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