2 * drivers/s390/cio/css.c
3 * driver for channel subsystem
5 * Copyright IBM Corp. 2002,2008
6 * Author(s): Arnd Bergmann (arndb@de.ibm.com)
7 * Cornelia Huck (cornelia.huck@de.ibm.com)
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/device.h>
12 #include <linux/slab.h>
13 #include <linux/errno.h>
14 #include <linux/list.h>
15 #include <linux/reboot.h>
18 #include "../s390mach.h"
21 #include "cio_debug.h"
28 int css_init_done
= 0;
29 static int need_reprobe
= 0;
30 static int max_ssid
= 0;
32 struct channel_subsystem
*channel_subsystems
[__MAX_CSSID
+ 1];
35 for_each_subchannel(int(*fn
)(struct subchannel_id
, void *), void *data
)
37 struct subchannel_id schid
;
40 init_subchannel_id(&schid
);
44 ret
= fn(schid
, data
);
47 } while (schid
.sch_no
++ < __MAX_SUBCHANNEL
);
49 } while (schid
.ssid
++ < max_ssid
);
56 int (*fn_known_sch
)(struct subchannel
*, void *);
57 int (*fn_unknown_sch
)(struct subchannel_id
, void *);
60 static int call_fn_known_sch(struct device
*dev
, void *data
)
62 struct subchannel
*sch
= to_subchannel(dev
);
63 struct cb_data
*cb
= data
;
66 idset_sch_del(cb
->set
, sch
->schid
);
68 rc
= cb
->fn_known_sch(sch
, cb
->data
);
72 static int call_fn_unknown_sch(struct subchannel_id schid
, void *data
)
74 struct cb_data
*cb
= data
;
77 if (idset_sch_contains(cb
->set
, schid
))
78 rc
= cb
->fn_unknown_sch(schid
, cb
->data
);
82 int for_each_subchannel_staged(int (*fn_known
)(struct subchannel
*, void *),
83 int (*fn_unknown
)(struct subchannel_id
,
89 cb
.set
= idset_sch_new();
94 cb
.fn_known_sch
= fn_known
;
95 cb
.fn_unknown_sch
= fn_unknown
;
96 /* Process registered subchannels. */
97 rc
= bus_for_each_dev(&css_bus_type
, NULL
, &cb
, call_fn_known_sch
);
100 /* Process unregistered subchannels. */
102 rc
= for_each_subchannel(call_fn_unknown_sch
, &cb
);
109 static struct subchannel
*
110 css_alloc_subchannel(struct subchannel_id schid
)
112 struct subchannel
*sch
;
115 sch
= kmalloc (sizeof (*sch
), GFP_KERNEL
| GFP_DMA
);
117 return ERR_PTR(-ENOMEM
);
118 ret
= cio_validate_subchannel (sch
, schid
);
127 css_free_subchannel(struct subchannel
*sch
)
130 /* Reset intparm to zeroes. */
131 sch
->schib
.pmcw
.intparm
= 0;
139 css_subchannel_release(struct device
*dev
)
141 struct subchannel
*sch
;
143 sch
= to_subchannel(dev
);
144 if (!cio_is_console(sch
->schid
)) {
150 static int css_sch_device_register(struct subchannel
*sch
)
154 mutex_lock(&sch
->reg_mutex
);
155 ret
= device_register(&sch
->dev
);
156 mutex_unlock(&sch
->reg_mutex
);
161 * css_sch_device_unregister - unregister a subchannel
162 * @sch: subchannel to be unregistered
164 void css_sch_device_unregister(struct subchannel
*sch
)
166 mutex_lock(&sch
->reg_mutex
);
167 device_unregister(&sch
->dev
);
168 mutex_unlock(&sch
->reg_mutex
);
170 EXPORT_SYMBOL_GPL(css_sch_device_unregister
);
172 static void ssd_from_pmcw(struct chsc_ssd_info
*ssd
, struct pmcw
*pmcw
)
177 memset(ssd
, 0, sizeof(struct chsc_ssd_info
));
178 ssd
->path_mask
= pmcw
->pim
;
179 for (i
= 0; i
< 8; i
++) {
181 if (pmcw
->pim
& mask
) {
182 chp_id_init(&ssd
->chpid
[i
]);
183 ssd
->chpid
[i
].id
= pmcw
->chpid
[i
];
188 static void ssd_register_chpids(struct chsc_ssd_info
*ssd
)
193 for (i
= 0; i
< 8; i
++) {
195 if (ssd
->path_mask
& mask
)
196 if (!chp_is_registered(ssd
->chpid
[i
]))
197 chp_new(ssd
->chpid
[i
]);
201 void css_update_ssd_info(struct subchannel
*sch
)
205 if (cio_is_console(sch
->schid
)) {
206 /* Console is initialized too early for functions requiring
207 * memory allocation. */
208 ssd_from_pmcw(&sch
->ssd_info
, &sch
->schib
.pmcw
);
210 ret
= chsc_get_ssd_info(sch
->schid
, &sch
->ssd_info
);
212 ssd_from_pmcw(&sch
->ssd_info
, &sch
->schib
.pmcw
);
213 ssd_register_chpids(&sch
->ssd_info
);
217 static ssize_t
type_show(struct device
*dev
, struct device_attribute
*attr
,
220 struct subchannel
*sch
= to_subchannel(dev
);
222 return sprintf(buf
, "%01x\n", sch
->st
);
225 static DEVICE_ATTR(type
, 0444, type_show
, NULL
);
227 static ssize_t
modalias_show(struct device
*dev
, struct device_attribute
*attr
,
230 struct subchannel
*sch
= to_subchannel(dev
);
232 return sprintf(buf
, "css:t%01X\n", sch
->st
);
235 static DEVICE_ATTR(modalias
, 0444, modalias_show
, NULL
);
237 static struct attribute
*subch_attrs
[] = {
239 &dev_attr_modalias
.attr
,
243 static struct attribute_group subch_attr_group
= {
244 .attrs
= subch_attrs
,
247 static struct attribute_group
*default_subch_attr_groups
[] = {
252 static int css_register_subchannel(struct subchannel
*sch
)
256 /* Initialize the subchannel structure */
257 sch
->dev
.parent
= &channel_subsystems
[0]->device
;
258 sch
->dev
.bus
= &css_bus_type
;
259 sch
->dev
.release
= &css_subchannel_release
;
260 sch
->dev
.groups
= default_subch_attr_groups
;
262 * We don't want to generate uevents for I/O subchannels that don't
263 * have a working ccw device behind them since they will be
264 * unregistered before they can be used anyway, so we delay the add
265 * uevent until after device recognition was successful.
266 * Note that we suppress the uevent for all subchannel types;
267 * the subchannel driver can decide itself when it wants to inform
268 * userspace of its existence.
270 sch
->dev
.uevent_suppress
= 1;
271 css_update_ssd_info(sch
);
272 /* make it known to the system */
273 ret
= css_sch_device_register(sch
);
275 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
276 sch
->schid
.ssid
, sch
->schid
.sch_no
, ret
);
281 * No driver matched. Generate the uevent now so that
282 * a fitting driver module may be loaded based on the
285 sch
->dev
.uevent_suppress
= 0;
286 kobject_uevent(&sch
->dev
.kobj
, KOBJ_ADD
);
291 int css_probe_device(struct subchannel_id schid
)
294 struct subchannel
*sch
;
296 sch
= css_alloc_subchannel(schid
);
299 ret
= css_register_subchannel(sch
);
301 css_free_subchannel(sch
);
306 check_subchannel(struct device
* dev
, void * data
)
308 struct subchannel
*sch
;
309 struct subchannel_id
*schid
= data
;
311 sch
= to_subchannel(dev
);
312 return schid_equal(&sch
->schid
, schid
);
316 get_subchannel_by_schid(struct subchannel_id schid
)
320 dev
= bus_find_device(&css_bus_type
, NULL
,
321 &schid
, check_subchannel
);
323 return dev
? to_subchannel(dev
) : NULL
;
327 * css_sch_is_valid() - check if a subchannel is valid
328 * @schib: subchannel information block for the subchannel
330 int css_sch_is_valid(struct schib
*schib
)
332 if ((schib
->pmcw
.st
== SUBCHANNEL_TYPE_IO
) && !schib
->pmcw
.dnv
)
334 if ((schib
->pmcw
.st
== SUBCHANNEL_TYPE_MSG
) && !schib
->pmcw
.w
)
338 EXPORT_SYMBOL_GPL(css_sch_is_valid
);
340 static int css_evaluate_new_subchannel(struct subchannel_id schid
, int slow
)
345 /* Will be done on the slow path. */
348 if (stsch_err(schid
, &schib
) || !css_sch_is_valid(&schib
)) {
349 /* Unusable - ignore. */
352 CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, unknown, "
353 "slow path.\n", schid
.ssid
, schid
.sch_no
, CIO_OPER
);
355 return css_probe_device(schid
);
358 static int css_evaluate_known_subchannel(struct subchannel
*sch
, int slow
)
363 if (sch
->driver
->sch_event
)
364 ret
= sch
->driver
->sch_event(sch
, slow
);
367 "Got subchannel machine check but "
368 "no sch_event handler provided.\n");
373 static void css_evaluate_subchannel(struct subchannel_id schid
, int slow
)
375 struct subchannel
*sch
;
378 sch
= get_subchannel_by_schid(schid
);
380 ret
= css_evaluate_known_subchannel(sch
, slow
);
381 put_device(&sch
->dev
);
383 ret
= css_evaluate_new_subchannel(schid
, slow
);
385 css_schedule_eval(schid
);
388 static struct idset
*slow_subchannel_set
;
389 static spinlock_t slow_subchannel_lock
;
391 static int __init
slow_subchannel_init(void)
393 spin_lock_init(&slow_subchannel_lock
);
394 slow_subchannel_set
= idset_sch_new();
395 if (!slow_subchannel_set
) {
396 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
402 static int slow_eval_known_fn(struct subchannel
*sch
, void *data
)
407 spin_lock_irq(&slow_subchannel_lock
);
408 eval
= idset_sch_contains(slow_subchannel_set
, sch
->schid
);
409 idset_sch_del(slow_subchannel_set
, sch
->schid
);
410 spin_unlock_irq(&slow_subchannel_lock
);
412 rc
= css_evaluate_known_subchannel(sch
, 1);
414 css_schedule_eval(sch
->schid
);
419 static int slow_eval_unknown_fn(struct subchannel_id schid
, void *data
)
424 spin_lock_irq(&slow_subchannel_lock
);
425 eval
= idset_sch_contains(slow_subchannel_set
, schid
);
426 idset_sch_del(slow_subchannel_set
, schid
);
427 spin_unlock_irq(&slow_subchannel_lock
);
429 rc
= css_evaluate_new_subchannel(schid
, 1);
432 css_schedule_eval(schid
);
438 /* These should abort looping */
447 static void css_slow_path_func(struct work_struct
*unused
)
449 CIO_TRACE_EVENT(4, "slowpath");
450 for_each_subchannel_staged(slow_eval_known_fn
, slow_eval_unknown_fn
,
454 static DECLARE_WORK(slow_path_work
, css_slow_path_func
);
455 struct workqueue_struct
*slow_path_wq
;
457 void css_schedule_eval(struct subchannel_id schid
)
461 spin_lock_irqsave(&slow_subchannel_lock
, flags
);
462 idset_sch_add(slow_subchannel_set
, schid
);
463 queue_work(slow_path_wq
, &slow_path_work
);
464 spin_unlock_irqrestore(&slow_subchannel_lock
, flags
);
467 void css_schedule_eval_all(void)
471 spin_lock_irqsave(&slow_subchannel_lock
, flags
);
472 idset_fill(slow_subchannel_set
);
473 queue_work(slow_path_wq
, &slow_path_work
);
474 spin_unlock_irqrestore(&slow_subchannel_lock
, flags
);
477 void css_wait_for_slow_path(void)
479 flush_workqueue(ccw_device_notify_work
);
480 flush_workqueue(slow_path_wq
);
483 /* Reprobe subchannel if unregistered. */
484 static int reprobe_subchannel(struct subchannel_id schid
, void *data
)
488 CIO_MSG_EVENT(6, "cio: reprobe 0.%x.%04x\n",
489 schid
.ssid
, schid
.sch_no
);
493 ret
= css_probe_device(schid
);
500 /* These should abort looping */
509 /* Work function used to reprobe all unregistered subchannels. */
510 static void reprobe_all(struct work_struct
*unused
)
514 CIO_MSG_EVENT(4, "reprobe start\n");
517 /* Make sure initial subchannel scan is done. */
518 wait_event(ccw_device_init_wq
,
519 atomic_read(&ccw_device_init_count
) == 0);
520 ret
= for_each_subchannel_staged(NULL
, reprobe_subchannel
, NULL
);
522 CIO_MSG_EVENT(4, "reprobe done (rc=%d, need_reprobe=%d)\n", ret
,
526 static DECLARE_WORK(css_reprobe_work
, reprobe_all
);
528 /* Schedule reprobing of all unregistered subchannels. */
529 void css_schedule_reprobe(void)
532 queue_work(slow_path_wq
, &css_reprobe_work
);
535 EXPORT_SYMBOL_GPL(css_schedule_reprobe
);
538 * Called from the machine check handler for subchannel report words.
540 static void css_process_crw(struct crw
*crw0
, struct crw
*crw1
, int overflow
)
542 struct subchannel_id mchk_schid
;
545 css_schedule_eval_all();
548 CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
549 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
550 crw0
->slct
, crw0
->oflw
, crw0
->chn
, crw0
->rsc
, crw0
->anc
,
551 crw0
->erc
, crw0
->rsid
);
553 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
554 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
555 crw1
->slct
, crw1
->oflw
, crw1
->chn
, crw1
->rsc
,
556 crw1
->anc
, crw1
->erc
, crw1
->rsid
);
557 init_subchannel_id(&mchk_schid
);
558 mchk_schid
.sch_no
= crw0
->rsid
;
560 mchk_schid
.ssid
= (crw1
->rsid
>> 8) & 3;
563 * Since we are always presented with IPI in the CRW, we have to
564 * use stsch() to find out if the subchannel in question has come
567 css_evaluate_subchannel(mchk_schid
, 0);
571 __init_channel_subsystem(struct subchannel_id schid
, void *data
)
573 struct subchannel
*sch
;
576 if (cio_is_console(schid
))
577 sch
= cio_get_console_subchannel();
579 sch
= css_alloc_subchannel(schid
);
588 panic("Out of memory in init_channel_subsystem\n");
589 /* -ENXIO: no more subchannels. */
592 /* -EIO: this subchannel set not supported. */
600 * We register ALL valid subchannels in ioinfo, even those
601 * that have been present before init_channel_subsystem.
602 * These subchannels can't have been registered yet (kmalloc
603 * not working) so we do it now. This is true e.g. for the
604 * console subchannel.
606 css_register_subchannel(sch
);
611 css_generate_pgid(struct channel_subsystem
*css
, u32 tod_high
)
613 if (css_general_characteristics
.mcss
) {
614 css
->global_pgid
.pgid_high
.ext_cssid
.version
= 0x80;
615 css
->global_pgid
.pgid_high
.ext_cssid
.cssid
= css
->cssid
;
618 css
->global_pgid
.pgid_high
.cpu_addr
= hard_smp_processor_id();
620 css
->global_pgid
.pgid_high
.cpu_addr
= 0;
623 css
->global_pgid
.cpu_id
= ((cpuid_t
*) __LC_CPUID
)->ident
;
624 css
->global_pgid
.cpu_model
= ((cpuid_t
*) __LC_CPUID
)->machine
;
625 css
->global_pgid
.tod_high
= tod_high
;
630 channel_subsystem_release(struct device
*dev
)
632 struct channel_subsystem
*css
;
635 mutex_destroy(&css
->mutex
);
640 css_cm_enable_show(struct device
*dev
, struct device_attribute
*attr
,
643 struct channel_subsystem
*css
= to_css(dev
);
648 mutex_lock(&css
->mutex
);
649 ret
= sprintf(buf
, "%x\n", css
->cm_enabled
);
650 mutex_unlock(&css
->mutex
);
655 css_cm_enable_store(struct device
*dev
, struct device_attribute
*attr
,
656 const char *buf
, size_t count
)
658 struct channel_subsystem
*css
= to_css(dev
);
662 ret
= strict_strtoul(buf
, 16, &val
);
665 mutex_lock(&css
->mutex
);
668 ret
= css
->cm_enabled
? chsc_secm(css
, 0) : 0;
671 ret
= css
->cm_enabled
? 0 : chsc_secm(css
, 1);
676 mutex_unlock(&css
->mutex
);
677 return ret
< 0 ? ret
: count
;
680 static DEVICE_ATTR(cm_enable
, 0644, css_cm_enable_show
, css_cm_enable_store
);
682 static int __init
setup_css(int nr
)
686 struct channel_subsystem
*css
;
688 css
= channel_subsystems
[nr
];
689 memset(css
, 0, sizeof(struct channel_subsystem
));
690 css
->pseudo_subchannel
=
691 kzalloc(sizeof(*css
->pseudo_subchannel
), GFP_KERNEL
);
692 if (!css
->pseudo_subchannel
)
694 css
->pseudo_subchannel
->dev
.parent
= &css
->device
;
695 css
->pseudo_subchannel
->dev
.release
= css_subchannel_release
;
696 sprintf(css
->pseudo_subchannel
->dev
.bus_id
, "defunct");
697 ret
= cio_create_sch_lock(css
->pseudo_subchannel
);
699 kfree(css
->pseudo_subchannel
);
702 mutex_init(&css
->mutex
);
705 sprintf(css
->device
.bus_id
, "css%x", nr
);
706 css
->device
.release
= channel_subsystem_release
;
707 tod_high
= (u32
) (get_clock() >> 32);
708 css_generate_pgid(css
, tod_high
);
712 static int css_reboot_event(struct notifier_block
*this,
719 for (i
= 0; i
<= __MAX_CSSID
; i
++) {
720 struct channel_subsystem
*css
;
722 css
= channel_subsystems
[i
];
723 mutex_lock(&css
->mutex
);
725 if (chsc_secm(css
, 0))
727 mutex_unlock(&css
->mutex
);
733 static struct notifier_block css_reboot_notifier
= {
734 .notifier_call
= css_reboot_event
,
738 * Now that the driver core is running, we can setup our channel subsystem.
739 * The struct subchannel's are created during probing (except for the
740 * static console subchannel).
743 init_channel_subsystem (void)
747 ret
= chsc_determine_css_characteristics();
749 goto out
; /* No need to continue. */
751 ret
= chsc_alloc_sei_area();
755 ret
= slow_subchannel_init();
759 ret
= s390_register_crw_handler(CRW_RSC_SCH
, css_process_crw
);
763 if ((ret
= bus_register(&css_bus_type
)))
766 /* Try to enable MSS. */
767 ret
= chsc_enable_facility(CHSC_SDA_OC_MSS
);
769 case 0: /* Success. */
770 max_ssid
= __MAX_SSID
;
777 /* Setup css structure. */
778 for (i
= 0; i
<= __MAX_CSSID
; i
++) {
779 struct channel_subsystem
*css
;
781 css
= kmalloc(sizeof(struct channel_subsystem
), GFP_KERNEL
);
786 channel_subsystems
[i
] = css
;
790 ret
= device_register(&css
->device
);
793 if (css_chsc_characteristics
.secm
) {
794 ret
= device_create_file(&css
->device
,
795 &dev_attr_cm_enable
);
799 ret
= device_register(&css
->pseudo_subchannel
->dev
);
803 ret
= register_reboot_notifier(&css_reboot_notifier
);
808 /* Enable default isc for I/O subchannels. */
809 isc_register(IO_SCH_ISC
);
811 for_each_subchannel(__init_channel_subsystem
, NULL
);
814 device_unregister(&channel_subsystems
[i
]->pseudo_subchannel
->dev
);
816 device_remove_file(&channel_subsystems
[i
]->device
,
817 &dev_attr_cm_enable
);
819 device_unregister(&channel_subsystems
[i
]->device
);
821 kfree(channel_subsystems
[i
]->pseudo_subchannel
->lock
);
822 kfree(channel_subsystems
[i
]->pseudo_subchannel
);
824 kfree(channel_subsystems
[i
]);
827 struct channel_subsystem
*css
;
830 css
= channel_subsystems
[i
];
831 device_unregister(&css
->pseudo_subchannel
->dev
);
832 if (css_chsc_characteristics
.secm
)
833 device_remove_file(&css
->device
,
834 &dev_attr_cm_enable
);
835 device_unregister(&css
->device
);
838 bus_unregister(&css_bus_type
);
840 s390_unregister_crw_handler(CRW_RSC_CSS
);
841 chsc_free_sei_area();
842 kfree(slow_subchannel_set
);
843 printk(KERN_WARNING
"cio: failed to initialize css driver (%d)!\n",
848 int sch_is_pseudo_sch(struct subchannel
*sch
)
850 return sch
== to_css(sch
->dev
.parent
)->pseudo_subchannel
;
853 static int css_bus_match(struct device
*dev
, struct device_driver
*drv
)
855 struct subchannel
*sch
= to_subchannel(dev
);
856 struct css_driver
*driver
= to_cssdriver(drv
);
857 struct css_device_id
*id
;
859 for (id
= driver
->subchannel_type
; id
->match_flags
; id
++) {
860 if (sch
->st
== id
->type
)
867 static int css_probe(struct device
*dev
)
869 struct subchannel
*sch
;
872 sch
= to_subchannel(dev
);
873 sch
->driver
= to_cssdriver(dev
->driver
);
874 ret
= sch
->driver
->probe
? sch
->driver
->probe(sch
) : 0;
880 static int css_remove(struct device
*dev
)
882 struct subchannel
*sch
;
885 sch
= to_subchannel(dev
);
886 ret
= sch
->driver
->remove
? sch
->driver
->remove(sch
) : 0;
891 static void css_shutdown(struct device
*dev
)
893 struct subchannel
*sch
;
895 sch
= to_subchannel(dev
);
896 if (sch
->driver
&& sch
->driver
->shutdown
)
897 sch
->driver
->shutdown(sch
);
900 static int css_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
902 struct subchannel
*sch
= to_subchannel(dev
);
905 ret
= add_uevent_var(env
, "ST=%01X", sch
->st
);
908 ret
= add_uevent_var(env
, "MODALIAS=css:t%01X", sch
->st
);
912 struct bus_type css_bus_type
= {
914 .match
= css_bus_match
,
916 .remove
= css_remove
,
917 .shutdown
= css_shutdown
,
918 .uevent
= css_uevent
,
922 * css_driver_register - register a css driver
923 * @cdrv: css driver to register
925 * This is mainly a wrapper around driver_register that sets name
926 * and bus_type in the embedded struct device_driver correctly.
928 int css_driver_register(struct css_driver
*cdrv
)
930 cdrv
->drv
.name
= cdrv
->name
;
931 cdrv
->drv
.bus
= &css_bus_type
;
932 cdrv
->drv
.owner
= cdrv
->owner
;
933 return driver_register(&cdrv
->drv
);
935 EXPORT_SYMBOL_GPL(css_driver_register
);
938 * css_driver_unregister - unregister a css driver
939 * @cdrv: css driver to unregister
941 * This is a wrapper around driver_unregister.
943 void css_driver_unregister(struct css_driver
*cdrv
)
945 driver_unregister(&cdrv
->drv
);
947 EXPORT_SYMBOL_GPL(css_driver_unregister
);
949 subsys_initcall(init_channel_subsystem
);
951 MODULE_LICENSE("GPL");
952 EXPORT_SYMBOL(css_bus_type
);