Re: [PATCH] [v2] scsi: ips: fix firmware timestamps for 32-bit

[Martin K. Petersen]

Arnd,

> do_gettimeofday() is deprecated since it will stop working in 2038 on
> 32-bit platforms, leading to incorrect times passed to the firmware.
> On 64-bit platforms the current code appears to be fine, as the
> calculation passes an 8-bit century number into the firmware that can
> represent times long in the future (possibly until 25599).
>
> Using ktime_get_real_seconds() to get a 64-bit seconds value and
> time64_to_tm() to convert it into the firmware format greatly
> simplifies the ips timekeeping code, makes 32-bit and 64-bit behave
> the same way here, and gets us closer to removing the deprecated
> interfaces.

Applied to 4.18/scsi-queue, thanks!

-- 
Martin K. Petersen  Oracle Linux Engineering

[PATCH] [v2] scsi: ips: fix firmware timestamps for 32-bit

[Arnd Bergmann]

do_gettimeofday() is deprecated since it will stop working in 2038 on
32-bit platforms, leading to incorrect times passed to the firmware.
On 64-bit platforms the current code appears to be fine, as the
calculation passes an 8-bit century number into the firmware that can
represent times long in the future (possibly until 25599).

Using ktime_get_real_seconds() to get a 64-bit seconds value and
time64_to_tm() to convert it into the firmware format greatly simplifies
the ips timekeeping code, makes 32-bit and 64-bit behave the same way
here, and gets us closer to removing the deprecated interfaces.

Signed-off-by: Arnd Bergmann 
---
v2: addressed review comments from Finn Thain:
  - rewrite changelog text
  - drop now-unused macros
  - fix incorrect century calculation
---
 drivers/scsi/ips.c | 78 +++---
 drivers/scsi/ips.h | 11 +---
 2 files changed, 17 insertions(+), 72 deletions(-)

diff --git a/drivers/scsi/ips.c b/drivers/scsi/ips.c
index a70f36a6d205..0e8a22c38c11 100644
--- a/drivers/scsi/ips.c
+++ b/drivers/scsi/ips.c
@@ -291,7 +291,7 @@ static void ips_freescb(ips_ha_t *, ips_scb_t *);
 static void ips_setup_funclist(ips_ha_t *);
 static void ips_statinit(ips_ha_t *);
 static void ips_statinit_memio(ips_ha_t *);
-static void ips_fix_ffdc_time(ips_ha_t *, ips_scb_t *, time_t);
+static void ips_fix_ffdc_time(ips_ha_t *, ips_scb_t *, time64_t);
 static void ips_ffdc_reset(ips_ha_t *, int);
 static void ips_ffdc_time(ips_ha_t *);
 static uint32_t ips_statupd_copperhead(ips_ha_t *);
@@ -985,10 +985,7 @@ static int __ips_eh_reset(struct scsi_cmnd *SC)
 
/* FFDC */
if (le32_to_cpu(ha->subsys->param[3]) & 0x30) {
-   struct timeval tv;
-
-   do_gettimeofday();
-   ha->last_ffdc = tv.tv_sec;
+   ha->last_ffdc = ktime_get_real_seconds();
ha->reset_count++;
ips_ffdc_reset(ha, IPS_INTR_IORL);
}
@@ -2392,7 +2389,6 @@ static int
 ips_hainit(ips_ha_t * ha)
 {
int i;
-   struct timeval tv;
 
METHOD_TRACE("ips_hainit", 1);
 
@@ -2407,8 +2403,7 @@ ips_hainit(ips_ha_t * ha)
 
/* Send FFDC */
ha->reset_count = 1;
-   do_gettimeofday();
-   ha->last_ffdc = tv.tv_sec;
+   ha->last_ffdc = ktime_get_real_seconds();
ips_ffdc_reset(ha, IPS_INTR_IORL);
 
if (!ips_read_config(ha, IPS_INTR_IORL)) {
@@ -2548,12 +2543,9 @@ ips_next(ips_ha_t * ha, int intr)
 
if ((ha->subsys->param[3] & 0x30)
&& (ha->scb_activelist.count == 0)) {
-   struct timeval tv;
-
-   do_gettimeofday();
-
-   if (tv.tv_sec - ha->last_ffdc > IPS_SECS_8HOURS) {
-   ha->last_ffdc = tv.tv_sec;
+   time64_t now = ktime_get_real_seconds();
+   if (now - ha->last_ffdc > IPS_SECS_8HOURS) {
+   ha->last_ffdc = now;
ips_ffdc_time(ha);
}
}
@@ -5988,59 +5980,21 @@ ips_ffdc_time(ips_ha_t * ha)
 /*  */
 //
 static void
-ips_fix_ffdc_time(ips_ha_t * ha, ips_scb_t * scb, time_t current_time)
+ips_fix_ffdc_time(ips_ha_t * ha, ips_scb_t * scb, time64_t current_time)
 {
-   long days;
-   long rem;
-   int i;
-   int year;
-   int yleap;
-   int year_lengths[2] = { IPS_DAYS_NORMAL_YEAR, IPS_DAYS_LEAP_YEAR };
-   int month_lengths[12][2] = { {31, 31},
-   {28, 29},
-   {31, 31},
-   {30, 30},
-   {31, 31},
-   {30, 30},
-   {31, 31},
-   {31, 31},
-   {30, 30},
-   {31, 31},
-   {30, 30},
-   {31, 31}
-   };
+   struct tm tm;
 
METHOD_TRACE("ips_fix_ffdc_time", 1);
 
-   days = current_time / IPS_SECS_DAY;
-   rem = current_time % IPS_SECS_DAY;
-
-   scb->cmd.ffdc.hour = (rem / IPS_SECS_HOUR);
-   rem = rem % IPS_SECS_HOUR;
-   scb->cmd.ffdc.minute = (rem / IPS_SECS_MIN);
-   scb->cmd.ffdc.second = (rem % IPS_SECS_MIN);
-
-   year = IPS_EPOCH_YEAR;
-   while (days < 0 || days >= year_lengths[yleap = 
IPS_IS_LEAP_YEAR(year)]) {
-   int newy;
-
-   newy = year + (days / IPS_DAYS_NORMAL_YEAR);
-   if (days < 0)
-   --newy;
-   days -= (newy - year) * IPS_DAYS_NORMAL_YEAR +
-   IPS_NUM_LEAP_YEARS_THROUGH(newy - 1) -
-   IPS_NUM_LEAP_YEARS_THROUGH(year - 1);
-   year = newy;
-   }
-
-   scb->cmd.ffdc.yearH = year / 100;
-   scb->cmd.ffdc.yearL = year % 100;
-
-   for (i = 0; days >= month_lengths[i][yleap]; ++i)
-   days -= month_lengths[i][yleap];
+   time64_to_tm(current_time, 0, );
 
-   scb->cmd.ffdc.month = i + 1;
-   scb->cmd.ffdc.day = days + 1;
+