RDMA/core: Add device method for registering dma-buf based memory region

Dma-buf based memory region requires one extra parameter and is processed
quite differently. Adding a separate method allows clean separation from
regular memory regions.

Link: https://lore.kernel.org/r/1608067636-98073-3-git-send-email-jianxin.xiong@intel.com
Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Acked-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Acked-by: Christian Koenig <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/core/device.c

@@ -2681,6 +2681,7 @@ void ib_set_device_ops(struct ib_device *dev, const struct ib_device_ops *ops)
 	SET_DEVICE_OP(dev_ops, read_counters);
 	SET_DEVICE_OP(dev_ops, reg_dm_mr);
 	SET_DEVICE_OP(dev_ops, reg_user_mr);
+	SET_DEVICE_OP(dev_ops, reg_user_mr_dmabuf);
 	SET_DEVICE_OP(dev_ops, req_ncomp_notif);
 	SET_DEVICE_OP(dev_ops, req_notify_cq);
 	SET_DEVICE_OP(dev_ops, rereg_user_mr);

include/rdma/ib_verbs.h

@@ -2,7 +2,7 @@
 /*
  * Copyright (c) 2004 Mellanox Technologies Ltd.  All rights reserved.
  * Copyright (c) 2004 Infinicon Corporation.  All rights reserved.
- * Copyright (c) 2004 Intel Corporation.  All rights reserved.
+ * Copyright (c) 2004, 2020 Intel Corporation.  All rights reserved.
  * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
  * Copyright (c) 2004 Voltaire Corporation.  All rights reserved.
  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
@@ -2434,6 +2434,10 @@ struct ib_device_ops {
 	struct ib_mr *(*reg_user_mr)(struct ib_pd *pd, u64 start, u64 length,
 				     u64 virt_addr, int mr_access_flags,
 				     struct ib_udata *udata);
+	struct ib_mr *(*reg_user_mr_dmabuf)(struct ib_pd *pd, u64 offset,
+					    u64 length, u64 virt_addr, int fd,
+					    int mr_access_flags,
+					    struct ib_udata *udata);
 	struct ib_mr *(*rereg_user_mr)(struct ib_mr *mr, int flags, u64 start,
 				       u64 length, u64 virt_addr,
 				       int mr_access_flags, struct ib_pd *pd,