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_PREFIX "u:"
16 
17 /* Create dynamic location entry within a 32-bit value */
18 #define DYN_LOC(offset, size) ((size) << 16 | (offset))
19 
20 /*
21  * Describes an event registration and stores the results of the registration.
22  * This structure is passed to the DIAG_IOCSREG ioctl, callers at a minimum
23  * must set the size and name_args before invocation.
24  */
25 struct user_reg {
26 
27 	/* Input: Size of the user_reg structure being used */
28 	__u32	size;
29 
30 	/* Input: Bit in enable address to use */
31 	__u8	enable_bit;
32 
33 	/* Input: Enable size in bytes at address */
34 	__u8	enable_size;
35 
36 	/* Input: Flags for future use, set to 0 */
37 	__u16	flags;
38 
39 	/* Input: Address to update when enabled */
40 	__u64	enable_addr;
41 
42 	/* Input: Pointer to string with event name, description and flags */
43 	__u64	name_args;
44 
45 	/* Output: Index of the event to use when writing data */
46 	__u32	write_index;
47 } __attribute__((__packed__));
48 
49 /*
50  * Describes an event unregister, callers must set the size, address and bit.
51  * This structure is passed to the DIAG_IOCSUNREG ioctl to disable bit updates.
52  */
53 struct user_unreg {
54 	/* Input: Size of the user_unreg structure being used */
55 	__u32	size;
56 
57 	/* Input: Bit to unregister */
58 	__u8	disable_bit;
59 
60 	/* Input: Reserved, set to 0 */
61 	__u8	__reserved;
62 
63 	/* Input: Reserved, set to 0 */
64 	__u16	__reserved2;
65 
66 	/* Input: Address to unregister */
67 	__u64	disable_addr;
68 } __attribute__((__packed__));
69 
70 #define DIAG_IOC_MAGIC '*'
71 
72 /* Request to register a user_event */
73 #define DIAG_IOCSREG _IOWR(DIAG_IOC_MAGIC, 0, struct user_reg *)
74 
75 /* Request to delete a user_event */
76 #define DIAG_IOCSDEL _IOW(DIAG_IOC_MAGIC, 1, char *)
77 
78 /* Requests to unregister a user_event */
79 #define DIAG_IOCSUNREG _IOW(DIAG_IOC_MAGIC, 2, struct user_unreg*)
80 
81 #endif /* _UAPI_LINUX_USER_EVENTS_H */
82