X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=datapath%2Flinux%2Fcompat%2Freciprocal_div.c;h=90ce7b1ca6432317206d81b9b27552ac3b4af5e7;hb=a27ce57b65959a3fb796ebb20958930624b0732e;hp=7ec75284052cfe0a535868c51c71012fb0105b10;hpb=1a65ba854469c6746f944b2e784100e4175e0bea;p=sliver-openvswitch.git

diff --git a/datapath/linux/compat/reciprocal_div.c b/datapath/linux/compat/reciprocal_div.c
index 7ec752840..90ce7b1ca 100644
--- a/datapath/linux/compat/reciprocal_div.c
+++ b/datapath/linux/compat/reciprocal_div.c
@@ -1,13 +1,25 @@
+#include <linux/kernel.h>
 #include <asm/div64.h>
 #include <linux/reciprocal_div.h>
 
-#include <linux/version.h>
-#if LINUX_VERSION_CODE < KERNEL_VERSION(3,3,0)
-/* definition is required since reciprocal_value() is not exported */
-u32 reciprocal_value(u32 k)
+/*
+ * For a description of the algorithm please have a look at
+ * include/linux/reciprocal_div.h
+ */
+
+struct reciprocal_value reciprocal_value(u32 d)
 {
-	u64 val = (1LL << 32) + (k - 1);
-	do_div(val, k);
-	return (u32)val;
+	struct reciprocal_value R;
+	u64 m;
+	int l;
+
+	l = fls(d - 1);
+	m = ((1ULL << 32) * ((1ULL << l) - d));
+	do_div(m, d);
+	++m;
+	R.m = (u32)m;
+	R.sh1 = min(l, 1);
+	R.sh2 = max(l - 1, 0);
+
+	return R;
 }
-#endif