1 files changed, 72 insertions, 0 deletions
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 00000000..a418d2dd
--- /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	U(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	(ULL(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) > (ULL(1) << L1_XLAT_ADDRESS_SHIFT)) ? 1 : 2)
+
+#endif /* __XLAT_TABLES_AARCH32_H__ */