Create RPMB backend interface

Add RPMB backend layer and RPMB related definitions for providing an
interface for RPMB hardware access.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: I64e253078171c4a8296e4125c53b22eed05e2092
diff --git a/components/service/rpmb/backend/rpmb_backend.h b/components/service/rpmb/backend/rpmb_backend.h
new file mode 100644
index 0000000..5800bb7
--- /dev/null
+++ b/components/service/rpmb/backend/rpmb_backend.h
@@ -0,0 +1,158 @@
+/*
+ * Copyright (c) 2023, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef RPMB_BACKEND_H_
+#define RPMB_BACKEND_H_
+
+#include "psa/error.h"
+#include "compiler.h"
+#include <stddef.h>
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \brief RPMB request/response message types
+ *
+ * Defined in eMMC 4.5 (JESD84-B51) standard's Table 18.
+ */
+#define RPMB_REQ_TYPE_AUTHENTICATION_KEY_WRITE	(0x0001)
+#define RPMB_REQ_TYPE_READ_WRITE_COUNTER	(0x0002)
+#define RPMB_REQ_TYPE_AUTHENTICATED_DATA_WRITE	(0x0003)
+#define RPMB_REQ_TYPE_AUTHENTICATED_DATA_READ	(0x0004)
+#define RPMB_REQ_TYPE_RESULT_READ_REQUEST	(0x0005)
+#define RPMB_REQ_TYPE_DEVICE_CONFIG_WRITE	(0x0006)
+#define RPMB_REQ_TYPE_DEVICE_CONFIG_READ	(0x0007)
+
+#define RPMB_RESP_TYPE_AUTHENTICATION_KEY_WRITE	(0x0100)
+#define RPMB_RESP_TYPE_READ_WRITE_COUNTER	(0x0200)
+#define RPMB_RESP_TYPE_AUTHENTICATED_DATA_WRITE	(0x0300)
+#define RPMB_RESP_TYPE_AUTHENTICATED_DATA_READ	(0x0400)
+#define RPMB_RESP_TYPE_DEVICE_CONFIG_WRITE	(0x0600)
+#define RPMB_RESP_TYPE_DEVICE_CONFIG_READ	(0x0700)
+
+/**
+ * \brief RPMB operation results
+ *
+ * Defined in eMMC 4.5 (JESD84-B51) standard's Table 20.
+ */
+#define RPMB_RES_OK			(0x0000)
+#define RPMB_RES_GENERAL_FAILURE	(0x0001)
+#define RPMB_RES_AUTHENTICATION_FAILURE	(0x0002)
+#define RPMB_RES_COUNTER_FAILURE	(0x0003)
+#define RPMB_RES_ADDRESS_FAILURE	(0x0004)
+#define RPMB_RES_WRITE_FAILURE		(0x0005)
+#define RPMB_RES_READ_FAILURE		(0x0006)
+#define RPMB_RES_KEY_NOT_PROGRAMMED	(0x0007)
+
+#define RPMB_RES_COUNTER_EXPIRED	(0x0080)
+
+/**
+ * \brief Additional RPMB related definitions
+ */
+#define RPMB_EMMC_CID_SIZE		(16)
+#define RPMB_CID_PRODUCT_REVISION	(9)
+#define RPMB_CID_CRC7			(15)
+#define RPMB_STUFF_DATA_SIZE		(196)
+#define RPMB_KEY_MAC_SIZE		(32)
+#define RPMB_DATA_SIZE			(256)
+#define RPMB_NONCE_SIZE			(16)
+#define RPMB_SIZE_MULT_UNIT		(128 * 1024)
+
+/**
+ * \brief RPMB device info
+ *
+ * The RPMB device info structure contains the Device Identification (CID) and RPMB_SIZE_MULT
+ * registers' value. The CID value is unique to each RPMB device and it can be involved into the
+ * authentication key generation process. The RPMB_SIZE_MULT value indicates the size of the RPMB
+ * in 128kB units.
+ */
+struct rpmb_dev_info {
+	uint8_t cid[RPMB_EMMC_CID_SIZE];
+	uint8_t rpmb_size_mult;
+} __packed;
+
+/**
+ * \brief RPMB data frame
+ *
+ * Defined in eMMC 4.5 (JESD84-B51) standard's Table 17.
+ */
+struct rpmb_data_frame {
+	uint8_t stuff_bytes[RPMB_STUFF_DATA_SIZE];
+	uint8_t key_mac[RPMB_KEY_MAC_SIZE];
+	uint8_t data[RPMB_DATA_SIZE];
+	uint8_t nonce[RPMB_NONCE_SIZE];
+	uint8_t write_counter[4];
+	uint8_t address[2];
+	uint8_t block_count[2];
+	uint8_t op_result[2];
+	uint8_t msg_type[2];
+} __packed;
+
+/**
+ * \brief RPMB backend interface
+ *
+ * The structure defines the function interface that the backend has to implement in order to
+ * provide hardware access to the RPMB device.
+ */
+struct rpmb_backend_interface {
+	psa_status_t (*get_dev_info)(void *context, uint32_t dev_id,
+				     struct rpmb_dev_info *dev_info);
+
+	psa_status_t (*data_request)(void *context, uint32_t dev_id,
+				     const struct rpmb_data_frame *request_frames,
+				     size_t request_frame_count,
+				     struct rpmb_data_frame *response_frames,
+				     size_t *response_frame_count);
+};
+
+/**
+ * \brief RPMB backend
+ *
+ * Generic object for storing the RPMB backend interface and the implementation specific context.
+ */
+struct rpmb_backend {
+	void *context;
+	const struct rpmb_backend_interface *interface;
+};
+
+/**
+ * \brief Query RPMB device info from the device
+ *
+ * \return Pointer to the base block_store or NULL on failure
+ * \param[in] instance	RPMB backend instance
+ * \param[in] dev_id	RPMB device ID
+ * \param[out] dev_info	Device info
+ * \return psa_status_t
+ */
+psa_status_t rpmb_backend_get_dev_info(struct rpmb_backend *instance, uint32_t dev_id,
+				       struct rpmb_dev_info *dev_info);
+
+/**
+ * \brief Write and read data frames into and from the RPMB device.
+ *
+ * \param[in] instance			RPMB backend instance
+ * \param[in] dev_id			RPMB device ID
+ * \param[in] request_frames		Request data frames
+ * \param[in] request_frame_count	Request data frame count
+ * \param[out] response_frames		Response data frames
+ * \param[inout] response_frame_count	in: maximal response data frame count, out: actual response
+ *					data frame count
+ * \return psa_status_t
+ */
+psa_status_t rpmb_backend_data_request(struct rpmb_backend *instance, uint32_t dev_id,
+				       const struct rpmb_data_frame *request_frames,
+				       size_t request_frame_count,
+				       struct rpmb_data_frame *response_frames,
+				       size_t *response_frame_count);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* RPMB_BACKEND_H_ */