Annotation of sys/arch/macppc/stand/alloc.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: alloc.c,v 1.5 2007/05/28 22:17:21 pyr Exp $ */
2: /* $NetBSD: alloc.c,v 1.1 1997/04/16 20:29:16 thorpej Exp $ */
3:
4: /*
5: * Copyright (c) 1997 Jason R. Thorpe. All rights reserved.
6: * Copyright (c) 1997 Christopher G. Demetriou. All rights reserved.
7: * Copyright (c) 1996
8: * Matthias Drochner. All rights reserved.
9: * Copyright (C) 1995, 1996 Wolfgang Solfrank.
10: * Copyright (C) 1995, 1996 TooLs GmbH.
11: * All rights reserved.
12: *
13: * Redistribution and use in source and binary forms, with or without
14: * modification, are permitted provided that the following conditions
15: * are met:
16: * 1. Redistributions of source code must retain the above copyright
17: * notice, this list of conditions and the following disclaimer.
18: * 2. Redistributions in binary form must reproduce the above copyright
19: * notice, this list of conditions and the following disclaimer in the
20: * documentation and/or other materials provided with the distribution.
21: * 3. All advertising materials mentioning features or use of this software
22: * must display the following acknowledgement:
23: * This product includes software developed by TooLs GmbH.
24: * 4. The name of TooLs GmbH may not be used to endorse or promote products
25: * derived from this software without specific prior written permission.
26: *
27: * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
28: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
29: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
30: * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
31: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
32: * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
33: * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
34: * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
35: * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
36: * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37: */
38:
39: /*
40: * Dynamic memory allocator suitable for use with OpenFirmware.
41: *
42: * Compile options:
43: *
44: * ALLOC_TRACE enable tracing of allocations/deallocations
45: *
46: * ALLOC_FIRST_FIT use a first-fit allocation algorithm, rather than
47: * the default best-fit algorithm.
48: *
49: * DEBUG enable debugging sanity checks.
50: */
51:
52: #include <sys/param.h>
53: #include <sys/queue.h>
54:
55: #include <lib/libsa/stand.h>
56:
57: #include <macppc/stand/openfirm.h>
58:
59: /*
60: * Each block actually has ALIGN(struct ml) + ALIGN(size) bytes allocated
61: * to it, as follows:
62: *
63: * 0 ... (sizeof(struct ml) - 1)
64: * allocated or unallocated: holds size of user-data part of block.
65: *
66: * sizeof(struct ml) ... (ALIGN(sizeof(struct ml)) - 1)
67: * allocated: unused
68: * unallocated: depends on packing of struct fl
69: *
70: * ALIGN(sizeof(struct ml)) ... (ALIGN(sizeof(struct ml)) +
71: * ALIGN(data size) - 1)
72: * allocated: user data
73: * unallocated: depends on packing of struct fl
74: *
75: * 'next' is only used when the block is unallocated (i.e. on the free list).
76: * However, note that ALIGN(sizeof(struct ml)) + ALIGN(data size) must
77: * be at least 'sizeof(struct fl)', so that blocks can be used as structures
78: * when on the free list.
79: */
80:
81: /*
82: * Memory lists.
83: */
84: struct ml {
85: unsigned size;
86: LIST_ENTRY(ml) list;
87: };
88:
89: /* XXX - this is from NetBSD */
90: #define LIST_HEAD_INITIALIZER(head) { NULL }
91:
92: LIST_HEAD(, ml) freelist = LIST_HEAD_INITIALIZER(freelist);
93: LIST_HEAD(, ml) allocatedlist = LIST_HEAD_INITIALIZER(allocatedlist);
94:
95: #define OVERHEAD ALIGN(sizeof (struct ml)) /* shorthand */
96:
97: void *
98: alloc(unsigned size)
99: {
100: struct ml *f, *bestf;
101: unsigned bestsize = 0xffffffff; /* greater than any real size */
102: char *help;
103: int failed;
104:
105: #ifdef ALLOC_TRACE
106: printf("alloc(%u)", size);
107: #endif
108:
109: /*
110: * Account for overhead now, so that we don't get an
111: * "exact fit" which doesn't have enough space.
112: */
113: size = ALIGN(size) + OVERHEAD;
114:
115: #ifdef ALLOC_FIRST_FIT
116: /* scan freelist */
117: LIST_FOREACH(f, &freelist, list)
118: if (f->size >= size)
119: break;
120: bestf = f;
121: failed = (bestf == (struct fl *)0);
122: #else
123: /* scan freelist */
124: LIST_FOREACH(f, &freelist, list) {
125: if (f->size >= size) {
126: if (f->size == size) /* exact match */
127: goto found;
128:
129: if (f->size < bestsize) {
130: /* keep best fit */
131: bestf = f;
132: bestsize = f->size;
133: }
134: }
135: }
136:
137: /* no match in freelist if bestsize unchanged */
138: failed = (bestsize == 0xffffffff);
139: #endif
140:
141: if (failed) { /* nothing found */
142: /*
143: * Allocate memory from the OpenFirmware, rounded
144: * to page size, and record the chunk size.
145: */
146: size = roundup(size, NBPG);
147: help = OF_claim(0, size, NBPG);
148: if (help == (char *)-1)
149: panic("alloc: out of memory");
150:
151: f = (struct ml *)help;
152: f->size = size;
153: #ifdef ALLOC_TRACE
154: printf("=%lx (new chunk size %u)\n",
155: (u_long)(help + OVERHEAD), f->size);
156: #endif
157: goto out;
158: }
159:
160: /* we take the best fit */
161: f = bestf;
162:
163: found:
164: /* remove from freelist */
165: LIST_REMOVE(f, list);
166: help = (char *)f;
167: #ifdef ALLOC_TRACE
168: printf("=%lx (origsize %u)\n", (u_long)(help + OVERHEAD), f->size);
169: #endif
170: out:
171: /* place on allocated list */
172: LIST_INSERT_HEAD(&allocatedlist, f, list);
173: return (help + OVERHEAD);
174: }
175:
176: void
177: free(void *ptr, unsigned size)
178: {
179: register struct ml *a = (struct ml *)((char *)ptr - OVERHEAD);
180:
181: #ifdef ALLOC_TRACE
182: printf("free(%lx, %u) (origsize %u)\n", (u_long)ptr, size, a->size);
183: #endif
184: #ifdef DEBUG
185: if (size > a->size)
186: printf("free %u bytes @%lx, should be <=%u\n",
187: size, (u_long)ptr, a->size);
188: #endif
189:
190: /* Remove from allocated list, place on freelist. */
191: LIST_REMOVE(a, list);
192: LIST_INSERT_HEAD(&freelist, a, list);
193: }
194:
195: void
196: freeall()
197: {
198: #ifdef __notyet__ /* Firmware bug ?! */
199: struct ml *m;
200:
201: /* Release chunks on freelist... */
202: while ((m = LIST_FIRST(&freelist)) != NULL) {
203: LIST_REMOVE(m, list);
204: OF_release(m, m->size);
205: }
206:
207: /* ...and allocated list. */
208: while ((m = LIST_FIRST(&allocated)) != NULL)) {
209: LIST_REMOVE(m, list);
210: OF_release(m, m->size);
211: }
212: #endif /* __notyet__ */
213: }
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