staging: rtl8188eu: rename HalSetBrateCfg() - style
[linux/fpc-iii.git] / drivers / s390 / cio / css.c
blobaea50292264629e63f131dfd2dfd87d3ff108799
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * driver for channel subsystem
5 * Copyright IBM Corp. 2002, 2010
7 * Author(s): Arnd Bergmann (arndb@de.ibm.com)
8 * Cornelia Huck (cornelia.huck@de.ibm.com)
9 */
11 #define KMSG_COMPONENT "cio"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
14 #include <linux/export.h>
15 #include <linux/init.h>
16 #include <linux/device.h>
17 #include <linux/slab.h>
18 #include <linux/errno.h>
19 #include <linux/list.h>
20 #include <linux/reboot.h>
21 #include <linux/suspend.h>
22 #include <linux/proc_fs.h>
23 #include <asm/isc.h>
24 #include <asm/crw.h>
26 #include "css.h"
27 #include "cio.h"
28 #include "blacklist.h"
29 #include "cio_debug.h"
30 #include "ioasm.h"
31 #include "chsc.h"
32 #include "device.h"
33 #include "idset.h"
34 #include "chp.h"
36 int css_init_done = 0;
37 int max_ssid;
39 #define MAX_CSS_IDX 0
40 struct channel_subsystem *channel_subsystems[MAX_CSS_IDX + 1];
41 static struct bus_type css_bus_type;
43 int
44 for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data)
46 struct subchannel_id schid;
47 int ret;
49 init_subchannel_id(&schid);
50 do {
51 do {
52 ret = fn(schid, data);
53 if (ret)
54 break;
55 } while (schid.sch_no++ < __MAX_SUBCHANNEL);
56 schid.sch_no = 0;
57 } while (schid.ssid++ < max_ssid);
58 return ret;
61 struct cb_data {
62 void *data;
63 struct idset *set;
64 int (*fn_known_sch)(struct subchannel *, void *);
65 int (*fn_unknown_sch)(struct subchannel_id, void *);
68 static int call_fn_known_sch(struct device *dev, void *data)
70 struct subchannel *sch = to_subchannel(dev);
71 struct cb_data *cb = data;
72 int rc = 0;
74 if (cb->set)
75 idset_sch_del(cb->set, sch->schid);
76 if (cb->fn_known_sch)
77 rc = cb->fn_known_sch(sch, cb->data);
78 return rc;
81 static int call_fn_unknown_sch(struct subchannel_id schid, void *data)
83 struct cb_data *cb = data;
84 int rc = 0;
86 if (idset_sch_contains(cb->set, schid))
87 rc = cb->fn_unknown_sch(schid, cb->data);
88 return rc;
91 static int call_fn_all_sch(struct subchannel_id schid, void *data)
93 struct cb_data *cb = data;
94 struct subchannel *sch;
95 int rc = 0;
97 sch = get_subchannel_by_schid(schid);
98 if (sch) {
99 if (cb->fn_known_sch)
100 rc = cb->fn_known_sch(sch, cb->data);
101 put_device(&sch->dev);
102 } else {
103 if (cb->fn_unknown_sch)
104 rc = cb->fn_unknown_sch(schid, cb->data);
107 return rc;
110 int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
111 int (*fn_unknown)(struct subchannel_id,
112 void *), void *data)
114 struct cb_data cb;
115 int rc;
117 cb.data = data;
118 cb.fn_known_sch = fn_known;
119 cb.fn_unknown_sch = fn_unknown;
121 if (fn_known && !fn_unknown) {
122 /* Skip idset allocation in case of known-only loop. */
123 cb.set = NULL;
124 return bus_for_each_dev(&css_bus_type, NULL, &cb,
125 call_fn_known_sch);
128 cb.set = idset_sch_new();
129 if (!cb.set)
130 /* fall back to brute force scanning in case of oom */
131 return for_each_subchannel(call_fn_all_sch, &cb);
133 idset_fill(cb.set);
135 /* Process registered subchannels. */
136 rc = bus_for_each_dev(&css_bus_type, NULL, &cb, call_fn_known_sch);
137 if (rc)
138 goto out;
139 /* Process unregistered subchannels. */
140 if (fn_unknown)
141 rc = for_each_subchannel(call_fn_unknown_sch, &cb);
142 out:
143 idset_free(cb.set);
145 return rc;
148 static void css_sch_todo(struct work_struct *work);
150 static int css_sch_create_locks(struct subchannel *sch)
152 sch->lock = kmalloc(sizeof(*sch->lock), GFP_KERNEL);
153 if (!sch->lock)
154 return -ENOMEM;
156 spin_lock_init(sch->lock);
157 mutex_init(&sch->reg_mutex);
159 return 0;
162 static void css_subchannel_release(struct device *dev)
164 struct subchannel *sch = to_subchannel(dev);
166 sch->config.intparm = 0;
167 cio_commit_config(sch);
168 kfree(sch->lock);
169 kfree(sch);
172 static int css_validate_subchannel(struct subchannel_id schid,
173 struct schib *schib)
175 int err;
177 switch (schib->pmcw.st) {
178 case SUBCHANNEL_TYPE_IO:
179 case SUBCHANNEL_TYPE_MSG:
180 if (!css_sch_is_valid(schib))
181 err = -ENODEV;
182 else if (is_blacklisted(schid.ssid, schib->pmcw.dev)) {
183 CIO_MSG_EVENT(6, "Blacklisted device detected "
184 "at devno %04X, subchannel set %x\n",
185 schib->pmcw.dev, schid.ssid);
186 err = -ENODEV;
187 } else
188 err = 0;
189 break;
190 default:
191 err = 0;
193 if (err)
194 goto out;
196 CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
197 schid.ssid, schid.sch_no, schib->pmcw.st);
198 out:
199 return err;
202 struct subchannel *css_alloc_subchannel(struct subchannel_id schid,
203 struct schib *schib)
205 struct subchannel *sch;
206 int ret;
208 ret = css_validate_subchannel(schid, schib);
209 if (ret < 0)
210 return ERR_PTR(ret);
212 sch = kzalloc(sizeof(*sch), GFP_KERNEL | GFP_DMA);
213 if (!sch)
214 return ERR_PTR(-ENOMEM);
216 sch->schid = schid;
217 sch->schib = *schib;
218 sch->st = schib->pmcw.st;
220 ret = css_sch_create_locks(sch);
221 if (ret)
222 goto err;
224 INIT_WORK(&sch->todo_work, css_sch_todo);
225 sch->dev.release = &css_subchannel_release;
226 device_initialize(&sch->dev);
227 return sch;
229 err:
230 kfree(sch);
231 return ERR_PTR(ret);
234 static int css_sch_device_register(struct subchannel *sch)
236 int ret;
238 mutex_lock(&sch->reg_mutex);
239 dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid,
240 sch->schid.sch_no);
241 ret = device_add(&sch->dev);
242 mutex_unlock(&sch->reg_mutex);
243 return ret;
247 * css_sch_device_unregister - unregister a subchannel
248 * @sch: subchannel to be unregistered
250 void css_sch_device_unregister(struct subchannel *sch)
252 mutex_lock(&sch->reg_mutex);
253 if (device_is_registered(&sch->dev))
254 device_unregister(&sch->dev);
255 mutex_unlock(&sch->reg_mutex);
257 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
259 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
261 int i;
262 int mask;
264 memset(ssd, 0, sizeof(struct chsc_ssd_info));
265 ssd->path_mask = pmcw->pim;
266 for (i = 0; i < 8; i++) {
267 mask = 0x80 >> i;
268 if (pmcw->pim & mask) {
269 chp_id_init(&ssd->chpid[i]);
270 ssd->chpid[i].id = pmcw->chpid[i];
275 static void ssd_register_chpids(struct chsc_ssd_info *ssd)
277 int i;
278 int mask;
280 for (i = 0; i < 8; i++) {
281 mask = 0x80 >> i;
282 if (ssd->path_mask & mask)
283 chp_new(ssd->chpid[i]);
287 void css_update_ssd_info(struct subchannel *sch)
289 int ret;
291 ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
292 if (ret)
293 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
295 ssd_register_chpids(&sch->ssd_info);
298 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
299 char *buf)
301 struct subchannel *sch = to_subchannel(dev);
303 return sprintf(buf, "%01x\n", sch->st);
306 static DEVICE_ATTR_RO(type);
308 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
309 char *buf)
311 struct subchannel *sch = to_subchannel(dev);
313 return sprintf(buf, "css:t%01X\n", sch->st);
316 static DEVICE_ATTR_RO(modalias);
318 static struct attribute *subch_attrs[] = {
319 &dev_attr_type.attr,
320 &dev_attr_modalias.attr,
321 NULL,
324 static struct attribute_group subch_attr_group = {
325 .attrs = subch_attrs,
328 static const struct attribute_group *default_subch_attr_groups[] = {
329 &subch_attr_group,
330 NULL,
333 static ssize_t chpids_show(struct device *dev,
334 struct device_attribute *attr,
335 char *buf)
337 struct subchannel *sch = to_subchannel(dev);
338 struct chsc_ssd_info *ssd = &sch->ssd_info;
339 ssize_t ret = 0;
340 int mask;
341 int chp;
343 for (chp = 0; chp < 8; chp++) {
344 mask = 0x80 >> chp;
345 if (ssd->path_mask & mask)
346 ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
347 else
348 ret += sprintf(buf + ret, "00 ");
350 ret += sprintf(buf + ret, "\n");
351 return ret;
353 static DEVICE_ATTR_RO(chpids);
355 static ssize_t pimpampom_show(struct device *dev,
356 struct device_attribute *attr,
357 char *buf)
359 struct subchannel *sch = to_subchannel(dev);
360 struct pmcw *pmcw = &sch->schib.pmcw;
362 return sprintf(buf, "%02x %02x %02x\n",
363 pmcw->pim, pmcw->pam, pmcw->pom);
365 static DEVICE_ATTR_RO(pimpampom);
367 static struct attribute *io_subchannel_type_attrs[] = {
368 &dev_attr_chpids.attr,
369 &dev_attr_pimpampom.attr,
370 NULL,
372 ATTRIBUTE_GROUPS(io_subchannel_type);
374 static const struct device_type io_subchannel_type = {
375 .groups = io_subchannel_type_groups,
378 int css_register_subchannel(struct subchannel *sch)
380 int ret;
382 /* Initialize the subchannel structure */
383 sch->dev.parent = &channel_subsystems[0]->device;
384 sch->dev.bus = &css_bus_type;
385 sch->dev.groups = default_subch_attr_groups;
387 if (sch->st == SUBCHANNEL_TYPE_IO)
388 sch->dev.type = &io_subchannel_type;
391 * We don't want to generate uevents for I/O subchannels that don't
392 * have a working ccw device behind them since they will be
393 * unregistered before they can be used anyway, so we delay the add
394 * uevent until after device recognition was successful.
395 * Note that we suppress the uevent for all subchannel types;
396 * the subchannel driver can decide itself when it wants to inform
397 * userspace of its existence.
399 dev_set_uevent_suppress(&sch->dev, 1);
400 css_update_ssd_info(sch);
401 /* make it known to the system */
402 ret = css_sch_device_register(sch);
403 if (ret) {
404 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
405 sch->schid.ssid, sch->schid.sch_no, ret);
406 return ret;
408 if (!sch->driver) {
410 * No driver matched. Generate the uevent now so that
411 * a fitting driver module may be loaded based on the
412 * modalias.
414 dev_set_uevent_suppress(&sch->dev, 0);
415 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
417 return ret;
420 static int css_probe_device(struct subchannel_id schid, struct schib *schib)
422 struct subchannel *sch;
423 int ret;
425 sch = css_alloc_subchannel(schid, schib);
426 if (IS_ERR(sch))
427 return PTR_ERR(sch);
429 ret = css_register_subchannel(sch);
430 if (ret)
431 put_device(&sch->dev);
433 return ret;
436 static int
437 check_subchannel(struct device * dev, void * data)
439 struct subchannel *sch;
440 struct subchannel_id *schid = data;
442 sch = to_subchannel(dev);
443 return schid_equal(&sch->schid, schid);
446 struct subchannel *
447 get_subchannel_by_schid(struct subchannel_id schid)
449 struct device *dev;
451 dev = bus_find_device(&css_bus_type, NULL,
452 &schid, check_subchannel);
454 return dev ? to_subchannel(dev) : NULL;
458 * css_sch_is_valid() - check if a subchannel is valid
459 * @schib: subchannel information block for the subchannel
461 int css_sch_is_valid(struct schib *schib)
463 if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
464 return 0;
465 if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w)
466 return 0;
467 return 1;
469 EXPORT_SYMBOL_GPL(css_sch_is_valid);
471 static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
473 struct schib schib;
474 int ccode;
476 if (!slow) {
477 /* Will be done on the slow path. */
478 return -EAGAIN;
481 * The first subchannel that is not-operational (ccode==3)
482 * indicates that there aren't any more devices available.
483 * If stsch gets an exception, it means the current subchannel set
484 * is not valid.
486 ccode = stsch(schid, &schib);
487 if (ccode)
488 return (ccode == 3) ? -ENXIO : ccode;
490 return css_probe_device(schid, &schib);
493 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
495 int ret = 0;
497 if (sch->driver) {
498 if (sch->driver->sch_event)
499 ret = sch->driver->sch_event(sch, slow);
500 else
501 dev_dbg(&sch->dev,
502 "Got subchannel machine check but "
503 "no sch_event handler provided.\n");
505 if (ret != 0 && ret != -EAGAIN) {
506 CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
507 sch->schid.ssid, sch->schid.sch_no, ret);
509 return ret;
512 static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
514 struct subchannel *sch;
515 int ret;
517 sch = get_subchannel_by_schid(schid);
518 if (sch) {
519 ret = css_evaluate_known_subchannel(sch, slow);
520 put_device(&sch->dev);
521 } else
522 ret = css_evaluate_new_subchannel(schid, slow);
523 if (ret == -EAGAIN)
524 css_schedule_eval(schid);
528 * css_sched_sch_todo - schedule a subchannel operation
529 * @sch: subchannel
530 * @todo: todo
532 * Schedule the operation identified by @todo to be performed on the slow path
533 * workqueue. Do nothing if another operation with higher priority is already
534 * scheduled. Needs to be called with subchannel lock held.
536 void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
538 CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
539 sch->schid.ssid, sch->schid.sch_no, todo);
540 if (sch->todo >= todo)
541 return;
542 /* Get workqueue ref. */
543 if (!get_device(&sch->dev))
544 return;
545 sch->todo = todo;
546 if (!queue_work(cio_work_q, &sch->todo_work)) {
547 /* Already queued, release workqueue ref. */
548 put_device(&sch->dev);
551 EXPORT_SYMBOL_GPL(css_sched_sch_todo);
553 static void css_sch_todo(struct work_struct *work)
555 struct subchannel *sch;
556 enum sch_todo todo;
557 int ret;
559 sch = container_of(work, struct subchannel, todo_work);
560 /* Find out todo. */
561 spin_lock_irq(sch->lock);
562 todo = sch->todo;
563 CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
564 sch->schid.sch_no, todo);
565 sch->todo = SCH_TODO_NOTHING;
566 spin_unlock_irq(sch->lock);
567 /* Perform todo. */
568 switch (todo) {
569 case SCH_TODO_NOTHING:
570 break;
571 case SCH_TODO_EVAL:
572 ret = css_evaluate_known_subchannel(sch, 1);
573 if (ret == -EAGAIN) {
574 spin_lock_irq(sch->lock);
575 css_sched_sch_todo(sch, todo);
576 spin_unlock_irq(sch->lock);
578 break;
579 case SCH_TODO_UNREG:
580 css_sch_device_unregister(sch);
581 break;
583 /* Release workqueue ref. */
584 put_device(&sch->dev);
587 static struct idset *slow_subchannel_set;
588 static spinlock_t slow_subchannel_lock;
589 static wait_queue_head_t css_eval_wq;
590 static atomic_t css_eval_scheduled;
592 static int __init slow_subchannel_init(void)
594 spin_lock_init(&slow_subchannel_lock);
595 atomic_set(&css_eval_scheduled, 0);
596 init_waitqueue_head(&css_eval_wq);
597 slow_subchannel_set = idset_sch_new();
598 if (!slow_subchannel_set) {
599 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
600 return -ENOMEM;
602 return 0;
605 static int slow_eval_known_fn(struct subchannel *sch, void *data)
607 int eval;
608 int rc;
610 spin_lock_irq(&slow_subchannel_lock);
611 eval = idset_sch_contains(slow_subchannel_set, sch->schid);
612 idset_sch_del(slow_subchannel_set, sch->schid);
613 spin_unlock_irq(&slow_subchannel_lock);
614 if (eval) {
615 rc = css_evaluate_known_subchannel(sch, 1);
616 if (rc == -EAGAIN)
617 css_schedule_eval(sch->schid);
619 return 0;
622 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
624 int eval;
625 int rc = 0;
627 spin_lock_irq(&slow_subchannel_lock);
628 eval = idset_sch_contains(slow_subchannel_set, schid);
629 idset_sch_del(slow_subchannel_set, schid);
630 spin_unlock_irq(&slow_subchannel_lock);
631 if (eval) {
632 rc = css_evaluate_new_subchannel(schid, 1);
633 switch (rc) {
634 case -EAGAIN:
635 css_schedule_eval(schid);
636 rc = 0;
637 break;
638 case -ENXIO:
639 case -ENOMEM:
640 case -EIO:
641 /* These should abort looping */
642 spin_lock_irq(&slow_subchannel_lock);
643 idset_sch_del_subseq(slow_subchannel_set, schid);
644 spin_unlock_irq(&slow_subchannel_lock);
645 break;
646 default:
647 rc = 0;
649 /* Allow scheduling here since the containing loop might
650 * take a while. */
651 cond_resched();
653 return rc;
656 static void css_slow_path_func(struct work_struct *unused)
658 unsigned long flags;
660 CIO_TRACE_EVENT(4, "slowpath");
661 for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
662 NULL);
663 spin_lock_irqsave(&slow_subchannel_lock, flags);
664 if (idset_is_empty(slow_subchannel_set)) {
665 atomic_set(&css_eval_scheduled, 0);
666 wake_up(&css_eval_wq);
668 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
671 static DECLARE_DELAYED_WORK(slow_path_work, css_slow_path_func);
672 struct workqueue_struct *cio_work_q;
674 void css_schedule_eval(struct subchannel_id schid)
676 unsigned long flags;
678 spin_lock_irqsave(&slow_subchannel_lock, flags);
679 idset_sch_add(slow_subchannel_set, schid);
680 atomic_set(&css_eval_scheduled, 1);
681 queue_delayed_work(cio_work_q, &slow_path_work, 0);
682 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
685 void css_schedule_eval_all(void)
687 unsigned long flags;
689 spin_lock_irqsave(&slow_subchannel_lock, flags);
690 idset_fill(slow_subchannel_set);
691 atomic_set(&css_eval_scheduled, 1);
692 queue_delayed_work(cio_work_q, &slow_path_work, 0);
693 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
696 static int __unset_registered(struct device *dev, void *data)
698 struct idset *set = data;
699 struct subchannel *sch = to_subchannel(dev);
701 idset_sch_del(set, sch->schid);
702 return 0;
705 void css_schedule_eval_all_unreg(unsigned long delay)
707 unsigned long flags;
708 struct idset *unreg_set;
710 /* Find unregistered subchannels. */
711 unreg_set = idset_sch_new();
712 if (!unreg_set) {
713 /* Fallback. */
714 css_schedule_eval_all();
715 return;
717 idset_fill(unreg_set);
718 bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered);
719 /* Apply to slow_subchannel_set. */
720 spin_lock_irqsave(&slow_subchannel_lock, flags);
721 idset_add_set(slow_subchannel_set, unreg_set);
722 atomic_set(&css_eval_scheduled, 1);
723 queue_delayed_work(cio_work_q, &slow_path_work, delay);
724 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
725 idset_free(unreg_set);
728 void css_wait_for_slow_path(void)
730 flush_workqueue(cio_work_q);
733 /* Schedule reprobing of all unregistered subchannels. */
734 void css_schedule_reprobe(void)
736 /* Schedule with a delay to allow merging of subsequent calls. */
737 css_schedule_eval_all_unreg(1 * HZ);
739 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
742 * Called from the machine check handler for subchannel report words.
744 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
746 struct subchannel_id mchk_schid;
747 struct subchannel *sch;
749 if (overflow) {
750 css_schedule_eval_all();
751 return;
753 CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
754 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
755 crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
756 crw0->erc, crw0->rsid);
757 if (crw1)
758 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
759 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
760 crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
761 crw1->anc, crw1->erc, crw1->rsid);
762 init_subchannel_id(&mchk_schid);
763 mchk_schid.sch_no = crw0->rsid;
764 if (crw1)
765 mchk_schid.ssid = (crw1->rsid >> 4) & 3;
767 if (crw0->erc == CRW_ERC_PMOD) {
768 sch = get_subchannel_by_schid(mchk_schid);
769 if (sch) {
770 css_update_ssd_info(sch);
771 put_device(&sch->dev);
775 * Since we are always presented with IPI in the CRW, we have to
776 * use stsch() to find out if the subchannel in question has come
777 * or gone.
779 css_evaluate_subchannel(mchk_schid, 0);
782 static void __init
783 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
785 struct cpuid cpu_id;
787 if (css_general_characteristics.mcss) {
788 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
789 css->global_pgid.pgid_high.ext_cssid.cssid =
790 (css->cssid < 0) ? 0 : css->cssid;
791 } else {
792 css->global_pgid.pgid_high.cpu_addr = stap();
794 get_cpu_id(&cpu_id);
795 css->global_pgid.cpu_id = cpu_id.ident;
796 css->global_pgid.cpu_model = cpu_id.machine;
797 css->global_pgid.tod_high = tod_high;
800 static void channel_subsystem_release(struct device *dev)
802 struct channel_subsystem *css = to_css(dev);
804 mutex_destroy(&css->mutex);
805 kfree(css);
808 static ssize_t real_cssid_show(struct device *dev, struct device_attribute *a,
809 char *buf)
811 struct channel_subsystem *css = to_css(dev);
813 if (css->cssid < 0)
814 return -EINVAL;
816 return sprintf(buf, "%x\n", css->cssid);
818 static DEVICE_ATTR_RO(real_cssid);
820 static ssize_t cm_enable_show(struct device *dev, struct device_attribute *a,
821 char *buf)
823 struct channel_subsystem *css = to_css(dev);
824 int ret;
826 mutex_lock(&css->mutex);
827 ret = sprintf(buf, "%x\n", css->cm_enabled);
828 mutex_unlock(&css->mutex);
829 return ret;
832 static ssize_t cm_enable_store(struct device *dev, struct device_attribute *a,
833 const char *buf, size_t count)
835 struct channel_subsystem *css = to_css(dev);
836 unsigned long val;
837 int ret;
839 ret = kstrtoul(buf, 16, &val);
840 if (ret)
841 return ret;
842 mutex_lock(&css->mutex);
843 switch (val) {
844 case 0:
845 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
846 break;
847 case 1:
848 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
849 break;
850 default:
851 ret = -EINVAL;
853 mutex_unlock(&css->mutex);
854 return ret < 0 ? ret : count;
856 static DEVICE_ATTR_RW(cm_enable);
858 static umode_t cm_enable_mode(struct kobject *kobj, struct attribute *attr,
859 int index)
861 return css_chsc_characteristics.secm ? attr->mode : 0;
864 static struct attribute *cssdev_attrs[] = {
865 &dev_attr_real_cssid.attr,
866 NULL,
869 static struct attribute_group cssdev_attr_group = {
870 .attrs = cssdev_attrs,
873 static struct attribute *cssdev_cm_attrs[] = {
874 &dev_attr_cm_enable.attr,
875 NULL,
878 static struct attribute_group cssdev_cm_attr_group = {
879 .attrs = cssdev_cm_attrs,
880 .is_visible = cm_enable_mode,
883 static const struct attribute_group *cssdev_attr_groups[] = {
884 &cssdev_attr_group,
885 &cssdev_cm_attr_group,
886 NULL,
889 static int __init setup_css(int nr)
891 struct channel_subsystem *css;
892 int ret;
894 css = kzalloc(sizeof(*css), GFP_KERNEL);
895 if (!css)
896 return -ENOMEM;
898 channel_subsystems[nr] = css;
899 dev_set_name(&css->device, "css%x", nr);
900 css->device.groups = cssdev_attr_groups;
901 css->device.release = channel_subsystem_release;
903 mutex_init(&css->mutex);
904 css->cssid = chsc_get_cssid(nr);
905 css_generate_pgid(css, (u32) (get_tod_clock() >> 32));
907 ret = device_register(&css->device);
908 if (ret) {
909 put_device(&css->device);
910 goto out_err;
913 css->pseudo_subchannel = kzalloc(sizeof(*css->pseudo_subchannel),
914 GFP_KERNEL);
915 if (!css->pseudo_subchannel) {
916 device_unregister(&css->device);
917 ret = -ENOMEM;
918 goto out_err;
921 css->pseudo_subchannel->dev.parent = &css->device;
922 css->pseudo_subchannel->dev.release = css_subchannel_release;
923 mutex_init(&css->pseudo_subchannel->reg_mutex);
924 ret = css_sch_create_locks(css->pseudo_subchannel);
925 if (ret) {
926 kfree(css->pseudo_subchannel);
927 device_unregister(&css->device);
928 goto out_err;
931 dev_set_name(&css->pseudo_subchannel->dev, "defunct");
932 ret = device_register(&css->pseudo_subchannel->dev);
933 if (ret) {
934 put_device(&css->pseudo_subchannel->dev);
935 device_unregister(&css->device);
936 goto out_err;
939 return ret;
940 out_err:
941 channel_subsystems[nr] = NULL;
942 return ret;
945 static int css_reboot_event(struct notifier_block *this,
946 unsigned long event,
947 void *ptr)
949 struct channel_subsystem *css;
950 int ret;
952 ret = NOTIFY_DONE;
953 for_each_css(css) {
954 mutex_lock(&css->mutex);
955 if (css->cm_enabled)
956 if (chsc_secm(css, 0))
957 ret = NOTIFY_BAD;
958 mutex_unlock(&css->mutex);
961 return ret;
964 static struct notifier_block css_reboot_notifier = {
965 .notifier_call = css_reboot_event,
969 * Since the css devices are neither on a bus nor have a class
970 * nor have a special device type, we cannot stop/restart channel
971 * path measurements via the normal suspend/resume callbacks, but have
972 * to use notifiers.
974 static int css_power_event(struct notifier_block *this, unsigned long event,
975 void *ptr)
977 struct channel_subsystem *css;
978 int ret;
980 switch (event) {
981 case PM_HIBERNATION_PREPARE:
982 case PM_SUSPEND_PREPARE:
983 ret = NOTIFY_DONE;
984 for_each_css(css) {
985 mutex_lock(&css->mutex);
986 if (!css->cm_enabled) {
987 mutex_unlock(&css->mutex);
988 continue;
990 ret = __chsc_do_secm(css, 0);
991 ret = notifier_from_errno(ret);
992 mutex_unlock(&css->mutex);
994 break;
995 case PM_POST_HIBERNATION:
996 case PM_POST_SUSPEND:
997 ret = NOTIFY_DONE;
998 for_each_css(css) {
999 mutex_lock(&css->mutex);
1000 if (!css->cm_enabled) {
1001 mutex_unlock(&css->mutex);
1002 continue;
1004 ret = __chsc_do_secm(css, 1);
1005 ret = notifier_from_errno(ret);
1006 mutex_unlock(&css->mutex);
1008 /* search for subchannels, which appeared during hibernation */
1009 css_schedule_reprobe();
1010 break;
1011 default:
1012 ret = NOTIFY_DONE;
1014 return ret;
1017 static struct notifier_block css_power_notifier = {
1018 .notifier_call = css_power_event,
1022 * Now that the driver core is running, we can setup our channel subsystem.
1023 * The struct subchannel's are created during probing.
1025 static int __init css_bus_init(void)
1027 int ret, i;
1029 ret = chsc_init();
1030 if (ret)
1031 return ret;
1033 chsc_determine_css_characteristics();
1034 /* Try to enable MSS. */
1035 ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
1036 if (ret)
1037 max_ssid = 0;
1038 else /* Success. */
1039 max_ssid = __MAX_SSID;
1041 ret = slow_subchannel_init();
1042 if (ret)
1043 goto out;
1045 ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
1046 if (ret)
1047 goto out;
1049 if ((ret = bus_register(&css_bus_type)))
1050 goto out;
1052 /* Setup css structure. */
1053 for (i = 0; i <= MAX_CSS_IDX; i++) {
1054 ret = setup_css(i);
1055 if (ret)
1056 goto out_unregister;
1058 ret = register_reboot_notifier(&css_reboot_notifier);
1059 if (ret)
1060 goto out_unregister;
1061 ret = register_pm_notifier(&css_power_notifier);
1062 if (ret) {
1063 unregister_reboot_notifier(&css_reboot_notifier);
1064 goto out_unregister;
1066 css_init_done = 1;
1068 /* Enable default isc for I/O subchannels. */
1069 isc_register(IO_SCH_ISC);
1071 return 0;
1072 out_unregister:
1073 while (i-- > 0) {
1074 struct channel_subsystem *css = channel_subsystems[i];
1075 device_unregister(&css->pseudo_subchannel->dev);
1076 device_unregister(&css->device);
1078 bus_unregister(&css_bus_type);
1079 out:
1080 crw_unregister_handler(CRW_RSC_SCH);
1081 idset_free(slow_subchannel_set);
1082 chsc_init_cleanup();
1083 pr_alert("The CSS device driver initialization failed with "
1084 "errno=%d\n", ret);
1085 return ret;
1088 static void __init css_bus_cleanup(void)
1090 struct channel_subsystem *css;
1092 for_each_css(css) {
1093 device_unregister(&css->pseudo_subchannel->dev);
1094 device_unregister(&css->device);
1096 bus_unregister(&css_bus_type);
1097 crw_unregister_handler(CRW_RSC_SCH);
1098 idset_free(slow_subchannel_set);
1099 chsc_init_cleanup();
1100 isc_unregister(IO_SCH_ISC);
1103 static int __init channel_subsystem_init(void)
1105 int ret;
1107 ret = css_bus_init();
1108 if (ret)
1109 return ret;
1110 cio_work_q = create_singlethread_workqueue("cio");
1111 if (!cio_work_q) {
1112 ret = -ENOMEM;
1113 goto out_bus;
1115 ret = io_subchannel_init();
1116 if (ret)
1117 goto out_wq;
1119 /* Register subchannels which are already in use. */
1120 cio_register_early_subchannels();
1121 /* Start initial subchannel evaluation. */
1122 css_schedule_eval_all();
1124 return ret;
1125 out_wq:
1126 destroy_workqueue(cio_work_q);
1127 out_bus:
1128 css_bus_cleanup();
1129 return ret;
1131 subsys_initcall(channel_subsystem_init);
1133 static int css_settle(struct device_driver *drv, void *unused)
1135 struct css_driver *cssdrv = to_cssdriver(drv);
1137 if (cssdrv->settle)
1138 return cssdrv->settle();
1139 return 0;
1142 int css_complete_work(void)
1144 int ret;
1146 /* Wait for the evaluation of subchannels to finish. */
1147 ret = wait_event_interruptible(css_eval_wq,
1148 atomic_read(&css_eval_scheduled) == 0);
1149 if (ret)
1150 return -EINTR;
1151 flush_workqueue(cio_work_q);
1152 /* Wait for the subchannel type specific initialization to finish */
1153 return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
1158 * Wait for the initialization of devices to finish, to make sure we are
1159 * done with our setup if the search for the root device starts.
1161 static int __init channel_subsystem_init_sync(void)
1163 css_complete_work();
1164 return 0;
1166 subsys_initcall_sync(channel_subsystem_init_sync);
1168 void channel_subsystem_reinit(void)
1170 struct channel_path *chp;
1171 struct chp_id chpid;
1173 chsc_enable_facility(CHSC_SDA_OC_MSS);
1174 chp_id_for_each(&chpid) {
1175 chp = chpid_to_chp(chpid);
1176 if (chp)
1177 chp_update_desc(chp);
1179 cmf_reactivate();
1182 #ifdef CONFIG_PROC_FS
1183 static ssize_t cio_settle_write(struct file *file, const char __user *buf,
1184 size_t count, loff_t *ppos)
1186 int ret;
1188 /* Handle pending CRW's. */
1189 crw_wait_for_channel_report();
1190 ret = css_complete_work();
1192 return ret ? ret : count;
1195 static const struct file_operations cio_settle_proc_fops = {
1196 .open = nonseekable_open,
1197 .write = cio_settle_write,
1198 .llseek = no_llseek,
1201 static int __init cio_settle_init(void)
1203 struct proc_dir_entry *entry;
1205 entry = proc_create("cio_settle", S_IWUSR, NULL,
1206 &cio_settle_proc_fops);
1207 if (!entry)
1208 return -ENOMEM;
1209 return 0;
1211 device_initcall(cio_settle_init);
1212 #endif /*CONFIG_PROC_FS*/
1214 int sch_is_pseudo_sch(struct subchannel *sch)
1216 return sch == to_css(sch->dev.parent)->pseudo_subchannel;
1219 static int css_bus_match(struct device *dev, struct device_driver *drv)
1221 struct subchannel *sch = to_subchannel(dev);
1222 struct css_driver *driver = to_cssdriver(drv);
1223 struct css_device_id *id;
1225 for (id = driver->subchannel_type; id->match_flags; id++) {
1226 if (sch->st == id->type)
1227 return 1;
1230 return 0;
1233 static int css_probe(struct device *dev)
1235 struct subchannel *sch;
1236 int ret;
1238 sch = to_subchannel(dev);
1239 sch->driver = to_cssdriver(dev->driver);
1240 ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
1241 if (ret)
1242 sch->driver = NULL;
1243 return ret;
1246 static int css_remove(struct device *dev)
1248 struct subchannel *sch;
1249 int ret;
1251 sch = to_subchannel(dev);
1252 ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
1253 sch->driver = NULL;
1254 return ret;
1257 static void css_shutdown(struct device *dev)
1259 struct subchannel *sch;
1261 sch = to_subchannel(dev);
1262 if (sch->driver && sch->driver->shutdown)
1263 sch->driver->shutdown(sch);
1266 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
1268 struct subchannel *sch = to_subchannel(dev);
1269 int ret;
1271 ret = add_uevent_var(env, "ST=%01X", sch->st);
1272 if (ret)
1273 return ret;
1274 ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
1275 return ret;
1278 static int css_pm_prepare(struct device *dev)
1280 struct subchannel *sch = to_subchannel(dev);
1281 struct css_driver *drv;
1283 if (mutex_is_locked(&sch->reg_mutex))
1284 return -EAGAIN;
1285 if (!sch->dev.driver)
1286 return 0;
1287 drv = to_cssdriver(sch->dev.driver);
1288 /* Notify drivers that they may not register children. */
1289 return drv->prepare ? drv->prepare(sch) : 0;
1292 static void css_pm_complete(struct device *dev)
1294 struct subchannel *sch = to_subchannel(dev);
1295 struct css_driver *drv;
1297 if (!sch->dev.driver)
1298 return;
1299 drv = to_cssdriver(sch->dev.driver);
1300 if (drv->complete)
1301 drv->complete(sch);
1304 static int css_pm_freeze(struct device *dev)
1306 struct subchannel *sch = to_subchannel(dev);
1307 struct css_driver *drv;
1309 if (!sch->dev.driver)
1310 return 0;
1311 drv = to_cssdriver(sch->dev.driver);
1312 return drv->freeze ? drv->freeze(sch) : 0;
1315 static int css_pm_thaw(struct device *dev)
1317 struct subchannel *sch = to_subchannel(dev);
1318 struct css_driver *drv;
1320 if (!sch->dev.driver)
1321 return 0;
1322 drv = to_cssdriver(sch->dev.driver);
1323 return drv->thaw ? drv->thaw(sch) : 0;
1326 static int css_pm_restore(struct device *dev)
1328 struct subchannel *sch = to_subchannel(dev);
1329 struct css_driver *drv;
1331 css_update_ssd_info(sch);
1332 if (!sch->dev.driver)
1333 return 0;
1334 drv = to_cssdriver(sch->dev.driver);
1335 return drv->restore ? drv->restore(sch) : 0;
1338 static const struct dev_pm_ops css_pm_ops = {
1339 .prepare = css_pm_prepare,
1340 .complete = css_pm_complete,
1341 .freeze = css_pm_freeze,
1342 .thaw = css_pm_thaw,
1343 .restore = css_pm_restore,
1346 static struct bus_type css_bus_type = {
1347 .name = "css",
1348 .match = css_bus_match,
1349 .probe = css_probe,
1350 .remove = css_remove,
1351 .shutdown = css_shutdown,
1352 .uevent = css_uevent,
1353 .pm = &css_pm_ops,
1357 * css_driver_register - register a css driver
1358 * @cdrv: css driver to register
1360 * This is mainly a wrapper around driver_register that sets name
1361 * and bus_type in the embedded struct device_driver correctly.
1363 int css_driver_register(struct css_driver *cdrv)
1365 cdrv->drv.bus = &css_bus_type;
1366 return driver_register(&cdrv->drv);
1368 EXPORT_SYMBOL_GPL(css_driver_register);
1371 * css_driver_unregister - unregister a css driver
1372 * @cdrv: css driver to unregister
1374 * This is a wrapper around driver_unregister.
1376 void css_driver_unregister(struct css_driver *cdrv)
1378 driver_unregister(&cdrv->drv);
1380 EXPORT_SYMBOL_GPL(css_driver_unregister);