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_subchannel_release(struct device *dev)
157 struct subchannel *sch;
159 sch = to_subchannel(dev);
160 if (!cio_is_console(sch->schid)) {
161 /* Reset intparm to zeroes. */
162 sch->config.intparm = 0;
163 cio_commit_config(sch);
169 static int css_sch_device_register(struct subchannel *sch)
173 mutex_lock(&sch->reg_mutex);
174 dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid,
176 ret = device_register(&sch->dev);
177 mutex_unlock(&sch->reg_mutex);
182 * css_sch_device_unregister - unregister a subchannel
183 * @sch: subchannel to be unregistered
185 void css_sch_device_unregister(struct subchannel *sch)
187 mutex_lock(&sch->reg_mutex);
188 if (device_is_registered(&sch->dev))
189 device_unregister(&sch->dev);
190 mutex_unlock(&sch->reg_mutex);
192 EXPORT_SYMBOL_GPL(css_sch_device_unregister);
194 static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
199 memset(ssd, 0, sizeof(struct chsc_ssd_info));
200 ssd->path_mask = pmcw->pim;
201 for (i = 0; i < 8; i++) {
203 if (pmcw->pim & mask) {
204 chp_id_init(&ssd->chpid[i]);
205 ssd->chpid[i].id = pmcw->chpid[i];
210 static void ssd_register_chpids(struct chsc_ssd_info *ssd)
215 for (i = 0; i < 8; i++) {
217 if (ssd->path_mask & mask)
218 if (!chp_is_registered(ssd->chpid[i]))
219 chp_new(ssd->chpid[i]);
223 void css_update_ssd_info(struct subchannel *sch)
227 if (cio_is_console(sch->schid)) {
228 /* Console is initialized too early for functions requiring
229 * memory allocation. */
230 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
232 ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
234 ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
235 ssd_register_chpids(&sch->ssd_info);
239 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
242 struct subchannel *sch = to_subchannel(dev);
244 return sprintf(buf, "%01x\n", sch->st);
247 static DEVICE_ATTR(type, 0444, type_show, NULL);
249 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
252 struct subchannel *sch = to_subchannel(dev);
254 return sprintf(buf, "css:t%01X\n", sch->st);
257 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
259 static struct attribute *subch_attrs[] = {
261 &dev_attr_modalias.attr,
265 static struct attribute_group subch_attr_group = {
266 .attrs = subch_attrs,
269 static struct attribute_group *default_subch_attr_groups[] = {
274 static int css_register_subchannel(struct subchannel *sch)
278 /* Initialize the subchannel structure */
279 sch->dev.parent = &channel_subsystems[0]->device;
280 sch->dev.bus = &css_bus_type;
281 sch->dev.release = &css_subchannel_release;
282 sch->dev.groups = default_subch_attr_groups;
284 * We don't want to generate uevents for I/O subchannels that don't
285 * have a working ccw device behind them since they will be
286 * unregistered before they can be used anyway, so we delay the add
287 * uevent until after device recognition was successful.
288 * Note that we suppress the uevent for all subchannel types;
289 * the subchannel driver can decide itself when it wants to inform
290 * userspace of its existence.
292 dev_set_uevent_suppress(&sch->dev, 1);
293 css_update_ssd_info(sch);
294 /* make it known to the system */
295 ret = css_sch_device_register(sch);
297 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
298 sch->schid.ssid, sch->schid.sch_no, ret);
303 * No driver matched. Generate the uevent now so that
304 * a fitting driver module may be loaded based on the
307 dev_set_uevent_suppress(&sch->dev, 0);
308 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
313 int css_probe_device(struct subchannel_id schid)
316 struct subchannel *sch;
318 sch = css_alloc_subchannel(schid);
321 ret = css_register_subchannel(sch);
323 put_device(&sch->dev);
328 check_subchannel(struct device * dev, void * data)
330 struct subchannel *sch;
331 struct subchannel_id *schid = data;
333 sch = to_subchannel(dev);
334 return schid_equal(&sch->schid, schid);
338 get_subchannel_by_schid(struct subchannel_id schid)
342 dev = bus_find_device(&css_bus_type, NULL,
343 &schid, check_subchannel);
345 return dev ? to_subchannel(dev) : NULL;
349 * css_sch_is_valid() - check if a subchannel is valid
350 * @schib: subchannel information block for the subchannel
352 int css_sch_is_valid(struct schib *schib)
354 if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
356 if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w)
360 EXPORT_SYMBOL_GPL(css_sch_is_valid);
362 static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
367 /* Will be done on the slow path. */
370 if (stsch_err(schid, &schib) || !css_sch_is_valid(&schib)) {
371 /* Unusable - ignore. */
374 CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, unknown, "
375 "slow path.\n", schid.ssid, schid.sch_no, CIO_OPER);
377 return css_probe_device(schid);
380 static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
385 if (sch->driver->sch_event)
386 ret = sch->driver->sch_event(sch, slow);
389 "Got subchannel machine check but "
390 "no sch_event handler provided.\n");
395 static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
397 struct subchannel *sch;
400 sch = get_subchannel_by_schid(schid);
402 ret = css_evaluate_known_subchannel(sch, slow);
403 put_device(&sch->dev);
405 ret = css_evaluate_new_subchannel(schid, slow);
407 css_schedule_eval(schid);
410 static struct idset *slow_subchannel_set;
411 static spinlock_t slow_subchannel_lock;
413 static int __init slow_subchannel_init(void)
415 spin_lock_init(&slow_subchannel_lock);
416 slow_subchannel_set = idset_sch_new();
417 if (!slow_subchannel_set) {
418 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
424 static int slow_eval_known_fn(struct subchannel *sch, void *data)
429 spin_lock_irq(&slow_subchannel_lock);
430 eval = idset_sch_contains(slow_subchannel_set, sch->schid);
431 idset_sch_del(slow_subchannel_set, sch->schid);
432 spin_unlock_irq(&slow_subchannel_lock);
434 rc = css_evaluate_known_subchannel(sch, 1);
436 css_schedule_eval(sch->schid);
441 static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
446 spin_lock_irq(&slow_subchannel_lock);
447 eval = idset_sch_contains(slow_subchannel_set, schid);
448 idset_sch_del(slow_subchannel_set, schid);
449 spin_unlock_irq(&slow_subchannel_lock);
451 rc = css_evaluate_new_subchannel(schid, 1);
454 css_schedule_eval(schid);
460 /* These should abort looping */
469 static void css_slow_path_func(struct work_struct *unused)
471 CIO_TRACE_EVENT(4, "slowpath");
472 for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
476 static DECLARE_WORK(slow_path_work, css_slow_path_func);
477 struct workqueue_struct *slow_path_wq;
479 void css_schedule_eval(struct subchannel_id schid)
483 spin_lock_irqsave(&slow_subchannel_lock, flags);
484 idset_sch_add(slow_subchannel_set, schid);
485 queue_work(slow_path_wq, &slow_path_work);
486 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
489 void css_schedule_eval_all(void)
493 spin_lock_irqsave(&slow_subchannel_lock, flags);
494 idset_fill(slow_subchannel_set);
495 queue_work(slow_path_wq, &slow_path_work);
496 spin_unlock_irqrestore(&slow_subchannel_lock, flags);
499 void css_wait_for_slow_path(void)
501 flush_workqueue(slow_path_wq);
504 /* Reprobe subchannel if unregistered. */
505 static int reprobe_subchannel(struct subchannel_id schid, void *data)
509 CIO_MSG_EVENT(6, "cio: reprobe 0.%x.%04x\n",
510 schid.ssid, schid.sch_no);
514 ret = css_probe_device(schid);
521 /* These should abort looping */
530 static void reprobe_after_idle(struct work_struct *unused)
532 /* Make sure initial subchannel scan is done. */
533 wait_event(ccw_device_init_wq,
534 atomic_read(&ccw_device_init_count) == 0);
536 css_schedule_reprobe();
539 static DECLARE_WORK(reprobe_idle_work, reprobe_after_idle);
541 /* Work function used to reprobe all unregistered subchannels. */
542 static void reprobe_all(struct work_struct *unused)
546 CIO_MSG_EVENT(4, "reprobe start\n");
548 /* Make sure initial subchannel scan is done. */
549 if (atomic_read(&ccw_device_init_count) != 0) {
550 queue_work(ccw_device_work, &reprobe_idle_work);
554 ret = for_each_subchannel_staged(NULL, reprobe_subchannel, NULL);
556 CIO_MSG_EVENT(4, "reprobe done (rc=%d, need_reprobe=%d)\n", ret,
560 static DECLARE_WORK(css_reprobe_work, reprobe_all);
562 /* Schedule reprobing of all unregistered subchannels. */
563 void css_schedule_reprobe(void)
566 queue_work(slow_path_wq, &css_reprobe_work);
569 EXPORT_SYMBOL_GPL(css_schedule_reprobe);
572 * Called from the machine check handler for subchannel report words.
574 static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
576 struct subchannel_id mchk_schid;
579 css_schedule_eval_all();
582 CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
583 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
584 crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
585 crw0->erc, crw0->rsid);
587 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
588 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
589 crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
590 crw1->anc, crw1->erc, crw1->rsid);
591 init_subchannel_id(&mchk_schid);
592 mchk_schid.sch_no = crw0->rsid;
594 mchk_schid.ssid = (crw1->rsid >> 8) & 3;
597 * Since we are always presented with IPI in the CRW, we have to
598 * use stsch() to find out if the subchannel in question has come
601 css_evaluate_subchannel(mchk_schid, 0);
605 __init_channel_subsystem(struct subchannel_id schid, void *data)
607 struct subchannel *sch;
610 if (cio_is_console(schid))
611 sch = cio_get_console_subchannel();
613 sch = css_alloc_subchannel(schid);
622 panic("Out of memory in init_channel_subsystem\n");
623 /* -ENXIO: no more subchannels. */
626 /* -EIO: this subchannel set not supported. */
634 * We register ALL valid subchannels in ioinfo, even those
635 * that have been present before init_channel_subsystem.
636 * These subchannels can't have been registered yet (kmalloc
637 * not working) so we do it now. This is true e.g. for the
638 * console subchannel.
640 if (css_register_subchannel(sch)) {
641 if (!cio_is_console(schid))
642 put_device(&sch->dev);
648 css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
650 if (css_general_characteristics.mcss) {
651 css->global_pgid.pgid_high.ext_cssid.version = 0x80;
652 css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
655 css->global_pgid.pgid_high.cpu_addr = stap();
657 css->global_pgid.pgid_high.cpu_addr = 0;
660 css->global_pgid.cpu_id = S390_lowcore.cpu_id.ident;
661 css->global_pgid.cpu_model = S390_lowcore.cpu_id.machine;
662 css->global_pgid.tod_high = tod_high;
667 channel_subsystem_release(struct device *dev)
669 struct channel_subsystem *css;
672 mutex_destroy(&css->mutex);
673 if (css->pseudo_subchannel) {
674 /* Implies that it has been generated but never registered. */
675 css_subchannel_release(&css->pseudo_subchannel->dev);
676 css->pseudo_subchannel = NULL;
682 css_cm_enable_show(struct device *dev, struct device_attribute *attr,
685 struct channel_subsystem *css = to_css(dev);
690 mutex_lock(&css->mutex);
691 ret = sprintf(buf, "%x\n", css->cm_enabled);
692 mutex_unlock(&css->mutex);
697 css_cm_enable_store(struct device *dev, struct device_attribute *attr,
698 const char *buf, size_t count)
700 struct channel_subsystem *css = to_css(dev);
704 ret = strict_strtoul(buf, 16, &val);
707 mutex_lock(&css->mutex);
710 ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
713 ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
718 mutex_unlock(&css->mutex);
719 return ret < 0 ? ret : count;
722 static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
724 static int __init setup_css(int nr)
728 struct channel_subsystem *css;
730 css = channel_subsystems[nr];
731 memset(css, 0, sizeof(struct channel_subsystem));
732 css->pseudo_subchannel =
733 kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
734 if (!css->pseudo_subchannel)
736 css->pseudo_subchannel->dev.parent = &css->device;
737 css->pseudo_subchannel->dev.release = css_subchannel_release;
738 dev_set_name(&css->pseudo_subchannel->dev, "defunct");
739 ret = cio_create_sch_lock(css->pseudo_subchannel);
741 kfree(css->pseudo_subchannel);
744 mutex_init(&css->mutex);
747 dev_set_name(&css->device, "css%x", nr);
748 css->device.release = channel_subsystem_release;
749 tod_high = (u32) (get_clock() >> 32);
750 css_generate_pgid(css, tod_high);
754 static int css_reboot_event(struct notifier_block *this,
761 for (i = 0; i <= __MAX_CSSID; i++) {
762 struct channel_subsystem *css;
764 css = channel_subsystems[i];
765 mutex_lock(&css->mutex);
767 if (chsc_secm(css, 0))
769 mutex_unlock(&css->mutex);
775 static struct notifier_block css_reboot_notifier = {
776 .notifier_call = css_reboot_event,
780 * Since the css devices are neither on a bus nor have a class
781 * nor have a special device type, we cannot stop/restart channel
782 * path measurements via the normal suspend/resume callbacks, but have
785 static int css_power_event(struct notifier_block *this, unsigned long event,
792 case PM_HIBERNATION_PREPARE:
793 case PM_SUSPEND_PREPARE:
795 for (i = 0; i <= __MAX_CSSID; i++) {
796 struct channel_subsystem *css;
798 css = channel_subsystems[i];
799 mutex_lock(&css->mutex);
800 if (!css->cm_enabled) {
801 mutex_unlock(&css->mutex);
804 secm_area = (void *)get_zeroed_page(GFP_KERNEL |
807 if (__chsc_do_secm(css, 0, secm_area))
809 free_page((unsigned long)secm_area);
813 mutex_unlock(&css->mutex);
816 case PM_POST_HIBERNATION:
817 case PM_POST_SUSPEND:
819 for (i = 0; i <= __MAX_CSSID; i++) {
820 struct channel_subsystem *css;
822 css = channel_subsystems[i];
823 mutex_lock(&css->mutex);
824 if (!css->cm_enabled) {
825 mutex_unlock(&css->mutex);
828 secm_area = (void *)get_zeroed_page(GFP_KERNEL |
831 if (__chsc_do_secm(css, 1, secm_area))
833 free_page((unsigned long)secm_area);
837 mutex_unlock(&css->mutex);
839 /* search for subchannels, which appeared during hibernation */
840 css_schedule_reprobe();
848 static struct notifier_block css_power_notifier = {
849 .notifier_call = css_power_event,
853 * Now that the driver core is running, we can setup our channel subsystem.
854 * The struct subchannel's are created during probing (except for the
855 * static console subchannel).
858 init_channel_subsystem (void)
862 ret = chsc_determine_css_characteristics();
864 goto out; /* No need to continue. */
866 ret = chsc_alloc_sei_area();
870 ret = slow_subchannel_init();
874 ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
878 if ((ret = bus_register(&css_bus_type)))
881 /* Try to enable MSS. */
882 ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
884 case 0: /* Success. */
885 max_ssid = __MAX_SSID;
892 /* Setup css structure. */
893 for (i = 0; i <= __MAX_CSSID; i++) {
894 struct channel_subsystem *css;
896 css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
901 channel_subsystems[i] = css;
904 kfree(channel_subsystems[i]);
907 ret = device_register(&css->device);
909 put_device(&css->device);
912 if (css_chsc_characteristics.secm) {
913 ret = device_create_file(&css->device,
914 &dev_attr_cm_enable);
918 ret = device_register(&css->pseudo_subchannel->dev);
920 put_device(&css->pseudo_subchannel->dev);
924 ret = register_reboot_notifier(&css_reboot_notifier);
927 ret = register_pm_notifier(&css_power_notifier);
929 unregister_reboot_notifier(&css_reboot_notifier);
934 /* Enable default isc for I/O subchannels. */
935 isc_register(IO_SCH_ISC);
937 for_each_subchannel(__init_channel_subsystem, NULL);
940 if (css_chsc_characteristics.secm)
941 device_remove_file(&channel_subsystems[i]->device,
942 &dev_attr_cm_enable);
944 device_unregister(&channel_subsystems[i]->device);
947 struct channel_subsystem *css;
950 css = channel_subsystems[i];
951 device_unregister(&css->pseudo_subchannel->dev);
952 css->pseudo_subchannel = NULL;
953 if (css_chsc_characteristics.secm)
954 device_remove_file(&css->device,
955 &dev_attr_cm_enable);
956 device_unregister(&css->device);
959 bus_unregister(&css_bus_type);
961 crw_unregister_handler(CRW_RSC_CSS);
962 chsc_free_sei_area();
963 kfree(slow_subchannel_set);
964 pr_alert("The CSS device driver initialization failed with "
969 int sch_is_pseudo_sch(struct subchannel *sch)
971 return sch == to_css(sch->dev.parent)->pseudo_subchannel;
974 static int css_bus_match(struct device *dev, struct device_driver *drv)
976 struct subchannel *sch = to_subchannel(dev);
977 struct css_driver *driver = to_cssdriver(drv);
978 struct css_device_id *id;
980 for (id = driver->subchannel_type; id->match_flags; id++) {
981 if (sch->st == id->type)
988 static int css_probe(struct device *dev)
990 struct subchannel *sch;
993 sch = to_subchannel(dev);
994 sch->driver = to_cssdriver(dev->driver);
995 ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
1001 static int css_remove(struct device *dev)
1003 struct subchannel *sch;
1006 sch = to_subchannel(dev);
1007 ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
1012 static void css_shutdown(struct device *dev)
1014 struct subchannel *sch;
1016 sch = to_subchannel(dev);
1017 if (sch->driver && sch->driver->shutdown)
1018 sch->driver->shutdown(sch);
1021 static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
1023 struct subchannel *sch = to_subchannel(dev);
1026 ret = add_uevent_var(env, "ST=%01X", sch->st);
1029 ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
1033 static int css_pm_prepare(struct device *dev)
1035 struct subchannel *sch = to_subchannel(dev);
1036 struct css_driver *drv;
1038 if (mutex_is_locked(&sch->reg_mutex))
1040 if (!sch->dev.driver)
1042 drv = to_cssdriver(sch->dev.driver);
1043 /* Notify drivers that they may not register children. */
1044 return drv->prepare ? drv->prepare(sch) : 0;
1047 static void css_pm_complete(struct device *dev)
1049 struct subchannel *sch = to_subchannel(dev);
1050 struct css_driver *drv;
1052 if (!sch->dev.driver)
1054 drv = to_cssdriver(sch->dev.driver);
1059 static int css_pm_freeze(struct device *dev)
1061 struct subchannel *sch = to_subchannel(dev);
1062 struct css_driver *drv;
1064 if (!sch->dev.driver)
1066 drv = to_cssdriver(sch->dev.driver);
1067 return drv->freeze ? drv->freeze(sch) : 0;
1070 static int css_pm_thaw(struct device *dev)
1072 struct subchannel *sch = to_subchannel(dev);
1073 struct css_driver *drv;
1075 if (!sch->dev.driver)
1077 drv = to_cssdriver(sch->dev.driver);
1078 return drv->thaw ? drv->thaw(sch) : 0;
1081 static int css_pm_restore(struct device *dev)
1083 struct subchannel *sch = to_subchannel(dev);
1084 struct css_driver *drv;
1086 if (!sch->dev.driver)
1088 drv = to_cssdriver(sch->dev.driver);
1089 return drv->restore ? drv->restore(sch) : 0;
1092 static struct dev_pm_ops css_pm_ops = {
1093 .prepare = css_pm_prepare,
1094 .complete = css_pm_complete,
1095 .freeze = css_pm_freeze,
1096 .thaw = css_pm_thaw,
1097 .restore = css_pm_restore,
1100 struct bus_type css_bus_type = {
1102 .match = css_bus_match,
1104 .remove = css_remove,
1105 .shutdown = css_shutdown,
1106 .uevent = css_uevent,
1111 * css_driver_register - register a css driver
1112 * @cdrv: css driver to register
1114 * This is mainly a wrapper around driver_register that sets name
1115 * and bus_type in the embedded struct device_driver correctly.
1117 int css_driver_register(struct css_driver *cdrv)
1119 cdrv->drv.name = cdrv->name;
1120 cdrv->drv.bus = &css_bus_type;
1121 cdrv->drv.owner = cdrv->owner;
1122 return driver_register(&cdrv->drv);
1124 EXPORT_SYMBOL_GPL(css_driver_register);
1127 * css_driver_unregister - unregister a css driver
1128 * @cdrv: css driver to unregister
1130 * This is a wrapper around driver_unregister.
1132 void css_driver_unregister(struct css_driver *cdrv)
1134 driver_unregister(&cdrv->drv);
1136 EXPORT_SYMBOL_GPL(css_driver_unregister);
1138 subsys_initcall(init_channel_subsystem);
1140 MODULE_LICENSE("GPL");
1141 EXPORT_SYMBOL(css_bus_type);