xref: /openbmc/linux/drivers/scsi/snic/snic_disc.c (revision 82e6fdd6)
1 /*
2  * Copyright 2014 Cisco Systems, Inc.  All rights reserved.
3  *
4  * This program is free software; you may redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; version 2 of the License.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
9  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
10  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
11  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
12  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
13  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
14  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
15  * SOFTWARE.
16  */
17 
18 #include <linux/errno.h>
19 #include <linux/mempool.h>
20 
21 #include <scsi/scsi_tcq.h>
22 
23 #include "snic_disc.h"
24 #include "snic.h"
25 #include "snic_io.h"
26 
27 
28 /* snic target types */
29 static const char * const snic_tgt_type_str[] = {
30 	[SNIC_TGT_DAS] = "DAS",
31 	[SNIC_TGT_SAN] = "SAN",
32 };
33 
34 static inline const char *
35 snic_tgt_type_to_str(int typ)
36 {
37 	return ((typ > SNIC_TGT_NONE && typ <= SNIC_TGT_SAN) ?
38 		 snic_tgt_type_str[typ] : "Unknown");
39 }
40 
41 static const char * const snic_tgt_state_str[] = {
42 	[SNIC_TGT_STAT_INIT]	= "INIT",
43 	[SNIC_TGT_STAT_ONLINE]	= "ONLINE",
44 	[SNIC_TGT_STAT_OFFLINE]	= "OFFLINE",
45 	[SNIC_TGT_STAT_DEL]	= "DELETION IN PROGRESS",
46 };
47 
48 const char *
49 snic_tgt_state_to_str(int state)
50 {
51 	return ((state >= SNIC_TGT_STAT_INIT && state <= SNIC_TGT_STAT_DEL) ?
52 		snic_tgt_state_str[state] : "UNKNOWN");
53 }
54 
55 /*
56  * Initiate report_tgt req desc
57  */
58 static void
59 snic_report_tgt_init(struct snic_host_req *req, u32 hid, u8 *buf, u32 len,
60 		     dma_addr_t rsp_buf_pa, ulong ctx)
61 {
62 	struct snic_sg_desc *sgd = NULL;
63 
64 
65 	snic_io_hdr_enc(&req->hdr, SNIC_REQ_REPORT_TGTS, 0, SCSI_NO_TAG, hid,
66 			1, ctx);
67 
68 	req->u.rpt_tgts.sg_cnt = cpu_to_le16(1);
69 	sgd = req_to_sgl(req);
70 	sgd[0].addr = cpu_to_le64(rsp_buf_pa);
71 	sgd[0].len = cpu_to_le32(len);
72 	sgd[0]._resvd = 0;
73 	req->u.rpt_tgts.sg_addr = cpu_to_le64((ulong)sgd);
74 }
75 
76 /*
77  * snic_queue_report_tgt_req: Queues report target request.
78  */
79 static int
80 snic_queue_report_tgt_req(struct snic *snic)
81 {
82 	struct snic_req_info *rqi = NULL;
83 	u32 ntgts, buf_len = 0;
84 	u8 *buf = NULL;
85 	dma_addr_t pa = 0;
86 	int ret = 0;
87 
88 	rqi = snic_req_init(snic, 1);
89 	if (!rqi) {
90 		ret = -ENOMEM;
91 		goto error;
92 	}
93 
94 	if (snic->fwinfo.max_tgts)
95 		ntgts = min_t(u32, snic->fwinfo.max_tgts, snic->shost->max_id);
96 	else
97 		ntgts = snic->shost->max_id;
98 
99 	/* Allocate Response Buffer */
100 	SNIC_BUG_ON(ntgts == 0);
101 	buf_len = ntgts * sizeof(struct snic_tgt_id) + SNIC_SG_DESC_ALIGN;
102 
103 	buf = kzalloc(buf_len, GFP_KERNEL|GFP_DMA);
104 	if (!buf) {
105 		snic_req_free(snic, rqi);
106 		SNIC_HOST_ERR(snic->shost, "Resp Buf Alloc Failed.\n");
107 
108 		ret = -ENOMEM;
109 		goto error;
110 	}
111 
112 	SNIC_BUG_ON((((unsigned long)buf) % SNIC_SG_DESC_ALIGN) != 0);
113 
114 	pa = pci_map_single(snic->pdev, buf, buf_len, PCI_DMA_FROMDEVICE);
115 	if (pci_dma_mapping_error(snic->pdev, pa)) {
116 		SNIC_HOST_ERR(snic->shost,
117 			      "Rpt-tgt rspbuf %p: PCI DMA Mapping Failed\n",
118 			      buf);
119 		kfree(buf);
120 		snic_req_free(snic, rqi);
121 		ret = -EINVAL;
122 
123 		goto error;
124 	}
125 
126 
127 	SNIC_BUG_ON(pa == 0);
128 	rqi->sge_va = (ulong) buf;
129 
130 	snic_report_tgt_init(rqi->req,
131 			     snic->config.hid,
132 			     buf,
133 			     buf_len,
134 			     pa,
135 			     (ulong)rqi);
136 
137 	snic_handle_untagged_req(snic, rqi);
138 
139 	ret = snic_queue_wq_desc(snic, rqi->req, rqi->req_len);
140 	if (ret) {
141 		pci_unmap_single(snic->pdev, pa, buf_len, PCI_DMA_FROMDEVICE);
142 		kfree(buf);
143 		rqi->sge_va = 0;
144 		snic_release_untagged_req(snic, rqi);
145 		SNIC_HOST_ERR(snic->shost, "Queuing Report Tgts Failed.\n");
146 
147 		goto error;
148 	}
149 
150 	SNIC_DISC_DBG(snic->shost, "Report Targets Issued.\n");
151 
152 	return ret;
153 
154 error:
155 	SNIC_HOST_ERR(snic->shost,
156 		      "Queuing Report Targets Failed, err = %d\n",
157 		      ret);
158 	return ret;
159 } /* end of snic_queue_report_tgt_req */
160 
161 /* call into SML */
162 static void
163 snic_scsi_scan_tgt(struct work_struct *work)
164 {
165 	struct snic_tgt *tgt = container_of(work, struct snic_tgt, scan_work);
166 	struct Scsi_Host *shost = dev_to_shost(&tgt->dev);
167 	unsigned long flags;
168 
169 	SNIC_HOST_INFO(shost, "Scanning Target id 0x%x\n", tgt->id);
170 	scsi_scan_target(&tgt->dev,
171 			 tgt->channel,
172 			 tgt->scsi_tgt_id,
173 			 SCAN_WILD_CARD,
174 			 SCSI_SCAN_RESCAN);
175 
176 	spin_lock_irqsave(shost->host_lock, flags);
177 	tgt->flags &= ~SNIC_TGT_SCAN_PENDING;
178 	spin_unlock_irqrestore(shost->host_lock, flags);
179 } /* end of snic_scsi_scan_tgt */
180 
181 /*
182  * snic_tgt_lookup :
183  */
184 static struct snic_tgt *
185 snic_tgt_lookup(struct snic *snic, struct snic_tgt_id *tgtid)
186 {
187 	struct list_head *cur, *nxt;
188 	struct snic_tgt *tgt = NULL;
189 
190 	list_for_each_safe(cur, nxt, &snic->disc.tgt_list) {
191 		tgt = list_entry(cur, struct snic_tgt, list);
192 		if (tgt->id == le32_to_cpu(tgtid->tgt_id))
193 			return tgt;
194 		tgt = NULL;
195 	}
196 
197 	return tgt;
198 } /* end of snic_tgt_lookup */
199 
200 /*
201  * snic_tgt_dev_release : Called on dropping last ref for snic_tgt object
202  */
203 void
204 snic_tgt_dev_release(struct device *dev)
205 {
206 	struct snic_tgt *tgt = dev_to_tgt(dev);
207 
208 	SNIC_HOST_INFO(snic_tgt_to_shost(tgt),
209 		       "Target Device ID %d (%s) Permanently Deleted.\n",
210 		       tgt->id,
211 		       dev_name(dev));
212 
213 	SNIC_BUG_ON(!list_empty(&tgt->list));
214 	kfree(tgt);
215 }
216 
217 /*
218  * snic_tgt_del : work function to delete snic_tgt
219  */
220 static void
221 snic_tgt_del(struct work_struct *work)
222 {
223 	struct snic_tgt *tgt = container_of(work, struct snic_tgt, del_work);
224 	struct Scsi_Host *shost = snic_tgt_to_shost(tgt);
225 
226 	if (tgt->flags & SNIC_TGT_SCAN_PENDING)
227 		scsi_flush_work(shost);
228 
229 	/* Block IOs on child devices, stops new IOs */
230 	scsi_target_block(&tgt->dev);
231 
232 	/* Cleanup IOs */
233 	snic_tgt_scsi_abort_io(tgt);
234 
235 	/* Unblock IOs now, to flush if there are any. */
236 	scsi_target_unblock(&tgt->dev, SDEV_TRANSPORT_OFFLINE);
237 
238 	/* Delete SCSI Target and sdevs */
239 	scsi_remove_target(&tgt->dev);  /* ?? */
240 	device_del(&tgt->dev);
241 	put_device(&tgt->dev);
242 } /* end of snic_tgt_del */
243 
244 /* snic_tgt_create: checks for existence of snic_tgt, if it doesn't
245  * it creates one.
246  */
247 static struct snic_tgt *
248 snic_tgt_create(struct snic *snic, struct snic_tgt_id *tgtid)
249 {
250 	struct snic_tgt *tgt = NULL;
251 	unsigned long flags;
252 	int ret;
253 
254 	tgt = snic_tgt_lookup(snic, tgtid);
255 	if (tgt) {
256 		/* update the information if required */
257 		return tgt;
258 	}
259 
260 	tgt = kzalloc(sizeof(*tgt), GFP_KERNEL);
261 	if (!tgt) {
262 		SNIC_HOST_ERR(snic->shost, "Failure to allocate snic_tgt.\n");
263 		ret = -ENOMEM;
264 
265 		return tgt;
266 	}
267 
268 	INIT_LIST_HEAD(&tgt->list);
269 	tgt->id = le32_to_cpu(tgtid->tgt_id);
270 	tgt->channel = 0;
271 
272 	SNIC_BUG_ON(le16_to_cpu(tgtid->tgt_type) > SNIC_TGT_SAN);
273 	tgt->tdata.typ = le16_to_cpu(tgtid->tgt_type);
274 
275 	/*
276 	 * Plugging into SML Device Tree
277 	 */
278 	tgt->tdata.disc_id = 0;
279 	tgt->state = SNIC_TGT_STAT_INIT;
280 	device_initialize(&tgt->dev);
281 	tgt->dev.parent = get_device(&snic->shost->shost_gendev);
282 	tgt->dev.release = snic_tgt_dev_release;
283 	INIT_WORK(&tgt->scan_work, snic_scsi_scan_tgt);
284 	INIT_WORK(&tgt->del_work, snic_tgt_del);
285 	switch (tgt->tdata.typ) {
286 	case SNIC_TGT_DAS:
287 		dev_set_name(&tgt->dev, "snic_das_tgt:%d:%d-%d",
288 			     snic->shost->host_no, tgt->channel, tgt->id);
289 		break;
290 
291 	case SNIC_TGT_SAN:
292 		dev_set_name(&tgt->dev, "snic_san_tgt:%d:%d-%d",
293 			     snic->shost->host_no, tgt->channel, tgt->id);
294 		break;
295 
296 	default:
297 		SNIC_HOST_INFO(snic->shost, "Target type Unknown Detected.\n");
298 		dev_set_name(&tgt->dev, "snic_das_tgt:%d:%d-%d",
299 			     snic->shost->host_no, tgt->channel, tgt->id);
300 		break;
301 	}
302 
303 	spin_lock_irqsave(snic->shost->host_lock, flags);
304 	list_add_tail(&tgt->list, &snic->disc.tgt_list);
305 	tgt->scsi_tgt_id = snic->disc.nxt_tgt_id++;
306 	tgt->state = SNIC_TGT_STAT_ONLINE;
307 	spin_unlock_irqrestore(snic->shost->host_lock, flags);
308 
309 	SNIC_HOST_INFO(snic->shost,
310 		       "Tgt %d, type = %s detected. Adding..\n",
311 		       tgt->id, snic_tgt_type_to_str(tgt->tdata.typ));
312 
313 	ret = device_add(&tgt->dev);
314 	if (ret) {
315 		SNIC_HOST_ERR(snic->shost,
316 			      "Snic Tgt: device_add, with err = %d\n",
317 			      ret);
318 
319 		put_device(&snic->shost->shost_gendev);
320 		kfree(tgt);
321 		tgt = NULL;
322 
323 		return tgt;
324 	}
325 
326 	SNIC_HOST_INFO(snic->shost, "Scanning %s.\n", dev_name(&tgt->dev));
327 
328 	scsi_queue_work(snic->shost, &tgt->scan_work);
329 
330 	return tgt;
331 } /* end of snic_tgt_create */
332 
333 /* Handler for discovery */
334 void
335 snic_handle_tgt_disc(struct work_struct *work)
336 {
337 	struct snic *snic = container_of(work, struct snic, tgt_work);
338 	struct snic_tgt_id *tgtid = NULL;
339 	struct snic_tgt *tgt = NULL;
340 	unsigned long flags;
341 	int i;
342 
343 	spin_lock_irqsave(&snic->snic_lock, flags);
344 	if (snic->in_remove) {
345 		spin_unlock_irqrestore(&snic->snic_lock, flags);
346 		kfree(snic->disc.rtgt_info);
347 
348 		return;
349 	}
350 	spin_unlock_irqrestore(&snic->snic_lock, flags);
351 
352 	mutex_lock(&snic->disc.mutex);
353 	/* Discover triggered during disc in progress */
354 	if (snic->disc.req_cnt) {
355 		snic->disc.state = SNIC_DISC_DONE;
356 		snic->disc.req_cnt = 0;
357 		mutex_unlock(&snic->disc.mutex);
358 		kfree(snic->disc.rtgt_info);
359 		snic->disc.rtgt_info = NULL;
360 
361 		SNIC_HOST_INFO(snic->shost, "tgt_disc: Discovery restart.\n");
362 		/* Start Discovery Again */
363 		snic_disc_start(snic);
364 
365 		return;
366 	}
367 
368 	tgtid = (struct snic_tgt_id *)snic->disc.rtgt_info;
369 
370 	SNIC_BUG_ON(snic->disc.rtgt_cnt == 0 || tgtid == NULL);
371 
372 	for (i = 0; i < snic->disc.rtgt_cnt; i++) {
373 		tgt = snic_tgt_create(snic, &tgtid[i]);
374 		if (!tgt) {
375 			int buf_sz = snic->disc.rtgt_cnt * sizeof(*tgtid);
376 
377 			SNIC_HOST_ERR(snic->shost, "Failed to create tgt.\n");
378 			snic_hex_dump("rpt_tgt_rsp", (char *)tgtid, buf_sz);
379 			break;
380 		}
381 	}
382 
383 	snic->disc.rtgt_info = NULL;
384 	snic->disc.state = SNIC_DISC_DONE;
385 	mutex_unlock(&snic->disc.mutex);
386 
387 	SNIC_HOST_INFO(snic->shost, "Discovery Completed.\n");
388 
389 	kfree(tgtid);
390 } /* end of snic_handle_tgt_disc */
391 
392 
393 int
394 snic_report_tgt_cmpl_handler(struct snic *snic, struct snic_fw_req *fwreq)
395 {
396 
397 	u8 typ, cmpl_stat;
398 	u32 cmnd_id, hid, tgt_cnt = 0;
399 	ulong ctx;
400 	struct snic_req_info *rqi = NULL;
401 	struct snic_tgt_id *tgtid;
402 	int i, ret = 0;
403 
404 	snic_io_hdr_dec(&fwreq->hdr, &typ, &cmpl_stat, &cmnd_id, &hid, &ctx);
405 	rqi = (struct snic_req_info *) ctx;
406 	tgtid = (struct snic_tgt_id *) rqi->sge_va;
407 
408 	tgt_cnt = le32_to_cpu(fwreq->u.rpt_tgts_cmpl.tgt_cnt);
409 	if (tgt_cnt == 0) {
410 		SNIC_HOST_ERR(snic->shost, "No Targets Found on this host.\n");
411 		ret = 1;
412 
413 		goto end;
414 	}
415 
416 	/* printing list of targets here */
417 	SNIC_HOST_INFO(snic->shost, "Target Count = %d\n", tgt_cnt);
418 
419 	SNIC_BUG_ON(tgt_cnt > snic->fwinfo.max_tgts);
420 
421 	for (i = 0; i < tgt_cnt; i++)
422 		SNIC_HOST_INFO(snic->shost,
423 			       "Tgt id = 0x%x\n",
424 			       le32_to_cpu(tgtid[i].tgt_id));
425 
426 	/*
427 	 * Queue work for further processing,
428 	 * Response Buffer Memory is freed after creating targets
429 	 */
430 	snic->disc.rtgt_cnt = tgt_cnt;
431 	snic->disc.rtgt_info = (u8 *) tgtid;
432 	queue_work(snic_glob->event_q, &snic->tgt_work);
433 	ret = 0;
434 
435 end:
436 	/* Unmap Response Buffer */
437 	snic_pci_unmap_rsp_buf(snic, rqi);
438 	if (ret)
439 		kfree(tgtid);
440 
441 	rqi->sge_va = 0;
442 	snic_release_untagged_req(snic, rqi);
443 
444 	return ret;
445 } /* end of snic_report_tgt_cmpl_handler */
446 
447 /* Discovery init fn */
448 void
449 snic_disc_init(struct snic_disc *disc)
450 {
451 	INIT_LIST_HEAD(&disc->tgt_list);
452 	mutex_init(&disc->mutex);
453 	disc->disc_id = 0;
454 	disc->nxt_tgt_id = 0;
455 	disc->state = SNIC_DISC_INIT;
456 	disc->req_cnt = 0;
457 	disc->rtgt_cnt = 0;
458 	disc->rtgt_info = NULL;
459 	disc->cb = NULL;
460 } /* end of snic_disc_init */
461 
462 /* Discovery, uninit fn */
463 void
464 snic_disc_term(struct snic *snic)
465 {
466 	struct snic_disc *disc = &snic->disc;
467 
468 	mutex_lock(&disc->mutex);
469 	if (disc->req_cnt) {
470 		disc->req_cnt = 0;
471 		SNIC_SCSI_DBG(snic->shost, "Terminating Discovery.\n");
472 	}
473 	mutex_unlock(&disc->mutex);
474 }
475 
476 /*
477  * snic_disc_start: Discovery Start ...
478  */
479 int
480 snic_disc_start(struct snic *snic)
481 {
482 	struct snic_disc *disc = &snic->disc;
483 	unsigned long flags;
484 	int ret = 0;
485 
486 	SNIC_SCSI_DBG(snic->shost, "Discovery Start.\n");
487 
488 	spin_lock_irqsave(&snic->snic_lock, flags);
489 	if (snic->in_remove) {
490 		spin_unlock_irqrestore(&snic->snic_lock, flags);
491 		SNIC_ERR("snic driver removal in progress ...\n");
492 		ret = 0;
493 
494 		return ret;
495 	}
496 	spin_unlock_irqrestore(&snic->snic_lock, flags);
497 
498 	mutex_lock(&disc->mutex);
499 	if (disc->state == SNIC_DISC_PENDING) {
500 		disc->req_cnt++;
501 		mutex_unlock(&disc->mutex);
502 
503 		return ret;
504 	}
505 	disc->state = SNIC_DISC_PENDING;
506 	mutex_unlock(&disc->mutex);
507 
508 	ret = snic_queue_report_tgt_req(snic);
509 	if (ret)
510 		SNIC_HOST_INFO(snic->shost, "Discovery Failed, err=%d.\n", ret);
511 
512 	return ret;
513 } /* end of snic_disc_start */
514 
515 /*
516  * snic_disc_work :
517  */
518 void
519 snic_handle_disc(struct work_struct *work)
520 {
521 	struct snic *snic = container_of(work, struct snic, disc_work);
522 	int ret = 0;
523 
524 	SNIC_HOST_INFO(snic->shost, "disc_work: Discovery\n");
525 
526 	ret = snic_disc_start(snic);
527 	if (ret)
528 		goto disc_err;
529 
530 disc_err:
531 	SNIC_HOST_ERR(snic->shost,
532 		      "disc_work: Discovery Failed w/ err = %d\n",
533 		      ret);
534 } /* end of snic_disc_work */
535 
536 /*
537  * snic_tgt_del_all : cleanup all snic targets
538  * Called on unbinding the interface
539  */
540 void
541 snic_tgt_del_all(struct snic *snic)
542 {
543 	struct snic_tgt *tgt = NULL;
544 	struct list_head *cur, *nxt;
545 	unsigned long flags;
546 
547 	scsi_flush_work(snic->shost);
548 
549 	mutex_lock(&snic->disc.mutex);
550 	spin_lock_irqsave(snic->shost->host_lock, flags);
551 
552 	list_for_each_safe(cur, nxt, &snic->disc.tgt_list) {
553 		tgt = list_entry(cur, struct snic_tgt, list);
554 		tgt->state = SNIC_TGT_STAT_DEL;
555 		list_del_init(&tgt->list);
556 		SNIC_HOST_INFO(snic->shost, "Tgt %d q'ing for del\n", tgt->id);
557 		queue_work(snic_glob->event_q, &tgt->del_work);
558 		tgt = NULL;
559 	}
560 	spin_unlock_irqrestore(snic->shost->host_lock, flags);
561 	mutex_unlock(&snic->disc.mutex);
562 
563 	flush_workqueue(snic_glob->event_q);
564 } /* end of snic_tgt_del_all */
565