Merge 3.9-rc5 into staging-next
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / s390 / cio / chp.c
1 /*
2 * Copyright IBM Corp. 1999, 2010
3 * Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
4 * Arnd Bergmann (arndb@de.ibm.com)
5 * Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
6 */
7
8 #include <linux/bug.h>
9 #include <linux/workqueue.h>
10 #include <linux/spinlock.h>
11 #include <linux/export.h>
12 #include <linux/sched.h>
13 #include <linux/init.h>
14 #include <linux/jiffies.h>
15 #include <linux/wait.h>
16 #include <linux/mutex.h>
17 #include <linux/errno.h>
18 #include <linux/slab.h>
19 #include <asm/chpid.h>
20 #include <asm/sclp.h>
21 #include <asm/crw.h>
22
23 #include "cio.h"
24 #include "css.h"
25 #include "ioasm.h"
26 #include "cio_debug.h"
27 #include "chp.h"
28
29 #define to_channelpath(device) container_of(device, struct channel_path, dev)
30 #define CHP_INFO_UPDATE_INTERVAL 1*HZ
31
32 enum cfg_task_t {
33 cfg_none,
34 cfg_configure,
35 cfg_deconfigure
36 };
37
38 /* Map for pending configure tasks. */
39 static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1];
40 static DEFINE_MUTEX(cfg_lock);
41 static int cfg_busy;
42
43 /* Map for channel-path status. */
44 static struct sclp_chp_info chp_info;
45 static DEFINE_MUTEX(info_lock);
46
47 /* Time after which channel-path status may be outdated. */
48 static unsigned long chp_info_expires;
49
50 /* Workqueue to perform pending configure tasks. */
51 static struct workqueue_struct *chp_wq;
52 static struct work_struct cfg_work;
53
54 /* Wait queue for configure completion events. */
55 static wait_queue_head_t cfg_wait_queue;
56
57 /* Set vary state for given chpid. */
58 static void set_chp_logically_online(struct chp_id chpid, int onoff)
59 {
60 chpid_to_chp(chpid)->state = onoff;
61 }
62
63 /* On success return 0 if channel-path is varied offline, 1 if it is varied
64 * online. Return -ENODEV if channel-path is not registered. */
65 int chp_get_status(struct chp_id chpid)
66 {
67 return (chpid_to_chp(chpid) ? chpid_to_chp(chpid)->state : -ENODEV);
68 }
69
70 /**
71 * chp_get_sch_opm - return opm for subchannel
72 * @sch: subchannel
73 *
74 * Calculate and return the operational path mask (opm) based on the chpids
75 * used by the subchannel and the status of the associated channel-paths.
76 */
77 u8 chp_get_sch_opm(struct subchannel *sch)
78 {
79 struct chp_id chpid;
80 int opm;
81 int i;
82
83 opm = 0;
84 chp_id_init(&chpid);
85 for (i = 0; i < 8; i++) {
86 opm <<= 1;
87 chpid.id = sch->schib.pmcw.chpid[i];
88 if (chp_get_status(chpid) != 0)
89 opm |= 1;
90 }
91 return opm;
92 }
93 EXPORT_SYMBOL_GPL(chp_get_sch_opm);
94
95 /**
96 * chp_is_registered - check if a channel-path is registered
97 * @chpid: channel-path ID
98 *
99 * Return non-zero if a channel-path with the given chpid is registered,
100 * zero otherwise.
101 */
102 int chp_is_registered(struct chp_id chpid)
103 {
104 return chpid_to_chp(chpid) != NULL;
105 }
106
107 /*
108 * Function: s390_vary_chpid
109 * Varies the specified chpid online or offline
110 */
111 static int s390_vary_chpid(struct chp_id chpid, int on)
112 {
113 char dbf_text[15];
114 int status;
115
116 sprintf(dbf_text, on?"varyon%x.%02x":"varyoff%x.%02x", chpid.cssid,
117 chpid.id);
118 CIO_TRACE_EVENT(2, dbf_text);
119
120 status = chp_get_status(chpid);
121 if (!on && !status)
122 return 0;
123
124 set_chp_logically_online(chpid, on);
125 chsc_chp_vary(chpid, on);
126 return 0;
127 }
128
129 /*
130 * Channel measurement related functions
131 */
132 static ssize_t chp_measurement_chars_read(struct file *filp,
133 struct kobject *kobj,
134 struct bin_attribute *bin_attr,
135 char *buf, loff_t off, size_t count)
136 {
137 struct channel_path *chp;
138 struct device *device;
139
140 device = container_of(kobj, struct device, kobj);
141 chp = to_channelpath(device);
142 if (!chp->cmg_chars)
143 return 0;
144
145 return memory_read_from_buffer(buf, count, &off,
146 chp->cmg_chars, sizeof(struct cmg_chars));
147 }
148
149 static struct bin_attribute chp_measurement_chars_attr = {
150 .attr = {
151 .name = "measurement_chars",
152 .mode = S_IRUSR,
153 },
154 .size = sizeof(struct cmg_chars),
155 .read = chp_measurement_chars_read,
156 };
157
158 static void chp_measurement_copy_block(struct cmg_entry *buf,
159 struct channel_subsystem *css,
160 struct chp_id chpid)
161 {
162 void *area;
163 struct cmg_entry *entry, reference_buf;
164 int idx;
165
166 if (chpid.id < 128) {
167 area = css->cub_addr1;
168 idx = chpid.id;
169 } else {
170 area = css->cub_addr2;
171 idx = chpid.id - 128;
172 }
173 entry = area + (idx * sizeof(struct cmg_entry));
174 do {
175 memcpy(buf, entry, sizeof(*entry));
176 memcpy(&reference_buf, entry, sizeof(*entry));
177 } while (reference_buf.values[0] != buf->values[0]);
178 }
179
180 static ssize_t chp_measurement_read(struct file *filp, struct kobject *kobj,
181 struct bin_attribute *bin_attr,
182 char *buf, loff_t off, size_t count)
183 {
184 struct channel_path *chp;
185 struct channel_subsystem *css;
186 struct device *device;
187 unsigned int size;
188
189 device = container_of(kobj, struct device, kobj);
190 chp = to_channelpath(device);
191 css = to_css(chp->dev.parent);
192
193 size = sizeof(struct cmg_entry);
194
195 /* Only allow single reads. */
196 if (off || count < size)
197 return 0;
198 chp_measurement_copy_block((struct cmg_entry *)buf, css, chp->chpid);
199 count = size;
200 return count;
201 }
202
203 static struct bin_attribute chp_measurement_attr = {
204 .attr = {
205 .name = "measurement",
206 .mode = S_IRUSR,
207 },
208 .size = sizeof(struct cmg_entry),
209 .read = chp_measurement_read,
210 };
211
212 void chp_remove_cmg_attr(struct channel_path *chp)
213 {
214 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
215 device_remove_bin_file(&chp->dev, &chp_measurement_attr);
216 }
217
218 int chp_add_cmg_attr(struct channel_path *chp)
219 {
220 int ret;
221
222 ret = device_create_bin_file(&chp->dev, &chp_measurement_chars_attr);
223 if (ret)
224 return ret;
225 ret = device_create_bin_file(&chp->dev, &chp_measurement_attr);
226 if (ret)
227 device_remove_bin_file(&chp->dev, &chp_measurement_chars_attr);
228 return ret;
229 }
230
231 /*
232 * Files for the channel path entries.
233 */
234 static ssize_t chp_status_show(struct device *dev,
235 struct device_attribute *attr, char *buf)
236 {
237 struct channel_path *chp = to_channelpath(dev);
238 int status;
239
240 mutex_lock(&chp->lock);
241 status = chp->state;
242 mutex_unlock(&chp->lock);
243
244 return status ? sprintf(buf, "online\n") : sprintf(buf, "offline\n");
245 }
246
247 static ssize_t chp_status_write(struct device *dev,
248 struct device_attribute *attr,
249 const char *buf, size_t count)
250 {
251 struct channel_path *cp = to_channelpath(dev);
252 char cmd[10];
253 int num_args;
254 int error;
255
256 num_args = sscanf(buf, "%5s", cmd);
257 if (!num_args)
258 return count;
259
260 if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1")) {
261 mutex_lock(&cp->lock);
262 error = s390_vary_chpid(cp->chpid, 1);
263 mutex_unlock(&cp->lock);
264 } else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0")) {
265 mutex_lock(&cp->lock);
266 error = s390_vary_chpid(cp->chpid, 0);
267 mutex_unlock(&cp->lock);
268 } else
269 error = -EINVAL;
270
271 return error < 0 ? error : count;
272 }
273
274 static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
275
276 static ssize_t chp_configure_show(struct device *dev,
277 struct device_attribute *attr, char *buf)
278 {
279 struct channel_path *cp;
280 int status;
281
282 cp = to_channelpath(dev);
283 status = chp_info_get_status(cp->chpid);
284 if (status < 0)
285 return status;
286
287 return snprintf(buf, PAGE_SIZE, "%d\n", status);
288 }
289
290 static int cfg_wait_idle(void);
291
292 static ssize_t chp_configure_write(struct device *dev,
293 struct device_attribute *attr,
294 const char *buf, size_t count)
295 {
296 struct channel_path *cp;
297 int val;
298 char delim;
299
300 if (sscanf(buf, "%d %c", &val, &delim) != 1)
301 return -EINVAL;
302 if (val != 0 && val != 1)
303 return -EINVAL;
304 cp = to_channelpath(dev);
305 chp_cfg_schedule(cp->chpid, val);
306 cfg_wait_idle();
307
308 return count;
309 }
310
311 static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write);
312
313 static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr,
314 char *buf)
315 {
316 struct channel_path *chp = to_channelpath(dev);
317 u8 type;
318
319 mutex_lock(&chp->lock);
320 type = chp->desc.desc;
321 mutex_unlock(&chp->lock);
322 return sprintf(buf, "%x\n", type);
323 }
324
325 static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
326
327 static ssize_t chp_cmg_show(struct device *dev, struct device_attribute *attr,
328 char *buf)
329 {
330 struct channel_path *chp = to_channelpath(dev);
331
332 if (!chp)
333 return 0;
334 if (chp->cmg == -1) /* channel measurements not available */
335 return sprintf(buf, "unknown\n");
336 return sprintf(buf, "%x\n", chp->cmg);
337 }
338
339 static DEVICE_ATTR(cmg, 0444, chp_cmg_show, NULL);
340
341 static ssize_t chp_shared_show(struct device *dev,
342 struct device_attribute *attr, char *buf)
343 {
344 struct channel_path *chp = to_channelpath(dev);
345
346 if (!chp)
347 return 0;
348 if (chp->shared == -1) /* channel measurements not available */
349 return sprintf(buf, "unknown\n");
350 return sprintf(buf, "%x\n", chp->shared);
351 }
352
353 static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL);
354
355 static struct attribute *chp_attrs[] = {
356 &dev_attr_status.attr,
357 &dev_attr_configure.attr,
358 &dev_attr_type.attr,
359 &dev_attr_cmg.attr,
360 &dev_attr_shared.attr,
361 NULL,
362 };
363 static struct attribute_group chp_attr_group = {
364 .attrs = chp_attrs,
365 };
366 static const struct attribute_group *chp_attr_groups[] = {
367 &chp_attr_group,
368 NULL,
369 };
370
371 static void chp_release(struct device *dev)
372 {
373 struct channel_path *cp;
374
375 cp = to_channelpath(dev);
376 kfree(cp);
377 }
378
379 /**
380 * chp_new - register a new channel-path
381 * @chpid - channel-path ID
382 *
383 * Create and register data structure representing new channel-path. Return
384 * zero on success, non-zero otherwise.
385 */
386 int chp_new(struct chp_id chpid)
387 {
388 struct channel_path *chp;
389 int ret;
390
391 if (chp_is_registered(chpid))
392 return 0;
393 chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL);
394 if (!chp)
395 return -ENOMEM;
396
397 /* fill in status, etc. */
398 chp->chpid = chpid;
399 chp->state = 1;
400 chp->dev.parent = &channel_subsystems[chpid.cssid]->device;
401 chp->dev.groups = chp_attr_groups;
402 chp->dev.release = chp_release;
403 mutex_init(&chp->lock);
404
405 /* Obtain channel path description and fill it in. */
406 ret = chsc_determine_base_channel_path_desc(chpid, &chp->desc);
407 if (ret)
408 goto out_free;
409 if ((chp->desc.flags & 0x80) == 0) {
410 ret = -ENODEV;
411 goto out_free;
412 }
413 /* Get channel-measurement characteristics. */
414 if (css_chsc_characteristics.scmc && css_chsc_characteristics.secm) {
415 ret = chsc_get_channel_measurement_chars(chp);
416 if (ret)
417 goto out_free;
418 } else {
419 chp->cmg = -1;
420 }
421 dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
422
423 /* make it known to the system */
424 ret = device_register(&chp->dev);
425 if (ret) {
426 CIO_MSG_EVENT(0, "Could not register chp%x.%02x: %d\n",
427 chpid.cssid, chpid.id, ret);
428 put_device(&chp->dev);
429 goto out;
430 }
431 mutex_lock(&channel_subsystems[chpid.cssid]->mutex);
432 if (channel_subsystems[chpid.cssid]->cm_enabled) {
433 ret = chp_add_cmg_attr(chp);
434 if (ret) {
435 device_unregister(&chp->dev);
436 mutex_unlock(&channel_subsystems[chpid.cssid]->mutex);
437 goto out;
438 }
439 }
440 channel_subsystems[chpid.cssid]->chps[chpid.id] = chp;
441 mutex_unlock(&channel_subsystems[chpid.cssid]->mutex);
442 goto out;
443 out_free:
444 kfree(chp);
445 out:
446 return ret;
447 }
448
449 /**
450 * chp_get_chp_desc - return newly allocated channel-path description
451 * @chpid: channel-path ID
452 *
453 * On success return a newly allocated copy of the channel-path description
454 * data associated with the given channel-path ID. Return %NULL on error.
455 */
456 void *chp_get_chp_desc(struct chp_id chpid)
457 {
458 struct channel_path *chp;
459 struct channel_path_desc *desc;
460
461 chp = chpid_to_chp(chpid);
462 if (!chp)
463 return NULL;
464 desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
465 if (!desc)
466 return NULL;
467
468 mutex_lock(&chp->lock);
469 memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
470 mutex_unlock(&chp->lock);
471 return desc;
472 }
473
474 /**
475 * chp_process_crw - process channel-path status change
476 * @crw0: channel report-word to handler
477 * @crw1: second channel-report word (always NULL)
478 * @overflow: crw overflow indication
479 *
480 * Handle channel-report-words indicating that the status of a channel-path
481 * has changed.
482 */
483 static void chp_process_crw(struct crw *crw0, struct crw *crw1,
484 int overflow)
485 {
486 struct chp_id chpid;
487
488 if (overflow) {
489 css_schedule_eval_all();
490 return;
491 }
492 CIO_CRW_EVENT(2, "CRW reports slct=%d, oflw=%d, "
493 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
494 crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
495 crw0->erc, crw0->rsid);
496 /*
497 * Check for solicited machine checks. These are
498 * created by reset channel path and need not be
499 * handled here.
500 */
501 if (crw0->slct) {
502 CIO_CRW_EVENT(2, "solicited machine check for "
503 "channel path %02X\n", crw0->rsid);
504 return;
505 }
506 chp_id_init(&chpid);
507 chpid.id = crw0->rsid;
508 switch (crw0->erc) {
509 case CRW_ERC_IPARM: /* Path has come. */
510 if (!chp_is_registered(chpid))
511 chp_new(chpid);
512 chsc_chp_online(chpid);
513 break;
514 case CRW_ERC_PERRI: /* Path has gone. */
515 case CRW_ERC_PERRN:
516 chsc_chp_offline(chpid);
517 break;
518 default:
519 CIO_CRW_EVENT(2, "Don't know how to handle erc=%x\n",
520 crw0->erc);
521 }
522 }
523
524 int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct chp_link *link)
525 {
526 int i;
527 int mask;
528
529 for (i = 0; i < 8; i++) {
530 mask = 0x80 >> i;
531 if (!(ssd->path_mask & mask))
532 continue;
533 if (!chp_id_is_equal(&ssd->chpid[i], &link->chpid))
534 continue;
535 if ((ssd->fla_valid_mask & mask) &&
536 ((ssd->fla[i] & link->fla_mask) != link->fla))
537 continue;
538 return mask;
539 }
540 return 0;
541 }
542 EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
543
544 static inline int info_bit_num(struct chp_id id)
545 {
546 return id.id + id.cssid * (__MAX_CHPID + 1);
547 }
548
549 /* Force chp_info refresh on next call to info_validate(). */
550 static void info_expire(void)
551 {
552 mutex_lock(&info_lock);
553 chp_info_expires = jiffies - 1;
554 mutex_unlock(&info_lock);
555 }
556
557 /* Ensure that chp_info is up-to-date. */
558 static int info_update(void)
559 {
560 int rc;
561
562 mutex_lock(&info_lock);
563 rc = 0;
564 if (time_after(jiffies, chp_info_expires)) {
565 /* Data is too old, update. */
566 rc = sclp_chp_read_info(&chp_info);
567 chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ;
568 }
569 mutex_unlock(&info_lock);
570
571 return rc;
572 }
573
574 /**
575 * chp_info_get_status - retrieve configure status of a channel-path
576 * @chpid: channel-path ID
577 *
578 * On success, return 0 for standby, 1 for configured, 2 for reserved,
579 * 3 for not recognized. Return negative error code on error.
580 */
581 int chp_info_get_status(struct chp_id chpid)
582 {
583 int rc;
584 int bit;
585
586 rc = info_update();
587 if (rc)
588 return rc;
589
590 bit = info_bit_num(chpid);
591 mutex_lock(&info_lock);
592 if (!chp_test_bit(chp_info.recognized, bit))
593 rc = CHP_STATUS_NOT_RECOGNIZED;
594 else if (chp_test_bit(chp_info.configured, bit))
595 rc = CHP_STATUS_CONFIGURED;
596 else if (chp_test_bit(chp_info.standby, bit))
597 rc = CHP_STATUS_STANDBY;
598 else
599 rc = CHP_STATUS_RESERVED;
600 mutex_unlock(&info_lock);
601
602 return rc;
603 }
604
605 /* Return configure task for chpid. */
606 static enum cfg_task_t cfg_get_task(struct chp_id chpid)
607 {
608 return chp_cfg_task[chpid.cssid][chpid.id];
609 }
610
611 /* Set configure task for chpid. */
612 static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg)
613 {
614 chp_cfg_task[chpid.cssid][chpid.id] = cfg;
615 }
616
617 /* Perform one configure/deconfigure request. Reschedule work function until
618 * last request. */
619 static void cfg_func(struct work_struct *work)
620 {
621 struct chp_id chpid;
622 enum cfg_task_t t;
623 int rc;
624
625 mutex_lock(&cfg_lock);
626 t = cfg_none;
627 chp_id_for_each(&chpid) {
628 t = cfg_get_task(chpid);
629 if (t != cfg_none) {
630 cfg_set_task(chpid, cfg_none);
631 break;
632 }
633 }
634 mutex_unlock(&cfg_lock);
635
636 switch (t) {
637 case cfg_configure:
638 rc = sclp_chp_configure(chpid);
639 if (rc)
640 CIO_MSG_EVENT(2, "chp: sclp_chp_configure(%x.%02x)="
641 "%d\n", chpid.cssid, chpid.id, rc);
642 else {
643 info_expire();
644 chsc_chp_online(chpid);
645 }
646 break;
647 case cfg_deconfigure:
648 rc = sclp_chp_deconfigure(chpid);
649 if (rc)
650 CIO_MSG_EVENT(2, "chp: sclp_chp_deconfigure(%x.%02x)="
651 "%d\n", chpid.cssid, chpid.id, rc);
652 else {
653 info_expire();
654 chsc_chp_offline(chpid);
655 }
656 break;
657 case cfg_none:
658 /* Get updated information after last change. */
659 info_update();
660 mutex_lock(&cfg_lock);
661 cfg_busy = 0;
662 mutex_unlock(&cfg_lock);
663 wake_up_interruptible(&cfg_wait_queue);
664 return;
665 }
666 queue_work(chp_wq, &cfg_work);
667 }
668
669 /**
670 * chp_cfg_schedule - schedule chpid configuration request
671 * @chpid - channel-path ID
672 * @configure - Non-zero for configure, zero for deconfigure
673 *
674 * Schedule a channel-path configuration/deconfiguration request.
675 */
676 void chp_cfg_schedule(struct chp_id chpid, int configure)
677 {
678 CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id,
679 configure);
680 mutex_lock(&cfg_lock);
681 cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure);
682 cfg_busy = 1;
683 mutex_unlock(&cfg_lock);
684 queue_work(chp_wq, &cfg_work);
685 }
686
687 /**
688 * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request
689 * @chpid - channel-path ID
690 *
691 * Cancel an active channel-path deconfiguration request if it has not yet
692 * been performed.
693 */
694 void chp_cfg_cancel_deconfigure(struct chp_id chpid)
695 {
696 CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id);
697 mutex_lock(&cfg_lock);
698 if (cfg_get_task(chpid) == cfg_deconfigure)
699 cfg_set_task(chpid, cfg_none);
700 mutex_unlock(&cfg_lock);
701 }
702
703 static int cfg_wait_idle(void)
704 {
705 if (wait_event_interruptible(cfg_wait_queue, !cfg_busy))
706 return -ERESTARTSYS;
707 return 0;
708 }
709
710 static int __init chp_init(void)
711 {
712 struct chp_id chpid;
713 int ret;
714
715 ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw);
716 if (ret)
717 return ret;
718 chp_wq = create_singlethread_workqueue("cio_chp");
719 if (!chp_wq) {
720 crw_unregister_handler(CRW_RSC_CPATH);
721 return -ENOMEM;
722 }
723 INIT_WORK(&cfg_work, cfg_func);
724 init_waitqueue_head(&cfg_wait_queue);
725 if (info_update())
726 return 0;
727 /* Register available channel-paths. */
728 chp_id_for_each(&chpid) {
729 if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED)
730 chp_new(chpid);
731 }
732
733 return 0;
734 }
735
736 subsys_initcall(chp_init);