1 files changed, 34 insertions, 18 deletions

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 50a8736757f3..ba3e502c955a 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -479,6 +479,7 @@ static inline void clocksource_dequeue_watchdog(struct clocksource *cs) { }
 static inline void clocksource_resume_watchdog(void) { }
 static inline int __clocksource_watchdog_kthread(void) { return 0; }
 static bool clocksource_is_watchdog(struct clocksource *cs) { return false; }
+void clocksource_mark_unstable(struct clocksource *cs) { }
 
 #endif /* CONFIG_CLOCKSOURCE_WATCHDOG */
 
@@ -537,40 +538,55 @@ static u32 clocksource_max_adjustment(struct clocksource *cs)
 }
 
 /**
- * clocksource_max_deferment - Returns max time the clocksource can be deferred
- * @cs:         Pointer to clocksource
- *
+ * clocks_calc_max_nsecs - Returns maximum nanoseconds that can be converted
+ * @mult:       cycle to nanosecond multiplier
+ * @shift:      cycle to nanosecond divisor (power of two)
+ * @maxadj:     maximum adjustment value to mult (~11%)
+ * @mask:       bitmask for two's complement subtraction of non 64 bit counters
  */
-static u64 clocksource_max_deferment(struct clocksource *cs)
+u64 clocks_calc_max_nsecs(u32 mult, u32 shift, u32 maxadj, u64 mask)
 {
         u64 max_nsecs, max_cycles;
 
         /*
          * Calculate the maximum number of cycles that we can pass to the
          * cyc2ns function without overflowing a 64-bit signed result. The
-         * maximum number of cycles is equal to ULLONG_MAX/(cs->mult+cs->maxadj)
+         * maximum number of cycles is equal to ULLONG_MAX/(mult+maxadj)
          * which is equivalent to the below.
-         * max_cycles < (2^63)/(cs->mult + cs->maxadj)
-         * max_cycles < 2^(log2((2^63)/(cs->mult + cs->maxadj)))
-         * max_cycles < 2^(log2(2^63) - log2(cs->mult + cs->maxadj))
-         * max_cycles < 2^(63 - log2(cs->mult + cs->maxadj))
-         * max_cycles < 1 << (63 - log2(cs->mult + cs->maxadj))
+         * max_cycles < (2^63)/(mult + maxadj)
+         * max_cycles < 2^(log2((2^63)/(mult + maxadj)))
+         * max_cycles < 2^(log2(2^63) - log2(mult + maxadj))
+         * max_cycles < 2^(63 - log2(mult + maxadj))
+         * max_cycles < 1 << (63 - log2(mult + maxadj))
          * Please note that we add 1 to the result of the log2 to account for
          * any rounding errors, ensure the above inequality is satisfied and
          * no overflow will occur.
          */
-        max_cycles = 1ULL << (63 - (ilog2(cs->mult + cs->maxadj) + 1));
+        max_cycles = 1ULL << (63 - (ilog2(mult + maxadj) + 1));
 
         /*
          * The actual maximum number of cycles we can defer the clocksource is
-         * determined by the minimum of max_cycles and cs->mask.
+         * determined by the minimum of max_cycles and mask.
          * Note: Here we subtract the maxadj to make sure we don't sleep for
          * too long if there's a large negative adjustment.
          */
-        max_cycles = min_t(u64, max_cycles, (u64) cs->mask);
-        max_nsecs = clocksource_cyc2ns(max_cycles, cs->mult - cs->maxadj,
-                                        cs->shift);
+        max_cycles = min(max_cycles, mask);
+        max_nsecs = clocksource_cyc2ns(max_cycles, mult - maxadj, shift);
+
+        return max_nsecs;
+}
+
+/**
+ * clocksource_max_deferment - Returns max time the clocksource can be deferred
+ * @cs:         Pointer to clocksource
+ *
+ */
+static u64 clocksource_max_deferment(struct clocksource *cs)
+{
+        u64 max_nsecs;
 
+        max_nsecs = clocks_calc_max_nsecs(cs->mult, cs->shift, cs->maxadj,
+                                          cs->mask);
         /*
          * To ensure that the clocksource does not wrap whilst we are idle,
          * limit the time the clocksource can be deferred by 12.5%. Please
@@ -893,7 +909,7 @@ sysfs_show_current_clocksources(struct device *dev,
         return count;
 }
 
-size_t sysfs_get_uname(const char *buf, char *dst, size_t cnt)
+ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt)
 {
         size_t ret = cnt;
 
@@ -924,7 +940,7 @@ static ssize_t sysfs_override_clocksource(struct device *dev,
                                           struct device_attribute *attr,
                                           const char *buf, size_t count)
 {
-        size_t ret;
+        ssize_t ret;
 
         mutex_lock(&clocksource_mutex);
 
@@ -952,7 +968,7 @@ static ssize_t sysfs_unbind_clocksource(struct device *dev,
 {
         struct clocksource *cs;
         char name[CS_NAME_LEN];
-        size_t ret;
+        ssize_t ret;
 
         ret = sysfs_get_uname(buf, name, count);
         if (ret < 0)