v4.19.13 snapshot.
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
new file mode 100644
index 0000000..3892e9c
--- /dev/null
+++ b/include/linux/hrtimer.h
@@ -0,0 +1,510 @@
+/*
+ * 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/percpu.h>
+#include <linux/timer.h>
+#include <linux/timerqueue.h>
+
+struct hrtimer_clock_base;
+struct hrtimer_cpu_base;
+
+/*
+ * Mode arguments of xxx_hrtimer functions:
+ *
+ * HRTIMER_MODE_ABS - Time value is absolute
+ * HRTIMER_MODE_REL - Time value is relative to now
+ * HRTIMER_MODE_PINNED - Timer is bound to CPU (is only considered
+ * when starting the timer)
+ * HRTIMER_MODE_SOFT - Timer callback function will be executed in
+ * soft irq context
+ */
+enum hrtimer_mode {
+ HRTIMER_MODE_ABS = 0x00,
+ HRTIMER_MODE_REL = 0x01,
+ HRTIMER_MODE_PINNED = 0x02,
+ HRTIMER_MODE_SOFT = 0x04,
+
+ HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS | HRTIMER_MODE_PINNED,
+ HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL | HRTIMER_MODE_PINNED,
+
+ HRTIMER_MODE_ABS_SOFT = HRTIMER_MODE_ABS | HRTIMER_MODE_SOFT,
+ HRTIMER_MODE_REL_SOFT = HRTIMER_MODE_REL | HRTIMER_MODE_SOFT,
+
+ HRTIMER_MODE_ABS_PINNED_SOFT = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_SOFT,
+ HRTIMER_MODE_REL_PINNED_SOFT = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_SOFT,
+
+};
+
+/*
+ * Return values for the callback function
+ */
+enum hrtimer_restart {
+ HRTIMER_NORESTART, /* Timer is not restarted */
+ HRTIMER_RESTART, /* Timer must be restarted */
+};
+
+/*
+ * Values to track state of the timer
+ *
+ * Possible states:
+ *
+ * 0x00 inactive
+ * 0x01 enqueued into rbtree
+ *
+ * The callback state is not part of the timer->state because clearing it would
+ * mean touching the timer after the callback, this makes it impossible to free
+ * the timer from the callback function.
+ *
+ * Therefore we track the callback state in:
+ *
+ * timer->base->cpu_base->running == timer
+ *
+ * On SMP it is possible to have a "callback function running and enqueued"
+ * status. It happens for example when a posix timer expired and the callback
+ * queued a signal. Between dropping the lock which protects the posix timer
+ * and reacquiring the base lock of the hrtimer, another CPU can deliver the
+ * signal and rearm the timer.
+ *
+ * All state transitions are protected by cpu_base->lock.
+ */
+#define HRTIMER_STATE_INACTIVE 0x00
+#define HRTIMER_STATE_ENQUEUED 0x01
+
+/**
+ * struct hrtimer - the basic hrtimer structure
+ * @node: timerqueue node, which also manages node.expires,
+ * the absolute expiry time in the hrtimers internal
+ * representation. The time is related to the clock on
+ * which the timer is based. Is setup by adding
+ * slack to the _softexpires value. For non range timers
+ * identical to _softexpires.
+ * @_softexpires: the absolute earliest expiry time of the hrtimer.
+ * The time which was given as expiry time when the timer
+ * was armed.
+ * @function: timer expiry callback function
+ * @base: pointer to the timer base (per cpu and per clock)
+ * @state: state information (See bit values above)
+ * @is_rel: Set if the timer was armed relative
+ * @is_soft: Set if hrtimer will be expired in soft interrupt context.
+ *
+ * The hrtimer structure must be initialized by hrtimer_init()
+ */
+struct hrtimer {
+ struct timerqueue_node node;
+ ktime_t _softexpires;
+ enum hrtimer_restart (*function)(struct hrtimer *);
+ struct hrtimer_clock_base *base;
+ u8 state;
+ u8 is_rel;
+ u8 is_soft;
+};
+
+/**
+ * struct hrtimer_sleeper - simple sleeper structure
+ * @timer: embedded timer structure
+ * @task: task to wake up
+ *
+ * task is set to NULL, when the timer expires.
+ */
+struct hrtimer_sleeper {
+ struct hrtimer timer;
+ struct task_struct *task;
+};
+
+#ifdef CONFIG_64BIT
+# define __hrtimer_clock_base_align ____cacheline_aligned
+#else
+# define __hrtimer_clock_base_align
+#endif
+
+/**
+ * struct hrtimer_clock_base - the timer base for a specific clock
+ * @cpu_base: per cpu clock base
+ * @index: clock type index for per_cpu support when moving a
+ * timer to a base on another cpu.
+ * @clockid: clock id for per_cpu support
+ * @seq: seqcount around __run_hrtimer
+ * @running: pointer to the currently running hrtimer
+ * @active: red black tree root node for the active timers
+ * @get_time: function to retrieve the current time of the clock
+ * @offset: offset of this clock to the monotonic base
+ */
+struct hrtimer_clock_base {
+ struct hrtimer_cpu_base *cpu_base;
+ unsigned int index;
+ clockid_t clockid;
+ seqcount_t seq;
+ struct hrtimer *running;
+ struct timerqueue_head active;
+ ktime_t (*get_time)(void);
+ ktime_t offset;
+} __hrtimer_clock_base_align;
+
+enum hrtimer_base_type {
+ HRTIMER_BASE_MONOTONIC,
+ HRTIMER_BASE_REALTIME,
+ HRTIMER_BASE_BOOTTIME,
+ HRTIMER_BASE_TAI,
+ HRTIMER_BASE_MONOTONIC_SOFT,
+ HRTIMER_BASE_REALTIME_SOFT,
+ HRTIMER_BASE_BOOTTIME_SOFT,
+ HRTIMER_BASE_TAI_SOFT,
+ HRTIMER_MAX_CLOCK_BASES,
+};
+
+/**
+ * struct hrtimer_cpu_base - the per cpu clock bases
+ * @lock: lock protecting the base and associated clock bases
+ * and timers
+ * @cpu: cpu number
+ * @active_bases: Bitfield to mark bases with active timers
+ * @clock_was_set_seq: Sequence counter of clock was set events
+ * @hres_active: State of high resolution mode
+ * @in_hrtirq: hrtimer_interrupt() is currently executing
+ * @hang_detected: The last hrtimer interrupt detected a hang
+ * @softirq_activated: displays, if the softirq is raised - update of softirq
+ * related settings is not required then.
+ * @nr_events: Total number of hrtimer interrupt events
+ * @nr_retries: Total number of hrtimer interrupt retries
+ * @nr_hangs: Total number of hrtimer interrupt hangs
+ * @max_hang_time: Maximum time spent in hrtimer_interrupt
+ * @expires_next: absolute time of the next event, is required for remote
+ * hrtimer enqueue; it is the total first expiry time (hard
+ * and soft hrtimer are taken into account)
+ * @next_timer: Pointer to the first expiring timer
+ * @softirq_expires_next: Time to check, if soft queues needs also to be expired
+ * @softirq_next_timer: Pointer to the first expiring softirq based timer
+ * @clock_base: array of clock bases for this cpu
+ *
+ * Note: next_timer is just an optimization for __remove_hrtimer().
+ * Do not dereference the pointer because it is not reliable on
+ * cross cpu removals.
+ */
+struct hrtimer_cpu_base {
+ raw_spinlock_t lock;
+ unsigned int cpu;
+ unsigned int active_bases;
+ unsigned int clock_was_set_seq;
+ unsigned int hres_active : 1,
+ in_hrtirq : 1,
+ hang_detected : 1,
+ softirq_activated : 1;
+#ifdef CONFIG_HIGH_RES_TIMERS
+ unsigned int nr_events;
+ unsigned short nr_retries;
+ unsigned short nr_hangs;
+ unsigned int max_hang_time;
+#endif
+ ktime_t expires_next;
+ struct hrtimer *next_timer;
+ ktime_t softirq_expires_next;
+ struct hrtimer *softirq_next_timer;
+ struct hrtimer_clock_base clock_base[HRTIMER_MAX_CLOCK_BASES];
+} ____cacheline_aligned;
+
+static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)
+{
+ timer->node.expires = time;
+ timer->_softexpires = time;
+}
+
+static inline void hrtimer_set_expires_range(struct hrtimer *timer, ktime_t time, ktime_t delta)
+{
+ timer->_softexpires = time;
+ timer->node.expires = ktime_add_safe(time, delta);
+}
+
+static inline void hrtimer_set_expires_range_ns(struct hrtimer *timer, ktime_t time, u64 delta)
+{
+ timer->_softexpires = time;
+ timer->node.expires = ktime_add_safe(time, ns_to_ktime(delta));
+}
+
+static inline void hrtimer_set_expires_tv64(struct hrtimer *timer, s64 tv64)
+{
+ timer->node.expires = tv64;
+ timer->_softexpires = tv64;
+}
+
+static inline void hrtimer_add_expires(struct hrtimer *timer, ktime_t time)
+{
+ timer->node.expires = ktime_add_safe(timer->node.expires, time);
+ timer->_softexpires = ktime_add_safe(timer->_softexpires, time);
+}
+
+static inline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 ns)
+{
+ timer->node.expires = ktime_add_ns(timer->node.expires, ns);
+ timer->_softexpires = ktime_add_ns(timer->_softexpires, ns);
+}
+
+static inline ktime_t hrtimer_get_expires(const struct hrtimer *timer)
+{
+ return timer->node.expires;
+}
+
+static inline ktime_t hrtimer_get_softexpires(const struct hrtimer *timer)
+{
+ return timer->_softexpires;
+}
+
+static inline s64 hrtimer_get_expires_tv64(const struct hrtimer *timer)
+{
+ return timer->node.expires;
+}
+static inline s64 hrtimer_get_softexpires_tv64(const struct hrtimer *timer)
+{
+ return timer->_softexpires;
+}
+
+static inline s64 hrtimer_get_expires_ns(const struct hrtimer *timer)
+{
+ return ktime_to_ns(timer->node.expires);
+}
+
+static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer)
+{
+ return ktime_sub(timer->node.expires, timer->base->get_time());
+}
+
+static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
+{
+ return timer->base->get_time();
+}
+
+static inline int hrtimer_is_hres_active(struct hrtimer *timer)
+{
+ return IS_ENABLED(CONFIG_HIGH_RES_TIMERS) ?
+ timer->base->cpu_base->hres_active : 0;
+}
+
+#ifdef CONFIG_HIGH_RES_TIMERS
+struct clock_event_device;
+
+extern void hrtimer_interrupt(struct clock_event_device *dev);
+
+/*
+ * The resolution of the clocks. The resolution value is returned in
+ * the clock_getres() system call to give application programmers an
+ * idea of the (in)accuracy of timers. Timer values are rounded up to
+ * this resolution values.
+ */
+# define HIGH_RES_NSEC 1
+# define KTIME_HIGH_RES (HIGH_RES_NSEC)
+# define MONOTONIC_RES_NSEC HIGH_RES_NSEC
+# define KTIME_MONOTONIC_RES KTIME_HIGH_RES
+
+extern void clock_was_set_delayed(void);
+
+extern unsigned int hrtimer_resolution;
+
+#else
+
+# define MONOTONIC_RES_NSEC LOW_RES_NSEC
+# define KTIME_MONOTONIC_RES KTIME_LOW_RES
+
+#define hrtimer_resolution (unsigned int)LOW_RES_NSEC
+
+static inline void clock_was_set_delayed(void) { }
+
+#endif
+
+static inline ktime_t
+__hrtimer_expires_remaining_adjusted(const struct hrtimer *timer, ktime_t now)
+{
+ ktime_t rem = ktime_sub(timer->node.expires, now);
+
+ /*
+ * Adjust relative timers for the extra we added in
+ * hrtimer_start_range_ns() to prevent short timeouts.
+ */
+ if (IS_ENABLED(CONFIG_TIME_LOW_RES) && timer->is_rel)
+ rem -= hrtimer_resolution;
+ return rem;
+}
+
+static inline ktime_t
+hrtimer_expires_remaining_adjusted(const struct hrtimer *timer)
+{
+ return __hrtimer_expires_remaining_adjusted(timer,
+ timer->base->get_time());
+}
+
+extern void clock_was_set(void);
+#ifdef CONFIG_TIMERFD
+extern void timerfd_clock_was_set(void);
+#else
+static inline void timerfd_clock_was_set(void) { }
+#endif
+extern void hrtimers_resume(void);
+
+DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
+
+
+/* Exported timer functions: */
+
+/* Initialize timers: */
+extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
+ enum hrtimer_mode mode);
+
+#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
+extern void hrtimer_init_on_stack(struct hrtimer *timer, clockid_t which_clock,
+ enum hrtimer_mode mode);
+
+extern void destroy_hrtimer_on_stack(struct hrtimer *timer);
+#else
+static inline void hrtimer_init_on_stack(struct hrtimer *timer,
+ clockid_t which_clock,
+ enum hrtimer_mode mode)
+{
+ hrtimer_init(timer, which_clock, mode);
+}
+static inline void destroy_hrtimer_on_stack(struct hrtimer *timer) { }
+#endif
+
+/* Basic timer operations: */
+extern void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
+ u64 range_ns, const enum hrtimer_mode mode);
+
+/**
+ * hrtimer_start - (re)start an hrtimer
+ * @timer: the timer to be added
+ * @tim: expiry time
+ * @mode: timer mode: absolute (HRTIMER_MODE_ABS) or
+ * relative (HRTIMER_MODE_REL), and pinned (HRTIMER_MODE_PINNED);
+ * softirq based mode is considered for debug purpose only!
+ */
+static inline void hrtimer_start(struct hrtimer *timer, ktime_t tim,
+ const enum hrtimer_mode mode)
+{
+ hrtimer_start_range_ns(timer, tim, 0, mode);
+}
+
+extern int hrtimer_cancel(struct hrtimer *timer);
+extern int hrtimer_try_to_cancel(struct hrtimer *timer);
+
+static inline void hrtimer_start_expires(struct hrtimer *timer,
+ enum hrtimer_mode mode)
+{
+ u64 delta;
+ ktime_t soft, hard;
+ soft = hrtimer_get_softexpires(timer);
+ hard = hrtimer_get_expires(timer);
+ delta = ktime_to_ns(ktime_sub(hard, soft));
+ hrtimer_start_range_ns(timer, soft, delta, mode);
+}
+
+static inline void hrtimer_restart(struct hrtimer *timer)
+{
+ hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
+}
+
+/* Query timers: */
+extern ktime_t __hrtimer_get_remaining(const struct hrtimer *timer, bool adjust);
+
+static inline ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
+{
+ return __hrtimer_get_remaining(timer, false);
+}
+
+extern u64 hrtimer_get_next_event(void);
+extern u64 hrtimer_next_event_without(const struct hrtimer *exclude);
+
+extern bool hrtimer_active(const struct hrtimer *timer);
+
+/*
+ * Helper function to check, whether the timer is on one of the queues
+ */
+static inline int hrtimer_is_queued(struct hrtimer *timer)
+{
+ return timer->state & HRTIMER_STATE_ENQUEUED;
+}
+
+/*
+ * Helper function to check, whether the timer is running the callback
+ * function
+ */
+static inline int hrtimer_callback_running(struct hrtimer *timer)
+{
+ return timer->base->running == timer;
+}
+
+/* Forward a hrtimer so it expires after now: */
+extern u64
+hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval);
+
+/**
+ * hrtimer_forward_now - forward the timer expiry so it expires after now
+ * @timer: hrtimer to forward
+ * @interval: the interval to forward
+ *
+ * Forward the timer expiry so it will expire after the current time
+ * of the hrtimer clock base. Returns the number of overruns.
+ *
+ * Can be safely called from the callback function of @timer. If
+ * called from other contexts @timer must neither be enqueued nor
+ * running the callback and the caller needs to take care of
+ * serialization.
+ *
+ * Note: This only updates the timer expiry value and does not requeue
+ * the timer.
+ */
+static inline u64 hrtimer_forward_now(struct hrtimer *timer,
+ ktime_t interval)
+{
+ return hrtimer_forward(timer, timer->base->get_time(), interval);
+}
+
+/* Precise sleep: */
+
+extern int nanosleep_copyout(struct restart_block *, struct timespec64 *);
+extern long hrtimer_nanosleep(const struct timespec64 *rqtp,
+ const enum hrtimer_mode mode,
+ const clockid_t clockid);
+
+extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
+ struct task_struct *tsk);
+
+extern int schedule_hrtimeout_range(ktime_t *expires, u64 delta,
+ const enum hrtimer_mode mode);
+extern int schedule_hrtimeout_range_clock(ktime_t *expires,
+ u64 delta,
+ const enum hrtimer_mode mode,
+ clockid_t clock_id);
+extern int schedule_hrtimeout(ktime_t *expires, const enum hrtimer_mode mode);
+
+/* Soft interrupt function to run the hrtimer queues: */
+extern void hrtimer_run_queues(void);
+
+/* Bootup initialization: */
+extern void __init hrtimers_init(void);
+
+/* Show pending timers: */
+extern void sysrq_timer_list_show(void);
+
+int hrtimers_prepare_cpu(unsigned int cpu);
+#ifdef CONFIG_HOTPLUG_CPU
+int hrtimers_dead_cpu(unsigned int cpu);
+#else
+#define hrtimers_dead_cpu NULL
+#endif
+
+#endif