From 6e0735723ab437793cfab02d50b3ae3539aeb520 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Wed, 6 Mar 2024 16:00:27 +0000
Subject: inet: move inet_ehash_secret and udp_ehash_secret into net_hotdata

"struct net_protocol" has a 32bit hole in 32bit arches.

Use it to store the 32bit secret used by UDP and TCP,
to increase cache locality in rx path.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240306160031.874438-15-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 include/net/hotdata.h      | 3 +++
 include/net/protocol.h     | 1 +
 net/ipv4/inet_hashtables.c | 3 +--
 net/ipv4/udp.c             | 2 --
 4 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/include/net/hotdata.h b/include/net/hotdata.h
index 87215f7ac200..7a210ea6899c 100644
--- a/include/net/hotdata.h
+++ b/include/net/hotdata.h
@@ -36,6 +36,9 @@ struct net_hotdata {
 	int			dev_rx_weight;
 };
 
+#define inet_ehash_secret	net_hotdata.tcp_protocol.secret
+#define udp_ehash_secret	net_hotdata.udp_protocol.secret
+
 extern struct net_hotdata net_hotdata;
 
 #endif /* _NET_HOTDATA_H */
diff --git a/include/net/protocol.h b/include/net/protocol.h
index 6aef8cb11cc8..3ff26e66735c 100644
--- a/include/net/protocol.h
+++ b/include/net/protocol.h
@@ -46,6 +46,7 @@ struct net_protocol {
 				 * socket lookup?
 				 */
 				icmp_strict_tag_validation:1;
+	u32			secret;
 };
 
 #if IS_ENABLED(CONFIG_IPV6)
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 308ff34002ea..7498af320164 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -24,6 +24,7 @@
 #include <net/inet6_hashtables.h>
 #endif
 #include <net/secure_seq.h>
+#include <net/hotdata.h>
 #include <net/ip.h>
 #include <net/tcp.h>
 #include <net/sock_reuseport.h>
@@ -32,8 +33,6 @@ u32 inet_ehashfn(const struct net *net, const __be32 laddr,
 		 const __u16 lport, const __be32 faddr,
 		 const __be16 fport)
 {
-	static u32 inet_ehash_secret __read_mostly;
-
 	net_get_random_once(&inet_ehash_secret, sizeof(inet_ehash_secret));
 
 	return __inet_ehashfn(laddr, lport, faddr, fport,
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index a8acea17b4e5..2beabf5b2d86 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -411,8 +411,6 @@ INDIRECT_CALLABLE_SCOPE
 u32 udp_ehashfn(const struct net *net, const __be32 laddr, const __u16 lport,
 		const __be32 faddr, const __be16 fport)
 {
-	static u32 udp_ehash_secret __read_mostly;
-
 	net_get_random_once(&udp_ehash_secret, sizeof(udp_ehash_secret));
 
 	return __inet_ehashfn(laddr, lport, faddr, fport,
-- 
cgit