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Message-Id: <1516210371-20732-2-git-send-email-u9012063@gmail.com>
Date: Wed, 17 Jan 2018 09:32:50 -0800
From: William Tu <u9012063@...il.com>
To: netdev@...r.kernel.org
Cc: pshelar@....org, jbenc@...hat.com
Subject: [PATCHv3 net-next 1/2] net: erspan: use bitfield instead of mask and offset
Originally the erspan fields are defined as a group into a __be16 field,
and use mask and offset to access each field. This is more costly due to
calling ntohs/htons. The patch changes it to use bitfields.
Signed-off-by: William Tu <u9012063@...il.com>
---
include/net/erspan.h | 127 ++++++++++++++++++++++++++++++++++++++-------------
net/ipv4/ip_gre.c | 38 ++++++---------
net/ipv6/ip6_gre.c | 36 ++++++---------
3 files changed, 121 insertions(+), 80 deletions(-)
diff --git a/include/net/erspan.h b/include/net/erspan.h
index acdf6843095d..2b75821e2ebe 100644
--- a/include/net/erspan.h
+++ b/include/net/erspan.h
@@ -65,16 +65,30 @@
#define GRA_MASK 0x0006
#define O_MASK 0x0001
+#define HWID_OFFSET 4
+#define DIR_OFFSET 3
+
/* ERSPAN version 2 metadata header */
struct erspan_md2 {
__be32 timestamp;
__be16 sgt; /* security group tag */
- __be16 flags;
-#define P_OFFSET 15
-#define FT_OFFSET 10
-#define HWID_OFFSET 4
-#define DIR_OFFSET 3
-#define GRA_OFFSET 1
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+ __u8 hwid_upper:2,
+ ft:5,
+ p:1;
+ __u8 o:1,
+ gra:2,
+ dir:1,
+ hwid:4;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+ __u8 p:1,
+ ft:5,
+ hwid_upper:2;
+ __u8 hwid:4,
+ dir:1,
+ gra:2,
+ o:1;
+#endif
};
enum erspan_encap_type {
@@ -95,15 +109,62 @@ struct erspan_metadata {
};
struct erspan_base_hdr {
- __be16 ver_vlan;
-#define VER_OFFSET 12
- __be16 session_id;
-#define COS_OFFSET 13
-#define EN_OFFSET 11
-#define BSO_OFFSET EN_OFFSET
-#define T_OFFSET 10
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+ __u8 vlan_upper:4,
+ ver:4;
+ __u8 vlan:8;
+ __u8 session_id_upper:2,
+ t:1,
+ en:2,
+ cos:3;
+ __u8 session_id:8;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+ __u8 ver: 4,
+ vlan_upper:4;
+ __u8 vlan:8;
+ __u8 cos:3,
+ en:2,
+ t:1,
+ session_id_upper:2;
+ __u8 session_id:8;
+#else
+#error "Please fix <asm/byteorder.h>"
+#endif
};
+static inline void set_session_id(struct erspan_base_hdr *ershdr, u16 id)
+{
+ ershdr->session_id = id & 0xff;
+ ershdr->session_id_upper = (id >> 8) & 0x3;
+}
+
+static inline u16 get_session_id(const struct erspan_base_hdr *ershdr)
+{
+ return (ershdr->session_id_upper << 8) + ershdr->session_id;
+}
+
+static inline void set_vlan(struct erspan_base_hdr *ershdr, u16 vlan)
+{
+ ershdr->vlan = vlan & 0xff;
+ ershdr->vlan_upper = (vlan >> 8) & 0xf;
+}
+
+static inline u16 get_vlan(const struct erspan_base_hdr *ershdr)
+{
+ return (ershdr->vlan_upper << 8) + ershdr->vlan;
+}
+
+static inline void set_hwid(struct erspan_md2 *md2, u8 hwid)
+{
+ md2->hwid = hwid & 0xf;
+ md2->hwid_upper = (hwid >> 4) & 0x3;
+}
+
+static inline u8 get_hwid(const struct erspan_md2 *md2)
+{
+ return (md2->hwid_upper << 4) + md2->hwid;
+}
+
static inline int erspan_hdr_len(int version)
{
return sizeof(struct erspan_base_hdr) +
@@ -120,7 +181,7 @@ static inline u8 tos_to_cos(u8 tos)
}
static inline void erspan_build_header(struct sk_buff *skb,
- __be32 id, u32 index,
+ u32 id, u32 index,
bool truncate, bool is_ipv4)
{
struct ethhdr *eth = eth_hdr(skb);
@@ -154,12 +215,12 @@ static inline void erspan_build_header(struct sk_buff *skb,
memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V1_MDSIZE);
/* Build base header */
- ershdr->ver_vlan = htons((vlan_tci & VLAN_MASK) |
- (ERSPAN_VERSION << VER_OFFSET));
- ershdr->session_id = htons((u16)(ntohl(id) & ID_MASK) |
- ((tos_to_cos(tos) << COS_OFFSET) & COS_MASK) |
- (enc_type << EN_OFFSET & EN_MASK) |
- ((truncate << T_OFFSET) & T_MASK));
+ ershdr->ver = ERSPAN_VERSION;
+ ershdr->cos = tos_to_cos(tos);
+ ershdr->en = enc_type;
+ ershdr->t = truncate;
+ set_vlan(ershdr, vlan_tci);
+ set_session_id(ershdr, id);
/* Build metadata */
ersmd = (struct erspan_metadata *)(ershdr + 1);
@@ -187,7 +248,7 @@ static inline __be32 erspan_get_timestamp(void)
}
static inline void erspan_build_header_v2(struct sk_buff *skb,
- __be32 id, u8 direction, u16 hwid,
+ u32 id, u8 direction, u16 hwid,
bool truncate, bool is_ipv4)
{
struct ethhdr *eth = eth_hdr(skb);
@@ -198,7 +259,6 @@ static inline void erspan_build_header_v2(struct sk_buff *skb,
__be16 tci;
} *qp;
u16 vlan_tci = 0;
- u16 session_id;
u8 gra = 0; /* 100 usec */
u8 bso = 0; /* Bad/Short/Oversized */
u8 sgt = 0;
@@ -221,22 +281,23 @@ static inline void erspan_build_header_v2(struct sk_buff *skb,
memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V2_MDSIZE);
/* Build base header */
- ershdr->ver_vlan = htons((vlan_tci & VLAN_MASK) |
- (ERSPAN_VERSION2 << VER_OFFSET));
- session_id = (u16)(ntohl(id) & ID_MASK) |
- ((tos_to_cos(tos) << COS_OFFSET) & COS_MASK) |
- (bso << BSO_OFFSET & BSO_MASK) |
- ((truncate << T_OFFSET) & T_MASK);
- ershdr->session_id = htons(session_id);
+ ershdr->ver = ERSPAN_VERSION2;
+ ershdr->cos = tos_to_cos(tos);
+ ershdr->en = bso;
+ ershdr->t = truncate;
+ set_vlan(ershdr, vlan_tci);
+ set_session_id(ershdr, id);
/* Build metadata */
md = (struct erspan_metadata *)(ershdr + 1);
md->u.md2.timestamp = erspan_get_timestamp();
md->u.md2.sgt = htons(sgt);
- md->u.md2.flags = htons(((1 << P_OFFSET) & P_MASK) |
- ((hwid << HWID_OFFSET) & HWID_MASK) |
- ((direction << DIR_OFFSET) & DIR_MASK) |
- ((gra << GRA_OFFSET) & GRA_MASK));
+ md->u.md2.p = 1;
+ md->u.md2.ft = 0;
+ md->u.md2.dir = direction;
+ md->u.md2.gra = gra;
+ md->u.md2.o = 0;
+ set_hwid(&md->u.md2, hwid);
}
#endif
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index b61f2285816d..6ec670fbbbdd 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -114,7 +114,7 @@ MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
static struct rtnl_link_ops ipgre_link_ops __read_mostly;
static int ipgre_tunnel_init(struct net_device *dev);
static void erspan_build_header(struct sk_buff *skb,
- __be32 id, u32 index,
+ u32 id, u32 index,
bool truncate, bool is_ipv4);
static unsigned int ipgre_net_id __read_mostly;
@@ -273,12 +273,12 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
iph = ip_hdr(skb);
ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len);
- ver = (ntohs(ershdr->ver_vlan) & VER_MASK) >> VER_OFFSET;
+ ver = ershdr->ver;
/* The original GRE header does not have key field,
* Use ERSPAN 10-bit session ID as key.
*/
- tpi->key = cpu_to_be32(ntohs(ershdr->session_id) & ID_MASK);
+ tpi->key = cpu_to_be32(get_session_id(ershdr));
tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
tpi->flags | TUNNEL_KEY,
iph->saddr, iph->daddr, tpi->key);
@@ -324,14 +324,8 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
if (ver == 1) {
tunnel->index = ntohl(pkt_md->u.index);
} else {
- u16 md2_flags;
- u16 dir, hwid;
-
- md2_flags = ntohs(pkt_md->u.md2.flags);
- dir = (md2_flags & DIR_MASK) >> DIR_OFFSET;
- hwid = (md2_flags & HWID_MASK) >> HWID_OFFSET;
- tunnel->dir = dir;
- tunnel->hwid = hwid;
+ tunnel->dir = pkt_md->u.md2.dir;
+ tunnel->hwid = get_hwid(&pkt_md->u.md2);
}
}
@@ -615,19 +609,14 @@ static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev,
}
if (version == 1) {
- erspan_build_header(skb, tunnel_id_to_key32(key->tun_id),
+ erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)),
ntohl(md->u.index), truncate, true);
} else if (version == 2) {
- u16 md2_flags;
- u8 direction;
- u16 hwid;
-
- md2_flags = ntohs(md->u.md2.flags);
- direction = (md2_flags & DIR_MASK) >> DIR_OFFSET;
- hwid = (md2_flags & HWID_MASK) >> HWID_OFFSET;
-
- erspan_build_header_v2(skb, tunnel_id_to_key32(key->tun_id),
- direction, hwid, truncate, true);
+ erspan_build_header_v2(skb,
+ ntohl(tunnel_id_to_key32(key->tun_id)),
+ md->u.md2.dir,
+ get_hwid(&md->u.md2),
+ truncate, true);
} else {
goto err_free_rt;
}
@@ -733,10 +722,11 @@ static netdev_tx_t erspan_xmit(struct sk_buff *skb,
/* Push ERSPAN header */
if (tunnel->erspan_ver == 1)
- erspan_build_header(skb, tunnel->parms.o_key, tunnel->index,
+ erspan_build_header(skb, ntohl(tunnel->parms.o_key),
+ tunnel->index,
truncate, true);
else
- erspan_build_header_v2(skb, tunnel->parms.o_key,
+ erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key),
tunnel->dir, tunnel->hwid,
truncate, true);
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index db99446e0276..9f35087f93bc 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -512,8 +512,8 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
ipv6h = ipv6_hdr(skb);
ershdr = (struct erspan_base_hdr *)skb->data;
- ver = (ntohs(ershdr->ver_vlan) & VER_MASK) >> VER_OFFSET;
- tpi->key = cpu_to_be32(ntohs(ershdr->session_id) & ID_MASK);
+ ver = ershdr->ver;
+ tpi->key = cpu_to_be32(get_session_id(ershdr));
tunnel = ip6gre_tunnel_lookup(skb->dev,
&ipv6h->saddr, &ipv6h->daddr, tpi->key,
@@ -564,14 +564,8 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
if (ver == 1) {
tunnel->parms.index = ntohl(pkt_md->u.index);
} else {
- u16 md2_flags;
- u16 dir, hwid;
-
- md2_flags = ntohs(pkt_md->u.md2.flags);
- dir = (md2_flags & DIR_MASK) >> DIR_OFFSET;
- hwid = (md2_flags & HWID_MASK) >> HWID_OFFSET;
- tunnel->parms.dir = dir;
- tunnel->parms.hwid = hwid;
+ tunnel->parms.dir = pkt_md->u.md2.dir;
+ tunnel->parms.hwid = get_hwid(&pkt_md->u.md2);
}
ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
@@ -924,6 +918,7 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
struct ip_tunnel_info *tun_info;
const struct ip_tunnel_key *key;
struct erspan_metadata *md;
+ __be32 tun_id;
tun_info = skb_tunnel_info(skb);
if (unlikely(!tun_info ||
@@ -943,23 +938,18 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
if (!md)
goto tx_err;
+ tun_id = tunnel_id_to_key32(key->tun_id);
if (md->version == 1) {
erspan_build_header(skb,
- tunnel_id_to_key32(key->tun_id),
+ ntohl(tun_id),
ntohl(md->u.index), truncate,
false);
} else if (md->version == 2) {
- u16 md2_flags;
- u16 dir, hwid;
-
- md2_flags = ntohs(md->u.md2.flags);
- dir = (md2_flags & DIR_MASK) >> DIR_OFFSET;
- hwid = (md2_flags & HWID_MASK) >> HWID_OFFSET;
-
erspan_build_header_v2(skb,
- tunnel_id_to_key32(key->tun_id),
- dir, hwid, truncate,
- false);
+ ntohl(tun_id),
+ md->u.md2.dir,
+ get_hwid(&md->u.md2),
+ truncate, false);
}
} else {
switch (skb->protocol) {
@@ -981,11 +971,11 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
}
if (t->parms.erspan_ver == 1)
- erspan_build_header(skb, t->parms.o_key,
+ erspan_build_header(skb, ntohl(t->parms.o_key),
t->parms.index,
truncate, false);
else
- erspan_build_header_v2(skb, t->parms.o_key,
+ erspan_build_header_v2(skb, ntohl(t->parms.o_key),
t->parms.dir,
t->parms.hwid,
truncate, false);
--
2.7.4
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