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/******************************************************************************
* Copyright (c) 2013 IBM Corporation
* All rights reserved.
* This program and the accompanying materials
* are made available under the terms of the BSD License
* which accompanies this distribution, and is available at
* http://www.opensource.org/licenses/bsd-license.php
*
* Contributors:
* IBM Corporation - initial implementation
*****************************************************************************/
/*
* All functions concerning interface to slof
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
#include <helpers.h>
#include <allocator.h>
#undef DEBUG
//#define DEBUG
#ifdef DEBUG
#define dprintf(_x ...) do { printf ("%s: ", __func__); printf(_x); } while (0);
#else
#define dprintf(_x ...)
#endif
#define DEFAULT_BLOCK_SIZE 4096
#define BM_WORD_SIZE (sizeof(unsigned long))
#define BM_WORD_BITS (BM_WORD_SIZE * 8)
struct bitmap {
unsigned long start;
unsigned long size;
unsigned long bm_size;
unsigned long block_size;
unsigned long free_blocks;
unsigned long bmw[];
};
#define BIT(x) (1UL << x)
#define BM_WORD(bmw, n) (bmw[n/BM_WORD_BITS])
#define BM_WORD_MODULO(n) (n % BM_WORD_BITS)
#define BM_NUM_BITS(reqsize, bsize) ((reqsize / bsize) + (reqsize % bsize? 1 : 0))
static void bm_clear_bit(unsigned long *bmw, int n)
{
BM_WORD(bmw, n) &= ~BIT(BM_WORD_MODULO(n));
}
static void bm_set_bit(unsigned long *bmw, int n)
{
BM_WORD(bmw, n) |= BIT(BM_WORD_MODULO(n));
}
static bool bm_test_bit(unsigned long *bmw, int n)
{
#ifdef DEBUG
//printf("BMW %x, bitpos %d, value %d\n", &BM_WORD(bmw, n), n, !!(BM_WORD(bmw, n) & BIT(BM_WORD_MODULO(n))));
#endif
return !!(BM_WORD(bmw, n) & BIT(BM_WORD_MODULO(n)));
}
/* Improvement: can use FFS routines to get faster results */
static int bm_find_bits(struct bitmap *bm, unsigned int n_bits)
{
unsigned int i, j, total_bits;
int found = -1;
dprintf("Finding %d bits set\n", n_bits);
total_bits = BM_NUM_BITS(bm->size, bm->block_size);
for(i = 0; i < total_bits; i++) {
if (!bm_test_bit(bm->bmw, i))
continue;
/* we have hit the boundary now, give up */
if (i + n_bits > total_bits)
break;
/* Lets find if we have consecutive bits set */
for(j = i; j < (i + n_bits); j++) {
if (!bm_test_bit(bm->bmw, (j)))
break;
}
/* Got it */
if (j == (i + n_bits)) {
found = i;
break;
}
}
return found;
}
void SLOF_bm_print(unsigned long handle)
{
struct bitmap *bm;
unsigned int i;
if (!handle)
return;
bm = (struct bitmap *) handle;
printf("BITMAP: start %lx, size %ld, blocksize %ld\n\n",
bm->start, bm->size, bm->block_size);
printf("0 16 32 48 63\n");
for(i = 0; i < BM_NUM_BITS(bm->size, bm->block_size); i++) {
if (i > 0 && (i % 64 == 0))
printf("\n");
else if (i > 0 && (i % 8 == 0))
printf(" ");
printf("%d", bm_test_bit(bm->bmw, i));
}
printf("\n\n");
}
unsigned long SLOF_bm_allocator_init(unsigned long start, unsigned long size,
unsigned long blocksize)
{
struct bitmap *bm;
unsigned long alloc_size, bm_size, n_bits;
dprintf("enter start %lx, size %ld, block-size %ld\n", start, size, blocksize);
if (!size)
return 0;
if (!blocksize)
blocksize = DEFAULT_BLOCK_SIZE;
n_bits = BM_NUM_BITS(size, blocksize);
bm_size = (n_bits / BM_WORD_BITS) + ((n_bits % BM_WORD_BITS)? 1 : 0);
alloc_size = sizeof(struct bitmap) + bm_size * BM_WORD_SIZE;
dprintf("Size %ld, blocksize %ld, bm_size %ld, alloc_size %ld\n",
size, blocksize, bm_size, alloc_size);
bm = (struct bitmap *) SLOF_alloc_mem(alloc_size);
if (!bm)
return 0;
bm->start = start;
bm->size = size;
bm->bm_size = bm_size;
bm->block_size = blocksize;
bm->free_blocks = n_bits;
memset(bm->bmw, 0xFF, bm_size*BM_WORD_SIZE);
return (unsigned long)bm;
}
unsigned long SLOF_bm_alloc(unsigned long handle, unsigned long size)
{
struct bitmap *bm;
unsigned long n_bits;
unsigned long addr;
unsigned int i;
int bitpos;
if (!handle)
return -1;
bm = (struct bitmap *) handle;
n_bits = BM_NUM_BITS(size, bm->block_size);
if (n_bits > bm->free_blocks)
return -1;
bitpos = bm_find_bits(bm, n_bits);
if (bitpos == -1)
return -1;
dprintf("BMW bitpos %d\n", bitpos);
dprintf("size %ld, block_size %ld, n_bits %ld\n", size, bm->block_size, n_bits);
for(i = bitpos; i < (bitpos + n_bits); i++) {
#ifdef DEBUG
if (!bm_test_bit(bm->bmw, i))
dprintf("Warning: Bit already in use: %d\n", i);
#endif
bm_clear_bit(bm->bmw, i);
}
bm->free_blocks -= n_bits;
addr = bm->start + bitpos * bm->block_size;
dprintf("BMW %d, bitpos %d addr %lx free_blocks %ld\n", i, bitpos, addr, bm->free_blocks);
return addr;
}
void SLOF_bm_free(unsigned long handle, unsigned long ptr, unsigned long size)
{
struct bitmap *bm;
unsigned long bitpos, n_bits;
unsigned long addr;
unsigned int i;
if (!handle)
return;
bm = (struct bitmap *) handle;
addr = (unsigned long ) ptr;
n_bits = BM_NUM_BITS(size, bm->block_size);
if (addr < bm->start || (bm->start + bm->size) < (addr + size)) {
printf("Error: Bitmap start %lx, size %ld, requested address %lx, size %ld\n",
bm->start, bm->size, addr, size);
return;
}
bitpos = (addr - bm->start) / bm->block_size;
bm->free_blocks += n_bits;
#ifdef DEBUG
dprintf("addr %lx, bitpos %ld\n", addr, bitpos);
dprintf("size %ld, block_size %ld, n_bits %ld, free_blocks %ld\n", size, bm->block_size, n_bits, bm->free_blocks);
if (addr % bm->block_size) {
dprintf("Warning: Address not aligned addr %lx\n", addr);
}
#endif
for(i = bitpos; i < (bitpos + n_bits); i++) {
#ifdef DEBUG
if (bm_test_bit(bm->bmw, i))
dprintf("Warning: Bit already set: %d\n", i);
#endif
bm_set_bit(bm->bmw, i);
}
return;
}
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