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 "blacklist.h"
29 #include "cio_debug.h"
36 int css_init_done
= 0;
40 struct channel_subsystem
*channel_subsystems
[MAX_CSS_IDX
+ 1];
41 static struct bus_type css_bus_type
;
44 for_each_subchannel(int(*fn
)(struct subchannel_id
, void *), void *data
)
46 struct subchannel_id schid
;
49 init_subchannel_id(&schid
);
52 ret
= fn(schid
, data
);
55 } while (schid
.sch_no
++ < __MAX_SUBCHANNEL
);
57 } while (schid
.ssid
++ < max_ssid
);
64 int (*fn_known_sch
)(struct subchannel
*, void *);
65 int (*fn_unknown_sch
)(struct subchannel_id
, void *);
68 static int call_fn_known_sch(struct device
*dev
, void *data
)
70 struct subchannel
*sch
= to_subchannel(dev
);
71 struct cb_data
*cb
= data
;
75 idset_sch_del(cb
->set
, sch
->schid
);
77 rc
= cb
->fn_known_sch(sch
, cb
->data
);
81 static int call_fn_unknown_sch(struct subchannel_id schid
, void *data
)
83 struct cb_data
*cb
= data
;
86 if (idset_sch_contains(cb
->set
, schid
))
87 rc
= cb
->fn_unknown_sch(schid
, cb
->data
);
91 static int call_fn_all_sch(struct subchannel_id schid
, void *data
)
93 struct cb_data
*cb
= data
;
94 struct subchannel
*sch
;
97 sch
= get_subchannel_by_schid(schid
);
100 rc
= cb
->fn_known_sch(sch
, cb
->data
);
101 put_device(&sch
->dev
);
103 if (cb
->fn_unknown_sch
)
104 rc
= cb
->fn_unknown_sch(schid
, cb
->data
);
110 int for_each_subchannel_staged(int (*fn_known
)(struct subchannel
*, void *),
111 int (*fn_unknown
)(struct subchannel_id
,
118 cb
.fn_known_sch
= fn_known
;
119 cb
.fn_unknown_sch
= fn_unknown
;
121 if (fn_known
&& !fn_unknown
) {
122 /* Skip idset allocation in case of known-only loop. */
124 return bus_for_each_dev(&css_bus_type
, NULL
, &cb
,
128 cb
.set
= idset_sch_new();
130 /* fall back to brute force scanning in case of oom */
131 return for_each_subchannel(call_fn_all_sch
, &cb
);
135 /* Process registered subchannels. */
136 rc
= bus_for_each_dev(&css_bus_type
, NULL
, &cb
, call_fn_known_sch
);
139 /* Process unregistered subchannels. */
141 rc
= for_each_subchannel(call_fn_unknown_sch
, &cb
);
148 static void css_sch_todo(struct work_struct
*work
);
150 static int css_sch_create_locks(struct subchannel
*sch
)
152 sch
->lock
= kmalloc(sizeof(*sch
->lock
), GFP_KERNEL
);
156 spin_lock_init(sch
->lock
);
157 mutex_init(&sch
->reg_mutex
);
162 static void css_subchannel_release(struct device
*dev
)
164 struct subchannel
*sch
= to_subchannel(dev
);
166 sch
->config
.intparm
= 0;
167 cio_commit_config(sch
);
172 static int css_validate_subchannel(struct subchannel_id schid
,
177 switch (schib
->pmcw
.st
) {
178 case SUBCHANNEL_TYPE_IO
:
179 case SUBCHANNEL_TYPE_MSG
:
180 if (!css_sch_is_valid(schib
))
182 else if (is_blacklisted(schid
.ssid
, schib
->pmcw
.dev
)) {
183 CIO_MSG_EVENT(6, "Blacklisted device detected "
184 "at devno %04X, subchannel set %x\n",
185 schib
->pmcw
.dev
, schid
.ssid
);
196 CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n",
197 schid
.ssid
, schid
.sch_no
, schib
->pmcw
.st
);
202 struct subchannel
*css_alloc_subchannel(struct subchannel_id schid
,
205 struct subchannel
*sch
;
208 ret
= css_validate_subchannel(schid
, schib
);
212 sch
= kzalloc(sizeof(*sch
), GFP_KERNEL
| GFP_DMA
);
214 return ERR_PTR(-ENOMEM
);
218 sch
->st
= schib
->pmcw
.st
;
220 ret
= css_sch_create_locks(sch
);
224 INIT_WORK(&sch
->todo_work
, css_sch_todo
);
225 sch
->dev
.release
= &css_subchannel_release
;
226 device_initialize(&sch
->dev
);
234 static int css_sch_device_register(struct subchannel
*sch
)
238 mutex_lock(&sch
->reg_mutex
);
239 dev_set_name(&sch
->dev
, "0.%x.%04x", sch
->schid
.ssid
,
241 ret
= device_add(&sch
->dev
);
242 mutex_unlock(&sch
->reg_mutex
);
247 * css_sch_device_unregister - unregister a subchannel
248 * @sch: subchannel to be unregistered
250 void css_sch_device_unregister(struct subchannel
*sch
)
252 mutex_lock(&sch
->reg_mutex
);
253 if (device_is_registered(&sch
->dev
))
254 device_unregister(&sch
->dev
);
255 mutex_unlock(&sch
->reg_mutex
);
257 EXPORT_SYMBOL_GPL(css_sch_device_unregister
);
259 static void ssd_from_pmcw(struct chsc_ssd_info
*ssd
, struct pmcw
*pmcw
)
264 memset(ssd
, 0, sizeof(struct chsc_ssd_info
));
265 ssd
->path_mask
= pmcw
->pim
;
266 for (i
= 0; i
< 8; i
++) {
268 if (pmcw
->pim
& mask
) {
269 chp_id_init(&ssd
->chpid
[i
]);
270 ssd
->chpid
[i
].id
= pmcw
->chpid
[i
];
275 static void ssd_register_chpids(struct chsc_ssd_info
*ssd
)
280 for (i
= 0; i
< 8; i
++) {
282 if (ssd
->path_mask
& mask
)
283 chp_new(ssd
->chpid
[i
]);
287 void css_update_ssd_info(struct subchannel
*sch
)
291 ret
= chsc_get_ssd_info(sch
->schid
, &sch
->ssd_info
);
293 ssd_from_pmcw(&sch
->ssd_info
, &sch
->schib
.pmcw
);
295 ssd_register_chpids(&sch
->ssd_info
);
298 static ssize_t
type_show(struct device
*dev
, struct device_attribute
*attr
,
301 struct subchannel
*sch
= to_subchannel(dev
);
303 return sprintf(buf
, "%01x\n", sch
->st
);
306 static DEVICE_ATTR_RO(type
);
308 static ssize_t
modalias_show(struct device
*dev
, struct device_attribute
*attr
,
311 struct subchannel
*sch
= to_subchannel(dev
);
313 return sprintf(buf
, "css:t%01X\n", sch
->st
);
316 static DEVICE_ATTR_RO(modalias
);
318 static struct attribute
*subch_attrs
[] = {
320 &dev_attr_modalias
.attr
,
324 static struct attribute_group subch_attr_group
= {
325 .attrs
= subch_attrs
,
328 static const struct attribute_group
*default_subch_attr_groups
[] = {
333 static ssize_t
chpids_show(struct device
*dev
,
334 struct device_attribute
*attr
,
337 struct subchannel
*sch
= to_subchannel(dev
);
338 struct chsc_ssd_info
*ssd
= &sch
->ssd_info
;
343 for (chp
= 0; chp
< 8; chp
++) {
345 if (ssd
->path_mask
& mask
)
346 ret
+= sprintf(buf
+ ret
, "%02x ", ssd
->chpid
[chp
].id
);
348 ret
+= sprintf(buf
+ ret
, "00 ");
350 ret
+= sprintf(buf
+ ret
, "\n");
353 static DEVICE_ATTR_RO(chpids
);
355 static ssize_t
pimpampom_show(struct device
*dev
,
356 struct device_attribute
*attr
,
359 struct subchannel
*sch
= to_subchannel(dev
);
360 struct pmcw
*pmcw
= &sch
->schib
.pmcw
;
362 return sprintf(buf
, "%02x %02x %02x\n",
363 pmcw
->pim
, pmcw
->pam
, pmcw
->pom
);
365 static DEVICE_ATTR_RO(pimpampom
);
367 static struct attribute
*io_subchannel_type_attrs
[] = {
368 &dev_attr_chpids
.attr
,
369 &dev_attr_pimpampom
.attr
,
372 ATTRIBUTE_GROUPS(io_subchannel_type
);
374 static const struct device_type io_subchannel_type
= {
375 .groups
= io_subchannel_type_groups
,
378 int css_register_subchannel(struct subchannel
*sch
)
382 /* Initialize the subchannel structure */
383 sch
->dev
.parent
= &channel_subsystems
[0]->device
;
384 sch
->dev
.bus
= &css_bus_type
;
385 sch
->dev
.groups
= default_subch_attr_groups
;
387 if (sch
->st
== SUBCHANNEL_TYPE_IO
)
388 sch
->dev
.type
= &io_subchannel_type
;
391 * We don't want to generate uevents for I/O subchannels that don't
392 * have a working ccw device behind them since they will be
393 * unregistered before they can be used anyway, so we delay the add
394 * uevent until after device recognition was successful.
395 * Note that we suppress the uevent for all subchannel types;
396 * the subchannel driver can decide itself when it wants to inform
397 * userspace of its existence.
399 dev_set_uevent_suppress(&sch
->dev
, 1);
400 css_update_ssd_info(sch
);
401 /* make it known to the system */
402 ret
= css_sch_device_register(sch
);
404 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
405 sch
->schid
.ssid
, sch
->schid
.sch_no
, ret
);
410 * No driver matched. Generate the uevent now so that
411 * a fitting driver module may be loaded based on the
414 dev_set_uevent_suppress(&sch
->dev
, 0);
415 kobject_uevent(&sch
->dev
.kobj
, KOBJ_ADD
);
420 static int css_probe_device(struct subchannel_id schid
, struct schib
*schib
)
422 struct subchannel
*sch
;
425 sch
= css_alloc_subchannel(schid
, schib
);
429 ret
= css_register_subchannel(sch
);
431 put_device(&sch
->dev
);
437 check_subchannel(struct device
* dev
, void * data
)
439 struct subchannel
*sch
;
440 struct subchannel_id
*schid
= data
;
442 sch
= to_subchannel(dev
);
443 return schid_equal(&sch
->schid
, schid
);
447 get_subchannel_by_schid(struct subchannel_id schid
)
451 dev
= bus_find_device(&css_bus_type
, NULL
,
452 &schid
, check_subchannel
);
454 return dev
? to_subchannel(dev
) : NULL
;
458 * css_sch_is_valid() - check if a subchannel is valid
459 * @schib: subchannel information block for the subchannel
461 int css_sch_is_valid(struct schib
*schib
)
463 if ((schib
->pmcw
.st
== SUBCHANNEL_TYPE_IO
) && !schib
->pmcw
.dnv
)
465 if ((schib
->pmcw
.st
== SUBCHANNEL_TYPE_MSG
) && !schib
->pmcw
.w
)
469 EXPORT_SYMBOL_GPL(css_sch_is_valid
);
471 static int css_evaluate_new_subchannel(struct subchannel_id schid
, int slow
)
477 /* Will be done on the slow path. */
481 * The first subchannel that is not-operational (ccode==3)
482 * indicates that there aren't any more devices available.
483 * If stsch gets an exception, it means the current subchannel set
486 ccode
= stsch(schid
, &schib
);
488 return (ccode
== 3) ? -ENXIO
: ccode
;
490 return css_probe_device(schid
, &schib
);
493 static int css_evaluate_known_subchannel(struct subchannel
*sch
, int slow
)
498 if (sch
->driver
->sch_event
)
499 ret
= sch
->driver
->sch_event(sch
, slow
);
502 "Got subchannel machine check but "
503 "no sch_event handler provided.\n");
505 if (ret
!= 0 && ret
!= -EAGAIN
) {
506 CIO_MSG_EVENT(2, "eval: sch 0.%x.%04x, rc=%d\n",
507 sch
->schid
.ssid
, sch
->schid
.sch_no
, ret
);
512 static void css_evaluate_subchannel(struct subchannel_id schid
, int slow
)
514 struct subchannel
*sch
;
517 sch
= get_subchannel_by_schid(schid
);
519 ret
= css_evaluate_known_subchannel(sch
, slow
);
520 put_device(&sch
->dev
);
522 ret
= css_evaluate_new_subchannel(schid
, slow
);
524 css_schedule_eval(schid
);
528 * css_sched_sch_todo - schedule a subchannel operation
532 * Schedule the operation identified by @todo to be performed on the slow path
533 * workqueue. Do nothing if another operation with higher priority is already
534 * scheduled. Needs to be called with subchannel lock held.
536 void css_sched_sch_todo(struct subchannel
*sch
, enum sch_todo todo
)
538 CIO_MSG_EVENT(4, "sch_todo: sched sch=0.%x.%04x todo=%d\n",
539 sch
->schid
.ssid
, sch
->schid
.sch_no
, todo
);
540 if (sch
->todo
>= todo
)
542 /* Get workqueue ref. */
543 if (!get_device(&sch
->dev
))
546 if (!queue_work(cio_work_q
, &sch
->todo_work
)) {
547 /* Already queued, release workqueue ref. */
548 put_device(&sch
->dev
);
551 EXPORT_SYMBOL_GPL(css_sched_sch_todo
);
553 static void css_sch_todo(struct work_struct
*work
)
555 struct subchannel
*sch
;
559 sch
= container_of(work
, struct subchannel
, todo_work
);
561 spin_lock_irq(sch
->lock
);
563 CIO_MSG_EVENT(4, "sch_todo: sch=0.%x.%04x, todo=%d\n", sch
->schid
.ssid
,
564 sch
->schid
.sch_no
, todo
);
565 sch
->todo
= SCH_TODO_NOTHING
;
566 spin_unlock_irq(sch
->lock
);
569 case SCH_TODO_NOTHING
:
572 ret
= css_evaluate_known_subchannel(sch
, 1);
573 if (ret
== -EAGAIN
) {
574 spin_lock_irq(sch
->lock
);
575 css_sched_sch_todo(sch
, todo
);
576 spin_unlock_irq(sch
->lock
);
580 css_sch_device_unregister(sch
);
583 /* Release workqueue ref. */
584 put_device(&sch
->dev
);
587 static struct idset
*slow_subchannel_set
;
588 static spinlock_t slow_subchannel_lock
;
589 static wait_queue_head_t css_eval_wq
;
590 static atomic_t css_eval_scheduled
;
592 static int __init
slow_subchannel_init(void)
594 spin_lock_init(&slow_subchannel_lock
);
595 atomic_set(&css_eval_scheduled
, 0);
596 init_waitqueue_head(&css_eval_wq
);
597 slow_subchannel_set
= idset_sch_new();
598 if (!slow_subchannel_set
) {
599 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
605 static int slow_eval_known_fn(struct subchannel
*sch
, void *data
)
610 spin_lock_irq(&slow_subchannel_lock
);
611 eval
= idset_sch_contains(slow_subchannel_set
, sch
->schid
);
612 idset_sch_del(slow_subchannel_set
, sch
->schid
);
613 spin_unlock_irq(&slow_subchannel_lock
);
615 rc
= css_evaluate_known_subchannel(sch
, 1);
617 css_schedule_eval(sch
->schid
);
622 static int slow_eval_unknown_fn(struct subchannel_id schid
, void *data
)
627 spin_lock_irq(&slow_subchannel_lock
);
628 eval
= idset_sch_contains(slow_subchannel_set
, schid
);
629 idset_sch_del(slow_subchannel_set
, schid
);
630 spin_unlock_irq(&slow_subchannel_lock
);
632 rc
= css_evaluate_new_subchannel(schid
, 1);
635 css_schedule_eval(schid
);
641 /* These should abort looping */
642 spin_lock_irq(&slow_subchannel_lock
);
643 idset_sch_del_subseq(slow_subchannel_set
, schid
);
644 spin_unlock_irq(&slow_subchannel_lock
);
649 /* Allow scheduling here since the containing loop might
656 static void css_slow_path_func(struct work_struct
*unused
)
660 CIO_TRACE_EVENT(4, "slowpath");
661 for_each_subchannel_staged(slow_eval_known_fn
, slow_eval_unknown_fn
,
663 spin_lock_irqsave(&slow_subchannel_lock
, flags
);
664 if (idset_is_empty(slow_subchannel_set
)) {
665 atomic_set(&css_eval_scheduled
, 0);
666 wake_up(&css_eval_wq
);
668 spin_unlock_irqrestore(&slow_subchannel_lock
, flags
);
671 static DECLARE_DELAYED_WORK(slow_path_work
, css_slow_path_func
);
672 struct workqueue_struct
*cio_work_q
;
674 void css_schedule_eval(struct subchannel_id schid
)
678 spin_lock_irqsave(&slow_subchannel_lock
, flags
);
679 idset_sch_add(slow_subchannel_set
, schid
);
680 atomic_set(&css_eval_scheduled
, 1);
681 queue_delayed_work(cio_work_q
, &slow_path_work
, 0);
682 spin_unlock_irqrestore(&slow_subchannel_lock
, flags
);
685 void css_schedule_eval_all(void)
689 spin_lock_irqsave(&slow_subchannel_lock
, flags
);
690 idset_fill(slow_subchannel_set
);
691 atomic_set(&css_eval_scheduled
, 1);
692 queue_delayed_work(cio_work_q
, &slow_path_work
, 0);
693 spin_unlock_irqrestore(&slow_subchannel_lock
, flags
);
696 static int __unset_registered(struct device
*dev
, void *data
)
698 struct idset
*set
= data
;
699 struct subchannel
*sch
= to_subchannel(dev
);
701 idset_sch_del(set
, sch
->schid
);
705 void css_schedule_eval_all_unreg(unsigned long delay
)
708 struct idset
*unreg_set
;
710 /* Find unregistered subchannels. */
711 unreg_set
= idset_sch_new();
714 css_schedule_eval_all();
717 idset_fill(unreg_set
);
718 bus_for_each_dev(&css_bus_type
, NULL
, unreg_set
, __unset_registered
);
719 /* Apply to slow_subchannel_set. */
720 spin_lock_irqsave(&slow_subchannel_lock
, flags
);
721 idset_add_set(slow_subchannel_set
, unreg_set
);
722 atomic_set(&css_eval_scheduled
, 1);
723 queue_delayed_work(cio_work_q
, &slow_path_work
, delay
);
724 spin_unlock_irqrestore(&slow_subchannel_lock
, flags
);
725 idset_free(unreg_set
);
728 void css_wait_for_slow_path(void)
730 flush_workqueue(cio_work_q
);
733 /* Schedule reprobing of all unregistered subchannels. */
734 void css_schedule_reprobe(void)
736 /* Schedule with a delay to allow merging of subsequent calls. */
737 css_schedule_eval_all_unreg(1 * HZ
);
739 EXPORT_SYMBOL_GPL(css_schedule_reprobe
);
742 * Called from the machine check handler for subchannel report words.
744 static void css_process_crw(struct crw
*crw0
, struct crw
*crw1
, int overflow
)
746 struct subchannel_id mchk_schid
;
747 struct subchannel
*sch
;
750 css_schedule_eval_all();
753 CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
754 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
755 crw0
->slct
, crw0
->oflw
, crw0
->chn
, crw0
->rsc
, crw0
->anc
,
756 crw0
->erc
, crw0
->rsid
);
758 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
759 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
760 crw1
->slct
, crw1
->oflw
, crw1
->chn
, crw1
->rsc
,
761 crw1
->anc
, crw1
->erc
, crw1
->rsid
);
762 init_subchannel_id(&mchk_schid
);
763 mchk_schid
.sch_no
= crw0
->rsid
;
765 mchk_schid
.ssid
= (crw1
->rsid
>> 4) & 3;
767 if (crw0
->erc
== CRW_ERC_PMOD
) {
768 sch
= get_subchannel_by_schid(mchk_schid
);
770 css_update_ssd_info(sch
);
771 put_device(&sch
->dev
);
775 * Since we are always presented with IPI in the CRW, we have to
776 * use stsch() to find out if the subchannel in question has come
779 css_evaluate_subchannel(mchk_schid
, 0);
783 css_generate_pgid(struct channel_subsystem
*css
, u32 tod_high
)
787 if (css_general_characteristics
.mcss
) {
788 css
->global_pgid
.pgid_high
.ext_cssid
.version
= 0x80;
789 css
->global_pgid
.pgid_high
.ext_cssid
.cssid
=
790 (css
->cssid
< 0) ? 0 : css
->cssid
;
792 css
->global_pgid
.pgid_high
.cpu_addr
= stap();
795 css
->global_pgid
.cpu_id
= cpu_id
.ident
;
796 css
->global_pgid
.cpu_model
= cpu_id
.machine
;
797 css
->global_pgid
.tod_high
= tod_high
;
800 static void channel_subsystem_release(struct device
*dev
)
802 struct channel_subsystem
*css
= to_css(dev
);
804 mutex_destroy(&css
->mutex
);
808 static ssize_t
real_cssid_show(struct device
*dev
, struct device_attribute
*a
,
811 struct channel_subsystem
*css
= to_css(dev
);
816 return sprintf(buf
, "%x\n", css
->cssid
);
818 static DEVICE_ATTR_RO(real_cssid
);
820 static ssize_t
cm_enable_show(struct device
*dev
, struct device_attribute
*a
,
823 struct channel_subsystem
*css
= to_css(dev
);
826 mutex_lock(&css
->mutex
);
827 ret
= sprintf(buf
, "%x\n", css
->cm_enabled
);
828 mutex_unlock(&css
->mutex
);
832 static ssize_t
cm_enable_store(struct device
*dev
, struct device_attribute
*a
,
833 const char *buf
, size_t count
)
835 struct channel_subsystem
*css
= to_css(dev
);
839 ret
= kstrtoul(buf
, 16, &val
);
842 mutex_lock(&css
->mutex
);
845 ret
= css
->cm_enabled
? chsc_secm(css
, 0) : 0;
848 ret
= css
->cm_enabled
? 0 : chsc_secm(css
, 1);
853 mutex_unlock(&css
->mutex
);
854 return ret
< 0 ? ret
: count
;
856 static DEVICE_ATTR_RW(cm_enable
);
858 static umode_t
cm_enable_mode(struct kobject
*kobj
, struct attribute
*attr
,
861 return css_chsc_characteristics
.secm
? attr
->mode
: 0;
864 static struct attribute
*cssdev_attrs
[] = {
865 &dev_attr_real_cssid
.attr
,
869 static struct attribute_group cssdev_attr_group
= {
870 .attrs
= cssdev_attrs
,
873 static struct attribute
*cssdev_cm_attrs
[] = {
874 &dev_attr_cm_enable
.attr
,
878 static struct attribute_group cssdev_cm_attr_group
= {
879 .attrs
= cssdev_cm_attrs
,
880 .is_visible
= cm_enable_mode
,
883 static const struct attribute_group
*cssdev_attr_groups
[] = {
885 &cssdev_cm_attr_group
,
889 static int __init
setup_css(int nr
)
891 struct channel_subsystem
*css
;
894 css
= kzalloc(sizeof(*css
), GFP_KERNEL
);
898 channel_subsystems
[nr
] = css
;
899 dev_set_name(&css
->device
, "css%x", nr
);
900 css
->device
.groups
= cssdev_attr_groups
;
901 css
->device
.release
= channel_subsystem_release
;
903 mutex_init(&css
->mutex
);
904 css
->cssid
= chsc_get_cssid(nr
);
905 css_generate_pgid(css
, (u32
) (get_tod_clock() >> 32));
907 ret
= device_register(&css
->device
);
909 put_device(&css
->device
);
913 css
->pseudo_subchannel
= kzalloc(sizeof(*css
->pseudo_subchannel
),
915 if (!css
->pseudo_subchannel
) {
916 device_unregister(&css
->device
);
921 css
->pseudo_subchannel
->dev
.parent
= &css
->device
;
922 css
->pseudo_subchannel
->dev
.release
= css_subchannel_release
;
923 mutex_init(&css
->pseudo_subchannel
->reg_mutex
);
924 ret
= css_sch_create_locks(css
->pseudo_subchannel
);
926 kfree(css
->pseudo_subchannel
);
927 device_unregister(&css
->device
);
931 dev_set_name(&css
->pseudo_subchannel
->dev
, "defunct");
932 ret
= device_register(&css
->pseudo_subchannel
->dev
);
934 put_device(&css
->pseudo_subchannel
->dev
);
935 device_unregister(&css
->device
);
941 channel_subsystems
[nr
] = NULL
;
945 static int css_reboot_event(struct notifier_block
*this,
949 struct channel_subsystem
*css
;
954 mutex_lock(&css
->mutex
);
956 if (chsc_secm(css
, 0))
958 mutex_unlock(&css
->mutex
);
964 static struct notifier_block css_reboot_notifier
= {
965 .notifier_call
= css_reboot_event
,
969 * Since the css devices are neither on a bus nor have a class
970 * nor have a special device type, we cannot stop/restart channel
971 * path measurements via the normal suspend/resume callbacks, but have
974 static int css_power_event(struct notifier_block
*this, unsigned long event
,
977 struct channel_subsystem
*css
;
981 case PM_HIBERNATION_PREPARE
:
982 case PM_SUSPEND_PREPARE
:
985 mutex_lock(&css
->mutex
);
986 if (!css
->cm_enabled
) {
987 mutex_unlock(&css
->mutex
);
990 ret
= __chsc_do_secm(css
, 0);
991 ret
= notifier_from_errno(ret
);
992 mutex_unlock(&css
->mutex
);
995 case PM_POST_HIBERNATION
:
996 case PM_POST_SUSPEND
:
999 mutex_lock(&css
->mutex
);
1000 if (!css
->cm_enabled
) {
1001 mutex_unlock(&css
->mutex
);
1004 ret
= __chsc_do_secm(css
, 1);
1005 ret
= notifier_from_errno(ret
);
1006 mutex_unlock(&css
->mutex
);
1008 /* search for subchannels, which appeared during hibernation */
1009 css_schedule_reprobe();
1017 static struct notifier_block css_power_notifier
= {
1018 .notifier_call
= css_power_event
,
1022 * Now that the driver core is running, we can setup our channel subsystem.
1023 * The struct subchannel's are created during probing.
1025 static int __init
css_bus_init(void)
1033 chsc_determine_css_characteristics();
1034 /* Try to enable MSS. */
1035 ret
= chsc_enable_facility(CHSC_SDA_OC_MSS
);
1039 max_ssid
= __MAX_SSID
;
1041 ret
= slow_subchannel_init();
1045 ret
= crw_register_handler(CRW_RSC_SCH
, css_process_crw
);
1049 if ((ret
= bus_register(&css_bus_type
)))
1052 /* Setup css structure. */
1053 for (i
= 0; i
<= MAX_CSS_IDX
; i
++) {
1056 goto out_unregister
;
1058 ret
= register_reboot_notifier(&css_reboot_notifier
);
1060 goto out_unregister
;
1061 ret
= register_pm_notifier(&css_power_notifier
);
1063 unregister_reboot_notifier(&css_reboot_notifier
);
1064 goto out_unregister
;
1068 /* Enable default isc for I/O subchannels. */
1069 isc_register(IO_SCH_ISC
);
1074 struct channel_subsystem
*css
= channel_subsystems
[i
];
1075 device_unregister(&css
->pseudo_subchannel
->dev
);
1076 device_unregister(&css
->device
);
1078 bus_unregister(&css_bus_type
);
1080 crw_unregister_handler(CRW_RSC_SCH
);
1081 idset_free(slow_subchannel_set
);
1082 chsc_init_cleanup();
1083 pr_alert("The CSS device driver initialization failed with "
1088 static void __init
css_bus_cleanup(void)
1090 struct channel_subsystem
*css
;
1093 device_unregister(&css
->pseudo_subchannel
->dev
);
1094 device_unregister(&css
->device
);
1096 bus_unregister(&css_bus_type
);
1097 crw_unregister_handler(CRW_RSC_SCH
);
1098 idset_free(slow_subchannel_set
);
1099 chsc_init_cleanup();
1100 isc_unregister(IO_SCH_ISC
);
1103 static int __init
channel_subsystem_init(void)
1107 ret
= css_bus_init();
1110 cio_work_q
= create_singlethread_workqueue("cio");
1115 ret
= io_subchannel_init();
1119 /* Register subchannels which are already in use. */
1120 cio_register_early_subchannels();
1121 /* Start initial subchannel evaluation. */
1122 css_schedule_eval_all();
1126 destroy_workqueue(cio_work_q
);
1131 subsys_initcall(channel_subsystem_init
);
1133 static int css_settle(struct device_driver
*drv
, void *unused
)
1135 struct css_driver
*cssdrv
= to_cssdriver(drv
);
1138 return cssdrv
->settle();
1142 int css_complete_work(void)
1146 /* Wait for the evaluation of subchannels to finish. */
1147 ret
= wait_event_interruptible(css_eval_wq
,
1148 atomic_read(&css_eval_scheduled
) == 0);
1151 flush_workqueue(cio_work_q
);
1152 /* Wait for the subchannel type specific initialization to finish */
1153 return bus_for_each_drv(&css_bus_type
, NULL
, NULL
, css_settle
);
1158 * Wait for the initialization of devices to finish, to make sure we are
1159 * done with our setup if the search for the root device starts.
1161 static int __init
channel_subsystem_init_sync(void)
1163 css_complete_work();
1166 subsys_initcall_sync(channel_subsystem_init_sync
);
1168 void channel_subsystem_reinit(void)
1170 struct channel_path
*chp
;
1171 struct chp_id chpid
;
1173 chsc_enable_facility(CHSC_SDA_OC_MSS
);
1174 chp_id_for_each(&chpid
) {
1175 chp
= chpid_to_chp(chpid
);
1177 chp_update_desc(chp
);
1182 #ifdef CONFIG_PROC_FS
1183 static ssize_t
cio_settle_write(struct file
*file
, const char __user
*buf
,
1184 size_t count
, loff_t
*ppos
)
1188 /* Handle pending CRW's. */
1189 crw_wait_for_channel_report();
1190 ret
= css_complete_work();
1192 return ret
? ret
: count
;
1195 static const struct file_operations cio_settle_proc_fops
= {
1196 .open
= nonseekable_open
,
1197 .write
= cio_settle_write
,
1198 .llseek
= no_llseek
,
1201 static int __init
cio_settle_init(void)
1203 struct proc_dir_entry
*entry
;
1205 entry
= proc_create("cio_settle", S_IWUSR
, NULL
,
1206 &cio_settle_proc_fops
);
1211 device_initcall(cio_settle_init
);
1212 #endif /*CONFIG_PROC_FS*/
1214 int sch_is_pseudo_sch(struct subchannel
*sch
)
1216 return sch
== to_css(sch
->dev
.parent
)->pseudo_subchannel
;
1219 static int css_bus_match(struct device
*dev
, struct device_driver
*drv
)
1221 struct subchannel
*sch
= to_subchannel(dev
);
1222 struct css_driver
*driver
= to_cssdriver(drv
);
1223 struct css_device_id
*id
;
1225 for (id
= driver
->subchannel_type
; id
->match_flags
; id
++) {
1226 if (sch
->st
== id
->type
)
1233 static int css_probe(struct device
*dev
)
1235 struct subchannel
*sch
;
1238 sch
= to_subchannel(dev
);
1239 sch
->driver
= to_cssdriver(dev
->driver
);
1240 ret
= sch
->driver
->probe
? sch
->driver
->probe(sch
) : 0;
1246 static int css_remove(struct device
*dev
)
1248 struct subchannel
*sch
;
1251 sch
= to_subchannel(dev
);
1252 ret
= sch
->driver
->remove
? sch
->driver
->remove(sch
) : 0;
1257 static void css_shutdown(struct device
*dev
)
1259 struct subchannel
*sch
;
1261 sch
= to_subchannel(dev
);
1262 if (sch
->driver
&& sch
->driver
->shutdown
)
1263 sch
->driver
->shutdown(sch
);
1266 static int css_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
1268 struct subchannel
*sch
= to_subchannel(dev
);
1271 ret
= add_uevent_var(env
, "ST=%01X", sch
->st
);
1274 ret
= add_uevent_var(env
, "MODALIAS=css:t%01X", sch
->st
);
1278 static int css_pm_prepare(struct device
*dev
)
1280 struct subchannel
*sch
= to_subchannel(dev
);
1281 struct css_driver
*drv
;
1283 if (mutex_is_locked(&sch
->reg_mutex
))
1285 if (!sch
->dev
.driver
)
1287 drv
= to_cssdriver(sch
->dev
.driver
);
1288 /* Notify drivers that they may not register children. */
1289 return drv
->prepare
? drv
->prepare(sch
) : 0;
1292 static void css_pm_complete(struct device
*dev
)
1294 struct subchannel
*sch
= to_subchannel(dev
);
1295 struct css_driver
*drv
;
1297 if (!sch
->dev
.driver
)
1299 drv
= to_cssdriver(sch
->dev
.driver
);
1304 static int css_pm_freeze(struct device
*dev
)
1306 struct subchannel
*sch
= to_subchannel(dev
);
1307 struct css_driver
*drv
;
1309 if (!sch
->dev
.driver
)
1311 drv
= to_cssdriver(sch
->dev
.driver
);
1312 return drv
->freeze
? drv
->freeze(sch
) : 0;
1315 static int css_pm_thaw(struct device
*dev
)
1317 struct subchannel
*sch
= to_subchannel(dev
);
1318 struct css_driver
*drv
;
1320 if (!sch
->dev
.driver
)
1322 drv
= to_cssdriver(sch
->dev
.driver
);
1323 return drv
->thaw
? drv
->thaw(sch
) : 0;
1326 static int css_pm_restore(struct device
*dev
)
1328 struct subchannel
*sch
= to_subchannel(dev
);
1329 struct css_driver
*drv
;
1331 css_update_ssd_info(sch
);
1332 if (!sch
->dev
.driver
)
1334 drv
= to_cssdriver(sch
->dev
.driver
);
1335 return drv
->restore
? drv
->restore(sch
) : 0;
1338 static const struct dev_pm_ops css_pm_ops
= {
1339 .prepare
= css_pm_prepare
,
1340 .complete
= css_pm_complete
,
1341 .freeze
= css_pm_freeze
,
1342 .thaw
= css_pm_thaw
,
1343 .restore
= css_pm_restore
,
1346 static struct bus_type css_bus_type
= {
1348 .match
= css_bus_match
,
1350 .remove
= css_remove
,
1351 .shutdown
= css_shutdown
,
1352 .uevent
= css_uevent
,
1357 * css_driver_register - register a css driver
1358 * @cdrv: css driver to register
1360 * This is mainly a wrapper around driver_register that sets name
1361 * and bus_type in the embedded struct device_driver correctly.
1363 int css_driver_register(struct css_driver
*cdrv
)
1365 cdrv
->drv
.bus
= &css_bus_type
;
1366 return driver_register(&cdrv
->drv
);
1368 EXPORT_SYMBOL_GPL(css_driver_register
);
1371 * css_driver_unregister - unregister a css driver
1372 * @cdrv: css driver to unregister
1374 * This is a wrapper around driver_unregister.
1376 void css_driver_unregister(struct css_driver
*cdrv
)
1378 driver_unregister(&cdrv
->drv
);
1380 EXPORT_SYMBOL_GPL(css_driver_unregister
);