Ard Biesheuvel | b7912e0 | 2017-01-11 16:41:53 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Scalar AES core transform |
| 3 | * |
| 4 | * Copyright (C) 2017 Linaro Ltd. |
| 5 | * Author: Ard Biesheuvel <ard.biesheuvel@linaro.org> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/linkage.h> |
| 13 | |
| 14 | .text |
| 15 | .align 5 |
| 16 | |
| 17 | rk .req r0 |
| 18 | rounds .req r1 |
| 19 | in .req r2 |
| 20 | out .req r3 |
| 21 | tt .req ip |
| 22 | |
| 23 | t0 .req lr |
| 24 | t1 .req r2 |
| 25 | t2 .req r3 |
| 26 | |
| 27 | .macro __select, out, in, idx |
| 28 | .if __LINUX_ARM_ARCH__ < 7 |
| 29 | and \out, \in, #0xff << (8 * \idx) |
| 30 | .else |
| 31 | ubfx \out, \in, #(8 * \idx), #8 |
| 32 | .endif |
| 33 | .endm |
| 34 | |
| 35 | .macro __load, out, in, idx |
| 36 | .if __LINUX_ARM_ARCH__ < 7 && \idx > 0 |
| 37 | ldr \out, [tt, \in, lsr #(8 * \idx) - 2] |
| 38 | .else |
| 39 | ldr \out, [tt, \in, lsl #2] |
| 40 | .endif |
| 41 | .endm |
| 42 | |
| 43 | .macro __hround, out0, out1, in0, in1, in2, in3, t3, t4, enc |
| 44 | __select \out0, \in0, 0 |
| 45 | __select t0, \in1, 1 |
| 46 | __load \out0, \out0, 0 |
| 47 | __load t0, t0, 1 |
| 48 | |
| 49 | .if \enc |
| 50 | __select \out1, \in1, 0 |
| 51 | __select t1, \in2, 1 |
| 52 | .else |
| 53 | __select \out1, \in3, 0 |
| 54 | __select t1, \in0, 1 |
| 55 | .endif |
| 56 | __load \out1, \out1, 0 |
| 57 | __select t2, \in2, 2 |
| 58 | __load t1, t1, 1 |
| 59 | __load t2, t2, 2 |
| 60 | |
| 61 | eor \out0, \out0, t0, ror #24 |
| 62 | |
| 63 | __select t0, \in3, 3 |
| 64 | .if \enc |
| 65 | __select \t3, \in3, 2 |
| 66 | __select \t4, \in0, 3 |
| 67 | .else |
| 68 | __select \t3, \in1, 2 |
| 69 | __select \t4, \in2, 3 |
| 70 | .endif |
| 71 | __load \t3, \t3, 2 |
| 72 | __load t0, t0, 3 |
| 73 | __load \t4, \t4, 3 |
| 74 | |
| 75 | eor \out1, \out1, t1, ror #24 |
| 76 | eor \out0, \out0, t2, ror #16 |
| 77 | ldm rk!, {t1, t2} |
| 78 | eor \out1, \out1, \t3, ror #16 |
| 79 | eor \out0, \out0, t0, ror #8 |
| 80 | eor \out1, \out1, \t4, ror #8 |
| 81 | eor \out0, \out0, t1 |
| 82 | eor \out1, \out1, t2 |
| 83 | .endm |
| 84 | |
| 85 | .macro fround, out0, out1, out2, out3, in0, in1, in2, in3 |
| 86 | __hround \out0, \out1, \in0, \in1, \in2, \in3, \out2, \out3, 1 |
| 87 | __hround \out2, \out3, \in2, \in3, \in0, \in1, \in1, \in2, 1 |
| 88 | .endm |
| 89 | |
| 90 | .macro iround, out0, out1, out2, out3, in0, in1, in2, in3 |
| 91 | __hround \out0, \out1, \in0, \in3, \in2, \in1, \out2, \out3, 0 |
| 92 | __hround \out2, \out3, \in2, \in1, \in0, \in3, \in1, \in0, 0 |
| 93 | .endm |
| 94 | |
| 95 | .macro __rev, out, in |
| 96 | .if __LINUX_ARM_ARCH__ < 6 |
| 97 | lsl t0, \in, #24 |
| 98 | and t1, \in, #0xff00 |
| 99 | and t2, \in, #0xff0000 |
| 100 | orr \out, t0, \in, lsr #24 |
| 101 | orr \out, \out, t1, lsl #8 |
| 102 | orr \out, \out, t2, lsr #8 |
| 103 | .else |
| 104 | rev \out, \in |
| 105 | .endif |
| 106 | .endm |
| 107 | |
| 108 | .macro __adrl, out, sym, c |
| 109 | .if __LINUX_ARM_ARCH__ < 7 |
| 110 | ldr\c \out, =\sym |
| 111 | .else |
| 112 | movw\c \out, #:lower16:\sym |
| 113 | movt\c \out, #:upper16:\sym |
| 114 | .endif |
| 115 | .endm |
| 116 | |
| 117 | .macro do_crypt, round, ttab, ltab |
| 118 | push {r3-r11, lr} |
| 119 | |
| 120 | ldr r4, [in] |
| 121 | ldr r5, [in, #4] |
| 122 | ldr r6, [in, #8] |
| 123 | ldr r7, [in, #12] |
| 124 | |
| 125 | ldm rk!, {r8-r11} |
| 126 | |
| 127 | #ifdef CONFIG_CPU_BIG_ENDIAN |
| 128 | __rev r4, r4 |
| 129 | __rev r5, r5 |
| 130 | __rev r6, r6 |
| 131 | __rev r7, r7 |
| 132 | #endif |
| 133 | |
| 134 | eor r4, r4, r8 |
| 135 | eor r5, r5, r9 |
| 136 | eor r6, r6, r10 |
| 137 | eor r7, r7, r11 |
| 138 | |
| 139 | __adrl tt, \ttab |
| 140 | |
| 141 | tst rounds, #2 |
| 142 | bne 1f |
| 143 | |
| 144 | 0: \round r8, r9, r10, r11, r4, r5, r6, r7 |
| 145 | \round r4, r5, r6, r7, r8, r9, r10, r11 |
| 146 | |
| 147 | 1: subs rounds, rounds, #4 |
| 148 | \round r8, r9, r10, r11, r4, r5, r6, r7 |
| 149 | __adrl tt, \ltab, ls |
| 150 | \round r4, r5, r6, r7, r8, r9, r10, r11 |
| 151 | bhi 0b |
| 152 | |
| 153 | #ifdef CONFIG_CPU_BIG_ENDIAN |
| 154 | __rev r4, r4 |
| 155 | __rev r5, r5 |
| 156 | __rev r6, r6 |
| 157 | __rev r7, r7 |
| 158 | #endif |
| 159 | |
| 160 | ldr out, [sp] |
| 161 | |
| 162 | str r4, [out] |
| 163 | str r5, [out, #4] |
| 164 | str r6, [out, #8] |
| 165 | str r7, [out, #12] |
| 166 | |
| 167 | pop {r3-r11, pc} |
| 168 | |
| 169 | .align 3 |
| 170 | .ltorg |
| 171 | .endm |
| 172 | |
| 173 | ENTRY(__aes_arm_encrypt) |
| 174 | do_crypt fround, crypto_ft_tab, crypto_fl_tab |
| 175 | ENDPROC(__aes_arm_encrypt) |
| 176 | |
| 177 | ENTRY(__aes_arm_decrypt) |
| 178 | do_crypt iround, crypto_it_tab, crypto_il_tab |
| 179 | ENDPROC(__aes_arm_decrypt) |