1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
  2/* Copyright (c) 2024-2025, NVIDIA CORPORATION & AFFILIATES.
  3 */
  4#ifndef _FWCTL_H
  5#define _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