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, cmd: cdb, opf, buffer: csdev->buffer, bufflen: len,
270 CLARIION_TIMEOUT * HZ, CLARIION_RETRIES,
271 args: &exec_args);
272 if (err) {
273 if (scsi_sense_valid(sshdr: &sshdr))
274 res = trespass_endio(sdev, sshdr: &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, buffer: 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, page: 0xC0, buf: 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(size: 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, csdev: h);
489 if (err != SCSI_DH_OK)
490 goto failed;
491
492 err = clariion_send_inquiry(sdev, csdev: 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(objp: h);
507 return err;
508}
509
510static void clariion_bus_detach(struct scsi_device *sdev)
511{
512 kfree(objp: 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(scsi_dh: &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(scsi_dh: &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

source code of linux/drivers/scsi/device_handler/scsi_dh_emc.c