incubator-nuttx/mm/mm_gran/mm_granreserve.c

91 lines
2.9 KiB
C

/****************************************************************************
* mm/mm_gran/mm_granreserve.c
*
* 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/gran.h>
#include "mm_gran/mm_gran.h"
#ifdef CONFIG_GRAN
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: gran_reserve
*
* Description:
* Reserve memory in the granule heap. This will reserve the granules
* that contain the start and end addresses plus all of the granules
* in between. This should be done early in the initialization sequence
* before any other allocations are made.
*
* Reserved memory can never be allocated (it can be freed however which
* essentially unreserves the memory).
*
* Input Parameters:
* handle - The handle previously returned by gran_initialize
* start - The address of the beginning of the region to be reserved.
* size - The size of the region to be reserved
*
* Returned Value:
* None
*
****************************************************************************/
void gran_reserve(GRAN_HANDLE handle, uintptr_t start, size_t size)
{
FAR struct gran_s *priv = (FAR struct gran_s *)handle;
DEBUGASSERT(priv != NULL);
if (size > 0)
{
uintptr_t mask = (1 << priv->log2gran) - 1;
uintptr_t end = start + size - 1;
unsigned int ngranules;
/* Get the aligned (down) start address and the aligned (up) end
* address
*/
start &= ~mask;
end = (end + mask) & ~mask;
/* Calculate the new size in granules */
ngranules = ((end - start) >> priv->log2gran) + 1;
/* And reserve the granules */
gran_mark_allocated(priv, start, ngranules);
}
}
#endif /* CONFIG_GRAN */