rpmb.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Copyright (C) 2015-2019 Intel Corp. All rights reserved
  4 * Copyright (C) 2021-2022 Linaro Ltd
  5 */
  6#ifndef __RPMB_H__
  7#define __RPMB_H__
  8
  9#include <linux/device.h>
 10#include <linux/types.h>
 11
 12/**
 13 * enum rpmb_type - type of underlying storage technology
 14 *
 15 * @RPMB_TYPE_EMMC  : emmc (JESD84-B50.1)
 16 * @RPMB_TYPE_UFS   : UFS (JESD220)
 17 * @RPMB_TYPE_NVME  : NVM Express
 18 */
 19enum rpmb_type {
 20	RPMB_TYPE_EMMC,
 21	RPMB_TYPE_UFS,
 22	RPMB_TYPE_NVME,
 23};
 24
 25/**
 26 * struct rpmb_descr - RPMB description provided by the underlying block device
 27 *
 28 * @type             : block device type
 29 * @route_frames     : routes frames to and from the RPMB device
 30 * @dev_id           : unique device identifier read from the hardware
 31 * @dev_id_len       : length of unique device identifier
 32 * @reliable_wr_count: number of sectors that can be written in one access
 33 * @capacity         : capacity of the device in units of 128K
 34 *
 35 * @dev_id is intended to be used as input when deriving the authenticaion key.
 36 */
 37struct rpmb_descr {
 38	enum rpmb_type type;
 39	int (*route_frames)(struct device *dev, u8 *req, unsigned int req_len,
 40			    u8 *resp, unsigned int resp_len);
 41	u8 *dev_id;
 42	size_t dev_id_len;
 43	u16 reliable_wr_count;
 44	u16 capacity;
 45};
 46
 47/**
 48 * struct rpmb_dev - device which can support RPMB partition
 49 *
 50 * @dev              : device
 51 * @id               : device_id
 52 * @list_node        : linked list node
 53 * @descr            : RPMB description
 54 */
 55struct rpmb_dev {
 56	struct device dev;
 57	int id;
 58	struct list_head list_node;
 59	struct rpmb_descr descr;
 60};
 61
 62#define to_rpmb_dev(x)		container_of((x), struct rpmb_dev, dev)
 63
 64/**
 65 * struct rpmb_frame - RPMB frame structure for authenticated access
 66 *
 67 * @stuff        : stuff bytes, a padding/reserved area of 196 bytes at the
 68 *                 beginning of the RPMB frame. They don’t carry meaningful
 69 *                 data but are required to make the frame exactly 512 bytes.
 70 * @key_mac      : The authentication key or the message authentication
 71 *                 code (MAC) depending on the request/response type.
 72 *                 The MAC will be delivered in the last (or the only)
 73 *                 block of data.
 74 * @data         : Data to be written or read by signed access.
 75 * @nonce        : Random number generated by the host for the requests
 76 *                 and copied to the response by the RPMB engine.
 77 * @write_counter: Counter value for the total amount of the successful
 78 *                 authenticated data write requests made by the host.
 79 * @addr         : Address of the data to be programmed to or read
 80 *                 from the RPMB. Address is the serial number of
 81 *                 the accessed block (half sector 256B).
 82 * @block_count  : Number of blocks (half sectors, 256B) requested to be
 83 *                 read/programmed.
 84 * @result       : Includes information about the status of the write counter
 85 *                 (valid, expired) and result of the access made to the RPMB.
 86 * @req_resp     : Defines the type of request and response to/from the memory.
 87 *
 88 * The stuff bytes and big-endian properties are modeled to fit to the spec.
 89 */
 90struct rpmb_frame {
 91	u8     stuff[196];
 92	u8     key_mac[32];
 93	u8     data[256];
 94	u8     nonce[16];
 95	__be32 write_counter;
 96	__be16 addr;
 97	__be16 block_count;
 98	__be16 result;
 99	__be16 req_resp;
100};
101
102#define RPMB_PROGRAM_KEY       0x1    /* Program RPMB Authentication Key */
103#define RPMB_GET_WRITE_COUNTER 0x2    /* Read RPMB write counter */
104#define RPMB_WRITE_DATA        0x3    /* Write data to RPMB partition */
105#define RPMB_READ_DATA         0x4    /* Read data from RPMB partition */
106#define RPMB_RESULT_READ       0x5    /* Read result request  (Internal) */
107
108#if IS_ENABLED(CONFIG_RPMB)
109struct rpmb_dev *rpmb_dev_get(struct rpmb_dev *rdev);
110void rpmb_dev_put(struct rpmb_dev *rdev);
111struct rpmb_dev *rpmb_dev_find_device(const void *data,
112				      const struct rpmb_dev *start,
113				      int (*match)(struct device *dev,
114						   const void *data));
115int rpmb_interface_register(struct class_interface *intf);
116void rpmb_interface_unregister(struct class_interface *intf);
117struct rpmb_dev *rpmb_dev_register(struct device *dev,
118				   struct rpmb_descr *descr);
119int rpmb_dev_unregister(struct rpmb_dev *rdev);
120
121int rpmb_route_frames(struct rpmb_dev *rdev, u8 *req,
122		      unsigned int req_len, u8 *resp, unsigned int resp_len);
123
124#else
125static inline struct rpmb_dev *rpmb_dev_get(struct rpmb_dev *rdev)
126{
127	return NULL;
128}
129
130static inline void rpmb_dev_put(struct rpmb_dev *rdev) { }
131
132static inline struct rpmb_dev *
133rpmb_dev_find_device(const void *data, const struct rpmb_dev *start,
134		     int (*match)(struct device *dev, const void *data))
135{
136	return NULL;
137}
138
139static inline int rpmb_interface_register(struct class_interface *intf)
140{
141	return -EOPNOTSUPP;
142}
143
144static inline void rpmb_interface_unregister(struct class_interface *intf)
145{
146}
147
148static inline struct rpmb_dev *
149rpmb_dev_register(struct device *dev, struct rpmb_descr *descr)
150{
151	return NULL;
152}
153
154static inline int rpmb_dev_unregister(struct rpmb_dev *dev)
155{
156	return 0;
157}
158
159static inline int rpmb_route_frames(struct rpmb_dev *rdev, u8 *req,
160				    unsigned int req_len, u8 *resp,
161				    unsigned int resp_len)
162{
163	return -EOPNOTSUPP;
164}
165#endif /* CONFIG_RPMB */
166
167#endif /* __RPMB_H__ */