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/* $OpenBSD: alloc.c,v 1.6 2008/05/25 16:55:31 miod Exp $ */
/* $NetBSD: alloc.c,v 1.1 1997/04/16 20:29:16 thorpej Exp $ */
/*
* Copyright (c) 1997 Jason R. Thorpe. All rights reserved.
* Copyright (c) 1997 Christopher G. Demetriou. All rights reserved.
* Copyright (c) 1996
* Matthias Drochner. All rights reserved.
* Copyright (C) 1995, 1996 Wolfgang Solfrank.
* Copyright (C) 1995, 1996 TooLs GmbH.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Dynamic memory allocator suitable for use with OpenFirmware.
*
* Compile options:
*
* ALLOC_TRACE enable tracing of allocations/deallocations
*
* ALLOC_FIRST_FIT use a first-fit allocation algorithm, rather than
* the default best-fit algorithm.
*
* DEBUG enable debugging sanity checks.
*/
#include <sys/param.h>
#include <sys/queue.h>
#include <lib/libsa/stand.h>
#include <macppc/stand/openfirm.h>
/*
* Each block actually has ALIGN(struct ml) + ALIGN(size) bytes allocated
* to it, as follows:
*
* 0 ... (sizeof(struct ml) - 1)
* allocated or unallocated: holds size of user-data part of block.
*
* sizeof(struct ml) ... (ALIGN(sizeof(struct ml)) - 1)
* allocated: unused
* unallocated: depends on packing of struct fl
*
* ALIGN(sizeof(struct ml)) ... (ALIGN(sizeof(struct ml)) +
* ALIGN(data size) - 1)
* allocated: user data
* unallocated: depends on packing of struct fl
*
* 'next' is only used when the block is unallocated (i.e. on the free list).
* However, note that ALIGN(sizeof(struct ml)) + ALIGN(data size) must
* be at least 'sizeof(struct fl)', so that blocks can be used as structures
* when on the free list.
*/
/*
* Memory lists.
*/
struct ml {
unsigned size;
LIST_ENTRY(ml) list;
};
LIST_HEAD(, ml) freelist = LIST_HEAD_INITIALIZER(freelist);
LIST_HEAD(, ml) allocatedlist = LIST_HEAD_INITIALIZER(allocatedlist);
#define OVERHEAD ALIGN(sizeof (struct ml)) /* shorthand */
void *
alloc(unsigned size)
{
struct ml *f, *bestf = NULL;
unsigned bestsize = 0xffffffff; /* greater than any real size */
char *help;
int failed;
#ifdef ALLOC_TRACE
printf("alloc(%u)", size);
#endif
/*
* Account for overhead now, so that we don't get an
* "exact fit" which doesn't have enough space.
*/
size = ALIGN(size) + OVERHEAD;
#ifdef ALLOC_FIRST_FIT
/* scan freelist */
LIST_FOREACH(f, &freelist, list)
if (f->size >= size)
break;
bestf = f;
failed = (bestf == (struct fl *)0);
#else
/* scan freelist */
LIST_FOREACH(f, &freelist, list) {
if (f->size >= size) {
if (f->size == size) /* exact match */
goto found;
if (f->size < bestsize) {
/* keep best fit */
bestf = f;
bestsize = f->size;
}
}
}
/* no match in freelist if bestsize unchanged */
failed = (bestsize == 0xffffffff);
#endif
if (failed) { /* nothing found */
/*
* Allocate memory from the OpenFirmware, rounded
* to page size, and record the chunk size.
*/
size = roundup(size, NBPG);
help = OF_claim(0, size, NBPG);
if (help == (char *)-1)
panic("alloc: out of memory");
f = (struct ml *)help;
f->size = size;
#ifdef ALLOC_TRACE
printf("=%lx (new chunk size %u)\n",
(u_long)(help + OVERHEAD), f->size);
#endif
goto out;
}
/* we take the best fit */
f = bestf;
found:
/* remove from freelist */
LIST_REMOVE(f, list);
help = (char *)f;
#ifdef ALLOC_TRACE
printf("=%lx (origsize %u)\n", (u_long)(help + OVERHEAD), f->size);
#endif
out:
/* place on allocated list */
LIST_INSERT_HEAD(&allocatedlist, f, list);
return (help + OVERHEAD);
}
void
free(void *ptr, unsigned size)
{
register struct ml *a = (struct ml *)((char *)ptr - OVERHEAD);
#ifdef ALLOC_TRACE
printf("free(%lx, %u) (origsize %u)\n", (u_long)ptr, size, a->size);
#endif
#ifdef DEBUG
if (size > a->size)
printf("free %u bytes @%lx, should be <=%u\n",
size, (u_long)ptr, a->size);
#endif
/* Remove from allocated list, place on freelist. */
LIST_REMOVE(a, list);
LIST_INSERT_HEAD(&freelist, a, list);
}
void
freeall()
{
#ifdef __notyet__ /* Firmware bug ?! */
struct ml *m;
/* Release chunks on freelist... */
while ((m = LIST_FIRST(&freelist)) != NULL) {
LIST_REMOVE(m, list);
OF_release(m, m->size);
}
/* ...and allocated list. */
while ((m = LIST_FIRST(&allocated)) != NULL)) {
LIST_REMOVE(m, list);
OF_release(m, m->size);
}
#endif /* __notyet__ */
}
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