f = bestf;
192
193 #ifndef ALLOC_FIRST_FIT
194 found:
195 #endif
196 /* remove from freelist */
197 LIST_REMOVE(f, list);
198 help = (char *)f;
199 #ifdef ALLOC_TRACE
200 printf("=%lx (origsize %u)\n", (u_long)(help + OVERHEAD), f->size);
201 #endif
202 out:
203 /* place on allocated list */
204 LIST_INSERT_HEAD(&allocatedlist, f, list);
205 return (help + OVERHEAD);
206 }
207
208 void
dealloc(void * ptr,size_t size)209 dealloc(void *ptr, size_t size)
210 {
211 register struct ml *a = (struct ml *)((char*)ptr - OVERHEAD);
212
213 #ifdef ALLOC_TRACE
214 printf("dealloc(%lx, %zu) (origsize %u)\n", (u_long)ptr, size, a->size);
215 #endif
216 #ifdef DEBUG
217 if (size > (size_t)a->size)
218 printf("dealloc %zu bytes @%lx, should be <=%u\n",
219 size, (u_long)ptr, a->size);
220 #endif
221
222 /* Remove from allocated list, place on freelist. */
223 LIST_REMOVE(a, list);
224 LIST_INSERT_HEAD(&freelist, a, list);
225 }
226
227 void
freeall(void)228 freeall(void)
229 {
230 #ifdef __notyet__ /* Firmware bug ?! */
231 struct ml *m;
232
233 /* Release chunks on freelist... */
234 while ((m = freelist.lh_first) != NULL) {
235 LIST_REMOVE(m, list);
236 OF_release(m, m->size);
237 }
238
239 /* ...and allocated list. */
240 while ((m = allocatedlist.lh_first) != NULL) {
241 LIST_REMOVE(m, list);
242 OF_release(m, m->size);
243 }
244 #endif /* __notyet__ */
245 }
246