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/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2010 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef GRUB_MM_PRIVATE_H
#define GRUB_MM_PRIVATE_H 1
#include <grub/mm.h>
#include <grub/misc.h>
/* For context, see kern/mm.c */
/* Magic words. */
#define GRUB_MM_FREE_MAGIC 0x2d3c2808
#define GRUB_MM_ALLOC_MAGIC 0x6db08fa4
/* A header describing a block of memory - either allocated or free */
typedef struct grub_mm_header
{
/*
* The 'next' free block in this region's circular free list.
* Only meaningful if the block is free.
*/
struct grub_mm_header *next;
/* The block size, not in bytes but the number of cells of
* GRUB_MM_ALIGN bytes. Includes the header cell.
*/
grub_size_t size;
/* either free or alloc magic, depending on the block type. */
grub_size_t magic;
/* pad to cell size: see the top of kern/mm.c. */
#if GRUB_CPU_SIZEOF_VOID_P == 4
char padding[4];
#elif GRUB_CPU_SIZEOF_VOID_P == 8
char padding[8];
#else
# error "unknown word size"
#endif
}
*grub_mm_header_t;
#if GRUB_CPU_SIZEOF_VOID_P == 4
# define GRUB_MM_ALIGN_LOG2 4
#elif GRUB_CPU_SIZEOF_VOID_P == 8
# define GRUB_MM_ALIGN_LOG2 5
#endif
#define GRUB_MM_ALIGN (1 << GRUB_MM_ALIGN_LOG2)
/* A region from which we can make allocations. */
typedef struct grub_mm_region
{
/* The first free block in this region. */
struct grub_mm_header *first;
/*
* The next region in the linked list of regions. Regions are initially
* sorted in order of increasing size, but can grow, in which case the
* ordering may not be preserved.
*/
struct grub_mm_region *next;
/*
* A grub_mm_region will always be aligned to cell size. The pre-size is
* the number of bytes we were given but had to skip in order to get that
* alignment.
*/
grub_size_t pre_size;
/*
* Likewise, the post-size is the number of bytes we wasted at the end
* of the allocation because it wasn't a multiple of GRUB_MM_ALIGN
*/
grub_size_t post_size;
/* How many bytes are in this region? (free and allocated) */
grub_size_t size;
/* pad to a multiple of cell size */
char padding[3 * GRUB_CPU_SIZEOF_VOID_P];
}
*grub_mm_region_t;
#ifndef GRUB_MACHINE_EMU
extern grub_mm_region_t EXPORT_VAR (grub_mm_base);
#endif
static inline void
grub_mm_size_sanity_check (void) {
/* Ensure we preserve alignment when doing h = (grub_mm_header_t) (r + 1). */
COMPILE_TIME_ASSERT ((sizeof (struct grub_mm_region) %
sizeof (struct grub_mm_header)) == 0);
/*
* GRUB_MM_ALIGN is supposed to represent cell size, and a mm_header is
* supposed to be 1 cell.
*/
COMPILE_TIME_ASSERT (sizeof (struct grub_mm_header) == GRUB_MM_ALIGN);
}
#endif
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