SAMA5D4-EK: In kernel build with address environment, need logic to map user virtual addresses to physical addresses, and vice versa

arch/arm/src/armv7-a/mmu.h

@@ -609,7 +609,8 @@
 
 /* Mapped section size */
 
-#define SECTION_SIZE          (1 << 20)   /* 1Mb */
+#define SECTION_SHIFT         (20)
+#define SECTION_SIZE          (1 << SECTION_SHIFT)   /* 1Mb */
 #define SECTION_MASK          (SECTION_SIZE - 1)
 
 /* The Cortex-A5 supports two translation table base address registers.  In

arch/arm/src/sama5/sam_allocateheap.c

@@ -195,7 +195,7 @@
 #endif
 
 /* The heap space in the primary memory region is added automatically when
- * up_allocate heap is called.  So if the memory region is the primary region,
+ * up_allocate_heap is called.  So if the memory region is the primary region,
  * it should not be added to the heap (again).
  */
 

arch/arm/src/sama5/sam_memories.c

@@ -43,7 +43,10 @@
 #include <assert.h>
 #include <debug.h>
 
+#include <nuttx/addrenv.h>
+
 #include "chip.h"
+#include "sam_pgalloc.h"
 #include "sam_memories.h"
 
 /****************************************************************************
@@ -901,6 +904,21 @@ uintptr_t sam_physramaddr(uintptr_t virtramaddr)
     }
 #endif
 
+#ifdef CONFIG_ARCH_ADDRENV
+  /* Check if the virtual address lies in the user data area and, if so
+   * get the mapping to the physical address in the page pool.
+   */
+
+  else
+    {
+      uintptr_t paddr = sam_physpgaddr(virtramaddr);
+      if (paddr != 0)
+        {
+          return paddr;
+        }
+    }
+#endif
+
   /* We will not get here unless we are called with an invalid or
    * unsupported RAM address.  Special case the NULL address.
    */
@@ -1019,6 +1037,21 @@ uintptr_t sam_virtramaddr(uintptr_t physramaddr)
     }
 #endif
 
+#ifdef CONFIG_ARCH_ADDRENV
+  /* Check if the physical address lies in the page pool and, if so
+   * get the mapping to the virtual address in the user data area.
+   */
+
+  else
+    {
+      uintptr_t vaddr = sam_virtpgaddr(physramaddr);
+      if (vaddr != 0)
+        {
+          return vaddr;
+        }
+    }
+#endif
+
   /* We will not get here unless we are called with an invalid or
    * unsupported RAM address.  Special case the NULL address.
    */

arch/arm/src/sama5/sam_memories.h

@@ -99,7 +99,7 @@ uintptr_t sam_physramaddr(uintptr_t vramaddr);
  * Name: sam_virtramaddr
  *
  * Description:
- *   Give the phsical address of a RAM memory location, return the virtual
+ *   Give the physical address of a RAM memory location, return the virtual
  *   address of that location.
  *
  ****************************************************************************/

arch/arm/src/sama5/sam_pgalloc.c

@@ -41,16 +41,22 @@
 
 #include <sys/types.h>
 #include <assert.h>
+#include <debug.h>
 
 #include <nuttx/arch.h>
+#include <nuttx/addrenv.h>
 #include <nuttx/pgalloc.h>
 
 #include "chip.h"
+#include "mmu.h"
+#include "cache.h"
+
+#include "sam_pgalloc.h"
 
 #ifdef CONFIG_MM_PGALLOC
 
 /****************************************************************************
- * Private Definitions
+ * Pre-processor Definitions
  ****************************************************************************/
 /* Currently, page cache memory must be allocated in DRAM.  There are other
  * possibilities, but the logic in this file will have to extended in order
@@ -104,9 +110,113 @@ void up_allocate_pgheap(FAR void **heap_start, size_t *heap_size)
 {
   DEBUGASSERT(heap_start && heap_size);
 
-  *heap_start = (FAR void *)((uintptr_t)SAM_DDRCS_VSECTION +
+  *heap_start = (FAR void *)((uintptr_t)SAM_DDRCS_PSECTION +
                              CONFIG_SAMA5_DDRCS_PGHEAP_OFFSET);
   *heap_size  = CONFIG_SAMA5_DDRCS_PGHEAP_SIZE;
 }
 
+/****************************************************************************
+ * Name: sam_physpgaddr
+ *
+ * Description:
+ *   Check if the virtual address lies in the user data area and, if so
+ *   get the mapping to the physical address in the page pool.
+ *
+ ****************************************************************************/
+
+uintptr_t sam_physpgaddr(uintptr_t vaddr)
+{
+  FAR uint32_t *l2table;
+  uint32_t l1entry;
+  uintptr_t paddr;
+  int index;
+
+  /* Check if this address is within the range of the virtualized .bss/.data,
+   * heap, or stack regions.
+   */
+
+  if ((vaddr >= CONFIG_ARCH_TEXT_VBASE && vaddr < ARCH_TEXT_VEND) ||
+      (vaddr >= CONFIG_ARCH_DATA_VBASE && vaddr < ARCH_DATA_VEND) ||
+      (vaddr >= CONFIG_ARCH_HEAP_VBASE && vaddr < ARCH_HEAP_VEND) ||
+      (vaddr >= CONFIG_ARCH_STACK_VBASE && vaddr < ARCH_STACK_VEND))
+    {
+      /* Yes.. Get Level 1 page table entry corresponding to this virtual
+       * address.
+       */
+
+      l1entry = mmu_l1_getentry(vaddr);
+      if ((l1entry & PMD_TYPE_MASK) == PMD_TYPE_PTE)
+        {
+          /* Get the physical address of the level 2 page table from level 1
+           * page table entry.
+           */
+
+          paddr = ((uintptr_t)l1entry & PMD_PTE_PADDR_MASK);
+
+          /* Extract the virtual address of the base of level 2 page table */
+
+          l2table = (FAR uint32_t *)sam_virtpgaddr(paddr);
+          if (l2table)
+            {
+              /* Invalidate D-Cache line containing this virtual address so that
+               * we re-read from physical memory
+               */
+
+              index = (vaddr & SECTION_MASK) >> MM_PGSHIFT;
+              arch_invalidate_dcache((uintptr_t)&l2table[index],
+                                     (uintptr_t)&l2table[index] + sizeof(uint32_t));
+
+              /* Get the Level 2 page table entry corresponding to this virtual
+               * address.  Extract the physical address of the page containing
+               * the mapping of the virtual address.
+               */
+
+              paddr = ((uintptr_t)l2table[index] & PTE_SMALL_PADDR_MASK);
+
+              /* Add the correct offset and return the physical address
+               * corresponding to the virtual address.
+               */
+
+              return paddr + (vaddr & MM_PGMASK);
+            }
+        }
+    }
+
+  /* No mapping available */
+
+  return 0;
+}
+
+/****************************************************************************
+ * Name: sam_virtpgaddr
+ *
+ * Description:
+ *   Check if the physical address lies in the page pool and, if so
+ *   get the mapping to the virtual address in the user data area.
+ *
+ ****************************************************************************/
+
+uintptr_t sam_virtpgaddr(uintptr_t paddr)
+{
+  uintptr_t poolstart;
+  uintptr_t poolend;
+
+  /* REVISIT: Not implemented correctly.  The reverse lookup from physical
+   * to virtual.  This will return a kernel accessible virtual address, but
+   * not an address usable by the user code.
+   *
+   * The correct solutions is complex and, perhaps, will never be needed.
+   */
+
+  poolstart = ((uintptr_t)SAM_DDRCS_PSECTION + CONFIG_SAMA5_DDRCS_PGHEAP_OFFSET);
+  poolend   = poolstart + CONFIG_SAMA5_DDRCS_PGHEAP_SIZE;
+
+  if (paddr >= poolstart && paddr < poolend)
+    {
+      return paddr - SAM_DDRCS_PSECTION + SAM_DDRCS_VSECTION;
+    }
+
+  return 0;
+}
+
 #endif /* CONFIG_MM_PGALLOC */

arch/arm/src/sama5/sam_pgalloc.h

@@ -0,0 +1,97 @@
+/****************************************************************************
+ * arch/arm/src/sama5/sam_pgalloc.h
+ *
+ *   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 __ARCH_ARM_SRC_SAMA5_SAM_PGALLOC_H
+#define __ARCH_ARM_SRC_SAMA5_SAM_PGALLOC_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <stdint.h>
+
+#ifdef CONFIG_MM_PGALLOC
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: sam_physpgaddr
+ *
+ * Description:
+ *   Check if the virtual address lies in the user data area and, if so
+ *   get the mapping to the physical address in the page pool.
+ *
+ ****************************************************************************/
+
+uintptr_t sam_physpgaddr(uintptr_t vaddr);
+
+/****************************************************************************
+ * Name: sam_virtpgaddr
+ *
+ * Description:
+ *   Check if the physical address lies in the page pool and, if so
+ *   get the mapping to the virtual address in the user data area.
+ *
+ ****************************************************************************/
+
+uintptr_t sam_virtpgaddr(uintptr_t paddr);
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* CONFIG_MM_PGALLOC */
+#endif /* __ARCH_ARM_SRC_SAMA5_SAM_PGALLOC_H */