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Subject[RFC][PATCH 1/14] Convert alpha to read/update_persistent_clock
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Date
This patch converts the alpha architecture to use the generic
read_persistent_clock and update_persistent_clock interfaces, reducing
the amount of arch specific code we have to maintain, and allowing for
further cleanups in the future.

I have not built or tested this patch, so help from arch maintainers
would be appreciated.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
---
Kconfig | 3 +
kernel/time.c | 101 ++++++++++++++++++++++++++--------------------------------
2 files changed, 50 insertions(+), 54 deletions(-)
Index: gettimeoffset/arch/alpha/Kconfig
===================================================================
--- gettimeoffset.orig/arch/alpha/Kconfig 2009-12-22 18:50:55.000000000 -0800
+++ gettimeoffset/arch/alpha/Kconfig 2009-12-22 18:51:01.000000000 -0800
@@ -54,6 +54,9 @@ config ARCH_USES_GETTIMEOFFSET
bool
default y

+config GENERIC_CMOS_UPDATE
+ def_bool y
+
config ZONE_DMA
bool
default y
Index: gettimeoffset/arch/alpha/kernel/time.c
===================================================================
--- gettimeoffset.orig/arch/alpha/kernel/time.c 2009-12-22 18:50:55.000000000 -0800
+++ gettimeoffset/arch/alpha/kernel/time.c 2009-12-22 18:51:01.000000000 -0800
@@ -75,8 +75,6 @@ static struct {
__u32 last_time;
/* ticks/cycle * 2^48 */
unsigned long scaled_ticks_per_cycle;
- /* last time the CMOS clock got updated */
- time_t last_rtc_update;
/* partial unused tick */
unsigned long partial_tick;
} state;
@@ -91,6 +89,52 @@ static inline __u32 rpcc(void)
return result;
}

+int update_persistent_clock(struct timespec now)
+{
+ return set_rtc_mmss(now.tv_sec);
+}
+
+void read_persistent_clock(struct timespec *ts)
+{
+ unsigned int year, mon, day, hour, min, sec, epoch;
+
+ sec = CMOS_READ(RTC_SECONDS);
+ min = CMOS_READ(RTC_MINUTES);
+ hour = CMOS_READ(RTC_HOURS);
+ day = CMOS_READ(RTC_DAY_OF_MONTH);
+ mon = CMOS_READ(RTC_MONTH);
+ year = CMOS_READ(RTC_YEAR);
+
+ if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+ sec = bcd2bin(sec);
+ min = bcd2bin(min);
+ hour = bcd2bin(hour);
+ day = bcd2bin(day);
+ mon = bcd2bin(mon);
+ year = bcd2bin(year);
+ }
+
+ /* PC-like is standard; used for year >= 70 */
+ epoch = 1900;
+ if (year < 20)
+ epoch = 2000;
+ else if (year >= 20 && year < 48)
+ /* NT epoch */
+ epoch = 1980;
+ else if (year >= 48 && year < 70)
+ /* Digital UNIX epoch */
+ epoch = 1952;
+
+ printk(KERN_INFO "Using epoch = %d\n", epoch);
+
+ if ((year += epoch) < 1970)
+ year += 100;
+
+ ts->tv_sec = mktime(year, mon, day, hour, min, sec);
+}
+
+
+
/*
* timer_interrupt() needs to keep up the real-time clock,
* as well as call the "do_timer()" routine every clocktick
@@ -123,19 +167,6 @@ irqreturn_t timer_interrupt(int irq, voi
if (nticks)
do_timer(nticks);

- /*
- * If we have an externally synchronized Linux clock, then update
- * CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
- * called as close as possible to 500 ms before the new second starts.
- */
- if (ntp_synced()
- && xtime.tv_sec > state.last_rtc_update + 660
- && xtime.tv_nsec >= 500000 - ((unsigned) TICK_SIZE) / 2
- && xtime.tv_nsec <= 500000 + ((unsigned) TICK_SIZE) / 2) {
- int tmp = set_rtc_mmss(xtime.tv_sec);
- state.last_rtc_update = xtime.tv_sec - (tmp ? 600 : 0);
- }
-
write_sequnlock(&xtime_lock);

#ifndef CONFIG_SMP
@@ -304,7 +335,7 @@ rpcc_after_update_in_progress(void)
void __init
time_init(void)
{
- unsigned int year, mon, day, hour, min, sec, cc1, cc2, epoch;
+ unsigned int cc1, cc2;
unsigned long cycle_freq, tolerance;
long diff;

@@ -348,43 +379,6 @@ time_init(void)
bogomips yet, but this is close on a 500Mhz box. */
__delay(1000000);

- sec = CMOS_READ(RTC_SECONDS);
- min = CMOS_READ(RTC_MINUTES);
- hour = CMOS_READ(RTC_HOURS);
- day = CMOS_READ(RTC_DAY_OF_MONTH);
- mon = CMOS_READ(RTC_MONTH);
- year = CMOS_READ(RTC_YEAR);
-
- if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
- sec = bcd2bin(sec);
- min = bcd2bin(min);
- hour = bcd2bin(hour);
- day = bcd2bin(day);
- mon = bcd2bin(mon);
- year = bcd2bin(year);
- }
-
- /* PC-like is standard; used for year >= 70 */
- epoch = 1900;
- if (year < 20)
- epoch = 2000;
- else if (year >= 20 && year < 48)
- /* NT epoch */
- epoch = 1980;
- else if (year >= 48 && year < 70)
- /* Digital UNIX epoch */
- epoch = 1952;
-
- printk(KERN_INFO "Using epoch = %d\n", epoch);
-
- if ((year += epoch) < 1970)
- year += 100;
-
- xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
- xtime.tv_nsec = 0;
-
- wall_to_monotonic.tv_sec -= xtime.tv_sec;
- wall_to_monotonic.tv_nsec = 0;

if (HZ > (1<<16)) {
extern void __you_loose (void);
@@ -394,7 +388,6 @@ time_init(void)
state.last_time = cc1;
state.scaled_ticks_per_cycle
= ((unsigned long) HZ << FIX_SHIFT) / cycle_freq;
- state.last_rtc_update = 0;
state.partial_tick = 0L;

/* Startup the timer source. */



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