xlat lib: Reorganize architectural defs

Move the header files that provide translation tables architectural
definitions from the library v2 source files to the library include
directory. This allows to share these definitions between both
versions (v1 and v2) of the library.

Create a new header file that includes the AArch32 or AArch64
definitions based on the AARCH32 build flag, so that the library user
doesn't have to worry about handling it on their side.

Also repurpose some of the definitions the header files provide to
concentrate on the things that differ between AArch32 and AArch64.
As a result they now contain the following information:
 - the first table level that allows block descriptors;
 - the architectural limits of the virtual address space;
 - the initial lookup level to cover the entire address space.

Additionally, move the XLAT_TABLE_LEVEL_MIN macro from
xlat_tables_defs.h to the AArch32/AArch64 architectural definitions.

This new organisation eliminates duplicated information in the AArch32
and AArch64 versions. It also decouples these architectural files from
any platform-specific information. Previously, they were dependent on
the address space size, which is platform-specific.

Finally, for the v2 of the library, move the compatibility code for
ADDR_SPACE_SIZE into a C file as it is not needed outside of this
file. For v1, this code hasn't been changed and stays in a header
file because it's needed by several files.

Change-Id: If746c684acd80eebf918abd3ab6e8481d004ac68
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
diff --git a/include/lib/xlat_tables/aarch32/xlat_tables_aarch32.h b/include/lib/xlat_tables/aarch32/xlat_tables_aarch32.h
new file mode 100644
index 0000000..28be8e3
--- /dev/null
+++ b/include/lib/xlat_tables/aarch32/xlat_tables_aarch32.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __XLAT_TABLES_AARCH32_H__
+#define __XLAT_TABLES_AARCH32_H__
+
+#include <arch.h>
+#include <utils_def.h>
+#include <xlat_tables_defs.h>
+
+#if !defined(PAGE_SIZE)
+#error "PAGE_SIZE is not defined."
+#endif
+
+/*
+ * In AArch32 state, the MMU only supports 4KB page granularity, which means
+ * that the first translation table level is either 1 or 2. Both of them are
+ * allowed to have block and table descriptors. See section G4.5.6 of the
+ * ARMv8-A Architecture Reference Manual (DDI 0487A.k) for more information.
+ *
+ * The define below specifies the first table level that allows block
+ * descriptors.
+ */
+#if PAGE_SIZE != (4 * 1024)
+#error "Invalid granule size. AArch32 supports 4KB pages only."
+#endif
+
+#define MIN_LVL_BLOCK_DESC 1
+
+#define XLAT_TABLE_LEVEL_MIN	U(1)
+
+/*
+ * Define the architectural limits of the virtual address space in AArch32
+ * state.
+ *
+ * TTBCR.TxSZ is calculated as 32 minus the width of said address space. The
+ * value of TTBCR.TxSZ must be in the range 0 to 7 [1], which means that the
+ * virtual address space width must be in the range 32 to 25 bits.
+ *
+ * [1] See the ARMv8-A Architecture Reference Manual (DDI 0487A.j) for more
+ * information, Section G4.6.5
+ */
+#define MIN_VIRT_ADDR_SPACE_SIZE	(1      << (32 - TTBCR_TxSZ_MAX))
+#define MAX_VIRT_ADDR_SPACE_SIZE	(ULL(1) << (32 - TTBCR_TxSZ_MIN))
+
+/*
+ * Here we calculate the initial lookup level from the value of the given
+ * virtual address space size. For a 4 KB page size,
+ * - level 1 supports virtual address spaces of widths 32 to 31 bits;
+ * - level 2 from 30 to 25.
+ *
+ * Wider or narrower address spaces are not supported. As a result, level 3
+ * cannot be used as the initial lookup level with 4 KB granularity.
+ * See the ARMv8-A Architecture Reference Manual (DDI 0487A.j) for more
+ * information, Section G4.6.5
+ *
+ * For example, for a 31-bit address space (i.e. virt_addr_space_size ==
+ * 1 << 31), TTBCR.TxSZ will be programmed to (32 - 31) = 1. According to Table
+ * G4-5 in the ARM ARM, the initial lookup level for an address space like that
+ * is 1.
+ *
+ * Note that this macro assumes that the given virtual address space size is
+ * valid. Therefore, the caller is expected to check it is the case using the
+ * CHECK_VIRT_ADDR_SPACE_SIZE() macro first.
+ */
+#define GET_XLAT_TABLE_LEVEL_BASE(virt_addr_space_size)			\
+	(((virt_addr_space_size) > (1 << L1_XLAT_ADDRESS_SHIFT)) ? 1 : 2)
+
+#endif /* __XLAT_TABLES_AARCH32_H__ */
diff --git a/include/lib/xlat_tables/aarch64/xlat_tables_aarch64.h b/include/lib/xlat_tables/aarch64/xlat_tables_aarch64.h
new file mode 100644
index 0000000..9cad035
--- /dev/null
+++ b/include/lib/xlat_tables/aarch64/xlat_tables_aarch64.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __XLAT_TABLES_AARCH64_H__
+#define __XLAT_TABLES_AARCH64_H__
+
+#include <arch.h>
+#include <utils_def.h>
+#include <xlat_tables_defs.h>
+
+#if !defined(PAGE_SIZE)
+#error "PAGE_SIZE is not defined."
+#endif
+
+/*
+ * In AArch64 state, the MMU may support 4 KB, 16 KB and 64 KB page
+ * granularity. For 4KB granularity, a level 0 table descriptor doesn't support
+ * block translation. For 16KB, the same thing happens to levels 0 and 1. For
+ * 64KB, same for level 1. See section D4.3.1 of the ARMv8-A Architecture
+ * Reference Manual (DDI 0487A.k) for more information.
+ *
+ * The define below specifies the first table level that allows block
+ * descriptors.
+ */
+#if PAGE_SIZE == (4 * 1024)
+# define MIN_LVL_BLOCK_DESC 1
+#elif PAGE_SIZE == (16 * 1024) || PAGE_SIZE == (64 * 1024)
+# define MIN_LVL_BLOCK_DESC 2
+#endif
+
+#define XLAT_TABLE_LEVEL_MIN	U(0)
+
+/*
+ * Define the architectural limits of the virtual address space in AArch64
+ * state.
+ *
+ * TCR.TxSZ is calculated as 64 minus the width of said address space.
+ * The value of TCR.TxSZ must be in the range 16 to 39 [1], which means that
+ * the virtual address space width must be in the range 48 to 25 bits.
+ *
+ * [1] See the ARMv8-A Architecture Reference Manual (DDI 0487A.j) for more
+ * information:
+ * Page 1730: 'Input address size', 'For all translation stages'.
+ */
+#define MIN_VIRT_ADDR_SPACE_SIZE	(1      << (64 - TCR_TxSZ_MAX))
+#define MAX_VIRT_ADDR_SPACE_SIZE	(ULL(1) << (64 - TCR_TxSZ_MIN))
+
+/*
+ * Here we calculate the initial lookup level from the value of the given
+ * virtual address space size. For a 4 KB page size,
+ * - level 0 supports virtual address spaces of widths 48 to 40 bits;
+ * - level 1 from 39 to 31;
+ * - level 2 from 30 to 25.
+ *
+ * Wider or narrower address spaces are not supported. As a result, level 3
+ * cannot be used as initial lookup level with 4 KB granularity. See section
+ * D4.2.5 in the ARMv8-A Architecture Reference Manual (DDI 0487A.j) for more
+ * information.
+ *
+ * For example, for a 35-bit address space (i.e. virt_addr_space_size ==
+ * 1 << 35), TCR.TxSZ will be programmed to (64 - 35) = 29. According to Table
+ * D4-11 in the ARM ARM, the initial lookup level for an address space like that
+ * is 1.
+ *
+ * Note that this macro assumes that the given virtual address space size is
+ * valid. Therefore, the caller is expected to check it is the case using the
+ * CHECK_VIRT_ADDR_SPACE_SIZE() macro first.
+ */
+#define GET_XLAT_TABLE_LEVEL_BASE(virt_addr_space_size)				\
+	(((virt_addr_space_size) > (ULL(1) << L0_XLAT_ADDRESS_SHIFT))		\
+	? 0									\
+	: (((virt_addr_space_size) > (1 << L1_XLAT_ADDRESS_SHIFT)) ? 1 : 2))
+
+#endif /* __XLAT_TABLES_AARCH64_H__ */
diff --git a/include/lib/xlat_tables/xlat_tables_arch.h b/include/lib/xlat_tables/xlat_tables_arch.h
new file mode 100644
index 0000000..165b161d
--- /dev/null
+++ b/include/lib/xlat_tables/xlat_tables_arch.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __XLAT_TABLES_ARCH_H__
+#define __XLAT_TABLES_ARCH_H__
+
+#ifdef AARCH32
+#include "aarch32/xlat_tables_aarch32.h"
+#else
+#include "aarch64/xlat_tables_aarch64.h"
+#endif
+
+/*
+ * Evaluates to 1 if the given virtual address space size is valid, or 0 if it's
+ * not.
+ *
+ * A valid size is one that is a power of 2 and is within the architectural
+ * limits. Not that these limits are different for AArch32 and AArch64.
+ */
+#define CHECK_VIRT_ADDR_SPACE_SIZE(size)			\
+	(((size) >= MIN_VIRT_ADDR_SPACE_SIZE) &&		\
+	((size) <= MAX_VIRT_ADDR_SPACE_SIZE) &&			\
+	IS_POWER_OF_TWO(size))
+
+/*
+ * Evaluates to 1 if the given physical address space size is a power of 2,
+ * or 0 if it's not.
+ */
+#define CHECK_PHY_ADDR_SPACE_SIZE(size)				\
+	(IS_POWER_OF_TWO(size))
+
+/*
+ * Compute the number of entries required at the initial lookup level to address
+ * the whole virtual address space.
+ */
+#define GET_NUM_BASE_LEVEL_ENTRIES(addr_space_size)			\
+	((addr_space_size) >>						\
+		XLAT_ADDR_SHIFT(GET_XLAT_TABLE_LEVEL_BASE(addr_space_size)))
+
+#endif /* __XLAT_TABLES_ARCH_H__ */
diff --git a/include/lib/xlat_tables/xlat_tables_defs.h b/include/lib/xlat_tables/xlat_tables_defs.h
index 4b993a0..779532e 100644
--- a/include/lib/xlat_tables/xlat_tables_defs.h
+++ b/include/lib/xlat_tables/xlat_tables_defs.h
@@ -59,12 +59,6 @@
 #define XLAT_TABLE_SIZE_SHIFT	PAGE_SIZE_SHIFT /* Size of one complete table */
 #define XLAT_TABLE_SIZE		(U(1) << XLAT_TABLE_SIZE_SHIFT)
 
-#ifdef AARCH32
-#define XLAT_TABLE_LEVEL_MIN	U(1)
-#else
-#define XLAT_TABLE_LEVEL_MIN	U(0)
-#endif /* AARCH32 */
-
 #define XLAT_TABLE_LEVEL_MAX	U(3)
 
 /* Values for number of entries in each MMU translation table */