nuttx/mm/mm_heap/mm_extend.c
Alin Jerpelea 339457dda3 mm: migrate to SPDX identifier
Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2024-09-13 08:49:05 +08:00

122 lines
3.8 KiB
C

/****************************************************************************
* mm/mm_heap/mm_extend.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <assert.h>
#include <nuttx/mm/mm.h>
#include "mm_heap/mm.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define MIN_EXTEND (2 * MM_SIZEOF_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)
{
FAR struct mm_allocnode_s *oldnode;
FAR 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 && region >= 0 &&
region < 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 mutex */
DEBUGVERIFY(mm_lock(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 + MM_SIZEOF_ALLOCNODE == blockstart);
/* The size of the old node now extends to the new terminal node.
* This is the old size (MM_SIZEOF_ALLOCNODE) plus the size of
* the block (size) minus the size of the new terminal node
* (MM_SIZEOF_ALLOCNODE) or simply:
*/
oldnode->size = size | (oldnode->size & MM_MASK_BIT);
/* The old node should already be marked as allocated */
DEBUGASSERT(MM_NODE_IS_ALLOC(oldnode));
/* Get and initialize the new terminal node in the heap */
newnode = (FAR struct mm_allocnode_s *)
(blockend - MM_SIZEOF_ALLOCNODE);
newnode->size = MM_SIZEOF_ALLOCNODE | MM_ALLOC_BIT;
heap->mm_heapend[region] = newnode;
/* Finally, increase the total heap size accordingly */
heap->mm_heapsize += size;
mm_unlock(heap);
/* Finally "free" the new block of memory where the old terminal node was
* located.
*/
mm_free(heap, mem);
}