From: Martin Schwidefsky <[email protected]>
[S390] Use CONFIG_GENERIC_TIME and define TOD clock source.
Fix too slow clock by using CONFIG_GENERIC_TIME and adding a
clock source for the s390 time-of-day clock. As added benefit
we get rid of the s390 specific definition of do_gettimeofday
and do_settimeofday.
Signed-off-by: Martin Schwidefsky <[email protected]>
---
arch/s390/Kconfig | 3 +
arch/s390/defconfig | 1
arch/s390/kernel/time.c | 88 ++++++++++--------------------------------------
3 files changed, 24 insertions(+), 68 deletions(-)
diff -urpN linux-2.6/arch/s390/defconfig linux-2.6-patched/arch/s390/defconfig
--- linux-2.6/arch/s390/defconfig 2006-10-06 16:29:54.000000000 +0200
+++ linux-2.6-patched/arch/s390/defconfig 2006-10-06 16:30:02.000000000 +0200
@@ -9,6 +9,7 @@ CONFIG_STACKTRACE_SUPPORT=y
CONFIG_RWSEM_XCHGADD_ALGORITHM=y
CONFIG_GENERIC_HWEIGHT=y
CONFIG_GENERIC_CALIBRATE_DELAY=y
+CONFIG_GENERIC_TIME=y
CONFIG_S390=y
CONFIG_DEFCONFIG_LIST="/lib/modules/$UNAME_RELEASE/.config"
diff -urpN linux-2.6/arch/s390/Kconfig linux-2.6-patched/arch/s390/Kconfig
--- linux-2.6/arch/s390/Kconfig 2006-10-06 16:29:26.000000000 +0200
+++ linux-2.6-patched/arch/s390/Kconfig 2006-10-06 16:30:02.000000000 +0200
@@ -30,6 +30,9 @@ config GENERIC_CALIBRATE_DELAY
bool
default y
+config GENERIC_TIME
+ def_bool y
+
config GENERIC_BUST_SPINLOCK
bool
diff -urpN linux-2.6/arch/s390/kernel/time.c linux-2.6-patched/arch/s390/kernel/time.c
--- linux-2.6/arch/s390/kernel/time.c 2006-10-06 16:30:00.000000000 +0200
+++ linux-2.6-patched/arch/s390/kernel/time.c 2006-10-06 16:30:02.000000000 +0200
@@ -28,6 +28,7 @@
#include <linux/profile.h>
#include <linux/timex.h>
#include <linux/notifier.h>
+#include <linux/clocksource.h>
#include <asm/uaccess.h>
#include <asm/delay.h>
@@ -82,74 +83,6 @@ void tod_to_timeval(__u64 todval, struct
xtime->tv_nsec = ((todval * 1000) >> 12);
}
-static inline unsigned long do_gettimeoffset(void)
-{
- __u64 now;
-
- now = (get_clock() - jiffies_timer_cc) >> 12;
- now -= (__u64) jiffies * USECS_PER_JIFFY;
- return (unsigned long) now;
-}
-
-/*
- * This version of gettimeofday has microsecond resolution.
- */
-void do_gettimeofday(struct timeval *tv)
-{
- unsigned long flags;
- unsigned long seq;
- unsigned long usec, sec;
-
- do {
- seq = read_seqbegin_irqsave(&xtime_lock, flags);
-
- sec = xtime.tv_sec;
- usec = xtime.tv_nsec / 1000 + do_gettimeoffset();
- } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
-
- while (usec >= 1000000) {
- usec -= 1000000;
- sec++;
- }
-
- tv->tv_sec = sec;
- tv->tv_usec = usec;
-}
-
-EXPORT_SYMBOL(do_gettimeofday);
-
-int do_settimeofday(struct timespec *tv)
-{
- time_t wtm_sec, sec = tv->tv_sec;
- long wtm_nsec, nsec = tv->tv_nsec;
-
- if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
- return -EINVAL;
-
- write_seqlock_irq(&xtime_lock);
- /* This is revolting. We need to set the xtime.tv_nsec
- * correctly. However, the value in this location is
- * is value at the last tick.
- * Discover what correction gettimeofday
- * would have done, and then undo it!
- */
- nsec -= do_gettimeoffset() * 1000;
-
- wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
- wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
-
- set_normalized_timespec(&xtime, sec, nsec);
- set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
-
- ntp_clear();
- write_sequnlock_irq(&xtime_lock);
- clock_was_set();
- return 0;
-}
-
-EXPORT_SYMBOL(do_settimeofday);
-
-
#ifdef CONFIG_PROFILING
#define s390_do_profile() profile_tick(CPU_PROFILING)
#else
@@ -340,6 +273,22 @@ void init_cpu_timer(void)
extern void vtime_init(void);
+static cycle_t read_tod_clock(void)
+{
+ return get_clock();
+}
+
+static struct clocksource clocksource_tod = {
+ .name = "tod",
+ .rating = 100,
+ .read = read_tod_clock,
+ .mask = -1ULL,
+ .mult = 1000,
+ .shift = 12,
+ .is_continuous = 1,
+};
+
+
/*
* Initialize the TOD clock and the CPU timer of
* the boot cpu.
@@ -384,6 +333,9 @@ void __init time_init(void)
&ext_int_info_cc) != 0)
panic("Couldn't request external interrupt 0x1004");
+ if (clocksource_register(&clocksource_tod) != 0)
+ panic("Could not register TOD clock source");
+
init_cpu_timer();
#ifdef CONFIG_NO_IDLE_HZ