2 * driver for channel subsystem
4 * Copyright IBM Corp. 2002, 2010
6 * Author(s): Arnd Bergmann (arndb@de.ibm.com)
7 * Cornelia Huck (cornelia.huck@de.ibm.com)
10 #define KMSG_COMPONENT "cio"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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>
27 #include "cio_debug.h"
34 int css_init_done = 0;
37 struct channel_subsystem *channel_subsystems[__MAX_CSSID + 1];
38 static struct bus_type css_bus_type;
41 for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data)
43 struct subchannel_id schid;
46 init_subchannel_id(&schid);
49 ret = fn(schid, data);
52 } while (schid.sch_no++ < __MAX_SUBCHANNEL);
54 } while (schid.ssid++ < max_ssid);
61 int (*fn_known_sch)(struct subchannel *, void *);
62 int (*fn_unknown_sch)(struct subchannel_id, void *);
65 static int call_fn_known_sch(struct device *dev, void *data)
67 struct subchannel *sch = to_subchannel(dev);
68 struct cb_data *cb = data;
72 idset_sch_del(cb->set, sch->schid);
74 rc = cb->fn_known_sch(sch, cb->data);
78 static int call_fn_unknown_sch(struct subchannel_id schid, void *data)
80 struct cb_data *cb = data;
83 if (idset_sch_contains(cb->set, schid))
84 rc = cb->fn_unknown_sch(schid, cb->data);
88 static int call_fn_all_sch(struct subchannel_id schid, void *data)
90 struct cb_data *cb = data;
91 struct subchannel *sch;
94 sch = get_subchannel_by_schid(schid);
97 rc = cb->fn_known_sch(sch, cb->data);
98 put_device(&sch->dev);
100 if (cb->fn_unknown_sch)
101 rc = cb->fn_unknown_sch(schid, cb->data);
107 int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
108 int (*fn_unknown)(struct subchannel_id,
115 cb.fn_known_sch = fn_known;
116 cb.fn_unknown_sch = fn_unknown;
118 if (fn_known && !fn_unknown) {
119 /* Skip idset allocation in case of known-only loop. */
121 return bus_for_each_dev(&css_bus_type, NULL, &cb,
125 cb.set = idset_sch_new();
127 /* fall back to brute force scanning in case of oom */
128 return for_each_subchannel(call_fn_all_sch, &cb);
132 /* Process registered subchannels. */
133 rc = bus_for_each_dev(&css_bus_type, NULL, &cb, call_fn_known_sch);
136 /* Process unregistered subchannels. */
138 rc = for_each_subchannel(call_fn_unknown_sch, &cb);
145 static void css_sch_todo(struct work_struct *work);
147 static int css_sch_create_locks(struct subchannel *sch)
149 sch->lock = kmalloc(sizeof(*sch->lock), GFP_KERNEL);
153 spin_lock_init(sch->lock);
154 mutex_init(&sch->reg_mutex);
159 static void css_subchannel_release(struct device *dev)
161 struct subchannel *sch = to_subchannel(dev);
163 sch->config.intparm = 0;
164 cio_commit_config(sch);
169 struct subchannel *css_alloc_subchannel(struct subchannel_id schid)
171 struct subchannel *sch;
174 sch = kzalloc(sizeof(*sch), GFP_KERNEL | GFP_DMA);
176 return ERR_PTR(-ENOMEM);
178 ret = cio_validate_subchannel(sch, schid);
182 ret = css_sch_create_locks(sch);
186 INIT_WORK(&sch->todo_work, css_sch_todo);
187 sch->dev.release = &css_subchannel_release;
188 device_initialize(&sch->dev);
196 static int css_sch_device_register(struct subchannel *sch)
200 mutex_lock(&sch->reg_mutex);
201 dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid,
203 ret = device_add(&sch->dev);
204 mutex_unlock(&sch->reg_mutex);
209 * css_sch_device_unregister - unregister a subchannel
210 * @sch: subchannel to be unregistered
212 void css_sch_device_unregister(struct subchannel *sch)
214 mutex_lock(&sch->reg_mutex);
215 if (device_is_registered(&sch->dev))
216 device_unregister(&sch->dev);
217 mutex_unlock(&sch->reg_mutex);
219 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
221 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
226 memset(ssd, 0, sizeof(struct chsc_ssd_info));
227 ssd->path_mask = pmcw->pim;
228 for (i = 0; i < 8; i++) {
230 if (pmcw->pim & mask) {
231 chp_id_init(&ssd->chpid[i]);
232 ssd->chpid[i].id = pmcw->chpid[i];
237 static void ssd_register_chpids(struct chsc_ssd_info *ssd)
242 for (i = 0; i < 8; i++) {
244 if (ssd->path_mask & mask)
245 if (!chp_is_registered(ssd->chpid[i]))
246 chp_new(ssd->chpid[i]);
250 void css_update_ssd_info(struct subchannel *sch)
254 ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
256 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
258 ssd_register_chpids(&sch->ssd_info);
261 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
264 struct subchannel *sch = to_subchannel(dev);
266 return sprintf(buf, "%01x\n", sch->st);
269 static DEVICE_ATTR(type, 0444, type_show, NULL);
271 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
274 struct subchannel *sch = to_subchannel(dev);
276 return sprintf(buf, "css:t%01X\n", sch->st);
279 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
281 static struct attribute *subch_attrs[] = {
283 &dev_attr_modalias.attr,
287 static struct attribute_group subch_attr_group = {
288 .attrs = subch_attrs,
291 static const struct attribute_group *default_subch_attr_groups[] = {
296 int css_register_subchannel(struct subchannel *sch)
300 /* Initialize the subchannel structure */
301 sch->dev.parent = &channel_subsystems[0]->device;
302 sch->dev.bus = &css_bus_type;
303 sch->dev.groups = default_subch_attr_groups;
305 * We don't want to generate uevents for I/O subchannels that don't
306 * have a working ccw device behind them since they will be
307 * unregistered before they can be used anyway, so we delay the add
308 * uevent until after device recognition was successful.
309 * Note that we suppress the uevent for all subchannel types;
310 * the subchannel driver can decide itself when it wants to inform
311 * userspace of its existence.
313 dev_set_uevent_suppress(&sch->dev, 1);
314 css_update_ssd_info(sch);
315 /* make it known to the system */
316 ret = css_sch_device_register(sch);
318 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
319 sch->schid.ssid, sch->schid.sch_no, ret);
324 * No driver matched. Generate the uevent now so that
325 * a fitting driver module may be loaded based on the
328 dev_set_uevent_suppress(&sch->dev, 0);
329 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
334 static int css_probe_device(struct subchannel_id schid)
336 struct subchannel *sch;
339 sch = css_alloc_subchannel(schid);
343 ret = css_register_subchannel(sch);
345 put_device(&sch->dev);
351 check_subchannel(struct device * dev, void * data)
353 struct subchannel *sch;
354 struct subchannel_id *schid = data;
356 sch = to_subchannel(dev);
357 return schid_equal(&sch->schid, schid);
361 get_subchannel_by_schid(struct subchannel_id schid)
365 dev = bus_find_device(&css_bus_type, NULL,
366 &schid, check_subchannel);
368 return dev ? to_subchannel(dev) : NULL;
372 * css_sch_is_valid() - check if a subchannel is valid
373 * @schib: subchannel information block for the subchannel
375 int css_sch_is_valid(struct schib *schib)
377 if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
379 if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w)
383 EXPORT_SYMBOL_GPL(css_sch_is_valid);
385 static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
390 /* Will be done on the slow path. */
393 if (stsch_err(schid, &schib)) {
394 /* Subchannel is not provided. */
397 if (!css_sch_is_valid(&schib)) {
398 /* Unusable - ignore. */
401 CIO_MSG_EVENT(4, "event: sch 0.%x.%04x, new\n", schid.ssid,
404 return css_probe_device(schid);
407 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
412 if (sch->driver->sch_event)
413 ret = sch->driver->sch_event(sch, slow);
416 "Got subchannel machine check but "
417 "no sch_event handler provided.\n");
419 if (ret != 0 && ret != -EAGAIN) {
420 CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
421 sch->schid.ssid, sch->schid.sch_no, ret);
426 static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
428 struct subchannel *sch;
431 sch = get_subchannel_by_schid(schid);
433 ret = css_evaluate_known_subchannel(sch, slow);
434 put_device(&sch->dev);
436 ret = css_evaluate_new_subchannel(schid, slow);
438 css_schedule_eval(schid);
442 * css_sched_sch_todo - schedule a subchannel operation
446 * Schedule the operation identified by @todo to be performed on the slow path
447 * workqueue. Do nothing if another operation with higher priority is already
448 * scheduled. Needs to be called with subchannel lock held.
450 void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
452 CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
453 sch->schid.ssid, sch->schid.sch_no, todo);
454 if (sch->todo >= todo)
456 /* Get workqueue ref. */
457 if (!get_device(&sch->dev))
460 if (!queue_work(cio_work_q, &sch->todo_work)) {
461 /* Already queued, release workqueue ref. */
462 put_device(&sch->dev);
465 EXPORT_SYMBOL_GPL(css_sched_sch_todo);
467 static void css_sch_todo(struct work_struct *work)
469 struct subchannel *sch;
473 sch = container_of(work, struct subchannel, todo_work);
475 spin_lock_irq(sch->lock);
477 CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
478 sch->schid.sch_no, todo);
479 sch->todo = SCH_TODO_NOTHING;
480 spin_unlock_irq(sch->lock);
483 case SCH_TODO_NOTHING:
486 ret = css_evaluate_known_subchannel(sch, 1);
487 if (ret == -EAGAIN) {
488 spin_lock_irq(sch->lock);
489 css_sched_sch_todo(sch, todo);
490 spin_unlock_irq(sch->lock);
494 css_sch_device_unregister(sch);
497 /* Release workqueue ref. */
498 put_device(&sch->dev);
501 static struct idset *slow_subchannel_set;
502 static spinlock_t slow_subchannel_lock;
503 static wait_queue_head_t css_eval_wq;
504 static atomic_t css_eval_scheduled;
506 static int __init slow_subchannel_init(void)
508 spin_lock_init(&slow_subchannel_lock);
509 atomic_set(&css_eval_scheduled, 0);
510 init_waitqueue_head(&css_eval_wq);
511 slow_subchannel_set = idset_sch_new();
512 if (!slow_subchannel_set) {
513 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
519 static int slow_eval_known_fn(struct subchannel *sch, void *data)
524 spin_lock_irq(&slow_subchannel_lock);
525 eval = idset_sch_contains(slow_subchannel_set, sch->schid);
526 idset_sch_del(slow_subchannel_set, sch->schid);
527 spin_unlock_irq(&slow_subchannel_lock);
529 rc = css_evaluate_known_subchannel(sch, 1);
531 css_schedule_eval(sch->schid);
536 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
541 spin_lock_irq(&slow_subchannel_lock);
542 eval = idset_sch_contains(slow_subchannel_set, schid);
543 idset_sch_del(slow_subchannel_set, schid);
544 spin_unlock_irq(&slow_subchannel_lock);
546 rc = css_evaluate_new_subchannel(schid, 1);
549 css_schedule_eval(schid);
555 /* These should abort looping */
556 spin_lock_irq(&slow_subchannel_lock);
557 idset_sch_del_subseq(slow_subchannel_set, schid);
558 spin_unlock_irq(&slow_subchannel_lock);
563 /* Allow scheduling here since the containing loop might
570 static void css_slow_path_func(struct work_struct *unused)
574 CIO_TRACE_EVENT(4, "slowpath");
575 for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
577 spin_lock_irqsave(&slow_subchannel_lock, flags);
578 if (idset_is_empty(slow_subchannel_set)) {
579 atomic_set(&css_eval_scheduled, 0);
580 wake_up(&css_eval_wq);
582 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
585 static DECLARE_DELAYED_WORK(slow_path_work, css_slow_path_func);
586 struct workqueue_struct *cio_work_q;
588 void css_schedule_eval(struct subchannel_id schid)
592 spin_lock_irqsave(&slow_subchannel_lock, flags);
593 idset_sch_add(slow_subchannel_set, schid);
594 atomic_set(&css_eval_scheduled, 1);
595 queue_delayed_work(cio_work_q, &slow_path_work, 0);
596 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
599 void css_schedule_eval_all(void)
603 spin_lock_irqsave(&slow_subchannel_lock, flags);
604 idset_fill(slow_subchannel_set);
605 atomic_set(&css_eval_scheduled, 1);
606 queue_delayed_work(cio_work_q, &slow_path_work, 0);
607 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
610 static int __unset_registered(struct device *dev, void *data)
612 struct idset *set = data;
613 struct subchannel *sch = to_subchannel(dev);
615 idset_sch_del(set, sch->schid);
619 void css_schedule_eval_all_unreg(unsigned long delay)
622 struct idset *unreg_set;
624 /* Find unregistered subchannels. */
625 unreg_set = idset_sch_new();
628 css_schedule_eval_all();
631 idset_fill(unreg_set);
632 bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered);
633 /* Apply to slow_subchannel_set. */
634 spin_lock_irqsave(&slow_subchannel_lock, flags);
635 idset_add_set(slow_subchannel_set, unreg_set);
636 atomic_set(&css_eval_scheduled, 1);
637 queue_delayed_work(cio_work_q, &slow_path_work, delay);
638 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
639 idset_free(unreg_set);
642 void css_wait_for_slow_path(void)
644 flush_workqueue(cio_work_q);
647 /* Schedule reprobing of all unregistered subchannels. */
648 void css_schedule_reprobe(void)
650 /* Schedule with a delay to allow merging of subsequent calls. */
651 css_schedule_eval_all_unreg(1 * HZ);
653 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
656 * Called from the machine check handler for subchannel report words.
658 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
660 struct subchannel_id mchk_schid;
661 struct subchannel *sch;
664 css_schedule_eval_all();
667 CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
668 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
669 crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
670 crw0->erc, crw0->rsid);
672 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
673 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
674 crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
675 crw1->anc, crw1->erc, crw1->rsid);
676 init_subchannel_id(&mchk_schid);
677 mchk_schid.sch_no = crw0->rsid;
679 mchk_schid.ssid = (crw1->rsid >> 4) & 3;
681 if (crw0->erc == CRW_ERC_PMOD) {
682 sch = get_subchannel_by_schid(mchk_schid);
684 css_update_ssd_info(sch);
685 put_device(&sch->dev);
689 * Since we are always presented with IPI in the CRW, we have to
690 * use stsch() to find out if the subchannel in question has come
693 css_evaluate_subchannel(mchk_schid, 0);
697 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
701 if (css_general_characteristics.mcss) {
702 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
703 css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
705 css->global_pgid.pgid_high.cpu_addr = stap();
708 css->global_pgid.cpu_id = cpu_id.ident;
709 css->global_pgid.cpu_model = cpu_id.machine;
710 css->global_pgid.tod_high = tod_high;
714 channel_subsystem_release(struct device *dev)
716 struct channel_subsystem *css;
719 mutex_destroy(&css->mutex);
720 if (css->pseudo_subchannel) {
721 /* Implies that it has been generated but never registered. */
722 css_subchannel_release(&css->pseudo_subchannel->dev);
723 css->pseudo_subchannel = NULL;
729 css_cm_enable_show(struct device *dev, struct device_attribute *attr,
732 struct channel_subsystem *css = to_css(dev);
737 mutex_lock(&css->mutex);
738 ret = sprintf(buf, "%x\n", css->cm_enabled);
739 mutex_unlock(&css->mutex);
744 css_cm_enable_store(struct device *dev, struct device_attribute *attr,
745 const char *buf, size_t count)
747 struct channel_subsystem *css = to_css(dev);
751 ret = kstrtoul(buf, 16, &val);
754 mutex_lock(&css->mutex);
757 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
760 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
765 mutex_unlock(&css->mutex);
766 return ret < 0 ? ret : count;
769 static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
771 static int __init setup_css(int nr)
775 struct channel_subsystem *css;
777 css = channel_subsystems[nr];
778 memset(css, 0, sizeof(struct channel_subsystem));
779 css->pseudo_subchannel =
780 kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
781 if (!css->pseudo_subchannel)
783 css->pseudo_subchannel->dev.parent = &css->device;
784 css->pseudo_subchannel->dev.release = css_subchannel_release;
785 dev_set_name(&css->pseudo_subchannel->dev, "defunct");
786 mutex_init(&css->pseudo_subchannel->reg_mutex);
787 ret = css_sch_create_locks(css->pseudo_subchannel);
789 kfree(css->pseudo_subchannel);
792 mutex_init(&css->mutex);
795 dev_set_name(&css->device, "css%x", nr);
796 css->device.release = channel_subsystem_release;
797 tod_high = (u32) (get_tod_clock() >> 32);
798 css_generate_pgid(css, tod_high);
802 static int css_reboot_event(struct notifier_block *this,
809 for (i = 0; i <= __MAX_CSSID; i++) {
810 struct channel_subsystem *css;
812 css = channel_subsystems[i];
813 mutex_lock(&css->mutex);
815 if (chsc_secm(css, 0))
817 mutex_unlock(&css->mutex);
823 static struct notifier_block css_reboot_notifier = {
824 .notifier_call = css_reboot_event,
828 * Since the css devices are neither on a bus nor have a class
829 * nor have a special device type, we cannot stop/restart channel
830 * path measurements via the normal suspend/resume callbacks, but have
833 static int css_power_event(struct notifier_block *this, unsigned long event,
839 case PM_HIBERNATION_PREPARE:
840 case PM_SUSPEND_PREPARE:
842 for (i = 0; i <= __MAX_CSSID; i++) {
843 struct channel_subsystem *css;
845 css = channel_subsystems[i];
846 mutex_lock(&css->mutex);
847 if (!css->cm_enabled) {
848 mutex_unlock(&css->mutex);
851 ret = __chsc_do_secm(css, 0);
852 ret = notifier_from_errno(ret);
853 mutex_unlock(&css->mutex);
856 case PM_POST_HIBERNATION:
857 case PM_POST_SUSPEND:
859 for (i = 0; i <= __MAX_CSSID; i++) {
860 struct channel_subsystem *css;
862 css = channel_subsystems[i];
863 mutex_lock(&css->mutex);
864 if (!css->cm_enabled) {
865 mutex_unlock(&css->mutex);
868 ret = __chsc_do_secm(css, 1);
869 ret = notifier_from_errno(ret);
870 mutex_unlock(&css->mutex);
872 /* search for subchannels, which appeared during hibernation */
873 css_schedule_reprobe();
881 static struct notifier_block css_power_notifier = {
882 .notifier_call = css_power_event,
886 * Now that the driver core is running, we can setup our channel subsystem.
887 * The struct subchannel's are created during probing.
889 static int __init css_bus_init(void)
897 chsc_determine_css_characteristics();
898 /* Try to enable MSS. */
899 ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
903 max_ssid = __MAX_SSID;
905 ret = slow_subchannel_init();
909 ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
913 if ((ret = bus_register(&css_bus_type)))
916 /* Setup css structure. */
917 for (i = 0; i <= __MAX_CSSID; i++) {
918 struct channel_subsystem *css;
920 css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
925 channel_subsystems[i] = css;
928 kfree(channel_subsystems[i]);
931 ret = device_register(&css->device);
933 put_device(&css->device);
936 if (css_chsc_characteristics.secm) {
937 ret = device_create_file(&css->device,
938 &dev_attr_cm_enable);
942 ret = device_register(&css->pseudo_subchannel->dev);
944 put_device(&css->pseudo_subchannel->dev);
948 ret = register_reboot_notifier(&css_reboot_notifier);
951 ret = register_pm_notifier(&css_power_notifier);
953 unregister_reboot_notifier(&css_reboot_notifier);
958 /* Enable default isc for I/O subchannels. */
959 isc_register(IO_SCH_ISC);
963 if (css_chsc_characteristics.secm)
964 device_remove_file(&channel_subsystems[i]->device,
965 &dev_attr_cm_enable);
967 device_unregister(&channel_subsystems[i]->device);
970 struct channel_subsystem *css;
973 css = channel_subsystems[i];
974 device_unregister(&css->pseudo_subchannel->dev);
975 css->pseudo_subchannel = NULL;
976 if (css_chsc_characteristics.secm)
977 device_remove_file(&css->device,
978 &dev_attr_cm_enable);
979 device_unregister(&css->device);
981 bus_unregister(&css_bus_type);
983 crw_unregister_handler(CRW_RSC_SCH);
984 idset_free(slow_subchannel_set);
986 pr_alert("The CSS device driver initialization failed with "
991 static void __init css_bus_cleanup(void)
993 struct channel_subsystem *css;
996 for (i = 0; i <= __MAX_CSSID; i++) {
997 css = channel_subsystems[i];
998 device_unregister(&css->pseudo_subchannel->dev);
999 css->pseudo_subchannel = NULL;
1000 if (css_chsc_characteristics.secm)
1001 device_remove_file(&css->device, &dev_attr_cm_enable);
1002 device_unregister(&css->device);
1004 bus_unregister(&css_bus_type);
1005 crw_unregister_handler(CRW_RSC_SCH);
1006 idset_free(slow_subchannel_set);
1007 chsc_init_cleanup();
1008 isc_unregister(IO_SCH_ISC);
1011 static int __init channel_subsystem_init(void)
1015 ret = css_bus_init();
1018 cio_work_q = create_singlethread_workqueue("cio");
1023 ret = io_subchannel_init();
1029 destroy_workqueue(cio_work_q);
1034 subsys_initcall(channel_subsystem_init);
1036 static int css_settle(struct device_driver *drv, void *unused)
1038 struct css_driver *cssdrv = to_cssdriver(drv);
1041 return cssdrv->settle();
1045 int css_complete_work(void)
1049 /* Wait for the evaluation of subchannels to finish. */
1050 ret = wait_event_interruptible(css_eval_wq,
1051 atomic_read(&css_eval_scheduled) == 0);
1054 flush_workqueue(cio_work_q);
1055 /* Wait for the subchannel type specific initialization to finish */
1056 return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
1061 * Wait for the initialization of devices to finish, to make sure we are
1062 * done with our setup if the search for the root device starts.
1064 static int __init channel_subsystem_init_sync(void)
1066 /* Register subchannels which are already in use. */
1067 cio_register_early_subchannels();
1068 /* Start initial subchannel evaluation. */
1069 css_schedule_eval_all();
1070 css_complete_work();
1073 subsys_initcall_sync(channel_subsystem_init_sync);
1075 void channel_subsystem_reinit(void)
1077 struct channel_path *chp;
1078 struct chp_id chpid;
1080 chsc_enable_facility(CHSC_SDA_OC_MSS);
1081 chp_id_for_each(&chpid) {
1082 chp = chpid_to_chp(chpid);
1084 chp_update_desc(chp);
1089 #ifdef CONFIG_PROC_FS
1090 static ssize_t cio_settle_write(struct file *file, const char __user *buf,
1091 size_t count, loff_t *ppos)
1095 /* Handle pending CRW's. */
1096 crw_wait_for_channel_report();
1097 ret = css_complete_work();
1099 return ret ? ret : count;
1102 static const struct file_operations cio_settle_proc_fops = {
1103 .open = nonseekable_open,
1104 .write = cio_settle_write,
1105 .llseek = no_llseek,
1108 static int __init cio_settle_init(void)
1110 struct proc_dir_entry *entry;
1112 entry = proc_create("cio_settle", S_IWUSR, NULL,
1113 &cio_settle_proc_fops);
1118 device_initcall(cio_settle_init);
1119 #endif /*CONFIG_PROC_FS*/
1121 int sch_is_pseudo_sch(struct subchannel *sch)
1123 return sch == to_css(sch->dev.parent)->pseudo_subchannel;
1126 static int css_bus_match(struct device *dev, struct device_driver *drv)
1128 struct subchannel *sch = to_subchannel(dev);
1129 struct css_driver *driver = to_cssdriver(drv);
1130 struct css_device_id *id;
1132 for (id = driver->subchannel_type; id->match_flags; id++) {
1133 if (sch->st == id->type)
1140 static int css_probe(struct device *dev)
1142 struct subchannel *sch;
1145 sch = to_subchannel(dev);
1146 sch->driver = to_cssdriver(dev->driver);
1147 ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
1153 static int css_remove(struct device *dev)
1155 struct subchannel *sch;
1158 sch = to_subchannel(dev);
1159 ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
1164 static void css_shutdown(struct device *dev)
1166 struct subchannel *sch;
1168 sch = to_subchannel(dev);
1169 if (sch->driver && sch->driver->shutdown)
1170 sch->driver->shutdown(sch);
1173 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
1175 struct subchannel *sch = to_subchannel(dev);
1178 ret = add_uevent_var(env, "ST=%01X", sch->st);
1181 ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
1185 static int css_pm_prepare(struct device *dev)
1187 struct subchannel *sch = to_subchannel(dev);
1188 struct css_driver *drv;
1190 if (mutex_is_locked(&sch->reg_mutex))
1192 if (!sch->dev.driver)
1194 drv = to_cssdriver(sch->dev.driver);
1195 /* Notify drivers that they may not register children. */
1196 return drv->prepare ? drv->prepare(sch) : 0;
1199 static void css_pm_complete(struct device *dev)
1201 struct subchannel *sch = to_subchannel(dev);
1202 struct css_driver *drv;
1204 if (!sch->dev.driver)
1206 drv = to_cssdriver(sch->dev.driver);
1211 static int css_pm_freeze(struct device *dev)
1213 struct subchannel *sch = to_subchannel(dev);
1214 struct css_driver *drv;
1216 if (!sch->dev.driver)
1218 drv = to_cssdriver(sch->dev.driver);
1219 return drv->freeze ? drv->freeze(sch) : 0;
1222 static int css_pm_thaw(struct device *dev)
1224 struct subchannel *sch = to_subchannel(dev);
1225 struct css_driver *drv;
1227 if (!sch->dev.driver)
1229 drv = to_cssdriver(sch->dev.driver);
1230 return drv->thaw ? drv->thaw(sch) : 0;
1233 static int css_pm_restore(struct device *dev)
1235 struct subchannel *sch = to_subchannel(dev);
1236 struct css_driver *drv;
1238 css_update_ssd_info(sch);
1239 if (!sch->dev.driver)
1241 drv = to_cssdriver(sch->dev.driver);
1242 return drv->restore ? drv->restore(sch) : 0;
1245 static const struct dev_pm_ops css_pm_ops = {
1246 .prepare = css_pm_prepare,
1247 .complete = css_pm_complete,
1248 .freeze = css_pm_freeze,
1249 .thaw = css_pm_thaw,
1250 .restore = css_pm_restore,
1253 static struct bus_type css_bus_type = {
1255 .match = css_bus_match,
1257 .remove = css_remove,
1258 .shutdown = css_shutdown,
1259 .uevent = css_uevent,
1264 * css_driver_register - register a css driver
1265 * @cdrv: css driver to register
1267 * This is mainly a wrapper around driver_register that sets name
1268 * and bus_type in the embedded struct device_driver correctly.
1270 int css_driver_register(struct css_driver *cdrv)
1272 cdrv->drv.bus = &css_bus_type;
1273 return driver_register(&cdrv->drv);
1275 EXPORT_SYMBOL_GPL(css_driver_register);
1278 * css_driver_unregister - unregister a css driver
1279 * @cdrv: css driver to unregister
1281 * This is a wrapper around driver_unregister.
1283 void css_driver_unregister(struct css_driver *cdrv)
1285 driver_unregister(&cdrv->drv);
1287 EXPORT_SYMBOL_GPL(css_driver_unregister);
1289 MODULE_LICENSE("GPL");