Refactor the xlat_tables library code

The AArch32 long descriptor format and the AArch64 descriptor format
correspond to each other which allows possible sharing of xlat_tables
library code between AArch64 and AArch32. This patch refactors the
xlat_tables library code to seperate the common functionality from
architecture specific code. Prior to this patch, all of the xlat_tables
library code were in `lib/aarch64/xlat_tables.c` file. The refactored code
is now in `lib/xlat_tables/` directory. The AArch64 specific programming
for xlat_tables is in `lib/xlat_tables/aarch64/xlat_tables.c` and the rest
of the code common to AArch64 and AArch32 is in
`lib/xlat_tables/xlat_tables_common.c`. Also the data types used in
xlat_tables library APIs are reworked to make it compatible between AArch64
and AArch32.

The `lib/aarch64/xlat_tables.c` file now includes the new xlat_tables
library files to retain compatibility for existing platform ports.
The macros related to xlat_tables library are also moved from
`include/lib/aarch64/arch.h` to the header `include/lib/xlat_tables.h`.

NOTE: THE `lib/aarch64/xlat_tables.c` FILE IS DEPRECATED AND PLATFORM PORTS
ARE EXPECTED TO INCLUDE THE NEW XLAT_TABLES LIBRARY FILES IN THEIR MAKEFILES.

Change-Id: I3d17217d24aaf3a05a4685d642a31d4d56255a0f
diff --git a/include/lib/xlat_tables.h b/include/lib/xlat_tables.h
new file mode 100644
index 0000000..abe46ed
--- /dev/null
+++ b/include/lib/xlat_tables.h
@@ -0,0 +1,187 @@
+/*
+ * Copyright (c) 2014-2016, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * 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.
+ *
+ * Neither the name of ARM 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 HOLDER 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 __XLAT_TABLES_H__
+#define __XLAT_TABLES_H__
+
+/* Miscellaneous MMU related constants */
+#define NUM_2MB_IN_GB		(1 << 9)
+#define NUM_4K_IN_2MB		(1 << 9)
+#define NUM_GB_IN_4GB		(1 << 2)
+
+#define TWO_MB_SHIFT		21
+#define ONE_GB_SHIFT		30
+#define FOUR_KB_SHIFT		12
+
+#define ONE_GB_INDEX(x)		((x) >> ONE_GB_SHIFT)
+#define TWO_MB_INDEX(x)		((x) >> TWO_MB_SHIFT)
+#define FOUR_KB_INDEX(x)	((x) >> FOUR_KB_SHIFT)
+
+#define INVALID_DESC		0x0
+#define BLOCK_DESC		0x1
+#define TABLE_DESC		0x3
+
+#define FIRST_LEVEL_DESC_N	ONE_GB_SHIFT
+#define SECOND_LEVEL_DESC_N	TWO_MB_SHIFT
+#define THIRD_LEVEL_DESC_N	FOUR_KB_SHIFT
+
+#define LEVEL1			1
+#define LEVEL2			2
+#define LEVEL3			3
+
+#define XN			(1ull << 2)
+#define PXN			(1ull << 1)
+#define CONT_HINT		(1ull << 0)
+
+#define UPPER_ATTRS(x)		(x & 0x7) << 52
+#define NON_GLOBAL		(1 << 9)
+#define ACCESS_FLAG		(1 << 8)
+#define NSH			(0x0 << 6)
+#define OSH			(0x2 << 6)
+#define ISH			(0x3 << 6)
+
+#define PAGE_SIZE_SHIFT		FOUR_KB_SHIFT
+#define PAGE_SIZE		(1 << PAGE_SIZE_SHIFT)
+#define PAGE_SIZE_MASK		(PAGE_SIZE - 1)
+#define IS_PAGE_ALIGNED(addr)	(((addr) & PAGE_SIZE_MASK) == 0)
+
+#define XLAT_ENTRY_SIZE_SHIFT	3 /* Each MMU table entry is 8 bytes (1 << 3) */
+#define XLAT_ENTRY_SIZE		(1 << XLAT_ENTRY_SIZE_SHIFT)
+
+#define XLAT_TABLE_SIZE_SHIFT	PAGE_SIZE_SHIFT
+#define XLAT_TABLE_SIZE		(1 << XLAT_TABLE_SIZE_SHIFT)
+
+/* Values for number of entries in each MMU translation table */
+#define XLAT_TABLE_ENTRIES_SHIFT (XLAT_TABLE_SIZE_SHIFT - XLAT_ENTRY_SIZE_SHIFT)
+#define XLAT_TABLE_ENTRIES	(1 << XLAT_TABLE_ENTRIES_SHIFT)
+#define XLAT_TABLE_ENTRIES_MASK	(XLAT_TABLE_ENTRIES - 1)
+
+/* Values to convert a memory address to an index into a translation table */
+#define L3_XLAT_ADDRESS_SHIFT	PAGE_SIZE_SHIFT
+#define L2_XLAT_ADDRESS_SHIFT	(L3_XLAT_ADDRESS_SHIFT + XLAT_TABLE_ENTRIES_SHIFT)
+#define L1_XLAT_ADDRESS_SHIFT	(L2_XLAT_ADDRESS_SHIFT + XLAT_TABLE_ENTRIES_SHIFT)
+
+/*
+ * AP[1] bit is ignored by hardware and is
+ * treated as if it is One in EL2/EL3
+ */
+#define AP_RO			(0x1 << 5)
+#define AP_RW			(0x0 << 5)
+
+#define NS				(0x1 << 3)
+#define ATTR_NON_CACHEABLE_INDEX	0x2
+#define ATTR_DEVICE_INDEX		0x1
+#define ATTR_IWBWA_OWBWA_NTR_INDEX	0x0
+#define LOWER_ATTRS(x)			(((x) & 0xfff) << 2)
+#define ATTR_NON_CACHEABLE		(0x44)
+#define ATTR_DEVICE			(0x4)
+#define ATTR_IWBWA_OWBWA_NTR		(0xff)
+#define MAIR_ATTR_SET(attr, index)	(attr << (index << 3))
+
+/*
+ * Flags to override default values used to program system registers while
+ * enabling the MMU.
+ */
+#define DISABLE_DCACHE		(1 << 0)
+
+#ifndef __ASSEMBLY__
+#include <stddef.h>
+#include <stdint.h>
+
+/* Helper macro to define entries for mmap_region_t. It creates
+ * identity mappings for each region.
+ */
+#define MAP_REGION_FLAT(adr, sz, attr) MAP_REGION(adr, adr, sz, attr)
+
+/* Helper macro to define entries for mmap_region_t. It allows to
+ * re-map address mappings from 'pa' to 'va' for each region.
+ */
+#define MAP_REGION(pa, va, sz, attr) {(pa), (va), (sz), (attr)}
+
+/*
+ * Shifts and masks to access fields of an mmap_attr_t
+ */
+#define MT_TYPE_MASK	0x7
+#define MT_TYPE(_attr)	((_attr) & MT_TYPE_MASK)
+/* Access permissions (RO/RW) */
+#define MT_PERM_SHIFT	3
+/* Security state (SECURE/NS) */
+#define MT_SEC_SHIFT	4
+
+/*
+ * Memory mapping attributes
+ */
+typedef enum  {
+	/*
+	 * Memory types supported.
+	 * These are organised so that, going down the list, the memory types
+	 * are getting weaker; conversely going up the list the memory types are
+	 * getting stronger.
+	 */
+	MT_DEVICE,
+	MT_NON_CACHEABLE,
+	MT_MEMORY,
+	/* Values up to 7 are reserved to add new memory types in the future */
+
+	/*
+	 * The following values are organised so that a clear bit gives a more
+	 * restrictive mapping than a set bit, that way a bitwise-and of two
+	 * sets of attributes will never give an attribute which has greater
+	 * access rights than any of the original attributes.
+	 */
+	MT_RO		= 0 << MT_PERM_SHIFT,
+	MT_RW		= 1 << MT_PERM_SHIFT,
+
+	MT_SECURE	= 0 << MT_SEC_SHIFT,
+	MT_NS		= 1 << MT_SEC_SHIFT,
+} mmap_attr_t;
+
+/*
+ * Structure for specifying a single region of memory.
+ */
+typedef struct mmap_region {
+	unsigned long long	base_pa;
+	uintptr_t		base_va;
+	size_t			size;
+	mmap_attr_t		attr;
+} mmap_region_t;
+
+/* Generic translation table APIs */
+void init_xlat_tables(void);
+void mmap_add_region(unsigned long long base_pa, uintptr_t base_va,
+				size_t size, unsigned int attr);
+void mmap_add(const mmap_region_t *mm);
+
+/* AArch64 specific translation table APIs */
+void enable_mmu_el1(unsigned int flags);
+void enable_mmu_el3(unsigned int flags);
+
+#endif /*__ASSEMBLY__*/
+#endif /* __XLAT_TABLES_H__ */