Enhance the GHASH implementation that uses 64-bit polynomial
multiplication by adding support for 4-way aggregation. This
more than doubles the performance, from 2.4 cycles per byte
to 1.1 cpb on Cortex-A53.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
arch/arm64/crypto/ghash-ce-core.S | 122 +++++++++++++++++---
arch/arm64/crypto/ghash-ce-glue.c | 71 ++++++------
2 files changed, 142 insertions(+), 51 deletions(-)
diff --git a/arch/arm64/crypto/ghash-ce-core.S b/arch/arm64/crypto/ghash-ce-core.S
index 344811c6a0ca..1b319b716d5e 100644
--- a/arch/arm64/crypto/ghash-ce-core.S
+++ b/arch/arm64/crypto/ghash-ce-core.S
@@ -46,6 +46,19 @@
ss3 .req v26
ss4 .req v27
+ XL2 .req v8
+ XM2 .req v9
+ XH2 .req v10
+ XL3 .req v11
+ XM3 .req v12
+ XH3 .req v13
+ TT3 .req v14
+ TT4 .req v15
+ HH .req v16
+ HH3 .req v17
+ HH4 .req v18
+ HH34 .req v19
+
.text
.arch armv8-a+crypto
@@ -134,11 +147,25 @@
.endm
.macro __pmull_pre_p64
+ add x8, x3, #16
+ ld1 {HH.2d-HH4.2d}, [x8]
+
+ trn1 SHASH2.2d, SHASH.2d, HH.2d
+ trn2 T1.2d, SHASH.2d, HH.2d
+ eor SHASH2.16b, SHASH2.16b, T1.16b
+
+ trn1 HH34.2d, HH3.2d, HH4.2d
+ trn2 T1.2d, HH3.2d, HH4.2d
+ eor HH34.16b, HH34.16b, T1.16b
+
movi MASK.16b, #0xe1
shl MASK.2d, MASK.2d, #57
.endm
.macro __pmull_pre_p8
+ ext SHASH2.16b, SHASH.16b, SHASH.16b, #8
+ eor SHASH2.16b, SHASH2.16b, SHASH.16b
+
// k00_16 := 0x0000000000000000_000000000000ffff
// k32_48 := 0x00000000ffffffff_0000ffffffffffff
movi k32_48.2d, #0xffffffff
@@ -215,8 +242,6 @@
.macro __pmull_ghash, pn
ld1 {SHASH.2d}, [x3]
ld1 {XL.2d}, [x1]
- ext SHASH2.16b, SHASH.16b, SHASH.16b, #8
- eor SHASH2.16b, SHASH2.16b, SHASH.16b
__pmull_pre_\pn
@@ -224,12 +249,79 @@
cbz x4, 0f
ld1 {T1.2d}, [x4]
mov x4, xzr
- b 1f
+ b 3f
+
+0: .ifc \pn, p64
+ tbnz w0, #0, 2f // skip until #blocks is a
+ tbnz w0, #1, 2f // round multiple of 4
+
+1: ld1 {XM3.16b-TT4.16b}, [x2], #64
+
+ sub w0, w0, #4
+
+ rev64 T1.16b, XM3.16b
+ rev64 T2.16b, XH3.16b
+ rev64 TT4.16b, TT4.16b
+ rev64 TT3.16b, TT3.16b
+
+ ext IN1.16b, TT4.16b, TT4.16b, #8
+ ext XL3.16b, TT3.16b, TT3.16b, #8
+
+ eor TT4.16b, TT4.16b, IN1.16b
+ pmull2 XH2.1q, SHASH.2d, IN1.2d // a1 * b1
+ pmull XL2.1q, SHASH.1d, IN1.1d // a0 * b0
+ pmull XM2.1q, SHASH2.1d, TT4.1d // (a1 + a0)(b1 + b0)
+
+ eor TT3.16b, TT3.16b, XL3.16b
+ pmull2 XH3.1q, HH.2d, XL3.2d // a1 * b1
+ pmull XL3.1q, HH.1d, XL3.1d // a0 * b0
+ pmull2 XM3.1q, SHASH2.2d, TT3.2d // (a1 + a0)(b1 + b0)
+
+ ext IN1.16b, T2.16b, T2.16b, #8
+ eor XL2.16b, XL2.16b, XL3.16b
+ eor XH2.16b, XH2.16b, XH3.16b
+ eor XM2.16b, XM2.16b, XM3.16b
+
+ eor T2.16b, T2.16b, IN1.16b
+ pmull2 XH3.1q, HH3.2d, IN1.2d // a1 * b1
+ pmull XL3.1q, HH3.1d, IN1.1d // a0 * b0
+ pmull XM3.1q, HH34.1d, T2.1d // (a1 + a0)(b1 + b0)
-0: ld1 {T1.2d}, [x2], #16
+ eor XL2.16b, XL2.16b, XL3.16b
+ eor XH2.16b, XH2.16b, XH3.16b
+ eor XM2.16b, XM2.16b, XM3.16b
+
+ ext IN1.16b, T1.16b, T1.16b, #8
+ ext TT3.16b, XL.16b, XL.16b, #8
+ eor XL.16b, XL.16b, IN1.16b
+ eor T1.16b, T1.16b, TT3.16b
+
+ pmull2 XH.1q, HH4.2d, XL.2d // a1 * b1
+ eor T1.16b, T1.16b, XL.16b
+ pmull XL.1q, HH4.1d, XL.1d // a0 * b0
+ pmull2 XM.1q, HH34.2d, T1.2d // (a1 + a0)(b1 + b0)
+
+ eor XL.16b, XL.16b, XL2.16b
+ eor XH.16b, XH.16b, XH2.16b
+ eor XM.16b, XM.16b, XM2.16b
+
+ eor T2.16b, XL.16b, XH.16b
+ ext T1.16b, XL.16b, XH.16b, #8
+ eor XM.16b, XM.16b, T2.16b
+
+ __pmull_reduce_p64
+
+ eor T2.16b, T2.16b, XH.16b
+ eor XL.16b, XL.16b, T2.16b
+
+ cbz w0, 5f
+ b 1b
+ .endif
+
+2: ld1 {T1.2d}, [x2], #16
sub w0, w0, #1
-1: /* multiply XL by SHASH in GF(2^128) */
+3: /* multiply XL by SHASH in GF(2^128) */
CPU_LE( rev64 T1.16b, T1.16b )
ext T2.16b, XL.16b, XL.16b, #8
@@ -242,7 +334,7 @@ CPU_LE( rev64 T1.16b, T1.16b )
__pmull_\pn XL, XL, SHASH // a0 * b0
__pmull_\pn XM, T1, SHASH2 // (a1 + a0)(b1 + b0)
- eor T2.16b, XL.16b, XH.16b
+4: eor T2.16b, XL.16b, XH.16b
ext T1.16b, XL.16b, XH.16b, #8
eor XM.16b, XM.16b, T2.16b
@@ -253,7 +345,7 @@ CPU_LE( rev64 T1.16b, T1.16b )
cbnz w0, 0b
- st1 {XL.2d}, [x1]
+5: st1 {XL.2d}, [x1]
ret
.endm
@@ -269,14 +361,10 @@ ENTRY(pmull_ghash_update_p8)
__pmull_ghash p8
ENDPROC(pmull_ghash_update_p8)
- KS0 .req v8
- KS1 .req v9
- INP0 .req v10
- INP1 .req v11
- HH .req v12
- XL2 .req v13
- XM2 .req v14
- XH2 .req v15
+ KS0 .req v12
+ KS1 .req v13
+ INP0 .req v14
+ INP1 .req v15
.macro load_round_keys, rounds, rk
cmp \rounds, #12
@@ -310,8 +398,8 @@ ENDPROC(pmull_ghash_update_p8)
.endm
.macro pmull_gcm_do_crypt, enc
- ld1 {HH.2d}, [x4], #16
- ld1 {SHASH.2d}, [x4]
+ ld1 {SHASH.2d}, [x4], #16
+ ld1 {HH.2d}, [x4]
ld1 {XL.2d}, [x1]
ldr x8, [x5, #8] // load lower counter
diff --git a/arch/arm64/crypto/ghash-ce-glue.c b/arch/arm64/crypto/ghash-ce-glue.c
index 03ce71ea81a2..08b49fd621cb 100644
--- a/arch/arm64/crypto/ghash-ce-glue.c
+++ b/arch/arm64/crypto/ghash-ce-glue.c
@@ -33,9 +33,12 @@ MODULE_ALIAS_CRYPTO("ghash");
#define GCM_IV_SIZE 12
struct ghash_key {
- u64 a;
- u64 b;
- be128 k;
+ u64 h[2];
+ u64 h2[2];
+ u64 h3[2];
+ u64 h4[2];
+
+ be128 k;
};
struct ghash_desc_ctx {
@@ -46,7 +49,6 @@ struct ghash_desc_ctx {
struct gcm_aes_ctx {
struct crypto_aes_ctx aes_key;
- u64 h2[2];
struct ghash_key ghash_key;
};
@@ -63,11 +65,12 @@ static void (*pmull_ghash_update)(int blocks, u64 dg[], const char *src,
const char *head);
asmlinkage void pmull_gcm_encrypt(int blocks, u64 dg[], u8 dst[],
- const u8 src[], u64 const *k, u8 ctr[],
- u32 const rk[], int rounds, u8 ks[]);
+ const u8 src[], struct ghash_key const *k,
+ u8 ctr[], u32 const rk[], int rounds,
+ u8 ks[]);
asmlinkage void pmull_gcm_decrypt(int blocks, u64 dg[], u8 dst[],
- const u8 src[], u64 const *k,
+ const u8 src[], struct ghash_key const *k,
u8 ctr[], u32 const rk[], int rounds);
asmlinkage void pmull_gcm_encrypt_block(u8 dst[], u8 const src[],
@@ -174,23 +177,36 @@ 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) & BIT(63) ? 1 : 0;
+
+ 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 ghash_key *key,
const u8 *inkey, unsigned int keylen)
{
- u64 a, b;
+ be128 h;
/* needed for the fallback */
memcpy(&key->k, inkey, GHASH_BLOCK_SIZE);
- /* perform multiplication by 'x' in GF(2^128) */
- b = get_unaligned_be64(inkey);
- a = get_unaligned_be64(inkey + 8);
+ ghash_reflect(key->h, &key->k);
+
+ h = key->k;
+ gf128mul_lle(&h, &key->k);
+ ghash_reflect(key->h2, &h);
- key->a = (a << 1) | (b >> 63);
- key->b = (b << 1) | (a >> 63);
+ gf128mul_lle(&h, &key->k);
+ ghash_reflect(key->h3, &h);
- if (b >> 63)
- key->b ^= 0xc200000000000000UL;
+ gf128mul_lle(&h, &key->k);
+ ghash_reflect(key->h4, &h);
return 0;
}
@@ -241,8 +257,7 @@ static int gcm_setkey(struct crypto_aead *tfm, const u8 *inkey,
unsigned int keylen)
{
struct gcm_aes_ctx *ctx = crypto_aead_ctx(tfm);
- be128 h1, h2;
- u8 *key = (u8 *)&h1;
+ u8 key[GHASH_BLOCK_SIZE];
int ret;
ret = crypto_aes_expand_key(&ctx->aes_key, inkey, keylen);
@@ -254,19 +269,7 @@ static int gcm_setkey(struct crypto_aead *tfm, const u8 *inkey,
__aes_arm64_encrypt(ctx->aes_key.key_enc, key, (u8[AES_BLOCK_SIZE]){},
num_rounds(&ctx->aes_key));
- __ghash_setkey(&ctx->ghash_key, key, sizeof(be128));
-
- /* calculate H^2 (used for 2-way aggregation) */
- h2 = h1;
- gf128mul_lle(&h2, &h1);
-
- ctx->h2[0] = (be64_to_cpu(h2.b) << 1) | (be64_to_cpu(h2.a) >> 63);
- ctx->h2[1] = (be64_to_cpu(h2.a) << 1) | (be64_to_cpu(h2.b) >> 63);
-
- if (be64_to_cpu(h2.a) >> 63)
- ctx->h2[1] ^= 0xc200000000000000UL;
-
- return 0;
+ return __ghash_setkey(&ctx->ghash_key, key, sizeof(be128));
}
static int gcm_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
@@ -402,8 +405,8 @@ static int gcm_encrypt(struct aead_request *req)
kernel_neon_begin();
pmull_gcm_encrypt(blocks, dg, walk.dst.virt.addr,
- walk.src.virt.addr, ctx->h2, iv,
- rk, nrounds, ks);
+ walk.src.virt.addr, &ctx->ghash_key,
+ iv, rk, nrounds, ks);
kernel_neon_end();
err = skcipher_walk_done(&walk,
@@ -513,8 +516,8 @@ static int gcm_decrypt(struct aead_request *req)
kernel_neon_begin();
pmull_gcm_decrypt(blocks, dg, walk.dst.virt.addr,
- walk.src.virt.addr, ctx->h2, iv,
- rk, nrounds);
+ walk.src.virt.addr, &ctx->ghash_key,
+ iv, rk, nrounds);
/* check if this is the final iteration of the loop */
if (rem < (2 * AES_BLOCK_SIZE)) {
--
2.18.0
