include/uapi/linux/mmtimer.h

Source file repositories/reference/linux-study-clean/include/uapi/linux/mmtimer.h

File Facts

System
Linux kernel
Corpus path
include/uapi/linux/mmtimer.h
Extension
.h
Size
2117 bytes
Lines
58
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _LINUX_MMTIMER_H
#define _LINUX_MMTIMER_H

/*
 * Breakdown of the ioctl's available.  An 'optional' next to the command
 * indicates that supporting this command is optional, while 'required'
 * commands must be implemented if conformance is desired.
 *
 * MMTIMER_GETOFFSET - optional
 *   Should return the offset (relative to the start of the page where the
 *   registers are mapped) for the counter in question.
 *
 * MMTIMER_GETRES - required
 *   The resolution of the clock in femto (10^-15) seconds
 *
 * MMTIMER_GETFREQ - required
 *   Frequency of the clock in Hz
 *
 * MMTIMER_GETBITS - required
 *   Number of bits in the clock's counter
 *
 * MMTIMER_MMAPAVAIL - required
 *   Returns nonzero if the registers can be mmap'd into userspace, 0 otherwise
 *
 * MMTIMER_GETCOUNTER - required
 *   Gets the current value in the counter
 */
#define MMTIMER_IOCTL_BASE 'm'

#define MMTIMER_GETOFFSET _IO(MMTIMER_IOCTL_BASE, 0)
#define MMTIMER_GETRES _IOR(MMTIMER_IOCTL_BASE, 1, unsigned long)
#define MMTIMER_GETFREQ _IOR(MMTIMER_IOCTL_BASE, 2, unsigned long)
#define MMTIMER_GETBITS _IO(MMTIMER_IOCTL_BASE, 4)
#define MMTIMER_MMAPAVAIL _IO(MMTIMER_IOCTL_BASE, 6)
#define MMTIMER_GETCOUNTER _IOR(MMTIMER_IOCTL_BASE, 9, unsigned long)

#endif /* _LINUX_MMTIMER_H */

Annotation

Implementation Notes