drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * sun8i-ss-cipher.c - hardware cryptographic offloader for
  * Allwinner A80/A83T SoC
  *
  * Copyright (C) 2016-2019 Corentin LABBE <clabbe.montjoie@gmail.com>
  *
  * This file add support for AES cipher with 128,192,256 bits keysize in
  * CBC and ECB mode.
  *
  * You could find a link for the datasheet in Documentation/arm/sunxi/README
  */

 #include <linux/crypto.h>
 #include <linux/dma-mapping.h>
 #include <linux/io.h>
 #include <linux/pm_runtime.h>
 #include <crypto/scatterwalk.h>
 #include <crypto/internal/skcipher.h>
 #include "sun8i-ss.h"

 static bool sun8i_ss_need_fallback(struct skcipher_request *areq)
 {
 	struct scatterlist *in_sg = areq->src;
 	struct scatterlist *out_sg = areq->dst;
 	struct scatterlist *sg;

 	if (areq->cryptlen == 0 || areq->cryptlen % 16)
 		return true;

 	if (sg_nents(areq->src) > 8 || sg_nents(areq->dst) > 8)
 		return true;

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

 	/* SS 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)
 			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 sun8i_ss_cipher_fallback(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
 	int err;

 	SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, op->fallback_tfm);
 #ifdef CONFIG_CRYPTO_DEV_SUN8I_SS_DEBUG
 	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
 	struct sun8i_ss_alg_template *algt;

 	algt = container_of(alg, struct sun8i_ss_alg_template, alg.skcipher);
 	algt->stat_fb++;
 #endif
 	skcipher_request_set_sync_tfm(subreq, op->fallback_tfm);
 	skcipher_request_set_callback(subreq, areq->base.flags, NULL, NULL);
 	skcipher_request_set_crypt(subreq, areq->src, areq->dst,
 				   areq->cryptlen, areq->iv);
 	if (rctx->op_dir & SS_DECRYPTION)
 		err = crypto_skcipher_decrypt(subreq);
 	else
 		err = crypto_skcipher_encrypt(subreq);
 	skcipher_request_zero(subreq);
 	return err;
 }

 static int sun8i_ss_cipher(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun8i_ss_dev *ss = op->ss;
 	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
 	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
 	struct sun8i_ss_alg_template *algt;
 	struct scatterlist *sg;
 	unsigned int todo, len, offset, ivsize;
 	void *backup_iv = NULL;
 	int nr_sgs = 0;
 	int nr_sgd = 0;
 	int err = 0;
 	int i;

 	algt = container_of(alg, struct sun8i_ss_alg_template, alg.skcipher);

 	dev_dbg(ss->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);

 #ifdef CONFIG_CRYPTO_DEV_SUN8I_SS_DEBUG
 	algt->stat_req++;
 #endif

 	rctx->op_mode = ss->variant->op_mode[algt->ss_blockmode];
 	rctx->method = ss->variant->alg_cipher[algt->ss_algo_id];
 	rctx->keylen = op->keylen;

 	rctx->p_key = dma_map_single(ss->dev, op->key, op->keylen, DMA_TO_DEVICE);
 	if (dma_mapping_error(ss->dev, rctx->p_key)) {
 		dev_err(ss->dev, "Cannot DMA MAP KEY\n");
 		err = -EFAULT;
 		goto theend;
 	}

 	ivsize = crypto_skcipher_ivsize(tfm);
 	if (areq->iv && crypto_skcipher_ivsize(tfm) > 0) {
 		rctx->ivlen = ivsize;
 		rctx->biv = kzalloc(ivsize, GFP_KERNEL | GFP_DMA);
 		if (!rctx->biv) {
 			err = -ENOMEM;
 			goto theend_key;
 		}
 		if (rctx->op_dir & SS_DECRYPTION) {
 			backup_iv = kzalloc(ivsize, GFP_KERNEL);
 			if (!backup_iv) {
 				err = -ENOMEM;
 				goto theend_key;
 			}
 			offset = areq->cryptlen - ivsize;
 			scatterwalk_map_and_copy(backup_iv, areq->src, offset,
 						 ivsize, 0);
 		}
 		memcpy(rctx->biv, areq->iv, ivsize);
 		rctx->p_iv = dma_map_single(ss->dev, rctx->biv, rctx->ivlen,
 					    DMA_TO_DEVICE);
 		if (dma_mapping_error(ss->dev, rctx->p_iv)) {
 			dev_err(ss->dev, "Cannot DMA MAP IV\n");
 			err = -ENOMEM;
 			goto theend_iv;
 		}
 	}
 	if (areq->src == areq->dst) {
 		nr_sgs = dma_map_sg(ss->dev, areq->src, sg_nents(areq->src),
 				    DMA_BIDIRECTIONAL);
 		if (nr_sgs <= 0 || nr_sgs > 8) {
 			dev_err(ss->dev, "Invalid sg number %d\n", nr_sgs);
 			err = -EINVAL;
 			goto theend_iv;
 		}
 		nr_sgd = nr_sgs;
 	} else {
 		nr_sgs = dma_map_sg(ss->dev, areq->src, sg_nents(areq->src),
 				    DMA_TO_DEVICE);
 		if (nr_sgs <= 0 || nr_sgs > 8) {
 			dev_err(ss->dev, "Invalid sg number %d\n", nr_sgs);
 			err = -EINVAL;
 			goto theend_iv;
 		}
 		nr_sgd = dma_map_sg(ss->dev, areq->dst, sg_nents(areq->dst),
 				    DMA_FROM_DEVICE);
 		if (nr_sgd <= 0 || nr_sgd > 8) {
 			dev_err(ss->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 / 4;
 		dev_dbg(ss->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(ss->dev, "remaining len %d\n", len);
 		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 / 4;
 		dev_dbg(ss->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(ss->dev, "remaining len %d\n", len);
 		err = -EINVAL;
 		goto theend_sgs;
 	}

 	err = sun8i_ss_run_task(ss, rctx, crypto_tfm_alg_name(areq->base.tfm));

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

 theend_iv:
 	if (rctx->p_iv)
 		dma_unmap_single(ss->dev, rctx->p_iv, rctx->ivlen,
 				 DMA_TO_DEVICE);

 	if (areq->iv && ivsize > 0) {
 		if (rctx->biv) {
 			offset = areq->cryptlen - ivsize;
 			if (rctx->op_dir & SS_DECRYPTION) {
 				memcpy(areq->iv, backup_iv, ivsize);
 				memzero_explicit(backup_iv, ivsize);
 				kzfree(backup_iv);
 			} else {
 				scatterwalk_map_and_copy(areq->iv, areq->dst, offset,
 							 ivsize, 0);
 			}
 			kfree(rctx->biv);
 		}
 	}

 theend_key:
 	dma_unmap_single(ss->dev, rctx->p_key, op->keylen, DMA_TO_DEVICE);

 theend:

 	return err;
 }

 static int sun8i_ss_handle_cipher_request(struct crypto_engine *engine, void *areq)
 {
 	int err;
 	struct skcipher_request *breq = container_of(areq, struct skcipher_request, base);

 	err = sun8i_ss_cipher(breq);
 	crypto_finalize_skcipher_request(engine, breq, err);

 	return 0;
 }

 int sun8i_ss_skdecrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
 	struct crypto_engine *engine;
 	int e;

 	memset(rctx, 0, sizeof(struct sun8i_cipher_req_ctx));
 	rctx->op_dir = SS_DECRYPTION;

 	if (sun8i_ss_need_fallback(areq))
 		return sun8i_ss_cipher_fallback(areq);

 	e = sun8i_ss_get_engine_number(op->ss);
 	engine = op->ss->flows[e].engine;
 	rctx->flow = e;

 	return crypto_transfer_skcipher_request_to_engine(engine, areq);
 }

 int sun8i_ss_skencrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
 	struct crypto_engine *engine;
 	int e;

 	memset(rctx, 0, sizeof(struct sun8i_cipher_req_ctx));
 	rctx->op_dir = SS_ENCRYPTION;

 	if (sun8i_ss_need_fallback(areq))
 		return sun8i_ss_cipher_fallback(areq);

 	e = sun8i_ss_get_engine_number(op->ss);
 	engine = op->ss->flows[e].engine;
 	rctx->flow = e;

 	return crypto_transfer_skcipher_request_to_engine(engine, areq);
 }

 int sun8i_ss_cipher_init(struct crypto_tfm *tfm)
 {
 	struct sun8i_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
 	struct sun8i_ss_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 sun8i_cipher_tfm_ctx));

 	algt = container_of(alg, struct sun8i_ss_alg_template, alg.skcipher);
 	op->ss = algt->ss;

 	sktfm->reqsize = sizeof(struct sun8i_cipher_req_ctx);

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

 	dev_info(op->ss->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->base)));

 	op->enginectx.op.do_one_request = sun8i_ss_handle_cipher_request;
 	op->enginectx.op.prepare_request = NULL;
 	op->enginectx.op.unprepare_request = NULL;

 	err = pm_runtime_get_sync(op->ss->dev);
 	if (err < 0) {
 		dev_err(op->ss->dev, "pm error %d\n", err);
 		goto error_pm;
 	}

 	return 0;
 error_pm:
 	crypto_free_sync_skcipher(op->fallback_tfm);
 	return err;
 }

 void sun8i_ss_cipher_exit(struct crypto_tfm *tfm)
 {
 	struct sun8i_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);

 	if (op->key) {
 		memzero_explicit(op->key, op->keylen);
 		kfree(op->key);
 	}
 	crypto_free_sync_skcipher(op->fallback_tfm);
 	pm_runtime_put_sync(op->ss->dev);
 }

 int sun8i_ss_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
 			unsigned int keylen)
 {
 	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun8i_ss_dev *ss = op->ss;

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

 	crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
 	crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);

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

 int sun8i_ss_des3_setkey(struct crypto_skcipher *tfm, const u8 *key,
 			 unsigned int keylen)
 {
 	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun8i_ss_dev *ss = op->ss;

 	if (unlikely(keylen != 3 * DES_KEY_SIZE)) {
 		dev_dbg(ss->dev, "Invalid keylen %u\n", keylen);
 		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 		return -EINVAL;
 	}

 	if (op->key) {
 		memzero_explicit(op->key, op->keylen);
 		kfree(op->key);
 	}
 	op->keylen = keylen;
 	op->key = kmemdup(key, keylen, GFP_KERNEL | GFP_DMA);
 	if (!op->key)
 		return -ENOMEM;

 	crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
 	crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);

 	return crypto_sync_skcipher_setkey(op->fallback_tfm, key, keylen);
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* sun8i-ss-cipher.c - hardware cryptographic offloader for
	* Allwinner A80/A83T SoC
	*
	* Copyright (C) 2016-2019 Corentin LABBE <clabbe.montjoie@gmail.com>
	*
	* This file add support for AES cipher with 128,192,256 bits keysize in
	* CBC and ECB mode.
	*
	* You could find a link for the datasheet in Documentation/arm/sunxi/README
	*/

	#include <linux/crypto.h>
	#include <linux/dma-mapping.h>
	#include <linux/io.h>
	#include <linux/pm_runtime.h>
	#include <crypto/scatterwalk.h>
	#include <crypto/internal/skcipher.h>
	#include "sun8i-ss.h"

	static bool sun8i_ss_need_fallback(struct skcipher_request *areq)
	{
	struct scatterlist *in_sg = areq->src;
	struct scatterlist *out_sg = areq->dst;
	struct scatterlist *sg;

	if (areq->cryptlen == 0 \|\| areq->cryptlen % 16)
	return true;

	if (sg_nents(areq->src) > 8 \|\| sg_nents(areq->dst) > 8)
	return true;

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

	/* SS 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)
	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 sun8i_ss_cipher_fallback(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
	int err;

	SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, op->fallback_tfm);
	#ifdef CONFIG_CRYPTO_DEV_SUN8I_SS_DEBUG
	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
	struct sun8i_ss_alg_template *algt;

	algt = container_of(alg, struct sun8i_ss_alg_template, alg.skcipher);
	algt->stat_fb++;
	#endif
	skcipher_request_set_sync_tfm(subreq, op->fallback_tfm);
	skcipher_request_set_callback(subreq, areq->base.flags, NULL, NULL);
	skcipher_request_set_crypt(subreq, areq->src, areq->dst,
	areq->cryptlen, areq->iv);
	if (rctx->op_dir & SS_DECRYPTION)
	err = crypto_skcipher_decrypt(subreq);
	else
	err = crypto_skcipher_encrypt(subreq);
	skcipher_request_zero(subreq);
	return err;
	}

	static int sun8i_ss_cipher(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun8i_ss_dev *ss = op->ss;
	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
	struct sun8i_ss_alg_template *algt;
	struct scatterlist *sg;
	unsigned int todo, len, offset, ivsize;
	void *backup_iv = NULL;
	int nr_sgs = 0;
	int nr_sgd = 0;
	int err = 0;
	int i;

	algt = container_of(alg, struct sun8i_ss_alg_template, alg.skcipher);

	dev_dbg(ss->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);

	#ifdef CONFIG_CRYPTO_DEV_SUN8I_SS_DEBUG
	algt->stat_req++;
	#endif

	rctx->op_mode = ss->variant->op_mode[algt->ss_blockmode];
	rctx->method = ss->variant->alg_cipher[algt->ss_algo_id];
	rctx->keylen = op->keylen;

	rctx->p_key = dma_map_single(ss->dev, op->key, op->keylen, DMA_TO_DEVICE);
	if (dma_mapping_error(ss->dev, rctx->p_key)) {
	dev_err(ss->dev, "Cannot DMA MAP KEY\n");
	err = -EFAULT;
	goto theend;
	}

	ivsize = crypto_skcipher_ivsize(tfm);
	if (areq->iv && crypto_skcipher_ivsize(tfm) > 0) {
	rctx->ivlen = ivsize;
	rctx->biv = kzalloc(ivsize, GFP_KERNEL \| GFP_DMA);
	if (!rctx->biv) {
	err = -ENOMEM;
	goto theend_key;
	}
	if (rctx->op_dir & SS_DECRYPTION) {
	backup_iv = kzalloc(ivsize, GFP_KERNEL);
	if (!backup_iv) {
	err = -ENOMEM;
	goto theend_key;
	}
	offset = areq->cryptlen - ivsize;
	scatterwalk_map_and_copy(backup_iv, areq->src, offset,
	ivsize, 0);
	}
	memcpy(rctx->biv, areq->iv, ivsize);
	rctx->p_iv = dma_map_single(ss->dev, rctx->biv, rctx->ivlen,
	DMA_TO_DEVICE);
	if (dma_mapping_error(ss->dev, rctx->p_iv)) {
	dev_err(ss->dev, "Cannot DMA MAP IV\n");
	err = -ENOMEM;
	goto theend_iv;
	}
	}
	if (areq->src == areq->dst) {
	nr_sgs = dma_map_sg(ss->dev, areq->src, sg_nents(areq->src),
	DMA_BIDIRECTIONAL);
	if (nr_sgs <= 0 \|\| nr_sgs > 8) {
	dev_err(ss->dev, "Invalid sg number %d\n", nr_sgs);
	err = -EINVAL;
	goto theend_iv;
	}
	nr_sgd = nr_sgs;
	} else {
	nr_sgs = dma_map_sg(ss->dev, areq->src, sg_nents(areq->src),
	DMA_TO_DEVICE);
	if (nr_sgs <= 0 \|\| nr_sgs > 8) {
	dev_err(ss->dev, "Invalid sg number %d\n", nr_sgs);
	err = -EINVAL;
	goto theend_iv;
	}
	nr_sgd = dma_map_sg(ss->dev, areq->dst, sg_nents(areq->dst),
	DMA_FROM_DEVICE);
	if (nr_sgd <= 0 \|\| nr_sgd > 8) {
	dev_err(ss->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 / 4;
	dev_dbg(ss->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(ss->dev, "remaining len %d\n", len);
	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 / 4;
	dev_dbg(ss->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(ss->dev, "remaining len %d\n", len);
	err = -EINVAL;
	goto theend_sgs;
	}

	err = sun8i_ss_run_task(ss, rctx, crypto_tfm_alg_name(areq->base.tfm));

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

	theend_iv:
	if (rctx->p_iv)
	dma_unmap_single(ss->dev, rctx->p_iv, rctx->ivlen,
	DMA_TO_DEVICE);

	if (areq->iv && ivsize > 0) {
	if (rctx->biv) {
	offset = areq->cryptlen - ivsize;
	if (rctx->op_dir & SS_DECRYPTION) {
	memcpy(areq->iv, backup_iv, ivsize);
	memzero_explicit(backup_iv, ivsize);
	kzfree(backup_iv);
	} else {
	scatterwalk_map_and_copy(areq->iv, areq->dst, offset,
	ivsize, 0);
	}
	kfree(rctx->biv);
	}
	}

	theend_key:
	dma_unmap_single(ss->dev, rctx->p_key, op->keylen, DMA_TO_DEVICE);

	theend:

	return err;
	}

	static int sun8i_ss_handle_cipher_request(struct crypto_engine engine, void areq)
	{
	int err;
	struct skcipher_request *breq = container_of(areq, struct skcipher_request, base);

	err = sun8i_ss_cipher(breq);
	crypto_finalize_skcipher_request(engine, breq, err);

	return 0;
	}

	int sun8i_ss_skdecrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
	struct crypto_engine *engine;
	int e;

	memset(rctx, 0, sizeof(struct sun8i_cipher_req_ctx));
	rctx->op_dir = SS_DECRYPTION;

	if (sun8i_ss_need_fallback(areq))
	return sun8i_ss_cipher_fallback(areq);

	e = sun8i_ss_get_engine_number(op->ss);
	engine = op->ss->flows[e].engine;
	rctx->flow = e;

	return crypto_transfer_skcipher_request_to_engine(engine, areq);
	}

	int sun8i_ss_skencrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);
	struct crypto_engine *engine;
	int e;

	memset(rctx, 0, sizeof(struct sun8i_cipher_req_ctx));
	rctx->op_dir = SS_ENCRYPTION;

	if (sun8i_ss_need_fallback(areq))
	return sun8i_ss_cipher_fallback(areq);

	e = sun8i_ss_get_engine_number(op->ss);
	engine = op->ss->flows[e].engine;
	rctx->flow = e;

	return crypto_transfer_skcipher_request_to_engine(engine, areq);
	}

	int sun8i_ss_cipher_init(struct crypto_tfm *tfm)
	{
	struct sun8i_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);
	struct sun8i_ss_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 sun8i_cipher_tfm_ctx));

	algt = container_of(alg, struct sun8i_ss_alg_template, alg.skcipher);
	op->ss = algt->ss;

	sktfm->reqsize = sizeof(struct sun8i_cipher_req_ctx);

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

	dev_info(op->ss->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->base)));

	op->enginectx.op.do_one_request = sun8i_ss_handle_cipher_request;
	op->enginectx.op.prepare_request = NULL;
	op->enginectx.op.unprepare_request = NULL;

	err = pm_runtime_get_sync(op->ss->dev);
	if (err < 0) {
	dev_err(op->ss->dev, "pm error %d\n", err);
	goto error_pm;
	}

	return 0;
	error_pm:
	crypto_free_sync_skcipher(op->fallback_tfm);
	return err;
	}

	void sun8i_ss_cipher_exit(struct crypto_tfm *tfm)
	{
	struct sun8i_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);

	if (op->key) {
	memzero_explicit(op->key, op->keylen);
	kfree(op->key);
	}
	crypto_free_sync_skcipher(op->fallback_tfm);
	pm_runtime_put_sync(op->ss->dev);
	}

	int sun8i_ss_aes_setkey(struct crypto_skcipher tfm, const u8 key,
	unsigned int keylen)
	{
	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun8i_ss_dev *ss = op->ss;

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

	crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
	crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);

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

	int sun8i_ss_des3_setkey(struct crypto_skcipher tfm, const u8 key,
	unsigned int keylen)
	{
	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun8i_ss_dev *ss = op->ss;

	if (unlikely(keylen != 3 * DES_KEY_SIZE)) {
	dev_dbg(ss->dev, "Invalid keylen %u\n", keylen);
	crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
	return -EINVAL;
	}

	if (op->key) {
	memzero_explicit(op->key, op->keylen);
	kfree(op->key);
	}
	op->keylen = keylen;
	op->key = kmemdup(key, keylen, GFP_KERNEL \| GFP_DMA);
	if (!op->key)
	return -ENOMEM;

	crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);
	crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);

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