net: xdp: pass full flags to xdp_update_skb_shared_info()

xdp_update_skb_shared_info() needs to update skb state which
was maintained in xdp_buff / frame. Pass full flags into it,
instead of breaking it out bit by bit. We will need to add
a bit for unreadable frags (even tho XDP doesn't support
those the driver paths may be common), at which point almost
all call sites would become:

    xdp_update_skb_shared_info(skb, num_frags,
                               sinfo->xdp_frags_size,
                               MY_PAGE_SIZE * num_frags,
                               xdp_buff_is_frag_pfmemalloc(xdp),
                               xdp_buff_is_frag_unreadable(xdp));

Keep a helper for accessing the flags, in case we need to
transform them somehow in the future (e.g. to cover up xdp_buff
vs xdp_frame differences).

While we are touching call callers - rename the helper to
xdp_update_skb_frags_info(), previous name may have implied that
it's shinfo that's updated. We are updating flags in struct sk_buff
based on frags that got attched.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://patch.msgid.link/20250905221539.2930285-2-kuba@kernel.org
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 11 insertions, 12 deletions

diff --git a/include/net/xdp.h b/include/net/xdp.h
index af60e11b336c..976cfd2f113c 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -116,15 +116,14 @@ static __always_inline void xdp_buff_clear_frags_flag(struct xdp_buff *xdp)
 	xdp->flags &= ~XDP_FLAGS_HAS_FRAGS;
 }
 
-static __always_inline bool
-xdp_buff_is_frag_pfmemalloc(const struct xdp_buff *xdp)
+static __always_inline void xdp_buff_set_frag_pfmemalloc(struct xdp_buff *xdp)
 {
-	return !!(xdp->flags & XDP_FLAGS_FRAGS_PF_MEMALLOC);
+	xdp->flags |= XDP_FLAGS_FRAGS_PF_MEMALLOC;
 }
 
-static __always_inline void xdp_buff_set_frag_pfmemalloc(struct xdp_buff *xdp)
+static __always_inline u32 xdp_buff_get_skb_flags(const struct xdp_buff *xdp)
 {
-	xdp->flags |= XDP_FLAGS_FRAGS_PF_MEMALLOC;
+	return xdp->flags;
 }
 
 static __always_inline void
@@ -294,10 +293,10 @@ static __always_inline bool xdp_frame_has_frags(const struct xdp_frame *frame)
 	return !!(frame->flags & XDP_FLAGS_HAS_FRAGS);
 }
 
-static __always_inline bool
-xdp_frame_is_frag_pfmemalloc(const struct xdp_frame *frame)
+static __always_inline u32
+xdp_frame_get_skb_flags(const struct xdp_frame *frame)
 {
-	return !!(frame->flags & XDP_FLAGS_FRAGS_PF_MEMALLOC);
+	return frame->flags;
 }
 
 #define XDP_BULK_QUEUE_SIZE	16
@@ -334,9 +333,9 @@ static inline void xdp_scrub_frame(struct xdp_frame *frame)
 }
 
 static inline void
-xdp_update_skb_shared_info(struct sk_buff *skb, u8 nr_frags,
-			   unsigned int size, unsigned int truesize,
-			   bool pfmemalloc)
+xdp_update_skb_frags_info(struct sk_buff *skb, u8 nr_frags,
+			  unsigned int size, unsigned int truesize,
+			  u32 xdp_flags)
 {
 	struct skb_shared_info *sinfo = skb_shinfo(skb);
 
@@ -350,7 +349,7 @@ xdp_update_skb_shared_info(struct sk_buff *skb, u8 nr_frags,
 	skb->len += size;
 	skb->data_len += size;
 	skb->truesize += truesize;
-	skb->pfmemalloc |= pfmemalloc;
+	skb->pfmemalloc |= !!(xdp_flags & XDP_FLAGS_FRAGS_PF_MEMALLOC);
 }
 
 /* Avoids inlining WARN macro in fast-path */