2 * Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com>
4 * Based on former do_div() implementation from asm-parisc/div64.h:
5 * Copyright (C) 1999 Hewlett-Packard Co
6 * Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
9 * Generic C version of 64bit/32bit division and modulo, with
10 * 64bit result and 32bit remainder.
12 * The fast case for (n>>32 == 0) is handled inline by do_div().
14 * Code generated for this function might be very inefficient
15 * for some CPUs. __div64_32() can be overridden by linking arch-specific
16 * assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S.
19 #include <linux/types.h>
20 #include <linux/module.h>
21 #include <asm/div64.h>
23 /* Not needed on 64bit architectures */
24 #if BITS_PER_LONG == 32
26 uint32_t __div64_32(uint64_t *n, uint32_t base)
28 uint32_t low, low2, high, rem;
30 low = *n & 0xffffffff;
32 rem = high % (uint32_t)base;
33 high = high / (uint32_t)base;
36 rem = low2 % (uint32_t)base;
37 low2 = low2 / (uint32_t)base;
40 rem = low % (uint32_t)base;
41 low = low / (uint32_t)base;
44 ((uint64_t)low2 << 16) +
45 ((uint64_t)high << 32);
50 EXPORT_SYMBOL(__div64_32);
52 #endif /* BITS_PER_LONG == 32 */