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)
12 #define KMSG_COMPONENT "cio"
13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15 #include <linux/export.h>
16 #include <linux/init.h>
17 #include <linux/device.h>
18 #include <linux/slab.h>
19 #include <linux/errno.h>
20 #include <linux/list.h>
21 #include <linux/reboot.h>
22 #include <linux/suspend.h>
23 #include <linux/proc_fs.h>
29 #include "cio_debug.h"
36 int css_init_done = 0;
40 struct channel_subsystem *channel_subsystems[MAX_CSS_IDX + 1];
41 static struct bus_type css_bus_type;
44 for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data)
46 struct subchannel_id schid;
49 init_subchannel_id(&schid);
52 ret = fn(schid, data);
55 } while (schid.sch_no++ < __MAX_SUBCHANNEL);
57 } while (schid.ssid++ < max_ssid);
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;
75 idset_sch_del(cb->set, sch->schid);
77 rc = cb->fn_known_sch(sch, cb->data);
81 static int call_fn_unknown_sch(struct subchannel_id schid, void *data)
83 struct cb_data *cb = data;
86 if (idset_sch_contains(cb->set, schid))
87 rc = cb->fn_unknown_sch(schid, cb->data);
91 static int call_fn_all_sch(struct subchannel_id schid, void *data)
93 struct cb_data *cb = data;
94 struct subchannel *sch;
97 sch = get_subchannel_by_schid(schid);
100 rc = cb->fn_known_sch(sch, cb->data);
101 put_device(&sch->dev);
103 if (cb->fn_unknown_sch)
104 rc = cb->fn_unknown_sch(schid, cb->data);
110 int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
111 int (*fn_unknown)(struct subchannel_id,
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. */
124 return bus_for_each_dev(&css_bus_type, NULL, &cb,
128 cb.set = idset_sch_new();
130 /* fall back to brute force scanning in case of oom */
131 return for_each_subchannel(call_fn_all_sch, &cb);
135 /* Process registered subchannels. */
136 rc = bus_for_each_dev(&css_bus_type, NULL, &cb, call_fn_known_sch);
139 /* Process unregistered subchannels. */
141 rc = for_each_subchannel(call_fn_unknown_sch, &cb);
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);
156 spin_lock_init(sch->lock);
157 mutex_init(&sch->reg_mutex);
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);
172 struct subchannel *css_alloc_subchannel(struct subchannel_id schid)
174 struct subchannel *sch;
177 sch = kzalloc(sizeof(*sch), GFP_KERNEL | GFP_DMA);
179 return ERR_PTR(-ENOMEM);
181 ret = cio_validate_subchannel(sch, schid);
185 ret = css_sch_create_locks(sch);
189 INIT_WORK(&sch->todo_work, css_sch_todo);
190 sch->dev.release = &css_subchannel_release;
191 device_initialize(&sch->dev);
199 static int css_sch_device_register(struct subchannel *sch)
203 mutex_lock(&sch->reg_mutex);
204 dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid,
206 ret = device_add(&sch->dev);
207 mutex_unlock(&sch->reg_mutex);
212 * css_sch_device_unregister - unregister a subchannel
213 * @sch: subchannel to be unregistered
215 void css_sch_device_unregister(struct subchannel *sch)
217 mutex_lock(&sch->reg_mutex);
218 if (device_is_registered(&sch->dev))
219 device_unregister(&sch->dev);
220 mutex_unlock(&sch->reg_mutex);
222 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
224 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
229 memset(ssd, 0, sizeof(struct chsc_ssd_info));
230 ssd->path_mask = pmcw->pim;
231 for (i = 0; i < 8; i++) {
233 if (pmcw->pim & mask) {
234 chp_id_init(&ssd->chpid[i]);
235 ssd->chpid[i].id = pmcw->chpid[i];
240 static void ssd_register_chpids(struct chsc_ssd_info *ssd)
245 for (i = 0; i < 8; i++) {
247 if (ssd->path_mask & mask)
248 if (!chp_is_registered(ssd->chpid[i]))
249 chp_new(ssd->chpid[i]);
253 void css_update_ssd_info(struct subchannel *sch)
257 ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
259 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
261 ssd_register_chpids(&sch->ssd_info);
264 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
267 struct subchannel *sch = to_subchannel(dev);
269 return sprintf(buf, "%01x\n", sch->st);
272 static DEVICE_ATTR(type, 0444, type_show, NULL);
274 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
277 struct subchannel *sch = to_subchannel(dev);
279 return sprintf(buf, "css:t%01X\n", sch->st);
282 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
284 static struct attribute *subch_attrs[] = {
286 &dev_attr_modalias.attr,
290 static struct attribute_group subch_attr_group = {
291 .attrs = subch_attrs,
294 static const struct attribute_group *default_subch_attr_groups[] = {
299 int css_register_subchannel(struct subchannel *sch)
303 /* Initialize the subchannel structure */
304 sch->dev.parent = &channel_subsystems[0]->device;
305 sch->dev.bus = &css_bus_type;
306 sch->dev.groups = default_subch_attr_groups;
308 * We don't want to generate uevents for I/O subchannels that don't
309 * have a working ccw device behind them since they will be
310 * unregistered before they can be used anyway, so we delay the add
311 * uevent until after device recognition was successful.
312 * Note that we suppress the uevent for all subchannel types;
313 * the subchannel driver can decide itself when it wants to inform
314 * userspace of its existence.
316 dev_set_uevent_suppress(&sch->dev, 1);
317 css_update_ssd_info(sch);
318 /* make it known to the system */
319 ret = css_sch_device_register(sch);
321 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
322 sch->schid.ssid, sch->schid.sch_no, ret);
327 * No driver matched. Generate the uevent now so that
328 * a fitting driver module may be loaded based on the
331 dev_set_uevent_suppress(&sch->dev, 0);
332 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
337 static int css_probe_device(struct subchannel_id schid)
339 struct subchannel *sch;
342 sch = css_alloc_subchannel(schid);
346 ret = css_register_subchannel(sch);
348 put_device(&sch->dev);
354 check_subchannel(struct device * dev, void * data)
356 struct subchannel *sch;
357 struct subchannel_id *schid = data;
359 sch = to_subchannel(dev);
360 return schid_equal(&sch->schid, schid);
364 get_subchannel_by_schid(struct subchannel_id schid)
368 dev = bus_find_device(&css_bus_type, NULL,
369 &schid, check_subchannel);
371 return dev ? to_subchannel(dev) : NULL;
375 * css_sch_is_valid() - check if a subchannel is valid
376 * @schib: subchannel information block for the subchannel
378 int css_sch_is_valid(struct schib *schib)
380 if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
382 if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w)
386 EXPORT_SYMBOL_GPL(css_sch_is_valid);
388 static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
393 /* Will be done on the slow path. */
396 if (stsch(schid, &schib)) {
397 /* Subchannel is not provided. */
400 if (!css_sch_is_valid(&schib)) {
401 /* Unusable - ignore. */
404 CIO_MSG_EVENT(4, "event: sch 0.%x.%04x, new\n", schid.ssid,
407 return css_probe_device(schid);
410 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
415 if (sch->driver->sch_event)
416 ret = sch->driver->sch_event(sch, slow);
419 "Got subchannel machine check but "
420 "no sch_event handler provided.\n");
422 if (ret != 0 && ret != -EAGAIN) {
423 CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
424 sch->schid.ssid, sch->schid.sch_no, ret);
429 static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
431 struct subchannel *sch;
434 sch = get_subchannel_by_schid(schid);
436 ret = css_evaluate_known_subchannel(sch, slow);
437 put_device(&sch->dev);
439 ret = css_evaluate_new_subchannel(schid, slow);
441 css_schedule_eval(schid);
445 * css_sched_sch_todo - schedule a subchannel operation
449 * Schedule the operation identified by @todo to be performed on the slow path
450 * workqueue. Do nothing if another operation with higher priority is already
451 * scheduled. Needs to be called with subchannel lock held.
453 void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
455 CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
456 sch->schid.ssid, sch->schid.sch_no, todo);
457 if (sch->todo >= todo)
459 /* Get workqueue ref. */
460 if (!get_device(&sch->dev))
463 if (!queue_work(cio_work_q, &sch->todo_work)) {
464 /* Already queued, release workqueue ref. */
465 put_device(&sch->dev);
468 EXPORT_SYMBOL_GPL(css_sched_sch_todo);
470 static void css_sch_todo(struct work_struct *work)
472 struct subchannel *sch;
476 sch = container_of(work, struct subchannel, todo_work);
478 spin_lock_irq(sch->lock);
480 CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
481 sch->schid.sch_no, todo);
482 sch->todo = SCH_TODO_NOTHING;
483 spin_unlock_irq(sch->lock);
486 case SCH_TODO_NOTHING:
489 ret = css_evaluate_known_subchannel(sch, 1);
490 if (ret == -EAGAIN) {
491 spin_lock_irq(sch->lock);
492 css_sched_sch_todo(sch, todo);
493 spin_unlock_irq(sch->lock);
497 css_sch_device_unregister(sch);
500 /* Release workqueue ref. */
501 put_device(&sch->dev);
504 static struct idset *slow_subchannel_set;
505 static spinlock_t slow_subchannel_lock;
506 static wait_queue_head_t css_eval_wq;
507 static atomic_t css_eval_scheduled;
509 static int __init slow_subchannel_init(void)
511 spin_lock_init(&slow_subchannel_lock);
512 atomic_set(&css_eval_scheduled, 0);
513 init_waitqueue_head(&css_eval_wq);
514 slow_subchannel_set = idset_sch_new();
515 if (!slow_subchannel_set) {
516 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
522 static int slow_eval_known_fn(struct subchannel *sch, void *data)
527 spin_lock_irq(&slow_subchannel_lock);
528 eval = idset_sch_contains(slow_subchannel_set, sch->schid);
529 idset_sch_del(slow_subchannel_set, sch->schid);
530 spin_unlock_irq(&slow_subchannel_lock);
532 rc = css_evaluate_known_subchannel(sch, 1);
534 css_schedule_eval(sch->schid);
539 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
544 spin_lock_irq(&slow_subchannel_lock);
545 eval = idset_sch_contains(slow_subchannel_set, schid);
546 idset_sch_del(slow_subchannel_set, schid);
547 spin_unlock_irq(&slow_subchannel_lock);
549 rc = css_evaluate_new_subchannel(schid, 1);
552 css_schedule_eval(schid);
558 /* These should abort looping */
559 spin_lock_irq(&slow_subchannel_lock);
560 idset_sch_del_subseq(slow_subchannel_set, schid);
561 spin_unlock_irq(&slow_subchannel_lock);
566 /* Allow scheduling here since the containing loop might
573 static void css_slow_path_func(struct work_struct *unused)
577 CIO_TRACE_EVENT(4, "slowpath");
578 for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
580 spin_lock_irqsave(&slow_subchannel_lock, flags);
581 if (idset_is_empty(slow_subchannel_set)) {
582 atomic_set(&css_eval_scheduled, 0);
583 wake_up(&css_eval_wq);
585 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
588 static DECLARE_DELAYED_WORK(slow_path_work, css_slow_path_func);
589 struct workqueue_struct *cio_work_q;
591 void css_schedule_eval(struct subchannel_id schid)
595 spin_lock_irqsave(&slow_subchannel_lock, flags);
596 idset_sch_add(slow_subchannel_set, schid);
597 atomic_set(&css_eval_scheduled, 1);
598 queue_delayed_work(cio_work_q, &slow_path_work, 0);
599 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
602 void css_schedule_eval_all(void)
606 spin_lock_irqsave(&slow_subchannel_lock, flags);
607 idset_fill(slow_subchannel_set);
608 atomic_set(&css_eval_scheduled, 1);
609 queue_delayed_work(cio_work_q, &slow_path_work, 0);
610 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
613 static int __unset_registered(struct device *dev, void *data)
615 struct idset *set = data;
616 struct subchannel *sch = to_subchannel(dev);
618 idset_sch_del(set, sch->schid);
622 void css_schedule_eval_all_unreg(unsigned long delay)
625 struct idset *unreg_set;
627 /* Find unregistered subchannels. */
628 unreg_set = idset_sch_new();
631 css_schedule_eval_all();
634 idset_fill(unreg_set);
635 bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered);
636 /* Apply to slow_subchannel_set. */
637 spin_lock_irqsave(&slow_subchannel_lock, flags);
638 idset_add_set(slow_subchannel_set, unreg_set);
639 atomic_set(&css_eval_scheduled, 1);
640 queue_delayed_work(cio_work_q, &slow_path_work, delay);
641 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
642 idset_free(unreg_set);
645 void css_wait_for_slow_path(void)
647 flush_workqueue(cio_work_q);
650 /* Schedule reprobing of all unregistered subchannels. */
651 void css_schedule_reprobe(void)
653 /* Schedule with a delay to allow merging of subsequent calls. */
654 css_schedule_eval_all_unreg(1 * HZ);
656 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
659 * Called from the machine check handler for subchannel report words.
661 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
663 struct subchannel_id mchk_schid;
664 struct subchannel *sch;
667 css_schedule_eval_all();
670 CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
671 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
672 crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
673 crw0->erc, crw0->rsid);
675 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
676 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
677 crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
678 crw1->anc, crw1->erc, crw1->rsid);
679 init_subchannel_id(&mchk_schid);
680 mchk_schid.sch_no = crw0->rsid;
682 mchk_schid.ssid = (crw1->rsid >> 4) & 3;
684 if (crw0->erc == CRW_ERC_PMOD) {
685 sch = get_subchannel_by_schid(mchk_schid);
687 css_update_ssd_info(sch);
688 put_device(&sch->dev);
692 * Since we are always presented with IPI in the CRW, we have to
693 * use stsch() to find out if the subchannel in question has come
696 css_evaluate_subchannel(mchk_schid, 0);
700 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
704 if (css_general_characteristics.mcss) {
705 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
706 css->global_pgid.pgid_high.ext_cssid.cssid =
707 (css->cssid < 0) ? 0 : css->cssid;
709 css->global_pgid.pgid_high.cpu_addr = stap();
712 css->global_pgid.cpu_id = cpu_id.ident;
713 css->global_pgid.cpu_model = cpu_id.machine;
714 css->global_pgid.tod_high = tod_high;
717 static void channel_subsystem_release(struct device *dev)
719 struct channel_subsystem *css = to_css(dev);
721 mutex_destroy(&css->mutex);
725 static ssize_t real_cssid_show(struct device *dev, struct device_attribute *a,
728 struct channel_subsystem *css = to_css(dev);
733 return sprintf(buf, "%x\n", css->cssid);
735 static DEVICE_ATTR_RO(real_cssid);
737 static ssize_t cm_enable_show(struct device *dev, struct device_attribute *a,
740 struct channel_subsystem *css = to_css(dev);
743 mutex_lock(&css->mutex);
744 ret = sprintf(buf, "%x\n", css->cm_enabled);
745 mutex_unlock(&css->mutex);
749 static ssize_t cm_enable_store(struct device *dev, struct device_attribute *a,
750 const char *buf, size_t count)
752 struct channel_subsystem *css = to_css(dev);
756 ret = kstrtoul(buf, 16, &val);
759 mutex_lock(&css->mutex);
762 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
765 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
770 mutex_unlock(&css->mutex);
771 return ret < 0 ? ret : count;
773 static DEVICE_ATTR_RW(cm_enable);
775 static umode_t cm_enable_mode(struct kobject *kobj, struct attribute *attr,
778 return css_chsc_characteristics.secm ? attr->mode : 0;
781 static struct attribute *cssdev_attrs[] = {
782 &dev_attr_real_cssid.attr,
786 static struct attribute_group cssdev_attr_group = {
787 .attrs = cssdev_attrs,
790 static struct attribute *cssdev_cm_attrs[] = {
791 &dev_attr_cm_enable.attr,
795 static struct attribute_group cssdev_cm_attr_group = {
796 .attrs = cssdev_cm_attrs,
797 .is_visible = cm_enable_mode,
800 static const struct attribute_group *cssdev_attr_groups[] = {
802 &cssdev_cm_attr_group,
806 static int __init setup_css(int nr)
808 struct channel_subsystem *css;
811 css = kzalloc(sizeof(*css), GFP_KERNEL);
815 channel_subsystems[nr] = css;
816 dev_set_name(&css->device, "css%x", nr);
817 css->device.groups = cssdev_attr_groups;
818 css->device.release = channel_subsystem_release;
820 mutex_init(&css->mutex);
821 css->cssid = chsc_get_cssid(nr);
822 css_generate_pgid(css, (u32) (get_tod_clock() >> 32));
824 ret = device_register(&css->device);
826 put_device(&css->device);
830 css->pseudo_subchannel = kzalloc(sizeof(*css->pseudo_subchannel),
832 if (!css->pseudo_subchannel) {
833 device_unregister(&css->device);
838 css->pseudo_subchannel->dev.parent = &css->device;
839 css->pseudo_subchannel->dev.release = css_subchannel_release;
840 mutex_init(&css->pseudo_subchannel->reg_mutex);
841 ret = css_sch_create_locks(css->pseudo_subchannel);
843 kfree(css->pseudo_subchannel);
844 device_unregister(&css->device);
848 dev_set_name(&css->pseudo_subchannel->dev, "defunct");
849 ret = device_register(&css->pseudo_subchannel->dev);
851 put_device(&css->pseudo_subchannel->dev);
852 device_unregister(&css->device);
858 channel_subsystems[nr] = NULL;
862 static int css_reboot_event(struct notifier_block *this,
866 struct channel_subsystem *css;
871 mutex_lock(&css->mutex);
873 if (chsc_secm(css, 0))
875 mutex_unlock(&css->mutex);
881 static struct notifier_block css_reboot_notifier = {
882 .notifier_call = css_reboot_event,
886 * Since the css devices are neither on a bus nor have a class
887 * nor have a special device type, we cannot stop/restart channel
888 * path measurements via the normal suspend/resume callbacks, but have
891 static int css_power_event(struct notifier_block *this, unsigned long event,
894 struct channel_subsystem *css;
898 case PM_HIBERNATION_PREPARE:
899 case PM_SUSPEND_PREPARE:
902 mutex_lock(&css->mutex);
903 if (!css->cm_enabled) {
904 mutex_unlock(&css->mutex);
907 ret = __chsc_do_secm(css, 0);
908 ret = notifier_from_errno(ret);
909 mutex_unlock(&css->mutex);
912 case PM_POST_HIBERNATION:
913 case PM_POST_SUSPEND:
916 mutex_lock(&css->mutex);
917 if (!css->cm_enabled) {
918 mutex_unlock(&css->mutex);
921 ret = __chsc_do_secm(css, 1);
922 ret = notifier_from_errno(ret);
923 mutex_unlock(&css->mutex);
925 /* search for subchannels, which appeared during hibernation */
926 css_schedule_reprobe();
934 static struct notifier_block css_power_notifier = {
935 .notifier_call = css_power_event,
939 * Now that the driver core is running, we can setup our channel subsystem.
940 * The struct subchannel's are created during probing.
942 static int __init css_bus_init(void)
950 chsc_determine_css_characteristics();
951 /* Try to enable MSS. */
952 ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
956 max_ssid = __MAX_SSID;
958 ret = slow_subchannel_init();
962 ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
966 if ((ret = bus_register(&css_bus_type)))
969 /* Setup css structure. */
970 for (i = 0; i <= MAX_CSS_IDX; i++) {
975 ret = register_reboot_notifier(&css_reboot_notifier);
978 ret = register_pm_notifier(&css_power_notifier);
980 unregister_reboot_notifier(&css_reboot_notifier);
985 /* Enable default isc for I/O subchannels. */
986 isc_register(IO_SCH_ISC);
991 struct channel_subsystem *css = channel_subsystems[i];
992 device_unregister(&css->pseudo_subchannel->dev);
993 device_unregister(&css->device);
995 bus_unregister(&css_bus_type);
997 crw_unregister_handler(CRW_RSC_SCH);
998 idset_free(slow_subchannel_set);
1000 pr_alert("The CSS device driver initialization failed with "
1005 static void __init css_bus_cleanup(void)
1007 struct channel_subsystem *css;
1010 device_unregister(&css->pseudo_subchannel->dev);
1011 device_unregister(&css->device);
1013 bus_unregister(&css_bus_type);
1014 crw_unregister_handler(CRW_RSC_SCH);
1015 idset_free(slow_subchannel_set);
1016 chsc_init_cleanup();
1017 isc_unregister(IO_SCH_ISC);
1020 static int __init channel_subsystem_init(void)
1024 ret = css_bus_init();
1027 cio_work_q = create_singlethread_workqueue("cio");
1032 ret = io_subchannel_init();
1038 destroy_workqueue(cio_work_q);
1043 subsys_initcall(channel_subsystem_init);
1045 static int css_settle(struct device_driver *drv, void *unused)
1047 struct css_driver *cssdrv = to_cssdriver(drv);
1050 return cssdrv->settle();
1054 int css_complete_work(void)
1058 /* Wait for the evaluation of subchannels to finish. */
1059 ret = wait_event_interruptible(css_eval_wq,
1060 atomic_read(&css_eval_scheduled) == 0);
1063 flush_workqueue(cio_work_q);
1064 /* Wait for the subchannel type specific initialization to finish */
1065 return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
1070 * Wait for the initialization of devices to finish, to make sure we are
1071 * done with our setup if the search for the root device starts.
1073 static int __init channel_subsystem_init_sync(void)
1075 /* Register subchannels which are already in use. */
1076 cio_register_early_subchannels();
1077 /* Start initial subchannel evaluation. */
1078 css_schedule_eval_all();
1079 css_complete_work();
1082 subsys_initcall_sync(channel_subsystem_init_sync);
1084 void channel_subsystem_reinit(void)
1086 struct channel_path *chp;
1087 struct chp_id chpid;
1089 chsc_enable_facility(CHSC_SDA_OC_MSS);
1090 chp_id_for_each(&chpid) {
1091 chp = chpid_to_chp(chpid);
1093 chp_update_desc(chp);
1098 #ifdef CONFIG_PROC_FS
1099 static ssize_t cio_settle_write(struct file *file, const char __user *buf,
1100 size_t count, loff_t *ppos)
1104 /* Handle pending CRW's. */
1105 crw_wait_for_channel_report();
1106 ret = css_complete_work();
1108 return ret ? ret : count;
1111 static const struct file_operations cio_settle_proc_fops = {
1112 .open = nonseekable_open,
1113 .write = cio_settle_write,
1114 .llseek = no_llseek,
1117 static int __init cio_settle_init(void)
1119 struct proc_dir_entry *entry;
1121 entry = proc_create("cio_settle", S_IWUSR, NULL,
1122 &cio_settle_proc_fops);
1127 device_initcall(cio_settle_init);
1128 #endif /*CONFIG_PROC_FS*/
1130 int sch_is_pseudo_sch(struct subchannel *sch)
1132 return sch == to_css(sch->dev.parent)->pseudo_subchannel;
1135 static int css_bus_match(struct device *dev, struct device_driver *drv)
1137 struct subchannel *sch = to_subchannel(dev);
1138 struct css_driver *driver = to_cssdriver(drv);
1139 struct css_device_id *id;
1141 for (id = driver->subchannel_type; id->match_flags; id++) {
1142 if (sch->st == id->type)
1149 static int css_probe(struct device *dev)
1151 struct subchannel *sch;
1154 sch = to_subchannel(dev);
1155 sch->driver = to_cssdriver(dev->driver);
1156 ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
1162 static int css_remove(struct device *dev)
1164 struct subchannel *sch;
1167 sch = to_subchannel(dev);
1168 ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
1173 static void css_shutdown(struct device *dev)
1175 struct subchannel *sch;
1177 sch = to_subchannel(dev);
1178 if (sch->driver && sch->driver->shutdown)
1179 sch->driver->shutdown(sch);
1182 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
1184 struct subchannel *sch = to_subchannel(dev);
1187 ret = add_uevent_var(env, "ST=%01X", sch->st);
1190 ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
1194 static int css_pm_prepare(struct device *dev)
1196 struct subchannel *sch = to_subchannel(dev);
1197 struct css_driver *drv;
1199 if (mutex_is_locked(&sch->reg_mutex))
1201 if (!sch->dev.driver)
1203 drv = to_cssdriver(sch->dev.driver);
1204 /* Notify drivers that they may not register children. */
1205 return drv->prepare ? drv->prepare(sch) : 0;
1208 static void css_pm_complete(struct device *dev)
1210 struct subchannel *sch = to_subchannel(dev);
1211 struct css_driver *drv;
1213 if (!sch->dev.driver)
1215 drv = to_cssdriver(sch->dev.driver);
1220 static int css_pm_freeze(struct device *dev)
1222 struct subchannel *sch = to_subchannel(dev);
1223 struct css_driver *drv;
1225 if (!sch->dev.driver)
1227 drv = to_cssdriver(sch->dev.driver);
1228 return drv->freeze ? drv->freeze(sch) : 0;
1231 static int css_pm_thaw(struct device *dev)
1233 struct subchannel *sch = to_subchannel(dev);
1234 struct css_driver *drv;
1236 if (!sch->dev.driver)
1238 drv = to_cssdriver(sch->dev.driver);
1239 return drv->thaw ? drv->thaw(sch) : 0;
1242 static int css_pm_restore(struct device *dev)
1244 struct subchannel *sch = to_subchannel(dev);
1245 struct css_driver *drv;
1247 css_update_ssd_info(sch);
1248 if (!sch->dev.driver)
1250 drv = to_cssdriver(sch->dev.driver);
1251 return drv->restore ? drv->restore(sch) : 0;
1254 static const struct dev_pm_ops css_pm_ops = {
1255 .prepare = css_pm_prepare,
1256 .complete = css_pm_complete,
1257 .freeze = css_pm_freeze,
1258 .thaw = css_pm_thaw,
1259 .restore = css_pm_restore,
1262 static struct bus_type css_bus_type = {
1264 .match = css_bus_match,
1266 .remove = css_remove,
1267 .shutdown = css_shutdown,
1268 .uevent = css_uevent,
1273 * css_driver_register - register a css driver
1274 * @cdrv: css driver to register
1276 * This is mainly a wrapper around driver_register that sets name
1277 * and bus_type in the embedded struct device_driver correctly.
1279 int css_driver_register(struct css_driver *cdrv)
1281 cdrv->drv.bus = &css_bus_type;
1282 return driver_register(&cdrv->drv);
1284 EXPORT_SYMBOL_GPL(css_driver_register);
1287 * css_driver_unregister - unregister a css driver
1288 * @cdrv: css driver to unregister
1290 * This is a wrapper around driver_unregister.
1292 void css_driver_unregister(struct css_driver *cdrv)
1294 driver_unregister(&cdrv->drv);
1296 EXPORT_SYMBOL_GPL(css_driver_unregister);