coreboot-kgpe-d16/payloads/libpayload/libc/malloc.c
Stefan Reinauer 14e2277962 Since some people disapprove of white space cleanups mixed in regular commits
while others dislike them being extra commits, let's clean them up once and
for all for the existing code. If it's ugly, let it only be ugly once :-)

Signed-off-by: Stefan Reinauer <stepan@coresystems.de>
Acked-by: Stefan Reinauer <stepan@coresystems.de>



git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5507 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
2010-04-27 06:56:47 +00:00

431 lines
10 KiB
C

/*
* This file is part of the libpayload project.
*
* Copyright (C) 2008 Advanced Micro Devices, Inc.
* Copyright (C) 2008-2010 coresystems GmbH
*
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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.
*/
/*
* This is a classically weak malloc() implementation. We have a relatively
* small and static heap, so we take the easy route with an O(N) loop
* through the tree for every malloc() and free(). Obviously, this doesn't
* scale past a few hundred KB (if that).
*
* We're also susceptible to the usual buffer overrun poisoning, though the
* risk is within acceptable ranges for this implementation (don't overrun
* your buffers, kids!).
*/
#define IN_MALLOC_C
#include <libpayload.h>
extern char _heap, _eheap; /* Defined in the ldscript. */
static void *hstart = (void *)&_heap;
static void *hend = (void *)&_eheap;
typedef unsigned int hdrtype_t;
#define MAGIC (0x2a << 26)
#define FLAG_FREE (1 << 25)
#define FLAG_USED (1 << 24)
#define SIZE(_h) ((_h) & 0xFFFFFF)
#define _HEADER(_s, _f) ((hdrtype_t) (MAGIC | (_f) | ((_s) & 0xFFFFFF)))
#define FREE_BLOCK(_s) _HEADER(_s, FLAG_FREE)
#define USED_BLOCK(_s) _HEADER(_s, FLAG_USED)
#define HDRSIZE (sizeof(hdrtype_t))
#define IS_FREE(_h) (((_h) & (MAGIC | FLAG_FREE)) == (MAGIC | FLAG_FREE))
#define HAS_MAGIC(_h) (((_h) & MAGIC) == MAGIC)
static int free_aligned(void* addr);
void print_malloc_map(void);
#ifdef CONFIG_DEBUG_MALLOC
static int heap_initialized = 0;
static int minimal_free = 0;
#endif
static void setup(void)
{
int size = (unsigned int)(&_eheap - &_heap) - HDRSIZE;
*((hdrtype_t *) hstart) = FREE_BLOCK(size);
#ifdef CONFIG_DEBUG_MALLOC
heap_initialized = 1;
minimal_free = size;
#endif
}
static void *alloc(int len)
{
hdrtype_t header;
void *ptr = hstart;
/* Align the size. */
len = (len + 3) & ~3;
if (!len || len > 0xffffff)
return (void *)NULL;
/* Make sure the region is setup correctly. */
if (!HAS_MAGIC(*((hdrtype_t *) ptr)))
setup();
/* Find some free space. */
do {
header = *((hdrtype_t *) ptr);
int size = SIZE(header);
if (!HAS_MAGIC(header) || size == 0) {
printf("memory allocator panic. (%s%s)\n",
!HAS_MAGIC(header) ? " no magic " : "",
size == 0 ? " size=0 " : "");
halt();
}
if (header & FLAG_FREE) {
if (len <= size) {
void *nptr = ptr + (HDRSIZE + len);
int nsize = size - (HDRSIZE + len);
/* If there is still room in this block,
* then mark it as such otherwise account
* the whole space for that block.
*/
if (nsize > 0) {
/* Mark the block as used. */
*((hdrtype_t *) ptr) = USED_BLOCK(len);
/* Create a new free block. */
*((hdrtype_t *) nptr) =
FREE_BLOCK(nsize);
} else {
/* Mark the block as used. */
*((hdrtype_t *) ptr) = USED_BLOCK(size);
}
return (void *)(ptr + HDRSIZE);
}
}
ptr += HDRSIZE + size;
} while (ptr < hend);
/* Nothing available. */
return (void *)NULL;
}
static void _consolidate(void)
{
void *ptr = hstart;
while (ptr < hend) {
void *nptr;
hdrtype_t hdr = *((hdrtype_t *) ptr);
unsigned int size = 0;
if (!IS_FREE(hdr)) {
ptr += HDRSIZE + SIZE(hdr);
continue;
}
size = SIZE(hdr);
nptr = ptr + HDRSIZE + SIZE(hdr);
while (nptr < hend) {
hdrtype_t nhdr = *((hdrtype_t *) nptr);
if (!(IS_FREE(nhdr)))
break;
size += SIZE(nhdr) + HDRSIZE;
*((hdrtype_t *) nptr) = 0;
nptr += (HDRSIZE + SIZE(nhdr));
}
*((hdrtype_t *) ptr) = FREE_BLOCK(size);
ptr = nptr;
}
}
void free(void *ptr)
{
hdrtype_t hdr;
if (free_aligned(ptr)) return;
ptr -= HDRSIZE;
/* Sanity check. */
if (ptr < hstart || ptr >= hend)
return;
hdr = *((hdrtype_t *) ptr);
/* Not our header (we're probably poisoned). */
if (!HAS_MAGIC(hdr))
return;
/* Double free. */
if (hdr & FLAG_FREE)
return;
*((hdrtype_t *) ptr) = FREE_BLOCK(SIZE(hdr));
_consolidate();
}
void *malloc(size_t size)
{
return alloc(size);
}
void *calloc(size_t nmemb, size_t size)
{
size_t total = nmemb * size;
void *ptr = alloc(total);
if (ptr)
memset(ptr, 0, total);
return ptr;
}
void *realloc(void *ptr, size_t size)
{
void *ret, *pptr;
unsigned int osize;
if (ptr == NULL)
return alloc(size);
pptr = ptr - HDRSIZE;
if (!HAS_MAGIC(*((hdrtype_t *) pptr)))
return NULL;
/* Get the original size of the block. */
osize = SIZE(*((hdrtype_t *) pptr));
/*
* Free the memory to update the tables - this won't touch the actual
* memory, so we can still use it for the copy after we have
* reallocated the new space.
*/
free(ptr);
ret = alloc(size);
/*
* if ret == NULL, then doh - failure.
* if ret == ptr then woo-hoo! no copy needed.
*/
if (ret == NULL || ret == ptr)
return ret;
/* Copy the memory to the new location. */
memcpy(ret, ptr, osize > size ? size : osize);
return ret;
}
struct align_region_t
{
int alignment;
/* start in memory, and size in bytes */
void* start;
int size;
/* layout within a region:
- num_elements bytes, 0: free, 1: used, 2: used, combines with next
- padding to alignment
- data section
- waste space
start_data points to the start of the data section
*/
void* start_data;
/* number of free blocks sized "alignment" */
int free;
struct align_region_t *next;
};
static struct align_region_t* align_regions = 0;
static struct align_region_t *allocate_region(int alignment, int num_elements)
{
struct align_region_t *new_region;
#ifdef CONFIG_DEBUG_MALLOC
printf("%s(old align_regions=%p, alignment=%u, num_elements=%u)\n",
__func__, align_regions, alignment, num_elements);
#endif
new_region = malloc(sizeof(struct align_region_t));
if (!new_region)
return NULL;
new_region->alignment = alignment;
new_region->start = malloc((num_elements+1) * alignment + num_elements);
if (!new_region->start) {
free(new_region);
return NULL;
}
new_region->start_data = (void*)((u32)(new_region->start + num_elements + alignment - 1) & (~(alignment-1)));
new_region->size = num_elements * alignment;
new_region->free = num_elements;
new_region->next = align_regions;
memset(new_region->start, 0, num_elements);
align_regions = new_region;
return new_region;
}
static int free_aligned(void* addr)
{
struct align_region_t *reg = align_regions;
while (reg != 0)
{
if ((addr >= reg->start_data) && (addr < reg->start_data + reg->size))
{
int i = (addr-reg->start_data)/reg->alignment;
while (((u8*)reg->start)[i]==2)
{
((u8*)reg->start)[i++]=0;
reg->free++;
}
((u8*)reg->start)[i]=0;
reg->free++;
return 1;
}
reg = reg->next;
}
return 0;
}
void *memalign(size_t align, size_t size)
{
if (size == 0) return 0;
if (align_regions == 0) {
align_regions = malloc(sizeof(struct align_region_t));
if (align_regions == NULL)
return NULL;
memset(align_regions, 0, sizeof(struct align_region_t));
}
struct align_region_t *reg = align_regions;
look_further:
while (reg != 0)
{
if ((reg->alignment == align) && (reg->free >= (size + align - 1)/align))
{
#ifdef CONFIG_DEBUG_MALLOC
printf(" found memalign region. %x free, %x required\n", reg->free, (size + align - 1)/align);
#endif
break;
}
reg = reg->next;
}
if (reg == 0)
{
#ifdef CONFIG_DEBUG_MALLOC
printf(" need to allocate a new memalign region\n");
#endif
/* get align regions */
reg = allocate_region(align, (size<1024)?(1024/align):(((size-1)/align)+1));
#ifdef CONFIG_DEBUG_MALLOC
printf(" ... returned %p\n", align_regions);
#endif
}
if (reg == 0) {
/* Nothing available. */
return (void *)NULL;
}
int i, count = 0, target = (size+align-1)/align;
for (i = 0; i < (reg->size/align); i++)
{
if (((u8*)reg->start)[i] == 0)
{
count++;
if (count == target) {
count = i+1-count;
for (i=0; i<target-1; i++)
{
((u8*)reg->start)[count+i]=2;
}
((u8*)reg->start)[count+target-1]=1;
reg->free -= target;
return reg->start_data+(align*count);
}
} else {
count = 0;
}
}
goto look_further; // end condition is once a new region is allocated - it always has enough space
}
/* This is for debugging purposes. */
#ifdef CONFIG_DEBUG_MALLOC
void print_malloc_map(void)
{
void *ptr = hstart;
int free_memory = 0;
while (ptr < hend) {
hdrtype_t hdr = *((hdrtype_t *) ptr);
if (!HAS_MAGIC(hdr)) {
if (heap_initialized)
printf("Poisoned magic - we're toast\n");
else
printf("No magic yet - going to initialize\n");
break;
}
/* FIXME: Verify the size of the block. */
printf("%x: %s (%x bytes)\n",
(unsigned int)(ptr - hstart),
hdr & FLAG_FREE ? "FREE" : "USED", SIZE(hdr));
if (hdr & FLAG_FREE)
free_memory += SIZE(hdr);
ptr += HDRSIZE + SIZE(hdr);
}
if (free_memory && (minimal_free > free_memory))
minimal_free = free_memory;
printf("Maximum memory consumption: %d bytes",
(unsigned int)(&_eheap - &_heap) - HDRSIZE - minimal_free);
}
#endif