xref: /linux/include/uapi/fwctl/fwctl.h (revision e2683c8868d03382da7e1ce8453b543a043066d1)
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 /* Copyright (c) 2024-2025, NVIDIA CORPORATION & AFFILIATES.
3  */
4 #ifndef _UAPI_FWCTL_H
5 #define _UAPI_FWCTL_H
6 
7 #include <linux/types.h>
8 #include <linux/ioctl.h>
9 
10 #define FWCTL_TYPE 0x9A
11 
12 /**
13  * DOC: General ioctl format
14  *
15  * The ioctl interface follows a general format to allow for extensibility. Each
16  * ioctl is passed a structure pointer as the argument providing the size of
17  * the structure in the first u32. The kernel checks that any structure space
18  * beyond what it understands is 0. This allows userspace to use the backward
19  * compatible portion while consistently using the newer, larger, structures.
20  *
21  * ioctls use a standard meaning for common errnos:
22  *
23  *  - ENOTTY: The IOCTL number itself is not supported at all
24  *  - E2BIG: The IOCTL number is supported, but the provided structure has
25  *    non-zero in a part the kernel does not understand.
26  *  - EOPNOTSUPP: The IOCTL number is supported, and the structure is
27  *    understood, however a known field has a value the kernel does not
28  *    understand or support.
29  *  - EINVAL: Everything about the IOCTL was understood, but a field is not
30  *    correct.
31  *  - ENOMEM: Out of memory.
32  *  - ENODEV: The underlying device has been hot-unplugged and the FD is
33  *            orphaned.
34  *
35  * As well as additional errnos, within specific ioctls.
36  */
37 enum {
38 	FWCTL_CMD_BASE = 0,
39 	FWCTL_CMD_INFO = 0,
40 	FWCTL_CMD_RPC = 1,
41 };
42 
43 enum fwctl_device_type {
44 	FWCTL_DEVICE_TYPE_ERROR = 0,
45 	FWCTL_DEVICE_TYPE_MLX5 = 1,
46 	FWCTL_DEVICE_TYPE_CXL = 2,
47 	FWCTL_DEVICE_TYPE_BNXT = 3,
48 	FWCTL_DEVICE_TYPE_PDS = 4,
49 };
50 
51 /**
52  * struct fwctl_info - ioctl(FWCTL_INFO)
53  * @size: sizeof(struct fwctl_info)
54  * @flags: Must be 0
55  * @out_device_type: Returns the type of the device from enum fwctl_device_type
56  * @device_data_len: On input the length of the out_device_data memory. On
57  *	output the size of the kernel's device_data which may be larger or
58  *	smaller than the input. Maybe 0 on input.
59  * @out_device_data: Pointer to a memory of device_data_len bytes. Kernel will
60  *	fill the entire memory, zeroing as required.
61  *
62  * Returns basic information about this fwctl instance, particularly what driver
63  * is being used to define the device_data format.
64  */
65 struct fwctl_info {
66 	__u32 size;
67 	__u32 flags;
68 	__u32 out_device_type;
69 	__u32 device_data_len;
70 	__aligned_u64 out_device_data;
71 };
72 #define FWCTL_INFO _IO(FWCTL_TYPE, FWCTL_CMD_INFO)
73 
74 /**
75  * enum fwctl_rpc_scope - Scope of access for the RPC
76  *
77  * Refer to fwctl.rst for a more detailed discussion of these scopes.
78  */
79 enum fwctl_rpc_scope {
80 	/**
81 	 * @FWCTL_RPC_CONFIGURATION: Device configuration access scope
82 	 *
83 	 * Read/write access to device configuration. When configuration
84 	 * is written to the device it remains in a fully supported state.
85 	 */
86 	FWCTL_RPC_CONFIGURATION = 0,
87 	/**
88 	 * @FWCTL_RPC_DEBUG_READ_ONLY: Read only access to debug information
89 	 *
90 	 * Readable debug information. Debug information is compatible with
91 	 * kernel lockdown, and does not disclose any sensitive information. For
92 	 * instance exposing any encryption secrets from this information is
93 	 * forbidden.
94 	 */
95 	FWCTL_RPC_DEBUG_READ_ONLY = 1,
96 	/**
97 	 * @FWCTL_RPC_DEBUG_WRITE: Writable access to lockdown compatible debug information
98 	 *
99 	 * Allows write access to data in the device which may leave a fully
100 	 * supported state. This is intended to permit intensive and possibly
101 	 * invasive debugging. This scope will taint the kernel.
102 	 */
103 	FWCTL_RPC_DEBUG_WRITE = 2,
104 	/**
105 	 * @FWCTL_RPC_DEBUG_WRITE_FULL: Write access to all debug information
106 	 *
107 	 * Allows read/write access to everything. Requires CAP_SYS_RAW_IO, so
108 	 * it is not required to follow lockdown principals. If in doubt
109 	 * debugging should be placed in this scope. This scope will taint the
110 	 * kernel.
111 	 */
112 	FWCTL_RPC_DEBUG_WRITE_FULL = 3,
113 };
114 
115 /**
116  * struct fwctl_rpc - ioctl(FWCTL_RPC)
117  * @size: sizeof(struct fwctl_rpc)
118  * @scope: One of enum fwctl_rpc_scope, required scope for the RPC
119  * @in_len: Length of the in memory
120  * @out_len: Length of the out memory
121  * @in: Request message in device specific format
122  * @out: Response message in device specific format
123  *
124  * Deliver a Remote Procedure Call to the device FW and return the response. The
125  * call's parameters and return are marshaled into linear buffers of memory. Any
126  * errno indicates that delivery of the RPC to the device failed. Return status
127  * originating in the device during a successful delivery must be encoded into
128  * out.
129  *
130  * The format of the buffers matches the out_device_type from FWCTL_INFO.
131  */
132 struct fwctl_rpc {
133 	__u32 size;
134 	__u32 scope;
135 	__u32 in_len;
136 	__u32 out_len;
137 	__aligned_u64 in;
138 	__aligned_u64 out;
139 };
140 #define FWCTL_RPC _IO(FWCTL_TYPE, FWCTL_CMD_RPC)
141 
142 #endif
143