1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
|
/*
* Copyright (c) 2015 Oracle. All rights reserved.
* Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
*/
/* Lightweight memory registration using Fast Registration Work
* Requests (FRWR). Also referred to sometimes as FRMR mode.
*
* FRWR features ordered asynchronous registration and deregistration
* of arbitrarily sized memory regions. This is the fastest and safest
* but most complex memory registration mode.
*/
#include "xprt_rdma.h"
#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
# define RPCDBG_FACILITY RPCDBG_TRANS
#endif
/* FRWR mode conveys a list of pages per chunk segment. The
* maximum length of that list is the FRWR page list depth.
*/
static size_t
frwr_op_maxpages(struct rpcrdma_xprt *r_xprt)
{
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
rpcrdma_max_segments(r_xprt) * ia->ri_max_frmr_depth);
}
/* Post a FAST_REG Work Request to register a memory region
* for remote access via RDMA READ or RDMA WRITE.
*/
static int
frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
int nsegs, bool writing)
{
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
struct rpcrdma_mr_seg *seg1 = seg;
struct rpcrdma_mw *mw = seg1->rl_mw;
struct rpcrdma_frmr *frmr = &mw->r.frmr;
struct ib_mr *mr = frmr->fr_mr;
struct ib_send_wr fastreg_wr, *bad_wr;
u8 key;
int len, pageoff;
int i, rc;
int seg_len;
u64 pa;
int page_no;
pageoff = offset_in_page(seg1->mr_offset);
seg1->mr_offset -= pageoff; /* start of page */
seg1->mr_len += pageoff;
len = -pageoff;
if (nsegs > ia->ri_max_frmr_depth)
nsegs = ia->ri_max_frmr_depth;
for (page_no = i = 0; i < nsegs;) {
rpcrdma_map_one(ia, seg, writing);
pa = seg->mr_dma;
for (seg_len = seg->mr_len; seg_len > 0; seg_len -= PAGE_SIZE) {
frmr->fr_pgl->page_list[page_no++] = pa;
pa += PAGE_SIZE;
}
len += seg->mr_len;
++seg;
++i;
/* Check for holes */
if ((i < nsegs && offset_in_page(seg->mr_offset)) ||
offset_in_page((seg-1)->mr_offset + (seg-1)->mr_len))
break;
}
dprintk("RPC: %s: Using frmr %p to map %d segments (%d bytes)\n",
__func__, mw, i, len);
frmr->fr_state = FRMR_IS_VALID;
memset(&fastreg_wr, 0, sizeof(fastreg_wr));
fastreg_wr.wr_id = (unsigned long)(void *)mw;
fastreg_wr.opcode = IB_WR_FAST_REG_MR;
fastreg_wr.wr.fast_reg.iova_start = seg1->mr_dma + pageoff;
fastreg_wr.wr.fast_reg.page_list = frmr->fr_pgl;
fastreg_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
fastreg_wr.wr.fast_reg.page_list_len = page_no;
fastreg_wr.wr.fast_reg.length = len;
fastreg_wr.wr.fast_reg.access_flags = writing ?
IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE :
IB_ACCESS_REMOTE_READ;
key = (u8)(mr->rkey & 0x000000FF);
ib_update_fast_reg_key(mr, ++key);
fastreg_wr.wr.fast_reg.rkey = mr->rkey;
DECR_CQCOUNT(&r_xprt->rx_ep);
rc = ib_post_send(ia->ri_id->qp, &fastreg_wr, &bad_wr);
if (rc)
goto out_senderr;
seg1->mr_rkey = mr->rkey;
seg1->mr_base = seg1->mr_dma + pageoff;
seg1->mr_nsegs = i;
seg1->mr_len = len;
return i;
out_senderr:
dprintk("RPC: %s: ib_post_send status %i\n", __func__, rc);
ib_update_fast_reg_key(mr, --key);
frmr->fr_state = FRMR_IS_INVALID;
while (i--)
rpcrdma_unmap_one(ia, --seg);
return rc;
}
/* Post a LOCAL_INV Work Request to prevent further remote access
* via RDMA READ or RDMA WRITE.
*/
static int
frwr_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
{
struct rpcrdma_mr_seg *seg1 = seg;
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
struct ib_send_wr invalidate_wr, *bad_wr;
int rc, nsegs = seg->mr_nsegs;
seg1->rl_mw->r.frmr.fr_state = FRMR_IS_INVALID;
memset(&invalidate_wr, 0, sizeof(invalidate_wr));
invalidate_wr.wr_id = (unsigned long)(void *)seg1->rl_mw;
invalidate_wr.opcode = IB_WR_LOCAL_INV;
invalidate_wr.ex.invalidate_rkey = seg1->rl_mw->r.frmr.fr_mr->rkey;
DECR_CQCOUNT(&r_xprt->rx_ep);
read_lock(&ia->ri_qplock);
while (seg1->mr_nsegs--)
rpcrdma_unmap_one(ia, seg++);
rc = ib_post_send(ia->ri_id->qp, &invalidate_wr, &bad_wr);
read_unlock(&ia->ri_qplock);
if (rc)
goto out_err;
return nsegs;
out_err:
/* Force rpcrdma_buffer_get() to retry */
seg1->rl_mw->r.frmr.fr_state = FRMR_IS_STALE;
dprintk("RPC: %s: ib_post_send status %i\n", __func__, rc);
return nsegs;
}
const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops = {
.ro_map = frwr_op_map,
.ro_unmap = frwr_op_unmap,
.ro_maxpages = frwr_op_maxpages,
.ro_displayname = "frwr",
};
|
