v4.19.13 snapshot.
diff --git a/net/rds/ib_mr.h b/net/rds/ib_mr.h
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+++ b/net/rds/ib_mr.h
@@ -0,0 +1,146 @@
+/*
+ * Copyright (c) 2016 Oracle.  All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef _RDS_IB_MR_H
+#define _RDS_IB_MR_H
+
+#include <linux/kernel.h>
+
+#include "rds.h"
+#include "ib.h"
+
+#define RDS_MR_1M_POOL_SIZE		(8192 / 2)
+#define RDS_MR_1M_MSG_SIZE		256
+#define RDS_MR_8K_MSG_SIZE		2
+#define RDS_MR_8K_SCALE			(256 / (RDS_MR_8K_MSG_SIZE + 1))
+#define RDS_MR_8K_POOL_SIZE		(RDS_MR_8K_SCALE * (8192 / 2))
+
+struct rds_ib_fmr {
+	struct ib_fmr		*fmr;
+};
+
+enum rds_ib_fr_state {
+	FRMR_IS_FREE,	/* mr invalidated & ready for use */
+	FRMR_IS_INUSE,	/* mr is in use or used & can be invalidated */
+	FRMR_IS_STALE,	/* Stale MR and needs to be dropped  */
+};
+
+struct rds_ib_frmr {
+	struct ib_mr		*mr;
+	enum rds_ib_fr_state	fr_state;
+	bool			fr_inv;
+	struct ib_send_wr	fr_wr;
+	unsigned int		dma_npages;
+	unsigned int		sg_byte_len;
+};
+
+/* This is stored as mr->r_trans_private. */
+struct rds_ib_mr {
+	struct rds_ib_device		*device;
+	struct rds_ib_mr_pool		*pool;
+	struct rds_ib_connection	*ic;
+
+	struct llist_node		llnode;
+
+	/* unmap_list is for freeing */
+	struct list_head		unmap_list;
+	unsigned int			remap_count;
+
+	struct scatterlist		*sg;
+	unsigned int			sg_len;
+	int				sg_dma_len;
+
+	union {
+		struct rds_ib_fmr	fmr;
+		struct rds_ib_frmr	frmr;
+	} u;
+};
+
+/* Our own little MR pool */
+struct rds_ib_mr_pool {
+	unsigned int            pool_type;
+	struct mutex		flush_lock;	/* serialize fmr invalidate */
+	struct delayed_work	flush_worker;	/* flush worker */
+
+	atomic_t		item_count;	/* total # of MRs */
+	atomic_t		dirty_count;	/* # dirty of MRs */
+
+	struct llist_head	drop_list;	/* MRs not reached max_maps */
+	struct llist_head	free_list;	/* unused MRs */
+	struct llist_head	clean_list;	/* unused & unmapped MRs */
+	wait_queue_head_t	flush_wait;
+
+	atomic_t		free_pinned;	/* memory pinned by free MRs */
+	unsigned long		max_items;
+	unsigned long		max_items_soft;
+	unsigned long		max_free_pinned;
+	struct ib_fmr_attr	fmr_attr;
+	bool			use_fastreg;
+};
+
+extern struct workqueue_struct *rds_ib_mr_wq;
+extern bool prefer_frmr;
+
+struct rds_ib_mr_pool *rds_ib_create_mr_pool(struct rds_ib_device *rds_dev,
+					     int npages);
+void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev,
+			struct rds_info_rdma_connection *iinfo);
+void rds6_ib_get_mr_info(struct rds_ib_device *rds_ibdev,
+			 struct rds6_info_rdma_connection *iinfo6);
+void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *);
+void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
+		    struct rds_sock *rs, u32 *key_ret,
+		    struct rds_connection *conn);
+void rds_ib_sync_mr(void *trans_private, int dir);
+void rds_ib_free_mr(void *trans_private, int invalidate);
+void rds_ib_flush_mrs(void);
+int rds_ib_mr_init(void);
+void rds_ib_mr_exit(void);
+
+void __rds_ib_teardown_mr(struct rds_ib_mr *);
+void rds_ib_teardown_mr(struct rds_ib_mr *);
+struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *, int);
+struct rds_ib_mr *rds_ib_reuse_mr(struct rds_ib_mr_pool *);
+int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *, int, struct rds_ib_mr **);
+struct rds_ib_mr *rds_ib_reg_fmr(struct rds_ib_device *, struct scatterlist *,
+				 unsigned long, u32 *);
+struct rds_ib_mr *rds_ib_try_reuse_ibmr(struct rds_ib_mr_pool *);
+void rds_ib_unreg_fmr(struct list_head *, unsigned int *,
+		      unsigned long *, unsigned int);
+void rds_ib_free_fmr_list(struct rds_ib_mr *);
+struct rds_ib_mr *rds_ib_reg_frmr(struct rds_ib_device *rds_ibdev,
+				  struct rds_ib_connection *ic,
+				  struct scatterlist *sg,
+				  unsigned long nents, u32 *key);
+void rds_ib_unreg_frmr(struct list_head *list, unsigned int *nfreed,
+		       unsigned long *unpinned, unsigned int goal);
+void rds_ib_free_frmr_list(struct rds_ib_mr *);
+#endif