tfrc.h

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#ifndef _TFRC_H_
#define _TFRC_H_
/*
 *  Copyright (c) 2007   The University of Aberdeen, Scotland, UK
 *  Copyright (c) 2005-6 The University of Waikato, Hamilton, New Zealand.
 *  Copyright (c) 2005-6 Ian McDonald <[email protected]>
 *  Copyright (c) 2005   Arnaldo Carvalho de Melo <[email protected]>
 *  Copyright (c) 2003   Nils-Erik Mattsson, Joacim Haggmark, Magnus Erixzon
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 */
#include <linux/types.h>
#include <linux/math64.h>
#include "../../dccp.h"

/* internal includes that this library exports: */
#include "loss_interval.h"
#include "packet_history.h"

#ifdef CONFIG_IP_DCCP_TFRC_DEBUG
extern bool tfrc_debug;
#define tfrc_pr_debug(format, a...) DCCP_PR_DEBUG(tfrc_debug, format, ##a)
#else
#define tfrc_pr_debug(format, a...)
#endif

/* integer-arithmetic divisions of type (a * 1000000)/b */
static inline u64 scaled_div(u64 a, u64 b)
{
    BUG_ON(b == 0);
    return div64_u64(a * 1000000, b);
}

static inline u32 scaled_div32(u64 a, u64 b)
{
    u64 result = scaled_div(a, b);

    if (result > UINT_MAX) {
        DCCP_CRIT("Overflow: %llu/%llu > UINT_MAX",
              (unsigned long long)a, (unsigned long long)b);
        return UINT_MAX;
    }
    return result;
}

static inline u32 tfrc_ewma(const u32 avg, const u32 newval, const u8 weight)
{
    return avg ? (weight * avg + (10 - weight) * newval) / 10 : newval;
}

extern u32  tfrc_calc_x(u16 s, u32 R, u32 p);
extern u32  tfrc_calc_x_reverse_lookup(u32 fvalue);
extern u32  tfrc_invert_loss_event_rate(u32 loss_event_rate);

extern int  tfrc_tx_packet_history_init(void);
extern void tfrc_tx_packet_history_exit(void);
extern int  tfrc_rx_packet_history_init(void);
extern void tfrc_rx_packet_history_exit(void);

extern int  tfrc_li_init(void);
extern void tfrc_li_exit(void);

#ifdef CONFIG_IP_DCCP_TFRC_LIB
extern int  tfrc_lib_init(void);
extern void tfrc_lib_exit(void);
#else
#define tfrc_lib_init() (0)
#define tfrc_lib_exit()
#endif
#endif /* _TFRC_H_ */