MIPS: malta: spaces.h: Add spaces.h file for Malta (EVA)

Add a spaces.h file for Malta to override certain memory macros
when operating in EVA mode.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>

arch/mips/include/asm/mach-malta/spaces.h

+/*
+ * 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.
+ *
+ * Copyright (C) 2014 Imagination Technologies Ltd.
+ */
+
+#ifndef _ASM_MALTA_SPACES_H
+#define _ASM_MALTA_SPACES_H
+
+#ifdef CONFIG_EVA
+
+/*
+ * Traditional Malta Board Memory Map for EVA
+ *
+ * 0x00000000 - 0x0fffffff: 1st RAM region, 256MB
+ * 0x10000000 - 0x1bffffff: GIC and CPC Control Registers
+ * 0x1c000000 - 0x1fffffff: I/O And Flash
+ * 0x20000000 - 0x7fffffff: 2nd RAM region, 1.5GB
+ * 0x80000000 - 0xffffffff: Physical memory aliases to 0x0 (2GB)
+ *
+ * The kernel is still located in 0x80000000(kseg0). However,
+ * the physical mask has been shifted to 0x80000000 which exploits the alias
+ * on the Malta board. As a result of which, we override the __pa_symbol
+ * to peform direct mapping from virtual to physical addresses. In other
+ * words, the 0x80000000 virtual address maps to 0x80000000 physical address
+ * which in turn aliases to 0x0. We do this in order to be able to use a flat
+ * 2GB of memory (0x80000000 - 0xffffffff) so we can avoid the I/O hole in
+ * 0x10000000 - 0x1fffffff.
+ * The last 64KB of physical memory are reserved for correct HIGHMEM
+ * macros arithmetics.
+ *
+ */
+
+#define PAGE_OFFSET	_AC(0x0, UL)
+#define PHYS_OFFSET	_AC(0x80000000, UL)
+#define HIGHMEM_START	_AC(0xffff0000, UL)
+
+#define __pa_symbol(x)	(RELOC_HIDE((unsigned long)(x), 0))
+
+#endif /* CONFIG_EVA */
+
+#include <asm/mach-generic/spaces.h>
+
+#endif /* _ASM_MALTA_SPACES_H */