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Diffstat (limited to 'nuttx/mm/mm_graninit.c')
| -rw-r--r-- | nuttx/mm/mm_graninit.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/nuttx/mm/mm_graninit.c b/nuttx/mm/mm_graninit.c new file mode 100644 index 000000000..99b499155 --- /dev/null +++ b/nuttx/mm/mm_graninit.c @@ -0,0 +1,163 @@ +/**************************************************************************** + * mm/mm_graninit.c + * + * Copyright (C) 2012 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 <nuttx/gran.h> + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Public Data + ****************************************************************************/ + +/* State of the single GRAN allocator */ + +#ifdef CONFIG_GRAN_SINGLE +FAR struct gran_s *g_graninfo; +#endif + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: gran_common_initialize + * + * Description: + * Perfrom common GRAN initialization. + * + * Input Parameters: + * info - Private granule data structure pointer + * heapstart - Start of the granule allocation heap + * heapsize - Size of heap in bytes + * log2gran - Log base 2 of the size of one granule. 0->1 byte, + * 1->2 bytes, 2->4 bytes, 3-> 8bytes, etc. + * + * Returned Value: + * On success, a non-NULL info structure is returned that may be used with + * other granule allocator interfaces. + * + ****************************************************************************/ + +static inline FAR struct gran_s *gran_common_initialize(FAR void *heapstart, + size_t heapsize, + uint8_t log2gran) +{ + FAR struct gran_s *priv; + uintptr_t heapend; + uintptr_t alignedstart; + unsigned int mask; + unsigned int alignedsize; + unsigned int ngranules; + + /* Determine the number of granules */ + + mask = (1 << log2gran) - 1; + heapend = (uintptr_t)heapstart + heapsize; + alignedstart = ((uintptr_t)heapstart + mask) & ~mask; + alignedsize = (heapend - alignedstart) & ~mask; + ngranules = alignedsize >> log2gran; + + /* Allocate the information structure with a granule table of the + * correct size. + */ + + priv = ( FAR struct gran_s *)zalloc(SIZEOF_GRAN_S(ngranules)); + if (priv) + { + /* Initialize non-zero elements of the granules heap info structure */ + + priv->log2gran = log2gran; + priv->ngranules = ngranules; + priv->heapstart = alignedstart + } + + return priv; +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: gran_initialize + * + * Description: + * Set up one granule allocator instance. Allocations will be aligned to + * the granule size; allocations will be in units of the granule size. + * Larger granules will give better performance and less overhead but more + * losses of memory due to alignment and quantization waste. + * + * NOTE: The current implementation also restricts the maximum allocation + * size to 32 granaules. That restriction could be eliminated with some + * additional coding effort. + * + * Input Parameters: + * heapstart - Start of the granule allocation heap + * heapsize - Size of heap in bytes + * log2gran - Log base 2 of the size of one granule. 0->1 byte, + * 1->2 bytes, 2->4 bytes, 3-> 8bytes, etc. + * + * Returned Value: + * On success, a non-NULL handle is returned that may be used with other + * granual allocator interfaces. + * + ****************************************************************************/ + +#ifdef CONFIG_GRAN_SINGLE +int gran_initialize(FAR void *heapstart, size_t heapsize, uint8_t log2gran) +{ + g_graninfo = gran_common_initialize(heapstart, heapsize, log2gran); + if (!g_granifo) + { + return -ENOMEM; + } + + return OK; +} +#else +GRAN_HANDLE gran_initialize(FAR void *heapstart, size_t heapsize, uint8_t log2gran) +{ + return (GRAN_HANDLE)gran_common_initialize(heapstart, heapsize, log2gran); +} +#endif + |