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 }; 46 47 /** 48 * struct fwctl_info - ioctl(FWCTL_INFO) 49 * @size: sizeof(struct fwctl_info) 50 * @flags: Must be 0 51 * @out_device_type: Returns the type of the device from enum fwctl_device_type 52 * @device_data_len: On input the length of the out_device_data memory. On 53 * output the size of the kernel's device_data which may be larger or 54 * smaller than the input. Maybe 0 on input. 55 * @out_device_data: Pointer to a memory of device_data_len bytes. Kernel will 56 * fill the entire memory, zeroing as required. 57 * 58 * Returns basic information about this fwctl instance, particularly what driver 59 * is being used to define the device_data format. 60 */ 61 struct fwctl_info { 62 __u32 size; 63 __u32 flags; 64 __u32 out_device_type; 65 __u32 device_data_len; 66 __aligned_u64 out_device_data; 67 }; 68 #define FWCTL_INFO _IO(FWCTL_TYPE, FWCTL_CMD_INFO) 69 70 /** 71 * enum fwctl_rpc_scope - Scope of access for the RPC 72 * 73 * Refer to fwctl.rst for a more detailed discussion of these scopes. 74 */ 75 enum fwctl_rpc_scope { 76 /** 77 * @FWCTL_RPC_CONFIGURATION: Device configuration access scope 78 * 79 * Read/write access to device configuration. When configuration 80 * is written to the device it remains in a fully supported state. 81 */ 82 FWCTL_RPC_CONFIGURATION = 0, 83 /** 84 * @FWCTL_RPC_DEBUG_READ_ONLY: Read only access to debug information 85 * 86 * Readable debug information. Debug information is compatible with 87 * kernel lockdown, and does not disclose any sensitive information. For 88 * instance exposing any encryption secrets from this information is 89 * forbidden. 90 */ 91 FWCTL_RPC_DEBUG_READ_ONLY = 1, 92 /** 93 * @FWCTL_RPC_DEBUG_WRITE: Writable access to lockdown compatible debug information 94 * 95 * Allows write access to data in the device which may leave a fully 96 * supported state. This is intended to permit intensive and possibly 97 * invasive debugging. This scope will taint the kernel. 98 */ 99 FWCTL_RPC_DEBUG_WRITE = 2, 100 /** 101 * @FWCTL_RPC_DEBUG_WRITE_FULL: Write access to all debug information 102 * 103 * Allows read/write access to everything. Requires CAP_SYS_RAW_IO, so 104 * it is not required to follow lockdown principals. If in doubt 105 * debugging should be placed in this scope. This scope will taint the 106 * kernel. 107 */ 108 FWCTL_RPC_DEBUG_WRITE_FULL = 3, 109 }; 110 111 /** 112 * struct fwctl_rpc - ioctl(FWCTL_RPC) 113 * @size: sizeof(struct fwctl_rpc) 114 * @scope: One of enum fwctl_rpc_scope, required scope for the RPC 115 * @in_len: Length of the in memory 116 * @out_len: Length of the out memory 117 * @in: Request message in device specific format 118 * @out: Response message in device specific format 119 * 120 * Deliver a Remote Procedure Call to the device FW and return the response. The 121 * call's parameters and return are marshaled into linear buffers of memory. Any 122 * errno indicates that delivery of the RPC to the device failed. Return status 123 * originating in the device during a successful delivery must be encoded into 124 * out. 125 * 126 * The format of the buffers matches the out_device_type from FWCTL_INFO. 127 */ 128 struct fwctl_rpc { 129 __u32 size; 130 __u32 scope; 131 __u32 in_len; 132 __u32 out_len; 133 __aligned_u64 in; 134 __aligned_u64 out; 135 }; 136 #define FWCTL_RPC _IO(FWCTL_TYPE, FWCTL_CMD_RPC) 137 138 #endif 139