On Mon, Mar 05, 2018 at 11:17:07AM -0800, Eric Biggers wrote:
> Add a NEON-accelerated implementation of Speck128-XTS and Speck64-XTS
> for ARM64. This is ported from the 32-bit version. It may be useful on
> devices with 64-bit ARM CPUs that don't have the Cryptography
> Extensions, so cannot do AES efficiently -- e.g. the Cortex-A53
> processor on the Raspberry Pi 3.
>
> It generally works the same way as the 32-bit version, but there are
> some slight differences due to the different instructions, registers,
> and syntax available in ARM64 vs. in ARM32. For example, in the 64-bit
> version there are enough registers to hold the XTS tweaks for each
> 128-byte chunk, so they don't need to be saved on the stack.
>
> Benchmarks on a Raspberry Pi 3 running a 64-bit kernel:
>
> Algorithm Encryption Decryption
> --------- ---------- ----------
> Speck64/128-XTS (NEON) 92.2 MB/s 92.2 MB/s
> Speck128/256-XTS (NEON) 75.0 MB/s 75.0 MB/s
> Speck128/256-XTS (generic) 47.4 MB/s 35.6 MB/s
> AES-128-XTS (NEON bit-sliced) 33.4 MB/s 29.6 MB/s
> AES-256-XTS (NEON bit-sliced) 24.6 MB/s 21.7 MB/s
>
> The code performs well on higher-end ARM64 processors as well, though
> such processors tend to have the Crypto Extensions which make AES
> preferred. For example, here are the same benchmarks run on a HiKey960
> (with CPU affinity set for the A73 cores), with the Crypto Extensions
> implementation of AES-256-XTS added:
>
> Algorithm Encryption Decryption
> --------- ----------- -----------
> AES-256-XTS (Crypto Extensions) 1273.3 MB/s 1274.7 MB/s
> Speck64/128-XTS (NEON) 359.8 MB/s 348.0 MB/s
> Speck128/256-XTS (NEON) 292.5 MB/s 286.1 MB/s
> Speck128/256-XTS (generic) 186.3 MB/s 181.8 MB/s
> AES-128-XTS (NEON bit-sliced) 142.0 MB/s 124.3 MB/s
> AES-256-XTS (NEON bit-sliced) 104.7 MB/s 91.1 MB/s
>
> Signed-off-by: Eric Biggers <ebigg...@google.com>
> ---
> arch/arm64/crypto/Kconfig | 6 +
> arch/arm64/crypto/Makefile | 3 +
> arch/arm64/crypto/speck-neon-core.S | 352 ++++++++++++++++++++++++++++
> arch/arm64/crypto/speck-neon-glue.c | 282 ++++++++++++++++++++++
> 4 files changed, 643 insertions(+)
> create mode 100644 arch/arm64/crypto/speck-neon-core.S
> create mode 100644 arch/arm64/crypto/speck-neon-glue.c
>
> diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig
> index 285c36c7b408..cb5a243110c4 100644
> --- a/arch/arm64/crypto/Kconfig
> +++ b/arch/arm64/crypto/Kconfig
> @@ -113,4 +113,10 @@ config CRYPTO_AES_ARM64_BS
> select CRYPTO_AES_ARM64
> select CRYPTO_SIMD
>
> +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/arm64/crypto/Makefile b/arch/arm64/crypto/Makefile
> index cee9b8d9830b..d94ebd15a859 100644
> --- a/arch/arm64/crypto/Makefile
> +++ b/arch/arm64/crypto/Makefile
> @@ -53,6 +53,9 @@ sha512-arm64-y := sha512-glue.o sha512-core.o
> obj-$(CONFIG_CRYPTO_CHACHA20_NEON) += chacha20-neon.o
> chacha20-neon-y := chacha20-neon-core.o chacha20-neon-glue.o
>
> +obj-$(CONFIG_CRYPTO_SPECK_NEON) += speck-neon.o
> +speck-neon-y := speck-neon-core.o speck-neon-glue.o
> +
> obj-$(CONFIG_CRYPTO_AES_ARM64) += aes-arm64.o
> aes-arm64-y := aes-cipher-core.o aes-cipher-glue.o
>
> diff --git a/arch/arm64/crypto/speck-neon-core.S
> b/arch/arm64/crypto/speck-neon-core.S
> new file mode 100644
> index 000000000000..b14463438b09
> --- /dev/null
> +++ b/arch/arm64/crypto/speck-neon-core.S
> @@ -0,0 +1,352 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * ARM64 NEON-accelerated implementation of Speck128-XTS and Speck64-XTS
> + *
> + * Copyright (c) 2018 Google, Inc
> + *
> + * Author: Eric Biggers <ebigg...@google.com>
> + */
> +
> +#include <linux/linkage.h>
> +
> + .text
> +
> + // arguments
> + ROUND_KEYS .req x0 // const {u64,u32} *round_keys
> + NROUNDS .req w1 // int nrounds
> + NROUNDS_X .req x1
> + DST .req x2 // void *dst
> + SRC .req x3 // const void *src
> + NBYTES .req w4 // unsigned int nbytes
> + TWEAK .req x5 // void *tweak
> +
> + // registers which hold the data being encrypted/decrypted
> + // (underscores avoid a naming collision with ARM64 registers x0-x3)
> + X_0 .req v0
> + Y_0 .req v1
> + X_1 .req v2
> + Y_1 .req v3
> + X_2 .req v4
> + Y_2 .req v5
> + X_3 .req v6
> + Y_3 .req v7
> +
> + // the round key, duplicated in all lanes
> + ROUND_KEY .req v8
> +
> + // index vector for tbl-based 8-bit rotates
> + ROTATE_TABLE .req v9
> + ROTATE_TABLE_Q .req q9
> +
> + // temporary registers
> + TMP0 .req v10
> + TMP1 .req v11
> + TMP2 .req v12
> + TMP3 .req v13
> +
> + // multiplication table for updating XTS tweaks
> + GFMUL_TABLE .req v14
> + GFMUL_TABLE_Q .req q14
> +
> + // next XTS tweak value(s)
> + TWEAKV_NEXT .req v15
> +
> + // XTS tweaks for the blocks currently being encrypted/decrypted
> + TWEAKV0 .req v16
> + TWEAKV1 .req v17
> + TWEAKV2 .req v18
> + TWEAKV3 .req v19
> + TWEAKV4 .req v20
> + TWEAKV5 .req v21
> + TWEAKV6 .req v22
> + TWEAKV7 .req v23
> +
> + .align 4
> +.Lror64_8_table:
> + .octa 0x080f0e0d0c0b0a090007060504030201
> +.Lror32_8_table:
> + .octa 0x0c0f0e0d080b0a090407060500030201
> +.Lrol64_8_table:
> + .octa 0x0e0d0c0b0a09080f0605040302010007
> +.Lrol32_8_table:
> + .octa 0x0e0d0c0f0a09080b0605040702010003
> +.Lgf128mul_table:
> + .octa 0x00000000000000870000000000000001
> +.Lgf64mul_table:
> + .octa 0x0000000000000000000000002d361b00
Won't this put the data in the image in an endianness-dependent layout?
Alternatively, if this doesn't matter, then why doesn't it matter?
(I don't claim to understand the code fully here...)
> +
> +/*
> + * _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.
> + * 'lanes' is the lane specifier: "2d" for Speck128 or "4s" for Speck64.
> + */
> +.macro _speck_round_128bytes n, lanes
> +
> + // x = ror(x, 8)
> + tbl X_0.16b, {X_0.16b}, ROTATE_TABLE.16b
> + tbl X_1.16b, {X_1.16b}, ROTATE_TABLE.16b
> + tbl X_2.16b, {X_2.16b}, ROTATE_TABLE.16b
> + tbl X_3.16b, {X_3.16b}, ROTATE_TABLE.16b
> +
> + // x += y
> + add X_0.\lanes, X_0.\lanes, Y_0.\lanes
> + add X_1.\lanes, X_1.\lanes, Y_1.\lanes
> + add X_2.\lanes, X_2.\lanes, Y_2.\lanes
> + add X_3.\lanes, X_3.\lanes, Y_3.\lanes
> +
> + // x ^= k
> + eor X_0.16b, X_0.16b, ROUND_KEY.16b
> + eor X_1.16b, X_1.16b, ROUND_KEY.16b
> + eor X_2.16b, X_2.16b, ROUND_KEY.16b
> + eor X_3.16b, X_3.16b, ROUND_KEY.16b
> +
> + // y = rol(y, 3)
> + shl TMP0.\lanes, Y_0.\lanes, #3
> + shl TMP1.\lanes, Y_1.\lanes, #3
> + shl TMP2.\lanes, Y_2.\lanes, #3
> + shl TMP3.\lanes, Y_3.\lanes, #3
> + sri TMP0.\lanes, Y_0.\lanes, #(\n - 3)
> + sri TMP1.\lanes, Y_1.\lanes, #(\n - 3)
> + sri TMP2.\lanes, Y_2.\lanes, #(\n - 3)
> + sri TMP3.\lanes, Y_3.\lanes, #(\n - 3)
> +
> + // y ^= x
> + eor Y_0.16b, TMP0.16b, X_0.16b
> + eor Y_1.16b, TMP1.16b, X_1.16b
> + eor Y_2.16b, TMP2.16b, X_2.16b
> + eor Y_3.16b, TMP3.16b, X_3.16b
> +.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, lanes
> +
> + // y ^= x
> + eor TMP0.16b, Y_0.16b, X_0.16b
> + eor TMP1.16b, Y_1.16b, X_1.16b
> + eor TMP2.16b, Y_2.16b, X_2.16b
> + eor TMP3.16b, Y_3.16b, X_3.16b
> +
> + // y = ror(y, 3)
> + ushr Y_0.\lanes, TMP0.\lanes, #3
> + ushr Y_1.\lanes, TMP1.\lanes, #3
> + ushr Y_2.\lanes, TMP2.\lanes, #3
> + ushr Y_3.\lanes, TMP3.\lanes, #3
> + sli Y_0.\lanes, TMP0.\lanes, #(\n - 3)
> + sli Y_1.\lanes, TMP1.\lanes, #(\n - 3)
> + sli Y_2.\lanes, TMP2.\lanes, #(\n - 3)
> + sli Y_3.\lanes, TMP3.\lanes, #(\n - 3)
> +
> + // x ^= k
> + eor X_0.16b, X_0.16b, ROUND_KEY.16b
> + eor X_1.16b, X_1.16b, ROUND_KEY.16b
> + eor X_2.16b, X_2.16b, ROUND_KEY.16b
> + eor X_3.16b, X_3.16b, ROUND_KEY.16b
> +
> + // x -= y
> + sub X_0.\lanes, X_0.\lanes, Y_0.\lanes
> + sub X_1.\lanes, X_1.\lanes, Y_1.\lanes
> + sub X_2.\lanes, X_2.\lanes, Y_2.\lanes
> + sub X_3.\lanes, X_3.\lanes, Y_3.\lanes
> +
> + // x = rol(x, 8)
> + tbl X_0.16b, {X_0.16b}, ROTATE_TABLE.16b
> + tbl X_1.16b, {X_1.16b}, ROTATE_TABLE.16b
> + tbl X_2.16b, {X_2.16b}, ROTATE_TABLE.16b
> + tbl X_3.16b, {X_3.16b}, ROTATE_TABLE.16b
> +.endm
> +
> +.macro _next_xts_tweak next, cur, tmp, n
> +.if \n == 64
> + /*
> + * Calculate the next tweak by multiplying the current one by x,
> + * modulo p(x) = x^128 + x^7 + x^2 + x + 1.
> + */
> + sshr \tmp\().2d, \cur\().2d, #63
> + and \tmp\().16b, \tmp\().16b, GFMUL_TABLE.16b
> + shl \next\().2d, \cur\().2d, #1
> + ext \tmp\().16b, \tmp\().16b, \tmp\().16b, #8
> + eor \next\().16b, \next\().16b, \tmp\().16b
> +.else
> + /*
> + * Calculate the next two tweaks by multiplying the current ones by x^2,
> + * modulo p(x) = x^64 + x^4 + x^3 + x + 1.
> + */
> + ushr \tmp\().2d, \cur\().2d, #62
> + shl \next\().2d, \cur\().2d, #2
> + tbl \tmp\().16b, {GFMUL_TABLE.16b}, \tmp\().16b
> + eor \next\().16b, \next\().16b, \tmp\().16b
> +.endif
> +.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, lanes, decrypting
> +
> + /*
> + * 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
> + mov NROUNDS, NROUNDS /* zero the high 32 bits */
> +.if \n == 64
> + add ROUND_KEYS, ROUND_KEYS, NROUNDS_X, lsl #3
> + sub ROUND_KEYS, ROUND_KEYS, #8
> +.else
> + add ROUND_KEYS, ROUND_KEYS, NROUNDS_X, lsl #2
> + sub ROUND_KEYS, ROUND_KEYS, #4
> +.endif
> +.endif
> +
> + // Load the index vector for tbl-based 8-bit rotates
> +.if \decrypting
> + ldr ROTATE_TABLE_Q, .Lrol\n\()_8_table
> +.else
> + ldr ROTATE_TABLE_Q, .Lror\n\()_8_table
> +.endif
> +
> + // One-time XTS preparation
> +.if \n == 64
> + // Load first tweak
> + ld1 {TWEAKV0.16b}, [TWEAK]
> +
> + // Load GF(2^128) multiplication table
> + ldr GFMUL_TABLE_Q, .Lgf128mul_table
> +.else
> + // Load first tweak
> + ld1 {TWEAKV0.8b}, [TWEAK]
> +
> + // Load GF(2^64) multiplication table
> + ldr GFMUL_TABLE_Q, .Lgf64mul_table
> +
> + // Calculate second tweak, packing it together with the first
> + ushr TMP0.2d, TWEAKV0.2d, #63
> + shl TMP1.2d, TWEAKV0.2d, #1
> + tbl TMP0.8b, {GFMUL_TABLE.16b}, TMP0.8b
> + eor TMP0.8b, TMP0.8b, TMP1.8b
> + mov TWEAKV0.d[1], TMP0.d[0]
> +.endif
> +
> +.Lnext_128bytes_\@:
> +
> + // Calculate XTS tweaks for next 128 bytes
> + _next_xts_tweak TWEAKV1, TWEAKV0, TMP0, \n
> + _next_xts_tweak TWEAKV2, TWEAKV1, TMP0, \n
> + _next_xts_tweak TWEAKV3, TWEAKV2, TMP0, \n
> + _next_xts_tweak TWEAKV4, TWEAKV3, TMP0, \n
> + _next_xts_tweak TWEAKV5, TWEAKV4, TMP0, \n
> + _next_xts_tweak TWEAKV6, TWEAKV5, TMP0, \n
> + _next_xts_tweak TWEAKV7, TWEAKV6, TMP0, \n
> + _next_xts_tweak TWEAKV_NEXT, TWEAKV7, TMP0, \n
> +
> + // Load the next source blocks into {X,Y}[0-3]
> + ld1 {X_0.16b-Y_1.16b}, [SRC], #64
> + ld1 {X_2.16b-Y_3.16b}, [SRC], #64
> +
> + // XOR the source blocks with their XTS tweaks
> + eor TMP0.16b, X_0.16b, TWEAKV0.16b
> + eor Y_0.16b, Y_0.16b, TWEAKV1.16b
> + eor TMP1.16b, X_1.16b, TWEAKV2.16b
> + eor Y_1.16b, Y_1.16b, TWEAKV3.16b
> + eor TMP2.16b, X_2.16b, TWEAKV4.16b
> + eor Y_2.16b, Y_2.16b, TWEAKV5.16b
> + eor TMP3.16b, X_3.16b, TWEAKV6.16b
> + eor Y_3.16b, Y_3.16b, TWEAKV7.16b
> +
> + /*
> + * 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).)
> + */
> + uzp2 X_0.\lanes, TMP0.\lanes, Y_0.\lanes
> + uzp1 Y_0.\lanes, TMP0.\lanes, Y_0.\lanes
> + uzp2 X_1.\lanes, TMP1.\lanes, Y_1.\lanes
> + uzp1 Y_1.\lanes, TMP1.\lanes, Y_1.\lanes
> + uzp2 X_2.\lanes, TMP2.\lanes, Y_2.\lanes
> + uzp1 Y_2.\lanes, TMP2.\lanes, Y_2.\lanes
> + uzp2 X_3.\lanes, TMP3.\lanes, Y_3.\lanes
> + uzp1 Y_3.\lanes, TMP3.\lanes, Y_3.\lanes
> +
> + // Do the cipher rounds
> + mov x6, ROUND_KEYS
> + mov w7, NROUNDS
> +.Lnext_round_\@:
> +.if \decrypting
> + ld1r {ROUND_KEY.\lanes}, [x6]
> + sub x6, x6, #( \n / 8 )
> + _speck_unround_128bytes \n, \lanes
> +.else
> + ld1r {ROUND_KEY.\lanes}, [x6], #( \n / 8 )
> + _speck_round_128bytes \n, \lanes
> +.endif
> + subs w7, w7, #1
> + bne .Lnext_round_\@
> +
> + // Re-interleave the 'x' and 'y' elements of each block
> + zip1 TMP0.\lanes, Y_0.\lanes, X_0.\lanes
> + zip2 Y_0.\lanes, Y_0.\lanes, X_0.\lanes
> + zip1 TMP1.\lanes, Y_1.\lanes, X_1.\lanes
> + zip2 Y_1.\lanes, Y_1.\lanes, X_1.\lanes
> + zip1 TMP2.\lanes, Y_2.\lanes, X_2.\lanes
> + zip2 Y_2.\lanes, Y_2.\lanes, X_2.\lanes
> + zip1 TMP3.\lanes, Y_3.\lanes, X_3.\lanes
> + zip2 Y_3.\lanes, Y_3.\lanes, X_3.\lanes
> +
> + // XOR the encrypted/decrypted blocks with the tweaks calculated earlier
> + eor X_0.16b, TMP0.16b, TWEAKV0.16b
> + eor Y_0.16b, Y_0.16b, TWEAKV1.16b
> + eor X_1.16b, TMP1.16b, TWEAKV2.16b
> + eor Y_1.16b, Y_1.16b, TWEAKV3.16b
> + eor X_2.16b, TMP2.16b, TWEAKV4.16b
> + eor Y_2.16b, Y_2.16b, TWEAKV5.16b
> + eor X_3.16b, TMP3.16b, TWEAKV6.16b
> + eor Y_3.16b, Y_3.16b, TWEAKV7.16b
> + mov TWEAKV0.16b, TWEAKV_NEXT.16b
> +
> + // Store the ciphertext in the destination buffer
> + st1 {X_0.16b-Y_1.16b}, [DST], #64
> + st1 {X_2.16b-Y_3.16b}, [DST], #64
> +
> + // Continue if there are more 128-byte chunks remaining
> + subs NBYTES, NBYTES, #128
> + bne .Lnext_128bytes_\@
> +
> + // Store the next tweak and return
> +.if \n == 64
> + st1 {TWEAKV_NEXT.16b}, [TWEAK]
> +.else
> + st1 {TWEAKV_NEXT.8b}, [TWEAK]
> +.endif
> + ret
> +.endm
> +
> +ENTRY(speck128_xts_encrypt_neon)
> + _speck_xts_crypt n=64, lanes=2d, decrypting=0
> +ENDPROC(speck128_xts_encrypt_neon)
> +
> +ENTRY(speck128_xts_decrypt_neon)
> + _speck_xts_crypt n=64, lanes=2d, decrypting=1
> +ENDPROC(speck128_xts_decrypt_neon)
> +
> +ENTRY(speck64_xts_encrypt_neon)
> + _speck_xts_crypt n=32, lanes=4s, decrypting=0
> +ENDPROC(speck64_xts_encrypt_neon)
> +
> +ENTRY(speck64_xts_decrypt_neon)
> + _speck_xts_crypt n=32, lanes=4s, decrypting=1
> +ENDPROC(speck64_xts_decrypt_neon)
> diff --git a/arch/arm64/crypto/speck-neon-glue.c
> b/arch/arm64/crypto/speck-neon-glue.c
> new file mode 100644
> index 000000000000..6e233aeb4ff4
> --- /dev/null
> +++ b/arch/arm64/crypto/speck-neon-glue.c
> @@ -0,0 +1,282 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * NEON-accelerated implementation of Speck128-XTS and Speck64-XTS
> + * (64-bit version; based on the 32-bit version)
> + *
> + * Copyright (c) 2018 Google, Inc
> + */
> +
> +#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);
Nitlet: you don't really need the (* ... ) around crypt_many here.
(If you want confirmation that it doesn't do anything, try
(****crypt_many).)
> + 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);
(Also here, and in a couple of other places for speck64. This is just a
stylistic thing though.)
> + 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_ASIMD))
> + return -ENODEV;
> + return crypto_register_skciphers(speck_algs, ARRAY_SIZE(speck_algs));
I haven't tried to understand everything here, but the kernel-mode NEON
integration looks OK to me.
> +}
> +
> +static void __exit speck_neon_module_exit(void)
> +{
> + crypto_unregister_skciphers(speck_algs, ARRAY_SIZE(speck_algs));
> +}
Cheers
---Dave
> +
> +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 <ebigg...@google.com>");
> +MODULE_ALIAS_CRYPTO("xts(speck128)");
> +MODULE_ALIAS_CRYPTO("xts-speck128-neon");
> +MODULE_ALIAS_CRYPTO("xts(speck64)");
> +MODULE_ALIAS_CRYPTO("xts-speck64-neon");
> --
> 2.16.2.395.g2e18187dfd-goog
>
>
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