]> git.openfabrics.org - ~shefty/rdma-dev.git/blob - drivers/s390/cio/css.c
autofs4 - remove ioctl mutex (bz23142)
[~shefty/rdma-dev.git] / drivers / s390 / cio / css.c
1 /*
2  * driver for channel subsystem
3  *
4  * Copyright IBM Corp. 2002, 2010
5  *
6  * Author(s): Arnd Bergmann (arndb@de.ibm.com)
7  *            Cornelia Huck (cornelia.huck@de.ibm.com)
8  */
9
10 #define KMSG_COMPONENT "cio"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/device.h>
16 #include <linux/slab.h>
17 #include <linux/errno.h>
18 #include <linux/list.h>
19 #include <linux/reboot.h>
20 #include <linux/suspend.h>
21 #include <linux/proc_fs.h>
22 #include <asm/isc.h>
23 #include <asm/crw.h>
24
25 #include "css.h"
26 #include "cio.h"
27 #include "cio_debug.h"
28 #include "ioasm.h"
29 #include "chsc.h"
30 #include "device.h"
31 #include "idset.h"
32 #include "chp.h"
33
34 int css_init_done = 0;
35 int max_ssid;
36
37 struct channel_subsystem *channel_subsystems[__MAX_CSSID + 1];
38
39 int
40 for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data)
41 {
42         struct subchannel_id schid;
43         int ret;
44
45         init_subchannel_id(&schid);
46         ret = -ENODEV;
47         do {
48                 do {
49                         ret = fn(schid, data);
50                         if (ret)
51                                 break;
52                 } while (schid.sch_no++ < __MAX_SUBCHANNEL);
53                 schid.sch_no = 0;
54         } while (schid.ssid++ < max_ssid);
55         return ret;
56 }
57
58 struct cb_data {
59         void *data;
60         struct idset *set;
61         int (*fn_known_sch)(struct subchannel *, void *);
62         int (*fn_unknown_sch)(struct subchannel_id, void *);
63 };
64
65 static int call_fn_known_sch(struct device *dev, void *data)
66 {
67         struct subchannel *sch = to_subchannel(dev);
68         struct cb_data *cb = data;
69         int rc = 0;
70
71         idset_sch_del(cb->set, sch->schid);
72         if (cb->fn_known_sch)
73                 rc = cb->fn_known_sch(sch, cb->data);
74         return rc;
75 }
76
77 static int call_fn_unknown_sch(struct subchannel_id schid, void *data)
78 {
79         struct cb_data *cb = data;
80         int rc = 0;
81
82         if (idset_sch_contains(cb->set, schid))
83                 rc = cb->fn_unknown_sch(schid, cb->data);
84         return rc;
85 }
86
87 static int call_fn_all_sch(struct subchannel_id schid, void *data)
88 {
89         struct cb_data *cb = data;
90         struct subchannel *sch;
91         int rc = 0;
92
93         sch = get_subchannel_by_schid(schid);
94         if (sch) {
95                 if (cb->fn_known_sch)
96                         rc = cb->fn_known_sch(sch, cb->data);
97                 put_device(&sch->dev);
98         } else {
99                 if (cb->fn_unknown_sch)
100                         rc = cb->fn_unknown_sch(schid, cb->data);
101         }
102
103         return rc;
104 }
105
106 int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
107                                int (*fn_unknown)(struct subchannel_id,
108                                void *), void *data)
109 {
110         struct cb_data cb;
111         int rc;
112
113         cb.data = data;
114         cb.fn_known_sch = fn_known;
115         cb.fn_unknown_sch = fn_unknown;
116
117         cb.set = idset_sch_new();
118         if (!cb.set)
119                 /* fall back to brute force scanning in case of oom */
120                 return for_each_subchannel(call_fn_all_sch, &cb);
121
122         idset_fill(cb.set);
123
124         /* Process registered subchannels. */
125         rc = bus_for_each_dev(&css_bus_type, NULL, &cb, call_fn_known_sch);
126         if (rc)
127                 goto out;
128         /* Process unregistered subchannels. */
129         if (fn_unknown)
130                 rc = for_each_subchannel(call_fn_unknown_sch, &cb);
131 out:
132         idset_free(cb.set);
133
134         return rc;
135 }
136
137 static void css_sch_todo(struct work_struct *work);
138
139 static struct subchannel *
140 css_alloc_subchannel(struct subchannel_id schid)
141 {
142         struct subchannel *sch;
143         int ret;
144
145         sch = kmalloc (sizeof (*sch), GFP_KERNEL | GFP_DMA);
146         if (sch == NULL)
147                 return ERR_PTR(-ENOMEM);
148         ret = cio_validate_subchannel (sch, schid);
149         if (ret < 0) {
150                 kfree(sch);
151                 return ERR_PTR(ret);
152         }
153         INIT_WORK(&sch->todo_work, css_sch_todo);
154         return sch;
155 }
156
157 static void
158 css_subchannel_release(struct device *dev)
159 {
160         struct subchannel *sch;
161
162         sch = to_subchannel(dev);
163         if (!cio_is_console(sch->schid)) {
164                 /* Reset intparm to zeroes. */
165                 sch->config.intparm = 0;
166                 cio_commit_config(sch);
167                 kfree(sch->lock);
168                 kfree(sch);
169         }
170 }
171
172 static int css_sch_device_register(struct subchannel *sch)
173 {
174         int ret;
175
176         mutex_lock(&sch->reg_mutex);
177         dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid,
178                      sch->schid.sch_no);
179         ret = device_register(&sch->dev);
180         mutex_unlock(&sch->reg_mutex);
181         return ret;
182 }
183
184 /**
185  * css_sch_device_unregister - unregister a subchannel
186  * @sch: subchannel to be unregistered
187  */
188 void css_sch_device_unregister(struct subchannel *sch)
189 {
190         mutex_lock(&sch->reg_mutex);
191         if (device_is_registered(&sch->dev))
192                 device_unregister(&sch->dev);
193         mutex_unlock(&sch->reg_mutex);
194 }
195 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
196
197 static void css_sch_todo(struct work_struct *work)
198 {
199         struct subchannel *sch;
200         enum sch_todo todo;
201
202         sch = container_of(work, struct subchannel, todo_work);
203         /* Find out todo. */
204         spin_lock_irq(sch->lock);
205         todo = sch->todo;
206         CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
207                       sch->schid.sch_no, todo);
208         sch->todo = SCH_TODO_NOTHING;
209         spin_unlock_irq(sch->lock);
210         /* Perform todo. */
211         if (todo == SCH_TODO_UNREG)
212                 css_sch_device_unregister(sch);
213         /* Release workqueue ref. */
214         put_device(&sch->dev);
215 }
216
217 /**
218  * css_sched_sch_todo - schedule a subchannel operation
219  * @sch: subchannel
220  * @todo: todo
221  *
222  * Schedule the operation identified by @todo to be performed on the slow path
223  * workqueue. Do nothing if another operation with higher priority is already
224  * scheduled. Needs to be called with subchannel lock held.
225  */
226 void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
227 {
228         CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
229                       sch->schid.ssid, sch->schid.sch_no, todo);
230         if (sch->todo >= todo)
231                 return;
232         /* Get workqueue ref. */
233         if (!get_device(&sch->dev))
234                 return;
235         sch->todo = todo;
236         if (!queue_work(cio_work_q, &sch->todo_work)) {
237                 /* Already queued, release workqueue ref. */
238                 put_device(&sch->dev);
239         }
240 }
241
242 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
243 {
244         int i;
245         int mask;
246
247         memset(ssd, 0, sizeof(struct chsc_ssd_info));
248         ssd->path_mask = pmcw->pim;
249         for (i = 0; i < 8; i++) {
250                 mask = 0x80 >> i;
251                 if (pmcw->pim & mask) {
252                         chp_id_init(&ssd->chpid[i]);
253                         ssd->chpid[i].id = pmcw->chpid[i];
254                 }
255         }
256 }
257
258 static void ssd_register_chpids(struct chsc_ssd_info *ssd)
259 {
260         int i;
261         int mask;
262
263         for (i = 0; i < 8; i++) {
264                 mask = 0x80 >> i;
265                 if (ssd->path_mask & mask)
266                         if (!chp_is_registered(ssd->chpid[i]))
267                                 chp_new(ssd->chpid[i]);
268         }
269 }
270
271 void css_update_ssd_info(struct subchannel *sch)
272 {
273         int ret;
274
275         if (cio_is_console(sch->schid)) {
276                 /* Console is initialized too early for functions requiring
277                  * memory allocation. */
278                 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
279         } else {
280                 ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
281                 if (ret)
282                         ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
283                 ssd_register_chpids(&sch->ssd_info);
284         }
285 }
286
287 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
288                          char *buf)
289 {
290         struct subchannel *sch = to_subchannel(dev);
291
292         return sprintf(buf, "%01x\n", sch->st);
293 }
294
295 static DEVICE_ATTR(type, 0444, type_show, NULL);
296
297 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
298                              char *buf)
299 {
300         struct subchannel *sch = to_subchannel(dev);
301
302         return sprintf(buf, "css:t%01X\n", sch->st);
303 }
304
305 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
306
307 static struct attribute *subch_attrs[] = {
308         &dev_attr_type.attr,
309         &dev_attr_modalias.attr,
310         NULL,
311 };
312
313 static struct attribute_group subch_attr_group = {
314         .attrs = subch_attrs,
315 };
316
317 static const struct attribute_group *default_subch_attr_groups[] = {
318         &subch_attr_group,
319         NULL,
320 };
321
322 static int css_register_subchannel(struct subchannel *sch)
323 {
324         int ret;
325
326         /* Initialize the subchannel structure */
327         sch->dev.parent = &channel_subsystems[0]->device;
328         sch->dev.bus = &css_bus_type;
329         sch->dev.release = &css_subchannel_release;
330         sch->dev.groups = default_subch_attr_groups;
331         /*
332          * We don't want to generate uevents for I/O subchannels that don't
333          * have a working ccw device behind them since they will be
334          * unregistered before they can be used anyway, so we delay the add
335          * uevent until after device recognition was successful.
336          * Note that we suppress the uevent for all subchannel types;
337          * the subchannel driver can decide itself when it wants to inform
338          * userspace of its existence.
339          */
340         dev_set_uevent_suppress(&sch->dev, 1);
341         css_update_ssd_info(sch);
342         /* make it known to the system */
343         ret = css_sch_device_register(sch);
344         if (ret) {
345                 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
346                               sch->schid.ssid, sch->schid.sch_no, ret);
347                 return ret;
348         }
349         if (!sch->driver) {
350                 /*
351                  * No driver matched. Generate the uevent now so that
352                  * a fitting driver module may be loaded based on the
353                  * modalias.
354                  */
355                 dev_set_uevent_suppress(&sch->dev, 0);
356                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
357         }
358         return ret;
359 }
360
361 int css_probe_device(struct subchannel_id schid)
362 {
363         int ret;
364         struct subchannel *sch;
365
366         if (cio_is_console(schid))
367                 sch = cio_get_console_subchannel();
368         else {
369                 sch = css_alloc_subchannel(schid);
370                 if (IS_ERR(sch))
371                         return PTR_ERR(sch);
372         }
373         ret = css_register_subchannel(sch);
374         if (ret) {
375                 if (!cio_is_console(schid))
376                         put_device(&sch->dev);
377         }
378         return ret;
379 }
380
381 static int
382 check_subchannel(struct device * dev, void * data)
383 {
384         struct subchannel *sch;
385         struct subchannel_id *schid = data;
386
387         sch = to_subchannel(dev);
388         return schid_equal(&sch->schid, schid);
389 }
390
391 struct subchannel *
392 get_subchannel_by_schid(struct subchannel_id schid)
393 {
394         struct device *dev;
395
396         dev = bus_find_device(&css_bus_type, NULL,
397                               &schid, check_subchannel);
398
399         return dev ? to_subchannel(dev) : NULL;
400 }
401
402 /**
403  * css_sch_is_valid() - check if a subchannel is valid
404  * @schib: subchannel information block for the subchannel
405  */
406 int css_sch_is_valid(struct schib *schib)
407 {
408         if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
409                 return 0;
410         if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w)
411                 return 0;
412         return 1;
413 }
414 EXPORT_SYMBOL_GPL(css_sch_is_valid);
415
416 static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
417 {
418         struct schib schib;
419
420         if (!slow) {
421                 /* Will be done on the slow path. */
422                 return -EAGAIN;
423         }
424         if (stsch_err(schid, &schib) || !css_sch_is_valid(&schib)) {
425                 /* Unusable - ignore. */
426                 return 0;
427         }
428         CIO_MSG_EVENT(4, "event: sch 0.%x.%04x, new\n", schid.ssid,
429                       schid.sch_no);
430
431         return css_probe_device(schid);
432 }
433
434 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
435 {
436         int ret = 0;
437
438         if (sch->driver) {
439                 if (sch->driver->sch_event)
440                         ret = sch->driver->sch_event(sch, slow);
441                 else
442                         dev_dbg(&sch->dev,
443                                 "Got subchannel machine check but "
444                                 "no sch_event handler provided.\n");
445         }
446         if (ret != 0 && ret != -EAGAIN) {
447                 CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
448                               sch->schid.ssid, sch->schid.sch_no, ret);
449         }
450         return ret;
451 }
452
453 static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
454 {
455         struct subchannel *sch;
456         int ret;
457
458         sch = get_subchannel_by_schid(schid);
459         if (sch) {
460                 ret = css_evaluate_known_subchannel(sch, slow);
461                 put_device(&sch->dev);
462         } else
463                 ret = css_evaluate_new_subchannel(schid, slow);
464         if (ret == -EAGAIN)
465                 css_schedule_eval(schid);
466 }
467
468 static struct idset *slow_subchannel_set;
469 static spinlock_t slow_subchannel_lock;
470 static wait_queue_head_t css_eval_wq;
471 static atomic_t css_eval_scheduled;
472
473 static int __init slow_subchannel_init(void)
474 {
475         spin_lock_init(&slow_subchannel_lock);
476         atomic_set(&css_eval_scheduled, 0);
477         init_waitqueue_head(&css_eval_wq);
478         slow_subchannel_set = idset_sch_new();
479         if (!slow_subchannel_set) {
480                 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
481                 return -ENOMEM;
482         }
483         return 0;
484 }
485
486 static int slow_eval_known_fn(struct subchannel *sch, void *data)
487 {
488         int eval;
489         int rc;
490
491         spin_lock_irq(&slow_subchannel_lock);
492         eval = idset_sch_contains(slow_subchannel_set, sch->schid);
493         idset_sch_del(slow_subchannel_set, sch->schid);
494         spin_unlock_irq(&slow_subchannel_lock);
495         if (eval) {
496                 rc = css_evaluate_known_subchannel(sch, 1);
497                 if (rc == -EAGAIN)
498                         css_schedule_eval(sch->schid);
499         }
500         return 0;
501 }
502
503 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
504 {
505         int eval;
506         int rc = 0;
507
508         spin_lock_irq(&slow_subchannel_lock);
509         eval = idset_sch_contains(slow_subchannel_set, schid);
510         idset_sch_del(slow_subchannel_set, schid);
511         spin_unlock_irq(&slow_subchannel_lock);
512         if (eval) {
513                 rc = css_evaluate_new_subchannel(schid, 1);
514                 switch (rc) {
515                 case -EAGAIN:
516                         css_schedule_eval(schid);
517                         rc = 0;
518                         break;
519                 case -ENXIO:
520                 case -ENOMEM:
521                 case -EIO:
522                         /* These should abort looping */
523                         break;
524                 default:
525                         rc = 0;
526                 }
527         }
528         return rc;
529 }
530
531 static void css_slow_path_func(struct work_struct *unused)
532 {
533         unsigned long flags;
534
535         CIO_TRACE_EVENT(4, "slowpath");
536         for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
537                                    NULL);
538         spin_lock_irqsave(&slow_subchannel_lock, flags);
539         if (idset_is_empty(slow_subchannel_set)) {
540                 atomic_set(&css_eval_scheduled, 0);
541                 wake_up(&css_eval_wq);
542         }
543         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
544 }
545
546 static DECLARE_WORK(slow_path_work, css_slow_path_func);
547 struct workqueue_struct *cio_work_q;
548
549 void css_schedule_eval(struct subchannel_id schid)
550 {
551         unsigned long flags;
552
553         spin_lock_irqsave(&slow_subchannel_lock, flags);
554         idset_sch_add(slow_subchannel_set, schid);
555         atomic_set(&css_eval_scheduled, 1);
556         queue_work(cio_work_q, &slow_path_work);
557         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
558 }
559
560 void css_schedule_eval_all(void)
561 {
562         unsigned long flags;
563
564         spin_lock_irqsave(&slow_subchannel_lock, flags);
565         idset_fill(slow_subchannel_set);
566         atomic_set(&css_eval_scheduled, 1);
567         queue_work(cio_work_q, &slow_path_work);
568         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
569 }
570
571 static int __unset_registered(struct device *dev, void *data)
572 {
573         struct idset *set = data;
574         struct subchannel *sch = to_subchannel(dev);
575
576         idset_sch_del(set, sch->schid);
577         return 0;
578 }
579
580 static void css_schedule_eval_all_unreg(void)
581 {
582         unsigned long flags;
583         struct idset *unreg_set;
584
585         /* Find unregistered subchannels. */
586         unreg_set = idset_sch_new();
587         if (!unreg_set) {
588                 /* Fallback. */
589                 css_schedule_eval_all();
590                 return;
591         }
592         idset_fill(unreg_set);
593         bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered);
594         /* Apply to slow_subchannel_set. */
595         spin_lock_irqsave(&slow_subchannel_lock, flags);
596         idset_add_set(slow_subchannel_set, unreg_set);
597         atomic_set(&css_eval_scheduled, 1);
598         queue_work(cio_work_q, &slow_path_work);
599         spin_unlock_irqrestore(&slow_subchannel_lock, flags);
600         idset_free(unreg_set);
601 }
602
603 void css_wait_for_slow_path(void)
604 {
605         flush_workqueue(cio_work_q);
606 }
607
608 /* Schedule reprobing of all unregistered subchannels. */
609 void css_schedule_reprobe(void)
610 {
611         css_schedule_eval_all_unreg();
612 }
613 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
614
615 /*
616  * Called from the machine check handler for subchannel report words.
617  */
618 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
619 {
620         struct subchannel_id mchk_schid;
621
622         if (overflow) {
623                 css_schedule_eval_all();
624                 return;
625         }
626         CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
627                       "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
628                       crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
629                       crw0->erc, crw0->rsid);
630         if (crw1)
631                 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
632                               "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
633                               crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
634                               crw1->anc, crw1->erc, crw1->rsid);
635         init_subchannel_id(&mchk_schid);
636         mchk_schid.sch_no = crw0->rsid;
637         if (crw1)
638                 mchk_schid.ssid = (crw1->rsid >> 8) & 3;
639
640         /*
641          * Since we are always presented with IPI in the CRW, we have to
642          * use stsch() to find out if the subchannel in question has come
643          * or gone.
644          */
645         css_evaluate_subchannel(mchk_schid, 0);
646 }
647
648 static void __init
649 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
650 {
651         struct cpuid cpu_id;
652
653         if (css_general_characteristics.mcss) {
654                 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
655                 css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
656         } else {
657 #ifdef CONFIG_SMP
658                 css->global_pgid.pgid_high.cpu_addr = stap();
659 #else
660                 css->global_pgid.pgid_high.cpu_addr = 0;
661 #endif
662         }
663         get_cpu_id(&cpu_id);
664         css->global_pgid.cpu_id = cpu_id.ident;
665         css->global_pgid.cpu_model = cpu_id.machine;
666         css->global_pgid.tod_high = tod_high;
667
668 }
669
670 static void
671 channel_subsystem_release(struct device *dev)
672 {
673         struct channel_subsystem *css;
674
675         css = to_css(dev);
676         mutex_destroy(&css->mutex);
677         if (css->pseudo_subchannel) {
678                 /* Implies that it has been generated but never registered. */
679                 css_subchannel_release(&css->pseudo_subchannel->dev);
680                 css->pseudo_subchannel = NULL;
681         }
682         kfree(css);
683 }
684
685 static ssize_t
686 css_cm_enable_show(struct device *dev, struct device_attribute *attr,
687                    char *buf)
688 {
689         struct channel_subsystem *css = to_css(dev);
690         int ret;
691
692         if (!css)
693                 return 0;
694         mutex_lock(&css->mutex);
695         ret = sprintf(buf, "%x\n", css->cm_enabled);
696         mutex_unlock(&css->mutex);
697         return ret;
698 }
699
700 static ssize_t
701 css_cm_enable_store(struct device *dev, struct device_attribute *attr,
702                     const char *buf, size_t count)
703 {
704         struct channel_subsystem *css = to_css(dev);
705         int ret;
706         unsigned long val;
707
708         ret = strict_strtoul(buf, 16, &val);
709         if (ret)
710                 return ret;
711         mutex_lock(&css->mutex);
712         switch (val) {
713         case 0:
714                 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
715                 break;
716         case 1:
717                 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
718                 break;
719         default:
720                 ret = -EINVAL;
721         }
722         mutex_unlock(&css->mutex);
723         return ret < 0 ? ret : count;
724 }
725
726 static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
727
728 static int __init setup_css(int nr)
729 {
730         u32 tod_high;
731         int ret;
732         struct channel_subsystem *css;
733
734         css = channel_subsystems[nr];
735         memset(css, 0, sizeof(struct channel_subsystem));
736         css->pseudo_subchannel =
737                 kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
738         if (!css->pseudo_subchannel)
739                 return -ENOMEM;
740         css->pseudo_subchannel->dev.parent = &css->device;
741         css->pseudo_subchannel->dev.release = css_subchannel_release;
742         dev_set_name(&css->pseudo_subchannel->dev, "defunct");
743         mutex_init(&css->pseudo_subchannel->reg_mutex);
744         ret = cio_create_sch_lock(css->pseudo_subchannel);
745         if (ret) {
746                 kfree(css->pseudo_subchannel);
747                 return ret;
748         }
749         mutex_init(&css->mutex);
750         css->valid = 1;
751         css->cssid = nr;
752         dev_set_name(&css->device, "css%x", nr);
753         css->device.release = channel_subsystem_release;
754         tod_high = (u32) (get_clock() >> 32);
755         css_generate_pgid(css, tod_high);
756         return 0;
757 }
758
759 static int css_reboot_event(struct notifier_block *this,
760                             unsigned long event,
761                             void *ptr)
762 {
763         int ret, i;
764
765         ret = NOTIFY_DONE;
766         for (i = 0; i <= __MAX_CSSID; i++) {
767                 struct channel_subsystem *css;
768
769                 css = channel_subsystems[i];
770                 mutex_lock(&css->mutex);
771                 if (css->cm_enabled)
772                         if (chsc_secm(css, 0))
773                                 ret = NOTIFY_BAD;
774                 mutex_unlock(&css->mutex);
775         }
776
777         return ret;
778 }
779
780 static struct notifier_block css_reboot_notifier = {
781         .notifier_call = css_reboot_event,
782 };
783
784 /*
785  * Since the css devices are neither on a bus nor have a class
786  * nor have a special device type, we cannot stop/restart channel
787  * path measurements via the normal suspend/resume callbacks, but have
788  * to use notifiers.
789  */
790 static int css_power_event(struct notifier_block *this, unsigned long event,
791                            void *ptr)
792 {
793         int ret, i;
794
795         switch (event) {
796         case PM_HIBERNATION_PREPARE:
797         case PM_SUSPEND_PREPARE:
798                 ret = NOTIFY_DONE;
799                 for (i = 0; i <= __MAX_CSSID; i++) {
800                         struct channel_subsystem *css;
801
802                         css = channel_subsystems[i];
803                         mutex_lock(&css->mutex);
804                         if (!css->cm_enabled) {
805                                 mutex_unlock(&css->mutex);
806                                 continue;
807                         }
808                         if (__chsc_do_secm(css, 0))
809                                 ret = NOTIFY_BAD;
810                         mutex_unlock(&css->mutex);
811                 }
812                 break;
813         case PM_POST_HIBERNATION:
814         case PM_POST_SUSPEND:
815                 ret = NOTIFY_DONE;
816                 for (i = 0; i <= __MAX_CSSID; i++) {
817                         struct channel_subsystem *css;
818
819                         css = channel_subsystems[i];
820                         mutex_lock(&css->mutex);
821                         if (!css->cm_enabled) {
822                                 mutex_unlock(&css->mutex);
823                                 continue;
824                         }
825                         if (__chsc_do_secm(css, 1))
826                                 ret = NOTIFY_BAD;
827                         mutex_unlock(&css->mutex);
828                 }
829                 /* search for subchannels, which appeared during hibernation */
830                 css_schedule_reprobe();
831                 break;
832         default:
833                 ret = NOTIFY_DONE;
834         }
835         return ret;
836
837 }
838 static struct notifier_block css_power_notifier = {
839         .notifier_call = css_power_event,
840 };
841
842 /*
843  * Now that the driver core is running, we can setup our channel subsystem.
844  * The struct subchannel's are created during probing (except for the
845  * static console subchannel).
846  */
847 static int __init css_bus_init(void)
848 {
849         int ret, i;
850
851         ret = chsc_init();
852         if (ret)
853                 return ret;
854
855         chsc_determine_css_characteristics();
856         /* Try to enable MSS. */
857         ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
858         if (ret)
859                 max_ssid = 0;
860         else /* Success. */
861                 max_ssid = __MAX_SSID;
862
863         ret = slow_subchannel_init();
864         if (ret)
865                 goto out;
866
867         ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
868         if (ret)
869                 goto out;
870
871         if ((ret = bus_register(&css_bus_type)))
872                 goto out;
873
874         /* Setup css structure. */
875         for (i = 0; i <= __MAX_CSSID; i++) {
876                 struct channel_subsystem *css;
877
878                 css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
879                 if (!css) {
880                         ret = -ENOMEM;
881                         goto out_unregister;
882                 }
883                 channel_subsystems[i] = css;
884                 ret = setup_css(i);
885                 if (ret) {
886                         kfree(channel_subsystems[i]);
887                         goto out_unregister;
888                 }
889                 ret = device_register(&css->device);
890                 if (ret) {
891                         put_device(&css->device);
892                         goto out_unregister;
893                 }
894                 if (css_chsc_characteristics.secm) {
895                         ret = device_create_file(&css->device,
896                                                  &dev_attr_cm_enable);
897                         if (ret)
898                                 goto out_device;
899                 }
900                 ret = device_register(&css->pseudo_subchannel->dev);
901                 if (ret) {
902                         put_device(&css->pseudo_subchannel->dev);
903                         goto out_file;
904                 }
905         }
906         ret = register_reboot_notifier(&css_reboot_notifier);
907         if (ret)
908                 goto out_unregister;
909         ret = register_pm_notifier(&css_power_notifier);
910         if (ret) {
911                 unregister_reboot_notifier(&css_reboot_notifier);
912                 goto out_unregister;
913         }
914         css_init_done = 1;
915
916         /* Enable default isc for I/O subchannels. */
917         isc_register(IO_SCH_ISC);
918
919         return 0;
920 out_file:
921         if (css_chsc_characteristics.secm)
922                 device_remove_file(&channel_subsystems[i]->device,
923                                    &dev_attr_cm_enable);
924 out_device:
925         device_unregister(&channel_subsystems[i]->device);
926 out_unregister:
927         while (i > 0) {
928                 struct channel_subsystem *css;
929
930                 i--;
931                 css = channel_subsystems[i];
932                 device_unregister(&css->pseudo_subchannel->dev);
933                 css->pseudo_subchannel = NULL;
934                 if (css_chsc_characteristics.secm)
935                         device_remove_file(&css->device,
936                                            &dev_attr_cm_enable);
937                 device_unregister(&css->device);
938         }
939         bus_unregister(&css_bus_type);
940 out:
941         crw_unregister_handler(CRW_RSC_SCH);
942         idset_free(slow_subchannel_set);
943         chsc_init_cleanup();
944         pr_alert("The CSS device driver initialization failed with "
945                  "errno=%d\n", ret);
946         return ret;
947 }
948
949 static void __init css_bus_cleanup(void)
950 {
951         struct channel_subsystem *css;
952         int i;
953
954         for (i = 0; i <= __MAX_CSSID; i++) {
955                 css = channel_subsystems[i];
956                 device_unregister(&css->pseudo_subchannel->dev);
957                 css->pseudo_subchannel = NULL;
958                 if (css_chsc_characteristics.secm)
959                         device_remove_file(&css->device, &dev_attr_cm_enable);
960                 device_unregister(&css->device);
961         }
962         bus_unregister(&css_bus_type);
963         crw_unregister_handler(CRW_RSC_SCH);
964         idset_free(slow_subchannel_set);
965         chsc_init_cleanup();
966         isc_unregister(IO_SCH_ISC);
967 }
968
969 static int __init channel_subsystem_init(void)
970 {
971         int ret;
972
973         ret = css_bus_init();
974         if (ret)
975                 return ret;
976         cio_work_q = create_singlethread_workqueue("cio");
977         if (!cio_work_q) {
978                 ret = -ENOMEM;
979                 goto out_bus;
980         }
981         ret = io_subchannel_init();
982         if (ret)
983                 goto out_wq;
984
985         return ret;
986 out_wq:
987         destroy_workqueue(cio_work_q);
988 out_bus:
989         css_bus_cleanup();
990         return ret;
991 }
992 subsys_initcall(channel_subsystem_init);
993
994 static int css_settle(struct device_driver *drv, void *unused)
995 {
996         struct css_driver *cssdrv = to_cssdriver(drv);
997
998         if (cssdrv->settle)
999                 return cssdrv->settle();
1000         return 0;
1001 }
1002
1003 int css_complete_work(void)
1004 {
1005         int ret;
1006
1007         /* Wait for the evaluation of subchannels to finish. */
1008         ret = wait_event_interruptible(css_eval_wq,
1009                                        atomic_read(&css_eval_scheduled) == 0);
1010         if (ret)
1011                 return -EINTR;
1012         flush_workqueue(cio_work_q);
1013         /* Wait for the subchannel type specific initialization to finish */
1014         return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
1015 }
1016
1017
1018 /*
1019  * Wait for the initialization of devices to finish, to make sure we are
1020  * done with our setup if the search for the root device starts.
1021  */
1022 static int __init channel_subsystem_init_sync(void)
1023 {
1024         /* Start initial subchannel evaluation. */
1025         css_schedule_eval_all();
1026         css_complete_work();
1027         return 0;
1028 }
1029 subsys_initcall_sync(channel_subsystem_init_sync);
1030
1031 void channel_subsystem_reinit(void)
1032 {
1033         struct channel_path *chp;
1034         struct chp_id chpid;
1035
1036         chsc_enable_facility(CHSC_SDA_OC_MSS);
1037         chp_id_for_each(&chpid) {
1038                 chp = chpid_to_chp(chpid);
1039                 if (!chp)
1040                         continue;
1041                 chsc_determine_base_channel_path_desc(chpid, &chp->desc);
1042         }
1043 }
1044
1045 #ifdef CONFIG_PROC_FS
1046 static ssize_t cio_settle_write(struct file *file, const char __user *buf,
1047                                 size_t count, loff_t *ppos)
1048 {
1049         int ret;
1050
1051         /* Handle pending CRW's. */
1052         crw_wait_for_channel_report();
1053         ret = css_complete_work();
1054
1055         return ret ? ret : count;
1056 }
1057
1058 static const struct file_operations cio_settle_proc_fops = {
1059         .open = nonseekable_open,
1060         .write = cio_settle_write,
1061         .llseek = no_llseek,
1062 };
1063
1064 static int __init cio_settle_init(void)
1065 {
1066         struct proc_dir_entry *entry;
1067
1068         entry = proc_create("cio_settle", S_IWUSR, NULL,
1069                             &cio_settle_proc_fops);
1070         if (!entry)
1071                 return -ENOMEM;
1072         return 0;
1073 }
1074 device_initcall(cio_settle_init);
1075 #endif /*CONFIG_PROC_FS*/
1076
1077 int sch_is_pseudo_sch(struct subchannel *sch)
1078 {
1079         return sch == to_css(sch->dev.parent)->pseudo_subchannel;
1080 }
1081
1082 static int css_bus_match(struct device *dev, struct device_driver *drv)
1083 {
1084         struct subchannel *sch = to_subchannel(dev);
1085         struct css_driver *driver = to_cssdriver(drv);
1086         struct css_device_id *id;
1087
1088         for (id = driver->subchannel_type; id->match_flags; id++) {
1089                 if (sch->st == id->type)
1090                         return 1;
1091         }
1092
1093         return 0;
1094 }
1095
1096 static int css_probe(struct device *dev)
1097 {
1098         struct subchannel *sch;
1099         int ret;
1100
1101         sch = to_subchannel(dev);
1102         sch->driver = to_cssdriver(dev->driver);
1103         ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
1104         if (ret)
1105                 sch->driver = NULL;
1106         return ret;
1107 }
1108
1109 static int css_remove(struct device *dev)
1110 {
1111         struct subchannel *sch;
1112         int ret;
1113
1114         sch = to_subchannel(dev);
1115         ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
1116         sch->driver = NULL;
1117         return ret;
1118 }
1119
1120 static void css_shutdown(struct device *dev)
1121 {
1122         struct subchannel *sch;
1123
1124         sch = to_subchannel(dev);
1125         if (sch->driver && sch->driver->shutdown)
1126                 sch->driver->shutdown(sch);
1127 }
1128
1129 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
1130 {
1131         struct subchannel *sch = to_subchannel(dev);
1132         int ret;
1133
1134         ret = add_uevent_var(env, "ST=%01X", sch->st);
1135         if (ret)
1136                 return ret;
1137         ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
1138         return ret;
1139 }
1140
1141 static int css_pm_prepare(struct device *dev)
1142 {
1143         struct subchannel *sch = to_subchannel(dev);
1144         struct css_driver *drv;
1145
1146         if (mutex_is_locked(&sch->reg_mutex))
1147                 return -EAGAIN;
1148         if (!sch->dev.driver)
1149                 return 0;
1150         drv = to_cssdriver(sch->dev.driver);
1151         /* Notify drivers that they may not register children. */
1152         return drv->prepare ? drv->prepare(sch) : 0;
1153 }
1154
1155 static void css_pm_complete(struct device *dev)
1156 {
1157         struct subchannel *sch = to_subchannel(dev);
1158         struct css_driver *drv;
1159
1160         if (!sch->dev.driver)
1161                 return;
1162         drv = to_cssdriver(sch->dev.driver);
1163         if (drv->complete)
1164                 drv->complete(sch);
1165 }
1166
1167 static int css_pm_freeze(struct device *dev)
1168 {
1169         struct subchannel *sch = to_subchannel(dev);
1170         struct css_driver *drv;
1171
1172         if (!sch->dev.driver)
1173                 return 0;
1174         drv = to_cssdriver(sch->dev.driver);
1175         return drv->freeze ? drv->freeze(sch) : 0;
1176 }
1177
1178 static int css_pm_thaw(struct device *dev)
1179 {
1180         struct subchannel *sch = to_subchannel(dev);
1181         struct css_driver *drv;
1182
1183         if (!sch->dev.driver)
1184                 return 0;
1185         drv = to_cssdriver(sch->dev.driver);
1186         return drv->thaw ? drv->thaw(sch) : 0;
1187 }
1188
1189 static int css_pm_restore(struct device *dev)
1190 {
1191         struct subchannel *sch = to_subchannel(dev);
1192         struct css_driver *drv;
1193
1194         css_update_ssd_info(sch);
1195         if (!sch->dev.driver)
1196                 return 0;
1197         drv = to_cssdriver(sch->dev.driver);
1198         return drv->restore ? drv->restore(sch) : 0;
1199 }
1200
1201 static const struct dev_pm_ops css_pm_ops = {
1202         .prepare = css_pm_prepare,
1203         .complete = css_pm_complete,
1204         .freeze = css_pm_freeze,
1205         .thaw = css_pm_thaw,
1206         .restore = css_pm_restore,
1207 };
1208
1209 struct bus_type css_bus_type = {
1210         .name     = "css",
1211         .match    = css_bus_match,
1212         .probe    = css_probe,
1213         .remove   = css_remove,
1214         .shutdown = css_shutdown,
1215         .uevent   = css_uevent,
1216         .pm = &css_pm_ops,
1217 };
1218
1219 /**
1220  * css_driver_register - register a css driver
1221  * @cdrv: css driver to register
1222  *
1223  * This is mainly a wrapper around driver_register that sets name
1224  * and bus_type in the embedded struct device_driver correctly.
1225  */
1226 int css_driver_register(struct css_driver *cdrv)
1227 {
1228         cdrv->drv.name = cdrv->name;
1229         cdrv->drv.bus = &css_bus_type;
1230         cdrv->drv.owner = cdrv->owner;
1231         return driver_register(&cdrv->drv);
1232 }
1233 EXPORT_SYMBOL_GPL(css_driver_register);
1234
1235 /**
1236  * css_driver_unregister - unregister a css driver
1237  * @cdrv: css driver to unregister
1238  *
1239  * This is a wrapper around driver_unregister.
1240  */
1241 void css_driver_unregister(struct css_driver *cdrv)
1242 {
1243         driver_unregister(&cdrv->drv);
1244 }
1245 EXPORT_SYMBOL_GPL(css_driver_unregister);
1246
1247 MODULE_LICENSE("GPL");
1248 EXPORT_SYMBOL(css_bus_type);