2 * drivers/s390/cio/device_pgid.c
4 * Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
6 * Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
7 * Martin Schwidefsky (schwidefsky@de.ibm.com)
9 * Path Group ID functions.
12 #include <linux/module.h>
13 #include <linux/init.h>
15 #include <asm/ccwdev.h>
17 #include <asm/delay.h>
18 #include <asm/lowcore.h>
21 #include "cio_debug.h"
27 * Helper function called from interrupt context to decide whether an
28 * operation should be tried again.
30 static int __ccw_device_should_retry(struct scsw *scsw)
32 /* CC is only valid if start function bit is set. */
33 if ((scsw->fctl & SCSW_FCTL_START_FUNC) && scsw->cc == 1)
35 /* No more activity. For sense and set PGID we stubbornly try again. */
42 * Start Sense Path Group ID helper function. Used in ccw_device_recog
43 * and ccw_device_sense_pgid.
46 __ccw_device_sense_pgid_start(struct ccw_device *cdev)
48 struct subchannel *sch;
53 sch = to_subchannel(cdev->dev.parent);
54 /* Return if we already checked on all paths. */
55 if (cdev->private->imask == 0)
56 return (sch->lpm == 0) ? -ENODEV : -EACCES;
57 i = 8 - ffs(cdev->private->imask);
59 /* Setup sense path group id channel program. */
60 ccw = cdev->private->iccws;
61 ccw->cmd_code = CCW_CMD_SENSE_PGID;
62 ccw->count = sizeof (struct pgid);
63 ccw->flags = CCW_FLAG_SLI;
65 /* Reset device status. */
66 memset(&cdev->private->irb, 0, sizeof(struct irb));
67 /* Try on every path. */
69 while (cdev->private->imask != 0) {
70 /* Try every path multiple times. */
71 ccw->cda = (__u32) __pa (&cdev->private->pgid[i]);
72 if (cdev->private->iretry > 0) {
73 cdev->private->iretry--;
74 ret = cio_start (sch, cdev->private->iccws,
75 cdev->private->imask);
76 /* ret is 0, -EBUSY, -EACCES or -ENODEV */
79 CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel "
80 "0.%x.%04x, lpm %02X, became 'not "
82 cdev->private->devno, sch->schid.ssid,
83 sch->schid.sch_no, cdev->private->imask);
86 cdev->private->imask >>= 1;
87 cdev->private->iretry = 5;
95 ccw_device_sense_pgid_start(struct ccw_device *cdev)
99 /* Set a timeout of 60s */
100 ccw_device_set_timeout(cdev, 60*HZ);
102 cdev->private->state = DEV_STATE_SENSE_PGID;
103 cdev->private->imask = 0x80;
104 cdev->private->iretry = 5;
105 memset (&cdev->private->pgid, 0, sizeof (cdev->private->pgid));
106 ret = __ccw_device_sense_pgid_start(cdev);
107 if (ret && ret != -EBUSY)
108 ccw_device_sense_pgid_done(cdev, ret);
112 * Called from interrupt context to check if a valid answer
113 * to Sense Path Group ID was received.
116 __ccw_device_check_sense_pgid(struct ccw_device *cdev)
118 struct subchannel *sch;
122 sch = to_subchannel(cdev->dev.parent);
123 irb = &cdev->private->irb;
124 if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
126 if (irb->esw.esw0.erw.cons &&
127 (irb->ecw[0]&(SNS0_CMD_REJECT|SNS0_INTERVENTION_REQ))) {
129 * If the device doesn't support the Sense Path Group ID
130 * command further retries wouldn't help ...
134 if (irb->esw.esw0.erw.cons) {
135 CIO_MSG_EVENT(2, "SNID - device 0.%x.%04x, unit check, "
136 "lpum %02X, cnt %02d, sns : "
137 "%02X%02X%02X%02X %02X%02X%02X%02X ...\n",
138 cdev->private->ssid, cdev->private->devno,
139 irb->esw.esw0.sublog.lpum,
140 irb->esw.esw0.erw.scnt,
141 irb->ecw[0], irb->ecw[1],
142 irb->ecw[2], irb->ecw[3],
143 irb->ecw[4], irb->ecw[5],
144 irb->ecw[6], irb->ecw[7]);
147 if (irb->scsw.cc == 3) {
148 CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x,"
149 " lpm %02X, became 'not operational'\n",
150 cdev->private->devno, sch->schid.ssid,
151 sch->schid.sch_no, sch->orb.lpm);
154 i = 8 - ffs(cdev->private->imask);
155 if (cdev->private->pgid[i].inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
156 CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
157 "is reserved by someone else\n",
158 cdev->private->devno, sch->schid.ssid,
166 * Got interrupt for Sense Path Group ID.
169 ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
171 struct subchannel *sch;
175 irb = (struct irb *) __LC_IRB;
177 if (irb->scsw.stctl ==
178 (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
179 if (__ccw_device_should_retry(&irb->scsw)) {
180 ret = __ccw_device_sense_pgid_start(cdev);
181 if (ret && ret != -EBUSY)
182 ccw_device_sense_pgid_done(cdev, ret);
186 if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
188 sch = to_subchannel(cdev->dev.parent);
189 ret = __ccw_device_check_sense_pgid(cdev);
190 memset(&cdev->private->irb, 0, sizeof(struct irb));
192 /* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
193 case -EOPNOTSUPP: /* Sense Path Group ID not supported */
194 ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
196 case -ETIME: /* Sense path group id stopped by timeout. */
197 ccw_device_sense_pgid_done(cdev, -ETIME);
199 case -EACCES: /* channel is not operational. */
200 sch->lpm &= ~cdev->private->imask;
202 case 0: /* Sense Path Group ID successful. */
203 cdev->private->imask >>= 1;
204 cdev->private->iretry = 5;
206 case -EAGAIN: /* Try again. */
207 ret = __ccw_device_sense_pgid_start(cdev);
208 if (ret != 0 && ret != -EBUSY)
209 ccw_device_sense_pgid_done(cdev, ret);
211 case -EUSERS: /* device is reserved for someone else. */
212 ccw_device_sense_pgid_done(cdev, -EUSERS);
218 * Path Group ID helper function.
221 __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
223 struct subchannel *sch;
227 sch = to_subchannel(cdev->dev.parent);
229 /* Setup sense path group id channel program. */
230 cdev->private->pgid[0].inf.fc = func;
231 ccw = cdev->private->iccws;
232 if (!cdev->private->flags.pgid_single) {
233 cdev->private->pgid[0].inf.fc |= SPID_FUNC_MULTI_PATH;
234 ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
237 ccw->flags = CCW_FLAG_SLI | CCW_FLAG_CC;
240 cdev->private->pgid[0].inf.fc |= SPID_FUNC_SINGLE_PATH;
242 ccw->cmd_code = CCW_CMD_SET_PGID;
243 ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
244 ccw->count = sizeof (struct pgid);
245 ccw->flags = CCW_FLAG_SLI;
247 /* Reset device status. */
248 memset(&cdev->private->irb, 0, sizeof(struct irb));
250 /* Try multiple times. */
252 if (cdev->private->iretry > 0) {
253 cdev->private->iretry--;
254 ret = cio_start (sch, cdev->private->iccws,
255 cdev->private->imask);
256 /* We expect an interrupt in case of success or busy
258 if ((ret == 0) || (ret == -EBUSY))
261 /* PGID command failed on this path. */
262 CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
263 "0.%x.%04x, lpm %02X, became 'not operational'\n",
264 cdev->private->devno, sch->schid.ssid,
265 sch->schid.sch_no, cdev->private->imask);
270 * Helper function to send a nop ccw down a path.
272 static int __ccw_device_do_nop(struct ccw_device *cdev)
274 struct subchannel *sch;
278 sch = to_subchannel(cdev->dev.parent);
280 /* Setup nop channel program. */
281 ccw = cdev->private->iccws;
282 ccw->cmd_code = CCW_CMD_NOOP;
285 ccw->flags = CCW_FLAG_SLI;
287 /* Reset device status. */
288 memset(&cdev->private->irb, 0, sizeof(struct irb));
290 /* Try multiple times. */
292 if (cdev->private->iretry > 0) {
293 cdev->private->iretry--;
294 ret = cio_start (sch, cdev->private->iccws,
295 cdev->private->imask);
296 /* We expect an interrupt in case of success or busy
298 if ((ret == 0) || (ret == -EBUSY))
301 /* nop command failed on this path. */
302 CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel "
303 "0.%x.%04x, lpm %02X, became 'not operational'\n",
304 cdev->private->devno, sch->schid.ssid,
305 sch->schid.sch_no, cdev->private->imask);
311 * Called from interrupt context to check if a valid answer
312 * to Set Path Group ID was received.
315 __ccw_device_check_pgid(struct ccw_device *cdev)
317 struct subchannel *sch;
320 sch = to_subchannel(cdev->dev.parent);
321 irb = &cdev->private->irb;
322 if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
324 if (irb->esw.esw0.erw.cons) {
325 if (irb->ecw[0] & SNS0_CMD_REJECT)
327 /* Hmm, whatever happened, try again. */
328 CIO_MSG_EVENT(2, "SPID - device 0.%x.%04x, unit check, "
330 "sns : %02X%02X%02X%02X %02X%02X%02X%02X ...\n",
332 cdev->private->devno, irb->esw.esw0.erw.scnt,
333 irb->ecw[0], irb->ecw[1],
334 irb->ecw[2], irb->ecw[3],
335 irb->ecw[4], irb->ecw[5],
336 irb->ecw[6], irb->ecw[7]);
339 if (irb->scsw.cc == 3) {
340 CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel 0.%x.%04x,"
341 " lpm %02X, became 'not operational'\n",
342 cdev->private->devno, sch->schid.ssid,
343 sch->schid.sch_no, cdev->private->imask);
350 * Called from interrupt context to check the path status after a nop has
353 static int __ccw_device_check_nop(struct ccw_device *cdev)
355 struct subchannel *sch;
358 sch = to_subchannel(cdev->dev.parent);
359 irb = &cdev->private->irb;
360 if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
362 if (irb->scsw.cc == 3) {
363 CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel 0.%x.%04x,"
364 " lpm %02X, became 'not operational'\n",
365 cdev->private->devno, sch->schid.ssid,
366 sch->schid.sch_no, cdev->private->imask);
373 __ccw_device_verify_start(struct ccw_device *cdev)
375 struct subchannel *sch;
379 sch = to_subchannel(cdev->dev.parent);
380 /* Repeat for all paths. */
381 for (; cdev->private->imask; cdev->private->imask >>= 1,
382 cdev->private->iretry = 5) {
383 if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)
384 /* Path not available, try next. */
386 if (cdev->private->options.pgroup) {
387 if (sch->opm & cdev->private->imask)
388 func = SPID_FUNC_ESTABLISH;
390 func = SPID_FUNC_RESIGN;
391 ret = __ccw_device_do_pgid(cdev, func);
393 ret = __ccw_device_do_nop(cdev);
394 /* We expect an interrupt in case of success or busy
396 if (ret == 0 || ret == -EBUSY)
398 /* Permanent path failure, try next. */
400 /* Done with all paths. */
401 ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);
405 * Got interrupt for Set Path Group ID.
408 ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
410 struct subchannel *sch;
414 irb = (struct irb *) __LC_IRB;
416 if (irb->scsw.stctl ==
417 (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
418 if (__ccw_device_should_retry(&irb->scsw))
419 __ccw_device_verify_start(cdev);
422 if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
424 sch = to_subchannel(cdev->dev.parent);
425 if (cdev->private->options.pgroup)
426 ret = __ccw_device_check_pgid(cdev);
428 ret = __ccw_device_check_nop(cdev);
429 memset(&cdev->private->irb, 0, sizeof(struct irb));
432 /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
434 /* Path verification ccw finished successfully, update lpm. */
435 sch->vpm |= sch->opm & cdev->private->imask;
436 /* Go on with next path. */
437 cdev->private->imask >>= 1;
438 cdev->private->iretry = 5;
439 __ccw_device_verify_start(cdev);
443 * One of those strange devices which claim to be able
444 * to do multipathing but not for Set Path Group ID.
446 if (cdev->private->flags.pgid_single)
447 cdev->private->options.pgroup = 0;
449 cdev->private->flags.pgid_single = 1;
452 cdev->private->imask = 0x80;
453 cdev->private->iretry = 5;
455 case -EAGAIN: /* Try again. */
456 __ccw_device_verify_start(cdev);
458 case -ETIME: /* Set path group id stopped by timeout. */
459 ccw_device_verify_done(cdev, -ETIME);
461 case -EACCES: /* channel is not operational. */
462 cdev->private->imask >>= 1;
463 cdev->private->iretry = 5;
464 __ccw_device_verify_start(cdev);
470 ccw_device_verify_start(struct ccw_device *cdev)
472 struct subchannel *sch = to_subchannel(cdev->dev.parent);
474 cdev->private->flags.pgid_single = 0;
475 cdev->private->imask = 0x80;
476 cdev->private->iretry = 5;
478 /* Start with empty vpm. */
481 /* Get current pam. */
482 if (stsch(sch->schid, &sch->schib)) {
483 ccw_device_verify_done(cdev, -ENODEV);
486 /* After 60s path verification is considered to have failed. */
487 ccw_device_set_timeout(cdev, 60*HZ);
488 __ccw_device_verify_start(cdev);
492 __ccw_device_disband_start(struct ccw_device *cdev)
494 struct subchannel *sch;
497 sch = to_subchannel(cdev->dev.parent);
498 while (cdev->private->imask != 0) {
499 if (sch->lpm & cdev->private->imask) {
500 ret = __ccw_device_do_pgid(cdev, SPID_FUNC_DISBAND);
504 cdev->private->iretry = 5;
505 cdev->private->imask >>= 1;
507 ccw_device_disband_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
511 * Got interrupt for Unset Path Group ID.
514 ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
516 struct subchannel *sch;
520 irb = (struct irb *) __LC_IRB;
522 if (irb->scsw.stctl ==
523 (SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
524 if (__ccw_device_should_retry(&irb->scsw))
525 __ccw_device_disband_start(cdev);
528 if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
530 sch = to_subchannel(cdev->dev.parent);
531 ret = __ccw_device_check_pgid(cdev);
532 memset(&cdev->private->irb, 0, sizeof(struct irb));
534 /* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
535 case 0: /* disband successful. */
536 ccw_device_disband_done(cdev, ret);
540 * One of those strange devices which claim to be able
541 * to do multipathing but not for Unset Path Group ID.
543 cdev->private->flags.pgid_single = 1;
545 case -EAGAIN: /* Try again. */
546 __ccw_device_disband_start(cdev);
548 case -ETIME: /* Set path group id stopped by timeout. */
549 ccw_device_disband_done(cdev, -ETIME);
551 case -EACCES: /* channel is not operational. */
552 cdev->private->imask >>= 1;
553 cdev->private->iretry = 5;
554 __ccw_device_disband_start(cdev);
560 ccw_device_disband_start(struct ccw_device *cdev)
562 /* After 60s disbanding is considered to have failed. */
563 ccw_device_set_timeout(cdev, 60*HZ);
565 cdev->private->flags.pgid_single = 0;
566 cdev->private->iretry = 5;
567 cdev->private->imask = 0x80;
568 __ccw_device_disband_start(cdev);