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Date: Wed, 9 Nov 2022 09:57:58 +0000
From: Eric Dumazet <edumazet@...gle.com>
To: "David S . Miller" <davem@...emloft.net>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>,
Daniel Borkmann <daniel@...earbox.net>,
Alexei Starovoitov <ast@...nel.org>,
Andrii Nakryiko <andrii@...nel.org>
Cc: netdev@...r.kernel.org, bpf@...r.kernel.org,
eric.dumazet@...il.com, Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH net-next 1/2] net: remove skb->vlan_present
skb->vlan_present seems redundant.
We can instead derive it from this boolean expression:
vlan_present = skb->vlan_proto != 0 || skb->vlan_tci != 0
Add a new union, to access both fields in a single load/store
when possible.
union {
u32 vlan_all;
struct {
__be16 vlan_proto;
__u16 vlan_tci;
};
};
This allows following patch to remove a conditional test in GRO stack.
Note:
We move remcsum_offload to keep TC_AT_INGRESS_MASK
and SKB_MONO_DELIVERY_TIME_MASK unchanged.
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
arch/sparc/net/bpf_jit_comp_32.c | 10 ++++-----
.../ethernet/marvell/octeontx2/nic/otx2_pf.c | 2 +-
include/linux/if_vlan.h | 9 +++-----
include/linux/skbuff.h | 18 ++++++++-------
lib/test_bpf.c | 1 -
net/core/filter.c | 22 +++++++++----------
6 files changed, 29 insertions(+), 33 deletions(-)
diff --git a/arch/sparc/net/bpf_jit_comp_32.c b/arch/sparc/net/bpf_jit_comp_32.c
index b1dbf2fa8c0ae82e4bdb5ed87b3ddc8964a96d6d..a74e5004c6c89c8267b0014cf78a72ae66ee4f89 100644
--- a/arch/sparc/net/bpf_jit_comp_32.c
+++ b/arch/sparc/net/bpf_jit_comp_32.c
@@ -555,11 +555,11 @@ void bpf_jit_compile(struct bpf_prog *fp)
emit_skb_load16(vlan_tci, r_A);
break;
case BPF_ANC | SKF_AD_VLAN_TAG_PRESENT:
- __emit_skb_load8(__pkt_vlan_present_offset, r_A);
- if (PKT_VLAN_PRESENT_BIT)
- emit_alu_K(SRL, PKT_VLAN_PRESENT_BIT);
- if (PKT_VLAN_PRESENT_BIT < 7)
- emit_andi(r_A, 1, r_A);
+ emit_skb_load32(vlan_all, r_A);
+ emit_cmpi(r_A, 0);
+ emit_branch_off(BE, 12);
+ emit_nop();
+ emit_loadimm(1, r_A);
break;
case BPF_LD | BPF_W | BPF_LEN:
emit_skb_load32(len, r_A);
diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
index 892ca88e0cf43be6cb590b1925a8f5b065ce9575..436fa19fa03723ff93f143df0760079e9e32cee9 100644
--- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
+++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_pf.c
@@ -1898,7 +1898,7 @@ static u16 otx2_select_queue(struct net_device *netdev, struct sk_buff *skb,
#endif
#ifdef CONFIG_DCB
- if (!skb->vlan_present)
+ if (!skb_vlan_tag_present(skb))
goto pick_tx;
vlan_prio = skb->vlan_tci >> 13;
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index e00c4ee81ff7f82e4343fe45c14d8e5d81d80e95..6864b89ef86818c4c360dc3b2adca1dfe65a21ff 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -76,7 +76,7 @@ static inline bool is_vlan_dev(const struct net_device *dev)
return dev->priv_flags & IFF_802_1Q_VLAN;
}
-#define skb_vlan_tag_present(__skb) ((__skb)->vlan_present)
+#define skb_vlan_tag_present(__skb) (!!(__skb)->vlan_all)
#define skb_vlan_tag_get(__skb) ((__skb)->vlan_tci)
#define skb_vlan_tag_get_id(__skb) ((__skb)->vlan_tci & VLAN_VID_MASK)
#define skb_vlan_tag_get_cfi(__skb) (!!((__skb)->vlan_tci & VLAN_CFI_MASK))
@@ -471,7 +471,7 @@ static inline struct sk_buff *vlan_insert_tag_set_proto(struct sk_buff *skb,
*/
static inline void __vlan_hwaccel_clear_tag(struct sk_buff *skb)
{
- skb->vlan_present = 0;
+ skb->vlan_all = 0;
}
/**
@@ -483,9 +483,7 @@ static inline void __vlan_hwaccel_clear_tag(struct sk_buff *skb)
*/
static inline void __vlan_hwaccel_copy_tag(struct sk_buff *dst, const struct sk_buff *src)
{
- dst->vlan_present = src->vlan_present;
- dst->vlan_proto = src->vlan_proto;
- dst->vlan_tci = src->vlan_tci;
+ dst->vlan_all = src->vlan_all;
}
/*
@@ -519,7 +517,6 @@ static inline void __vlan_hwaccel_put_tag(struct sk_buff *skb,
{
skb->vlan_proto = vlan_proto;
skb->vlan_tci = vlan_tci;
- skb->vlan_present = 1;
}
/**
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 59c9fd55699d63ab966665db0d97ba0b58de7404..4e464a27adafbca281675c0a36ce6911cadcd6f1 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -818,7 +818,7 @@ typedef unsigned char *sk_buff_data_t;
* @mark: Generic packet mark
* @reserved_tailroom: (aka @mark) number of bytes of free space available
* at the tail of an sk_buff
- * @vlan_present: VLAN tag is present
+ * @vlan_all: vlan fields (proto & tci)
* @vlan_proto: vlan encapsulation protocol
* @vlan_tci: vlan tag control information
* @inner_protocol: Protocol (encapsulation)
@@ -951,7 +951,7 @@ struct sk_buff {
/* private: */
__u8 __pkt_vlan_present_offset[0];
/* public: */
- __u8 vlan_present:1; /* See PKT_VLAN_PRESENT_BIT */
+ __u8 remcsum_offload:1;
__u8 csum_complete_sw:1;
__u8 csum_level:2;
__u8 dst_pending_confirm:1;
@@ -966,7 +966,6 @@ struct sk_buff {
__u8 ipvs_property:1;
__u8 inner_protocol_type:1;
- __u8 remcsum_offload:1;
#ifdef CONFIG_NET_SWITCHDEV
__u8 offload_fwd_mark:1;
__u8 offload_l3_fwd_mark:1;
@@ -999,8 +998,13 @@ struct sk_buff {
__u32 priority;
int skb_iif;
__u32 hash;
- __be16 vlan_proto;
- __u16 vlan_tci;
+ union {
+ u32 vlan_all;
+ struct {
+ __be16 vlan_proto;
+ __u16 vlan_tci;
+ };
+ };
#if defined(CONFIG_NET_RX_BUSY_POLL) || defined(CONFIG_XPS)
union {
unsigned int napi_id;
@@ -1059,15 +1063,13 @@ struct sk_buff {
#endif
#define PKT_TYPE_OFFSET offsetof(struct sk_buff, __pkt_type_offset)
-/* if you move pkt_vlan_present, tc_at_ingress, or mono_delivery_time
+/* if you move tc_at_ingress or mono_delivery_time
* around, you also must adapt these constants.
*/
#ifdef __BIG_ENDIAN_BITFIELD
-#define PKT_VLAN_PRESENT_BIT 7
#define TC_AT_INGRESS_MASK (1 << 0)
#define SKB_MONO_DELIVERY_TIME_MASK (1 << 2)
#else
-#define PKT_VLAN_PRESENT_BIT 0
#define TC_AT_INGRESS_MASK (1 << 7)
#define SKB_MONO_DELIVERY_TIME_MASK (1 << 5)
#endif
diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 5820704165a64ddcfc193b59158d06141f64fe92..ade9ac672adbbdb41504dbb639847be2ff8f6531 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -14346,7 +14346,6 @@ static struct sk_buff *populate_skb(char *buf, int size)
skb->hash = SKB_HASH;
skb->queue_mapping = SKB_QUEUE_MAP;
skb->vlan_tci = SKB_VLAN_TCI;
- skb->vlan_present = SKB_VLAN_PRESENT;
skb->vlan_proto = htons(ETH_P_IP);
dev_net_set(&dev, &init_net);
skb->dev = &dev;
diff --git a/net/core/filter.c b/net/core/filter.c
index bb0136e7a8e422b010477333c811db79aaf56e3f..358d5e70671a0808b4d10c2a59a78128925b0f31 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -325,11 +325,11 @@ static u32 convert_skb_access(int skb_field, int dst_reg, int src_reg,
offsetof(struct sk_buff, vlan_tci));
break;
case SKF_AD_VLAN_TAG_PRESENT:
- *insn++ = BPF_LDX_MEM(BPF_B, dst_reg, src_reg, PKT_VLAN_PRESENT_OFFSET);
- if (PKT_VLAN_PRESENT_BIT)
- *insn++ = BPF_ALU32_IMM(BPF_RSH, dst_reg, PKT_VLAN_PRESENT_BIT);
- if (PKT_VLAN_PRESENT_BIT < 7)
- *insn++ = BPF_ALU32_IMM(BPF_AND, dst_reg, 1);
+ BUILD_BUG_ON(sizeof_field(struct sk_buff, vlan_all) != 4);
+ *insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg,
+ offsetof(struct sk_buff, vlan_all));
+ *insn++ = BPF_JMP_IMM(BPF_JEQ, dst_reg, 0, 1);
+ *insn++ = BPF_ALU32_IMM(BPF_MOV, dst_reg, 1);
break;
}
@@ -9290,13 +9290,11 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type,
break;
case offsetof(struct __sk_buff, vlan_present):
- *target_size = 1;
- *insn++ = BPF_LDX_MEM(BPF_B, si->dst_reg, si->src_reg,
- PKT_VLAN_PRESENT_OFFSET);
- if (PKT_VLAN_PRESENT_BIT)
- *insn++ = BPF_ALU32_IMM(BPF_RSH, si->dst_reg, PKT_VLAN_PRESENT_BIT);
- if (PKT_VLAN_PRESENT_BIT < 7)
- *insn++ = BPF_ALU32_IMM(BPF_AND, si->dst_reg, 1);
+ *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->src_reg,
+ bpf_target_off(struct sk_buff,
+ vlan_all, 4, target_size));
+ *insn++ = BPF_JMP_IMM(BPF_JEQ, si->dst_reg, 0, 1);
+ *insn++ = BPF_ALU32_IMM(BPF_MOV, si->dst_reg, 1);
break;
case offsetof(struct __sk_buff, vlan_tci):
--
2.38.1.431.g37b22c650d-goog
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