[U-Boot] [PATCH v1 02/11] include: time.h: define time64_t

AKASHI Takahiro
2019-10-17T05:39:54Z

On Sat, Oct 12, 2019 at 01:40:32PM +0200, Heinrich Schuchardt wrote:
> On 10/11/19 9:41 AM, AKASHI Takahiro wrote:
> >Adding time64_t definition will help improve portability of linux kernel
> >code (in my case, lib/crypto/x509_cert_parser.c).
> >
> >Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> >---
> > include/linux/time.h | 24 ++++++++++++++++++++++++
> > 1 file changed, 24 insertions(+)
> >
> >diff --git a/include/linux/time.h b/include/linux/time.h
> >index b8d298eb4d68..6186985856d7 100644
> >--- a/include/linux/time.h
> >+++ b/include/linux/time.h
> >@@ -150,4 +150,28 @@ _DEFUN (ctime_r, (tim_p, result),
> > return asctime_r (localtime_r (tim_p, &tm), result);
> > }
> >
> >+/* from <linux>/kernel/time/time.c */
> >+typedef __s64 time64_t;
>
> Wouldn't we want to put these definitions into a file
> include/linux/time64.h?

Obviously, there is no problem at following your suggestion, but
I hesitate to do so as it adds only one line header file.
Moreover, mktime64(), which is the only reason for this patch,
is also declared in "linux/time.h" even in linux code.
# Please note that "linux/time64.h" is mainly for timespec64 helper
functions, which are never used in U-Boot.

So I'd like to leave as it is. I think that we can re-visit this issue
in the future when other definitions in time64.h are required.

> >+
> >+inline time64_t mktime64(const unsigned int year0, const unsigned int mon0,
> >+ const unsigned int day, const unsigned int hour,
> >+ const unsigned int min, const unsigned int sec)
>
>
> Where is the function description?
>
> The Linux kernel does not make this function an inline function. Why
> should we inline it in U-Boot?
>
> >+{
> >+ unsigned int mon = mon0, year = year0;
> >+
> >+ /* 1..12 -> 11,12,1..10 */
> >+ mon -= 2;
> >+ if (0 >= (int)mon) {
> >+ mon += 12; /* Puts Feb last since it has leap day */
> >+ year -= 1;
> >+ }
> >+
> >+ return ((((time64_t)
> >+ (year / 4 - year / 100 + year / 400 + 367 * mon / 12 + day) +
> >+ year * 365 - 719499
> >+ ) * 24 + hour /* now have hours - midnight tomorrow handled here */
> >+ ) * 60 + min /* now have minutes */
> >+ ) * 60 + sec; /* finally seconds */
>
> This code is duplicate to rtc_mktime().
>
> Duplication could be avoided by letting rtc_mktime() call mktime64().

Okay, but as an inline function in this case.
In addition, drivers/rtc/date.c will be moved to lib/ for general use
with CONFIG_LIB_DATE.

Thanks,
-Takahiro Akashi

> Best regards
>
> Heinrich
>
> >+}
> >+
> > #endif
> >
>