From 528b8f20eafa55d48749a6bcb80937aa0c810c2a Mon Sep 17 00:00:00 2001
From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: Wed, 20 Oct 2021 20:49:49 +0300
Subject: [PATCH 06/19] net: dsa: introduce helpers for iterating through ports
 using dp
Git-commit: 82b318983c515f29b8b3a0dad9f6a5fe8a68a7f4
Patch-mainline: v5.16-rc1
References: git-fixes

Since the DSA conversion from the ds->ports array into the dst->ports
list, the DSA API has encouraged driver writers, as well as the core
itself, to write inefficient code.

Currently, code that wants to filter by a specific type of port when
iterating, like {!unused, user, cpu, dsa}, uses the dsa_is_*_port helper.
Under the hood, this uses dsa_to_port which iterates again through
dst->ports. But the driver iterates through the port list already, so
the complexity is quadratic for the typical case of a single-switch
tree.

This patch introduces some iteration helpers where the iterator is
already a struct dsa_port *dp, so that the other variant of the
filtering functions, dsa_port_is_{unused,user,cpu_dsa}, can be used
directly on the iterator. This eliminates the second lookup.

These functions can be used both by the core and by drivers.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
 include/net/dsa.h | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/include/net/dsa.h b/include/net/dsa.h
index e483012b5522..85681498f2e2 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -462,6 +462,34 @@ static inline bool dsa_is_user_port(struct dsa_switch *ds, int p)
 	return dsa_to_port(ds, p)->type == DSA_PORT_TYPE_USER;
 }
 
+#define dsa_tree_for_each_user_port(_dp, _dst) \
+	list_for_each_entry((_dp), &(_dst)->ports, list) \
+		if (dsa_port_is_user((_dp)))
+
+#define dsa_switch_for_each_port(_dp, _ds) \
+	list_for_each_entry((_dp), &(_ds)->dst->ports, list) \
+		if ((_dp)->ds == (_ds))
+
+#define dsa_switch_for_each_port_safe(_dp, _next, _ds) \
+	list_for_each_entry_safe((_dp), (_next), &(_ds)->dst->ports, list) \
+		if ((_dp)->ds == (_ds))
+
+#define dsa_switch_for_each_port_continue_reverse(_dp, _ds) \
+	list_for_each_entry_continue_reverse((_dp), &(_ds)->dst->ports, list) \
+		if ((_dp)->ds == (_ds))
+
+#define dsa_switch_for_each_available_port(_dp, _ds) \
+	dsa_switch_for_each_port((_dp), (_ds)) \
+		if (!dsa_port_is_unused((_dp)))
+
+#define dsa_switch_for_each_user_port(_dp, _ds) \
+	dsa_switch_for_each_port((_dp), (_ds)) \
+		if (dsa_port_is_user((_dp)))
+
+#define dsa_switch_for_each_cpu_port(_dp, _ds) \
+	dsa_switch_for_each_port((_dp), (_ds)) \
+		if (dsa_port_is_cpu((_dp)))
+
 static inline u32 dsa_user_ports(struct dsa_switch *ds)
 {
 	u32 mask = 0;
-- 
2.16.4