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crypto: arm/ghash-ce - implement support for 4-way aggregation

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Speed up the GHASH algorithm based on 64-bit polynomial multiplication
by adding support for 4-way aggregation. This improves throughput by
~85% on Cortex-A53, from 1.7 cycles per byte to 0.9 cycles per byte.

When combined with AES into GCM, throughput improves by ~25%, from
3.8 cycles per byte to 3.0 cycles per byte.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Ard Biesheuvel 2018-08-23 15:48:51 +01:00 committed by Herbert Xu
parent ab8085c130
commit 00227e3a1d
3 changed files with 131 additions and 16 deletions
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1
arch/arm/crypto/Kconfig
View File

@ -99,6 +99,7 @@ config CRYPTO_GHASH_ARM_CE
depends on KERNEL_MODE_NEON
select CRYPTO_HASH
select CRYPTO_CRYPTD
select CRYPTO_GF128MUL
help
Use an implementation of GHASH (used by the GCM AEAD chaining mode)
that uses the 64x64 to 128 bit polynomial multiplication (vmull.p64)

108
arch/arm/crypto/ghash-ce-core.S
View File

@ -63,6 +63,33 @@
k48 .req d31
SHASH2_p64 .req d31
HH .req q10
HH3 .req q11
HH4 .req q12
HH34 .req q13
HH_L .req d20
HH_H .req d21
HH3_L .req d22
HH3_H .req d23
HH4_L .req d24
HH4_H .req d25
HH34_L .req d26
HH34_H .req d27
SHASH2_H .req d29
XL2 .req q5
XM2 .req q6
XH2 .req q7
T3 .req q8
XL2_L .req d10
XL2_H .req d11
XM2_L .req d12
XM2_H .req d13
T3_L .req d16
T3_H .req d17
.text
.fpu crypto-neon-fp-armv8
@ -175,12 +202,77 @@
beq 0f
vld1.64 {T1}, [ip]
teq r0, #0
b 1f
b 3f
0: vld1.64 {T1}, [r2]!
0: .ifc \pn, p64
tst r0, #3 // skip until #blocks is a
bne 2f // round multiple of 4
vld1.8 {XL2-XM2}, [r2]!
1: vld1.8 {T3-T2}, [r2]!
vrev64.8 XL2, XL2
vrev64.8 XM2, XM2
subs r0, r0, #4
vext.8 T1, XL2, XL2, #8
veor XL2_H, XL2_H, XL_L
veor XL, XL, T1
vrev64.8 T3, T3
vrev64.8 T1, T2
vmull.p64 XH, HH4_H, XL_H // a1 * b1
veor XL2_H, XL2_H, XL_H
vmull.p64 XL, HH4_L, XL_L // a0 * b0
vmull.p64 XM, HH34_H, XL2_H // (a1 + a0)(b1 + b0)
vmull.p64 XH2, HH3_H, XM2_L // a1 * b1
veor XM2_L, XM2_L, XM2_H
vmull.p64 XL2, HH3_L, XM2_H // a0 * b0
vmull.p64 XM2, HH34_L, XM2_L // (a1 + a0)(b1 + b0)
veor XH, XH, XH2
veor XL, XL, XL2
veor XM, XM, XM2
vmull.p64 XH2, HH_H, T3_L // a1 * b1
veor T3_L, T3_L, T3_H
vmull.p64 XL2, HH_L, T3_H // a0 * b0
vmull.p64 XM2, SHASH2_H, T3_L // (a1 + a0)(b1 + b0)
veor XH, XH, XH2
veor XL, XL, XL2
veor XM, XM, XM2
vmull.p64 XH2, SHASH_H, T1_L // a1 * b1
veor T1_L, T1_L, T1_H
vmull.p64 XL2, SHASH_L, T1_H // a0 * b0
vmull.p64 XM2, SHASH2_p64, T1_L // (a1 + a0)(b1 + b0)
veor XH, XH, XH2
veor XL, XL, XL2
veor XM, XM, XM2
beq 4f
vld1.8 {XL2-XM2}, [r2]!
veor T1, XL, XH
veor XM, XM, T1
__pmull_reduce_p64
veor T1, T1, XH
veor XL, XL, T1
b 1b
.endif
2: vld1.64 {T1}, [r2]!
subs r0, r0, #1
1: /* multiply XL by SHASH in GF(2^128) */
3: /* multiply XL by SHASH in GF(2^128) */
#ifndef CONFIG_CPU_BIG_ENDIAN
vrev64.8 T1, T1
#endif
@ -193,7 +285,7 @@
__pmull_\pn XL, XL_L, SHASH_L, s1l, s2l, s3l, s4l @ a0 * b0
__pmull_\pn XM, T1_L, SHASH2_\pn @ (a1+a0)(b1+b0)
veor T1, XL, XH
4: veor T1, XL, XH
veor XM, XM, T1
__pmull_reduce_\pn
@ -212,8 +304,14 @@
* struct ghash_key const *k, const char *head)
*/
ENTRY(pmull_ghash_update_p64)
vld1.64 {SHASH}, [r3]
vld1.64 {SHASH}, [r3]!
vld1.64 {HH}, [r3]!
vld1.64 {HH3-HH4}, [r3]
veor SHASH2_p64, SHASH_L, SHASH_H
veor SHASH2_H, HH_L, HH_H
veor HH34_L, HH3_L, HH3_H
veor HH34_H, HH4_L, HH4_H
vmov.i8 MASK, #0xe1
vshl.u64 MASK, MASK, #57

38
arch/arm/crypto/ghash-ce-glue.c
View File

@ -1,7 +1,7 @@
/*
* Accelerated GHASH implementation with ARMv8 vmull.p64 instructions.
*
* Copyright (C) 2015 Linaro Ltd. <ard.biesheuvel@linaro.org>
* Copyright (C) 2015 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
@ -28,8 +28,10 @@ MODULE_ALIAS_CRYPTO("ghash");
#define GHASH_DIGEST_SIZE 16
struct ghash_key {
u64 a;
u64 b;
u64 h[2];
u64 h2[2];
u64 h3[2];
u64 h4[2];
};
struct ghash_desc_ctx {
@ -117,26 +119,40 @@ static int ghash_final(struct shash_desc *desc, u8 *dst)
return 0;
}
static void ghash_reflect(u64 h[], const be128 *k)
{
u64 carry = be64_to_cpu(k->a) >> 63;
h[0] = (be64_to_cpu(k->b) << 1) | carry;
h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63);
if (carry)
h[1] ^= 0xc200000000000000UL;
}
static int ghash_setkey(struct crypto_shash *tfm,
const u8 *inkey, unsigned int keylen)
{
struct ghash_key *key = crypto_shash_ctx(tfm);
u64 a, b;
be128 h, k;
if (keylen != GHASH_BLOCK_SIZE) {
crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
return -EINVAL;
}
/* perform multiplication by 'x' in GF(2^128) */
b = get_unaligned_be64(inkey);
a = get_unaligned_be64(inkey + 8);
memcpy(&k, inkey, GHASH_BLOCK_SIZE);
ghash_reflect(key->h, &k);
key->a = (a << 1) | (b >> 63);
key->b = (b << 1) | (a >> 63);
h = k;
gf128mul_lle(&h, &k);
ghash_reflect(key->h2, &h);
if (b >> 63)
key->b ^= 0xc200000000000000UL;
gf128mul_lle(&h, &k);
ghash_reflect(key->h3, &h);
gf128mul_lle(&h, &k);
ghash_reflect(key->h4, &h);
return 0;
}