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+/*
+ * 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)