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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2009-04-14 15:36:28 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2009-04-14 15:37:27 +0200
commitb6112ccbff5ec580d46b584ecc3c3a773b830da2 (patch)
tree71553f09a2acfedec85f3c29a1c65e0a257001fb /arch/s390/kernel
parent5b409ed17bb32c8316b1f456466c70529454573a (diff)
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[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>
Diffstat (limited to 'arch/s390/kernel')
-rw-r--r--arch/s390/kernel/early.c16
-rw-r--r--arch/s390/kernel/head.S7
-rw-r--r--arch/s390/kernel/time.c28
3 files changed, 30 insertions, 21 deletions
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 unsigned long machine_flags;
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 @@ static void __init setup_boot_command_line(void)
*/
void __init startup_init(void)
{
+ reset_tod_clock();
ipl_save_parameters();
rescue_initrd();
clear_bss_section();
diff --git a/arch/s390/kernel/head.S b/arch/s390/kernel/head.S
index 1046c2c..16f8975 100644
--- a/arch/s390/kernel/head.S
+++ b/arch/s390/kernel/head.S
@@ -471,6 +471,8 @@ startup:basr %r13,0 # get base
.LPG0:
xc 0x200(256),0x200 # partially clear lowcore
xc 0x300(256),0x300
+ l %r1,5f-.LPG0(%r13)
+ stck 0(%r1)
#ifndef CONFIG_MARCH_G5
# check processor version against MARCH_{G5,Z900,Z990,Z9_109,Z10}
@@ -496,9 +498,10 @@ startup:basr %r13,0 # get base
brct %r0,0b
#endif
- l %r13,0f-.LPG0(%r13)
+ l %r13,4f-.LPG0(%r13)
b 0(%r13)
-0: .long startup_continue
+4: .long startup_continue
+5: .long sched_clock_base_cc
#
# params at 10400 (setup.h)
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 timing_alert_interrupt(__u16 code)
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 update_vsyscall_tz(void)
*/
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);