1 files changed, 121 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/arm/up_va2pte.c b/nuttx/arch/arm/src/arm/up_va2pte.c
new file mode 100755
index 000000000..5f92ad821
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+++ b/nuttx/arch/arm/src/arm/up_va2pte.c
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+/****************************************************************************
+ * arch/arm/src/arm/up_va2pte.c
+ * Utility to map a virtual address to a L2 page table entry.
+ *
+ *   Copyright (C) 2010 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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 <stdint.h>
+#include <debug.h>
+
+#include <nuttx/sched.h>
+#include <nuttx/page.h>
+
+#include "chip.h"
+#include "pg_macros.h"
+#include "up_internal.h"
+
+#ifdef CONFIG_PAGING
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_va2pte()
+ *
+ * Description:
+ *  Convert a virtual address within the paged text region into a pointer to
+ *  the corresponding page table entry.
+ *
+ * Input Parameters:
+ *   vaddr - The virtual address within the paged text region.
+ *
+ * Returned Value:
+ *   A pointer to  the corresponding page table entry.
+ *
+ * Assumptions:
+ *   - This function is called from the normal tasking context (but with
+ *     interrupts disabled).  The implementation must take whatever actions
+ *     are necessary to assure that the operation is safe within this
+ *     context.
+ *
+ ****************************************************************************/
+
+uint32_t *up_va2pte(uintptr_t vaddr)
+{
+  uint32_t L1;
+  uint32_t *L2;
+  unsigned int ndx;
+
+  /* The virtual address is expected to lie in the paged text region */
+
+  DEBUGASSERT(vaddr >= PG_PAGED_VBASE && vaddr < PG_PAGED_VEND);
+
+  /* Get the L1 table entry associated with this virtual address */
+
+  L1 = *(uint32_t*)PG_POOL_VA2L1VADDR(vaddr);
+
+  /* Get the address of the L2 page table from the L1 entry */
+
+  L2 = (uint32_t*)PG_POOL_L12VPTABLE(L1);
+
+  /* Get the index into the L2 page table.  Each L1 entry maps
+   * 256 x 4Kb or 1024 x 1Kb pages.
+   */
+
+  ndx = (vaddr & 0x000fffff) >> PAGESHIFT;
+
+  /* Return true if this virtual address is mapped. */
+
+  return &L2[ndx];
+}
+
+#endif /* CONFIG_PAGING */