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	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
286static 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
334static 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
347static 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);
368out:
369	return err;
370}
371
372static 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
384static 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
409done:
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 */
426static 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
472done:
473	return result;
474}
475
476static 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
505failed:
506	kfree(h);
507	return err;
508}
509
510static void clariion_bus_detach(struct scsi_device *sdev)
511{
512	kfree(sdev->handler_data);
513	sdev->handler_data = NULL;
514}
515
516static 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
527static 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
538static void __exit clariion_exit(void)
539{
540	scsi_unregister_device_handler(&clariion_dh);
541}
542
543module_init(clariion_init);
544module_exit(clariion_exit);
545
546MODULE_DESCRIPTION("EMC CX/AX/FC-family driver");
547MODULE_AUTHOR("Mike Christie <michaelc@cs.wisc.edu>, Chandra Seetharaman <sekharan@us.ibm.com>");
548MODULE_LICENSE("GPL");
549