1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2/*
3 * Copyright (c) 2021-2022, Microsoft Corporation.
4 *
5 * Authors:
6 *   Beau Belgrave <beaub@linux.microsoft.com>
7 */
8#ifndef _UAPI_LINUX_USER_EVENTS_H
9#define _UAPI_LINUX_USER_EVENTS_H
10
11#include <linux/types.h>
12#include <linux/ioctl.h>
13
14#define USER_EVENTS_SYSTEM "user_events"
15#define USER_EVENTS_MULTI_SYSTEM "user_events_multi"
16#define USER_EVENTS_PREFIX "u:"
17
18/* Create dynamic location entry within a 32-bit value */
19#define DYN_LOC(offset, size) ((size) << 16 | (offset))
20
21/* List of supported registration flags */
22enum user_reg_flag {
23	/* Event will not delete upon last reference closing */
24	USER_EVENT_REG_PERSIST		= 1U << 0,
25
26	/* Event will be allowed to have multiple formats */
27	USER_EVENT_REG_MULTI_FORMAT	= 1U << 1,
28
29	/* This value or above is currently non-ABI */
30	USER_EVENT_REG_MAX		= 1U << 2,
31};
32
33/*
34 * Describes an event registration and stores the results of the registration.
35 * This structure is passed to the DIAG_IOCSREG ioctl, callers at a minimum
36 * must set the size and name_args before invocation.
37 */
38struct user_reg {
39
40	/* Input: Size of the user_reg structure being used */
41	__u32	size;
42
43	/* Input: Bit in enable address to use */
44	__u8	enable_bit;
45
46	/* Input: Enable size in bytes at address */
47	__u8	enable_size;
48
49	/* Input: Flags to use, if any */
50	__u16	flags;
51
52	/* Input: Address to update when enabled */
53	__u64	enable_addr;
54
55	/* Input: Pointer to string with event name, description and flags */
56	__u64	name_args;
57
58	/* Output: Index of the event to use when writing data */
59	__u32	write_index;
60} __attribute__((__packed__));
61
62/*
63 * Describes an event unregister, callers must set the size, address and bit.
64 * This structure is passed to the DIAG_IOCSUNREG ioctl to disable bit updates.
65 */
66struct user_unreg {
67	/* Input: Size of the user_unreg structure being used */
68	__u32	size;
69
70	/* Input: Bit to unregister */
71	__u8	disable_bit;
72
73	/* Input: Reserved, set to 0 */
74	__u8	__reserved;
75
76	/* Input: Reserved, set to 0 */
77	__u16	__reserved2;
78
79	/* Input: Address to unregister */
80	__u64	disable_addr;
81} __attribute__((__packed__));
82
83#define DIAG_IOC_MAGIC '*'
84
85/* Request to register a user_event */
86#define DIAG_IOCSREG _IOWR(DIAG_IOC_MAGIC, 0, struct user_reg *)
87
88/* Request to delete a user_event */
89#define DIAG_IOCSDEL _IOW(DIAG_IOC_MAGIC, 1, char *)
90
91/* Requests to unregister a user_event */
92#define DIAG_IOCSUNREG _IOW(DIAG_IOC_MAGIC, 2, struct user_unreg*)
93
94#endif /* _UAPI_LINUX_USER_EVENTS_H */
95