128 lines
4.5 KiB
C
128 lines
4.5 KiB
C
/****************************************************************************
|
|
* mm/mm_heap/mm_extend.c
|
|
*
|
|
* Copyright (C) 2014 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 <nuttx/config.h>
|
|
|
|
#include <assert.h>
|
|
|
|
#include <nuttx/mm/mm.h>
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
#define MIN_EXTEND (2 * SIZEOF_MM_ALLOCNODE)
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: mm_extend
|
|
*
|
|
* Description:
|
|
* Extend a heap region by add a block of (virtually) contiguous memory
|
|
* to the end of the heap.
|
|
*
|
|
****************************************************************************/
|
|
|
|
void mm_extend(FAR struct mm_heap_s *heap, FAR void *mem, size_t size,
|
|
int region)
|
|
{
|
|
struct mm_allocnode_s *oldnode;
|
|
struct mm_allocnode_s *newnode;
|
|
uintptr_t blockstart;
|
|
uintptr_t blockend;
|
|
|
|
/* Make sure that we were passed valid parameters */
|
|
|
|
DEBUGASSERT(heap && mem);
|
|
#if CONFIG_MM_REGIONS > 1
|
|
DEBUGASSERT(size >= MIN_EXTEND && (size_t)region < (size_t)heap->mm_nregions);
|
|
#else
|
|
DEBUGASSERT(size >= MIN_EXTEND && region == 0);
|
|
#endif
|
|
|
|
/* Make sure that the memory region are properly aligned */
|
|
|
|
blockstart = (uintptr_t)mem;
|
|
blockend = blockstart + size;
|
|
|
|
DEBUGASSERT(MM_ALIGN_UP(blockstart) == blockstart);
|
|
DEBUGASSERT(MM_ALIGN_DOWN(blockend) == blockend);
|
|
|
|
/* Take the memory manager semaphore */
|
|
|
|
mm_takesemaphore(heap);
|
|
|
|
/* Get the terminal node in the old heap. The block to extend must
|
|
* immediately follow this node.
|
|
*/
|
|
|
|
oldnode = heap->mm_heapend[region];
|
|
DEBUGASSERT((uintptr_t)oldnode + SIZEOF_MM_ALLOCNODE == (uintptr_t)mem);
|
|
|
|
/* The size of the old node now extends to the new terminal node.
|
|
* This is the old size (SIZEOF_MM_ALLOCNODE) plus the size of
|
|
* the block (size) minus the size of the new terminal node
|
|
* (SIZEOF_MM_ALLOCNODE) or simply:
|
|
*/
|
|
|
|
oldnode->size = size;
|
|
|
|
/* The old node should already be marked as allocated */
|
|
|
|
DEBUGASSERT((oldnode->preceding & MM_ALLOC_BIT) != 0);
|
|
|
|
/* Get and initialize the new terminal node in the heap */
|
|
|
|
newnode = (FAR struct mm_allocnode_s *)(blockend - SIZEOF_MM_ALLOCNODE);
|
|
newnode->size = SIZEOF_MM_ALLOCNODE;
|
|
newnode->preceding = oldnode->size | MM_ALLOC_BIT;
|
|
|
|
heap->mm_heapend[region] = newnode;
|
|
mm_givesemaphore(heap);
|
|
|
|
/* Finally "free" the new block of memory where the old terminal node was
|
|
* located.
|
|
*/
|
|
|
|
mm_free(heap, (FAR void *)mem);
|
|
}
|