wprobe: add a header file that is missing in older kernel versions
authorFelix Fietkau <nbd@openwrt.org>
Fri, 8 May 2009 23:41:58 +0000 (23:41 +0000)
committerFelix Fietkau <nbd@openwrt.org>
Fri, 8 May 2009 23:41:58 +0000 (23:41 +0000)
SVN-Revision: 15726

package/wprobe/src/kernel/linux/math64.h [new file with mode: 0644]

diff --git a/package/wprobe/src/kernel/linux/math64.h b/package/wprobe/src/kernel/linux/math64.h
new file mode 100644 (file)
index 0000000..78621ae
--- /dev/null
@@ -0,0 +1,116 @@
+#ifndef _LINUX_MATH64_H
+#define _LINUX_MATH64_H
+
+#include <linux/types.h>
+#include <asm/div64.h>
+
+#if BITS_PER_LONG == 64
+
+/**
+ * div_u64_rem - unsigned 64bit divide with 32bit divisor with remainder
+ *
+ * This is commonly provided by 32bit archs to provide an optimized 64bit
+ * divide.
+ */
+static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
+{
+       *remainder = dividend % divisor;
+       return dividend / divisor;
+}
+
+/**
+ * div_s64_rem - signed 64bit divide with 32bit divisor with remainder
+ */
+static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
+{
+       *remainder = dividend % divisor;
+       return dividend / divisor;
+}
+
+/**
+ * div64_u64 - unsigned 64bit divide with 64bit divisor
+ */
+static inline u64 div64_u64(u64 dividend, u64 divisor)
+{
+       return dividend / divisor;
+}
+
+#elif BITS_PER_LONG == 32
+
+#ifndef div_u64_rem
+static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
+{
+       *remainder = do_div(dividend, divisor);
+       return dividend;
+}
+#endif
+
+#ifndef div_s64_rem
+static inline s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
+{
+       u64 quotient;
+
+       if (dividend < 0) {
+               quotient = div_u64_rem(-dividend, abs(divisor), (u32 *)remainder);
+               *remainder = -*remainder;
+               if (divisor > 0)
+                       quotient = -quotient;
+       } else {
+               quotient = div_u64_rem(dividend, abs(divisor), (u32 *)remainder);
+               if (divisor < 0)
+                       quotient = -quotient;
+       }
+       return quotient;
+}
+#endif
+
+#endif /* BITS_PER_LONG */
+
+/**
+ * div_u64 - unsigned 64bit divide with 32bit divisor
+ *
+ * This is the most common 64bit divide and should be used if possible,
+ * as many 32bit archs can optimize this variant better than a full 64bit
+ * divide.
+ */
+#ifndef div_u64
+static inline u64 div_u64(u64 dividend, u32 divisor)
+{
+       u32 remainder;
+       return div_u64_rem(dividend, divisor, &remainder);
+}
+#endif
+
+/**
+ * div_s64 - signed 64bit divide with 32bit divisor
+ */
+#ifndef div_s64
+static inline s64 div_s64(s64 dividend, s32 divisor)
+{
+       s32 remainder;
+       return div_s64_rem(dividend, divisor, &remainder);
+}
+#endif
+
+u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder);
+
+static __always_inline u32
+__iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder)
+{
+       u32 ret = 0;
+
+       while (dividend >= divisor) {
+               /* The following asm() prevents the compiler from
+                  optimising this loop into a modulo operation.  */
+               asm("" : "+rm"(dividend));
+
+               dividend -= divisor;
+               ret++;
+       }
+
+       *remainder = dividend;
+
+       return ret;
+}
+
+#endif /* _LINUX_MATH64_H */