1/* $NetBSD: alloc.c,v 1.6 2006/01/27 02:26:16 uwe 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 "extern.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 */ 112struct ml { 113 unsigned size; 114 LIST_ENTRY(ml) list; 115}; 116 117LIST_HEAD(, ml) freelist = LIST_HEAD_INITIALIZER(freelist); 118LIST_HEAD(, ml) allocatedlist = LIST_HEAD_INITIALIZER(allocatedlist); 119 120#define OVERHEAD ALIGN(sizeof (struct ml)) /* shorthand */ 121 122void * 123alloc(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 208void 209dealloc(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 227void 228freeall(void) 229{ 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} 244