util/membag.c File Reference

Memory bag allocator. More...

#include <assert.h>
#include <debug.h>
#include <interrupt.h>
#include <util.h>
#include <physmem.h>
#include <string.h>
#include <mempool.h>
#include <membag.h>
#include <app/membag.h>

Go to the source code of this file.

Data Structures
struct	membag
	Internal structure used by membag to keep track of memory. More...
Defines
#define	MEMBAG(objsize, nr_objs, pool)   { .block_size = objsize, .num_blocks = nr_objs, .phys_pool = pool }
	Macro for configuring memory bag allocator.
Functions
static void	membag_pool_init_physmem (struct membag *mb, unsigned int align_order)
void	membag_init (const unsigned int align_order)
	Initialize memory manager before use.
size_t	membag_get_total (void)
	Total amount of memory in bytes.
size_t	membag_get_smallest_free_block_size (void)
	Smallest free block in bytes.
size_t	membag_get_largest_free_block_size (void)
	Largest free block size in bytes.
void *	membag_alloc (size_t size)
	Allocate memory.
void	membag_free (void *ptr)
	Free previously allocated memory.
Variables
static struct membag	membags []
	Memory bag.

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Detailed Description

Memory bag allocator.

Copyright (C) 2009 Atmel Corporation. All rights reserved.

Definition in file membag.c.

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Define Documentation

#define MEMBAG	(	objsize,
		nr_objs,
		pool		)	{ .block_size = objsize, .num_blocks = nr_objs, .phys_pool = pool }

Macro for configuring memory bag allocator.

MEMBAG is used in user application to define the size and number of blocks for each bag. Please refer to description in membags.

Parameters:

	objsize	Size of each block in this bag
	nr_objs	Number of blocks in this bag
	pool	Pointer to physmem_pool to allocate this memory from.

See also:

physmem_pool

Definition at line 73 of file membag.c.

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Function Documentation

static void membag_pool_init_physmem	(	struct membag *	mb,
		unsigned int	align_order
	)			[static]

For internal use only.

Internal function for initializing each membag

Initialize a membag by getting memory from physmem.

This function essentially does the same as the mem_pool_init_physmem function, but keeps track of start and end of the allocated memory.

Parameters:

	mb	Pointer to membag structure to initialize
	align_order	log2 of the minimum object alignment in bytes.

Precondition:

Not in interrupt context.

Definition at line 115 of file membag.c.

References assert, membag::block_size, membag::end, mem_pool_init(), membag::num_blocks, PHYS_MAP_WRBACK, PHYS_MAP_WRBUF, membag::phys_pool, physmem_alloc(), PHYSMEM_ALLOC_ERR, physmem_map(), membag::pool, round_up, and membag::start.

Referenced by membag_init().

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Variable Documentation

struct membag membags[] [static]

Initial value:

 {
        APP_MEMBAG_INITIALIZER
}

Memory bag.

This structure represents one or more different size bags which memory can be allocated from. The fixed size memory bags avoid internal fragmentation when memory is allocated and freed.

The APP_MEMBAG_INITIALIZER macro needs to be defined in app/membags.h in the user application using the MEMBAG macro. Here is an example:

 define APP_MEMBAG_INITIALIZER  \
        MEMBAG(16, 2, &cpu_sram_pool),          \
        MEMBAG(32, 4, &cpu_sram_pool),

The definition above is used to configure membag to use one bag with 2 blocks of 16 bytes each and another bag with 4 blocks of 32 bytes each. Both bags are here allocated from the cpu_sram_pool.

See also:

MEMBAG

Definition at line 98 of file membag.c.