1 files changed, 388 insertions, 0 deletions

diff --git a/drivers/crypto/gemini/sl3516-ce-cipher.c b/drivers/crypto/gemini/sl3516-ce-cipher.c
new file mode 100644
index 000000000000..0b34a4971e49
--- /dev/null
+++ b/drivers/crypto/gemini/sl3516-ce-cipher.c
@@ -0,0 +1,388 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sl3516-ce-cipher.c - hardware cryptographic offloader for Stormlink 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/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 = areq->src;
+	struct scatterlist *out_sg = areq->dst;
+	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);
+	crypto_finalize_skcipher_request(engine, breq, err);
+
+	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);
+}