/*
* Scalar AES core transform
*
* Copyright (C) 2017 Linaro Ltd.
* Author: Ard Biesheuvel <ard.biesheuvel@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
.text
.align 5
rk .req r0
rounds .req r1
in .req r2
out .req r3
ttab .req ip
t0 .req lr
t1 .req r2
t2 .req r3
.macro __select, out, in, idx
.if __LINUX_ARM_ARCH__ < 7
and \out, \in, #0xff << (8 * \idx)
.else
ubfx \out, \in, #(8 * \idx), #8
.endif
.endm
.macro __load, out, in, idx
.if __LINUX_ARM_ARCH__ < 7 && \idx > 0
ldr \out, [ttab, \in, lsr #(8 * \idx) - 2]
.else
ldr \out, [ttab, \in, lsl #2]
.endif
.endm
.macro __hround, out0, out1, in0, in1, in2, in3, t3, t4, enc
__select \out0, \in0, 0
__select t0, \in1, 1
__load \out0, \out0, 0
__load t0, t0, 1
.if \enc
__select \out1, \in1, 0
__select t1, \in2, 1
.else
__select \out1, \in3, 0
__select t1, \in0, 1
.endif
__load \out1, \out1, 0
__select t2, \in2, 2
__load t1, t1, 1
__load t2, t2, 2
eor \out0, \out0, t0, ror #24
__select t0, \in3, 3
.if \enc
__select \t3, \in3, 2
__select \t4, \in0, 3
.else
__select \t3, \in1, 2
__select \t4, \in2, 3
.endif
__load \t3, \t3, 2
__load t0, t0, 3
__load \t4, \t4, 3
eor \out1, \out1, t1, ror #24
eor \out0, \out0, t2, ror #16
ldm rk!, {t1, t2}
eor \out1, \out1, \t3, ror #16
eor \out0, \out0, t0, ror #8
eor \out1, \out1, \t4, ror #8
eor \out0, \out0, t1
eor \out1, \out1, t2
.endm
.macro fround, out0, out1, out2, out3, in0, in1, in2, in3
__hround \out0, \out1, \in0, \in1, \in2, \in3, \out2, \out3, 1
__hround \out2, \out3, \in2, \in3, \in0, \in1, \in1, \in2, 1
.endm
.macro iround, out0, out1, out2, out3, in0, in1, in2, in3
__hround \out0, \out1, \in0, \in3, \in2, \in1, \out2, \out3, 0
__hround \out2, \out3, \in2, \in1, \in0, \in3, \in1, \in0, 0
.endm
.macro __rev, out, in
.if __LINUX_ARM_ARCH__ < 6
lsl t0, \in, #24
and t1, \in, #0xff00
and t2, \in, #0xff0000
orr \out, t0, \in, lsr #24
orr \out, \out, t1, lsl #8
orr \out, \out, t2, lsr #8
.else
rev \out, \in
.endif
.endm
.macro __adrl, out, sym, c
.if __LINUX_ARM_ARCH__ < 7
ldr\c \out, =\sym
.else
movw\c \out, #:lower16:\sym
movt\c \out, #:upper16:\sym
.endif
.endm
.macro do_crypt, round, ttab, ltab
push {r3-r11, lr}
ldr r4, [in]
ldr r5, [in, #4]
ldr r6, [in, #8]
ldr r7, [in, #12]
ldm rk!, {r8-r11}
#ifdef CONFIG_CPU_BIG_ENDIAN
__rev r4, r4
__rev r5, r5
__rev r6, r6
__rev r7, r7
#endif
eor r4, r4, r8
eor r5, r5, r9
eor r6, r6, r10
eor r7, r7, r11
__adrl ttab, \ttab
tst rounds, #2
bne 1f
0: \round r8, r9, r10, r11, r4, r5, r6, r7
\round r4, r5, r6, r7, r8, r9, r10, r11
1: subs rounds, rounds, #4
\round r8, r9, r10, r11, r4, r5, r6, r7
__adrl ttab, \ltab, ls
\round r4, r5, r6, r7, r8, r9, r10, r11
bhi 0b
#ifdef CONFIG_CPU_BIG_ENDIAN
__rev r4, r4
__rev r5, r5
__rev r6, r6
__rev r7, r7
#endif
ldr out, [sp]
str r4, [out]
str r5, [out, #4]
str r6, [out, #8]
str r7, [out, #12]
pop {r3-r11, pc}
.align 3
.ltorg
.endm
ENTRY(__aes_arm_encrypt)
do_crypt fround, crypto_ft_tab, crypto_fl_tab
ENDPROC(__aes_arm_encrypt)
ENTRY(__aes_arm_decrypt)
do_crypt iround, crypto_it_tab, crypto_il_tab
ENDPROC(__aes_arm_decrypt)
