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 ibmr->sg = sg;
208 ibmr->sg_len = sg_len;
209 ibmr->sg_dma_len = 0;
210 frmr->sg_byte_len = 0;
211 WARN_ON(ibmr->sg_dma_len);
212 ibmr->sg_dma_len = ib_dma_map_sg(dev, ibmr->sg, ibmr->sg_len,
213 DMA_BIDIRECTIONAL);
214 if (unlikely(!ibmr->sg_dma_len)) {
215 pr_warn("RDS/IB: %s failed!\n", __func__);
216 return -EBUSY;
217 }
218
219 frmr->sg_byte_len = 0;
220 frmr->dma_npages = 0;
221 len = 0;
222
223 ret = -EINVAL;
224 for (i = 0; i < ibmr->sg_dma_len; ++i) {
225 unsigned int dma_len = sg_dma_len(&ibmr->sg[i]);
226 u64 dma_addr = sg_dma_address(&ibmr->sg[i]);
227
228 frmr->sg_byte_len += dma_len;
229 if (dma_addr & ~PAGE_MASK) {
230 if (i > 0)
231 goto out_unmap;
232 else
233 ++frmr->dma_npages;
234 }
235
236 if ((dma_addr + dma_len) & ~PAGE_MASK) {
237 if (i < ibmr->sg_dma_len - 1)
238 goto out_unmap;
239 else
240 ++frmr->dma_npages;
241 }
242
243 len += dma_len;
244 }
245 frmr->dma_npages += len >> PAGE_SHIFT;
246
247 if (frmr->dma_npages > ibmr->pool->max_pages) {
248 ret = -EMSGSIZE;
249 goto out_unmap;
250 }
251
252 ret = rds_ib_post_reg_frmr(ibmr);
253 if (ret)
254 goto out_unmap;
255
256 if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
257 rds_ib_stats_inc(s_ib_rdma_mr_8k_used);
258 else
259 rds_ib_stats_inc(s_ib_rdma_mr_1m_used);
260
261 return ret;
262
263 out_unmap:
264 ib_dma_unmap_sg(rds_ibdev->dev, ibmr->sg, ibmr->sg_len,
265 DMA_BIDIRECTIONAL);
266 ibmr->sg_dma_len = 0;
267 return ret;
268 }
269
rds_ib_post_inv(struct rds_ib_mr * ibmr)270 static int rds_ib_post_inv(struct rds_ib_mr *ibmr)
271 {
272 struct ib_send_wr *s_wr;
273 struct rds_ib_frmr *frmr = &ibmr->u.frmr;
274 struct rdma_cm_id *i_cm_id = ibmr->ic->i_cm_id;
275 int ret = -EINVAL;
276
277 if (!i_cm_id || !i_cm_id->qp || !frmr->mr)
278 goto out;
279
280 if (frmr->fr_state != FRMR_IS_INUSE)
281 goto out;
282
283 while (atomic_dec_return(&ibmr->ic->i_fastreg_wrs) <= 0) {
284 atomic_inc(&ibmr->ic->i_fastreg_wrs);
285 cpu_relax();
286 }
287
288 frmr->fr_inv = true;
289 s_wr = &frmr->fr_wr;
290
291 memset(s_wr, 0, sizeof(*s_wr));
292 s_wr->wr_id = (unsigned long)(void *)ibmr;
293 s_wr->opcode = IB_WR_LOCAL_INV;
294 s_wr->ex.invalidate_rkey = frmr->mr->rkey;
295 s_wr->send_flags = IB_SEND_SIGNALED;
296
297 ret = ib_post_send(i_cm_id->qp, s_wr, NULL);
298 if (unlikely(ret)) {
299 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
300 frmr->fr_inv = false;
301 /* enforce order of frmr->fr_inv update
302 * before incrementing i_fastreg_wrs
303 */
304 smp_mb__before_atomic();
305 atomic_inc(&ibmr->ic->i_fastreg_wrs);
306 pr_err("RDS/IB: %s returned error(%d)\n", __func__, ret);
307 goto out;
308 }
309
310 /* Wait for the FRMR_IS_FREE (or FRMR_IS_STALE) transition in order to
311 * 1) avoid a silly bouncing between "clean_list" and "drop_list"
312 * triggered by function "rds_ib_reg_frmr" as it is releases frmr
313 * regions whose state is not "FRMR_IS_FREE" right away.
314 * 2) prevents an invalid access error in a race
315 * from a pending "IB_WR_LOCAL_INV" operation
316 * with a teardown ("dma_unmap_sg", "put_page")
317 * and de-registration ("ib_dereg_mr") of the corresponding
318 * memory region.
319 */
320 wait_event(frmr->fr_inv_done, frmr->fr_state != FRMR_IS_INUSE);
321
322 out:
323 return ret;
324 }
325
rds_ib_mr_cqe_handler(struct rds_ib_connection * ic,struct ib_wc * wc)326 void rds_ib_mr_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc)
327 {
328 struct rds_ib_mr *ibmr = (void *)(unsigned long)wc->wr_id;
329 struct rds_ib_frmr *frmr = &ibmr->u.frmr;
330
331 if (wc->status != IB_WC_SUCCESS) {
332 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE);
333 if (rds_conn_up(ic->conn))
334 rds_ib_conn_error(ic->conn,
335 "frmr completion <%pI4,%pI4> status %u(%s), vendor_err 0x%x, disconnecting and reconnecting\n",
336 &ic->conn->c_laddr,
337 &ic->conn->c_faddr,
338 wc->status,
339 ib_wc_status_msg(wc->status),
340 wc->vendor_err);
341 }
342
343 if (frmr->fr_inv) {
344 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_FREE);
345 frmr->fr_inv = false;
346 wake_up(&frmr->fr_inv_done);
347 }
348
349 if (frmr->fr_reg) {
350 frmr->fr_reg = false;
351 wake_up(&frmr->fr_reg_done);
352 }
353
354 /* enforce order of frmr->{fr_reg,fr_inv} update
355 * before incrementing i_fastreg_wrs
356 */
357 smp_mb__before_atomic();
358 atomic_inc(&ic->i_fastreg_wrs);
359 }
360
rds_ib_unreg_frmr(struct list_head * list,unsigned int * nfreed,unsigned long * unpinned,unsigned int goal)361 void rds_ib_unreg_frmr(struct list_head *list, unsigned int *nfreed,
362 unsigned long *unpinned, unsigned int goal)
363 {
364 struct rds_ib_mr *ibmr, *next;
365 struct rds_ib_frmr *frmr;
366 int ret = 0, ret2;
367 unsigned int freed = *nfreed;
368
369 /* String all ib_mr's onto one list and hand them to ib_unmap_fmr */
370 list_for_each_entry(ibmr, list, unmap_list) {
371 if (ibmr->sg_dma_len) {
372 ret2 = rds_ib_post_inv(ibmr);
373 if (ret2 && !ret)
374 ret = ret2;
375 }
376 }
377
378 if (ret)
379 pr_warn("RDS/IB: %s failed (err=%d)\n", __func__, ret);
380
381 /* Now we can destroy the DMA mapping and unpin any pages */
382 list_for_each_entry_safe(ibmr, next, list, unmap_list) {
383 *unpinned += ibmr->sg_len;
384 frmr = &ibmr->u.frmr;
385 __rds_ib_teardown_mr(ibmr);
386 if (freed < goal || frmr->fr_state == FRMR_IS_STALE) {
387 /* Don't de-allocate if the MR is not free yet */
388 if (frmr->fr_state == FRMR_IS_INUSE)
389 continue;
390
391 if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL)
392 rds_ib_stats_inc(s_ib_rdma_mr_8k_free);
393 else
394 rds_ib_stats_inc(s_ib_rdma_mr_1m_free);
395 list_del(&ibmr->unmap_list);
396 if (frmr->mr)
397 ib_dereg_mr(frmr->mr);
398 kfree(ibmr);
399 freed++;
400 }
401 }
402 *nfreed = freed;
403 }
404
rds_ib_reg_frmr(struct rds_ib_device * rds_ibdev,struct rds_ib_connection * ic,struct scatterlist * sg,unsigned long nents,u32 * key)405 struct rds_ib_mr *rds_ib_reg_frmr(struct rds_ib_device *rds_ibdev,
406 struct rds_ib_connection *ic,
407 struct scatterlist *sg,
408 unsigned long nents, u32 *key)
409 {
410 struct rds_ib_mr *ibmr = NULL;
411 struct rds_ib_frmr *frmr;
412 int ret;
413
414 if (!ic) {
415 /* TODO: Add FRWR support for RDS_GET_MR using proxy qp*/
416 return ERR_PTR(-EOPNOTSUPP);
417 }
418
419 do {
420 if (ibmr)
421 rds_ib_free_frmr(ibmr, true);
422 ibmr = rds_ib_alloc_frmr(rds_ibdev, nents);
423 if (IS_ERR(ibmr))
424 return ibmr;
425 frmr = &ibmr->u.frmr;
426 } while (frmr->fr_state != FRMR_IS_FREE);
427
428 ibmr->ic = ic;
429 ibmr->device = rds_ibdev;
430 ret = rds_ib_map_frmr(rds_ibdev, ibmr->pool, ibmr, sg, nents);
431 if (ret == 0) {
432 *key = frmr->mr->rkey;
433 } else {
434 rds_ib_free_frmr(ibmr, false);
435 ibmr = ERR_PTR(ret);
436 }
437
438 return ibmr;
439 }
440
rds_ib_free_frmr_list(struct rds_ib_mr * ibmr)441 void rds_ib_free_frmr_list(struct rds_ib_mr *ibmr)
442 {
443 struct rds_ib_mr_pool *pool = ibmr->pool;
444 struct rds_ib_frmr *frmr = &ibmr->u.frmr;
445
446 if (frmr->fr_state == FRMR_IS_STALE)
447 llist_add(&ibmr->llnode, &pool->drop_list);
448 else
449 llist_add(&ibmr->llnode, &pool->free_list);
450 }
451