From 065ce3273782b632f3e16ab789b432e12deb6823 Mon Sep 17 00:00:00 2001
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Tue, 22 Nov 2016 20:08:29 +0800
Subject: crypto: glue_helper - Add skcipher xts helpers

This patch adds xts helpers that use the skcipher interface rather
than blkcipher.  This will be used by aesni_intel.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
 arch/x86/crypto/glue_helper.c | 74 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 73 insertions(+), 1 deletion(-)

(limited to 'arch/x86/crypto')

diff --git a/arch/x86/crypto/glue_helper.c b/arch/x86/crypto/glue_helper.c
index 6a85598..260a060 100644
--- a/arch/x86/crypto/glue_helper.c
+++ b/arch/x86/crypto/glue_helper.c
@@ -27,10 +27,10 @@
 
 #include <linux/module.h>
 #include <crypto/b128ops.h>
+#include <crypto/internal/skcipher.h>
 #include <crypto/lrw.h>
 #include <crypto/xts.h>
 #include <asm/crypto/glue_helper.h>
-#include <crypto/scatterwalk.h>
 
 static int __glue_ecb_crypt_128bit(const struct common_glue_ctx *gctx,
 				   struct blkcipher_desc *desc,
@@ -339,6 +339,41 @@ done:
 	return nbytes;
 }
 
+static unsigned int __glue_xts_req_128bit(const struct common_glue_ctx *gctx,
+					  void *ctx,
+					  struct skcipher_walk *walk)
+{
+	const unsigned int bsize = 128 / 8;
+	unsigned int nbytes = walk->nbytes;
+	u128 *src = walk->src.virt.addr;
+	u128 *dst = 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,
+							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,
@@ -379,6 +414,43 @@ int glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
 }
 EXPORT_SYMBOL_GPL(glue_xts_crypt_128bit);
 
+int glue_xts_req_128bit(const struct common_glue_ctx *gctx,
+			struct skcipher_request *req,
+			common_glue_func_t tweak_fn, void *tweak_ctx,
+			void *crypt_ctx)
+{
+	const unsigned int bsize = 128 / 8;
+	struct skcipher_walk walk;
+	bool fpu_enabled = false;
+	unsigned int nbytes;
+	int err;
+
+	err = skcipher_walk_virt(&walk, req, false);
+	nbytes = walk.nbytes;
+	if (!nbytes)
+		return err;
+
+	/* set minimum length to bsize, for tweak_fn */
+	fpu_enabled = glue_skwalk_fpu_begin(bsize, gctx->fpu_blocks_limit,
+					    &walk, fpu_enabled,
+					    nbytes < bsize ? bsize : nbytes);
+
+	/* calculate first value of T */
+	tweak_fn(tweak_ctx, walk.iv, walk.iv);
+
+	while (nbytes) {
+		nbytes = __glue_xts_req_128bit(gctx, crypt_ctx, &walk);
+
+		err = skcipher_walk_done(&walk, nbytes);
+		nbytes = walk.nbytes;
+	}
+
+	glue_fpu_end(fpu_enabled);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(glue_xts_req_128bit);
+
 void glue_xts_crypt_128bit_one(void *ctx, u128 *dst, const u128 *src, le128 *iv,
 			       common_glue_func_t fn)
 {
-- 
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