[RFC PATCH HBK: 4/8] keys-trusted: re-factored caam based trusted key

[Pankaj Gupta]

Re-factored caam based trusted key code:
- Two separate definition for encap and decap having
  separate code for creating CAAM job descriptor.

Signed-off-by: Pankaj Gupta <pankaj.gupta@xxxxxxx>
---
 drivers/crypto/caam/blob_gen.c | 122 +++++++++++++++++++++++++++++----
 include/soc/fsl/caam-blob.h    |  28 +++-----
 2 files changed, 118 insertions(+), 32 deletions(-)

diff --git a/drivers/crypto/caam/blob_gen.c b/drivers/crypto/caam/blob_gen.c
index 6345c7269eb0..c128a83cc8dd 100644
--- a/drivers/crypto/caam/blob_gen.c
+++ b/drivers/crypto/caam/blob_gen.c
@@ -2,6 +2,7 @@
 /*
  * Copyright (C) 2015 Pengutronix, Steffen Trumtrar <kernel@xxxxxxxxxxxxxx>
  * Copyright (C) 2021 Pengutronix, Ahmad Fatoum <kernel@xxxxxxxxxxxxxx>
+ * Copyright 2022 NXP, Pankaj Gupta <pankaj.gupta@xxxxxxx>
  */
 
 #define pr_fmt(fmt) "caam blob_gen: " fmt
@@ -29,10 +30,6 @@
 	/* Command describing the operation to perform */		\
 	 CAAM_CMD_SZ)
 
-struct caam_blob_priv {
-	struct device jrdev;
-};
-
 struct caam_blob_job_result {
 	int err;
 	struct completion completion;
@@ -58,8 +55,19 @@ static void caam_blob_job_done(struct device *dev, u32 *desc, u32 err, void *con
 	complete(&res->completion);
 }
 
-int caam_process_blob(struct caam_blob_priv *priv,
-		      struct caam_blob_info *info, bool encap)
+
+
+/** caam_encap_blob - encapsulate blob
+ *
+ * @priv:   instance returned by caam_blob_gen_init
+ * @info:   pointer to blobbing info describing input key,
+ *          output blob and key modifier buffers.
+ *
+ * returns 0 and sets info->output_len on success and returns
+ * a negative error code otherwise.
+ */
+int caam_encap_blob(struct caam_blob_priv *priv,
+		    struct caam_blob_info *info)
 {
 	struct caam_blob_job_result testres;
 	struct device *jrdev = &priv->jrdev;
@@ -72,14 +80,102 @@ int caam_process_blob(struct caam_blob_priv *priv,
 	if (info->key_mod_len > CAAM_BLOB_KEYMOD_LENGTH)
 		return -EINVAL;
 
-	if (encap) {
-		op |= OP_TYPE_ENCAP_PROTOCOL;
-		output_len = info->input_len + CAAM_BLOB_OVERHEAD;
-	} else {
-		op |= OP_TYPE_DECAP_PROTOCOL;
-		output_len = info->input_len - CAAM_BLOB_OVERHEAD;
+	op |= OP_TYPE_ENCAP_PROTOCOL;
+	output_len = info->input_len + CAAM_BLOB_OVERHEAD;
+
+	desc = kzalloc(CAAM_BLOB_DESC_BYTES_MAX, GFP_KERNEL | GFP_DMA);
+	if (!desc)
+		return -ENOMEM;
+
+	dma_in = dma_map_single(jrdev, info->input, info->input_len,
+				DMA_TO_DEVICE);
+	if (dma_mapping_error(jrdev, dma_in)) {
+		dev_err(jrdev, "unable to map input DMA buffer\n");
+		ret = -ENOMEM;
+		goto out_free;
+	}
+
+	dma_out = dma_map_single(jrdev, info->output, output_len,
+				 DMA_FROM_DEVICE);
+	if (dma_mapping_error(jrdev, dma_out)) {
+		dev_err(jrdev, "unable to map output DMA buffer\n");
+		ret = -ENOMEM;
+		goto out_unmap_in;
+	}
+
+	/*
+	 * A data blob is encrypted using a blob key (BK); a random number.
+	 * The BK is used as an AES-CCM key. The initial block (B0) and the
+	 * initial counter (Ctr0) are generated automatically and stored in
+	 * Class 1 Context DWords 0+1+2+3. The random BK is stored in the
+	 * Class 1 Key Register. Operation Mode is set to AES-CCM.
+	 */
+
+	init_job_desc(desc, 0);
+	append_key_as_imm(desc, info->key_mod, info->key_mod_len,
+			  info->key_mod_len, CLASS_2 | KEY_DEST_CLASS_REG);
+	append_seq_in_ptr_intlen(desc, dma_in, info->input_len, 0);
+	append_seq_out_ptr_intlen(desc, dma_out, output_len, 0);
+	append_operation(desc, op);
+
+	print_hex_dump_debug("data@"__stringify(__LINE__)": ",
+			     DUMP_PREFIX_ADDRESS, 16, 1, info->input,
+			     info->input_len, false);
+	print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ",
+			     DUMP_PREFIX_ADDRESS, 16, 1, desc,
+			     desc_bytes(desc), false);
+
+	testres.err = 0;
+	init_completion(&testres.completion);
+
+	ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres);
+	if (ret == -EINPROGRESS) {
+		wait_for_completion(&testres.completion);
+		ret = testres.err;
+		print_hex_dump_debug("output@"__stringify(__LINE__)": ",
+				     DUMP_PREFIX_ADDRESS, 16, 1, info->output,
+				     output_len, false);
 	}
 
+	if (ret == 0)
+		info->output_len = output_len;
+
+	dma_unmap_single(jrdev, dma_out, output_len, DMA_FROM_DEVICE);
+out_unmap_in:
+	dma_unmap_single(jrdev, dma_in, info->input_len, DMA_TO_DEVICE);
+out_free:
+	kfree(desc);
+
+	return ret;
+}
+EXPORT_SYMBOL(caam_encap_blob);
+
+/** caam_decap_blob - decapsulate blob
+ *
+ * @priv:   instance returned by caam_blob_gen_init
+ * @info:   pointer to blobbing info describing output key,
+ *          input blob and key modifier buffers.
+ *
+ * returns 0 and sets info->output_len on success and returns
+ * a negative error code otherwise.
+ */
+int caam_decap_blob(struct caam_blob_priv *priv,
+		    struct caam_blob_info *info)
+{
+	struct caam_blob_job_result testres;
+	struct device *jrdev = &priv->jrdev;
+	dma_addr_t dma_in, dma_out;
+	int op = OP_PCLID_BLOB;
+	size_t output_len;
+	u32 *desc;
+	int ret;
+
+	if (info->key_mod_len > CAAM_BLOB_KEYMOD_LENGTH)
+		return -EINVAL;
+
+	op |= OP_TYPE_DECAP_PROTOCOL;
+	output_len = info->input_len - CAAM_BLOB_OVERHEAD;
+
 	desc = kzalloc(CAAM_BLOB_DESC_BYTES_MAX, GFP_KERNEL | GFP_DMA);
 	if (!desc)
 		return -ENOMEM;
@@ -145,7 +241,7 @@ int caam_process_blob(struct caam_blob_priv *priv,
 
 	return ret;
 }
-EXPORT_SYMBOL(caam_process_blob);
+EXPORT_SYMBOL(caam_decap_blob);
 
 struct caam_blob_priv *caam_blob_gen_init(void)
 {
diff --git a/include/soc/fsl/caam-blob.h b/include/soc/fsl/caam-blob.h
index 937cac52f36d..632944df29f7 100644
--- a/include/soc/fsl/caam-blob.h
+++ b/include/soc/fsl/caam-blob.h
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Copyright (C) 2020 Pengutronix, Ahmad Fatoum <kernel@xxxxxxxxxxxxxx>
+ * Copyright 2022 NXP, Pankaj Gupta <pankaj.gupta@xxxxxxx>
  */
 
 #ifndef __CAAM_BLOB_GEN
@@ -13,7 +14,10 @@
 #define CAAM_BLOB_OVERHEAD		(32 + 16)
 #define CAAM_BLOB_MAX_LEN		4096
 
-struct caam_blob_priv;
+struct caam_blob_priv {
+	struct device jrdev;
+};
+
 
 /**
  * struct caam_blob_info - information for CAAM blobbing
@@ -72,15 +76,8 @@ int caam_process_blob(struct caam_blob_priv *priv,
  * Return: %0 and sets ``info->output_len`` on success and
  * a negative error code otherwise.
  */
-static inline int caam_encap_blob(struct caam_blob_priv *priv,
-				  struct caam_blob_info *info)
-{
-	if (info->output_len < info->input_len + CAAM_BLOB_OVERHEAD)
-		return -EINVAL;
-
-	return caam_process_blob(priv, info, true);
-}
-
+int caam_encap_blob(struct caam_blob_priv *priv,
+		    struct caam_blob_info *info);
 /**
  * caam_decap_blob - decapsulate blob
  * @priv:   instance returned by caam_blob_gen_init()
@@ -90,14 +87,7 @@ static inline int caam_encap_blob(struct caam_blob_priv *priv,
  * Return: %0 and sets ``info->output_len`` on success and
  * a negative error code otherwise.
  */
-static inline int caam_decap_blob(struct caam_blob_priv *priv,
-				  struct caam_blob_info *info)
-{
-	if (info->input_len < CAAM_BLOB_OVERHEAD ||
-	    info->output_len < info->input_len - CAAM_BLOB_OVERHEAD)
-		return -EINVAL;
-
-	return caam_process_blob(priv, info, false);
-}
+int caam_decap_blob(struct caam_blob_priv *priv,
+		    struct caam_blob_info *info);
 
 #endif
-- 
2.17.1