From: Geliang Tang <tanggeliang@kylinos.cn>

This patch defines a new nvmf_transport_ops named nvme_mptcp_transport,
which is almost the same as nvme_tcp_transport except .type and
.allowed_opts.

MPTCP currently does not support TLS. The four TLS-related options
(NVMF_OPT_TLS, NVMF_OPT_KEYRING, NVMF_OPT_TLS_KEY, and NVMF_OPT_CONCAT)
have been removed from allowed_opts. They will be added back once MPTCP
TLS is supported.

It is registered in nvme_tcp_init_module() and unregistered in
nvme_tcp_cleanup_module().

A separate nvme_mptcp_ctrl_ops structure with .name = "mptcp" is defined
and used for MPTCP controllers.

A MODULE_ALIAS("nvme-mptcp") declaration alongside the other module
metadata is added at the end of the file.

v2:
 - use 'trtype' instead of '--mptcp' (Hannes)

v3:
 - check mptcp protocol from opts->transport instead of passing a
parameter (Hannes).

v4:
 - check CONFIG_MPTCP.

Cc: Hannes Reinecke <hare@suse.de>
Co-developed-by: zhenwei pi <zhenwei.pi@linux.dev>
Signed-off-by: zhenwei pi <zhenwei.pi@linux.dev>
Co-developed-by: Hui Zhu <zhuhui@kylinos.cn>
Signed-off-by: Hui Zhu <zhuhui@kylinos.cn>
Co-developed-by: Gang Yan <yangang@kylinos.cn>
Signed-off-by: Gang Yan <yangang@kylinos.cn>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 drivers/nvme/host/tcp.c | 44 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index f0ce09b0c142..c137fce4d358 100644
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -2880,6 +2880,24 @@ static const struct nvme_ctrl_ops nvme_tcp_ctrl_ops = {
 	.get_virt_boundary	= nvmf_get_virt_boundary,
 };
 
+#ifdef CONFIG_MPTCP
+static const struct nvme_ctrl_ops nvme_mptcp_ctrl_ops = {
+	.name			= "mptcp",
+	.module			= THIS_MODULE,
+	.flags			= NVME_F_FABRICS | NVME_F_BLOCKING,
+	.reg_read32		= nvmf_reg_read32,
+	.reg_read64		= nvmf_reg_read64,
+	.reg_write32		= nvmf_reg_write32,
+	.subsystem_reset	= nvmf_subsystem_reset,
+	.free_ctrl		= nvme_tcp_free_ctrl,
+	.submit_async_event	= nvme_tcp_submit_async_event,
+	.delete_ctrl		= nvme_tcp_delete_ctrl,
+	.get_address		= nvme_tcp_get_address,
+	.stop_ctrl		= nvme_tcp_stop_ctrl,
+	.get_virt_boundary	= nvmf_get_virt_boundary,
+};
+#endif
+
 static bool
 nvme_tcp_existing_controller(struct nvmf_ctrl_options *opts)
 {
@@ -2920,6 +2938,7 @@ static const struct nvme_tcp_sockops nvme_mptcp_sockops = {
 static struct nvme_tcp_ctrl *nvme_tcp_alloc_ctrl(struct device *dev,
 		struct nvmf_ctrl_options *opts)
 {
+	const struct nvme_ctrl_ops *ops;
 	struct nvme_tcp_ctrl *ctrl;
 	int ret;
 
@@ -2983,9 +3002,11 @@ static struct nvme_tcp_ctrl *nvme_tcp_alloc_ctrl(struct device *dev,
 
 	if (!strcmp(ctrl->ctrl.opts->transport, "tcp")) {
 		ctrl->sockops = &nvme_tcp_sockops;
+		ops = &nvme_tcp_ctrl_ops;
 #ifdef CONFIG_MPTCP
 	} else if (!strcmp(ctrl->ctrl.opts->transport, "mptcp")) {
 		ctrl->sockops = &nvme_mptcp_sockops;
+		ops = &nvme_mptcp_ctrl_ops;
 #endif
 	} else {
 		ret = -EINVAL;
@@ -2998,7 +3019,7 @@ static struct nvme_tcp_ctrl *nvme_tcp_alloc_ctrl(struct device *dev,
 		goto out_free_ctrl;
 	}
 
-	ret = nvme_init_ctrl(&ctrl->ctrl, dev, &nvme_tcp_ctrl_ops, 0);
+	ret = nvme_init_ctrl(&ctrl->ctrl, dev, ops, 0);
 	if (ret)
 		goto out_kfree_queues;
 
@@ -3065,6 +3086,20 @@ static struct nvmf_transport_ops nvme_tcp_transport = {
 	.create_ctrl	= nvme_tcp_create_ctrl,
 };
 
+#ifdef CONFIG_MPTCP
+static struct nvmf_transport_ops nvme_mptcp_transport = {
+	.name		= "mptcp",
+	.module		= THIS_MODULE,
+	.required_opts	= NVMF_OPT_TRADDR,
+	.allowed_opts	= NVMF_OPT_TRSVCID | NVMF_OPT_RECONNECT_DELAY |
+			  NVMF_OPT_HOST_TRADDR | NVMF_OPT_CTRL_LOSS_TMO |
+			  NVMF_OPT_HDR_DIGEST | NVMF_OPT_DATA_DIGEST |
+			  NVMF_OPT_NR_WRITE_QUEUES | NVMF_OPT_NR_POLL_QUEUES |
+			  NVMF_OPT_TOS | NVMF_OPT_HOST_IFACE,
+	.create_ctrl	= nvme_tcp_create_ctrl,
+};
+#endif
+
 static int __init nvme_tcp_init_module(void)
 {
 	unsigned int wq_flags = WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_SYSFS;
@@ -3090,6 +3125,9 @@ static int __init nvme_tcp_init_module(void)
 		atomic_set(&nvme_tcp_cpu_queues[cpu], 0);
 
 	nvmf_register_transport(&nvme_tcp_transport);
+#ifdef CONFIG_MPTCP
+	nvmf_register_transport(&nvme_mptcp_transport);
+#endif
 	return 0;
 }
 
@@ -3097,6 +3135,9 @@ static void __exit nvme_tcp_cleanup_module(void)
 {
 	struct nvme_tcp_ctrl *ctrl;
 
+#ifdef CONFIG_MPTCP
+	nvmf_unregister_transport(&nvme_mptcp_transport);
+#endif
 	nvmf_unregister_transport(&nvme_tcp_transport);
 
 	mutex_lock(&nvme_tcp_ctrl_mutex);
@@ -3113,3 +3154,4 @@ module_exit(nvme_tcp_cleanup_module);
 
 MODULE_DESCRIPTION("NVMe host TCP transport driver");
 MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("nvme-mptcp");
-- 
2.51.0