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)
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>
21
#include <linux/proc_fs.h>
27
#include "cio_debug.h"
34
int css_init_done = 0;
37
struct channel_subsystem *channel_subsystems[__MAX_CSSID + 1];
38
static struct bus_type css_bus_type;
41
for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *data)
43
struct subchannel_id schid;
46
init_subchannel_id(&schid);
50
ret = fn(schid, data);
53
} while (schid.sch_no++ < __MAX_SUBCHANNEL);
55
} while (schid.ssid++ < max_ssid);
62
int (*fn_known_sch)(struct subchannel *, void *);
63
int (*fn_unknown_sch)(struct subchannel_id, void *);
66
static int call_fn_known_sch(struct device *dev, void *data)
68
struct subchannel *sch = to_subchannel(dev);
69
struct cb_data *cb = data;
72
idset_sch_del(cb->set, sch->schid);
74
rc = cb->fn_known_sch(sch, cb->data);
78
static int call_fn_unknown_sch(struct subchannel_id schid, void *data)
80
struct cb_data *cb = data;
83
if (idset_sch_contains(cb->set, schid))
84
rc = cb->fn_unknown_sch(schid, cb->data);
88
static int call_fn_all_sch(struct subchannel_id schid, void *data)
90
struct cb_data *cb = data;
91
struct subchannel *sch;
94
sch = get_subchannel_by_schid(schid);
97
rc = cb->fn_known_sch(sch, cb->data);
98
put_device(&sch->dev);
100
if (cb->fn_unknown_sch)
101
rc = cb->fn_unknown_sch(schid, cb->data);
107
int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
108
int (*fn_unknown)(struct subchannel_id,
115
cb.fn_known_sch = fn_known;
116
cb.fn_unknown_sch = fn_unknown;
118
cb.set = idset_sch_new();
120
/* fall back to brute force scanning in case of oom */
121
return for_each_subchannel(call_fn_all_sch, &cb);
125
/* Process registered subchannels. */
126
rc = bus_for_each_dev(&css_bus_type, NULL, &cb, call_fn_known_sch);
129
/* Process unregistered subchannels. */
131
rc = for_each_subchannel(call_fn_unknown_sch, &cb);
138
static void css_sch_todo(struct work_struct *work);
140
static struct subchannel *
141
css_alloc_subchannel(struct subchannel_id schid)
143
struct subchannel *sch;
146
sch = kmalloc (sizeof (*sch), GFP_KERNEL | GFP_DMA);
148
return ERR_PTR(-ENOMEM);
149
ret = cio_validate_subchannel (sch, schid);
154
INIT_WORK(&sch->todo_work, css_sch_todo);
159
css_subchannel_release(struct device *dev)
161
struct subchannel *sch;
163
sch = to_subchannel(dev);
164
if (!cio_is_console(sch->schid)) {
165
/* Reset intparm to zeroes. */
166
sch->config.intparm = 0;
167
cio_commit_config(sch);
173
static int css_sch_device_register(struct subchannel *sch)
177
mutex_lock(&sch->reg_mutex);
178
dev_set_name(&sch->dev, "0.%x.%04x", sch->schid.ssid,
180
ret = device_register(&sch->dev);
181
mutex_unlock(&sch->reg_mutex);
186
* css_sch_device_unregister - unregister a subchannel
187
* @sch: subchannel to be unregistered
189
void css_sch_device_unregister(struct subchannel *sch)
191
mutex_lock(&sch->reg_mutex);
192
if (device_is_registered(&sch->dev))
193
device_unregister(&sch->dev);
194
mutex_unlock(&sch->reg_mutex);
196
EXPORT_SYMBOL_GPL(css_sch_device_unregister);
198
static void ssd_from_pmcw(struct chsc_ssd_info *ssd, struct pmcw *pmcw)
203
memset(ssd, 0, sizeof(struct chsc_ssd_info));
204
ssd->path_mask = pmcw->pim;
205
for (i = 0; i < 8; i++) {
207
if (pmcw->pim & mask) {
208
chp_id_init(&ssd->chpid[i]);
209
ssd->chpid[i].id = pmcw->chpid[i];
214
static void ssd_register_chpids(struct chsc_ssd_info *ssd)
219
for (i = 0; i < 8; i++) {
221
if (ssd->path_mask & mask)
222
if (!chp_is_registered(ssd->chpid[i]))
223
chp_new(ssd->chpid[i]);
227
void css_update_ssd_info(struct subchannel *sch)
231
if (cio_is_console(sch->schid)) {
232
/* Console is initialized too early for functions requiring
233
* memory allocation. */
234
ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
236
ret = chsc_get_ssd_info(sch->schid, &sch->ssd_info);
238
ssd_from_pmcw(&sch->ssd_info, &sch->schib.pmcw);
239
ssd_register_chpids(&sch->ssd_info);
243
static ssize_t type_show(struct device *dev, struct device_attribute *attr,
246
struct subchannel *sch = to_subchannel(dev);
248
return sprintf(buf, "%01x\n", sch->st);
251
static DEVICE_ATTR(type, 0444, type_show, NULL);
253
static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
256
struct subchannel *sch = to_subchannel(dev);
258
return sprintf(buf, "css:t%01X\n", sch->st);
261
static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
263
static struct attribute *subch_attrs[] = {
265
&dev_attr_modalias.attr,
269
static struct attribute_group subch_attr_group = {
270
.attrs = subch_attrs,
273
static const struct attribute_group *default_subch_attr_groups[] = {
278
static int css_register_subchannel(struct subchannel *sch)
282
/* Initialize the subchannel structure */
283
sch->dev.parent = &channel_subsystems[0]->device;
284
sch->dev.bus = &css_bus_type;
285
sch->dev.release = &css_subchannel_release;
286
sch->dev.groups = default_subch_attr_groups;
288
* We don't want to generate uevents for I/O subchannels that don't
289
* have a working ccw device behind them since they will be
290
* unregistered before they can be used anyway, so we delay the add
291
* uevent until after device recognition was successful.
292
* Note that we suppress the uevent for all subchannel types;
293
* the subchannel driver can decide itself when it wants to inform
294
* userspace of its existence.
296
dev_set_uevent_suppress(&sch->dev, 1);
297
css_update_ssd_info(sch);
298
/* make it known to the system */
299
ret = css_sch_device_register(sch);
301
CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
302
sch->schid.ssid, sch->schid.sch_no, ret);
307
* No driver matched. Generate the uevent now so that
308
* a fitting driver module may be loaded based on the
311
dev_set_uevent_suppress(&sch->dev, 0);
312
kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
317
int css_probe_device(struct subchannel_id schid)
320
struct subchannel *sch;
322
if (cio_is_console(schid))
323
sch = cio_get_console_subchannel();
325
sch = css_alloc_subchannel(schid);
329
ret = css_register_subchannel(sch);
331
if (!cio_is_console(schid))
332
put_device(&sch->dev);
338
check_subchannel(struct device * dev, void * data)
340
struct subchannel *sch;
341
struct subchannel_id *schid = data;
343
sch = to_subchannel(dev);
344
return schid_equal(&sch->schid, schid);
348
get_subchannel_by_schid(struct subchannel_id schid)
352
dev = bus_find_device(&css_bus_type, NULL,
353
&schid, check_subchannel);
355
return dev ? to_subchannel(dev) : NULL;
359
* css_sch_is_valid() - check if a subchannel is valid
360
* @schib: subchannel information block for the subchannel
362
int css_sch_is_valid(struct schib *schib)
364
if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
366
if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w)
370
EXPORT_SYMBOL_GPL(css_sch_is_valid);
372
static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
377
/* Will be done on the slow path. */
380
if (stsch_err(schid, &schib) || !css_sch_is_valid(&schib)) {
381
/* Unusable - ignore. */
384
CIO_MSG_EVENT(4, "event: sch 0.%x.%04x, new\n", schid.ssid,
387
return css_probe_device(schid);
390
static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
395
if (sch->driver->sch_event)
396
ret = sch->driver->sch_event(sch, slow);
399
"Got subchannel machine check but "
400
"no sch_event handler provided.\n");
402
if (ret != 0 && ret != -EAGAIN) {
403
CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
404
sch->schid.ssid, sch->schid.sch_no, ret);
409
static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
411
struct subchannel *sch;
414
sch = get_subchannel_by_schid(schid);
416
ret = css_evaluate_known_subchannel(sch, slow);
417
put_device(&sch->dev);
419
ret = css_evaluate_new_subchannel(schid, slow);
421
css_schedule_eval(schid);
425
* css_sched_sch_todo - schedule a subchannel operation
429
* Schedule the operation identified by @todo to be performed on the slow path
430
* workqueue. Do nothing if another operation with higher priority is already
431
* scheduled. Needs to be called with subchannel lock held.
433
void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo)
435
CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
436
sch->schid.ssid, sch->schid.sch_no, todo);
437
if (sch->todo >= todo)
439
/* Get workqueue ref. */
440
if (!get_device(&sch->dev))
443
if (!queue_work(cio_work_q, &sch->todo_work)) {
444
/* Already queued, release workqueue ref. */
445
put_device(&sch->dev);
449
static void css_sch_todo(struct work_struct *work)
451
struct subchannel *sch;
455
sch = container_of(work, struct subchannel, todo_work);
457
spin_lock_irq(sch->lock);
459
CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch->schid.ssid,
460
sch->schid.sch_no, todo);
461
sch->todo = SCH_TODO_NOTHING;
462
spin_unlock_irq(sch->lock);
465
case SCH_TODO_NOTHING:
468
ret = css_evaluate_known_subchannel(sch, 1);
469
if (ret == -EAGAIN) {
470
spin_lock_irq(sch->lock);
471
css_sched_sch_todo(sch, todo);
472
spin_unlock_irq(sch->lock);
476
css_sch_device_unregister(sch);
479
/* Release workqueue ref. */
480
put_device(&sch->dev);
483
static struct idset *slow_subchannel_set;
484
static spinlock_t slow_subchannel_lock;
485
static wait_queue_head_t css_eval_wq;
486
static atomic_t css_eval_scheduled;
488
static int __init slow_subchannel_init(void)
490
spin_lock_init(&slow_subchannel_lock);
491
atomic_set(&css_eval_scheduled, 0);
492
init_waitqueue_head(&css_eval_wq);
493
slow_subchannel_set = idset_sch_new();
494
if (!slow_subchannel_set) {
495
CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
501
static int slow_eval_known_fn(struct subchannel *sch, void *data)
506
spin_lock_irq(&slow_subchannel_lock);
507
eval = idset_sch_contains(slow_subchannel_set, sch->schid);
508
idset_sch_del(slow_subchannel_set, sch->schid);
509
spin_unlock_irq(&slow_subchannel_lock);
511
rc = css_evaluate_known_subchannel(sch, 1);
513
css_schedule_eval(sch->schid);
518
static int slow_eval_unknown_fn(struct subchannel_id schid, void *data)
523
spin_lock_irq(&slow_subchannel_lock);
524
eval = idset_sch_contains(slow_subchannel_set, schid);
525
idset_sch_del(slow_subchannel_set, schid);
526
spin_unlock_irq(&slow_subchannel_lock);
528
rc = css_evaluate_new_subchannel(schid, 1);
531
css_schedule_eval(schid);
537
/* These should abort looping */
546
static void css_slow_path_func(struct work_struct *unused)
550
CIO_TRACE_EVENT(4, "slowpath");
551
for_each_subchannel_staged(slow_eval_known_fn, slow_eval_unknown_fn,
553
spin_lock_irqsave(&slow_subchannel_lock, flags);
554
if (idset_is_empty(slow_subchannel_set)) {
555
atomic_set(&css_eval_scheduled, 0);
556
wake_up(&css_eval_wq);
558
spin_unlock_irqrestore(&slow_subchannel_lock, flags);
561
static DECLARE_WORK(slow_path_work, css_slow_path_func);
562
struct workqueue_struct *cio_work_q;
564
void css_schedule_eval(struct subchannel_id schid)
568
spin_lock_irqsave(&slow_subchannel_lock, flags);
569
idset_sch_add(slow_subchannel_set, schid);
570
atomic_set(&css_eval_scheduled, 1);
571
queue_work(cio_work_q, &slow_path_work);
572
spin_unlock_irqrestore(&slow_subchannel_lock, flags);
575
void css_schedule_eval_all(void)
579
spin_lock_irqsave(&slow_subchannel_lock, flags);
580
idset_fill(slow_subchannel_set);
581
atomic_set(&css_eval_scheduled, 1);
582
queue_work(cio_work_q, &slow_path_work);
583
spin_unlock_irqrestore(&slow_subchannel_lock, flags);
586
static int __unset_registered(struct device *dev, void *data)
588
struct idset *set = data;
589
struct subchannel *sch = to_subchannel(dev);
591
idset_sch_del(set, sch->schid);
595
static void css_schedule_eval_all_unreg(void)
598
struct idset *unreg_set;
600
/* Find unregistered subchannels. */
601
unreg_set = idset_sch_new();
604
css_schedule_eval_all();
607
idset_fill(unreg_set);
608
bus_for_each_dev(&css_bus_type, NULL, unreg_set, __unset_registered);
609
/* Apply to slow_subchannel_set. */
610
spin_lock_irqsave(&slow_subchannel_lock, flags);
611
idset_add_set(slow_subchannel_set, unreg_set);
612
atomic_set(&css_eval_scheduled, 1);
613
queue_work(cio_work_q, &slow_path_work);
614
spin_unlock_irqrestore(&slow_subchannel_lock, flags);
615
idset_free(unreg_set);
618
void css_wait_for_slow_path(void)
620
flush_workqueue(cio_work_q);
623
/* Schedule reprobing of all unregistered subchannels. */
624
void css_schedule_reprobe(void)
626
css_schedule_eval_all_unreg();
628
EXPORT_SYMBOL_GPL(css_schedule_reprobe);
631
* Called from the machine check handler for subchannel report words.
633
static void css_process_crw(struct crw *crw0, struct crw *crw1, int overflow)
635
struct subchannel_id mchk_schid;
636
struct subchannel *sch;
639
css_schedule_eval_all();
642
CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
643
"chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
644
crw0->slct, crw0->oflw, crw0->chn, crw0->rsc, crw0->anc,
645
crw0->erc, crw0->rsid);
647
CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
648
"chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
649
crw1->slct, crw1->oflw, crw1->chn, crw1->rsc,
650
crw1->anc, crw1->erc, crw1->rsid);
651
init_subchannel_id(&mchk_schid);
652
mchk_schid.sch_no = crw0->rsid;
654
mchk_schid.ssid = (crw1->rsid >> 4) & 3;
656
if (crw0->erc == CRW_ERC_PMOD) {
657
sch = get_subchannel_by_schid(mchk_schid);
659
css_update_ssd_info(sch);
660
put_device(&sch->dev);
664
* Since we are always presented with IPI in the CRW, we have to
665
* use stsch() to find out if the subchannel in question has come
668
css_evaluate_subchannel(mchk_schid, 0);
672
css_generate_pgid(struct channel_subsystem *css, u32 tod_high)
676
if (css_general_characteristics.mcss) {
677
css->global_pgid.pgid_high.ext_cssid.version = 0x80;
678
css->global_pgid.pgid_high.ext_cssid.cssid = css->cssid;
681
css->global_pgid.pgid_high.cpu_addr = stap();
683
css->global_pgid.pgid_high.cpu_addr = 0;
687
css->global_pgid.cpu_id = cpu_id.ident;
688
css->global_pgid.cpu_model = cpu_id.machine;
689
css->global_pgid.tod_high = tod_high;
694
channel_subsystem_release(struct device *dev)
696
struct channel_subsystem *css;
699
mutex_destroy(&css->mutex);
700
if (css->pseudo_subchannel) {
701
/* Implies that it has been generated but never registered. */
702
css_subchannel_release(&css->pseudo_subchannel->dev);
703
css->pseudo_subchannel = NULL;
709
css_cm_enable_show(struct device *dev, struct device_attribute *attr,
712
struct channel_subsystem *css = to_css(dev);
717
mutex_lock(&css->mutex);
718
ret = sprintf(buf, "%x\n", css->cm_enabled);
719
mutex_unlock(&css->mutex);
724
css_cm_enable_store(struct device *dev, struct device_attribute *attr,
725
const char *buf, size_t count)
727
struct channel_subsystem *css = to_css(dev);
731
ret = strict_strtoul(buf, 16, &val);
734
mutex_lock(&css->mutex);
737
ret = css->cm_enabled ? chsc_secm(css, 0) : 0;
740
ret = css->cm_enabled ? 0 : chsc_secm(css, 1);
745
mutex_unlock(&css->mutex);
746
return ret < 0 ? ret : count;
749
static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
751
static int __init setup_css(int nr)
755
struct channel_subsystem *css;
757
css = channel_subsystems[nr];
758
memset(css, 0, sizeof(struct channel_subsystem));
759
css->pseudo_subchannel =
760
kzalloc(sizeof(*css->pseudo_subchannel), GFP_KERNEL);
761
if (!css->pseudo_subchannel)
763
css->pseudo_subchannel->dev.parent = &css->device;
764
css->pseudo_subchannel->dev.release = css_subchannel_release;
765
dev_set_name(&css->pseudo_subchannel->dev, "defunct");
766
mutex_init(&css->pseudo_subchannel->reg_mutex);
767
ret = cio_create_sch_lock(css->pseudo_subchannel);
769
kfree(css->pseudo_subchannel);
772
mutex_init(&css->mutex);
775
dev_set_name(&css->device, "css%x", nr);
776
css->device.release = channel_subsystem_release;
777
tod_high = (u32) (get_clock() >> 32);
778
css_generate_pgid(css, tod_high);
782
static int css_reboot_event(struct notifier_block *this,
789
for (i = 0; i <= __MAX_CSSID; i++) {
790
struct channel_subsystem *css;
792
css = channel_subsystems[i];
793
mutex_lock(&css->mutex);
795
if (chsc_secm(css, 0))
797
mutex_unlock(&css->mutex);
803
static struct notifier_block css_reboot_notifier = {
804
.notifier_call = css_reboot_event,
808
* Since the css devices are neither on a bus nor have a class
809
* nor have a special device type, we cannot stop/restart channel
810
* path measurements via the normal suspend/resume callbacks, but have
813
static int css_power_event(struct notifier_block *this, unsigned long event,
819
case PM_HIBERNATION_PREPARE:
820
case PM_SUSPEND_PREPARE:
822
for (i = 0; i <= __MAX_CSSID; i++) {
823
struct channel_subsystem *css;
825
css = channel_subsystems[i];
826
mutex_lock(&css->mutex);
827
if (!css->cm_enabled) {
828
mutex_unlock(&css->mutex);
831
ret = __chsc_do_secm(css, 0);
832
ret = notifier_from_errno(ret);
833
mutex_unlock(&css->mutex);
836
case PM_POST_HIBERNATION:
837
case PM_POST_SUSPEND:
839
for (i = 0; i <= __MAX_CSSID; i++) {
840
struct channel_subsystem *css;
842
css = channel_subsystems[i];
843
mutex_lock(&css->mutex);
844
if (!css->cm_enabled) {
845
mutex_unlock(&css->mutex);
848
ret = __chsc_do_secm(css, 1);
849
ret = notifier_from_errno(ret);
850
mutex_unlock(&css->mutex);
852
/* search for subchannels, which appeared during hibernation */
853
css_schedule_reprobe();
861
static struct notifier_block css_power_notifier = {
862
.notifier_call = css_power_event,
866
* Now that the driver core is running, we can setup our channel subsystem.
867
* The struct subchannel's are created during probing (except for the
868
* static console subchannel).
870
static int __init css_bus_init(void)
878
chsc_determine_css_characteristics();
879
/* Try to enable MSS. */
880
ret = chsc_enable_facility(CHSC_SDA_OC_MSS);
884
max_ssid = __MAX_SSID;
886
ret = slow_subchannel_init();
890
ret = crw_register_handler(CRW_RSC_SCH, css_process_crw);
894
if ((ret = bus_register(&css_bus_type)))
897
/* Setup css structure. */
898
for (i = 0; i <= __MAX_CSSID; i++) {
899
struct channel_subsystem *css;
901
css = kmalloc(sizeof(struct channel_subsystem), GFP_KERNEL);
906
channel_subsystems[i] = css;
909
kfree(channel_subsystems[i]);
912
ret = device_register(&css->device);
914
put_device(&css->device);
917
if (css_chsc_characteristics.secm) {
918
ret = device_create_file(&css->device,
919
&dev_attr_cm_enable);
923
ret = device_register(&css->pseudo_subchannel->dev);
925
put_device(&css->pseudo_subchannel->dev);
929
ret = register_reboot_notifier(&css_reboot_notifier);
932
ret = register_pm_notifier(&css_power_notifier);
934
unregister_reboot_notifier(&css_reboot_notifier);
939
/* Enable default isc for I/O subchannels. */
940
isc_register(IO_SCH_ISC);
944
if (css_chsc_characteristics.secm)
945
device_remove_file(&channel_subsystems[i]->device,
946
&dev_attr_cm_enable);
948
device_unregister(&channel_subsystems[i]->device);
951
struct channel_subsystem *css;
954
css = channel_subsystems[i];
955
device_unregister(&css->pseudo_subchannel->dev);
956
css->pseudo_subchannel = NULL;
957
if (css_chsc_characteristics.secm)
958
device_remove_file(&css->device,
959
&dev_attr_cm_enable);
960
device_unregister(&css->device);
962
bus_unregister(&css_bus_type);
964
crw_unregister_handler(CRW_RSC_SCH);
965
idset_free(slow_subchannel_set);
967
pr_alert("The CSS device driver initialization failed with "
972
static void __init css_bus_cleanup(void)
974
struct channel_subsystem *css;
977
for (i = 0; i <= __MAX_CSSID; i++) {
978
css = channel_subsystems[i];
979
device_unregister(&css->pseudo_subchannel->dev);
980
css->pseudo_subchannel = NULL;
981
if (css_chsc_characteristics.secm)
982
device_remove_file(&css->device, &dev_attr_cm_enable);
983
device_unregister(&css->device);
985
bus_unregister(&css_bus_type);
986
crw_unregister_handler(CRW_RSC_SCH);
987
idset_free(slow_subchannel_set);
989
isc_unregister(IO_SCH_ISC);
992
static int __init channel_subsystem_init(void)
996
ret = css_bus_init();
999
cio_work_q = create_singlethread_workqueue("cio");
1004
ret = io_subchannel_init();
1010
destroy_workqueue(cio_work_q);
1015
subsys_initcall(channel_subsystem_init);
1017
static int css_settle(struct device_driver *drv, void *unused)
1019
struct css_driver *cssdrv = to_cssdriver(drv);
1022
return cssdrv->settle();
1026
int css_complete_work(void)
1030
/* Wait for the evaluation of subchannels to finish. */
1031
ret = wait_event_interruptible(css_eval_wq,
1032
atomic_read(&css_eval_scheduled) == 0);
1035
flush_workqueue(cio_work_q);
1036
/* Wait for the subchannel type specific initialization to finish */
1037
return bus_for_each_drv(&css_bus_type, NULL, NULL, css_settle);
1042
* Wait for the initialization of devices to finish, to make sure we are
1043
* done with our setup if the search for the root device starts.
1045
static int __init channel_subsystem_init_sync(void)
1047
/* Start initial subchannel evaluation. */
1048
css_schedule_eval_all();
1049
css_complete_work();
1052
subsys_initcall_sync(channel_subsystem_init_sync);
1054
void channel_subsystem_reinit(void)
1056
struct channel_path *chp;
1057
struct chp_id chpid;
1059
chsc_enable_facility(CHSC_SDA_OC_MSS);
1060
chp_id_for_each(&chpid) {
1061
chp = chpid_to_chp(chpid);
1064
chsc_determine_base_channel_path_desc(chpid, &chp->desc);
1068
#ifdef CONFIG_PROC_FS
1069
static ssize_t cio_settle_write(struct file *file, const char __user *buf,
1070
size_t count, loff_t *ppos)
1074
/* Handle pending CRW's. */
1075
crw_wait_for_channel_report();
1076
ret = css_complete_work();
1078
return ret ? ret : count;
1081
static const struct file_operations cio_settle_proc_fops = {
1082
.open = nonseekable_open,
1083
.write = cio_settle_write,
1084
.llseek = no_llseek,
1087
static int __init cio_settle_init(void)
1089
struct proc_dir_entry *entry;
1091
entry = proc_create("cio_settle", S_IWUSR, NULL,
1092
&cio_settle_proc_fops);
1097
device_initcall(cio_settle_init);
1098
#endif /*CONFIG_PROC_FS*/
1100
int sch_is_pseudo_sch(struct subchannel *sch)
1102
return sch == to_css(sch->dev.parent)->pseudo_subchannel;
1105
static int css_bus_match(struct device *dev, struct device_driver *drv)
1107
struct subchannel *sch = to_subchannel(dev);
1108
struct css_driver *driver = to_cssdriver(drv);
1109
struct css_device_id *id;
1111
for (id = driver->subchannel_type; id->match_flags; id++) {
1112
if (sch->st == id->type)
1119
static int css_probe(struct device *dev)
1121
struct subchannel *sch;
1124
sch = to_subchannel(dev);
1125
sch->driver = to_cssdriver(dev->driver);
1126
ret = sch->driver->probe ? sch->driver->probe(sch) : 0;
1132
static int css_remove(struct device *dev)
1134
struct subchannel *sch;
1137
sch = to_subchannel(dev);
1138
ret = sch->driver->remove ? sch->driver->remove(sch) : 0;
1143
static void css_shutdown(struct device *dev)
1145
struct subchannel *sch;
1147
sch = to_subchannel(dev);
1148
if (sch->driver && sch->driver->shutdown)
1149
sch->driver->shutdown(sch);
1152
static int css_uevent(struct device *dev, struct kobj_uevent_env *env)
1154
struct subchannel *sch = to_subchannel(dev);
1157
ret = add_uevent_var(env, "ST=%01X", sch->st);
1160
ret = add_uevent_var(env, "MODALIAS=css:t%01X", sch->st);
1164
static int css_pm_prepare(struct device *dev)
1166
struct subchannel *sch = to_subchannel(dev);
1167
struct css_driver *drv;
1169
if (mutex_is_locked(&sch->reg_mutex))
1171
if (!sch->dev.driver)
1173
drv = to_cssdriver(sch->dev.driver);
1174
/* Notify drivers that they may not register children. */
1175
return drv->prepare ? drv->prepare(sch) : 0;
1178
static void css_pm_complete(struct device *dev)
1180
struct subchannel *sch = to_subchannel(dev);
1181
struct css_driver *drv;
1183
if (!sch->dev.driver)
1185
drv = to_cssdriver(sch->dev.driver);
1190
static int css_pm_freeze(struct device *dev)
1192
struct subchannel *sch = to_subchannel(dev);
1193
struct css_driver *drv;
1195
if (!sch->dev.driver)
1197
drv = to_cssdriver(sch->dev.driver);
1198
return drv->freeze ? drv->freeze(sch) : 0;
1201
static int css_pm_thaw(struct device *dev)
1203
struct subchannel *sch = to_subchannel(dev);
1204
struct css_driver *drv;
1206
if (!sch->dev.driver)
1208
drv = to_cssdriver(sch->dev.driver);
1209
return drv->thaw ? drv->thaw(sch) : 0;
1212
static int css_pm_restore(struct device *dev)
1214
struct subchannel *sch = to_subchannel(dev);
1215
struct css_driver *drv;
1217
css_update_ssd_info(sch);
1218
if (!sch->dev.driver)
1220
drv = to_cssdriver(sch->dev.driver);
1221
return drv->restore ? drv->restore(sch) : 0;
1224
static const struct dev_pm_ops css_pm_ops = {
1225
.prepare = css_pm_prepare,
1226
.complete = css_pm_complete,
1227
.freeze = css_pm_freeze,
1228
.thaw = css_pm_thaw,
1229
.restore = css_pm_restore,
1232
static struct bus_type css_bus_type = {
1234
.match = css_bus_match,
1236
.remove = css_remove,
1237
.shutdown = css_shutdown,
1238
.uevent = css_uevent,
1243
* css_driver_register - register a css driver
1244
* @cdrv: css driver to register
1246
* This is mainly a wrapper around driver_register that sets name
1247
* and bus_type in the embedded struct device_driver correctly.
1249
int css_driver_register(struct css_driver *cdrv)
1251
cdrv->drv.bus = &css_bus_type;
1252
return driver_register(&cdrv->drv);
1254
EXPORT_SYMBOL_GPL(css_driver_register);
1257
* css_driver_unregister - unregister a css driver
1258
* @cdrv: css driver to unregister
1260
* This is a wrapper around driver_unregister.
1262
void css_driver_unregister(struct css_driver *cdrv)
1264
driver_unregister(&cdrv->drv);
1266
EXPORT_SYMBOL_GPL(css_driver_unregister);
1268
MODULE_LICENSE("GPL");