6 files changed, 497 insertions, 14 deletions

diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h
new file mode 100644
index 000000000000..4ea7e7bcfafe
--- /dev/null
+++ b/include/linux/clockchips.h
@@ -0,0 +1,142 @@
+/*  linux/include/linux/clockchips.h
+ *
+ *  This file contains the structure definitions for clockchips.
+ *
+ *  If you are not a clockchip, or the time of day code, you should
+ *  not be including this file!
+ */
+#ifndef _LINUX_CLOCKCHIPS_H
+#define _LINUX_CLOCKCHIPS_H
+
+#ifdef CONFIG_GENERIC_CLOCKEVENTS
+
+#include <linux/clocksource.h>
+#include <linux/cpumask.h>
+#include <linux/ktime.h>
+#include <linux/notifier.h>
+
+struct clock_event_device;
+
+/* Clock event mode commands */
+enum clock_event_mode {
+        CLOCK_EVT_MODE_UNUSED = 0,
+        CLOCK_EVT_MODE_SHUTDOWN,
+        CLOCK_EVT_MODE_PERIODIC,
+        CLOCK_EVT_MODE_ONESHOT,
+};
+
+/* Clock event notification values */
+enum clock_event_nofitiers {
+        CLOCK_EVT_NOTIFY_ADD,
+        CLOCK_EVT_NOTIFY_BROADCAST_ON,
+        CLOCK_EVT_NOTIFY_BROADCAST_OFF,
+        CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
+        CLOCK_EVT_NOTIFY_BROADCAST_EXIT,
+        CLOCK_EVT_NOTIFY_SUSPEND,
+        CLOCK_EVT_NOTIFY_RESUME,
+        CLOCK_EVT_NOTIFY_CPU_DEAD,
+};
+
+/*
+ * Clock event features
+ */
+#define CLOCK_EVT_FEAT_PERIODIC         0x000001
+#define CLOCK_EVT_FEAT_ONESHOT          0x000002
+/*
+ * x86(64) specific misfeatures:
+ *
+ * - Clockevent source stops in C3 State and needs broadcast support.
+ * - Local APIC timer is used as a dummy device.
+ */
+#define CLOCK_EVT_FEAT_C3STOP           0x000004
+#define CLOCK_EVT_FEAT_DUMMY            0x000008
+
+/**
+ * struct clock_event_device - clock event device descriptor
+ * @name:               ptr to clock event name
+ * @hints:              usage hints
+ * @max_delta_ns:       maximum delta value in ns
+ * @min_delta_ns:       minimum delta value in ns
+ * @mult:               nanosecond to cycles multiplier
+ * @shift:              nanoseconds to cycles divisor (power of two)
+ * @rating:             variable to rate clock event devices
+ * @irq:                irq number (only for non cpu local devices)
+ * @cpumask:            cpumask to indicate for which cpus this device works
+ * @set_next_event:     set next event
+ * @set_mode:           set mode function
+ * @evthandler:         Assigned by the framework to be called by the low
+ *                      level handler of the event source
+ * @broadcast:          function to broadcast events
+ * @list:               list head for the management code
+ * @mode:               operating mode assigned by the management code
+ * @next_event:         local storage for the next event in oneshot mode
+ */
+struct clock_event_device {
+        const char              *name;
+        unsigned int            features;
+        unsigned long           max_delta_ns;
+        unsigned long           min_delta_ns;
+        unsigned long           mult;
+        int                     shift;
+        int                     rating;
+        int                     irq;
+        cpumask_t               cpumask;
+        int                     (*set_next_event)(unsigned long evt,
+                                                  struct clock_event_device *);
+        void                    (*set_mode)(enum clock_event_mode mode,
+                                            struct clock_event_device *);
+        void                    (*event_handler)(struct clock_event_device *);
+        void                    (*broadcast)(cpumask_t mask);
+        struct list_head        list;
+        enum clock_event_mode   mode;
+        ktime_t                 next_event;
+};
+
+/*
+ * Calculate a multiplication factor for scaled math, which is used to convert
+ * nanoseconds based values to clock ticks:
+ *
+ * clock_ticks = (nanoseconds * factor) >> shift.
+ *
+ * div_sc is the rearranged equation to calculate a factor from a given clock
+ * ticks / nanoseconds ratio:
+ *
+ * factor = (clock_ticks << shift) / nanoseconds
+ */
+static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec,
+                                   int shift)
+{
+        uint64_t tmp = ((uint64_t)ticks) << shift;
+
+        do_div(tmp, nsec);
+        return (unsigned long) tmp;
+}
+
+/* Clock event layer functions */
+extern unsigned long clockevent_delta2ns(unsigned long latch,
+                                         struct clock_event_device *evt);
+extern void clockevents_register_device(struct clock_event_device *dev);
+
+extern void clockevents_exchange_device(struct clock_event_device *old,
+                                        struct clock_event_device *new);
+extern
+struct clock_event_device *clockevents_request_device(unsigned int features,
+                                                      cpumask_t cpumask);
+extern void clockevents_release_device(struct clock_event_device *dev);
+extern void clockevents_set_mode(struct clock_event_device *dev,
+                                 enum clock_event_mode mode);
+extern int clockevents_register_notifier(struct notifier_block *nb);
+extern void clockevents_unregister_notifier(struct notifier_block *nb);
+extern int clockevents_program_event(struct clock_event_device *dev,
+                                     ktime_t expires, ktime_t now);
+
+extern void clockevents_notify(unsigned long reason, void *arg);
+
+#else
+
+static inline void clockevents_resume_events(void) { }
+#define clockevents_notify(reason, arg) do { } while (0)
+
+#endif
+
+#endif
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 9041405d0b71..a759636fd09f 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -144,6 +144,8 @@ struct hrtimer_cpu_base {
  * is expired in the next softirq when the clock was advanced.
  */
 #define clock_was_set()         do { } while (0)
+extern ktime_t ktime_get(void);
+extern ktime_t ktime_get_real(void);
 
 /* Exported timer functions: */
 
@@ -196,9 +198,6 @@ extern void hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
 /* Soft interrupt function to run the hrtimer queues: */
 extern void hrtimer_run_queues(void);
 
-/* Resume notification */
-void hrtimer_notify_resume(void);
-
 /* Bootup initialization: */
 extern void __init hrtimers_init(void);
 
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index eca0f5593a75..a2310d1bebe1 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -46,7 +46,7 @@
  *
  * returns the time in ktime_t format
  */
-static ktime_t ktime_get(void)
+ktime_t ktime_get(void)
 {
         struct timespec now;
 
@@ -60,7 +60,7 @@ static ktime_t ktime_get(void)
  *
  * returns the time in ktime_t format
  */
-static ktime_t ktime_get_real(void)
+ktime_t ktime_get_real(void)
 {
         struct timespec now;
 
@@ -311,14 +311,6 @@ static unsigned long ktime_divns(const ktime_t kt, s64 div)
 #endif /* BITS_PER_LONG >= 64 */
 
 /*
- * Timekeeping resumed notification
- */
-void hrtimer_notify_resume(void)
-{
-        clock_was_set();
-}
-
-/*
  * Counterpart to lock_timer_base above:
  */
 static inline
@@ -889,6 +881,7 @@ static int __cpuinit hrtimer_cpu_notify(struct notifier_block *self,
 
 #ifdef CONFIG_HOTPLUG_CPU
         case CPU_DEAD:
+                clockevents_notify(CLOCK_EVT_NOTIFY_CPU_DEAD, &cpu);
                 migrate_hrtimers(cpu);
                 break;
 #endif
diff --git a/kernel/time/Makefile b/kernel/time/Makefile
index 61a3907d16fb..2bf1805914d0 100644
--- a/kernel/time/Makefile
+++ b/kernel/time/Makefile
@@ -1 +1,3 @@
 obj-y += ntp.o clocksource.o jiffies.o
+
+obj-$(CONFIG_GENERIC_CLOCKEVENTS) += clockevents.o
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
new file mode 100644
index 000000000000..67932ea78c17
--- /dev/null
+++ b/kernel/time/clockevents.c
@@ -0,0 +1,345 @@
+/*
+ * linux/kernel/time/clockevents.c
+ *
+ * This file contains functions which manage clock event devices.
+ *
+ * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
+ * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
+ * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
+ *
+ * This code is licenced under the GPL version 2. For details see
+ * kernel-base/COPYING.
+ */
+
+#include <linux/clockchips.h>
+#include <linux/hrtimer.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/smp.h>
+#include <linux/sysdev.h>
+
+/* The registered clock event devices */
+static LIST_HEAD(clockevent_devices);
+static LIST_HEAD(clockevents_released);
+
+/* Notification for clock events */
+static RAW_NOTIFIER_HEAD(clockevents_chain);
+
+/* Protection for the above */
+static DEFINE_SPINLOCK(clockevents_lock);
+
+/**
+ * clockevents_delta2ns - Convert a latch value (device ticks) to nanoseconds
+ * @latch:      value to convert
+ * @evt:        pointer to clock event device descriptor
+ *
+ * Math helper, returns latch value converted to nanoseconds (bound checked)
+ */
+unsigned long clockevent_delta2ns(unsigned long latch,
+                                  struct clock_event_device *evt)
+{
+        u64 clc = ((u64) latch << evt->shift);
+
+        do_div(clc, evt->mult);
+        if (clc < 1000)
+                clc = 1000;
+        if (clc > LONG_MAX)
+                clc = LONG_MAX;
+
+        return (unsigned long) clc;
+}
+
+/**
+ * clockevents_set_mode - set the operating mode of a clock event device
+ * @dev:        device to modify
+ * @mode:       new mode
+ *
+ * Must be called with interrupts disabled !
+ */
+void clockevents_set_mode(struct clock_event_device *dev,
+                                 enum clock_event_mode mode)
+{
+        if (dev->mode != mode) {
+                dev->set_mode(mode, dev);
+                dev->mode = mode;
+        }
+}
+
+/**
+ * clockevents_program_event - Reprogram the clock event device.
+ * @expires:    absolute expiry time (monotonic clock)
+ *
+ * Returns 0 on success, -ETIME when the event is in the past.
+ */
+int clockevents_program_event(struct clock_event_device *dev, ktime_t expires,
+                              ktime_t now)
+{
+        unsigned long long clc;
+        int64_t delta;
+
+        delta = ktime_to_ns(ktime_sub(expires, now));
+
+        if (delta <= 0)
+                return -ETIME;
+
+        dev->next_event = expires;
+
+        if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN)
+                return 0;
+
+        if (delta > dev->max_delta_ns)
+                delta = dev->max_delta_ns;
+        if (delta < dev->min_delta_ns)
+                delta = dev->min_delta_ns;
+
+        clc = delta * dev->mult;
+        clc >>= dev->shift;
+
+        return dev->set_next_event((unsigned long) clc, dev);
+}
+
+/**
+ * clockevents_register_notifier - register a clock events change listener
+ */
+int clockevents_register_notifier(struct notifier_block *nb)
+{
+        int ret;
+
+        spin_lock(&clockevents_lock);
+        ret = raw_notifier_chain_register(&clockevents_chain, nb);
+        spin_unlock(&clockevents_lock);
+
+        return ret;
+}
+
+/**
+ * clockevents_unregister_notifier - unregister a clock events change listener
+ */
+void clockevents_unregister_notifier(struct notifier_block *nb)
+{
+        spin_lock(&clockevents_lock);
+        raw_notifier_chain_unregister(&clockevents_chain, nb);
+        spin_unlock(&clockevents_lock);
+}
+
+/*
+ * Notify about a clock event change. Called with clockevents_lock
+ * held.
+ */
+static void clockevents_do_notify(unsigned long reason, void *dev)
+{
+        raw_notifier_call_chain(&clockevents_chain, reason, dev);
+}
+
+/*
+ * Called after a notify add to make devices availble which were
+ * released from the notifier call.
+ */
+static void clockevents_notify_released(void)
+{
+        struct clock_event_device *dev;
+
+        while (!list_empty(&clockevents_released)) {
+                dev = list_entry(clockevents_released.next,
+                                 struct clock_event_device, list);
+                list_del(&dev->list);
+                list_add(&dev->list, &clockevent_devices);
+                clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev);
+        }
+}
+
+/**
+ * clockevents_register_device - register a clock event device
+ * @dev:        device to register
+ */
+void clockevents_register_device(struct clock_event_device *dev)
+{
+        BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
+
+        spin_lock(&clockevents_lock);
+
+        list_add(&dev->list, &clockevent_devices);
+        clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev);
+        clockevents_notify_released();
+
+        spin_unlock(&clockevents_lock);
+}
+
+/*
+ * Noop handler when we shut down an event device
+ */
+static void clockevents_handle_noop(struct clock_event_device *dev)
+{
+}
+
+/**
+ * clockevents_exchange_device - release and request clock devices
+ * @old:        device to release (can be NULL)
+ * @new:        device to request (can be NULL)
+ *
+ * Called from the notifier chain. clockevents_lock is held already
+ */
+void clockevents_exchange_device(struct clock_event_device *old,
+                                 struct clock_event_device *new)
+{
+        unsigned long flags;
+
+        local_irq_save(flags);
+        /*
+         * Caller releases a clock event device. We queue it into the
+         * released list and do a notify add later.
+         */
+        if (old) {
+                old->event_handler = clockevents_handle_noop;
+                clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED);
+                list_del(&old->list);
+                list_add(&old->list, &clockevents_released);
+        }
+
+        if (new) {
+                BUG_ON(new->mode != CLOCK_EVT_MODE_UNUSED);
+                clockevents_set_mode(new, CLOCK_EVT_MODE_SHUTDOWN);
+        }
+        local_irq_restore(flags);
+}
+
+/**
+ * clockevents_request_device
+ */
+struct clock_event_device *clockevents_request_device(unsigned int features,
+                                                      cpumask_t cpumask)
+{
+        struct clock_event_device *cur, *dev = NULL;
+        struct list_head *tmp;
+
+        spin_lock(&clockevents_lock);
+
+        list_for_each(tmp, &clockevent_devices) {
+                cur = list_entry(tmp, struct clock_event_device, list);
+
+                if ((cur->features & features) == features &&
+                    cpus_equal(cpumask, cur->cpumask)) {
+                        if (!dev || dev->rating < cur->rating)
+                                dev = cur;
+                }
+        }
+
+        clockevents_exchange_device(NULL, dev);
+
+        spin_unlock(&clockevents_lock);
+
+        return dev;
+}
+
+/**
+ * clockevents_release_device
+ */
+void clockevents_release_device(struct clock_event_device *dev)
+{
+        spin_lock(&clockevents_lock);
+
+        clockevents_exchange_device(dev, NULL);
+        clockevents_notify_released();
+
+        spin_unlock(&clockevents_lock);
+}
+
+/**
+ * clockevents_notify - notification about relevant events
+ */
+void clockevents_notify(unsigned long reason, void *arg)
+{
+        spin_lock(&clockevents_lock);
+        clockevents_do_notify(reason, arg);
+
+        switch (reason) {
+        case CLOCK_EVT_NOTIFY_CPU_DEAD:
+                /*
+                 * Unregister the clock event devices which were
+                 * released from the users in the notify chain.
+                 */
+                while (!list_empty(&clockevents_released)) {
+                        struct clock_event_device *dev;
+
+                        dev = list_entry(clockevents_released.next,
+                                         struct clock_event_device, list);
+                        list_del(&dev->list);
+                }
+                break;
+        default:
+                break;
+        }
+        spin_unlock(&clockevents_lock);
+}
+EXPORT_SYMBOL_GPL(clockevents_notify);
+
+#ifdef CONFIG_SYSFS
+
+/**
+ * clockevents_show_registered - sysfs interface for listing clockevents
+ * @dev:        unused
+ * @buf:        char buffer to be filled with clock events list
+ *
+ * Provides sysfs interface for listing registered clock event devices
+ */
+static ssize_t clockevents_show_registered(struct sys_device *dev, char *buf)
+{
+        struct list_head *tmp;
+        char *p = buf;
+        int cpu;
+
+        spin_lock(&clockevents_lock);
+
+        list_for_each(tmp, &clockevent_devices) {
+                struct clock_event_device *ce;
+
+                ce = list_entry(tmp, struct clock_event_device, list);
+                p += sprintf(p, "%-20s F:%04x M:%d", ce->name,
+                             ce->features, ce->mode);
+                p += sprintf(p, " C:");
+                if (!cpus_equal(ce->cpumask, cpu_possible_map)) {
+                        for_each_cpu_mask(cpu, ce->cpumask)
+                                p += sprintf(p, " %d", cpu);
+                } else {
+                        /*
+                         * FIXME: Add the cpu which is handling this sucker
+                         */
+                }
+                p += sprintf(p, "\n");
+        }
+
+        spin_unlock(&clockevents_lock);
+
+        return p - buf;
+}
+
+/*
+ * Sysfs setup bits:
+ */
+static SYSDEV_ATTR(registered, 0600,
+                   clockevents_show_registered, NULL);
+
+static struct sysdev_class clockevents_sysclass = {
+        set_kset_name("clockevents"),
+};
+
+static struct sys_device clockevents_sys_device = {
+        .id     = 0,
+        .cls    = &clockevents_sysclass,
+};
+
+static int __init clockevents_sysfs_init(void)
+{
+        int error = sysdev_class_register(&clockevents_sysclass);
+
+        if (!error)
+                error = sysdev_register(&clockevents_sys_device);
+        if (!error)
+                error = sysdev_create_file(
+                                &clockevents_sys_device,
+                                &attr_registered);
+        return error;
+}
+device_initcall(clockevents_sysfs_init);
+#endif
diff --git a/kernel/timer.c b/kernel/timer.c
index 6d843e100e75..7d522bdf8265 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -34,6 +34,7 @@
 #include <linux/cpu.h>
 #include <linux/syscalls.h>
 #include <linux/delay.h>
+#include <linux/clockchips.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -970,7 +971,8 @@ static int timekeeping_resume(struct sys_device *dev)
         write_sequnlock_irqrestore(&xtime_lock, flags);
 
         touch_softlockup_watchdog();
-        hrtimer_notify_resume();
+        /* Resume hrtimers */
+        clock_was_set();
 
         return 0;
 }