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authorJiri Kosina <jkosina@suse.cz>2013-12-19 15:08:03 +0100
committerJiri Kosina <jkosina@suse.cz>2013-12-19 15:08:32 +0100
commite23c34bb41da65f354fb7eee04300c56ee48f60c (patch)
tree549fbe449d55273b81ef104a9755109bf4ae7817 /lib/div64.c
parentb481c2cb3534c85dca625973b33eba15f9af3e4c (diff)
parent319e2e3f63c348a9b66db4667efa73178e18b17d (diff)
Merge branch 'master' into for-next
Sync with Linus' tree to be able to apply fixes on top of newer things in tree (efi-stub). Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'lib/div64.c')
-rw-r--r--lib/div64.c40
1 files changed, 40 insertions, 0 deletions
diff --git a/lib/div64.c b/lib/div64.c
index a163b6caef73..4382ad77777e 100644
--- a/lib/div64.c
+++ b/lib/div64.c
@@ -79,6 +79,46 @@ EXPORT_SYMBOL(div_s64_rem);
#endif
/**
+ * div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder
+ * @dividend: 64bit dividend
+ * @divisor: 64bit divisor
+ * @remainder: 64bit remainder
+ *
+ * This implementation is a comparable to algorithm used by div64_u64.
+ * But this operation, which includes math for calculating the remainder,
+ * is kept distinct to avoid slowing down the div64_u64 operation on 32bit
+ * systems.
+ */
+#ifndef div64_u64_rem
+u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
+{
+ u32 high = divisor >> 32;
+ u64 quot;
+
+ if (high == 0) {
+ u32 rem32;
+ quot = div_u64_rem(dividend, divisor, &rem32);
+ *remainder = rem32;
+ } else {
+ int n = 1 + fls(high);
+ quot = div_u64(dividend >> n, divisor >> n);
+
+ if (quot != 0)
+ quot--;
+
+ *remainder = dividend - quot * divisor;
+ if (*remainder >= divisor) {
+ quot++;
+ *remainder -= divisor;
+ }
+ }
+
+ return quot;
+}
+EXPORT_SYMBOL(div64_u64_rem);
+#endif
+
+/**
* div64_u64 - unsigned 64bit divide with 64bit divisor
* @dividend: 64bit dividend
* @divisor: 64bit divisor