px4-firmware/nuttx/mm/mm_initialize.c

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/****************************************************************************
* mm/mm_initialize.c
*
* Copyright (C) 2007, 2009, 2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
* COPYRIGHT OWNER 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include "mm_environment.h"
#include "mm_internal.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Public Variables
****************************************************************************/
/* This is the size of the heap provided to mm */
size_t g_heapsize;
/* This is the first and last nodes of the heap */
FAR struct mm_allocnode_s *g_heapstart[CONFIG_MM_REGIONS];
FAR struct mm_allocnode_s *g_heapend[CONFIG_MM_REGIONS];
#if CONFIG_MM_REGIONS > 1
int g_nregions;
#endif
/* All free nodes are maintained in a doubly linked list. This array
* provides some hooks into the list at various points to speed searches for
* free nodes.
*/
FAR struct mm_freenode_s g_nodelist[MM_NNODES];
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: mm_initialize
*
* Description:
* This is an internal OS function called only at power-up boot time.
*
* Parameters:
* heapstart - Start of the initial heap region
* heapsize - Size of the initial heap region
*
* Return Value:
* None
*
* Assumptions:
*
****************************************************************************/
void mm_initialize(FAR void *heapstart, size_t heapsize)
{
int i;
mlldbg("Heap: start=%p size=%u\n", heapstart, heapsize);
/* The following two lines have cause problems for some older ZiLog
* compilers in the past (but not the more recent). Life is easier if we
* just the suppress them altogther for those tools.
*/
#ifndef __ZILOG__
CHECK_ALLOCNODE_SIZE;
CHECK_FREENODE_SIZE;
#endif
/* Set up global variables */
g_heapsize = 0;
#if CONFIG_MM_REGIONS > 1
g_nregions = 0;
#endif
/* Initialize the node array */
memset(g_nodelist, 0, sizeof(struct mm_freenode_s) * MM_NNODES);
for (i = 1; i < MM_NNODES; i++)
{
g_nodelist[i-1].flink = &g_nodelist[i];
g_nodelist[i].blink = &g_nodelist[i-1];
}
/* Initialize the malloc semaphore to one (to support one-at-
* a-time access to private data sets).
*/
mm_seminitialize();
/* Add the initial region of memory to the heap */
mm_addregion(heapstart, heapsize);
}
/****************************************************************************
* Name: mm_addregion
*
* Description:
* This function gives a region of contiguous memory to the memory manager
*
* Parameters:
* heapstart - Start of the heap region
* heapsize - Size of the heap region
*
* Return Value:
* None
*
* Assumptions:
*
****************************************************************************/
void mm_addregion(FAR void *heapstart, size_t heapsize)
{
FAR struct mm_freenode_s *node;
uintptr_t heapbase;
uintptr_t heapend;
#if CONFIG_MM_REGIONS > 1
int IDX = g_nregions;
#else
# define IDX 0
#endif
/* If the MCU handles wide addresses but the memory manager is configured
* for a small heap, then verify that the caller is not doing something
* crazy.
*/
#if defined(CONFIG_MM_SMALL) && !defined(CONFIG_SMALL_MEMORY)
DEBUGASSERT(heapsize <= MMSIZE_MAX+1);
#endif
/* Adjust the provide heap start and size so that they are both aligned
* with the MM_MIN_CHUNK size.
*/
heapbase = MM_ALIGN_UP((uintptr_t)heapstart);
heapend = MM_ALIGN_DOWN((uintptr_t)heapstart + (uintptr_t)heapsize);
heapsize = heapend - heapbase;
mlldbg("Region %d: base=%p size=%u\n", IDX+1, heapstart, heapsize);
/* Add the size of this region to the total size of the heap */
g_heapsize += heapsize;
/* Create two "allocated" guard nodes at the beginning and end of
* the heap. These only serve to keep us from allocating outside
* of the heap.
*
* And create one free node between the guard nodes that contains
* all available memory.
*/
g_heapstart[IDX] = (FAR struct mm_allocnode_s *)heapbase;
g_heapstart[IDX]->size = SIZEOF_MM_ALLOCNODE;
g_heapstart[IDX]->preceding = MM_ALLOC_BIT;
node = (FAR struct mm_freenode_s *)(heapbase + SIZEOF_MM_ALLOCNODE);
node->size = heapsize - 2*SIZEOF_MM_ALLOCNODE;
node->preceding = SIZEOF_MM_ALLOCNODE;
g_heapend[IDX] = (FAR struct mm_allocnode_s *)(heapend - SIZEOF_MM_ALLOCNODE);
g_heapend[IDX]->size = SIZEOF_MM_ALLOCNODE;
g_heapend[IDX]->preceding = node->size | MM_ALLOC_BIT;
#undef IDX
#if CONFIG_MM_REGIONS > 1
g_nregions++;
#endif
/* Add the single, large free node to the nodelist */
mm_addfreechunk(node);
}