page_pool: Store the XDP mem id

Store the XDP mem ID inside the page_pool struct so it can be retrieved
later for use in bpf_prog_run().
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/20220103150812.87914-4-toke@redhat.com

include/net/page_pool.h

@@ -96,6 +96,7 @@ struct page_pool {
 	unsigned int frag_offset;
 	struct page *frag_page;
 	long frag_users;
+	u32 xdp_mem_id;
 
 	/*
 	 * Data structure for allocation side
@@ -170,9 +171,12 @@ bool page_pool_return_skb_page(struct page *page);
 
 struct page_pool *page_pool_create(const struct page_pool_params *params);
 
+struct xdp_mem_info;
+
 #ifdef CONFIG_PAGE_POOL
 void page_pool_destroy(struct page_pool *pool);
-void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *));
+void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *),
+			   struct xdp_mem_info *mem);
 void page_pool_release_page(struct page_pool *pool, struct page *page);
 void page_pool_put_page_bulk(struct page_pool *pool, void **data,
 			     int count);
@@ -182,7 +186,8 @@ static inline void page_pool_destroy(struct page_pool *pool)
 }
 
 static inline void page_pool_use_xdp_mem(struct page_pool *pool,
-					 void (*disconnect)(void *))
+					 void (*disconnect)(void *),
+					 struct xdp_mem_info *mem)
 {
 }
 static inline void page_pool_release_page(struct page_pool *pool,

net/core/page_pool.c

@@ -693,10 +693,12 @@ static void page_pool_release_retry(struct work_struct *wq)
 	schedule_delayed_work(&pool->release_dw, DEFER_TIME);
 }
 
-void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *))
+void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *),
+			   struct xdp_mem_info *mem)
 {
 	refcount_inc(&pool->user_cnt);
 	pool->disconnect = disconnect;
+	pool->xdp_mem_id = mem->id;
 }
 
 void page_pool_destroy(struct page_pool *pool)

net/core/xdp.c

@@ -320,7 +320,7 @@ static struct xdp_mem_allocator *__xdp_reg_mem_model(struct xdp_mem_info *mem,
 	}
 
 	if (type == MEM_TYPE_PAGE_POOL)
-		page_pool_use_xdp_mem(allocator, mem_allocator_disconnect);
+		page_pool_use_xdp_mem(allocator, mem_allocator_disconnect, mem);
 
 	mutex_unlock(&mem_id_lock);