drivers/crypto/gemini/sl3516-ce-cipher.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * sl3516-ce-cipher.c - hardware cryptographic offloader for Storlink SL3516 SoC
  *
  * Copyright (C) 2021 Corentin LABBE <clabbe@baylibre.com>
  *
  * This file adds support for AES cipher with 128,192,256 bits keysize in
  * ECB mode.
  */

 #include <linux/crypto.h>
 #include <linux/dma-mapping.h>
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/pm_runtime.h>
 #include <crypto/scatterwalk.h>
 #include <crypto/internal/skcipher.h>
 #include "sl3516-ce.h"

 /* sl3516_ce_need_fallback - check if a request can be handled by the CE */
 static bool sl3516_ce_need_fallback(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sl3516_ce_dev *ce = op->ce;
 	struct scatterlist *in_sg;
 	struct scatterlist *out_sg;
 	struct scatterlist *sg;

 	if (areq->cryptlen == 0 || areq->cryptlen % 16) {
 		ce->fallback_mod16++;
 		return true;
 	}

 	/*
 	 * check if we have enough descriptors for TX
 	 * Note: TX need one control desc for each SG
 	 */
 	if (sg_nents(areq->src) > MAXDESC / 2) {
 		ce->fallback_sg_count_tx++;
 		return true;
 	}
 	/* check if we have enough descriptors for RX */
 	if (sg_nents(areq->dst) > MAXDESC) {
 		ce->fallback_sg_count_rx++;
 		return true;
 	}

 	sg = areq->src;
 	while (sg) {
 		if ((sg->length % 16) != 0) {
 			ce->fallback_mod16++;
 			return true;
 		}
 		if ((sg_dma_len(sg) % 16) != 0) {
 			ce->fallback_mod16++;
 			return true;
 		}
 		if (!IS_ALIGNED(sg->offset, 16)) {
 			ce->fallback_align16++;
 			return true;
 		}
 		sg = sg_next(sg);
 	}
 	sg = areq->dst;
 	while (sg) {
 		if ((sg->length % 16) != 0) {
 			ce->fallback_mod16++;
 			return true;
 		}
 		if ((sg_dma_len(sg) % 16) != 0) {
 			ce->fallback_mod16++;
 			return true;
 		}
 		if (!IS_ALIGNED(sg->offset, 16)) {
 			ce->fallback_align16++;
 			return true;
 		}
 		sg = sg_next(sg);
 	}

 	/* need same numbers of SG (with same length) for source and destination */
 	in_sg = areq->src;
 	out_sg = areq->dst;
 	while (in_sg && out_sg) {
 		if (in_sg->length != out_sg->length) {
 			ce->fallback_not_same_len++;
 			return true;
 		}
 		in_sg = sg_next(in_sg);
 		out_sg = sg_next(out_sg);
 	}
 	if (in_sg || out_sg)
 		return true;

 	return false;
 }

 static int sl3516_ce_cipher_fallback(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
 	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
 	struct sl3516_ce_alg_template *algt;
 	int err;

 	algt = container_of(alg, struct sl3516_ce_alg_template, alg.skcipher);
 	algt->stat_fb++;

 	skcipher_request_set_tfm(&rctx->fallback_req, op->fallback_tfm);
 	skcipher_request_set_callback(&rctx->fallback_req, areq->base.flags,
 				      areq->base.complete, areq->base.data);
 	skcipher_request_set_crypt(&rctx->fallback_req, areq->src, areq->dst,
 				   areq->cryptlen, areq->iv);
 	if (rctx->op_dir == CE_DECRYPTION)
 		err = crypto_skcipher_decrypt(&rctx->fallback_req);
 	else
 		err = crypto_skcipher_encrypt(&rctx->fallback_req);
 	return err;
 }

 static int sl3516_ce_cipher(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sl3516_ce_dev *ce = op->ce;
 	struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
 	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
 	struct sl3516_ce_alg_template *algt;
 	struct scatterlist *sg;
 	unsigned int todo, len;
 	struct pkt_control_ecb *ecb;
 	int nr_sgs = 0;
 	int nr_sgd = 0;
 	int err = 0;
 	int i;

 	algt = container_of(alg, struct sl3516_ce_alg_template, alg.skcipher);

 	dev_dbg(ce->dev, "%s %s %u %x IV(%p %u) key=%u\n", __func__,
 		crypto_tfm_alg_name(areq->base.tfm),
 		areq->cryptlen,
 		rctx->op_dir, areq->iv, crypto_skcipher_ivsize(tfm),
 		op->keylen);

 	algt->stat_req++;

 	if (areq->src == areq->dst) {
 		nr_sgs = dma_map_sg(ce->dev, areq->src, sg_nents(areq->src),
 				    DMA_BIDIRECTIONAL);
 		if (nr_sgs <= 0 || nr_sgs > MAXDESC / 2) {
 			dev_err(ce->dev, "Invalid sg number %d\n", nr_sgs);
 			err = -EINVAL;
 			goto theend;
 		}
 		nr_sgd = nr_sgs;
 	} else {
 		nr_sgs = dma_map_sg(ce->dev, areq->src, sg_nents(areq->src),
 				    DMA_TO_DEVICE);
 		if (nr_sgs <= 0 || nr_sgs > MAXDESC / 2) {
 			dev_err(ce->dev, "Invalid sg number %d\n", nr_sgs);
 			err = -EINVAL;
 			goto theend;
 		}
 		nr_sgd = dma_map_sg(ce->dev, areq->dst, sg_nents(areq->dst),
 				    DMA_FROM_DEVICE);
 		if (nr_sgd <= 0 || nr_sgd > MAXDESC) {
 			dev_err(ce->dev, "Invalid sg number %d\n", nr_sgd);
 			err = -EINVAL;
 			goto theend_sgs;
 		}
 	}

 	len = areq->cryptlen;
 	i = 0;
 	sg = areq->src;
 	while (i < nr_sgs && sg && len) {
 		if (sg_dma_len(sg) == 0)
 			goto sgs_next;
 		rctx->t_src[i].addr = sg_dma_address(sg);
 		todo = min(len, sg_dma_len(sg));
 		rctx->t_src[i].len = todo;
 		dev_dbg(ce->dev, "%s total=%u SGS(%d %u off=%d) todo=%u\n", __func__,
 			areq->cryptlen, i, rctx->t_src[i].len, sg->offset, todo);
 		len -= todo;
 		i++;
 sgs_next:
 		sg = sg_next(sg);
 	}
 	if (len > 0) {
 		dev_err(ce->dev, "remaining len %d/%u nr_sgs=%d\n", len, areq->cryptlen, nr_sgs);
 		err = -EINVAL;
 		goto theend_sgs;
 	}

 	len = areq->cryptlen;
 	i = 0;
 	sg = areq->dst;
 	while (i < nr_sgd && sg && len) {
 		if (sg_dma_len(sg) == 0)
 			goto sgd_next;
 		rctx->t_dst[i].addr = sg_dma_address(sg);
 		todo = min(len, sg_dma_len(sg));
 		rctx->t_dst[i].len = todo;
 		dev_dbg(ce->dev, "%s total=%u SGD(%d %u off=%d) todo=%u\n", __func__,
 			areq->cryptlen, i, rctx->t_dst[i].len, sg->offset, todo);
 		len -= todo;
 		i++;

 sgd_next:
 		sg = sg_next(sg);
 	}
 	if (len > 0) {
 		dev_err(ce->dev, "remaining len %d\n", len);
 		err = -EINVAL;
 		goto theend_sgs;
 	}

 	switch (algt->mode) {
 	case ECB_AES:
 		rctx->pctrllen = sizeof(struct pkt_control_ecb);
 		ecb = (struct pkt_control_ecb *)ce->pctrl;

 		rctx->tqflag = TQ0_TYPE_CTRL;
 		rctx->tqflag |= TQ1_CIPHER;
 		ecb->control.op_mode = rctx->op_dir;
 		ecb->control.cipher_algorithm = ECB_AES;
 		ecb->cipher.header_len = 0;
 		ecb->cipher.algorithm_len = areq->cryptlen;
 		cpu_to_be32_array((__be32 *)ecb->key, (u32 *)op->key, op->keylen / 4);
 		rctx->h = &ecb->cipher;

 		rctx->tqflag |= TQ4_KEY0;
 		rctx->tqflag |= TQ5_KEY4;
 		rctx->tqflag |= TQ6_KEY6;
 		ecb->control.aesnk = op->keylen / 4;
 		break;
 	}

 	rctx->nr_sgs = nr_sgs;
 	rctx->nr_sgd = nr_sgd;
 	err = sl3516_ce_run_task(ce, rctx, crypto_tfm_alg_name(areq->base.tfm));

 theend_sgs:
 	if (areq->src == areq->dst) {
 		dma_unmap_sg(ce->dev, areq->src, sg_nents(areq->src),
 			     DMA_BIDIRECTIONAL);
 	} else {
 		dma_unmap_sg(ce->dev, areq->src, sg_nents(areq->src),
 			     DMA_TO_DEVICE);
 		dma_unmap_sg(ce->dev, areq->dst, sg_nents(areq->dst),
 			     DMA_FROM_DEVICE);
 	}

 theend:

 	return err;
 }

 static int sl3516_ce_handle_cipher_request(struct crypto_engine *engine, void *areq)
 {
 	int err;
 	struct skcipher_request *breq = container_of(areq, struct skcipher_request, base);

 	err = sl3516_ce_cipher(breq);
 	local_bh_disable();
 	crypto_finalize_skcipher_request(engine, breq, err);
 	local_bh_enable();

 	return 0;
 }

 int sl3516_ce_skdecrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
 	struct crypto_engine *engine;

 	memset(rctx, 0, sizeof(struct sl3516_ce_cipher_req_ctx));
 	rctx->op_dir = CE_DECRYPTION;

 	if (sl3516_ce_need_fallback(areq))
 		return sl3516_ce_cipher_fallback(areq);

 	engine = op->ce->engine;

 	return crypto_transfer_skcipher_request_to_engine(engine, areq);
 }

 int sl3516_ce_skencrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
 	struct crypto_engine *engine;

 	memset(rctx, 0, sizeof(struct sl3516_ce_cipher_req_ctx));
 	rctx->op_dir = CE_ENCRYPTION;

 	if (sl3516_ce_need_fallback(areq))
 		return sl3516_ce_cipher_fallback(areq);

 	engine = op->ce->engine;

 	return crypto_transfer_skcipher_request_to_engine(engine, areq);
 }

 int sl3516_ce_cipher_init(struct crypto_tfm *tfm)
 {
 	struct sl3516_ce_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
 	struct sl3516_ce_alg_template *algt;
 	const char *name = crypto_tfm_alg_name(tfm);
 	struct crypto_skcipher *sktfm = __crypto_skcipher_cast(tfm);
 	struct skcipher_alg *alg = crypto_skcipher_alg(sktfm);
 	int err;

 	memset(op, 0, sizeof(struct sl3516_ce_cipher_tfm_ctx));

 	algt = container_of(alg, struct sl3516_ce_alg_template, alg.skcipher);
 	op->ce = algt->ce;

 	op->fallback_tfm = crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);
 	if (IS_ERR(op->fallback_tfm)) {
 		dev_err(op->ce->dev, "ERROR: Cannot allocate fallback for %s %ld\n",
 			name, PTR_ERR(op->fallback_tfm));
 		return PTR_ERR(op->fallback_tfm);
 	}

 	sktfm->reqsize = sizeof(struct sl3516_ce_cipher_req_ctx) +
 			 crypto_skcipher_reqsize(op->fallback_tfm);

 	dev_info(op->ce->dev, "Fallback for %s is %s\n",
 		 crypto_tfm_alg_driver_name(&sktfm->base),
 		 crypto_tfm_alg_driver_name(crypto_skcipher_tfm(op->fallback_tfm)));

 	op->enginectx.op.do_one_request = sl3516_ce_handle_cipher_request;
 	op->enginectx.op.prepare_request = NULL;
 	op->enginectx.op.unprepare_request = NULL;

 	err = pm_runtime_get_sync(op->ce->dev);
 	if (err < 0)
 		goto error_pm;

 	return 0;
 error_pm:
 	pm_runtime_put_noidle(op->ce->dev);
 	crypto_free_skcipher(op->fallback_tfm);
 	return err;
 }

 void sl3516_ce_cipher_exit(struct crypto_tfm *tfm)
 {
 	struct sl3516_ce_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);

 	kfree_sensitive(op->key);
 	crypto_free_skcipher(op->fallback_tfm);
 	pm_runtime_put_sync_suspend(op->ce->dev);
 }

 int sl3516_ce_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
 			 unsigned int keylen)
 {
 	struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sl3516_ce_dev *ce = op->ce;

 	switch (keylen) {
 	case 128 / 8:
 		break;
 	case 192 / 8:
 		break;
 	case 256 / 8:
 		break;
 	default:
 		dev_dbg(ce->dev, "ERROR: Invalid keylen %u\n", keylen);
 		return -EINVAL;
 	}
 	kfree_sensitive(op->key);
 	op->keylen = keylen;
 	op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
 	if (!op->key)
 		return -ENOMEM;

 	crypto_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
 	crypto_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);

 	return crypto_skcipher_setkey(op->fallback_tfm, key, keylen);
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* sl3516-ce-cipher.c - hardware cryptographic offloader for Storlink SL3516 SoC
	*
	* Copyright (C) 2021 Corentin LABBE <clabbe@baylibre.com>
	*
	* This file adds support for AES cipher with 128,192,256 bits keysize in
	* ECB mode.
	*/

	#include <linux/crypto.h>
	#include <linux/dma-mapping.h>
	#include <linux/delay.h>
	#include <linux/io.h>
	#include <linux/pm_runtime.h>
	#include <crypto/scatterwalk.h>
	#include <crypto/internal/skcipher.h>
	#include "sl3516-ce.h"

	/* sl3516_ce_need_fallback - check if a request can be handled by the CE */
	static bool sl3516_ce_need_fallback(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sl3516_ce_dev *ce = op->ce;
	struct scatterlist *in_sg;
	struct scatterlist *out_sg;
	struct scatterlist *sg;

	if (areq->cryptlen == 0 \|\| areq->cryptlen % 16) {
	ce->fallback_mod16++;
	return true;
	}

	/*
	* check if we have enough descriptors for TX
	* Note: TX need one control desc for each SG
	*/
	if (sg_nents(areq->src) > MAXDESC / 2) {
	ce->fallback_sg_count_tx++;
	return true;
	}
	/* check if we have enough descriptors for RX */
	if (sg_nents(areq->dst) > MAXDESC) {
	ce->fallback_sg_count_rx++;
	return true;
	}

	sg = areq->src;
	while (sg) {
	if ((sg->length % 16) != 0) {
	ce->fallback_mod16++;
	return true;
	}
	if ((sg_dma_len(sg) % 16) != 0) {
	ce->fallback_mod16++;
	return true;
	}
	if (!IS_ALIGNED(sg->offset, 16)) {
	ce->fallback_align16++;
	return true;
	}
	sg = sg_next(sg);
	}
	sg = areq->dst;
	while (sg) {
	if ((sg->length % 16) != 0) {
	ce->fallback_mod16++;
	return true;
	}
	if ((sg_dma_len(sg) % 16) != 0) {
	ce->fallback_mod16++;
	return true;
	}
	if (!IS_ALIGNED(sg->offset, 16)) {
	ce->fallback_align16++;
	return true;
	}
	sg = sg_next(sg);
	}

	/* need same numbers of SG (with same length) for source and destination */
	in_sg = areq->src;
	out_sg = areq->dst;
	while (in_sg && out_sg) {
	if (in_sg->length != out_sg->length) {
	ce->fallback_not_same_len++;
	return true;
	}
	in_sg = sg_next(in_sg);
	out_sg = sg_next(out_sg);
	}
	if (in_sg \|\| out_sg)
	return true;

	return false;
	}

	static int sl3516_ce_cipher_fallback(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
	struct sl3516_ce_alg_template *algt;
	int err;

	algt = container_of(alg, struct sl3516_ce_alg_template, alg.skcipher);
	algt->stat_fb++;

	skcipher_request_set_tfm(&rctx->fallback_req, op->fallback_tfm);
	skcipher_request_set_callback(&rctx->fallback_req, areq->base.flags,
	areq->base.complete, areq->base.data);
	skcipher_request_set_crypt(&rctx->fallback_req, areq->src, areq->dst,
	areq->cryptlen, areq->iv);
	if (rctx->op_dir == CE_DECRYPTION)
	err = crypto_skcipher_decrypt(&rctx->fallback_req);
	else
	err = crypto_skcipher_encrypt(&rctx->fallback_req);
	return err;
	}

	static int sl3516_ce_cipher(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sl3516_ce_dev *ce = op->ce;
	struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
	struct sl3516_ce_alg_template *algt;
	struct scatterlist *sg;
	unsigned int todo, len;
	struct pkt_control_ecb *ecb;
	int nr_sgs = 0;
	int nr_sgd = 0;
	int err = 0;
	int i;

	algt = container_of(alg, struct sl3516_ce_alg_template, alg.skcipher);

	dev_dbg(ce->dev, "%s %s %u %x IV(%p %u) key=%u\n", __func__,
	crypto_tfm_alg_name(areq->base.tfm),
	areq->cryptlen,
	rctx->op_dir, areq->iv, crypto_skcipher_ivsize(tfm),
	op->keylen);

	algt->stat_req++;

	if (areq->src == areq->dst) {
	nr_sgs = dma_map_sg(ce->dev, areq->src, sg_nents(areq->src),
	DMA_BIDIRECTIONAL);
	if (nr_sgs <= 0 \|\| nr_sgs > MAXDESC / 2) {
	dev_err(ce->dev, "Invalid sg number %d\n", nr_sgs);
	err = -EINVAL;
	goto theend;
	}
	nr_sgd = nr_sgs;
	} else {
	nr_sgs = dma_map_sg(ce->dev, areq->src, sg_nents(areq->src),
	DMA_TO_DEVICE);
	if (nr_sgs <= 0 \|\| nr_sgs > MAXDESC / 2) {
	dev_err(ce->dev, "Invalid sg number %d\n", nr_sgs);
	err = -EINVAL;
	goto theend;
	}
	nr_sgd = dma_map_sg(ce->dev, areq->dst, sg_nents(areq->dst),
	DMA_FROM_DEVICE);
	if (nr_sgd <= 0 \|\| nr_sgd > MAXDESC) {
	dev_err(ce->dev, "Invalid sg number %d\n", nr_sgd);
	err = -EINVAL;
	goto theend_sgs;
	}
	}

	len = areq->cryptlen;
	i = 0;
	sg = areq->src;
	while (i < nr_sgs && sg && len) {
	if (sg_dma_len(sg) == 0)
	goto sgs_next;
	rctx->t_src[i].addr = sg_dma_address(sg);
	todo = min(len, sg_dma_len(sg));
	rctx->t_src[i].len = todo;
	dev_dbg(ce->dev, "%s total=%u SGS(%d %u off=%d) todo=%u\n", __func__,
	areq->cryptlen, i, rctx->t_src[i].len, sg->offset, todo);
	len -= todo;
	i++;
	sgs_next:
	sg = sg_next(sg);
	}
	if (len > 0) {
	dev_err(ce->dev, "remaining len %d/%u nr_sgs=%d\n", len, areq->cryptlen, nr_sgs);
	err = -EINVAL;
	goto theend_sgs;
	}

	len = areq->cryptlen;
	i = 0;
	sg = areq->dst;
	while (i < nr_sgd && sg && len) {
	if (sg_dma_len(sg) == 0)
	goto sgd_next;
	rctx->t_dst[i].addr = sg_dma_address(sg);
	todo = min(len, sg_dma_len(sg));
	rctx->t_dst[i].len = todo;
	dev_dbg(ce->dev, "%s total=%u SGD(%d %u off=%d) todo=%u\n", __func__,
	areq->cryptlen, i, rctx->t_dst[i].len, sg->offset, todo);
	len -= todo;
	i++;

	sgd_next:
	sg = sg_next(sg);
	}
	if (len > 0) {
	dev_err(ce->dev, "remaining len %d\n", len);
	err = -EINVAL;
	goto theend_sgs;
	}

	switch (algt->mode) {
	case ECB_AES:
	rctx->pctrllen = sizeof(struct pkt_control_ecb);
	ecb = (struct pkt_control_ecb *)ce->pctrl;

	rctx->tqflag = TQ0_TYPE_CTRL;
	rctx->tqflag \|= TQ1_CIPHER;
	ecb->control.op_mode = rctx->op_dir;
	ecb->control.cipher_algorithm = ECB_AES;
	ecb->cipher.header_len = 0;
	ecb->cipher.algorithm_len = areq->cryptlen;
	cpu_to_be32_array((__be32 )ecb->key, (u32 )op->key, op->keylen / 4);
	rctx->h = &ecb->cipher;

	rctx->tqflag \|= TQ4_KEY0;
	rctx->tqflag \|= TQ5_KEY4;
	rctx->tqflag \|= TQ6_KEY6;
	ecb->control.aesnk = op->keylen / 4;
	break;
	}

	rctx->nr_sgs = nr_sgs;
	rctx->nr_sgd = nr_sgd;
	err = sl3516_ce_run_task(ce, rctx, crypto_tfm_alg_name(areq->base.tfm));

	theend_sgs:
	if (areq->src == areq->dst) {
	dma_unmap_sg(ce->dev, areq->src, sg_nents(areq->src),
	DMA_BIDIRECTIONAL);
	} else {
	dma_unmap_sg(ce->dev, areq->src, sg_nents(areq->src),
	DMA_TO_DEVICE);
	dma_unmap_sg(ce->dev, areq->dst, sg_nents(areq->dst),
	DMA_FROM_DEVICE);
	}

	theend:

	return err;
	}

	static int sl3516_ce_handle_cipher_request(struct crypto_engine engine, void areq)
	{
	int err;
	struct skcipher_request *breq = container_of(areq, struct skcipher_request, base);

	err = sl3516_ce_cipher(breq);
	local_bh_disable();
	crypto_finalize_skcipher_request(engine, breq, err);
	local_bh_enable();

	return 0;
	}

	int sl3516_ce_skdecrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
	struct crypto_engine *engine;

	memset(rctx, 0, sizeof(struct sl3516_ce_cipher_req_ctx));
	rctx->op_dir = CE_DECRYPTION;

	if (sl3516_ce_need_fallback(areq))
	return sl3516_ce_cipher_fallback(areq);

	engine = op->ce->engine;

	return crypto_transfer_skcipher_request_to_engine(engine, areq);
	}

	int sl3516_ce_skencrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sl3516_ce_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
	struct crypto_engine *engine;

	memset(rctx, 0, sizeof(struct sl3516_ce_cipher_req_ctx));
	rctx->op_dir = CE_ENCRYPTION;

	if (sl3516_ce_need_fallback(areq))
	return sl3516_ce_cipher_fallback(areq);

	engine = op->ce->engine;

	return crypto_transfer_skcipher_request_to_engine(engine, areq);
	}

	int sl3516_ce_cipher_init(struct crypto_tfm *tfm)
	{
	struct sl3516_ce_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
	struct sl3516_ce_alg_template *algt;
	const char *name = crypto_tfm_alg_name(tfm);
	struct crypto_skcipher *sktfm = __crypto_skcipher_cast(tfm);
	struct skcipher_alg *alg = crypto_skcipher_alg(sktfm);
	int err;

	memset(op, 0, sizeof(struct sl3516_ce_cipher_tfm_ctx));

	algt = container_of(alg, struct sl3516_ce_alg_template, alg.skcipher);
	op->ce = algt->ce;

	op->fallback_tfm = crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);
	if (IS_ERR(op->fallback_tfm)) {
	dev_err(op->ce->dev, "ERROR: Cannot allocate fallback for %s %ld\n",
	name, PTR_ERR(op->fallback_tfm));
	return PTR_ERR(op->fallback_tfm);
	}

	sktfm->reqsize = sizeof(struct sl3516_ce_cipher_req_ctx) +
	crypto_skcipher_reqsize(op->fallback_tfm);

	dev_info(op->ce->dev, "Fallback for %s is %s\n",
	crypto_tfm_alg_driver_name(&sktfm->base),
	crypto_tfm_alg_driver_name(crypto_skcipher_tfm(op->fallback_tfm)));

	op->enginectx.op.do_one_request = sl3516_ce_handle_cipher_request;
	op->enginectx.op.prepare_request = NULL;
	op->enginectx.op.unprepare_request = NULL;

	err = pm_runtime_get_sync(op->ce->dev);
	if (err < 0)
	goto error_pm;

	return 0;
	error_pm:
	pm_runtime_put_noidle(op->ce->dev);
	crypto_free_skcipher(op->fallback_tfm);
	return err;
	}

	void sl3516_ce_cipher_exit(struct crypto_tfm *tfm)
	{
	struct sl3516_ce_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);

	kfree_sensitive(op->key);
	crypto_free_skcipher(op->fallback_tfm);
	pm_runtime_put_sync_suspend(op->ce->dev);
	}

	int sl3516_ce_aes_setkey(struct crypto_skcipher tfm, const u8 key,
	unsigned int keylen)
	{
	struct sl3516_ce_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sl3516_ce_dev *ce = op->ce;

	switch (keylen) {
	case 128 / 8:
	break;
	case 192 / 8:
	break;
	case 256 / 8:
	break;
	default:
	dev_dbg(ce->dev, "ERROR: Invalid keylen %u\n", keylen);
	return -EINVAL;
	}
	kfree_sensitive(op->key);
	op->keylen = keylen;
	op->key = kmemdup(key, keylen, GFP_KERNEL \| GFP_DMA);
	if (!op->key)
	return -ENOMEM;

	crypto_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
	crypto_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);

	return crypto_skcipher_setkey(op->fallback_tfm, key, keylen);
	}