1 /* $NetBSD: alloc.c,v 1.3 2002/09/20 03:20:24 wrstuden 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 unsigned bestsize = 0xffffffff; /* greater than any real size */ 134 char *help; 135 int failed; 136 137 #ifdef ALLOC_TRACE 138 printf("alloc(%u)", size); 139 #endif 140 141 /* 142 * Account for overhead now, so that we don't get an 143 * "exact fit" which doesn't have enough space. 144 */ 145 size = ALIGN(size) + OVERHEAD; 146 147 #ifdef ALLOC_FIRST_FIT 148 /* scan freelist */ 149 for (f = freelist.lh_first; f != NULL && f->size < size; 150 f = f->list.le_next) 151 /* noop */ ; 152 bestf = f; 153 failed = (bestf == (struct fl *)0); 154 #else 155 /* scan freelist */ 156 f = freelist.lh_first; 157 while (f != NULL) { 158 if (f->size >= size) { 159 if (f->size == size) /* exact match */ 160 goto found; 161 162 if (f->size < bestsize) { 163 /* keep best fit */ 164 bestf = f; 165 bestsize = f->size; 166 } 167 } 168 f = f->list.le_next; 169 } 170 171 /* no match in freelist if bestsize unchanged */ 172 failed = (bestsize == 0xffffffff); 173 #endif 174 175 if (failed) { /* nothing found */ 176 /* 177 * Allocate memory from the OpenFirmware, rounded 178 * to page size, and record the chunk size. 179 */ 180 size = roundup(size, NBPG); 181 help = OF_claim(0, size, NBPG); 182 if (help == (char *)-1) 183 panic("alloc: out of memory"); 184 185 f = (struct ml *)help; 186 f->size = size; 187 #ifdef ALLOC_TRACE 188 printf("=%lx (new chunk size %u)\n", 189 (u_long)(help + OVERHEAD), f->f_size); 190 #endif 191 goto out; 192 } 193 194 /* we take the best fit */ 195 f = bestf; 196 197 found: 198 /* remove from freelist */ 199 LIST_REMOVE(f, list); 200 help = (char *)f; 201 #ifdef ALLOC_TRACE 202 printf("=%lx (origsize %u)\n", (u_long)(help + OVERHEAD), f->size); 203 #endif 204 out: 205 /* place on allocated list */ 206 LIST_INSERT_HEAD(&allocatedlist, f, list); 207 return (help + OVERHEAD); 208 } 209 210 void 211 free(ptr, size) 212 void *ptr; 213 unsigned size; /* only for consistenct check */ 214 { 215 register struct ml *a = (struct ml *)((char*)ptr - OVERHEAD); 216 217 #ifdef ALLOC_TRACE 218 printf("free(%lx, %u) (origsize %u)\n", (u_long)ptr, size, a->size); 219 #endif 220 #ifdef DEBUG 221 if (size > a->size) 222 printf("free %u bytes @%lx, should be <=%u\n", 223 size, (u_long)ptr, a->size); 224 #endif 225 226 /* Remove from allocated list, place on freelist. */ 227 LIST_REMOVE(a, list); 228 LIST_INSERT_HEAD(&freelist, a, list); 229 } 230 231 void 232 freeall() 233 { 234 #ifdef __notyet__ /* Firmware bug ?! */ 235 struct ml *m; 236 237 /* Release chunks on freelist... */ 238 while ((m = freelist.lh_first) != NULL) { 239 LIST_REMOVE(m, list); 240 OF_release(m, m->size); 241 } 242 243 /* ...and allocated list. */ 244 while ((m = allocatedlist.lh_first) != NULL) { 245 LIST_REMOVE(m, list); 246 OF_release(m, m->size); 247 } 248 #endif /* __notyet__ */ 249 } 250