Antonio Nino Diaz | 233c7c1 | 2017-03-08 14:40:23 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved. |
| 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions are met: |
| 6 | * |
| 7 | * Redistributions of source code must retain the above copyright notice, this |
| 8 | * list of conditions and the following disclaimer. |
| 9 | * |
| 10 | * Redistributions in binary form must reproduce the above copyright notice, |
| 11 | * this list of conditions and the following disclaimer in the documentation |
| 12 | * and/or other materials provided with the distribution. |
| 13 | * |
| 14 | * Neither the name of ARM nor the names of its contributors may be used |
| 15 | * to endorse or promote products derived from this software without specific |
| 16 | * prior written permission. |
| 17 | * |
| 18 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| 19 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 20 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 21 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE |
| 22 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 23 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 24 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 25 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 26 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 27 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 28 | * POSSIBILITY OF SUCH DAMAGE. |
| 29 | */ |
| 30 | |
| 31 | #ifndef __XLAT_TABLES_ARCH_H__ |
| 32 | #define __XLAT_TABLES_ARCH_H__ |
| 33 | |
| 34 | #include <arch.h> |
| 35 | #include <platform_def.h> |
| 36 | #include <xlat_tables_defs.h> |
| 37 | |
| 38 | /* |
| 39 | * In AArch32 state, the MMU only supports 4KB page granularity, which means |
| 40 | * that the first translation table level is either 1 or 2. Both of them are |
| 41 | * allowed to have block and table descriptors. See section G4.5.6 of the |
| 42 | * ARMv8-A Architecture Reference Manual (DDI 0487A.k) for more information. |
| 43 | * |
| 44 | * The define below specifies the first table level that allows block |
| 45 | * descriptors. |
| 46 | */ |
| 47 | |
| 48 | #define MIN_LVL_BLOCK_DESC 1 |
| 49 | |
| 50 | /* |
| 51 | * Each platform can define the size of the virtual address space, which is |
| 52 | * defined in PLAT_VIRT_ADDR_SPACE_SIZE. TTBCR.TxSZ is calculated as 32 minus |
| 53 | * the width of said address space. The value of TTBCR.TxSZ must be in the |
| 54 | * range 0 to 7 [1], which means that the virtual address space width must be |
| 55 | * in the range 32 to 25 bits. |
| 56 | * |
| 57 | * Here we calculate the initial lookup level from the value of |
| 58 | * PLAT_VIRT_ADDR_SPACE_SIZE. For a 4 KB page size, level 1 supports virtual |
| 59 | * address spaces of widths 32 to 31 bits, and level 2 from 30 to 25. Wider or |
| 60 | * narrower address spaces are not supported. As a result, level 3 cannot be |
| 61 | * used as initial lookup level with 4 KB granularity [1]. |
| 62 | * |
| 63 | * For example, for a 31-bit address space (i.e. PLAT_VIRT_ADDR_SPACE_SIZE == |
| 64 | * 1 << 31), TTBCR.TxSZ will be programmed to (32 - 31) = 1. According to Table |
| 65 | * G4-5 in the ARM ARM, the initial lookup level for an address space like that |
| 66 | * is 1. |
| 67 | * |
| 68 | * See the ARMv8-A Architecture Reference Manual (DDI 0487A.j) for more |
| 69 | * information: |
| 70 | * [1] Section G4.6.5 |
| 71 | */ |
| 72 | |
| 73 | #if PLAT_VIRT_ADDR_SPACE_SIZE > (1ULL << (32 - TTBCR_TxSZ_MIN)) |
| 74 | |
| 75 | # error "PLAT_VIRT_ADDR_SPACE_SIZE is too big." |
| 76 | |
| 77 | #elif PLAT_VIRT_ADDR_SPACE_SIZE > (1 << L1_XLAT_ADDRESS_SHIFT) |
| 78 | |
| 79 | # define XLAT_TABLE_LEVEL_BASE 1 |
| 80 | # define NUM_BASE_LEVEL_ENTRIES \ |
| 81 | (PLAT_VIRT_ADDR_SPACE_SIZE >> L1_XLAT_ADDRESS_SHIFT) |
| 82 | |
| 83 | #elif PLAT_VIRT_ADDR_SPACE_SIZE >= (1 << (32 - TTBCR_TxSZ_MAX)) |
| 84 | |
| 85 | # define XLAT_TABLE_LEVEL_BASE 2 |
| 86 | # define NUM_BASE_LEVEL_ENTRIES \ |
| 87 | (PLAT_VIRT_ADDR_SPACE_SIZE >> L2_XLAT_ADDRESS_SHIFT) |
| 88 | |
| 89 | #else |
| 90 | |
| 91 | # error "PLAT_VIRT_ADDR_SPACE_SIZE is too small." |
| 92 | |
| 93 | #endif |
| 94 | |
| 95 | #endif /* __XLAT_TABLES_ARCH_H__ */ |