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1/* SPDX-License-Identifier: MIT */
2/*
3 * Copyright (C) 2019,2021 Advanced Micro Devices, Inc.
4 *
5 * Author: Rijo Thomas <[email protected]>
6 * Author: Devaraj Rangasamy <[email protected]>
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);
114int tee_restore(struct psp_device *psp);
115
116#endif /* __TEE_DEV_H__ */