xref: /linux/drivers/crypto/ccp/tee-dev.h (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
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  */
30 struct 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  */
45 struct 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 
53 struct 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  */
67 enum 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  */
80 enum 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  */
99 struct 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 
112 int tee_dev_init(struct psp_device *psp);
113 void tee_dev_destroy(struct psp_device *psp);
114 
115 #endif /* __TEE_DEV_H__ */
116