Revision 42270035c6550101f7dc742a630c2590dd2d3ae0 authored by Linus Torvalds on 04 March 2007, 21:15:48 UTC, committed by Linus Torvalds on 04 March 2007, 21:15:48 UTC
* master.kernel.org:/home/rmk/linux-2.6-arm: (30 commits)
  [ARM] Acorn: move the i2c bus driver into drivers/i2c
  [ARM] ARM SCSI: Don't try to dma_map_sg too many scatterlist entries
  [ARM] ARM FAS216: don't modify scsi_cmnd request_bufflen
  [ARM] rtc-pcf8583: Final fixes for this RTC on RiscPC
  [ARM] rtc-pcf8583: correct month and year offsets
  [ARM] rtc-pcf8583: don't use BCD_TO_BIN/BIN_TO_BCD
  [ARM] EBSA110: Work around build errors
  [ARM] 4241/1: Define mb() as compiler barrier on a uniprocessor system
  [ARM] 4239/1: S3C24XX: Update kconfig entries for PM
  [ARM] 4238/1: S3C24XX: docs: update suspend and resume
  [ARM] 4237/2: oprofile: Always allow backtraces on ARM
  [ARM] Yet more asm/apm-emulation.h stuff
  ARM: OMAP: Add missing get_irqnr_preamble and arch_ret_to_user for omap2
  ARM: OMAP: Use linux/delay.h not asm/delay.h
  ARM: OMAP: Remove obsolete alsa typedefs
  ARM: OMAP: omap1510->15xx conversions needed for sx1
  ARM: OMAP: Add missing includes to board-nokia770
  ARM: OMAP: Workqueue changes for board-h4.c
  ARM: OMAP: dmtimer.c omap1 register fix
  ARM: OMAP: board-nokia770: correct lcd name
  ...
2 parent s 2c89a8d + 8d91cba
Raw File
div64.c
/*
 * 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/types.h>
#include <linux/module.h>
#include <asm/div64.h>

/* Not needed on 64bit architectures */
#if BITS_PER_LONG == 32

uint32_t __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);

#endif /* BITS_PER_LONG == 32 */
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