/**************************************************************************** * mm/mm_graninit.c * * Copyright (C) 2012 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include "mm_gran.h" #ifdef CONFIG_GRAN /**************************************************************************** * 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: * 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-> 8 bytes, etc. * log2align - Log base 2 of required alignment. 0->1 byte, * 1->2 bytes, 2->4 bytes, 3-> 8 bytes, etc. Note that * log2gran must be greater than or equal to log2align * so that all contiguous granules in memory will meet * the minimum alignment requirement. A value of zero * would mean that no alignment is required. * * 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, uint8_t log2align) { FAR struct gran_s *priv; uintptr_t heapend; uintptr_t alignedstart; unsigned int mask; unsigned int alignedsize; unsigned int ngranules; /* Check parameters if debug is on. Note the the size of a granual is * limited to 2**31 bytes and that the size of the granule must be greater * than the alignment size. */ DEBUGASSERT(heapstart && heapsize > 0 && log2gran > 0 && log2gran < 32 && log2gran > log2align); /* Get the aligned start of the heap */ mask = (1 << log2align) - 1; alignedstart = ((uintptr_t)heapstart + mask) & ~mask; /* Determine the number of granules */ mask = (1 << log2gran) - 1; heapend = (uintptr_t)heapstart + heapsize; 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; /* Initialize mutual exclusion support */ #ifndef CONFIG_GRAN_INTR sem_init(&priv->exclsem, 0, 1); #endif } return priv; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: gran_initialize * * Description: * Set up one granule allocator instance. Allocations will be aligned to * the alignment size (log2align; allocations will be in units of the * granule size (log2gran). Larger granules will give better performance * and less overhead but more losses of memory due to quantization waste. * Additional memory waste can occur from alignment; log2align should be * set to 0 unless you are using the granule allocator to manage DMA memory * and your hardware has specific memory alignment requirements. * * Geneneral Usage Summary. This is an example using the GCC section * attribute to position a DMA heap in memory (logic in the linker script * would assign the section .dmaheap to the DMA memory. * * FAR uint32_t g_dmaheap[DMAHEAP_SIZE] __attribute__((section(.dmaheap))); * * The heap is created by calling gran_initialize(). Here the granual size * is set to 64 bytes (2**6) and the alignment to 16 bytes (2**4): * * GRAN_HANDLE handle = gran_initialize(g_dmaheap, DMAHEAP_SIZE, 6, 4); * * Then the GRAN_HANDLE can be used to allocate memory (There is no * GRAN_HANDLE if CONFIG_GRAN_SINGLE=y): * * FAR uint8_t *dma_memory = (FAR uint8_t *)gran_alloc(handle, 47); * * The actual memory allocates will be 64 byte (wasting 17 bytes) and * will be aligned at least to (1 << log2align). * * NOTE: The current implementation also restricts the maximum allocation * size to 32 granules. 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-> 8 bytes, etc. * log2align - Log base 2 of required alignment. 0->1 byte, * 1->2 bytes, 2->4 bytes, 3-> 8 bytes, etc. Note that * log2gran must be greater than or equal to log2align * so that all contiguous granules in memory will meet * the minimum alignment requirement. A value of zero * would mean that no alignment is required. * * 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, uint8_t log2align) { g_graninfo = gran_common_initialize(heapstart, heapsize, log2gran, log2align); if (!g_graninfo) { return -ENOMEM; } return OK; } #else GRAN_HANDLE gran_initialize(FAR void *heapstart, size_t heapsize, uint8_t log2gran, uint8_t log2align) { return (GRAN_HANDLE)gran_common_initialize(heapstart, heapsize, log2gran, log2align); } #endif #endif /* CONFIG_GRAN */