[S390] add read_persistent_clock
Add a read_persistent_clock function that does not just return 0.
Since timekeeping_init calls the function before time_init has been
called move reset_tod_clock to early.c to make sure that the TOD
clock is running when read_persistent_clock is invoked.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 05f93e7..369ff02 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -52,9 +52,6 @@
#define USECS_PER_JIFFY ((unsigned long) 1000000/HZ)
#define CLK_TICKS_PER_JIFFY ((unsigned long) USECS_PER_JIFFY << 12)
-/* The value of the TOD clock for 1.1.1970. */
-#define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
-
/*
* Create a small time difference between the timer interrupts
* on the different cpus to avoid lock contention.
@@ -63,9 +60,10 @@
#define TICK_SIZE tick
+u64 sched_clock_base_cc = -1; /* Force to data section. */
+
static ext_int_info_t ext_int_info_cc;
static ext_int_info_t ext_int_etr_cc;
-static u64 sched_clock_base_cc;
static DEFINE_PER_CPU(struct clock_event_device, comparators);
@@ -195,22 +193,12 @@
static void etr_reset(void);
static void stp_reset(void);
-/*
- * Get the TOD clock running.
- */
-static u64 __init reset_tod_clock(void)
+unsigned long read_persistent_clock(void)
{
- u64 time;
+ struct timespec ts;
- etr_reset();
- stp_reset();
- if (store_clock(&time) == 0)
- return time;
- /* TOD clock not running. Set the clock to Unix Epoch. */
- if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0)
- panic("TOD clock not operational.");
-
- return TOD_UNIX_EPOCH;
+ tod_to_timeval(get_clock() - TOD_UNIX_EPOCH, &ts);
+ return ts.tv_sec;
}
static cycle_t read_tod_clock(void)
@@ -265,7 +253,9 @@
*/
void __init time_init(void)
{
- sched_clock_base_cc = reset_tod_clock();
+ /* Reset time synchronization interfaces. */
+ etr_reset();
+ stp_reset();
/* set xtime */
tod_to_timeval(sched_clock_base_cc - TOD_UNIX_EPOCH, &xtime);