crypto: x86/poly1305 - depend on generic library not generic shash

Remove the dependency on the generic Poly1305 driver. Instead, depend
on the generic library so that we only reuse code without pulling in
the generic skcipher implementation as well.

While at it, remove the logic that prefers the non-SIMD path for short
inputs - this is no longer necessary after recent FPU handling changes
on x86.

Since this removes the last remaining user of the routines exported
by the generic shash driver, unexport them and make them static.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 55 insertions, 11 deletions

diff --git a/arch/x86/crypto/poly1305_glue.c b/arch/x86/crypto/poly1305_glue.c
index b43b93c95e79..a5b3a054604c 100644
--- a/arch/x86/crypto/poly1305_glue.c
+++ b/arch/x86/crypto/poly1305_glue.c
@@ -34,6 +34,24 @@ static void poly1305_simd_mult(u32 *a, const u32 *b)
 	poly1305_block_sse2(a, m, b, 1);
 }
 
+static unsigned int poly1305_scalar_blocks(struct poly1305_desc_ctx *dctx,
+					   const u8 *src, unsigned int srclen)
+{
+	unsigned int datalen;
+
+	if (unlikely(!dctx->sset)) {
+		datalen = crypto_poly1305_setdesckey(dctx, src, srclen);
+		src += srclen - datalen;
+		srclen = datalen;
+	}
+	if (srclen >= POLY1305_BLOCK_SIZE) {
+		poly1305_core_blocks(&dctx->h, dctx->r, src,
+				     srclen / POLY1305_BLOCK_SIZE, 1);
+		srclen %= POLY1305_BLOCK_SIZE;
+	}
+	return srclen;
+}
+
 static unsigned int poly1305_simd_blocks(struct poly1305_desc_ctx *dctx,
 					 const u8 *src, unsigned int srclen)
 {
@@ -91,12 +109,6 @@ static int poly1305_simd_update(struct shash_desc *desc,
 	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
 	unsigned int bytes;
 
-	/* kernel_fpu_begin/end is costly, use fallback for small updates */
-	if (srclen <= 288 || !crypto_simd_usable())
-		return crypto_poly1305_update(desc, src, srclen);
-
-	kernel_fpu_begin();
-
 	if (unlikely(dctx->buflen)) {
 		bytes = min(srclen, POLY1305_BLOCK_SIZE - dctx->buflen);
 		memcpy(dctx->buf + dctx->buflen, src, bytes);
@@ -105,25 +117,57 @@ static int poly1305_simd_update(struct shash_desc *desc,
 		dctx->buflen += bytes;
 
 		if (dctx->buflen == POLY1305_BLOCK_SIZE) {
-			poly1305_simd_blocks(dctx, dctx->buf,
-					     POLY1305_BLOCK_SIZE);
+			if (likely(crypto_simd_usable())) {
+				kernel_fpu_begin();
+				poly1305_simd_blocks(dctx, dctx->buf,
+						     POLY1305_BLOCK_SIZE);
+				kernel_fpu_end();
+			} else {
+				poly1305_scalar_blocks(dctx, dctx->buf,
+						       POLY1305_BLOCK_SIZE);
+			}
 			dctx->buflen = 0;
 		}
 	}
 
 	if (likely(srclen >= POLY1305_BLOCK_SIZE)) {
-		bytes = poly1305_simd_blocks(dctx, src, srclen);
+		if (likely(crypto_simd_usable())) {
+			kernel_fpu_begin();
+			bytes = poly1305_simd_blocks(dctx, src, srclen);
+			kernel_fpu_end();
+		} else {
+			bytes = poly1305_scalar_blocks(dctx, src, srclen);
+		}
 		src += srclen - bytes;
 		srclen = bytes;
 	}
 
-	kernel_fpu_end();
-
 	if (unlikely(srclen)) {
 		dctx->buflen = srclen;
 		memcpy(dctx->buf, src, srclen);
 	}
+}
+
+static int crypto_poly1305_init(struct shash_desc *desc)
+{
+	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
+
+	poly1305_core_init(&dctx->h);
+	dctx->buflen = 0;
+	dctx->rset = 0;
+	dctx->sset = false;
+
+	return 0;
+}
+
+static int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
+{
+	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
+
+	if (unlikely(!dctx->sset))
+		return -ENOKEY;
 
+	poly1305_final_generic(dctx, dst);
 	return 0;
 }