drivers/crypto/qce/skcipher.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (c) 2010-2014, The Linux Foundation. All rights reserved.
  */

 #include <linux/device.h>
 #include <linux/dma-mapping.h>
 #include <linux/interrupt.h>
 #include <linux/moduleparam.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <crypto/aes.h>
 #include <crypto/internal/des.h>
 #include <crypto/internal/skcipher.h>

 #include "cipher.h"

 static unsigned int aes_sw_max_len = CONFIG_CRYPTO_DEV_QCE_SW_MAX_LEN;
 module_param(aes_sw_max_len, uint, 0644);
 MODULE_PARM_DESC(aes_sw_max_len,
 		 "Only use hardware for AES requests larger than this "
 		 "[0=always use hardware; anything <16 breaks AES-GCM; default="
 		 __stringify(CONFIG_CRYPTO_DEV_QCE_SW_MAX_LEN)"]");

 static LIST_HEAD(skcipher_algs);

 static void qce_skcipher_done(void *data)
 {
 	struct crypto_async_request *async_req = data;
 	struct skcipher_request *req = skcipher_request_cast(async_req);
 	struct qce_cipher_reqctx *rctx = skcipher_request_ctx(req);
 	struct qce_alg_template *tmpl = to_cipher_tmpl(crypto_skcipher_reqtfm(req));
 	struct qce_device *qce = tmpl->qce;
 	struct qce_result_dump *result_buf = qce->dma.result_buf;
 	enum dma_data_direction dir_src, dir_dst;
 	u32 status;
 	int error;
 	bool diff_dst;

 	diff_dst = (req->src != req->dst) ? true : false;
 	dir_src = diff_dst ? DMA_TO_DEVICE : DMA_BIDIRECTIONAL;
 	dir_dst = diff_dst ? DMA_FROM_DEVICE : DMA_BIDIRECTIONAL;

 	error = qce_dma_terminate_all(&qce->dma);
 	if (error)
 		dev_dbg(qce->dev, "skcipher dma termination error (%d)\n",
 			error);

 	if (diff_dst)
 		dma_unmap_sg(qce->dev, rctx->src_sg, rctx->src_nents, dir_src);
 	dma_unmap_sg(qce->dev, rctx->dst_sg, rctx->dst_nents, dir_dst);

 	sg_free_table(&rctx->dst_tbl);

 	error = qce_check_status(qce, &status);
 	if (error < 0)
 		dev_dbg(qce->dev, "skcipher operation error (%x)\n", status);

 	memcpy(rctx->iv, result_buf->encr_cntr_iv, rctx->ivsize);
 	qce->async_req_done(tmpl->qce, error);
 }

 static int
 qce_skcipher_async_req_handle(struct crypto_async_request *async_req)
 {
 	struct skcipher_request *req = skcipher_request_cast(async_req);
 	struct qce_cipher_reqctx *rctx = skcipher_request_ctx(req);
 	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
 	struct qce_alg_template *tmpl = to_cipher_tmpl(crypto_skcipher_reqtfm(req));
 	struct qce_device *qce = tmpl->qce;
 	enum dma_data_direction dir_src, dir_dst;
 	struct scatterlist *sg;
 	bool diff_dst;
 	gfp_t gfp;
 	int dst_nents, src_nents, ret;

 	rctx->iv = req->iv;
 	rctx->ivsize = crypto_skcipher_ivsize(skcipher);
 	rctx->cryptlen = req->cryptlen;

 	diff_dst = (req->src != req->dst) ? true : false;
 	dir_src = diff_dst ? DMA_TO_DEVICE : DMA_BIDIRECTIONAL;
 	dir_dst = diff_dst ? DMA_FROM_DEVICE : DMA_BIDIRECTIONAL;

 	rctx->src_nents = sg_nents_for_len(req->src, req->cryptlen);
 	if (diff_dst)
 		rctx->dst_nents = sg_nents_for_len(req->dst, req->cryptlen);
 	else
 		rctx->dst_nents = rctx->src_nents;
 	if (rctx->src_nents < 0) {
 		dev_err(qce->dev, "Invalid numbers of src SG.\n");
 		return rctx->src_nents;
 	}
 	if (rctx->dst_nents < 0) {
 		dev_err(qce->dev, "Invalid numbers of dst SG.\n");
 		return -rctx->dst_nents;
 	}

 	rctx->dst_nents += 1;

 	gfp = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
 						GFP_KERNEL : GFP_ATOMIC;

 	ret = sg_alloc_table(&rctx->dst_tbl, rctx->dst_nents, gfp);
 	if (ret)
 		return ret;

 	sg_init_one(&rctx->result_sg, qce->dma.result_buf, QCE_RESULT_BUF_SZ);

 	sg = qce_sgtable_add(&rctx->dst_tbl, req->dst, req->cryptlen);
 	if (IS_ERR(sg)) {
 		ret = PTR_ERR(sg);
 		goto error_free;
 	}

 	sg = qce_sgtable_add(&rctx->dst_tbl, &rctx->result_sg,
 			     QCE_RESULT_BUF_SZ);
 	if (IS_ERR(sg)) {
 		ret = PTR_ERR(sg);
 		goto error_free;
 	}

 	sg_mark_end(sg);
 	rctx->dst_sg = rctx->dst_tbl.sgl;

 	dst_nents = dma_map_sg(qce->dev, rctx->dst_sg, rctx->dst_nents, dir_dst);
 	if (!dst_nents) {
 		ret = -EIO;
 		goto error_free;
 	}

 	if (diff_dst) {
 		src_nents = dma_map_sg(qce->dev, req->src, rctx->src_nents, dir_src);
 		if (!src_nents) {
 			ret = -EIO;
 			goto error_unmap_dst;
 		}
 		rctx->src_sg = req->src;
 	} else {
 		rctx->src_sg = rctx->dst_sg;
 		src_nents = dst_nents - 1;
 	}

 	ret = qce_dma_prep_sgs(&qce->dma, rctx->src_sg, src_nents,
 			       rctx->dst_sg, dst_nents,
 			       qce_skcipher_done, async_req);
 	if (ret)
 		goto error_unmap_src;

 	qce_dma_issue_pending(&qce->dma);

 	ret = qce_start(async_req, tmpl->crypto_alg_type);
 	if (ret)
 		goto error_terminate;

 	return 0;

 error_terminate:
 	qce_dma_terminate_all(&qce->dma);
 error_unmap_src:
 	if (diff_dst)
 		dma_unmap_sg(qce->dev, req->src, rctx->src_nents, dir_src);
 error_unmap_dst:
 	dma_unmap_sg(qce->dev, rctx->dst_sg, rctx->dst_nents, dir_dst);
 error_free:
 	sg_free_table(&rctx->dst_tbl);
 	return ret;
 }

 static int qce_skcipher_setkey(struct crypto_skcipher *ablk, const u8 *key,
 				 unsigned int keylen)
 {
 	struct crypto_tfm *tfm = crypto_skcipher_tfm(ablk);
 	struct qce_cipher_ctx *ctx = crypto_tfm_ctx(tfm);
 	unsigned long flags = to_cipher_tmpl(ablk)->alg_flags;
 	unsigned int __keylen;
 	int ret;

 	if (!key || !keylen)
 		return -EINVAL;

 	/*
 	 * AES XTS key1 = key2 not supported by crypto engine.
 	 * Revisit to request a fallback cipher in this case.
 	 */
 	if (IS_XTS(flags)) {
 		__keylen = keylen >> 1;
 		if (!memcmp(key, key + __keylen, __keylen))
 			return -ENOKEY;
 	} else {
 		__keylen = keylen;
 	}

 	switch (__keylen) {
 	case AES_KEYSIZE_128:
 	case AES_KEYSIZE_256:
 		memcpy(ctx->enc_key, key, keylen);
 		break;
 	case AES_KEYSIZE_192:
 		break;
 	default:
 		return -EINVAL;
 	}

 	ret = crypto_skcipher_setkey(ctx->fallback, key, keylen);
 	if (!ret)
 		ctx->enc_keylen = keylen;
 	return ret;
 }

 static int qce_des_setkey(struct crypto_skcipher *ablk, const u8 *key,
 			  unsigned int keylen)
 {
 	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(ablk);
 	int err;

 	err = verify_skcipher_des_key(ablk, key);
 	if (err)
 		return err;

 	ctx->enc_keylen = keylen;
 	memcpy(ctx->enc_key, key, keylen);
 	return 0;
 }

 static int qce_des3_setkey(struct crypto_skcipher *ablk, const u8 *key,
 			   unsigned int keylen)
 {
 	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(ablk);
 	u32 _key[6];
 	int err;

 	err = verify_skcipher_des3_key(ablk, key);
 	if (err)
 		return err;

 	/*
 	 * The crypto engine does not support any two keys
 	 * being the same for triple des algorithms. The
 	 * verify_skcipher_des3_key does not check for all the
 	 * below conditions. Return -ENOKEY in case any two keys
 	 * are the same. Revisit to see if a fallback cipher
 	 * is needed to handle this condition.
 	 */
 	memcpy(_key, key, DES3_EDE_KEY_SIZE);
 	if (!((_key[0] ^ _key[2]) | (_key[1] ^ _key[3])) ||
 	    !((_key[2] ^ _key[4]) | (_key[3] ^ _key[5])) ||
 	    !((_key[0] ^ _key[4]) | (_key[1] ^ _key[5])))
 		return -ENOKEY;

 	ctx->enc_keylen = keylen;
 	memcpy(ctx->enc_key, key, keylen);
 	return 0;
 }

 static int qce_skcipher_crypt(struct skcipher_request *req, int encrypt)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);
 	struct qce_cipher_reqctx *rctx = skcipher_request_ctx(req);
 	struct qce_alg_template *tmpl = to_cipher_tmpl(tfm);
 	unsigned int blocksize = crypto_skcipher_blocksize(tfm);
 	int keylen;
 	int ret;

 	rctx->flags = tmpl->alg_flags;
 	rctx->flags |= encrypt ? QCE_ENCRYPT : QCE_DECRYPT;
 	keylen = IS_XTS(rctx->flags) ? ctx->enc_keylen >> 1 : ctx->enc_keylen;

 	/* CE does not handle 0 length messages */
 	if (!req->cryptlen)
 		return 0;

 	/*
 	 * ECB and CBC algorithms require message lengths to be
 	 * multiples of block size.
 	 */
 	if (IS_ECB(rctx->flags) || IS_CBC(rctx->flags))
 		if (!IS_ALIGNED(req->cryptlen, blocksize))
 			return -EINVAL;

 	/*
 	 * Conditions for requesting a fallback cipher
 	 * AES-192 (not supported by crypto engine (CE))
 	 * AES-XTS request with len <= 512 byte (not recommended to use CE)
 	 * AES-XTS request with len > QCE_SECTOR_SIZE and
 	 * is not a multiple of it.(Revisit this condition to check if it is
 	 * needed in all versions of CE)
 	 */
 	if (IS_AES(rctx->flags) &&
 	    ((keylen != AES_KEYSIZE_128 && keylen != AES_KEYSIZE_256) ||
 	    (IS_XTS(rctx->flags) && ((req->cryptlen <= aes_sw_max_len) ||
 	    (req->cryptlen > QCE_SECTOR_SIZE &&
 	    req->cryptlen % QCE_SECTOR_SIZE))))) {
 		skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback);
 		skcipher_request_set_callback(&rctx->fallback_req,
 					      req->base.flags,
 					      req->base.complete,
 					      req->base.data);
 		skcipher_request_set_crypt(&rctx->fallback_req, req->src,
 					   req->dst, req->cryptlen, req->iv);
 		ret = encrypt ? crypto_skcipher_encrypt(&rctx->fallback_req) :
 				crypto_skcipher_decrypt(&rctx->fallback_req);
 		return ret;
 	}

 	return tmpl->qce->async_req_enqueue(tmpl->qce, &req->base);
 }

 static int qce_skcipher_encrypt(struct skcipher_request *req)
 {
 	return qce_skcipher_crypt(req, 1);
 }

 static int qce_skcipher_decrypt(struct skcipher_request *req)
 {
 	return qce_skcipher_crypt(req, 0);
 }

 static int qce_skcipher_init(struct crypto_skcipher *tfm)
 {
 	/* take the size without the fallback skcipher_request at the end */
 	crypto_skcipher_set_reqsize(tfm, offsetof(struct qce_cipher_reqctx,
 						  fallback_req));
 	return 0;
 }

 static int qce_skcipher_init_fallback(struct crypto_skcipher *tfm)
 {
 	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);

 	ctx->fallback = crypto_alloc_skcipher(crypto_tfm_alg_name(&tfm->base),
 					      0, CRYPTO_ALG_NEED_FALLBACK);
 	if (IS_ERR(ctx->fallback))
 		return PTR_ERR(ctx->fallback);

 	crypto_skcipher_set_reqsize(tfm, sizeof(struct qce_cipher_reqctx) +
 					 crypto_skcipher_reqsize(ctx->fallback));
 	return 0;
 }

 static void qce_skcipher_exit(struct crypto_skcipher *tfm)
 {
 	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);

 	crypto_free_skcipher(ctx->fallback);
 }

 struct qce_skcipher_def {
 	unsigned long flags;
 	const char *name;
 	const char *drv_name;
 	unsigned int blocksize;
 	unsigned int chunksize;
 	unsigned int ivsize;
 	unsigned int min_keysize;
 	unsigned int max_keysize;
 };

 static const struct qce_skcipher_def skcipher_def[] = {
 	{
 		.flags		= QCE_ALG_AES | QCE_MODE_ECB,
 		.name		= "ecb(aes)",
 		.drv_name	= "ecb-aes-qce",
 		.blocksize	= AES_BLOCK_SIZE,
 		.ivsize		= 0,
 		.min_keysize	= AES_MIN_KEY_SIZE,
 		.max_keysize	= AES_MAX_KEY_SIZE,
 	},
 	{
 		.flags		= QCE_ALG_AES | QCE_MODE_CBC,
 		.name		= "cbc(aes)",
 		.drv_name	= "cbc-aes-qce",
 		.blocksize	= AES_BLOCK_SIZE,
 		.ivsize		= AES_BLOCK_SIZE,
 		.min_keysize	= AES_MIN_KEY_SIZE,
 		.max_keysize	= AES_MAX_KEY_SIZE,
 	},
 	{
 		.flags		= QCE_ALG_AES | QCE_MODE_CTR,
 		.name		= "ctr(aes)",
 		.drv_name	= "ctr-aes-qce",
 		.blocksize	= 1,
 		.chunksize	= AES_BLOCK_SIZE,
 		.ivsize		= AES_BLOCK_SIZE,
 		.min_keysize	= AES_MIN_KEY_SIZE,
 		.max_keysize	= AES_MAX_KEY_SIZE,
 	},
 	{
 		.flags		= QCE_ALG_AES | QCE_MODE_XTS,
 		.name		= "xts(aes)",
 		.drv_name	= "xts-aes-qce",
 		.blocksize	= AES_BLOCK_SIZE,
 		.ivsize		= AES_BLOCK_SIZE,
 		.min_keysize	= AES_MIN_KEY_SIZE * 2,
 		.max_keysize	= AES_MAX_KEY_SIZE * 2,
 	},
 	{
 		.flags		= QCE_ALG_DES | QCE_MODE_ECB,
 		.name		= "ecb(des)",
 		.drv_name	= "ecb-des-qce",
 		.blocksize	= DES_BLOCK_SIZE,
 		.ivsize		= 0,
 		.min_keysize	= DES_KEY_SIZE,
 		.max_keysize	= DES_KEY_SIZE,
 	},
 	{
 		.flags		= QCE_ALG_DES | QCE_MODE_CBC,
 		.name		= "cbc(des)",
 		.drv_name	= "cbc-des-qce",
 		.blocksize	= DES_BLOCK_SIZE,
 		.ivsize		= DES_BLOCK_SIZE,
 		.min_keysize	= DES_KEY_SIZE,
 		.max_keysize	= DES_KEY_SIZE,
 	},
 	{
 		.flags		= QCE_ALG_3DES | QCE_MODE_ECB,
 		.name		= "ecb(des3_ede)",
 		.drv_name	= "ecb-3des-qce",
 		.blocksize	= DES3_EDE_BLOCK_SIZE,
 		.ivsize		= 0,
 		.min_keysize	= DES3_EDE_KEY_SIZE,
 		.max_keysize	= DES3_EDE_KEY_SIZE,
 	},
 	{
 		.flags		= QCE_ALG_3DES | QCE_MODE_CBC,
 		.name		= "cbc(des3_ede)",
 		.drv_name	= "cbc-3des-qce",
 		.blocksize	= DES3_EDE_BLOCK_SIZE,
 		.ivsize		= DES3_EDE_BLOCK_SIZE,
 		.min_keysize	= DES3_EDE_KEY_SIZE,
 		.max_keysize	= DES3_EDE_KEY_SIZE,
 	},
 };

 static int qce_skcipher_register_one(const struct qce_skcipher_def *def,
 				       struct qce_device *qce)
 {
 	struct qce_alg_template *tmpl;
 	struct skcipher_alg *alg;
 	int ret;

 	tmpl = kzalloc(sizeof(*tmpl), GFP_KERNEL);
 	if (!tmpl)
 		return -ENOMEM;

 	alg = &tmpl->alg.skcipher;

 	snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
 	snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
 		 def->drv_name);

 	alg->base.cra_blocksize		= def->blocksize;
 	alg->chunksize			= def->chunksize;
 	alg->ivsize			= def->ivsize;
 	alg->min_keysize		= def->min_keysize;
 	alg->max_keysize		= def->max_keysize;
 	alg->setkey			= IS_3DES(def->flags) ? qce_des3_setkey :
 					  IS_DES(def->flags) ? qce_des_setkey :
 					  qce_skcipher_setkey;
 	alg->encrypt			= qce_skcipher_encrypt;
 	alg->decrypt			= qce_skcipher_decrypt;

 	alg->base.cra_priority		= 300;
 	alg->base.cra_flags		= CRYPTO_ALG_ASYNC |
 					  CRYPTO_ALG_ALLOCATES_MEMORY |
 					  CRYPTO_ALG_KERN_DRIVER_ONLY;
 	alg->base.cra_ctxsize		= sizeof(struct qce_cipher_ctx);
 	alg->base.cra_alignmask		= 0;
 	alg->base.cra_module		= THIS_MODULE;

 	if (IS_AES(def->flags)) {
 		alg->base.cra_flags    |= CRYPTO_ALG_NEED_FALLBACK;
 		alg->init		= qce_skcipher_init_fallback;
 		alg->exit		= qce_skcipher_exit;
 	} else {
 		alg->init		= qce_skcipher_init;
 	}

 	INIT_LIST_HEAD(&tmpl->entry);
 	tmpl->crypto_alg_type = CRYPTO_ALG_TYPE_SKCIPHER;
 	tmpl->alg_flags = def->flags;
 	tmpl->qce = qce;

 	ret = crypto_register_skcipher(alg);
 	if (ret) {
 		dev_err(qce->dev, "%s registration failed\n", alg->base.cra_name);
 		kfree(tmpl);
 		return ret;
 	}

 	list_add_tail(&tmpl->entry, &skcipher_algs);
 	dev_dbg(qce->dev, "%s is registered\n", alg->base.cra_name);
 	return 0;
 }

 static void qce_skcipher_unregister(struct qce_device *qce)
 {
 	struct qce_alg_template *tmpl, *n;

 	list_for_each_entry_safe(tmpl, n, &skcipher_algs, entry) {
 		crypto_unregister_skcipher(&tmpl->alg.skcipher);
 		list_del(&tmpl->entry);
 		kfree(tmpl);
 	}
 }

 static int qce_skcipher_register(struct qce_device *qce)
 {
 	int ret, i;

 	for (i = 0; i < ARRAY_SIZE(skcipher_def); i++) {
 		ret = qce_skcipher_register_one(&skcipher_def[i], qce);
 		if (ret)
 			goto err;
 	}

 	return 0;
 err:
 	qce_skcipher_unregister(qce);
 	return ret;
 }

 const struct qce_algo_ops skcipher_ops = {
 	.type = CRYPTO_ALG_TYPE_SKCIPHER,
 	.register_algs = qce_skcipher_register,
 	.unregister_algs = qce_skcipher_unregister,
 	.async_req_handle = qce_skcipher_async_req_handle,
 };
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (c) 2010-2014, The Linux Foundation. All rights reserved.
	*/

	#include <linux/device.h>
	#include <linux/dma-mapping.h>
	#include <linux/interrupt.h>
	#include <linux/moduleparam.h>
	#include <linux/types.h>
	#include <linux/errno.h>
	#include <crypto/aes.h>
	#include <crypto/internal/des.h>
	#include <crypto/internal/skcipher.h>

	#include "cipher.h"

	static unsigned int aes_sw_max_len = CONFIG_CRYPTO_DEV_QCE_SW_MAX_LEN;
	module_param(aes_sw_max_len, uint, 0644);
	MODULE_PARM_DESC(aes_sw_max_len,
	"Only use hardware for AES requests larger than this "
	"[0=always use hardware; anything <16 breaks AES-GCM; default="
	__stringify(CONFIG_CRYPTO_DEV_QCE_SW_MAX_LEN)"]");

	static LIST_HEAD(skcipher_algs);

	static void qce_skcipher_done(void *data)
	{
	struct crypto_async_request *async_req = data;
	struct skcipher_request *req = skcipher_request_cast(async_req);
	struct qce_cipher_reqctx *rctx = skcipher_request_ctx(req);
	struct qce_alg_template *tmpl = to_cipher_tmpl(crypto_skcipher_reqtfm(req));
	struct qce_device *qce = tmpl->qce;
	struct qce_result_dump *result_buf = qce->dma.result_buf;
	enum dma_data_direction dir_src, dir_dst;
	u32 status;
	int error;
	bool diff_dst;

	diff_dst = (req->src != req->dst) ? true : false;
	dir_src = diff_dst ? DMA_TO_DEVICE : DMA_BIDIRECTIONAL;
	dir_dst = diff_dst ? DMA_FROM_DEVICE : DMA_BIDIRECTIONAL;

	error = qce_dma_terminate_all(&qce->dma);
	if (error)
	dev_dbg(qce->dev, "skcipher dma termination error (%d)\n",
	error);

	if (diff_dst)
	dma_unmap_sg(qce->dev, rctx->src_sg, rctx->src_nents, dir_src);
	dma_unmap_sg(qce->dev, rctx->dst_sg, rctx->dst_nents, dir_dst);

	sg_free_table(&rctx->dst_tbl);

	error = qce_check_status(qce, &status);
	if (error < 0)
	dev_dbg(qce->dev, "skcipher operation error (%x)\n", status);

	memcpy(rctx->iv, result_buf->encr_cntr_iv, rctx->ivsize);
	qce->async_req_done(tmpl->qce, error);
	}

	static int
	qce_skcipher_async_req_handle(struct crypto_async_request *async_req)
	{
	struct skcipher_request *req = skcipher_request_cast(async_req);
	struct qce_cipher_reqctx *rctx = skcipher_request_ctx(req);
	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
	struct qce_alg_template *tmpl = to_cipher_tmpl(crypto_skcipher_reqtfm(req));
	struct qce_device *qce = tmpl->qce;
	enum dma_data_direction dir_src, dir_dst;
	struct scatterlist *sg;
	bool diff_dst;
	gfp_t gfp;
	int dst_nents, src_nents, ret;

	rctx->iv = req->iv;
	rctx->ivsize = crypto_skcipher_ivsize(skcipher);
	rctx->cryptlen = req->cryptlen;

	diff_dst = (req->src != req->dst) ? true : false;
	dir_src = diff_dst ? DMA_TO_DEVICE : DMA_BIDIRECTIONAL;
	dir_dst = diff_dst ? DMA_FROM_DEVICE : DMA_BIDIRECTIONAL;

	rctx->src_nents = sg_nents_for_len(req->src, req->cryptlen);
	if (diff_dst)
	rctx->dst_nents = sg_nents_for_len(req->dst, req->cryptlen);
	else
	rctx->dst_nents = rctx->src_nents;
	if (rctx->src_nents < 0) {
	dev_err(qce->dev, "Invalid numbers of src SG.\n");
	return rctx->src_nents;
	}
	if (rctx->dst_nents < 0) {
	dev_err(qce->dev, "Invalid numbers of dst SG.\n");
	return -rctx->dst_nents;
	}

	rctx->dst_nents += 1;

	gfp = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
	GFP_KERNEL : GFP_ATOMIC;

	ret = sg_alloc_table(&rctx->dst_tbl, rctx->dst_nents, gfp);
	if (ret)
	return ret;

	sg_init_one(&rctx->result_sg, qce->dma.result_buf, QCE_RESULT_BUF_SZ);

	sg = qce_sgtable_add(&rctx->dst_tbl, req->dst, req->cryptlen);
	if (IS_ERR(sg)) {
	ret = PTR_ERR(sg);
	goto error_free;
	}

	sg = qce_sgtable_add(&rctx->dst_tbl, &rctx->result_sg,
	QCE_RESULT_BUF_SZ);
	if (IS_ERR(sg)) {
	ret = PTR_ERR(sg);
	goto error_free;
	}

	sg_mark_end(sg);
	rctx->dst_sg = rctx->dst_tbl.sgl;

	dst_nents = dma_map_sg(qce->dev, rctx->dst_sg, rctx->dst_nents, dir_dst);
	if (!dst_nents) {
	ret = -EIO;
	goto error_free;
	}

	if (diff_dst) {
	src_nents = dma_map_sg(qce->dev, req->src, rctx->src_nents, dir_src);
	if (!src_nents) {
	ret = -EIO;
	goto error_unmap_dst;
	}
	rctx->src_sg = req->src;
	} else {
	rctx->src_sg = rctx->dst_sg;
	src_nents = dst_nents - 1;
	}

	ret = qce_dma_prep_sgs(&qce->dma, rctx->src_sg, src_nents,
	rctx->dst_sg, dst_nents,
	qce_skcipher_done, async_req);
	if (ret)
	goto error_unmap_src;

	qce_dma_issue_pending(&qce->dma);

	ret = qce_start(async_req, tmpl->crypto_alg_type);
	if (ret)
	goto error_terminate;

	return 0;

	error_terminate:
	qce_dma_terminate_all(&qce->dma);
	error_unmap_src:
	if (diff_dst)
	dma_unmap_sg(qce->dev, req->src, rctx->src_nents, dir_src);
	error_unmap_dst:
	dma_unmap_sg(qce->dev, rctx->dst_sg, rctx->dst_nents, dir_dst);
	error_free:
	sg_free_table(&rctx->dst_tbl);
	return ret;
	}

	static int qce_skcipher_setkey(struct crypto_skcipher ablk, const u8 key,
	unsigned int keylen)
	{
	struct crypto_tfm *tfm = crypto_skcipher_tfm(ablk);
	struct qce_cipher_ctx *ctx = crypto_tfm_ctx(tfm);
	unsigned long flags = to_cipher_tmpl(ablk)->alg_flags;
	unsigned int __keylen;
	int ret;

	if (!key \|\| !keylen)
	return -EINVAL;

	/*
	* AES XTS key1 = key2 not supported by crypto engine.
	* Revisit to request a fallback cipher in this case.
	*/
	if (IS_XTS(flags)) {
	__keylen = keylen >> 1;
	if (!memcmp(key, key + __keylen, __keylen))
	return -ENOKEY;
	} else {
	__keylen = keylen;
	}

	switch (__keylen) {
	case AES_KEYSIZE_128:
	case AES_KEYSIZE_256:
	memcpy(ctx->enc_key, key, keylen);
	break;
	case AES_KEYSIZE_192:
	break;
	default:
	return -EINVAL;
	}

	ret = crypto_skcipher_setkey(ctx->fallback, key, keylen);
	if (!ret)
	ctx->enc_keylen = keylen;
	return ret;
	}

	static int qce_des_setkey(struct crypto_skcipher ablk, const u8 key,
	unsigned int keylen)
	{
	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(ablk);
	int err;

	err = verify_skcipher_des_key(ablk, key);
	if (err)
	return err;

	ctx->enc_keylen = keylen;
	memcpy(ctx->enc_key, key, keylen);
	return 0;
	}

	static int qce_des3_setkey(struct crypto_skcipher ablk, const u8 key,
	unsigned int keylen)
	{
	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(ablk);
	u32 _key[6];
	int err;

	err = verify_skcipher_des3_key(ablk, key);
	if (err)
	return err;

	/*
	* The crypto engine does not support any two keys
	* being the same for triple des algorithms. The
	* verify_skcipher_des3_key does not check for all the
	* below conditions. Return -ENOKEY in case any two keys
	* are the same. Revisit to see if a fallback cipher
	* is needed to handle this condition.
	*/
	memcpy(_key, key, DES3_EDE_KEY_SIZE);
	if (!((_key[0] ^ _key[2]) \| (_key[1] ^ _key[3])) \|\|
	!((_key[2] ^ _key[4]) \| (_key[3] ^ _key[5])) \|\|
	!((_key[0] ^ _key[4]) \| (_key[1] ^ _key[5])))
	return -ENOKEY;

	ctx->enc_keylen = keylen;
	memcpy(ctx->enc_key, key, keylen);
	return 0;
	}

	static int qce_skcipher_crypt(struct skcipher_request *req, int encrypt)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct qce_cipher_reqctx *rctx = skcipher_request_ctx(req);
	struct qce_alg_template *tmpl = to_cipher_tmpl(tfm);
	unsigned int blocksize = crypto_skcipher_blocksize(tfm);
	int keylen;
	int ret;

	rctx->flags = tmpl->alg_flags;
	rctx->flags \|= encrypt ? QCE_ENCRYPT : QCE_DECRYPT;
	keylen = IS_XTS(rctx->flags) ? ctx->enc_keylen >> 1 : ctx->enc_keylen;

	/* CE does not handle 0 length messages */
	if (!req->cryptlen)
	return 0;

	/*
	* ECB and CBC algorithms require message lengths to be
	* multiples of block size.
	*/
	if (IS_ECB(rctx->flags) \|\| IS_CBC(rctx->flags))
	if (!IS_ALIGNED(req->cryptlen, blocksize))
	return -EINVAL;

	/*
	* Conditions for requesting a fallback cipher
	* AES-192 (not supported by crypto engine (CE))
	* AES-XTS request with len <= 512 byte (not recommended to use CE)
	* AES-XTS request with len > QCE_SECTOR_SIZE and
	* is not a multiple of it.(Revisit this condition to check if it is
	* needed in all versions of CE)
	*/
	if (IS_AES(rctx->flags) &&
	((keylen != AES_KEYSIZE_128 && keylen != AES_KEYSIZE_256) \|\|
	(IS_XTS(rctx->flags) && ((req->cryptlen <= aes_sw_max_len) \|\|
	(req->cryptlen > QCE_SECTOR_SIZE &&
	req->cryptlen % QCE_SECTOR_SIZE))))) {
	skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback);
	skcipher_request_set_callback(&rctx->fallback_req,
	req->base.flags,
	req->base.complete,
	req->base.data);
	skcipher_request_set_crypt(&rctx->fallback_req, req->src,
	req->dst, req->cryptlen, req->iv);
	ret = encrypt ? crypto_skcipher_encrypt(&rctx->fallback_req) :
	crypto_skcipher_decrypt(&rctx->fallback_req);
	return ret;
	}

	return tmpl->qce->async_req_enqueue(tmpl->qce, &req->base);
	}

	static int qce_skcipher_encrypt(struct skcipher_request *req)
	{
	return qce_skcipher_crypt(req, 1);
	}

	static int qce_skcipher_decrypt(struct skcipher_request *req)
	{
	return qce_skcipher_crypt(req, 0);
	}

	static int qce_skcipher_init(struct crypto_skcipher *tfm)
	{
	/* take the size without the fallback skcipher_request at the end */
	crypto_skcipher_set_reqsize(tfm, offsetof(struct qce_cipher_reqctx,
	fallback_req));
	return 0;
	}

	static int qce_skcipher_init_fallback(struct crypto_skcipher *tfm)
	{
	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);

	ctx->fallback = crypto_alloc_skcipher(crypto_tfm_alg_name(&tfm->base),
	0, CRYPTO_ALG_NEED_FALLBACK);
	if (IS_ERR(ctx->fallback))
	return PTR_ERR(ctx->fallback);

	crypto_skcipher_set_reqsize(tfm, sizeof(struct qce_cipher_reqctx) +
	crypto_skcipher_reqsize(ctx->fallback));
	return 0;
	}

	static void qce_skcipher_exit(struct crypto_skcipher *tfm)
	{
	struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);

	crypto_free_skcipher(ctx->fallback);
	}

	struct qce_skcipher_def {
	unsigned long flags;
	const char *name;
	const char *drv_name;
	unsigned int blocksize;
	unsigned int chunksize;
	unsigned int ivsize;
	unsigned int min_keysize;
	unsigned int max_keysize;
	};

	static const struct qce_skcipher_def skcipher_def[] = {
	{
	.flags = QCE_ALG_AES \| QCE_MODE_ECB,
	.name = "ecb(aes)",
	.drv_name = "ecb-aes-qce",
	.blocksize = AES_BLOCK_SIZE,
	.ivsize = 0,
	.min_keysize = AES_MIN_KEY_SIZE,
	.max_keysize = AES_MAX_KEY_SIZE,
	},
	{
	.flags = QCE_ALG_AES \| QCE_MODE_CBC,
	.name = "cbc(aes)",
	.drv_name = "cbc-aes-qce",
	.blocksize = AES_BLOCK_SIZE,
	.ivsize = AES_BLOCK_SIZE,
	.min_keysize = AES_MIN_KEY_SIZE,
	.max_keysize = AES_MAX_KEY_SIZE,
	},
	{
	.flags = QCE_ALG_AES \| QCE_MODE_CTR,
	.name = "ctr(aes)",
	.drv_name = "ctr-aes-qce",
	.blocksize = 1,
	.chunksize = AES_BLOCK_SIZE,
	.ivsize = AES_BLOCK_SIZE,
	.min_keysize = AES_MIN_KEY_SIZE,
	.max_keysize = AES_MAX_KEY_SIZE,
	},
	{
	.flags = QCE_ALG_AES \| QCE_MODE_XTS,
	.name = "xts(aes)",
	.drv_name = "xts-aes-qce",
	.blocksize = AES_BLOCK_SIZE,
	.ivsize = AES_BLOCK_SIZE,
	.min_keysize = AES_MIN_KEY_SIZE * 2,
	.max_keysize = AES_MAX_KEY_SIZE * 2,
	},
	{
	.flags = QCE_ALG_DES \| QCE_MODE_ECB,
	.name = "ecb(des)",
	.drv_name = "ecb-des-qce",
	.blocksize = DES_BLOCK_SIZE,
	.ivsize = 0,
	.min_keysize = DES_KEY_SIZE,
	.max_keysize = DES_KEY_SIZE,
	},
	{
	.flags = QCE_ALG_DES \| QCE_MODE_CBC,
	.name = "cbc(des)",
	.drv_name = "cbc-des-qce",
	.blocksize = DES_BLOCK_SIZE,
	.ivsize = DES_BLOCK_SIZE,
	.min_keysize = DES_KEY_SIZE,
	.max_keysize = DES_KEY_SIZE,
	},
	{
	.flags = QCE_ALG_3DES \| QCE_MODE_ECB,
	.name = "ecb(des3_ede)",
	.drv_name = "ecb-3des-qce",
	.blocksize = DES3_EDE_BLOCK_SIZE,
	.ivsize = 0,
	.min_keysize = DES3_EDE_KEY_SIZE,
	.max_keysize = DES3_EDE_KEY_SIZE,
	},
	{
	.flags = QCE_ALG_3DES \| QCE_MODE_CBC,
	.name = "cbc(des3_ede)",
	.drv_name = "cbc-3des-qce",
	.blocksize = DES3_EDE_BLOCK_SIZE,
	.ivsize = DES3_EDE_BLOCK_SIZE,
	.min_keysize = DES3_EDE_KEY_SIZE,
	.max_keysize = DES3_EDE_KEY_SIZE,
	},
	};

	static int qce_skcipher_register_one(const struct qce_skcipher_def *def,
	struct qce_device *qce)
	{
	struct qce_alg_template *tmpl;
	struct skcipher_alg *alg;
	int ret;

	tmpl = kzalloc(sizeof(*tmpl), GFP_KERNEL);
	if (!tmpl)
	return -ENOMEM;

	alg = &tmpl->alg.skcipher;

	snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
	snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
	def->drv_name);

	alg->base.cra_blocksize = def->blocksize;
	alg->chunksize = def->chunksize;
	alg->ivsize = def->ivsize;
	alg->min_keysize = def->min_keysize;
	alg->max_keysize = def->max_keysize;
	alg->setkey = IS_3DES(def->flags) ? qce_des3_setkey :
	IS_DES(def->flags) ? qce_des_setkey :
	qce_skcipher_setkey;
	alg->encrypt = qce_skcipher_encrypt;
	alg->decrypt = qce_skcipher_decrypt;

	alg->base.cra_priority = 300;
	alg->base.cra_flags = CRYPTO_ALG_ASYNC \|
	CRYPTO_ALG_ALLOCATES_MEMORY \|
	CRYPTO_ALG_KERN_DRIVER_ONLY;
	alg->base.cra_ctxsize = sizeof(struct qce_cipher_ctx);
	alg->base.cra_alignmask = 0;
	alg->base.cra_module = THIS_MODULE;

	if (IS_AES(def->flags)) {
	alg->base.cra_flags \|= CRYPTO_ALG_NEED_FALLBACK;
	alg->init = qce_skcipher_init_fallback;
	alg->exit = qce_skcipher_exit;
	} else {
	alg->init = qce_skcipher_init;
	}

	INIT_LIST_HEAD(&tmpl->entry);
	tmpl->crypto_alg_type = CRYPTO_ALG_TYPE_SKCIPHER;
	tmpl->alg_flags = def->flags;
	tmpl->qce = qce;

	ret = crypto_register_skcipher(alg);
	if (ret) {
	dev_err(qce->dev, "%s registration failed\n", alg->base.cra_name);
	kfree(tmpl);
	return ret;
	}

	list_add_tail(&tmpl->entry, &skcipher_algs);
	dev_dbg(qce->dev, "%s is registered\n", alg->base.cra_name);
	return 0;
	}

	static void qce_skcipher_unregister(struct qce_device *qce)
	{
	struct qce_alg_template tmpl, n;

	list_for_each_entry_safe(tmpl, n, &skcipher_algs, entry) {
	crypto_unregister_skcipher(&tmpl->alg.skcipher);
	list_del(&tmpl->entry);
	kfree(tmpl);
	}
	}

	static int qce_skcipher_register(struct qce_device *qce)
	{
	int ret, i;

	for (i = 0; i < ARRAY_SIZE(skcipher_def); i++) {
	ret = qce_skcipher_register_one(&skcipher_def[i], qce);
	if (ret)
	goto err;
	}

	return 0;
	err:
	qce_skcipher_unregister(qce);
	return ret;
	}

	const struct qce_algo_ops skcipher_ops = {
	.type = CRYPTO_ALG_TYPE_SKCIPHER,
	.register_algs = qce_skcipher_register,
	.unregister_algs = qce_skcipher_unregister,
	.async_req_handle = qce_skcipher_async_req_handle,
	};