[PATCH] torture: use ktime_t consistently

[Arnd Bergmann <arnd@arndb.de>]

A recent change accidentally introduced a 64-bit division in torture_shutdown,
which fails to build on 32-bit architectures:

kernel/built-in.o: In function `torture_shutdown':
:(.text+0x4b29a): undefined reference to `__aeabi_uldivmod'

This converts the function to use ktime_t instead, which also simplifies
it a little.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: b4aa201e0c7c ("torture: Convert torture_shutdown() to hrtimer")
---
 kernel/torture.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/kernel/torture.c b/kernel/torture.c
index 55f0a317fbb5..bbcc92088bf9 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -448,7 +448,7 @@ EXPORT_SYMBOL_GPL(torture_shuffle_cleanup);
  */
 static int shutdown_secs;		/* desired test duration in seconds. */
 static struct task_struct *shutdown_task;
-static unsigned long shutdown_time;	/* jiffies to system shutdown. */
+static ktime_t shutdown_time;		/* time of system shutdown. */
 static void (*torture_shutdown_hook)(void);
 
 /*
@@ -471,24 +471,19 @@ EXPORT_SYMBOL_GPL(torture_shutdown_absorb);
  */
 static int torture_shutdown(void *arg)
 {
-	unsigned long long delta;
-	unsigned long jiffies_snap;
-	ktime_t wait_duration;
+	ktime_t now, delta;
 
 	VERBOSE_TOROUT_STRING("torture_shutdown task started");
-	jiffies_snap = jiffies;
-	while (ULONG_CMP_LT(jiffies_snap, shutdown_time) &&
-	       !torture_must_stop()) {
-		delta = shutdown_time - jiffies_snap;
+	now = ktime_get();
+	while (ktime_before(now, shutdown_time) && !torture_must_stop()) {
+		delta = ktime_sub(shutdown_time, now);
 		if (verbose)
 			pr_alert("%s" TORTURE_FLAG
-				 "torture_shutdown task: %llu jiffies remaining\n",
-				 torture_type, delta);
-		delta = delta * 1000ULL * 1000ULL * 1000ULL / HZ;
-		wait_duration = ns_to_ktime(delta);
+				 "torture_shutdown task: %llu ms remaining\n",
+				 torture_type, ktime_to_ms(delta));
 		set_current_state(TASK_INTERRUPTIBLE);
-		schedule_hrtimeout(&wait_duration, HRTIMER_MODE_REL);
-		jiffies_snap = jiffies;
+		schedule_hrtimeout(&delta, HRTIMER_MODE_REL);
+		now = ktime_get();
 	}
 	if (torture_must_stop()) {
 		torture_kthread_stopping("torture_shutdown");
@@ -518,7 +513,7 @@ int torture_shutdown_init(int ssecs, void (*cleanup)(void))
 	shutdown_secs = ssecs;
 	torture_shutdown_hook = cleanup;
 	if (shutdown_secs > 0) {
-		shutdown_time = jiffies + shutdown_secs * HZ;
+		shutdown_time = ktime_add(ktime_get(), ktime_set(ssecs, 0));
 		ret = torture_create_kthread(torture_shutdown, NULL,
 					     shutdown_task);
 	}
-- 
2.9.0