[PATCH 14/18] dsa: ocelot: fix mixed module-builtin object

[Alexander Lobakin <alobakin@pm.me>]

With CONFIG_NET_DSA_MSCC_FELIX=m and CONFIG_NET_DSA_MSCC_SEVILLE=y
(or vice versa), felix.o are linked to a module and also to vmlinux
even though the expected CFLAGS are different between builtins and
modules.
This is the same situation as fixed by
commit 637a642f5ca5 ("zstd: Fixing mixed module-builtin objects").
There's also no need to duplicate relatively big piece of object
code into two modules.

Introduce the new module, mscc_core, to provide the common functions
to both mscc_felix and mscc_seville.

Fixes: d60bc62de4ae ("net: dsa: seville: build as separate module")
Suggested-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Alexander Lobakin <alobakin@pm.me>
---
 drivers/net/dsa/ocelot/Kconfig           | 18 ++++++++++--------
 drivers/net/dsa/ocelot/Makefile          | 12 +++++-------
 drivers/net/dsa/ocelot/felix.c           |  6 ++++++
 drivers/net/dsa/ocelot/felix_vsc9959.c   |  2 ++
 drivers/net/dsa/ocelot/seville_vsc9953.c |  2 ++
 5 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/drivers/net/dsa/ocelot/Kconfig b/drivers/net/dsa/ocelot/Kconfig
index 08db9cf76818..59845274e374 100644
--- a/drivers/net/dsa/ocelot/Kconfig
+++ b/drivers/net/dsa/ocelot/Kconfig
@@ -1,4 +1,12 @@
 # SPDX-License-Identifier: GPL-2.0-only
+
+config NET_DSA_MSCC_CORE
+	tristate
+	select MSCC_OCELOT_SWITCH_LIB
+	select NET_DSA_TAG_OCELOT_8021Q
+	select NET_DSA_TAG_OCELOT
+	select PCS_LYNX
+
 config NET_DSA_MSCC_FELIX
 	tristate "Ocelot / Felix Ethernet switch support"
 	depends on NET_DSA && PCI
@@ -7,11 +15,8 @@ config NET_DSA_MSCC_FELIX
 	depends on HAS_IOMEM
 	depends on PTP_1588_CLOCK_OPTIONAL
 	depends on NET_SCH_TAPRIO || NET_SCH_TAPRIO=n
-	select MSCC_OCELOT_SWITCH_LIB
-	select NET_DSA_TAG_OCELOT_8021Q
-	select NET_DSA_TAG_OCELOT
+	select NET_DSA_MSCC_CORE
 	select FSL_ENETC_MDIO
-	select PCS_LYNX
 	help
 	  This driver supports the VSC9959 (Felix) switch, which is embedded as
 	  a PCIe function of the NXP LS1028A ENETC RCiEP.
@@ -22,11 +27,8 @@ config NET_DSA_MSCC_SEVILLE
 	depends on NET_VENDOR_MICROSEMI
 	depends on HAS_IOMEM
 	depends on PTP_1588_CLOCK_OPTIONAL
+	select NET_DSA_MSCC_CORE
 	select MDIO_MSCC_MIIM
-	select MSCC_OCELOT_SWITCH_LIB
-	select NET_DSA_TAG_OCELOT_8021Q
-	select NET_DSA_TAG_OCELOT
-	select PCS_LYNX
 	help
 	  This driver supports the VSC9953 (Seville) switch, which is embedded
 	  as a platform device on the NXP T1040 SoC.
diff --git a/drivers/net/dsa/ocelot/Makefile b/drivers/net/dsa/ocelot/Makefile
index f6dd131e7491..f8c74b59b996 100644
--- a/drivers/net/dsa/ocelot/Makefile
+++ b/drivers/net/dsa/ocelot/Makefile
@@ -1,11 +1,9 @@
 # SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_NET_DSA_MSCC_CORE) += mscc_core.o
 obj-$(CONFIG_NET_DSA_MSCC_FELIX) += mscc_felix.o
 obj-$(CONFIG_NET_DSA_MSCC_SEVILLE) += mscc_seville.o

-mscc_felix-objs := \
-	felix.o \
-	felix_vsc9959.o
-
-mscc_seville-objs := \
-	felix.o \
-	seville_vsc9953.o
+mscc_core-objs := felix.o
+mscc_felix-objs := felix_vsc9959.o
+mscc_seville-objs := seville_vsc9953.o
diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index dd3a18cc89dd..f9d0a24ebc3a 100644
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -2112,6 +2112,7 @@ const struct dsa_switch_ops felix_switch_ops = {
 	.port_set_host_flood		= felix_port_set_host_flood,
 	.port_change_master		= felix_port_change_master,
 };
+EXPORT_SYMBOL_NS_GPL(felix_switch_ops, NET_DSA_MSCC_CORE);

 struct net_device *felix_port_to_netdev(struct ocelot *ocelot, int port)
 {
@@ -2123,6 +2124,7 @@ struct net_device *felix_port_to_netdev(struct ocelot *ocelot, int port)

 	return dsa_to_port(ds, port)->slave;
 }
+EXPORT_SYMBOL_NS_GPL(felix_port_to_netdev, NET_DSA_MSCC_CORE);

 int felix_netdev_to_port(struct net_device *dev)
 {
@@ -2134,3 +2136,7 @@ int felix_netdev_to_port(struct net_device *dev)

 	return dp->index;
 }
+EXPORT_SYMBOL_NS_GPL(felix_netdev_to_port, NET_DSA_MSCC_CORE);
+
+MODULE_DESCRIPTION("MSCC Switch driver core");
+MODULE_LICENSE("GPL");
diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c
index 26a35ae322d1..52c8bff79fa3 100644
--- a/drivers/net/dsa/ocelot/felix_vsc9959.c
+++ b/drivers/net/dsa/ocelot/felix_vsc9959.c
@@ -2736,5 +2736,7 @@ static struct pci_driver felix_vsc9959_pci_driver = {
 };
 module_pci_driver(felix_vsc9959_pci_driver);

+MODULE_IMPORT_NS(NET_DSA_MSCC_CORE);
+
 MODULE_DESCRIPTION("Felix Switch driver");
 MODULE_LICENSE("GPL v2");
diff --git a/drivers/net/dsa/ocelot/seville_vsc9953.c b/drivers/net/dsa/ocelot/seville_vsc9953.c
index 7af33b2c685d..e9c63c642489 100644
--- a/drivers/net/dsa/ocelot/seville_vsc9953.c
+++ b/drivers/net/dsa/ocelot/seville_vsc9953.c
@@ -1115,5 +1115,7 @@ static struct platform_driver seville_vsc9953_driver = {
 };
 module_platform_driver(seville_vsc9953_driver);

+MODULE_IMPORT_NS(NET_DSA_MSCC_CORE);
+
 MODULE_DESCRIPTION("Seville Switch driver");
 MODULE_LICENSE("GPL v2");
--
2.38.1