2015-07-26 10:53:30

by Xunlei Pang

[permalink] [raw]
Subject: [PATCH v3 1/2] time: Add the common weak version of update_persistent_clock()

From: Xunlei Pang <[email protected]>

The weak update_persistent_clock64() calls update_persistent_clock(),
if the architecture defines an update_persistent_clock64() to replace
and remove its update_persistent_clock() version, when building the
kernel the linker will throw an undefined symbol error, that is, any
arch that switches to update_persistent_clock64() will have this issue.

To solve the issue, we add the common weak update_persistent_clock().

Cc: John Stultz <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Signed-off-by: Xunlei Pang <[email protected]>
---
v2->v3:
Improve the changelog according to Thomas's comments.

kernel/time/ntp.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index fb4d98c..df68cb8 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -487,6 +487,11 @@ out:
}

#ifdef CONFIG_GENERIC_CMOS_UPDATE
+int __weak update_persistent_clock(struct timespec now)
+{
+ return -ENODEV;
+}
+
int __weak update_persistent_clock64(struct timespec64 now64)
{
struct timespec now;
--
1.9.1


2015-07-26 10:53:29

by Xunlei Pang

[permalink] [raw]
Subject: [PATCH v3 2/2] mn10300: time: Provide 64-bit persistent clock time

From: Xunlei Pang <[email protected]>

As part of addressing the "y2038 problem" for in-kernel uses,
convert update_persistent_clock() to update_persistent_clock64(),
read_persistent_clock() to read_persistent_clock64() using
timespec64 for MN10300.

Cc: John Stultz <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Signed-off-by: Xunlei Pang <[email protected]>
---
v2->v3:
no changes.

arch/mn10300/kernel/rtc.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/arch/mn10300/kernel/rtc.c b/arch/mn10300/kernel/rtc.c
index 48d7058..038ae16 100644
--- a/arch/mn10300/kernel/rtc.c
+++ b/arch/mn10300/kernel/rtc.c
@@ -23,19 +23,19 @@ EXPORT_SYMBOL(rtc_lock);
/*
* Read the current RTC time
*/
-void read_persistent_clock(struct timespec *ts)
+void read_persistent_clock64(struct timespec64 *ts)
{
struct rtc_time tm;

get_rtc_time(&tm);

ts->tv_nsec = 0;
- ts->tv_sec = mktime(tm.tm_year, tm.tm_mon, tm.tm_mday,
+ ts->tv_sec = mktime64(tm.tm_year, tm.tm_mon, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec);

/* if rtc is way off in the past, set something reasonable */
if (ts->tv_sec < 0)
- ts->tv_sec = mktime(2009, 1, 1, 12, 0, 0);
+ ts->tv_sec = mktime64(2009, 1, 1, 12, 0, 0);
}

/*
@@ -48,7 +48,7 @@ void read_persistent_clock(struct timespec *ts)
* BUG: This routine does not handle hour overflow properly; it just
* sets the minutes. Usually you'll only notice that after reboot!
*/
-static int set_rtc_mmss(unsigned long nowtime)
+static int set_rtc_mmss(time64_t nowtime)
{
unsigned char save_control, save_freq_select;
int retval = 0;
@@ -74,8 +74,7 @@ static int set_rtc_mmss(unsigned long nowtime)
* messing with unknown time zones but requires your
* RTC not to be off by more than 15 minutes
*/
- real_seconds = nowtime % 60;
- real_minutes = nowtime / 60;
+ real_minutes = div_s64_rem(nowtime, 60, &real_seconds);
if (((abs(real_minutes - cmos_minutes) + 15) / 30) & 1)
/* correct for half hour time zone */
real_minutes += 30;
@@ -109,7 +108,7 @@ static int set_rtc_mmss(unsigned long nowtime)
return retval;
}

-int update_persistent_clock(struct timespec now)
+int update_persistent_clock64(struct timespec64 now)
{
return set_rtc_mmss(now.tv_sec);
}
--
1.9.1

2015-07-29 22:05:32

by John Stultz

[permalink] [raw]
Subject: Re: [PATCH v3 1/2] time: Add the common weak version of update_persistent_clock()

On Sun, Jul 26, 2015 at 3:45 AM, Xunlei Pang <[email protected]> wrote:
> From: Xunlei Pang <[email protected]>
>
> The weak update_persistent_clock64() calls update_persistent_clock(),
> if the architecture defines an update_persistent_clock64() to replace
> and remove its update_persistent_clock() version, when building the
> kernel the linker will throw an undefined symbol error, that is, any
> arch that switches to update_persistent_clock64() will have this issue.
>
> To solve the issue, we add the common weak update_persistent_clock().

So I'm ok with taking this patch. I'm also ok with taking the
dependent MN10300 patch if I can get acks from maintainers.

Or if the MN10300 maintainers would prefer, they can take both patches w/ my:
Acked-by: John Stultz <[email protected]>

thanks
-john