2 * drivers/s390/cio/css.c
3 * driver for channel subsystem
5 * Copyright IBM Corp. 2002,2008
6 * Author(s): Arnd Bergmann (arndb@de.ibm.com)
7 * Cornelia Huck (cornelia.huck@de.ibm.com)
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/device.h>
12 #include <linux/slab.h>
13 #include <linux/errno.h>
14 #include <linux/list.h>
15 #include <linux/reboot.h>
17 #include "../s390mach.h"
20 #include "cio_debug.h"
27 int css_init_done = 0;
28 static int need_reprobe = 0;
29 static int max_ssid = 0;
31 struct channel_subsystem *channel_subsystems[__MAX_CSSID + 1];
33 int css_characteristics_avail = 0;
36 for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data)
38 struct subchannel_id schid;
41 init_subchannel_id(&schid);
45 ret = fn(schid, data);
48 } while (schid.sch_no++ < __MAX_SUBCHANNEL);
50 } while (schid.ssid++ < max_ssid);
57 int (*fn_known_sch)(struct subchannel *, void *);
58 int (*fn_unknown_sch)(struct subchannel_id, void *);
61 static int call_fn_known_sch(struct device *dev, void *data)
63 struct subchannel *sch = to_subchannel(dev);
64 struct cb_data *cb = data;
67 idset_sch_del(cb->set, sch->schid);
69 rc = cb->fn_known_sch(sch, cb->data);
73 static int call_fn_unknown_sch(struct subchannel_id schid, void *data)
75 struct cb_data *cb = data;
78 if (idset_sch_contains(cb->set, schid))
79 rc = cb->fn_unknown_sch(schid, cb->data);
83 int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
84 int (*fn_unknown)(struct subchannel_id,
90 cb.set = idset_sch_new();
95 cb.fn_known_sch = fn_known;
96 cb.fn_unknown_sch = fn_unknown;
97 /* Process registered subchannels. */
98 rc = bus_for_each_dev(&css_bus_type, NULL, &cb, call_fn_known_sch);
101 /* Process unregistered subchannels. */
103 rc = for_each_subchannel(call_fn_unknown_sch, &cb);
110 static struct subchannel *
111 css_alloc_subchannel(struct subchannel_id schid)
113 struct subchannel *sch;
116 sch = kmalloc (sizeof (*sch), GFP_KERNEL | GFP_DMA);
118 return ERR_PTR(-ENOMEM);
119 ret = cio_validate_subchannel (sch, schid);
128 css_free_subchannel(struct subchannel *sch)
131 /* Reset intparm to zeroes. */
132 sch->schib.pmcw.intparm = 0;
140 css_subchannel_release(struct device *dev)
142 struct subchannel *sch;
144 sch = to_subchannel(dev);
145 if (!cio_is_console(sch->schid)) {
151 static int css_sch_device_register(struct subchannel *sch)
155 mutex_lock(&sch->reg_mutex);
156 ret = device_register(&sch->dev);
157 mutex_unlock(&sch->reg_mutex);
162 * css_sch_device_unregister - unregister a subchannel
163 * @sch: subchannel to be unregistered
165 void css_sch_device_unregister(struct subchannel *sch)
167 mutex_lock(&sch->reg_mutex);
168 device_unregister(&sch->dev);
169 mutex_unlock(&sch->reg_mutex);
171 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
173 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
178 memset(ssd, 0, sizeof(struct chsc_ssd_info));
179 ssd->path_mask = pmcw->pim;
180 for (i = 0; i < 8; i++) {
182 if (pmcw->pim & mask) {
183 chp_id_init(&ssd->chpid[i]);
184 ssd->chpid[i].id = pmcw->chpid[i];
189 static void ssd_register_chpids(struct chsc_ssd_info *ssd)
194 for (i = 0; i < 8; i++) {
196 if (ssd->path_mask & mask)
197 if (!chp_is_registered(ssd->chpid[i]))
198 chp_new(ssd->chpid[i]);
202 void css_update_ssd_info(struct subchannel *sch)
206 if (cio_is_console(sch->schid)) {
207 /* Console is initialized too early for functions requiring
208 * memory allocation. */
209 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
211 ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
213 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
214 ssd_register_chpids(&sch->ssd_info);
218 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
221 struct subchannel *sch = to_subchannel(dev);
223 return sprintf(buf, "%01x\n", sch->st);
226 static DEVICE_ATTR(type, 0444, type_show, NULL);
228 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
231 struct subchannel *sch = to_subchannel(dev);
233 return sprintf(buf, "css:t%01X\n", sch->st);
236 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
238 static struct attribute *subch_attrs[] = {
240 &dev_attr_modalias.attr,
244 static struct attribute_group subch_attr_group = {
245 .attrs = subch_attrs,
248 static struct attribute_group *default_subch_attr_groups[] = {
253 static int css_register_subchannel(struct subchannel *sch)
257 /* Initialize the subchannel structure */
258 sch->dev.parent = &channel_subsystems[0]->device;
259 sch->dev.bus = &css_bus_type;
260 sch->dev.release = &css_subchannel_release;
261 sch->dev.groups = default_subch_attr_groups;
263 * We don't want to generate uevents for I/O subchannels that don't
264 * have a working ccw device behind them since they will be
265 * unregistered before they can be used anyway, so we delay the add
266 * uevent until after device recognition was successful.
267 * Note that we suppress the uevent for all subchannel types;
268 * the subchannel driver can decide itself when it wants to inform
269 * userspace of its existence.
271 sch->dev.uevent_suppress = 1;
272 css_update_ssd_info(sch);
273 /* make it known to the system */
274 ret = css_sch_device_register(sch);
276 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
277 sch->schid.ssid, sch->schid.sch_no, ret);
282 * No driver matched. Generate the uevent now so that
283 * a fitting driver module may be loaded based on the
286 sch->dev.uevent_suppress = 0;
287 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
292 int css_probe_device(struct subchannel_id schid)
295 struct subchannel *sch;
297 sch = css_alloc_subchannel(schid);
300 ret = css_register_subchannel(sch);
302 css_free_subchannel(sch);
307 check_subchannel(struct device * dev, void * data)
309 struct subchannel *sch;
310 struct subchannel_id *schid = data;
312 sch = to_subchannel(dev);
313 return schid_equal(&sch->schid, schid);
317 get_subchannel_by_schid(struct subchannel_id schid)
321 dev = bus_find_device(&css_bus_type, NULL,
322 &schid, check_subchannel);
324 return dev ? to_subchannel(dev) : NULL;
328 * css_sch_is_valid() - check if a subchannel is valid
329 * @schib: subchannel information block for the subchannel
331 int css_sch_is_valid(struct schib *schib)
333 if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
337 EXPORT_SYMBOL_GPL(css_sch_is_valid);
339 static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
344 /* Will be done on the slow path. */
347 if (stsch_err(schid, &schib) || !css_sch_is_valid(&schib)) {
348 /* Unusable - ignore. */
351 CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, unknown, "
352 "slow path.\n", schid.ssid, schid.sch_no, CIO_OPER);
354 return css_probe_device(schid);
357 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
362 if (sch->driver->sch_event)
363 ret = sch->driver->sch_event(sch, slow);
366 "Got subchannel machine check but "
367 "no sch_event handler provided.\n");
372 static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
374 struct subchannel *sch;
377 sch = get_subchannel_by_schid(schid);
379 ret = css_evaluate_known_subchannel(sch, slow);
380 put_device(&sch->dev);
382 ret = css_evaluate_new_subchannel(schid, slow);
384 css_schedule_eval(schid);
387 static struct idset *slow_subchannel_set;
388 static spinlock_t slow_subchannel_lock;
390 static int __init slow_subchannel_init(void)
392 spin_lock_init(&slow_subchannel_lock);
393 slow_subchannel_set = idset_sch_new();
394 if (!slow_subchannel_set) {
395 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
401 static int slow_eval_known_fn(struct subchannel *sch, void *data)
406 spin_lock_irq(&slow_subchannel_lock);
407 eval = idset_sch_contains(slow_subchannel_set, sch->schid);
408 idset_sch_del(slow_subchannel_set, sch->schid);
409 spin_unlock_irq(&slow_subchannel_lock);
411 rc = css_evaluate_known_subchannel(sch, 1);
413 css_schedule_eval(sch->schid);
418 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
423 spin_lock_irq(&slow_subchannel_lock);
424 eval = idset_sch_contains(slow_subchannel_set, schid);
425 idset_sch_del(slow_subchannel_set, schid);
426 spin_unlock_irq(&slow_subchannel_lock);
428 rc = css_evaluate_new_subchannel(schid, 1);
431 css_schedule_eval(schid);
437 /* These should abort looping */
446 static void css_slow_path_func(struct work_struct *unused)
448 CIO_TRACE_EVENT(4, "slowpath");
449 for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
453 static DECLARE_WORK(slow_path_work, css_slow_path_func);
454 struct workqueue_struct *slow_path_wq;
456 void css_schedule_eval(struct subchannel_id schid)
460 spin_lock_irqsave(&slow_subchannel_lock, flags);
461 idset_sch_add(slow_subchannel_set, schid);
462 queue_work(slow_path_wq, &slow_path_work);
463 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
466 void css_schedule_eval_all(void)
470 spin_lock_irqsave(&slow_subchannel_lock, flags);
471 idset_fill(slow_subchannel_set);
472 queue_work(slow_path_wq, &slow_path_work);
473 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
476 void css_wait_for_slow_path(void)
478 flush_workqueue(ccw_device_notify_work);
479 flush_workqueue(slow_path_wq);
482 /* Reprobe subchannel if unregistered. */
483 static int reprobe_subchannel(struct subchannel_id schid, void *data)
487 CIO_MSG_EVENT(6, "cio: reprobe 0.%x.%04x\n",
488 schid.ssid, schid.sch_no);
492 ret = css_probe_device(schid);
499 /* These should abort looping */
508 /* Work function used to reprobe all unregistered subchannels. */
509 static void reprobe_all(struct work_struct *unused)
513 CIO_MSG_EVENT(4, "reprobe start\n");
516 /* Make sure initial subchannel scan is done. */
517 wait_event(ccw_device_init_wq,
518 atomic_read(&ccw_device_init_count) == 0);
519 ret = for_each_subchannel_staged(NULL, reprobe_subchannel, NULL);
521 CIO_MSG_EVENT(4, "reprobe done (rc=%d, need_reprobe=%d)\n", ret,
525 static DECLARE_WORK(css_reprobe_work, reprobe_all);
527 /* Schedule reprobing of all unregistered subchannels. */
528 void css_schedule_reprobe(void)
531 queue_work(slow_path_wq, &css_reprobe_work);
534 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
537 * Called from the machine check handler for subchannel report words.
539 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
541 struct subchannel_id mchk_schid;
544 css_schedule_eval_all();
547 CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
548 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
549 crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
550 crw0->erc, crw0->rsid);
552 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
553 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
554 crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
555 crw1->anc, crw1->erc, crw1->rsid);
556 init_subchannel_id(&mchk_schid);
557 mchk_schid.sch_no = crw0->rsid;
559 mchk_schid.ssid = (crw1->rsid >> 8) & 3;
562 * Since we are always presented with IPI in the CRW, we have to
563 * use stsch() to find out if the subchannel in question has come
566 css_evaluate_subchannel(mchk_schid, 0);
570 __init_channel_subsystem(struct subchannel_id schid, void *data)
572 struct subchannel *sch;
575 if (cio_is_console(schid))
576 sch = cio_get_console_subchannel();
578 sch = css_alloc_subchannel(schid);
587 panic("Out of memory in init_channel_subsystem\n");
588 /* -ENXIO: no more subchannels. */
591 /* -EIO: this subchannel set not supported. */
599 * We register ALL valid subchannels in ioinfo, even those
600 * that have been present before init_channel_subsystem.
601 * These subchannels can't have been registered yet (kmalloc
602 * not working) so we do it now. This is true e.g. for the
603 * console subchannel.
605 css_register_subchannel(sch);
610 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
612 if (css_characteristics_avail && css_general_characteristics.mcss) {
613 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
614 css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
617 css->global_pgid.pgid_high.cpu_addr = hard_smp_processor_id();
619 css->global_pgid.pgid_high.cpu_addr = 0;
622 css->global_pgid.cpu_id = ((cpuid_t *) __LC_CPUID)->ident;
623 css->global_pgid.cpu_model = ((cpuid_t *) __LC_CPUID)->machine;
624 css->global_pgid.tod_high = tod_high;
629 channel_subsystem_release(struct device *dev)
631 struct channel_subsystem *css;
634 mutex_destroy(&css->mutex);
639 css_cm_enable_show(struct device *dev, struct device_attribute *attr,
642 struct channel_subsystem *css = to_css(dev);
647 mutex_lock(&css->mutex);
648 ret = sprintf(buf, "%x\n", css->cm_enabled);
649 mutex_unlock(&css->mutex);
654 css_cm_enable_store(struct device *dev, struct device_attribute *attr,
655 const char *buf, size_t count)
657 struct channel_subsystem *css = to_css(dev);
661 ret = strict_strtoul(buf, 16, &val);
664 mutex_lock(&css->mutex);
667 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
670 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
675 mutex_unlock(&css->mutex);
676 return ret < 0 ? ret : count;
679 static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
681 static int __init setup_css(int nr)
685 struct channel_subsystem *css;
687 css = channel_subsystems[nr];
688 memset(css, 0, sizeof(struct channel_subsystem));
689 css->pseudo_subchannel =
690 kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
691 if (!css->pseudo_subchannel)
693 css->pseudo_subchannel->dev.parent = &css->device;
694 css->pseudo_subchannel->dev.release = css_subchannel_release;
695 sprintf(css->pseudo_subchannel->dev.bus_id, "defunct");
696 ret = cio_create_sch_lock(css->pseudo_subchannel);
698 kfree(css->pseudo_subchannel);
701 mutex_init(&css->mutex);
704 sprintf(css->device.bus_id, "css%x", nr);
705 css->device.release = channel_subsystem_release;
706 tod_high = (u32) (get_clock() >> 32);
707 css_generate_pgid(css, tod_high);
711 static int css_reboot_event(struct notifier_block *this,
718 for (i = 0; i <= __MAX_CSSID; i++) {
719 struct channel_subsystem *css;
721 css = channel_subsystems[i];
722 mutex_lock(&css->mutex);
724 if (chsc_secm(css, 0))
726 mutex_unlock(&css->mutex);
732 static struct notifier_block css_reboot_notifier = {
733 .notifier_call = css_reboot_event,
737 * Now that the driver core is running, we can setup our channel subsystem.
738 * The struct subchannel's are created during probing (except for the
739 * static console subchannel).
742 init_channel_subsystem (void)
746 ret = chsc_determine_css_characteristics();
748 goto out; /* No need to continue. */
750 css_characteristics_avail = 1;
752 ret = chsc_alloc_sei_area();
756 ret = slow_subchannel_init();
760 ret = s390_register_crw_handler(CRW_RSC_SCH, css_process_crw);
764 if ((ret = bus_register(&css_bus_type)))
767 /* Try to enable MSS. */
768 ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
770 case 0: /* Success. */
771 max_ssid = __MAX_SSID;
778 /* Setup css structure. */
779 for (i = 0; i <= __MAX_CSSID; i++) {
780 struct channel_subsystem *css;
782 css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
787 channel_subsystems[i] = css;
791 ret = device_register(&css->device);
794 if (css_characteristics_avail &&
795 css_chsc_characteristics.secm) {
796 ret = device_create_file(&css->device,
797 &dev_attr_cm_enable);
801 ret = device_register(&css->pseudo_subchannel->dev);
805 ret = register_reboot_notifier(&css_reboot_notifier);
812 for_each_subchannel(__init_channel_subsystem, NULL);
815 device_unregister(&channel_subsystems[i]->pseudo_subchannel->dev);
817 device_remove_file(&channel_subsystems[i]->device,
818 &dev_attr_cm_enable);
820 device_unregister(&channel_subsystems[i]->device);
822 kfree(channel_subsystems[i]->pseudo_subchannel->lock);
823 kfree(channel_subsystems[i]->pseudo_subchannel);
825 kfree(channel_subsystems[i]);
828 struct channel_subsystem *css;
831 css = channel_subsystems[i];
832 device_unregister(&css->pseudo_subchannel->dev);
833 if (css_characteristics_avail && css_chsc_characteristics.secm)
834 device_remove_file(&css->device,
835 &dev_attr_cm_enable);
836 device_unregister(&css->device);
839 bus_unregister(&css_bus_type);
841 s390_unregister_crw_handler(CRW_RSC_CSS);
842 chsc_free_sei_area();
843 kfree(slow_subchannel_set);
844 printk(KERN_WARNING"cio: failed to initialize css driver (%d)!\n",
849 int sch_is_pseudo_sch(struct subchannel *sch)
851 return sch == to_css(sch->dev.parent)->pseudo_subchannel;
855 * find a driver for a subchannel. They identify by the subchannel
856 * type with the exception that the console subchannel driver has its own
857 * subchannel type although the device is an i/o subchannel
860 css_bus_match (struct device *dev, struct device_driver *drv)
862 struct subchannel *sch = to_subchannel(dev);
863 struct css_driver *driver = to_cssdriver(drv);
865 if (sch->st == driver->subchannel_type)
871 static int css_probe(struct device *dev)
873 struct subchannel *sch;
876 sch = to_subchannel(dev);
877 sch->driver = to_cssdriver(dev->driver);
878 ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
884 static int css_remove(struct device *dev)
886 struct subchannel *sch;
889 sch = to_subchannel(dev);
890 ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
895 static void css_shutdown(struct device *dev)
897 struct subchannel *sch;
899 sch = to_subchannel(dev);
900 if (sch->driver && sch->driver->shutdown)
901 sch->driver->shutdown(sch);
904 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
906 struct subchannel *sch = to_subchannel(dev);
909 ret = add_uevent_var(env, "ST=%01X", sch->st);
912 ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
916 struct bus_type css_bus_type = {
918 .match = css_bus_match,
920 .remove = css_remove,
921 .shutdown = css_shutdown,
922 .uevent = css_uevent,
926 * css_driver_register - register a css driver
927 * @cdrv: css driver to register
929 * This is mainly a wrapper around driver_register that sets name
930 * and bus_type in the embedded struct device_driver correctly.
932 int css_driver_register(struct css_driver *cdrv)
934 cdrv->drv.name = cdrv->name;
935 cdrv->drv.bus = &css_bus_type;
936 cdrv->drv.owner = cdrv->owner;
937 return driver_register(&cdrv->drv);
939 EXPORT_SYMBOL_GPL(css_driver_register);
942 * css_driver_unregister - unregister a css driver
943 * @cdrv: css driver to unregister
945 * This is a wrapper around driver_unregister.
947 void css_driver_unregister(struct css_driver *cdrv)
949 driver_unregister(&cdrv->drv);
951 EXPORT_SYMBOL_GPL(css_driver_unregister);
953 subsys_initcall(init_channel_subsystem);
955 MODULE_LICENSE("GPL");
956 EXPORT_SYMBOL(css_bus_type);
957 EXPORT_SYMBOL_GPL(css_characteristics_avail);