net: hns3: Add *Asserting Reset* mailbox message & handling in VF

Reset Asserting message is forwarded by PF to inform VF about
the hardware reset which is about to happen. This might be due
to the earlier VF reset request received by the PF or because PF
for any reason decides to undergo reset. This message results in
VF to go in pending state in which it polls the hardware to
complete the reset and then further resets/tears its own stack.
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hclge_mbx.h

@@ -11,6 +11,7 @@
 
 enum HCLGE_MBX_OPCODE {
 	HCLGE_MBX_RESET = 0x01,		/* (VF -> PF) assert reset */
+	HCLGE_MBX_ASSERTING_RESET,	/* (PF -> VF) PF is asserting reset*/
 	HCLGE_MBX_SET_UNICAST,		/* (VF -> PF) set UC addr */
 	HCLGE_MBX_SET_MULTICAST,	/* (VF -> PF) set MC addr */
 	HCLGE_MBX_SET_VLAN,		/* (VF -> PF) set VLAN */

drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_mbx.c

@@ -170,6 +170,7 @@ void hclgevf_mbx_handler(struct hclgevf_dev *hdev)
 			}
 			break;
 		case HCLGE_MBX_LINK_STAT_CHANGE:
+		case HCLGE_MBX_ASSERTING_RESET:
 			/* set this mbx event as pending. This is required as we
 			 * might loose interrupt event when mbx task is busy
 			 * handling. This shall be cleared when mbx task just
@@ -241,6 +242,17 @@ void hclgevf_mbx_async_handler(struct hclgevf_dev *hdev)
 			hclgevf_update_link_status(hdev, link_status);
 			hclgevf_update_speed_duplex(hdev, speed, duplex);
 
+			break;
+		case HCLGE_MBX_ASSERTING_RESET:
+			/* PF has asserted reset hence VF should go in pending
+			 * state and poll for the hardware reset status till it
+			 * has been completely reset. After this stack should
+			 * eventually be re-initialized.
+			 */
+			hdev->nic.reset_level = HNAE3_VF_RESET;
+			set_bit(HCLGEVF_RESET_PENDING, &hdev->reset_state);
+			hclgevf_reset_task_schedule(hdev);
+
 			break;
 		default:
 			dev_err(&hdev->pdev->dev,