[PATCH v2] poly1305: generic C can be faster on chips with slow unaligned access

From: Jason A. Donenfeld
Date: Mon Nov 07 2016 - 14:14:04 EST


By using the unaligned access helpers, we drastically improve
performance on small MIPS routers that have to go through the exception
fix-up handler for these unaligned accesses.

Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
---
crypto/poly1305_generic.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/crypto/poly1305_generic.c b/crypto/poly1305_generic.c
index 2df9835d..0b86f4e 100644
--- a/crypto/poly1305_generic.c
+++ b/crypto/poly1305_generic.c
@@ -66,9 +66,9 @@ static void poly1305_setrkey(struct poly1305_desc_ctx *dctx, const u8 *key)
{
/* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
dctx->r[0] = (le32_to_cpuvp(key + 0) >> 0) & 0x3ffffff;
- dctx->r[1] = (le32_to_cpuvp(key + 3) >> 2) & 0x3ffff03;
- dctx->r[2] = (le32_to_cpuvp(key + 6) >> 4) & 0x3ffc0ff;
- dctx->r[3] = (le32_to_cpuvp(key + 9) >> 6) & 0x3f03fff;
+ dctx->r[1] = (get_unaligned_le32(key + 3) >> 2) & 0x3ffff03;
+ dctx->r[2] = (get_unaligned_le32(key + 6) >> 4) & 0x3ffc0ff;
+ dctx->r[3] = (get_unaligned_le32(key + 9) >> 6) & 0x3f03fff;
dctx->r[4] = (le32_to_cpuvp(key + 12) >> 8) & 0x00fffff;
}

@@ -138,9 +138,9 @@ static unsigned int poly1305_blocks(struct poly1305_desc_ctx *dctx,

/* h += m[i] */
h0 += (le32_to_cpuvp(src + 0) >> 0) & 0x3ffffff;
- h1 += (le32_to_cpuvp(src + 3) >> 2) & 0x3ffffff;
- h2 += (le32_to_cpuvp(src + 6) >> 4) & 0x3ffffff;
- h3 += (le32_to_cpuvp(src + 9) >> 6) & 0x3ffffff;
+ h1 += (get_unaligned_le32(src + 3) >> 2) & 0x3ffffff;
+ h2 += (get_unaligned_le32(src + 6) >> 4) & 0x3ffffff;
+ h3 += (get_unaligned_le32(src + 9) >> 6) & 0x3ffffff;
h4 += (le32_to_cpuvp(src + 12) >> 8) | hibit;

/* h *= r */
--
2.10.2