1/* SPDX-License-Identifier: MIT */
2/*
3 * Copyright (C) 2019,2021 Advanced Micro Devices, Inc.
4 *
5 * Author: Rijo Thomas <Rijo-john.Thomas@amd.com>
6 * Author: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
7 *
8 */
9
10/* This file describes the TEE communication interface between host and AMD
11 * Secure Processor
12 */
13
14#ifndef __TEE_DEV_H__
15#define __TEE_DEV_H__
16
17#include <linux/device.h>
18#include <linux/mutex.h>
19
20#define TEE_DEFAULT_CMD_TIMEOUT		(10 * MSEC_PER_SEC)
21#define TEE_DEFAULT_RING_TIMEOUT	10
22#define MAX_BUFFER_SIZE			988
23
24/**
25 * struct tee_init_ring_cmd - Command to init TEE ring buffer
26 * @low_addr:  bits [31:0] of the physical address of ring buffer
27 * @hi_addr:   bits [63:32] of the physical address of ring buffer
28 * @size:      size of ring buffer in bytes
29 */
30struct tee_init_ring_cmd {
31	u32 low_addr;
32	u32 hi_addr;
33	u32 size;
34};
35
36#define MAX_RING_BUFFER_ENTRIES		32
37
38/**
39 * struct ring_buf_manager - Helper structure to manage ring buffer.
40 * @ring_start:  starting address of ring buffer
41 * @ring_size:   size of ring buffer in bytes
42 * @ring_pa:     physical address of ring buffer
43 * @wptr:        index to the last written entry in ring buffer
44 */
45struct ring_buf_manager {
46	struct mutex mutex;	/* synchronizes access to ring buffer */
47	void *ring_start;
48	u32 ring_size;
49	phys_addr_t ring_pa;
50	u32 wptr;
51};
52
53struct psp_tee_device {
54	struct device *dev;
55	struct psp_device *psp;
56	void __iomem *io_regs;
57	struct tee_vdata *vdata;
58	struct ring_buf_manager rb_mgr;
59};
60
61/**
62 * enum tee_cmd_state - TEE command states for the ring buffer interface
63 * @TEE_CMD_STATE_INIT:      initial state of command when sent from host
64 * @TEE_CMD_STATE_PROCESS:   command being processed by TEE environment
65 * @TEE_CMD_STATE_COMPLETED: command processing completed
66 */
67enum tee_cmd_state {
68	TEE_CMD_STATE_INIT,
69	TEE_CMD_STATE_PROCESS,
70	TEE_CMD_STATE_COMPLETED,
71};
72
73/**
74 * enum cmd_resp_state - TEE command's response status maintained by driver
75 * @CMD_RESPONSE_INVALID:      initial state when no command is written to ring
76 * @CMD_WAITING_FOR_RESPONSE:  driver waiting for response from TEE
77 * @CMD_RESPONSE_TIMEDOUT:     failed to get response from TEE
78 * @CMD_RESPONSE_COPIED:       driver has copied response from TEE
79 */
80enum cmd_resp_state {
81	CMD_RESPONSE_INVALID,
82	CMD_WAITING_FOR_RESPONSE,
83	CMD_RESPONSE_TIMEDOUT,
84	CMD_RESPONSE_COPIED,
85};
86
87/**
88 * struct tee_ring_cmd - Structure of the command buffer in TEE ring
89 * @cmd_id:      refers to &enum tee_cmd_id. Command id for the ring buffer
90 *               interface
91 * @cmd_state:   refers to &enum tee_cmd_state
92 * @status:      status of TEE command execution
93 * @res0:        reserved region
94 * @pdata:       private data (currently unused)
95 * @res1:        reserved region
96 * @buf:         TEE command specific buffer
97 * @flag:	 refers to &enum cmd_resp_state
98 */
99struct tee_ring_cmd {
100	u32 cmd_id;
101	u32 cmd_state;
102	u32 status;
103	u32 res0[1];
104	u64 pdata;
105	u32 res1[2];
106	u8 buf[MAX_BUFFER_SIZE];
107	u32 flag;
108
109	/* Total size: 1024 bytes */
110} __packed;
111
112int tee_dev_init(struct psp_device *psp);
113void tee_dev_destroy(struct psp_device *psp);
114
115#endif /* __TEE_DEV_H__ */
116