Re: [PATCH v3 3/5] crypto: arm/speck - add NEON-accelerated implementation of Speck-XTS

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Hi Eric,

On 14.02.2018 19:42, Eric Biggers wrote:
> Add an ARM NEON-accelerated implementation of Speck-XTS.  It operates on
> 128-byte chunks at a time, i.e. 8 blocks for Speck128 or 16 blocks for
> Speck64.  Each 128-byte chunk goes through XTS preprocessing, then is
> encrypted/decrypted (doing one cipher round for all the blocks, then the
> next round, etc.), then goes through XTS postprocessing.
> 
> The performance depends on the processor but can be about 3 times faster
> than the generic code.  For example, on an ARMv7 processor we observe
> the following performance with Speck128/256-XTS:
> 
>     xts-speck128-neon:     Encryption 107.9 MB/s, Decryption 108.1 MB/s
>     xts(speck128-generic): Encryption  32.1 MB/s, Decryption  36.6 MB/s
> 
> In comparison to AES-256-XTS without the Cryptography Extensions:
> 
>     xts-aes-neonbs:        Encryption  41.2 MB/s, Decryption  36.7 MB/s
>     xts(aes-asm):          Encryption  31.7 MB/s, Decryption  30.8 MB/s
>     xts(aes-generic):      Encryption  21.2 MB/s, Decryption  20.9 MB/s
> 
> Speck64/128-XTS is even faster:
> 
>     xts-speck64-neon:      Encryption 138.6 MB/s, Decryption 139.1 MB/s
> 
> Note that as with the generic code, only the Speck128 and Speck64
> variants are supported.  Also, for now only the XTS mode of operation is
> supported, to target the disk and file encryption use cases.  The NEON
> code also only handles the portion of the data that is evenly divisible
> into 128-byte chunks, with any remainder handled by a C fallback.  Of
> course, other modes of operation could be added later if needed, and/or
> the NEON code could be updated to handle other buffer sizes.
> 
> The XTS specification is only defined for AES which has a 128-bit block
> size, so for the GF(2^64) math needed for Speck64-XTS we use the
> reducing polynomial 'x^64 + x^4 + x^3 + x + 1' given by the original XEX
> paper.  Of course, when possible users should use Speck128-XTS, but even
> that may be too slow on some processors; Speck64-XTS can be faster.
> 
> Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
> ---
>  arch/arm/crypto/Kconfig           |   6 +
>  arch/arm/crypto/Makefile          |   2 +
>  arch/arm/crypto/speck-neon-core.S | 432 ++++++++++++++++++++++++++++++
>  arch/arm/crypto/speck-neon-glue.c | 288 ++++++++++++++++++++
>  4 files changed, 728 insertions(+)
>  create mode 100644 arch/arm/crypto/speck-neon-core.S
>  create mode 100644 arch/arm/crypto/speck-neon-glue.c
> 
> diff --git a/arch/arm/crypto/Kconfig b/arch/arm/crypto/Kconfig
> index b8e69fe282b8..925d1364727a 100644
> --- a/arch/arm/crypto/Kconfig
> +++ b/arch/arm/crypto/Kconfig
> @@ -121,4 +121,10 @@ config CRYPTO_CHACHA20_NEON
>  	select CRYPTO_BLKCIPHER
>  	select CRYPTO_CHACHA20
>  
> +config CRYPTO_SPECK_NEON
> +	tristate "NEON accelerated Speck cipher algorithms"
> +	depends on KERNEL_MODE_NEON
> +	select CRYPTO_BLKCIPHER
> +	select CRYPTO_SPECK
> +
>  endif
> diff --git a/arch/arm/crypto/Makefile b/arch/arm/crypto/Makefile
> index 30ef8e291271..a758107c5525 100644
> --- a/arch/arm/crypto/Makefile
> +++ b/arch/arm/crypto/Makefile
> @@ -10,6 +10,7 @@ obj-$(CONFIG_CRYPTO_SHA1_ARM_NEON) += sha1-arm-neon.o
>  obj-$(CONFIG_CRYPTO_SHA256_ARM) += sha256-arm.o
>  obj-$(CONFIG_CRYPTO_SHA512_ARM) += sha512-arm.o
>  obj-$(CONFIG_CRYPTO_CHACHA20_NEON) += chacha20-neon.o
> +obj-$(CONFIG_CRYPTO_SPECK_NEON) += speck-neon.o
>  
>  ce-obj-$(CONFIG_CRYPTO_AES_ARM_CE) += aes-arm-ce.o
>  ce-obj-$(CONFIG_CRYPTO_SHA1_ARM_CE) += sha1-arm-ce.o
> @@ -53,6 +54,7 @@ ghash-arm-ce-y	:= ghash-ce-core.o ghash-ce-glue.o
>  crct10dif-arm-ce-y	:= crct10dif-ce-core.o crct10dif-ce-glue.o
>  crc32-arm-ce-y:= crc32-ce-core.o crc32-ce-glue.o
>  chacha20-neon-y := chacha20-neon-core.o chacha20-neon-glue.o
> +speck-neon-y := speck-neon-core.o speck-neon-glue.o
>  
>  quiet_cmd_perl = PERL    $@
>        cmd_perl = $(PERL) $(<) > $(@)
> diff --git a/arch/arm/crypto/speck-neon-core.S
> b/arch/arm/crypto/speck-neon-core.S
> new file mode 100644
> index 000000000000..3c1e203e53b9
> --- /dev/null
> +++ b/arch/arm/crypto/speck-neon-core.S
> @@ -0,0 +1,432 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * NEON-accelerated implementation of Speck128-XTS and Speck64-XTS
> + *
> + * Copyright (c) 2018 Google, Inc
> + *
> + * Author: Eric Biggers <ebiggers@xxxxxxxxxx>
> + */
> +
> +#include <linux/linkage.h>
> +
> +	.text
> +	.fpu		neon
> +
> +	// arguments
> +	ROUND_KEYS	.req	r0	// const {u64,u32} *round_keys
> +	NROUNDS		.req	r1	// int nrounds
> +	DST		.req	r2	// void *dst
> +	SRC		.req	r3	// const void *src
> +	NBYTES		.req	r4	// unsigned int nbytes
> +	TWEAK		.req	r5	// void *tweak
> +
> +	// registers which hold the data being encrypted/decrypted
> +	X0		.req	q0
> +	X0_L		.req	d0
> +	X0_H		.req	d1
> +	Y0		.req	q1
> +	Y0_H		.req	d3
> +	X1		.req	q2
> +	X1_L		.req	d4
> +	X1_H		.req	d5
> +	Y1		.req	q3
> +	Y1_H		.req	d7
> +	X2		.req	q4
> +	X2_L		.req	d8
> +	X2_H		.req	d9
> +	Y2		.req	q5
> +	Y2_H		.req	d11
> +	X3		.req	q6
> +	X3_L		.req	d12
> +	X3_H		.req	d13
> +	Y3		.req	q7
> +	Y3_H		.req	d15
> +
> +	// the round key, duplicated in all lanes
> +	ROUND_KEY	.req	q8
> +	ROUND_KEY_L	.req	d16
> +	ROUND_KEY_H	.req	d17
> +
> +	// index vector for vtbl-based 8-bit rotates
> +	ROTATE_TABLE	.req	d18
> +
> +	// multiplication table for updating XTS tweaks
> +	GF128MUL_TABLE	.req	d19
> +	GF64MUL_TABLE	.req	d19
> +
> +	// current XTS tweak value(s)
> +	TWEAKV		.req	q10
> +	TWEAKV_L	.req	d20
> +	TWEAKV_H	.req	d21
> +
> +	TMP0		.req	q12
> +	TMP0_L		.req	d24
> +	TMP0_H		.req	d25
> +	TMP1		.req	q13
> +	TMP2		.req	q14
> +	TMP3		.req	q15
> +
> +	.align		4
> +.Lror64_8_table:
> +	.byte		1, 2, 3, 4, 5, 6, 7, 0
> +.Lror32_8_table:
> +	.byte		1, 2, 3, 0, 5, 6, 7, 4
> +.Lrol64_8_table:
> +	.byte		7, 0, 1, 2, 3, 4, 5, 6
> +.Lrol32_8_table:
> +	.byte		3, 0, 1, 2, 7, 4, 5, 6
> +.Lgf128mul_table:
> +	.byte		0, 0x87
> +	.fill		14
> +.Lgf64mul_table:
> +	.byte		0, 0x1b, (0x1b << 1), (0x1b << 1) ^ 0x1b
> +	.fill		12
> +
> +/*
> + * _speck_round_128bytes() - Speck encryption round on 128 bytes at a time
> + *
> + * Do one Speck encryption round on the 128 bytes (8 blocks for
> Speck128, 16 for
> + * Speck64) stored in X0-X3 and Y0-Y3, using the round key stored in all lanes
> + * of ROUND_KEY.  'n' is the lane size: 64 for Speck128, or 32 for Speck64.
> + *
> + * The 8-bit rotates are implemented using vtbl instead of vshr + vsli because
> + * the vtbl approach is faster on some processors and the same speed on others.
> + */
> +.macro _speck_round_128bytes	n
> +
> +	// x = ror(x, 8)
> +	vtbl.8		X0_L, {X0_L}, ROTATE_TABLE
> +	vtbl.8		X0_H, {X0_H}, ROTATE_TABLE
> +	vtbl.8		X1_L, {X1_L}, ROTATE_TABLE
> +	vtbl.8		X1_H, {X1_H}, ROTATE_TABLE
> +	vtbl.8		X2_L, {X2_L}, ROTATE_TABLE
> +	vtbl.8		X2_H, {X2_H}, ROTATE_TABLE
> +	vtbl.8		X3_L, {X3_L}, ROTATE_TABLE
> +	vtbl.8		X3_H, {X3_H}, ROTATE_TABLE
> +
> +	// x += y
> +	vadd.u\n	X0, Y0
> +	vadd.u\n	X1, Y1
> +	vadd.u\n	X2, Y2
> +	vadd.u\n	X3, Y3
> +
> +	// x ^= k
> +	veor		X0, ROUND_KEY
> +	veor		X1, ROUND_KEY
> +	veor		X2, ROUND_KEY
> +	veor		X3, ROUND_KEY
> +
> +	// y = rol(y, 3)
> +	vshl.u\n	TMP0, Y0, #3
> +	vshl.u\n	TMP1, Y1, #3
> +	vshl.u\n	TMP2, Y2, #3
> +	vshl.u\n	TMP3, Y3, #3
> +	vsri.u\n	TMP0, Y0, #(\n - 3)
> +	vsri.u\n	TMP1, Y1, #(\n - 3)
> +	vsri.u\n	TMP2, Y2, #(\n - 3)
> +	vsri.u\n	TMP3, Y3, #(\n - 3)
> +
> +	// y ^= x
> +	veor		Y0, TMP0, X0
> +	veor		Y1, TMP1, X1
> +	veor		Y2, TMP2, X2
> +	veor		Y3, TMP3, X3
> +.endm
> +
> +/*
> + * _speck_unround_128bytes() - Speck decryption round on 128 bytes at a time
> + *
> + * This is the inverse of _speck_round_128bytes().
> + */
> +.macro _speck_unround_128bytes	n
> +
> +	// y ^= x
> +	veor		TMP0, Y0, X0
> +	veor		TMP1, Y1, X1
> +	veor		TMP2, Y2, X2
> +	veor		TMP3, Y3, X3
> +
> +	// y = ror(y, 3)
> +	vshr.u\n	Y0, TMP0, #3
> +	vshr.u\n	Y1, TMP1, #3
> +	vshr.u\n	Y2, TMP2, #3
> +	vshr.u\n	Y3, TMP3, #3
> +	vsli.u\n	Y0, TMP0, #(\n - 3)
> +	vsli.u\n	Y1, TMP1, #(\n - 3)
> +	vsli.u\n	Y2, TMP2, #(\n - 3)
> +	vsli.u\n	Y3, TMP3, #(\n - 3)
> +
> +	// x ^= k
> +	veor		X0, ROUND_KEY
> +	veor		X1, ROUND_KEY
> +	veor		X2, ROUND_KEY
> +	veor		X3, ROUND_KEY
> +
> +	// x -= y
> +	vsub.u\n	X0, Y0
> +	vsub.u\n	X1, Y1
> +	vsub.u\n	X2, Y2
> +	vsub.u\n	X3, Y3
> +
> +	// x = rol(x, 8);
> +	vtbl.8		X0_L, {X0_L}, ROTATE_TABLE
> +	vtbl.8		X0_H, {X0_H}, ROTATE_TABLE
> +	vtbl.8		X1_L, {X1_L}, ROTATE_TABLE
> +	vtbl.8		X1_H, {X1_H}, ROTATE_TABLE
> +	vtbl.8		X2_L, {X2_L}, ROTATE_TABLE
> +	vtbl.8		X2_H, {X2_H}, ROTATE_TABLE
> +	vtbl.8		X3_L, {X3_L}, ROTATE_TABLE
> +	vtbl.8		X3_H, {X3_H}, ROTATE_TABLE
> +.endm
> +
> +.macro _xts128_precrypt_one	dst_reg, tweak_buf, tmp
> +
> +	// Load the next source block
> +	vld1.8		{\dst_reg}, [SRC]!
> +
> +	// Save the current tweak in the tweak buffer
> +	vst1.8		{TWEAKV}, [\tweak_buf:128]!
> +
> +	// XOR the next source block with the current tweak
> +	veor		\dst_reg, TWEAKV
> +
> +	/*
> +	 * Calculate the next tweak by multiplying the current one by x,
> +	 * modulo p(x) = x^128 + x^7 + x^2 + x + 1.
> +	 */
> +	vshr.u64	\tmp, TWEAKV, #63
> +	vshl.u64	TWEAKV, #1
> +	veor		TWEAKV_H, \tmp\()_L
> +	vtbl.8		\tmp\()_H, {GF128MUL_TABLE}, \tmp\()_H
> +	veor		TWEAKV_L, \tmp\()_H
> +.endm
> +
> +.macro _xts64_precrypt_two	dst_reg, tweak_buf, tmp
> +
> +	// Load the next two source blocks
> +	vld1.8		{\dst_reg}, [SRC]!
> +
> +	// Save the current two tweaks in the tweak buffer
> +	vst1.8		{TWEAKV}, [\tweak_buf:128]!
> +
> +	// XOR the next two source blocks with the current two tweaks
> +	veor		\dst_reg, TWEAKV
> +
> +	/*
> +	 * Calculate the next two tweaks by multiplying the current ones by x^2,
> +	 * modulo p(x) = x^64 + x^4 + x^3 + x + 1.
> +	 */
> +	vshr.u64	\tmp, TWEAKV, #62
> +	vshl.u64	TWEAKV, #2
> +	vtbl.8		\tmp\()_L, {GF64MUL_TABLE}, \tmp\()_L
> +	vtbl.8		\tmp\()_H, {GF64MUL_TABLE}, \tmp\()_H
> +	veor		TWEAKV, \tmp
> +.endm
> +
> +/*
> + * _speck_xts_crypt() - Speck-XTS encryption/decryption
> + *
> + * Encrypt or decrypt NBYTES bytes of data from the SRC buffer to the
> DST buffer
> + * using Speck-XTS, specifically the variant with a block size of
> '2n' and round
> + * count given by NROUNDS.  The expanded round keys are given in
> ROUND_KEYS, and
> + * the current XTS tweak value is given in TWEAK.  It's assumed that
> NBYTES is a
> + * nonzero multiple of 128.
> + */
> +.macro _speck_xts_crypt	n, decrypting
> +	push		{r4-r7}
> +	mov		r7, sp
> +
> +	/*
> +	 * The first four parameters were passed in registers r0-r3.  Load the
> +	 * additional parameters, which were passed on the stack.
> +	 */
> +	ldr		NBYTES, [sp, #16]
> +	ldr		TWEAK, [sp, #20]
> +
> +	/*
> +	 * If decrypting, modify the ROUND_KEYS parameter to point to the last
> +	 * round key rather than the first, since for decryption the round keys
> +	 * are used in reverse order.
> +	 */
> +.if \decrypting
> +.if \n == 64
> +	add		ROUND_KEYS, ROUND_KEYS, NROUNDS, lsl #3
> +	sub		ROUND_KEYS, #8
> +.else
> +	add		ROUND_KEYS, ROUND_KEYS, NROUNDS, lsl #2
> +	sub		ROUND_KEYS, #4
> +.endif
> +.endif
> +
> +	// Load the index vector for vtbl-based 8-bit rotates
> +.if \decrypting
> +	ldr		r12, =.Lrol\n\()_8_table
> +.else
> +	ldr		r12, =.Lror\n\()_8_table
> +.endif
> +	vld1.8		{ROTATE_TABLE}, [r12:64]
> +
> +	// One-time XTS preparation
> +
> +	/*
> +	 * Allocate stack space to store 128 bytes worth of tweaks.  For
> +	 * performance, this space is aligned to a 16-byte boundary so that we
> +	 * can use the load/store instructions that declare 16-byte alignment.
> +	 */
> +	sub		sp, #128
> +	bic		sp, #0xf


This fails here when building with CONFIG_THUMB2_KERNEL=y

  AS      arch/arm/crypto/speck-neon-core.o                             
                                                                   
arch/arm/crypto/speck-neon-core.S: Assembler messages:                  
                                                                   
arch/arm/crypto/speck-neon-core.S:419: Error: r13 not allowed here --
`bic sp,#0xf'                                                         
arch/arm/crypto/speck-neon-core.S:423: Error: r13 not allowed here --
`bic sp,#0xf'                                                         
arch/arm/crypto/speck-neon-core.S:427: Error: r13 not allowed here --
`bic sp,#0xf'                                                         
arch/arm/crypto/speck-neon-core.S:431: Error: r13 not allowed here --
`bic sp,#0xf'

In a quick hack this change seems to address it:


-       sub             sp, #128
-       bic             sp, #0xf
+       mov             r6, sp
+       sub             r6, #128
+       bic             r6, #0xf
+       mov             sp, r6

But there is probably a better solution to address this.

--
Stefan


> +
> +.if \n == 64
> +	// Load first tweak
> +	vld1.8		{TWEAKV}, [TWEAK]
> +
> +	// Load GF(2^128) multiplication table
> +	ldr		r12, =.Lgf128mul_table
> +	vld1.8		{GF128MUL_TABLE}, [r12:64]
> +.else
> +	// Load first tweak
> +	vld1.8		{TWEAKV_L}, [TWEAK]
> +
> +	// Load GF(2^64) multiplication table
> +	ldr		r12, =.Lgf64mul_table
> +	vld1.8		{GF64MUL_TABLE}, [r12:64]
> +
> +	// Calculate second tweak, packing it together with the first
> +	vshr.u64	TMP0_L, TWEAKV_L, #63
> +	vtbl.u8		TMP0_L, {GF64MUL_TABLE}, TMP0_L
> +	vshl.u64	TWEAKV_H, TWEAKV_L, #1
> +	veor		TWEAKV_H, TMP0_L
> +.endif
> +
> +.Lnext_128bytes_\@:
> +
> +	/*
> +	 * Load the source blocks into {X,Y}[0-3], XOR them with their XTS tweak
> +	 * values, and save the tweaks on the stack for later.  Then
> +	 * de-interleave the 'x' and 'y' elements of each block, i.e. make it so
> +	 * that the X[0-3] registers contain only the second halves of blocks,
> +	 * and the Y[0-3] registers contain only the first halves of blocks.
> +	 * (Speck uses the order (y, x) rather than the more intuitive (x, y).)
> +	 */
> +	mov		r12, sp
> +.if \n == 64
> +	_xts128_precrypt_one	X0, r12, TMP0
> +	_xts128_precrypt_one	Y0, r12, TMP0
> +	_xts128_precrypt_one	X1, r12, TMP0
> +	_xts128_precrypt_one	Y1, r12, TMP0
> +	_xts128_precrypt_one	X2, r12, TMP0
> +	_xts128_precrypt_one	Y2, r12, TMP0
> +	_xts128_precrypt_one	X3, r12, TMP0
> +	_xts128_precrypt_one	Y3, r12, TMP0
> +	vswp		X0_L, Y0_H
> +	vswp		X1_L, Y1_H
> +	vswp		X2_L, Y2_H
> +	vswp		X3_L, Y3_H
> +.else
> +	_xts64_precrypt_two	X0, r12, TMP0
> +	_xts64_precrypt_two	Y0, r12, TMP0
> +	_xts64_precrypt_two	X1, r12, TMP0
> +	_xts64_precrypt_two	Y1, r12, TMP0
> +	_xts64_precrypt_two	X2, r12, TMP0
> +	_xts64_precrypt_two	Y2, r12, TMP0
> +	_xts64_precrypt_two	X3, r12, TMP0
> +	_xts64_precrypt_two	Y3, r12, TMP0
> +	vuzp.32		Y0, X0
> +	vuzp.32		Y1, X1
> +	vuzp.32		Y2, X2
> +	vuzp.32		Y3, X3
> +.endif
> +
> +	// Do the cipher rounds
> +
> +	mov		r12, ROUND_KEYS
> +	mov		r6, NROUNDS
> +
> +.Lnext_round_\@:
> +.if \decrypting
> +.if \n == 64
> +	vld1.64		ROUND_KEY_L, [r12]
> +	sub		r12, #8
> +	vmov		ROUND_KEY_H, ROUND_KEY_L
> +.else
> +	vld1.32		{ROUND_KEY_L[],ROUND_KEY_H[]}, [r12]
> +	sub		r12, #4
> +.endif
> +	_speck_unround_128bytes	\n
> +.else
> +.if \n == 64
> +	vld1.64		ROUND_KEY_L, [r12]!
> +	vmov		ROUND_KEY_H, ROUND_KEY_L
> +.else
> +	vld1.32		{ROUND_KEY_L[],ROUND_KEY_H[]}, [r12]!
> +.endif
> +	_speck_round_128bytes	\n
> +.endif
> +	subs		r6, r6, #1
> +	bne		.Lnext_round_\@
> +
> +	// Re-interleave the 'x' and 'y' elements of each block
> +.if \n == 64
> +	vswp		X0_L, Y0_H
> +	vswp		X1_L, Y1_H
> +	vswp		X2_L, Y2_H
> +	vswp		X3_L, Y3_H
> +.else
> +	vzip.32		Y0, X0
> +	vzip.32		Y1, X1
> +	vzip.32		Y2, X2
> +	vzip.32		Y3, X3
> +.endif
> +
> +	// XOR the encrypted/decrypted blocks with the tweaks we saved earlier
> +	mov		r12, sp
> +	vld1.8		{TMP0, TMP1}, [r12:128]!
> +	vld1.8		{TMP2, TMP3}, [r12:128]!
> +	veor		X0, TMP0
> +	veor		Y0, TMP1
> +	veor		X1, TMP2
> +	veor		Y1, TMP3
> +	vld1.8		{TMP0, TMP1}, [r12:128]!
> +	vld1.8		{TMP2, TMP3}, [r12:128]!
> +	veor		X2, TMP0
> +	veor		Y2, TMP1
> +	veor		X3, TMP2
> +	veor		Y3, TMP3
> +
> +	// Store the ciphertext in the destination buffer
> +	vst1.8		{X0, Y0}, [DST]!
> +	vst1.8		{X1, Y1}, [DST]!
> +	vst1.8		{X2, Y2}, [DST]!
> +	vst1.8		{X3, Y3}, [DST]!
> +
> +	// Continue if there are more 128-byte chunks remaining, else return
> +	subs		NBYTES, #128
> +	bne		.Lnext_128bytes_\@
> +
> +	// Store the next tweak
> +.if \n == 64
> +	vst1.8		{TWEAKV}, [TWEAK]
> +.else
> +	vst1.8		{TWEAKV_L}, [TWEAK]
> +.endif
> +
> +	mov		sp, r7
> +	pop		{r4-r7}
> +	bx		lr
> +.endm
> +
> +ENTRY(speck128_xts_encrypt_neon)
> +	_speck_xts_crypt	n=64, decrypting=0
> +ENDPROC(speck128_xts_encrypt_neon)
> +
> +ENTRY(speck128_xts_decrypt_neon)
> +	_speck_xts_crypt	n=64, decrypting=1
> +ENDPROC(speck128_xts_decrypt_neon)
> +
> +ENTRY(speck64_xts_encrypt_neon)
> +	_speck_xts_crypt	n=32, decrypting=0
> +ENDPROC(speck64_xts_encrypt_neon)
> +
> +ENTRY(speck64_xts_decrypt_neon)
> +	_speck_xts_crypt	n=32, decrypting=1
> +ENDPROC(speck64_xts_decrypt_neon)
> diff --git a/arch/arm/crypto/speck-neon-glue.c
> b/arch/arm/crypto/speck-neon-glue.c
> new file mode 100644
> index 000000000000..f012c3ea998f
> --- /dev/null
> +++ b/arch/arm/crypto/speck-neon-glue.c
> @@ -0,0 +1,288 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * NEON-accelerated implementation of Speck128-XTS and Speck64-XTS
> + *
> + * Copyright (c) 2018 Google, Inc
> + *
> + * Note: the NIST recommendation for XTS only specifies a 128-bit block size,
> + * but a 64-bit version (needed for Speck64) is fairly
> straightforward; the math
> + * is just done in GF(2^64) instead of GF(2^128), with the reducing polynomial
> + * x^64 + x^4 + x^3 + x + 1 from the original XEX paper (Rogaway, 2004:
> + * "Efficient Instantiations of Tweakable Blockciphers and Refinements to Modes
> + * OCB and PMAC"), represented as 0x1B.
> + */
> +
> +#include <asm/hwcap.h>
> +#include <asm/neon.h>
> +#include <asm/simd.h>
> +#include <crypto/algapi.h>
> +#include <crypto/gf128mul.h>
> +#include <crypto/internal/skcipher.h>
> +#include <crypto/speck.h>
> +#include <crypto/xts.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +
> +/* The assembly functions only handle multiples of 128 bytes */
> +#define SPECK_NEON_CHUNK_SIZE	128
> +
> +/* Speck128 */
> +
> +struct speck128_xts_tfm_ctx {
> +	struct speck128_tfm_ctx main_key;
> +	struct speck128_tfm_ctx tweak_key;
> +};
> +
> +asmlinkage void speck128_xts_encrypt_neon(const u64 *round_keys, int nrounds,
> +					  void *dst, const void *src,
> +					  unsigned int nbytes, void *tweak);
> +
> +asmlinkage void speck128_xts_decrypt_neon(const u64 *round_keys, int nrounds,
> +					  void *dst, const void *src,
> +					  unsigned int nbytes, void *tweak);
> +
> +typedef void (*speck128_crypt_one_t)(const struct speck128_tfm_ctx *,
> +				     u8 *, const u8 *);
> +typedef void (*speck128_xts_crypt_many_t)(const u64 *, int, void *,
> +					  const void *, unsigned int, void *);
> +
> +static __always_inline int
> +__speck128_xts_crypt(struct skcipher_request *req,
> +		     speck128_crypt_one_t crypt_one,
> +		     speck128_xts_crypt_many_t crypt_many)
> +{
> +	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
> +	const struct speck128_xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
> +	struct skcipher_walk walk;
> +	le128 tweak;
> +	int err;
> +
> +	err = skcipher_walk_virt(&walk, req, true);
> +
> +	crypto_speck128_encrypt(&ctx->tweak_key, (u8 *)&tweak, walk.iv);
> +
> +	while (walk.nbytes > 0) {
> +		unsigned int nbytes = walk.nbytes;
> +		u8 *dst = walk.dst.virt.addr;
> +		const u8 *src = walk.src.virt.addr;
> +
> +		if (nbytes >= SPECK_NEON_CHUNK_SIZE && may_use_simd()) {
> +			unsigned int count;
> +
> +			count = round_down(nbytes, SPECK_NEON_CHUNK_SIZE);
> +			kernel_neon_begin();
> +			(*crypt_many)(ctx->main_key.round_keys,
> +				      ctx->main_key.nrounds,
> +				      dst, src, count, &tweak);
> +			kernel_neon_end();
> +			dst += count;
> +			src += count;
> +			nbytes -= count;
> +		}
> +
> +		/* Handle any remainder with generic code */
> +		while (nbytes >= sizeof(tweak)) {
> +			le128_xor((le128 *)dst, (const le128 *)src, &tweak);
> +			(*crypt_one)(&ctx->main_key, dst, dst);
> +			le128_xor((le128 *)dst, (const le128 *)dst, &tweak);
> +			gf128mul_x_ble(&tweak, &tweak);
> +
> +			dst += sizeof(tweak);
> +			src += sizeof(tweak);
> +			nbytes -= sizeof(tweak);
> +		}
> +		err = skcipher_walk_done(&walk, nbytes);
> +	}
> +
> +	return err;
> +}
> +
> +static int speck128_xts_encrypt(struct skcipher_request *req)
> +{
> +	return __speck128_xts_crypt(req, crypto_speck128_encrypt,
> +				    speck128_xts_encrypt_neon);
> +}
> +
> +static int speck128_xts_decrypt(struct skcipher_request *req)
> +{
> +	return __speck128_xts_crypt(req, crypto_speck128_decrypt,
> +				    speck128_xts_decrypt_neon);
> +}
> +
> +static int speck128_xts_setkey(struct crypto_skcipher *tfm, const u8 *key,
> +			       unsigned int keylen)
> +{
> +	struct speck128_xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
> +	int err;
> +
> +	err = xts_verify_key(tfm, key, keylen);
> +	if (err)
> +		return err;
> +
> +	keylen /= 2;
> +
> +	err = crypto_speck128_setkey(&ctx->main_key, key, keylen);
> +	if (err)
> +		return err;
> +
> +	return crypto_speck128_setkey(&ctx->tweak_key, key + keylen, keylen);
> +}
> +
> +/* Speck64 */
> +
> +struct speck64_xts_tfm_ctx {
> +	struct speck64_tfm_ctx main_key;
> +	struct speck64_tfm_ctx tweak_key;
> +};
> +
> +asmlinkage void speck64_xts_encrypt_neon(const u32 *round_keys, int nrounds,
> +					 void *dst, const void *src,
> +					 unsigned int nbytes, void *tweak);
> +
> +asmlinkage void speck64_xts_decrypt_neon(const u32 *round_keys, int nrounds,
> +					 void *dst, const void *src,
> +					 unsigned int nbytes, void *tweak);
> +
> +typedef void (*speck64_crypt_one_t)(const struct speck64_tfm_ctx *,
> +				    u8 *, const u8 *);
> +typedef void (*speck64_xts_crypt_many_t)(const u32 *, int, void *,
> +					 const void *, unsigned int, void *);
> +
> +static __always_inline int
> +__speck64_xts_crypt(struct skcipher_request *req, speck64_crypt_one_t
> crypt_one,
> +		    speck64_xts_crypt_many_t crypt_many)
> +{
> +	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
> +	const struct speck64_xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
> +	struct skcipher_walk walk;
> +	__le64 tweak;
> +	int err;
> +
> +	err = skcipher_walk_virt(&walk, req, true);
> +
> +	crypto_speck64_encrypt(&ctx->tweak_key, (u8 *)&tweak, walk.iv);
> +
> +	while (walk.nbytes > 0) {
> +		unsigned int nbytes = walk.nbytes;
> +		u8 *dst = walk.dst.virt.addr;
> +		const u8 *src = walk.src.virt.addr;
> +
> +		if (nbytes >= SPECK_NEON_CHUNK_SIZE && may_use_simd()) {
> +			unsigned int count;
> +
> +			count = round_down(nbytes, SPECK_NEON_CHUNK_SIZE);
> +			kernel_neon_begin();
> +			(*crypt_many)(ctx->main_key.round_keys,
> +				      ctx->main_key.nrounds,
> +				      dst, src, count, &tweak);
> +			kernel_neon_end();
> +			dst += count;
> +			src += count;
> +			nbytes -= count;
> +		}
> +
> +		/* Handle any remainder with generic code */
> +		while (nbytes >= sizeof(tweak)) {
> +			*(__le64 *)dst = *(__le64 *)src ^ tweak;
> +			(*crypt_one)(&ctx->main_key, dst, dst);
> +			*(__le64 *)dst ^= tweak;
> +			tweak = cpu_to_le64((le64_to_cpu(tweak) << 1) ^
> +					    ((tweak & cpu_to_le64(1ULL << 63)) ?
> +					     0x1B : 0));
> +			dst += sizeof(tweak);
> +			src += sizeof(tweak);
> +			nbytes -= sizeof(tweak);
> +		}
> +		err = skcipher_walk_done(&walk, nbytes);
> +	}
> +
> +	return err;
> +}
> +
> +static int speck64_xts_encrypt(struct skcipher_request *req)
> +{
> +	return __speck64_xts_crypt(req, crypto_speck64_encrypt,
> +				   speck64_xts_encrypt_neon);
> +}
> +
> +static int speck64_xts_decrypt(struct skcipher_request *req)
> +{
> +	return __speck64_xts_crypt(req, crypto_speck64_decrypt,
> +				   speck64_xts_decrypt_neon);
> +}
> +
> +static int speck64_xts_setkey(struct crypto_skcipher *tfm, const u8 *key,
> +			      unsigned int keylen)
> +{
> +	struct speck64_xts_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
> +	int err;
> +
> +	err = xts_verify_key(tfm, key, keylen);
> +	if (err)
> +		return err;
> +
> +	keylen /= 2;
> +
> +	err = crypto_speck64_setkey(&ctx->main_key, key, keylen);
> +	if (err)
> +		return err;
> +
> +	return crypto_speck64_setkey(&ctx->tweak_key, key + keylen, keylen);
> +}
> +
> +static struct skcipher_alg speck_algs[] = {
> +	{
> +		.base.cra_name		= "xts(speck128)",
> +		.base.cra_driver_name	= "xts-speck128-neon",
> +		.base.cra_priority	= 300,
> +		.base.cra_blocksize	= SPECK128_BLOCK_SIZE,
> +		.base.cra_ctxsize	= sizeof(struct speck128_xts_tfm_ctx),
> +		.base.cra_alignmask	= 7,
> +		.base.cra_module	= THIS_MODULE,
> +		.min_keysize		= 2 * SPECK128_128_KEY_SIZE,
> +		.max_keysize		= 2 * SPECK128_256_KEY_SIZE,
> +		.ivsize			= SPECK128_BLOCK_SIZE,
> +		.walksize		= SPECK_NEON_CHUNK_SIZE,
> +		.setkey			= speck128_xts_setkey,
> +		.encrypt		= speck128_xts_encrypt,
> +		.decrypt		= speck128_xts_decrypt,
> +	}, {
> +		.base.cra_name		= "xts(speck64)",
> +		.base.cra_driver_name	= "xts-speck64-neon",
> +		.base.cra_priority	= 300,
> +		.base.cra_blocksize	= SPECK64_BLOCK_SIZE,
> +		.base.cra_ctxsize	= sizeof(struct speck64_xts_tfm_ctx),
> +		.base.cra_alignmask	= 7,
> +		.base.cra_module	= THIS_MODULE,
> +		.min_keysize		= 2 * SPECK64_96_KEY_SIZE,
> +		.max_keysize		= 2 * SPECK64_128_KEY_SIZE,
> +		.ivsize			= SPECK64_BLOCK_SIZE,
> +		.walksize		= SPECK_NEON_CHUNK_SIZE,
> +		.setkey			= speck64_xts_setkey,
> +		.encrypt		= speck64_xts_encrypt,
> +		.decrypt		= speck64_xts_decrypt,
> +	}
> +};
> +
> +static int __init speck_neon_module_init(void)
> +{
> +	if (!(elf_hwcap & HWCAP_NEON))
> +		return -ENODEV;
> +	return crypto_register_skciphers(speck_algs, ARRAY_SIZE(speck_algs));
> +}
> +
> +static void __exit speck_neon_module_exit(void)
> +{
> +	crypto_unregister_skciphers(speck_algs, ARRAY_SIZE(speck_algs));
> +}
> +
> +module_init(speck_neon_module_init);
> +module_exit(speck_neon_module_exit);
> +
> +MODULE_DESCRIPTION("Speck block cipher (NEON-accelerated)");
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Eric Biggers <ebiggers@xxxxxxxxxx>");
> +MODULE_ALIAS_CRYPTO("xts(speck128)");
> +MODULE_ALIAS_CRYPTO("xts-speck128-neon");
> +MODULE_ALIAS_CRYPTO("xts(speck64)");
> +MODULE_ALIAS_CRYPTO("xts-speck64-neon");



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