xref: /linux/drivers/scsi/snic/snic_disc.c (revision b4db9f840283caca0d904436f187ef56a9126eaa)
1 // SPDX-License-Identifier: GPL-2.0-only
2 // Copyright 2014 Cisco Systems, Inc.  All rights reserved.
3 
4 #include <linux/errno.h>
5 #include <linux/mempool.h>
6 
7 #include <scsi/scsi_tcq.h>
8 
9 #include "snic_disc.h"
10 #include "snic.h"
11 #include "snic_io.h"
12 
13 
14 /* snic target types */
15 static const char * const snic_tgt_type_str[] = {
16 	[SNIC_TGT_DAS] = "DAS",
17 	[SNIC_TGT_SAN] = "SAN",
18 };
19 
20 static inline const char *
21 snic_tgt_type_to_str(int typ)
22 {
23 	return ((typ > SNIC_TGT_NONE && typ <= SNIC_TGT_SAN) ?
24 		 snic_tgt_type_str[typ] : "Unknown");
25 }
26 
27 static const char * const snic_tgt_state_str[] = {
28 	[SNIC_TGT_STAT_INIT]	= "INIT",
29 	[SNIC_TGT_STAT_ONLINE]	= "ONLINE",
30 	[SNIC_TGT_STAT_OFFLINE]	= "OFFLINE",
31 	[SNIC_TGT_STAT_DEL]	= "DELETION IN PROGRESS",
32 };
33 
34 const char *
35 snic_tgt_state_to_str(int state)
36 {
37 	return ((state >= SNIC_TGT_STAT_INIT && state <= SNIC_TGT_STAT_DEL) ?
38 		snic_tgt_state_str[state] : "UNKNOWN");
39 }
40 
41 /*
42  * Initiate report_tgt req desc
43  */
44 static void
45 snic_report_tgt_init(struct snic_host_req *req, u32 hid, u8 *buf, u32 len,
46 		     dma_addr_t rsp_buf_pa, ulong ctx)
47 {
48 	struct snic_sg_desc *sgd = NULL;
49 
50 
51 	snic_io_hdr_enc(&req->hdr, SNIC_REQ_REPORT_TGTS, 0, SCSI_NO_TAG, hid,
52 			1, ctx);
53 
54 	req->u.rpt_tgts.sg_cnt = cpu_to_le16(1);
55 	sgd = req_to_sgl(req);
56 	sgd[0].addr = cpu_to_le64(rsp_buf_pa);
57 	sgd[0].len = cpu_to_le32(len);
58 	sgd[0]._resvd = 0;
59 	req->u.rpt_tgts.sg_addr = cpu_to_le64((ulong)sgd);
60 }
61 
62 /*
63  * snic_queue_report_tgt_req: Queues report target request.
64  */
65 static int
66 snic_queue_report_tgt_req(struct snic *snic)
67 {
68 	struct snic_req_info *rqi = NULL;
69 	u32 ntgts, buf_len = 0;
70 	u8 *buf = NULL;
71 	dma_addr_t pa = 0;
72 	int ret = 0;
73 
74 	rqi = snic_req_init(snic, 1);
75 	if (!rqi) {
76 		ret = -ENOMEM;
77 		goto error;
78 	}
79 
80 	if (snic->fwinfo.max_tgts)
81 		ntgts = min_t(u32, snic->fwinfo.max_tgts, snic->shost->max_id);
82 	else
83 		ntgts = snic->shost->max_id;
84 
85 	/* Allocate Response Buffer */
86 	SNIC_BUG_ON(ntgts == 0);
87 	buf_len = ntgts * sizeof(struct snic_tgt_id) + SNIC_SG_DESC_ALIGN;
88 
89 	buf = kzalloc(buf_len, GFP_KERNEL);
90 	if (!buf) {
91 		snic_req_free(snic, rqi);
92 		SNIC_HOST_ERR(snic->shost, "Resp Buf Alloc Failed.\n");
93 
94 		ret = -ENOMEM;
95 		goto error;
96 	}
97 
98 	SNIC_BUG_ON((((unsigned long)buf) % SNIC_SG_DESC_ALIGN) != 0);
99 
100 	pa = dma_map_single(&snic->pdev->dev, buf, buf_len, DMA_FROM_DEVICE);
101 	if (dma_mapping_error(&snic->pdev->dev, pa)) {
102 		SNIC_HOST_ERR(snic->shost,
103 			      "Rpt-tgt rspbuf %p: PCI DMA Mapping Failed\n",
104 			      buf);
105 		kfree(buf);
106 		snic_req_free(snic, rqi);
107 		ret = -EINVAL;
108 
109 		goto error;
110 	}
111 
112 
113 	SNIC_BUG_ON(pa == 0);
114 	rqi->sge_va = (ulong) buf;
115 
116 	snic_report_tgt_init(rqi->req,
117 			     snic->config.hid,
118 			     buf,
119 			     buf_len,
120 			     pa,
121 			     (ulong)rqi);
122 
123 	snic_handle_untagged_req(snic, rqi);
124 
125 	ret = snic_queue_wq_desc(snic, rqi->req, rqi->req_len);
126 	if (ret) {
127 		dma_unmap_single(&snic->pdev->dev, pa, buf_len,
128 				 DMA_FROM_DEVICE);
129 		kfree(buf);
130 		rqi->sge_va = 0;
131 		snic_release_untagged_req(snic, rqi);
132 		SNIC_HOST_ERR(snic->shost, "Queuing Report Tgts Failed.\n");
133 
134 		goto error;
135 	}
136 
137 	SNIC_DISC_DBG(snic->shost, "Report Targets Issued.\n");
138 
139 	return ret;
140 
141 error:
142 	SNIC_HOST_ERR(snic->shost,
143 		      "Queuing Report Targets Failed, err = %d\n",
144 		      ret);
145 	return ret;
146 } /* end of snic_queue_report_tgt_req */
147 
148 /* call into SML */
149 static void
150 snic_scsi_scan_tgt(struct work_struct *work)
151 {
152 	struct snic_tgt *tgt = container_of(work, struct snic_tgt, scan_work);
153 	struct Scsi_Host *shost = dev_to_shost(&tgt->dev);
154 	unsigned long flags;
155 
156 	SNIC_HOST_INFO(shost, "Scanning Target id 0x%x\n", tgt->id);
157 	scsi_scan_target(&tgt->dev,
158 			 tgt->channel,
159 			 tgt->scsi_tgt_id,
160 			 SCAN_WILD_CARD,
161 			 SCSI_SCAN_RESCAN);
162 
163 	spin_lock_irqsave(shost->host_lock, flags);
164 	tgt->flags &= ~SNIC_TGT_SCAN_PENDING;
165 	spin_unlock_irqrestore(shost->host_lock, flags);
166 } /* end of snic_scsi_scan_tgt */
167 
168 /*
169  * snic_tgt_lookup :
170  */
171 static struct snic_tgt *
172 snic_tgt_lookup(struct snic *snic, struct snic_tgt_id *tgtid)
173 {
174 	struct list_head *cur, *nxt;
175 	struct snic_tgt *tgt = NULL;
176 
177 	list_for_each_safe(cur, nxt, &snic->disc.tgt_list) {
178 		tgt = list_entry(cur, struct snic_tgt, list);
179 		if (tgt->id == le32_to_cpu(tgtid->tgt_id))
180 			return tgt;
181 		tgt = NULL;
182 	}
183 
184 	return tgt;
185 } /* end of snic_tgt_lookup */
186 
187 /*
188  * snic_tgt_dev_release : Called on dropping last ref for snic_tgt object
189  */
190 void
191 snic_tgt_dev_release(struct device *dev)
192 {
193 	struct snic_tgt *tgt = dev_to_tgt(dev);
194 
195 	SNIC_HOST_INFO(snic_tgt_to_shost(tgt),
196 		       "Target Device ID %d (%s) Permanently Deleted.\n",
197 		       tgt->id,
198 		       dev_name(dev));
199 
200 	SNIC_BUG_ON(!list_empty(&tgt->list));
201 	kfree(tgt);
202 }
203 
204 /*
205  * snic_tgt_del : work function to delete snic_tgt
206  */
207 static void
208 snic_tgt_del(struct work_struct *work)
209 {
210 	struct snic_tgt *tgt = container_of(work, struct snic_tgt, del_work);
211 	struct Scsi_Host *shost = snic_tgt_to_shost(tgt);
212 
213 	if (tgt->flags & SNIC_TGT_SCAN_PENDING)
214 		scsi_flush_work(shost);
215 
216 	/* Block IOs on child devices, stops new IOs */
217 	scsi_block_targets(shost, &tgt->dev);
218 
219 	/* Cleanup IOs */
220 	snic_tgt_scsi_abort_io(tgt);
221 
222 	/* Unblock IOs now, to flush if there are any. */
223 	scsi_target_unblock(&tgt->dev, SDEV_TRANSPORT_OFFLINE);
224 
225 	/* Delete SCSI Target and sdevs */
226 	scsi_remove_target(&tgt->dev);  /* ?? */
227 	device_del(&tgt->dev);
228 	put_device(&tgt->dev);
229 } /* end of snic_tgt_del */
230 
231 /* snic_tgt_create: checks for existence of snic_tgt, if it doesn't
232  * it creates one.
233  */
234 static struct snic_tgt *
235 snic_tgt_create(struct snic *snic, struct snic_tgt_id *tgtid)
236 {
237 	struct snic_tgt *tgt = NULL;
238 	unsigned long flags;
239 	int ret;
240 
241 	tgt = snic_tgt_lookup(snic, tgtid);
242 	if (tgt) {
243 		/* update the information if required */
244 		return tgt;
245 	}
246 
247 	tgt = kzalloc(sizeof(*tgt), GFP_KERNEL);
248 	if (!tgt) {
249 		SNIC_HOST_ERR(snic->shost, "Failure to allocate snic_tgt.\n");
250 		ret = -ENOMEM;
251 
252 		return tgt;
253 	}
254 
255 	INIT_LIST_HEAD(&tgt->list);
256 	tgt->id = le32_to_cpu(tgtid->tgt_id);
257 	tgt->channel = 0;
258 
259 	SNIC_BUG_ON(le16_to_cpu(tgtid->tgt_type) > SNIC_TGT_SAN);
260 	tgt->tdata.typ = le16_to_cpu(tgtid->tgt_type);
261 
262 	/*
263 	 * Plugging into SML Device Tree
264 	 */
265 	tgt->tdata.disc_id = 0;
266 	tgt->state = SNIC_TGT_STAT_INIT;
267 	device_initialize(&tgt->dev);
268 	tgt->dev.parent = get_device(&snic->shost->shost_gendev);
269 	tgt->dev.release = snic_tgt_dev_release;
270 	INIT_WORK(&tgt->scan_work, snic_scsi_scan_tgt);
271 	INIT_WORK(&tgt->del_work, snic_tgt_del);
272 	switch (tgt->tdata.typ) {
273 	case SNIC_TGT_DAS:
274 		dev_set_name(&tgt->dev, "snic_das_tgt:%d:%d-%d",
275 			     snic->shost->host_no, tgt->channel, tgt->id);
276 		break;
277 
278 	case SNIC_TGT_SAN:
279 		dev_set_name(&tgt->dev, "snic_san_tgt:%d:%d-%d",
280 			     snic->shost->host_no, tgt->channel, tgt->id);
281 		break;
282 
283 	default:
284 		SNIC_HOST_INFO(snic->shost, "Target type Unknown Detected.\n");
285 		dev_set_name(&tgt->dev, "snic_das_tgt:%d:%d-%d",
286 			     snic->shost->host_no, tgt->channel, tgt->id);
287 		break;
288 	}
289 
290 	spin_lock_irqsave(snic->shost->host_lock, flags);
291 	list_add_tail(&tgt->list, &snic->disc.tgt_list);
292 	tgt->scsi_tgt_id = snic->disc.nxt_tgt_id++;
293 	tgt->state = SNIC_TGT_STAT_ONLINE;
294 	spin_unlock_irqrestore(snic->shost->host_lock, flags);
295 
296 	SNIC_HOST_INFO(snic->shost,
297 		       "Tgt %d, type = %s detected. Adding..\n",
298 		       tgt->id, snic_tgt_type_to_str(tgt->tdata.typ));
299 
300 	ret = device_add(&tgt->dev);
301 	if (ret) {
302 		SNIC_HOST_ERR(snic->shost,
303 			      "Snic Tgt: device_add, with err = %d\n",
304 			      ret);
305 
306 		put_device(&snic->shost->shost_gendev);
307 		spin_lock_irqsave(snic->shost->host_lock, flags);
308 		list_del(&tgt->list);
309 		spin_unlock_irqrestore(snic->shost->host_lock, flags);
310 		put_device(&tgt->dev);
311 		tgt = NULL;
312 
313 		return tgt;
314 	}
315 
316 	SNIC_HOST_INFO(snic->shost, "Scanning %s.\n", dev_name(&tgt->dev));
317 
318 	scsi_queue_work(snic->shost, &tgt->scan_work);
319 
320 	return tgt;
321 } /* end of snic_tgt_create */
322 
323 /* Handler for discovery */
324 void
325 snic_handle_tgt_disc(struct work_struct *work)
326 {
327 	struct snic *snic = container_of(work, struct snic, tgt_work);
328 	struct snic_tgt_id *tgtid = NULL;
329 	struct snic_tgt *tgt = NULL;
330 	unsigned long flags;
331 	int i;
332 
333 	spin_lock_irqsave(&snic->snic_lock, flags);
334 	if (snic->in_remove) {
335 		spin_unlock_irqrestore(&snic->snic_lock, flags);
336 		kfree(snic->disc.rtgt_info);
337 
338 		return;
339 	}
340 	spin_unlock_irqrestore(&snic->snic_lock, flags);
341 
342 	mutex_lock(&snic->disc.mutex);
343 	/* Discover triggered during disc in progress */
344 	if (snic->disc.req_cnt) {
345 		snic->disc.state = SNIC_DISC_DONE;
346 		snic->disc.req_cnt = 0;
347 		mutex_unlock(&snic->disc.mutex);
348 		kfree(snic->disc.rtgt_info);
349 		snic->disc.rtgt_info = NULL;
350 
351 		SNIC_HOST_INFO(snic->shost, "tgt_disc: Discovery restart.\n");
352 		/* Start Discovery Again */
353 		snic_disc_start(snic);
354 
355 		return;
356 	}
357 
358 	tgtid = (struct snic_tgt_id *)snic->disc.rtgt_info;
359 
360 	SNIC_BUG_ON(snic->disc.rtgt_cnt == 0 || tgtid == NULL);
361 
362 	for (i = 0; i < snic->disc.rtgt_cnt; i++) {
363 		tgt = snic_tgt_create(snic, &tgtid[i]);
364 		if (!tgt) {
365 			int buf_sz = snic->disc.rtgt_cnt * sizeof(*tgtid);
366 
367 			SNIC_HOST_ERR(snic->shost, "Failed to create tgt.\n");
368 			snic_hex_dump("rpt_tgt_rsp", (char *)tgtid, buf_sz);
369 			break;
370 		}
371 	}
372 
373 	snic->disc.rtgt_info = NULL;
374 	snic->disc.state = SNIC_DISC_DONE;
375 	mutex_unlock(&snic->disc.mutex);
376 
377 	SNIC_HOST_INFO(snic->shost, "Discovery Completed.\n");
378 
379 	kfree(tgtid);
380 } /* end of snic_handle_tgt_disc */
381 
382 
383 int
384 snic_report_tgt_cmpl_handler(struct snic *snic, struct snic_fw_req *fwreq)
385 {
386 
387 	u8 typ, cmpl_stat;
388 	u32 cmnd_id, hid, tgt_cnt = 0;
389 	ulong ctx;
390 	struct snic_req_info *rqi = NULL;
391 	struct snic_tgt_id *tgtid;
392 	int i, ret = 0;
393 
394 	snic_io_hdr_dec(&fwreq->hdr, &typ, &cmpl_stat, &cmnd_id, &hid, &ctx);
395 	rqi = (struct snic_req_info *) ctx;
396 	tgtid = (struct snic_tgt_id *) rqi->sge_va;
397 
398 	tgt_cnt = le32_to_cpu(fwreq->u.rpt_tgts_cmpl.tgt_cnt);
399 	if (tgt_cnt == 0) {
400 		SNIC_HOST_ERR(snic->shost, "No Targets Found on this host.\n");
401 		ret = 1;
402 
403 		goto end;
404 	}
405 
406 	/* printing list of targets here */
407 	SNIC_HOST_INFO(snic->shost, "Target Count = %d\n", tgt_cnt);
408 
409 	SNIC_BUG_ON(tgt_cnt > snic->fwinfo.max_tgts);
410 
411 	for (i = 0; i < tgt_cnt; i++)
412 		SNIC_HOST_INFO(snic->shost,
413 			       "Tgt id = 0x%x\n",
414 			       le32_to_cpu(tgtid[i].tgt_id));
415 
416 	/*
417 	 * Queue work for further processing,
418 	 * Response Buffer Memory is freed after creating targets
419 	 */
420 	snic->disc.rtgt_cnt = tgt_cnt;
421 	snic->disc.rtgt_info = (u8 *) tgtid;
422 	queue_work(snic_glob->event_q, &snic->tgt_work);
423 	ret = 0;
424 
425 end:
426 	/* Unmap Response Buffer */
427 	snic_pci_unmap_rsp_buf(snic, rqi);
428 	if (ret)
429 		kfree(tgtid);
430 
431 	rqi->sge_va = 0;
432 	snic_release_untagged_req(snic, rqi);
433 
434 	return ret;
435 } /* end of snic_report_tgt_cmpl_handler */
436 
437 /* Discovery init fn */
438 void
439 snic_disc_init(struct snic_disc *disc)
440 {
441 	INIT_LIST_HEAD(&disc->tgt_list);
442 	mutex_init(&disc->mutex);
443 	disc->disc_id = 0;
444 	disc->nxt_tgt_id = 0;
445 	disc->state = SNIC_DISC_INIT;
446 	disc->req_cnt = 0;
447 	disc->rtgt_cnt = 0;
448 	disc->rtgt_info = NULL;
449 	disc->cb = NULL;
450 } /* end of snic_disc_init */
451 
452 /* Discovery, uninit fn */
453 void
454 snic_disc_term(struct snic *snic)
455 {
456 	struct snic_disc *disc = &snic->disc;
457 
458 	mutex_lock(&disc->mutex);
459 	if (disc->req_cnt) {
460 		disc->req_cnt = 0;
461 		SNIC_SCSI_DBG(snic->shost, "Terminating Discovery.\n");
462 	}
463 	mutex_unlock(&disc->mutex);
464 }
465 
466 /*
467  * snic_disc_start: Discovery Start ...
468  */
469 int
470 snic_disc_start(struct snic *snic)
471 {
472 	struct snic_disc *disc = &snic->disc;
473 	unsigned long flags;
474 	int ret = 0;
475 
476 	SNIC_SCSI_DBG(snic->shost, "Discovery Start.\n");
477 
478 	spin_lock_irqsave(&snic->snic_lock, flags);
479 	if (snic->in_remove) {
480 		spin_unlock_irqrestore(&snic->snic_lock, flags);
481 		SNIC_ERR("snic driver removal in progress ...\n");
482 		ret = 0;
483 
484 		return ret;
485 	}
486 	spin_unlock_irqrestore(&snic->snic_lock, flags);
487 
488 	mutex_lock(&disc->mutex);
489 	if (disc->state == SNIC_DISC_PENDING) {
490 		disc->req_cnt++;
491 		mutex_unlock(&disc->mutex);
492 
493 		return ret;
494 	}
495 	disc->state = SNIC_DISC_PENDING;
496 	mutex_unlock(&disc->mutex);
497 
498 	ret = snic_queue_report_tgt_req(snic);
499 	if (ret)
500 		SNIC_HOST_INFO(snic->shost, "Discovery Failed, err=%d.\n", ret);
501 
502 	return ret;
503 } /* end of snic_disc_start */
504 
505 /*
506  * snic_disc_work :
507  */
508 void
509 snic_handle_disc(struct work_struct *work)
510 {
511 	struct snic *snic = container_of(work, struct snic, disc_work);
512 	int ret = 0;
513 
514 	SNIC_HOST_INFO(snic->shost, "disc_work: Discovery\n");
515 
516 	ret = snic_disc_start(snic);
517 	if (ret)
518 		goto disc_err;
519 
520 disc_err:
521 	SNIC_HOST_ERR(snic->shost,
522 		      "disc_work: Discovery Failed w/ err = %d\n",
523 		      ret);
524 } /* end of snic_disc_work */
525 
526 /*
527  * snic_tgt_del_all : cleanup all snic targets
528  * Called on unbinding the interface
529  */
530 void
531 snic_tgt_del_all(struct snic *snic)
532 {
533 	struct snic_tgt *tgt = NULL;
534 	struct list_head *cur, *nxt;
535 	unsigned long flags;
536 
537 	scsi_flush_work(snic->shost);
538 
539 	mutex_lock(&snic->disc.mutex);
540 	spin_lock_irqsave(snic->shost->host_lock, flags);
541 
542 	list_for_each_safe(cur, nxt, &snic->disc.tgt_list) {
543 		tgt = list_entry(cur, struct snic_tgt, list);
544 		tgt->state = SNIC_TGT_STAT_DEL;
545 		list_del_init(&tgt->list);
546 		SNIC_HOST_INFO(snic->shost, "Tgt %d q'ing for del\n", tgt->id);
547 		queue_work(snic_glob->event_q, &tgt->del_work);
548 		tgt = NULL;
549 	}
550 	spin_unlock_irqrestore(snic->shost->host_lock, flags);
551 	mutex_unlock(&snic->disc.mutex);
552 
553 	flush_workqueue(snic_glob->event_q);
554 } /* end of snic_tgt_del_all */
555