Merge branch 'hns3-VF-reset'

Salil Mehta says:

====================
Add support of VF Reset to HNS3 VF driver

This patch-set adds the support of VF reset to the existing VF driver.
VF Reset can be triggered due to TX watchdog firing  as a result of TX
data-path not working. VF reset could also be a result of some internal
configuration changes if that requires reset, or as a result of the
PF/Core/Global/IMP(Integrated Management Processor) reset happened in
the PF.

Summary of Patches:
* Watchdog timer trigger chnages are present in Patch 1.
* Reset Service Task and related Event handling is present in Patches {2,3}
* Changes to send reset request to PF, reset stack and re-initialization
  of the hclge device is present in Patches {4,5,6}
* Changes related to ARQ (Asynchronous Receive Queue) and its event handling
  are present in Patches {7,8}
* Changes required in PF to handle the VF Reset request and actually perform
  hardware VF reset is there in Patch 9.

NOTE: This patch depends upon "[PATCH net-next 00/11] fix some bugs for HNS3 driver"
	Link: https://lkml.org/lkml/2018/3/21/72
====================

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 */
@@ -85,6 +86,21 @@ struct hclge_mbx_pf_to_vf_cmd {
 	u16 msg[8];
 };
 
+/* used by VF to store the received Async responses from PF */
+struct hclgevf_mbx_arq_ring {
+#define HCLGE_MBX_MAX_ARQ_MSG_SIZE	8
+#define HCLGE_MBX_MAX_ARQ_MSG_NUM	1024
+	struct hclgevf_dev *hdev;
+	u32 head;
+	u32 tail;
+	u32 count;
+	u16 msg_q[HCLGE_MBX_MAX_ARQ_MSG_NUM][HCLGE_MBX_MAX_ARQ_MSG_SIZE];
+};
+
 #define hclge_mbx_ring_ptr_move_crq(crq) \
 	(crq->next_to_use = (crq->next_to_use + 1) % crq->desc_num)
+#define hclge_mbx_tail_ptr_move_arq(arq) \
+	(arq.tail = (arq.tail + 1) % HCLGE_MBX_MAX_ARQ_MSG_SIZE)
+#define hclge_mbx_head_ptr_move_arq(arq) \
+		(arq.head = (arq.head + 1) % HCLGE_MBX_MAX_ARQ_MSG_SIZE)
 #endif

drivers/net/ethernet/hisilicon/hns3/hnae3.h

@@ -118,6 +118,8 @@ enum hnae3_reset_notify_type {
 };
 
 enum hnae3_reset_type {
+	HNAE3_VF_RESET,
+	HNAE3_VF_FULL_RESET,
 	HNAE3_FUNC_RESET,
 	HNAE3_CORE_RESET,
 	HNAE3_GLOBAL_RESET,
@@ -400,8 +402,7 @@ struct hnae3_ae_ops {
 	int (*set_vf_vlan_filter)(struct hnae3_handle *handle, int vfid,
 				  u16 vlan, u8 qos, __be16 proto);
 	int (*enable_hw_strip_rxvtag)(struct hnae3_handle *handle, bool enable);
-	void (*reset_event)(struct hnae3_handle *handle,
-			    enum hnae3_reset_type reset);
+	void (*reset_event)(struct hnae3_handle *handle);
 	void (*get_channels)(struct hnae3_handle *handle,
 			     struct ethtool_channels *ch);
 	void (*get_tqps_and_rss_info)(struct hnae3_handle *h,
@@ -495,6 +496,9 @@ struct hnae3_handle {
 	struct hnae3_ae_algo *ae_algo;  /* the class who provides this handle */
 	u64 flags; /* Indicate the capabilities for this handle*/
 
+	unsigned long last_reset_time;
+	enum hnae3_reset_type reset_level;
+
 	union {
 		struct net_device *netdev; /* first member */
 		struct hnae3_knic_private_info kinfo;

drivers/net/ethernet/hisilicon/hns3/hns3_enet.c

@@ -320,7 +320,7 @@ static int hns3_nic_net_open(struct net_device *netdev)
 		return ret;
 	}
 
-	priv->last_reset_time = jiffies;
+	priv->ae_handle->last_reset_time = jiffies;
 	return 0;
 }
 
@@ -1543,7 +1543,6 @@ static bool hns3_get_tx_timeo_queue_info(struct net_device *ndev)
 static void hns3_nic_net_timeout(struct net_device *ndev)
 {
 	struct hns3_nic_priv *priv = netdev_priv(ndev);
-	unsigned long last_reset_time = priv->last_reset_time;
 	struct hnae3_handle *h = priv->ae_handle;
 
 	if (!hns3_get_tx_timeo_queue_info(ndev))
@@ -1551,24 +1550,12 @@ static void hns3_nic_net_timeout(struct net_device *ndev)
 
 	priv->tx_timeout_count++;
 
-	/* This timeout is far away enough from last timeout,
-	 * if timeout again,set the reset type to PF reset
-	 */
-	if (time_after(jiffies, (last_reset_time + 20 * HZ)))
-		priv->reset_level = HNAE3_FUNC_RESET;
-
-	/* Don't do any new action before the next timeout */
-	else if (time_before(jiffies, (last_reset_time + ndev->watchdog_timeo)))
+	if (time_before(jiffies, (h->last_reset_time + ndev->watchdog_timeo)))
 		return;
 
-	priv->last_reset_time = jiffies;
-
+	/* request the reset */
 	if (h->ae_algo->ops->reset_event)
-		h->ae_algo->ops->reset_event(h, priv->reset_level);
-
-	priv->reset_level++;
-	if (priv->reset_level > HNAE3_GLOBAL_RESET)
-		priv->reset_level = HNAE3_GLOBAL_RESET;
+		h->ae_algo->ops->reset_event(h);
 }
 
 static const struct net_device_ops hns3_nic_netdev_ops = {
@@ -3122,8 +3109,8 @@ static int hns3_client_init(struct hnae3_handle *handle)
 	priv->dev = &pdev->dev;
 	priv->netdev = netdev;
 	priv->ae_handle = handle;
-	priv->last_reset_time = jiffies;
-	priv->reset_level = HNAE3_FUNC_RESET;
+	priv->ae_handle->reset_level = HNAE3_NONE_RESET;
+	priv->ae_handle->last_reset_time = jiffies;
 	priv->tx_timeout_count = 0;
 
 	handle->kinfo.netdev = netdev;
@@ -3355,7 +3342,6 @@ static int hns3_reset_notify_down_enet(struct hnae3_handle *handle)
 static int hns3_reset_notify_up_enet(struct hnae3_handle *handle)
 {
 	struct hnae3_knic_private_info *kinfo = &handle->kinfo;
-	struct hns3_nic_priv *priv = netdev_priv(kinfo->netdev);
 	int ret = 0;
 
 	if (netif_running(kinfo->netdev)) {
@@ -3365,8 +3351,7 @@ static int hns3_reset_notify_up_enet(struct hnae3_handle *handle)
 				   "hns net up fail, ret=%d!\n", ret);
 			return ret;
 		}
-
-		priv->last_reset_time = jiffies;
+		handle->last_reset_time = jiffies;
 	}
 
 	return ret;
@@ -3378,7 +3363,6 @@ static int hns3_reset_notify_init_enet(struct hnae3_handle *handle)
 	struct hns3_nic_priv *priv = netdev_priv(netdev);
 	int ret;
 
-	priv->reset_level = 1;
 	hns3_init_mac_addr(netdev);
 	hns3_nic_set_rx_mode(netdev);
 	hns3_recover_hw_addr(netdev);

drivers/net/ethernet/hisilicon/hns3/hns3_enet.h

@@ -532,8 +532,6 @@ struct hns3_nic_priv {
 	/* The most recently read link state */
 	int link;
 	u64 tx_timeout_count;
-	enum hnae3_reset_type reset_level;
-	unsigned long last_reset_time;
 
 	unsigned long state;
 

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c

@@ -2749,7 +2749,7 @@ static int hclge_reset_wait(struct hclge_dev *hdev)
 	return 0;
 }
 
-static int hclge_func_reset_cmd(struct hclge_dev *hdev, int func_id)
+int hclge_func_reset_cmd(struct hclge_dev *hdev, int func_id)
 {
 	struct hclge_desc desc;
 	struct hclge_reset_cmd *req = (struct hclge_reset_cmd *)desc.data;
@@ -2845,27 +2845,31 @@ static void hclge_reset(struct hclge_dev *hdev)
 	hclge_notify_client(hdev, HNAE3_UP_CLIENT);
 }
 
-static void hclge_reset_event(struct hnae3_handle *handle,
-			      enum hnae3_reset_type reset)
+static void hclge_reset_event(struct hnae3_handle *handle)
 {
 	struct hclge_vport *vport = hclge_get_vport(handle);
 	struct hclge_dev *hdev = vport->back;
 
-	dev_info(&hdev->pdev->dev,
-		 "Receive reset event , reset_type is %d", reset);
+	/* check if this is a new reset request and we are not here just because
+	 * last reset attempt did not succeed and watchdog hit us again. We will
+	 * know this if last reset request did not occur very recently (watchdog
+	 * timer = 5*HZ, let us check after sufficiently large time, say 4*5*Hz)
+	 * In case of new request we reset the "reset level" to PF reset.
+	 */
+	if (time_after(jiffies, (handle->last_reset_time + 4 * 5 * HZ)))
+		handle->reset_level = HNAE3_FUNC_RESET;
 
-	switch (reset) {
-	case HNAE3_FUNC_RESET:
-	case HNAE3_CORE_RESET:
-	case HNAE3_GLOBAL_RESET:
-		/* request reset & schedule reset task */
-		set_bit(reset, &hdev->reset_request);
-		hclge_reset_task_schedule(hdev);
-		break;
-	default:
-		dev_warn(&hdev->pdev->dev, "Unsupported reset event:%d", reset);
-		break;
-	}
+	dev_info(&hdev->pdev->dev, "received reset event , reset type is %d",
+		 handle->reset_level);
+
+	/* request reset & schedule reset task */
+	set_bit(handle->reset_level, &hdev->reset_request);
+	hclge_reset_task_schedule(hdev);
+
+	if (handle->reset_level < HNAE3_GLOBAL_RESET)
+		handle->reset_level++;
+
+	handle->last_reset_time = jiffies;
 }
 
 static void hclge_reset_subtask(struct hclge_dev *hdev)

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.h

@@ -657,4 +657,5 @@ void hclge_mbx_handler(struct hclge_dev *hdev);
 void hclge_reset_tqp(struct hnae3_handle *handle, u16 queue_id);
 void hclge_reset_vf_queue(struct hclge_vport *vport, u16 queue_id);
 int hclge_cfg_flowctrl(struct hclge_dev *hdev);
+int hclge_func_reset_cmd(struct hclge_dev *hdev, int func_id);
 #endif

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_mbx.c

@@ -79,6 +79,18 @@ static int hclge_send_mbx_msg(struct hclge_vport *vport, u8 *msg, u16 msg_len,
 	return status;
 }
 
+int hclge_inform_reset_assert_to_vf(struct hclge_vport *vport)
+{
+	u8 msg_data[2];
+	u8 dest_vfid;
+
+	dest_vfid = (u8)vport->vport_id;
+
+	/* send this requested info to VF */
+	return hclge_send_mbx_msg(vport, msg_data, sizeof(u8),
+				  HCLGE_MBX_ASSERTING_RESET, dest_vfid);
+}
+
 static void hclge_free_vector_ring_chain(struct hnae3_ring_chain_node *head)
 {
 	struct hnae3_ring_chain_node *chain_tmp, *chain;
@@ -339,6 +351,33 @@ static void hclge_mbx_reset_vf_queue(struct hclge_vport *vport,
 	hclge_gen_resp_to_vf(vport, mbx_req, 0, NULL, 0);
 }
 
+static void hclge_reset_vf(struct hclge_vport *vport,
+			   struct hclge_mbx_vf_to_pf_cmd *mbx_req)
+{
+	struct hclge_dev *hdev = vport->back;
+	int ret;
+
+	dev_warn(&hdev->pdev->dev, "PF received VF reset request from VF %d!",
+		 mbx_req->mbx_src_vfid);
+
+	/* Acknowledge VF that PF is now about to assert the reset for the VF.
+	 * On receiving this message VF will get into pending state and will
+	 * start polling for the hardware reset completion status.
+	 */
+	ret = hclge_inform_reset_assert_to_vf(vport);
+	if (ret) {
+		dev_err(&hdev->pdev->dev,
+			"PF fail(%d) to inform VF(%d)of reset, reset failed!\n",
+			ret, vport->vport_id);
+		return;
+	}
+
+	dev_warn(&hdev->pdev->dev, "PF is now resetting VF %d.\n",
+		 mbx_req->mbx_src_vfid);
+	/* reset this virtual function */
+	hclge_func_reset_cmd(hdev, mbx_req->mbx_src_vfid);
+}
+
 void hclge_mbx_handler(struct hclge_dev *hdev)
 {
 	struct hclge_cmq_ring *crq = &hdev->hw.cmq.crq;
@@ -416,6 +455,9 @@ void hclge_mbx_handler(struct hclge_dev *hdev)
 		case HCLGE_MBX_QUEUE_RESET:
 			hclge_mbx_reset_vf_queue(vport, req);
 			break;
+		case HCLGE_MBX_RESET:
+			hclge_reset_vf(vport, req);
+			break;
 		default:
 			dev_err(&hdev->pdev->dev,
 				"un-supported mailbox message, code = %d\n",

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

@@ -315,6 +315,12 @@ int hclgevf_cmd_init(struct hclgevf_dev *hdev)
 		goto err_csq;
 	}
 
+	/* initialize the pointers of async rx queue of mailbox */
+	hdev->arq.hdev = hdev;
+	hdev->arq.head = 0;
+	hdev->arq.tail = 0;
+	hdev->arq.count = 0;
+
 	/* get firmware version */
 	ret = hclgevf_cmd_query_firmware_version(&hdev->hw, &version);
 	if (ret) {

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

@@ -2,6 +2,7 @@
 // Copyright (c) 2016-2017 Hisilicon Limited.
 
 #include <linux/etherdevice.h>
+#include <net/rtnetlink.h>
 #include "hclgevf_cmd.h"
 #include "hclgevf_main.h"
 #include "hclge_mbx.h"
@@ -9,6 +10,8 @@
 
 #define HCLGEVF_NAME	"hclgevf"
 
+static int hclgevf_init_hdev(struct hclgevf_dev *hdev);
+static void hclgevf_uninit_hdev(struct hclgevf_dev *hdev);
 static struct hnae3_ae_algo ae_algovf;
 
 static const struct pci_device_id ae_algovf_pci_tbl[] = {
@@ -208,6 +211,12 @@ static int hclgevf_alloc_tqps(struct hclgevf_dev *hdev)
 	struct hclgevf_tqp *tqp;
 	int i;
 
+	/* if this is on going reset then we need to re-allocate the TPQs
+	 * since we cannot assume we would get same number of TPQs back from PF
+	 */
+	if (hclgevf_dev_ongoing_reset(hdev))
+		devm_kfree(&hdev->pdev->dev, hdev->htqp);
+
 	hdev->htqp = devm_kcalloc(&hdev->pdev->dev, hdev->num_tqps,
 				  sizeof(struct hclgevf_tqp), GFP_KERNEL);
 	if (!hdev->htqp)
@@ -251,6 +260,12 @@ static int hclgevf_knic_setup(struct hclgevf_dev *hdev)
 	new_tqps = kinfo->rss_size * kinfo->num_tc;
 	kinfo->num_tqps = min(new_tqps, hdev->num_tqps);
 
+	/* if this is on going reset then we need to re-allocate the hnae queues
+	 * as well since number of TPQs from PF might have changed.
+	 */
+	if (hclgevf_dev_ongoing_reset(hdev))
+		devm_kfree(&hdev->pdev->dev, kinfo->tqp);
+
 	kinfo->tqp = devm_kcalloc(&hdev->pdev->dev, kinfo->num_tqps,
 				  sizeof(struct hnae3_queue *), GFP_KERNEL);
 	if (!kinfo->tqp)
@@ -832,6 +847,138 @@ static void hclgevf_reset_tqp(struct hnae3_handle *handle, u16 queue_id)
 			     2, true, NULL, 0);
 }
 
+static int hclgevf_notify_client(struct hclgevf_dev *hdev,
+				 enum hnae3_reset_notify_type type)
+{
+	struct hnae3_client *client = hdev->nic_client;
+	struct hnae3_handle *handle = &hdev->nic;
+
+	if (!client->ops->reset_notify)
+		return -EOPNOTSUPP;
+
+	return client->ops->reset_notify(handle, type);
+}
+
+static int hclgevf_reset_wait(struct hclgevf_dev *hdev)
+{
+#define HCLGEVF_RESET_WAIT_MS	500
+#define HCLGEVF_RESET_WAIT_CNT	20
+	u32 val, cnt = 0;
+
+	/* wait to check the hardware reset completion status */
+	val = hclgevf_read_dev(&hdev->hw, HCLGEVF_FUN_RST_ING);
+	while (hnae_get_bit(val, HCLGEVF_FUN_RST_ING_B) &&
+			    (cnt < HCLGEVF_RESET_WAIT_CNT)) {
+		msleep(HCLGEVF_RESET_WAIT_MS);
+		val = hclgevf_read_dev(&hdev->hw, HCLGEVF_FUN_RST_ING);
+		cnt++;
+	}
+
+	/* hardware completion status should be available by this time */
+	if (cnt >= HCLGEVF_RESET_WAIT_CNT) {
+		dev_warn(&hdev->pdev->dev,
+			 "could'nt get reset done status from h/w, timeout!\n");
+		return -EBUSY;
+	}
+
+	/* we will wait a bit more to let reset of the stack to complete. This
+	 * might happen in case reset assertion was made by PF. Yes, this also
+	 * means we might end up waiting bit more even for VF reset.
+	 */
+	msleep(5000);
+
+	return 0;
+}
+
+static int hclgevf_reset_stack(struct hclgevf_dev *hdev)
+{
+	int ret;
+
+	/* uninitialize the nic client */
+	hclgevf_notify_client(hdev, HNAE3_UNINIT_CLIENT);
+
+	/* re-initialize the hclge device */
+	ret = hclgevf_init_hdev(hdev);
+	if (ret) {
+		dev_err(&hdev->pdev->dev,
+			"hclge device re-init failed, VF is disabled!\n");
+		return ret;
+	}
+
+	/* bring up the nic client again */
+	hclgevf_notify_client(hdev, HNAE3_INIT_CLIENT);
+
+	return 0;
+}
+
+static int hclgevf_reset(struct hclgevf_dev *hdev)
+{
+	int ret;
+
+	rtnl_lock();
+
+	/* bring down the nic to stop any ongoing TX/RX */
+	hclgevf_notify_client(hdev, HNAE3_DOWN_CLIENT);
+
+	/* check if VF could successfully fetch the hardware reset completion
+	 * status from the hardware
+	 */
+	ret = hclgevf_reset_wait(hdev);
+	if (ret) {
+		/* can't do much in this situation, will disable VF */
+		dev_err(&hdev->pdev->dev,
+			"VF failed(=%d) to fetch H/W reset completion status\n",
+			ret);
+
+		dev_warn(&hdev->pdev->dev, "VF reset failed, disabling VF!\n");
+		hclgevf_notify_client(hdev, HNAE3_UNINIT_CLIENT);
+
+		rtnl_unlock();
+		return ret;
+	}
+
+	/* now, re-initialize the nic client and ae device*/
+	ret = hclgevf_reset_stack(hdev);
+	if (ret)
+		dev_err(&hdev->pdev->dev, "failed to reset VF stack\n");
+
+	/* bring up the nic to enable TX/RX again */
+	hclgevf_notify_client(hdev, HNAE3_UP_CLIENT);
+
+	rtnl_unlock();
+
+	return ret;
+}
+
+static int hclgevf_do_reset(struct hclgevf_dev *hdev)
+{
+	int status;
+	u8 respmsg;
+
+	status = hclgevf_send_mbx_msg(hdev, HCLGE_MBX_RESET, 0, NULL,
+				      0, false, &respmsg, sizeof(u8));
+	if (status)
+		dev_err(&hdev->pdev->dev,
+			"VF reset request to PF failed(=%d)\n", status);
+
+	return status;
+}
+
+static void hclgevf_reset_event(struct hnae3_handle *handle)
+{
+	struct hclgevf_dev *hdev = hclgevf_ae_get_hdev(handle);
+
+	dev_info(&hdev->pdev->dev, "received reset request from VF enet\n");
+
+	handle->reset_level = HNAE3_VF_RESET;
+
+	/* reset of this VF requested */
+	set_bit(HCLGEVF_RESET_REQUESTED, &hdev->reset_state);
+	hclgevf_reset_task_schedule(hdev);
+
+	handle->last_reset_time = jiffies;
+}
+
 static u32 hclgevf_get_fw_version(struct hnae3_handle *handle)
 {
 	struct hclgevf_dev *hdev = hclgevf_ae_get_hdev(handle);
@@ -854,10 +1001,22 @@ static void hclgevf_get_misc_vector(struct hclgevf_dev *hdev)
 	hdev->num_msi_used += 1;
 }
 
-static void hclgevf_mbx_task_schedule(struct hclgevf_dev *hdev)
+void hclgevf_reset_task_schedule(struct hclgevf_dev *hdev)
 {
-	if (!test_and_set_bit(HCLGEVF_STATE_MBX_SERVICE_SCHED, &hdev->state))
+	if (!test_bit(HCLGEVF_STATE_RST_SERVICE_SCHED, &hdev->state) &&
+	    !test_bit(HCLGEVF_STATE_RST_HANDLING, &hdev->state)) {
+		set_bit(HCLGEVF_STATE_RST_SERVICE_SCHED, &hdev->state);
+		schedule_work(&hdev->rst_service_task);
+	}
+}
+
+void hclgevf_mbx_task_schedule(struct hclgevf_dev *hdev)
+{
+	if (!test_bit(HCLGEVF_STATE_MBX_SERVICE_SCHED, &hdev->state) &&
+	    !test_bit(HCLGEVF_STATE_MBX_HANDLING, &hdev->state)) {
+		set_bit(HCLGEVF_STATE_MBX_SERVICE_SCHED, &hdev->state);
 		schedule_work(&hdev->mbx_service_task);
+	}
 }
 
 static void hclgevf_task_schedule(struct hclgevf_dev *hdev)
@@ -867,6 +1026,16 @@ static void hclgevf_task_schedule(struct hclgevf_dev *hdev)
 		schedule_work(&hdev->service_task);
 }
 
+static void hclgevf_deferred_task_schedule(struct hclgevf_dev *hdev)
+{
+	/* if we have any pending mailbox event then schedule the mbx task */
+	if (hdev->mbx_event_pending)
+		hclgevf_mbx_task_schedule(hdev);
+
+	if (test_bit(HCLGEVF_RESET_PENDING, &hdev->reset_state))
+		hclgevf_reset_task_schedule(hdev);
+}
+
 static void hclgevf_service_timer(struct timer_list *t)
 {
 	struct hclgevf_dev *hdev = from_timer(hdev, t, service_timer);
@@ -876,6 +1045,75 @@ static void hclgevf_service_timer(struct timer_list *t)
 	hclgevf_task_schedule(hdev);
 }
 
+static void hclgevf_reset_service_task(struct work_struct *work)
+{
+	struct hclgevf_dev *hdev =
+		container_of(work, struct hclgevf_dev, rst_service_task);
+	int ret;
+
+	if (test_and_set_bit(HCLGEVF_STATE_RST_HANDLING, &hdev->state))
+		return;
+
+	clear_bit(HCLGEVF_STATE_RST_SERVICE_SCHED, &hdev->state);
+
+	if (test_and_clear_bit(HCLGEVF_RESET_PENDING,
+			       &hdev->reset_state)) {
+		/* PF has initmated that it is about to reset the hardware.
+		 * We now have to poll & check if harware has actually completed
+		 * the reset sequence. On hardware reset completion, VF needs to
+		 * reset the client and ae device.
+		 */
+		hdev->reset_attempts = 0;
+
+		ret = hclgevf_reset(hdev);
+		if (ret)
+			dev_err(&hdev->pdev->dev, "VF stack reset failed.\n");
+	} else if (test_and_clear_bit(HCLGEVF_RESET_REQUESTED,
+				      &hdev->reset_state)) {
+		/* we could be here when either of below happens:
+		 * 1. reset was initiated due to watchdog timeout due to
+		 *    a. IMP was earlier reset and our TX got choked down and
+		 *       which resulted in watchdog reacting and inducing VF
+		 *       reset. This also means our cmdq would be unreliable.
+		 *    b. problem in TX due to other lower layer(example link
+		 *       layer not functioning properly etc.)
+		 * 2. VF reset might have been initiated due to some config
+		 *    change.
+		 *
+		 * NOTE: Theres no clear way to detect above cases than to react
+		 * to the response of PF for this reset request. PF will ack the
+		 * 1b and 2. cases but we will not get any intimation about 1a
+		 * from PF as cmdq would be in unreliable state i.e. mailbox
+		 * communication between PF and VF would be broken.
+		 */
+
+		/* if we are never geting into pending state it means either:
+		 * 1. PF is not receiving our request which could be due to IMP
+		 *    reset
+		 * 2. PF is screwed
+		 * We cannot do much for 2. but to check first we can try reset
+		 * our PCIe + stack and see if it alleviates the problem.
+		 */
+		if (hdev->reset_attempts > 3) {
+			/* prepare for full reset of stack + pcie interface */
+			hdev->nic.reset_level = HNAE3_VF_FULL_RESET;
+
+			/* "defer" schedule the reset task again */
+			set_bit(HCLGEVF_RESET_PENDING, &hdev->reset_state);
+		} else {
+			hdev->reset_attempts++;
+
+			/* request PF for resetting this VF via mailbox */
+			ret = hclgevf_do_reset(hdev);
+			if (ret)
+				dev_warn(&hdev->pdev->dev,
+					 "VF rst fail, stack will call\n");
+		}
+	}
+
+	clear_bit(HCLGEVF_STATE_RST_HANDLING, &hdev->state);
+}
+
 static void hclgevf_mailbox_service_task(struct work_struct *work)
 {
 	struct hclgevf_dev *hdev;
@@ -887,7 +1125,7 @@ static void hclgevf_mailbox_service_task(struct work_struct *work)
 
 	clear_bit(HCLGEVF_STATE_MBX_SERVICE_SCHED, &hdev->state);
 
-	hclgevf_mbx_handler(hdev);
+	hclgevf_mbx_async_handler(hdev);
 
 	clear_bit(HCLGEVF_STATE_MBX_HANDLING, &hdev->state);
 }
@@ -903,6 +1141,8 @@ static void hclgevf_service_task(struct work_struct *work)
 	 */
 	hclgevf_request_link_info(hdev);
 
+	hclgevf_deferred_task_schedule(hdev);
+
 	clear_bit(HCLGEVF_STATE_SERVICE_SCHED, &hdev->state);
 }
 
@@ -945,8 +1185,7 @@ static irqreturn_t hclgevf_misc_irq_handle(int irq, void *data)
 	if (!hclgevf_check_event_cause(hdev, &clearval))
 		goto skip_sched;
 
-	/* schedule the VF mailbox service task, if not already scheduled */
-	hclgevf_mbx_task_schedule(hdev);
+	hclgevf_mbx_handler(hdev);
 
 	hclgevf_clear_event_cause(hdev, clearval);
 
@@ -968,6 +1207,22 @@ static int hclgevf_configure(struct hclgevf_dev *hdev)
 	return hclgevf_get_tc_info(hdev);
 }
 
+static int hclgevf_alloc_hdev(struct hnae3_ae_dev *ae_dev)
+{
+	struct pci_dev *pdev = ae_dev->pdev;
+	struct hclgevf_dev *hdev = ae_dev->priv;
+
+	hdev = devm_kzalloc(&pdev->dev, sizeof(*hdev), GFP_KERNEL);
+	if (!hdev)
+		return -ENOMEM;
+
+	hdev->pdev = pdev;
+	hdev->ae_dev = ae_dev;
+	ae_dev->priv = hdev;
+
+	return 0;
+}
+
 static int hclgevf_init_roce_base_info(struct hclgevf_dev *hdev)
 {
 	struct hnae3_handle *roce = &hdev->roce;
@@ -1073,6 +1328,10 @@ static void hclgevf_ae_stop(struct hnae3_handle *handle)
 
 static void hclgevf_state_init(struct hclgevf_dev *hdev)
 {
+	/* if this is on going reset then skip this initialization */
+	if (hclgevf_dev_ongoing_reset(hdev))
+		return;
+
 	/* setup tasks for the MBX */
 	INIT_WORK(&hdev->mbx_service_task, hclgevf_mailbox_service_task);
 	clear_bit(HCLGEVF_STATE_MBX_SERVICE_SCHED, &hdev->state);
@@ -1084,6 +1343,8 @@ static void hclgevf_state_init(struct hclgevf_dev *hdev)
 	INIT_WORK(&hdev->service_task, hclgevf_service_task);
 	clear_bit(HCLGEVF_STATE_SERVICE_SCHED, &hdev->state);
 
+	INIT_WORK(&hdev->rst_service_task, hclgevf_reset_service_task);
+
 	mutex_init(&hdev->mbx_resp.mbx_mutex);
 
 	/* bring the device down */
@@ -1100,6 +1361,8 @@ static void hclgevf_state_uninit(struct hclgevf_dev *hdev)
 		cancel_work_sync(&hdev->service_task);
 	if (hdev->mbx_service_task.func)
 		cancel_work_sync(&hdev->mbx_service_task);
+	if (hdev->rst_service_task.func)
+		cancel_work_sync(&hdev->rst_service_task);
 
 	mutex_destroy(&hdev->mbx_resp.mbx_mutex);
 }
@@ -1110,6 +1373,10 @@ static int hclgevf_init_msi(struct hclgevf_dev *hdev)
 	int vectors;
 	int i;
 
+	/* if this is on going reset then skip this initialization */
+	if (hclgevf_dev_ongoing_reset(hdev))
+		return 0;
+
 	hdev->num_msi = HCLGEVF_MAX_VF_VECTOR_NUM;
 
 	vectors = pci_alloc_irq_vectors(pdev, 1, hdev->num_msi,
@@ -1160,6 +1427,10 @@ static int hclgevf_misc_irq_init(struct hclgevf_dev *hdev)
 {
 	int ret = 0;
 
+	/* if this is on going reset then skip this initialization */
+	if (hclgevf_dev_ongoing_reset(hdev))
+		return 0;
+
 	hclgevf_get_misc_vector(hdev);
 
 	ret = request_irq(hdev->misc_vector.vector_irq, hclgevf_misc_irq_handle,
@@ -1270,6 +1541,14 @@ static int hclgevf_pci_init(struct hclgevf_dev *hdev)
 	struct hclgevf_hw *hw;
 	int ret;
 
+	/* check if we need to skip initialization of pci. This will happen if
+	 * device is undergoing VF reset. Otherwise, we would need to
+	 * re-initialize pci interface again i.e. when device is not going
+	 * through *any* reset or actually undergoing full reset.
+	 */
+	if (hclgevf_dev_ongoing_reset(hdev))
+		return 0;
+
 	ret = pci_enable_device(pdev);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to enable PCI device\n");
@@ -1321,19 +1600,16 @@ static void hclgevf_pci_uninit(struct hclgevf_dev *hdev)
 	pci_set_drvdata(pdev, NULL);
 }
 
-static int hclgevf_init_ae_dev(struct hnae3_ae_dev *ae_dev)
+static int hclgevf_init_hdev(struct hclgevf_dev *hdev)
 {
-	struct pci_dev *pdev = ae_dev->pdev;
-	struct hclgevf_dev *hdev;
+	struct pci_dev *pdev = hdev->pdev;
 	int ret;
 
-	hdev = devm_kzalloc(&pdev->dev, sizeof(*hdev), GFP_KERNEL);
-	if (!hdev)
-		return -ENOMEM;
-
-	hdev->pdev = pdev;
-	hdev->ae_dev = ae_dev;
-	ae_dev->priv = hdev;
+	/* check if device is on-going full reset(i.e. pcie as well) */
+	if (hclgevf_dev_ongoing_full_reset(hdev)) {
+		dev_warn(&pdev->dev, "device is going full reset\n");
+		hclgevf_uninit_hdev(hdev);
+	}
 
 	ret = hclgevf_pci_init(hdev);
 	if (ret) {
@@ -1418,15 +1694,38 @@ err_irq_init:
 	return ret;
 }
 
-static void hclgevf_uninit_ae_dev(struct hnae3_ae_dev *ae_dev)
+static void hclgevf_uninit_hdev(struct hclgevf_dev *hdev)
 {
-	struct hclgevf_dev *hdev = ae_dev->priv;
-
 	hclgevf_cmd_uninit(hdev);
 	hclgevf_misc_irq_uninit(hdev);
 	hclgevf_state_uninit(hdev);
 	hclgevf_uninit_msi(hdev);
 	hclgevf_pci_uninit(hdev);
+}
+
+static int hclgevf_init_ae_dev(struct hnae3_ae_dev *ae_dev)
+{
+	struct pci_dev *pdev = ae_dev->pdev;
+	int ret;
+
+	ret = hclgevf_alloc_hdev(ae_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "hclge device allocation failed\n");
+		return ret;
+	}
+
+	ret = hclgevf_init_hdev(ae_dev->priv);
+	if (ret)
+		dev_err(&pdev->dev, "hclge device initialization failed\n");
+
+	return ret;
+}
+
+static void hclgevf_uninit_ae_dev(struct hnae3_ae_dev *ae_dev)
+{
+	struct hclgevf_dev *hdev = ae_dev->priv;
+
+	hclgevf_uninit_hdev(hdev);
 	ae_dev->priv = NULL;
 }
 
@@ -1526,6 +1825,7 @@ static const struct hnae3_ae_ops hclgevf_ops = {
 	.get_tc_size = hclgevf_get_tc_size,
 	.get_fw_version = hclgevf_get_fw_version,
 	.set_vlan_filter = hclgevf_set_vlan_filter,
+	.reset_event = hclgevf_reset_event,
 	.get_channels = hclgevf_get_channels,
 	.get_tqps_and_rss_info = hclgevf_get_tqps_and_rss_info,
 	.get_status = hclgevf_get_status,

drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_main.h

@@ -34,6 +34,9 @@
 #define HCLGEVF_VECTOR0_RX_CMDQ_INT_B	1
 
 #define HCLGEVF_TQP_RESET_TRY_TIMES	10
+/* Reset related Registers */
+#define HCLGEVF_FUN_RST_ING		0x20C00
+#define HCLGEVF_FUN_RST_ING_B		0
 
 #define HCLGEVF_RSS_IND_TBL_SIZE		512
 #define HCLGEVF_RSS_SET_BITMAP_MSK	0xffff
@@ -52,6 +55,8 @@ enum hclgevf_states {
 	HCLGEVF_STATE_DISABLED,
 	/* task states */
 	HCLGEVF_STATE_SERVICE_SCHED,
+	HCLGEVF_STATE_RST_SERVICE_SCHED,
+	HCLGEVF_STATE_RST_HANDLING,
 	HCLGEVF_STATE_MBX_SERVICE_SCHED,
 	HCLGEVF_STATE_MBX_HANDLING,
 };
@@ -122,6 +127,11 @@ struct hclgevf_dev {
 	struct hclgevf_rss_cfg rss_cfg;
 	unsigned long state;
 
+#define HCLGEVF_RESET_REQUESTED		0
+#define HCLGEVF_RESET_PENDING		1
+	unsigned long reset_state;	/* requested, pending */
+	u32 reset_attempts;
+
 	u32 fw_version;
 	u16 num_tqps;		/* num task queue pairs of this PF */
 
@@ -142,10 +152,13 @@ struct hclgevf_dev {
 	int *vector_irq;
 
 	bool accept_mta_mc; /* whether to accept mta filter multicast */
+	bool mbx_event_pending;
 	struct hclgevf_mbx_resp_status mbx_resp; /* mailbox response */
+	struct hclgevf_mbx_arq_ring arq; /* mailbox async rx queue */
 
 	struct timer_list service_timer;
 	struct work_struct service_task;
+	struct work_struct rst_service_task;
 	struct work_struct mbx_service_task;
 
 	struct hclgevf_tqp *htqp;
@@ -158,11 +171,29 @@ struct hclgevf_dev {
 	u32 flag;
 };
 
+static inline bool hclgevf_dev_ongoing_reset(struct hclgevf_dev *hdev)
+{
+	return (hdev &&
+		(test_bit(HCLGEVF_STATE_RST_HANDLING, &hdev->state)) &&
+		(hdev->nic.reset_level == HNAE3_VF_RESET));
+}
+
+static inline bool hclgevf_dev_ongoing_full_reset(struct hclgevf_dev *hdev)
+{
+	return (hdev &&
+		(test_bit(HCLGEVF_STATE_RST_HANDLING, &hdev->state)) &&
+		(hdev->nic.reset_level == HNAE3_VF_FULL_RESET));
+}
+
 int hclgevf_send_mbx_msg(struct hclgevf_dev *hdev, u16 code, u16 subcode,
 			 const u8 *msg_data, u8 msg_len, bool need_resp,
 			 u8 *resp_data, u16 resp_len);
 void hclgevf_mbx_handler(struct hclgevf_dev *hdev);
+void hclgevf_mbx_async_handler(struct hclgevf_dev *hdev);
+
 void hclgevf_update_link_status(struct hclgevf_dev *hdev, int link_state);
 void hclgevf_update_speed_duplex(struct hclgevf_dev *hdev, u32 speed,
 				 u8 duplex);
+void hclgevf_reset_task_schedule(struct hclgevf_dev *hdev);
+void hclgevf_mbx_task_schedule(struct hclgevf_dev *hdev);
 #endif

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

@@ -132,9 +132,8 @@ void hclgevf_mbx_handler(struct hclgevf_dev *hdev)
 	struct hclge_mbx_pf_to_vf_cmd *req;
 	struct hclgevf_cmq_ring *crq;
 	struct hclgevf_desc *desc;
-	u16 link_status, flag;
-	u32 speed;
-	u8 duplex;
+	u16 *msg_q;
+	u16 flag;
 	u8 *temp;
 	int i;
 
@@ -146,6 +145,12 @@ void hclgevf_mbx_handler(struct hclgevf_dev *hdev)
 		desc = &crq->desc[crq->next_to_use];
 		req = (struct hclge_mbx_pf_to_vf_cmd *)desc->data;
 
+		/* synchronous messages are time critical and need preferential
+		 * treatment. Therefore, we need to acknowledge all the sync
+		 * responses as quickly as possible so that waiting tasks do not
+		 * timeout and simultaneously queue the async messages for later
+		 * prcessing in context of mailbox task i.e. the slow path.
+		 */
 		switch (req->msg[0]) {
 		case HCLGE_MBX_PF_VF_RESP:
 			if (resp->received_resp)
@@ -165,13 +170,31 @@ void hclgevf_mbx_handler(struct hclgevf_dev *hdev)
 			}
 			break;
 		case HCLGE_MBX_LINK_STAT_CHANGE:
-			link_status = le16_to_cpu(req->msg[1]);
-			memcpy(&speed, &req->msg[2], sizeof(speed));
-			duplex = (u8)le16_to_cpu(req->msg[4]);
+		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
+			 * enters handling state.
+			 */
+			hdev->mbx_event_pending = true;
 
-			/* update upper layer with new link link status */
-			hclgevf_update_link_status(hdev, link_status);
-			hclgevf_update_speed_duplex(hdev, speed, duplex);
+			/* we will drop the async msg if we find ARQ as full
+			 * and continue with next message
+			 */
+			if (hdev->arq.count >= HCLGE_MBX_MAX_ARQ_MSG_NUM) {
+				dev_warn(&hdev->pdev->dev,
+					 "Async Q full, dropping msg(%d)\n",
+					 req->msg[1]);
+				break;
+			}
+
+			/* tail the async message in arq */
+			msg_q = hdev->arq.msg_q[hdev->arq.tail];
+			memcpy(&msg_q[0], req->msg, HCLGE_MBX_MAX_ARQ_MSG_SIZE);
+			hclge_mbx_tail_ptr_move_arq(hdev->arq);
+			hdev->arq.count++;
+
+			hclgevf_mbx_task_schedule(hdev);
 
 			break;
 		default:
@@ -189,3 +212,57 @@ void hclgevf_mbx_handler(struct hclgevf_dev *hdev)
 	hclgevf_write_dev(&hdev->hw, HCLGEVF_NIC_CRQ_HEAD_REG,
 			  crq->next_to_use);
 }
+
+void hclgevf_mbx_async_handler(struct hclgevf_dev *hdev)
+{
+	u16 link_status;
+	u16 *msg_q;
+	u8 duplex;
+	u32 speed;
+	u32 tail;
+
+	/* we can safely clear it now as we are at start of the async message
+	 * processing
+	 */
+	hdev->mbx_event_pending = false;
+
+	tail = hdev->arq.tail;
+
+	/* process all the async queue messages */
+	while (tail != hdev->arq.head) {
+		msg_q = hdev->arq.msg_q[hdev->arq.head];
+
+		switch (msg_q[0]) {
+		case HCLGE_MBX_LINK_STAT_CHANGE:
+			link_status = le16_to_cpu(msg_q[1]);
+			memcpy(&speed, &msg_q[2], sizeof(speed));
+			duplex = (u8)le16_to_cpu(msg_q[4]);
+
+			/* update upper layer with new link link status */
+			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,
+				"fetched unsupported(%d) message from arq\n",
+				msg_q[0]);
+			break;
+		}
+
+		hclge_mbx_head_ptr_move_arq(hdev->arq);
+		hdev->arq.count--;
+		msg_q = hdev->arq.msg_q[hdev->arq.head];
+	}
+}