[PATCH v2 1/2] MIPS: Convert read_persistent_clock() to read_persistent_clock64()

[PATCH v2 1/2] MIPS: Convert read_persistent_clock() to read_persistent_clock64()

[Baolin Wang]

Since struct timespec is not y2038 safe on 32bit machines, this patch
converts read_persistent_clock() to read_persistent_clock64() using
struct timespec64, as well as converting mktime() to mktime64().

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
Changes since v1:
 - No updates.
---
 arch/mips/dec/time.c                   |    4 ++--
 arch/mips/include/asm/mc146818-time.h  |    4 ++--
 arch/mips/lasat/ds1603.c               |    2 +-
 arch/mips/loongson64/common/time.c     |    2 +-
 arch/mips/mti-malta/malta-time.c       |    2 +-
 arch/mips/sibyte/swarm/rtc_m41t81.c    |    4 ++--
 arch/mips/sibyte/swarm/rtc_xicor1241.c |    4 ++--
 arch/mips/sibyte/swarm/setup.c         |   10 +++++-----
 8 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/arch/mips/dec/time.c b/arch/mips/dec/time.c
index a2a150e..9e992cf 100644
--- a/arch/mips/dec/time.c
+++ b/arch/mips/dec/time.c
@@ -19,7 +19,7 @@
 #include <asm/dec/ioasic.h>
 #include <asm/dec/machtype.h>
 
-void read_persistent_clock(struct timespec *ts)
+void read_persistent_clock64(struct timespec64 *ts)
 {
 	unsigned int year, mon, day, hour, min, sec, real_year;
 	unsigned long flags;
@@ -54,7 +54,7 @@ void read_persistent_clock(struct timespec *ts)
 
 	year += real_year - 72 + 2000;
 
-	ts->tv_sec = mktime(year, mon, day, hour, min, sec);
+	ts->tv_sec = mktime64(year, mon, day, hour, min, sec);
 	ts->tv_nsec = 0;
 }
 
diff --git a/arch/mips/include/asm/mc146818-time.h b/arch/mips/include/asm/mc146818-time.h
index 9e1ad26..cbf5cec 100644
--- a/arch/mips/include/asm/mc146818-time.h
+++ b/arch/mips/include/asm/mc146818-time.h
@@ -86,7 +86,7 @@ static inline int mc146818_set_rtc_mmss(unsigned long nowtime)
 	return retval;
 }
 
-static inline unsigned long mc146818_get_cmos_time(void)
+static inline time64_t mc146818_get_cmos_time(void)
 {
 	unsigned int year, mon, day, hour, min, sec;
 	unsigned long flags;
@@ -113,7 +113,7 @@ static inline unsigned long mc146818_get_cmos_time(void)
 	spin_unlock_irqrestore(&rtc_lock, flags);
 	year = mc146818_decode_year(year);
 
-	return mktime(year, mon, day, hour, min, sec);
+	return mktime64(year, mon, day, hour, min, sec);
 }
 
 #endif /* __ASM_MC146818_TIME_H */
diff --git a/arch/mips/lasat/ds1603.c b/arch/mips/lasat/ds1603.c
index 8bd5cf8..d75c887 100644
--- a/arch/mips/lasat/ds1603.c
+++ b/arch/mips/lasat/ds1603.c
@@ -136,7 +136,7 @@ static void rtc_end_op(void)
 	lasat_ndelay(1000);
 }
 
-void read_persistent_clock(struct timespec *ts)
+void read_persistent_clock64(struct timespec64 *ts)
 {
 	unsigned long word;
 	unsigned long flags;
diff --git a/arch/mips/loongson64/common/time.c b/arch/mips/loongson64/common/time.c
index e1a5382a..0ba53c5 100644
--- a/arch/mips/loongson64/common/time.c
+++ b/arch/mips/loongson64/common/time.c
@@ -29,7 +29,7 @@ void __init plat_time_init(void)
 #endif
 }
 
-void read_persistent_clock(struct timespec *ts)
+void read_persistent_clock64(struct timespec64 *ts)
 {
 	ts->tv_sec = mc146818_get_cmos_time();
 	ts->tv_nsec = 0;
diff --git a/arch/mips/mti-malta/malta-time.c b/arch/mips/mti-malta/malta-time.c
index 66c8667..d22b7ed 100644
--- a/arch/mips/mti-malta/malta-time.c
+++ b/arch/mips/mti-malta/malta-time.c
@@ -134,7 +134,7 @@ static void __init estimate_frequencies(void)
 	}
 }
 
-void read_persistent_clock(struct timespec *ts)
+void read_persistent_clock64(struct timespec64 *ts)
 {
 	ts->tv_sec = mc146818_get_cmos_time();
 	ts->tv_nsec = 0;
diff --git a/arch/mips/sibyte/swarm/rtc_m41t81.c b/arch/mips/sibyte/swarm/rtc_m41t81.c
index e624664..aa27a22 100644
--- a/arch/mips/sibyte/swarm/rtc_m41t81.c
+++ b/arch/mips/sibyte/swarm/rtc_m41t81.c
@@ -188,7 +188,7 @@ int m41t81_set_time(unsigned long t)
 	return 0;
 }
 
-unsigned long m41t81_get_time(void)
+time64_t m41t81_get_time(void)
 {
 	unsigned int year, mon, day, hour, min, sec;
 	unsigned long flags;
@@ -218,7 +218,7 @@ unsigned long m41t81_get_time(void)
 
 	year += 2000;
 
-	return mktime(year, mon, day, hour, min, sec);
+	return mktime64(year, mon, day, hour, min, sec);
 }
 
 int m41t81_probe(void)
diff --git a/arch/mips/sibyte/swarm/rtc_xicor1241.c b/arch/mips/sibyte/swarm/rtc_xicor1241.c
index 50a82c4..a2121c1 100644
--- a/arch/mips/sibyte/swarm/rtc_xicor1241.c
+++ b/arch/mips/sibyte/swarm/rtc_xicor1241.c
@@ -168,7 +168,7 @@ int xicor_set_time(unsigned long t)
 	return 0;
 }
 
-unsigned long xicor_get_time(void)
+time64_t xicor_get_time(void)
 {
 	unsigned int year, mon, day, hour, min, sec, y2k;
 	unsigned long flags;
@@ -201,7 +201,7 @@ unsigned long xicor_get_time(void)
 
 	year += (y2k * 100);
 
-	return mktime(year, mon, day, hour, min, sec);
+	return mktime64(year, mon, day, hour, min, sec);
 }
 
 int xicor_probe(void)
diff --git a/arch/mips/sibyte/swarm/setup.c b/arch/mips/sibyte/swarm/setup.c
index 494fb0a..7073940 100644
--- a/arch/mips/sibyte/swarm/setup.c
+++ b/arch/mips/sibyte/swarm/setup.c
@@ -58,11 +58,11 @@
 
 extern int xicor_probe(void);
 extern int xicor_set_time(unsigned long);
-extern unsigned long xicor_get_time(void);
+extern time64_t xicor_get_time(void);
 
 extern int m41t81_probe(void);
 extern int m41t81_set_time(unsigned long);
-extern unsigned long m41t81_get_time(void);
+extern time64_t m41t81_get_time(void);
 
 const char *get_system_type(void)
 {
@@ -87,9 +87,9 @@ enum swarm_rtc_type {
 
 enum swarm_rtc_type swarm_rtc_type;
 
-void read_persistent_clock(struct timespec *ts)
+void read_persistent_clock64(struct timespec64 *ts)
 {
-	unsigned long sec;
+	time64_t sec;
 
 	switch (swarm_rtc_type) {
 	case RTC_XICOR:
@@ -102,7 +102,7 @@ void read_persistent_clock(struct timespec *ts)
 
 	case RTC_NONE:
 	default:
-		sec = mktime(2000, 1, 1, 0, 0, 0);
+		sec = mktime64(2000, 1, 1, 0, 0, 0);
 		break;
 	}
 	ts->tv_sec = sec;
-- 
1.7.9.5

[PATCH v2 2/2] MIPS: Convert update_persistent_clock() to update_persistent_clock64()

[Baolin Wang]

Since struct timespec is not y2038 safe on 32bit machines, this patch
converts update_persistent_clock() to update_persistent_clock64() using
struct timespec64.

The rtc_mips_set_time() and rtc_mips_set_mmss() interfaces were using
'unsigned long' type that is not y2038 safe on 32bit machines, moreover
there is only one platform implementing rtc_mips_set_time() and two
platforms implementing rtc_mips_set_mmss(), so we can just make them each
implement update_persistent_clock64() directly, to get that helper out
of the common mips code by removing rtc_mips_set_time() and
rtc_mips_set_mmss() interfaces.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
Changes since v1:
 - Remove rtc_mips_set_time() and rtc_mips_set_mmss() interfaces.
---
 arch/mips/dec/time.c                   |    5 +++--
 arch/mips/include/asm/time.h           |    9 ---------
 arch/mips/kernel/time.c                |   15 ---------------
 arch/mips/lasat/ds1603.c               |    5 +++--
 arch/mips/lasat/sysctl.c               |    8 ++++++--
 arch/mips/sibyte/swarm/rtc_m41t81.c    |    4 ++--
 arch/mips/sibyte/swarm/rtc_xicor1241.c |    4 ++--
 arch/mips/sibyte/swarm/setup.c         |    8 +++++---
 8 files changed, 21 insertions(+), 37 deletions(-)

diff --git a/arch/mips/dec/time.c b/arch/mips/dec/time.c
index 9e992cf..934db6f 100644
--- a/arch/mips/dec/time.c
+++ b/arch/mips/dec/time.c
@@ -59,14 +59,15 @@ void read_persistent_clock64(struct timespec64 *ts)
 }
 
 /*
- * In order to set the CMOS clock precisely, rtc_mips_set_mmss has to
+ * In order to set the CMOS clock precisely, update_persistent_clock64 has to
  * be called 500 ms after the second nowtime has started, because when
  * nowtime is written into the registers of the CMOS clock, it will
  * jump to the next second precisely 500 ms later.  Check the Dallas
  * DS1287 data sheet for details.
  */
-int rtc_mips_set_mmss(unsigned long nowtime)
+int update_persistent_clock64(struct timespec64 now)
 {
+	time64_t nowtime = now.tv_sec;
 	int retval = 0;
 	int real_seconds, real_minutes, cmos_minutes;
 	unsigned char save_control, save_freq_select;
diff --git a/arch/mips/include/asm/time.h b/arch/mips/include/asm/time.h
index 17d4cd2..b85ec64 100644
--- a/arch/mips/include/asm/time.h
+++ b/arch/mips/include/asm/time.h
@@ -22,15 +22,6 @@
 extern spinlock_t rtc_lock;
 
 /*
- * RTC ops.  By default, they point to weak no-op RTC functions.
- *	rtc_mips_set_time - reverse the above translation and set time to RTC.
- *	rtc_mips_set_mmss - similar to rtc_set_time, but only min and sec need
- *			to be set.  Used by RTC sync-up.
- */
-extern int rtc_mips_set_time(unsigned long);
-extern int rtc_mips_set_mmss(unsigned long);
-
-/*
  * board specific routines required by time_init().
  */
 extern void plat_time_init(void);
diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c
index a6ebc81..bfe02de 100644
--- a/arch/mips/kernel/time.c
+++ b/arch/mips/kernel/time.c
@@ -34,21 +34,6 @@
 DEFINE_SPINLOCK(rtc_lock);
 EXPORT_SYMBOL(rtc_lock);
 
-int __weak rtc_mips_set_time(unsigned long sec)
-{
-	return -ENODEV;
-}
-
-int __weak rtc_mips_set_mmss(unsigned long nowtime)
-{
-	return rtc_mips_set_time(nowtime);
-}
-
-int update_persistent_clock(struct timespec now)
-{
-	return rtc_mips_set_mmss(now.tv_sec);
-}
-
 static int null_perf_irq(void)
 {
 	return 0;
diff --git a/arch/mips/lasat/ds1603.c b/arch/mips/lasat/ds1603.c
index d75c887..061815e 100644
--- a/arch/mips/lasat/ds1603.c
+++ b/arch/mips/lasat/ds1603.c
@@ -98,7 +98,7 @@ static void rtc_write_byte(unsigned int byte)
 	}
 }
 
-static void rtc_write_word(unsigned long word)
+static void rtc_write_word(time64_t word)
 {
 	int i;
 
@@ -152,8 +152,9 @@ void read_persistent_clock64(struct timespec64 *ts)
 	ts->tv_nsec = 0;
 }
 
-int rtc_mips_set_mmss(unsigned long time)
+int update_persistent_clock64(struct timespec64 now)
 {
+	time64_t time = now.tv_sec;
 	unsigned long flags;
 
 	spin_lock_irqsave(&rtc_lock, flags);
diff --git a/arch/mips/lasat/sysctl.c b/arch/mips/lasat/sysctl.c
index 6f74224..76f7b62 100644
--- a/arch/mips/lasat/sysctl.c
+++ b/arch/mips/lasat/sysctl.c
@@ -73,8 +73,12 @@ int proc_dolasatrtc(struct ctl_table *table, int write,
 	if (r)
 		return r;
 
-	if (write)
-		rtc_mips_set_mmss(rtctmp);
+	if (write) {
+		ts.tv_sec = rtctmp;
+		ts.tv_nsec = 0;
+
+		update_persistent_clock64(ts);
+	}
 
 	return 0;
 }
diff --git a/arch/mips/sibyte/swarm/rtc_m41t81.c b/arch/mips/sibyte/swarm/rtc_m41t81.c
index aa27a22..4ac8ccd 100644
--- a/arch/mips/sibyte/swarm/rtc_m41t81.c
+++ b/arch/mips/sibyte/swarm/rtc_m41t81.c
@@ -141,13 +141,13 @@ static int m41t81_write(uint8_t addr, int b)
 	return 0;
 }
 
-int m41t81_set_time(unsigned long t)
+int m41t81_set_time(time64_t t)
 {
 	struct rtc_time tm;
 	unsigned long flags;
 
 	/* Note we don't care about the century */
-	rtc_time_to_tm(t, &tm);
+	rtc_time64_to_tm(t, &tm);
 
 	/*
 	 * Note the write order matters as it ensures the correctness.
diff --git a/arch/mips/sibyte/swarm/rtc_xicor1241.c b/arch/mips/sibyte/swarm/rtc_xicor1241.c
index a2121c1..2dcaaa7 100644
--- a/arch/mips/sibyte/swarm/rtc_xicor1241.c
+++ b/arch/mips/sibyte/swarm/rtc_xicor1241.c
@@ -109,13 +109,13 @@ static int xicor_write(uint8_t addr, int b)
 	}
 }
 
-int xicor_set_time(unsigned long t)
+int xicor_set_time(time64_t t)
 {
 	struct rtc_time tm;
 	int tmp;
 	unsigned long flags;
 
-	rtc_time_to_tm(t, &tm);
+	rtc_time64_to_tm(t, &tm);
 	tm.tm_year += 1900;
 
 	spin_lock_irqsave(&rtc_lock, flags);
diff --git a/arch/mips/sibyte/swarm/setup.c b/arch/mips/sibyte/swarm/setup.c
index 7073940..152ca71 100644
--- a/arch/mips/sibyte/swarm/setup.c
+++ b/arch/mips/sibyte/swarm/setup.c
@@ -57,11 +57,11 @@
 #endif
 
 extern int xicor_probe(void);
-extern int xicor_set_time(unsigned long);
+extern int xicor_set_time(time64_t);
 extern time64_t xicor_get_time(void);
 
 extern int m41t81_probe(void);
-extern int m41t81_set_time(unsigned long);
+extern int m41t81_set_time(time64_t);
 extern time64_t m41t81_get_time(void);
 
 const char *get_system_type(void)
@@ -109,8 +109,10 @@ void read_persistent_clock64(struct timespec64 *ts)
 	ts->tv_nsec = 0;
 }
 
-int rtc_mips_set_time(unsigned long sec)
+int update_persistent_clock64(struct timespec64 now)
 {
+	time64_t sec = now.tv_sec;
+
 	switch (swarm_rtc_type) {
 	case RTC_XICOR:
 		return xicor_set_time(sec);
-- 
1.7.9.5

Re: [PATCH v2 2/2] MIPS: Convert update_persistent_clock() to update_persistent_clock64()

[Arnd Bergmann]

On Fri, May 4, 2018 at 3:07 AM, Baolin Wang <baolin.wang@linaro.org> wrote:
> Since struct timespec is not y2038 safe on 32bit machines, this patch
> converts update_persistent_clock() to update_persistent_clock64() using
> struct timespec64.
>
> The rtc_mips_set_time() and rtc_mips_set_mmss() interfaces were using
> 'unsigned long' type that is not y2038 safe on 32bit machines, moreover
> there is only one platform implementing rtc_mips_set_time() and two
> platforms implementing rtc_mips_set_mmss(), so we can just make them each
> implement update_persistent_clock64() directly, to get that helper out
> of the common mips code by removing rtc_mips_set_time() and
> rtc_mips_set_mmss() interfaces.
>
> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>

Looks good overall, but I still found a bug and one minor issue. With
those fixed,

Acked-by: Arnd Bergmann <arnd@arndb.de>

> diff --git a/arch/mips/dec/time.c b/arch/mips/dec/time.c
> index 9e992cf..934db6f 100644
> --- a/arch/mips/dec/time.c
> +++ b/arch/mips/dec/time.c
> @@ -59,14 +59,15 @@ void read_persistent_clock64(struct timespec64 *ts)
>  }
>
>  /*
> - * In order to set the CMOS clock precisely, rtc_mips_set_mmss has to
> + * In order to set the CMOS clock precisely, update_persistent_clock64 has to
>   * be called 500 ms after the second nowtime has started, because when
>   * nowtime is written into the registers of the CMOS clock, it will
>   * jump to the next second precisely 500 ms later.  Check the Dallas
>   * DS1287 data sheet for details.
>   */
> -int rtc_mips_set_mmss(unsigned long nowtime)
> +int update_persistent_clock64(struct timespec64 now)
>  {
> +       time64_t nowtime = now.tv_sec;
>         int retval = 0;
>         int real_seconds, real_minutes, cmos_minutes;
>         unsigned char save_control, save_freq_select;


It looks like you now get an invalid 64-bit division in here,
you have to change it to either use div_u64_rem() or possibly
time64_to_tm() or rtc_time64_to_tm() (the latter requires
CONFIG_RTC_LIB).

> diff --git a/arch/mips/lasat/ds1603.c b/arch/mips/lasat/ds1603.c
> index d75c887..061815e 100644
> --- a/arch/mips/lasat/ds1603.c
> +++ b/arch/mips/lasat/ds1603.c
> @@ -98,7 +98,7 @@ static void rtc_write_byte(unsigned int byte)
>         }
>  }
>
> -static void rtc_write_word(unsigned long word)
> +static void rtc_write_word(time64_t word)
>  {
>         int i;
>

I would say this function should take a 'u32' argument (or keep the
unsigned long) to match the name and implementation, but then have a
type cast in the caller with a comment about the loss of range and overflow
in y2106.

> diff --git a/arch/mips/lasat/sysctl.c b/arch/mips/lasat/sysctl.c
> index 6f74224..76f7b62 100644
> --- a/arch/mips/lasat/sysctl.c
> +++ b/arch/mips/lasat/sysctl.c
> @@ -73,8 +73,12 @@ int proc_dolasatrtc(struct ctl_table *table, int write,
>         if (r)
>                 return r;
>
> -       if (write)
> -               rtc_mips_set_mmss(rtctmp);
> +       if (write) {
> +               ts.tv_sec = rtctmp;
> +               ts.tv_nsec = 0;
> +
> +               update_persistent_clock64(ts);
> +       }
>
... and probably also a comment here to explain that we can't actually use
the full 64-bit range because of HW limits.

         Arnd

Re: [PATCH v2 2/2] MIPS: Convert update_persistent_clock() to update_persistent_clock64()

[Baolin Wang]

On 6 May 2018 at 11:04, Arnd Bergmann <arnd@arndb.de> wrote:
> On Fri, May 4, 2018 at 3:07 AM, Baolin Wang <baolin.wang@linaro.org> wrote:
>> Since struct timespec is not y2038 safe on 32bit machines, this patch
>> converts update_persistent_clock() to update_persistent_clock64() using
>> struct timespec64.
>>
>> The rtc_mips_set_time() and rtc_mips_set_mmss() interfaces were using
>> 'unsigned long' type that is not y2038 safe on 32bit machines, moreover
>> there is only one platform implementing rtc_mips_set_time() and two
>> platforms implementing rtc_mips_set_mmss(), so we can just make them each
>> implement update_persistent_clock64() directly, to get that helper out
>> of the common mips code by removing rtc_mips_set_time() and
>> rtc_mips_set_mmss() interfaces.
>>
>> Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
>
> Looks good overall, but I still found a bug and one minor issue. With
> those fixed,
>
> Acked-by: Arnd Bergmann <arnd@arndb.de>
>
>> diff --git a/arch/mips/dec/time.c b/arch/mips/dec/time.c
>> index 9e992cf..934db6f 100644
>> --- a/arch/mips/dec/time.c
>> +++ b/arch/mips/dec/time.c
>> @@ -59,14 +59,15 @@ void read_persistent_clock64(struct timespec64 *ts)
>>  }
>>
>>  /*
>> - * In order to set the CMOS clock precisely, rtc_mips_set_mmss has to
>> + * In order to set the CMOS clock precisely, update_persistent_clock64 has to
>>   * be called 500 ms after the second nowtime has started, because when
>>   * nowtime is written into the registers of the CMOS clock, it will
>>   * jump to the next second precisely 500 ms later.  Check the Dallas
>>   * DS1287 data sheet for details.
>>   */
>> -int rtc_mips_set_mmss(unsigned long nowtime)
>> +int update_persistent_clock64(struct timespec64 now)
>>  {
>> +       time64_t nowtime = now.tv_sec;
>>         int retval = 0;
>>         int real_seconds, real_minutes, cmos_minutes;
>>         unsigned char save_control, save_freq_select;
>
>
> It looks like you now get an invalid 64-bit division in here,
> you have to change it to either use div_u64_rem() or possibly
> time64_to_tm() or rtc_time64_to_tm() (the latter requires
> CONFIG_RTC_LIB).

I will use div_u64_rem() to calculate real_seconds and real_minutes.

>
>> diff --git a/arch/mips/lasat/ds1603.c b/arch/mips/lasat/ds1603.c
>> index d75c887..061815e 100644
>> --- a/arch/mips/lasat/ds1603.c
>> +++ b/arch/mips/lasat/ds1603.c
>> @@ -98,7 +98,7 @@ static void rtc_write_byte(unsigned int byte)
>>         }
>>  }
>>
>> -static void rtc_write_word(unsigned long word)
>> +static void rtc_write_word(time64_t word)
>>  {
>>         int i;
>>
>
> I would say this function should take a 'u32' argument (or keep the
> unsigned long) to match the name and implementation, but then have a
> type cast in the caller with a comment about the loss of range and overflow
> in y2106.

OK.

>
>> diff --git a/arch/mips/lasat/sysctl.c b/arch/mips/lasat/sysctl.c
>> index 6f74224..76f7b62 100644
>> --- a/arch/mips/lasat/sysctl.c
>> +++ b/arch/mips/lasat/sysctl.c
>> @@ -73,8 +73,12 @@ int proc_dolasatrtc(struct ctl_table *table, int write,
>>         if (r)
>>                 return r;
>>
>> -       if (write)
>> -               rtc_mips_set_mmss(rtctmp);
>> +       if (write) {
>> +               ts.tv_sec = rtctmp;
>> +               ts.tv_nsec = 0;
>> +
>> +               update_persistent_clock64(ts);
>> +       }
>>
> ... and probably also a comment here to explain that we can't actually use
> the full 64-bit range because of HW limits.
>

OK. Thanks for your comments.

-- 
Baolin.wang
Best Regards