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

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5129 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 84 insertions, 0 deletions

diff --git a/nuttx/mm/mm_gran.h b/nuttx/mm/mm_gran.h
new file mode 100644
index 000000000..6f5f890ed
--- /dev/null
+++ b/nuttx/mm/mm_gran.h
@@ -0,0 +1,84 @@
+/****************************************************************************
+ * mm/mm_gran.h
+ *
+ *   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.
+ *
+ ****************************************************************************/
+
+#ifndef __MM_MM_GRAN_H
+#define __MM_MM_GRAN_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <nuttx/gran.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define SIZEOF_GAT(n) \
+  ((n + 31) >> 5)
+#define SIZEOF_GRAN_S(n) \
+  (sizeof(struct gran_s) + sizeof(uint32_t) * (SIZEOF_GAT(n) - 1))
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/* This structure represents the state of on granual allocation */
+
+struct gran_s
+{
+  uint8_t    log2gran;  /* Log base 2 of the size of one granule */
+  uint16_t   ngranules; /* The total number of (aligned) granules in the heap */
+  uintptr_t  heapstart; /* The aligned start of the granule heap */
+  uint32_t   gat[i];    /* Start of the granule allocation table */
+};
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/* State of the single GRAN allocator */
+
+#ifdef CONFIG_GRAN_SINGLE
+extern FAR struct gran_s *g_graninfo;
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#endif /* __MM_MM_GRAN_H */