xref: /linux/include/uapi/fwctl/fwctl.h (revision 52929c21420412b74858ee4ce71480ff9f398019)
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 };
47 
48 /**
49  * struct fwctl_info - ioctl(FWCTL_INFO)
50  * @size: sizeof(struct fwctl_info)
51  * @flags: Must be 0
52  * @out_device_type: Returns the type of the device from enum fwctl_device_type
53  * @device_data_len: On input the length of the out_device_data memory. On
54  *	output the size of the kernel's device_data which may be larger or
55  *	smaller than the input. Maybe 0 on input.
56  * @out_device_data: Pointer to a memory of device_data_len bytes. Kernel will
57  *	fill the entire memory, zeroing as required.
58  *
59  * Returns basic information about this fwctl instance, particularly what driver
60  * is being used to define the device_data format.
61  */
62 struct fwctl_info {
63 	__u32 size;
64 	__u32 flags;
65 	__u32 out_device_type;
66 	__u32 device_data_len;
67 	__aligned_u64 out_device_data;
68 };
69 #define FWCTL_INFO _IO(FWCTL_TYPE, FWCTL_CMD_INFO)
70 
71 /**
72  * enum fwctl_rpc_scope - Scope of access for the RPC
73  *
74  * Refer to fwctl.rst for a more detailed discussion of these scopes.
75  */
76 enum fwctl_rpc_scope {
77 	/**
78 	 * @FWCTL_RPC_CONFIGURATION: Device configuration access scope
79 	 *
80 	 * Read/write access to device configuration. When configuration
81 	 * is written to the device it remains in a fully supported state.
82 	 */
83 	FWCTL_RPC_CONFIGURATION = 0,
84 	/**
85 	 * @FWCTL_RPC_DEBUG_READ_ONLY: Read only access to debug information
86 	 *
87 	 * Readable debug information. Debug information is compatible with
88 	 * kernel lockdown, and does not disclose any sensitive information. For
89 	 * instance exposing any encryption secrets from this information is
90 	 * forbidden.
91 	 */
92 	FWCTL_RPC_DEBUG_READ_ONLY = 1,
93 	/**
94 	 * @FWCTL_RPC_DEBUG_WRITE: Writable access to lockdown compatible debug information
95 	 *
96 	 * Allows write access to data in the device which may leave a fully
97 	 * supported state. This is intended to permit intensive and possibly
98 	 * invasive debugging. This scope will taint the kernel.
99 	 */
100 	FWCTL_RPC_DEBUG_WRITE = 2,
101 	/**
102 	 * @FWCTL_RPC_DEBUG_WRITE_FULL: Write access to all debug information
103 	 *
104 	 * Allows read/write access to everything. Requires CAP_SYS_RAW_IO, so
105 	 * it is not required to follow lockdown principals. If in doubt
106 	 * debugging should be placed in this scope. This scope will taint the
107 	 * kernel.
108 	 */
109 	FWCTL_RPC_DEBUG_WRITE_FULL = 3,
110 };
111 
112 /**
113  * struct fwctl_rpc - ioctl(FWCTL_RPC)
114  * @size: sizeof(struct fwctl_rpc)
115  * @scope: One of enum fwctl_rpc_scope, required scope for the RPC
116  * @in_len: Length of the in memory
117  * @out_len: Length of the out memory
118  * @in: Request message in device specific format
119  * @out: Response message in device specific format
120  *
121  * Deliver a Remote Procedure Call to the device FW and return the response. The
122  * call's parameters and return are marshaled into linear buffers of memory. Any
123  * errno indicates that delivery of the RPC to the device failed. Return status
124  * originating in the device during a successful delivery must be encoded into
125  * out.
126  *
127  * The format of the buffers matches the out_device_type from FWCTL_INFO.
128  */
129 struct fwctl_rpc {
130 	__u32 size;
131 	__u32 scope;
132 	__u32 in_len;
133 	__u32 out_len;
134 	__aligned_u64 in;
135 	__aligned_u64 out;
136 };
137 #define FWCTL_RPC _IO(FWCTL_TYPE, FWCTL_CMD_RPC)
138 
139 #endif
140