static int s390_next_event(unsigned long delta,
struct clock_event_device *evt)
{
S390_lowcore.clock_comparator = get_clock() + delta;
set_clock_comparator(S390_lowcore.clock_comparator);
return 0;
}
/*
* Set up per cpu jiffy timer and set the clock comparator.
*/
static void setup_jiffy_timer(void)
{
/* Set up clock comparator to next jiffy. */
S390_lowcore.jiffy_timer =
jiffies_timer_cc + (jiffies_64 + 1) * CLK_TICKS_PER_JIFFY;
set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
}
/*
* Set up lowcore and control register of the current cpu to
* enable TOD clock and clock comparator interrupts.
*/
void init_cpu_timer(void)
{
struct clock_event_device *cd;
int cpu;
S390_lowcore.clock_comparator = -1ULL;
set_clock_comparator(S390_lowcore.clock_comparator);
cpu = smp_processor_id();
cd = &per_cpu(comparators, cpu);
cd->name = "comparator";
cd->features = CLOCK_EVT_FEAT_ONESHOT;
cd->mult = 16777;
cd->shift = 12;
cd->min_delta_ns = 1;
cd->max_delta_ns = LONG_MAX;
cd->rating = 400;
cd->cpumask = cpumask_of(cpu);
cd->set_next_event = s390_next_event;
cd->set_mode = s390_set_mode;
clockevents_register_device(cd);
/* Enable clock comparator timer interrupt. */
__ctl_set_bit(0,11);
/* Always allow the timing alert external interrupt. */
__ctl_set_bit(0, 4);
}
static void clock_comparator_interrupt(unsigned int ext_int_code,
unsigned int param32,
unsigned long param64)
{
if (S390_lowcore.clock_comparator == -1ULL)
set_clock_comparator(S390_lowcore.clock_comparator);
}
/*
* Fixup the clock comparator.
*/
static void fixup_clock_comparator(unsigned long long delta)
{
/* If nobody is waiting there's nothing to fix. */
if (S390_lowcore.clock_comparator == -1ULL)
return;
S390_lowcore.clock_comparator += delta;
set_clock_comparator(S390_lowcore.clock_comparator);
}
static void clock_comparator_interrupt(struct ext_code ext_code,
unsigned int param32,
unsigned long param64)
{
inc_irq_stat(IRQEXT_CLK);
if (S390_lowcore.clock_comparator == -1ULL)
set_clock_comparator(S390_lowcore.clock_comparator);
}
static void clock_comparator_interrupt(struct ext_code ext_code,
unsigned int param32,
unsigned long param64)
{
kstat_cpu(smp_processor_id()).irqs[EXTINT_CLK]++;
if (S390_lowcore.clock_comparator == -1ULL)
set_clock_comparator(S390_lowcore.clock_comparator);
}
void clock_comparator_work(void)
{
struct clock_event_device *cd;
S390_lowcore.clock_comparator = -1ULL;
set_clock_comparator(S390_lowcore.clock_comparator);
cd = &__get_cpu_var(comparators);
cd->event_handler(cd);
}
/*
* Start the HZ tick on the current CPU.
* Only cpu_idle may call this function.
*/
static void start_hz_timer(void)
{
BUG_ON(!in_interrupt());
if (!cpu_isset(smp_processor_id(), nohz_cpu_mask))
return;
account_ticks(get_clock());
set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
cpu_clear(smp_processor_id(), nohz_cpu_mask);
}
static int s390_next_ktime(ktime_t expires,
struct clock_event_device *evt)
{
struct timespec ts;
u64 nsecs;
ts.tv_sec = ts.tv_nsec = 0;
monotonic_to_bootbased(&ts);
nsecs = ktime_to_ns(ktime_add(timespec_to_ktime(ts), expires));
do_div(nsecs, 125);
S390_lowcore.clock_comparator = sched_clock_base_cc + (nsecs << 9);
set_clock_comparator(S390_lowcore.clock_comparator);
return 0;
}
static int s390_next_ktime(ktime_t expires,
struct clock_event_device *evt)
{
struct timespec ts;
u64 nsecs;
ts.tv_sec = ts.tv_nsec = 0;
monotonic_to_bootbased(&ts);
nsecs = ktime_to_ns(ktime_add(timespec_to_ktime(ts), expires));
do_div(nsecs, 125);
S390_lowcore.clock_comparator = sched_clock_base_cc + (nsecs << 9);
/* Program the maximum value if we have an overflow (== year 2042) */
if (unlikely(S390_lowcore.clock_comparator < sched_clock_base_cc))
S390_lowcore.clock_comparator = -1ULL;
set_clock_comparator(S390_lowcore.clock_comparator);
return 0;
}
/*
* Stop the HZ tick on the current CPU.
* Only cpu_idle may call this function.
*/
static void stop_hz_timer(void)
{
unsigned long flags;
unsigned long seq, next;
__u64 timer, todval;
int cpu = smp_processor_id();
if (sysctl_hz_timer != 0)
return;
cpu_set(cpu, nohz_cpu_mask);
/*
* Leave the clock comparator set up for the next timer
* tick if either rcu or a softirq is pending.
*/
if (rcu_needs_cpu(cpu) || local_softirq_pending()) {
cpu_clear(cpu, nohz_cpu_mask);
return;
}
/*
* This cpu is going really idle. Set up the clock comparator
* for the next event.
*/
next = next_timer_interrupt();
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
timer = ((__u64) next) - ((__u64) jiffies) + jiffies_64;
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
todval = -1ULL;
/* Be careful about overflows. */
if (timer < (-1ULL / CLK_TICKS_PER_JIFFY)) {
timer = jiffies_timer_cc + timer * CLK_TICKS_PER_JIFFY;
if (timer >= jiffies_timer_cc)
todval = timer;
}
set_clock_comparator(todval);
}
static void clock_comparator_interrupt(__u16 code)
{
/* set clock comparator for next tick */
set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
}
static void clock_comparator_interrupt(__u16 code)
{
if (S390_lowcore.clock_comparator == -1ULL)
set_clock_comparator(S390_lowcore.clock_comparator);
}