crypto: marvell/cesa - add a new driver for Marvell's CESA

The existing mv_cesa driver supports some features of the CESA IP but is
quite limited, and reworking it to support new features (like involving the
TDMA engine to offload the CPU) is almost impossible.
This driver has been rewritten from scratch to take those new features into
account.

This commit introduce the base infrastructure allowing us to add support
for DMA optimization.
It also includes support for one hash (SHA1) and one cipher (AES)
algorithm, and enable those features on the Armada 370 SoC.

Other algorithms and platforms will be added later on.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 331 insertions, 0 deletions

diff --git a/drivers/crypto/marvell/cipher.c b/drivers/crypto/marvell/cipher.c
new file mode 100644
index 000000000000..e6eea488f11e
--- /dev/null
+++ b/drivers/crypto/marvell/cipher.c
@@ -0,0 +1,331 @@
+/*
+ * Cipher algorithms supported by the CESA: DES, 3DES and AES.
+ *
+ * Author: Boris Brezillon <boris.brezillon@free-electrons.com>
+ * Author: Arnaud Ebalard <arno@natisbad.org>
+ *
+ * This work is based on an initial version written by
+ * Sebastian Andrzej Siewior < sebastian at breakpoint dot cc >
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <crypto/aes.h>
+
+#include "cesa.h"
+
+struct mv_cesa_aes_ctx {
+	struct mv_cesa_ctx base;
+	struct crypto_aes_ctx aes;
+};
+
+static void mv_cesa_ablkcipher_std_step(struct ablkcipher_request *req)
+{
+	struct mv_cesa_ablkcipher_req *creq = ablkcipher_request_ctx(req);
+	struct mv_cesa_ablkcipher_std_req *sreq = &creq->req.std;
+	struct mv_cesa_engine *engine = sreq->base.engine;
+	size_t  len = min_t(size_t, req->nbytes - sreq->offset,
+			    CESA_SA_SRAM_PAYLOAD_SIZE);
+
+	len = sg_pcopy_to_buffer(req->src, creq->src_nents,
+				 engine->sram + CESA_SA_DATA_SRAM_OFFSET,
+				 len, sreq->offset);
+
+	sreq->size = len;
+	mv_cesa_set_crypt_op_len(&sreq->op, len);
+
+	/* FIXME: only update enc_len field */
+	if (!sreq->skip_ctx) {
+		memcpy(engine->sram, &sreq->op, sizeof(sreq->op));
+		sreq->skip_ctx = true;
+	} else {
+		memcpy(engine->sram, &sreq->op, sizeof(sreq->op.desc));
+	}
+
+	mv_cesa_set_int_mask(engine, CESA_SA_INT_ACCEL0_DONE);
+	writel(CESA_SA_CFG_PARA_DIS, engine->regs + CESA_SA_CFG);
+	writel(CESA_SA_CMD_EN_CESA_SA_ACCL0, engine->regs + CESA_SA_CMD);
+}
+
+static int mv_cesa_ablkcipher_std_process(struct ablkcipher_request *req,
+					  u32 status)
+{
+	struct mv_cesa_ablkcipher_req *creq = ablkcipher_request_ctx(req);
+	struct mv_cesa_ablkcipher_std_req *sreq = &creq->req.std;
+	struct mv_cesa_engine *engine = sreq->base.engine;
+	size_t len;
+
+	len = sg_pcopy_from_buffer(req->dst, creq->dst_nents,
+				   engine->sram + CESA_SA_DATA_SRAM_OFFSET,
+				   sreq->size, sreq->offset);
+
+	sreq->offset += len;
+	if (sreq->offset < req->nbytes)
+		return -EINPROGRESS;
+
+	return 0;
+}
+
+static int mv_cesa_ablkcipher_process(struct crypto_async_request *req,
+				      u32 status)
+{
+	struct ablkcipher_request *ablkreq = ablkcipher_request_cast(req);
+	struct mv_cesa_ablkcipher_req *creq = ablkcipher_request_ctx(ablkreq);
+	struct mv_cesa_ablkcipher_std_req *sreq = &creq->req.std;
+	struct mv_cesa_engine *engine = sreq->base.engine;
+	int ret;
+
+	ret = mv_cesa_ablkcipher_std_process(ablkreq, status);
+	if (ret)
+		return ret;
+
+	memcpy(ablkreq->info, engine->sram + CESA_SA_CRYPT_IV_SRAM_OFFSET,
+	       crypto_ablkcipher_ivsize(crypto_ablkcipher_reqtfm(ablkreq)));
+
+	return 0;
+}
+
+static void mv_cesa_ablkcipher_step(struct crypto_async_request *req)
+{
+	struct ablkcipher_request *ablkreq = ablkcipher_request_cast(req);
+
+	mv_cesa_ablkcipher_std_step(ablkreq);
+}
+
+static inline void
+mv_cesa_ablkcipher_std_prepare(struct ablkcipher_request *req)
+{
+	struct mv_cesa_ablkcipher_req *creq = ablkcipher_request_ctx(req);
+	struct mv_cesa_ablkcipher_std_req *sreq = &creq->req.std;
+	struct mv_cesa_engine *engine = sreq->base.engine;
+
+	sreq->size = 0;
+	sreq->offset = 0;
+	mv_cesa_adjust_op(engine, &sreq->op);
+	memcpy(engine->sram, &sreq->op, sizeof(sreq->op));
+}
+
+static inline void mv_cesa_ablkcipher_prepare(struct crypto_async_request *req,
+					      struct mv_cesa_engine *engine)
+{
+	struct ablkcipher_request *ablkreq = ablkcipher_request_cast(req);
+	struct mv_cesa_ablkcipher_req *creq = ablkcipher_request_ctx(ablkreq);
+
+	creq->req.base.engine = engine;
+
+	mv_cesa_ablkcipher_std_prepare(ablkreq);
+}
+
+static inline void
+mv_cesa_ablkcipher_req_cleanup(struct crypto_async_request *req)
+{
+}
+
+static const struct mv_cesa_req_ops mv_cesa_ablkcipher_req_ops = {
+	.step = mv_cesa_ablkcipher_step,
+	.process = mv_cesa_ablkcipher_process,
+	.prepare = mv_cesa_ablkcipher_prepare,
+	.cleanup = mv_cesa_ablkcipher_req_cleanup,
+};
+
+static int mv_cesa_ablkcipher_cra_init(struct crypto_tfm *tfm)
+{
+	struct mv_cesa_aes_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	ctx->base.ops = &mv_cesa_ablkcipher_req_ops;
+
+	tfm->crt_ablkcipher.reqsize = sizeof(struct mv_cesa_ablkcipher_req);
+
+	return 0;
+}
+
+static int mv_cesa_aes_setkey(struct crypto_ablkcipher *cipher, const u8 *key,
+			      unsigned int len)
+{
+	struct crypto_tfm *tfm = crypto_ablkcipher_tfm(cipher);
+	struct mv_cesa_aes_ctx *ctx = crypto_tfm_ctx(tfm);
+	int remaining;
+	int offset;
+	int ret;
+	int i;
+
+	ret = crypto_aes_expand_key(&ctx->aes, key, len);
+	if (ret) {
+		crypto_ablkcipher_set_flags(cipher, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return ret;
+	}
+
+	remaining = (ctx->aes.key_length - 16) / 4;
+	offset = ctx->aes.key_length + 24 - remaining;
+	for (i = 0; i < remaining; i++)
+		ctx->aes.key_dec[4 + i] =
+			cpu_to_le32(ctx->aes.key_enc[offset + i]);
+
+	return 0;
+}
+
+static inline int
+mv_cesa_ablkcipher_std_req_init(struct ablkcipher_request *req,
+				const struct mv_cesa_op_ctx *op_templ)
+{
+	struct mv_cesa_ablkcipher_req *creq = ablkcipher_request_ctx(req);
+	struct mv_cesa_ablkcipher_std_req *sreq = &creq->req.std;
+
+	sreq->base.type = CESA_STD_REQ;
+	sreq->op = *op_templ;
+	sreq->skip_ctx = false;
+
+	return 0;
+}
+
+static int mv_cesa_ablkcipher_req_init(struct ablkcipher_request *req,
+				       struct mv_cesa_op_ctx *tmpl)
+{
+	struct mv_cesa_ablkcipher_req *creq = ablkcipher_request_ctx(req);
+	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
+	unsigned int blksize = crypto_ablkcipher_blocksize(tfm);
+
+	if (!IS_ALIGNED(req->nbytes, blksize))
+		return -EINVAL;
+
+	creq->src_nents = sg_nents_for_len(req->src, req->nbytes);
+	creq->dst_nents = sg_nents_for_len(req->dst, req->nbytes);
+
+	mv_cesa_update_op_cfg(tmpl, CESA_SA_DESC_CFG_OP_CRYPT_ONLY,
+			      CESA_SA_DESC_CFG_OP_MSK);
+
+	return mv_cesa_ablkcipher_std_req_init(req, tmpl);
+}
+
+static int mv_cesa_aes_op(struct ablkcipher_request *req,
+			  struct mv_cesa_op_ctx *tmpl)
+{
+	struct mv_cesa_aes_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
+	int ret, i;
+	u32 *key;
+	u32 cfg;
+
+	cfg = CESA_SA_DESC_CFG_CRYPTM_AES;
+
+	if (mv_cesa_get_op_cfg(tmpl) & CESA_SA_DESC_CFG_DIR_DEC)
+		key = ctx->aes.key_dec;
+	else
+		key = ctx->aes.key_enc;
+
+	for (i = 0; i < ctx->aes.key_length / sizeof(u32); i++)
+		tmpl->ctx.blkcipher.key[i] = cpu_to_le32(key[i]);
+
+	if (ctx->aes.key_length == 24)
+		cfg |= CESA_SA_DESC_CFG_AES_LEN_192;
+	else if (ctx->aes.key_length == 32)
+		cfg |= CESA_SA_DESC_CFG_AES_LEN_256;
+
+	mv_cesa_update_op_cfg(tmpl, cfg,
+			      CESA_SA_DESC_CFG_CRYPTM_MSK |
+			      CESA_SA_DESC_CFG_AES_LEN_MSK);
+
+	ret = mv_cesa_ablkcipher_req_init(req, tmpl);
+	if (ret)
+		return ret;
+
+	return mv_cesa_queue_req(&req->base);
+}
+
+static int mv_cesa_ecb_aes_encrypt(struct ablkcipher_request *req)
+{
+	struct mv_cesa_op_ctx tmpl;
+
+	mv_cesa_set_op_cfg(&tmpl,
+			   CESA_SA_DESC_CFG_CRYPTCM_ECB |
+			   CESA_SA_DESC_CFG_DIR_ENC);
+
+	return mv_cesa_aes_op(req, &tmpl);
+}
+
+static int mv_cesa_ecb_aes_decrypt(struct ablkcipher_request *req)
+{
+	struct mv_cesa_op_ctx tmpl;
+
+	mv_cesa_set_op_cfg(&tmpl,
+			   CESA_SA_DESC_CFG_CRYPTCM_ECB |
+			   CESA_SA_DESC_CFG_DIR_DEC);
+
+	return mv_cesa_aes_op(req, &tmpl);
+}
+
+struct crypto_alg mv_cesa_ecb_aes_alg = {
+	.cra_name = "ecb(aes)",
+	.cra_driver_name = "mv-ecb-aes",
+	.cra_priority = 300,
+	.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER |
+		     CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_ASYNC,
+	.cra_blocksize = AES_BLOCK_SIZE,
+	.cra_ctxsize = sizeof(struct mv_cesa_aes_ctx),
+	.cra_alignmask = 0,
+	.cra_type = &crypto_ablkcipher_type,
+	.cra_module = THIS_MODULE,
+	.cra_init = mv_cesa_ablkcipher_cra_init,
+	.cra_u = {
+		.ablkcipher = {
+			.min_keysize = AES_MIN_KEY_SIZE,
+			.max_keysize = AES_MAX_KEY_SIZE,
+			.setkey = mv_cesa_aes_setkey,
+			.encrypt = mv_cesa_ecb_aes_encrypt,
+			.decrypt = mv_cesa_ecb_aes_decrypt,
+		},
+	},
+};
+
+static int mv_cesa_cbc_aes_op(struct ablkcipher_request *req,
+			      struct mv_cesa_op_ctx *tmpl)
+{
+	mv_cesa_update_op_cfg(tmpl, CESA_SA_DESC_CFG_CRYPTCM_CBC,
+			      CESA_SA_DESC_CFG_CRYPTCM_MSK);
+	memcpy(tmpl->ctx.blkcipher.iv, req->info, AES_BLOCK_SIZE);
+
+	return mv_cesa_aes_op(req, tmpl);
+}
+
+static int mv_cesa_cbc_aes_encrypt(struct ablkcipher_request *req)
+{
+	struct mv_cesa_op_ctx tmpl;
+
+	mv_cesa_set_op_cfg(&tmpl, CESA_SA_DESC_CFG_DIR_ENC);
+
+	return mv_cesa_cbc_aes_op(req, &tmpl);
+}
+
+static int mv_cesa_cbc_aes_decrypt(struct ablkcipher_request *req)
+{
+	struct mv_cesa_op_ctx tmpl;
+
+	mv_cesa_set_op_cfg(&tmpl, CESA_SA_DESC_CFG_DIR_DEC);
+
+	return mv_cesa_cbc_aes_op(req, &tmpl);
+}
+
+struct crypto_alg mv_cesa_cbc_aes_alg = {
+	.cra_name = "cbc(aes)",
+	.cra_driver_name = "mv-cbc-aes",
+	.cra_priority = 300,
+	.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER |
+		     CRYPTO_ALG_KERN_DRIVER_ONLY | CRYPTO_ALG_ASYNC,
+	.cra_blocksize = AES_BLOCK_SIZE,
+	.cra_ctxsize = sizeof(struct mv_cesa_aes_ctx),
+	.cra_alignmask = 0,
+	.cra_type = &crypto_ablkcipher_type,
+	.cra_module = THIS_MODULE,
+	.cra_init = mv_cesa_ablkcipher_cra_init,
+	.cra_u = {
+		.ablkcipher = {
+			.min_keysize = AES_MIN_KEY_SIZE,
+			.max_keysize = AES_MAX_KEY_SIZE,
+			.ivsize = AES_BLOCK_SIZE,
+			.setkey = mv_cesa_aes_setkey,
+			.encrypt = mv_cesa_cbc_aes_encrypt,
+			.decrypt = mv_cesa_cbc_aes_decrypt,
+		},
+	},
+};