Add beginning of a simple granule allocator to support DMA IO buffer allocation

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@5129 7fd9a85b-ad96-42d3-883c-3090e2eb8679

2 files changed, 162 insertions, 1 deletions

diff --git a/nuttx/include/nuttx/fs/fat.h b/nuttx/include/nuttx/fs/fat.h
index 3ae0fbee2..680aefbe9 100644
--- a/nuttx/include/nuttx/fs/fat.h
+++ b/nuttx/include/nuttx/fs/fat.h
@@ -106,7 +106,7 @@ EXTERN int fat_setattrib(const char *path, fat_attrib_t setbits, fat_attrib_t cl
  ****************************************************************************/
 
 EXTERN FAR void *fat_dma_alloc(size_t size);
-EXTERN void fat_dma_free(FAR void *memory);
+EXTERN void fat_dma_free(FAR void *memory, size_t size);
 
 #undef EXTERN
 #ifdef __cplusplus
diff --git a/nuttx/include/nuttx/gran.h b/nuttx/include/nuttx/gran.h
new file mode 100644
index 000000000..2036a29a1
--- /dev/null
+++ b/nuttx/include/nuttx/gran.h
@@ -0,0 +1,161 @@
+/****************************************************************************
+ * include/nuttx/gran.h
+ * General purpose granule memory allocator.
+ *
+ *   Copyright (C) 2009 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.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_NUTTX_GRAN_H
+#define __INCLUDE_NUTTX_GRAN_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+/* Configuration ************************************************************/
+/* CONFIG_GRAN - Enable granual allocator support
+ * CONFIG_GRAN_SINGLE - Select if there is only one instance of the
+ *   granule allocator (i.e., gran_initialize will be called only once.
+ *   In this case, (1) there are a few optimizations that can can be done
+ *   and (2) the GRAN_HANDLE is not needed.
+ */
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+#ifndef CONFIG_GRAN_SINGLE
+typedef FAR void *GRAN_HANDLE;
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C" {
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * 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
+EXTERN void gran_initialize(FAR void *heapstart, size_t heapsize,
+                            uint8_t log2gran);
+#else
+EXTERN GRAN_HANDLE gran_initialize(FAR void *heapstart, size_t heapsize,
+                                   uint8_t log2gran);
+#endif
+
+/****************************************************************************
+ * Name: gran_alloc
+ *
+ * Description:
+ *   Allocate memory from the granule heap.
+ *
+ *   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:
+ *   handle - The handle previously returned by gran_initialize
+ *   size   - The size of the memory region to allocate.
+ *
+ * Returned Value:
+ *   On success, either a non-NULL pointer to the allocated memory (if
+ *   CONFIG_GRAN_SINGLE) or zero  (if !CONFIG_GRAN_SINGLE) is returned.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_GRAN_SINGLE
+EXTERN FAR void *gran_alloc(size_t size);
+#else
+EXTERN FAR void *gran_alloc(GRAN_HANDLE handle, size_t size);
+#endif
+
+/****************************************************************************
+ * Name: gran_free
+ *
+ * Description:
+ *   Return memory to the granule heap.
+ *
+ * Input Parameters:
+ *   handle - The handle previously returned by gran_initialize
+ *   memory - A pointer to memory previoiusly allocated by gran_alloc.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_GRAN_SINGLE
+EXTERN void gran_free(FAR void *memory, size_t size);
+#else
+EXTERN void gran_free(GRAN_HANDLE handle, FAR void *memory, size_t size);
+#endif
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __INCLUDE_NUTTX_GRAN_H */