RDMA/cma: Remove unused rdma_res_to_id

JIRA: https://issues.redhat.com/browse/RHEL-110100

commit 0403939
Author: Dr. David Alan Gilbert <linux@treblig.org>
Date:   Fri Apr 18 17:58:48 2025 +0100

    RDMA/cma: Remove unused rdma_res_to_id

    The last use of rdma_res_to_id() was removed in 2020 by
    commi t211cd9459fda ("RDMA: Add dedicated CM_ID resource tracker function")

    Remove it.

    Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
    Link: https://patch.msgid.link/20250418165848.241305-1-linux@treblig.org
    Signed-off-by: Leon Romanovsky <leon@kernel.org>

Signed-off-by: Kamal Heib <kheib@redhat.com>

Author: Kamalheib

drivers/infiniband/core/cma.c

@@ -146,19 +146,6 @@ struct iw_cm_id *rdma_iw_cm_id(struct rdma_cm_id *id)
 }
 EXPORT_SYMBOL(rdma_iw_cm_id);
 
-/**
- * rdma_res_to_id() - return the rdma_cm_id pointer for this restrack.
- * @res: rdma resource tracking entry pointer
- */
-struct rdma_cm_id *rdma_res_to_id(struct rdma_restrack_entry *res)
-{
-	struct rdma_id_private *id_priv =
-		container_of(res, struct rdma_id_private, res);
-
-	return &id_priv->id;
-}
-EXPORT_SYMBOL(rdma_res_to_id);
-
 static int cma_add_one(struct ib_device *device);
 static void cma_remove_one(struct ib_device *device, void *client_data);
 

include/rdma/rdma_cm.h

@@ -388,6 +388,5 @@ void rdma_read_gids(struct rdma_cm_id *cm_id, union ib_gid *sgid,
 		    union ib_gid *dgid);
 
 struct iw_cm_id *rdma_iw_cm_id(struct rdma_cm_id *cm_id);
-struct rdma_cm_id *rdma_res_to_id(struct rdma_restrack_entry *res);
 
 #endif /* RDMA_CM_H */