[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/early.c b/arch/s390/kernel/early.c
index d4e1e5b..cf09948 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -38,6 +38,21 @@
static void __init setup_boot_command_line(void);
+/*
+ * Get the TOD clock running.
+ */
+static void __init reset_tod_clock(void)
+{
+ u64 time;
+
+ if (store_clock(&time) == 0)
+ return;
+ /* TOD clock not running. Set the clock to Unix Epoch. */
+ if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0)
+ disabled_wait(0);
+
+ sched_clock_base_cc = TOD_UNIX_EPOCH;
+}
#ifdef CONFIG_SHARED_KERNEL
int __init savesys_ipl_nss(char *cmd, const int cmdlen);
@@ -372,6 +387,7 @@
*/
void __init startup_init(void)
{
+ reset_tod_clock();
ipl_save_parameters();
rescue_initrd();
clear_bss_section();