nios2: Page table management

This patch adds support for page table management.

Signed-off-by: Ley Foon Tan <lftan@altera.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/arch/nios2/include/asm/pgtable-bits.h b/arch/nios2/include/asm/pgtable-bits.h
new file mode 100644
index 000000000000..ce9e7069aa96
--- /dev/null
+++ b/arch/nios2/include/asm/pgtable-bits.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
+ * Copyright (C) 2009 Wind River Systems Inc
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#ifndef _ASM_NIOS2_PGTABLE_BITS_H
+#define _ASM_NIOS2_PGTABLE_BITS_H
+
+/*
+ * These are actual hardware defined protection bits in the tlbacc register
+ * which looks like this:
+ *
+ * 31 30 ... 26 25 24 23 22 21 20 19 18 ...  1  0
+ * ignored........  C  R  W  X  G PFN............
+ */
+#define _PAGE_GLOBAL	(1<<20)
+#define _PAGE_EXEC	(1<<21)
+#define _PAGE_WRITE	(1<<22)
+#define _PAGE_READ	(1<<23)
+#define _PAGE_CACHED	(1<<24)	/* C: data access cacheable */
+
+/*
+ * Software defined bits. They are ignored by the hardware and always read back
+ * as zero, but can be written as non-zero.
+ */
+#define _PAGE_PRESENT	(1<<25)	/* PTE contains a translation */
+#define _PAGE_ACCESSED	(1<<26)	/* page referenced */
+#define _PAGE_DIRTY	(1<<27)	/* dirty page */
+#define _PAGE_FILE	(1<<28)	/* PTE used for file mapping or swap */
+
+#endif /* _ASM_NIOS2_PGTABLE_BITS_H */