[PATCH 28/29] ibmvfc: implement nvme-fc FCP abort callback

[Tyrel Datwyler <tyreld@linux.ibm.com>]

Implement the NVMe-FC FCP abort callback by issuing an NVMF cancel MAD
on the same submission queue used by the original FCP request.

Use the original request event stored in abort_req->private to recover
the associated ibmvfc queue, then allocate a new event from that queue
so the cancel is sent on the matching nvme_scrq. Factor the TMF setup
into a dedicated helper, mirroring the LS abort path, and populate the
cancel key, task tag, target WWPN, and association ID needed for the
VIOS NVMF abort request.

The abort path sends the cancel synchronously, waits for completion,
frees the temporary event, and logs non-zero MAD status values for
debugging.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
---
 drivers/scsi/ibmvscsi/ibmvfc-nvme.c | 64 +++++++++++++++++++++++++++++
 1 file changed, 64 insertions(+)

diff --git a/drivers/scsi/ibmvscsi/ibmvfc-nvme.c b/drivers/scsi/ibmvscsi/ibmvfc-nvme.c
index 18e8657abc44..92937f9aa464 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc-nvme.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc-nvme.c
@@ -374,11 +374,75 @@ static int ibmvfc_nvme_fcp_io(struct nvme_fc_local_port *lport,
 	return rc;
 }
 
+static void ibmvfc_init_fcp_abort(struct ibmvfc_event *evt,
+				  struct nvmefc_fcp_req *abort_req)
+{
+	struct ibmvfc_tmf *tmf;
+	struct ibmvfc_event *abt_evt = abort_req->private;
+	struct ibmvfc_target *tgt = abt_evt->tgt;
+
+	tmf = &evt->iu.tmf;
+	memset(tmf, 0, sizeof(*tmf));
+	tmf->common.version = cpu_to_be32(2);
+	tmf->common.opcode = cpu_to_be32(IBMVFC_NVMF_TMF_MAD);
+	tmf->common.length = cpu_to_be16(sizeof(*tmf));
+	tmf->flags = cpu_to_be32(IBMVFC_TMF_ABORT_TASK | IBMVFC_TMF_NVMF_ASSOC);
+	tmf->cancel_key = cpu_to_be32((u64)abt_evt);
+	tmf->my_cancel_key = cpu_to_be32((u64)evt);
+	tmf->target_wwpn = cpu_to_be64(tgt->wwpn);
+	tmf->assoc_id = cpu_to_be64(tgt->assoc_id);
+	tmf->task_tag = cpu_to_be64((u64)abt_evt);
+
+	init_completion(&evt->comp);
+}
+
 static void ibmvfc_nvme_fcp_abort(struct nvme_fc_local_port *lport,
 				  struct nvme_fc_remote_port *rport,
 				  void *hw_queue_handle,
 				  struct nvmefc_fcp_req *abort_req)
 {
+	struct ibmvfc_host *vhost = lport->private;
+	struct ibmvfc_target *tgt = rport->private;
+	struct ibmvfc_event *evt, *abt_evt = abort_req->private;
+	struct ibmvfc_queue *queue;
+	union ibmvfc_iu rsp;
+	unsigned long flags;
+	u16 status = 0;
+
+	if (!abt_evt)
+		return;
+
+	queue = abt_evt->queue;
+	if (!vhost->logged_in || !queue)
+		return;
+
+	evt = ibmvfc_get_event(queue);
+	if (!evt)
+		return;
+
+	spin_lock_irqsave(queue->q_lock, flags);
+	kref_get(&tgt->kref);
+	ibmvfc_init_event(evt, ibmvfc_sync_nvme_completion, IBMVFC_MAD_FORMAT);
+	ibmvfc_init_fcp_abort(evt, abort_req);
+	evt->sync_iu = &rsp;
+
+	if (ibmvfc_send_event(evt, vhost, default_timeout))
+		goto out;
+
+	spin_unlock_irqrestore(queue->q_lock, flags);
+
+	wait_for_completion(&evt->comp);
+	status = be16_to_cpu(rsp.mad_common.status);
+
+	spin_lock_irqsave(queue->q_lock, flags);
+	ibmvfc_free_event(evt);
+out:
+	spin_unlock_irqrestore(queue->q_lock, flags);
+
+	if (status)
+		ibmvfc_dbg(vhost, "fcp_abort: cancel failed with rc=%x\n", status);
+
+	kref_put(&tgt->kref, ibmvfc_release_tgt);
 }
 
 static struct nvme_fc_port_template ibmvfc_nvme_fc_transport = {
-- 
2.54.0