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crypto: adiantum optimizations

PATCH In review Eric Biggers 2 participants 6 messages Oct 10, 2023 – Oct 20, 2023

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cover crypto: adiantum optimizations

This series slightly improves the performance of adiantum encryption and decryption on single-page messages.

Eric Biggers (4):
crypto: adiantum - add fast path for single-page messages
crypto: arm/nhpoly1305 - implement ->digest
crypto: arm64/nhpoly1305 - implement ->digest
crypto: x86/nhpoly1305 - implement ->digest

 arch/arm/crypto/nhpoly1305-neon-glue.c   |  9 ++++
 arch/arm64/crypto/nhpoly1305-neon-glue.c |  9 ++++
 arch/x86/crypto/nhpoly1305-avx2-glue.c   |  9 ++++
 arch/x86/crypto/nhpoly1305-sse2-glue.c   |  9 ++++
 crypto/adiantum.c                        | 65 +++++++++++++++++-------
 5 files changed, 83 insertions(+), 18 deletions(-)

base-commit: 8468516f9f93a41dc65158b6428a1a1039c68f20

Signature · 1 line
2.42.0
#1 lore raw

PATCH 1/4 crypto: adiantum - add fast path for single-page messages

From: Eric Biggers <[email protected]>

When the source scatterlist is a single page, optimize the first hash step of adiantum to use crypto_shash_digest() instead of init/update/final, and use the same local kmap for both hashing the bulk part and loading the narrow part of the source data.

Likewise, when the destination scatterlist is a single page, optimize the second hash step of adiantum to use crypto_shash_digest() instead of init/update/final, and use the same local kmap for both hashing the bulk part and storing the narrow part of the destination data.

In some cases these optimizations improve performance significantly.

Note: ideally, for optimal performance each architecture should implement the full "adiantum(xchacha12,aes)" algorithm and fully optimize the contiguous buffer case to use no indirect calls. That's not something I've gotten around to doing, though. This commit just makes a relatively small change that provides some benefit with the existing template-based approach.

---
 crypto/adiantum.c | 65 ++++++++++++++++++++++++++++++++++-------------
 1 file changed, 47 insertions(+), 18 deletions(-)
crypto/adiantum.c +47 -18
index c33ba22a66389..cd2b8f5042dc9 100644
@@ -238,39 +238,35 @@ static void adiantum_hash_header(struct skcipher_request *req)
 
 	BUILD_BUG_ON(TWEAK_SIZE % POLY1305_BLOCK_SIZE != 0);
 	poly1305_core_blocks(&state, &tctx->header_hash_key, req->iv,
 			     TWEAK_SIZE / POLY1305_BLOCK_SIZE, 1);
 
 	poly1305_core_emit(&state, NULL, &rctx->header_hash);
 }
 
 /* Hash the left-hand part (the "bulk") of the message using NHPoly1305 */
 static int adiantum_hash_message(struct skcipher_request *req,
-				 struct scatterlist *sgl, le128 *digest)
+				 struct scatterlist *sgl, unsigned int nents,
+				 le128 *digest)
 {
-	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
-	const struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
 	struct adiantum_request_ctx *rctx = skcipher_request_ctx(req);
 	const unsigned int bulk_len = req->cryptlen - BLOCKCIPHER_BLOCK_SIZE;
 	struct shash_desc *hash_desc = &rctx->u.hash_desc;
 	struct sg_mapping_iter miter;
 	unsigned int i, n;
 	int err;
 
-	hash_desc->tfm = tctx->hash;
-
 	err = crypto_shash_init(hash_desc);
 	if (err)
 		return err;
 
-	sg_miter_start(&miter, sgl, sg_nents(sgl),
-		       SG_MITER_FROM_SG | SG_MITER_ATOMIC);
+	sg_miter_start(&miter, sgl, nents, SG_MITER_FROM_SG | SG_MITER_ATOMIC);
 	for (i = 0; i < bulk_len; i += n) {
 		sg_miter_next(&miter);
 		n = min_t(unsigned int, miter.length, bulk_len - i);
 		err = crypto_shash_update(hash_desc, miter.addr, n);
 		if (err)
 			break;
 	}
 	sg_miter_stop(&miter);
 	if (err)
 		return err;
@@ -278,80 +274,113 @@ static int adiantum_hash_message(struct skcipher_request *req,
 	return crypto_shash_final(hash_desc, (u8 *)digest);
 }
 
 /* Continue Adiantum encryption/decryption after the stream cipher step */
 static int adiantum_finish(struct skcipher_request *req)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 	const struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
 	struct adiantum_request_ctx *rctx = skcipher_request_ctx(req);
 	const unsigned int bulk_len = req->cryptlen - BLOCKCIPHER_BLOCK_SIZE;
+	struct scatterlist *dst = req->dst;
+	const unsigned int dst_nents = sg_nents(dst);
 	le128 digest;
 	int err;
 
 	/* If decrypting, decrypt C_M with the block cipher to get P_M */
 	if (!rctx->enc)
 		crypto_cipher_decrypt_one(tctx->blockcipher, rctx->rbuf.bytes,
 					  rctx->rbuf.bytes);
 
 	/*
 	 * Second hash step
 	 *	enc: C_R = C_M - H_{K_H}(T, C_L)
 	 *	dec: P_R = P_M - H_{K_H}(T, P_L)
 	 */
-	err = adiantum_hash_message(req, req->dst, &digest);
-	if (err)
-		return err;
-	le128_add(&digest, &digest, &rctx->header_hash);
-	le128_sub(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &digest);
-	scatterwalk_map_and_copy(&rctx->rbuf.bignum, req->dst,
-				 bulk_len, BLOCKCIPHER_BLOCK_SIZE, 1);
+	rctx->u.hash_desc.tfm = tctx->hash;
+	le128_sub(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &rctx->header_hash);
+	if (dst_nents == 1 && dst->offset + req->cryptlen <= PAGE_SIZE) {
+		/* Fast path for single-page destination */
+		void *virt = kmap_local_page(sg_page(dst)) + dst->offset;
+
+		err = crypto_shash_digest(&rctx->u.hash_desc, virt, bulk_len,
+					  (u8 *)&digest);
+		if (err) {
+			kunmap_local(virt);
+			return err;
+		}
+		le128_sub(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &digest);
+		memcpy(virt + bulk_len, &rctx->rbuf.bignum, sizeof(le128));
+		kunmap_local(virt);
+	} else {
+		/* Slow path that works for any destination scatterlist */
+		err = adiantum_hash_message(req, dst, dst_nents, &digest);
+		if (err)
+			return err;
+		le128_sub(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &digest);
+		scatterwalk_map_and_copy(&rctx->rbuf.bignum, dst,
+					 bulk_len, sizeof(le128), 1);
+	}
 	return 0;
 }
 
 static void adiantum_streamcipher_done(void *data, int err)
 {
 	struct skcipher_request *req = data;
 
 	if (!err)
 		err = adiantum_finish(req);
 
 	skcipher_request_complete(req, err);
 }
 
 static int adiantum_crypt(struct skcipher_request *req, bool enc)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 	const struct adiantum_tfm_ctx *tctx = crypto_skcipher_ctx(tfm);
 	struct adiantum_request_ctx *rctx = skcipher_request_ctx(req);
 	const unsigned int bulk_len = req->cryptlen - BLOCKCIPHER_BLOCK_SIZE;
+	struct scatterlist *src = req->src;
+	const unsigned int src_nents = sg_nents(src);
 	unsigned int stream_len;
 	le128 digest;
 	int err;
 
 	if (req->cryptlen < BLOCKCIPHER_BLOCK_SIZE)
 		return -EINVAL;
 
 	rctx->enc = enc;
 
 	/*
 	 * First hash step
 	 *	enc: P_M = P_R + H_{K_H}(T, P_L)
 	 *	dec: C_M = C_R + H_{K_H}(T, C_L)
 	 */
 	adiantum_hash_header(req);
-	err = adiantum_hash_message(req, req->src, &digest);
+	rctx->u.hash_desc.tfm = tctx->hash;
+	if (src_nents == 1 && src->offset + req->cryptlen <= PAGE_SIZE) {
+		/* Fast path for single-page source */
+		void *virt = kmap_local_page(sg_page(src)) + src->offset;
+
+		err = crypto_shash_digest(&rctx->u.hash_desc, virt, bulk_len,
+					  (u8 *)&digest);
+		memcpy(&rctx->rbuf.bignum, virt + bulk_len, sizeof(le128));
+		kunmap_local(virt);
+	} else {
+		/* Slow path that works for any source scatterlist */
+		err = adiantum_hash_message(req, src, src_nents, &digest);
+		scatterwalk_map_and_copy(&rctx->rbuf.bignum, src,
+					 bulk_len, sizeof(le128), 0);
+	}
 	if (err)
 		return err;
-	le128_add(&digest, &digest, &rctx->header_hash);
-	scatterwalk_map_and_copy(&rctx->rbuf.bignum, req->src,
-				 bulk_len, BLOCKCIPHER_BLOCK_SIZE, 0);
+	le128_add(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &rctx->header_hash);
 	le128_add(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &digest);
 
 	/* If encrypting, encrypt P_M with the block cipher to get C_M */
 	if (enc)
 		crypto_cipher_encrypt_one(tctx->blockcipher, rctx->rbuf.bytes,
 					  rctx->rbuf.bytes);
 
 	/* Initialize the rest of the XChaCha IV (first part is C_M) */
 	BUILD_BUG_ON(BLOCKCIPHER_BLOCK_SIZE != 16);
 	BUILD_BUG_ON(XCHACHA_IV_SIZE != 32);	/* nonce || stream position */
Signature · 1 line
2.42.0
#2 lore raw

PATCH 2/4 crypto: arm/nhpoly1305 - implement ->digest

In reply to Eric Biggers

From: Eric Biggers <[email protected]>

Implement the ->digest method to improve performance on single-page messages by reducing the number of indirect calls.

---
 arch/arm/crypto/nhpoly1305-neon-glue.c | 9 +++++++++
 1 file changed, 9 insertions(+)
arch/arm/crypto/nhpoly1305-neon-glue.c +9 -0
index e93e41ff26566..62cf7ccdde736 100644
@@ -27,30 +27,39 @@ static int nhpoly1305_neon_update(struct shash_desc *desc,
 
 		kernel_neon_begin();
 		crypto_nhpoly1305_update_helper(desc, src, n, nh_neon);
 		kernel_neon_end();
 		src += n;
 		srclen -= n;
 	} while (srclen);
 	return 0;
 }
 
+static int nhpoly1305_neon_digest(struct shash_desc *desc,
+				  const u8 *src, unsigned int srclen, u8 *out)
+{
+	return crypto_nhpoly1305_init(desc) ?:
+	       nhpoly1305_neon_update(desc, src, srclen) ?:
+	       crypto_nhpoly1305_final(desc, out);
+}
+
 static struct shash_alg nhpoly1305_alg = {
 	.base.cra_name		= "nhpoly1305",
 	.base.cra_driver_name	= "nhpoly1305-neon",
 	.base.cra_priority	= 200,
 	.base.cra_ctxsize	= sizeof(struct nhpoly1305_key),
 	.base.cra_module	= THIS_MODULE,
 	.digestsize		= POLY1305_DIGEST_SIZE,
 	.init			= crypto_nhpoly1305_init,
 	.update			= nhpoly1305_neon_update,
 	.final			= crypto_nhpoly1305_final,
+	.digest			= nhpoly1305_neon_digest,
 	.setkey			= crypto_nhpoly1305_setkey,
 	.descsize		= sizeof(struct nhpoly1305_state),
 };
 
 static int __init nhpoly1305_mod_init(void)
 {
 	if (!(elf_hwcap & HWCAP_NEON))
 		return -ENODEV;
 
 	return crypto_register_shash(&nhpoly1305_alg);
Signature · 1 line
2.42.0
#3 lore raw

PATCH 3/4 crypto: arm64/nhpoly1305 - implement ->digest

In reply to Eric Biggers

From: Eric Biggers <[email protected]>

Implement the ->digest method to improve performance on single-page messages by reducing the number of indirect calls.

---
 arch/arm64/crypto/nhpoly1305-neon-glue.c | 9 +++++++++
 1 file changed, 9 insertions(+)
arch/arm64/crypto/nhpoly1305-neon-glue.c +9 -0
index cd882c35d9252..e4a0b463f080e 100644
@@ -27,30 +27,39 @@ static int nhpoly1305_neon_update(struct shash_desc *desc,
 
 		kernel_neon_begin();
 		crypto_nhpoly1305_update_helper(desc, src, n, nh_neon);
 		kernel_neon_end();
 		src += n;
 		srclen -= n;
 	} while (srclen);
 	return 0;
 }
 
+static int nhpoly1305_neon_digest(struct shash_desc *desc,
+				  const u8 *src, unsigned int srclen, u8 *out)
+{
+	return crypto_nhpoly1305_init(desc) ?:
+	       nhpoly1305_neon_update(desc, src, srclen) ?:
+	       crypto_nhpoly1305_final(desc, out);
+}
+
 static struct shash_alg nhpoly1305_alg = {
 	.base.cra_name		= "nhpoly1305",
 	.base.cra_driver_name	= "nhpoly1305-neon",
 	.base.cra_priority	= 200,
 	.base.cra_ctxsize	= sizeof(struct nhpoly1305_key),
 	.base.cra_module	= THIS_MODULE,
 	.digestsize		= POLY1305_DIGEST_SIZE,
 	.init			= crypto_nhpoly1305_init,
 	.update			= nhpoly1305_neon_update,
 	.final			= crypto_nhpoly1305_final,
+	.digest			= nhpoly1305_neon_digest,
 	.setkey			= crypto_nhpoly1305_setkey,
 	.descsize		= sizeof(struct nhpoly1305_state),
 };
 
 static int __init nhpoly1305_mod_init(void)
 {
 	if (!cpu_have_named_feature(ASIMD))
 		return -ENODEV;
 
 	return crypto_register_shash(&nhpoly1305_alg);
Signature · 1 line
2.42.0
#4 lore raw

PATCH 4/4 crypto: x86/nhpoly1305 - implement ->digest

In reply to Eric Biggers

From: Eric Biggers <[email protected]>

Implement the ->digest method to improve performance on single-page messages by reducing the number of indirect calls.

---
 arch/x86/crypto/nhpoly1305-avx2-glue.c | 9 +++++++++
 arch/x86/crypto/nhpoly1305-sse2-glue.c | 9 +++++++++
 2 files changed, 18 insertions(+)
arch/x86/crypto/nhpoly1305-avx2-glue.c +9 -0
index 46b036204ed91..c3a872f4d6a77 100644
@@ -27,30 +27,39 @@ static int nhpoly1305_avx2_update(struct shash_desc *desc,
 
 		kernel_fpu_begin();
 		crypto_nhpoly1305_update_helper(desc, src, n, nh_avx2);
 		kernel_fpu_end();
 		src += n;
 		srclen -= n;
 	} while (srclen);
 	return 0;
 }
 
+static int nhpoly1305_avx2_digest(struct shash_desc *desc,
+				  const u8 *src, unsigned int srclen, u8 *out)
+{
+	return crypto_nhpoly1305_init(desc) ?:
+	       nhpoly1305_avx2_update(desc, src, srclen) ?:
+	       crypto_nhpoly1305_final(desc, out);
+}
+
 static struct shash_alg nhpoly1305_alg = {
 	.base.cra_name		= "nhpoly1305",
 	.base.cra_driver_name	= "nhpoly1305-avx2",
 	.base.cra_priority	= 300,
 	.base.cra_ctxsize	= sizeof(struct nhpoly1305_key),
 	.base.cra_module	= THIS_MODULE,
 	.digestsize		= POLY1305_DIGEST_SIZE,
 	.init			= crypto_nhpoly1305_init,
 	.update			= nhpoly1305_avx2_update,
 	.final			= crypto_nhpoly1305_final,
+	.digest			= nhpoly1305_avx2_digest,
 	.setkey			= crypto_nhpoly1305_setkey,
 	.descsize		= sizeof(struct nhpoly1305_state),
 };
 
 static int __init nhpoly1305_mod_init(void)
 {
 	if (!boot_cpu_has(X86_FEATURE_AVX2) ||
 	    !boot_cpu_has(X86_FEATURE_OSXSAVE))
 		return -ENODEV;
 
arch/x86/crypto/nhpoly1305-sse2-glue.c +9 -0
index 4a4970d751076..a268a8439a5c9 100644
@@ -27,30 +27,39 @@ static int nhpoly1305_sse2_update(struct shash_desc *desc,
 
 		kernel_fpu_begin();
 		crypto_nhpoly1305_update_helper(desc, src, n, nh_sse2);
 		kernel_fpu_end();
 		src += n;
 		srclen -= n;
 	} while (srclen);
 	return 0;
 }
 
+static int nhpoly1305_sse2_digest(struct shash_desc *desc,
+				  const u8 *src, unsigned int srclen, u8 *out)
+{
+	return crypto_nhpoly1305_init(desc) ?:
+	       nhpoly1305_sse2_update(desc, src, srclen) ?:
+	       crypto_nhpoly1305_final(desc, out);
+}
+
 static struct shash_alg nhpoly1305_alg = {
 	.base.cra_name		= "nhpoly1305",
 	.base.cra_driver_name	= "nhpoly1305-sse2",
 	.base.cra_priority	= 200,
 	.base.cra_ctxsize	= sizeof(struct nhpoly1305_key),
 	.base.cra_module	= THIS_MODULE,
 	.digestsize		= POLY1305_DIGEST_SIZE,
 	.init			= crypto_nhpoly1305_init,
 	.update			= nhpoly1305_sse2_update,
 	.final			= crypto_nhpoly1305_final,
+	.digest			= nhpoly1305_sse2_digest,
 	.setkey			= crypto_nhpoly1305_setkey,
 	.descsize		= sizeof(struct nhpoly1305_state),
 };
 
 static int __init nhpoly1305_mod_init(void)
 {
 	if (!boot_cpu_has(X86_FEATURE_XMM2))
 		return -ENODEV;
 
 	return crypto_register_shash(&nhpoly1305_alg);
Signature · 1 line
2.42.0
maintainer
#5 lore raw
In reply to Eric Biggers
Quoted 9 lines · Eric Biggers

This series slightly improves the performance of adiantum encryption and decryption on single-page messages.

Eric Biggers (4):
crypto: adiantum - add fast path for single-page messages
crypto: arm/nhpoly1305 - implement ->digest
crypto: arm64/nhpoly1305 - implement ->digest
crypto: x86/nhpoly1305 - implement ->digest

Quoted 8 lines
arch/arm/crypto/nhpoly1305-neon-glue.c   |  9 ++++
arch/arm64/crypto/nhpoly1305-neon-glue.c |  9 ++++
arch/x86/crypto/nhpoly1305-avx2-glue.c   |  9 ++++
arch/x86/crypto/nhpoly1305-sse2-glue.c   |  9 ++++
crypto/adiantum.c                        | 65 +++++++++++++++++-------
5 files changed, 83 insertions(+), 18 deletions(-)

base-commit: 8468516f9f93a41dc65158b6428a1a1039c68f20

All applied. Thanks.

Signature · 3 lines
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt