x86/smpboot: Init apic mapping before usage

[cascardo/linux.git] / lib / reciprocal_div.c

diff --git a/lib/reciprocal_div.c b/lib/reciprocal_div.c
index 75510e9..4641524 100644 (file)
--- a/lib/reciprocal_div.c
+++ b/lib/reciprocal_div.c
@@ -1,11 +1,27 @@
+#include <linux/kernel.h>
 #include <asm/div64.h>
 #include <linux/reciprocal_div.h>
 #include <linux/export.h>
 
-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;
 }
 EXPORT_SYMBOL(reciprocal_value);