xref: /linux/include/uapi/fwctl/fwctl.h (revision 4f9786035f9e519db41375818e1d0b5f20da2f10)
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_PDS = 4,
48 };
49 
50 /**
51  * struct fwctl_info - ioctl(FWCTL_INFO)
52  * @size: sizeof(struct fwctl_info)
53  * @flags: Must be 0
54  * @out_device_type: Returns the type of the device from enum fwctl_device_type
55  * @device_data_len: On input the length of the out_device_data memory. On
56  *	output the size of the kernel's device_data which may be larger or
57  *	smaller than the input. Maybe 0 on input.
58  * @out_device_data: Pointer to a memory of device_data_len bytes. Kernel will
59  *	fill the entire memory, zeroing as required.
60  *
61  * Returns basic information about this fwctl instance, particularly what driver
62  * is being used to define the device_data format.
63  */
64 struct fwctl_info {
65 	__u32 size;
66 	__u32 flags;
67 	__u32 out_device_type;
68 	__u32 device_data_len;
69 	__aligned_u64 out_device_data;
70 };
71 #define FWCTL_INFO _IO(FWCTL_TYPE, FWCTL_CMD_INFO)
72 
73 /**
74  * enum fwctl_rpc_scope - Scope of access for the RPC
75  *
76  * Refer to fwctl.rst for a more detailed discussion of these scopes.
77  */
78 enum fwctl_rpc_scope {
79 	/**
80 	 * @FWCTL_RPC_CONFIGURATION: Device configuration access scope
81 	 *
82 	 * Read/write access to device configuration. When configuration
83 	 * is written to the device it remains in a fully supported state.
84 	 */
85 	FWCTL_RPC_CONFIGURATION = 0,
86 	/**
87 	 * @FWCTL_RPC_DEBUG_READ_ONLY: Read only access to debug information
88 	 *
89 	 * Readable debug information. Debug information is compatible with
90 	 * kernel lockdown, and does not disclose any sensitive information. For
91 	 * instance exposing any encryption secrets from this information is
92 	 * forbidden.
93 	 */
94 	FWCTL_RPC_DEBUG_READ_ONLY = 1,
95 	/**
96 	 * @FWCTL_RPC_DEBUG_WRITE: Writable access to lockdown compatible debug information
97 	 *
98 	 * Allows write access to data in the device which may leave a fully
99 	 * supported state. This is intended to permit intensive and possibly
100 	 * invasive debugging. This scope will taint the kernel.
101 	 */
102 	FWCTL_RPC_DEBUG_WRITE = 2,
103 	/**
104 	 * @FWCTL_RPC_DEBUG_WRITE_FULL: Write access to all debug information
105 	 *
106 	 * Allows read/write access to everything. Requires CAP_SYS_RAW_IO, so
107 	 * it is not required to follow lockdown principals. If in doubt
108 	 * debugging should be placed in this scope. This scope will taint the
109 	 * kernel.
110 	 */
111 	FWCTL_RPC_DEBUG_WRITE_FULL = 3,
112 };
113 
114 /**
115  * struct fwctl_rpc - ioctl(FWCTL_RPC)
116  * @size: sizeof(struct fwctl_rpc)
117  * @scope: One of enum fwctl_rpc_scope, required scope for the RPC
118  * @in_len: Length of the in memory
119  * @out_len: Length of the out memory
120  * @in: Request message in device specific format
121  * @out: Response message in device specific format
122  *
123  * Deliver a Remote Procedure Call to the device FW and return the response. The
124  * call's parameters and return are marshaled into linear buffers of memory. Any
125  * errno indicates that delivery of the RPC to the device failed. Return status
126  * originating in the device during a successful delivery must be encoded into
127  * out.
128  *
129  * The format of the buffers matches the out_device_type from FWCTL_INFO.
130  */
131 struct fwctl_rpc {
132 	__u32 size;
133 	__u32 scope;
134 	__u32 in_len;
135 	__u32 out_len;
136 	__aligned_u64 in;
137 	__aligned_u64 out;
138 };
139 #define FWCTL_RPC _IO(FWCTL_TYPE, FWCTL_CMD_RPC)
140 
141 #endif
142