xref: /openbmc/linux/include/uapi/linux/psp-dbc.h (revision e2cfe05e)
1 /* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
2 /*
3  * Userspace interface for AMD Dynamic Boost Control (DBC)
4  *
5  * Copyright (C) 2023 Advanced Micro Devices, Inc.
6  *
7  * Author: Mario Limonciello <mario.limonciello@amd.com>
8  */
9 
10 #ifndef __PSP_DBC_USER_H__
11 #define __PSP_DBC_USER_H__
12 
13 #include <linux/types.h>
14 
15 /**
16  * DOC: AMD Dynamic Boost Control (DBC) interface
17  */
18 
19 #define DBC_NONCE_SIZE		16
20 #define DBC_SIG_SIZE		32
21 #define DBC_UID_SIZE		16
22 
23 /**
24  * struct dbc_user_nonce - Nonce exchange structure (input/output).
25  * @auth_needed: Whether the PSP should authenticate this request (input).
26  *               0: no authentication, PSP will return single use nonce.
27  *               1: authentication: PSP will return multi-use nonce.
28  * @nonce:       8 byte value used for future authentication (output).
29  * @signature:   Optional 32 byte signature created by software using a
30  *               previous nonce (input).
31  */
32 struct dbc_user_nonce {
33 	__u32	auth_needed;
34 	__u8	nonce[DBC_NONCE_SIZE];
35 	__u8	signature[DBC_SIG_SIZE];
36 } __packed;
37 
38 /**
39  * struct dbc_user_setuid - UID exchange structure (input).
40  * @uid:       16 byte value representing software identity
41  * @signature: 32 byte signature created by software using a previous nonce
42  */
43 struct dbc_user_setuid {
44 	__u8	uid[DBC_UID_SIZE];
45 	__u8	signature[DBC_SIG_SIZE];
46 } __packed;
47 
48 /**
49  * struct dbc_user_param - Parameter exchange structure (input/output).
50  * @msg_index: Message indicating what parameter to set or get (input)
51  * @param:     4 byte parameter, units are message specific. (input/output)
52  * @signature: 32 byte signature.
53  *             - When sending a message this is to be created by software
54  *               using a previous nonce (input)
55  *             - For interpreting results, this signature is updated by the
56  *               PSP to allow software to validate the authenticity of the
57  *               results.
58  */
59 struct dbc_user_param {
60 	__u32	msg_index;
61 	__u32	param;
62 	__u8	signature[DBC_SIG_SIZE];
63 } __packed;
64 
65 /**
66  * Dynamic Boost Control (DBC) IOC
67  *
68  * possible return codes for all DBC IOCTLs:
69  *  0:          success
70  *  -EINVAL:    invalid input
71  *  -E2BIG:     excess data passed
72  *  -EFAULT:    failed to copy to/from userspace
73  *  -EBUSY:     mailbox in recovery or in use
74  *  -ENODEV:    driver not bound with PSP device
75  *  -EACCES:    request isn't authorized
76  *  -EINVAL:    invalid parameter
77  *  -ETIMEDOUT: request timed out
78  *  -EAGAIN:    invalid request for state machine
79  *  -ENOENT:    not implemented
80  *  -ENFILE:    overflow
81  *  -EPERM:     invalid signature
82  *  -EIO:       unknown error
83  */
84 #define DBC_IOC_TYPE	'D'
85 
86 /**
87  * DBCIOCNONCE - Fetch a nonce from the PSP for authenticating commands.
88  *               If a nonce is fetched without authentication it can only
89  *               be utilized for one command.
90  *               If a nonce is fetched with authentication it can be used
91  *               for multiple requests.
92  */
93 #define DBCIOCNONCE	_IOWR(DBC_IOC_TYPE, 0x1, struct dbc_user_nonce)
94 
95 /**
96  * DBCIOCUID - Set the user ID (UID) of a calling process.
97  *             The user ID is 8 bytes long. It must be programmed using a
98  *             32 byte signature built using the nonce fetched from
99  *             DBCIOCNONCE.
100  *             The UID can only be set once until the system is rebooted.
101  */
102 #define DBCIOCUID	_IOW(DBC_IOC_TYPE, 0x2, struct dbc_user_setuid)
103 
104 /**
105  * DBCIOCPARAM - Set or get a parameter from the PSP.
106  *               This request will only work after DBCIOCUID has successfully
107  *               set the UID of the calling process.
108  *               Whether the parameter is set or get is controlled by the
109  *               message ID in the request.
110  *               This command must be sent using a 32 byte signature built
111  *               using the nonce fetched from DBCIOCNONCE.
112  *               When the command succeeds, the 32 byte signature will be
113  *               updated by the PSP for software to authenticate the results.
114  */
115 #define DBCIOCPARAM	_IOWR(DBC_IOC_TYPE, 0x3, struct dbc_user_param)
116 
117 /**
118  * enum dbc_cmd_msg - Messages utilized by DBCIOCPARAM
119  * @PARAM_GET_FMAX_CAP:		Get frequency cap (MHz)
120  * @PARAM_SET_FMAX_CAP:		Set frequency cap (MHz)
121  * @PARAM_GET_PWR_CAP:		Get socket power cap (mW)
122  * @PARAM_SET_PWR_CAP:		Set socket power cap (mW)
123  * @PARAM_GET_GFX_MODE:		Get graphics mode (0/1)
124  * @PARAM_SET_GFX_MODE:		Set graphics mode (0/1)
125  * @PARAM_GET_CURR_TEMP:	Get current temperature (degrees C)
126  * @PARAM_GET_FMAX_MAX:		Get maximum allowed value for frequency (MHz)
127  * @PARAM_GET_FMAX_MIN:		Get minimum allowed value for frequency (MHz)
128  * @PARAM_GET_SOC_PWR_MAX:	Get maximum allowed value for SoC power (mw)
129  * @PARAM_GET_SOC_PWR_MIN:	Get minimum allowed value for SoC power (mw)
130  * @PARAM_GET_SOC_PWR_CUR:	Get current value for SoC Power (mW)
131  */
132 enum dbc_cmd_msg {
133 	PARAM_GET_FMAX_CAP	= 0x3,
134 	PARAM_SET_FMAX_CAP	= 0x4,
135 	PARAM_GET_PWR_CAP	= 0x5,
136 	PARAM_SET_PWR_CAP	= 0x6,
137 	PARAM_GET_GFX_MODE	= 0x7,
138 	PARAM_SET_GFX_MODE	= 0x8,
139 	PARAM_GET_CURR_TEMP	= 0x9,
140 	PARAM_GET_FMAX_MAX	= 0xA,
141 	PARAM_GET_FMAX_MIN	= 0xB,
142 	PARAM_GET_SOC_PWR_MAX	= 0xC,
143 	PARAM_GET_SOC_PWR_MIN	= 0xD,
144 	PARAM_GET_SOC_PWR_CUR	= 0xE,
145 };
146 
147 #endif /* __PSP_DBC_USER_H__ */
148