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