net: group skb_shinfo zerocopy related bits together.

In preparation for expanded zerocopy (TX and RX), move
the zerocopy related bits out of tx_flags into their own
flag word.

Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 21 insertions, 17 deletions

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index f6a3cee5c967..7b5adc511ac6 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -430,28 +430,32 @@ enum {
 	/* device driver is going to provide hardware time stamp */
 	SKBTX_IN_PROGRESS = 1 << 2,
 
-	/* device driver supports TX zero-copy buffers */
-	SKBTX_DEV_ZEROCOPY = 1 << 3,
-
 	/* generate wifi status information (where possible) */
 	SKBTX_WIFI_STATUS = 1 << 4,
 
-	/* This indicates at least one fragment might be overwritten
-	 * (as in vmsplice(), sendfile() ...)
-	 * If we need to compute a TX checksum, we'll need to copy
-	 * all frags to avoid possible bad checksum
-	 */
-	SKBTX_SHARED_FRAG = 1 << 5,
-
 	/* generate software time stamp when entering packet scheduling */
 	SKBTX_SCHED_TSTAMP = 1 << 6,
 };
 
-#define SKBTX_ZEROCOPY_FRAG	(SKBTX_DEV_ZEROCOPY | SKBTX_SHARED_FRAG)
 #define SKBTX_ANY_SW_TSTAMP	(SKBTX_SW_TSTAMP    | \
 				 SKBTX_SCHED_TSTAMP)
 #define SKBTX_ANY_TSTAMP	(SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP)
 
+/* Definitions for flags in struct skb_shared_info */
+enum {
+	/* use zcopy routines */
+	SKBFL_ZEROCOPY_ENABLE = BIT(0),
+
+	/* This indicates at least one fragment might be overwritten
+	 * (as in vmsplice(), sendfile() ...)
+	 * If we need to compute a TX checksum, we'll need to copy
+	 * all frags to avoid possible bad checksum
+	 */
+	SKBFL_SHARED_FRAG = BIT(1),
+};
+
+#define SKBFL_ZEROCOPY_FRAG	(SKBFL_ZEROCOPY_ENABLE | SKBFL_SHARED_FRAG)
+
 /*
  * The callback notifies userspace to release buffers when skb DMA is done in
  * lower device, the skb last reference should be 0 when calling this.
@@ -506,7 +510,7 @@ int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
  * the end of the header data, ie. at skb->end.
  */
 struct skb_shared_info {
-	__u8		__unused;
+	__u8		flags;
 	__u8		meta_len;
 	__u8		nr_frags;
 	__u8		tx_flags;
@@ -1433,7 +1437,7 @@ static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
 
 static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb)
 {
-	bool is_zcopy = skb && skb_shinfo(skb)->tx_flags & SKBTX_DEV_ZEROCOPY;
+	bool is_zcopy = skb && skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE;
 
 	return is_zcopy ? skb_uarg(skb) : NULL;
 }
@@ -1452,14 +1456,14 @@ static inline void skb_zcopy_set(struct sk_buff *skb, struct ubuf_info *uarg,
 		else
 			skb_zcopy_get(uarg);
 		skb_shinfo(skb)->destructor_arg = uarg;
-		skb_shinfo(skb)->tx_flags |= SKBTX_ZEROCOPY_FRAG;
+		skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;
 	}
 }
 
 static inline void skb_zcopy_set_nouarg(struct sk_buff *skb, void *val)
 {
 	skb_shinfo(skb)->destructor_arg = (void *)((uintptr_t) val | 0x1UL);
-	skb_shinfo(skb)->tx_flags |= SKBTX_ZEROCOPY_FRAG;
+	skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;
 }
 
 static inline bool skb_zcopy_is_nouarg(struct sk_buff *skb)
@@ -1497,7 +1501,7 @@ static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success)
 		if (!skb_zcopy_is_nouarg(skb))
 			uarg->callback(skb, uarg, zerocopy_success);
 
-		skb_shinfo(skb)->tx_flags &= ~SKBTX_ZEROCOPY_FRAG;
+		skb_shinfo(skb)->flags &= ~SKBFL_ZEROCOPY_FRAG;
 	}
 }
 
@@ -3323,7 +3327,7 @@ static inline int skb_linearize(struct sk_buff *skb)
 static inline bool skb_has_shared_frag(const struct sk_buff *skb)
 {
 	return skb_is_nonlinear(skb) &&
-	       skb_shinfo(skb)->tx_flags & SKBTX_SHARED_FRAG;
+	       skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG;
 }
 
 /**