1 files changed, 41 insertions, 0 deletions
diff --git a/include/net/netmem.h b/include/net/netmem.h
new file mode 100644
index 0000000000..d8b810245c
--- /dev/null
+++ b/include/net/netmem.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ *	Network memory
+ *
+ *	Author:	Mina Almasry <almasrymina@google.com>
+ */
+
+#ifndef _NET_NETMEM_H
+#define _NET_NETMEM_H
+
+/**
+ * typedef netmem_ref - a nonexistent type marking a reference to generic
+ * network memory.
+ *
+ * A netmem_ref currently is always a reference to a struct page. This
+ * abstraction is introduced so support for new memory types can be added.
+ *
+ * Use the supplied helpers to obtain the underlying memory pointer and fields.
+ */
+typedef unsigned long __bitwise netmem_ref;
+
+/* This conversion fails (returns NULL) if the netmem_ref is not struct page
+ * backed.
+ *
+ * Currently struct page is the only possible netmem, and this helper never
+ * fails.
+ */
+static inline struct page *netmem_to_page(netmem_ref netmem)
+{
+	return (__force struct page *)netmem;
+}
+
+/* Converting from page to netmem is always safe, because a page can always be
+ * a netmem.
+ */
+static inline netmem_ref page_to_netmem(struct page *page)
+{
+	return (__force netmem_ref)page;
+}
+
+#endif /* _NET_NETMEM_H */