Add (stub) functions for doing netmem allocations.  We want to allocate
memory from the netmem buffering as that does bulk DMA and IOMMU
management.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Paulo Alcantara <pc@manguebit.org>
cc: Shyam Prasad N <sprasad@microsoft.com>
cc: Tom Talpey <tom@talpey.com>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
---
 fs/smb/client/cifsproto.h |  3 +++
 fs/smb/client/transport.c | 15 +++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h
index 074b65bb57a5..ccd70a402567 100644
--- a/fs/smb/client/cifsproto.h
+++ b/fs/smb/client/cifsproto.h
@@ -766,4 +766,7 @@ void smb_get_message(struct smb_message *smb, enum smb_message_trace trace);
 void smb_put_message(struct smb_message *smb, enum smb_message_trace trace);
 void smb_put_messages(struct smb_message *smb);
 
+void *cifs_allocate_tx_buf(struct TCP_Server_Info *server, size_t size);
+void cifs_free_tx_buf(void *p);
+
 #endif			/* _CIFSPROTO_H */
diff --git a/fs/smb/client/transport.c b/fs/smb/client/transport.c
index 2ccfdd6b958b..b497bf319a7e 100644
--- a/fs/smb/client/transport.c
+++ b/fs/smb/client/transport.c
@@ -32,6 +32,21 @@
 #include "smbdirect.h"
 #include "compress.h"
 
+/*
+ * Allocate transmission buffers for a socket.  This memory will be allocated
+ * from the netmem buffers.  It comes with a page ref that we need to drop.
+ * The networking layer can pin it by getting its own ref.
+ */
+void *cifs_allocate_tx_buf(struct TCP_Server_Info *server, size_t size)
+{
+	return NULL; /* TODO */
+}
+
+void cifs_free_tx_buf(void *p)
+{
+	/* TODO */
+}
+
 struct smb_message *smb_message_alloc(enum smb2_command cmd, gfp_t gfp)
 {
 	static atomic_t debug_ids;