diff mbox series

[v6,1/6] crypto: arm64/gcm-aes-ce - remove non-SIMD fallback path

Message ID 20210526100729.12939-2-ardb@kernel.org
State Accepted
Commit b9e699f91236cb1cc97a3d02ccb8063af5e4cc46
Headers show
Series [v6,1/6] crypto: arm64/gcm-aes-ce - remove non-SIMD fallback path | expand

Commit Message

Ard Biesheuvel May 26, 2021, 10:07 a.m. UTC 
Now that kernel mode SIMD is guaranteed to be available when executing
in task or softirq context, we no longer need scalar fallbacks to use
when the NEON is unavailable. So get rid of them.

Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 arch/arm64/crypto/ghash-ce-glue.c | 209 +++++---------------
 1 file changed, 51 insertions(+), 158 deletions(-)
diff mbox series

Patch

diff --git a/arch/arm64/crypto/ghash-ce-glue.c b/arch/arm64/crypto/ghash-ce-glue.c
index 720cd3a58da3..15794fe21a0b 100644
--- a/arch/arm64/crypto/ghash-ce-glue.c
+++ b/arch/arm64/crypto/ghash-ce-glue.c
@@ -362,84 +362,36 @@  static int gcm_encrypt(struct aead_request *req)
 
 	err = skcipher_walk_aead_encrypt(&walk, req, false);
 
-	if (likely(crypto_simd_usable())) {
-		do {
-			const u8 *src = walk.src.virt.addr;
-			u8 *dst = walk.dst.virt.addr;
-			int nbytes = walk.nbytes;
-
-			tag = (u8 *)&lengths;
-
-			if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) {
-				src = dst = memcpy(buf + sizeof(buf) - nbytes,
-						   src, nbytes);
-			} else if (nbytes < walk.total) {
-				nbytes &= ~(AES_BLOCK_SIZE - 1);
-				tag = NULL;
-			}
-
-			kernel_neon_begin();
-			pmull_gcm_encrypt(nbytes, dst, src, ctx->ghash_key.h,
-					  dg, iv, ctx->aes_key.key_enc, nrounds,
-					  tag);
-			kernel_neon_end();
-
-			if (unlikely(!nbytes))
-				break;
-
-			if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE))
-				memcpy(walk.dst.virt.addr,
-				       buf + sizeof(buf) - nbytes, nbytes);
-
-			err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
-		} while (walk.nbytes);
-	} else {
-		while (walk.nbytes >= AES_BLOCK_SIZE) {
-			int blocks = walk.nbytes / AES_BLOCK_SIZE;
-			const u8 *src = walk.src.virt.addr;
-			u8 *dst = walk.dst.virt.addr;
-			int remaining = blocks;
-
-			do {
-				aes_encrypt(&ctx->aes_key, buf, iv);
-				crypto_xor_cpy(dst, src, buf, AES_BLOCK_SIZE);
-				crypto_inc(iv, AES_BLOCK_SIZE);
-
-				dst += AES_BLOCK_SIZE;
-				src += AES_BLOCK_SIZE;
-			} while (--remaining > 0);
-
-			ghash_do_update(blocks, dg, walk.dst.virt.addr,
-					&ctx->ghash_key, NULL);
-
-			err = skcipher_walk_done(&walk,
-						 walk.nbytes % AES_BLOCK_SIZE);
-		}
-
-		/* handle the tail */
-		if (walk.nbytes) {
-			aes_encrypt(&ctx->aes_key, buf, iv);
+	do {
+		const u8 *src = walk.src.virt.addr;
+		u8 *dst = walk.dst.virt.addr;
+		int nbytes = walk.nbytes;
 
-			crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr,
-				       buf, walk.nbytes);
+		tag = (u8 *)&lengths;
 
-			memcpy(buf, walk.dst.virt.addr, walk.nbytes);
-			memset(buf + walk.nbytes, 0, sizeof(buf) - walk.nbytes);
+		if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) {
+			src = dst = memcpy(buf + sizeof(buf) - nbytes,
+					   src, nbytes);
+		} else if (nbytes < walk.total) {
+			nbytes &= ~(AES_BLOCK_SIZE - 1);
+			tag = NULL;
 		}
 
-		tag = (u8 *)&lengths;
-		ghash_do_update(1, dg, tag, &ctx->ghash_key,
-				walk.nbytes ? buf : NULL);
+		kernel_neon_begin();
+		pmull_gcm_encrypt(nbytes, dst, src, ctx->ghash_key.h,
+				  dg, iv, ctx->aes_key.key_enc, nrounds,
+				  tag);
+		kernel_neon_end();
 
-		if (walk.nbytes)
-			err = skcipher_walk_done(&walk, 0);
+		if (unlikely(!nbytes))
+			break;
 
-		put_unaligned_be64(dg[1], tag);
-		put_unaligned_be64(dg[0], tag + 8);
-		put_unaligned_be32(1, iv + GCM_IV_SIZE);
-		aes_encrypt(&ctx->aes_key, iv, iv);
-		crypto_xor(tag, iv, AES_BLOCK_SIZE);
-	}
+		if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE))
+			memcpy(walk.dst.virt.addr,
+			       buf + sizeof(buf) - nbytes, nbytes);
+
+		err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
+	} while (walk.nbytes);
 
 	if (err)
 		return err;
@@ -464,6 +416,7 @@  static int gcm_decrypt(struct aead_request *req)
 	u64 dg[2] = {};
 	be128 lengths;
 	u8 *tag;
+	int ret;
 	int err;
 
 	lengths.a = cpu_to_be64(req->assoclen * 8);
@@ -481,101 +434,41 @@  static int gcm_decrypt(struct aead_request *req)
 
 	err = skcipher_walk_aead_decrypt(&walk, req, false);
 
-	if (likely(crypto_simd_usable())) {
-		int ret;
-
-		do {
-			const u8 *src = walk.src.virt.addr;
-			u8 *dst = walk.dst.virt.addr;
-			int nbytes = walk.nbytes;
-
-			tag = (u8 *)&lengths;
-
-			if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) {
-				src = dst = memcpy(buf + sizeof(buf) - nbytes,
-						   src, nbytes);
-			} else if (nbytes < walk.total) {
-				nbytes &= ~(AES_BLOCK_SIZE - 1);
-				tag = NULL;
-			}
-
-			kernel_neon_begin();
-			ret = pmull_gcm_decrypt(nbytes, dst, src,
-						ctx->ghash_key.h,
-						dg, iv, ctx->aes_key.key_enc,
-						nrounds, tag, otag, authsize);
-			kernel_neon_end();
-
-			if (unlikely(!nbytes))
-				break;
-
-			if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE))
-				memcpy(walk.dst.virt.addr,
-				       buf + sizeof(buf) - nbytes, nbytes);
-
-			err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
-		} while (walk.nbytes);
-
-		if (err)
-			return err;
-		if (ret)
-			return -EBADMSG;
-	} else {
-		while (walk.nbytes >= AES_BLOCK_SIZE) {
-			int blocks = walk.nbytes / AES_BLOCK_SIZE;
-			const u8 *src = walk.src.virt.addr;
-			u8 *dst = walk.dst.virt.addr;
-
-			ghash_do_update(blocks, dg, walk.src.virt.addr,
-					&ctx->ghash_key, NULL);
-
-			do {
-				aes_encrypt(&ctx->aes_key, buf, iv);
-				crypto_xor_cpy(dst, src, buf, AES_BLOCK_SIZE);
-				crypto_inc(iv, AES_BLOCK_SIZE);
-
-				dst += AES_BLOCK_SIZE;
-				src += AES_BLOCK_SIZE;
-			} while (--blocks > 0);
+	do {
+		const u8 *src = walk.src.virt.addr;
+		u8 *dst = walk.dst.virt.addr;
+		int nbytes = walk.nbytes;
 
-			err = skcipher_walk_done(&walk,
-						 walk.nbytes % AES_BLOCK_SIZE);
-		}
+		tag = (u8 *)&lengths;
 
-		/* handle the tail */
-		if (walk.nbytes) {
-			memcpy(buf, walk.src.virt.addr, walk.nbytes);
-			memset(buf + walk.nbytes, 0, sizeof(buf) - walk.nbytes);
+		if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) {
+			src = dst = memcpy(buf + sizeof(buf) - nbytes,
+					   src, nbytes);
+		} else if (nbytes < walk.total) {
+			nbytes &= ~(AES_BLOCK_SIZE - 1);
+			tag = NULL;
 		}
 
-		tag = (u8 *)&lengths;
-		ghash_do_update(1, dg, tag, &ctx->ghash_key,
-				walk.nbytes ? buf : NULL);
-
-		if (walk.nbytes) {
-			aes_encrypt(&ctx->aes_key, buf, iv);
+		kernel_neon_begin();
+		ret = pmull_gcm_decrypt(nbytes, dst, src, ctx->ghash_key.h,
+					dg, iv, ctx->aes_key.key_enc,
+					nrounds, tag, otag, authsize);
+		kernel_neon_end();
 
-			crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr,
-				       buf, walk.nbytes);
+		if (unlikely(!nbytes))
+			break;
 
-			err = skcipher_walk_done(&walk, 0);
-		}
+		if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE))
+			memcpy(walk.dst.virt.addr,
+			       buf + sizeof(buf) - nbytes, nbytes);
 
-		if (err)
-			return err;
+		err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
+	} while (walk.nbytes);
 
-		put_unaligned_be64(dg[1], tag);
-		put_unaligned_be64(dg[0], tag + 8);
-		put_unaligned_be32(1, iv + GCM_IV_SIZE);
-		aes_encrypt(&ctx->aes_key, iv, iv);
-		crypto_xor(tag, iv, AES_BLOCK_SIZE);
+	if (err)
+		return err;
 
-		if (crypto_memneq(tag, otag, authsize)) {
-			memzero_explicit(tag, AES_BLOCK_SIZE);
-			return -EBADMSG;
-		}
-	}
-	return 0;
+	return ret ? -EBADMSG : 0;
 }
 
 static struct aead_alg gcm_aes_alg = {