Commit ede96221 authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: arm/speck - add NEON-accelerated implementation of Speck-XTS 



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: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent c8c36413

arch/arm/crypto/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -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

arch/arm/crypto/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -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) $(<) > $(@)

arch/arm/crypto/speck-neon-core.S

0 → 100644
+432 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * NEON-accelerated implementation of Speck128-XTS and Speck64-XTS

 *

 * Copyright (c) 2018 Google, Inc

 *

 * Author: Eric Biggers <ebiggers@google.com>

 */



#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



.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)

arch/arm/crypto/speck-neon-glue.c

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// 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@google.com>");

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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