From 8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Tue, 15 Dec 2015 14:52:16 -0300
Subject: Linux-libre 4.3.2-gnu

---
 kernel/time/time.c | 53 ++++++++++++++++++++++++++++-------------------------
 1 file changed, 28 insertions(+), 25 deletions(-)

(limited to 'kernel/time/time.c')

diff --git a/kernel/time/time.c b/kernel/time/time.c
index 85d5bb1d6..86751c68e 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -268,10 +268,14 @@ EXPORT_SYMBOL(jiffies_to_msecs);
 
 unsigned int jiffies_to_usecs(const unsigned long j)
 {
-#if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ)
+	/*
+	 * Hz usually doesn't go much further MSEC_PER_SEC.
+	 * jiffies_to_usecs() and usecs_to_jiffies() depend on that.
+	 */
+	BUILD_BUG_ON(HZ > USEC_PER_SEC);
+
+#if !(USEC_PER_SEC % HZ)
 	return (USEC_PER_SEC / HZ) * j;
-#elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC)
-	return (j + (HZ / USEC_PER_SEC) - 1)/(HZ / USEC_PER_SEC);
 #else
 # if BITS_PER_LONG == 32
 	return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32;
@@ -287,26 +291,20 @@ EXPORT_SYMBOL(jiffies_to_usecs);
  * @t: Timespec
  * @gran: Granularity in ns.
  *
- * Truncate a timespec to a granularity. gran must be smaller than a second.
- * Always rounds down.
- *
- * This function should be only used for timestamps returned by
- * current_kernel_time() or CURRENT_TIME, not with do_gettimeofday() because
- * it doesn't handle the better resolution of the latter.
+ * Truncate a timespec to a granularity. Always rounds down. gran must
+ * not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns).
  */
 struct timespec timespec_trunc(struct timespec t, unsigned gran)
 {
-	/*
-	 * Division is pretty slow so avoid it for common cases.
-	 * Currently current_kernel_time() never returns better than
-	 * jiffies resolution. Exploit that.
-	 */
-	if (gran <= jiffies_to_usecs(1) * 1000) {
+	/* Avoid division in the common cases 1 ns and 1 s. */
+	if (gran == 1) {
 		/* nothing */
-	} else if (gran == 1000000000) {
+	} else if (gran == NSEC_PER_SEC) {
 		t.tv_nsec = 0;
-	} else {
+	} else if (gran > 1 && gran < NSEC_PER_SEC) {
 		t.tv_nsec -= t.tv_nsec % gran;
+	} else {
+		WARN(1, "illegal file time granularity: %u", gran);
 	}
 	return t;
 }
@@ -546,7 +544,7 @@ EXPORT_SYMBOL(__usecs_to_jiffies);
  * value to a scaled second value.
  */
 static unsigned long
-__timespec_to_jiffies(unsigned long sec, long nsec)
+__timespec64_to_jiffies(u64 sec, long nsec)
 {
 	nsec = nsec + TICK_NSEC - 1;
 
@@ -554,22 +552,27 @@ __timespec_to_jiffies(unsigned long sec, long nsec)
 		sec = MAX_SEC_IN_JIFFIES;
 		nsec = 0;
 	}
-	return (((u64)sec * SEC_CONVERSION) +
+	return ((sec * SEC_CONVERSION) +
 		(((u64)nsec * NSEC_CONVERSION) >>
 		 (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC;
 
 }
 
-unsigned long
-timespec_to_jiffies(const struct timespec *value)
+static unsigned long
+__timespec_to_jiffies(unsigned long sec, long nsec)
 {
-	return __timespec_to_jiffies(value->tv_sec, value->tv_nsec);
+	return __timespec64_to_jiffies((u64)sec, nsec);
 }
 
-EXPORT_SYMBOL(timespec_to_jiffies);
+unsigned long
+timespec64_to_jiffies(const struct timespec64 *value)
+{
+	return __timespec64_to_jiffies(value->tv_sec, value->tv_nsec);
+}
+EXPORT_SYMBOL(timespec64_to_jiffies);
 
 void
-jiffies_to_timespec(const unsigned long jiffies, struct timespec *value)
+jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value)
 {
 	/*
 	 * Convert jiffies to nanoseconds and separate with
@@ -580,7 +583,7 @@ jiffies_to_timespec(const unsigned long jiffies, struct timespec *value)
 				    NSEC_PER_SEC, &rem);
 	value->tv_nsec = rem;
 }
-EXPORT_SYMBOL(jiffies_to_timespec);
+EXPORT_SYMBOL(jiffies_to_timespec64);
 
 /*
  * We could use a similar algorithm to timespec_to_jiffies (with a
-- 
cgit v1.2.3-54-g00ecf