net: hns3: add PCIe FLR support for PF

This patch implements the .reset_prepare and .reset_done
ops from pci framework to support the PF FLR.
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -127,6 +127,7 @@ enum hnae3_reset_type {
 	HNAE3_VF_FUNC_RESET,
 	HNAE3_VF_PF_FUNC_RESET,
 	HNAE3_VF_FULL_RESET,
+	HNAE3_FLR_RESET,
 	HNAE3_FUNC_RESET,
 	HNAE3_CORE_RESET,
 	HNAE3_GLOBAL_RESET,
@@ -134,6 +135,11 @@ enum hnae3_reset_type {
 	HNAE3_NONE_RESET,
 };
 
+enum hnae3_flr_state {
+	HNAE3_FLR_DOWN,
+	HNAE3_FLR_DONE,
+};
+
 struct hnae3_vector_info {
 	u8 __iomem *io_addr;
 	int vector;
@@ -299,7 +305,8 @@ struct hnae3_ae_dev {
 struct hnae3_ae_ops {
 	int (*init_ae_dev)(struct hnae3_ae_dev *ae_dev);
 	void (*uninit_ae_dev)(struct hnae3_ae_dev *ae_dev);
-
+	void (*flr_prepare)(struct hnae3_ae_dev *ae_dev);
+	void (*flr_done)(struct hnae3_ae_dev *ae_dev);
 	int (*init_client_instance)(struct hnae3_client *client,
 				    struct hnae3_ae_dev *ae_dev);
 	void (*uninit_client_instance)(struct hnae3_client *client,

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

@@ -1851,9 +1851,29 @@ static pci_ers_result_t hns3_slot_reset(struct pci_dev *pdev)
 	return PCI_ERS_RESULT_DISCONNECT;
 }
 
+static void hns3_reset_prepare(struct pci_dev *pdev)
+{
+	struct hnae3_ae_dev *ae_dev = pci_get_drvdata(pdev);
+
+	dev_info(&pdev->dev, "hns3 flr prepare\n");
+	if (ae_dev && ae_dev->ops && ae_dev->ops->flr_prepare)
+		ae_dev->ops->flr_prepare(ae_dev);
+}
+
+static void hns3_reset_done(struct pci_dev *pdev)
+{
+	struct hnae3_ae_dev *ae_dev = pci_get_drvdata(pdev);
+
+	dev_info(&pdev->dev, "hns3 flr done\n");
+	if (ae_dev && ae_dev->ops && ae_dev->ops->flr_done)
+		ae_dev->ops->flr_done(ae_dev);
+}
+
 static const struct pci_error_handlers hns3_err_handler = {
 	.error_detected = hns3_error_detected,
 	.slot_reset     = hns3_slot_reset,
+	.reset_prepare	= hns3_reset_prepare,
+	.reset_done	= hns3_reset_done,
 };
 
 static struct pci_driver hns3_driver = {

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

@@ -594,7 +594,9 @@ static inline void hns3_write_reg(void __iomem *base, u32 reg, u32 value)
 static inline bool hns3_dev_ongoing_func_reset(struct hnae3_ae_dev *ae_dev)
 {
 	return (ae_dev && (ae_dev->reset_type == HNAE3_FUNC_RESET ||
+			   ae_dev->reset_type == HNAE3_FLR_RESET ||
 			   ae_dev->reset_type == HNAE3_VF_FUNC_RESET ||
+			   ae_dev->reset_type == HNAE3_VF_FULL_RESET ||
 			   ae_dev->reset_type == HNAE3_VF_PF_FUNC_RESET));
 }
 

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

@@ -2374,6 +2374,8 @@ static int hclge_reset_wait(struct hclge_dev *hdev)
 		reg = HCLGE_FUN_RST_ING;
 		reg_bit = HCLGE_FUN_RST_ING_B;
 		break;
+	case HNAE3_FLR_RESET:
+		break;
 	default:
 		dev_err(&hdev->pdev->dev,
 			"Wait for unsupported reset type: %d\n",
@@ -2381,6 +2383,20 @@ static int hclge_reset_wait(struct hclge_dev *hdev)
 		return -EINVAL;
 	}
 
+	if (hdev->reset_type == HNAE3_FLR_RESET) {
+		while (!test_bit(HNAE3_FLR_DONE, &hdev->flr_state) &&
+		       cnt++ < HCLGE_RESET_WAIT_CNT)
+			msleep(HCLGE_RESET_WATI_MS);
+
+		if (!test_bit(HNAE3_FLR_DONE, &hdev->flr_state)) {
+			dev_err(&hdev->pdev->dev,
+				"flr wait timeout: %d\n", cnt);
+			return -EBUSY;
+		}
+
+		return 0;
+	}
+
 	val = hclge_read_dev(&hdev->hw, reg);
 	while (hnae3_get_bit(val, reg_bit) && cnt < HCLGE_RESET_WAIT_CNT) {
 		msleep(HCLGE_RESET_WATI_MS);
@@ -2488,6 +2504,12 @@ static void hclge_do_reset(struct hclge_dev *hdev)
 		set_bit(HNAE3_FUNC_RESET, &hdev->reset_pending);
 		hclge_reset_task_schedule(hdev);
 		break;
+	case HNAE3_FLR_RESET:
+		dev_info(&pdev->dev, "FLR requested\n");
+		/* schedule again to check later */
+		set_bit(HNAE3_FLR_RESET, &hdev->reset_pending);
+		hclge_reset_task_schedule(hdev);
+		break;
 	default:
 		dev_warn(&pdev->dev,
 			 "Unsupported reset type: %d\n", hdev->reset_type);
@@ -2519,6 +2541,9 @@ static enum hnae3_reset_type hclge_get_reset_level(struct hclge_dev *hdev,
 	} else if (test_bit(HNAE3_FUNC_RESET, addr)) {
 		rst_level = HNAE3_FUNC_RESET;
 		clear_bit(HNAE3_FUNC_RESET, addr);
+	} else if (test_bit(HNAE3_FLR_RESET, addr)) {
+		rst_level = HNAE3_FLR_RESET;
+		clear_bit(HNAE3_FLR_RESET, addr);
 	}
 
 	return rst_level;
@@ -2555,6 +2580,8 @@ static int hclge_reset_prepare_down(struct hclge_dev *hdev)
 
 	switch (hdev->reset_type) {
 	case HNAE3_FUNC_RESET:
+		/* fall through */
+	case HNAE3_FLR_RESET:
 		ret = hclge_set_all_vf_rst(hdev, true);
 		break;
 	default:
@@ -2589,6 +2616,14 @@ static int hclge_reset_prepare_wait(struct hclge_dev *hdev)
 		 */
 		set_bit(HCLGE_STATE_CMD_DISABLE, &hdev->state);
 		break;
+	case HNAE3_FLR_RESET:
+		/* There is no mechanism for PF to know if VF has stopped IO
+		 * for now, just wait 100 ms for VF to stop IO
+		 */
+		msleep(100);
+		set_bit(HCLGE_STATE_CMD_DISABLE, &hdev->state);
+		set_bit(HNAE3_FLR_DOWN, &hdev->flr_state);
+		break;
 	case HNAE3_IMP_RESET:
 		reg_val = hclge_read_dev(&hdev->hw, HCLGE_PF_OTHER_INT_REG);
 		hclge_write_dev(&hdev->hw, HCLGE_PF_OTHER_INT_REG,
@@ -2647,6 +2682,8 @@ static int hclge_reset_prepare_up(struct hclge_dev *hdev)
 
 	switch (hdev->reset_type) {
 	case HNAE3_FUNC_RESET:
+		/* fall through */
+	case HNAE3_FLR_RESET:
 		ret = hclge_set_all_vf_rst(hdev, false);
 		break;
 	default:
@@ -6917,6 +6954,34 @@ static void hclge_state_uninit(struct hclge_dev *hdev)
 		cancel_work_sync(&hdev->mbx_service_task);
 }
 
+static void hclge_flr_prepare(struct hnae3_ae_dev *ae_dev)
+{
+#define HCLGE_FLR_WAIT_MS	100
+#define HCLGE_FLR_WAIT_CNT	50
+	struct hclge_dev *hdev = ae_dev->priv;
+	int cnt = 0;
+
+	clear_bit(HNAE3_FLR_DOWN, &hdev->flr_state);
+	clear_bit(HNAE3_FLR_DONE, &hdev->flr_state);
+	set_bit(HNAE3_FLR_RESET, &hdev->default_reset_request);
+	hclge_reset_event(hdev->pdev, NULL);
+
+	while (!test_bit(HNAE3_FLR_DOWN, &hdev->flr_state) &&
+	       cnt++ < HCLGE_FLR_WAIT_CNT)
+		msleep(HCLGE_FLR_WAIT_MS);
+
+	if (!test_bit(HNAE3_FLR_DOWN, &hdev->flr_state))
+		dev_err(&hdev->pdev->dev,
+			"flr wait down timeout: %d\n", cnt);
+}
+
+static void hclge_flr_done(struct hnae3_ae_dev *ae_dev)
+{
+	struct hclge_dev *hdev = ae_dev->priv;
+
+	set_bit(HNAE3_FLR_DONE, &hdev->flr_state);
+}
+
 static int hclge_init_ae_dev(struct hnae3_ae_dev *ae_dev)
 {
 	struct pci_dev *pdev = ae_dev->pdev;
@@ -7575,6 +7640,8 @@ static void hclge_get_link_mode(struct hnae3_handle *handle,
 static const struct hnae3_ae_ops hclge_ops = {
 	.init_ae_dev = hclge_init_ae_dev,
 	.uninit_ae_dev = hclge_uninit_ae_dev,
+	.flr_prepare = hclge_flr_prepare,
+	.flr_done = hclge_flr_done,
 	.init_client_instance = hclge_init_client_instance,
 	.uninit_client_instance = hclge_uninit_client_instance,
 	.map_ring_to_vector = hclge_map_ring_to_vector,

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

@@ -597,6 +597,7 @@ struct hclge_dev {
 	struct hclge_misc_vector misc_vector;
 	struct hclge_hw_stats hw_stats;
 	unsigned long state;
+	unsigned long flr_state;
 	unsigned long last_reset_time;
 
 	enum hnae3_reset_type reset_type;

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

@@ -90,6 +90,8 @@ int hclge_inform_reset_assert_to_vf(struct hclge_vport *vport)
 
 	if (hdev->reset_type == HNAE3_FUNC_RESET)
 		reset_type = HNAE3_VF_PF_FUNC_RESET;
+	else if (hdev->reset_type == HNAE3_FLR_RESET)
+		reset_type = HNAE3_VF_FULL_RESET;
 	else
 		return -EINVAL;