1 files changed, 110 insertions, 0 deletions
diff --git a/lib/div64.c b/lib/div64.c
new file mode 100644
index 0000000..a111eb8
--- /dev/null
+++ b/lib/div64.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com>
+ *
+ * Based on former do_div() implementation from asm-parisc/div64.h:
+ *	Copyright (C) 1999 Hewlett-Packard Co
+ *	Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
+ *
+ *
+ * Generic C version of 64bit/32bit division and modulo, with
+ * 64bit result and 32bit remainder.
+ *
+ * The fast case for (n>>32 == 0) is handled inline by do_div(). 
+ *
+ * Code generated for this function might be very inefficient
+ * for some CPUs. __div64_32() can be overridden by linking arch-specific
+ * assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S.
+ */
+
+#include <linux/module.h>
+#include <linux/math64.h>
+
+/* Not needed on 64bit architectures */
+#if BITS_PER_LONG == 32
+
+uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base)
+{
+	uint64_t rem = *n;
+	uint64_t b = base;
+	uint64_t res, d = 1;
+	uint32_t high = rem >> 32;
+
+	/* Reduce the thing a bit first */
+	res = 0;
+	if (high >= base) {
+		high /= base;
+		res = (uint64_t) high << 32;
+		rem -= (uint64_t) (high*base) << 32;
+	}
+
+	while ((int64_t)b > 0 && b < rem) {
+		b = b+b;
+		d = d+d;
+	}
+
+	do {
+		if (rem >= b) {
+			rem -= b;
+			res += d;
+		}
+		b >>= 1;
+		d >>= 1;
+	} while (d);
+
+	*n = res;
+	return rem;
+}
+
+EXPORT_SYMBOL(__div64_32);
+
+#ifndef div_s64_rem
+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;
+}
+EXPORT_SYMBOL(div_s64_rem);
+#endif
+
+/* 64bit divisor, dividend and result. dynamic precision */
+#ifndef div64_u64
+u64 div64_u64(u64 dividend, u64 divisor)
+{
+	u32 high, d;
+
+	high = divisor >> 32;
+	if (high) {
+		unsigned int shift = fls(high);
+
+		d = divisor >> shift;
+		dividend >>= shift;
+	} else
+		d = divisor;
+
+	return div_u64(dividend, d);
+}
+EXPORT_SYMBOL(div64_u64);
+#endif
+
+#endif /* BITS_PER_LONG == 32 */
+
+/*
+ * Iterative div/mod for use when dividend is not expected to be much
+ * bigger than divisor.
+ */
+u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder)
+{
+	return __iter_div_u64_rem(dividend, divisor, remainder);
+}
+EXPORT_SYMBOL(iter_div_u64_rem);