RDMA/erdma: Support dynamic mtu

Hardware now support jumbo frame for RDMA. So we introduce a new CMDQ
message to support mtu change notification.
Signed-off-by: Cheng Xu <chengyou@linux.alibaba.com>
Link: https://lore.kernel.org/r/20220909093822.33868-5-chengyou@linux.alibaba.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/hw/erdma/erdma.h

@@ -197,6 +197,7 @@ struct erdma_dev {
 	struct erdma_devattr attrs;
 	/* physical port state (only one port per device) */
 	enum ib_port_state state;
+	u32 mtu;
 
 	/* cmdq and aeq use the same msix vector */
 	struct erdma_irq comm_irq;

drivers/infiniband/hw/erdma/erdma_hw.h

@@ -153,6 +153,7 @@ enum CMDQ_COMMON_OPCODE {
 	CMDQ_OPCODE_CREATE_EQ = 0,
 	CMDQ_OPCODE_DESTROY_EQ = 1,
 	CMDQ_OPCODE_QUERY_FW_INFO = 2,
+	CMDQ_OPCODE_CONF_MTU = 3,
 };
 
 /* cmdq-SQE HDR */
@@ -190,6 +191,11 @@ struct erdma_cmdq_destroy_eq_req {
 	u8 qtype;
 };
 
+struct erdma_cmdq_config_mtu_req {
+	u64 hdr;
+	u32 mtu;
+};
+
 /* create_cq cfg0 */
 #define ERDMA_CMD_CREATE_CQ_DEPTH_MASK GENMASK(31, 24)
 #define ERDMA_CMD_CREATE_CQ_PAGESIZE_MASK GENMASK(23, 20)

drivers/infiniband/hw/erdma/erdma_main.c

@@ -34,10 +34,15 @@ static int erdma_netdev_event(struct notifier_block *nb, unsigned long event,
 		dev->state = IB_PORT_DOWN;
 		erdma_port_event(dev, IB_EVENT_PORT_ERR);
 		break;
+	case NETDEV_CHANGEMTU:
+		if (dev->mtu != netdev->mtu) {
+			erdma_set_mtu(dev, netdev->mtu);
+			dev->mtu = netdev->mtu;
+		}
+		break;
 	case NETDEV_REGISTER:
 	case NETDEV_UNREGISTER:
 	case NETDEV_CHANGEADDR:
-	case NETDEV_CHANGEMTU:
 	case NETDEV_GOING_DOWN:
 	case NETDEV_CHANGE:
 	default:
@@ -95,6 +100,7 @@ static int erdma_device_register(struct erdma_dev *dev)
 	if (ret)
 		return ret;
 
+	dev->mtu = dev->netdev->mtu;
 	addrconf_addr_eui48((u8 *)&ibdev->node_guid, dev->netdev->dev_addr);
 
 	ret = ib_register_device(ibdev, "erdma_%d", &dev->pdev->dev);

drivers/infiniband/hw/erdma/erdma_verbs.c

@@ -1436,6 +1436,17 @@ int erdma_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr,
 	return ret;
 }
 
+void erdma_set_mtu(struct erdma_dev *dev, u32 mtu)
+{
+	struct erdma_cmdq_config_mtu_req req;
+
+	erdma_cmdq_build_reqhdr(&req.hdr, CMDQ_SUBMOD_COMMON,
+				CMDQ_OPCODE_CONF_MTU);
+	req.mtu = mtu;
+
+	erdma_post_cmd_wait(&dev->cmdq, &req, sizeof(req), NULL, NULL);
+}
+
 void erdma_port_event(struct erdma_dev *dev, enum ib_event_type reason)
 {
 	struct ib_event event;

drivers/infiniband/hw/erdma/erdma_verbs.h

@@ -330,5 +330,6 @@ struct ib_mr *erdma_ib_alloc_mr(struct ib_pd *ibpd, enum ib_mr_type mr_type,
 int erdma_map_mr_sg(struct ib_mr *ibmr, struct scatterlist *sg, int sg_nents,
 		    unsigned int *sg_offset);
 void erdma_port_event(struct erdma_dev *dev, enum ib_event_type reason);
+void erdma_set_mtu(struct erdma_dev *dev, u32 mtu);
 
 #endif