1 /*
2 * Copyright (c) 2016 Oracle. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 */
32
33 #include "ib_mr.h"
34
35 static inline void
36 rds_transition_frwr_state(struct rds_ib_mr *ibmr,
37 enum rds_ib_fr_state old_state,
38 enum rds_ib_fr_state new_state)
39 {
40 if (cmpxchg(&ibmr->u.frmr.fr_state,
41 old_state, new_state) == old_state &&
42 old_state == FRMR_IS_INUSE) {
43 /* enforce order of ibmr->u.frmr.fr_state update
44 * before decrementing i_fastreg_inuse_count
45 */
46 smp_mb__before_atomic();
47 atomic_dec(&ibmr->ic->i_fastreg_inuse_count);
48 if (waitqueue_active(&rds_ib_ring_empty_wait))
49 wake_up(&rds_ib_ring_empty_wait);
50 }
51 }
52
53 static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev,
54 int npages)
55 {
56 struct rds_ib_mr_pool *pool;
57 struct rds_ib_mr *ibmr = NULL;
58 struct rds_ib_frmr *frmr;
59 int err = 0;
60
61 if (npages <= RDS_MR_8K_MSG_SIZE)
62 pool = rds_ibdev->mr_8k_pool;
63 else
64 pool = rds_ibdev->mr_1m_pool;
65
66 ibmr = rds_ib_try_reuse_ibmr(pool);
67 if (ibmr)
68 return ibmr;
69
70 ibmr = kzalloc_node(sizeof(*ibmr), GFP_KERNEL,
71 rdsibdev_to_node(rds_ibdev));
72 if (!ibmr) {
73 err = -ENOMEM;
74 goto out_no_cigar;
75 }
76
77 frmr = &ibmr->u.frmr;
78 frmr->mr = ib_alloc_mr(rds_ibdev->pd, IB_MR_TYPE_MEM_REG,
79 pool->max_pages);
80 if (IS_ERR(frmr->mr)) {
81 pr_warn("RDS/IB: %s failed to allocate MR", __func__);
82 err = PTR_ERR(frmr->mr);
83 goto out_no_cigar;
84 }
85
86 ibmr->pool = pool;
87 if (pool->pool_type == RDS_IB_MR_8K_POOL)
88 rds_ib_stats_inc(s_ib_rdma_mr_8k_alloc);
89 else
90 rds_ib_stats_inc(s_ib_rdma_mr_1m_alloc);
91
92 if (atomic_read(&pool->item_count) > pool->max_items_soft)
93 pool->max_items_soft = pool->max_items;
94
95 frmr->fr_state = FRMR_IS_FREE;
96 init_waitqueue_head(&frmr->fr_inv_done);
97 init_waitqueue_head(&frmr->fr_reg_done);
98 return ibmr;
99
100 out_no_cigar:
101 kfree(ibmr);
102 atomic_dec(&pool->item_count);
103 return ERR_PTR(err);
104 }
105
106 static void rds_ib_free_frmr(struct rds_ib_mr *ibmr, bool drop)
107 {
108 struct rds_ib_mr_pool *pool = ibmr->pool;
109
110 if (drop)
111 llist_add(&ibmr->llnode, &pool->drop_list);
112 else
113 llist_add(&ibmr->llnode, &pool->free_list);
114 atomic_add(ibmr->sg_len, &pool->free_pinned);
115 atomic_inc(&pool->dirty_count);
116
117 /* If we've pinned too many pages, request a flush */
118 if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
119 atomic_read(&pool->dirty_count) >= pool->max_items / 5)
120 queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);
121 }
122
123 static int rds_ib_post_reg_frmr(struct rds_ib_mr *ibmr)
124 {
125 struct rds_ib_frmr *frmr = &ibmr->u.frmr;
126 struct ib_reg_wr reg_wr;
127 int ret, off = 0;
128
129 while (atomic_dec_return(&ibmr->ic->i_fastreg_wrs) <= 0) {
130 atomic_inc(&ibmr->ic->i_fastreg_wrs);
131 cpu_relax();
132 }
133
134 ret = ib_map_mr_sg_zbva(frmr->mr, ibmr->sg, ibmr->sg_dma_len,
135 &off, PAGE_SIZE);
136 if (unlikely(ret != ibmr->sg_dma_len))
137 return ret < 0 ? ret : -EINVAL;
138
139 if (cmpxchg(&frmr->fr_state,
140 FRMR_IS_FREE, FRMR_IS_INUSE) != FRMR_IS_FREE)
141 return -EBUSY;
142
143 atomic_inc(&ibmr->ic->i_fastreg_inuse_count);
144
145 /* Perform a WR for the fast_reg_mr. Each individual page
146 * in the sg list is added to the fast reg page list and placed
147 * inside the fast_reg_mr WR. The key used is a rolling 8bit
148 * counter, which should guarantee uniqueness.
149 */
150 ib_update_fast_reg_key(frmr->mr, ibmr->remap_count++);
151 frmr->fr_reg = true;
152
153 memset(®_wr, 0, sizeof(reg_wr));
154 reg_wr.wr.wr_id = (unsigned long)(void *)ibmr;
155 reg_wr.wr.opcode = IB_WR_REG_MR;
156 reg_wr.wr.num_sge = 0;
157 reg_wr.mr = frmr->mr;
158 reg_wr.key = frmr->mr->rkey;
159 reg_wr.access = IB_ACCESS_LOCAL_WRITE |
160 IB_ACCESS_REMOTE_READ |
161 IB_ACCESS_REMOTE_WRITE;
162 reg_wr.wr.send_flags = IB_SEND_SIGNALED;
163
164 ret = ib_post_send(ibmr->ic->i_cm_id->qp, ®_wr.wr, NULL);
165 if (unlikely(ret)) {
166 /* Failure here can be because of -ENOMEM as well */
167 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
168
169 atomic_inc(&ibmr->ic->i_fastreg_wrs);
170 if (printk_ratelimit())
171 pr_warn("RDS/IB: %s returned error(%d)\n",
172 __func__, ret);
173 goto out;
174 }
175
176 /* Wait for the registration to complete in order to prevent an invalid
177 * access error resulting from a race between the memory region already
178 * being accessed while registration is still pending.
179 */
180 wait_event(frmr->fr_reg_done, !frmr->fr_reg);
181
182 out:
183
184 return ret;
185 }
186
187 static int rds_ib_map_frmr(struct rds_ib_device *rds_ibdev,
188 struct rds_ib_mr_pool *pool,
189 struct rds_ib_mr *ibmr,
190 struct scatterlist *sg, unsigned int sg_len)
191 {
192 struct ib_device *dev = rds_ibdev->dev;
193 struct rds_ib_frmr *frmr = &ibmr->u.frmr;
194 int i;
195 u32 len;
196 int ret = 0;
197
198 /* We want to teardown old ibmr values here and fill it up with
199 * new sg values
200 */
201 rds_ib_teardown_mr(ibmr);
202
203 ibmr->sg = sg;
204 ibmr->sg_len = sg_len;
205 ibmr->sg_dma_len = 0;
206 frmr->sg_byte_len = 0;
207 WARN_ON(ibmr->sg_dma_len);
208 ibmr->sg_dma_len = ib_dma_map_sg(dev, ibmr->sg, ibmr->sg_len,
209 DMA_BIDIRECTIONAL);
210 if (unlikely(!ibmr->sg_dma_len)) {
211 pr_warn("RDS/IB: %s failed!\n", __func__);
212 return -EBUSY;
213 }
214
215 frmr->sg_byte_len = 0;
216 frmr->dma_npages = 0;
217 len = 0;
218
219 ret = -EINVAL;
220 for (i = 0; i < ibmr->sg_dma_len; ++i) {
221 unsigned int dma_len = sg_dma_len(&ibmr->sg[i]);
222 u64 dma_addr = sg_dma_address(&ibmr->sg[i]);
223
224 frmr->sg_byte_len += dma_len;
225 if (dma_addr & ~PAGE_MASK) {
226 if (i > 0)
227 goto out_unmap;
228 else
229 ++frmr->dma_npages;
230 }
231
232 if ((dma_addr + dma_len) & ~PAGE_MASK) {
233 if (i < ibmr->sg_dma_len - 1)
234 goto out_unmap;
235 else
236 ++frmr->dma_npages;
237 }
238
239 len += dma_len;
240 }
241 frmr->dma_npages += len >> PAGE_SHIFT;
242
243 if (frmr->dma_npages > ibmr->pool->max_pages) {
244 ret = -EMSGSIZE;
245 goto out_unmap;
246 }
247
248 ret = rds_ib_post_reg_frmr(ibmr);
249 if (ret)
250 goto out_unmap;
251
252 if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
253 rds_ib_stats_inc(s_ib_rdma_mr_8k_used);
254 else
255 rds_ib_stats_inc(s_ib_rdma_mr_1m_used);
256
257 return ret;
258
259 out_unmap:
260 ib_dma_unmap_sg(rds_ibdev->dev, ibmr->sg, ibmr->sg_len,
261 DMA_BIDIRECTIONAL);
262 ibmr->sg_dma_len = 0;
263 return ret;
264 }
265
266 static int rds_ib_post_inv(struct rds_ib_mr *ibmr)
267 {
268 struct ib_send_wr *s_wr;
269 struct rds_ib_frmr *frmr = &ibmr->u.frmr;
270 struct rdma_cm_id *i_cm_id = ibmr->ic->i_cm_id;
271 int ret = -EINVAL;
272
273 if (!i_cm_id || !i_cm_id->qp || !frmr->mr)
274 goto out;
275
276 if (frmr->fr_state != FRMR_IS_INUSE)
277 goto out;
278
279 while (atomic_dec_return(&ibmr->ic->i_fastreg_wrs) <= 0) {
280 atomic_inc(&ibmr->ic->i_fastreg_wrs);
281 cpu_relax();
282 }
283
284 frmr->fr_inv = true;
285 s_wr = &frmr->fr_wr;
286
287 memset(s_wr, 0, sizeof(*s_wr));
288 s_wr->wr_id = (unsigned long)(void *)ibmr;
289 s_wr->opcode = IB_WR_LOCAL_INV;
290 s_wr->ex.invalidate_rkey = frmr->mr->rkey;
291 s_wr->send_flags = IB_SEND_SIGNALED;
292
293 ret = ib_post_send(i_cm_id->qp, s_wr, NULL);
294 if (unlikely(ret)) {
295 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
296 frmr->fr_inv = false;
297 /* enforce order of frmr->fr_inv update
298 * before incrementing i_fastreg_wrs
299 */
300 smp_mb__before_atomic();
301 atomic_inc(&ibmr->ic->i_fastreg_wrs);
302 pr_err("RDS/IB: %s returned error(%d)\n", __func__, ret);
303 goto out;
304 }
305
306 /* Wait for the FRMR_IS_FREE (or FRMR_IS_STALE) transition in order to
307 * 1) avoid a silly bouncing between "clean_list" and "drop_list"
308 * triggered by function "rds_ib_reg_frmr" as it is releases frmr
309 * regions whose state is not "FRMR_IS_FREE" right away.
310 * 2) prevents an invalid access error in a race
311 * from a pending "IB_WR_LOCAL_INV" operation
312 * with a teardown ("dma_unmap_sg", "put_page")
313 * and de-registration ("ib_dereg_mr") of the corresponding
314 * memory region.
315 */
316 wait_event(frmr->fr_inv_done, frmr->fr_state != FRMR_IS_INUSE);
317
318 out:
319 return ret;
320 }
321
322 void rds_ib_mr_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc)
323 {
324 struct rds_ib_mr *ibmr = (void *)(unsigned long)wc->wr_id;
325 struct rds_ib_frmr *frmr = &ibmr->u.frmr;
326
327 if (wc->status != IB_WC_SUCCESS) {
328 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
329 if (rds_conn_up(ic->conn))
330 rds_ib_conn_error(ic->conn,
331 "frmr completion <%pI4,%pI4> status %u(%s), vendor_err 0x%x, disconnecting and reconnecting\n",
332 &ic->conn->c_laddr,
333 &ic->conn->c_faddr,
334 wc->status,
335 ib_wc_status_msg(wc->status),
336 wc->vendor_err);
337 }
338
339 if (frmr->fr_inv) {
340 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_FREE);
341 frmr->fr_inv = false;
342 wake_up(&frmr->fr_inv_done);
343 }
344
345 if (frmr->fr_reg) {
346 frmr->fr_reg = false;
347 wake_up(&frmr->fr_reg_done);
348 }
349
350 /* enforce order of frmr->{fr_reg,fr_inv} update
351 * before incrementing i_fastreg_wrs
352 */
353 smp_mb__before_atomic();
354 atomic_inc(&ic->i_fastreg_wrs);
355 }
356
357 void rds_ib_unreg_frmr(struct list_head *list, unsigned int *nfreed,
358 unsigned long *unpinned, unsigned int goal)
359 {
360 struct rds_ib_mr *ibmr, *next;
361 struct rds_ib_frmr *frmr;
362 int ret = 0, ret2;
363 unsigned int freed = *nfreed;
364
365 /* String all ib_mr's onto one list and hand them to ib_unmap_fmr */
366 list_for_each_entry(ibmr, list, unmap_list) {
367 if (ibmr->sg_dma_len) {
368 ret2 = rds_ib_post_inv(ibmr);
369 if (ret2 && !ret)
370 ret = ret2;
371 }
372 }
373
374 if (ret)
375 pr_warn("RDS/IB: %s failed (err=%d)\n", __func__, ret);
376
377 /* Now we can destroy the DMA mapping and unpin any pages */
378 list_for_each_entry_safe(ibmr, next, list, unmap_list) {
379 *unpinned += ibmr->sg_len;
380 frmr = &ibmr->u.frmr;
381 __rds_ib_teardown_mr(ibmr);
382 if (freed < goal || frmr->fr_state == FRMR_IS_STALE) {
383 /* Don't de-allocate if the MR is not free yet */
384 if (frmr->fr_state == FRMR_IS_INUSE)
385 continue;
386
387 if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
388 rds_ib_stats_inc(s_ib_rdma_mr_8k_free);
389 else
390 rds_ib_stats_inc(s_ib_rdma_mr_1m_free);
391 list_del(&ibmr->unmap_list);
392 if (frmr->mr)
393 ib_dereg_mr(frmr->mr);
394 kfree(ibmr);
395 freed++;
396 }
397 }
398 *nfreed = freed;
399 }
400
401 struct rds_ib_mr *rds_ib_reg_frmr(struct rds_ib_device *rds_ibdev,
402 struct rds_ib_connection *ic,
403 struct scatterlist *sg,
404 unsigned long nents, u32 *key)
405 {
406 struct rds_ib_mr *ibmr = NULL;
407 struct rds_ib_frmr *frmr;
408 int ret;
409
410 if (!ic) {
411 /* TODO: Add FRWR support for RDS_GET_MR using proxy qp*/
412 return ERR_PTR(-EOPNOTSUPP);
413 }
414
415 do {
416 if (ibmr)
417 rds_ib_free_frmr(ibmr, true);
418 ibmr = rds_ib_alloc_frmr(rds_ibdev, nents);
419 if (IS_ERR(ibmr))
420 return ibmr;
421 frmr = &ibmr->u.frmr;
422 } while (frmr->fr_state != FRMR_IS_FREE);
423
424 ibmr->ic = ic;
425 ibmr->device = rds_ibdev;
426 ret = rds_ib_map_frmr(rds_ibdev, ibmr->pool, ibmr, sg, nents);
427 if (ret == 0) {
428 *key = frmr->mr->rkey;
429 } else {
430 rds_ib_free_frmr(ibmr, false);
431 ibmr = ERR_PTR(ret);
432 }
433
434 return ibmr;
435 }
436
437 void rds_ib_free_frmr_list(struct rds_ib_mr *ibmr)
438 {
439 struct rds_ib_mr_pool *pool = ibmr->pool;
440 struct rds_ib_frmr *frmr = &ibmr->u.frmr;
441
442 if (frmr->fr_state == FRMR_IS_STALE)
443 llist_add(&ibmr->llnode, &pool->drop_list);
444 else
445 llist_add(&ibmr->llnode, &pool->free_list);
446 }
447
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