xref: /openbmc/linux/net/smc/smc_wr.c (revision a9d85efb)
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 */
55 static inline bool smc_wr_is_tx_pend(struct smc_link *link)
56 {
57 	if (find_first_bit(link->wr_tx_mask, link->wr_tx_cnt) !=
58 							link->wr_tx_cnt) {
59 		return true;
60 	}
61 	return false;
62 }
63 
64 /* wait till all pending tx work requests on the given link are completed */
65 int smc_wr_tx_wait_no_pending_sends(struct smc_link *link)
66 {
67 	if (wait_event_timeout(link->wr_tx_wait, !smc_wr_is_tx_pend(link),
68 			       SMC_WR_TX_WAIT_PENDING_TIME))
69 		return 0;
70 	else /* timeout */
71 		return -EPIPE;
72 }
73 
74 static inline int smc_wr_tx_find_pending_index(struct smc_link *link, u64 wr_id)
75 {
76 	u32 i;
77 
78 	for (i = 0; i < link->wr_tx_cnt; i++) {
79 		if (link->wr_tx_pends[i].wr_id == wr_id)
80 			return i;
81 	}
82 	return link->wr_tx_cnt;
83 }
84 
85 static inline void smc_wr_tx_process_cqe(struct ib_wc *wc)
86 {
87 	struct smc_wr_tx_pend pnd_snd;
88 	struct smc_link *link;
89 	u32 pnd_snd_idx;
90 	int i;
91 
92 	link = wc->qp->qp_context;
93 
94 	if (wc->opcode == IB_WC_REG_MR) {
95 		if (wc->status)
96 			link->wr_reg_state = FAILED;
97 		else
98 			link->wr_reg_state = CONFIRMED;
99 		smc_wr_wakeup_reg_wait(link);
100 		return;
101 	}
102 
103 	pnd_snd_idx = smc_wr_tx_find_pending_index(link, wc->wr_id);
104 	if (pnd_snd_idx == link->wr_tx_cnt)
105 		return;
106 	link->wr_tx_pends[pnd_snd_idx].wc_status = wc->status;
107 	if (link->wr_tx_pends[pnd_snd_idx].compl_requested)
108 		complete(&link->wr_tx_compl[pnd_snd_idx]);
109 	memcpy(&pnd_snd, &link->wr_tx_pends[pnd_snd_idx], sizeof(pnd_snd));
110 	/* clear the full struct smc_wr_tx_pend including .priv */
111 	memset(&link->wr_tx_pends[pnd_snd_idx], 0,
112 	       sizeof(link->wr_tx_pends[pnd_snd_idx]));
113 	memset(&link->wr_tx_bufs[pnd_snd_idx], 0,
114 	       sizeof(link->wr_tx_bufs[pnd_snd_idx]));
115 	if (!test_and_clear_bit(pnd_snd_idx, link->wr_tx_mask))
116 		return;
117 	if (wc->status) {
118 		for_each_set_bit(i, link->wr_tx_mask, link->wr_tx_cnt) {
119 			/* clear full struct smc_wr_tx_pend including .priv */
120 			memset(&link->wr_tx_pends[i], 0,
121 			       sizeof(link->wr_tx_pends[i]));
122 			memset(&link->wr_tx_bufs[i], 0,
123 			       sizeof(link->wr_tx_bufs[i]));
124 			clear_bit(i, link->wr_tx_mask);
125 		}
126 		/* terminate link */
127 		smcr_link_down_cond_sched(link);
128 	}
129 	if (pnd_snd.handler)
130 		pnd_snd.handler(&pnd_snd.priv, link, wc->status);
131 	wake_up(&link->wr_tx_wait);
132 }
133 
134 static void smc_wr_tx_tasklet_fn(struct tasklet_struct *t)
135 {
136 	struct smc_ib_device *dev = from_tasklet(dev, t, send_tasklet);
137 	struct ib_wc wc[SMC_WR_MAX_POLL_CQE];
138 	int i = 0, rc;
139 	int polled = 0;
140 
141 again:
142 	polled++;
143 	do {
144 		memset(&wc, 0, sizeof(wc));
145 		rc = ib_poll_cq(dev->roce_cq_send, SMC_WR_MAX_POLL_CQE, wc);
146 		if (polled == 1) {
147 			ib_req_notify_cq(dev->roce_cq_send,
148 					 IB_CQ_NEXT_COMP |
149 					 IB_CQ_REPORT_MISSED_EVENTS);
150 		}
151 		if (!rc)
152 			break;
153 		for (i = 0; i < rc; i++)
154 			smc_wr_tx_process_cqe(&wc[i]);
155 	} while (rc > 0);
156 	if (polled == 1)
157 		goto again;
158 }
159 
160 void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context)
161 {
162 	struct smc_ib_device *dev = (struct smc_ib_device *)cq_context;
163 
164 	tasklet_schedule(&dev->send_tasklet);
165 }
166 
167 /*---------------------------- request submission ---------------------------*/
168 
169 static inline int smc_wr_tx_get_free_slot_index(struct smc_link *link, u32 *idx)
170 {
171 	*idx = link->wr_tx_cnt;
172 	if (!smc_link_usable(link))
173 		return -ENOLINK;
174 	for_each_clear_bit(*idx, link->wr_tx_mask, link->wr_tx_cnt) {
175 		if (!test_and_set_bit(*idx, link->wr_tx_mask))
176 			return 0;
177 	}
178 	*idx = link->wr_tx_cnt;
179 	return -EBUSY;
180 }
181 
182 /**
183  * smc_wr_tx_get_free_slot() - returns buffer for message assembly,
184  *			and sets info for pending transmit tracking
185  * @link:		Pointer to smc_link used to later send the message.
186  * @handler:		Send completion handler function pointer.
187  * @wr_buf:		Out value returns pointer to message buffer.
188  * @wr_rdma_buf:	Out value returns pointer to rdma work request.
189  * @wr_pend_priv:	Out value returns pointer serving as handler context.
190  *
191  * Return: 0 on success, or -errno on error.
192  */
193 int smc_wr_tx_get_free_slot(struct smc_link *link,
194 			    smc_wr_tx_handler handler,
195 			    struct smc_wr_buf **wr_buf,
196 			    struct smc_rdma_wr **wr_rdma_buf,
197 			    struct smc_wr_tx_pend_priv **wr_pend_priv)
198 {
199 	struct smc_link_group *lgr = smc_get_lgr(link);
200 	struct smc_wr_tx_pend *wr_pend;
201 	u32 idx = link->wr_tx_cnt;
202 	struct ib_send_wr *wr_ib;
203 	u64 wr_id;
204 	int rc;
205 
206 	*wr_buf = NULL;
207 	*wr_pend_priv = NULL;
208 	if (in_softirq() || lgr->terminating) {
209 		rc = smc_wr_tx_get_free_slot_index(link, &idx);
210 		if (rc)
211 			return rc;
212 	} else {
213 		rc = wait_event_interruptible_timeout(
214 			link->wr_tx_wait,
215 			!smc_link_usable(link) ||
216 			lgr->terminating ||
217 			(smc_wr_tx_get_free_slot_index(link, &idx) != -EBUSY),
218 			SMC_WR_TX_WAIT_FREE_SLOT_TIME);
219 		if (!rc) {
220 			/* timeout - terminate link */
221 			smcr_link_down_cond_sched(link);
222 			return -EPIPE;
223 		}
224 		if (idx == link->wr_tx_cnt)
225 			return -EPIPE;
226 	}
227 	wr_id = smc_wr_tx_get_next_wr_id(link);
228 	wr_pend = &link->wr_tx_pends[idx];
229 	wr_pend->wr_id = wr_id;
230 	wr_pend->handler = handler;
231 	wr_pend->link = link;
232 	wr_pend->idx = idx;
233 	wr_ib = &link->wr_tx_ibs[idx];
234 	wr_ib->wr_id = wr_id;
235 	*wr_buf = &link->wr_tx_bufs[idx];
236 	if (wr_rdma_buf)
237 		*wr_rdma_buf = &link->wr_tx_rdmas[idx];
238 	*wr_pend_priv = &wr_pend->priv;
239 	return 0;
240 }
241 
242 int smc_wr_tx_put_slot(struct smc_link *link,
243 		       struct smc_wr_tx_pend_priv *wr_pend_priv)
244 {
245 	struct smc_wr_tx_pend *pend;
246 
247 	pend = container_of(wr_pend_priv, struct smc_wr_tx_pend, priv);
248 	if (pend->idx < link->wr_tx_cnt) {
249 		u32 idx = pend->idx;
250 
251 		/* clear the full struct smc_wr_tx_pend including .priv */
252 		memset(&link->wr_tx_pends[idx], 0,
253 		       sizeof(link->wr_tx_pends[idx]));
254 		memset(&link->wr_tx_bufs[idx], 0,
255 		       sizeof(link->wr_tx_bufs[idx]));
256 		test_and_clear_bit(idx, link->wr_tx_mask);
257 		wake_up(&link->wr_tx_wait);
258 		return 1;
259 	}
260 
261 	return 0;
262 }
263 
264 /* Send prepared WR slot via ib_post_send.
265  * @priv: pointer to smc_wr_tx_pend_priv identifying prepared message buffer
266  */
267 int smc_wr_tx_send(struct smc_link *link, struct smc_wr_tx_pend_priv *priv)
268 {
269 	struct smc_wr_tx_pend *pend;
270 	int rc;
271 
272 	ib_req_notify_cq(link->smcibdev->roce_cq_send,
273 			 IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
274 	pend = container_of(priv, struct smc_wr_tx_pend, priv);
275 	rc = ib_post_send(link->roce_qp, &link->wr_tx_ibs[pend->idx], NULL);
276 	if (rc) {
277 		smc_wr_tx_put_slot(link, priv);
278 		smcr_link_down_cond_sched(link);
279 	}
280 	return rc;
281 }
282 
283 /* Send prepared WR slot via ib_post_send and wait for send completion
284  * notification.
285  * @priv: pointer to smc_wr_tx_pend_priv identifying prepared message buffer
286  */
287 int smc_wr_tx_send_wait(struct smc_link *link, struct smc_wr_tx_pend_priv *priv,
288 			unsigned long timeout)
289 {
290 	struct smc_wr_tx_pend *pend;
291 	int rc;
292 
293 	pend = container_of(priv, struct smc_wr_tx_pend, priv);
294 	pend->compl_requested = 1;
295 	init_completion(&link->wr_tx_compl[pend->idx]);
296 
297 	rc = smc_wr_tx_send(link, priv);
298 	if (rc)
299 		return rc;
300 	/* wait for completion by smc_wr_tx_process_cqe() */
301 	rc = wait_for_completion_interruptible_timeout(
302 					&link->wr_tx_compl[pend->idx], timeout);
303 	if (rc <= 0)
304 		rc = -ENODATA;
305 	if (rc > 0)
306 		rc = 0;
307 	return rc;
308 }
309 
310 /* Register a memory region and wait for result. */
311 int smc_wr_reg_send(struct smc_link *link, struct ib_mr *mr)
312 {
313 	int rc;
314 
315 	ib_req_notify_cq(link->smcibdev->roce_cq_send,
316 			 IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
317 	link->wr_reg_state = POSTED;
318 	link->wr_reg.wr.wr_id = (u64)(uintptr_t)mr;
319 	link->wr_reg.mr = mr;
320 	link->wr_reg.key = mr->rkey;
321 	rc = ib_post_send(link->roce_qp, &link->wr_reg.wr, NULL);
322 	if (rc)
323 		return rc;
324 
325 	atomic_inc(&link->wr_reg_refcnt);
326 	rc = wait_event_interruptible_timeout(link->wr_reg_wait,
327 					      (link->wr_reg_state != POSTED),
328 					      SMC_WR_REG_MR_WAIT_TIME);
329 	if (atomic_dec_and_test(&link->wr_reg_refcnt))
330 		wake_up_all(&link->wr_reg_wait);
331 	if (!rc) {
332 		/* timeout - terminate link */
333 		smcr_link_down_cond_sched(link);
334 		return -EPIPE;
335 	}
336 	if (rc == -ERESTARTSYS)
337 		return -EINTR;
338 	switch (link->wr_reg_state) {
339 	case CONFIRMED:
340 		rc = 0;
341 		break;
342 	case FAILED:
343 		rc = -EIO;
344 		break;
345 	case POSTED:
346 		rc = -EPIPE;
347 		break;
348 	}
349 	return rc;
350 }
351 
352 void smc_wr_tx_dismiss_slots(struct smc_link *link, u8 wr_tx_hdr_type,
353 			     smc_wr_tx_filter filter,
354 			     smc_wr_tx_dismisser dismisser,
355 			     unsigned long data)
356 {
357 	struct smc_wr_tx_pend_priv *tx_pend;
358 	struct smc_wr_rx_hdr *wr_tx;
359 	int i;
360 
361 	for_each_set_bit(i, link->wr_tx_mask, link->wr_tx_cnt) {
362 		wr_tx = (struct smc_wr_rx_hdr *)&link->wr_tx_bufs[i];
363 		if (wr_tx->type != wr_tx_hdr_type)
364 			continue;
365 		tx_pend = &link->wr_tx_pends[i].priv;
366 		if (filter(tx_pend, data))
367 			dismisser(tx_pend);
368 	}
369 }
370 
371 /****************************** receive queue ********************************/
372 
373 int smc_wr_rx_register_handler(struct smc_wr_rx_handler *handler)
374 {
375 	struct smc_wr_rx_handler *h_iter;
376 	int rc = 0;
377 
378 	spin_lock(&smc_wr_rx_hash_lock);
379 	hash_for_each_possible(smc_wr_rx_hash, h_iter, list, handler->type) {
380 		if (h_iter->type == handler->type) {
381 			rc = -EEXIST;
382 			goto out_unlock;
383 		}
384 	}
385 	hash_add(smc_wr_rx_hash, &handler->list, handler->type);
386 out_unlock:
387 	spin_unlock(&smc_wr_rx_hash_lock);
388 	return rc;
389 }
390 
391 /* Demultiplex a received work request based on the message type to its handler.
392  * Relies on smc_wr_rx_hash having been completely filled before any IB WRs,
393  * and not being modified any more afterwards so we don't need to lock it.
394  */
395 static inline void smc_wr_rx_demultiplex(struct ib_wc *wc)
396 {
397 	struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
398 	struct smc_wr_rx_handler *handler;
399 	struct smc_wr_rx_hdr *wr_rx;
400 	u64 temp_wr_id;
401 	u32 index;
402 
403 	if (wc->byte_len < sizeof(*wr_rx))
404 		return; /* short message */
405 	temp_wr_id = wc->wr_id;
406 	index = do_div(temp_wr_id, link->wr_rx_cnt);
407 	wr_rx = (struct smc_wr_rx_hdr *)&link->wr_rx_bufs[index];
408 	hash_for_each_possible(smc_wr_rx_hash, handler, list, wr_rx->type) {
409 		if (handler->type == wr_rx->type)
410 			handler->handler(wc, wr_rx);
411 	}
412 }
413 
414 static inline void smc_wr_rx_process_cqes(struct ib_wc wc[], int num)
415 {
416 	struct smc_link *link;
417 	int i;
418 
419 	for (i = 0; i < num; i++) {
420 		link = wc[i].qp->qp_context;
421 		if (wc[i].status == IB_WC_SUCCESS) {
422 			link->wr_rx_tstamp = jiffies;
423 			smc_wr_rx_demultiplex(&wc[i]);
424 			smc_wr_rx_post(link); /* refill WR RX */
425 		} else {
426 			/* handle status errors */
427 			switch (wc[i].status) {
428 			case IB_WC_RETRY_EXC_ERR:
429 			case IB_WC_RNR_RETRY_EXC_ERR:
430 			case IB_WC_WR_FLUSH_ERR:
431 				smcr_link_down_cond_sched(link);
432 				break;
433 			default:
434 				smc_wr_rx_post(link); /* refill WR RX */
435 				break;
436 			}
437 		}
438 	}
439 }
440 
441 static void smc_wr_rx_tasklet_fn(struct tasklet_struct *t)
442 {
443 	struct smc_ib_device *dev = from_tasklet(dev, t, recv_tasklet);
444 	struct ib_wc wc[SMC_WR_MAX_POLL_CQE];
445 	int polled = 0;
446 	int rc;
447 
448 again:
449 	polled++;
450 	do {
451 		memset(&wc, 0, sizeof(wc));
452 		rc = ib_poll_cq(dev->roce_cq_recv, SMC_WR_MAX_POLL_CQE, wc);
453 		if (polled == 1) {
454 			ib_req_notify_cq(dev->roce_cq_recv,
455 					 IB_CQ_SOLICITED_MASK
456 					 | IB_CQ_REPORT_MISSED_EVENTS);
457 		}
458 		if (!rc)
459 			break;
460 		smc_wr_rx_process_cqes(&wc[0], rc);
461 	} while (rc > 0);
462 	if (polled == 1)
463 		goto again;
464 }
465 
466 void smc_wr_rx_cq_handler(struct ib_cq *ib_cq, void *cq_context)
467 {
468 	struct smc_ib_device *dev = (struct smc_ib_device *)cq_context;
469 
470 	tasklet_schedule(&dev->recv_tasklet);
471 }
472 
473 int smc_wr_rx_post_init(struct smc_link *link)
474 {
475 	u32 i;
476 	int rc = 0;
477 
478 	for (i = 0; i < link->wr_rx_cnt; i++)
479 		rc = smc_wr_rx_post(link);
480 	return rc;
481 }
482 
483 /***************************** init, exit, misc ******************************/
484 
485 void smc_wr_remember_qp_attr(struct smc_link *lnk)
486 {
487 	struct ib_qp_attr *attr = &lnk->qp_attr;
488 	struct ib_qp_init_attr init_attr;
489 
490 	memset(attr, 0, sizeof(*attr));
491 	memset(&init_attr, 0, sizeof(init_attr));
492 	ib_query_qp(lnk->roce_qp, attr,
493 		    IB_QP_STATE |
494 		    IB_QP_CUR_STATE |
495 		    IB_QP_PKEY_INDEX |
496 		    IB_QP_PORT |
497 		    IB_QP_QKEY |
498 		    IB_QP_AV |
499 		    IB_QP_PATH_MTU |
500 		    IB_QP_TIMEOUT |
501 		    IB_QP_RETRY_CNT |
502 		    IB_QP_RNR_RETRY |
503 		    IB_QP_RQ_PSN |
504 		    IB_QP_ALT_PATH |
505 		    IB_QP_MIN_RNR_TIMER |
506 		    IB_QP_SQ_PSN |
507 		    IB_QP_PATH_MIG_STATE |
508 		    IB_QP_CAP |
509 		    IB_QP_DEST_QPN,
510 		    &init_attr);
511 
512 	lnk->wr_tx_cnt = min_t(size_t, SMC_WR_BUF_CNT,
513 			       lnk->qp_attr.cap.max_send_wr);
514 	lnk->wr_rx_cnt = min_t(size_t, SMC_WR_BUF_CNT * 3,
515 			       lnk->qp_attr.cap.max_recv_wr);
516 }
517 
518 static void smc_wr_init_sge(struct smc_link *lnk)
519 {
520 	u32 i;
521 
522 	for (i = 0; i < lnk->wr_tx_cnt; i++) {
523 		lnk->wr_tx_sges[i].addr =
524 			lnk->wr_tx_dma_addr + i * SMC_WR_BUF_SIZE;
525 		lnk->wr_tx_sges[i].length = SMC_WR_TX_SIZE;
526 		lnk->wr_tx_sges[i].lkey = lnk->roce_pd->local_dma_lkey;
527 		lnk->wr_tx_rdma_sges[i].tx_rdma_sge[0].wr_tx_rdma_sge[0].lkey =
528 			lnk->roce_pd->local_dma_lkey;
529 		lnk->wr_tx_rdma_sges[i].tx_rdma_sge[0].wr_tx_rdma_sge[1].lkey =
530 			lnk->roce_pd->local_dma_lkey;
531 		lnk->wr_tx_rdma_sges[i].tx_rdma_sge[1].wr_tx_rdma_sge[0].lkey =
532 			lnk->roce_pd->local_dma_lkey;
533 		lnk->wr_tx_rdma_sges[i].tx_rdma_sge[1].wr_tx_rdma_sge[1].lkey =
534 			lnk->roce_pd->local_dma_lkey;
535 		lnk->wr_tx_ibs[i].next = NULL;
536 		lnk->wr_tx_ibs[i].sg_list = &lnk->wr_tx_sges[i];
537 		lnk->wr_tx_ibs[i].num_sge = 1;
538 		lnk->wr_tx_ibs[i].opcode = IB_WR_SEND;
539 		lnk->wr_tx_ibs[i].send_flags =
540 			IB_SEND_SIGNALED | IB_SEND_SOLICITED;
541 		lnk->wr_tx_rdmas[i].wr_tx_rdma[0].wr.opcode = IB_WR_RDMA_WRITE;
542 		lnk->wr_tx_rdmas[i].wr_tx_rdma[1].wr.opcode = IB_WR_RDMA_WRITE;
543 		lnk->wr_tx_rdmas[i].wr_tx_rdma[0].wr.sg_list =
544 			lnk->wr_tx_rdma_sges[i].tx_rdma_sge[0].wr_tx_rdma_sge;
545 		lnk->wr_tx_rdmas[i].wr_tx_rdma[1].wr.sg_list =
546 			lnk->wr_tx_rdma_sges[i].tx_rdma_sge[1].wr_tx_rdma_sge;
547 	}
548 	for (i = 0; i < lnk->wr_rx_cnt; i++) {
549 		lnk->wr_rx_sges[i].addr =
550 			lnk->wr_rx_dma_addr + i * SMC_WR_BUF_SIZE;
551 		lnk->wr_rx_sges[i].length = SMC_WR_BUF_SIZE;
552 		lnk->wr_rx_sges[i].lkey = lnk->roce_pd->local_dma_lkey;
553 		lnk->wr_rx_ibs[i].next = NULL;
554 		lnk->wr_rx_ibs[i].sg_list = &lnk->wr_rx_sges[i];
555 		lnk->wr_rx_ibs[i].num_sge = 1;
556 	}
557 	lnk->wr_reg.wr.next = NULL;
558 	lnk->wr_reg.wr.num_sge = 0;
559 	lnk->wr_reg.wr.send_flags = IB_SEND_SIGNALED;
560 	lnk->wr_reg.wr.opcode = IB_WR_REG_MR;
561 	lnk->wr_reg.access = IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE;
562 }
563 
564 void smc_wr_free_link(struct smc_link *lnk)
565 {
566 	struct ib_device *ibdev;
567 
568 	if (!lnk->smcibdev)
569 		return;
570 	ibdev = lnk->smcibdev->ibdev;
571 
572 	smc_wr_wakeup_reg_wait(lnk);
573 	smc_wr_wakeup_tx_wait(lnk);
574 
575 	if (smc_wr_tx_wait_no_pending_sends(lnk))
576 		memset(lnk->wr_tx_mask, 0,
577 		       BITS_TO_LONGS(SMC_WR_BUF_CNT) *
578 						sizeof(*lnk->wr_tx_mask));
579 	wait_event(lnk->wr_reg_wait, (!atomic_read(&lnk->wr_reg_refcnt)));
580 	wait_event(lnk->wr_tx_wait, (!atomic_read(&lnk->wr_tx_refcnt)));
581 
582 	if (lnk->wr_rx_dma_addr) {
583 		ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
584 				    SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
585 				    DMA_FROM_DEVICE);
586 		lnk->wr_rx_dma_addr = 0;
587 	}
588 	if (lnk->wr_tx_dma_addr) {
589 		ib_dma_unmap_single(ibdev, lnk->wr_tx_dma_addr,
590 				    SMC_WR_BUF_SIZE * lnk->wr_tx_cnt,
591 				    DMA_TO_DEVICE);
592 		lnk->wr_tx_dma_addr = 0;
593 	}
594 }
595 
596 void smc_wr_free_link_mem(struct smc_link *lnk)
597 {
598 	kfree(lnk->wr_tx_compl);
599 	lnk->wr_tx_compl = NULL;
600 	kfree(lnk->wr_tx_pends);
601 	lnk->wr_tx_pends = NULL;
602 	kfree(lnk->wr_tx_mask);
603 	lnk->wr_tx_mask = NULL;
604 	kfree(lnk->wr_tx_sges);
605 	lnk->wr_tx_sges = NULL;
606 	kfree(lnk->wr_tx_rdma_sges);
607 	lnk->wr_tx_rdma_sges = NULL;
608 	kfree(lnk->wr_rx_sges);
609 	lnk->wr_rx_sges = NULL;
610 	kfree(lnk->wr_tx_rdmas);
611 	lnk->wr_tx_rdmas = NULL;
612 	kfree(lnk->wr_rx_ibs);
613 	lnk->wr_rx_ibs = NULL;
614 	kfree(lnk->wr_tx_ibs);
615 	lnk->wr_tx_ibs = NULL;
616 	kfree(lnk->wr_tx_bufs);
617 	lnk->wr_tx_bufs = NULL;
618 	kfree(lnk->wr_rx_bufs);
619 	lnk->wr_rx_bufs = NULL;
620 }
621 
622 int smc_wr_alloc_link_mem(struct smc_link *link)
623 {
624 	/* allocate link related memory */
625 	link->wr_tx_bufs = kcalloc(SMC_WR_BUF_CNT, SMC_WR_BUF_SIZE, GFP_KERNEL);
626 	if (!link->wr_tx_bufs)
627 		goto no_mem;
628 	link->wr_rx_bufs = kcalloc(SMC_WR_BUF_CNT * 3, SMC_WR_BUF_SIZE,
629 				   GFP_KERNEL);
630 	if (!link->wr_rx_bufs)
631 		goto no_mem_wr_tx_bufs;
632 	link->wr_tx_ibs = kcalloc(SMC_WR_BUF_CNT, sizeof(link->wr_tx_ibs[0]),
633 				  GFP_KERNEL);
634 	if (!link->wr_tx_ibs)
635 		goto no_mem_wr_rx_bufs;
636 	link->wr_rx_ibs = kcalloc(SMC_WR_BUF_CNT * 3,
637 				  sizeof(link->wr_rx_ibs[0]),
638 				  GFP_KERNEL);
639 	if (!link->wr_rx_ibs)
640 		goto no_mem_wr_tx_ibs;
641 	link->wr_tx_rdmas = kcalloc(SMC_WR_BUF_CNT,
642 				    sizeof(link->wr_tx_rdmas[0]),
643 				    GFP_KERNEL);
644 	if (!link->wr_tx_rdmas)
645 		goto no_mem_wr_rx_ibs;
646 	link->wr_tx_rdma_sges = kcalloc(SMC_WR_BUF_CNT,
647 					sizeof(link->wr_tx_rdma_sges[0]),
648 					GFP_KERNEL);
649 	if (!link->wr_tx_rdma_sges)
650 		goto no_mem_wr_tx_rdmas;
651 	link->wr_tx_sges = kcalloc(SMC_WR_BUF_CNT, sizeof(link->wr_tx_sges[0]),
652 				   GFP_KERNEL);
653 	if (!link->wr_tx_sges)
654 		goto no_mem_wr_tx_rdma_sges;
655 	link->wr_rx_sges = kcalloc(SMC_WR_BUF_CNT * 3,
656 				   sizeof(link->wr_rx_sges[0]),
657 				   GFP_KERNEL);
658 	if (!link->wr_rx_sges)
659 		goto no_mem_wr_tx_sges;
660 	link->wr_tx_mask = kcalloc(BITS_TO_LONGS(SMC_WR_BUF_CNT),
661 				   sizeof(*link->wr_tx_mask),
662 				   GFP_KERNEL);
663 	if (!link->wr_tx_mask)
664 		goto no_mem_wr_rx_sges;
665 	link->wr_tx_pends = kcalloc(SMC_WR_BUF_CNT,
666 				    sizeof(link->wr_tx_pends[0]),
667 				    GFP_KERNEL);
668 	if (!link->wr_tx_pends)
669 		goto no_mem_wr_tx_mask;
670 	link->wr_tx_compl = kcalloc(SMC_WR_BUF_CNT,
671 				    sizeof(link->wr_tx_compl[0]),
672 				    GFP_KERNEL);
673 	if (!link->wr_tx_compl)
674 		goto no_mem_wr_tx_pends;
675 	return 0;
676 
677 no_mem_wr_tx_pends:
678 	kfree(link->wr_tx_pends);
679 no_mem_wr_tx_mask:
680 	kfree(link->wr_tx_mask);
681 no_mem_wr_rx_sges:
682 	kfree(link->wr_rx_sges);
683 no_mem_wr_tx_sges:
684 	kfree(link->wr_tx_sges);
685 no_mem_wr_tx_rdma_sges:
686 	kfree(link->wr_tx_rdma_sges);
687 no_mem_wr_tx_rdmas:
688 	kfree(link->wr_tx_rdmas);
689 no_mem_wr_rx_ibs:
690 	kfree(link->wr_rx_ibs);
691 no_mem_wr_tx_ibs:
692 	kfree(link->wr_tx_ibs);
693 no_mem_wr_rx_bufs:
694 	kfree(link->wr_rx_bufs);
695 no_mem_wr_tx_bufs:
696 	kfree(link->wr_tx_bufs);
697 no_mem:
698 	return -ENOMEM;
699 }
700 
701 void smc_wr_remove_dev(struct smc_ib_device *smcibdev)
702 {
703 	tasklet_kill(&smcibdev->recv_tasklet);
704 	tasklet_kill(&smcibdev->send_tasklet);
705 }
706 
707 void smc_wr_add_dev(struct smc_ib_device *smcibdev)
708 {
709 	tasklet_setup(&smcibdev->recv_tasklet, smc_wr_rx_tasklet_fn);
710 	tasklet_setup(&smcibdev->send_tasklet, smc_wr_tx_tasklet_fn);
711 }
712 
713 int smc_wr_create_link(struct smc_link *lnk)
714 {
715 	struct ib_device *ibdev = lnk->smcibdev->ibdev;
716 	int rc = 0;
717 
718 	smc_wr_tx_set_wr_id(&lnk->wr_tx_id, 0);
719 	lnk->wr_rx_id = 0;
720 	lnk->wr_rx_dma_addr = ib_dma_map_single(
721 		ibdev, lnk->wr_rx_bufs,	SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
722 		DMA_FROM_DEVICE);
723 	if (ib_dma_mapping_error(ibdev, lnk->wr_rx_dma_addr)) {
724 		lnk->wr_rx_dma_addr = 0;
725 		rc = -EIO;
726 		goto out;
727 	}
728 	lnk->wr_tx_dma_addr = ib_dma_map_single(
729 		ibdev, lnk->wr_tx_bufs,	SMC_WR_BUF_SIZE * lnk->wr_tx_cnt,
730 		DMA_TO_DEVICE);
731 	if (ib_dma_mapping_error(ibdev, lnk->wr_tx_dma_addr)) {
732 		rc = -EIO;
733 		goto dma_unmap;
734 	}
735 	smc_wr_init_sge(lnk);
736 	memset(lnk->wr_tx_mask, 0,
737 	       BITS_TO_LONGS(SMC_WR_BUF_CNT) * sizeof(*lnk->wr_tx_mask));
738 	init_waitqueue_head(&lnk->wr_tx_wait);
739 	atomic_set(&lnk->wr_tx_refcnt, 0);
740 	init_waitqueue_head(&lnk->wr_reg_wait);
741 	atomic_set(&lnk->wr_reg_refcnt, 0);
742 	return rc;
743 
744 dma_unmap:
745 	ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
746 			    SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
747 			    DMA_FROM_DEVICE);
748 	lnk->wr_rx_dma_addr = 0;
749 out:
750 	return rc;
751 }
752