1 files changed, 595 insertions, 0 deletions

diff --git a/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c b/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
new file mode 100644
index 000000000000..cb2b0874f68f
--- /dev/null
+++ b/drivers/crypto/allwinner/sun4i-ss/sun4i-ss-cipher.c
@@ -0,0 +1,595 @@
+// 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;
+	/* 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;
+	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;
+	}
+
+	spin_lock_irqsave(&ss->slock, flags);
+
+	for (i = 0; i < op->keylen; i += 4)
+		writel(*(op->key + i / 4), ss->base + SS_KEY0 + i);
+
+	if (areq->iv) {
+		for (i = 0; i < 4 && i < ivsize / 4; i++) {
+			v = *(u32 *)(areq->iv + i * 4);
+			writel(v, ss->base + SS_IV0 + i * 4);
+		}
+	}
+	writel(mode, ss->base + SS_CTL);
+
+	sg_miter_start(&mi, areq->src, sg_nents(areq->src),
+		       SG_MITER_FROM_SG | SG_MITER_ATOMIC);
+	sg_miter_start(&mo, areq->dst, sg_nents(areq->dst),
+		       SG_MITER_TO_SG | SG_MITER_ATOMIC);
+	sg_miter_next(&mi);
+	sg_miter_next(&mo);
+	if (!mi.addr || !mo.addr) {
+		dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
+		err = -EINVAL;
+		goto release_ss;
+	}
+
+	ileft = areq->cryptlen / 4;
+	oleft = areq->cryptlen / 4;
+	oi = 0;
+	oo = 0;
+	do {
+		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) {
+			sg_miter_next(&mi);
+			oi = 0;
+		}
+
+		spaces = readl(ss->base + SS_FCSR);
+		rx_cnt = SS_RXFIFO_SPACES(spaces);
+		tx_cnt = SS_TXFIFO_SPACES(spaces);
+
+		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) {
+			sg_miter_next(&mo);
+			oo = 0;
+		}
+	} while (oleft);
+
+	if (areq->iv) {
+		for (i = 0; i < 4 && i < ivsize / 4; i++) {
+			v = readl(ss->base + SS_IV0 + i * 4);
+			*(u32 *)(areq->iv + i * 4) = v;
+		}
+	}
+
+release_ss:
+	sg_miter_stop(&mi);
+	sg_miter_stop(&mo);
+	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);
+	SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, op->fallback_tfm);
+	int err;
+
+	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 (ctx->mode & SS_DECRYPTION)
+		err = crypto_skcipher_decrypt(subreq);
+	else
+		err = crypto_skcipher_encrypt(subreq);
+	skcipher_request_zero(subreq);
+
+	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;
+	struct sg_mapping_iter mi, mo;
+	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;
+
+	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 % 4)
+			no_chunk = 0;
+		in_sg = sg_next(in_sg);
+	}
+	while (out_sg && no_chunk == 1) {
+		if (out_sg->length % 4)
+			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);
+
+	spin_lock_irqsave(&ss->slock, flags);
+
+	for (i = 0; i < op->keylen; i += 4)
+		writel(*(op->key + i / 4), ss->base + SS_KEY0 + i);
+
+	if (areq->iv) {
+		for (i = 0; i < 4 && i < ivsize / 4; i++) {
+			v = *(u32 *)(areq->iv + i * 4);
+			writel(v, ss->base + SS_IV0 + i * 4);
+		}
+	}
+	writel(mode, ss->base + SS_CTL);
+
+	sg_miter_start(&mi, areq->src, sg_nents(areq->src),
+		       SG_MITER_FROM_SG | SG_MITER_ATOMIC);
+	sg_miter_start(&mo, areq->dst, sg_nents(areq->dst),
+		       SG_MITER_TO_SG | SG_MITER_ATOMIC);
+	sg_miter_next(&mi);
+	sg_miter_next(&mo);
+	if (!mi.addr || !mo.addr) {
+		dev_err_ratelimited(ss->dev, "ERROR: sg_miter return null\n");
+		err = -EINVAL;
+		goto release_ss;
+	}
+	ileft = areq->cryptlen;
+	oleft = areq->cryptlen;
+	oi = 0;
+	oo = 0;
+
+	while (oleft) {
+		if (ileft) {
+			char buf[4 * SS_RX_MAX];/* buffer for linearize SG src */
+
+			/*
+			 * 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(buf + ob, mi.addr + oi, todo);
+				ileft -= todo;
+				oi += todo;
+				ob += todo;
+				if (!(ob % 4)) {
+					writesl(ss->base + SS_RXFIFO, buf,
+						ob / 4);
+					ob = 0;
+				}
+			}
+			if (oi == mi.length) {
+				sg_miter_next(&mi);
+				oi = 0;
+			}
+		}
+
+		spaces = readl(ss->base + SS_FCSR);
+		rx_cnt = SS_RXFIFO_SPACES(spaces);
+		tx_cnt = SS_TXFIFO_SPACES(spaces);
+		dev_dbg(ss->dev,
+			"%x %u/%zu %u/%u cnt=%u %u/%zu %u/%u cnt=%u %u\n",
+			mode,
+			oi, mi.length, ileft, areq->cryptlen, rx_cnt,
+			oo, mo.length, oleft, areq->cryptlen, tx_cnt, ob);
+
+		if (!tx_cnt)
+			continue;
+		/* 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) {
+				sg_miter_next(&mo);
+				oo = 0;
+			}
+		} else {
+			char bufo[4 * SS_TX_MAX]; /* buffer for linearize SG dst */
+
+			/*
+			 * read obl bytes in bufo, we read at maximum for
+			 * emptying the device
+			 */
+			readsl(ss->base + SS_TXFIFO, 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, bufo + obo, todo);
+				oleft -= todo;
+				obo += todo;
+				oo += todo;
+				if (oo == mo.length) {
+					sg_miter_next(&mo);
+					oo = 0;
+				}
+			} while (obo < obl);
+			/* bufo must be fully used here */
+		}
+	}
+	if (areq->iv) {
+		for (i = 0; i < 4 && i < ivsize / 4; i++) {
+			v = readl(ss->base + SS_IV0 + i * 4);
+			*(u32 *)(areq->iv + i * 4) = v;
+		}
+	}
+
+release_ss:
+	sg_miter_stop(&mi);
+	sg_miter_stop(&mo);
+	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;
+
+	crypto_skcipher_set_reqsize(__crypto_skcipher_cast(tfm),
+				    sizeof(struct sun4i_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);
+	}
+
+	err = pm_runtime_get_sync(op->ss->dev);
+	if (err < 0)
+		goto error_pm;
+
+	return 0;
+error_pm:
+	crypto_free_sync_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_sync_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);
+		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+	op->keylen = keylen;
+	memcpy(op->key, key, keylen);
+
+	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);
+}
+
+/* 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_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);
+}
+
+/* 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_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);
+
+}