xref: /openbmc/linux/include/uapi/linux/user_events.h (revision 2fc3d0ac)
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 /* List of supported registration flags */
21 enum user_reg_flag {
22 	/* Event will not delete upon last reference closing */
23 	USER_EVENT_REG_PERSIST		= 1U << 0,
24 
25 	/* This value or above is currently non-ABI */
26 	USER_EVENT_REG_MAX		= 1U << 1,
27 };
28 
29 /*
30  * Describes an event registration and stores the results of the registration.
31  * This structure is passed to the DIAG_IOCSREG ioctl, callers at a minimum
32  * must set the size and name_args before invocation.
33  */
34 struct user_reg {
35 
36 	/* Input: Size of the user_reg structure being used */
37 	__u32	size;
38 
39 	/* Input: Bit in enable address to use */
40 	__u8	enable_bit;
41 
42 	/* Input: Enable size in bytes at address */
43 	__u8	enable_size;
44 
45 	/* Input: Flags to use, if any */
46 	__u16	flags;
47 
48 	/* Input: Address to update when enabled */
49 	__u64	enable_addr;
50 
51 	/* Input: Pointer to string with event name, description and flags */
52 	__u64	name_args;
53 
54 	/* Output: Index of the event to use when writing data */
55 	__u32	write_index;
56 } __attribute__((__packed__));
57 
58 /*
59  * Describes an event unregister, callers must set the size, address and bit.
60  * This structure is passed to the DIAG_IOCSUNREG ioctl to disable bit updates.
61  */
62 struct user_unreg {
63 	/* Input: Size of the user_unreg structure being used */
64 	__u32	size;
65 
66 	/* Input: Bit to unregister */
67 	__u8	disable_bit;
68 
69 	/* Input: Reserved, set to 0 */
70 	__u8	__reserved;
71 
72 	/* Input: Reserved, set to 0 */
73 	__u16	__reserved2;
74 
75 	/* Input: Address to unregister */
76 	__u64	disable_addr;
77 } __attribute__((__packed__));
78 
79 #define DIAG_IOC_MAGIC '*'
80 
81 /* Request to register a user_event */
82 #define DIAG_IOCSREG _IOWR(DIAG_IOC_MAGIC, 0, struct user_reg *)
83 
84 /* Request to delete a user_event */
85 #define DIAG_IOCSDEL _IOW(DIAG_IOC_MAGIC, 1, char *)
86 
87 /* Requests to unregister a user_event */
88 #define DIAG_IOCSUNREG _IOW(DIAG_IOC_MAGIC, 2, struct user_unreg*)
89 
90 #endif /* _UAPI_LINUX_USER_EVENTS_H */
91