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
37static 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
46static 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
54static const char * lun_state[] =
55{
56    "not bound",
57    "bound",
58    "owned",
59};
60
61struct 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 */
100static 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
135static 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;
183out:
184	return err;
185}
186
187#define emc_default_str "FC (Legacy)"
188
189static 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
231out:
232	return sp_model;
233}
234
235static 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	u64 req_flags = REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
243		REQ_FAILFAST_DRIVER;
244
245	if (csdev->flags & CLARIION_SHORT_TRESPASS) {
246		page22 = short_trespass;
247		if (!(csdev->flags & CLARIION_HONOR_RESERVATIONS))
248			/* Set Honor Reservations bit */
249			page22[6] |= 0x80;
250		len = sizeof(short_trespass);
251		cdb[0] = MODE_SELECT;
252		cdb[1] = 0x10;
253		cdb[4] = len;
254	} else {
255		page22 = long_trespass;
256		if (!(csdev->flags & CLARIION_HONOR_RESERVATIONS))
257			/* Set Honor Reservations bit */
258			page22[10] |= 0x80;
259		len = sizeof(long_trespass);
260		cdb[0] = MODE_SELECT_10;
261		cdb[8] = len;
262	}
263	BUG_ON((len > CLARIION_BUFFER_SIZE));
264	memcpy(csdev->buffer, page22, len);
265
266	err = scsi_execute(sdev, cdb, DMA_TO_DEVICE, csdev->buffer, len, NULL,
267			&sshdr, CLARIION_TIMEOUT * HZ, CLARIION_RETRIES,
268			req_flags, 0, NULL);
269	if (err) {
270		if (scsi_sense_valid(&sshdr))
271			res = trespass_endio(sdev, &sshdr);
272		else {
273			sdev_printk(KERN_INFO, sdev,
274				    "%s: failed to send MODE SELECT: %x\n",
275				    CLARIION_NAME, err);
276			res = SCSI_DH_IO;
277		}
278	}
279
280	return res;
281}
282
283static enum scsi_disposition clariion_check_sense(struct scsi_device *sdev,
284					struct scsi_sense_hdr *sense_hdr)
285{
286	switch (sense_hdr->sense_key) {
287	case NOT_READY:
288		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x03)
289			/*
290			 * LUN Not Ready - Manual Intervention Required
291			 * indicates this is a passive path.
292			 *
293			 * FIXME: However, if this is seen and EVPD C0
294			 * indicates that this is due to a NDU in
295			 * progress, we should set FAIL_PATH too.
296			 * This indicates we might have to do a SCSI
297			 * inquiry in the end_io path. Ugh.
298			 *
299			 * Can return FAILED only when we want the error
300			 * recovery process to kick in.
301			 */
302			return SUCCESS;
303		break;
304	case ILLEGAL_REQUEST:
305		if (sense_hdr->asc == 0x25 && sense_hdr->ascq == 0x01)
306			/*
307			 * An array based copy is in progress. Do not
308			 * fail the path, do not bypass to another PG,
309			 * do not retry. Fail the IO immediately.
310			 * (Actually this is the same conclusion as in
311			 * the default handler, but lets make sure.)
312			 *
313			 * Can return FAILED only when we want the error
314			 * recovery process to kick in.
315			 */
316			return SUCCESS;
317		break;
318	case UNIT_ATTENTION:
319		if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)
320			/*
321			 * Unit Attention Code. This is the first IO
322			 * to the new path, so just retry.
323			 */
324			return ADD_TO_MLQUEUE;
325		break;
326	}
327
328	return SCSI_RETURN_NOT_HANDLED;
329}
330
331static blk_status_t clariion_prep_fn(struct scsi_device *sdev,
332		struct request *req)
333{
334	struct clariion_dh_data *h = sdev->handler_data;
335
336	if (h->lun_state != CLARIION_LUN_OWNED) {
337		req->rq_flags |= RQF_QUIET;
338		return BLK_STS_IOERR;
339	}
340
341	return BLK_STS_OK;
342}
343
344static int clariion_std_inquiry(struct scsi_device *sdev,
345				struct clariion_dh_data *csdev)
346{
347	int err = SCSI_DH_OK;
348	char *sp_model;
349
350	sp_model = parse_sp_model(sdev, sdev->inquiry);
351	if (!sp_model) {
352		err = SCSI_DH_DEV_UNSUPP;
353		goto out;
354	}
355
356	/*
357	 * FC Series arrays do not support long trespass
358	 */
359	if (!strlen(sp_model) || !strncmp(sp_model, "FC",2))
360		csdev->flags |= CLARIION_SHORT_TRESPASS;
361
362	sdev_printk(KERN_INFO, sdev,
363		    "%s: detected Clariion %s, flags %x\n",
364		    CLARIION_NAME, sp_model, csdev->flags);
365out:
366	return err;
367}
368
369static int clariion_send_inquiry(struct scsi_device *sdev,
370				 struct clariion_dh_data *csdev)
371{
372	int err = SCSI_DH_IO;
373
374	if (!scsi_get_vpd_page(sdev, 0xC0, csdev->buffer,
375			       CLARIION_BUFFER_SIZE))
376		err = parse_sp_info_reply(sdev, csdev);
377
378	return err;
379}
380
381static int clariion_activate(struct scsi_device *sdev,
382				activate_complete fn, void *data)
383{
384	struct clariion_dh_data *csdev = sdev->handler_data;
385	int result;
386
387	result = clariion_send_inquiry(sdev, csdev);
388	if (result != SCSI_DH_OK)
389		goto done;
390
391	if (csdev->lun_state == CLARIION_LUN_OWNED)
392		goto done;
393
394	result = send_trespass_cmd(sdev, csdev);
395	if (result != SCSI_DH_OK)
396		goto done;
397	sdev_printk(KERN_INFO, sdev,"%s: %s trespass command sent\n",
398		    CLARIION_NAME,
399		    csdev->flags&CLARIION_SHORT_TRESPASS?"short":"long" );
400
401	/* Update status */
402	result = clariion_send_inquiry(sdev, csdev);
403	if (result != SCSI_DH_OK)
404		goto done;
405
406done:
407	sdev_printk(KERN_INFO, sdev,
408		    "%s: at SP %c Port %d (%s, default SP %c)\n",
409		    CLARIION_NAME, csdev->current_sp + 'A',
410		    csdev->port, lun_state[csdev->lun_state],
411		    csdev->default_sp + 'A');
412
413	if (fn)
414		fn(data, result);
415	return 0;
416}
417/*
418 * params - parameters in the following format
419 *      "no_of_params\0param1\0param2\0param3\0...\0"
420 *      for example, string for 2 parameters with value 10 and 21
421 *      is specified as "2\010\021\0".
422 */
423static int clariion_set_params(struct scsi_device *sdev, const char *params)
424{
425	struct clariion_dh_data *csdev = sdev->handler_data;
426	unsigned int hr = 0, st = 0, argc;
427	const char *p = params;
428	int result = SCSI_DH_OK;
429
430	if ((sscanf(params, "%u", &argc) != 1) || (argc != 2))
431		return -EINVAL;
432
433	while (*p++)
434		;
435	if ((sscanf(p, "%u", &st) != 1) || (st > 1))
436		return -EINVAL;
437
438	while (*p++)
439		;
440	if ((sscanf(p, "%u", &hr) != 1) || (hr > 1))
441		return -EINVAL;
442
443	if (st)
444		csdev->flags |= CLARIION_SHORT_TRESPASS;
445	else
446		csdev->flags &= ~CLARIION_SHORT_TRESPASS;
447
448	if (hr)
449		csdev->flags |= CLARIION_HONOR_RESERVATIONS;
450	else
451		csdev->flags &= ~CLARIION_HONOR_RESERVATIONS;
452
453	/*
454	 * If this path is owned, we have to send a trespass command
455	 * with the new parameters. If not, simply return. Next trespass
456	 * command would use the parameters.
457	 */
458	if (csdev->lun_state != CLARIION_LUN_OWNED)
459		goto done;
460
461	csdev->lun_state = CLARIION_LUN_UNINITIALIZED;
462	result = send_trespass_cmd(sdev, csdev);
463	if (result != SCSI_DH_OK)
464		goto done;
465
466	/* Update status */
467	result = clariion_send_inquiry(sdev, csdev);
468
469done:
470	return result;
471}
472
473static int clariion_bus_attach(struct scsi_device *sdev)
474{
475	struct clariion_dh_data *h;
476	int err;
477
478	h = kzalloc(sizeof(*h) , GFP_KERNEL);
479	if (!h)
480		return SCSI_DH_NOMEM;
481	h->lun_state = CLARIION_LUN_UNINITIALIZED;
482	h->default_sp = CLARIION_UNBOUND_LU;
483	h->current_sp = CLARIION_UNBOUND_LU;
484
485	err = clariion_std_inquiry(sdev, h);
486	if (err != SCSI_DH_OK)
487		goto failed;
488
489	err = clariion_send_inquiry(sdev, h);
490	if (err != SCSI_DH_OK)
491		goto failed;
492
493	sdev_printk(KERN_INFO, sdev,
494		    "%s: connected to SP %c Port %d (%s, default SP %c)\n",
495		    CLARIION_NAME, h->current_sp + 'A',
496		    h->port, lun_state[h->lun_state],
497		    h->default_sp + 'A');
498
499	sdev->handler_data = h;
500	return SCSI_DH_OK;
501
502failed:
503	kfree(h);
504	return err;
505}
506
507static void clariion_bus_detach(struct scsi_device *sdev)
508{
509	kfree(sdev->handler_data);
510	sdev->handler_data = NULL;
511}
512
513static struct scsi_device_handler clariion_dh = {
514	.name		= CLARIION_NAME,
515	.module		= THIS_MODULE,
516	.attach		= clariion_bus_attach,
517	.detach		= clariion_bus_detach,
518	.check_sense	= clariion_check_sense,
519	.activate	= clariion_activate,
520	.prep_fn	= clariion_prep_fn,
521	.set_params	= clariion_set_params,
522};
523
524static int __init clariion_init(void)
525{
526	int r;
527
528	r = scsi_register_device_handler(&clariion_dh);
529	if (r != 0)
530		printk(KERN_ERR "%s: Failed to register scsi device handler.",
531			CLARIION_NAME);
532	return r;
533}
534
535static void __exit clariion_exit(void)
536{
537	scsi_unregister_device_handler(&clariion_dh);
538}
539
540module_init(clariion_init);
541module_exit(clariion_exit);
542
543MODULE_DESCRIPTION("EMC CX/AX/FC-family driver");
544MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, Chandra Seetharaman <sekharan@us.ibm.com>");
545MODULE_LICENSE("GPL");
546