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a0ce85f5 CL |
1 | /* |
2 | * Copyright (c) 2015 Oracle. All rights reserved. | |
3 | * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved. | |
4 | */ | |
5 | ||
6 | /* Lightweight memory registration using Fast Registration Work | |
7 | * Requests (FRWR). Also referred to sometimes as FRMR mode. | |
8 | * | |
9 | * FRWR features ordered asynchronous registration and deregistration | |
10 | * of arbitrarily sized memory regions. This is the fastest and safest | |
11 | * but most complex memory registration mode. | |
12 | */ | |
13 | ||
14 | #include "xprt_rdma.h" | |
15 | ||
16 | #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) | |
17 | # define RPCDBG_FACILITY RPCDBG_TRANS | |
18 | #endif | |
19 | ||
91e70e70 CL |
20 | static int |
21 | __frwr_init(struct rpcrdma_mw *r, struct ib_pd *pd, struct ib_device *device, | |
22 | unsigned int depth) | |
23 | { | |
24 | struct rpcrdma_frmr *f = &r->r.frmr; | |
25 | int rc; | |
26 | ||
27 | f->fr_mr = ib_alloc_fast_reg_mr(pd, depth); | |
28 | if (IS_ERR(f->fr_mr)) | |
29 | goto out_mr_err; | |
30 | f->fr_pgl = ib_alloc_fast_reg_page_list(device, depth); | |
31 | if (IS_ERR(f->fr_pgl)) | |
32 | goto out_list_err; | |
33 | return 0; | |
34 | ||
35 | out_mr_err: | |
36 | rc = PTR_ERR(f->fr_mr); | |
37 | dprintk("RPC: %s: ib_alloc_fast_reg_mr status %i\n", | |
38 | __func__, rc); | |
39 | return rc; | |
40 | ||
41 | out_list_err: | |
42 | rc = PTR_ERR(f->fr_pgl); | |
43 | dprintk("RPC: %s: ib_alloc_fast_reg_page_list status %i\n", | |
44 | __func__, rc); | |
45 | ib_dereg_mr(f->fr_mr); | |
46 | return rc; | |
47 | } | |
48 | ||
31a701a9 CL |
49 | static void |
50 | __frwr_release(struct rpcrdma_mw *r) | |
51 | { | |
52 | int rc; | |
53 | ||
54 | rc = ib_dereg_mr(r->r.frmr.fr_mr); | |
55 | if (rc) | |
56 | dprintk("RPC: %s: ib_dereg_mr status %i\n", | |
57 | __func__, rc); | |
58 | ib_free_fast_reg_page_list(r->r.frmr.fr_pgl); | |
59 | } | |
60 | ||
3968cb58 CL |
61 | static int |
62 | frwr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep, | |
63 | struct rpcrdma_create_data_internal *cdata) | |
64 | { | |
65 | struct ib_device_attr *devattr = &ia->ri_devattr; | |
66 | int depth, delta; | |
67 | ||
68 | ia->ri_max_frmr_depth = | |
69 | min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS, | |
70 | devattr->max_fast_reg_page_list_len); | |
71 | dprintk("RPC: %s: device's max FR page list len = %u\n", | |
72 | __func__, ia->ri_max_frmr_depth); | |
73 | ||
74 | /* Add room for frmr register and invalidate WRs. | |
75 | * 1. FRMR reg WR for head | |
76 | * 2. FRMR invalidate WR for head | |
77 | * 3. N FRMR reg WRs for pagelist | |
78 | * 4. N FRMR invalidate WRs for pagelist | |
79 | * 5. FRMR reg WR for tail | |
80 | * 6. FRMR invalidate WR for tail | |
81 | * 7. The RDMA_SEND WR | |
82 | */ | |
83 | depth = 7; | |
84 | ||
85 | /* Calculate N if the device max FRMR depth is smaller than | |
86 | * RPCRDMA_MAX_DATA_SEGS. | |
87 | */ | |
88 | if (ia->ri_max_frmr_depth < RPCRDMA_MAX_DATA_SEGS) { | |
89 | delta = RPCRDMA_MAX_DATA_SEGS - ia->ri_max_frmr_depth; | |
90 | do { | |
91 | depth += 2; /* FRMR reg + invalidate */ | |
92 | delta -= ia->ri_max_frmr_depth; | |
93 | } while (delta > 0); | |
94 | } | |
95 | ||
96 | ep->rep_attr.cap.max_send_wr *= depth; | |
97 | if (ep->rep_attr.cap.max_send_wr > devattr->max_qp_wr) { | |
98 | cdata->max_requests = devattr->max_qp_wr / depth; | |
99 | if (!cdata->max_requests) | |
100 | return -EINVAL; | |
101 | ep->rep_attr.cap.max_send_wr = cdata->max_requests * | |
102 | depth; | |
103 | } | |
104 | ||
105 | return 0; | |
106 | } | |
107 | ||
1c9351ee CL |
108 | /* FRWR mode conveys a list of pages per chunk segment. The |
109 | * maximum length of that list is the FRWR page list depth. | |
110 | */ | |
111 | static size_t | |
112 | frwr_op_maxpages(struct rpcrdma_xprt *r_xprt) | |
113 | { | |
114 | struct rpcrdma_ia *ia = &r_xprt->rx_ia; | |
115 | ||
116 | return min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS, | |
117 | rpcrdma_max_segments(r_xprt) * ia->ri_max_frmr_depth); | |
118 | } | |
119 | ||
e46ac34c CL |
120 | /* If FAST_REG or LOCAL_INV failed, indicate the frmr needs to be reset. */ |
121 | static void | |
122 | frwr_sendcompletion(struct ib_wc *wc) | |
123 | { | |
124 | struct rpcrdma_mw *r; | |
125 | ||
126 | if (likely(wc->status == IB_WC_SUCCESS)) | |
127 | return; | |
128 | ||
129 | /* WARNING: Only wr_id and status are reliable at this point */ | |
130 | r = (struct rpcrdma_mw *)(unsigned long)wc->wr_id; | |
131 | dprintk("RPC: %s: frmr %p (stale), status %d\n", | |
132 | __func__, r, wc->status); | |
133 | r->r.frmr.fr_state = FRMR_IS_STALE; | |
134 | } | |
135 | ||
91e70e70 CL |
136 | static int |
137 | frwr_op_init(struct rpcrdma_xprt *r_xprt) | |
138 | { | |
139 | struct rpcrdma_buffer *buf = &r_xprt->rx_buf; | |
140 | struct ib_device *device = r_xprt->rx_ia.ri_id->device; | |
141 | unsigned int depth = r_xprt->rx_ia.ri_max_frmr_depth; | |
142 | struct ib_pd *pd = r_xprt->rx_ia.ri_pd; | |
143 | int i; | |
144 | ||
145 | INIT_LIST_HEAD(&buf->rb_mws); | |
146 | INIT_LIST_HEAD(&buf->rb_all); | |
147 | ||
148 | i = (buf->rb_max_requests + 1) * RPCRDMA_MAX_SEGS; | |
149 | dprintk("RPC: %s: initalizing %d FRMRs\n", __func__, i); | |
150 | ||
151 | while (i--) { | |
152 | struct rpcrdma_mw *r; | |
153 | int rc; | |
154 | ||
155 | r = kzalloc(sizeof(*r), GFP_KERNEL); | |
156 | if (!r) | |
157 | return -ENOMEM; | |
158 | ||
159 | rc = __frwr_init(r, pd, device, depth); | |
160 | if (rc) { | |
161 | kfree(r); | |
162 | return rc; | |
163 | } | |
164 | ||
165 | list_add(&r->mw_list, &buf->rb_mws); | |
166 | list_add(&r->mw_all, &buf->rb_all); | |
e46ac34c | 167 | r->mw_sendcompletion = frwr_sendcompletion; |
91e70e70 CL |
168 | } |
169 | ||
170 | return 0; | |
171 | } | |
172 | ||
9c1b4d77 CL |
173 | /* Post a FAST_REG Work Request to register a memory region |
174 | * for remote access via RDMA READ or RDMA WRITE. | |
175 | */ | |
176 | static int | |
177 | frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg, | |
178 | int nsegs, bool writing) | |
179 | { | |
180 | struct rpcrdma_ia *ia = &r_xprt->rx_ia; | |
d654788e CL |
181 | struct ib_device *device = ia->ri_id->device; |
182 | enum dma_data_direction direction = rpcrdma_data_dir(writing); | |
9c1b4d77 CL |
183 | struct rpcrdma_mr_seg *seg1 = seg; |
184 | struct rpcrdma_mw *mw = seg1->rl_mw; | |
185 | struct rpcrdma_frmr *frmr = &mw->r.frmr; | |
186 | struct ib_mr *mr = frmr->fr_mr; | |
187 | struct ib_send_wr fastreg_wr, *bad_wr; | |
188 | u8 key; | |
189 | int len, pageoff; | |
190 | int i, rc; | |
191 | int seg_len; | |
192 | u64 pa; | |
193 | int page_no; | |
194 | ||
195 | pageoff = offset_in_page(seg1->mr_offset); | |
196 | seg1->mr_offset -= pageoff; /* start of page */ | |
197 | seg1->mr_len += pageoff; | |
198 | len = -pageoff; | |
199 | if (nsegs > ia->ri_max_frmr_depth) | |
200 | nsegs = ia->ri_max_frmr_depth; | |
201 | for (page_no = i = 0; i < nsegs;) { | |
d654788e | 202 | rpcrdma_map_one(device, seg, direction); |
9c1b4d77 CL |
203 | pa = seg->mr_dma; |
204 | for (seg_len = seg->mr_len; seg_len > 0; seg_len -= PAGE_SIZE) { | |
205 | frmr->fr_pgl->page_list[page_no++] = pa; | |
206 | pa += PAGE_SIZE; | |
207 | } | |
208 | len += seg->mr_len; | |
209 | ++seg; | |
210 | ++i; | |
211 | /* Check for holes */ | |
212 | if ((i < nsegs && offset_in_page(seg->mr_offset)) || | |
213 | offset_in_page((seg-1)->mr_offset + (seg-1)->mr_len)) | |
214 | break; | |
215 | } | |
216 | dprintk("RPC: %s: Using frmr %p to map %d segments (%d bytes)\n", | |
217 | __func__, mw, i, len); | |
218 | ||
219 | frmr->fr_state = FRMR_IS_VALID; | |
220 | ||
221 | memset(&fastreg_wr, 0, sizeof(fastreg_wr)); | |
222 | fastreg_wr.wr_id = (unsigned long)(void *)mw; | |
223 | fastreg_wr.opcode = IB_WR_FAST_REG_MR; | |
224 | fastreg_wr.wr.fast_reg.iova_start = seg1->mr_dma + pageoff; | |
225 | fastreg_wr.wr.fast_reg.page_list = frmr->fr_pgl; | |
226 | fastreg_wr.wr.fast_reg.page_shift = PAGE_SHIFT; | |
227 | fastreg_wr.wr.fast_reg.page_list_len = page_no; | |
228 | fastreg_wr.wr.fast_reg.length = len; | |
229 | fastreg_wr.wr.fast_reg.access_flags = writing ? | |
230 | IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE : | |
231 | IB_ACCESS_REMOTE_READ; | |
232 | key = (u8)(mr->rkey & 0x000000FF); | |
233 | ib_update_fast_reg_key(mr, ++key); | |
234 | fastreg_wr.wr.fast_reg.rkey = mr->rkey; | |
235 | ||
236 | DECR_CQCOUNT(&r_xprt->rx_ep); | |
237 | rc = ib_post_send(ia->ri_id->qp, &fastreg_wr, &bad_wr); | |
238 | if (rc) | |
239 | goto out_senderr; | |
240 | ||
241 | seg1->mr_rkey = mr->rkey; | |
242 | seg1->mr_base = seg1->mr_dma + pageoff; | |
243 | seg1->mr_nsegs = i; | |
244 | seg1->mr_len = len; | |
245 | return i; | |
246 | ||
247 | out_senderr: | |
248 | dprintk("RPC: %s: ib_post_send status %i\n", __func__, rc); | |
249 | ib_update_fast_reg_key(mr, --key); | |
250 | frmr->fr_state = FRMR_IS_INVALID; | |
251 | while (i--) | |
d654788e | 252 | rpcrdma_unmap_one(device, --seg); |
9c1b4d77 CL |
253 | return rc; |
254 | } | |
255 | ||
6814baea CL |
256 | /* Post a LOCAL_INV Work Request to prevent further remote access |
257 | * via RDMA READ or RDMA WRITE. | |
258 | */ | |
259 | static int | |
260 | frwr_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg) | |
261 | { | |
262 | struct rpcrdma_mr_seg *seg1 = seg; | |
263 | struct rpcrdma_ia *ia = &r_xprt->rx_ia; | |
264 | struct ib_send_wr invalidate_wr, *bad_wr; | |
265 | int rc, nsegs = seg->mr_nsegs; | |
d654788e | 266 | struct ib_device *device; |
6814baea CL |
267 | |
268 | seg1->rl_mw->r.frmr.fr_state = FRMR_IS_INVALID; | |
269 | ||
270 | memset(&invalidate_wr, 0, sizeof(invalidate_wr)); | |
271 | invalidate_wr.wr_id = (unsigned long)(void *)seg1->rl_mw; | |
272 | invalidate_wr.opcode = IB_WR_LOCAL_INV; | |
273 | invalidate_wr.ex.invalidate_rkey = seg1->rl_mw->r.frmr.fr_mr->rkey; | |
274 | DECR_CQCOUNT(&r_xprt->rx_ep); | |
275 | ||
276 | read_lock(&ia->ri_qplock); | |
d654788e | 277 | device = ia->ri_id->device; |
6814baea | 278 | while (seg1->mr_nsegs--) |
d654788e | 279 | rpcrdma_unmap_one(device, seg++); |
6814baea CL |
280 | rc = ib_post_send(ia->ri_id->qp, &invalidate_wr, &bad_wr); |
281 | read_unlock(&ia->ri_qplock); | |
282 | if (rc) | |
283 | goto out_err; | |
284 | return nsegs; | |
285 | ||
286 | out_err: | |
287 | /* Force rpcrdma_buffer_get() to retry */ | |
288 | seg1->rl_mw->r.frmr.fr_state = FRMR_IS_STALE; | |
289 | dprintk("RPC: %s: ib_post_send status %i\n", __func__, rc); | |
290 | return nsegs; | |
291 | } | |
292 | ||
31a701a9 CL |
293 | /* After a disconnect, a flushed FAST_REG_MR can leave an FRMR in |
294 | * an unusable state. Find FRMRs in this state and dereg / reg | |
295 | * each. FRMRs that are VALID and attached to an rpcrdma_req are | |
296 | * also torn down. | |
297 | * | |
298 | * This gives all in-use FRMRs a fresh rkey and leaves them INVALID. | |
299 | * | |
300 | * This is invoked only in the transport connect worker in order | |
301 | * to serialize with rpcrdma_register_frmr_external(). | |
302 | */ | |
303 | static void | |
304 | frwr_op_reset(struct rpcrdma_xprt *r_xprt) | |
305 | { | |
306 | struct rpcrdma_buffer *buf = &r_xprt->rx_buf; | |
307 | struct ib_device *device = r_xprt->rx_ia.ri_id->device; | |
308 | unsigned int depth = r_xprt->rx_ia.ri_max_frmr_depth; | |
309 | struct ib_pd *pd = r_xprt->rx_ia.ri_pd; | |
310 | struct rpcrdma_mw *r; | |
311 | int rc; | |
312 | ||
313 | list_for_each_entry(r, &buf->rb_all, mw_all) { | |
314 | if (r->r.frmr.fr_state == FRMR_IS_INVALID) | |
315 | continue; | |
316 | ||
317 | __frwr_release(r); | |
318 | rc = __frwr_init(r, pd, device, depth); | |
319 | if (rc) { | |
320 | dprintk("RPC: %s: mw %p left %s\n", | |
321 | __func__, r, | |
322 | (r->r.frmr.fr_state == FRMR_IS_STALE ? | |
323 | "stale" : "valid")); | |
324 | continue; | |
325 | } | |
326 | ||
327 | r->r.frmr.fr_state = FRMR_IS_INVALID; | |
328 | } | |
329 | } | |
330 | ||
4561f347 CL |
331 | static void |
332 | frwr_op_destroy(struct rpcrdma_buffer *buf) | |
333 | { | |
334 | struct rpcrdma_mw *r; | |
335 | ||
336 | while (!list_empty(&buf->rb_all)) { | |
337 | r = list_entry(buf->rb_all.next, struct rpcrdma_mw, mw_all); | |
338 | list_del(&r->mw_all); | |
339 | __frwr_release(r); | |
340 | kfree(r); | |
341 | } | |
342 | } | |
343 | ||
a0ce85f5 | 344 | const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops = { |
9c1b4d77 | 345 | .ro_map = frwr_op_map, |
6814baea | 346 | .ro_unmap = frwr_op_unmap, |
3968cb58 | 347 | .ro_open = frwr_op_open, |
1c9351ee | 348 | .ro_maxpages = frwr_op_maxpages, |
91e70e70 | 349 | .ro_init = frwr_op_init, |
31a701a9 | 350 | .ro_reset = frwr_op_reset, |
4561f347 | 351 | .ro_destroy = frwr_op_destroy, |
a0ce85f5 CL |
352 | .ro_displayname = "frwr", |
353 | }; |