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Diffstat (limited to 'arch/s390/kernel/time.c')
-rw-r--r--arch/s390/kernel/time.c65
1 files changed, 45 insertions, 20 deletions
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 192efdfac918..15abecba068e 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -51,8 +51,15 @@
#include <asm/cio.h>
#include "entry.h"
-u64 sched_clock_base_cc = -1; /* Force to data section. */
-EXPORT_SYMBOL_GPL(sched_clock_base_cc);
+unsigned char tod_clock_base[16] __aligned(8) = {
+ /* Force to data section. */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
+};
+EXPORT_SYMBOL_GPL(tod_clock_base);
+
+u64 clock_comparator_max = -1ULL;
+EXPORT_SYMBOL_GPL(clock_comparator_max);
static DEFINE_PER_CPU(struct clock_event_device, comparators);
@@ -75,7 +82,7 @@ void __init time_early_init(void)
struct ptff_qui qui;
/* Initialize TOD steering parameters */
- tod_steering_end = sched_clock_base_cc;
+ tod_steering_end = *(unsigned long long *) &tod_clock_base[1];
vdso_data->ts_end = tod_steering_end;
if (!test_facility(28))
@@ -111,22 +118,27 @@ unsigned long long monotonic_clock(void)
}
EXPORT_SYMBOL(monotonic_clock);
-static void tod_to_timeval(__u64 todval, struct timespec64 *xt)
+static void ext_to_timespec64(unsigned char *clk, struct timespec64 *xt)
{
- unsigned long long sec;
+ unsigned long long high, low, rem, sec, nsec;
+
+ /* Split extendnd TOD clock to micro-seconds and sub-micro-seconds */
+ high = (*(unsigned long long *) clk) >> 4;
+ low = (*(unsigned long long *)&clk[7]) << 4;
+ /* Calculate seconds and nano-seconds */
+ sec = high;
+ rem = do_div(sec, 1000000);
+ nsec = (((low >> 32) + (rem << 32)) * 1000) >> 32;
- sec = todval >> 12;
- do_div(sec, 1000000);
xt->tv_sec = sec;
- todval -= (sec * 1000000) << 12;
- xt->tv_nsec = ((todval * 1000) >> 12);
+ xt->tv_nsec = nsec;
}
void clock_comparator_work(void)
{
struct clock_event_device *cd;
- S390_lowcore.clock_comparator = -1ULL;
+ S390_lowcore.clock_comparator = clock_comparator_max;
cd = this_cpu_ptr(&comparators);
cd->event_handler(cd);
}
@@ -148,7 +160,7 @@ void init_cpu_timer(void)
struct clock_event_device *cd;
int cpu;
- S390_lowcore.clock_comparator = -1ULL;
+ S390_lowcore.clock_comparator = clock_comparator_max;
set_clock_comparator(S390_lowcore.clock_comparator);
cpu = smp_processor_id();
@@ -179,7 +191,7 @@ static void clock_comparator_interrupt(struct ext_code ext_code,
unsigned long param64)
{
inc_irq_stat(IRQEXT_CLK);
- if (S390_lowcore.clock_comparator == -1ULL)
+ if (S390_lowcore.clock_comparator == clock_comparator_max)
set_clock_comparator(S390_lowcore.clock_comparator);
}
@@ -197,18 +209,28 @@ static void stp_reset(void);
void read_persistent_clock64(struct timespec64 *ts)
{
- __u64 clock;
+ unsigned char clk[STORE_CLOCK_EXT_SIZE];
+ __u64 delta;
- clock = get_tod_clock() - initial_leap_seconds;
- tod_to_timeval(clock - TOD_UNIX_EPOCH, ts);
+ delta = initial_leap_seconds + TOD_UNIX_EPOCH;
+ get_tod_clock_ext(clk);
+ *(__u64 *) &clk[1] -= delta;
+ if (*(__u64 *) &clk[1] > delta)
+ clk[0]--;
+ ext_to_timespec64(clk, ts);
}
void read_boot_clock64(struct timespec64 *ts)
{
- __u64 clock;
+ unsigned char clk[STORE_CLOCK_EXT_SIZE];
+ __u64 delta;
- clock = sched_clock_base_cc - initial_leap_seconds;
- tod_to_timeval(clock - TOD_UNIX_EPOCH, ts);
+ delta = initial_leap_seconds + TOD_UNIX_EPOCH;
+ memcpy(clk, tod_clock_base, 16);
+ *(__u64 *) &clk[1] -= delta;
+ if (*(__u64 *) &clk[1] > delta)
+ clk[0]--;
+ ext_to_timespec64(clk, ts);
}
static u64 read_tod_clock(struct clocksource *cs)
@@ -406,7 +428,10 @@ static void clock_sync_global(unsigned long long delta)
struct ptff_qto qto;
/* Fixup the monotonic sched clock. */
- sched_clock_base_cc += delta;
+ *(unsigned long long *) &tod_clock_base[1] += delta;
+ if (*(unsigned long long *) &tod_clock_base[1] < delta)
+ /* Epoch overflow */
+ tod_clock_base[0]++;
/* Adjust TOD steering parameters. */
vdso_data->tb_update_count++;
now = get_tod_clock();
@@ -437,7 +462,7 @@ static void clock_sync_global(unsigned long long delta)
static void clock_sync_local(unsigned long long delta)
{
/* Add the delta to the clock comparator. */
- if (S390_lowcore.clock_comparator != -1ULL) {
+ if (S390_lowcore.clock_comparator != clock_comparator_max) {
S390_lowcore.clock_comparator += delta;
set_clock_comparator(S390_lowcore.clock_comparator);
}