include/uapi/linux/counter.h

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

File Facts

System
Linux kernel
Corpus path
include/uapi/linux/counter.h
Extension
.h
Size
4970 bytes
Lines
173
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

struct counter_component {
	__u8 type;
	__u8 scope;
	__u8 parent;
	__u8 id;
};

/* Event type definitions */
enum counter_event_type {
	/* Count value increased past ceiling */
	COUNTER_EVENT_OVERFLOW,
	/* Count value decreased past floor */
	COUNTER_EVENT_UNDERFLOW,
	/* Count value increased past ceiling, or decreased past floor */
	COUNTER_EVENT_OVERFLOW_UNDERFLOW,
	/* Count value reached threshold */
	COUNTER_EVENT_THRESHOLD,
	/* Index signal detected */
	COUNTER_EVENT_INDEX,
	/* State of counter is changed */
	COUNTER_EVENT_CHANGE_OF_STATE,
	/* Count value captured */
	COUNTER_EVENT_CAPTURE,
	/* Direction change detected */
	COUNTER_EVENT_DIRECTION_CHANGE,
};

/**
 * struct counter_watch - Counter component watch configuration
 * @component: component to watch when event triggers
 * @event: event that triggers (one of enum counter_event_type)
 * @channel: event channel (typically 0 unless the device supports concurrent
 *	     events of the same type)
 */
struct counter_watch {
	struct counter_component component;
	__u8 event;
	__u8 channel;
};

/*
 * Queues a Counter watch for the specified event.
 *
 * The queued watches will not be applied until COUNTER_ENABLE_EVENTS_IOCTL is
 * called.
 */
#define COUNTER_ADD_WATCH_IOCTL _IOW(0x3E, 0x00, struct counter_watch)
/*
 * Enables monitoring the events specified by the Counter watches that were
 * queued by COUNTER_ADD_WATCH_IOCTL.
 *
 * If events are already enabled, the new set of watches replaces the old one.
 * Calling this ioctl also has the effect of clearing the queue of watches added
 * by COUNTER_ADD_WATCH_IOCTL.
 */
#define COUNTER_ENABLE_EVENTS_IOCTL _IO(0x3E, 0x01)
/*
 * Stops monitoring the previously enabled events.
 */
#define COUNTER_DISABLE_EVENTS_IOCTL _IO(0x3E, 0x02)

/**
 * struct counter_event - Counter event data
 * @timestamp: best estimate of time of event occurrence, in nanoseconds
 * @value: component value
 * @watch: component watch configuration
 * @status: return status (system error number)
 */
struct counter_event {
	__aligned_u64 timestamp;
	__aligned_u64 value;
	struct counter_watch watch;
	__u8 status;
};

/* Count direction values */
enum counter_count_direction {
	COUNTER_COUNT_DIRECTION_FORWARD,
	COUNTER_COUNT_DIRECTION_BACKWARD,
};

/* Count mode values */
enum counter_count_mode {
	COUNTER_COUNT_MODE_NORMAL,
	COUNTER_COUNT_MODE_RANGE_LIMIT,
	COUNTER_COUNT_MODE_NON_RECYCLE,
	COUNTER_COUNT_MODE_MODULO_N,
	COUNTER_COUNT_MODE_INTERRUPT_ON_TERMINAL_COUNT,
	COUNTER_COUNT_MODE_HARDWARE_RETRIGGERABLE_ONESHOT,
	COUNTER_COUNT_MODE_RATE_GENERATOR,

Annotation

Implementation Notes