From: Vlad Buslov <vladbu@mellanox.com>
Date: Wed, 30 Oct 2019 16:09:04 +0200
Subject: net: sched: modify stats helper functions to support regular stats
Patch-mainline: v5.5-rc1
Git-commit: 5e174d5e73dfbfb2c4bc4804f58f2f2aa34c9281
References: bsc#1154353

Modify stats update helper functions introduced in previous patches in this
series to fallback to regular tc_action->tcfa_{b|q}stats if cpu stats are
not allocated for the action argument. If regular non-percpu allocated
counters are in use, then obtain action tcfa_lock while modifying them.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 include/net/act_api.h |   30 +++++++++++++++++++++---------
 net/sched/act_api.c   |   19 ++++++++++++++-----
 2 files changed, 35 insertions(+), 14 deletions(-)

--- a/include/net/act_api.h
+++ b/include/net/act_api.h
@@ -190,23 +190,35 @@ int tcf_action_dump_1(struct sk_buff *sk
 static inline void tcf_action_update_bstats(struct tc_action *a,
 					    struct sk_buff *skb)
 {
-	bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), skb);
-}
-
-static inline struct gnet_stats_queue *
-tcf_action_get_qstats(struct tc_action *a)
-{
-	return this_cpu_ptr(a->cpu_qstats);
+	if (likely(a->cpu_bstats)) {
+		bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), skb);
+		return;
+	}
+	spin_lock(&a->tcfa_lock);
+	bstats_update(&a->tcfa_bstats, skb);
+	spin_unlock(&a->tcfa_lock);
 }
 
 static inline void tcf_action_inc_drop_qstats(struct tc_action *a)
 {
-	qstats_drop_inc(this_cpu_ptr(a->cpu_qstats));
+	if (likely(a->cpu_qstats)) {
+		qstats_drop_inc(this_cpu_ptr(a->cpu_qstats));
+		return;
+	}
+	spin_lock(&a->tcfa_lock);
+	qstats_drop_inc(&a->tcfa_qstats);
+	spin_unlock(&a->tcfa_lock);
 }
 
 static inline void tcf_action_inc_overlimit_qstats(struct tc_action *a)
 {
-	qstats_overlimit_inc(this_cpu_ptr(a->cpu_qstats));
+	if (likely(a->cpu_qstats)) {
+		qstats_overlimit_inc(this_cpu_ptr(a->cpu_qstats));
+		return;
+	}
+	spin_lock(&a->tcfa_lock);
+	qstats_overlimit_inc(&a->tcfa_qstats);
+	spin_unlock(&a->tcfa_lock);
 }
 
 void tcf_action_update_stats(struct tc_action *a, u64 bytes, u32 packets,
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -992,14 +992,23 @@ err:
 void tcf_action_update_stats(struct tc_action *a, u64 bytes, u32 packets,
 			     bool drop, bool hw)
 {
-	_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
+	if (a->cpu_bstats) {
+		_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
 
-	if (drop)
-		this_cpu_ptr(a->cpu_qstats)->drops += packets;
+		if (drop)
+			this_cpu_ptr(a->cpu_qstats)->drops += packets;
+
+		if (hw)
+			_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
+					   bytes, packets);
+		return;
+	}
 
+	_bstats_update(&a->tcfa_bstats, bytes, packets);
+	if (drop)
+		a->tcfa_qstats.drops += packets;
 	if (hw)
-		_bstats_cpu_update(this_cpu_ptr(a->cpu_bstats_hw),
-				   bytes, packets);
+		_bstats_update(&a->tcfa_bstats_hw, bytes, packets);
 }
 EXPORT_SYMBOL(tcf_action_update_stats);