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/*
* Copyright (c) 2017-2018, 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 <lib/utils_def.h>
#include <lib/xlat_tables/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 != PAGE_SIZE_4KB
#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) << (U(32) - TTBCR_TxSZ_MAX))
#define MAX_VIRT_ADDR_SPACE_SIZE (ULL(1) << (U(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.
*/
#define GET_XLAT_TABLE_LEVEL_BASE(_virt_addr_space_sz) \
(((_virt_addr_space_sz) > (ULL(1) << L1_XLAT_ADDRESS_SHIFT)) ? \
U(1) : U(2))
#endif /* XLAT_TABLES_AARCH32_H */