[PATCH v2 net-next] ipvlan: remove ipvlan_ht_addr_lookup()

[Eric Dumazet <edumazet@google.com>]

ipvlan_ht_addr_lookup() is called four times and not inlined.

Split it to ipvlan_ht_addr_lookup6() and ipvlan_ht_addr_lookup4()
and rework ipvlan_addr_lookup() to call these helpers once,
so that they are (auto)inlined.

After this change, ipvlan_addr_lookup() is faster, and we save
350 bytes of text on x86_64.

$ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
add/remove: 0/2 grow/shrink: 1/0 up/down: 123/-473 (-350)
Function                                     old     new   delta
ipvlan_addr_lookup                           467     590    +123
__pfx_ipvlan_ht_addr_lookup                   16       -     -16
ipvlan_ht_addr_lookup                        457       -    -457
Total: Before=22571833, After=22571483, chg -0.00%

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mahesh Bandewar <maheshb@google.com>
---
v2: guard ipvlan_ht_addr_lookup6() with CONFIG_IPV6 (kernel test robot)
v1: https://lore.kernel.org/netdev/20260121215728.560645-1-edumazet@google.com/
 drivers/net/ipvlan/ipvlan_core.c | 55 ++++++++++++++++++++------------
 1 file changed, 34 insertions(+), 21 deletions(-)

diff --git a/drivers/net/ipvlan/ipvlan_core.c b/drivers/net/ipvlan/ipvlan_core.c
index 2efa3ba148aa7efed999dc3c06ccbb787eca92e5..f1568d50f5cc8259e6166993bda8a3425e4e5937 100644
--- a/drivers/net/ipvlan/ipvlan_core.c
+++ b/drivers/net/ipvlan/ipvlan_core.c
@@ -48,11 +48,9 @@ static u8 ipvlan_get_v6_hash(const void *iaddr)
 }
 #endif
 
-static u8 ipvlan_get_v4_hash(const void *iaddr)
+static u8 ipvlan_get_v4_hash(__be32 addr)
 {
-	const struct in_addr *ip4_addr = iaddr;
-
-	return jhash_1word((__force u32)ip4_addr->s_addr, ipvlan_jhash_secret) &
+	return jhash_1word((__force u32)addr, ipvlan_jhash_secret) &
 			   IPVLAN_HASH_MASK;
 }
 
@@ -73,16 +71,30 @@ static bool addr_equal(bool is_v6, struct ipvl_addr *addr, const void *iaddr)
 	return false;
 }
 
-static struct ipvl_addr *ipvlan_ht_addr_lookup(const struct ipvl_port *port,
-					       const void *iaddr, bool is_v6)
+#if IS_ENABLED(CONFIG_IPV6)
+static struct ipvl_addr *ipvlan_ht_addr_lookup6(const struct ipvl_port *port,
+						const void *iaddr)
 {
 	struct ipvl_addr *addr;
 	u8 hash;
 
-	hash = is_v6 ? ipvlan_get_v6_hash(iaddr) :
-	       ipvlan_get_v4_hash(iaddr);
+	hash = ipvlan_get_v6_hash(iaddr);
 	hlist_for_each_entry_rcu(addr, &port->hlhead[hash], hlnode)
-		if (addr_equal(is_v6, addr, iaddr))
+		if (addr_equal(true, addr, iaddr))
+			return addr;
+	return NULL;
+}
+#endif
+
+static struct ipvl_addr *ipvlan_ht_addr_lookup4(const struct ipvl_port *port,
+						__be32 addr4)
+{
+	struct ipvl_addr *addr;
+	u8 hash;
+
+	hash = ipvlan_get_v4_hash(addr4);
+	hlist_for_each_entry_rcu(addr, &port->hlhead[hash], hlnode)
+		if (addr->atype == IPVL_IPV4 && addr->ip4addr.s_addr == addr4)
 			return addr;
 	return NULL;
 }
@@ -94,7 +106,7 @@ void ipvlan_ht_addr_add(struct ipvl_dev *ipvlan, struct ipvl_addr *addr)
 
 	hash = (addr->atype == IPVL_IPV6) ?
 	       ipvlan_get_v6_hash(&addr->ip6addr) :
-	       ipvlan_get_v4_hash(&addr->ip4addr);
+	       ipvlan_get_v4_hash(addr->ip4addr.s_addr);
 	if (hlist_unhashed(&addr->hlnode))
 		hlist_add_head_rcu(&addr->hlnode, &port->hlhead[hash]);
 }
@@ -357,21 +369,24 @@ struct ipvl_addr *ipvlan_addr_lookup(struct ipvl_port *port, void *lyr3h,
 				     int addr_type, bool use_dest)
 {
 	struct ipvl_addr *addr = NULL;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct in6_addr *i6addr;
+#endif
+	__be32 addr4;
 
 	switch (addr_type) {
 #if IS_ENABLED(CONFIG_IPV6)
 	case IPVL_IPV6: {
 		struct ipv6hdr *ip6h;
-		struct in6_addr *i6addr;
 
 		ip6h = (struct ipv6hdr *)lyr3h;
 		i6addr = use_dest ? &ip6h->daddr : &ip6h->saddr;
-		addr = ipvlan_ht_addr_lookup(port, i6addr, true);
+lookup6:
+		addr = ipvlan_ht_addr_lookup6(port, i6addr);
 		break;
 	}
 	case IPVL_ICMPV6: {
 		struct nd_msg *ndmh;
-		struct in6_addr *i6addr;
 
 		/* Make sure that the NeighborSolicitation ICMPv6 packets
 		 * are handled to avoid DAD issue.
@@ -379,24 +394,23 @@ struct ipvl_addr *ipvlan_addr_lookup(struct ipvl_port *port, void *lyr3h,
 		ndmh = (struct nd_msg *)lyr3h;
 		if (ndmh->icmph.icmp6_type == NDISC_NEIGHBOUR_SOLICITATION) {
 			i6addr = &ndmh->target;
-			addr = ipvlan_ht_addr_lookup(port, i6addr, true);
+			goto lookup6;
 		}
 		break;
 	}
 #endif
 	case IPVL_IPV4: {
 		struct iphdr *ip4h;
-		__be32 *i4addr;
 
 		ip4h = (struct iphdr *)lyr3h;
-		i4addr = use_dest ? &ip4h->daddr : &ip4h->saddr;
-		addr = ipvlan_ht_addr_lookup(port, i4addr, false);
+		addr4 = use_dest ? ip4h->daddr : ip4h->saddr;
+lookup4:
+		addr = ipvlan_ht_addr_lookup4(port, addr4);
 		break;
 	}
 	case IPVL_ARP: {
 		struct arphdr *arph;
 		unsigned char *arp_ptr;
-		__be32 dip;
 
 		arph = (struct arphdr *)lyr3h;
 		arp_ptr = (unsigned char *)(arph + 1);
@@ -405,9 +419,8 @@ struct ipvl_addr *ipvlan_addr_lookup(struct ipvl_port *port, void *lyr3h,
 		else
 			arp_ptr += port->dev->addr_len;
 
-		memcpy(&dip, arp_ptr, 4);
-		addr = ipvlan_ht_addr_lookup(port, &dip, false);
-		break;
+		addr4 = get_unaligned((__be32 *)arp_ptr);
+		goto lookup4;
 	}
 	}
 
-- 
2.52.0.457.g6b5491de43-goog