include/uapi/linux/user_events.h

   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 */
  22 enum 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  */
  38 struct 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  */
  66 struct 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 */