[PATCH v4 060/145] smb: smbdirect: introduce the basic smbdirect.ko

[Stefan Metzmacher]

This exports the functions needed by cifs.ko and ksmbd.ko.

It doesn't yet provide a generic socket layer, but it
is a good start to introduce that on top.
It will be much easier after Davids refactoring
using MSG_SPLICE_PAGES, will make it easier to
use the socket layer without an additional copy.

Cc: Steve French <smfrench at gmail.com>
Cc: Tom Talpey <tom at talpey.com>
Cc: Long Li <longli at microsoft.com>
Cc: Namjae Jeon <linkinjeon at kernel.org>
Cc: David Howells <dhowells at redhat.com>
Cc: linux-cifs at vger.kernel.org
Cc: samba-technical at lists.samba.org
Signed-off-by: Stefan Metzmacher <metze at samba.org>
Signed-off-by: Steve French <stfrench at microsoft.com>
---
 fs/smb/Kconfig                               |  2 +
 fs/smb/common/Makefile                       |  1 +
 fs/smb/common/smbdirect/Kconfig              |  9 +++++
 fs/smb/common/smbdirect/Makefile             | 16 ++++++++
 fs/smb/common/smbdirect/smbdirect_internal.h |  9 +++++
 fs/smb/common/smbdirect/smbdirect_main.c     | 40 ++++++++++++++++++++
 6 files changed, 77 insertions(+)
 create mode 100644 fs/smb/common/smbdirect/Kconfig
 create mode 100644 fs/smb/common/smbdirect/Makefile
 create mode 100644 fs/smb/common/smbdirect/smbdirect_main.c

diff --git a/fs/smb/Kconfig b/fs/smb/Kconfig
index ef425789fa6a..065c0aa130e7 100644
--- a/fs/smb/Kconfig
+++ b/fs/smb/Kconfig
@@ -9,3 +9,5 @@ config SMBFS
 	tristate
 	default y if CIFS=y || SMB_SERVER=y
 	default m if CIFS=m || SMB_SERVER=m
+
+source "fs/smb/common/smbdirect/Kconfig"
diff --git a/fs/smb/common/Makefile b/fs/smb/common/Makefile
index 9e0730a385fb..e6ee65c31b5d 100644
--- a/fs/smb/common/Makefile
+++ b/fs/smb/common/Makefile
@@ -4,3 +4,4 @@
 #
 
 obj-$(CONFIG_SMBFS) += cifs_md4.o
+obj-$(CONFIG_SMB_COMMON_SMBDIRECT) += smbdirect/
diff --git a/fs/smb/common/smbdirect/Kconfig b/fs/smb/common/smbdirect/Kconfig
new file mode 100644
index 000000000000..d8d8cde23860
--- /dev/null
+++ b/fs/smb/common/smbdirect/Kconfig
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# smbdirect configuration
+
+config SMB_COMMON_SMBDIRECT
+	def_tristate n
+	depends on INFINIBAND && INFINIBAND_ADDR_TRANS
+	depends on m || INFINIBAND != m
+	select SG_POOL
diff --git a/fs/smb/common/smbdirect/Makefile b/fs/smb/common/smbdirect/Makefile
new file mode 100644
index 000000000000..bae6281fdd39
--- /dev/null
+++ b/fs/smb/common/smbdirect/Makefile
@@ -0,0 +1,16 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Makefile for smbdirect support
+#
+
+obj-$(CONFIG_SMB_COMMON_SMBDIRECT) += smbdirect.o
+
+smbdirect-y := \
+	smbdirect_socket.o	\
+	smbdirect_connection.o	\
+	smbdirect_mr.o		\
+	smbdirect_rw.o		\
+	smbdirect_debug.o	\
+	smbdirect_connect.o	\
+	smbdirect_accept.o	\
+	smbdirect_main.o
diff --git a/fs/smb/common/smbdirect/smbdirect_internal.h b/fs/smb/common/smbdirect/smbdirect_internal.h
index a2018670749f..eecc8f6b197b 100644
--- a/fs/smb/common/smbdirect/smbdirect_internal.h
+++ b/fs/smb/common/smbdirect/smbdirect_internal.h
@@ -14,6 +14,15 @@
 #include "smbdirect.h"
 #include "smbdirect_pdu.h"
 #include "smbdirect_public.h"
+
+#include <linux/mutex.h>
+
+struct smbdirect_module_state {
+	struct mutex mutex;
+};
+
+extern struct smbdirect_module_state smbdirect_globals;
+
 #include "smbdirect_socket.h"
 
 #ifdef SMBDIRECT_USE_INLINE_C_FILES
diff --git a/fs/smb/common/smbdirect/smbdirect_main.c b/fs/smb/common/smbdirect/smbdirect_main.c
new file mode 100644
index 000000000000..c61ae8d7f4f0
--- /dev/null
+++ b/fs/smb/common/smbdirect/smbdirect_main.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   Copyright (c) 2025, Stefan Metzmacher
+ */
+
+#include "smbdirect_internal.h"
+#include <linux/module.h>
+
+struct smbdirect_module_state smbdirect_globals = {
+	.mutex = __MUTEX_INITIALIZER(smbdirect_globals.mutex),
+};
+
+static __init int smbdirect_module_init(void)
+{
+	pr_notice("subsystem loading...\n");
+	mutex_lock(&smbdirect_globals.mutex);
+
+	/* TODO... */
+
+	mutex_unlock(&smbdirect_globals.mutex);
+	pr_notice("subsystem loaded\n");
+	return 0;
+}
+
+static __exit void smbdirect_module_exit(void)
+{
+	pr_notice("subsystem unloading...\n");
+	mutex_lock(&smbdirect_globals.mutex);
+
+	/* TODO... */
+
+	mutex_unlock(&smbdirect_globals.mutex);
+	pr_notice("subsystem unloaded\n");
+}
+
+module_init(smbdirect_module_init);
+module_exit(smbdirect_module_exit);
+
+MODULE_DESCRIPTION("smbdirect subsystem");
+MODULE_LICENSE("GPL");
-- 
2.43.0