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Commit e0bd888d authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Herbert Xu
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crypto: arm64/aes-ce-gcm - implement 2-way aggregation 



Implement a faster version of the GHASH transform which amortizes
the reduction modulo the characteristic polynomial across two
input blocks at a time.

On a Cortex-A53, the gcm(aes) performance increases 24%, from
3.0 cycles per byte to 2.4 cpb for large input sizes.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 71e52c27

arch/arm64/crypto/ghash-ce-core.S

+29 −57
Original line number Diff line number Diff line
@@ -290,6 +290,10 @@ ENDPROC(pmull_ghash_update_p8) 
	KS1		.req	v9

	INP0		.req	v10

	INP1		.req	v11

	HH		.req	v12

	XL2		.req	v13

	XM2		.req	v14

	XH2		.req	v15



	.macro		load_round_keys, rounds, rk

	cmp		\rounds, #12
@@ -323,6 +327,7 @@ ENDPROC(pmull_ghash_update_p8) 
	.endm



	.macro		pmull_gcm_do_crypt, enc

	ld1		{HH.2d}, [x4], #16

	ld1		{SHASH.2d}, [x4]

	ld1		{XL.2d}, [x1]

	ldr		x8, [x5, #8]			// load lower counter
@@ -330,10 +335,11 @@ ENDPROC(pmull_ghash_update_p8) 
	load_round_keys	w7, x6



	movi		MASK.16b, #0xe1

	ext		SHASH2.16b, SHASH.16b, SHASH.16b, #8

	trn1		SHASH2.2d, SHASH.2d, HH.2d

	trn2		T1.2d, SHASH.2d, HH.2d

CPU_LE(	rev		x8, x8		)

	shl		MASK.2d, MASK.2d, #57

	eor		SHASH2.16b, SHASH2.16b, SHASH.16b

	eor		SHASH2.16b, SHASH2.16b, T1.16b



	.if		\enc == 1

	ldr		x10, [sp]
@@ -358,116 +364,82 @@ CPU_LE( rev x8, x8 ) 
	ins		KS0.d[1], x9			// set lower counter

	ins		KS1.d[1], x11



	rev64		T1.16b, INP0.16b

	rev64		T1.16b, INP1.16b



	cmp		w7, #12

	b.ge		2f				// AES-192/256?



1:	enc_round	KS0, v21



	ext		T2.16b, XL.16b, XL.16b, #8

	ext		IN1.16b, T1.16b, T1.16b, #8



	enc_round	KS1, v21



	eor		T1.16b, T1.16b, T2.16b

	eor		XL.16b, XL.16b, IN1.16b

	pmull2		XH2.1q, SHASH.2d, IN1.2d	// a1 * b1



	enc_round	KS0, v22



	pmull2		XH.1q, SHASH.2d, XL.2d		// a1 * b1

	eor		T1.16b, T1.16b, XL.16b

	eor		T1.16b, T1.16b, IN1.16b



	enc_round	KS1, v22



	pmull		XL.1q, SHASH.1d, XL.1d		// a0 * b0

	pmull		XM.1q, SHASH2.1d, T1.1d		// (a1 + a0)(b1 + b0)

	pmull		XL2.1q, SHASH.1d, IN1.1d	// a0 * b0



	enc_round	KS0, v23



	ext		T1.16b, XL.16b, XH.16b, #8

	eor		T2.16b, XL.16b, XH.16b

	eor		XM.16b, XM.16b, T1.16b

	pmull		XM2.1q, SHASH2.1d, T1.1d	// (a1 + a0)(b1 + b0)



	enc_round	KS1, v23



	eor		XM.16b, XM.16b, T2.16b

	pmull		T2.1q, XL.1d, MASK.1d

	rev64		T1.16b, INP0.16b

	ext		T2.16b, XL.16b, XL.16b, #8



	enc_round	KS0, v24



	mov		XH.d[0], XM.d[1]

	mov		XM.d[1], XL.d[0]

	ext		IN1.16b, T1.16b, T1.16b, #8

	eor		T1.16b, T1.16b, T2.16b



	enc_round	KS1, v24



	eor		XL.16b, XM.16b, T2.16b

	eor		XL.16b, XL.16b, IN1.16b



	enc_round	KS0, v25



	ext		T2.16b, XL.16b, XL.16b, #8

	eor		T1.16b, T1.16b, XL.16b



	enc_round	KS1, v25



	pmull		XL.1q, XL.1d, MASK.1d

	eor		T2.16b, T2.16b, XH.16b

	pmull2		XH.1q, HH.2d, XL.2d		// a1 * b1



	enc_round	KS0, v26



	eor		XL.16b, XL.16b, T2.16b

	rev64		T1.16b, INP1.16b

	pmull		XL.1q, HH.1d, XL.1d		// a0 * b0



	enc_round	KS1, v26



	ext		T2.16b, XL.16b, XL.16b, #8

	ext		IN1.16b, T1.16b, T1.16b, #8

	pmull2		XM.1q, SHASH2.2d, T1.2d		// (a1 + a0)(b1 + b0)



	enc_round	KS0, v27



	eor		T1.16b, T1.16b, T2.16b

	eor		XL.16b, XL.16b, IN1.16b

	eor		XL.16b, XL.16b, XL2.16b

	eor		XH.16b, XH.16b, XH2.16b



	enc_round	KS1, v27



	pmull2		XH.1q, SHASH.2d, XL.2d		// a1 * b1

	eor		T1.16b, T1.16b, XL.16b

	eor		XM.16b, XM.16b, XM2.16b

	ext		T1.16b, XL.16b, XH.16b, #8



	enc_round	KS0, v28



	pmull		XL.1q, SHASH.1d, XL.1d		// a0 * b0

	pmull		XM.1q, SHASH2.1d, T1.1d		// (a1 + a0)(b1 + b0)



	enc_round	KS1, v28



	ext		T1.16b, XL.16b, XH.16b, #8

	eor		T2.16b, XL.16b, XH.16b

	eor		XM.16b, XM.16b, T1.16b



	enc_round	KS0, v29



	enc_round	KS1, v28

	eor		XM.16b, XM.16b, T2.16b



	enc_round	KS0, v29

	pmull		T2.1q, XL.1d, MASK.1d



	enc_round	KS1, v29



	mov		XH.d[0], XM.d[1]

	mov		XM.d[1], XL.d[0]



	aese		KS0.16b, v30.16b



	eor		XL.16b, XM.16b, T2.16b



	aese		KS1.16b, v30.16b



	ext		T2.16b, XL.16b, XL.16b, #8



	eor		KS0.16b, KS0.16b, v31.16b



	pmull		XL.1q, XL.1d, MASK.1d

	eor		T2.16b, T2.16b, XH.16b



	eor		KS1.16b, KS1.16b, v31.16b



	eor		XL.16b, XL.16b, T2.16b



	.if		\enc == 0

arch/arm64/crypto/ghash-ce-glue.c

+23 −11
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ struct ghash_desc_ctx { 


struct gcm_aes_ctx {

	struct crypto_aes_ctx	aes_key;

	u64			h2[2];

	struct ghash_key	ghash_key;

};
@@ -62,12 +63,11 @@ 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[], struct ghash_key const *k,

				  u8 ctr[], u32 const rk[], int rounds,

				  u8 ks[]);

				  const u8 src[], u64 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[], struct ghash_key const *k,

				  const u8 src[], u64 const *k,

				  u8 ctr[], u32 const rk[], int rounds);



asmlinkage void pmull_gcm_encrypt_block(u8 dst[], u8 const src[],
@@ -232,7 +232,8 @@ static int gcm_setkey(struct crypto_aead *tfm, const u8 *inkey, 
		      unsigned int keylen)

{

	struct gcm_aes_ctx *ctx = crypto_aead_ctx(tfm);

	u8 key[GHASH_BLOCK_SIZE];

	be128 h1, h2;

	u8 *key = (u8 *)&h1;

	int ret;



	ret = crypto_aes_expand_key(&ctx->aes_key, inkey, keylen);
@@ -244,7 +245,19 @@ 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));



	return __ghash_setkey(&ctx->ghash_key, key, sizeof(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;

}



static int gcm_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
@@ -378,9 +391,8 @@ 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->ghash_key,

					  iv, ctx->aes_key.key_enc, nrounds,

					  ks);

					  walk.src.virt.addr, ctx->h2, iv,

					  ctx->aes_key.key_enc, nrounds, ks);

			kernel_neon_end();



			err = skcipher_walk_done(&walk,
@@ -486,8 +498,8 @@ 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->ghash_key,

					  iv, ctx->aes_key.key_enc, nrounds);

					  walk.src.virt.addr, ctx->h2, iv,

					  ctx->aes_key.key_enc, nrounds);

			kernel_neon_end();



			err = skcipher_walk_done(&walk,