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
rds_transition_frwr_state(struct rds_ib_mr * ibmr,enum rds_ib_fr_state old_state,enum rds_ib_fr_state new_state)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
rds_ib_alloc_frmr(struct rds_ib_device * rds_ibdev,int npages)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
rds_ib_free_frmr(struct rds_ib_mr * ibmr,bool drop)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
rds_ib_post_reg_frmr(struct rds_ib_mr * ibmr)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 ret = ret < 0 ? ret : -EINVAL;
138 goto out_inc;
139 }
140
141 if (cmpxchg(&frmr->fr_state, FRMR_IS_FREE, FRMR_IS_INUSE) != FRMR_IS_FREE) {
142 ret = -EBUSY;
143 goto out_inc;
144 }
145
146 atomic_inc(&ibmr->ic->i_fastreg_inuse_count);
147
148 /* Perform a WR for the fast_reg_mr. Each individual page
149 * in the sg list is added to the fast reg page list and placed
150 * inside the fast_reg_mr WR. The key used is a rolling 8bit
151 * counter, which should guarantee uniqueness.
152 */
153 ib_update_fast_reg_key(frmr->mr, ibmr->remap_count++);
154 frmr->fr_reg = true;
155
156 memset(®_wr, 0, sizeof(reg_wr));
157 reg_wr.wr.wr_id = (unsigned long)(void *)ibmr;
158 reg_wr.wr.opcode = IB_WR_REG_MR;
159 reg_wr.wr.num_sge = 0;
160 reg_wr.mr = frmr->mr;
161 reg_wr.key = frmr->mr->rkey;
162 reg_wr.access = IB_ACCESS_LOCAL_WRITE |
163 IB_ACCESS_REMOTE_READ |
164 IB_ACCESS_REMOTE_WRITE;
165 reg_wr.wr.send_flags = IB_SEND_SIGNALED;
166
167 ret = ib_post_send(ibmr->ic->i_cm_id->qp, ®_wr.wr, NULL);
168 if (unlikely(ret)) {
169 /* Failure here can be because of -ENOMEM as well */
170 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
171
172 if (printk_ratelimit())
173 pr_warn("RDS/IB: %s returned error(%d)\n",
174 __func__, ret);
175 goto out_inc;
176 }
177
178 /* Wait for the registration to complete in order to prevent an invalid
179 * access error resulting from a race between the memory region already
180 * being accessed while registration is still pending.
181 */
182 wait_event(frmr->fr_reg_done, !frmr->fr_reg);
183
184 return ret;
185
186 out_inc:
187 atomic_inc(&ibmr->ic->i_fastreg_wrs);
188 return ret;
189 }
190
rds_ib_map_frmr(struct rds_ib_device * rds_ibdev,struct rds_ib_mr_pool * pool,struct rds_ib_mr * ibmr,struct scatterlist * sg,unsigned int sg_len)191 static int rds_ib_map_frmr(struct rds_ib_device *rds_ibdev,
192 struct rds_ib_mr_pool *pool,
193 struct rds_ib_mr *ibmr,
194 struct scatterlist *sg, unsigned int sg_len)
195 {
196 struct ib_device *dev = rds_ibdev->dev;
197 struct rds_ib_frmr *frmr = &ibmr->u.frmr;
198 int i;
199 u32 len;
200 int ret = 0;
201
202 /* We want to teardown old ibmr values here and fill it up with
203 * new sg values
204 */
205 rds_ib_teardown_mr(ibmr);
206
207 frmr->sg_byte_len = 0;
208 ibmr->sg_dma_len = ib_dma_map_sg(dev, sg, 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 ibmr->sg = sg;
216 ibmr->sg_len = sg_len;
217 frmr->dma_npages = 0;
218 len = 0;
219
220 ret = -EINVAL;
221 for (i = 0; i < ibmr->sg_dma_len; ++i) {
222 unsigned int dma_len = sg_dma_len(&ibmr->sg[i]);
223 u64 dma_addr = sg_dma_address(&ibmr->sg[i]);
224
225 frmr->sg_byte_len += dma_len;
226 if (dma_addr & ~PAGE_MASK) {
227 if (i > 0)
228 goto out_unmap;
229 else
230 ++frmr->dma_npages;
231 }
232
233 if ((dma_addr + dma_len) & ~PAGE_MASK) {
234 if (i < ibmr->sg_dma_len - 1)
235 goto out_unmap;
236 else
237 ++frmr->dma_npages;
238 }
239
240 len += dma_len;
241 }
242 frmr->dma_npages += len >> PAGE_SHIFT;
243
244 if (frmr->dma_npages > ibmr->pool->max_pages) {
245 ret = -EMSGSIZE;
246 goto out_unmap;
247 }
248
249 ret = rds_ib_post_reg_frmr(ibmr);
250 if (ret)
251 goto out_unmap;
252
253 if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
254 rds_ib_stats_inc(s_ib_rdma_mr_8k_used);
255 else
256 rds_ib_stats_inc(s_ib_rdma_mr_1m_used);
257
258 return ret;
259
260 out_unmap:
261 ib_dma_unmap_sg(rds_ibdev->dev, ibmr->sg, ibmr->sg_len,
262 DMA_BIDIRECTIONAL);
263 ibmr->sg_dma_len = 0;
264 ibmr->sg = NULL;
265 ibmr->sg_len = 0;
266 return ret;
267 }
268
rds_ib_post_inv(struct rds_ib_mr * ibmr)269 static int rds_ib_post_inv(struct rds_ib_mr *ibmr)
270 {
271 struct ib_send_wr *s_wr;
272 struct rds_ib_frmr *frmr = &ibmr->u.frmr;
273 struct rdma_cm_id *i_cm_id = ibmr->ic->i_cm_id;
274 int ret = -EINVAL;
275
276 if (!i_cm_id || !i_cm_id->qp || !frmr->mr)
277 goto out;
278
279 if (frmr->fr_state != FRMR_IS_INUSE)
280 goto out;
281
282 while (atomic_dec_return(&ibmr->ic->i_fastreg_wrs) <= 0) {
283 atomic_inc(&ibmr->ic->i_fastreg_wrs);
284 cpu_relax();
285 }
286
287 frmr->fr_inv = true;
288 s_wr = &frmr->fr_wr;
289
290 memset(s_wr, 0, sizeof(*s_wr));
291 s_wr->wr_id = (unsigned long)(void *)ibmr;
292 s_wr->opcode = IB_WR_LOCAL_INV;
293 s_wr->ex.invalidate_rkey = frmr->mr->rkey;
294 s_wr->send_flags = IB_SEND_SIGNALED;
295
296 ret = ib_post_send(i_cm_id->qp, s_wr, NULL);
297 if (unlikely(ret)) {
298 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
299 frmr->fr_inv = false;
300 /* enforce order of frmr->fr_inv update
301 * before incrementing i_fastreg_wrs
302 */
303 smp_mb__before_atomic();
304 atomic_inc(&ibmr->ic->i_fastreg_wrs);
305 pr_err("RDS/IB: %s returned error(%d)\n", __func__, ret);
306 goto out;
307 }
308
309 /* Wait for the FRMR_IS_FREE (or FRMR_IS_STALE) transition in order to
310 * 1) avoid a silly bouncing between "clean_list" and "drop_list"
311 * triggered by function "rds_ib_reg_frmr" as it is releases frmr
312 * regions whose state is not "FRMR_IS_FREE" right away.
313 * 2) prevents an invalid access error in a race
314 * from a pending "IB_WR_LOCAL_INV" operation
315 * with a teardown ("dma_unmap_sg", "put_page")
316 * and de-registration ("ib_dereg_mr") of the corresponding
317 * memory region.
318 */
319 wait_event(frmr->fr_inv_done, frmr->fr_state != FRMR_IS_INUSE);
320
321 out:
322 return ret;
323 }
324
rds_ib_mr_cqe_handler(struct rds_ib_connection * ic,struct ib_wc * wc)325 void rds_ib_mr_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc)
326 {
327 struct rds_ib_mr *ibmr = (void *)(unsigned long)wc->wr_id;
328 struct rds_ib_frmr *frmr = &ibmr->u.frmr;
329
330 if (wc->status != IB_WC_SUCCESS) {
331 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
332 if (rds_conn_up(ic->conn))
333 rds_ib_conn_error(ic->conn,
334 "frmr completion <%pI4,%pI4> status %u(%s), vendor_err 0x%x, disconnecting and reconnecting\n",
335 &ic->conn->c_laddr,
336 &ic->conn->c_faddr,
337 wc->status,
338 ib_wc_status_msg(wc->status),
339 wc->vendor_err);
340 }
341
342 if (frmr->fr_inv) {
343 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_FREE);
344 frmr->fr_inv = false;
345 wake_up(&frmr->fr_inv_done);
346 }
347
348 if (frmr->fr_reg) {
349 frmr->fr_reg = false;
350 wake_up(&frmr->fr_reg_done);
351 }
352
353 /* enforce order of frmr->{fr_reg,fr_inv} update
354 * before incrementing i_fastreg_wrs
355 */
356 smp_mb__before_atomic();
357 atomic_inc(&ic->i_fastreg_wrs);
358 }
359
rds_ib_unreg_frmr(struct list_head * list,unsigned int * nfreed,unsigned long * unpinned,unsigned int goal)360 void rds_ib_unreg_frmr(struct list_head *list, unsigned int *nfreed,
361 unsigned long *unpinned, unsigned int goal)
362 {
363 struct rds_ib_mr *ibmr, *next;
364 struct rds_ib_frmr *frmr;
365 int ret = 0, ret2;
366 unsigned int freed = *nfreed;
367
368 /* String all ib_mr's onto one list and hand them to ib_unmap_fmr */
369 list_for_each_entry(ibmr, list, unmap_list) {
370 if (ibmr->sg_dma_len) {
371 ret2 = rds_ib_post_inv(ibmr);
372 if (ret2 && !ret)
373 ret = ret2;
374 }
375 }
376
377 if (ret)
378 pr_warn("RDS/IB: %s failed (err=%d)\n", __func__, ret);
379
380 /* Now we can destroy the DMA mapping and unpin any pages */
381 list_for_each_entry_safe(ibmr, next, list, unmap_list) {
382 *unpinned += ibmr->sg_len;
383 frmr = &ibmr->u.frmr;
384 __rds_ib_teardown_mr(ibmr);
385 if (freed < goal || frmr->fr_state == FRMR_IS_STALE) {
386 /* Don't de-allocate if the MR is not free yet */
387 if (frmr->fr_state == FRMR_IS_INUSE)
388 continue;
389
390 if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
391 rds_ib_stats_inc(s_ib_rdma_mr_8k_free);
392 else
393 rds_ib_stats_inc(s_ib_rdma_mr_1m_free);
394 list_del(&ibmr->unmap_list);
395 if (frmr->mr)
396 ib_dereg_mr(frmr->mr);
397 kfree(ibmr);
398 freed++;
399 }
400 }
401 *nfreed = freed;
402 }
403
rds_ib_reg_frmr(struct rds_ib_device * rds_ibdev,struct rds_ib_connection * ic,struct scatterlist * sg,unsigned long nents,u32 * key)404 struct rds_ib_mr *rds_ib_reg_frmr(struct rds_ib_device *rds_ibdev,
405 struct rds_ib_connection *ic,
406 struct scatterlist *sg,
407 unsigned long nents, u32 *key)
408 {
409 struct rds_ib_mr *ibmr = NULL;
410 struct rds_ib_frmr *frmr;
411 int ret;
412
413 if (!ic) {
414 /* TODO: Add FRWR support for RDS_GET_MR using proxy qp*/
415 return ERR_PTR(-EOPNOTSUPP);
416 }
417
418 do {
419 if (ibmr)
420 rds_ib_free_frmr(ibmr, true);
421 ibmr = rds_ib_alloc_frmr(rds_ibdev, nents);
422 if (IS_ERR(ibmr))
423 return ibmr;
424 frmr = &ibmr->u.frmr;
425 } while (frmr->fr_state != FRMR_IS_FREE);
426
427 ibmr->ic = ic;
428 ibmr->device = rds_ibdev;
429 ret = rds_ib_map_frmr(rds_ibdev, ibmr->pool, ibmr, sg, nents);
430 if (ret == 0) {
431 *key = frmr->mr->rkey;
432 } else {
433 rds_ib_free_frmr(ibmr, false);
434 ibmr = ERR_PTR(ret);
435 }
436
437 return ibmr;
438 }
439
rds_ib_free_frmr_list(struct rds_ib_mr * ibmr)440 void rds_ib_free_frmr_list(struct rds_ib_mr *ibmr)
441 {
442 struct rds_ib_mr_pool *pool = ibmr->pool;
443 struct rds_ib_frmr *frmr = &ibmr->u.frmr;
444
445 if (frmr->fr_state == FRMR_IS_STALE)
446 llist_add(&ibmr->llnode, &pool->drop_list);
447 else
448 llist_add(&ibmr->llnode, &pool->free_list);
449 }
450