1/*
2 * Copyright (c) 2015 Oracle.  All rights reserved.
3 * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
4 */
5
6/* No-op chunk preparation. All client memory is pre-registered.
7 * Sometimes referred to as ALLPHYSICAL mode.
8 *
9 * Physical registration is simple because all client memory is
10 * pre-registered and never deregistered. This mode is good for
11 * adapter bring up, but is considered not safe: the server is
12 * trusted not to abuse its access to client memory not involved
13 * in RDMA I/O.
14 */
15
16#include "xprt_rdma.h"
17
18#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
19# define RPCDBG_FACILITY	RPCDBG_TRANS
20#endif
21
22static int
23physical_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
24		 struct rpcrdma_create_data_internal *cdata)
25{
26	return 0;
27}
28
29/* PHYSICAL memory registration conveys one page per chunk segment.
30 */
31static size_t
32physical_op_maxpages(struct rpcrdma_xprt *r_xprt)
33{
34	return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
35		     rpcrdma_max_segments(r_xprt));
36}
37
38static int
39physical_op_init(struct rpcrdma_xprt *r_xprt)
40{
41	return 0;
42}
43
44/* The client's physical memory is already exposed for
45 * remote access via RDMA READ or RDMA WRITE.
46 */
47static int
48physical_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
49		int nsegs, bool writing)
50{
51	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
52
53	rpcrdma_map_one(ia->ri_id->device, seg,
54			rpcrdma_data_dir(writing));
55	seg->mr_rkey = ia->ri_bind_mem->rkey;
56	seg->mr_base = seg->mr_dma;
57	seg->mr_nsegs = 1;
58	return 1;
59}
60
61/* Unmap a memory region, but leave it registered.
62 */
63static int
64physical_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
65{
66	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
67
68	read_lock(&ia->ri_qplock);
69	rpcrdma_unmap_one(ia->ri_id->device, seg);
70	read_unlock(&ia->ri_qplock);
71
72	return 1;
73}
74
75static void
76physical_op_reset(struct rpcrdma_xprt *r_xprt)
77{
78}
79
80static void
81physical_op_destroy(struct rpcrdma_buffer *buf)
82{
83}
84
85const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops = {
86	.ro_map				= physical_op_map,
87	.ro_unmap			= physical_op_unmap,
88	.ro_open			= physical_op_open,
89	.ro_maxpages			= physical_op_maxpages,
90	.ro_init			= physical_op_init,
91	.ro_reset			= physical_op_reset,
92	.ro_destroy			= physical_op_destroy,
93	.ro_displayname			= "physical",
94};
95