1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Shared Memory Communications over RDMA (SMC-R) and RoCE
4 *
5 * Work Requests exploiting Infiniband API
6 *
7 * Work requests (WR) of type ib_post_send or ib_post_recv respectively
8 * are submitted to either RC SQ or RC RQ respectively
9 * (reliably connected send/receive queue)
10 * and become work queue entries (WQEs).
11 * While an SQ WR/WQE is pending, we track it until transmission completion.
12 * Through a send or receive completion queue (CQ) respectively,
13 * we get completion queue entries (CQEs) [aka work completions (WCs)].
14 * Since the CQ callback is called from IRQ context, we split work by using
15 * bottom halves implemented by tasklets.
16 *
17 * SMC uses this to exchange LLC (link layer control)
18 * and CDC (connection data control) messages.
19 *
20 * Copyright IBM Corp. 2016
21 *
22 * Author(s): Steffen Maier <maier@linux.vnet.ibm.com>
23 */
24
25 #include <linux/atomic.h>
26 #include <linux/hashtable.h>
27 #include <linux/wait.h>
28 #include <rdma/ib_verbs.h>
29 #include <asm/div64.h>
30
31 #include "smc.h"
32 #include "smc_wr.h"
33
34 #define SMC_WR_MAX_POLL_CQE 10 /* max. # of compl. queue elements in 1 poll */
35
36 #define SMC_WR_RX_HASH_BITS 4
37 static DEFINE_HASHTABLE(smc_wr_rx_hash, SMC_WR_RX_HASH_BITS);
38 static DEFINE_SPINLOCK(smc_wr_rx_hash_lock);
39
40 struct smc_wr_tx_pend { /* control data for a pending send request */
41 u64 wr_id; /* work request id sent */
42 smc_wr_tx_handler handler;
43 enum ib_wc_status wc_status; /* CQE status */
44 struct smc_link *link;
45 u32 idx;
46 struct smc_wr_tx_pend_priv priv;
47 u8 compl_requested;
48 };
49
50 /******************************** send queue *********************************/
51
52 /*------------------------------- completion --------------------------------*/
53
54 /* returns true if at least one tx work request is pending on the given link */
smc_wr_is_tx_pend(struct smc_link * link)55 static inline bool smc_wr_is_tx_pend(struct smc_link *link)
56 {
57 return !bitmap_empty(link->wr_tx_mask, link->wr_tx_cnt);
58 }
59
60 /* wait till all pending tx work requests on the given link are completed */
smc_wr_tx_wait_no_pending_sends(struct smc_link * link)61 void smc_wr_tx_wait_no_pending_sends(struct smc_link *link)
62 {
63 wait_event(link->wr_tx_wait, !smc_wr_is_tx_pend(link));
64 }
65
smc_wr_tx_find_pending_index(struct smc_link * link,u64 wr_id)66 static inline int smc_wr_tx_find_pending_index(struct smc_link *link, u64 wr_id)
67 {
68 u32 i;
69
70 for (i = 0; i < link->wr_tx_cnt; i++) {
71 if (link->wr_tx_pends[i].wr_id == wr_id)
72 return i;
73 }
74 return link->wr_tx_cnt;
75 }
76
smc_wr_tx_process_cqe(struct ib_wc * wc)77 static inline void smc_wr_tx_process_cqe(struct ib_wc *wc)
78 {
79 struct smc_wr_tx_pend pnd_snd;
80 struct smc_link *link;
81 u32 pnd_snd_idx;
82
83 link = wc->qp->qp_context;
84
85 if (wc->opcode == IB_WC_REG_MR) {
86 if (wc->status)
87 link->wr_reg_state = FAILED;
88 else
89 link->wr_reg_state = CONFIRMED;
90 smc_wr_wakeup_reg_wait(link);
91 return;
92 }
93
94 pnd_snd_idx = smc_wr_tx_find_pending_index(link, wc->wr_id);
95 if (pnd_snd_idx == link->wr_tx_cnt) {
96 if (link->lgr->smc_version != SMC_V2 ||
97 link->wr_tx_v2_pend->wr_id != wc->wr_id)
98 return;
99 link->wr_tx_v2_pend->wc_status = wc->status;
100 memcpy(&pnd_snd, link->wr_tx_v2_pend, sizeof(pnd_snd));
101 /* clear the full struct smc_wr_tx_pend including .priv */
102 memset(link->wr_tx_v2_pend, 0,
103 sizeof(*link->wr_tx_v2_pend));
104 memset(link->lgr->wr_tx_buf_v2, 0,
105 sizeof(*link->lgr->wr_tx_buf_v2));
106 } else {
107 link->wr_tx_pends[pnd_snd_idx].wc_status = wc->status;
108 if (link->wr_tx_pends[pnd_snd_idx].compl_requested)
109 complete(&link->wr_tx_compl[pnd_snd_idx]);
110 memcpy(&pnd_snd, &link->wr_tx_pends[pnd_snd_idx],
111 sizeof(pnd_snd));
112 /* clear the full struct smc_wr_tx_pend including .priv */
113 memset(&link->wr_tx_pends[pnd_snd_idx], 0,
114 sizeof(link->wr_tx_pends[pnd_snd_idx]));
115 memset(&link->wr_tx_bufs[pnd_snd_idx], 0,
116 sizeof(link->wr_tx_bufs[pnd_snd_idx]));
117 if (!test_and_clear_bit(pnd_snd_idx, link->wr_tx_mask))
118 return;
119 }
120
121 if (wc->status) {
122 if (link->lgr->smc_version == SMC_V2) {
123 memset(link->wr_tx_v2_pend, 0,
124 sizeof(*link->wr_tx_v2_pend));
125 memset(link->lgr->wr_tx_buf_v2, 0,
126 sizeof(*link->lgr->wr_tx_buf_v2));
127 }
128 /* terminate link */
129 smcr_link_down_cond_sched(link);
130 }
131 if (pnd_snd.handler)
132 pnd_snd.handler(&pnd_snd.priv, link, wc->status);
133 wake_up(&link->wr_tx_wait);
134 }
135
smc_wr_tx_tasklet_fn(struct tasklet_struct * t)136 static void smc_wr_tx_tasklet_fn(struct tasklet_struct *t)
137 {
138 struct smc_ib_device *dev = from_tasklet(dev, t, send_tasklet);
139 struct ib_wc wc[SMC_WR_MAX_POLL_CQE];
140 int i = 0, rc;
141 int polled = 0;
142
143 again:
144 polled++;
145 do {
146 memset(&wc, 0, sizeof(wc));
147 rc = ib_poll_cq(dev->roce_cq_send, SMC_WR_MAX_POLL_CQE, wc);
148 if (polled == 1) {
149 ib_req_notify_cq(dev->roce_cq_send,
150 IB_CQ_NEXT_COMP |
151 IB_CQ_REPORT_MISSED_EVENTS);
152 }
153 if (!rc)
154 break;
155 for (i = 0; i < rc; i++)
156 smc_wr_tx_process_cqe(&wc[i]);
157 } while (rc > 0);
158 if (polled == 1)
159 goto again;
160 }
161
smc_wr_tx_cq_handler(struct ib_cq * ib_cq,void * cq_context)162 void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context)
163 {
164 struct smc_ib_device *dev = (struct smc_ib_device *)cq_context;
165
166 tasklet_schedule(&dev->send_tasklet);
167 }
168
169 /*---------------------------- request submission ---------------------------*/
170
smc_wr_tx_get_free_slot_index(struct smc_link * link,u32 * idx)171 static inline int smc_wr_tx_get_free_slot_index(struct smc_link *link, u32 *idx)
172 {
173 *idx = link->wr_tx_cnt;
174 if (!smc_link_sendable(link))
175 return -ENOLINK;
176 for_each_clear_bit(*idx, link->wr_tx_mask, link->wr_tx_cnt) {
177 if (!test_and_set_bit(*idx, link->wr_tx_mask))
178 return 0;
179 }
180 *idx = link->wr_tx_cnt;
181 return -EBUSY;
182 }
183
184 /**
185 * smc_wr_tx_get_free_slot() - returns buffer for message assembly,
186 * and sets info for pending transmit tracking
187 * @link: Pointer to smc_link used to later send the message.
188 * @handler: Send completion handler function pointer.
189 * @wr_buf: Out value returns pointer to message buffer.
190 * @wr_rdma_buf: Out value returns pointer to rdma work request.
191 * @wr_pend_priv: Out value returns pointer serving as handler context.
192 *
193 * Return: 0 on success, or -errno on error.
194 */
smc_wr_tx_get_free_slot(struct smc_link * link,smc_wr_tx_handler handler,struct smc_wr_buf ** wr_buf,struct smc_rdma_wr ** wr_rdma_buf,struct smc_wr_tx_pend_priv ** wr_pend_priv)195 int smc_wr_tx_get_free_slot(struct smc_link *link,
196 smc_wr_tx_handler handler,
197 struct smc_wr_buf **wr_buf,
198 struct smc_rdma_wr **wr_rdma_buf,
199 struct smc_wr_tx_pend_priv **wr_pend_priv)
200 {
201 struct smc_link_group *lgr = smc_get_lgr(link);
202 struct smc_wr_tx_pend *wr_pend;
203 u32 idx = link->wr_tx_cnt;
204 struct ib_send_wr *wr_ib;
205 u64 wr_id;
206 int rc;
207
208 *wr_buf = NULL;
209 *wr_pend_priv = NULL;
210 if (in_softirq() || lgr->terminating) {
211 rc = smc_wr_tx_get_free_slot_index(link, &idx);
212 if (rc)
213 return rc;
214 } else {
215 rc = wait_event_interruptible_timeout(
216 link->wr_tx_wait,
217 !smc_link_sendable(link) ||
218 lgr->terminating ||
219 (smc_wr_tx_get_free_slot_index(link, &idx) != -EBUSY),
220 SMC_WR_TX_WAIT_FREE_SLOT_TIME);
221 if (!rc) {
222 /* timeout - terminate link */
223 smcr_link_down_cond_sched(link);
224 return -EPIPE;
225 }
226 if (idx == link->wr_tx_cnt)
227 return -EPIPE;
228 }
229 wr_id = smc_wr_tx_get_next_wr_id(link);
230 wr_pend = &link->wr_tx_pends[idx];
231 wr_pend->wr_id = wr_id;
232 wr_pend->handler = handler;
233 wr_pend->link = link;
234 wr_pend->idx = idx;
235 wr_ib = &link->wr_tx_ibs[idx];
236 wr_ib->wr_id = wr_id;
237 *wr_buf = &link->wr_tx_bufs[idx];
238 if (wr_rdma_buf)
239 *wr_rdma_buf = &link->wr_tx_rdmas[idx];
240 *wr_pend_priv = &wr_pend->priv;
241 return 0;
242 }
243
smc_wr_tx_get_v2_slot(struct smc_link * link,smc_wr_tx_handler handler,struct smc_wr_v2_buf ** wr_buf,struct smc_wr_tx_pend_priv ** wr_pend_priv)244 int smc_wr_tx_get_v2_slot(struct smc_link *link,
245 smc_wr_tx_handler handler,
246 struct smc_wr_v2_buf **wr_buf,
247 struct smc_wr_tx_pend_priv **wr_pend_priv)
248 {
249 struct smc_wr_tx_pend *wr_pend;
250 struct ib_send_wr *wr_ib;
251 u64 wr_id;
252
253 if (link->wr_tx_v2_pend->idx == link->wr_tx_cnt)
254 return -EBUSY;
255
256 *wr_buf = NULL;
257 *wr_pend_priv = NULL;
258 wr_id = smc_wr_tx_get_next_wr_id(link);
259 wr_pend = link->wr_tx_v2_pend;
260 wr_pend->wr_id = wr_id;
261 wr_pend->handler = handler;
262 wr_pend->link = link;
263 wr_pend->idx = link->wr_tx_cnt;
264 wr_ib = link->wr_tx_v2_ib;
265 wr_ib->wr_id = wr_id;
266 *wr_buf = link->lgr->wr_tx_buf_v2;
267 *wr_pend_priv = &wr_pend->priv;
268 return 0;
269 }
270
smc_wr_tx_put_slot(struct smc_link * link,struct smc_wr_tx_pend_priv * wr_pend_priv)271 int smc_wr_tx_put_slot(struct smc_link *link,
272 struct smc_wr_tx_pend_priv *wr_pend_priv)
273 {
274 struct smc_wr_tx_pend *pend;
275
276 pend = container_of(wr_pend_priv, struct smc_wr_tx_pend, priv);
277 if (pend->idx < link->wr_tx_cnt) {
278 u32 idx = pend->idx;
279
280 /* clear the full struct smc_wr_tx_pend including .priv */
281 memset(&link->wr_tx_pends[idx], 0,
282 sizeof(link->wr_tx_pends[idx]));
283 memset(&link->wr_tx_bufs[idx], 0,
284 sizeof(link->wr_tx_bufs[idx]));
285 test_and_clear_bit(idx, link->wr_tx_mask);
286 wake_up(&link->wr_tx_wait);
287 return 1;
288 } else if (link->lgr->smc_version == SMC_V2 &&
289 pend->idx == link->wr_tx_cnt) {
290 /* Large v2 buffer */
291 memset(&link->wr_tx_v2_pend, 0,
292 sizeof(link->wr_tx_v2_pend));
293 memset(&link->lgr->wr_tx_buf_v2, 0,
294 sizeof(link->lgr->wr_tx_buf_v2));
295 return 1;
296 }
297
298 return 0;
299 }
300
301 /* Send prepared WR slot via ib_post_send.
302 * @priv: pointer to smc_wr_tx_pend_priv identifying prepared message buffer
303 */
smc_wr_tx_send(struct smc_link * link,struct smc_wr_tx_pend_priv * priv)304 int smc_wr_tx_send(struct smc_link *link, struct smc_wr_tx_pend_priv *priv)
305 {
306 struct smc_wr_tx_pend *pend;
307 int rc;
308
309 ib_req_notify_cq(link->smcibdev->roce_cq_send,
310 IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
311 pend = container_of(priv, struct smc_wr_tx_pend, priv);
312 rc = ib_post_send(link->roce_qp, &link->wr_tx_ibs[pend->idx], NULL);
313 if (rc) {
314 smc_wr_tx_put_slot(link, priv);
315 smcr_link_down_cond_sched(link);
316 }
317 return rc;
318 }
319
smc_wr_tx_v2_send(struct smc_link * link,struct smc_wr_tx_pend_priv * priv,int len)320 int smc_wr_tx_v2_send(struct smc_link *link, struct smc_wr_tx_pend_priv *priv,
321 int len)
322 {
323 int rc;
324
325 link->wr_tx_v2_ib->sg_list[0].length = len;
326 ib_req_notify_cq(link->smcibdev->roce_cq_send,
327 IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
328 rc = ib_post_send(link->roce_qp, link->wr_tx_v2_ib, NULL);
329 if (rc) {
330 smc_wr_tx_put_slot(link, priv);
331 smcr_link_down_cond_sched(link);
332 }
333 return rc;
334 }
335
336 /* Send prepared WR slot via ib_post_send and wait for send completion
337 * notification.
338 * @priv: pointer to smc_wr_tx_pend_priv identifying prepared message buffer
339 */
smc_wr_tx_send_wait(struct smc_link * link,struct smc_wr_tx_pend_priv * priv,unsigned long timeout)340 int smc_wr_tx_send_wait(struct smc_link *link, struct smc_wr_tx_pend_priv *priv,
341 unsigned long timeout)
342 {
343 struct smc_wr_tx_pend *pend;
344 u32 pnd_idx;
345 int rc;
346
347 pend = container_of(priv, struct smc_wr_tx_pend, priv);
348 pend->compl_requested = 1;
349 pnd_idx = pend->idx;
350 init_completion(&link->wr_tx_compl[pnd_idx]);
351
352 rc = smc_wr_tx_send(link, priv);
353 if (rc)
354 return rc;
355 /* wait for completion by smc_wr_tx_process_cqe() */
356 rc = wait_for_completion_interruptible_timeout(
357 &link->wr_tx_compl[pnd_idx], timeout);
358 if (rc <= 0)
359 rc = -ENODATA;
360 if (rc > 0)
361 rc = 0;
362 return rc;
363 }
364
365 /* Register a memory region and wait for result. */
smc_wr_reg_send(struct smc_link * link,struct ib_mr * mr)366 int smc_wr_reg_send(struct smc_link *link, struct ib_mr *mr)
367 {
368 int rc;
369
370 ib_req_notify_cq(link->smcibdev->roce_cq_send,
371 IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
372 link->wr_reg_state = POSTED;
373 link->wr_reg.wr.wr_id = (u64)(uintptr_t)mr;
374 link->wr_reg.mr = mr;
375 link->wr_reg.key = mr->rkey;
376 rc = ib_post_send(link->roce_qp, &link->wr_reg.wr, NULL);
377 if (rc)
378 return rc;
379
380 percpu_ref_get(&link->wr_reg_refs);
381 rc = wait_event_interruptible_timeout(link->wr_reg_wait,
382 (link->wr_reg_state != POSTED),
383 SMC_WR_REG_MR_WAIT_TIME);
384 percpu_ref_put(&link->wr_reg_refs);
385 if (!rc) {
386 /* timeout - terminate link */
387 smcr_link_down_cond_sched(link);
388 return -EPIPE;
389 }
390 if (rc == -ERESTARTSYS)
391 return -EINTR;
392 switch (link->wr_reg_state) {
393 case CONFIRMED:
394 rc = 0;
395 break;
396 case FAILED:
397 rc = -EIO;
398 break;
399 case POSTED:
400 rc = -EPIPE;
401 break;
402 }
403 return rc;
404 }
405
406 /****************************** receive queue ********************************/
407
smc_wr_rx_register_handler(struct smc_wr_rx_handler * handler)408 int smc_wr_rx_register_handler(struct smc_wr_rx_handler *handler)
409 {
410 struct smc_wr_rx_handler *h_iter;
411 int rc = 0;
412
413 spin_lock(&smc_wr_rx_hash_lock);
414 hash_for_each_possible(smc_wr_rx_hash, h_iter, list, handler->type) {
415 if (h_iter->type == handler->type) {
416 rc = -EEXIST;
417 goto out_unlock;
418 }
419 }
420 hash_add(smc_wr_rx_hash, &handler->list, handler->type);
421 out_unlock:
422 spin_unlock(&smc_wr_rx_hash_lock);
423 return rc;
424 }
425
426 /* Demultiplex a received work request based on the message type to its handler.
427 * Relies on smc_wr_rx_hash having been completely filled before any IB WRs,
428 * and not being modified any more afterwards so we don't need to lock it.
429 */
smc_wr_rx_demultiplex(struct ib_wc * wc)430 static inline void smc_wr_rx_demultiplex(struct ib_wc *wc)
431 {
432 struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
433 struct smc_wr_rx_handler *handler;
434 struct smc_wr_rx_hdr *wr_rx;
435 u64 temp_wr_id;
436 u32 index;
437
438 if (wc->byte_len < sizeof(*wr_rx))
439 return; /* short message */
440 temp_wr_id = wc->wr_id;
441 index = do_div(temp_wr_id, link->wr_rx_cnt);
442 wr_rx = (struct smc_wr_rx_hdr *)&link->wr_rx_bufs[index];
443 hash_for_each_possible(smc_wr_rx_hash, handler, list, wr_rx->type) {
444 if (handler->type == wr_rx->type)
445 handler->handler(wc, wr_rx);
446 }
447 }
448
smc_wr_rx_process_cqes(struct ib_wc wc[],int num)449 static inline void smc_wr_rx_process_cqes(struct ib_wc wc[], int num)
450 {
451 struct smc_link *link;
452 int i;
453
454 for (i = 0; i < num; i++) {
455 link = wc[i].qp->qp_context;
456 link->wr_rx_id_compl = wc[i].wr_id;
457 if (wc[i].status == IB_WC_SUCCESS) {
458 link->wr_rx_tstamp = jiffies;
459 smc_wr_rx_demultiplex(&wc[i]);
460 smc_wr_rx_post(link); /* refill WR RX */
461 } else {
462 /* handle status errors */
463 switch (wc[i].status) {
464 case IB_WC_RETRY_EXC_ERR:
465 case IB_WC_RNR_RETRY_EXC_ERR:
466 case IB_WC_WR_FLUSH_ERR:
467 smcr_link_down_cond_sched(link);
468 if (link->wr_rx_id_compl == link->wr_rx_id)
469 wake_up(&link->wr_rx_empty_wait);
470 break;
471 default:
472 smc_wr_rx_post(link); /* refill WR RX */
473 break;
474 }
475 }
476 }
477 }
478
smc_wr_rx_tasklet_fn(struct tasklet_struct * t)479 static void smc_wr_rx_tasklet_fn(struct tasklet_struct *t)
480 {
481 struct smc_ib_device *dev = from_tasklet(dev, t, recv_tasklet);
482 struct ib_wc wc[SMC_WR_MAX_POLL_CQE];
483 int polled = 0;
484 int rc;
485
486 again:
487 polled++;
488 do {
489 memset(&wc, 0, sizeof(wc));
490 rc = ib_poll_cq(dev->roce_cq_recv, SMC_WR_MAX_POLL_CQE, wc);
491 if (polled == 1) {
492 ib_req_notify_cq(dev->roce_cq_recv,
493 IB_CQ_SOLICITED_MASK
494 | IB_CQ_REPORT_MISSED_EVENTS);
495 }
496 if (!rc)
497 break;
498 smc_wr_rx_process_cqes(&wc[0], rc);
499 } while (rc > 0);
500 if (polled == 1)
501 goto again;
502 }
503
smc_wr_rx_cq_handler(struct ib_cq * ib_cq,void * cq_context)504 void smc_wr_rx_cq_handler(struct ib_cq *ib_cq, void *cq_context)
505 {
506 struct smc_ib_device *dev = (struct smc_ib_device *)cq_context;
507
508 tasklet_schedule(&dev->recv_tasklet);
509 }
510
smc_wr_rx_post_init(struct smc_link * link)511 int smc_wr_rx_post_init(struct smc_link *link)
512 {
513 u32 i;
514 int rc = 0;
515
516 for (i = 0; i < link->wr_rx_cnt; i++)
517 rc = smc_wr_rx_post(link);
518 return rc;
519 }
520
521 /***************************** init, exit, misc ******************************/
522
smc_wr_remember_qp_attr(struct smc_link * lnk)523 void smc_wr_remember_qp_attr(struct smc_link *lnk)
524 {
525 struct ib_qp_attr *attr = &lnk->qp_attr;
526 struct ib_qp_init_attr init_attr;
527
528 memset(attr, 0, sizeof(*attr));
529 memset(&init_attr, 0, sizeof(init_attr));
530 ib_query_qp(lnk->roce_qp, attr,
531 IB_QP_STATE |
532 IB_QP_CUR_STATE |
533 IB_QP_PKEY_INDEX |
534 IB_QP_PORT |
535 IB_QP_QKEY |
536 IB_QP_AV |
537 IB_QP_PATH_MTU |
538 IB_QP_TIMEOUT |
539 IB_QP_RETRY_CNT |
540 IB_QP_RNR_RETRY |
541 IB_QP_RQ_PSN |
542 IB_QP_ALT_PATH |
543 IB_QP_MIN_RNR_TIMER |
544 IB_QP_SQ_PSN |
545 IB_QP_PATH_MIG_STATE |
546 IB_QP_CAP |
547 IB_QP_DEST_QPN,
548 &init_attr);
549
550 lnk->wr_tx_cnt = min_t(size_t, SMC_WR_BUF_CNT,
551 lnk->qp_attr.cap.max_send_wr);
552 lnk->wr_rx_cnt = min_t(size_t, SMC_WR_BUF_CNT * 3,
553 lnk->qp_attr.cap.max_recv_wr);
554 }
555
smc_wr_init_sge(struct smc_link * lnk)556 static void smc_wr_init_sge(struct smc_link *lnk)
557 {
558 int sges_per_buf = (lnk->lgr->smc_version == SMC_V2) ? 2 : 1;
559 bool send_inline = (lnk->qp_attr.cap.max_inline_data > SMC_WR_TX_SIZE);
560 u32 i;
561
562 for (i = 0; i < lnk->wr_tx_cnt; i++) {
563 lnk->wr_tx_sges[i].addr = send_inline ? (uintptr_t)(&lnk->wr_tx_bufs[i]) :
564 lnk->wr_tx_dma_addr + i * SMC_WR_BUF_SIZE;
565 lnk->wr_tx_sges[i].length = SMC_WR_TX_SIZE;
566 lnk->wr_tx_sges[i].lkey = lnk->roce_pd->local_dma_lkey;
567 lnk->wr_tx_rdma_sges[i].tx_rdma_sge[0].wr_tx_rdma_sge[0].lkey =
568 lnk->roce_pd->local_dma_lkey;
569 lnk->wr_tx_rdma_sges[i].tx_rdma_sge[0].wr_tx_rdma_sge[1].lkey =
570 lnk->roce_pd->local_dma_lkey;
571 lnk->wr_tx_rdma_sges[i].tx_rdma_sge[1].wr_tx_rdma_sge[0].lkey =
572 lnk->roce_pd->local_dma_lkey;
573 lnk->wr_tx_rdma_sges[i].tx_rdma_sge[1].wr_tx_rdma_sge[1].lkey =
574 lnk->roce_pd->local_dma_lkey;
575 lnk->wr_tx_ibs[i].next = NULL;
576 lnk->wr_tx_ibs[i].sg_list = &lnk->wr_tx_sges[i];
577 lnk->wr_tx_ibs[i].num_sge = 1;
578 lnk->wr_tx_ibs[i].opcode = IB_WR_SEND;
579 lnk->wr_tx_ibs[i].send_flags =
580 IB_SEND_SIGNALED | IB_SEND_SOLICITED;
581 if (send_inline)
582 lnk->wr_tx_ibs[i].send_flags |= IB_SEND_INLINE;
583 lnk->wr_tx_rdmas[i].wr_tx_rdma[0].wr.opcode = IB_WR_RDMA_WRITE;
584 lnk->wr_tx_rdmas[i].wr_tx_rdma[1].wr.opcode = IB_WR_RDMA_WRITE;
585 lnk->wr_tx_rdmas[i].wr_tx_rdma[0].wr.sg_list =
586 lnk->wr_tx_rdma_sges[i].tx_rdma_sge[0].wr_tx_rdma_sge;
587 lnk->wr_tx_rdmas[i].wr_tx_rdma[1].wr.sg_list =
588 lnk->wr_tx_rdma_sges[i].tx_rdma_sge[1].wr_tx_rdma_sge;
589 }
590
591 if (lnk->lgr->smc_version == SMC_V2) {
592 lnk->wr_tx_v2_sge->addr = lnk->wr_tx_v2_dma_addr;
593 lnk->wr_tx_v2_sge->length = SMC_WR_BUF_V2_SIZE;
594 lnk->wr_tx_v2_sge->lkey = lnk->roce_pd->local_dma_lkey;
595
596 lnk->wr_tx_v2_ib->next = NULL;
597 lnk->wr_tx_v2_ib->sg_list = lnk->wr_tx_v2_sge;
598 lnk->wr_tx_v2_ib->num_sge = 1;
599 lnk->wr_tx_v2_ib->opcode = IB_WR_SEND;
600 lnk->wr_tx_v2_ib->send_flags =
601 IB_SEND_SIGNALED | IB_SEND_SOLICITED;
602 }
603
604 /* With SMC-Rv2 there can be messages larger than SMC_WR_TX_SIZE.
605 * Each ib_recv_wr gets 2 sges, the second one is a spillover buffer
606 * and the same buffer for all sges. When a larger message arrived then
607 * the content of the first small sge is copied to the beginning of
608 * the larger spillover buffer, allowing easy data mapping.
609 */
610 for (i = 0; i < lnk->wr_rx_cnt; i++) {
611 int x = i * sges_per_buf;
612
613 lnk->wr_rx_sges[x].addr =
614 lnk->wr_rx_dma_addr + i * SMC_WR_BUF_SIZE;
615 lnk->wr_rx_sges[x].length = SMC_WR_TX_SIZE;
616 lnk->wr_rx_sges[x].lkey = lnk->roce_pd->local_dma_lkey;
617 if (lnk->lgr->smc_version == SMC_V2) {
618 lnk->wr_rx_sges[x + 1].addr =
619 lnk->wr_rx_v2_dma_addr + SMC_WR_TX_SIZE;
620 lnk->wr_rx_sges[x + 1].length =
621 SMC_WR_BUF_V2_SIZE - SMC_WR_TX_SIZE;
622 lnk->wr_rx_sges[x + 1].lkey =
623 lnk->roce_pd->local_dma_lkey;
624 }
625 lnk->wr_rx_ibs[i].next = NULL;
626 lnk->wr_rx_ibs[i].sg_list = &lnk->wr_rx_sges[x];
627 lnk->wr_rx_ibs[i].num_sge = sges_per_buf;
628 }
629 lnk->wr_reg.wr.next = NULL;
630 lnk->wr_reg.wr.num_sge = 0;
631 lnk->wr_reg.wr.send_flags = IB_SEND_SIGNALED;
632 lnk->wr_reg.wr.opcode = IB_WR_REG_MR;
633 lnk->wr_reg.access = IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE;
634 }
635
smc_wr_free_link(struct smc_link * lnk)636 void smc_wr_free_link(struct smc_link *lnk)
637 {
638 struct ib_device *ibdev;
639
640 if (!lnk->smcibdev)
641 return;
642 ibdev = lnk->smcibdev->ibdev;
643
644 smc_wr_drain_cq(lnk);
645 smc_wr_wakeup_reg_wait(lnk);
646 smc_wr_wakeup_tx_wait(lnk);
647
648 smc_wr_tx_wait_no_pending_sends(lnk);
649 percpu_ref_kill(&lnk->wr_reg_refs);
650 wait_for_completion(&lnk->reg_ref_comp);
651 percpu_ref_exit(&lnk->wr_reg_refs);
652 percpu_ref_kill(&lnk->wr_tx_refs);
653 wait_for_completion(&lnk->tx_ref_comp);
654 percpu_ref_exit(&lnk->wr_tx_refs);
655
656 if (lnk->wr_rx_dma_addr) {
657 ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
658 SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
659 DMA_FROM_DEVICE);
660 lnk->wr_rx_dma_addr = 0;
661 }
662 if (lnk->wr_rx_v2_dma_addr) {
663 ib_dma_unmap_single(ibdev, lnk->wr_rx_v2_dma_addr,
664 SMC_WR_BUF_V2_SIZE,
665 DMA_FROM_DEVICE);
666 lnk->wr_rx_v2_dma_addr = 0;
667 }
668 if (lnk->wr_tx_dma_addr) {
669 ib_dma_unmap_single(ibdev, lnk->wr_tx_dma_addr,
670 SMC_WR_BUF_SIZE * lnk->wr_tx_cnt,
671 DMA_TO_DEVICE);
672 lnk->wr_tx_dma_addr = 0;
673 }
674 if (lnk->wr_tx_v2_dma_addr) {
675 ib_dma_unmap_single(ibdev, lnk->wr_tx_v2_dma_addr,
676 SMC_WR_BUF_V2_SIZE,
677 DMA_TO_DEVICE);
678 lnk->wr_tx_v2_dma_addr = 0;
679 }
680 }
681
smc_wr_free_lgr_mem(struct smc_link_group * lgr)682 void smc_wr_free_lgr_mem(struct smc_link_group *lgr)
683 {
684 if (lgr->smc_version < SMC_V2)
685 return;
686
687 kfree(lgr->wr_rx_buf_v2);
688 lgr->wr_rx_buf_v2 = NULL;
689 kfree(lgr->wr_tx_buf_v2);
690 lgr->wr_tx_buf_v2 = NULL;
691 }
692
smc_wr_free_link_mem(struct smc_link * lnk)693 void smc_wr_free_link_mem(struct smc_link *lnk)
694 {
695 kfree(lnk->wr_tx_v2_ib);
696 lnk->wr_tx_v2_ib = NULL;
697 kfree(lnk->wr_tx_v2_sge);
698 lnk->wr_tx_v2_sge = NULL;
699 kfree(lnk->wr_tx_v2_pend);
700 lnk->wr_tx_v2_pend = NULL;
701 kfree(lnk->wr_tx_compl);
702 lnk->wr_tx_compl = NULL;
703 kfree(lnk->wr_tx_pends);
704 lnk->wr_tx_pends = NULL;
705 bitmap_free(lnk->wr_tx_mask);
706 lnk->wr_tx_mask = NULL;
707 kfree(lnk->wr_tx_sges);
708 lnk->wr_tx_sges = NULL;
709 kfree(lnk->wr_tx_rdma_sges);
710 lnk->wr_tx_rdma_sges = NULL;
711 kfree(lnk->wr_rx_sges);
712 lnk->wr_rx_sges = NULL;
713 kfree(lnk->wr_tx_rdmas);
714 lnk->wr_tx_rdmas = NULL;
715 kfree(lnk->wr_rx_ibs);
716 lnk->wr_rx_ibs = NULL;
717 kfree(lnk->wr_tx_ibs);
718 lnk->wr_tx_ibs = NULL;
719 kfree(lnk->wr_tx_bufs);
720 lnk->wr_tx_bufs = NULL;
721 kfree(lnk->wr_rx_bufs);
722 lnk->wr_rx_bufs = NULL;
723 }
724
smc_wr_alloc_lgr_mem(struct smc_link_group * lgr)725 int smc_wr_alloc_lgr_mem(struct smc_link_group *lgr)
726 {
727 if (lgr->smc_version < SMC_V2)
728 return 0;
729
730 lgr->wr_rx_buf_v2 = kzalloc(SMC_WR_BUF_V2_SIZE, GFP_KERNEL);
731 if (!lgr->wr_rx_buf_v2)
732 return -ENOMEM;
733 lgr->wr_tx_buf_v2 = kzalloc(SMC_WR_BUF_V2_SIZE, GFP_KERNEL);
734 if (!lgr->wr_tx_buf_v2) {
735 kfree(lgr->wr_rx_buf_v2);
736 return -ENOMEM;
737 }
738 return 0;
739 }
740
smc_wr_alloc_link_mem(struct smc_link * link)741 int smc_wr_alloc_link_mem(struct smc_link *link)
742 {
743 int sges_per_buf = link->lgr->smc_version == SMC_V2 ? 2 : 1;
744
745 /* allocate link related memory */
746 link->wr_tx_bufs = kcalloc(SMC_WR_BUF_CNT, SMC_WR_BUF_SIZE, GFP_KERNEL);
747 if (!link->wr_tx_bufs)
748 goto no_mem;
749 link->wr_rx_bufs = kcalloc(SMC_WR_BUF_CNT * 3, SMC_WR_BUF_SIZE,
750 GFP_KERNEL);
751 if (!link->wr_rx_bufs)
752 goto no_mem_wr_tx_bufs;
753 link->wr_tx_ibs = kcalloc(SMC_WR_BUF_CNT, sizeof(link->wr_tx_ibs[0]),
754 GFP_KERNEL);
755 if (!link->wr_tx_ibs)
756 goto no_mem_wr_rx_bufs;
757 link->wr_rx_ibs = kcalloc(SMC_WR_BUF_CNT * 3,
758 sizeof(link->wr_rx_ibs[0]),
759 GFP_KERNEL);
760 if (!link->wr_rx_ibs)
761 goto no_mem_wr_tx_ibs;
762 link->wr_tx_rdmas = kcalloc(SMC_WR_BUF_CNT,
763 sizeof(link->wr_tx_rdmas[0]),
764 GFP_KERNEL);
765 if (!link->wr_tx_rdmas)
766 goto no_mem_wr_rx_ibs;
767 link->wr_tx_rdma_sges = kcalloc(SMC_WR_BUF_CNT,
768 sizeof(link->wr_tx_rdma_sges[0]),
769 GFP_KERNEL);
770 if (!link->wr_tx_rdma_sges)
771 goto no_mem_wr_tx_rdmas;
772 link->wr_tx_sges = kcalloc(SMC_WR_BUF_CNT, sizeof(link->wr_tx_sges[0]),
773 GFP_KERNEL);
774 if (!link->wr_tx_sges)
775 goto no_mem_wr_tx_rdma_sges;
776 link->wr_rx_sges = kcalloc(SMC_WR_BUF_CNT * 3,
777 sizeof(link->wr_rx_sges[0]) * sges_per_buf,
778 GFP_KERNEL);
779 if (!link->wr_rx_sges)
780 goto no_mem_wr_tx_sges;
781 link->wr_tx_mask = bitmap_zalloc(SMC_WR_BUF_CNT, GFP_KERNEL);
782 if (!link->wr_tx_mask)
783 goto no_mem_wr_rx_sges;
784 link->wr_tx_pends = kcalloc(SMC_WR_BUF_CNT,
785 sizeof(link->wr_tx_pends[0]),
786 GFP_KERNEL);
787 if (!link->wr_tx_pends)
788 goto no_mem_wr_tx_mask;
789 link->wr_tx_compl = kcalloc(SMC_WR_BUF_CNT,
790 sizeof(link->wr_tx_compl[0]),
791 GFP_KERNEL);
792 if (!link->wr_tx_compl)
793 goto no_mem_wr_tx_pends;
794
795 if (link->lgr->smc_version == SMC_V2) {
796 link->wr_tx_v2_ib = kzalloc(sizeof(*link->wr_tx_v2_ib),
797 GFP_KERNEL);
798 if (!link->wr_tx_v2_ib)
799 goto no_mem_tx_compl;
800 link->wr_tx_v2_sge = kzalloc(sizeof(*link->wr_tx_v2_sge),
801 GFP_KERNEL);
802 if (!link->wr_tx_v2_sge)
803 goto no_mem_v2_ib;
804 link->wr_tx_v2_pend = kzalloc(sizeof(*link->wr_tx_v2_pend),
805 GFP_KERNEL);
806 if (!link->wr_tx_v2_pend)
807 goto no_mem_v2_sge;
808 }
809 return 0;
810
811 no_mem_v2_sge:
812 kfree(link->wr_tx_v2_sge);
813 no_mem_v2_ib:
814 kfree(link->wr_tx_v2_ib);
815 no_mem_tx_compl:
816 kfree(link->wr_tx_compl);
817 no_mem_wr_tx_pends:
818 kfree(link->wr_tx_pends);
819 no_mem_wr_tx_mask:
820 kfree(link->wr_tx_mask);
821 no_mem_wr_rx_sges:
822 kfree(link->wr_rx_sges);
823 no_mem_wr_tx_sges:
824 kfree(link->wr_tx_sges);
825 no_mem_wr_tx_rdma_sges:
826 kfree(link->wr_tx_rdma_sges);
827 no_mem_wr_tx_rdmas:
828 kfree(link->wr_tx_rdmas);
829 no_mem_wr_rx_ibs:
830 kfree(link->wr_rx_ibs);
831 no_mem_wr_tx_ibs:
832 kfree(link->wr_tx_ibs);
833 no_mem_wr_rx_bufs:
834 kfree(link->wr_rx_bufs);
835 no_mem_wr_tx_bufs:
836 kfree(link->wr_tx_bufs);
837 no_mem:
838 return -ENOMEM;
839 }
840
smc_wr_remove_dev(struct smc_ib_device * smcibdev)841 void smc_wr_remove_dev(struct smc_ib_device *smcibdev)
842 {
843 tasklet_kill(&smcibdev->recv_tasklet);
844 tasklet_kill(&smcibdev->send_tasklet);
845 }
846
smc_wr_add_dev(struct smc_ib_device * smcibdev)847 void smc_wr_add_dev(struct smc_ib_device *smcibdev)
848 {
849 tasklet_setup(&smcibdev->recv_tasklet, smc_wr_rx_tasklet_fn);
850 tasklet_setup(&smcibdev->send_tasklet, smc_wr_tx_tasklet_fn);
851 }
852
smcr_wr_tx_refs_free(struct percpu_ref * ref)853 static void smcr_wr_tx_refs_free(struct percpu_ref *ref)
854 {
855 struct smc_link *lnk = container_of(ref, struct smc_link, wr_tx_refs);
856
857 complete(&lnk->tx_ref_comp);
858 }
859
smcr_wr_reg_refs_free(struct percpu_ref * ref)860 static void smcr_wr_reg_refs_free(struct percpu_ref *ref)
861 {
862 struct smc_link *lnk = container_of(ref, struct smc_link, wr_reg_refs);
863
864 complete(&lnk->reg_ref_comp);
865 }
866
smc_wr_create_link(struct smc_link * lnk)867 int smc_wr_create_link(struct smc_link *lnk)
868 {
869 struct ib_device *ibdev = lnk->smcibdev->ibdev;
870 int rc = 0;
871
872 smc_wr_tx_set_wr_id(&lnk->wr_tx_id, 0);
873 lnk->wr_rx_id = 0;
874 lnk->wr_rx_dma_addr = ib_dma_map_single(
875 ibdev, lnk->wr_rx_bufs, SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
876 DMA_FROM_DEVICE);
877 if (ib_dma_mapping_error(ibdev, lnk->wr_rx_dma_addr)) {
878 lnk->wr_rx_dma_addr = 0;
879 rc = -EIO;
880 goto out;
881 }
882 if (lnk->lgr->smc_version == SMC_V2) {
883 lnk->wr_rx_v2_dma_addr = ib_dma_map_single(ibdev,
884 lnk->lgr->wr_rx_buf_v2, SMC_WR_BUF_V2_SIZE,
885 DMA_FROM_DEVICE);
886 if (ib_dma_mapping_error(ibdev, lnk->wr_rx_v2_dma_addr)) {
887 lnk->wr_rx_v2_dma_addr = 0;
888 rc = -EIO;
889 goto dma_unmap;
890 }
891 lnk->wr_tx_v2_dma_addr = ib_dma_map_single(ibdev,
892 lnk->lgr->wr_tx_buf_v2, SMC_WR_BUF_V2_SIZE,
893 DMA_TO_DEVICE);
894 if (ib_dma_mapping_error(ibdev, lnk->wr_tx_v2_dma_addr)) {
895 lnk->wr_tx_v2_dma_addr = 0;
896 rc = -EIO;
897 goto dma_unmap;
898 }
899 }
900 lnk->wr_tx_dma_addr = ib_dma_map_single(
901 ibdev, lnk->wr_tx_bufs, SMC_WR_BUF_SIZE * lnk->wr_tx_cnt,
902 DMA_TO_DEVICE);
903 if (ib_dma_mapping_error(ibdev, lnk->wr_tx_dma_addr)) {
904 rc = -EIO;
905 goto dma_unmap;
906 }
907 smc_wr_init_sge(lnk);
908 bitmap_zero(lnk->wr_tx_mask, SMC_WR_BUF_CNT);
909 init_waitqueue_head(&lnk->wr_tx_wait);
910 rc = percpu_ref_init(&lnk->wr_tx_refs, smcr_wr_tx_refs_free, 0, GFP_KERNEL);
911 if (rc)
912 goto dma_unmap;
913 init_completion(&lnk->tx_ref_comp);
914 init_waitqueue_head(&lnk->wr_reg_wait);
915 rc = percpu_ref_init(&lnk->wr_reg_refs, smcr_wr_reg_refs_free, 0, GFP_KERNEL);
916 if (rc)
917 goto cancel_ref;
918 init_completion(&lnk->reg_ref_comp);
919 init_waitqueue_head(&lnk->wr_rx_empty_wait);
920 return rc;
921
922 cancel_ref:
923 percpu_ref_exit(&lnk->wr_tx_refs);
924 dma_unmap:
925 if (lnk->wr_rx_v2_dma_addr) {
926 ib_dma_unmap_single(ibdev, lnk->wr_rx_v2_dma_addr,
927 SMC_WR_BUF_V2_SIZE,
928 DMA_FROM_DEVICE);
929 lnk->wr_rx_v2_dma_addr = 0;
930 }
931 if (lnk->wr_tx_v2_dma_addr) {
932 ib_dma_unmap_single(ibdev, lnk->wr_tx_v2_dma_addr,
933 SMC_WR_BUF_V2_SIZE,
934 DMA_TO_DEVICE);
935 lnk->wr_tx_v2_dma_addr = 0;
936 }
937 ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
938 SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
939 DMA_FROM_DEVICE);
940 lnk->wr_rx_dma_addr = 0;
941 out:
942 return rc;
943 }
944