netdev - [PATCH] ibmvnic: driver initialization for kdump/kexec

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Message-Id: <20170615184809.42218.80768.stgit@ltcalpine2-lp23.aus.stglabs.ibm.com>
Date:   Thu, 15 Jun 2017 14:48:09 -0400
From:   Nathan Fontenot <nfont@...ux.vnet.ibm.com>
To:     netdev@...r.kernel.org
Cc:     jallen@...ux.vnet.ibm.com, tlfalcon@...ux.vnet.ibm.com
Subject: [PATCH] ibmvnic: driver initialization for kdump/kexec

When booting into the kdump/kexec kernel, pHyp and vios
are not prepared for the initialization crq request and
a failover transport event is generated. This is not
handled correctly.

At this point in initialization the driver is still in
the 'probing' state and cannot handle a full reset of the
driver as is normally done for a failover transport event.

To correct this we catch driver resets while still in the
'probing' state and return EAGAIN. This results in the
driver tearing down the main crq and calling ibmvnic_init()
again.

Signed-off-by: Nathan Fontenot <nfont@...ux.vnet.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c |   24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 59ea7a5..50ac1dc 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1447,6 +1447,12 @@ static void ibmvnic_reset(struct ibmvnic_adapter *adapter,
 		return;
 	}
 
+	if (adapter->state == VNIC_PROBING) {
+		netdev_warn(netdev, "Adapter reset during probe\n");
+		adapter->init_done_rc = EAGAIN;
+		return;
+	}
+
 	mutex_lock(&adapter->rwi_lock);
 
 	list_for_each(entry, &adapter->rwi_list) {
@@ -3634,12 +3640,18 @@ static int ibmvnic_init(struct ibmvnic_adapter *adapter)
 	adapter->from_passive_init = false;
 
 	init_completion(&adapter->init_done);
+	adapter->init_done_rc = 0;
 	ibmvnic_send_crq_init(adapter);
 	if (!wait_for_completion_timeout(&adapter->init_done, timeout)) {
 		dev_err(dev, "Initialization sequence timed out\n");
 		return -1;
 	}
 
+	if (adapter->init_done_rc) {
+		release_crq_queue(adapter);
+		return adapter->init_done_rc;
+	}
+
 	if (adapter->from_passive_init) {
 		adapter->state = VNIC_OPEN;
 		adapter->from_passive_init = false;
@@ -3708,11 +3720,13 @@ static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id)
 	mutex_init(&adapter->rwi_lock);
 	adapter->resetting = false;
 
-	rc = ibmvnic_init(adapter);
-	if (rc) {
-		free_netdev(netdev);
-		return rc;
-	}
+	do {
+		rc = ibmvnic_init(adapter);
+		if (rc != EAGAIN) {
+			free_netdev(netdev);
+			return rc;
+		}
+	} while (rc == EAGAIN);
 
 	netdev->mtu = adapter->req_mtu - ETH_HLEN;