[PATCH] hrtimer: hrtimer core code
hrtimer subsystem core. It is initialized at bootup and expired by the timer
interrupt, but is otherwise not utilized by any other subsystem yet.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
new file mode 100644
index 0000000..64f8d55
--- /dev/null
+++ b/include/linux/hrtimer.h
@@ -0,0 +1,130 @@
+/*
+ * include/linux/hrtimer.h
+ *
+ * hrtimers - High-resolution kernel timers
+ *
+ * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
+ * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
+ *
+ * data type definitions, declarations, prototypes
+ *
+ * Started by: Thomas Gleixner and Ingo Molnar
+ *
+ * For licencing details see kernel-base/COPYING
+ */
+#ifndef _LINUX_HRTIMER_H
+#define _LINUX_HRTIMER_H
+
+#include <linux/rbtree.h>
+#include <linux/ktime.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/wait.h>
+
+/*
+ * Mode arguments of xxx_hrtimer functions:
+ */
+enum hrtimer_mode {
+ HRTIMER_ABS, /* Time value is absolute */
+ HRTIMER_REL, /* Time value is relative to now */
+};
+
+enum hrtimer_restart {
+ HRTIMER_NORESTART,
+ HRTIMER_RESTART,
+};
+
+/*
+ * Timer states:
+ */
+enum hrtimer_state {
+ HRTIMER_INACTIVE, /* Timer is inactive */
+ HRTIMER_EXPIRED, /* Timer is expired */
+ HRTIMER_PENDING, /* Timer is pending */
+};
+
+struct hrtimer_base;
+
+/**
+ * struct hrtimer - the basic hrtimer structure
+ *
+ * @node: red black tree node for time ordered insertion
+ * @list: list head for easier access to the time ordered list,
+ * without walking the red black tree.
+ * @expires: the absolute expiry time in the hrtimers internal
+ * representation. The time is related to the clock on
+ * which the timer is based.
+ * @state: state of the timer
+ * @function: timer expiry callback function
+ * @data: argument for the callback function
+ * @base: pointer to the timer base (per cpu and per clock)
+ *
+ * The hrtimer structure must be initialized by init_hrtimer_#CLOCKTYPE()
+ */
+struct hrtimer {
+ struct rb_node node;
+ struct list_head list;
+ ktime_t expires;
+ enum hrtimer_state state;
+ int (*function)(void *);
+ void *data;
+ struct hrtimer_base *base;
+};
+
+/**
+ * struct hrtimer_base - the timer base for a specific clock
+ *
+ * @index: clock type index for per_cpu support when moving a timer
+ * to a base on another cpu.
+ * @lock: lock protecting the base and associated timers
+ * @active: red black tree root node for the active timers
+ * @pending: list of pending timers for simple time ordered access
+ * @resolution: the resolution of the clock, in nanoseconds
+ * @get_time: function to retrieve the current time of the clock
+ * @curr_timer: the timer which is executing a callback right now
+ */
+struct hrtimer_base {
+ clockid_t index;
+ spinlock_t lock;
+ struct rb_root active;
+ struct list_head pending;
+ unsigned long resolution;
+ ktime_t (*get_time)(void);
+ struct hrtimer *curr_timer;
+};
+
+/* Exported timer functions: */
+
+/* Initialize timers: */
+extern void hrtimer_init(struct hrtimer *timer, const clockid_t which_clock);
+extern void hrtimer_rebase(struct hrtimer *timer, const clockid_t which_clock);
+
+
+/* Basic timer operations: */
+extern int hrtimer_start(struct hrtimer *timer, ktime_t tim,
+ const enum hrtimer_mode mode);
+extern int hrtimer_cancel(struct hrtimer *timer);
+extern int hrtimer_try_to_cancel(struct hrtimer *timer);
+
+#define hrtimer_restart(timer) hrtimer_start((timer), (timer)->expires, HRTIMER_ABS)
+
+/* Query timers: */
+extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
+extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);
+
+static inline int hrtimer_active(const struct hrtimer *timer)
+{
+ return timer->state == HRTIMER_PENDING;
+}
+
+/* Forward a hrtimer so it expires after now: */
+extern unsigned long hrtimer_forward(struct hrtimer *timer,
+ const ktime_t interval);
+
+/* Soft interrupt function to run the hrtimer queues: */
+extern void hrtimer_run_queues(void);
+
+/* Bootup initialization: */
+extern void __init hrtimers_init(void);
+
+#endif