/* * 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 #include #include #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 */