crypto: x86 - add more optimized XTS-mode for serpent-avx
This patch adds AVX optimized XTS-mode helper functions/macros and converts
serpent-avx to use the new facilities. Benefits are slightly improved speed
and reduced stack usage as use of temporary IV-array is avoided.
tcrypt results, with Intel i5-2450M:
enc dec
16B 1.00x 1.00x
64B 1.00x 1.00x
256B 1.04x 1.06x
1024B 1.09x 1.09x
8192B 1.10x 1.09x
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/arch/x86/crypto/glue_helper.c b/arch/x86/crypto/glue_helper.c
index 22ce4f6..432f1d76 100644
--- a/arch/x86/crypto/glue_helper.c
+++ b/arch/x86/crypto/glue_helper.c
@@ -1,7 +1,7 @@
/*
* Shared glue code for 128bit block ciphers
*
- * Copyright (c) 2012 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
+ * Copyright © 2012-2013 Jussi Kivilinna <jussi.kivilinna@iki.fi>
*
* CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:
* Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
@@ -304,4 +304,99 @@
}
EXPORT_SYMBOL_GPL(glue_ctr_crypt_128bit);
+static unsigned int __glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
+ void *ctx,
+ struct blkcipher_desc *desc,
+ struct blkcipher_walk *walk)
+{
+ const unsigned int bsize = 128 / 8;
+ unsigned int nbytes = walk->nbytes;
+ u128 *src = (u128 *)walk->src.virt.addr;
+ u128 *dst = (u128 *)walk->dst.virt.addr;
+ unsigned int num_blocks, func_bytes;
+ unsigned int i;
+
+ /* Process multi-block batch */
+ for (i = 0; i < gctx->num_funcs; i++) {
+ num_blocks = gctx->funcs[i].num_blocks;
+ func_bytes = bsize * num_blocks;
+
+ if (nbytes >= func_bytes) {
+ do {
+ gctx->funcs[i].fn_u.xts(ctx, dst, src,
+ (le128 *)walk->iv);
+
+ src += num_blocks;
+ dst += num_blocks;
+ nbytes -= func_bytes;
+ } while (nbytes >= func_bytes);
+
+ if (nbytes < bsize)
+ goto done;
+ }
+ }
+
+done:
+ return nbytes;
+}
+
+/* for implementations implementing faster XTS IV generator */
+int glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
+ struct blkcipher_desc *desc, struct scatterlist *dst,
+ struct scatterlist *src, unsigned int nbytes,
+ void (*tweak_fn)(void *ctx, u8 *dst, const u8 *src),
+ void *tweak_ctx, void *crypt_ctx)
+{
+ const unsigned int bsize = 128 / 8;
+ bool fpu_enabled = false;
+ struct blkcipher_walk walk;
+ int err;
+
+ blkcipher_walk_init(&walk, dst, src, nbytes);
+
+ err = blkcipher_walk_virt(desc, &walk);
+ nbytes = walk.nbytes;
+ if (!nbytes)
+ return err;
+
+ /* set minimum length to bsize, for tweak_fn */
+ fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
+ desc, fpu_enabled,
+ nbytes < bsize ? bsize : nbytes);
+
+ /* calculate first value of T */
+ tweak_fn(tweak_ctx, walk.iv, walk.iv);
+
+ while (nbytes) {
+ nbytes = __glue_xts_crypt_128bit(gctx, crypt_ctx, desc, &walk);
+
+ err = blkcipher_walk_done(desc, &walk, nbytes);
+ nbytes = walk.nbytes;
+ }
+
+ glue_fpu_end(fpu_enabled);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(glue_xts_crypt_128bit);
+
+void glue_xts_crypt_128bit_one(void *ctx, u128 *dst, const u128 *src, le128 *iv,
+ common_glue_func_t fn)
+{
+ le128 ivblk = *iv;
+
+ /* generate next IV */
+ le128_gf128mul_x_ble(iv, &ivblk);
+
+ /* CC <- T xor C */
+ u128_xor(dst, src, (u128 *)&ivblk);
+
+ /* PP <- D(Key2,CC) */
+ fn(ctx, (u8 *)dst, (u8 *)dst);
+
+ /* P <- T xor PP */
+ u128_xor(dst, dst, (u128 *)&ivblk);
+}
+EXPORT_SYMBOL_GPL(glue_xts_crypt_128bit_one);
+
MODULE_LICENSE("GPL");