1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * CCW device PGID and path verification I/O handling.
4 *
5 * Copyright IBM Corp. 2002, 2009
6 * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
7 * Martin Schwidefsky <schwidefsky@de.ibm.com>
8 * Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
9 */
10
11 #include <linux/kernel.h>
12 #include <linux/string.h>
13 #include <linux/bitops.h>
14 #include <linux/types.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/io.h>
18 #include <asm/ccwdev.h>
19 #include <asm/cio.h>
20
21 #include "cio.h"
22 #include "cio_debug.h"
23 #include "device.h"
24 #include "io_sch.h"
25
26 #define PGID_RETRIES 256
27 #define PGID_TIMEOUT (10 * HZ)
28
29 static void verify_start(struct ccw_device *cdev);
30
31 /*
32 * Process path verification data and report result.
33 */
verify_done(struct ccw_device * cdev,int rc)34 static void verify_done(struct ccw_device *cdev, int rc)
35 {
36 struct subchannel *sch = to_subchannel(cdev->dev.parent);
37 struct ccw_dev_id *id = &cdev->private->dev_id;
38 int mpath = cdev->private->flags.mpath;
39 int pgroup = cdev->private->flags.pgroup;
40
41 if (rc)
42 goto out;
43 /* Ensure consistent multipathing state at device and channel. */
44 if (sch->config.mp != mpath) {
45 sch->config.mp = mpath;
46 rc = cio_commit_config(sch);
47 }
48 out:
49 CIO_MSG_EVENT(2, "vrfy: device 0.%x.%04x: rc=%d pgroup=%d mpath=%d "
50 "vpm=%02x\n", id->ssid, id->devno, rc, pgroup, mpath,
51 sch->vpm);
52 ccw_device_verify_done(cdev, rc);
53 }
54
55 /*
56 * Create channel program to perform a NOOP.
57 */
nop_build_cp(struct ccw_device * cdev)58 static void nop_build_cp(struct ccw_device *cdev)
59 {
60 struct ccw_request *req = &cdev->private->req;
61 struct ccw1 *cp = cdev->private->dma_area->iccws;
62
63 cp->cmd_code = CCW_CMD_NOOP;
64 cp->cda = 0;
65 cp->count = 0;
66 cp->flags = CCW_FLAG_SLI;
67 req->cp = cp;
68 }
69
70 /*
71 * Perform NOOP on a single path.
72 */
nop_do(struct ccw_device * cdev)73 static void nop_do(struct ccw_device *cdev)
74 {
75 struct subchannel *sch = to_subchannel(cdev->dev.parent);
76 struct ccw_request *req = &cdev->private->req;
77
78 req->lpm = lpm_adjust(req->lpm, sch->schib.pmcw.pam & sch->opm &
79 ~cdev->private->path_noirq_mask);
80 if (!req->lpm)
81 goto out_nopath;
82 nop_build_cp(cdev);
83 ccw_request_start(cdev);
84 return;
85
86 out_nopath:
87 verify_done(cdev, sch->vpm ? 0 : -EACCES);
88 }
89
90 /*
91 * Adjust NOOP I/O status.
92 */
nop_filter(struct ccw_device * cdev,void * data,struct irb * irb,enum io_status status)93 static enum io_status nop_filter(struct ccw_device *cdev, void *data,
94 struct irb *irb, enum io_status status)
95 {
96 /* Only subchannel status might indicate a path error. */
97 if (status == IO_STATUS_ERROR && irb->scsw.cmd.cstat == 0)
98 return IO_DONE;
99 return status;
100 }
101
102 /*
103 * Process NOOP request result for a single path.
104 */
nop_callback(struct ccw_device * cdev,void * data,int rc)105 static void nop_callback(struct ccw_device *cdev, void *data, int rc)
106 {
107 struct subchannel *sch = to_subchannel(cdev->dev.parent);
108 struct ccw_request *req = &cdev->private->req;
109
110 switch (rc) {
111 case 0:
112 sch->vpm |= req->lpm;
113 break;
114 case -ETIME:
115 cdev->private->path_noirq_mask |= req->lpm;
116 break;
117 case -EACCES:
118 cdev->private->path_notoper_mask |= req->lpm;
119 break;
120 default:
121 goto err;
122 }
123 /* Continue on the next path. */
124 req->lpm >>= 1;
125 nop_do(cdev);
126 return;
127
128 err:
129 verify_done(cdev, rc);
130 }
131
132 /*
133 * Create channel program to perform SET PGID on a single path.
134 */
spid_build_cp(struct ccw_device * cdev,u8 fn)135 static void spid_build_cp(struct ccw_device *cdev, u8 fn)
136 {
137 struct ccw_request *req = &cdev->private->req;
138 struct ccw1 *cp = cdev->private->dma_area->iccws;
139 int i = pathmask_to_pos(req->lpm);
140 struct pgid *pgid = &cdev->private->dma_area->pgid[i];
141
142 pgid->inf.fc = fn;
143 cp->cmd_code = CCW_CMD_SET_PGID;
144 cp->cda = (u32)virt_to_phys(pgid);
145 cp->count = sizeof(*pgid);
146 cp->flags = CCW_FLAG_SLI;
147 req->cp = cp;
148 }
149
pgid_wipeout_callback(struct ccw_device * cdev,void * data,int rc)150 static void pgid_wipeout_callback(struct ccw_device *cdev, void *data, int rc)
151 {
152 if (rc) {
153 /* We don't know the path groups' state. Abort. */
154 verify_done(cdev, rc);
155 return;
156 }
157 /*
158 * Path groups have been reset. Restart path verification but
159 * leave paths in path_noirq_mask out.
160 */
161 cdev->private->flags.pgid_unknown = 0;
162 verify_start(cdev);
163 }
164
165 /*
166 * Reset pathgroups and restart path verification, leave unusable paths out.
167 */
pgid_wipeout_start(struct ccw_device * cdev)168 static void pgid_wipeout_start(struct ccw_device *cdev)
169 {
170 struct subchannel *sch = to_subchannel(cdev->dev.parent);
171 struct ccw_dev_id *id = &cdev->private->dev_id;
172 struct ccw_request *req = &cdev->private->req;
173 u8 fn;
174
175 CIO_MSG_EVENT(2, "wipe: device 0.%x.%04x: pvm=%02x nim=%02x\n",
176 id->ssid, id->devno, cdev->private->pgid_valid_mask,
177 cdev->private->path_noirq_mask);
178
179 /* Initialize request data. */
180 memset(req, 0, sizeof(*req));
181 req->timeout = PGID_TIMEOUT;
182 req->maxretries = PGID_RETRIES;
183 req->lpm = sch->schib.pmcw.pam;
184 req->callback = pgid_wipeout_callback;
185 fn = SPID_FUNC_DISBAND;
186 if (cdev->private->flags.mpath)
187 fn |= SPID_FUNC_MULTI_PATH;
188 spid_build_cp(cdev, fn);
189 ccw_request_start(cdev);
190 }
191
192 /*
193 * Perform establish/resign SET PGID on a single path.
194 */
spid_do(struct ccw_device * cdev)195 static void spid_do(struct ccw_device *cdev)
196 {
197 struct subchannel *sch = to_subchannel(cdev->dev.parent);
198 struct ccw_request *req = &cdev->private->req;
199 u8 fn;
200
201 /* Use next available path that is not already in correct state. */
202 req->lpm = lpm_adjust(req->lpm, cdev->private->pgid_todo_mask);
203 if (!req->lpm)
204 goto out_nopath;
205 /* Channel program setup. */
206 if (req->lpm & sch->opm)
207 fn = SPID_FUNC_ESTABLISH;
208 else
209 fn = SPID_FUNC_RESIGN;
210 if (cdev->private->flags.mpath)
211 fn |= SPID_FUNC_MULTI_PATH;
212 spid_build_cp(cdev, fn);
213 ccw_request_start(cdev);
214 return;
215
216 out_nopath:
217 if (cdev->private->flags.pgid_unknown) {
218 /* At least one SPID could be partially done. */
219 pgid_wipeout_start(cdev);
220 return;
221 }
222 verify_done(cdev, sch->vpm ? 0 : -EACCES);
223 }
224
225 /*
226 * Process SET PGID request result for a single path.
227 */
spid_callback(struct ccw_device * cdev,void * data,int rc)228 static void spid_callback(struct ccw_device *cdev, void *data, int rc)
229 {
230 struct subchannel *sch = to_subchannel(cdev->dev.parent);
231 struct ccw_request *req = &cdev->private->req;
232
233 switch (rc) {
234 case 0:
235 sch->vpm |= req->lpm & sch->opm;
236 break;
237 case -ETIME:
238 cdev->private->flags.pgid_unknown = 1;
239 cdev->private->path_noirq_mask |= req->lpm;
240 break;
241 case -EACCES:
242 cdev->private->path_notoper_mask |= req->lpm;
243 break;
244 case -EOPNOTSUPP:
245 if (cdev->private->flags.mpath) {
246 /* Try without multipathing. */
247 cdev->private->flags.mpath = 0;
248 goto out_restart;
249 }
250 /* Try without pathgrouping. */
251 cdev->private->flags.pgroup = 0;
252 goto out_restart;
253 default:
254 goto err;
255 }
256 req->lpm >>= 1;
257 spid_do(cdev);
258 return;
259
260 out_restart:
261 verify_start(cdev);
262 return;
263 err:
264 verify_done(cdev, rc);
265 }
266
spid_start(struct ccw_device * cdev)267 static void spid_start(struct ccw_device *cdev)
268 {
269 struct ccw_request *req = &cdev->private->req;
270
271 /* Initialize request data. */
272 memset(req, 0, sizeof(*req));
273 req->timeout = PGID_TIMEOUT;
274 req->maxretries = PGID_RETRIES;
275 req->lpm = 0x80;
276 req->singlepath = 1;
277 req->callback = spid_callback;
278 spid_do(cdev);
279 }
280
pgid_is_reset(struct pgid * p)281 static int pgid_is_reset(struct pgid *p)
282 {
283 char *c;
284
285 for (c = (char *)p + 1; c < (char *)(p + 1); c++) {
286 if (*c != 0)
287 return 0;
288 }
289 return 1;
290 }
291
pgid_cmp(struct pgid * p1,struct pgid * p2)292 static int pgid_cmp(struct pgid *p1, struct pgid *p2)
293 {
294 return memcmp((char *) p1 + 1, (char *) p2 + 1,
295 sizeof(struct pgid) - 1);
296 }
297
298 /*
299 * Determine pathgroup state from PGID data.
300 */
pgid_analyze(struct ccw_device * cdev,struct pgid ** p,int * mismatch,u8 * reserved,u8 * reset)301 static void pgid_analyze(struct ccw_device *cdev, struct pgid **p,
302 int *mismatch, u8 *reserved, u8 *reset)
303 {
304 struct pgid *pgid = &cdev->private->dma_area->pgid[0];
305 struct pgid *first = NULL;
306 int lpm;
307 int i;
308
309 *mismatch = 0;
310 *reserved = 0;
311 *reset = 0;
312 for (i = 0, lpm = 0x80; i < 8; i++, pgid++, lpm >>= 1) {
313 if ((cdev->private->pgid_valid_mask & lpm) == 0)
314 continue;
315 if (pgid->inf.ps.state2 == SNID_STATE2_RESVD_ELSE)
316 *reserved |= lpm;
317 if (pgid_is_reset(pgid)) {
318 *reset |= lpm;
319 continue;
320 }
321 if (!first) {
322 first = pgid;
323 continue;
324 }
325 if (pgid_cmp(pgid, first) != 0)
326 *mismatch = 1;
327 }
328 if (!first)
329 first = &channel_subsystems[0]->global_pgid;
330 *p = first;
331 }
332
pgid_to_donepm(struct ccw_device * cdev)333 static u8 pgid_to_donepm(struct ccw_device *cdev)
334 {
335 struct subchannel *sch = to_subchannel(cdev->dev.parent);
336 struct pgid *pgid;
337 int i;
338 int lpm;
339 u8 donepm = 0;
340
341 /* Set bits for paths which are already in the target state. */
342 for (i = 0; i < 8; i++) {
343 lpm = 0x80 >> i;
344 if ((cdev->private->pgid_valid_mask & lpm) == 0)
345 continue;
346 pgid = &cdev->private->dma_area->pgid[i];
347 if (sch->opm & lpm) {
348 if (pgid->inf.ps.state1 != SNID_STATE1_GROUPED)
349 continue;
350 } else {
351 if (pgid->inf.ps.state1 != SNID_STATE1_UNGROUPED)
352 continue;
353 }
354 if (cdev->private->flags.mpath) {
355 if (pgid->inf.ps.state3 != SNID_STATE3_MULTI_PATH)
356 continue;
357 } else {
358 if (pgid->inf.ps.state3 != SNID_STATE3_SINGLE_PATH)
359 continue;
360 }
361 donepm |= lpm;
362 }
363
364 return donepm;
365 }
366
pgid_fill(struct ccw_device * cdev,struct pgid * pgid)367 static void pgid_fill(struct ccw_device *cdev, struct pgid *pgid)
368 {
369 int i;
370
371 for (i = 0; i < 8; i++)
372 memcpy(&cdev->private->dma_area->pgid[i], pgid,
373 sizeof(struct pgid));
374 }
375
376 /*
377 * Process SENSE PGID data and report result.
378 */
snid_done(struct ccw_device * cdev,int rc)379 static void snid_done(struct ccw_device *cdev, int rc)
380 {
381 struct ccw_dev_id *id = &cdev->private->dev_id;
382 struct subchannel *sch = to_subchannel(cdev->dev.parent);
383 struct pgid *pgid;
384 int mismatch = 0;
385 u8 reserved = 0;
386 u8 reset = 0;
387 u8 donepm;
388
389 if (rc)
390 goto out;
391 pgid_analyze(cdev, &pgid, &mismatch, &reserved, &reset);
392 if (reserved == cdev->private->pgid_valid_mask)
393 rc = -EUSERS;
394 else if (mismatch)
395 rc = -EOPNOTSUPP;
396 else {
397 donepm = pgid_to_donepm(cdev);
398 sch->vpm = donepm & sch->opm;
399 cdev->private->pgid_reset_mask |= reset;
400 cdev->private->pgid_todo_mask &=
401 ~(donepm | cdev->private->path_noirq_mask);
402 pgid_fill(cdev, pgid);
403 }
404 out:
405 CIO_MSG_EVENT(2, "snid: device 0.%x.%04x: rc=%d pvm=%02x vpm=%02x "
406 "todo=%02x mism=%d rsvd=%02x reset=%02x\n", id->ssid,
407 id->devno, rc, cdev->private->pgid_valid_mask, sch->vpm,
408 cdev->private->pgid_todo_mask, mismatch, reserved, reset);
409 switch (rc) {
410 case 0:
411 if (cdev->private->flags.pgid_unknown) {
412 pgid_wipeout_start(cdev);
413 return;
414 }
415 /* Anything left to do? */
416 if (cdev->private->pgid_todo_mask == 0) {
417 verify_done(cdev, sch->vpm == 0 ? -EACCES : 0);
418 return;
419 }
420 /* Perform path-grouping. */
421 spid_start(cdev);
422 break;
423 case -EOPNOTSUPP:
424 /* Path-grouping not supported. */
425 cdev->private->flags.pgroup = 0;
426 cdev->private->flags.mpath = 0;
427 verify_start(cdev);
428 break;
429 default:
430 verify_done(cdev, rc);
431 }
432 }
433
434 /*
435 * Create channel program to perform a SENSE PGID on a single path.
436 */
snid_build_cp(struct ccw_device * cdev)437 static void snid_build_cp(struct ccw_device *cdev)
438 {
439 struct ccw_request *req = &cdev->private->req;
440 struct ccw1 *cp = cdev->private->dma_area->iccws;
441 int i = pathmask_to_pos(req->lpm);
442
443 /* Channel program setup. */
444 cp->cmd_code = CCW_CMD_SENSE_PGID;
445 cp->cda = (u32)virt_to_phys(&cdev->private->dma_area->pgid[i]);
446 cp->count = sizeof(struct pgid);
447 cp->flags = CCW_FLAG_SLI;
448 req->cp = cp;
449 }
450
451 /*
452 * Perform SENSE PGID on a single path.
453 */
snid_do(struct ccw_device * cdev)454 static void snid_do(struct ccw_device *cdev)
455 {
456 struct subchannel *sch = to_subchannel(cdev->dev.parent);
457 struct ccw_request *req = &cdev->private->req;
458 int ret;
459
460 req->lpm = lpm_adjust(req->lpm, sch->schib.pmcw.pam &
461 ~cdev->private->path_noirq_mask);
462 if (!req->lpm)
463 goto out_nopath;
464 snid_build_cp(cdev);
465 ccw_request_start(cdev);
466 return;
467
468 out_nopath:
469 if (cdev->private->pgid_valid_mask)
470 ret = 0;
471 else if (cdev->private->path_noirq_mask)
472 ret = -ETIME;
473 else
474 ret = -EACCES;
475 snid_done(cdev, ret);
476 }
477
478 /*
479 * Process SENSE PGID request result for single path.
480 */
snid_callback(struct ccw_device * cdev,void * data,int rc)481 static void snid_callback(struct ccw_device *cdev, void *data, int rc)
482 {
483 struct ccw_request *req = &cdev->private->req;
484
485 switch (rc) {
486 case 0:
487 cdev->private->pgid_valid_mask |= req->lpm;
488 break;
489 case -ETIME:
490 cdev->private->flags.pgid_unknown = 1;
491 cdev->private->path_noirq_mask |= req->lpm;
492 break;
493 case -EACCES:
494 cdev->private->path_notoper_mask |= req->lpm;
495 break;
496 default:
497 goto err;
498 }
499 /* Continue on the next path. */
500 req->lpm >>= 1;
501 snid_do(cdev);
502 return;
503
504 err:
505 snid_done(cdev, rc);
506 }
507
508 /*
509 * Perform path verification.
510 */
verify_start(struct ccw_device * cdev)511 static void verify_start(struct ccw_device *cdev)
512 {
513 struct subchannel *sch = to_subchannel(cdev->dev.parent);
514 struct ccw_request *req = &cdev->private->req;
515 struct ccw_dev_id *devid = &cdev->private->dev_id;
516
517 sch->vpm = 0;
518 sch->lpm = sch->schib.pmcw.pam;
519
520 /* Initialize PGID data. */
521 memset(cdev->private->dma_area->pgid, 0,
522 sizeof(cdev->private->dma_area->pgid));
523 cdev->private->pgid_valid_mask = 0;
524 cdev->private->pgid_todo_mask = sch->schib.pmcw.pam;
525 cdev->private->path_notoper_mask = 0;
526
527 /* Initialize request data. */
528 memset(req, 0, sizeof(*req));
529 req->timeout = PGID_TIMEOUT;
530 req->maxretries = PGID_RETRIES;
531 req->lpm = 0x80;
532 req->singlepath = 1;
533 if (cdev->private->flags.pgroup) {
534 CIO_TRACE_EVENT(4, "snid");
535 CIO_HEX_EVENT(4, devid, sizeof(*devid));
536 req->callback = snid_callback;
537 snid_do(cdev);
538 } else {
539 CIO_TRACE_EVENT(4, "nop");
540 CIO_HEX_EVENT(4, devid, sizeof(*devid));
541 req->filter = nop_filter;
542 req->callback = nop_callback;
543 nop_do(cdev);
544 }
545 }
546
547 /**
548 * ccw_device_verify_start - perform path verification
549 * @cdev: ccw device
550 *
551 * Perform an I/O on each available channel path to @cdev to determine which
552 * paths are operational. The resulting path mask is stored in sch->vpm.
553 * If device options specify pathgrouping, establish a pathgroup for the
554 * operational paths. When finished, call ccw_device_verify_done with a
555 * return code specifying the result.
556 */
ccw_device_verify_start(struct ccw_device * cdev)557 void ccw_device_verify_start(struct ccw_device *cdev)
558 {
559 CIO_TRACE_EVENT(4, "vrfy");
560 CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
561 /*
562 * Initialize pathgroup and multipath state with target values.
563 * They may change in the course of path verification.
564 */
565 cdev->private->flags.pgroup = cdev->private->options.pgroup;
566 cdev->private->flags.mpath = cdev->private->options.mpath;
567 cdev->private->flags.doverify = 0;
568 cdev->private->path_noirq_mask = 0;
569 verify_start(cdev);
570 }
571
572 /*
573 * Process disband SET PGID request result.
574 */
disband_callback(struct ccw_device * cdev,void * data,int rc)575 static void disband_callback(struct ccw_device *cdev, void *data, int rc)
576 {
577 struct subchannel *sch = to_subchannel(cdev->dev.parent);
578 struct ccw_dev_id *id = &cdev->private->dev_id;
579
580 if (rc)
581 goto out;
582 /* Ensure consistent multipathing state at device and channel. */
583 cdev->private->flags.mpath = 0;
584 if (sch->config.mp) {
585 sch->config.mp = 0;
586 rc = cio_commit_config(sch);
587 }
588 out:
589 CIO_MSG_EVENT(0, "disb: device 0.%x.%04x: rc=%d\n", id->ssid, id->devno,
590 rc);
591 ccw_device_disband_done(cdev, rc);
592 }
593
594 /**
595 * ccw_device_disband_start - disband pathgroup
596 * @cdev: ccw device
597 *
598 * Execute a SET PGID channel program on @cdev to disband a previously
599 * established pathgroup. When finished, call ccw_device_disband_done with
600 * a return code specifying the result.
601 */
ccw_device_disband_start(struct ccw_device * cdev)602 void ccw_device_disband_start(struct ccw_device *cdev)
603 {
604 struct subchannel *sch = to_subchannel(cdev->dev.parent);
605 struct ccw_request *req = &cdev->private->req;
606 u8 fn;
607
608 CIO_TRACE_EVENT(4, "disb");
609 CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
610 /* Request setup. */
611 memset(req, 0, sizeof(*req));
612 req->timeout = PGID_TIMEOUT;
613 req->maxretries = PGID_RETRIES;
614 req->lpm = sch->schib.pmcw.pam & sch->opm;
615 req->singlepath = 1;
616 req->callback = disband_callback;
617 fn = SPID_FUNC_DISBAND;
618 if (cdev->private->flags.mpath)
619 fn |= SPID_FUNC_MULTI_PATH;
620 spid_build_cp(cdev, fn);
621 ccw_request_start(cdev);
622 }
623
624 struct stlck_data {
625 struct completion done;
626 int rc;
627 };
628
stlck_build_cp(struct ccw_device * cdev,void * buf1,void * buf2)629 static void stlck_build_cp(struct ccw_device *cdev, void *buf1, void *buf2)
630 {
631 struct ccw_request *req = &cdev->private->req;
632 struct ccw1 *cp = cdev->private->dma_area->iccws;
633
634 cp[0].cmd_code = CCW_CMD_STLCK;
635 cp[0].cda = (u32)virt_to_phys(buf1);
636 cp[0].count = 32;
637 cp[0].flags = CCW_FLAG_CC;
638 cp[1].cmd_code = CCW_CMD_RELEASE;
639 cp[1].cda = (u32)virt_to_phys(buf2);
640 cp[1].count = 32;
641 cp[1].flags = 0;
642 req->cp = cp;
643 }
644
stlck_callback(struct ccw_device * cdev,void * data,int rc)645 static void stlck_callback(struct ccw_device *cdev, void *data, int rc)
646 {
647 struct stlck_data *sdata = data;
648
649 sdata->rc = rc;
650 complete(&sdata->done);
651 }
652
653 /**
654 * ccw_device_stlck_start - perform unconditional release
655 * @cdev: ccw device
656 * @data: data pointer to be passed to ccw_device_stlck_done
657 * @buf1: data pointer used in channel program
658 * @buf2: data pointer used in channel program
659 *
660 * Execute a channel program on @cdev to release an existing PGID reservation.
661 */
ccw_device_stlck_start(struct ccw_device * cdev,void * data,void * buf1,void * buf2)662 static void ccw_device_stlck_start(struct ccw_device *cdev, void *data,
663 void *buf1, void *buf2)
664 {
665 struct subchannel *sch = to_subchannel(cdev->dev.parent);
666 struct ccw_request *req = &cdev->private->req;
667
668 CIO_TRACE_EVENT(4, "stlck");
669 CIO_HEX_EVENT(4, &cdev->private->dev_id, sizeof(cdev->private->dev_id));
670 /* Request setup. */
671 memset(req, 0, sizeof(*req));
672 req->timeout = PGID_TIMEOUT;
673 req->maxretries = PGID_RETRIES;
674 req->lpm = sch->schib.pmcw.pam & sch->opm;
675 req->data = data;
676 req->callback = stlck_callback;
677 stlck_build_cp(cdev, buf1, buf2);
678 ccw_request_start(cdev);
679 }
680
681 /*
682 * Perform unconditional reserve + release.
683 */
ccw_device_stlck(struct ccw_device * cdev)684 int ccw_device_stlck(struct ccw_device *cdev)
685 {
686 struct subchannel *sch = to_subchannel(cdev->dev.parent);
687 struct stlck_data data;
688 u8 *buffer;
689 int rc;
690
691 /* Check if steal lock operation is valid for this device. */
692 if (cdev->drv) {
693 if (!cdev->private->options.force)
694 return -EINVAL;
695 }
696 buffer = kzalloc(64, GFP_DMA | GFP_KERNEL);
697 if (!buffer)
698 return -ENOMEM;
699 init_completion(&data.done);
700 data.rc = -EIO;
701 spin_lock_irq(sch->lock);
702 rc = cio_enable_subchannel(sch, (u32)virt_to_phys(sch));
703 if (rc)
704 goto out_unlock;
705 /* Perform operation. */
706 cdev->private->state = DEV_STATE_STEAL_LOCK;
707 ccw_device_stlck_start(cdev, &data, &buffer[0], &buffer[32]);
708 spin_unlock_irq(sch->lock);
709 /* Wait for operation to finish. */
710 if (wait_for_completion_interruptible(&data.done)) {
711 /* Got a signal. */
712 spin_lock_irq(sch->lock);
713 ccw_request_cancel(cdev);
714 spin_unlock_irq(sch->lock);
715 wait_for_completion(&data.done);
716 }
717 rc = data.rc;
718 /* Check results. */
719 spin_lock_irq(sch->lock);
720 cio_disable_subchannel(sch);
721 cdev->private->state = DEV_STATE_BOXED;
722 out_unlock:
723 spin_unlock_irq(sch->lock);
724 kfree(buffer);
725
726 return rc;
727 }
728