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>

diff --git a/drivers/net/tap.c b/drivers/net/tap.c
index 3f51f37..f7a19d9 100644 (file)
--- a/drivers/net/tap.c
+++ b/drivers/net/tap.c
@@ -723,8 +723,7 @@ static ssize_t tap_get_user(struct tap_queue *q, void *msg_control,
        /* copy skb_ubuf_info for callback when skb has no error */
        if (zerocopy) {
                skb_shinfo(skb)->destructor_arg = msg_control;
-               skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
-               skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
+               skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;
        } else if (msg_control) {
                struct ubuf_info *uarg = msg_control;
                uarg->callback(NULL, uarg, false);

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 862c906..d8f1c3d 100644 (file)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1815,8 +1815,7 @@ drop:
        /* copy skb_ubuf_info for callback when skb has no error */
        if (zerocopy) {
                skb_shinfo(skb)->destructor_arg = msg_control;
-               skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
-               skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
+               skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_FRAG;
        } else if (msg_control) {
                struct ubuf_info *uarg = msg_control;
                uarg->callback(NULL, uarg, false);

diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c
index acb786d..08b0e3d 100644 (file)
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -47,7 +47,7 @@
 /* Number of bytes allowed on the internal guest Rx queue. */
 #define XENVIF_RX_QUEUE_BYTES (XEN_NETIF_RX_RING_SIZE/2 * PAGE_SIZE)
 
-/* This function is used to set SKBTX_DEV_ZEROCOPY as well as
+/* This function is used to set SKBFL_ZEROCOPY_ENABLE as well as
  * increasing the inflight counter. We need to increase the inflight
  * counter because core driver calls into xenvif_zerocopy_callback
  * which calls xenvif_skb_zerocopy_complete.
@@ -55,7 +55,7 @@
 void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
                                 struct sk_buff *skb)
 {
-       skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
+       skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_ENABLE;
        atomic_inc(&queue->inflight_packets);
 }
 

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index f6a3cee..7b5adc5 100644 (file)
--- 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;
 }
 
 /**

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index bcd5676..5b9e52c 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1327,7 +1327,7 @@ static int skb_zerocopy_clone(struct sk_buff *nskb, struct sk_buff *orig,
  *     @skb: the skb to modify
  *     @gfp_mask: allocation priority
  *
- *     This must be called on SKBTX_DEV_ZEROCOPY skb.
+ *     This must be called on skb with SKBFL_ZEROCOPY_ENABLE.
  *     It will copy all frags into kernel and drop the reference
  *     to userspace pages.
  *
@@ -3264,8 +3264,7 @@ void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len)
 {
        int pos = skb_headlen(skb);
 
-       skb_shinfo(skb1)->tx_flags |= skb_shinfo(skb)->tx_flags &
-                                     SKBTX_SHARED_FRAG;
+       skb_shinfo(skb1)->flags |= skb_shinfo(skb)->flags & SKBFL_SHARED_FRAG;
        skb_zerocopy_clone(skb1, skb, 0);
        if (len < pos)  /* Split line is inside header. */
                skb_split_inside_header(skb, skb1, len, pos);
@@ -3954,8 +3953,8 @@ normal:
                skb_copy_from_linear_data_offset(head_skb, offset,
                                                 skb_put(nskb, hsize), hsize);
 
-               skb_shinfo(nskb)->tx_flags |= skb_shinfo(head_skb)->tx_flags &
-                                             SKBTX_SHARED_FRAG;
+               skb_shinfo(nskb)->flags |= skb_shinfo(head_skb)->flags &
+                                          SKBFL_SHARED_FRAG;
 
                if (skb_orphan_frags(frag_skb, GFP_ATOMIC) ||
                    skb_zerocopy_clone(nskb, frag_skb, GFP_ATOMIC))

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 2882d52..1954190 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1010,7 +1010,7 @@ new_segment:
        }
 
        if (!(flags & MSG_NO_SHARED_FRAGS))
-               skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
+               skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG;
 
        skb->len += copy;
        skb->data_len += copy;

diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c
index a9eb616..d0b56ff 100644 (file)
--- a/net/kcm/kcmsock.c
+++ b/net/kcm/kcmsock.c
@@ -786,7 +786,7 @@ static ssize_t kcm_sendpage(struct socket *sock, struct page *page,
 
                if (skb_can_coalesce(skb, i, page, offset)) {
                        skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], size);
-                       skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
+                       skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG;
                        goto coalesced;
                }
 
@@ -834,7 +834,7 @@ static ssize_t kcm_sendpage(struct socket *sock, struct page *page,
 
        get_page(page);
        skb_fill_page_desc(skb, i, page, offset, size);
-       skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
+       skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG;
 
 coalesced:
        skb->len += size;