xsk: Create and free buffer pool independently from umem

Create and free the buffer pool independently from the umem. Move
these operations that are performed on the buffer pool from the
umem create and destroy functions to new create and destroy
functions just for the buffer pool. This so that in later commits
we can instantiate multiple buffer pools per umem when sharing a
umem between HW queues and/or devices. We also erradicate the
back pointer from the umem to the buffer pool as this will not
work when we introduce the possibility to have multiple buffer
pools per umem.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Link: https://lore.kernel.org/bpf/1598603189-32145-4-git-send-email-magnus.karlsson@intel.com

1 files changed, 10 insertions, 3 deletions

diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h
index f851b0a68324..4025486cc057 100644
--- a/include/net/xsk_buff_pool.h
+++ b/include/net/xsk_buff_pool.h
@@ -14,6 +14,7 @@ struct xdp_rxq_info;
 struct xsk_queue;
 struct xdp_desc;
 struct xdp_umem;
+struct xdp_sock;
 struct device;
 struct page;
 
@@ -46,16 +47,22 @@ struct xsk_buff_pool {
 	struct xdp_umem *umem;
 	void *addrs;
 	struct device *dev;
+	refcount_t users;
+	struct work_struct work;
 	struct xdp_buff_xsk *free_heads[];
 };
 
 /* AF_XDP core. */
-struct xsk_buff_pool *xp_create(struct xdp_umem *umem, u32 chunks,
-				u32 chunk_size, u32 headroom, u64 size,
-				bool unaligned);
+struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
+						struct xdp_umem *umem);
+int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev,
+		  u16 queue_id, u16 flags);
 void xp_set_fq(struct xsk_buff_pool *pool, struct xsk_queue *fq);
 void xp_destroy(struct xsk_buff_pool *pool);
 void xp_release(struct xdp_buff_xsk *xskb);
+void xp_get_pool(struct xsk_buff_pool *pool);
+void xp_put_pool(struct xsk_buff_pool *pool);
+void xp_clear_dev(struct xsk_buff_pool *pool);
 
 /* AF_XDP, and XDP core. */
 void xp_free(struct xdp_buff_xsk *xskb);