[PATCH 1/4] ktime: add a roundup function

Jacob Pan
2015-11-13T19:54:07Z

ktime roundup function can be used to keep timer aligned and
prevent drift for recurring timeouts.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
include/linux/ktime.h | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/include/linux/ktime.h b/include/linux/ktime.h
index 2b6a204..2e293fa 100644
--- a/include/linux/ktime.h
+++ b/include/linux/ktime.h
@@ -233,6 +233,16 @@ static inline ktime_t ktime_sub_us(const ktime_t kt, const u64 usec)

extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs);

+static inline ktime_t ktime_roundup(ktime_t x, ktime_t y)
+{
+ u64 temp_tv64;
+
+ temp_tv64 = x.tv64 + y.tv64 - 1;
+ temp_tv64 = div64_u64(temp_tv64, y.tv64);
+ x.tv64 = temp_tv64 * y.tv64;
+
+ return x;
+}
/**
* ktime_to_timespec_cond - convert a ktime_t variable to timespec
* format only if the variable contains data
--
1.9.1