xsk: Move xskmap.c to net/xdp/

The XSKMAP is partly implemented by net/xdp/xsk.c. Move xskmap.c from
kernel/bpf/ to net/xdp/, which is the logical place for AF_XDP related
code. Also, move AF_XDP struct definitions, and function declarations
only used by AF_XDP internals into net/xdp/xsk.h.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200520192103.355233-3-bjorn.topel@gmail.com

include/net/xdp_sock.h

@@ -65,22 +65,12 @@ struct xdp_umem {
 	struct list_head xsk_tx_list;
 };
 
-/* Nodes are linked in the struct xdp_sock map_list field, and used to
- * track which maps a certain socket reside in.
- */
-
 struct xsk_map {
 	struct bpf_map map;
 	spinlock_t lock; /* Synchronize map updates */
 	struct xdp_sock *xsk_map[];
 };
 
-struct xsk_map_node {
-	struct list_head node;
-	struct xsk_map *map;
-	struct xdp_sock **map_entry;
-};
-
 struct xdp_sock {
 	/* struct sock must be the first member of struct xdp_sock */
 	struct sock sk;
@@ -114,7 +104,6 @@ struct xdp_sock {
 struct xdp_buff;
 #ifdef CONFIG_XDP_SOCKETS
 int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp);
-bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs);
 /* Used from netdev driver */
 bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt);
 bool xsk_umem_peek_addr(struct xdp_umem *umem, u64 *addr);
@@ -133,10 +122,6 @@ void xsk_clear_rx_need_wakeup(struct xdp_umem *umem);
 void xsk_clear_tx_need_wakeup(struct xdp_umem *umem);
 bool xsk_umem_uses_need_wakeup(struct xdp_umem *umem);
 
-void xsk_map_try_sock_delete(struct xsk_map *map, struct xdp_sock *xs,
-			     struct xdp_sock **map_entry);
-int xsk_map_inc(struct xsk_map *map);
-void xsk_map_put(struct xsk_map *map);
 int __xsk_map_redirect(struct xdp_sock *xs, struct xdp_buff *xdp);
 void __xsk_map_flush(void);
 
@@ -248,11 +233,6 @@ static inline int xsk_generic_rcv(struct xdp_sock *xs, struct xdp_buff *xdp)
 	return -ENOTSUPP;
 }
 
-static inline bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs)
-{
-	return false;
-}
-
 static inline bool xsk_umem_has_addrs(struct xdp_umem *umem, u32 cnt)
 {
 	return false;

kernel/bpf/Makefile

@@ -12,9 +12,6 @@ obj-$(CONFIG_BPF_JIT) += dispatcher.o
 ifeq ($(CONFIG_NET),y)
 obj-$(CONFIG_BPF_SYSCALL) += devmap.o
 obj-$(CONFIG_BPF_SYSCALL) += cpumap.o
-ifeq ($(CONFIG_XDP_SOCKETS),y)
-obj-$(CONFIG_BPF_SYSCALL) += xskmap.o
-endif
 obj-$(CONFIG_BPF_SYSCALL) += offload.o
 endif
 ifeq ($(CONFIG_PERF_EVENTS),y)

net/xdp/Makefile

@@ -1,3 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
-obj-$(CONFIG_XDP_SOCKETS) += xsk.o xdp_umem.o xsk_queue.o
+obj-$(CONFIG_XDP_SOCKETS) += xsk.o xdp_umem.o xsk_queue.o xskmap.o
 obj-$(CONFIG_XDP_SOCKETS_DIAG) += xsk_diag.o

net/xdp/xsk.h

@@ -17,9 +17,25 @@ struct xdp_mmap_offsets_v1 {
 	struct xdp_ring_offset_v1 cr;
 };
 
+/* Nodes are linked in the struct xdp_sock map_list field, and used to
+ * track which maps a certain socket reside in.
+ */
+
+struct xsk_map_node {
+	struct list_head node;
+	struct xsk_map *map;
+	struct xdp_sock **map_entry;
+};
+
 static inline struct xdp_sock *xdp_sk(struct sock *sk)
 {
 	return (struct xdp_sock *)sk;
 }
 
+bool xsk_is_setup_for_bpf_map(struct xdp_sock *xs);
+void xsk_map_try_sock_delete(struct xsk_map *map, struct xdp_sock *xs,
+			     struct xdp_sock **map_entry);
+int xsk_map_inc(struct xsk_map *map);
+void xsk_map_put(struct xsk_map *map);
+
 #endif /* XSK_H_ */

net/xdp/xskmap.c

@@ -9,6 +9,8 @@
 #include <linux/slab.h>
 #include <linux/sched.h>
 
+#include "xsk.h"
+
 int xsk_map_inc(struct xsk_map *map)
 {
 	bpf_map_inc(&map->map);