#include <linux/init.h>
#include <linux/smp.h>
#include <linux/types.h>
+#include <linux/timex.h>
+#include <linux/config.h>
#include <asm/uaccess.h>
#include <asm/delay.h>
#include <asm/s390_ext.h>
#include <asm/div64.h>
-
-#include <linux/timex.h>
-#include <linux/config.h>
-
#include <asm/irq.h>
+#ifdef CONFIG_VIRT_TIMER
+#include <asm/timer.h>
+#endif
/* change this if you have some constant time drift */
#define USECS_PER_JIFFY ((unsigned long) 1000000/HZ)
EXPORT_SYMBOL(jiffies_64);
-static ext_int_info_t ext_int_info_timer;
+static ext_int_info_t ext_int_info_cc;
static u64 init_timer_cc;
static u64 jiffies_timer_cc;
static u64 xtime_cc;
extern unsigned long wall_jiffies;
+#ifdef CONFIG_VIRT_TIMER
+#define VTIMER_MAGIC (0x4b87ad6e + 1)
+static ext_int_info_t ext_int_info_timer;
+DEFINE_PER_CPU(struct vtimer_queue, virt_cpu_timer);
+#endif
+
/*
* Scheduler clock - returns current time in nanosec units.
*/
#endif
}
+#ifdef CONFIG_VIRT_TIMER
+void start_cpu_timer(void)
+{
+ struct vtimer_queue *vt_list;
+
+ vt_list = &per_cpu(virt_cpu_timer, smp_processor_id());
+ set_vtimer(vt_list->idle);
+}
+
+int stop_cpu_timer(void)
+{
+ __u64 done;
+ struct vtimer_queue *vt_list;
+
+ vt_list = &per_cpu(virt_cpu_timer, smp_processor_id());
+
+ /* nothing to do */
+ if (list_empty(&vt_list->list)) {
+ vt_list->idle = VTIMER_MAX_SLICE;
+ goto fire;
+ }
+
+ /* store progress */
+ asm volatile ("STPT %0" : "=m" (done));
+
+ /*
+ * If done is negative we do not stop the CPU timer
+ * because we will get instantly an interrupt that
+ * will start the CPU timer again.
+ */
+ if (done & 1LL<<63)
+ return 1;
+ else
+ vt_list->offset += vt_list->to_expire - done;
+
+ /* save the actual expire value */
+ vt_list->idle = done;
+
+ /*
+ * We cannot halt the CPU timer, we just write a value that
+ * nearly never expires (only after 71 years) and re-write
+ * the stored expire value if we continue the timer
+ */
+ fire:
+ set_vtimer(VTIMER_MAX_SLICE);
+ return 0;
+}
+
+void do_monitor_call(struct pt_regs *regs, long interruption_code)
+{
+ /* disable monitor call class 0 */
+ __ctl_clear_bit(8, 15);
+
+ start_cpu_timer();
+}
+
+/*
+ * called from cpu_idle to stop any timers
+ * returns 1 if CPU should not be stopped
+ */
+int stop_timers(void)
+{
+ if (stop_cpu_timer())
+ return 1;
+
+ /* enable monitor call class 0 */
+ __ctl_set_bit(8, 15);
+
+ return 0;
+}
+
+void set_vtimer(__u64 expires)
+{
+ asm volatile ("SPT %0" : : "m" (expires));
+
+ /* store expire time for this CPU timer */
+ per_cpu(virt_cpu_timer, smp_processor_id()).to_expire = expires;
+}
+
+/*
+ * Sorted add to a list. List is linear searched until first bigger
+ * element is found.
+ */
+void list_add_sorted(struct vtimer_list *timer, struct list_head *head)
+{
+ struct vtimer_list *event;
+
+ list_for_each_entry(event, head, entry) {
+ if (event->expires > timer->expires) {
+ list_add_tail(&timer->entry, &event->entry);
+ return;
+ }
+ }
+ list_add_tail(&timer->entry, head);
+}
+
+/*
+ * Do the callback functions of expired vtimer events.
+ * Called from within the interrupt handler.
+ */
+static void do_callbacks(struct list_head *cb_list, struct pt_regs *regs)
+{
+ struct vtimer_queue *vt_list;
+ struct vtimer_list *event, *tmp;
+ void (*fn)(unsigned long, struct pt_regs*);
+ unsigned long data;
+
+ if (list_empty(cb_list))
+ return;
+
+ vt_list = &per_cpu(virt_cpu_timer, smp_processor_id());
+
+ list_for_each_entry_safe(event, tmp, cb_list, entry) {
+ fn = event->function;
+ data = event->data;
+ fn(data, regs);
+
+ if (!event->interval)
+ /* delete one shot timer */
+ list_del_init(&event->entry);
+ else {
+ /* move interval timer back to list */
+ spin_lock(&vt_list->lock);
+ list_del_init(&event->entry);
+ list_add_sorted(event, &vt_list->list);
+ spin_unlock(&vt_list->lock);
+ }
+ }
+}
+
+/*
+ * Handler for the virtual CPU timer.
+ */
+static void do_cpu_timer_interrupt(struct pt_regs *regs, __u16 error_code)
+{
+ int cpu;
+ __u64 next, delta;
+ struct vtimer_queue *vt_list;
+ struct vtimer_list *event, *tmp;
+ struct list_head *ptr;
+ /* the callback queue */
+ struct list_head cb_list;
+
+ INIT_LIST_HEAD(&cb_list);
+ cpu = smp_processor_id();
+ vt_list = &per_cpu(virt_cpu_timer, cpu);
+
+ /* walk timer list, fire all expired events */
+ spin_lock(&vt_list->lock);
+
+ if (vt_list->to_expire < VTIMER_MAX_SLICE)
+ vt_list->offset += vt_list->to_expire;
+
+ list_for_each_entry_safe(event, tmp, &vt_list->list, entry) {
+ if (event->expires > vt_list->offset)
+ /* found first unexpired event, leave */
+ break;
+
+ /* re-charge interval timer, we have to add the offset */
+ if (event->interval)
+ event->expires = event->interval + vt_list->offset;
+
+ /* move expired timer to the callback queue */
+ list_move_tail(&event->entry, &cb_list);
+ }
+ spin_unlock(&vt_list->lock);
+ do_callbacks(&cb_list, regs);
+
+ /* next event is first in list */
+ spin_lock(&vt_list->lock);
+ if (!list_empty(&vt_list->list)) {
+ ptr = vt_list->list.next;
+ event = list_entry(ptr, struct vtimer_list, entry);
+ next = event->expires - vt_list->offset;
+
+ /* add the expired time from this interrupt handler
+ * and the callback functions
+ */
+ asm volatile ("STPT %0" : "=m" (delta));
+ delta = 0xffffffffffffffffLL - delta + 1;
+ vt_list->offset += delta;
+ next -= delta;
+ } else {
+ vt_list->offset = 0;
+ next = VTIMER_MAX_SLICE;
+ }
+ spin_unlock(&vt_list->lock);
+ set_vtimer(next);
+}
+#endif
+
/*
- * Start the clock comparator on the current CPU.
+ * Start the clock comparator and the virtual CPU timer
+ * on the current CPU.
*/
void init_cpu_timer(void)
{
unsigned long cr0;
__u64 timer;
+#ifdef CONFIG_VIRT_TIMER
+ struct vtimer_queue *vt_list;
+#endif
timer = jiffies_timer_cc + jiffies_64 * CLK_TICKS_PER_JIFFY;
S390_lowcore.jiffy_timer = timer + CLK_TICKS_PER_JIFFY;
__ctl_store(cr0, 0, 0);
cr0 |= 0x800;
__ctl_load(cr0, 0, 0);
+
+#ifdef CONFIG_VIRT_TIMER
+ /* kick the virtual timer */
+ timer = VTIMER_MAX_SLICE;
+ asm volatile ("SPT %0" : : "m" (timer));
+ __ctl_store(cr0, 0, 0);
+ cr0 |= 0x400;
+ __ctl_load(cr0, 0, 0);
+
+ vt_list = &per_cpu(virt_cpu_timer, smp_processor_id());
+ INIT_LIST_HEAD(&vt_list->list);
+ spin_lock_init(&vt_list->lock);
+ vt_list->to_expire = 0;
+ vt_list->offset = 0;
+ vt_list->idle = 0;
+#endif
}
/*
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
- /* request the 0x1004 external interrupt */
+ /* request the clock comparator external interrupt */
if (register_early_external_interrupt(0x1004, 0,
- &ext_int_info_timer) != 0)
+ &ext_int_info_cc) != 0)
panic("Couldn't request external interrupt 0x1004");
- /* init CPU timer */
+#ifdef CONFIG_VIRT_TIMER
+ /* request the cpu timer external interrupt */
+ if (register_early_external_interrupt(0x1005, do_cpu_timer_interrupt,
+ &ext_int_info_timer) != 0)
+ panic("Couldn't request external interrupt 0x1005");
+#endif
+
init_cpu_timer();
}
+
+#ifdef CONFIG_VIRT_TIMER
+void init_virt_timer(struct vtimer_list *timer)
+{
+ timer->magic = VTIMER_MAGIC;
+ timer->function = NULL;
+ INIT_LIST_HEAD(&timer->entry);
+ spin_lock_init(&timer->lock);
+}
+
+static inline int check_vtimer(struct vtimer_list *timer)
+{
+ if (timer->magic != VTIMER_MAGIC)
+ return -EINVAL;
+ return 0;
+}
+
+static inline int vtimer_pending(struct vtimer_list *timer)
+{
+ return (!list_empty(&timer->entry));
+}
+
+/*
+ * this function should only run on the specified CPU
+ */
+static void internal_add_vtimer(struct vtimer_list *timer)
+{
+ unsigned long flags;
+ __u64 done;
+ struct vtimer_list *event;
+ struct vtimer_queue *vt_list;
+
+ vt_list = &per_cpu(virt_cpu_timer, timer->cpu);
+ spin_lock_irqsave(&vt_list->lock, flags);
+
+ if (timer->cpu != smp_processor_id())
+ printk("internal_add_vtimer: BUG, running on wrong CPU");
+
+ /* if list is empty we only have to set the timer */
+ if (list_empty(&vt_list->list)) {
+ /* reset the offset, this may happen if the last timer was
+ * just deleted by mod_virt_timer and the interrupt
+ * didn't happen until here
+ */
+ vt_list->offset = 0;
+ goto fire;
+ }
+
+ /* save progress */
+ asm volatile ("STPT %0" : "=m" (done));
+
+ /* calculate completed work */
+ done = vt_list->to_expire - done + vt_list->offset;
+ vt_list->offset = 0;
+
+ list_for_each_entry(event, &vt_list->list, entry)
+ event->expires -= done;
+
+ fire:
+ list_add_sorted(timer, &vt_list->list);
+
+ /* get first element, which is the next vtimer slice */
+ event = list_entry(vt_list->list.next, struct vtimer_list, entry);
+
+ set_vtimer(event->expires);
+ spin_unlock_irqrestore(&vt_list->lock, flags);
+ /* release CPU aquired in prepare_vtimer or mod_virt_timer() */
+ put_cpu();
+}
+
+static inline int prepare_vtimer(struct vtimer_list *timer)
+{
+ if (check_vtimer(timer) || !timer->function) {
+ printk("add_virt_timer: uninitialized timer\n");
+ return -EINVAL;
+ }
+
+ if (!timer->expires || timer->expires > VTIMER_MAX_SLICE) {
+ printk("add_virt_timer: invalid timer expire value!\n");
+ return -EINVAL;
+ }
+
+ if (vtimer_pending(timer)) {
+ printk("add_virt_timer: timer pending\n");
+ return -EBUSY;
+ }
+
+ timer->cpu = get_cpu();
+ return 0;
+}
+
+/*
+ * add_virt_timer - add an oneshot virtual CPU timer
+ */
+void add_virt_timer(void *new)
+{
+ struct vtimer_list *timer;
+
+ timer = (struct vtimer_list *)new;
+
+ if (prepare_vtimer(timer) < 0)
+ return;
+
+ timer->interval = 0;
+ internal_add_vtimer(timer);
+}
+
+/*
+ * add_virt_timer_int - add an interval virtual CPU timer
+ */
+void add_virt_timer_periodic(void *new)
+{
+ struct vtimer_list *timer;
+
+ timer = (struct vtimer_list *)new;
+
+ if (prepare_vtimer(timer) < 0)
+ return;
+
+ timer->interval = timer->expires;
+ internal_add_vtimer(timer);
+}
+
+/*
+ * If we change a pending timer the function must be called on the CPU
+ * where the timer is running on, e.g. by smp_call_function_on()
+ *
+ * The original mod_timer adds the timer if it is not pending. For compatibility
+ * we do the same. The timer will be added on the current CPU as a oneshot timer.
+ *
+ * returns whether it has modified a pending timer (1) or not (0)
+ */
+int mod_virt_timer(struct vtimer_list *timer, __u64 expires)
+{
+ struct vtimer_queue *vt_list;
+ unsigned long flags;
+ int cpu;
+
+ if (check_vtimer(timer) || !timer->function) {
+ printk("mod_virt_timer: uninitialized timer\n");
+ return -EINVAL;
+ }
+
+ if (!expires || expires > VTIMER_MAX_SLICE) {
+ printk("mod_virt_timer: invalid expire range\n");
+ return -EINVAL;
+ }
+
+ /*
+ * This is a common optimization triggered by the
+ * networking code - if the timer is re-modified
+ * to be the same thing then just return:
+ */
+ if (timer->expires == expires && vtimer_pending(timer))
+ return 1;
+
+ cpu = get_cpu();
+ vt_list = &per_cpu(virt_cpu_timer, cpu);
+
+ /* disable interrupts before test if timer is pending */
+ spin_lock_irqsave(&vt_list->lock, flags);
+
+ /* if timer isn't pending add it on the current CPU */
+ if (!vtimer_pending(timer)) {
+ spin_unlock_irqrestore(&vt_list->lock, flags);
+ /* we do not activate an interval timer with mod_virt_timer */
+ timer->interval = 0;
+ timer->expires = expires;
+ timer->cpu = cpu;
+ internal_add_vtimer(timer);
+ return 0;
+ }
+
+ /* check if we run on the right CPU */
+ if (timer->cpu != cpu) {
+ printk("mod_virt_timer: running on wrong CPU, check your code\n");
+ spin_unlock_irqrestore(&vt_list->lock, flags);
+ put_cpu();
+ return -EINVAL;
+ }
+
+ list_del_init(&timer->entry);
+ timer->expires = expires;
+
+ /* also change the interval if we have an interval timer */
+ if (timer->interval)
+ timer->interval = expires;
+
+ /* the timer can't expire anymore so we can release the lock */
+ spin_unlock_irqrestore(&vt_list->lock, flags);
+ internal_add_vtimer(timer);
+ return 1;
+}
+
+/*
+ * delete a virtual timer
+ *
+ * returns whether the deleted timer was pending (1) or not (0)
+ */
+int del_virt_timer(struct vtimer_list *timer)
+{
+ unsigned long flags;
+ struct vtimer_queue *vt_list;
+
+ if (check_vtimer(timer)) {
+ printk("del_virt_timer: timer not initialized\n");
+ return -EINVAL;
+ }
+
+ /* check if timer is pending */
+ if (!vtimer_pending(timer))
+ return 0;
+
+ if (!cpu_online(timer->cpu)) {
+ printk("del_virt_timer: CPU not present!\n");
+ return -1;
+ }
+
+ vt_list = &per_cpu(virt_cpu_timer, timer->cpu);
+ spin_lock_irqsave(&vt_list->lock, flags);
+
+ /* we don't interrupt a running timer, just let it expire! */
+ list_del_init(&timer->entry);
+
+ /* last timer removed */
+ if (list_empty(&vt_list->list)) {
+ vt_list->to_expire = 0;
+ vt_list->offset = 0;
+ }
+
+ spin_unlock_irqrestore(&vt_list->lock, flags);
+ return 1;
+}
+#endif
+
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