1 /* $NetBSD: alloc.c,v 1.1 2002/02/10 01:58:16 thorpej 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 /* 40 * Copyright (c) 1997 Christopher G. Demetriou. All rights reserved. 41 * Copyright (c) 1996 42 * Matthias Drochner. All rights reserved. 43 * Copyright (C) 1995, 1996 Wolfgang Solfrank. 44 * Copyright (C) 1995, 1996 TooLs GmbH. 45 * All rights reserved. 46 * 47 * Redistribution and use in source and binary forms, with or without 48 * modification, are permitted provided that the following conditions 49 * are met: 50 * 1. Redistributions of source code must retain the above copyright 51 * notice, this list of conditions and the following disclaimer. 52 * 2. Redistributions in binary form must reproduce the above copyright 53 * notice, this list of conditions and the following disclaimer in the 54 * documentation and/or other materials provided with the distribution. 55 * 3. All advertising materials mentioning features or use of this software 56 * must display the following acknowledgement: 57 * This product includes software developed by TooLs GmbH. 58 * 4. The name of TooLs GmbH may not be used to endorse or promote products 59 * derived from this software without specific prior written permission. 60 * 61 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 62 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 63 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 64 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 65 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 66 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 67 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 68 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 69 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 70 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 71 */ 72 73 /* 74 * Dynamic memory allocator suitable for use with OpenFirmware. 75 * 76 * Compile options: 77 * 78 * ALLOC_TRACE enable tracing of allocations/deallocations 79 * 80 * ALLOC_FIRST_FIT use a first-fit allocation algorithm, rather than 81 * the default best-fit algorithm. 82 * 83 * DEBUG enable debugging sanity checks. 84 */ 85 86 #include <sys/param.h> 87 #include <sys/queue.h> 88 89 #include <lib/libsa/stand.h> 90 91 #include "openfirm.h" 92 93 /* 94 * Each block actually has ALIGN(struct ml) + ALIGN(size) bytes allocated 95 * to it, as follows: 96 * 97 * 0 ... (sizeof(struct ml) - 1) 98 * allocated or unallocated: holds size of user-data part of block. 99 * 100 * sizeof(struct ml) ... (ALIGN(sizeof(struct ml)) - 1) 101 * allocated: unused 102 * unallocated: depends on packing of struct fl 103 * 104 * ALIGN(sizeof(struct ml)) ... (ALIGN(sizeof(struct ml)) + 105 * ALIGN(data size) - 1) 106 * allocated: user data 107 * unallocated: depends on packing of struct fl 108 * 109 * 'next' is only used when the block is unallocated (i.e. on the free list). 110 * However, note that ALIGN(sizeof(struct ml)) + ALIGN(data size) must 111 * be at least 'sizeof(struct fl)', so that blocks can be used as structures 112 * when on the free list. 113 */ 114 115 /* 116 * Memory lists. 117 */ 118 struct ml { 119 unsigned size; 120 LIST_ENTRY(ml) list; 121 }; 122 123 LIST_HEAD(, ml) freelist = LIST_HEAD_INITIALIZER(freelist); 124 LIST_HEAD(, ml) allocatedlist = LIST_HEAD_INITIALIZER(allocatedlist); 125 126 #define OVERHEAD ALIGN(sizeof (struct ml)) /* shorthand */ 127 128 void * 129 alloc(size) 130 unsigned size; 131 { 132 struct ml *f, *bestf; 133 #ifndef ALLOC_FIRST_FIT 134 unsigned bestsize = 0xffffffff; /* greater than any real size */ 135 #endif 136 char *help; 137 int failed; 138 139 #ifdef ALLOC_TRACE 140 printf("alloc(%u)", size); 141 #endif 142 143 /* 144 * Account for overhead now, so that we don't get an 145 * "exact fit" which doesn't have enough space. 146 */ 147 size = ALIGN(size) + OVERHEAD; 148 149 #ifdef ALLOC_FIRST_FIT 150 /* scan freelist */ 151 for (f = freelist.lh_first; f != NULL && f->size < size; 152 f = f->list.le_next) 153 /* noop */ ; 154 bestf = f; 155 failed = (bestf == (struct fl *)0); 156 #else 157 /* scan freelist */ 158 f = freelist.lh_first; 159 while (f != NULL) { 160 if (f->size >= size) { 161 if (f->size == size) /* exact match */ 162 goto found; 163 164 if (f->size < bestsize) { 165 /* keep best fit */ 166 bestf = f; 167 bestsize = f->size; 168 } 169 } 170 f = f->list.le_next; 171 } 172 173 /* no match in freelist if bestsize unchanged */ 174 failed = (bestsize == 0xffffffff); 175 #endif 176 177 if (failed) { /* nothing found */ 178 /* 179 * Allocate memory from the OpenFirmware, rounded 180 * to page size, and record the chunk size. 181 */ 182 size = roundup(size, NBPG); 183 help = OF_claim(NULL, size, NBPG); 184 if (help == (char *)-1) 185 panic("alloc: out of memory"); 186 187 f = (struct ml *)help; 188 f->size = size; 189 #ifdef ALLOC_TRACE 190 printf("=%lx (new chunk size %u)\n", 191 (u_long)(help + OVERHEAD), f->size); 192 #endif 193 goto out; 194 } 195 196 /* we take the best fit */ 197 f = bestf; 198 199 #ifndef ALLOC_FIRST_FIT 200 found: 201 #endif 202 /* remove from freelist */ 203 LIST_REMOVE(f, list); 204 help = (char *)f; 205 #ifdef ALLOC_TRACE 206 printf("=%lx (origsize %u)\n", (u_long)(help + OVERHEAD), f->size); 207 #endif 208 out: 209 /* place on allocated list */ 210 LIST_INSERT_HEAD(&allocatedlist, f, list); 211 return (help + OVERHEAD); 212 } 213 214 void 215 free(ptr, size) 216 void *ptr; 217 unsigned size; /* only for consistenct check */ 218 { 219 register struct ml *a = (struct ml *)((char*)ptr - OVERHEAD); 220 221 #ifdef ALLOC_TRACE 222 printf("free(%lx, %u) (origsize %u)\n", (u_long)ptr, size, a->size); 223 #endif 224 #ifdef DEBUG 225 if (size > a->size) 226 printf("free %u bytes @%lx, should be <=%u\n", 227 size, (u_long)ptr, a->size); 228 #endif 229 230 /* Remove from allocated list, place on freelist. */ 231 LIST_REMOVE(a, list); 232 LIST_INSERT_HEAD(&freelist, a, list); 233 } 234 235 void 236 freeall() 237 { 238 struct ml *m; 239 240 /* Release chunks on freelist... */ 241 while ((m = freelist.lh_first) != NULL) { 242 LIST_REMOVE(m, list); 243 OF_release(m, m->size); 244 } 245 246 /* ...and allocated list. */ 247 while ((m = allocatedlist.lh_first) != NULL) { 248 LIST_REMOVE(m, list); 249 OF_release(m, m->size); 250 } 251 } 252