include/nuttx/pgalloc.h and mm/mm_pgalloc.c: Add a simple page allocator based on the existing NuttX granule allocator. I am not certain if the granule allocator is sufficiently deterministic for long range use, but it gets get a page allocator in place for testing very quickly.

include/nuttx/gran.h

@@ -52,7 +52,7 @@
  * Pre-Processor Definitions
  ****************************************************************************/
 /* Configuration ************************************************************/
-/* CONFIG_GRAN - Enable granual allocator support
+/* CONFIG_GRAN - Enable granule 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
@@ -62,7 +62,7 @@
  *   mutual exclusion logic will disable interrupts.  While this options is
  *   more invasive to system performance, it will also support use of the
  *   granule allocator from interrupt level logic.
- * CONFIG_DEBUG_GRAN - Just like CONFIG_DEBUG_MM, but only generates ouput
+ * CONFIG_DEBUG_GRAN - Just like CONFIG_DEBUG_MM, but only generates output
  *   from the gran allocation logic.
  */
 
@@ -80,7 +80,8 @@ typedef FAR void *GRAN_HANDLE;
 
 #ifdef __cplusplus
 #define EXTERN extern "C"
-extern "C" {
+extern "C"
+{
 #else
 #define EXTERN extern
 #endif
@@ -94,16 +95,17 @@ extern "C" {
  *   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
+ *   set to 0 unless you are using the granule allocator to manage DMA
- *   and your hardware has specific memory alignment requirements.
+ *   or page-aligned memory and your hardware has specific memory alignment
+ *   requirements.
  *
- *   Geneneral Usage Summary.  This is an example using the GCC section
+ *   General 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
+ *   The heap is created by calling gran_initialize.  Here the granule size
  *   is set to 64 bytes and the alignment to 16 bytes:
  *
  *     GRAN_HANDLE handle = gran_initialize(g_dmaheap, DMAHEAP_SIZE, 6, 4);
@@ -124,9 +126,9 @@ extern "C" {
  *   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.
+ *               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
+ *               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

include/nuttx/pgalloc.h

@@ -0,0 +1,201 @@
+/****************************************************************************
+ * include/nuttx/pgalloc.h
+ * Page memory allocator.
+ *
+ *   Copyright (C) 2014 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_PGALLOC_H
+#define __INCLUDE_NUTTX_PGALLOC_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+
+#ifdef CONFIG_MM_PGALLOC
+
+/****************************************************************************
+ * Pre-Processor Definitions
+ ****************************************************************************/
+/* Configuration ************************************************************/
+/* CONFIG_MM_PGALLOC - Enable page allocator support
+ * CONFIG_MM_PGSIZE - The page size.  Must be one of {1024, 2048,
+ *   4096, 8192, or 16384}.  This is easily extensible, but only those
+ *   values are currently support.
+ * CONFIG_MM_PGPOOL_PADDR - Physical address of the start of the page
+ *   memory pool.  This will be aligned to the page size if it is not
+ *   already aligned.
+ * CONFIG_MM_PGPOOL_SIZE - The size of the page memory pool in bytes.  This
+ *   will be aligned if it is not already aligned.
+ * CONFIG_DEBUG_PGALLOC - Just like CONFIG_DEBUG_MM, but only generates
+ *   output from the page allocation logic.
+ *
+ * Dependencies:  CONFIG_ARCH_HAVE_MMU and CONFIG_GRAN
+ */
+ 
+#ifndef CONFIG_MM_PGALLOC_PGSIZE
+#  define CONFIG_MM_PGALLOC_PGSIZE 4096
+#endif
+
+#ifndef CONFIG_MM_PGPOOL_PADDR
+#  error CONFIG_MM_PGPOOL_PADDR must be defined
+#endif
+
+#ifndef CONFIG_MM_PGPOOL_SIZE
+#  error CONFIG_MM_PGPOOL_SIZE must be defined
+#endif
+
+#if CONFIG_MM_PGSIZE == 1024
+#  define MM_PGSIZE  1024
+#  define MM_PGSHIFT 10
+#elif CONFIG_MM_PGSIZE == 2048
+#  define MM_PGSIZE  2048
+#  define MM_PGSHIFT 11
+#elif CONFIG_MM_PGSIZE == 4096
+#  define MM_PGSIZE  4096
+#  define MM_PGSHIFT 12
+#elif CONFIG_MM_PGSIZE == 8192
+#  define MM_PGSIZE  8192
+#  define MM_PGSHIFT 13
+#elif CONFIG_MM_PGSIZE == 16384
+#  define MM_PGSIZE  16384
+#  define MM_PGSHIFT 14
+#else
+#  error CONFIG_MM_PGSIZE not supported
+#endif
+
+#define MM_PGMASK    (MM_PGSIZE - 1)
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Name: mm_pginitialize
+ *
+ * Description:
+ *   Initialize the page allocator.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   Mpme
+ *
+ ****************************************************************************/
+
+void mm_pginitialize(void);
+
+/****************************************************************************
+ * Name: mm_pgreserve
+ *
+ * Description:
+ *   Reserve memory in the page memory pool.  This will reserve the pages
+ *   that contain the start and end addresses plus all of the pages
+ *   in between.  This should be done early in the initialization sequence
+ *   before any other allocations are made.
+ *
+ *   Reserved memory can never be allocated (it can be freed however which
+ *   essentially unreserves the memory).
+ *
+ * Input Parameters:
+ *   start  - The address of the beginning of the region to be reserved.
+ *   size   - The size of the region to be reserved
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void mm_pgreserve(uintptr_t start, size_t size);
+
+/****************************************************************************
+ * Name: mm_pgalloc
+ *
+ * Description:
+ *   Allocate page memory from the page memory pool.
+ *
+ * Input Parameters:
+ *   npages - The number of pages to allocate, each of size CONFIG_MM_PGSIZE.
+ *
+ * Returned Value:
+ *   On success, a non-zero, physical address of the allocated page memory
+ *   is returned.  Zero is returned on failure.  NOTE:  This is an unmapped
+ *   physical address and cannot be used until it is appropriately mapped.
+ *
+ ****************************************************************************/
+
+uintptr_t mm_pgalloc(unsigned int npages);
+
+/****************************************************************************
+ * Name: mm_pgfree
+ *
+ * Description:
+ *   Return page memory to the page memory pool.
+ *
+ * Input Parameters:
+ *   paddr  - A physical address to a page in the page memory pool previously
+ *            allocated by mm_pgalloc.
+ *   npages - The number of contiguous pages to be return to the page memory
+ *            pool, beginning with the page at paddr;
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void mm_pgfree(uintptr_t paddr, unsigned int npages);
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* CONFIG_MM_PGALLOC */
+#endif /* __INCLUDE_NUTTX_PGALLOC_H */

mm/Kconfig

@@ -101,7 +101,7 @@ config GRAN
 	bool "Enable Granule Allocator"
 	default n
 	---help---
-		Enable granual allocator support.  Allocations will be aligned to the
+		Enable granule allocator support.  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.
@@ -136,5 +136,46 @@ config DEBUG_GRAN
 	default n
 	depends on GRAN && DEBUG
 	---help---
-		Just like DEBUG_MM, but only generates ouput from the gran
+		Just like DEBUG_MM, but only generates output from the gran
 		allocation logic.
+
+config MM_PGALLOC
+	bool "Enable Page Allocator"
+	default n
+	depends on ARCH_HAVE_MMU
+	select GRAN
+	---help---
+		Enable support for a MMU physical page allocator based on the
+		granule allocator.
+
+if MM_PGALLOC
+
+config MM_PGSIZE
+	int "Page Size"
+	default 4096
+	--help---
+		The MMU page size.  Must be one of {1024, 2048, 4096, 8192, or
+		16384}.  This is easily extensible, but only those values are
+		currently support.
+
+config MM_PGPOOL_PADDR
+	hex "Page Memory Pool Start"
+	---help---
+		Physical address of the start of the page memory pool.  This
+		will be aligned to the page size if it is not already aligned.
+
+config MM_PGPOOL_SIZE
+	int "Page Memory Pool Size"
+	---help---
+		The size of the page memory pool in bytes.  This will be aligned
+		if it is not already aligned.
+
+config DEBUG_PGALLOC
+	bool "Page Allocator Debug"
+	default n
+	depends on DEBUG
+	---help---
+		Just like DEBUG_MM, but only generates output from the page
+		allocation logic.
+
+endif # MM_PGALLOC

mm/Makefile

@@ -69,6 +69,12 @@ endif
 ifeq ($(CONFIG_GRAN),y)
 CSRCS += mm_graninit.c mm_granreserve.c mm_granalloc.c mm_granmark.c
 CSRCS += mm_granfree.c mm_grancritical.c
+
+# A page allocator based on the granule allocator
+
+ifeq ($(CONFIG_MM_PGALLOC),y)
+CSRCS += mm_pgalloc.c
+endif
 endif
 
 BINDIR ?= bin

mm/mm_gran.h

@@ -63,19 +63,19 @@
 
 #ifdef CONFIG_CPP_HAVE_VARARGS
 #  ifdef CONFIG_DEBUG_GRAM
-#    define gramdbg(format, ...)       dbg(format, ##__VA_ARGS__)
+#    define grandbg(format, ...)       dbg(format, ##__VA_ARGS__)
-#    define gramvdbg(format, ...)      vdbg(format, ##__VA_ARGS__)
+#    define granvdbg(format, ...)      vdbg(format, ##__VA_ARGS__)
 #  else
-#    define gramdbg(format, ...)       mdbg(format, ##__VA_ARGS__)
+#    define grandbg(format, ...)       mdbg(format, ##__VA_ARGS__)
-#    define gramvdbg(format, ...)      mvdbg(format, ##__VA_ARGS__)
+#    define granvdbg(format, ...)      mvdbg(format, ##__VA_ARGS__)
 #  endif
 #else
 #  ifdef CONFIG_DEBUG_GRAM
-#    define gramdbg                    dbg
+#    define grandbg                    dbg
-#    define gramvdbg                   vdbg
+#    define granvdbg                   vdbg
 #  else
-#    define gramdbg                    (void)
+#    define grandbg                    (void)
-#    define gramvdbg                   (void)
+#    define granvdbg                   (void)
 #  endif
 #endif
 

mm/mm_granalloc.c

@@ -235,7 +235,7 @@ static inline FAR void *gran_common_alloc(FAR struct gran_s *priv, size_t size)
                 }
 
               /* Set up for the next time through the loop.  Perform a 64
-               * bit shift to move to the next gram position andi ncrement
+               * bit shift to move to the next gran position andi ncrement
                * to the next candidate allocation address.
                */
 

mm/mm_graninit.c

@@ -102,7 +102,7 @@ gran_common_initialize(FAR void *heapstart, size_t heapsize, uint8_t log2gran,
   unsigned int       alignedsize;
   unsigned int       ngranules;
 
-  /* Check parameters if debug is on.  Note the size of a granual is
+  /* Check parameters if debug is on.  Note the size of a granule is
    * limited to 2**31 bytes and that the size of the granule must be greater
    * than the alignment size.
    */
@@ -159,16 +159,17 @@ gran_common_initialize(FAR void *heapstart, size_t heapsize, uint8_t log2gran,
  *   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
+ *   set to 0 unless you are using the granule allocator to manage DMA
- *   and your hardware has specific memory alignment requirements.
+ *   or page-aligned memory and your hardware has specific memory alignment
+ *   requirements.
  *
- *   Geneneral Usage Summary.  This is an example using the GCC section
+ *   General 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
+ *   The heap is created by calling gran_initialize().  Here the granule 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);
@@ -189,9 +190,9 @@ gran_common_initialize(FAR void *heapstart, size_t heapsize, uint8_t log2gran,
  *   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.
+ *               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
+ *               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
@@ -199,7 +200,7 @@ gran_common_initialize(FAR void *heapstart, size_t heapsize, uint8_t log2gran,
  *
  * Returned Value:
  *   On success, a non-NULL handle is returned that may be used with other
- *   granual allocator interfaces.
+ *   granule allocator interfaces.
  *
  ****************************************************************************/
 

mm/mm_granreserve.c

@@ -93,7 +93,7 @@ static inline void gran_common_reserve(FAR struct gran_s *priv,
       start &= ~mask;
       end = (end + mask) & ~mask;
 
-      /* Calculate the new size in granuales */
+      /* Calculate the new size in granules */
 
       ngranules = ((end - start) >> priv->log2gran) + 1;
 

mm/mm_pgalloc.c

@@ -0,0 +1,223 @@
+/****************************************************************************
+ * mm/mm_pgalloc.c
+ *
+ *   Copyright (C) 2014 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 <assert.h>
+
+#include <nuttx/gran.h>
+#include <nuttx/pgalloc.h>
+
+#include "mm_gran.h"
+
+#ifdef CONFIG_MM_PGALLOC
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+/* Configuration ************************************************************/
+/* CONFIG_MM_PGALLOC - Enable page allocator support
+ * CONFIG_MM_PGSIZE - The page size.  Must be one of {1024, 2048,
+ *   4096, 8192, or 16384}.  This is easily extensible, but only those
+ *   values are currently support.
+ * CONFIG_MM_PGPOOL_PADDR - Physical address of the start of the page
+ *   memory pool.  This will be aligned to the page size if it is not
+ *   already aligned.
+ * CONFIG_MM_PGPOOL_SIZE - The size of the page memory pool in bytes.  This
+ *   will be aligned if it is not already aligned.
+ * CONFIG_DEBUG_PGALLOC - Just like CONFIG_DEBUG_MM, but only generates
+ *   output from the page allocation logic.
+ *
+ * Dependencies:  CONFIG_ARCH_HAVE_MMU and CONFIG_GRAN
+ */
+ 
+/* Debug */
+
+#ifdef CONFIG_CPP_HAVE_VARARGS
+#  ifdef CONFIG_DEBUG_PGALLOC
+#    define pgadbg(format, ...)       dbg(format, ##__VA_ARGS__)
+#    define pgavdbg(format, ...)      vdbg(format, ##__VA_ARGS__)
+#  else
+#    define pgadbg(format, ...)       mdbg(format, ##__VA_ARGS__)
+#    define pgavdbg(format, ...)      mvdbg(format, ##__VA_ARGS__)
+#  endif
+#else
+#  ifdef CONFIG_DEBUG_PGALLOC
+#    define pgadbg                    dbg
+#    define pgavdbg                   vdbg
+#  else
+#    define pgadbg                    (void)
+#    define pgavdbg                   (void)
+#  endif
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+#ifndef CONFIG_GRAN_SINGLE
+/* The state of the page allocator */
+
+static GRAN_HANDLE g_pgalloc;
+#endif
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mm_pginitialize
+ *
+ * Description:
+ *   Initialize the page allocator.
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   Mpme
+ *
+ ****************************************************************************/
+
+void mm_pginitialize(void)
+{
+#ifdef CONFIG_GRAN_SINGLE
+  int ret;
+
+  ret = gran_initialize((FAR void *)CONFIG_MM_PGPOOL_PADDR,
+                        CONFIG_MM_PGPOOL_SIZE,
+                        MM_PGSHIFT, MM_PGSHIFT);
+  DEBUGASSERT(ret == OK);
+  UNUSED(ret);
+
+#else
+  g_pgalloc = gran_initialize((FAR void *)CONFIG_MM_PGPOOL_PADDR,
+                              CONFIG_MM_PGPOOL_SIZE,
+                              MM_PGSHIFT, MM_PGSHIFT);
+  DEBUGASSERT(pg_alloc != NULL);
+
+#endif
+}
+
+/****************************************************************************
+ * Name: mm_pgreserve
+ *
+ * Description:
+ *   Reserve memory in the page memory pool.  This will reserve the pages
+ *   that contain the start and end addresses plus all of the pages
+ *   in between.  This should be done early in the initialization sequence
+ *   before any other allocations are made.
+ *
+ *   Reserved memory can never be allocated (it can be freed however which
+ *   essentially unreserves the memory).
+ *
+ * Input Parameters:
+ *   start  - The address of the beginning of the region to be reserved.
+ *   size   - The size of the region to be reserved
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void mm_pgreserve(uintptr_t start, size_t size)
+{
+#ifdef CONFIG_GRAN_SINGLE
+  gran_reserve(start, size);
+#else
+  gran_reserve(g_pgalloc, start, size);
+#endif
+}
+
+/****************************************************************************
+ * Name: mm_pgalloc
+ *
+ * Description:
+ *   Allocate page memory from the page memory pool.
+ *
+ * Input Parameters:
+ *   npages - The number of pages to allocate, each of size CONFIG_MM_PGSIZE.
+ *
+ * Returned Value:
+ *   On success, a non-zero, physical address of the allocated page memory
+ *   is returned.  Zero is returned on failure.  NOTE:  This is an unmapped
+ *   physical address and cannot be used until it is appropriately mapped.
+ *
+ ****************************************************************************/
+
+uintptr_t mm_pgalloc(unsigned int npages)
+{
+#ifdef CONFIG_GRAN_SINGLE
+  return (uintptr_t)gran_alloc((size_t)1 << MM_PGSHIFT);
+#else
+  return (uintptr_t)gran_alloc(g_pgalloc, (size_t)1 << MM_PGSHIFT);
+#endif
+}
+
+/****************************************************************************
+ * Name: mm_pgfree
+ *
+ * Description:
+ *   Return page memory to the page memory pool.
+ *
+ * Input Parameters:
+ *   paddr  - A physical address to a page in the page memory pool previously
+ *            allocated by mm_pgalloc.
+ *   npages - The number of contiguous pages to be return to the page memory
+ *            pool, beginning with the page at paddr;
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void mm_pgfree(uintptr_t paddr, unsigned int npages)
+{
+#ifdef CONFIG_GRAN_SINGLE
+  gran_free((FAR void*)paddr, (size_t)npages << MM_PGSHIFT);
+#else
+  gran_free(g_pgalloc, (FAR void*)paddr, (size_t)npages << MM_PGSHIFT);
+#endif
+}
+
+#endif /* CONFIG_MM_PGALLOC */