[PATCH net-next 0/4] net/vlan: prepare for removal of VLAN_TAG_PRESENT

[PATCH net-next 0/4] net/vlan: prepare for removal of VLAN_TAG_PRESENT

[Michał Mirosław]

This is a preparatory patchset before removing the use of VLAN_TAG_PRESENT
bit in skb->vlan_tci as indication of VLAN offload. This set includes
only cleanups that allow abstracting of code testing VLAN tag presence
in drivers and networking code.

Michał Mirosław (4):
  net/vlan: introduce __vlan_hwaccel_clear_tag() helper
  net/vlan: introduce __vlan_hwaccel_copy_tag() helper
  net/vlan: include the shift in skb_vlan_tag_get_prio()
  net/vlan: remove unused #define HAVE_VLAN_GET_TAG

 include/linux/if_vlan.h   | 30 ++++++++++++++++++++++++++----
 net/core/flow_dissector.c |  3 +--
 2 files changed, 27 insertions(+), 6 deletions(-)

-- 
2.19.1

[PATCH net-next 2/4] net/vlan: introduce __vlan_hwaccel_copy_tag() helper

[Michał Mirosław]

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
 include/linux/if_vlan.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index c438fa0a1c6a..941da4bf3929 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -472,6 +472,19 @@ static inline void __vlan_hwaccel_clear_tag(struct sk_buff *skb)
 	skb->vlan_tci = 0;
 }
 
+/**
+ * __vlan_hwaccel_copy_tag - copy hardware accelerated VLAN info from another skb
+ * @dst: skbuff to copy to
+ * @src: skbuff to copy from
+ *
+ * Copies VLAN information from @src to @dst (for branchless code)
+ */
+static inline void __vlan_hwaccel_copy_tag(struct sk_buff *dst, const struct sk_buff *src)
+{
+	dst->vlan_proto = src->vlan_proto;
+	dst->vlan_tci = src->vlan_tci;
+}
+
 /*
  * __vlan_hwaccel_push_inside - pushes vlan tag to the payload
  * @skb: skbuff to tag
-- 
2.19.1

[PATCH net-next 1/4] net/vlan: introduce __vlan_hwaccel_clear_tag() helper

[Michał Mirosław]

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
 include/linux/if_vlan.h | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 83ea4df6ab81..c438fa0a1c6a 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -461,6 +461,17 @@ static inline struct sk_buff *vlan_insert_tag_set_proto(struct sk_buff *skb,
 	return skb;
 }
 
+/**
+ * __vlan_hwaccel_clear_tag - clear hardware accelerated VLAN info
+ * @skb: skbuff to clear
+ *
+ * Clears the VLAN information from @skb
+ */
+static inline void __vlan_hwaccel_clear_tag(struct sk_buff *skb)
+{
+	skb->vlan_tci = 0;
+}
+
 /*
  * __vlan_hwaccel_push_inside - pushes vlan tag to the payload
  * @skb: skbuff to tag
@@ -475,7 +486,7 @@ static inline struct sk_buff *__vlan_hwaccel_push_inside(struct sk_buff *skb)
 	skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto,
 					skb_vlan_tag_get(skb));
 	if (likely(skb))
-		skb->vlan_tci = 0;
+		__vlan_hwaccel_clear_tag(skb);
 	return skb;
 }
 
-- 
2.19.1

[PATCH net-next 3/4] net/vlan: include the shift in skb_vlan_tag_get_prio()

[Michał Mirosław]

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
 include/linux/if_vlan.h   | 2 +-
 net/core/flow_dissector.c | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 941da4bf3929..b14bf87999aa 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -81,7 +81,7 @@ static inline bool is_vlan_dev(const struct net_device *dev)
 #define skb_vlan_tag_present(__skb)	((__skb)->vlan_tci & VLAN_TAG_PRESENT)
 #define skb_vlan_tag_get(__skb)		((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)
 #define skb_vlan_tag_get_id(__skb)	((__skb)->vlan_tci & VLAN_VID_MASK)
-#define skb_vlan_tag_get_prio(__skb)	((__skb)->vlan_tci & VLAN_PRIO_MASK)
+#define skb_vlan_tag_get_prio(__skb)	(((__skb)->vlan_tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT)
 
 static inline int vlan_get_rx_ctag_filter_info(struct net_device *dev)
 {
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 676f3ad629f9..56d1e9b73142 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -952,8 +952,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
 
 			if (!vlan) {
 				key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
-				key_vlan->vlan_priority =
-					(skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
+				key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb);
 			} else {
 				key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
 					VLAN_VID_MASK;
-- 
2.19.1

[PATCH net-next 4/4] net/vlan: remove unused #define HAVE_VLAN_GET_TAG

[Michał Mirosław]

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
 include/linux/if_vlan.h | 2 --
 1 file changed, 2 deletions(-)

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index b14bf87999aa..03b08ffded07 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -555,8 +555,6 @@ static inline int __vlan_hwaccel_get_tag(const struct sk_buff *skb,
 	}
 }
 
-#define HAVE_VLAN_GET_TAG
-
 /**
  * vlan_get_tag - get the VLAN ID from the skb
  * @skb: skbuff to query
-- 
2.19.1

Re: [PATCH net-next 0/4] net/vlan: prepare for removal of VLAN_TAG_PRESENT

[David Miller]

From: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Date: Wed, 07 Nov 2018 18:07:02 +0100

> This is a preparatory patchset before removing the use of VLAN_TAG_PRESENT
> bit in skb->vlan_tci as indication of VLAN offload. This set includes
> only cleanups that allow abstracting of code testing VLAN tag presence
> in drivers and networking code.

Series applied.