xref: /linux/net/smc/smc_wr.c (revision 9406b485dea5e25bed7c81cd822747d494cc8bde)
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 };
48 
49 /******************************** send queue *********************************/
50 
51 /*------------------------------- completion --------------------------------*/
52 
53 /* returns true if at least one tx work request is pending on the given link */
54 static inline bool smc_wr_is_tx_pend(struct smc_link *link)
55 {
56 	if (find_first_bit(link->wr_tx_mask, link->wr_tx_cnt) !=
57 							link->wr_tx_cnt) {
58 		return true;
59 	}
60 	return false;
61 }
62 
63 /* wait till all pending tx work requests on the given link are completed */
64 int smc_wr_tx_wait_no_pending_sends(struct smc_link *link)
65 {
66 	if (wait_event_timeout(link->wr_tx_wait, !smc_wr_is_tx_pend(link),
67 			       SMC_WR_TX_WAIT_PENDING_TIME))
68 		return 0;
69 	else /* timeout */
70 		return -EPIPE;
71 }
72 
73 static inline int smc_wr_tx_find_pending_index(struct smc_link *link, u64 wr_id)
74 {
75 	u32 i;
76 
77 	for (i = 0; i < link->wr_tx_cnt; i++) {
78 		if (link->wr_tx_pends[i].wr_id == wr_id)
79 			return i;
80 	}
81 	return link->wr_tx_cnt;
82 }
83 
84 static inline void smc_wr_tx_process_cqe(struct ib_wc *wc)
85 {
86 	struct smc_wr_tx_pend pnd_snd;
87 	struct smc_link *link;
88 	u32 pnd_snd_idx;
89 	int i;
90 
91 	link = wc->qp->qp_context;
92 
93 	if (wc->opcode == IB_WC_REG_MR) {
94 		if (wc->status)
95 			link->wr_reg_state = FAILED;
96 		else
97 			link->wr_reg_state = CONFIRMED;
98 		smc_wr_wakeup_reg_wait(link);
99 		return;
100 	}
101 
102 	pnd_snd_idx = smc_wr_tx_find_pending_index(link, wc->wr_id);
103 	if (pnd_snd_idx == link->wr_tx_cnt)
104 		return;
105 	link->wr_tx_pends[pnd_snd_idx].wc_status = wc->status;
106 	memcpy(&pnd_snd, &link->wr_tx_pends[pnd_snd_idx], sizeof(pnd_snd));
107 	/* clear the full struct smc_wr_tx_pend including .priv */
108 	memset(&link->wr_tx_pends[pnd_snd_idx], 0,
109 	       sizeof(link->wr_tx_pends[pnd_snd_idx]));
110 	memset(&link->wr_tx_bufs[pnd_snd_idx], 0,
111 	       sizeof(link->wr_tx_bufs[pnd_snd_idx]));
112 	if (!test_and_clear_bit(pnd_snd_idx, link->wr_tx_mask))
113 		return;
114 	if (wc->status) {
115 		for_each_set_bit(i, link->wr_tx_mask, link->wr_tx_cnt) {
116 			/* clear full struct smc_wr_tx_pend including .priv */
117 			memset(&link->wr_tx_pends[i], 0,
118 			       sizeof(link->wr_tx_pends[i]));
119 			memset(&link->wr_tx_bufs[i], 0,
120 			       sizeof(link->wr_tx_bufs[i]));
121 			clear_bit(i, link->wr_tx_mask);
122 		}
123 		/* terminate link */
124 		smcr_link_down_cond_sched(link);
125 	}
126 	if (pnd_snd.handler)
127 		pnd_snd.handler(&pnd_snd.priv, link, wc->status);
128 	wake_up(&link->wr_tx_wait);
129 }
130 
131 static void smc_wr_tx_tasklet_fn(unsigned long data)
132 {
133 	struct smc_ib_device *dev = (struct smc_ib_device *)data;
134 	struct ib_wc wc[SMC_WR_MAX_POLL_CQE];
135 	int i = 0, rc;
136 	int polled = 0;
137 
138 again:
139 	polled++;
140 	do {
141 		memset(&wc, 0, sizeof(wc));
142 		rc = ib_poll_cq(dev->roce_cq_send, SMC_WR_MAX_POLL_CQE, wc);
143 		if (polled == 1) {
144 			ib_req_notify_cq(dev->roce_cq_send,
145 					 IB_CQ_NEXT_COMP |
146 					 IB_CQ_REPORT_MISSED_EVENTS);
147 		}
148 		if (!rc)
149 			break;
150 		for (i = 0; i < rc; i++)
151 			smc_wr_tx_process_cqe(&wc[i]);
152 	} while (rc > 0);
153 	if (polled == 1)
154 		goto again;
155 }
156 
157 void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context)
158 {
159 	struct smc_ib_device *dev = (struct smc_ib_device *)cq_context;
160 
161 	tasklet_schedule(&dev->send_tasklet);
162 }
163 
164 /*---------------------------- request submission ---------------------------*/
165 
166 static inline int smc_wr_tx_get_free_slot_index(struct smc_link *link, u32 *idx)
167 {
168 	*idx = link->wr_tx_cnt;
169 	for_each_clear_bit(*idx, link->wr_tx_mask, link->wr_tx_cnt) {
170 		if (!test_and_set_bit(*idx, link->wr_tx_mask))
171 			return 0;
172 	}
173 	*idx = link->wr_tx_cnt;
174 	return -EBUSY;
175 }
176 
177 /**
178  * smc_wr_tx_get_free_slot() - returns buffer for message assembly,
179  *			and sets info for pending transmit tracking
180  * @link:		Pointer to smc_link used to later send the message.
181  * @handler:		Send completion handler function pointer.
182  * @wr_buf:		Out value returns pointer to message buffer.
183  * @wr_rdma_buf:	Out value returns pointer to rdma work request.
184  * @wr_pend_priv:	Out value returns pointer serving as handler context.
185  *
186  * Return: 0 on success, or -errno on error.
187  */
188 int smc_wr_tx_get_free_slot(struct smc_link *link,
189 			    smc_wr_tx_handler handler,
190 			    struct smc_wr_buf **wr_buf,
191 			    struct smc_rdma_wr **wr_rdma_buf,
192 			    struct smc_wr_tx_pend_priv **wr_pend_priv)
193 {
194 	struct smc_link_group *lgr = smc_get_lgr(link);
195 	struct smc_wr_tx_pend *wr_pend;
196 	u32 idx = link->wr_tx_cnt;
197 	struct ib_send_wr *wr_ib;
198 	u64 wr_id;
199 	int rc;
200 
201 	*wr_buf = NULL;
202 	*wr_pend_priv = NULL;
203 	if (in_softirq() || lgr->terminating) {
204 		rc = smc_wr_tx_get_free_slot_index(link, &idx);
205 		if (rc)
206 			return rc;
207 	} else {
208 		rc = wait_event_interruptible_timeout(
209 			link->wr_tx_wait,
210 			!smc_link_usable(link) ||
211 			lgr->terminating ||
212 			(smc_wr_tx_get_free_slot_index(link, &idx) != -EBUSY),
213 			SMC_WR_TX_WAIT_FREE_SLOT_TIME);
214 		if (!rc) {
215 			/* timeout - terminate link */
216 			smcr_link_down_cond_sched(link);
217 			return -EPIPE;
218 		}
219 		if (idx == link->wr_tx_cnt)
220 			return -EPIPE;
221 	}
222 	wr_id = smc_wr_tx_get_next_wr_id(link);
223 	wr_pend = &link->wr_tx_pends[idx];
224 	wr_pend->wr_id = wr_id;
225 	wr_pend->handler = handler;
226 	wr_pend->link = link;
227 	wr_pend->idx = idx;
228 	wr_ib = &link->wr_tx_ibs[idx];
229 	wr_ib->wr_id = wr_id;
230 	*wr_buf = &link->wr_tx_bufs[idx];
231 	if (wr_rdma_buf)
232 		*wr_rdma_buf = &link->wr_tx_rdmas[idx];
233 	*wr_pend_priv = &wr_pend->priv;
234 	return 0;
235 }
236 
237 int smc_wr_tx_put_slot(struct smc_link *link,
238 		       struct smc_wr_tx_pend_priv *wr_pend_priv)
239 {
240 	struct smc_wr_tx_pend *pend;
241 
242 	pend = container_of(wr_pend_priv, struct smc_wr_tx_pend, priv);
243 	if (pend->idx < link->wr_tx_cnt) {
244 		u32 idx = pend->idx;
245 
246 		/* clear the full struct smc_wr_tx_pend including .priv */
247 		memset(&link->wr_tx_pends[idx], 0,
248 		       sizeof(link->wr_tx_pends[idx]));
249 		memset(&link->wr_tx_bufs[idx], 0,
250 		       sizeof(link->wr_tx_bufs[idx]));
251 		test_and_clear_bit(idx, link->wr_tx_mask);
252 		wake_up(&link->wr_tx_wait);
253 		return 1;
254 	}
255 
256 	return 0;
257 }
258 
259 /* Send prepared WR slot via ib_post_send.
260  * @priv: pointer to smc_wr_tx_pend_priv identifying prepared message buffer
261  */
262 int smc_wr_tx_send(struct smc_link *link, struct smc_wr_tx_pend_priv *priv)
263 {
264 	struct smc_wr_tx_pend *pend;
265 	int rc;
266 
267 	ib_req_notify_cq(link->smcibdev->roce_cq_send,
268 			 IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
269 	pend = container_of(priv, struct smc_wr_tx_pend, priv);
270 	rc = ib_post_send(link->roce_qp, &link->wr_tx_ibs[pend->idx], NULL);
271 	if (rc) {
272 		smc_wr_tx_put_slot(link, priv);
273 		smcr_link_down_cond_sched(link);
274 	}
275 	return rc;
276 }
277 
278 /* Register a memory region and wait for result. */
279 int smc_wr_reg_send(struct smc_link *link, struct ib_mr *mr)
280 {
281 	int rc;
282 
283 	ib_req_notify_cq(link->smcibdev->roce_cq_send,
284 			 IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS);
285 	link->wr_reg_state = POSTED;
286 	link->wr_reg.wr.wr_id = (u64)(uintptr_t)mr;
287 	link->wr_reg.mr = mr;
288 	link->wr_reg.key = mr->rkey;
289 	rc = ib_post_send(link->roce_qp, &link->wr_reg.wr, NULL);
290 	if (rc)
291 		return rc;
292 
293 	rc = wait_event_interruptible_timeout(link->wr_reg_wait,
294 					      (link->wr_reg_state != POSTED),
295 					      SMC_WR_REG_MR_WAIT_TIME);
296 	if (!rc) {
297 		/* timeout - terminate link */
298 		smcr_link_down_cond_sched(link);
299 		return -EPIPE;
300 	}
301 	if (rc == -ERESTARTSYS)
302 		return -EINTR;
303 	switch (link->wr_reg_state) {
304 	case CONFIRMED:
305 		rc = 0;
306 		break;
307 	case FAILED:
308 		rc = -EIO;
309 		break;
310 	case POSTED:
311 		rc = -EPIPE;
312 		break;
313 	}
314 	return rc;
315 }
316 
317 void smc_wr_tx_dismiss_slots(struct smc_link *link, u8 wr_tx_hdr_type,
318 			     smc_wr_tx_filter filter,
319 			     smc_wr_tx_dismisser dismisser,
320 			     unsigned long data)
321 {
322 	struct smc_wr_tx_pend_priv *tx_pend;
323 	struct smc_wr_rx_hdr *wr_tx;
324 	int i;
325 
326 	for_each_set_bit(i, link->wr_tx_mask, link->wr_tx_cnt) {
327 		wr_tx = (struct smc_wr_rx_hdr *)&link->wr_tx_bufs[i];
328 		if (wr_tx->type != wr_tx_hdr_type)
329 			continue;
330 		tx_pend = &link->wr_tx_pends[i].priv;
331 		if (filter(tx_pend, data))
332 			dismisser(tx_pend);
333 	}
334 }
335 
336 /****************************** receive queue ********************************/
337 
338 int smc_wr_rx_register_handler(struct smc_wr_rx_handler *handler)
339 {
340 	struct smc_wr_rx_handler *h_iter;
341 	int rc = 0;
342 
343 	spin_lock(&smc_wr_rx_hash_lock);
344 	hash_for_each_possible(smc_wr_rx_hash, h_iter, list, handler->type) {
345 		if (h_iter->type == handler->type) {
346 			rc = -EEXIST;
347 			goto out_unlock;
348 		}
349 	}
350 	hash_add(smc_wr_rx_hash, &handler->list, handler->type);
351 out_unlock:
352 	spin_unlock(&smc_wr_rx_hash_lock);
353 	return rc;
354 }
355 
356 /* Demultiplex a received work request based on the message type to its handler.
357  * Relies on smc_wr_rx_hash having been completely filled before any IB WRs,
358  * and not being modified any more afterwards so we don't need to lock it.
359  */
360 static inline void smc_wr_rx_demultiplex(struct ib_wc *wc)
361 {
362 	struct smc_link *link = (struct smc_link *)wc->qp->qp_context;
363 	struct smc_wr_rx_handler *handler;
364 	struct smc_wr_rx_hdr *wr_rx;
365 	u64 temp_wr_id;
366 	u32 index;
367 
368 	if (wc->byte_len < sizeof(*wr_rx))
369 		return; /* short message */
370 	temp_wr_id = wc->wr_id;
371 	index = do_div(temp_wr_id, link->wr_rx_cnt);
372 	wr_rx = (struct smc_wr_rx_hdr *)&link->wr_rx_bufs[index];
373 	hash_for_each_possible(smc_wr_rx_hash, handler, list, wr_rx->type) {
374 		if (handler->type == wr_rx->type)
375 			handler->handler(wc, wr_rx);
376 	}
377 }
378 
379 static inline void smc_wr_rx_process_cqes(struct ib_wc wc[], int num)
380 {
381 	struct smc_link *link;
382 	int i;
383 
384 	for (i = 0; i < num; i++) {
385 		link = wc[i].qp->qp_context;
386 		if (wc[i].status == IB_WC_SUCCESS) {
387 			link->wr_rx_tstamp = jiffies;
388 			smc_wr_rx_demultiplex(&wc[i]);
389 			smc_wr_rx_post(link); /* refill WR RX */
390 		} else {
391 			/* handle status errors */
392 			switch (wc[i].status) {
393 			case IB_WC_RETRY_EXC_ERR:
394 			case IB_WC_RNR_RETRY_EXC_ERR:
395 			case IB_WC_WR_FLUSH_ERR:
396 				smcr_link_down_cond_sched(link);
397 				break;
398 			default:
399 				smc_wr_rx_post(link); /* refill WR RX */
400 				break;
401 			}
402 		}
403 	}
404 }
405 
406 static void smc_wr_rx_tasklet_fn(unsigned long data)
407 {
408 	struct smc_ib_device *dev = (struct smc_ib_device *)data;
409 	struct ib_wc wc[SMC_WR_MAX_POLL_CQE];
410 	int polled = 0;
411 	int rc;
412 
413 again:
414 	polled++;
415 	do {
416 		memset(&wc, 0, sizeof(wc));
417 		rc = ib_poll_cq(dev->roce_cq_recv, SMC_WR_MAX_POLL_CQE, wc);
418 		if (polled == 1) {
419 			ib_req_notify_cq(dev->roce_cq_recv,
420 					 IB_CQ_SOLICITED_MASK
421 					 | IB_CQ_REPORT_MISSED_EVENTS);
422 		}
423 		if (!rc)
424 			break;
425 		smc_wr_rx_process_cqes(&wc[0], rc);
426 	} while (rc > 0);
427 	if (polled == 1)
428 		goto again;
429 }
430 
431 void smc_wr_rx_cq_handler(struct ib_cq *ib_cq, void *cq_context)
432 {
433 	struct smc_ib_device *dev = (struct smc_ib_device *)cq_context;
434 
435 	tasklet_schedule(&dev->recv_tasklet);
436 }
437 
438 int smc_wr_rx_post_init(struct smc_link *link)
439 {
440 	u32 i;
441 	int rc = 0;
442 
443 	for (i = 0; i < link->wr_rx_cnt; i++)
444 		rc = smc_wr_rx_post(link);
445 	return rc;
446 }
447 
448 /***************************** init, exit, misc ******************************/
449 
450 void smc_wr_remember_qp_attr(struct smc_link *lnk)
451 {
452 	struct ib_qp_attr *attr = &lnk->qp_attr;
453 	struct ib_qp_init_attr init_attr;
454 
455 	memset(attr, 0, sizeof(*attr));
456 	memset(&init_attr, 0, sizeof(init_attr));
457 	ib_query_qp(lnk->roce_qp, attr,
458 		    IB_QP_STATE |
459 		    IB_QP_CUR_STATE |
460 		    IB_QP_PKEY_INDEX |
461 		    IB_QP_PORT |
462 		    IB_QP_QKEY |
463 		    IB_QP_AV |
464 		    IB_QP_PATH_MTU |
465 		    IB_QP_TIMEOUT |
466 		    IB_QP_RETRY_CNT |
467 		    IB_QP_RNR_RETRY |
468 		    IB_QP_RQ_PSN |
469 		    IB_QP_ALT_PATH |
470 		    IB_QP_MIN_RNR_TIMER |
471 		    IB_QP_SQ_PSN |
472 		    IB_QP_PATH_MIG_STATE |
473 		    IB_QP_CAP |
474 		    IB_QP_DEST_QPN,
475 		    &init_attr);
476 
477 	lnk->wr_tx_cnt = min_t(size_t, SMC_WR_BUF_CNT,
478 			       lnk->qp_attr.cap.max_send_wr);
479 	lnk->wr_rx_cnt = min_t(size_t, SMC_WR_BUF_CNT * 3,
480 			       lnk->qp_attr.cap.max_recv_wr);
481 }
482 
483 static void smc_wr_init_sge(struct smc_link *lnk)
484 {
485 	u32 i;
486 
487 	for (i = 0; i < lnk->wr_tx_cnt; i++) {
488 		lnk->wr_tx_sges[i].addr =
489 			lnk->wr_tx_dma_addr + i * SMC_WR_BUF_SIZE;
490 		lnk->wr_tx_sges[i].length = SMC_WR_TX_SIZE;
491 		lnk->wr_tx_sges[i].lkey = lnk->roce_pd->local_dma_lkey;
492 		lnk->wr_tx_rdma_sges[i].tx_rdma_sge[0].wr_tx_rdma_sge[0].lkey =
493 			lnk->roce_pd->local_dma_lkey;
494 		lnk->wr_tx_rdma_sges[i].tx_rdma_sge[0].wr_tx_rdma_sge[1].lkey =
495 			lnk->roce_pd->local_dma_lkey;
496 		lnk->wr_tx_rdma_sges[i].tx_rdma_sge[1].wr_tx_rdma_sge[0].lkey =
497 			lnk->roce_pd->local_dma_lkey;
498 		lnk->wr_tx_rdma_sges[i].tx_rdma_sge[1].wr_tx_rdma_sge[1].lkey =
499 			lnk->roce_pd->local_dma_lkey;
500 		lnk->wr_tx_ibs[i].next = NULL;
501 		lnk->wr_tx_ibs[i].sg_list = &lnk->wr_tx_sges[i];
502 		lnk->wr_tx_ibs[i].num_sge = 1;
503 		lnk->wr_tx_ibs[i].opcode = IB_WR_SEND;
504 		lnk->wr_tx_ibs[i].send_flags =
505 			IB_SEND_SIGNALED | IB_SEND_SOLICITED;
506 		lnk->wr_tx_rdmas[i].wr_tx_rdma[0].wr.opcode = IB_WR_RDMA_WRITE;
507 		lnk->wr_tx_rdmas[i].wr_tx_rdma[1].wr.opcode = IB_WR_RDMA_WRITE;
508 		lnk->wr_tx_rdmas[i].wr_tx_rdma[0].wr.sg_list =
509 			lnk->wr_tx_rdma_sges[i].tx_rdma_sge[0].wr_tx_rdma_sge;
510 		lnk->wr_tx_rdmas[i].wr_tx_rdma[1].wr.sg_list =
511 			lnk->wr_tx_rdma_sges[i].tx_rdma_sge[1].wr_tx_rdma_sge;
512 	}
513 	for (i = 0; i < lnk->wr_rx_cnt; i++) {
514 		lnk->wr_rx_sges[i].addr =
515 			lnk->wr_rx_dma_addr + i * SMC_WR_BUF_SIZE;
516 		lnk->wr_rx_sges[i].length = SMC_WR_BUF_SIZE;
517 		lnk->wr_rx_sges[i].lkey = lnk->roce_pd->local_dma_lkey;
518 		lnk->wr_rx_ibs[i].next = NULL;
519 		lnk->wr_rx_ibs[i].sg_list = &lnk->wr_rx_sges[i];
520 		lnk->wr_rx_ibs[i].num_sge = 1;
521 	}
522 	lnk->wr_reg.wr.next = NULL;
523 	lnk->wr_reg.wr.num_sge = 0;
524 	lnk->wr_reg.wr.send_flags = IB_SEND_SIGNALED;
525 	lnk->wr_reg.wr.opcode = IB_WR_REG_MR;
526 	lnk->wr_reg.access = IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_WRITE;
527 }
528 
529 void smc_wr_free_link(struct smc_link *lnk)
530 {
531 	struct ib_device *ibdev;
532 
533 	if (smc_wr_tx_wait_no_pending_sends(lnk))
534 		memset(lnk->wr_tx_mask, 0,
535 		       BITS_TO_LONGS(SMC_WR_BUF_CNT) *
536 						sizeof(*lnk->wr_tx_mask));
537 
538 	if (!lnk->smcibdev)
539 		return;
540 	ibdev = lnk->smcibdev->ibdev;
541 
542 	if (lnk->wr_rx_dma_addr) {
543 		ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
544 				    SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
545 				    DMA_FROM_DEVICE);
546 		lnk->wr_rx_dma_addr = 0;
547 	}
548 	if (lnk->wr_tx_dma_addr) {
549 		ib_dma_unmap_single(ibdev, lnk->wr_tx_dma_addr,
550 				    SMC_WR_BUF_SIZE * lnk->wr_tx_cnt,
551 				    DMA_TO_DEVICE);
552 		lnk->wr_tx_dma_addr = 0;
553 	}
554 }
555 
556 void smc_wr_free_link_mem(struct smc_link *lnk)
557 {
558 	kfree(lnk->wr_tx_pends);
559 	lnk->wr_tx_pends = NULL;
560 	kfree(lnk->wr_tx_mask);
561 	lnk->wr_tx_mask = NULL;
562 	kfree(lnk->wr_tx_sges);
563 	lnk->wr_tx_sges = NULL;
564 	kfree(lnk->wr_tx_rdma_sges);
565 	lnk->wr_tx_rdma_sges = NULL;
566 	kfree(lnk->wr_rx_sges);
567 	lnk->wr_rx_sges = NULL;
568 	kfree(lnk->wr_tx_rdmas);
569 	lnk->wr_tx_rdmas = NULL;
570 	kfree(lnk->wr_rx_ibs);
571 	lnk->wr_rx_ibs = NULL;
572 	kfree(lnk->wr_tx_ibs);
573 	lnk->wr_tx_ibs = NULL;
574 	kfree(lnk->wr_tx_bufs);
575 	lnk->wr_tx_bufs = NULL;
576 	kfree(lnk->wr_rx_bufs);
577 	lnk->wr_rx_bufs = NULL;
578 }
579 
580 int smc_wr_alloc_link_mem(struct smc_link *link)
581 {
582 	/* allocate link related memory */
583 	link->wr_tx_bufs = kcalloc(SMC_WR_BUF_CNT, SMC_WR_BUF_SIZE, GFP_KERNEL);
584 	if (!link->wr_tx_bufs)
585 		goto no_mem;
586 	link->wr_rx_bufs = kcalloc(SMC_WR_BUF_CNT * 3, SMC_WR_BUF_SIZE,
587 				   GFP_KERNEL);
588 	if (!link->wr_rx_bufs)
589 		goto no_mem_wr_tx_bufs;
590 	link->wr_tx_ibs = kcalloc(SMC_WR_BUF_CNT, sizeof(link->wr_tx_ibs[0]),
591 				  GFP_KERNEL);
592 	if (!link->wr_tx_ibs)
593 		goto no_mem_wr_rx_bufs;
594 	link->wr_rx_ibs = kcalloc(SMC_WR_BUF_CNT * 3,
595 				  sizeof(link->wr_rx_ibs[0]),
596 				  GFP_KERNEL);
597 	if (!link->wr_rx_ibs)
598 		goto no_mem_wr_tx_ibs;
599 	link->wr_tx_rdmas = kcalloc(SMC_WR_BUF_CNT,
600 				    sizeof(link->wr_tx_rdmas[0]),
601 				    GFP_KERNEL);
602 	if (!link->wr_tx_rdmas)
603 		goto no_mem_wr_rx_ibs;
604 	link->wr_tx_rdma_sges = kcalloc(SMC_WR_BUF_CNT,
605 					sizeof(link->wr_tx_rdma_sges[0]),
606 					GFP_KERNEL);
607 	if (!link->wr_tx_rdma_sges)
608 		goto no_mem_wr_tx_rdmas;
609 	link->wr_tx_sges = kcalloc(SMC_WR_BUF_CNT, sizeof(link->wr_tx_sges[0]),
610 				   GFP_KERNEL);
611 	if (!link->wr_tx_sges)
612 		goto no_mem_wr_tx_rdma_sges;
613 	link->wr_rx_sges = kcalloc(SMC_WR_BUF_CNT * 3,
614 				   sizeof(link->wr_rx_sges[0]),
615 				   GFP_KERNEL);
616 	if (!link->wr_rx_sges)
617 		goto no_mem_wr_tx_sges;
618 	link->wr_tx_mask = kcalloc(BITS_TO_LONGS(SMC_WR_BUF_CNT),
619 				   sizeof(*link->wr_tx_mask),
620 				   GFP_KERNEL);
621 	if (!link->wr_tx_mask)
622 		goto no_mem_wr_rx_sges;
623 	link->wr_tx_pends = kcalloc(SMC_WR_BUF_CNT,
624 				    sizeof(link->wr_tx_pends[0]),
625 				    GFP_KERNEL);
626 	if (!link->wr_tx_pends)
627 		goto no_mem_wr_tx_mask;
628 	return 0;
629 
630 no_mem_wr_tx_mask:
631 	kfree(link->wr_tx_mask);
632 no_mem_wr_rx_sges:
633 	kfree(link->wr_rx_sges);
634 no_mem_wr_tx_sges:
635 	kfree(link->wr_tx_sges);
636 no_mem_wr_tx_rdma_sges:
637 	kfree(link->wr_tx_rdma_sges);
638 no_mem_wr_tx_rdmas:
639 	kfree(link->wr_tx_rdmas);
640 no_mem_wr_rx_ibs:
641 	kfree(link->wr_rx_ibs);
642 no_mem_wr_tx_ibs:
643 	kfree(link->wr_tx_ibs);
644 no_mem_wr_rx_bufs:
645 	kfree(link->wr_rx_bufs);
646 no_mem_wr_tx_bufs:
647 	kfree(link->wr_tx_bufs);
648 no_mem:
649 	return -ENOMEM;
650 }
651 
652 void smc_wr_remove_dev(struct smc_ib_device *smcibdev)
653 {
654 	tasklet_kill(&smcibdev->recv_tasklet);
655 	tasklet_kill(&smcibdev->send_tasklet);
656 }
657 
658 void smc_wr_add_dev(struct smc_ib_device *smcibdev)
659 {
660 	tasklet_init(&smcibdev->recv_tasklet, smc_wr_rx_tasklet_fn,
661 		     (unsigned long)smcibdev);
662 	tasklet_init(&smcibdev->send_tasklet, smc_wr_tx_tasklet_fn,
663 		     (unsigned long)smcibdev);
664 }
665 
666 int smc_wr_create_link(struct smc_link *lnk)
667 {
668 	struct ib_device *ibdev = lnk->smcibdev->ibdev;
669 	int rc = 0;
670 
671 	smc_wr_tx_set_wr_id(&lnk->wr_tx_id, 0);
672 	lnk->wr_rx_id = 0;
673 	lnk->wr_rx_dma_addr = ib_dma_map_single(
674 		ibdev, lnk->wr_rx_bufs,	SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
675 		DMA_FROM_DEVICE);
676 	if (ib_dma_mapping_error(ibdev, lnk->wr_rx_dma_addr)) {
677 		lnk->wr_rx_dma_addr = 0;
678 		rc = -EIO;
679 		goto out;
680 	}
681 	lnk->wr_tx_dma_addr = ib_dma_map_single(
682 		ibdev, lnk->wr_tx_bufs,	SMC_WR_BUF_SIZE * lnk->wr_tx_cnt,
683 		DMA_TO_DEVICE);
684 	if (ib_dma_mapping_error(ibdev, lnk->wr_tx_dma_addr)) {
685 		rc = -EIO;
686 		goto dma_unmap;
687 	}
688 	smc_wr_init_sge(lnk);
689 	memset(lnk->wr_tx_mask, 0,
690 	       BITS_TO_LONGS(SMC_WR_BUF_CNT) * sizeof(*lnk->wr_tx_mask));
691 	init_waitqueue_head(&lnk->wr_tx_wait);
692 	init_waitqueue_head(&lnk->wr_reg_wait);
693 	return rc;
694 
695 dma_unmap:
696 	ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr,
697 			    SMC_WR_BUF_SIZE * lnk->wr_rx_cnt,
698 			    DMA_FROM_DEVICE);
699 	lnk->wr_rx_dma_addr = 0;
700 out:
701 	return rc;
702 }
703