drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * sun4i-ss-cipher.c - hardware cryptographic accelerator for Allwinner A20 SoC
  *
  * Copyright (C) 2013-2015 Corentin LABBE <clabbe.montjoie@gmail.com>
  *
  * This file add support for AES cipher with 128,192,256 bits
  * keysize in CBC and ECB mode.
  * Add support also for DES and 3DES in CBC and ECB mode.
  *
  * You could find the datasheet in Documentation/arm/sunxi.rst
  */
 #include "sun4i-ss.h"

 static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_ss_ctx *ss = op->ss;
 	unsigned int ivsize = crypto_skcipher_ivsize(tfm);
 	struct sun4i_cipher_req_ctx *ctx = skcipher_request_ctx(areq);
 	u32 mode = ctx->mode;
 	void *backup_iv = NULL;
 	/* when activating SS, the default FIFO space is SS_RX_DEFAULT(32) */
 	u32 rx_cnt = SS_RX_DEFAULT;
 	u32 tx_cnt = 0;
 	u32 spaces;
 	u32 v;
 	int err = 0;
 	unsigned int i;
 	unsigned int ileft = areq->cryptlen;
 	unsigned int oleft = areq->cryptlen;
 	unsigned int todo;
 	unsigned long pi = 0, po = 0; /* progress for in and out */
 	bool miter_err;
 	struct sg_mapping_iter mi, mo;
 	unsigned int oi, oo; /* offset for in and out */
 	unsigned long flags;

 	if (!areq->cryptlen)
 		return 0;

 	if (!areq->src || !areq->dst) {
 		dev_err_ratelimited(ss->dev, "ERROR: Some SGs are NULL\n");
 		return -EINVAL;
 	}

 	if (areq->iv && ivsize > 0 && mode & SS_DECRYPTION) {
 		backup_iv = kzalloc(ivsize, GFP_KERNEL);
 		if (!backup_iv)
 			return -ENOMEM;
 		scatterwalk_map_and_copy(backup_iv, areq->src, areq->cryptlen - ivsize, ivsize, 0);
 	}

 	spin_lock_irqsave(&ss->slock, flags);

 	for (i = 0; i < op->keylen / 4; i++)
 		writesl(ss->base + SS_KEY0 + i * 4, &op->key[i], 1);

 	if (areq->iv) {
 		for (i = 0; i < 4 && i < ivsize / 4; i++) {
 			v = *(u32 *)(areq->iv + i * 4);
 			writesl(ss->base + SS_IV0 + i * 4, &v, 1);
 		}
 	}
 	writel(mode, ss->base + SS_CTL);


 	ileft = areq->cryptlen / 4;
 	oleft = areq->cryptlen / 4;
 	oi = 0;
 	oo = 0;
 	do {
 		if (ileft) {
 			sg_miter_start(&mi, areq->src, sg_nents(areq->src),
 					SG_MITER_FROM_SG | SG_MITER_ATOMIC);
 			if (pi)
 				sg_miter_skip(&mi, pi);
 			miter_err = sg_miter_next(&mi);
 			if (!miter_err || !mi.addr) {
 				dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
 				err = -EINVAL;
 				goto release_ss;
 			}
 			todo = min(rx_cnt, ileft);
 			todo = min_t(size_t, todo, (mi.length - oi) / 4);
 			if (todo) {
 				ileft -= todo;
 				writesl(ss->base + SS_RXFIFO, mi.addr + oi, todo);
 				oi += todo * 4;
 			}
 			if (oi == mi.length) {
 				pi += mi.length;
 				oi = 0;
 			}
 			sg_miter_stop(&mi);
 		}

 		spaces = readl(ss->base + SS_FCSR);
 		rx_cnt = SS_RXFIFO_SPACES(spaces);
 		tx_cnt = SS_TXFIFO_SPACES(spaces);

 		sg_miter_start(&mo, areq->dst, sg_nents(areq->dst),
 			       SG_MITER_TO_SG | SG_MITER_ATOMIC);
 		if (po)
 			sg_miter_skip(&mo, po);
 		miter_err = sg_miter_next(&mo);
 		if (!miter_err || !mo.addr) {
 			dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
 			err = -EINVAL;
 			goto release_ss;
 		}
 		todo = min(tx_cnt, oleft);
 		todo = min_t(size_t, todo, (mo.length - oo) / 4);
 		if (todo) {
 			oleft -= todo;
 			readsl(ss->base + SS_TXFIFO, mo.addr + oo, todo);
 			oo += todo * 4;
 		}
 		if (oo == mo.length) {
 			oo = 0;
 			po += mo.length;
 		}
 		sg_miter_stop(&mo);
 	} while (oleft);

 	if (areq->iv) {
 		if (mode & SS_DECRYPTION) {
 			memcpy(areq->iv, backup_iv, ivsize);
 			kfree_sensitive(backup_iv);
 		} else {
 			scatterwalk_map_and_copy(areq->iv, areq->dst, areq->cryptlen - ivsize,
 						 ivsize, 0);
 		}
 	}

 release_ss:
 	writel(0, ss->base + SS_CTL);
 	spin_unlock_irqrestore(&ss->slock, flags);
 	return err;
 }


 static int noinline_for_stack sun4i_ss_cipher_poll_fallback(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_cipher_req_ctx *ctx = skcipher_request_ctx(areq);
 	int err;

 	skcipher_request_set_tfm(&ctx->fallback_req, op->fallback_tfm);
 	skcipher_request_set_callback(&ctx->fallback_req, areq->base.flags,
 				      areq->base.complete, areq->base.data);
 	skcipher_request_set_crypt(&ctx->fallback_req, areq->src, areq->dst,
 				   areq->cryptlen, areq->iv);
 	if (ctx->mode & SS_DECRYPTION)
 		err = crypto_skcipher_decrypt(&ctx->fallback_req);
 	else
 		err = crypto_skcipher_encrypt(&ctx->fallback_req);

 	return err;
 }

 /* Generic function that support SG with size not multiple of 4 */
 static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_ss_ctx *ss = op->ss;
 	int no_chunk = 1;
 	struct scatterlist *in_sg = areq->src;
 	struct scatterlist *out_sg = areq->dst;
 	unsigned int ivsize = crypto_skcipher_ivsize(tfm);
 	struct sun4i_cipher_req_ctx *ctx = skcipher_request_ctx(areq);
 	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
 	struct sun4i_ss_alg_template *algt;
 	u32 mode = ctx->mode;
 	/* when activating SS, the default FIFO space is SS_RX_DEFAULT(32) */
 	u32 rx_cnt = SS_RX_DEFAULT;
 	u32 tx_cnt = 0;
 	u32 v;
 	u32 spaces;
 	int err = 0;
 	unsigned int i;
 	unsigned int ileft = areq->cryptlen;
 	unsigned int oleft = areq->cryptlen;
 	unsigned int todo;
 	void *backup_iv = NULL;
 	struct sg_mapping_iter mi, mo;
 	unsigned long pi = 0, po = 0; /* progress for in and out */
 	bool miter_err;
 	unsigned int oi, oo;	/* offset for in and out */
 	unsigned int ob = 0;	/* offset in buf */
 	unsigned int obo = 0;	/* offset in bufo*/
 	unsigned int obl = 0;	/* length of data in bufo */
 	unsigned long flags;
 	bool need_fallback = false;

 	if (!areq->cryptlen)
 		return 0;

 	if (!areq->src || !areq->dst) {
 		dev_err_ratelimited(ss->dev, "ERROR: Some SGs are NULL\n");
 		return -EINVAL;
 	}

 	algt = container_of(alg, struct sun4i_ss_alg_template, alg.crypto);
 	if (areq->cryptlen % algt->alg.crypto.base.cra_blocksize)
 		need_fallback = true;

 	/*
 	 * if we have only SGs with size multiple of 4,
 	 * we can use the SS optimized function
 	 */
 	while (in_sg && no_chunk == 1) {
 		if ((in_sg->length | in_sg->offset) & 3u)
 			no_chunk = 0;
 		in_sg = sg_next(in_sg);
 	}
 	while (out_sg && no_chunk == 1) {
 		if ((out_sg->length | out_sg->offset) & 3u)
 			no_chunk = 0;
 		out_sg = sg_next(out_sg);
 	}

 	if (no_chunk == 1 && !need_fallback)
 		return sun4i_ss_opti_poll(areq);

 	if (need_fallback)
 		return sun4i_ss_cipher_poll_fallback(areq);

 	if (areq->iv && ivsize > 0 && mode & SS_DECRYPTION) {
 		backup_iv = kzalloc(ivsize, GFP_KERNEL);
 		if (!backup_iv)
 			return -ENOMEM;
 		scatterwalk_map_and_copy(backup_iv, areq->src, areq->cryptlen - ivsize, ivsize, 0);
 	}

 	spin_lock_irqsave(&ss->slock, flags);

 	for (i = 0; i < op->keylen / 4; i++)
 		writesl(ss->base + SS_KEY0 + i * 4, &op->key[i], 1);

 	if (areq->iv) {
 		for (i = 0; i < 4 && i < ivsize / 4; i++) {
 			v = *(u32 *)(areq->iv + i * 4);
 			writesl(ss->base + SS_IV0 + i * 4, &v, 1);
 		}
 	}
 	writel(mode, ss->base + SS_CTL);

 	ileft = areq->cryptlen;
 	oleft = areq->cryptlen;
 	oi = 0;
 	oo = 0;

 	while (oleft) {
 		if (ileft) {
 			sg_miter_start(&mi, areq->src, sg_nents(areq->src),
 				       SG_MITER_FROM_SG | SG_MITER_ATOMIC);
 			if (pi)
 				sg_miter_skip(&mi, pi);
 			miter_err = sg_miter_next(&mi);
 			if (!miter_err || !mi.addr) {
 				dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
 				err = -EINVAL;
 				goto release_ss;
 			}
 			/*
 			 * todo is the number of consecutive 4byte word that we
 			 * can read from current SG
 			 */
 			todo = min(rx_cnt, ileft / 4);
 			todo = min_t(size_t, todo, (mi.length - oi) / 4);
 			if (todo && !ob) {
 				writesl(ss->base + SS_RXFIFO, mi.addr + oi,
 					todo);
 				ileft -= todo * 4;
 				oi += todo * 4;
 			} else {
 				/*
 				 * not enough consecutive bytes, so we need to
 				 * linearize in buf. todo is in bytes
 				 * After that copy, if we have a multiple of 4
 				 * we need to be able to write all buf in one
 				 * pass, so it is why we min() with rx_cnt
 				 */
 				todo = min(rx_cnt * 4 - ob, ileft);
 				todo = min_t(size_t, todo, mi.length - oi);
 				memcpy(ss->buf + ob, mi.addr + oi, todo);
 				ileft -= todo;
 				oi += todo;
 				ob += todo;
 				if (!(ob % 4)) {
 					writesl(ss->base + SS_RXFIFO, ss->buf,
 						ob / 4);
 					ob = 0;
 				}
 			}
 			if (oi == mi.length) {
 				pi += mi.length;
 				oi = 0;
 			}
 			sg_miter_stop(&mi);
 		}

 		spaces = readl(ss->base + SS_FCSR);
 		rx_cnt = SS_RXFIFO_SPACES(spaces);
 		tx_cnt = SS_TXFIFO_SPACES(spaces);

 		if (!tx_cnt)
 			continue;
 		sg_miter_start(&mo, areq->dst, sg_nents(areq->dst),
 			       SG_MITER_TO_SG | SG_MITER_ATOMIC);
 		if (po)
 			sg_miter_skip(&mo, po);
 		miter_err = sg_miter_next(&mo);
 		if (!miter_err || !mo.addr) {
 			dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
 			err = -EINVAL;
 			goto release_ss;
 		}
 		/* todo in 4bytes word */
 		todo = min(tx_cnt, oleft / 4);
 		todo = min_t(size_t, todo, (mo.length - oo) / 4);

 		if (todo) {
 			readsl(ss->base + SS_TXFIFO, mo.addr + oo, todo);
 			oleft -= todo * 4;
 			oo += todo * 4;
 			if (oo == mo.length) {
 				po += mo.length;
 				oo = 0;
 			}
 		} else {
 			/*
 			 * read obl bytes in bufo, we read at maximum for
 			 * emptying the device
 			 */
 			readsl(ss->base + SS_TXFIFO, ss->bufo, tx_cnt);
 			obl = tx_cnt * 4;
 			obo = 0;
 			do {
 				/*
 				 * how many bytes we can copy ?
 				 * no more than remaining SG size
 				 * no more than remaining buffer
 				 * no need to test against oleft
 				 */
 				todo = min_t(size_t,
 					     mo.length - oo, obl - obo);
 				memcpy(mo.addr + oo, ss->bufo + obo, todo);
 				oleft -= todo;
 				obo += todo;
 				oo += todo;
 				if (oo == mo.length) {
 					po += mo.length;
 					sg_miter_next(&mo);
 					oo = 0;
 				}
 			} while (obo < obl);
 			/* bufo must be fully used here */
 		}
 		sg_miter_stop(&mo);
 	}
 	if (areq->iv) {
 		if (mode & SS_DECRYPTION) {
 			memcpy(areq->iv, backup_iv, ivsize);
 			kfree_sensitive(backup_iv);
 		} else {
 			scatterwalk_map_and_copy(areq->iv, areq->dst, areq->cryptlen - ivsize,
 						 ivsize, 0);
 		}
 	}

 release_ss:
 	writel(0, ss->base + SS_CTL);
 	spin_unlock_irqrestore(&ss->slock, flags);

 	return err;
 }

 /* CBC AES */
 int sun4i_ss_cbc_aes_encrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

 	rctx->mode = SS_OP_AES | SS_CBC | SS_ENABLED | SS_ENCRYPTION |
 		op->keymode;
 	return sun4i_ss_cipher_poll(areq);
 }

 int sun4i_ss_cbc_aes_decrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

 	rctx->mode = SS_OP_AES | SS_CBC | SS_ENABLED | SS_DECRYPTION |
 		op->keymode;
 	return sun4i_ss_cipher_poll(areq);
 }

 /* ECB AES */
 int sun4i_ss_ecb_aes_encrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

 	rctx->mode = SS_OP_AES | SS_ECB | SS_ENABLED | SS_ENCRYPTION |
 		op->keymode;
 	return sun4i_ss_cipher_poll(areq);
 }

 int sun4i_ss_ecb_aes_decrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

 	rctx->mode = SS_OP_AES | SS_ECB | SS_ENABLED | SS_DECRYPTION |
 		op->keymode;
 	return sun4i_ss_cipher_poll(areq);
 }

 /* CBC DES */
 int sun4i_ss_cbc_des_encrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

 	rctx->mode = SS_OP_DES | SS_CBC | SS_ENABLED | SS_ENCRYPTION |
 		op->keymode;
 	return sun4i_ss_cipher_poll(areq);
 }

 int sun4i_ss_cbc_des_decrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

 	rctx->mode = SS_OP_DES | SS_CBC | SS_ENABLED | SS_DECRYPTION |
 		op->keymode;
 	return sun4i_ss_cipher_poll(areq);
 }

 /* ECB DES */
 int sun4i_ss_ecb_des_encrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

 	rctx->mode = SS_OP_DES | SS_ECB | SS_ENABLED | SS_ENCRYPTION |
 		op->keymode;
 	return sun4i_ss_cipher_poll(areq);
 }

 int sun4i_ss_ecb_des_decrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

 	rctx->mode = SS_OP_DES | SS_ECB | SS_ENABLED | SS_DECRYPTION |
 		op->keymode;
 	return sun4i_ss_cipher_poll(areq);
 }

 /* CBC 3DES */
 int sun4i_ss_cbc_des3_encrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

 	rctx->mode = SS_OP_3DES | SS_CBC | SS_ENABLED | SS_ENCRYPTION |
 		op->keymode;
 	return sun4i_ss_cipher_poll(areq);
 }

 int sun4i_ss_cbc_des3_decrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

 	rctx->mode = SS_OP_3DES | SS_CBC | SS_ENABLED | SS_DECRYPTION |
 		op->keymode;
 	return sun4i_ss_cipher_poll(areq);
 }

 /* ECB 3DES */
 int sun4i_ss_ecb_des3_encrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

 	rctx->mode = SS_OP_3DES | SS_ECB | SS_ENABLED | SS_ENCRYPTION |
 		op->keymode;
 	return sun4i_ss_cipher_poll(areq);
 }

 int sun4i_ss_ecb_des3_decrypt(struct skcipher_request *areq)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

 	rctx->mode = SS_OP_3DES | SS_ECB | SS_ENABLED | SS_DECRYPTION |
 		op->keymode;
 	return sun4i_ss_cipher_poll(areq);
 }

 int sun4i_ss_cipher_init(struct crypto_tfm *tfm)
 {
 	struct sun4i_tfm_ctx *op = crypto_tfm_ctx(tfm);
 	struct sun4i_ss_alg_template *algt;
 	const char *name = crypto_tfm_alg_name(tfm);
 	int err;

 	memset(op, 0, sizeof(struct sun4i_tfm_ctx));

 	algt = container_of(tfm->__crt_alg, struct sun4i_ss_alg_template,
 			    alg.crypto.base);
 	op->ss = algt->ss;

 	op->fallback_tfm = crypto_alloc_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);
 	}

 	crypto_skcipher_set_reqsize(__crypto_skcipher_cast(tfm),
 				    sizeof(struct sun4i_cipher_req_ctx) +
 				    crypto_skcipher_reqsize(op->fallback_tfm));


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

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

 void sun4i_ss_cipher_exit(struct crypto_tfm *tfm)
 {
 	struct sun4i_tfm_ctx *op = crypto_tfm_ctx(tfm);

 	crypto_free_skcipher(op->fallback_tfm);
 	pm_runtime_put(op->ss->dev);
 }

 /* check and set the AES key, prepare the mode to be used */
 int sun4i_ss_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
 			unsigned int keylen)
 {
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	struct sun4i_ss_ctx *ss = op->ss;

 	switch (keylen) {
 	case 128 / 8:
 		op->keymode = SS_AES_128BITS;
 		break;
 	case 192 / 8:
 		op->keymode = SS_AES_192BITS;
 		break;
 	case 256 / 8:
 		op->keymode = SS_AES_256BITS;
 		break;
 	default:
 		dev_dbg(ss->dev, "ERROR: Invalid keylen %u\n", keylen);
 		return -EINVAL;
 	}
 	op->keylen = keylen;
 	memcpy(op->key, key, keylen);

 	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);
 }

 /* check and set the DES key, prepare the mode to be used */
 int sun4i_ss_des_setkey(struct crypto_skcipher *tfm, const u8 *key,
 			unsigned int keylen)
 {
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	int err;

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

 	op->keylen = keylen;
 	memcpy(op->key, key, keylen);

 	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);
 }

 /* check and set the 3DES key, prepare the mode to be used */
 int sun4i_ss_des3_setkey(struct crypto_skcipher *tfm, const u8 *key,
 			 unsigned int keylen)
 {
 	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
 	int err;

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

 	op->keylen = keylen;
 	memcpy(op->key, key, keylen);

 	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-or-later
	/*
	* sun4i-ss-cipher.c - hardware cryptographic accelerator for Allwinner A20 SoC
	*
	* Copyright (C) 2013-2015 Corentin LABBE <clabbe.montjoie@gmail.com>
	*
	* This file add support for AES cipher with 128,192,256 bits
	* keysize in CBC and ECB mode.
	* Add support also for DES and 3DES in CBC and ECB mode.
	*
	* You could find the datasheet in Documentation/arm/sunxi.rst
	*/
	#include "sun4i-ss.h"

	static int noinline_for_stack sun4i_ss_opti_poll(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_ss_ctx *ss = op->ss;
	unsigned int ivsize = crypto_skcipher_ivsize(tfm);
	struct sun4i_cipher_req_ctx *ctx = skcipher_request_ctx(areq);
	u32 mode = ctx->mode;
	void *backup_iv = NULL;
	/* when activating SS, the default FIFO space is SS_RX_DEFAULT(32) */
	u32 rx_cnt = SS_RX_DEFAULT;
	u32 tx_cnt = 0;
	u32 spaces;
	u32 v;
	int err = 0;
	unsigned int i;
	unsigned int ileft = areq->cryptlen;
	unsigned int oleft = areq->cryptlen;
	unsigned int todo;
	unsigned long pi = 0, po = 0; /* progress for in and out */
	bool miter_err;
	struct sg_mapping_iter mi, mo;
	unsigned int oi, oo; /* offset for in and out */
	unsigned long flags;

	if (!areq->cryptlen)
	return 0;

	if (!areq->src \|\| !areq->dst) {
	dev_err_ratelimited(ss->dev, "ERROR: Some SGs are NULL\n");
	return -EINVAL;
	}

	if (areq->iv && ivsize > 0 && mode & SS_DECRYPTION) {
	backup_iv = kzalloc(ivsize, GFP_KERNEL);
	if (!backup_iv)
	return -ENOMEM;
	scatterwalk_map_and_copy(backup_iv, areq->src, areq->cryptlen - ivsize, ivsize, 0);
	}

	spin_lock_irqsave(&ss->slock, flags);

	for (i = 0; i < op->keylen / 4; i++)
	writesl(ss->base + SS_KEY0 + i * 4, &op->key[i], 1);

	if (areq->iv) {
	for (i = 0; i < 4 && i < ivsize / 4; i++) {
	v = (u32 )(areq->iv + i * 4);
	writesl(ss->base + SS_IV0 + i * 4, &v, 1);
	}
	}
	writel(mode, ss->base + SS_CTL);


	ileft = areq->cryptlen / 4;
	oleft = areq->cryptlen / 4;
	oi = 0;
	oo = 0;
	do {
	if (ileft) {
	sg_miter_start(&mi, areq->src, sg_nents(areq->src),
	SG_MITER_FROM_SG \| SG_MITER_ATOMIC);
	if (pi)
	sg_miter_skip(&mi, pi);
	miter_err = sg_miter_next(&mi);
	if (!miter_err \|\| !mi.addr) {
	dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
	err = -EINVAL;
	goto release_ss;
	}
	todo = min(rx_cnt, ileft);
	todo = min_t(size_t, todo, (mi.length - oi) / 4);
	if (todo) {
	ileft -= todo;
	writesl(ss->base + SS_RXFIFO, mi.addr + oi, todo);
	oi += todo * 4;
	}
	if (oi == mi.length) {
	pi += mi.length;
	oi = 0;
	}
	sg_miter_stop(&mi);
	}

	spaces = readl(ss->base + SS_FCSR);
	rx_cnt = SS_RXFIFO_SPACES(spaces);
	tx_cnt = SS_TXFIFO_SPACES(spaces);

	sg_miter_start(&mo, areq->dst, sg_nents(areq->dst),
	SG_MITER_TO_SG \| SG_MITER_ATOMIC);
	if (po)
	sg_miter_skip(&mo, po);
	miter_err = sg_miter_next(&mo);
	if (!miter_err \|\| !mo.addr) {
	dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
	err = -EINVAL;
	goto release_ss;
	}
	todo = min(tx_cnt, oleft);
	todo = min_t(size_t, todo, (mo.length - oo) / 4);
	if (todo) {
	oleft -= todo;
	readsl(ss->base + SS_TXFIFO, mo.addr + oo, todo);
	oo += todo * 4;
	}
	if (oo == mo.length) {
	oo = 0;
	po += mo.length;
	}
	sg_miter_stop(&mo);
	} while (oleft);

	if (areq->iv) {
	if (mode & SS_DECRYPTION) {
	memcpy(areq->iv, backup_iv, ivsize);
	kfree_sensitive(backup_iv);
	} else {
	scatterwalk_map_and_copy(areq->iv, areq->dst, areq->cryptlen - ivsize,
	ivsize, 0);
	}
	}

	release_ss:
	writel(0, ss->base + SS_CTL);
	spin_unlock_irqrestore(&ss->slock, flags);
	return err;
	}


	static int noinline_for_stack sun4i_ss_cipher_poll_fallback(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_cipher_req_ctx *ctx = skcipher_request_ctx(areq);
	int err;

	skcipher_request_set_tfm(&ctx->fallback_req, op->fallback_tfm);
	skcipher_request_set_callback(&ctx->fallback_req, areq->base.flags,
	areq->base.complete, areq->base.data);
	skcipher_request_set_crypt(&ctx->fallback_req, areq->src, areq->dst,
	areq->cryptlen, areq->iv);
	if (ctx->mode & SS_DECRYPTION)
	err = crypto_skcipher_decrypt(&ctx->fallback_req);
	else
	err = crypto_skcipher_encrypt(&ctx->fallback_req);

	return err;
	}

	/* Generic function that support SG with size not multiple of 4 */
	static int sun4i_ss_cipher_poll(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_ss_ctx *ss = op->ss;
	int no_chunk = 1;
	struct scatterlist *in_sg = areq->src;
	struct scatterlist *out_sg = areq->dst;
	unsigned int ivsize = crypto_skcipher_ivsize(tfm);
	struct sun4i_cipher_req_ctx *ctx = skcipher_request_ctx(areq);
	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
	struct sun4i_ss_alg_template *algt;
	u32 mode = ctx->mode;
	/* when activating SS, the default FIFO space is SS_RX_DEFAULT(32) */
	u32 rx_cnt = SS_RX_DEFAULT;
	u32 tx_cnt = 0;
	u32 v;
	u32 spaces;
	int err = 0;
	unsigned int i;
	unsigned int ileft = areq->cryptlen;
	unsigned int oleft = areq->cryptlen;
	unsigned int todo;
	void *backup_iv = NULL;
	struct sg_mapping_iter mi, mo;
	unsigned long pi = 0, po = 0; /* progress for in and out */
	bool miter_err;
	unsigned int oi, oo; /* offset for in and out */
	unsigned int ob = 0; /* offset in buf */
	unsigned int obo = 0; /* offset in bufo*/
	unsigned int obl = 0; /* length of data in bufo */
	unsigned long flags;
	bool need_fallback = false;

	if (!areq->cryptlen)
	return 0;

	if (!areq->src \|\| !areq->dst) {
	dev_err_ratelimited(ss->dev, "ERROR: Some SGs are NULL\n");
	return -EINVAL;
	}

	algt = container_of(alg, struct sun4i_ss_alg_template, alg.crypto);
	if (areq->cryptlen % algt->alg.crypto.base.cra_blocksize)
	need_fallback = true;

	/*
	* if we have only SGs with size multiple of 4,
	* we can use the SS optimized function
	*/
	while (in_sg && no_chunk == 1) {
	if ((in_sg->length \| in_sg->offset) & 3u)
	no_chunk = 0;
	in_sg = sg_next(in_sg);
	}
	while (out_sg && no_chunk == 1) {
	if ((out_sg->length \| out_sg->offset) & 3u)
	no_chunk = 0;
	out_sg = sg_next(out_sg);
	}

	if (no_chunk == 1 && !need_fallback)
	return sun4i_ss_opti_poll(areq);

	if (need_fallback)
	return sun4i_ss_cipher_poll_fallback(areq);

	if (areq->iv && ivsize > 0 && mode & SS_DECRYPTION) {
	backup_iv = kzalloc(ivsize, GFP_KERNEL);
	if (!backup_iv)
	return -ENOMEM;
	scatterwalk_map_and_copy(backup_iv, areq->src, areq->cryptlen - ivsize, ivsize, 0);
	}

	spin_lock_irqsave(&ss->slock, flags);

	for (i = 0; i < op->keylen / 4; i++)
	writesl(ss->base + SS_KEY0 + i * 4, &op->key[i], 1);

	if (areq->iv) {
	for (i = 0; i < 4 && i < ivsize / 4; i++) {
	v = (u32 )(areq->iv + i * 4);
	writesl(ss->base + SS_IV0 + i * 4, &v, 1);
	}
	}
	writel(mode, ss->base + SS_CTL);

	ileft = areq->cryptlen;
	oleft = areq->cryptlen;
	oi = 0;
	oo = 0;

	while (oleft) {
	if (ileft) {
	sg_miter_start(&mi, areq->src, sg_nents(areq->src),
	SG_MITER_FROM_SG \| SG_MITER_ATOMIC);
	if (pi)
	sg_miter_skip(&mi, pi);
	miter_err = sg_miter_next(&mi);
	if (!miter_err \|\| !mi.addr) {
	dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
	err = -EINVAL;
	goto release_ss;
	}
	/*
	* todo is the number of consecutive 4byte word that we
	* can read from current SG
	*/
	todo = min(rx_cnt, ileft / 4);
	todo = min_t(size_t, todo, (mi.length - oi) / 4);
	if (todo && !ob) {
	writesl(ss->base + SS_RXFIFO, mi.addr + oi,
	todo);
	ileft -= todo * 4;
	oi += todo * 4;
	} else {
	/*
	* not enough consecutive bytes, so we need to
	* linearize in buf. todo is in bytes
	* After that copy, if we have a multiple of 4
	* we need to be able to write all buf in one
	* pass, so it is why we min() with rx_cnt
	*/
	todo = min(rx_cnt * 4 - ob, ileft);
	todo = min_t(size_t, todo, mi.length - oi);
	memcpy(ss->buf + ob, mi.addr + oi, todo);
	ileft -= todo;
	oi += todo;
	ob += todo;
	if (!(ob % 4)) {
	writesl(ss->base + SS_RXFIFO, ss->buf,
	ob / 4);
	ob = 0;
	}
	}
	if (oi == mi.length) {
	pi += mi.length;
	oi = 0;
	}
	sg_miter_stop(&mi);
	}

	spaces = readl(ss->base + SS_FCSR);
	rx_cnt = SS_RXFIFO_SPACES(spaces);
	tx_cnt = SS_TXFIFO_SPACES(spaces);

	if (!tx_cnt)
	continue;
	sg_miter_start(&mo, areq->dst, sg_nents(areq->dst),
	SG_MITER_TO_SG \| SG_MITER_ATOMIC);
	if (po)
	sg_miter_skip(&mo, po);
	miter_err = sg_miter_next(&mo);
	if (!miter_err \|\| !mo.addr) {
	dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
	err = -EINVAL;
	goto release_ss;
	}
	/* todo in 4bytes word */
	todo = min(tx_cnt, oleft / 4);
	todo = min_t(size_t, todo, (mo.length - oo) / 4);

	if (todo) {
	readsl(ss->base + SS_TXFIFO, mo.addr + oo, todo);
	oleft -= todo * 4;
	oo += todo * 4;
	if (oo == mo.length) {
	po += mo.length;
	oo = 0;
	}
	} else {
	/*
	* read obl bytes in bufo, we read at maximum for
	* emptying the device
	*/
	readsl(ss->base + SS_TXFIFO, ss->bufo, tx_cnt);
	obl = tx_cnt * 4;
	obo = 0;
	do {
	/*
	* how many bytes we can copy ?
	* no more than remaining SG size
	* no more than remaining buffer
	* no need to test against oleft
	*/
	todo = min_t(size_t,
	mo.length - oo, obl - obo);
	memcpy(mo.addr + oo, ss->bufo + obo, todo);
	oleft -= todo;
	obo += todo;
	oo += todo;
	if (oo == mo.length) {
	po += mo.length;
	sg_miter_next(&mo);
	oo = 0;
	}
	} while (obo < obl);
	/* bufo must be fully used here */
	}
	sg_miter_stop(&mo);
	}
	if (areq->iv) {
	if (mode & SS_DECRYPTION) {
	memcpy(areq->iv, backup_iv, ivsize);
	kfree_sensitive(backup_iv);
	} else {
	scatterwalk_map_and_copy(areq->iv, areq->dst, areq->cryptlen - ivsize,
	ivsize, 0);
	}
	}

	release_ss:
	writel(0, ss->base + SS_CTL);
	spin_unlock_irqrestore(&ss->slock, flags);

	return err;
	}

	/* CBC AES */
	int sun4i_ss_cbc_aes_encrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	rctx->mode = SS_OP_AES \| SS_CBC \| SS_ENABLED \| SS_ENCRYPTION \|
	op->keymode;
	return sun4i_ss_cipher_poll(areq);
	}

	int sun4i_ss_cbc_aes_decrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	rctx->mode = SS_OP_AES \| SS_CBC \| SS_ENABLED \| SS_DECRYPTION \|
	op->keymode;
	return sun4i_ss_cipher_poll(areq);
	}

	/* ECB AES */
	int sun4i_ss_ecb_aes_encrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	rctx->mode = SS_OP_AES \| SS_ECB \| SS_ENABLED \| SS_ENCRYPTION \|
	op->keymode;
	return sun4i_ss_cipher_poll(areq);
	}

	int sun4i_ss_ecb_aes_decrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	rctx->mode = SS_OP_AES \| SS_ECB \| SS_ENABLED \| SS_DECRYPTION \|
	op->keymode;
	return sun4i_ss_cipher_poll(areq);
	}

	/* CBC DES */
	int sun4i_ss_cbc_des_encrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	rctx->mode = SS_OP_DES \| SS_CBC \| SS_ENABLED \| SS_ENCRYPTION \|
	op->keymode;
	return sun4i_ss_cipher_poll(areq);
	}

	int sun4i_ss_cbc_des_decrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	rctx->mode = SS_OP_DES \| SS_CBC \| SS_ENABLED \| SS_DECRYPTION \|
	op->keymode;
	return sun4i_ss_cipher_poll(areq);
	}

	/* ECB DES */
	int sun4i_ss_ecb_des_encrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	rctx->mode = SS_OP_DES \| SS_ECB \| SS_ENABLED \| SS_ENCRYPTION \|
	op->keymode;
	return sun4i_ss_cipher_poll(areq);
	}

	int sun4i_ss_ecb_des_decrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	rctx->mode = SS_OP_DES \| SS_ECB \| SS_ENABLED \| SS_DECRYPTION \|
	op->keymode;
	return sun4i_ss_cipher_poll(areq);
	}

	/* CBC 3DES */
	int sun4i_ss_cbc_des3_encrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	rctx->mode = SS_OP_3DES \| SS_CBC \| SS_ENABLED \| SS_ENCRYPTION \|
	op->keymode;
	return sun4i_ss_cipher_poll(areq);
	}

	int sun4i_ss_cbc_des3_decrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	rctx->mode = SS_OP_3DES \| SS_CBC \| SS_ENABLED \| SS_DECRYPTION \|
	op->keymode;
	return sun4i_ss_cipher_poll(areq);
	}

	/* ECB 3DES */
	int sun4i_ss_ecb_des3_encrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	rctx->mode = SS_OP_3DES \| SS_ECB \| SS_ENABLED \| SS_ENCRYPTION \|
	op->keymode;
	return sun4i_ss_cipher_poll(areq);
	}

	int sun4i_ss_ecb_des3_decrypt(struct skcipher_request *areq)
	{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	rctx->mode = SS_OP_3DES \| SS_ECB \| SS_ENABLED \| SS_DECRYPTION \|
	op->keymode;
	return sun4i_ss_cipher_poll(areq);
	}

	int sun4i_ss_cipher_init(struct crypto_tfm *tfm)
	{
	struct sun4i_tfm_ctx *op = crypto_tfm_ctx(tfm);
	struct sun4i_ss_alg_template *algt;
	const char *name = crypto_tfm_alg_name(tfm);
	int err;

	memset(op, 0, sizeof(struct sun4i_tfm_ctx));

	algt = container_of(tfm->__crt_alg, struct sun4i_ss_alg_template,
	alg.crypto.base);
	op->ss = algt->ss;

	op->fallback_tfm = crypto_alloc_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);
	}

	crypto_skcipher_set_reqsize(__crypto_skcipher_cast(tfm),
	sizeof(struct sun4i_cipher_req_ctx) +
	crypto_skcipher_reqsize(op->fallback_tfm));


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

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

	void sun4i_ss_cipher_exit(struct crypto_tfm *tfm)
	{
	struct sun4i_tfm_ctx *op = crypto_tfm_ctx(tfm);

	crypto_free_skcipher(op->fallback_tfm);
	pm_runtime_put(op->ss->dev);
	}

	/* check and set the AES key, prepare the mode to be used */
	int sun4i_ss_aes_setkey(struct crypto_skcipher tfm, const u8 key,
	unsigned int keylen)
	{
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	struct sun4i_ss_ctx *ss = op->ss;

	switch (keylen) {
	case 128 / 8:
	op->keymode = SS_AES_128BITS;
	break;
	case 192 / 8:
	op->keymode = SS_AES_192BITS;
	break;
	case 256 / 8:
	op->keymode = SS_AES_256BITS;
	break;
	default:
	dev_dbg(ss->dev, "ERROR: Invalid keylen %u\n", keylen);
	return -EINVAL;
	}
	op->keylen = keylen;
	memcpy(op->key, key, keylen);

	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);
	}

	/* check and set the DES key, prepare the mode to be used */
	int sun4i_ss_des_setkey(struct crypto_skcipher tfm, const u8 key,
	unsigned int keylen)
	{
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	int err;

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

	op->keylen = keylen;
	memcpy(op->key, key, keylen);

	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);
	}

	/* check and set the 3DES key, prepare the mode to be used */
	int sun4i_ss_des3_setkey(struct crypto_skcipher tfm, const u8 key,
	unsigned int keylen)
	{
	struct sun4i_tfm_ctx *op = crypto_skcipher_ctx(tfm);
	int err;

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

	op->keylen = keylen;
	memcpy(op->key, key, keylen);

	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);

	}