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 */
37enum {
38 FWCTL_CMD_BASE = 0,
39 FWCTL_CMD_INFO = 0,
40 FWCTL_CMD_RPC = 1,
41};
42
43enum 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 */
64struct 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 */
78enum 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 */
131struct 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

source code of linux/include/uapi/fwctl/fwctl.h