1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Target driver for EMC CLARiiON AX/CX-series hardware.
4  * Based on code from Lars Marowsky-Bree <lmb@suse.de>
5  * and Ed Goggin <egoggin@emc.com>.
6  *
7  * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
8  * Copyright (C) 2006 Mike Christie
9  */
10 #include <linux/slab.h>
11 #include <linux/module.h>
12 #include <scsi/scsi.h>
13 #include <scsi/scsi_eh.h>
14 #include <scsi/scsi_dh.h>
15 #include <scsi/scsi_device.h>
16 
17 #define CLARIION_NAME			"emc"
18 
19 #define CLARIION_TRESPASS_PAGE		0x22
20 #define CLARIION_BUFFER_SIZE		0xFC
21 #define CLARIION_TIMEOUT		(60 * HZ)
22 #define CLARIION_RETRIES		3
23 #define CLARIION_UNBOUND_LU		-1
24 #define CLARIION_SP_A			0
25 #define CLARIION_SP_B			1
26 
27 /* Flags */
28 #define CLARIION_SHORT_TRESPASS		1
29 #define CLARIION_HONOR_RESERVATIONS	2
30 
31 /* LUN states */
32 #define CLARIION_LUN_UNINITIALIZED	-1
33 #define CLARIION_LUN_UNBOUND		0
34 #define CLARIION_LUN_BOUND		1
35 #define CLARIION_LUN_OWNED		2
36 
37 static unsigned char long_trespass[] = {
38 	0, 0, 0, 0, 0, 0, 0, 0,
39 	CLARIION_TRESPASS_PAGE,	/* Page code */
40 	0x09,			/* Page length - 2 */
41 	0x01,			/* Trespass code */
42 	0xff, 0xff,		/* Trespass target */
43 	0, 0, 0, 0, 0, 0	/* Reserved bytes / unknown */
44 };
45 
46 static unsigned char short_trespass[] = {
47 	0, 0, 0, 0,
48 	CLARIION_TRESPASS_PAGE,	/* Page code */
49 	0x02,			/* Page length - 2 */
50 	0x01,			/* Trespass code */
51 	0xff,			/* Trespass target */
52 };
53 
54 static const char * lun_state[] =
55 {
56     "not bound",
57     "bound",
58     "owned",
59 };
60 
61 struct clariion_dh_data {
62 	/*
63 	 * Flags:
64 	 *  CLARIION_SHORT_TRESPASS
65 	 * Use short trespass command (FC-series) or the long version
66 	 * (default for AX/CX CLARiiON arrays).
67 	 *
68 	 *  CLARIION_HONOR_RESERVATIONS
69 	 * Whether or not (default) to honor SCSI reservations when
70 	 * initiating a switch-over.
71 	 */
72 	unsigned flags;
73 	/*
74 	 * I/O buffer for both MODE_SELECT and INQUIRY commands.
75 	 */
76 	unsigned char buffer[CLARIION_BUFFER_SIZE];
77 	/*
78 	 * LUN state
79 	 */
80 	int lun_state;
81 	/*
82 	 * SP Port number
83 	 */
84 	int port;
85 	/*
86 	 * which SP (A=0,B=1,UNBOUND=-1) is the default SP for this
87 	 * path's mapped LUN
88 	 */
89 	int default_sp;
90 	/*
91 	 * which SP (A=0,B=1,UNBOUND=-1) is the active SP for this
92 	 * path's mapped LUN
93 	 */
94 	int current_sp;
95 };
96 
97 /*
98  * Parse MODE_SELECT cmd reply.
99  */
100 static int trespass_endio(struct scsi_device *sdev,
101 			  struct scsi_sense_hdr *sshdr)
102 {
103 	int err = SCSI_DH_IO;
104 
105 	sdev_printk(KERN_ERR, sdev, "%s: Found valid sense data 0x%2x, "
106 		    "0x%2x, 0x%2x while sending CLARiiON trespass "
107 		    "command.\n", CLARIION_NAME, sshdr->sense_key,
108 		    sshdr->asc, sshdr->ascq);
109 
110 	if (sshdr->sense_key == 0x05 && sshdr->asc == 0x04 &&
111 	    sshdr->ascq == 0x00) {
112 		/*
113 		 * Array based copy in progress -- do not send
114 		 * mode_select or copy will be aborted mid-stream.
115 		 */
116 		sdev_printk(KERN_INFO, sdev, "%s: Array Based Copy in "
117 			    "progress while sending CLARiiON trespass "
118 			    "command.\n", CLARIION_NAME);
119 		err = SCSI_DH_DEV_TEMP_BUSY;
120 	} else if (sshdr->sense_key == 0x02 && sshdr->asc == 0x04 &&
121 		   sshdr->ascq == 0x03) {
122 		/*
123 		 * LUN Not Ready - Manual Intervention Required
124 		 * indicates in-progress ucode upgrade (NDU).
125 		 */
126 		sdev_printk(KERN_INFO, sdev, "%s: Detected in-progress "
127 			    "ucode upgrade NDU operation while sending "
128 			    "CLARiiON trespass command.\n", CLARIION_NAME);
129 		err = SCSI_DH_DEV_TEMP_BUSY;
130 	} else
131 		err = SCSI_DH_DEV_FAILED;
132 	return err;
133 }
134 
135 static int parse_sp_info_reply(struct scsi_device *sdev,
136 			       struct clariion_dh_data *csdev)
137 {
138 	int err = SCSI_DH_OK;
139 
140 	/* check for in-progress ucode upgrade (NDU) */
141 	if (csdev->buffer[48] != 0) {
142 		sdev_printk(KERN_NOTICE, sdev, "%s: Detected in-progress "
143 			    "ucode upgrade NDU operation while finding "
144 			    "current active SP.", CLARIION_NAME);
145 		err = SCSI_DH_DEV_TEMP_BUSY;
146 		goto out;
147 	}
148 	if (csdev->buffer[4] > 2) {
149 		/* Invalid buffer format */
150 		sdev_printk(KERN_NOTICE, sdev,
151 			    "%s: invalid VPD page 0xC0 format\n",
152 			    CLARIION_NAME);
153 		err = SCSI_DH_NOSYS;
154 		goto out;
155 	}
156 	switch (csdev->buffer[28] & 0x0f) {
157 	case 6:
158 		sdev_printk(KERN_NOTICE, sdev,
159 			    "%s: ALUA failover mode detected\n",
160 			    CLARIION_NAME);
161 		break;
162 	case 4:
163 		/* Linux failover */
164 		break;
165 	default:
166 		sdev_printk(KERN_WARNING, sdev,
167 			    "%s: Invalid failover mode %d\n",
168 			    CLARIION_NAME, csdev->buffer[28] & 0x0f);
169 		err = SCSI_DH_NOSYS;
170 		goto out;
171 	}
172 
173 	csdev->default_sp = csdev->buffer[5];
174 	csdev->lun_state = csdev->buffer[4];
175 	csdev->current_sp = csdev->buffer[8];
176 	csdev->port = csdev->buffer[7];
177 	if (csdev->lun_state == CLARIION_LUN_OWNED)
178 		sdev->access_state = SCSI_ACCESS_STATE_OPTIMAL;
179 	else
180 		sdev->access_state = SCSI_ACCESS_STATE_STANDBY;
181 	if (csdev->default_sp == csdev->current_sp)
182 		sdev->access_state |= SCSI_ACCESS_STATE_PREFERRED;
183 out:
184 	return err;
185 }
186 
187 #define emc_default_str "FC (Legacy)"
188 
189 static char * parse_sp_model(struct scsi_device *sdev, unsigned char *buffer)
190 {
191 	unsigned char len = buffer[4] + 5;
192 	char *sp_model = NULL;
193 	unsigned char sp_len, serial_len;
194 
195 	if (len < 160) {
196 		sdev_printk(KERN_WARNING, sdev,
197 			    "%s: Invalid information section length %d\n",
198 			    CLARIION_NAME, len);
199 		/* Check for old FC arrays */
200 		if (!strncmp(buffer + 8, "DGC", 3)) {
201 			/* Old FC array, not supporting extended information */
202 			sp_model = emc_default_str;
203 		}
204 		goto out;
205 	}
206 
207 	/*
208 	 * Parse extended information for SP model number
209 	 */
210 	serial_len = buffer[160];
211 	if (serial_len == 0 || serial_len + 161 > len) {
212 		sdev_printk(KERN_WARNING, sdev,
213 			    "%s: Invalid array serial number length %d\n",
214 			    CLARIION_NAME, serial_len);
215 		goto out;
216 	}
217 	sp_len = buffer[99];
218 	if (sp_len == 0 || serial_len + sp_len + 161 > len) {
219 		sdev_printk(KERN_WARNING, sdev,
220 			    "%s: Invalid model number length %d\n",
221 			    CLARIION_NAME, sp_len);
222 		goto out;
223 	}
224 	sp_model = &buffer[serial_len + 161];
225 	/* Strip whitespace at the end */
226 	while (sp_len > 1 && sp_model[sp_len - 1] == ' ')
227 		sp_len--;
228 
229 	sp_model[sp_len] = '\0';
230 
231 out:
232 	return sp_model;
233 }
234 
235 static int send_trespass_cmd(struct scsi_device *sdev,
236 			    struct clariion_dh_data *csdev)
237 {
238 	unsigned char *page22;
239 	unsigned char cdb[MAX_COMMAND_SIZE];
240 	int err, res = SCSI_DH_OK, len;
241 	struct scsi_sense_hdr sshdr;
242 	blk_opf_t opf = REQ_OP_DRV_OUT | REQ_FAILFAST_DEV |
243 				REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER;
244 	const struct scsi_exec_args exec_args = {
245 		.sshdr = &sshdr,
246 	};
247 
248 	if (csdev->flags & CLARIION_SHORT_TRESPASS) {
249 		page22 = short_trespass;
250 		if (!(csdev->flags & CLARIION_HONOR_RESERVATIONS))
251 			/* Set Honor Reservations bit */
252 			page22[6] |= 0x80;
253 		len = sizeof(short_trespass);
254 		cdb[0] = MODE_SELECT;
255 		cdb[1] = 0x10;
256 		cdb[4] = len;
257 	} else {
258 		page22 = long_trespass;
259 		if (!(csdev->flags & CLARIION_HONOR_RESERVATIONS))
260 			/* Set Honor Reservations bit */
261 			page22[10] |= 0x80;
262 		len = sizeof(long_trespass);
263 		cdb[0] = MODE_SELECT_10;
264 		cdb[8] = len;
265 	}
266 	BUG_ON((len > CLARIION_BUFFER_SIZE));
267 	memcpy(csdev->buffer, page22, len);
268 
269 	err = scsi_execute_cmd(sdev, cdb, opf, csdev->buffer, len,
270 			       CLARIION_TIMEOUT * HZ, CLARIION_RETRIES,
271 			       &exec_args);
272 	if (err) {
273 		if (scsi_sense_valid(&sshdr))
274 			res = trespass_endio(sdev, &sshdr);
275 		else {
276 			sdev_printk(KERN_INFO, sdev,
277 				    "%s: failed to send MODE SELECT: %x\n",
278 				    CLARIION_NAME, err);
279 			res = SCSI_DH_IO;
280 		}
281 	}
282 
283 	return res;
284 }
285 
286 static enum scsi_disposition clariion_check_sense(struct scsi_device *sdev,
287 					struct scsi_sense_hdr *sense_hdr)
288 {
289 	switch (sense_hdr->sense_key) {
290 	case NOT_READY:
291 		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x03)
292 			/*
293 			 * LUN Not Ready - Manual Intervention Required
294 			 * indicates this is a passive path.
295 			 *
296 			 * FIXME: However, if this is seen and EVPD C0
297 			 * indicates that this is due to a NDU in
298 			 * progress, we should set FAIL_PATH too.
299 			 * This indicates we might have to do a SCSI
300 			 * inquiry in the end_io path. Ugh.
301 			 *
302 			 * Can return FAILED only when we want the error
303 			 * recovery process to kick in.
304 			 */
305 			return SUCCESS;
306 		break;
307 	case ILLEGAL_REQUEST:
308 		if (sense_hdr->asc == 0x25 && sense_hdr->ascq == 0x01)
309 			/*
310 			 * An array based copy is in progress. Do not
311 			 * fail the path, do not bypass to another PG,
312 			 * do not retry. Fail the IO immediately.
313 			 * (Actually this is the same conclusion as in
314 			 * the default handler, but lets make sure.)
315 			 *
316 			 * Can return FAILED only when we want the error
317 			 * recovery process to kick in.
318 			 */
319 			return SUCCESS;
320 		break;
321 	case UNIT_ATTENTION:
322 		if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
323 			/*
324 			 * Unit Attention Code. This is the first IO
325 			 * to the new path, so just retry.
326 			 */
327 			return ADD_TO_MLQUEUE;
328 		break;
329 	}
330 
331 	return SCSI_RETURN_NOT_HANDLED;
332 }
333 
334 static blk_status_t clariion_prep_fn(struct scsi_device *sdev,
335 		struct request *req)
336 {
337 	struct clariion_dh_data *h = sdev->handler_data;
338 
339 	if (h->lun_state != CLARIION_LUN_OWNED) {
340 		req->rq_flags |= RQF_QUIET;
341 		return BLK_STS_IOERR;
342 	}
343 
344 	return BLK_STS_OK;
345 }
346 
347 static int clariion_std_inquiry(struct scsi_device *sdev,
348 				struct clariion_dh_data *csdev)
349 {
350 	int err = SCSI_DH_OK;
351 	char *sp_model;
352 
353 	sp_model = parse_sp_model(sdev, sdev->inquiry);
354 	if (!sp_model) {
355 		err = SCSI_DH_DEV_UNSUPP;
356 		goto out;
357 	}
358 
359 	/*
360 	 * FC Series arrays do not support long trespass
361 	 */
362 	if (!strlen(sp_model) || !strncmp(sp_model, "FC",2))
363 		csdev->flags |= CLARIION_SHORT_TRESPASS;
364 
365 	sdev_printk(KERN_INFO, sdev,
366 		    "%s: detected Clariion %s, flags %x\n",
367 		    CLARIION_NAME, sp_model, csdev->flags);
368 out:
369 	return err;
370 }
371 
372 static int clariion_send_inquiry(struct scsi_device *sdev,
373 				 struct clariion_dh_data *csdev)
374 {
375 	int err = SCSI_DH_IO;
376 
377 	if (!scsi_get_vpd_page(sdev, 0xC0, csdev->buffer,
378 			       CLARIION_BUFFER_SIZE))
379 		err = parse_sp_info_reply(sdev, csdev);
380 
381 	return err;
382 }
383 
384 static int clariion_activate(struct scsi_device *sdev,
385 				activate_complete fn, void *data)
386 {
387 	struct clariion_dh_data *csdev = sdev->handler_data;
388 	int result;
389 
390 	result = clariion_send_inquiry(sdev, csdev);
391 	if (result != SCSI_DH_OK)
392 		goto done;
393 
394 	if (csdev->lun_state == CLARIION_LUN_OWNED)
395 		goto done;
396 
397 	result = send_trespass_cmd(sdev, csdev);
398 	if (result != SCSI_DH_OK)
399 		goto done;
400 	sdev_printk(KERN_INFO, sdev,"%s: %s trespass command sent\n",
401 		    CLARIION_NAME,
402 		    csdev->flags&CLARIION_SHORT_TRESPASS?"short":"long" );
403 
404 	/* Update status */
405 	result = clariion_send_inquiry(sdev, csdev);
406 	if (result != SCSI_DH_OK)
407 		goto done;
408 
409 done:
410 	sdev_printk(KERN_INFO, sdev,
411 		    "%s: at SP %c Port %d (%s, default SP %c)\n",
412 		    CLARIION_NAME, csdev->current_sp + 'A',
413 		    csdev->port, lun_state[csdev->lun_state],
414 		    csdev->default_sp + 'A');
415 
416 	if (fn)
417 		fn(data, result);
418 	return 0;
419 }
420 /*
421  * params - parameters in the following format
422  *      "no_of_params\0param1\0param2\0param3\0...\0"
423  *      for example, string for 2 parameters with value 10 and 21
424  *      is specified as "2\010\021\0".
425  */
426 static int clariion_set_params(struct scsi_device *sdev, const char *params)
427 {
428 	struct clariion_dh_data *csdev = sdev->handler_data;
429 	unsigned int hr = 0, st = 0, argc;
430 	const char *p = params;
431 	int result = SCSI_DH_OK;
432 
433 	if ((sscanf(params, "%u", &argc) != 1) || (argc != 2))
434 		return -EINVAL;
435 
436 	while (*p++)
437 		;
438 	if ((sscanf(p, "%u", &st) != 1) || (st > 1))
439 		return -EINVAL;
440 
441 	while (*p++)
442 		;
443 	if ((sscanf(p, "%u", &hr) != 1) || (hr > 1))
444 		return -EINVAL;
445 
446 	if (st)
447 		csdev->flags |= CLARIION_SHORT_TRESPASS;
448 	else
449 		csdev->flags &= ~CLARIION_SHORT_TRESPASS;
450 
451 	if (hr)
452 		csdev->flags |= CLARIION_HONOR_RESERVATIONS;
453 	else
454 		csdev->flags &= ~CLARIION_HONOR_RESERVATIONS;
455 
456 	/*
457 	 * If this path is owned, we have to send a trespass command
458 	 * with the new parameters. If not, simply return. Next trespass
459 	 * command would use the parameters.
460 	 */
461 	if (csdev->lun_state != CLARIION_LUN_OWNED)
462 		goto done;
463 
464 	csdev->lun_state = CLARIION_LUN_UNINITIALIZED;
465 	result = send_trespass_cmd(sdev, csdev);
466 	if (result != SCSI_DH_OK)
467 		goto done;
468 
469 	/* Update status */
470 	result = clariion_send_inquiry(sdev, csdev);
471 
472 done:
473 	return result;
474 }
475 
476 static int clariion_bus_attach(struct scsi_device *sdev)
477 {
478 	struct clariion_dh_data *h;
479 	int err;
480 
481 	h = kzalloc(sizeof(*h) , GFP_KERNEL);
482 	if (!h)
483 		return SCSI_DH_NOMEM;
484 	h->lun_state = CLARIION_LUN_UNINITIALIZED;
485 	h->default_sp = CLARIION_UNBOUND_LU;
486 	h->current_sp = CLARIION_UNBOUND_LU;
487 
488 	err = clariion_std_inquiry(sdev, h);
489 	if (err != SCSI_DH_OK)
490 		goto failed;
491 
492 	err = clariion_send_inquiry(sdev, h);
493 	if (err != SCSI_DH_OK)
494 		goto failed;
495 
496 	sdev_printk(KERN_INFO, sdev,
497 		    "%s: connected to SP %c Port %d (%s, default SP %c)\n",
498 		    CLARIION_NAME, h->current_sp + 'A',
499 		    h->port, lun_state[h->lun_state],
500 		    h->default_sp + 'A');
501 
502 	sdev->handler_data = h;
503 	return SCSI_DH_OK;
504 
505 failed:
506 	kfree(h);
507 	return err;
508 }
509 
510 static void clariion_bus_detach(struct scsi_device *sdev)
511 {
512 	kfree(sdev->handler_data);
513 	sdev->handler_data = NULL;
514 }
515 
516 static struct scsi_device_handler clariion_dh = {
517 	.name		= CLARIION_NAME,
518 	.module		= THIS_MODULE,
519 	.attach		= clariion_bus_attach,
520 	.detach		= clariion_bus_detach,
521 	.check_sense	= clariion_check_sense,
522 	.activate	= clariion_activate,
523 	.prep_fn	= clariion_prep_fn,
524 	.set_params	= clariion_set_params,
525 };
526 
527 static int __init clariion_init(void)
528 {
529 	int r;
530 
531 	r = scsi_register_device_handler(&clariion_dh);
532 	if (r != 0)
533 		printk(KERN_ERR "%s: Failed to register scsi device handler.",
534 			CLARIION_NAME);
535 	return r;
536 }
537 
538 static void __exit clariion_exit(void)
539 {
540 	scsi_unregister_device_handler(&clariion_dh);
541 }
542 
543 module_init(clariion_init);
544 module_exit(clariion_exit);
545 
546 MODULE_DESCRIPTION("EMC CX/AX/FC-family driver");
547 MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, Chandra Seetharaman <sekharan@us.ibm.com>");
548 MODULE_LICENSE("GPL");
549