1#ifndef _TFRC_H_
2#define _TFRC_H_
3/*
4 *  net/dccp/ccids/lib/tfrc.h
5 *
6 *  Copyright (c) 2005 The University of Waikato, Hamilton, New Zealand.
7 *  Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz>
8 *  Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@conectiva.com.br>
9 *  Copyright (c) 2003 Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
10 *
11 *  This program is free software; you can redistribute it and/or modify
12 *  it under the terms of the GNU General Public License as published by
13 *  the Free Software Foundation; either version 2 of the License, or
14 *  (at your option) any later version.
15 */
16#include <linux/types.h>
17#include <asm/div64.h>
18
19/* integer-arithmetic divisions of type (a * 1000000)/b */
20static inline u64 scaled_div(u64 a, u32 b)
21{
22	BUG_ON(b==0);
23	a *= 1000000;
24	do_div(a, b);
25	return a;
26}
27
28static inline u32 scaled_div32(u64 a, u32 b)
29{
30	u64 result = scaled_div(a, b);
31
32	if (result > UINT_MAX) {
33		DCCP_CRIT("Overflow: a(%llu)/b(%u) > ~0U",
34			  (unsigned long long)a, b);
35		return UINT_MAX;
36	}
37	return result;
38}
39
40extern u32 tfrc_calc_x(u16 s, u32 R, u32 p);
41extern u32 tfrc_calc_x_reverse_lookup(u32 fvalue);
42
43#endif /* _TFRC_H_ */
44