From cedd78cf13852882ab79b738c4025c74921374b2 Mon Sep 17 00:00:00 2001

From: Tyrel Datwyler <tyreld@linux.ibm.com>

Date: Thu, 11 Feb 2021 12:57:40 -0600

Subject: [PATCH 2/4] ibmvfc: fix invalid sub-CRQ handles after hard reset

References: bsc#1182632 ltc#191222

Patch-mainline: submitted https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=229197

A hard reset results in a complete transport disconnect such that the

CRQ connection with the partner VIOS is broken. This has the side effect

of also invalidating the associated sub-CRQs. The current code assumes

that the sub-CRQs are perserved resulting in a protocol violation after

trying to reconnect them with the VIOS. This introduces an infinite loop

such that the VIOS forces a disconnect after each subsequent attempt to

re-register with invalid handles.

Avoid the aforementioned issue by releasing the sub-CRQs prior to CRQ

disconnect, and driving a reinitialization of the sub-CRQs once a new

CRQ is registered with the hypervisor.

fixes: faacf8c5f1d5 ("ibmvfc: add alloc/dealloc routines for SCSI Sub-CRQ Channels")

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>

Reviewed-by: Brian King <brking@linux.vnet.ibm.com>

Acked-by: Michal Suchanek <msuchanek@suse.de>

---

 drivers/scsi/ibmvscsi/ibmvfc.c | 21 +++++++++------------

 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c

index 7be437e9d805..5030e1e974e7 100644

--- a/drivers/scsi/ibmvscsi/ibmvfc.c

+++ b/drivers/scsi/ibmvscsi/ibmvfc.c

@@ -158,6 +158,9 @@ static void ibmvfc_npiv_logout(struct ibmvfc_host *);

 static void ibmvfc_tgt_implicit_logout_and_del(struct ibmvfc_target *);

 static void ibmvfc_tgt_move_login(struct ibmvfc_target *);

+static void ibmvfc_release_sub_crqs(struct ibmvfc_host *);

+static void ibmvfc_init_sub_crqs(struct ibmvfc_host *);

+

 static const char *unknown_error = "unknown error";

 static long h_reg_sub_crq(unsigned long unit_address, unsigned long ioba,

@@ -926,8 +929,8 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost)

 	unsigned long flags;

 	struct vio_dev *vdev = to_vio_dev(vhost->dev);

 	struct ibmvfc_queue *crq = &vhost->crq;

-	struct ibmvfc_queue *scrq;

-	int i;

+

+	ibmvfc_release_sub_crqs(vhost);

 	/* Close the CRQ */

 	do {

@@ -947,16 +950,6 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost)

 	memset(crq->msgs.crq, 0, PAGE_SIZE);

 	crq->cur = 0;

-	if (vhost->scsi_scrqs.scrqs) {

-		for (i = 0; i < nr_scsi_hw_queues; i++) {

-			scrq = &vhost->scsi_scrqs.scrqs[i];

-			spin_lock(scrq->q_lock);

-			memset(scrq->msgs.scrq, 0, PAGE_SIZE);

-			scrq->cur = 0;

-			spin_unlock(scrq->q_lock);

-		}

-	}

-

 	/* And re-open it again */

 	rc = plpar_hcall_norets(H_REG_CRQ, vdev->unit_address,

 				crq->msg_token, PAGE_SIZE);

@@ -966,6 +959,9 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost)

 		dev_warn(vhost->dev, "Partner adapter not ready\n");

 	else if (rc != 0)

 		dev_warn(vhost->dev, "Couldn't register crq (rc=%d)\n", rc);

+

+	ibmvfc_init_sub_crqs(vhost);

+

 	spin_unlock(vhost->crq.q_lock);

 	spin_unlock_irqrestore(vhost->host->host_lock, flags);

@@ -5694,6 +5690,7 @@ static void ibmvfc_deregister_scsi_channel(struct ibmvfc_host *vhost, int index)

 	free_irq(scrq->irq, scrq);

 	irq_dispose_mapping(scrq->irq);

+	scrq->irq = 0;

 	do {

 		rc = plpar_hcall_norets(H_FREE_SUB_CRQ, vdev->unit_address,

-- 

2.26.2