crypto: aesni_intel - add more optimized XTS mode for x86-64

Add more optimized XTS code for aesni_intel in 64-bit mode, for smaller stack
usage and boost for speed.

tcrypt results, with Intel i5-2450M:
256-bit key
        enc     dec
16B     0.98x   0.99x
64B     0.64x   0.63x
256B    1.29x   1.32x
1024B   1.54x   1.58x
8192B   1.57x   1.60x

512-bit key
        enc     dec
16B     0.98x   0.99x
64B     0.60x   0.59x
256B    1.24x   1.25x
1024B   1.39x   1.42x
8192B   1.38x   1.42x

I chose not to optimize smaller than block size of 256 bytes, since XTS is
practically always used with data blocks of size 512 bytes. This is why
performance is reduced in tcrypt for 64 byte long blocks.

Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 80 insertions, 0 deletions

diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index a0795da22c02..f80e668785c0 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -39,6 +39,9 @@
 #include <crypto/internal/aead.h>
 #include <linux/workqueue.h>
 #include <linux/spinlock.h>
+#ifdef CONFIG_X86_64
+#include <asm/crypto/glue_helper.h>
+#endif
 
 #if defined(CONFIG_CRYPTO_PCBC) || defined(CONFIG_CRYPTO_PCBC_MODULE)
 #define HAS_PCBC
@@ -102,6 +105,9 @@ void crypto_fpu_exit(void);
 asmlinkage void aesni_ctr_enc(struct crypto_aes_ctx *ctx, u8 *out,
 			      const u8 *in, unsigned int len, u8 *iv);
 
+asmlinkage void aesni_xts_crypt8(struct crypto_aes_ctx *ctx, u8 *out,
+				 const u8 *in, bool enc, u8 *iv);
+
 /* asmlinkage void aesni_gcm_enc()
  * void *ctx,  AES Key schedule. Starts on a 16 byte boundary.
  * u8 *out, Ciphertext output. Encrypt in-place is allowed.
@@ -510,6 +516,78 @@ static void aesni_xts_tweak(void *ctx, u8 *out, const u8 *in)
 	aesni_enc(ctx, out, in);
 }
 
+#ifdef CONFIG_X86_64
+
+static void aesni_xts_enc(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+{
+	glue_xts_crypt_128bit_one(ctx, dst, src, iv, GLUE_FUNC_CAST(aesni_enc));
+}
+
+static void aesni_xts_dec(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+{
+	glue_xts_crypt_128bit_one(ctx, dst, src, iv, GLUE_FUNC_CAST(aesni_dec));
+}
+
+static void aesni_xts_enc8(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+{
+	aesni_xts_crypt8(ctx, (u8 *)dst, (const u8 *)src, true, (u8 *)iv);
+}
+
+static void aesni_xts_dec8(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+{
+	aesni_xts_crypt8(ctx, (u8 *)dst, (const u8 *)src, false, (u8 *)iv);
+}
+
+static const struct common_glue_ctx aesni_enc_xts = {
+	.num_funcs = 2,
+	.fpu_blocks_limit = 1,
+
+	.funcs = { {
+		.num_blocks = 8,
+		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(aesni_xts_enc8) }
+	}, {
+		.num_blocks = 1,
+		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(aesni_xts_enc) }
+	} }
+};
+
+static const struct common_glue_ctx aesni_dec_xts = {
+	.num_funcs = 2,
+	.fpu_blocks_limit = 1,
+
+	.funcs = { {
+		.num_blocks = 8,
+		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(aesni_xts_dec8) }
+	}, {
+		.num_blocks = 1,
+		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(aesni_xts_dec) }
+	} }
+};
+
+static int xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
+		       struct scatterlist *src, unsigned int nbytes)
+{
+	struct aesni_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
+
+	return glue_xts_crypt_128bit(&aesni_enc_xts, desc, dst, src, nbytes,
+				     XTS_TWEAK_CAST(aesni_xts_tweak),
+				     aes_ctx(ctx->raw_tweak_ctx),
+				     aes_ctx(ctx->raw_crypt_ctx));
+}
+
+static int xts_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
+		       struct scatterlist *src, unsigned int nbytes)
+{
+	struct aesni_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
+
+	return glue_xts_crypt_128bit(&aesni_dec_xts, desc, dst, src, nbytes,
+				     XTS_TWEAK_CAST(aesni_xts_tweak),
+				     aes_ctx(ctx->raw_tweak_ctx),
+				     aes_ctx(ctx->raw_crypt_ctx));
+}
+
+#else
+
 static int xts_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 		       struct scatterlist *src, unsigned int nbytes)
 {
@@ -560,6 +638,8 @@ static int xts_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
 	return ret;
 }
 
+#endif
+
 #ifdef CONFIG_X86_64
 static int rfc4106_init(struct crypto_tfm *tfm)
 {