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571e557cba
Tweak the round key logic so that they can be loaded using a single branchless sequence using overlapping loads. This is shorter and simpler, and puts the conditional branches based on the key size further apart, which might benefit microarchitectures that cannot record taken branches at every instruction. For these branches, use test-bit-branch instructions that don't clobber the condition flags. Note that none of this has any impact on performance, positive or otherwise (and the branch prediction benefit would only benefit AES-192 which nobody uses). It does make for nicer code, though. While at it, use \@ to generate the labels inside the macros, which is more robust than using fixed numbers, which could clash inadvertently. Also, bring aes-neon.S in line with these changes, including the switch to test-and-branch instructions, to avoid surprises in the future when we might start relying on the condition flags being preserved in the chaining mode wrappers in aes-modes.S Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
251 lines
7.5 KiB
ArmAsm
251 lines
7.5 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* linux/arch/arm64/crypto/aes-neon.S - AES cipher for ARMv8 NEON
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*
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* Copyright (C) 2013 - 2017 Linaro Ltd. <ard.biesheuvel@linaro.org>
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*/
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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#define AES_FUNC_START(func) SYM_FUNC_START(neon_ ## func)
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#define AES_FUNC_END(func) SYM_FUNC_END(neon_ ## func)
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xtsmask .req v7
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cbciv .req v7
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vctr .req v4
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.macro xts_reload_mask, tmp
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xts_load_mask \tmp
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.endm
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/* special case for the neon-bs driver calling into this one for CTS */
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.macro xts_cts_skip_tw, reg, lbl
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tbnz \reg, #1, \lbl
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.endm
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/* multiply by polynomial 'x' in GF(2^8) */
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.macro mul_by_x, out, in, temp, const
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sshr \temp, \in, #7
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shl \out, \in, #1
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and \temp, \temp, \const
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eor \out, \out, \temp
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.endm
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/* multiply by polynomial 'x^2' in GF(2^8) */
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.macro mul_by_x2, out, in, temp, const
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ushr \temp, \in, #6
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shl \out, \in, #2
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pmul \temp, \temp, \const
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eor \out, \out, \temp
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.endm
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/* preload the entire Sbox */
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.macro prepare, sbox, shiftrows, temp
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movi v12.16b, #0x1b
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ldr_l q13, \shiftrows, \temp
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ldr_l q14, .Lror32by8, \temp
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adr_l \temp, \sbox
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ld1 {v16.16b-v19.16b}, [\temp], #64
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ld1 {v20.16b-v23.16b}, [\temp], #64
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ld1 {v24.16b-v27.16b}, [\temp], #64
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ld1 {v28.16b-v31.16b}, [\temp]
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.endm
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/* do preload for encryption */
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.macro enc_prepare, ignore0, ignore1, temp
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prepare crypto_aes_sbox, .LForward_ShiftRows, \temp
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.endm
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.macro enc_switch_key, ignore0, ignore1, temp
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/* do nothing */
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.endm
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/* do preload for decryption */
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.macro dec_prepare, ignore0, ignore1, temp
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prepare crypto_aes_inv_sbox, .LReverse_ShiftRows, \temp
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.endm
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/* apply SubBytes transformation using the preloaded Sbox */
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.macro sub_bytes, in
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sub v9.16b, \in\().16b, v15.16b
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tbl \in\().16b, {v16.16b-v19.16b}, \in\().16b
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sub v10.16b, v9.16b, v15.16b
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tbx \in\().16b, {v20.16b-v23.16b}, v9.16b
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sub v11.16b, v10.16b, v15.16b
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tbx \in\().16b, {v24.16b-v27.16b}, v10.16b
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tbx \in\().16b, {v28.16b-v31.16b}, v11.16b
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.endm
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/* apply MixColumns transformation */
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.macro mix_columns, in, enc
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.if \enc == 0
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/* Inverse MixColumns: pre-multiply by { 5, 0, 4, 0 } */
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mul_by_x2 v8.16b, \in\().16b, v9.16b, v12.16b
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eor \in\().16b, \in\().16b, v8.16b
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rev32 v8.8h, v8.8h
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eor \in\().16b, \in\().16b, v8.16b
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.endif
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mul_by_x v9.16b, \in\().16b, v8.16b, v12.16b
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rev32 v8.8h, \in\().8h
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eor v8.16b, v8.16b, v9.16b
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eor \in\().16b, \in\().16b, v8.16b
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tbl \in\().16b, {\in\().16b}, v14.16b
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eor \in\().16b, \in\().16b, v8.16b
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.endm
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.macro do_block, enc, in, rounds, rk, rkp, i
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ld1 {v15.4s}, [\rk]
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add \rkp, \rk, #16
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mov \i, \rounds
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.La\@: eor \in\().16b, \in\().16b, v15.16b /* ^round key */
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movi v15.16b, #0x40
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tbl \in\().16b, {\in\().16b}, v13.16b /* ShiftRows */
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sub_bytes \in
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sub \i, \i, #1
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ld1 {v15.4s}, [\rkp], #16
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cbz \i, .Lb\@
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mix_columns \in, \enc
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b .La\@
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.Lb\@: eor \in\().16b, \in\().16b, v15.16b /* ^round key */
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.endm
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.macro encrypt_block, in, rounds, rk, rkp, i
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do_block 1, \in, \rounds, \rk, \rkp, \i
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.endm
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.macro decrypt_block, in, rounds, rk, rkp, i
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do_block 0, \in, \rounds, \rk, \rkp, \i
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.endm
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/*
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* Interleaved versions: functionally equivalent to the
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* ones above, but applied to AES states in parallel.
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*/
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.macro sub_bytes_4x, in0, in1, in2, in3
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sub v8.16b, \in0\().16b, v15.16b
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tbl \in0\().16b, {v16.16b-v19.16b}, \in0\().16b
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sub v9.16b, \in1\().16b, v15.16b
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tbl \in1\().16b, {v16.16b-v19.16b}, \in1\().16b
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sub v10.16b, \in2\().16b, v15.16b
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tbl \in2\().16b, {v16.16b-v19.16b}, \in2\().16b
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sub v11.16b, \in3\().16b, v15.16b
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tbl \in3\().16b, {v16.16b-v19.16b}, \in3\().16b
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tbx \in0\().16b, {v20.16b-v23.16b}, v8.16b
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tbx \in1\().16b, {v20.16b-v23.16b}, v9.16b
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sub v8.16b, v8.16b, v15.16b
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tbx \in2\().16b, {v20.16b-v23.16b}, v10.16b
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sub v9.16b, v9.16b, v15.16b
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tbx \in3\().16b, {v20.16b-v23.16b}, v11.16b
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sub v10.16b, v10.16b, v15.16b
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tbx \in0\().16b, {v24.16b-v27.16b}, v8.16b
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sub v11.16b, v11.16b, v15.16b
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tbx \in1\().16b, {v24.16b-v27.16b}, v9.16b
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sub v8.16b, v8.16b, v15.16b
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tbx \in2\().16b, {v24.16b-v27.16b}, v10.16b
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sub v9.16b, v9.16b, v15.16b
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tbx \in3\().16b, {v24.16b-v27.16b}, v11.16b
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sub v10.16b, v10.16b, v15.16b
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tbx \in0\().16b, {v28.16b-v31.16b}, v8.16b
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sub v11.16b, v11.16b, v15.16b
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tbx \in1\().16b, {v28.16b-v31.16b}, v9.16b
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tbx \in2\().16b, {v28.16b-v31.16b}, v10.16b
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tbx \in3\().16b, {v28.16b-v31.16b}, v11.16b
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.endm
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.macro mul_by_x_2x, out0, out1, in0, in1, tmp0, tmp1, const
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sshr \tmp0\().16b, \in0\().16b, #7
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shl \out0\().16b, \in0\().16b, #1
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sshr \tmp1\().16b, \in1\().16b, #7
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and \tmp0\().16b, \tmp0\().16b, \const\().16b
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shl \out1\().16b, \in1\().16b, #1
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and \tmp1\().16b, \tmp1\().16b, \const\().16b
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eor \out0\().16b, \out0\().16b, \tmp0\().16b
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eor \out1\().16b, \out1\().16b, \tmp1\().16b
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.endm
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.macro mul_by_x2_2x, out0, out1, in0, in1, tmp0, tmp1, const
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ushr \tmp0\().16b, \in0\().16b, #6
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shl \out0\().16b, \in0\().16b, #2
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ushr \tmp1\().16b, \in1\().16b, #6
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pmul \tmp0\().16b, \tmp0\().16b, \const\().16b
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shl \out1\().16b, \in1\().16b, #2
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pmul \tmp1\().16b, \tmp1\().16b, \const\().16b
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eor \out0\().16b, \out0\().16b, \tmp0\().16b
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eor \out1\().16b, \out1\().16b, \tmp1\().16b
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.endm
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.macro mix_columns_2x, in0, in1, enc
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.if \enc == 0
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/* Inverse MixColumns: pre-multiply by { 5, 0, 4, 0 } */
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mul_by_x2_2x v8, v9, \in0, \in1, v10, v11, v12
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eor \in0\().16b, \in0\().16b, v8.16b
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rev32 v8.8h, v8.8h
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eor \in1\().16b, \in1\().16b, v9.16b
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rev32 v9.8h, v9.8h
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eor \in0\().16b, \in0\().16b, v8.16b
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eor \in1\().16b, \in1\().16b, v9.16b
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.endif
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mul_by_x_2x v8, v9, \in0, \in1, v10, v11, v12
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rev32 v10.8h, \in0\().8h
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rev32 v11.8h, \in1\().8h
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eor v10.16b, v10.16b, v8.16b
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eor v11.16b, v11.16b, v9.16b
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eor \in0\().16b, \in0\().16b, v10.16b
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eor \in1\().16b, \in1\().16b, v11.16b
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tbl \in0\().16b, {\in0\().16b}, v14.16b
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tbl \in1\().16b, {\in1\().16b}, v14.16b
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eor \in0\().16b, \in0\().16b, v10.16b
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eor \in1\().16b, \in1\().16b, v11.16b
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.endm
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.macro do_block_4x, enc, in0, in1, in2, in3, rounds, rk, rkp, i
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ld1 {v15.4s}, [\rk]
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add \rkp, \rk, #16
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mov \i, \rounds
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.La\@: eor \in0\().16b, \in0\().16b, v15.16b /* ^round key */
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eor \in1\().16b, \in1\().16b, v15.16b /* ^round key */
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eor \in2\().16b, \in2\().16b, v15.16b /* ^round key */
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eor \in3\().16b, \in3\().16b, v15.16b /* ^round key */
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movi v15.16b, #0x40
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tbl \in0\().16b, {\in0\().16b}, v13.16b /* ShiftRows */
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tbl \in1\().16b, {\in1\().16b}, v13.16b /* ShiftRows */
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tbl \in2\().16b, {\in2\().16b}, v13.16b /* ShiftRows */
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tbl \in3\().16b, {\in3\().16b}, v13.16b /* ShiftRows */
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sub_bytes_4x \in0, \in1, \in2, \in3
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sub \i, \i, #1
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ld1 {v15.4s}, [\rkp], #16
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cbz \i, .Lb\@
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mix_columns_2x \in0, \in1, \enc
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mix_columns_2x \in2, \in3, \enc
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b .La\@
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.Lb\@: eor \in0\().16b, \in0\().16b, v15.16b /* ^round key */
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eor \in1\().16b, \in1\().16b, v15.16b /* ^round key */
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eor \in2\().16b, \in2\().16b, v15.16b /* ^round key */
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eor \in3\().16b, \in3\().16b, v15.16b /* ^round key */
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.endm
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.macro encrypt_block4x, in0, in1, in2, in3, rounds, rk, rkp, i
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do_block_4x 1, \in0, \in1, \in2, \in3, \rounds, \rk, \rkp, \i
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.endm
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.macro decrypt_block4x, in0, in1, in2, in3, rounds, rk, rkp, i
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do_block_4x 0, \in0, \in1, \in2, \in3, \rounds, \rk, \rkp, \i
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.endm
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#include "aes-modes.S"
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.section ".rodata", "a"
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.align 4
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.LForward_ShiftRows:
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.octa 0x0b06010c07020d08030e09040f0a0500
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.LReverse_ShiftRows:
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.octa 0x0306090c0f0205080b0e0104070a0d00
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.Lror32by8:
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.octa 0x0c0f0e0d080b0a090407060500030201
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