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);
50 ret = fn(schid, data);
53 } while (schid.sch_no++ < __MAX_SUBCHANNEL);
55 } while (schid.ssid++ < max_ssid);
62 int (*fn_known_sch)(struct subchannel *, void *);
63 int (*fn_unknown_sch)(struct subchannel_id, void *);
66 static int call_fn_known_sch(struct device *dev, void *data)
68 struct subchannel *sch = to_subchannel(dev);
69 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 cb.set = idset_sch_new();
120 /* fall back to brute force scanning in case of oom */
121 return for_each_subchannel(call_fn_all_sch, &cb);
125 /* Process registered subchannels. */
126 rc = bus_for_each_dev(&css_bus_type, NULL, &cb, call_fn_known_sch);
129 /* Process unregistered subchannels. */
131 rc = for_each_subchannel(call_fn_unknown_sch, &cb);
138 static void css_sch_todo(struct work_struct *work);
140 static int css_sch_create_locks(struct subchannel *sch)
142 sch->lock = kmalloc(sizeof(*sch->lock), GFP_KERNEL);
146 spin_lock_init(sch->lock);
147 mutex_init(&sch->reg_mutex);
152 static void css_subchannel_release(struct device *dev)
154 struct subchannel *sch = to_subchannel(dev);
156 sch->config.intparm = 0;
157 cio_commit_config(sch);
162 struct subchannel *css_alloc_subchannel(struct subchannel_id schid)
164 struct subchannel *sch;
167 sch = kzalloc(sizeof(*sch), GFP_KERNEL | GFP_DMA);
169 return ERR_PTR(-ENOMEM);
171 ret = cio_validate_subchannel(sch, schid);
175 ret = css_sch_create_locks(sch);
179 INIT_WORK(&sch->todo_work, css_sch_todo);
180 sch->dev.release = &css_subchannel_release;
181 device_initialize(&sch->dev);
189 static int css_sch_device_register(struct subchannel *sch)
193 mutex_lock(&sch->reg_mutex);
194 dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid,
196 ret = device_add(&sch->dev);
197 mutex_unlock(&sch->reg_mutex);
202 * css_sch_device_unregister - unregister a subchannel
203 * @sch: subchannel to be unregistered
205 void css_sch_device_unregister(struct subchannel *sch)
207 mutex_lock(&sch->reg_mutex);
208 if (device_is_registered(&sch->dev))
209 device_unregister(&sch->dev);
210 mutex_unlock(&sch->reg_mutex);
212 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
214 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
219 memset(ssd, 0, sizeof(struct chsc_ssd_info));
220 ssd->path_mask = pmcw->pim;
221 for (i = 0; i < 8; i++) {
223 if (pmcw->pim & mask) {
224 chp_id_init(&ssd->chpid[i]);
225 ssd->chpid[i].id = pmcw->chpid[i];
230 static void ssd_register_chpids(struct chsc_ssd_info *ssd)
235 for (i = 0; i < 8; i++) {
237 if (ssd->path_mask & mask)
238 if (!chp_is_registered(ssd->chpid[i]))
239 chp_new(ssd->chpid[i]);
243 void css_update_ssd_info(struct subchannel *sch)
247 ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
249 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
251 ssd_register_chpids(&sch->ssd_info);
254 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
257 struct subchannel *sch = to_subchannel(dev);
259 return sprintf(buf, "%01x\n", sch->st);
262 static DEVICE_ATTR(type, 0444, type_show, NULL);
264 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
267 struct subchannel *sch = to_subchannel(dev);
269 return sprintf(buf, "css:t%01X\n", sch->st);
272 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
274 static struct attribute *subch_attrs[] = {
276 &dev_attr_modalias.attr,
280 static struct attribute_group subch_attr_group = {
281 .attrs = subch_attrs,
284 static const struct attribute_group *default_subch_attr_groups[] = {
289 int css_register_subchannel(struct subchannel *sch)
293 /* Initialize the subchannel structure */
294 sch->dev.parent = &channel_subsystems[0]->device;
295 sch->dev.bus = &css_bus_type;
296 sch->dev.groups = default_subch_attr_groups;
298 * We don't want to generate uevents for I/O subchannels that don't
299 * have a working ccw device behind them since they will be
300 * unregistered before they can be used anyway, so we delay the add
301 * uevent until after device recognition was successful.
302 * Note that we suppress the uevent for all subchannel types;
303 * the subchannel driver can decide itself when it wants to inform
304 * userspace of its existence.
306 dev_set_uevent_suppress(&sch->dev, 1);
307 css_update_ssd_info(sch);
308 /* make it known to the system */
309 ret = css_sch_device_register(sch);
311 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
312 sch->schid.ssid, sch->schid.sch_no, ret);
317 * No driver matched. Generate the uevent now so that
318 * a fitting driver module may be loaded based on the
321 dev_set_uevent_suppress(&sch->dev, 0);
322 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
327 static int css_probe_device(struct subchannel_id schid)
329 struct subchannel *sch;
332 sch = css_alloc_subchannel(schid);
336 ret = css_register_subchannel(sch);
338 put_device(&sch->dev);
344 check_subchannel(struct device * dev, void * data)
346 struct subchannel *sch;
347 struct subchannel_id *schid = data;
349 sch = to_subchannel(dev);
350 return schid_equal(&sch->schid, schid);
354 get_subchannel_by_schid(struct subchannel_id schid)
358 dev = bus_find_device(&css_bus_type, NULL,
359 &schid, check_subchannel);
361 return dev ? to_subchannel(dev) : NULL;
365 * css_sch_is_valid() - check if a subchannel is valid
366 * @schib: subchannel information block for the subchannel
368 int css_sch_is_valid(struct schib *schib)
370 if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
372 if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w)
376 EXPORT_SYMBOL_GPL(css_sch_is_valid);
378 static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
383 /* Will be done on the slow path. */
386 if (stsch_err(schid, &schib)) {
387 /* Subchannel is not provided. */
390 if (!css_sch_is_valid(&schib)) {
391 /* Unusable - ignore. */
394 CIO_MSG_EVENT(4, "event: sch 0.%x.%04x, new\n", schid.ssid,
397 return css_probe_device(schid);
400 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
405 if (sch->driver->sch_event)
406 ret = sch->driver->sch_event(sch, slow);
409 "Got subchannel machine check but "
410 "no sch_event handler provided.\n");
412 if (ret != 0 && ret != -EAGAIN) {
413 CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
414 sch->schid.ssid, sch->schid.sch_no, ret);
419 static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
421 struct subchannel *sch;
424 sch = get_subchannel_by_schid(schid);
426 ret = css_evaluate_known_subchannel(sch, slow);
427 put_device(&sch->dev);
429 ret = css_evaluate_new_subchannel(schid, slow);
431 css_schedule_eval(schid);
435 * css_sched_sch_todo - schedule a subchannel operation
439 * Schedule the operation identified by @todo to be performed on the slow path
440 * workqueue. Do nothing if another operation with higher priority is already
441 * scheduled. Needs to be called with subchannel lock held.
443 void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
445 CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
446 sch->schid.ssid, sch->schid.sch_no, todo);
447 if (sch->todo >= todo)
449 /* Get workqueue ref. */
450 if (!get_device(&sch->dev))
453 if (!queue_work(cio_work_q, &sch->todo_work)) {
454 /* Already queued, release workqueue ref. */
455 put_device(&sch->dev);
458 EXPORT_SYMBOL_GPL(css_sched_sch_todo);
460 static void css_sch_todo(struct work_struct *work)
462 struct subchannel *sch;
466 sch = container_of(work, struct subchannel, todo_work);
468 spin_lock_irq(sch->lock);
470 CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
471 sch->schid.sch_no, todo);
472 sch->todo = SCH_TODO_NOTHING;
473 spin_unlock_irq(sch->lock);
476 case SCH_TODO_NOTHING:
479 ret = css_evaluate_known_subchannel(sch, 1);
480 if (ret == -EAGAIN) {
481 spin_lock_irq(sch->lock);
482 css_sched_sch_todo(sch, todo);
483 spin_unlock_irq(sch->lock);
487 css_sch_device_unregister(sch);
490 /* Release workqueue ref. */
491 put_device(&sch->dev);
494 static struct idset *slow_subchannel_set;
495 static spinlock_t slow_subchannel_lock;
496 static wait_queue_head_t css_eval_wq;
497 static atomic_t css_eval_scheduled;
499 static int __init slow_subchannel_init(void)
501 spin_lock_init(&slow_subchannel_lock);
502 atomic_set(&css_eval_scheduled, 0);
503 init_waitqueue_head(&css_eval_wq);
504 slow_subchannel_set = idset_sch_new();
505 if (!slow_subchannel_set) {
506 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
512 static int slow_eval_known_fn(struct subchannel *sch, void *data)
517 spin_lock_irq(&slow_subchannel_lock);
518 eval = idset_sch_contains(slow_subchannel_set, sch->schid);
519 idset_sch_del(slow_subchannel_set, sch->schid);
520 spin_unlock_irq(&slow_subchannel_lock);
522 rc = css_evaluate_known_subchannel(sch, 1);
524 css_schedule_eval(sch->schid);
529 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
534 spin_lock_irq(&slow_subchannel_lock);
535 eval = idset_sch_contains(slow_subchannel_set, schid);
536 idset_sch_del(slow_subchannel_set, schid);
537 spin_unlock_irq(&slow_subchannel_lock);
539 rc = css_evaluate_new_subchannel(schid, 1);
542 css_schedule_eval(schid);
548 /* These should abort looping */
549 idset_sch_del_subseq(slow_subchannel_set, schid);
558 static void css_slow_path_func(struct work_struct *unused)
562 CIO_TRACE_EVENT(4, "slowpath");
563 for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
565 spin_lock_irqsave(&slow_subchannel_lock, flags);
566 if (idset_is_empty(slow_subchannel_set)) {
567 atomic_set(&css_eval_scheduled, 0);
568 wake_up(&css_eval_wq);
570 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
573 static DECLARE_WORK(slow_path_work, css_slow_path_func);
574 struct workqueue_struct *cio_work_q;
576 void css_schedule_eval(struct subchannel_id schid)
580 spin_lock_irqsave(&slow_subchannel_lock, flags);
581 idset_sch_add(slow_subchannel_set, schid);
582 atomic_set(&css_eval_scheduled, 1);
583 queue_work(cio_work_q, &slow_path_work);
584 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
587 void css_schedule_eval_all(void)
591 spin_lock_irqsave(&slow_subchannel_lock, flags);
592 idset_fill(slow_subchannel_set);
593 atomic_set(&css_eval_scheduled, 1);
594 queue_work(cio_work_q, &slow_path_work);
595 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
598 static int __unset_registered(struct device *dev, void *data)
600 struct idset *set = data;
601 struct subchannel *sch = to_subchannel(dev);
603 idset_sch_del(set, sch->schid);
607 static void css_schedule_eval_all_unreg(void)
610 struct idset *unreg_set;
612 /* Find unregistered subchannels. */
613 unreg_set = idset_sch_new();
616 css_schedule_eval_all();
619 idset_fill(unreg_set);
620 bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered);
621 /* Apply to slow_subchannel_set. */
622 spin_lock_irqsave(&slow_subchannel_lock, flags);
623 idset_add_set(slow_subchannel_set, unreg_set);
624 atomic_set(&css_eval_scheduled, 1);
625 queue_work(cio_work_q, &slow_path_work);
626 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
627 idset_free(unreg_set);
630 void css_wait_for_slow_path(void)
632 flush_workqueue(cio_work_q);
635 /* Schedule reprobing of all unregistered subchannels. */
636 void css_schedule_reprobe(void)
638 css_schedule_eval_all_unreg();
640 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
643 * Called from the machine check handler for subchannel report words.
645 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
647 struct subchannel_id mchk_schid;
648 struct subchannel *sch;
651 css_schedule_eval_all();
654 CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
655 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
656 crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
657 crw0->erc, crw0->rsid);
659 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
660 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
661 crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
662 crw1->anc, crw1->erc, crw1->rsid);
663 init_subchannel_id(&mchk_schid);
664 mchk_schid.sch_no = crw0->rsid;
666 mchk_schid.ssid = (crw1->rsid >> 4) & 3;
668 if (crw0->erc == CRW_ERC_PMOD) {
669 sch = get_subchannel_by_schid(mchk_schid);
671 css_update_ssd_info(sch);
672 put_device(&sch->dev);
676 * Since we are always presented with IPI in the CRW, we have to
677 * use stsch() to find out if the subchannel in question has come
680 css_evaluate_subchannel(mchk_schid, 0);
684 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
688 if (css_general_characteristics.mcss) {
689 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
690 css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
693 css->global_pgid.pgid_high.cpu_addr = stap();
695 css->global_pgid.pgid_high.cpu_addr = 0;
699 css->global_pgid.cpu_id = cpu_id.ident;
700 css->global_pgid.cpu_model = cpu_id.machine;
701 css->global_pgid.tod_high = tod_high;
706 channel_subsystem_release(struct device *dev)
708 struct channel_subsystem *css;
711 mutex_destroy(&css->mutex);
712 if (css->pseudo_subchannel) {
713 /* Implies that it has been generated but never registered. */
714 css_subchannel_release(&css->pseudo_subchannel->dev);
715 css->pseudo_subchannel = NULL;
721 css_cm_enable_show(struct device *dev, struct device_attribute *attr,
724 struct channel_subsystem *css = to_css(dev);
729 mutex_lock(&css->mutex);
730 ret = sprintf(buf, "%x\n", css->cm_enabled);
731 mutex_unlock(&css->mutex);
736 css_cm_enable_store(struct device *dev, struct device_attribute *attr,
737 const char *buf, size_t count)
739 struct channel_subsystem *css = to_css(dev);
743 ret = strict_strtoul(buf, 16, &val);
746 mutex_lock(&css->mutex);
749 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
752 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
757 mutex_unlock(&css->mutex);
758 return ret < 0 ? ret : count;
761 static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
763 static int __init setup_css(int nr)
767 struct channel_subsystem *css;
769 css = channel_subsystems[nr];
770 memset(css, 0, sizeof(struct channel_subsystem));
771 css->pseudo_subchannel =
772 kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
773 if (!css->pseudo_subchannel)
775 css->pseudo_subchannel->dev.parent = &css->device;
776 css->pseudo_subchannel->dev.release = css_subchannel_release;
777 dev_set_name(&css->pseudo_subchannel->dev, "defunct");
778 mutex_init(&css->pseudo_subchannel->reg_mutex);
779 ret = css_sch_create_locks(css->pseudo_subchannel);
781 kfree(css->pseudo_subchannel);
784 mutex_init(&css->mutex);
787 dev_set_name(&css->device, "css%x", nr);
788 css->device.release = channel_subsystem_release;
789 tod_high = (u32) (get_tod_clock() >> 32);
790 css_generate_pgid(css, tod_high);
794 static int css_reboot_event(struct notifier_block *this,
801 for (i = 0; i <= __MAX_CSSID; i++) {
802 struct channel_subsystem *css;
804 css = channel_subsystems[i];
805 mutex_lock(&css->mutex);
807 if (chsc_secm(css, 0))
809 mutex_unlock(&css->mutex);
815 static struct notifier_block css_reboot_notifier = {
816 .notifier_call = css_reboot_event,
820 * Since the css devices are neither on a bus nor have a class
821 * nor have a special device type, we cannot stop/restart channel
822 * path measurements via the normal suspend/resume callbacks, but have
825 static int css_power_event(struct notifier_block *this, unsigned long event,
831 case PM_HIBERNATION_PREPARE:
832 case PM_SUSPEND_PREPARE:
834 for (i = 0; i <= __MAX_CSSID; i++) {
835 struct channel_subsystem *css;
837 css = channel_subsystems[i];
838 mutex_lock(&css->mutex);
839 if (!css->cm_enabled) {
840 mutex_unlock(&css->mutex);
843 ret = __chsc_do_secm(css, 0);
844 ret = notifier_from_errno(ret);
845 mutex_unlock(&css->mutex);
848 case PM_POST_HIBERNATION:
849 case PM_POST_SUSPEND:
851 for (i = 0; i <= __MAX_CSSID; i++) {
852 struct channel_subsystem *css;
854 css = channel_subsystems[i];
855 mutex_lock(&css->mutex);
856 if (!css->cm_enabled) {
857 mutex_unlock(&css->mutex);
860 ret = __chsc_do_secm(css, 1);
861 ret = notifier_from_errno(ret);
862 mutex_unlock(&css->mutex);
864 /* search for subchannels, which appeared during hibernation */
865 css_schedule_reprobe();
873 static struct notifier_block css_power_notifier = {
874 .notifier_call = css_power_event,
878 * Now that the driver core is running, we can setup our channel subsystem.
879 * The struct subchannel's are created during probing.
881 static int __init css_bus_init(void)
889 chsc_determine_css_characteristics();
890 /* Try to enable MSS. */
891 ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
895 max_ssid = __MAX_SSID;
897 ret = slow_subchannel_init();
901 ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
905 if ((ret = bus_register(&css_bus_type)))
908 /* Setup css structure. */
909 for (i = 0; i <= __MAX_CSSID; i++) {
910 struct channel_subsystem *css;
912 css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
917 channel_subsystems[i] = css;
920 kfree(channel_subsystems[i]);
923 ret = device_register(&css->device);
925 put_device(&css->device);
928 if (css_chsc_characteristics.secm) {
929 ret = device_create_file(&css->device,
930 &dev_attr_cm_enable);
934 ret = device_register(&css->pseudo_subchannel->dev);
936 put_device(&css->pseudo_subchannel->dev);
940 ret = register_reboot_notifier(&css_reboot_notifier);
943 ret = register_pm_notifier(&css_power_notifier);
945 unregister_reboot_notifier(&css_reboot_notifier);
950 /* Enable default isc for I/O subchannels. */
951 isc_register(IO_SCH_ISC);
955 if (css_chsc_characteristics.secm)
956 device_remove_file(&channel_subsystems[i]->device,
957 &dev_attr_cm_enable);
959 device_unregister(&channel_subsystems[i]->device);
962 struct channel_subsystem *css;
965 css = channel_subsystems[i];
966 device_unregister(&css->pseudo_subchannel->dev);
967 css->pseudo_subchannel = NULL;
968 if (css_chsc_characteristics.secm)
969 device_remove_file(&css->device,
970 &dev_attr_cm_enable);
971 device_unregister(&css->device);
973 bus_unregister(&css_bus_type);
975 crw_unregister_handler(CRW_RSC_SCH);
976 idset_free(slow_subchannel_set);
978 pr_alert("The CSS device driver initialization failed with "
983 static void __init css_bus_cleanup(void)
985 struct channel_subsystem *css;
988 for (i = 0; i <= __MAX_CSSID; i++) {
989 css = channel_subsystems[i];
990 device_unregister(&css->pseudo_subchannel->dev);
991 css->pseudo_subchannel = NULL;
992 if (css_chsc_characteristics.secm)
993 device_remove_file(&css->device, &dev_attr_cm_enable);
994 device_unregister(&css->device);
996 bus_unregister(&css_bus_type);
997 crw_unregister_handler(CRW_RSC_SCH);
998 idset_free(slow_subchannel_set);
1000 isc_unregister(IO_SCH_ISC);
1003 static int __init channel_subsystem_init(void)
1007 ret = css_bus_init();
1010 cio_work_q = create_singlethread_workqueue("cio");
1015 ret = io_subchannel_init();
1021 destroy_workqueue(cio_work_q);
1026 subsys_initcall(channel_subsystem_init);
1028 static int css_settle(struct device_driver *drv, void *unused)
1030 struct css_driver *cssdrv = to_cssdriver(drv);
1033 return cssdrv->settle();
1037 int css_complete_work(void)
1041 /* Wait for the evaluation of subchannels to finish. */
1042 ret = wait_event_interruptible(css_eval_wq,
1043 atomic_read(&css_eval_scheduled) == 0);
1046 flush_workqueue(cio_work_q);
1047 /* Wait for the subchannel type specific initialization to finish */
1048 return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
1053 * Wait for the initialization of devices to finish, to make sure we are
1054 * done with our setup if the search for the root device starts.
1056 static int __init channel_subsystem_init_sync(void)
1058 /* Register subchannels which are already in use. */
1059 cio_register_early_subchannels();
1060 /* Start initial subchannel evaluation. */
1061 css_schedule_eval_all();
1062 css_complete_work();
1065 subsys_initcall_sync(channel_subsystem_init_sync);
1067 void channel_subsystem_reinit(void)
1069 struct channel_path *chp;
1070 struct chp_id chpid;
1072 chsc_enable_facility(CHSC_SDA_OC_MSS);
1073 chp_id_for_each(&chpid) {
1074 chp = chpid_to_chp(chpid);
1076 chp_update_desc(chp);
1080 #ifdef CONFIG_PROC_FS
1081 static ssize_t cio_settle_write(struct file *file, const char __user *buf,
1082 size_t count, loff_t *ppos)
1086 /* Handle pending CRW's. */
1087 crw_wait_for_channel_report();
1088 ret = css_complete_work();
1090 return ret ? ret : count;
1093 static const struct file_operations cio_settle_proc_fops = {
1094 .open = nonseekable_open,
1095 .write = cio_settle_write,
1096 .llseek = no_llseek,
1099 static int __init cio_settle_init(void)
1101 struct proc_dir_entry *entry;
1103 entry = proc_create("cio_settle", S_IWUSR, NULL,
1104 &cio_settle_proc_fops);
1109 device_initcall(cio_settle_init);
1110 #endif /*CONFIG_PROC_FS*/
1112 int sch_is_pseudo_sch(struct subchannel *sch)
1114 return sch == to_css(sch->dev.parent)->pseudo_subchannel;
1117 static int css_bus_match(struct device *dev, struct device_driver *drv)
1119 struct subchannel *sch = to_subchannel(dev);
1120 struct css_driver *driver = to_cssdriver(drv);
1121 struct css_device_id *id;
1123 for (id = driver->subchannel_type; id->match_flags; id++) {
1124 if (sch->st == id->type)
1131 static int css_probe(struct device *dev)
1133 struct subchannel *sch;
1136 sch = to_subchannel(dev);
1137 sch->driver = to_cssdriver(dev->driver);
1138 ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
1144 static int css_remove(struct device *dev)
1146 struct subchannel *sch;
1149 sch = to_subchannel(dev);
1150 ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
1155 static void css_shutdown(struct device *dev)
1157 struct subchannel *sch;
1159 sch = to_subchannel(dev);
1160 if (sch->driver && sch->driver->shutdown)
1161 sch->driver->shutdown(sch);
1164 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
1166 struct subchannel *sch = to_subchannel(dev);
1169 ret = add_uevent_var(env, "ST=%01X", sch->st);
1172 ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
1176 static int css_pm_prepare(struct device *dev)
1178 struct subchannel *sch = to_subchannel(dev);
1179 struct css_driver *drv;
1181 if (mutex_is_locked(&sch->reg_mutex))
1183 if (!sch->dev.driver)
1185 drv = to_cssdriver(sch->dev.driver);
1186 /* Notify drivers that they may not register children. */
1187 return drv->prepare ? drv->prepare(sch) : 0;
1190 static void css_pm_complete(struct device *dev)
1192 struct subchannel *sch = to_subchannel(dev);
1193 struct css_driver *drv;
1195 if (!sch->dev.driver)
1197 drv = to_cssdriver(sch->dev.driver);
1202 static int css_pm_freeze(struct device *dev)
1204 struct subchannel *sch = to_subchannel(dev);
1205 struct css_driver *drv;
1207 if (!sch->dev.driver)
1209 drv = to_cssdriver(sch->dev.driver);
1210 return drv->freeze ? drv->freeze(sch) : 0;
1213 static int css_pm_thaw(struct device *dev)
1215 struct subchannel *sch = to_subchannel(dev);
1216 struct css_driver *drv;
1218 if (!sch->dev.driver)
1220 drv = to_cssdriver(sch->dev.driver);
1221 return drv->thaw ? drv->thaw(sch) : 0;
1224 static int css_pm_restore(struct device *dev)
1226 struct subchannel *sch = to_subchannel(dev);
1227 struct css_driver *drv;
1229 css_update_ssd_info(sch);
1230 if (!sch->dev.driver)
1232 drv = to_cssdriver(sch->dev.driver);
1233 return drv->restore ? drv->restore(sch) : 0;
1236 static const struct dev_pm_ops css_pm_ops = {
1237 .prepare = css_pm_prepare,
1238 .complete = css_pm_complete,
1239 .freeze = css_pm_freeze,
1240 .thaw = css_pm_thaw,
1241 .restore = css_pm_restore,
1244 static struct bus_type css_bus_type = {
1246 .match = css_bus_match,
1248 .remove = css_remove,
1249 .shutdown = css_shutdown,
1250 .uevent = css_uevent,
1255 * css_driver_register - register a css driver
1256 * @cdrv: css driver to register
1258 * This is mainly a wrapper around driver_register that sets name
1259 * and bus_type in the embedded struct device_driver correctly.
1261 int css_driver_register(struct css_driver *cdrv)
1263 cdrv->drv.bus = &css_bus_type;
1264 return driver_register(&cdrv->drv);
1266 EXPORT_SYMBOL_GPL(css_driver_register);
1269 * css_driver_unregister - unregister a css driver
1270 * @cdrv: css driver to unregister
1272 * This is a wrapper around driver_unregister.
1274 void css_driver_unregister(struct css_driver *cdrv)
1276 driver_unregister(&cdrv->drv);
1278 EXPORT_SYMBOL_GPL(css_driver_unregister);
1280 MODULE_LICENSE("GPL");