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williamtudavem330
williamtu
authored and
davem330
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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 <[email protected]> Acked-by: Pravin B Shelar <[email protected]> Signed-off-by: David S. Miller <[email protected]>
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3 files changed

+121
-80
lines changed

3 files changed

+121
-80
lines changed

‎include/net/erspan.h

Lines changed: 94 additions & 33 deletions
Original file line numberDiff line numberDiff line change
@@ -65,16 +65,30 @@
6565
#define GRA_MASK 0x0006
6666
#define O_MASK 0x0001
6767

68+
#define HWID_OFFSET 4
69+
#define DIR_OFFSET 3
70+
6871
/* ERSPAN version 2 metadata header */
6972
struct erspan_md2 {
7073
__be32 timestamp;
7174
__be16 sgt; /* security group tag */
72-
__be16 flags;
73-
#define P_OFFSET 15
74-
#define FT_OFFSET 10
75-
#define HWID_OFFSET 4
76-
#define DIR_OFFSET 3
77-
#define GRA_OFFSET 1
75+
#if defined(__LITTLE_ENDIAN_BITFIELD)
76+
__u8 hwid_upper:2,
77+
ft:5,
78+
p:1;
79+
__u8 o:1,
80+
gra:2,
81+
dir:1,
82+
hwid:4;
83+
#elif defined(__BIG_ENDIAN_BITFIELD)
84+
__u8 p:1,
85+
ft:5,
86+
hwid_upper:2;
87+
__u8 hwid:4,
88+
dir:1,
89+
gra:2,
90+
o:1;
91+
#endif
7892
};
7993

8094
enum erspan_encap_type {
@@ -95,15 +109,62 @@ struct erspan_metadata {
95109
};
96110

97111
struct erspan_base_hdr {
98-
__be16 ver_vlan;
99-
#define VER_OFFSET 12
100-
__be16 session_id;
101-
#define COS_OFFSET 13
102-
#define EN_OFFSET 11
103-
#define BSO_OFFSET EN_OFFSET
104-
#define T_OFFSET 10
112+
#if defined(__LITTLE_ENDIAN_BITFIELD)
113+
__u8 vlan_upper:4,
114+
ver:4;
115+
__u8 vlan:8;
116+
__u8 session_id_upper:2,
117+
t:1,
118+
en:2,
119+
cos:3;
120+
__u8 session_id:8;
121+
#elif defined(__BIG_ENDIAN_BITFIELD)
122+
__u8 ver: 4,
123+
vlan_upper:4;
124+
__u8 vlan:8;
125+
__u8 cos:3,
126+
en:2,
127+
t:1,
128+
session_id_upper:2;
129+
__u8 session_id:8;
130+
#else
131+
#error "Please fix <asm/byteorder.h>"
132+
#endif
105133
};
106134

135+
static inline void set_session_id(struct erspan_base_hdr *ershdr, u16 id)
136+
{
137+
ershdr->session_id = id & 0xff;
138+
ershdr->session_id_upper = (id >> 8) & 0x3;
139+
}
140+
141+
static inline u16 get_session_id(const struct erspan_base_hdr *ershdr)
142+
{
143+
return (ershdr->session_id_upper << 8) + ershdr->session_id;
144+
}
145+
146+
static inline void set_vlan(struct erspan_base_hdr *ershdr, u16 vlan)
147+
{
148+
ershdr->vlan = vlan & 0xff;
149+
ershdr->vlan_upper = (vlan >> 8) & 0xf;
150+
}
151+
152+
static inline u16 get_vlan(const struct erspan_base_hdr *ershdr)
153+
{
154+
return (ershdr->vlan_upper << 8) + ershdr->vlan;
155+
}
156+
157+
static inline void set_hwid(struct erspan_md2 *md2, u8 hwid)
158+
{
159+
md2->hwid = hwid & 0xf;
160+
md2->hwid_upper = (hwid >> 4) & 0x3;
161+
}
162+
163+
static inline u8 get_hwid(const struct erspan_md2 *md2)
164+
{
165+
return (md2->hwid_upper << 4) + md2->hwid;
166+
}
167+
107168
static inline int erspan_hdr_len(int version)
108169
{
109170
return sizeof(struct erspan_base_hdr) +
@@ -120,7 +181,7 @@ static inline u8 tos_to_cos(u8 tos)
120181
}
121182

122183
static inline void erspan_build_header(struct sk_buff *skb,
123-
__be32 id, u32 index,
184+
u32 id, u32 index,
124185
bool truncate, bool is_ipv4)
125186
{
126187
struct ethhdr *eth = (struct ethhdr *)skb->data;
@@ -154,12 +215,12 @@ static inline void erspan_build_header(struct sk_buff *skb,
154215
memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V1_MDSIZE);
155216

156217
/* Build base header */
157-
ershdr->ver_vlan = htons((vlan_tci & VLAN_MASK) |
158-
(ERSPAN_VERSION << VER_OFFSET));
159-
ershdr->session_id = htons((u16)(ntohl(id) & ID_MASK) |
160-
((tos_to_cos(tos) << COS_OFFSET) & COS_MASK) |
161-
(enc_type << EN_OFFSET & EN_MASK) |
162-
((truncate << T_OFFSET) & T_MASK));
218+
ershdr->ver = ERSPAN_VERSION;
219+
ershdr->cos = tos_to_cos(tos);
220+
ershdr->en = enc_type;
221+
ershdr->t = truncate;
222+
set_vlan(ershdr, vlan_tci);
223+
set_session_id(ershdr, id);
163224

164225
/* Build metadata */
165226
ersmd = (struct erspan_metadata *)(ershdr + 1);
@@ -187,7 +248,7 @@ static inline __be32 erspan_get_timestamp(void)
187248
}
188249

189250
static inline void erspan_build_header_v2(struct sk_buff *skb,
190-
__be32 id, u8 direction, u16 hwid,
251+
u32 id, u8 direction, u16 hwid,
191252
bool truncate, bool is_ipv4)
192253
{
193254
struct ethhdr *eth = (struct ethhdr *)skb->data;
@@ -198,7 +259,6 @@ static inline void erspan_build_header_v2(struct sk_buff *skb,
198259
__be16 tci;
199260
} *qp;
200261
u16 vlan_tci = 0;
201-
u16 session_id;
202262
u8 gra = 0; /* 100 usec */
203263
u8 bso = 0; /* Bad/Short/Oversized */
204264
u8 sgt = 0;
@@ -221,22 +281,23 @@ static inline void erspan_build_header_v2(struct sk_buff *skb,
221281
memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V2_MDSIZE);
222282

223283
/* Build base header */
224-
ershdr->ver_vlan = htons((vlan_tci & VLAN_MASK) |
225-
(ERSPAN_VERSION2 << VER_OFFSET));
226-
session_id = (u16)(ntohl(id) & ID_MASK) |
227-
((tos_to_cos(tos) << COS_OFFSET) & COS_MASK) |
228-
(bso << BSO_OFFSET & BSO_MASK) |
229-
((truncate << T_OFFSET) & T_MASK);
230-
ershdr->session_id = htons(session_id);
284+
ershdr->ver = ERSPAN_VERSION2;
285+
ershdr->cos = tos_to_cos(tos);
286+
ershdr->en = bso;
287+
ershdr->t = truncate;
288+
set_vlan(ershdr, vlan_tci);
289+
set_session_id(ershdr, id);
231290

232291
/* Build metadata */
233292
md = (struct erspan_metadata *)(ershdr + 1);
234293
md->u.md2.timestamp = erspan_get_timestamp();
235294
md->u.md2.sgt = htons(sgt);
236-
md->u.md2.flags = htons(((1 << P_OFFSET) & P_MASK) |
237-
((hwid << HWID_OFFSET) & HWID_MASK) |
238-
((direction << DIR_OFFSET) & DIR_MASK) |
239-
((gra << GRA_OFFSET) & GRA_MASK));
295+
md->u.md2.p = 1;
296+
md->u.md2.ft = 0;
297+
md->u.md2.dir = direction;
298+
md->u.md2.gra = gra;
299+
md->u.md2.o = 0;
300+
set_hwid(&md->u.md2, hwid);
240301
}
241302

242303
#endif

‎net/ipv4/ip_gre.c

Lines changed: 14 additions & 24 deletions
Original file line numberDiff line numberDiff line change
@@ -114,7 +114,7 @@ MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
114114
static struct rtnl_link_ops ipgre_link_ops __read_mostly;
115115
static int ipgre_tunnel_init(struct net_device *dev);
116116
static void erspan_build_header(struct sk_buff *skb,
117-
__be32 id, u32 index,
117+
u32 id, u32 index,
118118
bool truncate, bool is_ipv4);
119119

120120
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,
273273

274274
iph = ip_hdr(skb);
275275
ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len);
276-
ver = (ntohs(ershdr->ver_vlan) & VER_MASK) >> VER_OFFSET;
276+
ver = ershdr->ver;
277277

278278
/* The original GRE header does not have key field,
279279
* Use ERSPAN 10-bit session ID as key.
280280
*/
281-
tpi->key = cpu_to_be32(ntohs(ershdr->session_id) & ID_MASK);
281+
tpi->key = cpu_to_be32(get_session_id(ershdr));
282282
tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
283283
tpi->flags | TUNNEL_KEY,
284284
iph->saddr, iph->daddr, tpi->key);
@@ -324,14 +324,8 @@ static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
324324
if (ver == 1) {
325325
tunnel->index = ntohl(pkt_md->u.index);
326326
} else {
327-
u16 md2_flags;
328-
u16 dir, hwid;
329-
330-
md2_flags = ntohs(pkt_md->u.md2.flags);
331-
dir = (md2_flags & DIR_MASK) >> DIR_OFFSET;
332-
hwid = (md2_flags & HWID_MASK) >> HWID_OFFSET;
333-
tunnel->dir = dir;
334-
tunnel->hwid = hwid;
327+
tunnel->dir = pkt_md->u.md2.dir;
328+
tunnel->hwid = get_hwid(&pkt_md->u.md2);
335329
}
336330

337331
}
@@ -615,19 +609,14 @@ static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev,
615609
}
616610

617611
if (version == 1) {
618-
erspan_build_header(skb, tunnel_id_to_key32(key->tun_id),
612+
erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)),
619613
ntohl(md->u.index), truncate, true);
620614
} else if (version == 2) {
621-
u16 md2_flags;
622-
u8 direction;
623-
u16 hwid;
624-
625-
md2_flags = ntohs(md->u.md2.flags);
626-
direction = (md2_flags & DIR_MASK) >> DIR_OFFSET;
627-
hwid = (md2_flags & HWID_MASK) >> HWID_OFFSET;
628-
629-
erspan_build_header_v2(skb, tunnel_id_to_key32(key->tun_id),
630-
direction, hwid, truncate, true);
615+
erspan_build_header_v2(skb,
616+
ntohl(tunnel_id_to_key32(key->tun_id)),
617+
md->u.md2.dir,
618+
get_hwid(&md->u.md2),
619+
truncate, true);
631620
} else {
632621
goto err_free_rt;
633622
}
@@ -733,10 +722,11 @@ static netdev_tx_t erspan_xmit(struct sk_buff *skb,
733722

734723
/* Push ERSPAN header */
735724
if (tunnel->erspan_ver == 1)
736-
erspan_build_header(skb, tunnel->parms.o_key, tunnel->index,
725+
erspan_build_header(skb, ntohl(tunnel->parms.o_key),
726+
tunnel->index,
737727
truncate, true);
738728
else
739-
erspan_build_header_v2(skb, tunnel->parms.o_key,
729+
erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key),
740730
tunnel->dir, tunnel->hwid,
741731
truncate, true);
742732

‎net/ipv6/ip6_gre.c

Lines changed: 13 additions & 23 deletions
Original file line numberDiff line numberDiff line change
@@ -513,8 +513,8 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
513513

514514
ipv6h = ipv6_hdr(skb);
515515
ershdr = (struct erspan_base_hdr *)skb->data;
516-
ver = (ntohs(ershdr->ver_vlan) & VER_MASK) >> VER_OFFSET;
517-
tpi->key = cpu_to_be32(ntohs(ershdr->session_id) & ID_MASK);
516+
ver = ershdr->ver;
517+
tpi->key = cpu_to_be32(get_session_id(ershdr));
518518

519519
tunnel = ip6gre_tunnel_lookup(skb->dev,
520520
&ipv6h->saddr, &ipv6h->daddr, tpi->key,
@@ -565,14 +565,8 @@ static int ip6erspan_rcv(struct sk_buff *skb, int gre_hdr_len,
565565
if (ver == 1) {
566566
tunnel->parms.index = ntohl(pkt_md->u.index);
567567
} else {
568-
u16 md2_flags;
569-
u16 dir, hwid;
570-
571-
md2_flags = ntohs(pkt_md->u.md2.flags);
572-
dir = (md2_flags & DIR_MASK) >> DIR_OFFSET;
573-
hwid = (md2_flags & HWID_MASK) >> HWID_OFFSET;
574-
tunnel->parms.dir = dir;
575-
tunnel->parms.hwid = hwid;
568+
tunnel->parms.dir = pkt_md->u.md2.dir;
569+
tunnel->parms.hwid = get_hwid(&pkt_md->u.md2);
576570
}
577571

578572
ip6_tnl_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
@@ -925,6 +919,7 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
925919
struct ip_tunnel_info *tun_info;
926920
const struct ip_tunnel_key *key;
927921
struct erspan_metadata *md;
922+
__be32 tun_id;
928923

929924
tun_info = skb_tunnel_info(skb);
930925
if (unlikely(!tun_info ||
@@ -944,23 +939,18 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
944939
if (!md)
945940
goto tx_err;
946941

942+
tun_id = tunnel_id_to_key32(key->tun_id);
947943
if (md->version == 1) {
948944
erspan_build_header(skb,
949-
tunnel_id_to_key32(key->tun_id),
945+
ntohl(tun_id),
950946
ntohl(md->u.index), truncate,
951947
false);
952948
} else if (md->version == 2) {
953-
u16 md2_flags;
954-
u16 dir, hwid;
955-
956-
md2_flags = ntohs(md->u.md2.flags);
957-
dir = (md2_flags & DIR_MASK) >> DIR_OFFSET;
958-
hwid = (md2_flags & HWID_MASK) >> HWID_OFFSET;
959-
960949
erspan_build_header_v2(skb,
961-
tunnel_id_to_key32(key->tun_id),
962-
dir, hwid, truncate,
963-
false);
950+
ntohl(tun_id),
951+
md->u.md2.dir,
952+
get_hwid(&md->u.md2),
953+
truncate, false);
964954
}
965955
} else {
966956
switch (skb->protocol) {
@@ -982,11 +972,11 @@ static netdev_tx_t ip6erspan_tunnel_xmit(struct sk_buff *skb,
982972
}
983973

984974
if (t->parms.erspan_ver == 1)
985-
erspan_build_header(skb, t->parms.o_key,
975+
erspan_build_header(skb, ntohl(t->parms.o_key),
986976
t->parms.index,
987977
truncate, false);
988978
else
989-
erspan_build_header_v2(skb, t->parms.o_key,
979+
erspan_build_header_v2(skb, ntohl(t->parms.o_key),
990980
t->parms.dir,
991981
t->parms.hwid,
992982
truncate, false);

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