xref: /illumos-gate/usr/src/uts/common/io/scsi/adapters/scsi_vhci/fops/tpgs.c (revision 8883f1c270cc8e33c18dd088e744840092b47bbb)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * Implementation of "scsi_vhci_f_tpgs" T10 standard based failover_ops.
29  *
30  * NOTE: for non-sequential devices only.
31  */
32 
33 #include <sys/conf.h>
34 #include <sys/file.h>
35 #include <sys/ddi.h>
36 #include <sys/sunddi.h>
37 #include <sys/scsi/scsi.h>
38 #include <sys/scsi/adapters/scsi_vhci.h>
39 #include <sys/scsi/adapters/scsi_vhci_tpgs.h>
40 
41 /* Supported device table entries.  */
42 char	*std_dev_table[] = { NULL };
43 
44 /* Failover module plumbing. */
45 SCSI_FAILOVER_OP(SFO_NAME_TPGS, std);
46 
47 #define	STD_FO_CMD_RETRY_DELAY	1000000 /* 1 seconds */
48 #define	STD_FO_RETRY_DELAY	2000000 /* 2 seconds */
49 /*
50  * max time for failover to complete is 3 minutes.  Compute
51  * number of retries accordingly, to ensure we wait for at least
52  * 3 minutes
53  */
54 #define	STD_FO_MAX_RETRIES	(3*60*1000000)/STD_FO_RETRY_DELAY
55 
56 
57 /* ARGSUSED */
58 static int
59 std_device_probe(struct scsi_device *sd, struct scsi_inquiry *inq,
60     void **ctpriv)
61 {
62 	int		mode, state, xlf, preferred = 0;
63 
64 	VHCI_DEBUG(6, (CE_NOTE, NULL, "std_device_probe: vidpid %s\n",
65 	    inq->inq_vid));
66 
67 	if (inq->inq_tpgs == TPGS_FAILOVER_NONE) {
68 		VHCI_DEBUG(4, (CE_WARN, NULL,
69 		    "!std_device_probe: not a standard tpgs device"));
70 		return (SFO_DEVICE_PROBE_PHCI);
71 	}
72 
73 	if (inq->inq_dtype == DTYPE_SEQUENTIAL) {
74 		VHCI_DEBUG(4, (CE_NOTE, NULL,
75 		    "!std_device_probe: Detected a "
76 		    "Standard Asymmetric device "
77 		    "not yet supported\n"));
78 		return (SFO_DEVICE_PROBE_PHCI);
79 	}
80 
81 	if (vhci_tpgs_get_target_fo_mode(sd, &mode, &state, &xlf, &preferred)) {
82 		VHCI_DEBUG(4, (CE_WARN, NULL, "!unable to fetch fo "
83 		    "mode: sd(%p)", (void *) sd));
84 		return (SFO_DEVICE_PROBE_PHCI);
85 	}
86 
87 	if (inq->inq_tpgs == TPGS_FAILOVER_IMPLICIT) {
88 		VHCI_DEBUG(1, (CE_NOTE, NULL,
89 		    "!std_device_probe: Detected a "
90 		    "Standard Asymmetric device "
91 		    "with implicit failover\n"));
92 		return (SFO_DEVICE_PROBE_VHCI);
93 	}
94 	if (inq->inq_tpgs == TPGS_FAILOVER_EXPLICIT) {
95 		VHCI_DEBUG(1, (CE_NOTE, NULL,
96 		    "!std_device_probe: Detected a "
97 		    "Standard Asymmetric device "
98 		    "with explicit failover\n"));
99 		return (SFO_DEVICE_PROBE_VHCI);
100 	}
101 	if (inq->inq_tpgs == TPGS_FAILOVER_BOTH) {
102 		VHCI_DEBUG(1, (CE_NOTE, NULL,
103 		    "!std_device_probe: Detected a "
104 		    "Standard Asymmetric device "
105 		    "which supports both implicit and explicit failover\n"));
106 		return (SFO_DEVICE_PROBE_VHCI);
107 	}
108 	VHCI_DEBUG(1, (CE_WARN, NULL,
109 	    "!std_device_probe: "
110 	    "Unknown tpgs_bits: %x", inq->inq_tpgs));
111 	return (SFO_DEVICE_PROBE_PHCI);
112 }
113 
114 /* ARGSUSED */
115 static void
116 std_device_unprobe(struct scsi_device *sd, void *ctpriv)
117 {
118 	/*
119 	 * For future use
120 	 */
121 }
122 
123 /* ARGSUSED */
124 static int
125 std_activate_explicit(struct scsi_device *sd, int xlf_capable)
126 {
127 	cmn_err(CE_NOTE, "Explicit Activation is done by "
128 	    "vhci_tpgs_set_target_groups() call from MPAPI");
129 	return (1);
130 }
131 
132 /*
133  * Process the packet reason of CMD_PKT_CMPLT - return 0 if no
134  * retry and 1 if a retry should be done
135  */
136 static int
137 std_process_cmplt_pkt(struct scsi_device *sd, struct scsi_pkt *pkt,
138     int *retry_cnt)
139 {
140 	uint8_t *sns, skey, asc, ascq;
141 
142 	/*
143 	 * Re-initialize retry_cmd_cnt. Allow transport and
144 	 * cmd errors to go through a full retry count when
145 	 * these are encountered.  This way TRAN/CMD errors
146 	 * retry count is not exhausted due to CMD_CMPLTs
147 	 * delay. This allows the system
148 	 * to brave a hick-up on the link at any given time,
149 	 * while waiting for the fo to complete.
150 	 */
151 	if (pkt->pkt_state & STATE_ARQ_DONE) {
152 		sns = (uint8_t *)
153 		    &(((struct scsi_arq_status *)(uintptr_t)
154 		    (pkt->pkt_scbp))->sts_sensedata);
155 		skey = scsi_sense_key(sns);
156 		asc = scsi_sense_asc(sns);
157 		ascq = scsi_sense_ascq(sns);
158 		if (skey == KEY_UNIT_ATTENTION) {
159 			/*
160 			 * tpgs access state changed
161 			 */
162 			if (asc == STD_SCSI_ASC_STATE_CHG &&
163 			    ascq == STD_SCSI_ASCQ_STATE_CHG_SUCC) {
164 				/* XXX: update path info? */
165 				cmn_err(CE_WARN, "!Device failover"
166 				    " state change");
167 			}
168 			return (1);
169 		} else if (skey == KEY_NOT_READY) {
170 			if ((*retry_cnt)++ >=
171 			    STD_FO_MAX_RETRIES) {
172 				cmn_err(CE_WARN, "!Device failover"
173 				    " failed: timed out waiting "
174 				    "for path to become active");
175 				return (0);
176 			}
177 			VHCI_DEBUG(6, (CE_NOTE, NULL,
178 			    "!(sd:%p)lun "
179 			    "becoming active...\n", (void *)sd));
180 			drv_usecwait(STD_FO_RETRY_DELAY);
181 			return (1);
182 		}
183 		cmn_err(CE_NOTE, "!Failover failed;"
184 		    " sense key:%x, ASC: %x, "
185 		    "ASCQ:%x", skey, asc, ascq);
186 		return (0);
187 	}
188 	switch (SCBP_C(pkt)) {
189 		case STATUS_GOOD:
190 			break;
191 		case STATUS_CHECK:
192 			VHCI_DEBUG(4, (CE_WARN, NULL,
193 			    "!(sd:%p):"
194 			    " status returned CHECK during std"
195 			    " path activation", (void *)sd));
196 			return (0);
197 		case STATUS_QFULL:
198 			VHCI_DEBUG(6, (CE_NOTE, NULL, "QFULL "
199 			    "status returned QFULL during std "
200 			    "path activation for %p\n", (void *)sd));
201 			drv_usecwait(5000);
202 			return (1);
203 		case STATUS_BUSY:
204 			VHCI_DEBUG(6, (CE_NOTE, NULL, "BUSY "
205 			    "status returned BUSY during std "
206 			    "path activation for %p\n", (void *)sd));
207 			drv_usecwait(5000);
208 			return (1);
209 		default:
210 			VHCI_DEBUG(4, (CE_WARN, NULL,
211 			    "!(sd:%p) Bad status returned during std "
212 			    "activation (pkt %p, status %x)",
213 			    (void *)sd, (void *)pkt, SCBP_C(pkt)));
214 			return (0);
215 	}
216 	return (0);
217 }
218 
219 /*
220  * For now we are going to use primary/online and secondary/online.
221  * There is no standby path returned by the dsp and we may have
222  * to do something different for other devices that use standby
223  */
224 /* ARGSUSED */
225 static int
226 std_path_activate(struct scsi_device *sd, char *pathclass,
227     void *ctpriv)
228 {
229 	struct buf			*bp;
230 	struct scsi_pkt			*pkt;
231 	struct scsi_address		*ap;
232 	int				err, retry_cnt, retry_cmd_cnt;
233 	int				mode, state, retval, xlf, preferred;
234 
235 	ap = &sd->sd_address;
236 
237 	mode = state = 0;
238 
239 	if (vhci_tpgs_get_target_fo_mode(sd, &mode, &state, &xlf, &preferred)) {
240 		VHCI_DEBUG(1, (CE_NOTE, NULL, "!std_path_activate:"
241 		    " failed vhci_tpgs_get_target_fo_mode\n"));
242 		return (1);
243 	}
244 	if ((state == STD_ACTIVE_OPTIMIZED) ||
245 	    (state == STD_ACTIVE_NONOPTIMIZED)) {
246 		VHCI_DEBUG(4, (CE_NOTE, NULL, "!path already active for %p\n",
247 		    (void *)sd));
248 		return (0);
249 	}
250 
251 	if (mode != SCSI_IMPLICIT_FAILOVER) {
252 		VHCI_DEBUG(4, (CE_NOTE, NULL,
253 		    "!mode is EXPLICIT for %p xlf %x\n",
254 		    (void *)sd, xlf));
255 		retval = std_activate_explicit(sd, xlf);
256 		if (retval != 0) {
257 			VHCI_DEBUG(4, (CE_NOTE, NULL,
258 			    "!(sd:%p)std_path_activate failed(1)\n",
259 			    (void *)sd));
260 			return (1);
261 		}
262 	} else {
263 		VHCI_DEBUG(4, (CE_NOTE, NULL, "STD mode is IMPLICIT for %p\n",
264 		    (void *)sd));
265 	}
266 
267 	bp = scsi_alloc_consistent_buf(ap, (struct buf *)NULL, DEV_BSIZE,
268 	    B_READ, NULL, NULL);
269 	if (!bp) {
270 		VHCI_DEBUG(4, (CE_WARN, NULL,
271 		    "!(sd:%p)std_path_activate failed to alloc buffer",
272 		    (void *)sd));
273 		return (1);
274 	}
275 
276 	pkt = scsi_init_pkt(ap, NULL, bp, CDB_GROUP1,
277 	    sizeof (struct scsi_arq_status), 0, PKT_CONSISTENT, NULL, NULL);
278 	if (!pkt) {
279 		VHCI_DEBUG(4, (CE_WARN, NULL,
280 		    "!(sd:%p)std_path_activate failed to initialize packet",
281 		    (void *)sd));
282 		scsi_free_consistent_buf(bp);
283 		return (1);
284 	}
285 
286 	(void) scsi_setup_cdb((union scsi_cdb *)(uintptr_t)pkt->pkt_cdbp,
287 	    SCMD_READ, 1, 1, 0);
288 	pkt->pkt_time = 3*30;
289 	pkt->pkt_flags |= FLAG_NOINTR;
290 
291 	retry_cnt = 0;
292 	retry_cmd_cnt = 0;
293 retry:
294 	err = scsi_transport(pkt);
295 	if (err != TRAN_ACCEPT) {
296 		/*
297 		 * Retry TRAN_BUSY till STD_FO_MAX_RETRIES is exhausted.
298 		 * All other errors are fatal and should not be retried.
299 		 */
300 		if ((err == TRAN_BUSY) &&
301 		    (retry_cnt++ < STD_FO_MAX_RETRIES)) {
302 			drv_usecwait(STD_FO_RETRY_DELAY);
303 			goto retry;
304 		}
305 		cmn_err(CE_WARN, "Failover failed, "
306 		    "couldn't transport packet");
307 		scsi_destroy_pkt(pkt);
308 		scsi_free_consistent_buf(bp);
309 		return (1);
310 	}
311 	switch (pkt->pkt_reason) {
312 		case CMD_CMPLT:
313 			retry_cmd_cnt = 0;
314 			retval = std_process_cmplt_pkt(sd, pkt, &retry_cnt);
315 			if (retval != 0) {
316 				goto retry;
317 			}
318 			break;
319 		case CMD_TIMEOUT:
320 			cmn_err(CE_WARN, "!Failover failed: timed out ");
321 			retval = 1;
322 			break;
323 		case CMD_INCOMPLETE:
324 		case CMD_RESET:
325 		case CMD_ABORTED:
326 		case CMD_TRAN_ERR:
327 			/*
328 			 * Increased the number of retries when these error
329 			 * cases are encountered.  Also added a 1 sec wait
330 			 * before retrying.
331 			 */
332 			if (retry_cmd_cnt++ < STD_FO_MAX_CMD_RETRIES) {
333 				drv_usecwait(STD_FO_CMD_RETRY_DELAY);
334 				VHCI_DEBUG(4, (CE_WARN, NULL,
335 				    "!Retrying path activation due to "
336 				    "pkt reason:%x, retry cnt:%d",
337 				    pkt->pkt_reason, retry_cmd_cnt));
338 				goto retry;
339 			}
340 			/* FALLTHROUGH */
341 		default:
342 			cmn_err(CE_WARN, "!Path activation did not "
343 			    "complete successfully,"
344 			    "(pkt reason %x)", pkt->pkt_reason);
345 			retval = 1;
346 			break;
347 	}
348 
349 
350 	VHCI_DEBUG(4, (CE_NOTE, NULL, "!Path activation success\n"));
351 	scsi_destroy_pkt(pkt);
352 	scsi_free_consistent_buf(bp);
353 	return (retval);
354 }
355 
356 /* ARGSUSED */
357 static int std_path_deactivate(struct scsi_device *sd, char *pathclass,
358     void *ctpriv)
359 {
360 	return (0);
361 }
362 
363 /* ARGSUSED */
364 static int
365 std_path_get_opinfo(struct scsi_device *sd, struct scsi_path_opinfo *opinfo,
366     void *ctpriv)
367 {
368 	int			mode, preferred, state, xlf;
369 
370 	opinfo->opinfo_rev = OPINFO_REV;
371 
372 	if (vhci_tpgs_get_target_fo_mode(sd, &mode, &state, &xlf, &preferred)) {
373 		VHCI_DEBUG(1, (CE_NOTE, NULL, "!std_path_getopinfo:"
374 		    " failed vhci_tpgs_get_target_fo_mode\n"));
375 		return (1);
376 	}
377 
378 	if (state == STD_ACTIVE_OPTIMIZED) {
379 		opinfo->opinfo_path_state = SCSI_PATH_ACTIVE;
380 	} else if (state == STD_ACTIVE_NONOPTIMIZED) {
381 		opinfo->opinfo_path_state = SCSI_PATH_ACTIVE_NONOPT;
382 	} else if (state == STD_STANDBY) {
383 		opinfo->opinfo_path_state = SCSI_PATH_INACTIVE;
384 	} else if (state == STD_UNAVAILABLE) {
385 		opinfo->opinfo_path_state = SCSI_PATH_INACTIVE;
386 	}
387 	if (preferred) {
388 		(void) strcpy(opinfo->opinfo_path_attr, PCLASS_PRIMARY);
389 	} else {
390 		(void) strcpy(opinfo->opinfo_path_attr, PCLASS_SECONDARY);
391 	}
392 	VHCI_DEBUG(4, (CE_NOTE, NULL, "std_path_get_opinfo: "
393 	    "class: %s state: %s\n", opinfo->opinfo_path_attr,
394 	    opinfo->opinfo_path_state == SCSI_PATH_ACTIVE ?
395 	    "ACTIVE" : "INACTIVE"));
396 	opinfo->opinfo_xlf_capable = 0;
397 	opinfo->opinfo_pswtch_best = 30;
398 	opinfo->opinfo_pswtch_worst = 3*30;
399 	opinfo->opinfo_preferred = (uint16_t)preferred;
400 	opinfo->opinfo_mode = (uint16_t)mode;
401 
402 	return (0);
403 }
404 
405 /* ARGSUSED */
406 static int std_path_ping(struct scsi_device *sd, void *ctpriv)
407 {
408 	/*
409 	 * For future use
410 	 */
411 	return (1);
412 }
413 
414 /*
415  * Analyze the sense code to determine whether failover process
416  */
417 /* ARGSUSED */
418 static int
419 std_analyze_sense(struct scsi_device *sd, uint8_t *sense,
420     void *ctpriv)
421 {
422 	int rval = SCSI_SENSE_UNKNOWN;
423 
424 	uint8_t skey, asc, ascq;
425 
426 	skey = scsi_sense_key(sense);
427 	asc = scsi_sense_asc(sense);
428 	ascq = scsi_sense_ascq(sense);
429 
430 	if ((skey == KEY_UNIT_ATTENTION) &&
431 	    (asc == STD_SCSI_ASC_STATE_CHG) &&
432 	    (ascq == STD_SCSI_ASCQ_STATE_CHG_SUCC)) {
433 		rval = SCSI_SENSE_STATE_CHANGED;
434 		VHCI_DEBUG(4, (CE_NOTE, NULL, "!std_analyze_sense:"
435 		    " sense_key:%x, add_code: %x, qual_code:%x"
436 		    " sense:%x\n", skey, asc, ascq, rval));
437 	} else if ((skey == KEY_NOT_READY) &&
438 	    (asc == STD_LOGICAL_UNIT_NOT_ACCESSIBLE) &&
439 	    (ascq == STD_TGT_PORT_UNAVAILABLE)) {
440 		rval = SCSI_SENSE_INACTIVE;
441 		VHCI_DEBUG(4, (CE_NOTE, NULL, "!std_analyze_sense:"
442 		    " sense_key:%x, add_code: %x, qual_code:%x"
443 		    " sense:%x\n", skey, asc, ascq, rval));
444 	} else if ((skey == KEY_ILLEGAL_REQUEST) &&
445 	    (asc == STD_SCSI_ASC_INVAL_PARAM_LIST)) {
446 		rval = SCSI_SENSE_NOFAILOVER;
447 		VHCI_DEBUG(1, (CE_NOTE, NULL, "!std_analyze_sense:"
448 		    " sense_key:%x, add_code: %x, qual_code:%x"
449 		    " sense:%x\n", skey, asc, ascq, rval));
450 	} else if ((skey == KEY_ILLEGAL_REQUEST) &&
451 	    (asc == STD_SCSI_ASC_INVAL_CMD_OPCODE)) {
452 		rval = SCSI_SENSE_NOFAILOVER;
453 		VHCI_DEBUG(1, (CE_NOTE, NULL, "!std_analyze_sense:"
454 		    " sense_key:%x, add_code: %x, qual_code:%x"
455 		    " sense:%x\n", skey, asc, ascq, rval));
456 	} else {
457 		/*
458 		 * At this point sense data may be for power-on-reset
459 		 * UNIT ATTN hardware errors, vendor unqiue sense data etc.
460 		 * For all these cases, return SCSI_SENSE_UNKNOWN.
461 		 */
462 		VHCI_DEBUG(1, (CE_NOTE, NULL, "!Analyze sense UNKNOWN:"
463 		    " sense key:%x, ASC:%x, ASCQ:%x\n", skey, asc, ascq));
464 	}
465 
466 	return (rval);
467 }
468 
469 /* ARGSUSED */
470 static int
471 std_pathclass_next(char *cur, char **nxt, void *ctpriv)
472 {
473 	/*
474 	 * The first phase does not have a standby path so
475 	 * there will be no explicit failover - when standard tpgs.
476 	 * standard defines preferred flag then we should start
477 	 * using this as the selection mechanism - there can be
478 	 * preferred primary standby that we should fail to first and then
479 	 * nonpreferred secondary standby.
480 	 */
481 	if (cur == NULL) {
482 		*nxt = PCLASS_PRIMARY;
483 		return (0);
484 	} else if (strcmp(cur, PCLASS_PRIMARY) == 0) {
485 		*nxt = PCLASS_SECONDARY;
486 		return (0);
487 	} else if (strcmp(cur, PCLASS_SECONDARY) == 0) {
488 		return (ENOENT);
489 	} else {
490 		return (EINVAL);
491 	}
492 }
493