Diskcipher supports cryptographic operations of inline crypto engines like
FMP. Inline crypto engine refers to hardware and solutions implemented
to encrypt data stored in storage device.

When encrypting using the FMP, Additional control is required
to carry and maintain the crypto information between
the encryption user(fscrypt, DM-crypt) and FMP driver.
Diskcipher provides this control.

Diskcipher is a symmetric key cipher in linux crypto API to support FMP.
FMP are registered with the cihper algorithm that uses diskcipher.

Diskcipher has three major steps.
The first step is to assign a cipher and set the key.
The second step is to pass the cipher through the BIO to the storage
driver.
The third step is to get the cipher from BIO and request a crypt
to FMP algorithm.

In the first step, encryption users such as fscrypt or dm-crypt
allocate/release a diskcipher and set key into the diskcipher.
Diskcipher provides allocate(), free(), and setkey() that are similar
to existing ciphers.

In the second step, BIO is used to pass the diskcipher to the storage
driver.
The BIO submitters such as ext4, f2fs and DM-crypt set diskcipher to BIO.
Diskcipher provides the set () API for this.

In the third step, the storage driver extracts the diskcipher from the BIO
and requests the actual encryption behavior to inline crypto engine driver.
Diskcipher provides get() and crypt() APIs for this.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Boojin Kim <redacted>
---
 crypto/Kconfig              |   9 ++
 crypto/Makefile             |   1 +
 crypto/diskcipher.c         | 349
++++++++++++++++++++++++++++++++++++++++++++
 crypto/testmgr.c            | 157 ++++++++++++++++++++
 include/crypto/diskcipher.h | 245 +++++++++++++++++++++++++++++++
 include/linux/crypto.h      |   1 +
 6 files changed, 762 insertions(+)
 create mode 100644 crypto/diskcipher.c
 create mode 100644 include/crypto/diskcipher.h

diff --git a/crypto/Kconfig b/crypto/Kconfig
index 455a335..382d43a 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig

@@ -1636,6 +1636,15 @@ config CRYPTO_TWOFISH_AVX_X86_64
          See also:
          <http://www.schneier.com/twofish.html>

+config CRYPTO_DISKCIPHER
+       bool "Diskcipher support"
+       default n
+       help
+         Disk cipher algorithm
+
+         This cipher supports the crypt operation of the block host device
+         that has inline crypto engine.
+
 comment "Compression"

 config CRYPTO_DEFLATE

diff --git a/crypto/Makefile b/crypto/Makefile
index 0d2cdd5..71df76a 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile

@@ -165,6 +165,7 @@ obj-$(CONFIG_CRYPTO_USER_API_AEAD) += algif_aead.o
 obj-$(CONFIG_CRYPTO_ZSTD) += zstd.o
 obj-$(CONFIG_CRYPTO_OFB) += ofb.o
 obj-$(CONFIG_CRYPTO_ECC) += ecc.o
+obj-$(CONFIG_CRYPTO_DISKCIPHER) += diskcipher.o

 ecdh_generic-y += ecdh.o
 ecdh_generic-y += ecdh_helper.o

diff --git a/crypto/diskcipher.c b/crypto/diskcipher.c
new file mode 100644
index 0000000..ffe95a5
--- /dev/null
+++ b/crypto/diskcipher.c

@@ -0,0 +1,349 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2017 Samsung Electronics Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <linux/string.h>
+#include <linux/crypto.h>
+#include <crypto/algapi.h>
+#include <crypto/diskcipher.h>
+#include <linux/delay.h>
+#include <linux/mm_types.h>
+#include <linux/fs.h>
+#include <linux/fscrypt.h>
+
+#include "internal.h"
+
+static int crypto_diskcipher_check(struct bio *bio)
+{
+       struct crypto_diskcipher *ci = NULL;
+       struct inode *inode = NULL;
+       struct page *page = NULL;
+
+       if (!bio) {
+               pr_err("%s: doesn't exist bio\n", __func__);
+               return 0;
+       }
+
+       /* enc without fscrypt */
+       ci = bio->bi_aux_private;
+       if (!ci->inode)
+               return 0;
+       if (ci->algo == 0)
+               return 0;
+
+       page = bio->bi_io_vec[0].bv_page;
+       if (!page || PageAnon(page) || !page->mapping ||

!page->mapping->host)