1 // SPDX-License-Identifier: GPL-2.0
3 * driver for channel subsystem
5 * Copyright IBM Corp. 2002, 2010
7 * Author(s): Arnd Bergmann (arndb@de.ibm.com)
8 * Cornelia Huck (cornelia.huck@de.ibm.com)
11 #define KMSG_COMPONENT "cio"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
14 #include <linux/export.h>
15 #include <linux/init.h>
16 #include <linux/device.h>
17 #include <linux/slab.h>
18 #include <linux/errno.h>
19 #include <linux/list.h>
20 #include <linux/reboot.h>
21 #include <linux/suspend.h>
22 #include <linux/proc_fs.h>
28 #include "cio_debug.h"
35 int css_init_done
= 0;
39 struct channel_subsystem
*channel_subsystems
[MAX_CSS_IDX
+ 1];
40 static struct bus_type css_bus_type
;
43 for_each_subchannel(int(*fn
)(struct subchannel_id
, void *), void *data
)
45 struct subchannel_id schid
;
48 init_subchannel_id(&schid
);
51 ret
= fn(schid
, data
);
54 } while (schid
.sch_no
++ < __MAX_SUBCHANNEL
);
56 } while (schid
.ssid
++ < max_ssid
);
63 int (*fn_known_sch
)(struct subchannel
*, void *);
64 int (*fn_unknown_sch
)(struct subchannel_id
, void *);
67 static int call_fn_known_sch(struct device
*dev
, void *data
)
69 struct subchannel
*sch
= to_subchannel(dev
);
70 struct cb_data
*cb
= data
;
74 idset_sch_del(cb
->set
, sch
->schid
);
76 rc
= cb
->fn_known_sch(sch
, cb
->data
);
80 static int call_fn_unknown_sch(struct subchannel_id schid
, void *data
)
82 struct cb_data
*cb
= data
;
85 if (idset_sch_contains(cb
->set
, schid
))
86 rc
= cb
->fn_unknown_sch(schid
, cb
->data
);
90 static int call_fn_all_sch(struct subchannel_id schid
, void *data
)
92 struct cb_data
*cb
= data
;
93 struct subchannel
*sch
;
96 sch
= get_subchannel_by_schid(schid
);
99 rc
= cb
->fn_known_sch(sch
, cb
->data
);
100 put_device(&sch
->dev
);
102 if (cb
->fn_unknown_sch
)
103 rc
= cb
->fn_unknown_sch(schid
, cb
->data
);
109 int for_each_subchannel_staged(int (*fn_known
)(struct subchannel
*, void *),
110 int (*fn_unknown
)(struct subchannel_id
,
117 cb
.fn_known_sch
= fn_known
;
118 cb
.fn_unknown_sch
= fn_unknown
;
120 if (fn_known
&& !fn_unknown
) {
121 /* Skip idset allocation in case of known-only loop. */
123 return bus_for_each_dev(&css_bus_type
, NULL
, &cb
,
127 cb
.set
= idset_sch_new();
129 /* fall back to brute force scanning in case of oom */
130 return for_each_subchannel(call_fn_all_sch
, &cb
);
134 /* Process registered subchannels. */
135 rc
= bus_for_each_dev(&css_bus_type
, NULL
, &cb
, call_fn_known_sch
);
138 /* Process unregistered subchannels. */
140 rc
= for_each_subchannel(call_fn_unknown_sch
, &cb
);
147 static void css_sch_todo(struct work_struct
*work
);
149 static int css_sch_create_locks(struct subchannel
*sch
)
151 sch
->lock
= kmalloc(sizeof(*sch
->lock
), GFP_KERNEL
);
155 spin_lock_init(sch
->lock
);
156 mutex_init(&sch
->reg_mutex
);
161 static void css_subchannel_release(struct device
*dev
)
163 struct subchannel
*sch
= to_subchannel(dev
);
165 sch
->config
.intparm
= 0;
166 cio_commit_config(sch
);
171 struct subchannel
*css_alloc_subchannel(struct subchannel_id schid
)
173 struct subchannel
*sch
;
176 sch
= kzalloc(sizeof(*sch
), GFP_KERNEL
| GFP_DMA
);
178 return ERR_PTR(-ENOMEM
);
180 ret
= cio_validate_subchannel(sch
, schid
);
184 ret
= css_sch_create_locks(sch
);
188 INIT_WORK(&sch
->todo_work
, css_sch_todo
);
189 sch
->dev
.release
= &css_subchannel_release
;
190 device_initialize(&sch
->dev
);
198 static int css_sch_device_register(struct subchannel
*sch
)
202 mutex_lock(&sch
->reg_mutex
);
203 dev_set_name(&sch
->dev
, "0.%x.%04x", sch
->schid
.ssid
,
205 ret
= device_add(&sch
->dev
);
206 mutex_unlock(&sch
->reg_mutex
);
211 * css_sch_device_unregister - unregister a subchannel
212 * @sch: subchannel to be unregistered
214 void css_sch_device_unregister(struct subchannel
*sch
)
216 mutex_lock(&sch
->reg_mutex
);
217 if (device_is_registered(&sch
->dev
))
218 device_unregister(&sch
->dev
);
219 mutex_unlock(&sch
->reg_mutex
);
221 EXPORT_SYMBOL_GPL(css_sch_device_unregister
);
223 static void ssd_from_pmcw(struct chsc_ssd_info
*ssd
, struct pmcw
*pmcw
)
228 memset(ssd
, 0, sizeof(struct chsc_ssd_info
));
229 ssd
->path_mask
= pmcw
->pim
;
230 for (i
= 0; i
< 8; i
++) {
232 if (pmcw
->pim
& mask
) {
233 chp_id_init(&ssd
->chpid
[i
]);
234 ssd
->chpid
[i
].id
= pmcw
->chpid
[i
];
239 static void ssd_register_chpids(struct chsc_ssd_info
*ssd
)
244 for (i
= 0; i
< 8; i
++) {
246 if (ssd
->path_mask
& mask
)
247 if (!chp_is_registered(ssd
->chpid
[i
]))
248 chp_new(ssd
->chpid
[i
]);
252 void css_update_ssd_info(struct subchannel
*sch
)
256 ret
= chsc_get_ssd_info(sch
->schid
, &sch
->ssd_info
);
258 ssd_from_pmcw(&sch
->ssd_info
, &sch
->schib
.pmcw
);
260 ssd_register_chpids(&sch
->ssd_info
);
263 static ssize_t
type_show(struct device
*dev
, struct device_attribute
*attr
,
266 struct subchannel
*sch
= to_subchannel(dev
);
268 return sprintf(buf
, "%01x\n", sch
->st
);
271 static DEVICE_ATTR_RO(type
);
273 static ssize_t
modalias_show(struct device
*dev
, struct device_attribute
*attr
,
276 struct subchannel
*sch
= to_subchannel(dev
);
278 return sprintf(buf
, "css:t%01X\n", sch
->st
);
281 static DEVICE_ATTR_RO(modalias
);
283 static struct attribute
*subch_attrs
[] = {
285 &dev_attr_modalias
.attr
,
289 static struct attribute_group subch_attr_group
= {
290 .attrs
= subch_attrs
,
293 static const struct attribute_group
*default_subch_attr_groups
[] = {
298 static ssize_t
chpids_show(struct device
*dev
,
299 struct device_attribute
*attr
,
302 struct subchannel
*sch
= to_subchannel(dev
);
303 struct chsc_ssd_info
*ssd
= &sch
->ssd_info
;
308 for (chp
= 0; chp
< 8; chp
++) {
310 if (ssd
->path_mask
& mask
)
311 ret
+= sprintf(buf
+ ret
, "%02x ", ssd
->chpid
[chp
].id
);
313 ret
+= sprintf(buf
+ ret
, "00 ");
315 ret
+= sprintf(buf
+ ret
, "\n");
318 static DEVICE_ATTR_RO(chpids
);
320 static ssize_t
pimpampom_show(struct device
*dev
,
321 struct device_attribute
*attr
,
324 struct subchannel
*sch
= to_subchannel(dev
);
325 struct pmcw
*pmcw
= &sch
->schib
.pmcw
;
327 return sprintf(buf
, "%02x %02x %02x\n",
328 pmcw
->pim
, pmcw
->pam
, pmcw
->pom
);
330 static DEVICE_ATTR_RO(pimpampom
);
332 static struct attribute
*io_subchannel_type_attrs
[] = {
333 &dev_attr_chpids
.attr
,
334 &dev_attr_pimpampom
.attr
,
337 ATTRIBUTE_GROUPS(io_subchannel_type
);
339 static const struct device_type io_subchannel_type
= {
340 .groups
= io_subchannel_type_groups
,
343 int css_register_subchannel(struct subchannel
*sch
)
347 /* Initialize the subchannel structure */
348 sch
->dev
.parent
= &channel_subsystems
[0]->device
;
349 sch
->dev
.bus
= &css_bus_type
;
350 sch
->dev
.groups
= default_subch_attr_groups
;
352 if (sch
->st
== SUBCHANNEL_TYPE_IO
)
353 sch
->dev
.type
= &io_subchannel_type
;
356 * We don't want to generate uevents for I/O subchannels that don't
357 * have a working ccw device behind them since they will be
358 * unregistered before they can be used anyway, so we delay the add
359 * uevent until after device recognition was successful.
360 * Note that we suppress the uevent for all subchannel types;
361 * the subchannel driver can decide itself when it wants to inform
362 * userspace of its existence.
364 dev_set_uevent_suppress(&sch
->dev
, 1);
365 css_update_ssd_info(sch
);
366 /* make it known to the system */
367 ret
= css_sch_device_register(sch
);
369 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
370 sch
->schid
.ssid
, sch
->schid
.sch_no
, ret
);
375 * No driver matched. Generate the uevent now so that
376 * a fitting driver module may be loaded based on the
379 dev_set_uevent_suppress(&sch
->dev
, 0);
380 kobject_uevent(&sch
->dev
.kobj
, KOBJ_ADD
);
385 static int css_probe_device(struct subchannel_id schid
)
387 struct subchannel
*sch
;
390 sch
= css_alloc_subchannel(schid
);
394 ret
= css_register_subchannel(sch
);
396 put_device(&sch
->dev
);
402 check_subchannel(struct device
* dev
, void * data
)
404 struct subchannel
*sch
;
405 struct subchannel_id
*schid
= data
;
407 sch
= to_subchannel(dev
);
408 return schid_equal(&sch
->schid
, schid
);
412 get_subchannel_by_schid(struct subchannel_id schid
)
416 dev
= bus_find_device(&css_bus_type
, NULL
,
417 &schid
, check_subchannel
);
419 return dev
? to_subchannel(dev
) : NULL
;
423 * css_sch_is_valid() - check if a subchannel is valid
424 * @schib: subchannel information block for the subchannel
426 int css_sch_is_valid(struct schib
*schib
)
428 if ((schib
->pmcw
.st
== SUBCHANNEL_TYPE_IO
) && !schib
->pmcw
.dnv
)
430 if ((schib
->pmcw
.st
== SUBCHANNEL_TYPE_MSG
) && !schib
->pmcw
.w
)
434 EXPORT_SYMBOL_GPL(css_sch_is_valid
);
436 static int css_evaluate_new_subchannel(struct subchannel_id schid
, int slow
)
441 /* Will be done on the slow path. */
444 if (stsch(schid
, &schib
)) {
445 /* Subchannel is not provided. */
448 if (!css_sch_is_valid(&schib
)) {
449 /* Unusable - ignore. */
452 CIO_MSG_EVENT(4, "event: sch 0.%x.%04x, new\n", schid
.ssid
,
455 return css_probe_device(schid
);
458 static int css_evaluate_known_subchannel(struct subchannel
*sch
, int slow
)
463 if (sch
->driver
->sch_event
)
464 ret
= sch
->driver
->sch_event(sch
, slow
);
467 "Got subchannel machine check but "
468 "no sch_event handler provided.\n");
470 if (ret
!= 0 && ret
!= -EAGAIN
) {
471 CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
472 sch
->schid
.ssid
, sch
->schid
.sch_no
, ret
);
477 static void css_evaluate_subchannel(struct subchannel_id schid
, int slow
)
479 struct subchannel
*sch
;
482 sch
= get_subchannel_by_schid(schid
);
484 ret
= css_evaluate_known_subchannel(sch
, slow
);
485 put_device(&sch
->dev
);
487 ret
= css_evaluate_new_subchannel(schid
, slow
);
489 css_schedule_eval(schid
);
493 * css_sched_sch_todo - schedule a subchannel operation
497 * Schedule the operation identified by @todo to be performed on the slow path
498 * workqueue. Do nothing if another operation with higher priority is already
499 * scheduled. Needs to be called with subchannel lock held.
501 void css_sched_sch_todo(struct subchannel
*sch
, enum sch_todo todo
)
503 CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
504 sch
->schid
.ssid
, sch
->schid
.sch_no
, todo
);
505 if (sch
->todo
>= todo
)
507 /* Get workqueue ref. */
508 if (!get_device(&sch
->dev
))
511 if (!queue_work(cio_work_q
, &sch
->todo_work
)) {
512 /* Already queued, release workqueue ref. */
513 put_device(&sch
->dev
);
516 EXPORT_SYMBOL_GPL(css_sched_sch_todo
);
518 static void css_sch_todo(struct work_struct
*work
)
520 struct subchannel
*sch
;
524 sch
= container_of(work
, struct subchannel
, todo_work
);
526 spin_lock_irq(sch
->lock
);
528 CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch
->schid
.ssid
,
529 sch
->schid
.sch_no
, todo
);
530 sch
->todo
= SCH_TODO_NOTHING
;
531 spin_unlock_irq(sch
->lock
);
534 case SCH_TODO_NOTHING
:
537 ret
= css_evaluate_known_subchannel(sch
, 1);
538 if (ret
== -EAGAIN
) {
539 spin_lock_irq(sch
->lock
);
540 css_sched_sch_todo(sch
, todo
);
541 spin_unlock_irq(sch
->lock
);
545 css_sch_device_unregister(sch
);
548 /* Release workqueue ref. */
549 put_device(&sch
->dev
);
552 static struct idset
*slow_subchannel_set
;
553 static spinlock_t slow_subchannel_lock
;
554 static wait_queue_head_t css_eval_wq
;
555 static atomic_t css_eval_scheduled
;
557 static int __init
slow_subchannel_init(void)
559 spin_lock_init(&slow_subchannel_lock
);
560 atomic_set(&css_eval_scheduled
, 0);
561 init_waitqueue_head(&css_eval_wq
);
562 slow_subchannel_set
= idset_sch_new();
563 if (!slow_subchannel_set
) {
564 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
570 static int slow_eval_known_fn(struct subchannel
*sch
, void *data
)
575 spin_lock_irq(&slow_subchannel_lock
);
576 eval
= idset_sch_contains(slow_subchannel_set
, sch
->schid
);
577 idset_sch_del(slow_subchannel_set
, sch
->schid
);
578 spin_unlock_irq(&slow_subchannel_lock
);
580 rc
= css_evaluate_known_subchannel(sch
, 1);
582 css_schedule_eval(sch
->schid
);
587 static int slow_eval_unknown_fn(struct subchannel_id schid
, void *data
)
592 spin_lock_irq(&slow_subchannel_lock
);
593 eval
= idset_sch_contains(slow_subchannel_set
, schid
);
594 idset_sch_del(slow_subchannel_set
, schid
);
595 spin_unlock_irq(&slow_subchannel_lock
);
597 rc
= css_evaluate_new_subchannel(schid
, 1);
600 css_schedule_eval(schid
);
606 /* These should abort looping */
607 spin_lock_irq(&slow_subchannel_lock
);
608 idset_sch_del_subseq(slow_subchannel_set
, schid
);
609 spin_unlock_irq(&slow_subchannel_lock
);
614 /* Allow scheduling here since the containing loop might
621 static void css_slow_path_func(struct work_struct
*unused
)
625 CIO_TRACE_EVENT(4, "slowpath");
626 for_each_subchannel_staged(slow_eval_known_fn
, slow_eval_unknown_fn
,
628 spin_lock_irqsave(&slow_subchannel_lock
, flags
);
629 if (idset_is_empty(slow_subchannel_set
)) {
630 atomic_set(&css_eval_scheduled
, 0);
631 wake_up(&css_eval_wq
);
633 spin_unlock_irqrestore(&slow_subchannel_lock
, flags
);
636 static DECLARE_DELAYED_WORK(slow_path_work
, css_slow_path_func
);
637 struct workqueue_struct
*cio_work_q
;
639 void css_schedule_eval(struct subchannel_id schid
)
643 spin_lock_irqsave(&slow_subchannel_lock
, flags
);
644 idset_sch_add(slow_subchannel_set
, schid
);
645 atomic_set(&css_eval_scheduled
, 1);
646 queue_delayed_work(cio_work_q
, &slow_path_work
, 0);
647 spin_unlock_irqrestore(&slow_subchannel_lock
, flags
);
650 void css_schedule_eval_all(void)
654 spin_lock_irqsave(&slow_subchannel_lock
, flags
);
655 idset_fill(slow_subchannel_set
);
656 atomic_set(&css_eval_scheduled
, 1);
657 queue_delayed_work(cio_work_q
, &slow_path_work
, 0);
658 spin_unlock_irqrestore(&slow_subchannel_lock
, flags
);
661 static int __unset_registered(struct device
*dev
, void *data
)
663 struct idset
*set
= data
;
664 struct subchannel
*sch
= to_subchannel(dev
);
666 idset_sch_del(set
, sch
->schid
);
670 void css_schedule_eval_all_unreg(unsigned long delay
)
673 struct idset
*unreg_set
;
675 /* Find unregistered subchannels. */
676 unreg_set
= idset_sch_new();
679 css_schedule_eval_all();
682 idset_fill(unreg_set
);
683 bus_for_each_dev(&css_bus_type
, NULL
, unreg_set
, __unset_registered
);
684 /* Apply to slow_subchannel_set. */
685 spin_lock_irqsave(&slow_subchannel_lock
, flags
);
686 idset_add_set(slow_subchannel_set
, unreg_set
);
687 atomic_set(&css_eval_scheduled
, 1);
688 queue_delayed_work(cio_work_q
, &slow_path_work
, delay
);
689 spin_unlock_irqrestore(&slow_subchannel_lock
, flags
);
690 idset_free(unreg_set
);
693 void css_wait_for_slow_path(void)
695 flush_workqueue(cio_work_q
);
698 /* Schedule reprobing of all unregistered subchannels. */
699 void css_schedule_reprobe(void)
701 /* Schedule with a delay to allow merging of subsequent calls. */
702 css_schedule_eval_all_unreg(1 * HZ
);
704 EXPORT_SYMBOL_GPL(css_schedule_reprobe
);
707 * Called from the machine check handler for subchannel report words.
709 static void css_process_crw(struct crw
*crw0
, struct crw
*crw1
, int overflow
)
711 struct subchannel_id mchk_schid
;
712 struct subchannel
*sch
;
715 css_schedule_eval_all();
718 CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
719 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
720 crw0
->slct
, crw0
->oflw
, crw0
->chn
, crw0
->rsc
, crw0
->anc
,
721 crw0
->erc
, crw0
->rsid
);
723 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
724 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
725 crw1
->slct
, crw1
->oflw
, crw1
->chn
, crw1
->rsc
,
726 crw1
->anc
, crw1
->erc
, crw1
->rsid
);
727 init_subchannel_id(&mchk_schid
);
728 mchk_schid
.sch_no
= crw0
->rsid
;
730 mchk_schid
.ssid
= (crw1
->rsid
>> 4) & 3;
732 if (crw0
->erc
== CRW_ERC_PMOD
) {
733 sch
= get_subchannel_by_schid(mchk_schid
);
735 css_update_ssd_info(sch
);
736 put_device(&sch
->dev
);
740 * Since we are always presented with IPI in the CRW, we have to
741 * use stsch() to find out if the subchannel in question has come
744 css_evaluate_subchannel(mchk_schid
, 0);
748 css_generate_pgid(struct channel_subsystem
*css
, u32 tod_high
)
752 if (css_general_characteristics
.mcss
) {
753 css
->global_pgid
.pgid_high
.ext_cssid
.version
= 0x80;
754 css
->global_pgid
.pgid_high
.ext_cssid
.cssid
=
755 (css
->cssid
< 0) ? 0 : css
->cssid
;
757 css
->global_pgid
.pgid_high
.cpu_addr
= stap();
760 css
->global_pgid
.cpu_id
= cpu_id
.ident
;
761 css
->global_pgid
.cpu_model
= cpu_id
.machine
;
762 css
->global_pgid
.tod_high
= tod_high
;
765 static void channel_subsystem_release(struct device
*dev
)
767 struct channel_subsystem
*css
= to_css(dev
);
769 mutex_destroy(&css
->mutex
);
773 static ssize_t
real_cssid_show(struct device
*dev
, struct device_attribute
*a
,
776 struct channel_subsystem
*css
= to_css(dev
);
781 return sprintf(buf
, "%x\n", css
->cssid
);
783 static DEVICE_ATTR_RO(real_cssid
);
785 static ssize_t
cm_enable_show(struct device
*dev
, struct device_attribute
*a
,
788 struct channel_subsystem
*css
= to_css(dev
);
791 mutex_lock(&css
->mutex
);
792 ret
= sprintf(buf
, "%x\n", css
->cm_enabled
);
793 mutex_unlock(&css
->mutex
);
797 static ssize_t
cm_enable_store(struct device
*dev
, struct device_attribute
*a
,
798 const char *buf
, size_t count
)
800 struct channel_subsystem
*css
= to_css(dev
);
804 ret
= kstrtoul(buf
, 16, &val
);
807 mutex_lock(&css
->mutex
);
810 ret
= css
->cm_enabled
? chsc_secm(css
, 0) : 0;
813 ret
= css
->cm_enabled
? 0 : chsc_secm(css
, 1);
818 mutex_unlock(&css
->mutex
);
819 return ret
< 0 ? ret
: count
;
821 static DEVICE_ATTR_RW(cm_enable
);
823 static umode_t
cm_enable_mode(struct kobject
*kobj
, struct attribute
*attr
,
826 return css_chsc_characteristics
.secm
? attr
->mode
: 0;
829 static struct attribute
*cssdev_attrs
[] = {
830 &dev_attr_real_cssid
.attr
,
834 static struct attribute_group cssdev_attr_group
= {
835 .attrs
= cssdev_attrs
,
838 static struct attribute
*cssdev_cm_attrs
[] = {
839 &dev_attr_cm_enable
.attr
,
843 static struct attribute_group cssdev_cm_attr_group
= {
844 .attrs
= cssdev_cm_attrs
,
845 .is_visible
= cm_enable_mode
,
848 static const struct attribute_group
*cssdev_attr_groups
[] = {
850 &cssdev_cm_attr_group
,
854 static int __init
setup_css(int nr
)
856 struct channel_subsystem
*css
;
859 css
= kzalloc(sizeof(*css
), GFP_KERNEL
);
863 channel_subsystems
[nr
] = css
;
864 dev_set_name(&css
->device
, "css%x", nr
);
865 css
->device
.groups
= cssdev_attr_groups
;
866 css
->device
.release
= channel_subsystem_release
;
868 mutex_init(&css
->mutex
);
869 css
->cssid
= chsc_get_cssid(nr
);
870 css_generate_pgid(css
, (u32
) (get_tod_clock() >> 32));
872 ret
= device_register(&css
->device
);
874 put_device(&css
->device
);
878 css
->pseudo_subchannel
= kzalloc(sizeof(*css
->pseudo_subchannel
),
880 if (!css
->pseudo_subchannel
) {
881 device_unregister(&css
->device
);
886 css
->pseudo_subchannel
->dev
.parent
= &css
->device
;
887 css
->pseudo_subchannel
->dev
.release
= css_subchannel_release
;
888 mutex_init(&css
->pseudo_subchannel
->reg_mutex
);
889 ret
= css_sch_create_locks(css
->pseudo_subchannel
);
891 kfree(css
->pseudo_subchannel
);
892 device_unregister(&css
->device
);
896 dev_set_name(&css
->pseudo_subchannel
->dev
, "defunct");
897 ret
= device_register(&css
->pseudo_subchannel
->dev
);
899 put_device(&css
->pseudo_subchannel
->dev
);
900 device_unregister(&css
->device
);
906 channel_subsystems
[nr
] = NULL
;
910 static int css_reboot_event(struct notifier_block
*this,
914 struct channel_subsystem
*css
;
919 mutex_lock(&css
->mutex
);
921 if (chsc_secm(css
, 0))
923 mutex_unlock(&css
->mutex
);
929 static struct notifier_block css_reboot_notifier
= {
930 .notifier_call
= css_reboot_event
,
934 * Since the css devices are neither on a bus nor have a class
935 * nor have a special device type, we cannot stop/restart channel
936 * path measurements via the normal suspend/resume callbacks, but have
939 static int css_power_event(struct notifier_block
*this, unsigned long event
,
942 struct channel_subsystem
*css
;
946 case PM_HIBERNATION_PREPARE
:
947 case PM_SUSPEND_PREPARE
:
950 mutex_lock(&css
->mutex
);
951 if (!css
->cm_enabled
) {
952 mutex_unlock(&css
->mutex
);
955 ret
= __chsc_do_secm(css
, 0);
956 ret
= notifier_from_errno(ret
);
957 mutex_unlock(&css
->mutex
);
960 case PM_POST_HIBERNATION
:
961 case PM_POST_SUSPEND
:
964 mutex_lock(&css
->mutex
);
965 if (!css
->cm_enabled
) {
966 mutex_unlock(&css
->mutex
);
969 ret
= __chsc_do_secm(css
, 1);
970 ret
= notifier_from_errno(ret
);
971 mutex_unlock(&css
->mutex
);
973 /* search for subchannels, which appeared during hibernation */
974 css_schedule_reprobe();
982 static struct notifier_block css_power_notifier
= {
983 .notifier_call
= css_power_event
,
987 * Now that the driver core is running, we can setup our channel subsystem.
988 * The struct subchannel's are created during probing.
990 static int __init
css_bus_init(void)
998 chsc_determine_css_characteristics();
999 /* Try to enable MSS. */
1000 ret
= chsc_enable_facility(CHSC_SDA_OC_MSS
);
1004 max_ssid
= __MAX_SSID
;
1006 ret
= slow_subchannel_init();
1010 ret
= crw_register_handler(CRW_RSC_SCH
, css_process_crw
);
1014 if ((ret
= bus_register(&css_bus_type
)))
1017 /* Setup css structure. */
1018 for (i
= 0; i
<= MAX_CSS_IDX
; i
++) {
1021 goto out_unregister
;
1023 ret
= register_reboot_notifier(&css_reboot_notifier
);
1025 goto out_unregister
;
1026 ret
= register_pm_notifier(&css_power_notifier
);
1028 unregister_reboot_notifier(&css_reboot_notifier
);
1029 goto out_unregister
;
1033 /* Enable default isc for I/O subchannels. */
1034 isc_register(IO_SCH_ISC
);
1039 struct channel_subsystem
*css
= channel_subsystems
[i
];
1040 device_unregister(&css
->pseudo_subchannel
->dev
);
1041 device_unregister(&css
->device
);
1043 bus_unregister(&css_bus_type
);
1045 crw_unregister_handler(CRW_RSC_SCH
);
1046 idset_free(slow_subchannel_set
);
1047 chsc_init_cleanup();
1048 pr_alert("The CSS device driver initialization failed with "
1053 static void __init
css_bus_cleanup(void)
1055 struct channel_subsystem
*css
;
1058 device_unregister(&css
->pseudo_subchannel
->dev
);
1059 device_unregister(&css
->device
);
1061 bus_unregister(&css_bus_type
);
1062 crw_unregister_handler(CRW_RSC_SCH
);
1063 idset_free(slow_subchannel_set
);
1064 chsc_init_cleanup();
1065 isc_unregister(IO_SCH_ISC
);
1068 static int __init
channel_subsystem_init(void)
1072 ret
= css_bus_init();
1075 cio_work_q
= create_singlethread_workqueue("cio");
1080 ret
= io_subchannel_init();
1086 destroy_workqueue(cio_work_q
);
1091 subsys_initcall(channel_subsystem_init
);
1093 static int css_settle(struct device_driver
*drv
, void *unused
)
1095 struct css_driver
*cssdrv
= to_cssdriver(drv
);
1098 return cssdrv
->settle();
1102 int css_complete_work(void)
1106 /* Wait for the evaluation of subchannels to finish. */
1107 ret
= wait_event_interruptible(css_eval_wq
,
1108 atomic_read(&css_eval_scheduled
) == 0);
1111 flush_workqueue(cio_work_q
);
1112 /* Wait for the subchannel type specific initialization to finish */
1113 return bus_for_each_drv(&css_bus_type
, NULL
, NULL
, css_settle
);
1118 * Wait for the initialization of devices to finish, to make sure we are
1119 * done with our setup if the search for the root device starts.
1121 static int __init
channel_subsystem_init_sync(void)
1123 /* Register subchannels which are already in use. */
1124 cio_register_early_subchannels();
1125 /* Start initial subchannel evaluation. */
1126 css_schedule_eval_all();
1127 css_complete_work();
1130 subsys_initcall_sync(channel_subsystem_init_sync
);
1132 void channel_subsystem_reinit(void)
1134 struct channel_path
*chp
;
1135 struct chp_id chpid
;
1137 chsc_enable_facility(CHSC_SDA_OC_MSS
);
1138 chp_id_for_each(&chpid
) {
1139 chp
= chpid_to_chp(chpid
);
1141 chp_update_desc(chp
);
1146 #ifdef CONFIG_PROC_FS
1147 static ssize_t
cio_settle_write(struct file
*file
, const char __user
*buf
,
1148 size_t count
, loff_t
*ppos
)
1152 /* Handle pending CRW's. */
1153 crw_wait_for_channel_report();
1154 ret
= css_complete_work();
1156 return ret
? ret
: count
;
1159 static const struct file_operations cio_settle_proc_fops
= {
1160 .open
= nonseekable_open
,
1161 .write
= cio_settle_write
,
1162 .llseek
= no_llseek
,
1165 static int __init
cio_settle_init(void)
1167 struct proc_dir_entry
*entry
;
1169 entry
= proc_create("cio_settle", S_IWUSR
, NULL
,
1170 &cio_settle_proc_fops
);
1175 device_initcall(cio_settle_init
);
1176 #endif /*CONFIG_PROC_FS*/
1178 int sch_is_pseudo_sch(struct subchannel
*sch
)
1180 return sch
== to_css(sch
->dev
.parent
)->pseudo_subchannel
;
1183 static int css_bus_match(struct device
*dev
, struct device_driver
*drv
)
1185 struct subchannel
*sch
= to_subchannel(dev
);
1186 struct css_driver
*driver
= to_cssdriver(drv
);
1187 struct css_device_id
*id
;
1189 for (id
= driver
->subchannel_type
; id
->match_flags
; id
++) {
1190 if (sch
->st
== id
->type
)
1197 static int css_probe(struct device
*dev
)
1199 struct subchannel
*sch
;
1202 sch
= to_subchannel(dev
);
1203 sch
->driver
= to_cssdriver(dev
->driver
);
1204 ret
= sch
->driver
->probe
? sch
->driver
->probe(sch
) : 0;
1210 static int css_remove(struct device
*dev
)
1212 struct subchannel
*sch
;
1215 sch
= to_subchannel(dev
);
1216 ret
= sch
->driver
->remove
? sch
->driver
->remove(sch
) : 0;
1221 static void css_shutdown(struct device
*dev
)
1223 struct subchannel
*sch
;
1225 sch
= to_subchannel(dev
);
1226 if (sch
->driver
&& sch
->driver
->shutdown
)
1227 sch
->driver
->shutdown(sch
);
1230 static int css_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
1232 struct subchannel
*sch
= to_subchannel(dev
);
1235 ret
= add_uevent_var(env
, "ST=%01X", sch
->st
);
1238 ret
= add_uevent_var(env
, "MODALIAS=css:t%01X", sch
->st
);
1242 static int css_pm_prepare(struct device
*dev
)
1244 struct subchannel
*sch
= to_subchannel(dev
);
1245 struct css_driver
*drv
;
1247 if (mutex_is_locked(&sch
->reg_mutex
))
1249 if (!sch
->dev
.driver
)
1251 drv
= to_cssdriver(sch
->dev
.driver
);
1252 /* Notify drivers that they may not register children. */
1253 return drv
->prepare
? drv
->prepare(sch
) : 0;
1256 static void css_pm_complete(struct device
*dev
)
1258 struct subchannel
*sch
= to_subchannel(dev
);
1259 struct css_driver
*drv
;
1261 if (!sch
->dev
.driver
)
1263 drv
= to_cssdriver(sch
->dev
.driver
);
1268 static int css_pm_freeze(struct device
*dev
)
1270 struct subchannel
*sch
= to_subchannel(dev
);
1271 struct css_driver
*drv
;
1273 if (!sch
->dev
.driver
)
1275 drv
= to_cssdriver(sch
->dev
.driver
);
1276 return drv
->freeze
? drv
->freeze(sch
) : 0;
1279 static int css_pm_thaw(struct device
*dev
)
1281 struct subchannel
*sch
= to_subchannel(dev
);
1282 struct css_driver
*drv
;
1284 if (!sch
->dev
.driver
)
1286 drv
= to_cssdriver(sch
->dev
.driver
);
1287 return drv
->thaw
? drv
->thaw(sch
) : 0;
1290 static int css_pm_restore(struct device
*dev
)
1292 struct subchannel
*sch
= to_subchannel(dev
);
1293 struct css_driver
*drv
;
1295 css_update_ssd_info(sch
);
1296 if (!sch
->dev
.driver
)
1298 drv
= to_cssdriver(sch
->dev
.driver
);
1299 return drv
->restore
? drv
->restore(sch
) : 0;
1302 static const struct dev_pm_ops css_pm_ops
= {
1303 .prepare
= css_pm_prepare
,
1304 .complete
= css_pm_complete
,
1305 .freeze
= css_pm_freeze
,
1306 .thaw
= css_pm_thaw
,
1307 .restore
= css_pm_restore
,
1310 static struct bus_type css_bus_type
= {
1312 .match
= css_bus_match
,
1314 .remove
= css_remove
,
1315 .shutdown
= css_shutdown
,
1316 .uevent
= css_uevent
,
1321 * css_driver_register - register a css driver
1322 * @cdrv: css driver to register
1324 * This is mainly a wrapper around driver_register that sets name
1325 * and bus_type in the embedded struct device_driver correctly.
1327 int css_driver_register(struct css_driver
*cdrv
)
1329 cdrv
->drv
.bus
= &css_bus_type
;
1330 return driver_register(&cdrv
->drv
);
1332 EXPORT_SYMBOL_GPL(css_driver_register
);
1335 * css_driver_unregister - unregister a css driver
1336 * @cdrv: css driver to unregister
1338 * This is a wrapper around driver_unregister.
1340 void css_driver_unregister(struct css_driver
*cdrv
)
1342 driver_unregister(&cdrv
->drv
);
1344 EXPORT_SYMBOL_GPL(css_driver_unregister
);