scsi: qedf: Add schedule recovery handler

Implement recovery handler to be used by QED to signal the need for
recovery to come out of an error condition like ramrod struck and firmware
context reset.

Link: https://lore.kernel.org/r/20200416084314.18851-8-skashyap@marvell.com
Signed-off-by: Chad Dupuis <cdupuis@marvell.com>
Signed-off-by: Saurav Kashyap <skashyap@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qedf/qedf.h

@@ -387,6 +387,7 @@ struct qedf_ctx {
 #define QEDF_IO_WORK_MIN		64
 	mempool_t *io_mempool;
 	struct workqueue_struct *dpc_wq;
+	struct delayed_work recovery_work;
 	struct delayed_work grcdump_work;
 	struct delayed_work stag_work;
 

drivers/scsi/qedf/qedf_main.c

@@ -28,6 +28,8 @@ const struct qed_fcoe_ops *qed_ops;
 static int qedf_probe(struct pci_dev *pdev, const struct pci_device_id *id);
 static void qedf_remove(struct pci_dev *pdev);
 static void qedf_shutdown(struct pci_dev *pdev);
+static void qedf_schedule_recovery_handler(void *dev);
+static void qedf_recovery_handler(struct work_struct *work);
 
 /*
  * Driver module parameters.
@@ -662,6 +664,7 @@ static struct qed_fcoe_cb_ops qedf_cb_ops = {
 	{
 		.link_update = qedf_link_update,
 		.bw_update = qedf_bw_update,
+		.schedule_recovery_handler = qedf_schedule_recovery_handler,
 		.dcbx_aen = qedf_dcbx_handler,
 		.get_generic_tlv_data = qedf_get_generic_tlv_data,
 		.get_protocol_tlv_data = qedf_get_protocol_tlv_data,
@@ -3502,6 +3505,7 @@ static int __qedf_probe(struct pci_dev *pdev, int mode)
 		    qedf->lport->host->host_no);
 		qedf->dpc_wq = create_workqueue(host_buf);
 	}
+	INIT_DELAYED_WORK(&qedf->recovery_work, qedf_recovery_handler);
 
 	/*
 	 * GRC dump and sysfs parameters are not reaped during the recovery
@@ -3817,6 +3821,45 @@ static void qedf_shutdown(struct pci_dev *pdev)
 	__qedf_remove(pdev, QEDF_MODE_NORMAL);
 }
 
+/*
+ * Recovery handler code
+ */
+static void qedf_schedule_recovery_handler(void *dev)
+{
+	struct qedf_ctx *qedf = dev;
+
+	QEDF_ERR(&qedf->dbg_ctx, "Recovery handler scheduled.\n");
+	schedule_delayed_work(&qedf->recovery_work, 0);
+}
+
+static void qedf_recovery_handler(struct work_struct *work)
+{
+	struct qedf_ctx *qedf =
+	    container_of(work, struct qedf_ctx, recovery_work.work);
+
+	if (test_and_set_bit(QEDF_IN_RECOVERY, &qedf->flags))
+		return;
+
+	/*
+	 * Call common_ops->recovery_prolog to allow the MFW to quiesce
+	 * any PCI transactions.
+	 */
+	qed_ops->common->recovery_prolog(qedf->cdev);
+
+	QEDF_ERR(&qedf->dbg_ctx, "Recovery work start.\n");
+	__qedf_remove(qedf->pdev, QEDF_MODE_RECOVERY);
+	/*
+	 * Reset link and dcbx to down state since we will not get a link down
+	 * event from the MFW but calling __qedf_remove will essentially be a
+	 * link down event.
+	 */
+	atomic_set(&qedf->link_state, QEDF_LINK_DOWN);
+	atomic_set(&qedf->dcbx, QEDF_DCBX_PENDING);
+	__qedf_probe(qedf->pdev, QEDF_MODE_RECOVERY);
+	clear_bit(QEDF_IN_RECOVERY, &qedf->flags);
+	QEDF_ERR(&qedf->dbg_ctx, "Recovery work complete.\n");
+}
+
 /* Generic TLV data callback */
 void qedf_get_generic_tlv_data(void *dev, struct qed_generic_tlvs *data)
 {