nuttx/mm/mm_gran/mm_granreserve.c
Yanfeng Liu 102a62c7e3 mm/mm_gran: remove allocation size limitation
This patch refactors granule allocator to remove the 32 granules
limitation with the help of a gran_range_s structure and related
functions, see "mm_grantable.h" for details.

Below are the major functions explaining how this works:

- The gran_match() checks if a gran range all in the given state.
  it gives last mismatch position when fails free range matching.
- The gran_search() tries to find the position of a free range.
  It leverages last mismatch position from gran_match() to speed
  up the search.

range size handling is mainly in gran_match() and gran_set_().

Signed-off-by: Yanfeng Liu <yfliu2008@qq.com>
2024-04-20 16:24:37 -03:00

96 lines
2.6 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 <debug.h>
#include <nuttx/mm/gran.h>
#include "mm_gran/mm_gran.h"
#include "mm_gran/mm_grantable.h"
#ifdef CONFIG_GRAN
/****************************************************************************
* Public Functions
****************************************************************************/
FAR void *gran_reserve(GRAN_HANDLE handle, uintptr_t start, size_t size)
{
FAR gran_t *gran = (FAR gran_t *)handle;
uintptr_t end;
size_t ngran;
size_t posi;
bool avail;
DEBUGASSERT(gran);
if (!size || size > GRANBYTE(gran))
{
return NULL;
}
/* align down/up start/ending addresses */
end = END_RSRV(gran, start, size);
if (!GRAN_INRANGE(gran, end))
{
return NULL;
}
start = MEM_RSRV(gran, start);
if (!GRAN_INRANGE(gran, start))
{
return NULL;
}
/* convert unit to granule */
posi = MEM2GRAN(gran, start);
ngran = ((end - start) >> gran->log2gran) + 1;
/* lock the granule allocator */
if (gran_enter_critical(gran) < 0)
{
return NULL;
}
avail = gran_match(gran, posi, ngran, 0, NULL);
if (avail)
{
gran_set(gran, posi, ngran);
}
gran_leave_critical(gran);
graninfo("%s posi=%zu retp=%zx size=%zu n=%zu\n",
avail ? " done" : " error", posi, (size_t)start, size, ngran);
return avail ? (FAR void *)start : NULL;
}
#endif /* CONFIG_GRAN */