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)) {
178 static int css_sch_device_register(struct subchannel *sch)
182 mutex_lock(&sch->reg_mutex);
183 ret = device_register(&sch->dev);
184 mutex_unlock(&sch->reg_mutex);
189 * css_sch_device_unregister - unregister a subchannel
190 * @sch: subchannel to be unregistered
192 void css_sch_device_unregister(struct subchannel *sch)
194 mutex_lock(&sch->reg_mutex);
195 if (device_is_registered(&sch->dev))
196 device_unregister(&sch->dev);
197 mutex_unlock(&sch->reg_mutex);
199 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
201 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
206 memset(ssd, 0, sizeof(struct chsc_ssd_info));
207 ssd->path_mask = pmcw->pim;
208 for (i = 0; i < 8; i++) {
210 if (pmcw->pim & mask) {
211 chp_id_init(&ssd->chpid[i]);
212 ssd->chpid[i].id = pmcw->chpid[i];
217 static void ssd_register_chpids(struct chsc_ssd_info *ssd)
222 for (i = 0; i < 8; i++) {
224 if (ssd->path_mask & mask)
225 if (!chp_is_registered(ssd->chpid[i]))
226 chp_new(ssd->chpid[i]);
230 void css_update_ssd_info(struct subchannel *sch)
234 if (cio_is_console(sch->schid)) {
235 /* Console is initialized too early for functions requiring
236 * memory allocation. */
237 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
239 ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
241 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
242 ssd_register_chpids(&sch->ssd_info);
246 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
249 struct subchannel *sch = to_subchannel(dev);
251 return sprintf(buf, "%01x\n", sch->st);
254 static DEVICE_ATTR(type, 0444, type_show, NULL);
256 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
259 struct subchannel *sch = to_subchannel(dev);
261 return sprintf(buf, "css:t%01X\n", sch->st);
264 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
266 static struct attribute *subch_attrs[] = {
268 &dev_attr_modalias.attr,
272 static struct attribute_group subch_attr_group = {
273 .attrs = subch_attrs,
276 static struct attribute_group *default_subch_attr_groups[] = {
281 static int css_register_subchannel(struct subchannel *sch)
285 /* Initialize the subchannel structure */
286 sch->dev.parent = &channel_subsystems[0]->device;
287 sch->dev.bus = &css_bus_type;
288 sch->dev.release = &css_subchannel_release;
289 sch->dev.groups = default_subch_attr_groups;
291 * We don't want to generate uevents for I/O subchannels that don't
292 * have a working ccw device behind them since they will be
293 * unregistered before they can be used anyway, so we delay the add
294 * uevent until after device recognition was successful.
295 * Note that we suppress the uevent for all subchannel types;
296 * the subchannel driver can decide itself when it wants to inform
297 * userspace of its existence.
299 dev_set_uevent_suppress(&sch->dev, 1);
300 css_update_ssd_info(sch);
301 /* make it known to the system */
302 ret = css_sch_device_register(sch);
304 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
305 sch->schid.ssid, sch->schid.sch_no, ret);
310 * No driver matched. Generate the uevent now so that
311 * a fitting driver module may be loaded based on the
314 dev_set_uevent_suppress(&sch->dev, 0);
315 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
320 int css_probe_device(struct subchannel_id schid)
323 struct subchannel *sch;
325 sch = css_alloc_subchannel(schid);
328 ret = css_register_subchannel(sch);
330 css_free_subchannel(sch);
335 check_subchannel(struct device * dev, void * data)
337 struct subchannel *sch;
338 struct subchannel_id *schid = data;
340 sch = to_subchannel(dev);
341 return schid_equal(&sch->schid, schid);
345 get_subchannel_by_schid(struct subchannel_id schid)
349 dev = bus_find_device(&css_bus_type, NULL,
350 &schid, check_subchannel);
352 return dev ? to_subchannel(dev) : NULL;
356 * css_sch_is_valid() - check if a subchannel is valid
357 * @schib: subchannel information block for the subchannel
359 int css_sch_is_valid(struct schib *schib)
361 if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
363 if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w)
367 EXPORT_SYMBOL_GPL(css_sch_is_valid);
369 static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
374 /* Will be done on the slow path. */
377 if (stsch_err(schid, &schib) || !css_sch_is_valid(&schib)) {
378 /* Unusable - ignore. */
381 CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, unknown, "
382 "slow path.\n", schid.ssid, schid.sch_no, CIO_OPER);
384 return css_probe_device(schid);
387 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
392 if (sch->driver->sch_event)
393 ret = sch->driver->sch_event(sch, slow);
396 "Got subchannel machine check but "
397 "no sch_event handler provided.\n");
402 static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
404 struct subchannel *sch;
407 sch = get_subchannel_by_schid(schid);
409 ret = css_evaluate_known_subchannel(sch, slow);
410 put_device(&sch->dev);
412 ret = css_evaluate_new_subchannel(schid, slow);
414 css_schedule_eval(schid);
417 static struct idset *slow_subchannel_set;
418 static spinlock_t slow_subchannel_lock;
420 static int __init slow_subchannel_init(void)
422 spin_lock_init(&slow_subchannel_lock);
423 slow_subchannel_set = idset_sch_new();
424 if (!slow_subchannel_set) {
425 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
431 static int slow_eval_known_fn(struct subchannel *sch, void *data)
436 spin_lock_irq(&slow_subchannel_lock);
437 eval = idset_sch_contains(slow_subchannel_set, sch->schid);
438 idset_sch_del(slow_subchannel_set, sch->schid);
439 spin_unlock_irq(&slow_subchannel_lock);
441 rc = css_evaluate_known_subchannel(sch, 1);
443 css_schedule_eval(sch->schid);
448 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
453 spin_lock_irq(&slow_subchannel_lock);
454 eval = idset_sch_contains(slow_subchannel_set, schid);
455 idset_sch_del(slow_subchannel_set, schid);
456 spin_unlock_irq(&slow_subchannel_lock);
458 rc = css_evaluate_new_subchannel(schid, 1);
461 css_schedule_eval(schid);
467 /* These should abort looping */
476 static void css_slow_path_func(struct work_struct *unused)
478 CIO_TRACE_EVENT(4, "slowpath");
479 for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
483 static DECLARE_WORK(slow_path_work, css_slow_path_func);
484 struct workqueue_struct *slow_path_wq;
486 void css_schedule_eval(struct subchannel_id schid)
490 spin_lock_irqsave(&slow_subchannel_lock, flags);
491 idset_sch_add(slow_subchannel_set, schid);
492 queue_work(slow_path_wq, &slow_path_work);
493 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
496 void css_schedule_eval_all(void)
500 spin_lock_irqsave(&slow_subchannel_lock, flags);
501 idset_fill(slow_subchannel_set);
502 queue_work(slow_path_wq, &slow_path_work);
503 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
506 void css_wait_for_slow_path(void)
508 flush_workqueue(slow_path_wq);
511 /* Reprobe subchannel if unregistered. */
512 static int reprobe_subchannel(struct subchannel_id schid, void *data)
516 CIO_MSG_EVENT(6, "cio: reprobe 0.%x.%04x\n",
517 schid.ssid, schid.sch_no);
521 ret = css_probe_device(schid);
528 /* These should abort looping */
537 static void reprobe_after_idle(struct work_struct *unused)
539 /* Make sure initial subchannel scan is done. */
540 wait_event(ccw_device_init_wq,
541 atomic_read(&ccw_device_init_count) == 0);
543 css_schedule_reprobe();
546 static DECLARE_WORK(reprobe_idle_work, reprobe_after_idle);
548 /* Work function used to reprobe all unregistered subchannels. */
549 static void reprobe_all(struct work_struct *unused)
553 CIO_MSG_EVENT(4, "reprobe start\n");
555 /* Make sure initial subchannel scan is done. */
556 if (atomic_read(&ccw_device_init_count) != 0) {
557 queue_work(ccw_device_work, &reprobe_idle_work);
561 ret = for_each_subchannel_staged(NULL, reprobe_subchannel, NULL);
563 CIO_MSG_EVENT(4, "reprobe done (rc=%d, need_reprobe=%d)\n", ret,
567 static DECLARE_WORK(css_reprobe_work, reprobe_all);
569 /* Schedule reprobing of all unregistered subchannels. */
570 void css_schedule_reprobe(void)
573 queue_work(slow_path_wq, &css_reprobe_work);
576 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
579 * Called from the machine check handler for subchannel report words.
581 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
583 struct subchannel_id mchk_schid;
586 css_schedule_eval_all();
589 CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
590 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
591 crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
592 crw0->erc, crw0->rsid);
594 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
595 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
596 crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
597 crw1->anc, crw1->erc, crw1->rsid);
598 init_subchannel_id(&mchk_schid);
599 mchk_schid.sch_no = crw0->rsid;
601 mchk_schid.ssid = (crw1->rsid >> 8) & 3;
604 * Since we are always presented with IPI in the CRW, we have to
605 * use stsch() to find out if the subchannel in question has come
608 css_evaluate_subchannel(mchk_schid, 0);
612 __init_channel_subsystem(struct subchannel_id schid, void *data)
614 struct subchannel *sch;
617 if (cio_is_console(schid))
618 sch = cio_get_console_subchannel();
620 sch = css_alloc_subchannel(schid);
629 panic("Out of memory in init_channel_subsystem\n");
630 /* -ENXIO: no more subchannels. */
633 /* -EIO: this subchannel set not supported. */
641 * We register ALL valid subchannels in ioinfo, even those
642 * that have been present before init_channel_subsystem.
643 * These subchannels can't have been registered yet (kmalloc
644 * not working) so we do it now. This is true e.g. for the
645 * console subchannel.
647 css_register_subchannel(sch);
652 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
654 if (css_general_characteristics.mcss) {
655 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
656 css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
659 css->global_pgid.pgid_high.cpu_addr = stap();
661 css->global_pgid.pgid_high.cpu_addr = 0;
664 css->global_pgid.cpu_id = ((cpuid_t *) __LC_CPUID)->ident;
665 css->global_pgid.cpu_model = ((cpuid_t *) __LC_CPUID)->machine;
666 css->global_pgid.tod_high = tod_high;
671 channel_subsystem_release(struct device *dev)
673 struct channel_subsystem *css;
676 mutex_destroy(&css->mutex);
677 if (css->pseudo_subchannel) {
678 /* Implies that it has been generated but never registered. */
679 css_subchannel_release(&css->pseudo_subchannel->dev);
680 css->pseudo_subchannel = NULL;
686 css_cm_enable_show(struct device *dev, struct device_attribute *attr,
689 struct channel_subsystem *css = to_css(dev);
694 mutex_lock(&css->mutex);
695 ret = sprintf(buf, "%x\n", css->cm_enabled);
696 mutex_unlock(&css->mutex);
701 css_cm_enable_store(struct device *dev, struct device_attribute *attr,
702 const char *buf, size_t count)
704 struct channel_subsystem *css = to_css(dev);
708 ret = strict_strtoul(buf, 16, &val);
711 mutex_lock(&css->mutex);
714 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
717 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
722 mutex_unlock(&css->mutex);
723 return ret < 0 ? ret : count;
726 static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
728 static int __init setup_css(int nr)
732 struct channel_subsystem *css;
734 css = channel_subsystems[nr];
735 memset(css, 0, sizeof(struct channel_subsystem));
736 css->pseudo_subchannel =
737 kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
738 if (!css->pseudo_subchannel)
740 css->pseudo_subchannel->dev.parent = &css->device;
741 css->pseudo_subchannel->dev.release = css_subchannel_release;
742 dev_set_name(&css->pseudo_subchannel->dev, "defunct");
743 ret = cio_create_sch_lock(css->pseudo_subchannel);
745 kfree(css->pseudo_subchannel);
748 mutex_init(&css->mutex);
751 dev_set_name(&css->device, "css%x", nr);
752 css->device.release = channel_subsystem_release;
753 tod_high = (u32) (get_clock() >> 32);
754 css_generate_pgid(css, tod_high);
758 static int css_reboot_event(struct notifier_block *this,
765 for (i = 0; i <= __MAX_CSSID; i++) {
766 struct channel_subsystem *css;
768 css = channel_subsystems[i];
769 mutex_lock(&css->mutex);
771 if (chsc_secm(css, 0))
773 mutex_unlock(&css->mutex);
779 static struct notifier_block css_reboot_notifier = {
780 .notifier_call = css_reboot_event,
784 * Since the css devices are neither on a bus nor have a class
785 * nor have a special device type, we cannot stop/restart channel
786 * path measurements via the normal suspend/resume callbacks, but have
789 static int css_power_event(struct notifier_block *this, unsigned long event,
796 case PM_HIBERNATION_PREPARE:
797 case PM_SUSPEND_PREPARE:
799 for (i = 0; i <= __MAX_CSSID; i++) {
800 struct channel_subsystem *css;
802 css = channel_subsystems[i];
803 mutex_lock(&css->mutex);
804 if (!css->cm_enabled) {
805 mutex_unlock(&css->mutex);
808 secm_area = (void *)get_zeroed_page(GFP_KERNEL |
811 if (__chsc_do_secm(css, 0, secm_area))
813 free_page((unsigned long)secm_area);
817 mutex_unlock(&css->mutex);
820 case PM_POST_HIBERNATION:
821 case PM_POST_SUSPEND:
823 for (i = 0; i <= __MAX_CSSID; i++) {
824 struct channel_subsystem *css;
826 css = channel_subsystems[i];
827 mutex_lock(&css->mutex);
828 if (!css->cm_enabled) {
829 mutex_unlock(&css->mutex);
832 secm_area = (void *)get_zeroed_page(GFP_KERNEL |
835 if (__chsc_do_secm(css, 1, secm_area))
837 free_page((unsigned long)secm_area);
841 mutex_unlock(&css->mutex);
843 /* search for subchannels, which appeared during hibernation */
844 css_schedule_reprobe();
852 static struct notifier_block css_power_notifier = {
853 .notifier_call = css_power_event,
857 * Now that the driver core is running, we can setup our channel subsystem.
858 * The struct subchannel's are created during probing (except for the
859 * static console subchannel).
862 init_channel_subsystem (void)
866 ret = chsc_determine_css_characteristics();
868 goto out; /* No need to continue. */
870 ret = chsc_alloc_sei_area();
874 ret = slow_subchannel_init();
878 ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
882 if ((ret = bus_register(&css_bus_type)))
885 /* Try to enable MSS. */
886 ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
888 case 0: /* Success. */
889 max_ssid = __MAX_SSID;
896 /* Setup css structure. */
897 for (i = 0; i <= __MAX_CSSID; i++) {
898 struct channel_subsystem *css;
900 css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
905 channel_subsystems[i] = css;
908 kfree(channel_subsystems[i]);
911 ret = device_register(&css->device);
913 put_device(&css->device);
916 if (css_chsc_characteristics.secm) {
917 ret = device_create_file(&css->device,
918 &dev_attr_cm_enable);
922 ret = device_register(&css->pseudo_subchannel->dev);
926 ret = register_reboot_notifier(&css_reboot_notifier);
929 ret = register_pm_notifier(&css_power_notifier);
931 unregister_reboot_notifier(&css_reboot_notifier);
936 /* Enable default isc for I/O subchannels. */
937 isc_register(IO_SCH_ISC);
939 for_each_subchannel(__init_channel_subsystem, NULL);
942 if (css_chsc_characteristics.secm)
943 device_remove_file(&channel_subsystems[i]->device,
944 &dev_attr_cm_enable);
946 device_unregister(&channel_subsystems[i]->device);
949 struct channel_subsystem *css;
952 css = channel_subsystems[i];
953 device_unregister(&css->pseudo_subchannel->dev);
954 css->pseudo_subchannel = NULL;
955 if (css_chsc_characteristics.secm)
956 device_remove_file(&css->device,
957 &dev_attr_cm_enable);
958 device_unregister(&css->device);
961 bus_unregister(&css_bus_type);
963 crw_unregister_handler(CRW_RSC_CSS);
964 chsc_free_sei_area();
965 kfree(slow_subchannel_set);
966 pr_alert("The CSS device driver initialization failed with "
971 int sch_is_pseudo_sch(struct subchannel *sch)
973 return sch == to_css(sch->dev.parent)->pseudo_subchannel;
976 static int css_bus_match(struct device *dev, struct device_driver *drv)
978 struct subchannel *sch = to_subchannel(dev);
979 struct css_driver *driver = to_cssdriver(drv);
980 struct css_device_id *id;
982 for (id = driver->subchannel_type; id->match_flags; id++) {
983 if (sch->st == id->type)
990 static int css_probe(struct device *dev)
992 struct subchannel *sch;
995 sch = to_subchannel(dev);
996 sch->driver = to_cssdriver(dev->driver);
997 ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
1003 static int css_remove(struct device *dev)
1005 struct subchannel *sch;
1008 sch = to_subchannel(dev);
1009 ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
1014 static void css_shutdown(struct device *dev)
1016 struct subchannel *sch;
1018 sch = to_subchannel(dev);
1019 if (sch->driver && sch->driver->shutdown)
1020 sch->driver->shutdown(sch);
1023 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
1025 struct subchannel *sch = to_subchannel(dev);
1028 ret = add_uevent_var(env, "ST=%01X", sch->st);
1031 ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
1035 static int css_pm_prepare(struct device *dev)
1037 struct subchannel *sch = to_subchannel(dev);
1038 struct css_driver *drv;
1040 if (mutex_is_locked(&sch->reg_mutex))
1042 if (!sch->dev.driver)
1044 drv = to_cssdriver(sch->dev.driver);
1045 /* Notify drivers that they may not register children. */
1046 return drv->prepare ? drv->prepare(sch) : 0;
1049 static void css_pm_complete(struct device *dev)
1051 struct subchannel *sch = to_subchannel(dev);
1052 struct css_driver *drv;
1054 if (!sch->dev.driver)
1056 drv = to_cssdriver(sch->dev.driver);
1061 static int css_pm_freeze(struct device *dev)
1063 struct subchannel *sch = to_subchannel(dev);
1064 struct css_driver *drv;
1066 if (!sch->dev.driver)
1068 drv = to_cssdriver(sch->dev.driver);
1069 return drv->freeze ? drv->freeze(sch) : 0;
1072 static int css_pm_thaw(struct device *dev)
1074 struct subchannel *sch = to_subchannel(dev);
1075 struct css_driver *drv;
1077 if (!sch->dev.driver)
1079 drv = to_cssdriver(sch->dev.driver);
1080 return drv->thaw ? drv->thaw(sch) : 0;
1083 static int css_pm_restore(struct device *dev)
1085 struct subchannel *sch = to_subchannel(dev);
1086 struct css_driver *drv;
1088 if (!sch->dev.driver)
1090 drv = to_cssdriver(sch->dev.driver);
1091 return drv->restore ? drv->restore(sch) : 0;
1094 static struct dev_pm_ops css_pm_ops = {
1095 .prepare = css_pm_prepare,
1096 .complete = css_pm_complete,
1097 .freeze = css_pm_freeze,
1098 .thaw = css_pm_thaw,
1099 .restore = css_pm_restore,
1102 struct bus_type css_bus_type = {
1104 .match = css_bus_match,
1106 .remove = css_remove,
1107 .shutdown = css_shutdown,
1108 .uevent = css_uevent,
1113 * css_driver_register - register a css driver
1114 * @cdrv: css driver to register
1116 * This is mainly a wrapper around driver_register that sets name
1117 * and bus_type in the embedded struct device_driver correctly.
1119 int css_driver_register(struct css_driver *cdrv)
1121 cdrv->drv.name = cdrv->name;
1122 cdrv->drv.bus = &css_bus_type;
1123 cdrv->drv.owner = cdrv->owner;
1124 return driver_register(&cdrv->drv);
1126 EXPORT_SYMBOL_GPL(css_driver_register);
1129 * css_driver_unregister - unregister a css driver
1130 * @cdrv: css driver to unregister
1132 * This is a wrapper around driver_unregister.
1134 void css_driver_unregister(struct css_driver *cdrv)
1136 driver_unregister(&cdrv->drv);
1138 EXPORT_SYMBOL_GPL(css_driver_unregister);
1140 subsys_initcall(init_channel_subsystem);
1142 MODULE_LICENSE("GPL");
1143 EXPORT_SYMBOL(css_bus_type);