[NET]: div64_64 consolidate (rev3)

Here is the current version of the 64 bit divide common code.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 22 insertions, 0 deletions

diff --git a/lib/div64.c b/lib/div64.c
index 365719f84832..c3d7655cdfb5 100644
--- a/lib/div64.c
+++ b/lib/div64.c
@@ -58,4 +58,26 @@ uint32_t __div64_32(uint64_t *n, uint32_t base)
 
 EXPORT_SYMBOL(__div64_32);
 
+/* 64bit divisor, dividend and result. dynamic precision */
+uint64_t div64_64(uint64_t dividend, uint64_t divisor)
+{
+        uint32_t d = divisor;
+
+        if (divisor > 0xffffffffULL) {
+                unsigned int shift = fls(divisor >> 32);
+
+                d = divisor >> shift;
+                dividend >>= shift;
+        }
+
+        /* avoid 64 bit division if possible */
+        if (dividend >> 32)
+                do_div(dividend, d);
+        else
+                dividend = (uint32_t) dividend / d;
+
+        return dividend;
+}
+EXPORT_SYMBOL(div64_64);
+
 #endif /* BITS_PER_LONG == 32 */