1 /* $NetBSD: alloc.c,v 1.10 2008/04/28 20:23:27 martin 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 86 /* 87 * Each block actually has ALIGN(struct ml) + ALIGN(size) bytes allocated 88 * to it, as follows: 89 * 90 * 0 ... (sizeof(struct ml) - 1) 91 * allocated or unallocated: holds size of user-data part of block. 92 * 93 * sizeof(struct ml) ... (ALIGN(sizeof(struct ml)) - 1) 94 * allocated: unused 95 * unallocated: depends on packing of struct fl 96 * 97 * ALIGN(sizeof(struct ml)) ... (ALIGN(sizeof(struct ml)) + 98 * ALIGN(data size) - 1) 99 * allocated: user data 100 * unallocated: depends on packing of struct fl 101 * 102 * 'next' is only used when the block is unallocated (i.e. on the free list). 103 * However, note that ALIGN(sizeof(struct ml)) + ALIGN(data size) must 104 * be at least 'sizeof(struct fl)', so that blocks can be used as structures 105 * when on the free list. 106 */ 107 108 /* 109 * Memory lists. 110 */ 111 struct ml { 112 unsigned size; 113 LIST_ENTRY(ml) list; 114 }; 115 116 LIST_HEAD(, ml) freelist = LIST_HEAD_INITIALIZER(freelist); 117 LIST_HEAD(, ml) allocatedlist = LIST_HEAD_INITIALIZER(allocatedlist); 118 119 #define OVERHEAD ALIGN(sizeof (struct ml)) /* shorthand */ 120 121 void * 122 alloc(size_t size) 123 { 124 struct ml *f, *bestf; 125 #ifndef ALLOC_FIRST_FIT 126 unsigned bestsize = 0xffffffff; /* greater than any real size */ 127 #endif 128 char *help; 129 int failed; 130 131 #ifdef ALLOC_TRACE 132 printf("alloc(%zu)", size); 133 #endif 134 135 /* 136 * Account for overhead now, so that we don't get an 137 * "exact fit" which doesn't have enough space. 138 */ 139 size = ALIGN(size) + OVERHEAD; 140 141 #ifdef ALLOC_FIRST_FIT 142 /* scan freelist */ 143 for (f = freelist.lh_first; f != NULL && (size_t)f->size < size; 144 f = f->list.le_next) 145 /* noop */ ; 146 bestf = f; 147 failed = (bestf == NULL); 148 #else 149 /* scan freelist */ 150 bestf = NULL; /* XXXGCC: -Wuninitialized */ 151 f = freelist.lh_first; 152 while (f != NULL) { 153 if ((size_t)f->size >= size) { 154 if ((size_t)f->size == size) /* exact match */ 155 goto found; 156 157 if (f->size < bestsize) { 158 /* keep best fit */ 159 bestf = f; 160 bestsize = f->size; 161 } 162 } 163 f = f->list.le_next; 164 } 165 166 /* no match in freelist if bestsize unchanged */ 167 failed = (bestsize == 0xffffffff); 168 #endif 169 170 if (failed) { /* nothing found */ 171 /* 172 * Allocate memory from the OpenFirmware, rounded 173 * to page size, and record the chunk size. 174 */ 175 size = roundup(size, NBPG); 176 help = OF_claim(NULL, (unsigned)size, NBPG); 177 if (help == (char *)-1) 178 panic("alloc: out of memory"); 179 180 f = (struct ml *)help; 181 f->size = (unsigned)size; 182 #ifdef ALLOC_TRACE 183 printf("=%lx (new chunk size %u)\n", 184 (u_long)(help + OVERHEAD), f->size); 185 #endif 186 goto out; 187 } 188 189 /* we take the best fit */ 190 f = bestf; 191 192 #ifndef ALLOC_FIRST_FIT 193 found: 194 #endif 195 /* remove from freelist */ 196 LIST_REMOVE(f, list); 197 help = (char *)f; 198 #ifdef ALLOC_TRACE 199 printf("=%lx (origsize %u)\n", (u_long)(help + OVERHEAD), f->size); 200 #endif 201 out: 202 /* place on allocated list */ 203 LIST_INSERT_HEAD(&allocatedlist, f, list); 204 return (help + OVERHEAD); 205 } 206 207 void 208 dealloc(void *ptr, size_t size) 209 { 210 register struct ml *a = (struct ml *)((char*)ptr - OVERHEAD); 211 212 #ifdef ALLOC_TRACE 213 printf("dealloc(%lx, %zu) (origsize %u)\n", (u_long)ptr, size, a->size); 214 #endif 215 #ifdef DEBUG 216 if (size > (size_t)a->size) 217 printf("dealloc %zu bytes @%lx, should be <=%u\n", 218 size, (u_long)ptr, a->size); 219 #endif 220 221 /* Remove from allocated list, place on freelist. */ 222 LIST_REMOVE(a, list); 223 LIST_INSERT_HEAD(&freelist, a, list); 224 } 225 226 void 227 freeall(void) 228 { 229 #ifdef __notyet__ 230 struct ml *m; 231 232 /* Release chunks on freelist... */ 233 while ((m = freelist.lh_first) != NULL) { 234 LIST_REMOVE(m, list); 235 OF_release(m, m->size); 236 } 237 238 /* ...and allocated list. */ 239 while ((m = allocatedlist.lh_first) != NULL) { 240 LIST_REMOVE(m, list); 241 OF_release(m, m->size); 242 } 243 #endif /* __notyet__ */ 244 } 245