2 * driver for channel subsystem
4 * Copyright IBM Corp. 2002, 2009
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>
26 #include "cio_debug.h"
33 int css_init_done = 0;
34 static int need_reprobe = 0;
35 static int max_ssid = 0;
37 struct channel_subsystem *channel_subsystems[__MAX_CSSID + 1];
40 for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data)
42 struct subchannel_id schid;
45 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;
71 idset_sch_del(cb->set, sch->schid);
73 rc = cb->fn_known_sch(sch, cb->data);
77 static int call_fn_unknown_sch(struct subchannel_id schid, void *data)
79 struct cb_data *cb = data;
82 if (idset_sch_contains(cb->set, schid))
83 rc = cb->fn_unknown_sch(schid, cb->data);
87 static int call_fn_all_sch(struct subchannel_id schid, void *data)
89 struct cb_data *cb = data;
90 struct subchannel *sch;
93 sch = get_subchannel_by_schid(schid);
96 rc = cb->fn_known_sch(sch, cb->data);
97 put_device(&sch->dev);
99 if (cb->fn_unknown_sch)
100 rc = cb->fn_unknown_sch(schid, cb->data);
106 int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
107 int (*fn_unknown)(struct subchannel_id,
114 cb.fn_known_sch = fn_known;
115 cb.fn_unknown_sch = fn_unknown;
117 cb.set = idset_sch_new();
119 /* fall back to brute force scanning in case of oom */
120 return for_each_subchannel(call_fn_all_sch, &cb);
124 /* Process registered subchannels. */
125 rc = bus_for_each_dev(&css_bus_type, NULL, &cb, call_fn_known_sch);
128 /* Process unregistered subchannels. */
130 rc = for_each_subchannel(call_fn_unknown_sch, &cb);
137 static struct subchannel *
138 css_alloc_subchannel(struct subchannel_id schid)
140 struct subchannel *sch;
143 sch = kmalloc (sizeof (*sch), GFP_KERNEL | GFP_DMA);
145 return ERR_PTR(-ENOMEM);
146 ret = cio_validate_subchannel (sch, schid);
155 css_free_subchannel(struct subchannel *sch)
158 /* Reset intparm to zeroes. */
159 sch->config.intparm = 0;
160 cio_commit_config(sch);
167 css_subchannel_release(struct device *dev)
169 struct subchannel *sch;
171 sch = to_subchannel(dev);
172 if (!cio_is_console(sch->schid)) {
173 /* Reset intparm to zeroes. */
174 sch->config.intparm = 0;
175 cio_commit_config(sch);
181 static int css_sch_device_register(struct subchannel *sch)
185 mutex_lock(&sch->reg_mutex);
186 dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid,
188 ret = device_register(&sch->dev);
189 mutex_unlock(&sch->reg_mutex);
194 * css_sch_device_unregister - unregister a subchannel
195 * @sch: subchannel to be unregistered
197 void css_sch_device_unregister(struct subchannel *sch)
199 mutex_lock(&sch->reg_mutex);
200 if (device_is_registered(&sch->dev))
201 device_unregister(&sch->dev);
202 mutex_unlock(&sch->reg_mutex);
204 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
206 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
211 memset(ssd, 0, sizeof(struct chsc_ssd_info));
212 ssd->path_mask = pmcw->pim;
213 for (i = 0; i < 8; i++) {
215 if (pmcw->pim & mask) {
216 chp_id_init(&ssd->chpid[i]);
217 ssd->chpid[i].id = pmcw->chpid[i];
222 static void ssd_register_chpids(struct chsc_ssd_info *ssd)
227 for (i = 0; i < 8; i++) {
229 if (ssd->path_mask & mask)
230 if (!chp_is_registered(ssd->chpid[i]))
231 chp_new(ssd->chpid[i]);
235 void css_update_ssd_info(struct subchannel *sch)
239 if (cio_is_console(sch->schid)) {
240 /* Console is initialized too early for functions requiring
241 * memory allocation. */
242 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
244 ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
246 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
247 ssd_register_chpids(&sch->ssd_info);
251 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
254 struct subchannel *sch = to_subchannel(dev);
256 return sprintf(buf, "%01x\n", sch->st);
259 static DEVICE_ATTR(type, 0444, type_show, NULL);
261 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
264 struct subchannel *sch = to_subchannel(dev);
266 return sprintf(buf, "css:t%01X\n", sch->st);
269 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
271 static struct attribute *subch_attrs[] = {
273 &dev_attr_modalias.attr,
277 static struct attribute_group subch_attr_group = {
278 .attrs = subch_attrs,
281 static struct attribute_group *default_subch_attr_groups[] = {
286 static int css_register_subchannel(struct subchannel *sch)
290 /* Initialize the subchannel structure */
291 sch->dev.parent = &channel_subsystems[0]->device;
292 sch->dev.bus = &css_bus_type;
293 sch->dev.release = &css_subchannel_release;
294 sch->dev.groups = default_subch_attr_groups;
296 * We don't want to generate uevents for I/O subchannels that don't
297 * have a working ccw device behind them since they will be
298 * unregistered before they can be used anyway, so we delay the add
299 * uevent until after device recognition was successful.
300 * Note that we suppress the uevent for all subchannel types;
301 * the subchannel driver can decide itself when it wants to inform
302 * userspace of its existence.
304 dev_set_uevent_suppress(&sch->dev, 1);
305 css_update_ssd_info(sch);
306 /* make it known to the system */
307 ret = css_sch_device_register(sch);
309 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
310 sch->schid.ssid, sch->schid.sch_no, ret);
315 * No driver matched. Generate the uevent now so that
316 * a fitting driver module may be loaded based on the
319 dev_set_uevent_suppress(&sch->dev, 0);
320 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
325 int css_probe_device(struct subchannel_id schid)
328 struct subchannel *sch;
330 sch = css_alloc_subchannel(schid);
333 ret = css_register_subchannel(sch);
335 css_free_subchannel(sch);
340 check_subchannel(struct device * dev, void * data)
342 struct subchannel *sch;
343 struct subchannel_id *schid = data;
345 sch = to_subchannel(dev);
346 return schid_equal(&sch->schid, schid);
350 get_subchannel_by_schid(struct subchannel_id schid)
354 dev = bus_find_device(&css_bus_type, NULL,
355 &schid, check_subchannel);
357 return dev ? to_subchannel(dev) : NULL;
361 * css_sch_is_valid() - check if a subchannel is valid
362 * @schib: subchannel information block for the subchannel
364 int css_sch_is_valid(struct schib *schib)
366 if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
368 if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w)
372 EXPORT_SYMBOL_GPL(css_sch_is_valid);
374 static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
379 /* Will be done on the slow path. */
382 if (stsch_err(schid, &schib) || !css_sch_is_valid(&schib)) {
383 /* Unusable - ignore. */
386 CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, unknown, "
387 "slow path.\n", schid.ssid, schid.sch_no, CIO_OPER);
389 return css_probe_device(schid);
392 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
397 if (sch->driver->sch_event)
398 ret = sch->driver->sch_event(sch, slow);
401 "Got subchannel machine check but "
402 "no sch_event handler provided.\n");
407 static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
409 struct subchannel *sch;
412 sch = get_subchannel_by_schid(schid);
414 ret = css_evaluate_known_subchannel(sch, slow);
415 put_device(&sch->dev);
417 ret = css_evaluate_new_subchannel(schid, slow);
419 css_schedule_eval(schid);
422 static struct idset *slow_subchannel_set;
423 static spinlock_t slow_subchannel_lock;
425 static int __init slow_subchannel_init(void)
427 spin_lock_init(&slow_subchannel_lock);
428 slow_subchannel_set = idset_sch_new();
429 if (!slow_subchannel_set) {
430 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
436 static int slow_eval_known_fn(struct subchannel *sch, void *data)
441 spin_lock_irq(&slow_subchannel_lock);
442 eval = idset_sch_contains(slow_subchannel_set, sch->schid);
443 idset_sch_del(slow_subchannel_set, sch->schid);
444 spin_unlock_irq(&slow_subchannel_lock);
446 rc = css_evaluate_known_subchannel(sch, 1);
448 css_schedule_eval(sch->schid);
453 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
458 spin_lock_irq(&slow_subchannel_lock);
459 eval = idset_sch_contains(slow_subchannel_set, schid);
460 idset_sch_del(slow_subchannel_set, schid);
461 spin_unlock_irq(&slow_subchannel_lock);
463 rc = css_evaluate_new_subchannel(schid, 1);
466 css_schedule_eval(schid);
472 /* These should abort looping */
481 static void css_slow_path_func(struct work_struct *unused)
483 CIO_TRACE_EVENT(4, "slowpath");
484 for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
488 static DECLARE_WORK(slow_path_work, css_slow_path_func);
489 struct workqueue_struct *slow_path_wq;
491 void css_schedule_eval(struct subchannel_id schid)
495 spin_lock_irqsave(&slow_subchannel_lock, flags);
496 idset_sch_add(slow_subchannel_set, schid);
497 queue_work(slow_path_wq, &slow_path_work);
498 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
501 void css_schedule_eval_all(void)
505 spin_lock_irqsave(&slow_subchannel_lock, flags);
506 idset_fill(slow_subchannel_set);
507 queue_work(slow_path_wq, &slow_path_work);
508 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
511 void css_wait_for_slow_path(void)
513 flush_workqueue(slow_path_wq);
516 /* Reprobe subchannel if unregistered. */
517 static int reprobe_subchannel(struct subchannel_id schid, void *data)
521 CIO_MSG_EVENT(6, "cio: reprobe 0.%x.%04x\n",
522 schid.ssid, schid.sch_no);
526 ret = css_probe_device(schid);
533 /* These should abort looping */
542 static void reprobe_after_idle(struct work_struct *unused)
544 /* Make sure initial subchannel scan is done. */
545 wait_event(ccw_device_init_wq,
546 atomic_read(&ccw_device_init_count) == 0);
548 css_schedule_reprobe();
551 static DECLARE_WORK(reprobe_idle_work, reprobe_after_idle);
553 /* Work function used to reprobe all unregistered subchannels. */
554 static void reprobe_all(struct work_struct *unused)
558 CIO_MSG_EVENT(4, "reprobe start\n");
560 /* Make sure initial subchannel scan is done. */
561 if (atomic_read(&ccw_device_init_count) != 0) {
562 queue_work(ccw_device_work, &reprobe_idle_work);
566 ret = for_each_subchannel_staged(NULL, reprobe_subchannel, NULL);
568 CIO_MSG_EVENT(4, "reprobe done (rc=%d, need_reprobe=%d)\n", ret,
572 static DECLARE_WORK(css_reprobe_work, reprobe_all);
574 /* Schedule reprobing of all unregistered subchannels. */
575 void css_schedule_reprobe(void)
578 queue_work(slow_path_wq, &css_reprobe_work);
581 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
584 * Called from the machine check handler for subchannel report words.
586 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
588 struct subchannel_id mchk_schid;
591 css_schedule_eval_all();
594 CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
595 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
596 crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
597 crw0->erc, crw0->rsid);
599 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
600 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
601 crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
602 crw1->anc, crw1->erc, crw1->rsid);
603 init_subchannel_id(&mchk_schid);
604 mchk_schid.sch_no = crw0->rsid;
606 mchk_schid.ssid = (crw1->rsid >> 8) & 3;
609 * Since we are always presented with IPI in the CRW, we have to
610 * use stsch() to find out if the subchannel in question has come
613 css_evaluate_subchannel(mchk_schid, 0);
617 __init_channel_subsystem(struct subchannel_id schid, void *data)
619 struct subchannel *sch;
622 if (cio_is_console(schid))
623 sch = cio_get_console_subchannel();
625 sch = css_alloc_subchannel(schid);
634 panic("Out of memory in init_channel_subsystem\n");
635 /* -ENXIO: no more subchannels. */
638 /* -EIO: this subchannel set not supported. */
646 * We register ALL valid subchannels in ioinfo, even those
647 * that have been present before init_channel_subsystem.
648 * These subchannels can't have been registered yet (kmalloc
649 * not working) so we do it now. This is true e.g. for the
650 * console subchannel.
652 css_register_subchannel(sch);
657 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
659 if (css_general_characteristics.mcss) {
660 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
661 css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
664 css->global_pgid.pgid_high.cpu_addr = stap();
666 css->global_pgid.pgid_high.cpu_addr = 0;
669 css->global_pgid.cpu_id = ((cpuid_t *) __LC_CPUID)->ident;
670 css->global_pgid.cpu_model = ((cpuid_t *) __LC_CPUID)->machine;
671 css->global_pgid.tod_high = tod_high;
676 channel_subsystem_release(struct device *dev)
678 struct channel_subsystem *css;
681 mutex_destroy(&css->mutex);
682 if (css->pseudo_subchannel) {
683 /* Implies that it has been generated but never registered. */
684 css_subchannel_release(&css->pseudo_subchannel->dev);
685 css->pseudo_subchannel = NULL;
691 css_cm_enable_show(struct device *dev, struct device_attribute *attr,
694 struct channel_subsystem *css = to_css(dev);
699 mutex_lock(&css->mutex);
700 ret = sprintf(buf, "%x\n", css->cm_enabled);
701 mutex_unlock(&css->mutex);
706 css_cm_enable_store(struct device *dev, struct device_attribute *attr,
707 const char *buf, size_t count)
709 struct channel_subsystem *css = to_css(dev);
713 ret = strict_strtoul(buf, 16, &val);
716 mutex_lock(&css->mutex);
719 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
722 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
727 mutex_unlock(&css->mutex);
728 return ret < 0 ? ret : count;
731 static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
733 static int __init setup_css(int nr)
737 struct channel_subsystem *css;
739 css = channel_subsystems[nr];
740 memset(css, 0, sizeof(struct channel_subsystem));
741 css->pseudo_subchannel =
742 kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
743 if (!css->pseudo_subchannel)
745 css->pseudo_subchannel->dev.parent = &css->device;
746 css->pseudo_subchannel->dev.release = css_subchannel_release;
747 dev_set_name(&css->pseudo_subchannel->dev, "defunct");
748 ret = cio_create_sch_lock(css->pseudo_subchannel);
750 kfree(css->pseudo_subchannel);
753 mutex_init(&css->mutex);
756 dev_set_name(&css->device, "css%x", nr);
757 css->device.release = channel_subsystem_release;
758 tod_high = (u32) (get_clock() >> 32);
759 css_generate_pgid(css, tod_high);
763 static int css_reboot_event(struct notifier_block *this,
770 for (i = 0; i <= __MAX_CSSID; i++) {
771 struct channel_subsystem *css;
773 css = channel_subsystems[i];
774 mutex_lock(&css->mutex);
776 if (chsc_secm(css, 0))
778 mutex_unlock(&css->mutex);
784 static struct notifier_block css_reboot_notifier = {
785 .notifier_call = css_reboot_event,
789 * Since the css devices are neither on a bus nor have a class
790 * nor have a special device type, we cannot stop/restart channel
791 * path measurements via the normal suspend/resume callbacks, but have
794 static int css_power_event(struct notifier_block *this, unsigned long event,
801 case PM_HIBERNATION_PREPARE:
802 case PM_SUSPEND_PREPARE:
804 for (i = 0; i <= __MAX_CSSID; i++) {
805 struct channel_subsystem *css;
807 css = channel_subsystems[i];
808 mutex_lock(&css->mutex);
809 if (!css->cm_enabled) {
810 mutex_unlock(&css->mutex);
813 secm_area = (void *)get_zeroed_page(GFP_KERNEL |
816 if (__chsc_do_secm(css, 0, secm_area))
818 free_page((unsigned long)secm_area);
822 mutex_unlock(&css->mutex);
825 case PM_POST_HIBERNATION:
826 case PM_POST_SUSPEND:
828 for (i = 0; i <= __MAX_CSSID; i++) {
829 struct channel_subsystem *css;
831 css = channel_subsystems[i];
832 mutex_lock(&css->mutex);
833 if (!css->cm_enabled) {
834 mutex_unlock(&css->mutex);
837 secm_area = (void *)get_zeroed_page(GFP_KERNEL |
840 if (__chsc_do_secm(css, 1, secm_area))
842 free_page((unsigned long)secm_area);
846 mutex_unlock(&css->mutex);
848 /* search for subchannels, which appeared during hibernation */
849 css_schedule_reprobe();
857 static struct notifier_block css_power_notifier = {
858 .notifier_call = css_power_event,
862 * Now that the driver core is running, we can setup our channel subsystem.
863 * The struct subchannel's are created during probing (except for the
864 * static console subchannel).
867 init_channel_subsystem (void)
871 ret = chsc_determine_css_characteristics();
873 goto out; /* No need to continue. */
875 ret = chsc_alloc_sei_area();
879 ret = slow_subchannel_init();
883 ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
887 if ((ret = bus_register(&css_bus_type)))
890 /* Try to enable MSS. */
891 ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
893 case 0: /* Success. */
894 max_ssid = __MAX_SSID;
901 /* Setup css structure. */
902 for (i = 0; i <= __MAX_CSSID; i++) {
903 struct channel_subsystem *css;
905 css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
910 channel_subsystems[i] = css;
913 kfree(channel_subsystems[i]);
916 ret = device_register(&css->device);
918 put_device(&css->device);
921 if (css_chsc_characteristics.secm) {
922 ret = device_create_file(&css->device,
923 &dev_attr_cm_enable);
927 ret = device_register(&css->pseudo_subchannel->dev);
931 ret = register_reboot_notifier(&css_reboot_notifier);
934 ret = register_pm_notifier(&css_power_notifier);
936 unregister_reboot_notifier(&css_reboot_notifier);
941 /* Enable default isc for I/O subchannels. */
942 isc_register(IO_SCH_ISC);
944 for_each_subchannel(__init_channel_subsystem, NULL);
947 if (css_chsc_characteristics.secm)
948 device_remove_file(&channel_subsystems[i]->device,
949 &dev_attr_cm_enable);
951 device_unregister(&channel_subsystems[i]->device);
954 struct channel_subsystem *css;
957 css = channel_subsystems[i];
958 device_unregister(&css->pseudo_subchannel->dev);
959 css->pseudo_subchannel = NULL;
960 if (css_chsc_characteristics.secm)
961 device_remove_file(&css->device,
962 &dev_attr_cm_enable);
963 device_unregister(&css->device);
966 bus_unregister(&css_bus_type);
968 crw_unregister_handler(CRW_RSC_CSS);
969 chsc_free_sei_area();
970 kfree(slow_subchannel_set);
971 pr_alert("The CSS device driver initialization failed with "
976 int sch_is_pseudo_sch(struct subchannel *sch)
978 return sch == to_css(sch->dev.parent)->pseudo_subchannel;
981 static int css_bus_match(struct device *dev, struct device_driver *drv)
983 struct subchannel *sch = to_subchannel(dev);
984 struct css_driver *driver = to_cssdriver(drv);
985 struct css_device_id *id;
987 for (id = driver->subchannel_type; id->match_flags; id++) {
988 if (sch->st == id->type)
995 static int css_probe(struct device *dev)
997 struct subchannel *sch;
1000 sch = to_subchannel(dev);
1001 sch->driver = to_cssdriver(dev->driver);
1002 ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
1008 static int css_remove(struct device *dev)
1010 struct subchannel *sch;
1013 sch = to_subchannel(dev);
1014 ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
1019 static void css_shutdown(struct device *dev)
1021 struct subchannel *sch;
1023 sch = to_subchannel(dev);
1024 if (sch->driver && sch->driver->shutdown)
1025 sch->driver->shutdown(sch);
1028 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
1030 struct subchannel *sch = to_subchannel(dev);
1033 ret = add_uevent_var(env, "ST=%01X", sch->st);
1036 ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
1040 static int css_pm_prepare(struct device *dev)
1042 struct subchannel *sch = to_subchannel(dev);
1043 struct css_driver *drv;
1045 if (mutex_is_locked(&sch->reg_mutex))
1047 if (!sch->dev.driver)
1049 drv = to_cssdriver(sch->dev.driver);
1050 /* Notify drivers that they may not register children. */
1051 return drv->prepare ? drv->prepare(sch) : 0;
1054 static void css_pm_complete(struct device *dev)
1056 struct subchannel *sch = to_subchannel(dev);
1057 struct css_driver *drv;
1059 if (!sch->dev.driver)
1061 drv = to_cssdriver(sch->dev.driver);
1066 static int css_pm_freeze(struct device *dev)
1068 struct subchannel *sch = to_subchannel(dev);
1069 struct css_driver *drv;
1071 if (!sch->dev.driver)
1073 drv = to_cssdriver(sch->dev.driver);
1074 return drv->freeze ? drv->freeze(sch) : 0;
1077 static int css_pm_thaw(struct device *dev)
1079 struct subchannel *sch = to_subchannel(dev);
1080 struct css_driver *drv;
1082 if (!sch->dev.driver)
1084 drv = to_cssdriver(sch->dev.driver);
1085 return drv->thaw ? drv->thaw(sch) : 0;
1088 static int css_pm_restore(struct device *dev)
1090 struct subchannel *sch = to_subchannel(dev);
1091 struct css_driver *drv;
1093 if (!sch->dev.driver)
1095 drv = to_cssdriver(sch->dev.driver);
1096 return drv->restore ? drv->restore(sch) : 0;
1099 static struct dev_pm_ops css_pm_ops = {
1100 .prepare = css_pm_prepare,
1101 .complete = css_pm_complete,
1102 .freeze = css_pm_freeze,
1103 .thaw = css_pm_thaw,
1104 .restore = css_pm_restore,
1107 struct bus_type css_bus_type = {
1109 .match = css_bus_match,
1111 .remove = css_remove,
1112 .shutdown = css_shutdown,
1113 .uevent = css_uevent,
1118 * css_driver_register - register a css driver
1119 * @cdrv: css driver to register
1121 * This is mainly a wrapper around driver_register that sets name
1122 * and bus_type in the embedded struct device_driver correctly.
1124 int css_driver_register(struct css_driver *cdrv)
1126 cdrv->drv.name = cdrv->name;
1127 cdrv->drv.bus = &css_bus_type;
1128 cdrv->drv.owner = cdrv->owner;
1129 return driver_register(&cdrv->drv);
1131 EXPORT_SYMBOL_GPL(css_driver_register);
1134 * css_driver_unregister - unregister a css driver
1135 * @cdrv: css driver to unregister
1137 * This is a wrapper around driver_unregister.
1139 void css_driver_unregister(struct css_driver *cdrv)
1141 driver_unregister(&cdrv->drv);
1143 EXPORT_SYMBOL_GPL(css_driver_unregister);
1145 subsys_initcall(init_channel_subsystem);
1147 MODULE_LICENSE("GPL");
1148 EXPORT_SYMBOL(css_bus_type);