[PATCH 07/29] ibmvfc: add wrapper to get vhost associated with a channel struct

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

Add ibmvfc_channels_to_vhost() to recover the parent struct ibmvfc_host
from a protocol-specific struct ibmvfc_channels.

Later patches need to operate on either the SCSI or NVMe channel group
and still access host-wide state such as the primary CRQ, device, and
logging context. Centralize that mapping in a helper instead of open-
coding container lookups at each call site.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
---
 drivers/scsi/ibmvscsi/ibmvfc.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.h b/drivers/scsi/ibmvscsi/ibmvfc.h
index 454968de925b..67f546ff092e 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.h
+++ b/drivers/scsi/ibmvscsi/ibmvfc.h
@@ -1011,6 +1011,16 @@ struct ibmvfc_host {
 	wait_queue_head_t work_wait_q;
 };
 
+static inline struct ibmvfc_host *ibmvfc_channels_to_vhost(struct ibmvfc_channels *channels)
+{
+	if (channels->protocol == IBMVFC_PROTO_SCSI)
+		return container_of(channels, struct ibmvfc_host, scsi_scrqs);
+	else if (channels->protocol == IBMVFC_PROTO_NVME)
+		return container_of(channels, struct ibmvfc_host, nvme_scrqs);
+
+	return NULL;
+}
+
 #define DBG_CMD(CMD) do { if (ibmvfc_debug) CMD; } while (0)
 
 #define tgt_dbg(t, fmt, ...)			\
-- 
2.54.0