net: mana: Build the PCI transport as a separate module

Build the shared GDMA and Ethernet code as gdma_core.ko, selected by
MICROSOFT_GDMA_CORE. Build the PCI transport separately as mana.ko and
export the required core symbols.

Preserve the PCI module name, device table, and mana.eth/mana.rdma
auxiliary-device names. Each transport registers its own bus driver.

Signed-off-by: Manish Awasthi <mawasthi@linux.microsoft.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Link: https://patch.msgid.link/20260924173054.589291-4-mawasthi@linux.microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/microsoft/Kconfig

@@ -15,15 +15,19 @@ config NET_VENDOR_MICROSOFT
 
 if NET_VENDOR_MICROSOFT
 
+config MICROSOFT_GDMA_CORE
+	tristate
+	select AUXILIARY_BUS
+	select DIMLIB
+	select PAGE_POOL
+	select NET_SHAPER
+
 config MICROSOFT_MANA
 	tristate "Microsoft Azure Network Adapter (MANA) support"
 	depends on PCI_MSI
 	depends on X86_64 || (ARM64 && !CPU_BIG_ENDIAN)
 	depends on PCI_HYPERV
-	select AUXILIARY_BUS
-	select DIMLIB
-	select PAGE_POOL
-	select NET_SHAPER
+	select MICROSOFT_GDMA_CORE
 	help
 	  This driver supports Microsoft Azure Network Adapter (MANA).
 	  So far, the driver is only supported on X86_64.

drivers/net/ethernet/microsoft/Makefile

@@ -2,4 +2,4 @@
 # Makefile for the Microsoft Azure network device driver.
 #
 
-obj-$(CONFIG_MICROSOFT_MANA) += mana/
+obj-$(CONFIG_MICROSOFT_GDMA_CORE) += mana/

drivers/net/ethernet/microsoft/mana/Makefile

@@ -2,6 +2,9 @@
 #
 # Makefile for the Microsoft Azure Network Adapter driver
 
+obj-$(CONFIG_MICROSOFT_GDMA_CORE) += gdma_core.o
+gdma_core-y := gdma_main.o shm_channel.o hw_channel.o mana_en.o mana_ethtool.o \
+	       mana_bpf.o
+
 obj-$(CONFIG_MICROSOFT_MANA) += mana.o
-mana-y := gdma_main.o shm_channel.o hw_channel.o mana_en.o mana_ethtool.o mana_bpf.o \
-	  gdma_pci.o
+mana-y := gdma_pci.o

drivers/net/ethernet/microsoft/mana/gdma_main.c

@@ -1991,6 +1991,7 @@ int mana_gd_setup(struct gdma_context *gc)
 	dev_err(gc->dev, "%s failed (error %d)\n", __func__, err);
 	return err;
 }
+EXPORT_SYMBOL_NS(mana_gd_setup, "NET_MANA");
 
 void mana_gd_cleanup(struct gdma_context *gc)
 {
@@ -2005,36 +2006,24 @@ void mana_gd_cleanup(struct gdma_context *gc)
 
 	dev_dbg(gc->dev, "mana gdma cleanup successful\n");
 }
+EXPORT_SYMBOL_NS(mana_gd_cleanup, "NET_MANA");
 
-static int __init mana_driver_init(void)
+static int __init gdma_core_init(void)
 {
-	int err;
-
 	mana_debugfs_root = debugfs_create_dir("mana", NULL);
 
-	err = mana_pci_driver_register();
-	if (err)
-		goto err_debugfs;
-
 	return 0;
-
-err_debugfs:
-	debugfs_remove(mana_debugfs_root);
-	mana_debugfs_root = NULL;
-	return err;
 }
 
-static void __exit mana_driver_exit(void)
+static void __exit gdma_core_exit(void)
 {
-	mana_pci_driver_unregister();
-
 	debugfs_remove(mana_debugfs_root);
 
 	mana_debugfs_root = NULL;
 }
 
-module_init(mana_driver_init);
-module_exit(mana_driver_exit);
+module_init(gdma_core_init);
+module_exit(gdma_core_exit);
 
 MODULE_LICENSE("Dual BSD/GPL");
-MODULE_DESCRIPTION("Microsoft Azure Network Adapter driver");
+MODULE_DESCRIPTION("Microsoft Azure Network Adapter GDMA core");

drivers/net/ethernet/microsoft/mana/gdma_pci.c

@@ -878,7 +878,7 @@ static struct pci_driver mana_driver = {
 
 MODULE_DEVICE_TABLE(pci, mana_id_table);
 
-int mana_pci_driver_register(void)
+static int __init mana_driver_init(void)
 {
 	INIT_LIST_HEAD(&mana_dev_recovery_work.dev_list);
 	spin_lock_init(&mana_dev_recovery_work.lock);
@@ -888,7 +888,7 @@ int mana_pci_driver_register(void)
 	return pci_register_driver(&mana_driver);
 }
 
-void mana_pci_driver_unregister(void)
+static void __exit mana_driver_exit(void)
 {
 	struct mana_dev_recovery *dev;
 	unsigned long flags;
@@ -907,3 +907,10 @@ void mana_pci_driver_unregister(void)
 
 	pci_unregister_driver(&mana_driver);
 }
+
+module_init(mana_driver_init);
+module_exit(mana_driver_exit);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("Microsoft Azure Network Adapter driver");
+MODULE_IMPORT_NS("NET_MANA");

drivers/net/ethernet/microsoft/mana/mana_en.c

@@ -3957,7 +3957,8 @@ static int add_adev(struct gdma_dev *gd, const char *name)
 
 	/* madev is owned by the auxiliary device */
 	madev = NULL;
-	ret = auxiliary_device_add(adev);
+	/* Keep the established mana.{eth,rdma} auxiliary match names. */
+	ret = __auxiliary_device_add(adev, "mana");
 	if (ret)
 		goto add_fail;
 
@@ -4194,6 +4195,7 @@ int mana_probe(struct gdma_dev *gd, bool resuming)
 
 	return err;
 }
+EXPORT_SYMBOL_NS(mana_probe, "NET_MANA");
 
 void mana_remove(struct gdma_dev *gd, bool suspending)
 {
@@ -4272,6 +4274,7 @@ void mana_remove(struct gdma_dev *gd, bool suspending)
 	kfree(ac);
 	dev_dbg(dev, "%s succeeded\n", __func__);
 }
+EXPORT_SYMBOL_NS(mana_remove, "NET_MANA");
 
 int mana_rdma_probe(struct gdma_dev *gd)
 {
@@ -4307,6 +4310,7 @@ int mana_rdma_probe(struct gdma_dev *gd)
 
 	return err;
 }
+EXPORT_SYMBOL_NS(mana_rdma_probe, "NET_MANA");
 
 void mana_rdma_remove(struct gdma_dev *gd)
 {
@@ -4327,6 +4331,7 @@ void mana_rdma_remove(struct gdma_dev *gd)
 
 	mana_gd_deregister_device(gd);
 }
+EXPORT_SYMBOL_NS(mana_rdma_remove, "NET_MANA");
 
 struct net_device *mana_get_primary_netdev(struct mana_context *ac,
 					   u32 port_index,

include/net/mana/gdma.h

@@ -1175,7 +1175,4 @@ int mana_gd_query_device_cfg(struct gdma_context *gc, u32 proto_major_ver,
 			     u16 *max_num_vports, u8 *bm_hostmode);
 int mana_gd_dev_reset(struct gdma_context *gc);
 
-int mana_pci_driver_register(void);
-void mana_pci_driver_unregister(void);
-
 #endif /* _GDMA_H */