net: move skb ref helpers to new header

Add a new header, linux/skbuff_ref.h, which contains all the skb_*_ref()
helpers. Many of the consumers of skbuff.h do not actually use any of
the skb ref helpers, and we can speed up compilation a bit by minimizing
this header file.

Additionally in the later patch in the series we add page_pool support
to skb_frag_ref(), which requires some page_pool dependencies. We can
now add these dependencies to skbuff_ref.h instead of a very ubiquitous
skbuff.h

Signed-off-by: Mina Almasry <almasrymina@google.com>
Link: https://lore.kernel.org/r/20240410190505.1225848-2-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/chelsio/inline_crypto/ch_ktls/chcr_ktls.c

@@ -10,6 +10,7 @@
 #include <net/ipv6.h>
 #include <linux/netdevice.h>
 #include <crypto/aes.h>
+#include <linux/skbuff_ref.h>
 #include "chcr_ktls.h"
 
 static LIST_HEAD(uld_ctx_list);

drivers/net/ethernet/marvell/sky2.c

@@ -34,6 +34,7 @@
 #include <linux/mii.h>
 #include <linux/of_net.h>
 #include <linux/dmi.h>
+#include <linux/skbuff_ref.h>
 
 #include <asm/irq.h>
 

drivers/net/ethernet/mellanox/mlx4/en_rx.c

@@ -42,6 +42,7 @@
 #include <linux/if_vlan.h>
 #include <linux/vmalloc.h>
 #include <linux/irq.h>
+#include <linux/skbuff_ref.h>
 
 #include <net/ip.h>
 #if IS_ENABLED(CONFIG_IPV6)

drivers/net/ethernet/sun/cassini.c

@@ -73,6 +73,7 @@
 #include <linux/netdevice.h>
 #include <linux/etherdevice.h>
 #include <linux/skbuff.h>
+#include <linux/skbuff_ref.h>
 #include <linux/ethtool.h>
 #include <linux/crc32.h>
 #include <linux/random.h>

drivers/net/veth.c

@@ -26,6 +26,7 @@
 #include <linux/ptr_ring.h>
 #include <linux/bpf_trace.h>
 #include <linux/net_tstamp.h>
+#include <linux/skbuff_ref.h>
 #include <net/page_pool/helpers.h>
 
 #define DRV_NAME	"veth"

drivers/net/xen-netback/netback.c

@@ -38,6 +38,7 @@
 #include <linux/if_vlan.h>
 #include <linux/udp.h>
 #include <linux/highmem.h>
+#include <linux/skbuff_ref.h>
 
 #include <net/tcp.h>
 

include/linux/skbuff.h

@@ -3492,73 +3492,10 @@ static inline struct page *skb_frag_page(const skb_frag_t *frag)
 	return netmem_to_page(frag->netmem);
 }
 
-/**
- * __skb_frag_ref - take an addition reference on a paged fragment.
- * @frag: the paged fragment
- *
- * Takes an additional reference on the paged fragment @frag.
- */
-static inline void __skb_frag_ref(skb_frag_t *frag)
-{
-	get_page(skb_frag_page(frag));
-}
-
-/**
- * skb_frag_ref - take an addition reference on a paged fragment of an skb.
- * @skb: the buffer
- * @f: the fragment offset.
- *
- * Takes an additional reference on the @f'th paged fragment of @skb.
- */
-static inline void skb_frag_ref(struct sk_buff *skb, int f)
-{
-	__skb_frag_ref(&skb_shinfo(skb)->frags[f]);
-}
-
 int skb_pp_cow_data(struct page_pool *pool, struct sk_buff **pskb,
 		    unsigned int headroom);
 int skb_cow_data_for_xdp(struct page_pool *pool, struct sk_buff **pskb,
 			 struct bpf_prog *prog);
-bool napi_pp_put_page(struct page *page);
-
-static inline void
-skb_page_unref(struct page *page, bool recycle)
-{
-#ifdef CONFIG_PAGE_POOL
-	if (recycle && napi_pp_put_page(page))
-		return;
-#endif
-	put_page(page);
-}
-
-/**
- * __skb_frag_unref - release a reference on a paged fragment.
- * @frag: the paged fragment
- * @recycle: recycle the page if allocated via page_pool
- *
- * Releases a reference on the paged fragment @frag
- * or recycles the page via the page_pool API.
- */
-static inline void __skb_frag_unref(skb_frag_t *frag, bool recycle)
-{
-	skb_page_unref(skb_frag_page(frag), recycle);
-}
-
-/**
- * skb_frag_unref - release a reference on a paged fragment of an skb.
- * @skb: the buffer
- * @f: the fragment offset
- *
- * Releases a reference on the @f'th paged fragment of @skb.
- */
-static inline void skb_frag_unref(struct sk_buff *skb, int f)
-{
-	struct skb_shared_info *shinfo = skb_shinfo(skb);
-
-	if (!skb_zcopy_managed(skb))
-		__skb_frag_unref(&shinfo->frags[f], skb->pp_recycle);
-}
-
 /**
  * skb_frag_address - gets the address of the data contained in a paged fragment
  * @frag: the paged fragment buffer

include/linux/skbuff_ref.h

@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ *	Skb ref helpers.
+ *
+ */
+
+#ifndef _LINUX_SKBUFF_REF_H
+#define _LINUX_SKBUFF_REF_H
+
+#include <linux/skbuff.h>
+
+/**
+ * __skb_frag_ref - take an addition reference on a paged fragment.
+ * @frag: the paged fragment
+ *
+ * Takes an additional reference on the paged fragment @frag.
+ */
+static inline void __skb_frag_ref(skb_frag_t *frag)
+{
+	get_page(skb_frag_page(frag));
+}
+
+/**
+ * skb_frag_ref - take an addition reference on a paged fragment of an skb.
+ * @skb: the buffer
+ * @f: the fragment offset.
+ *
+ * Takes an additional reference on the @f'th paged fragment of @skb.
+ */
+static inline void skb_frag_ref(struct sk_buff *skb, int f)
+{
+	__skb_frag_ref(&skb_shinfo(skb)->frags[f]);
+}
+
+bool napi_pp_put_page(struct page *page);
+
+static inline void
+skb_page_unref(struct page *page, bool recycle)
+{
+#ifdef CONFIG_PAGE_POOL
+	if (recycle && napi_pp_put_page(page))
+		return;
+#endif
+	put_page(page);
+}
+
+/**
+ * __skb_frag_unref - release a reference on a paged fragment.
+ * @frag: the paged fragment
+ * @recycle: recycle the page if allocated via page_pool
+ *
+ * Releases a reference on the paged fragment @frag
+ * or recycles the page via the page_pool API.
+ */
+static inline void __skb_frag_unref(skb_frag_t *frag, bool recycle)
+{
+	skb_page_unref(skb_frag_page(frag), recycle);
+}
+
+/**
+ * skb_frag_unref - release a reference on a paged fragment of an skb.
+ * @skb: the buffer
+ * @f: the fragment offset
+ *
+ * Releases a reference on the @f'th paged fragment of @skb.
+ */
+static inline void skb_frag_unref(struct sk_buff *skb, int f)
+{
+	struct skb_shared_info *shinfo = skb_shinfo(skb);
+
+	if (!skb_zcopy_managed(skb))
+		__skb_frag_unref(&shinfo->frags[f], skb->pp_recycle);
+}
+
+#endif	/* _LINUX_SKBUFF_REF_H */

net/core/gro.c

@@ -3,6 +3,7 @@
 #include <net/dst_metadata.h>
 #include <net/busy_poll.h>
 #include <trace/events/net.h>
+#include <linux/skbuff_ref.h>
 
 #define MAX_GRO_SKBS 8
 

net/core/skbuff.c

@@ -51,6 +51,7 @@
 #endif
 #include <linux/string.h>
 #include <linux/skbuff.h>
+#include <linux/skbuff_ref.h>
 #include <linux/splice.h>
 #include <linux/cache.h>
 #include <linux/rtnetlink.h>

net/ipv4/esp4.c

@@ -20,6 +20,7 @@
 #include <net/udp.h>
 #include <net/tcp.h>
 #include <net/espintcp.h>
+#include <linux/skbuff_ref.h>
 
 #include <linux/highmem.h>
 

net/ipv4/tcp_output.c

@@ -44,6 +44,7 @@
 #include <linux/gfp.h>
 #include <linux/module.h>
 #include <linux/static_key.h>
+#include <linux/skbuff_ref.h>
 
 #include <trace/events/tcp.h>
 

net/ipv6/esp6.c

@@ -36,6 +36,7 @@
 #include <net/tcp.h>
 #include <net/espintcp.h>
 #include <net/inet6_hashtables.h>
+#include <linux/skbuff_ref.h>
 
 #include <linux/highmem.h>
 

net/tls/tls_device.c

@@ -37,6 +37,7 @@
 #include <net/inet_connection_sock.h>
 #include <net/tcp.h>
 #include <net/tls.h>
+#include <linux/skbuff_ref.h>
 
 #include "tls.h"
 #include "trace.h"

net/tls/tls_device_fallback.c

@@ -33,6 +33,7 @@
 #include <crypto/aead.h>
 #include <crypto/scatterwalk.h>
 #include <net/ip6_checksum.h>
+#include <linux/skbuff_ref.h>
 
 #include "tls.h"
 

net/tls/tls_strp.c

@@ -2,6 +2,7 @@
 /* Copyright (c) 2016 Tom Herbert <tom@herbertland.com> */
 
 #include <linux/skbuff.h>
+#include <linux/skbuff_ref.h>
 #include <linux/workqueue.h>
 #include <net/strparser.h>
 #include <net/tcp.h>