More updates to MPU control logic

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5735 42af7a65-404d-4744-a932-0658087f49c3

ChangeLog

@@ -4320,3 +4320,5 @@
 	  for better supportability. (2013-03-11)
 	* configs/open1788/kernel, knsh, and scripts:  Add a kernel mode build
 	  configuration for the WaveShare Open1788 board. (2013-03-11)
+	* arch/arm/src/armv7-m/up_mpu.c:  Several fixes to MPU logic.
+	  (2013-03-12).

arch/arm/src/armv7-m/mpu.h

@@ -127,7 +127,8 @@
 #undef EXTERN
 #if defined(__cplusplus)
 #define EXTERN extern "C"
-extern "C" {
+extern "C"
+{
 #else
 #define EXTERN extern
 #endif
@@ -140,10 +141,10 @@ extern "C" {
  *
  ****************************************************************************/
 
-EXTERN unsigned int mpu_allocregion(void);
+unsigned int mpu_allocregion(void);
 
 /****************************************************************************
- * Name: mpu_log2regionsize
+ * Name: mpu_log2regionceil
  *
  * Description:
  *   Determine the smallest value of l2size (log base 2 size) such that the
@@ -153,7 +154,20 @@ EXTERN unsigned int mpu_allocregion(void);
  *
  ****************************************************************************/
 
-EXTERN uint8_t mpu_log2regionsize(size_t size);
+uint8_t mpu_log2regionceil(size_t size);
+
+/****************************************************************************
+ * Name: mpu_log2regionfloor
+ *
+ * Description:
+ *   Determine the largest value of l2size (log base 2 size) such that the
+ *   following is true:
+ *
+ *   size >= (1 << l2size)
+ *
+ ****************************************************************************/
+
+uint8_t mpu_log2regionfloor(size_t size);
 
 /****************************************************************************
  * Name: mpu_subregion
@@ -165,11 +179,11 @@ EXTERN uint8_t mpu_log2regionsize(size_t size);
  *
  * Assumption:
  *   l2size has the same properties as the return value from
- *   mpu_log2regionsize()
+ *   mpu_log2regionceil()
  *
  ****************************************************************************/
 
-EXTERN uint32_t mpu_subregion(size_t size, uint8_t l2size);
+uint32_t mpu_subregion(size_t size, uint8_t l2size);
 
 /************************************************************************************
  * Inline Functions
@@ -249,7 +263,7 @@ static inline void mpu_userflash(uintptr_t base, size_t size)
 
   /* Select the region size and the sub-region map */
 
-  l2size     = mpu_log2regionsize(size);
+  l2size     = mpu_log2regionceil(size);
   subregions = mpu_subregion(size, l2size);
 
   /* The configure the region */
@@ -287,7 +301,7 @@ static inline void mpu_privflash(uintptr_t base, size_t size)
 
   /* Select the region size and the sub-region map */
 
-  l2size     = mpu_log2regionsize(size);
+  l2size     = mpu_log2regionceil(size);
   subregions = mpu_subregion(size, l2size);
 
   /* The configure the region */
@@ -325,7 +339,7 @@ static inline void mpu_userintsram(uintptr_t base, size_t size)
 
   /* Select the region size and the sub-region map */
 
-  l2size     = mpu_log2regionsize(size);
+  l2size     = mpu_log2regionceil(size);
   subregions = mpu_subregion(size, l2size);
 
   /* The configure the region */
@@ -364,7 +378,7 @@ static inline void mpu_privintsram(uintptr_t base, size_t size)
 
   /* Select the region size and the sub-region map */
 
-  l2size     = mpu_log2regionsize(size);
+  l2size     = mpu_log2regionceil(size);
   subregions = mpu_subregion(size, l2size);
 
   /* The configure the region */
@@ -403,7 +417,7 @@ static inline void mpu_userextsram(uintptr_t base, size_t size)
 
   /* Select the region size and the sub-region map */
 
-  l2size     = mpu_log2regionsize(size);
+  l2size     = mpu_log2regionceil(size);
   subregions = mpu_subregion(size, l2size);
 
   /* The configure the region */
@@ -443,7 +457,7 @@ static inline void mpu_privextsram(uintptr_t base, size_t size)
 
   /* Select the region size and the sub-region map */
 
-  l2size     = mpu_log2regionsize(size);
+  l2size     = mpu_log2regionceil(size);
   subregions = mpu_subregion(size, l2size);
 
   /* The configure the region */
@@ -483,7 +497,7 @@ static inline void mpu_peripheral(uintptr_t base, size_t size)
 
   /* Select the region size and the sub-region map */
 
-  l2size     = mpu_log2regionsize(size);
+  l2size     = mpu_log2regionceil(size);
   subregions = mpu_subregion(size, l2size);
 
   /* The configure the region */

arch/arm/src/armv7-m/up_mpu.c

@@ -101,7 +101,7 @@ unsigned int mpu_allocregion(void)
 }
 
 /****************************************************************************
- * Name: mpu_log2regionsize
+ * Name: mpu_log2regionceil
  *
  * Description:
  *   Determine the smallest value of l2size (log base 2 size) such that the
@@ -111,9 +111,9 @@ unsigned int mpu_allocregion(void)
  *
  ****************************************************************************/
 
-uint8_t mpu_log2regionsize(size_t size)
+uint8_t mpu_log2regionceil(size_t size)
 {
-  uint32_t l2size;
+  uint8_t l2size;
 
   /* The minimum permitted region size is 16 bytes (log2(16) = 4. */
 
@@ -121,6 +121,29 @@ uint8_t mpu_log2regionsize(size_t size)
   return l2size;
 }
 
+/****************************************************************************
+ * Name: mpu_log2regionfloor
+ *
+ * Description:
+ *   Determine the largest value of l2size (log base 2 size) such that the
+ *   following is true:
+ *
+ *   size >= (1 << l2size)
+ *
+ ****************************************************************************/
+
+uint8_t mpu_log2regionfloor(size_t size)
+{
+  uint8_t l2size = mpu_log2regionceil(size);
+
+  if (l2size > 4 && size < (1 << l2size))
+    {
+      l2size--;
+    }
+
+  return l2size;
+}
+
 /****************************************************************************
  * Name: mpu_subregion
  *
@@ -131,7 +154,7 @@ uint8_t mpu_log2regionsize(size_t size)
  *
  * Assumption:
  *   l2size has the same properties as the return value from
- *   mpu_log2regionsize()
+ *   mpu_log2regionceil()
  *
  ****************************************************************************/
 

arch/arm/src/lpc17xx/lpc17_allocateheap.c

@@ -211,7 +211,7 @@ void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
    * is aligned to the MPU requirement.
    */
 
-  log2  = (int)mpu_log2regionsize(usize);
+  log2  = (int)mpu_log2regionfloor(usize);
   DEBUGASSERT((CONFIG_DRAM_END & ((1 << log2) - 1)) == 0);
 
   usize = (1 << log2);
@@ -262,7 +262,7 @@ void up_allocate_kheap(FAR void **heap_start, size_t *heap_size)
    * is aligned to the MPU requirement.
    */
 
-  log2  = (int)mpu_log2regionsize(usize);
+  log2  = (int)mpu_log2regionfloor(usize);
   DEBUGASSERT((CONFIG_DRAM_END & ((1 << log2) - 1)) == 0);
 
   usize = (1 << log2);

arch/arm/src/lpc17xx/lpc17_start.c

@@ -210,6 +210,7 @@ void __start(void)
     {
       *dest++ = 0;
     }
+
   showprogress('B');
 
   /* Move the intialized data section from his temporary holding spot in
@@ -222,6 +223,7 @@ void __start(void)
     {
       *dest++ = *src++;
     }
+
   showprogress('C');
 
   /* Perform early serial initialization */

arch/arm/src/lpc17xx/lpc17_userspace.c

@@ -50,7 +50,7 @@
 #ifdef CONFIG_NUTTX_KERNEL
 
 /****************************************************************************
- * Private Definitions
+ * Pre-processor Definitions
  ****************************************************************************/
 
 /****************************************************************************

arch/arm/src/sam3u/sam3u_allocateheap.c

@@ -122,7 +122,7 @@ void up_allocate_heap(FAR void **heap_start, size_t *heap_size)
    * is aligned to the MPU requirement.
    */
 
-  log2  = (int)mpu_log2regionsize(usize);
+  log2  = (int)mpu_log2regionfloor(usize);
   DEBUGASSERT((CONFIG_DRAM_END & ((1 << log2) - 1)) == 0);
 
   usize = (1 << log2);
@@ -173,7 +173,7 @@ void up_allocate_kheap(FAR void **heap_start, size_t *heap_size)
    * is aligned to the MPU requirement.
    */
 
-  log2  = (int)mpu_log2regionsize(usize);
+  log2  = (int)mpu_log2regionfloor(usize);
   DEBUGASSERT((CONFIG_DRAM_END & ((1 << log2) - 1)) == 0);
 
   usize = (1 << log2);