4 files changed, 29 insertions, 26 deletions

diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c
index f813077234b7..a1929f33d703 100644
--- a/net/dccp/ccids/ccid3.c
+++ b/net/dccp/ccids/ccid3.c
@@ -159,8 +159,8 @@ static void ccid3_hc_tx_update_x(struct sock *sk, ktime_t *stamp)
 	} else if (ktime_us_delta(now, hctx->ccid3hctx_t_ld)
 				- (s64)hctx->ccid3hctx_rtt >= 0) {
 
-		hctx->ccid3hctx_x =
-			max(min(2 * hctx->ccid3hctx_x, min_rate),
+		hctx->ccid3hctx_x = min(2 * hctx->ccid3hctx_x, min_rate);
+		hctx->ccid3hctx_x = max(hctx->ccid3hctx_x,
 			    scaled_div(((__u64)hctx->ccid3hctx_s) << 6,
 				       hctx->ccid3hctx_rtt));
 		hctx->ccid3hctx_t_ld = now;
@@ -329,8 +329,14 @@ static int ccid3_hc_tx_send_packet(struct sock *sk, struct sk_buff *skb)
 			hctx->ccid3hctx_x    = rfc3390_initial_rate(sk);
 			hctx->ccid3hctx_t_ld = now;
 		} else {
-			/* Sender does not have RTT sample: X_pps = 1 pkt/sec */
-			hctx->ccid3hctx_x = hctx->ccid3hctx_s;
+			/*
+			 * Sender does not have RTT sample:
+			 * - set fallback RTT (RFC 4340, 3.4) since a RTT value
+			 *   is needed in several parts (e.g.  window counter);
+			 * - set sending rate X_pps = 1pps as per RFC 3448, 4.2.
+			 */
+			hctx->ccid3hctx_rtt = DCCP_FALLBACK_RTT;
+			hctx->ccid3hctx_x   = hctx->ccid3hctx_s;
 			hctx->ccid3hctx_x <<= 6;
 		}
 		ccid3_update_send_interval(hctx);
diff --git a/net/dccp/ccids/lib/tfrc.c b/net/dccp/ccids/lib/tfrc.c
index d1dfbb8de64c..97ecec0a8e76 100644
--- a/net/dccp/ccids/lib/tfrc.c
+++ b/net/dccp/ccids/lib/tfrc.c
@@ -14,14 +14,6 @@ module_param(tfrc_debug, bool, 0444);
 MODULE_PARM_DESC(tfrc_debug, "Enable debug messages");
 #endif
 
-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);
-
 static int __init tfrc_module_init(void)
 {
 	int rc = tfrc_li_init();
diff --git a/net/dccp/ccids/lib/tfrc.h b/net/dccp/ccids/lib/tfrc.h
index 1fb1187bbf1c..ed9857527acf 100644
--- a/net/dccp/ccids/lib/tfrc.h
+++ b/net/dccp/ccids/lib/tfrc.h
@@ -15,7 +15,7 @@
  *  (at your option) any later version.
  */
 #include <linux/types.h>
-#include <asm/div64.h>
+#include <linux/math64.h>
 #include "../../dccp.h"
 /* internal includes that this module exports: */
 #include "loss_interval.h"
@@ -29,21 +29,19 @@ extern int tfrc_debug;
 #endif
 
 /* integer-arithmetic divisions of type (a * 1000000)/b */
-static inline u64 scaled_div(u64 a, u32 b)
+static inline u64 scaled_div(u64 a, u64 b)
 {
 	BUG_ON(b==0);
-	a *= 1000000;
-	do_div(a, b);
-	return a;
+	return div64_u64(a * 1000000, b);
 }
 
-static inline u32 scaled_div32(u64 a, u32 b)
+static inline u32 scaled_div32(u64 a, u64 b)
 {
 	u64 result = scaled_div(a, b);
 
 	if (result > UINT_MAX) {
-		DCCP_CRIT("Overflow: a(%llu)/b(%u) > ~0U",
-			  (unsigned long long)a, b);
+		DCCP_CRIT("Overflow: %llu/%llu > UINT_MAX",
+			  (unsigned long long)a, (unsigned long long)b);
 		return UINT_MAX;
 	}
 	return result;
@@ -58,7 +56,14 @@ 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_calc_x(u16 s, u32 R, u32 p);
+extern u32  tfrc_calc_x_reverse_lookup(u32 fvalue);
 
+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);
 #endif /* _TFRC_H_ */
diff --git a/net/dccp/ccids/lib/tfrc_equation.c b/net/dccp/ccids/lib/tfrc_equation.c
index e4e64b76c10c..2f20a29cffe4 100644
--- a/net/dccp/ccids/lib/tfrc_equation.c
+++ b/net/dccp/ccids/lib/tfrc_equation.c
@@ -661,7 +661,7 @@ u32 tfrc_calc_x(u16 s, u32 R, u32 p)
 
 EXPORT_SYMBOL_GPL(tfrc_calc_x);
 
-/*
+/**
  *  tfrc_calc_x_reverse_lookup  -  try to find p given f(p)
  *
  *  @fvalue: function value to match, scaled by 1000000
@@ -676,11 +676,11 @@ u32 tfrc_calc_x_reverse_lookup(u32 fvalue)
 
 	/* Error cases. */
 	if (fvalue < tfrc_calc_x_lookup[0][1]) {
-		DCCP_WARN("fvalue %d smaller than resolution\n", fvalue);
-		return tfrc_calc_x_lookup[0][1];
+		DCCP_WARN("fvalue %u smaller than resolution\n", fvalue);
+		return TFRC_SMALLEST_P;
 	}
 	if (fvalue > tfrc_calc_x_lookup[TFRC_CALC_X_ARRSIZE - 1][0]) {
-		DCCP_WARN("fvalue %d exceeds bounds!\n", fvalue);
+		DCCP_WARN("fvalue %u exceeds bounds!\n", fvalue);
 		return 1000000;
 	}