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)
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>
22 #include "../s390mach.h"
25 #include "cio_debug.h"
32 int css_init_done
= 0;
33 static int need_reprobe
= 0;
34 static int max_ssid
= 0;
36 struct channel_subsystem
*channel_subsystems
[__MAX_CSSID
+ 1];
39 for_each_subchannel(int(*fn
)(struct subchannel_id
, void *), void *data
)
41 struct subchannel_id schid
;
44 init_subchannel_id(&schid
);
48 ret
= fn(schid
, data
);
51 } while (schid
.sch_no
++ < __MAX_SUBCHANNEL
);
53 } while (schid
.ssid
++ < max_ssid
);
60 int (*fn_known_sch
)(struct subchannel
*, void *);
61 int (*fn_unknown_sch
)(struct subchannel_id
, void *);
64 static int call_fn_known_sch(struct device
*dev
, void *data
)
66 struct subchannel
*sch
= to_subchannel(dev
);
67 struct cb_data
*cb
= data
;
70 idset_sch_del(cb
->set
, sch
->schid
);
72 rc
= cb
->fn_known_sch(sch
, cb
->data
);
76 static int call_fn_unknown_sch(struct subchannel_id schid
, void *data
)
78 struct cb_data
*cb
= data
;
81 if (idset_sch_contains(cb
->set
, schid
))
82 rc
= cb
->fn_unknown_sch(schid
, cb
->data
);
86 int for_each_subchannel_staged(int (*fn_known
)(struct subchannel
*, void *),
87 int (*fn_unknown
)(struct subchannel_id
,
93 cb
.set
= idset_sch_new();
98 cb
.fn_known_sch
= fn_known
;
99 cb
.fn_unknown_sch
= fn_unknown
;
100 /* Process registered subchannels. */
101 rc
= bus_for_each_dev(&css_bus_type
, NULL
, &cb
, call_fn_known_sch
);
104 /* Process unregistered subchannels. */
106 rc
= for_each_subchannel(call_fn_unknown_sch
, &cb
);
113 static struct subchannel
*
114 css_alloc_subchannel(struct subchannel_id schid
)
116 struct subchannel
*sch
;
119 sch
= kmalloc (sizeof (*sch
), GFP_KERNEL
| GFP_DMA
);
121 return ERR_PTR(-ENOMEM
);
122 ret
= cio_validate_subchannel (sch
, schid
);
131 css_free_subchannel(struct subchannel
*sch
)
134 /* Reset intparm to zeroes. */
135 sch
->config
.intparm
= 0;
136 cio_commit_config(sch
);
143 css_subchannel_release(struct device
*dev
)
145 struct subchannel
*sch
;
147 sch
= to_subchannel(dev
);
148 if (!cio_is_console(sch
->schid
)) {
154 static int css_sch_device_register(struct subchannel
*sch
)
158 mutex_lock(&sch
->reg_mutex
);
159 ret
= device_register(&sch
->dev
);
160 mutex_unlock(&sch
->reg_mutex
);
165 * css_sch_device_unregister - unregister a subchannel
166 * @sch: subchannel to be unregistered
168 void css_sch_device_unregister(struct subchannel
*sch
)
170 mutex_lock(&sch
->reg_mutex
);
171 if (device_is_registered(&sch
->dev
))
172 device_unregister(&sch
->dev
);
173 mutex_unlock(&sch
->reg_mutex
);
175 EXPORT_SYMBOL_GPL(css_sch_device_unregister
);
177 static void ssd_from_pmcw(struct chsc_ssd_info
*ssd
, struct pmcw
*pmcw
)
182 memset(ssd
, 0, sizeof(struct chsc_ssd_info
));
183 ssd
->path_mask
= pmcw
->pim
;
184 for (i
= 0; i
< 8; i
++) {
186 if (pmcw
->pim
& mask
) {
187 chp_id_init(&ssd
->chpid
[i
]);
188 ssd
->chpid
[i
].id
= pmcw
->chpid
[i
];
193 static void ssd_register_chpids(struct chsc_ssd_info
*ssd
)
198 for (i
= 0; i
< 8; i
++) {
200 if (ssd
->path_mask
& mask
)
201 if (!chp_is_registered(ssd
->chpid
[i
]))
202 chp_new(ssd
->chpid
[i
]);
206 void css_update_ssd_info(struct subchannel
*sch
)
210 if (cio_is_console(sch
->schid
)) {
211 /* Console is initialized too early for functions requiring
212 * memory allocation. */
213 ssd_from_pmcw(&sch
->ssd_info
, &sch
->schib
.pmcw
);
215 ret
= chsc_get_ssd_info(sch
->schid
, &sch
->ssd_info
);
217 ssd_from_pmcw(&sch
->ssd_info
, &sch
->schib
.pmcw
);
218 ssd_register_chpids(&sch
->ssd_info
);
222 static ssize_t
type_show(struct device
*dev
, struct device_attribute
*attr
,
225 struct subchannel
*sch
= to_subchannel(dev
);
227 return sprintf(buf
, "%01x\n", sch
->st
);
230 static DEVICE_ATTR(type
, 0444, type_show
, NULL
);
232 static ssize_t
modalias_show(struct device
*dev
, struct device_attribute
*attr
,
235 struct subchannel
*sch
= to_subchannel(dev
);
237 return sprintf(buf
, "css:t%01X\n", sch
->st
);
240 static DEVICE_ATTR(modalias
, 0444, modalias_show
, NULL
);
242 static struct attribute
*subch_attrs
[] = {
244 &dev_attr_modalias
.attr
,
248 static struct attribute_group subch_attr_group
= {
249 .attrs
= subch_attrs
,
252 static struct attribute_group
*default_subch_attr_groups
[] = {
257 static int css_register_subchannel(struct subchannel
*sch
)
261 /* Initialize the subchannel structure */
262 sch
->dev
.parent
= &channel_subsystems
[0]->device
;
263 sch
->dev
.bus
= &css_bus_type
;
264 sch
->dev
.release
= &css_subchannel_release
;
265 sch
->dev
.groups
= default_subch_attr_groups
;
267 * We don't want to generate uevents for I/O subchannels that don't
268 * have a working ccw device behind them since they will be
269 * unregistered before they can be used anyway, so we delay the add
270 * uevent until after device recognition was successful.
271 * Note that we suppress the uevent for all subchannel types;
272 * the subchannel driver can decide itself when it wants to inform
273 * userspace of its existence.
275 sch
->dev
.uevent_suppress
= 1;
276 css_update_ssd_info(sch
);
277 /* make it known to the system */
278 ret
= css_sch_device_register(sch
);
280 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
281 sch
->schid
.ssid
, sch
->schid
.sch_no
, ret
);
286 * No driver matched. Generate the uevent now so that
287 * a fitting driver module may be loaded based on the
290 sch
->dev
.uevent_suppress
= 0;
291 kobject_uevent(&sch
->dev
.kobj
, KOBJ_ADD
);
296 int css_probe_device(struct subchannel_id schid
)
299 struct subchannel
*sch
;
301 sch
= css_alloc_subchannel(schid
);
304 ret
= css_register_subchannel(sch
);
306 css_free_subchannel(sch
);
311 check_subchannel(struct device
* dev
, void * data
)
313 struct subchannel
*sch
;
314 struct subchannel_id
*schid
= data
;
316 sch
= to_subchannel(dev
);
317 return schid_equal(&sch
->schid
, schid
);
321 get_subchannel_by_schid(struct subchannel_id schid
)
325 dev
= bus_find_device(&css_bus_type
, NULL
,
326 &schid
, check_subchannel
);
328 return dev
? to_subchannel(dev
) : NULL
;
332 * css_sch_is_valid() - check if a subchannel is valid
333 * @schib: subchannel information block for the subchannel
335 int css_sch_is_valid(struct schib
*schib
)
337 if ((schib
->pmcw
.st
== SUBCHANNEL_TYPE_IO
) && !schib
->pmcw
.dnv
)
339 if ((schib
->pmcw
.st
== SUBCHANNEL_TYPE_MSG
) && !schib
->pmcw
.w
)
343 EXPORT_SYMBOL_GPL(css_sch_is_valid
);
345 static int css_evaluate_new_subchannel(struct subchannel_id schid
, int slow
)
350 /* Will be done on the slow path. */
353 if (stsch_err(schid
, &schib
) || !css_sch_is_valid(&schib
)) {
354 /* Unusable - ignore. */
357 CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, unknown, "
358 "slow path.\n", schid
.ssid
, schid
.sch_no
, CIO_OPER
);
360 return css_probe_device(schid
);
363 static int css_evaluate_known_subchannel(struct subchannel
*sch
, int slow
)
368 if (sch
->driver
->sch_event
)
369 ret
= sch
->driver
->sch_event(sch
, slow
);
372 "Got subchannel machine check but "
373 "no sch_event handler provided.\n");
378 static void css_evaluate_subchannel(struct subchannel_id schid
, int slow
)
380 struct subchannel
*sch
;
383 sch
= get_subchannel_by_schid(schid
);
385 ret
= css_evaluate_known_subchannel(sch
, slow
);
386 put_device(&sch
->dev
);
388 ret
= css_evaluate_new_subchannel(schid
, slow
);
390 css_schedule_eval(schid
);
393 static struct idset
*slow_subchannel_set
;
394 static spinlock_t slow_subchannel_lock
;
396 static int __init
slow_subchannel_init(void)
398 spin_lock_init(&slow_subchannel_lock
);
399 slow_subchannel_set
= idset_sch_new();
400 if (!slow_subchannel_set
) {
401 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
407 static int slow_eval_known_fn(struct subchannel
*sch
, void *data
)
412 spin_lock_irq(&slow_subchannel_lock
);
413 eval
= idset_sch_contains(slow_subchannel_set
, sch
->schid
);
414 idset_sch_del(slow_subchannel_set
, sch
->schid
);
415 spin_unlock_irq(&slow_subchannel_lock
);
417 rc
= css_evaluate_known_subchannel(sch
, 1);
419 css_schedule_eval(sch
->schid
);
424 static int slow_eval_unknown_fn(struct subchannel_id schid
, void *data
)
429 spin_lock_irq(&slow_subchannel_lock
);
430 eval
= idset_sch_contains(slow_subchannel_set
, schid
);
431 idset_sch_del(slow_subchannel_set
, schid
);
432 spin_unlock_irq(&slow_subchannel_lock
);
434 rc
= css_evaluate_new_subchannel(schid
, 1);
437 css_schedule_eval(schid
);
443 /* These should abort looping */
452 static void css_slow_path_func(struct work_struct
*unused
)
454 CIO_TRACE_EVENT(4, "slowpath");
455 for_each_subchannel_staged(slow_eval_known_fn
, slow_eval_unknown_fn
,
459 static DECLARE_WORK(slow_path_work
, css_slow_path_func
);
460 struct workqueue_struct
*slow_path_wq
;
462 void css_schedule_eval(struct subchannel_id schid
)
466 spin_lock_irqsave(&slow_subchannel_lock
, flags
);
467 idset_sch_add(slow_subchannel_set
, schid
);
468 queue_work(slow_path_wq
, &slow_path_work
);
469 spin_unlock_irqrestore(&slow_subchannel_lock
, flags
);
472 void css_schedule_eval_all(void)
476 spin_lock_irqsave(&slow_subchannel_lock
, flags
);
477 idset_fill(slow_subchannel_set
);
478 queue_work(slow_path_wq
, &slow_path_work
);
479 spin_unlock_irqrestore(&slow_subchannel_lock
, flags
);
482 void css_wait_for_slow_path(void)
484 flush_workqueue(slow_path_wq
);
487 /* Reprobe subchannel if unregistered. */
488 static int reprobe_subchannel(struct subchannel_id schid
, void *data
)
492 CIO_MSG_EVENT(6, "cio: reprobe 0.%x.%04x\n",
493 schid
.ssid
, schid
.sch_no
);
497 ret
= css_probe_device(schid
);
504 /* These should abort looping */
513 /* Work function used to reprobe all unregistered subchannels. */
514 static void reprobe_all(struct work_struct
*unused
)
518 CIO_MSG_EVENT(4, "reprobe start\n");
521 /* Make sure initial subchannel scan is done. */
522 wait_event(ccw_device_init_wq
,
523 atomic_read(&ccw_device_init_count
) == 0);
524 ret
= for_each_subchannel_staged(NULL
, reprobe_subchannel
, NULL
);
526 CIO_MSG_EVENT(4, "reprobe done (rc=%d, need_reprobe=%d)\n", ret
,
530 static DECLARE_WORK(css_reprobe_work
, reprobe_all
);
532 /* Schedule reprobing of all unregistered subchannels. */
533 void css_schedule_reprobe(void)
536 queue_work(slow_path_wq
, &css_reprobe_work
);
539 EXPORT_SYMBOL_GPL(css_schedule_reprobe
);
542 * Called from the machine check handler for subchannel report words.
544 static void css_process_crw(struct crw
*crw0
, struct crw
*crw1
, int overflow
)
546 struct subchannel_id mchk_schid
;
549 css_schedule_eval_all();
552 CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
553 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
554 crw0
->slct
, crw0
->oflw
, crw0
->chn
, crw0
->rsc
, crw0
->anc
,
555 crw0
->erc
, crw0
->rsid
);
557 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
558 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
559 crw1
->slct
, crw1
->oflw
, crw1
->chn
, crw1
->rsc
,
560 crw1
->anc
, crw1
->erc
, crw1
->rsid
);
561 init_subchannel_id(&mchk_schid
);
562 mchk_schid
.sch_no
= crw0
->rsid
;
564 mchk_schid
.ssid
= (crw1
->rsid
>> 8) & 3;
567 * Since we are always presented with IPI in the CRW, we have to
568 * use stsch() to find out if the subchannel in question has come
571 css_evaluate_subchannel(mchk_schid
, 0);
575 __init_channel_subsystem(struct subchannel_id schid
, void *data
)
577 struct subchannel
*sch
;
580 if (cio_is_console(schid
))
581 sch
= cio_get_console_subchannel();
583 sch
= css_alloc_subchannel(schid
);
592 panic("Out of memory in init_channel_subsystem\n");
593 /* -ENXIO: no more subchannels. */
596 /* -EIO: this subchannel set not supported. */
604 * We register ALL valid subchannels in ioinfo, even those
605 * that have been present before init_channel_subsystem.
606 * These subchannels can't have been registered yet (kmalloc
607 * not working) so we do it now. This is true e.g. for the
608 * console subchannel.
610 css_register_subchannel(sch
);
615 css_generate_pgid(struct channel_subsystem
*css
, u32 tod_high
)
617 if (css_general_characteristics
.mcss
) {
618 css
->global_pgid
.pgid_high
.ext_cssid
.version
= 0x80;
619 css
->global_pgid
.pgid_high
.ext_cssid
.cssid
= css
->cssid
;
622 css
->global_pgid
.pgid_high
.cpu_addr
= hard_smp_processor_id();
624 css
->global_pgid
.pgid_high
.cpu_addr
= 0;
627 css
->global_pgid
.cpu_id
= ((cpuid_t
*) __LC_CPUID
)->ident
;
628 css
->global_pgid
.cpu_model
= ((cpuid_t
*) __LC_CPUID
)->machine
;
629 css
->global_pgid
.tod_high
= tod_high
;
634 channel_subsystem_release(struct device
*dev
)
636 struct channel_subsystem
*css
;
639 mutex_destroy(&css
->mutex
);
640 if (css
->pseudo_subchannel
) {
641 /* Implies that it has been generated but never registered. */
642 css_subchannel_release(&css
->pseudo_subchannel
->dev
);
643 css
->pseudo_subchannel
= NULL
;
649 css_cm_enable_show(struct device
*dev
, struct device_attribute
*attr
,
652 struct channel_subsystem
*css
= to_css(dev
);
657 mutex_lock(&css
->mutex
);
658 ret
= sprintf(buf
, "%x\n", css
->cm_enabled
);
659 mutex_unlock(&css
->mutex
);
664 css_cm_enable_store(struct device
*dev
, struct device_attribute
*attr
,
665 const char *buf
, size_t count
)
667 struct channel_subsystem
*css
= to_css(dev
);
671 ret
= strict_strtoul(buf
, 16, &val
);
674 mutex_lock(&css
->mutex
);
677 ret
= css
->cm_enabled
? chsc_secm(css
, 0) : 0;
680 ret
= css
->cm_enabled
? 0 : chsc_secm(css
, 1);
685 mutex_unlock(&css
->mutex
);
686 return ret
< 0 ? ret
: count
;
689 static DEVICE_ATTR(cm_enable
, 0644, css_cm_enable_show
, css_cm_enable_store
);
691 static int __init
setup_css(int nr
)
695 struct channel_subsystem
*css
;
697 css
= channel_subsystems
[nr
];
698 memset(css
, 0, sizeof(struct channel_subsystem
));
699 css
->pseudo_subchannel
=
700 kzalloc(sizeof(*css
->pseudo_subchannel
), GFP_KERNEL
);
701 if (!css
->pseudo_subchannel
)
703 css
->pseudo_subchannel
->dev
.parent
= &css
->device
;
704 css
->pseudo_subchannel
->dev
.release
= css_subchannel_release
;
705 dev_set_name(&css
->pseudo_subchannel
->dev
, "defunct");
706 ret
= cio_create_sch_lock(css
->pseudo_subchannel
);
708 kfree(css
->pseudo_subchannel
);
711 mutex_init(&css
->mutex
);
714 dev_set_name(&css
->device
, "css%x", nr
);
715 css
->device
.release
= channel_subsystem_release
;
716 tod_high
= (u32
) (get_clock() >> 32);
717 css_generate_pgid(css
, tod_high
);
721 static int css_reboot_event(struct notifier_block
*this,
728 for (i
= 0; i
<= __MAX_CSSID
; i
++) {
729 struct channel_subsystem
*css
;
731 css
= channel_subsystems
[i
];
732 mutex_lock(&css
->mutex
);
734 if (chsc_secm(css
, 0))
736 mutex_unlock(&css
->mutex
);
742 static struct notifier_block css_reboot_notifier
= {
743 .notifier_call
= css_reboot_event
,
747 * Now that the driver core is running, we can setup our channel subsystem.
748 * The struct subchannel's are created during probing (except for the
749 * static console subchannel).
752 init_channel_subsystem (void)
756 ret
= chsc_determine_css_characteristics();
758 goto out
; /* No need to continue. */
760 ret
= chsc_alloc_sei_area();
764 ret
= slow_subchannel_init();
768 ret
= s390_register_crw_handler(CRW_RSC_SCH
, css_process_crw
);
772 if ((ret
= bus_register(&css_bus_type
)))
775 /* Try to enable MSS. */
776 ret
= chsc_enable_facility(CHSC_SDA_OC_MSS
);
778 case 0: /* Success. */
779 max_ssid
= __MAX_SSID
;
786 /* Setup css structure. */
787 for (i
= 0; i
<= __MAX_CSSID
; i
++) {
788 struct channel_subsystem
*css
;
790 css
= kmalloc(sizeof(struct channel_subsystem
), GFP_KERNEL
);
795 channel_subsystems
[i
] = css
;
798 kfree(channel_subsystems
[i
]);
801 ret
= device_register(&css
->device
);
803 put_device(&css
->device
);
806 if (css_chsc_characteristics
.secm
) {
807 ret
= device_create_file(&css
->device
,
808 &dev_attr_cm_enable
);
812 ret
= device_register(&css
->pseudo_subchannel
->dev
);
816 ret
= register_reboot_notifier(&css_reboot_notifier
);
821 /* Enable default isc for I/O subchannels. */
822 isc_register(IO_SCH_ISC
);
824 for_each_subchannel(__init_channel_subsystem
, NULL
);
827 if (css_chsc_characteristics
.secm
)
828 device_remove_file(&channel_subsystems
[i
]->device
,
829 &dev_attr_cm_enable
);
831 device_unregister(&channel_subsystems
[i
]->device
);
834 struct channel_subsystem
*css
;
837 css
= channel_subsystems
[i
];
838 device_unregister(&css
->pseudo_subchannel
->dev
);
839 css
->pseudo_subchannel
= NULL
;
840 if (css_chsc_characteristics
.secm
)
841 device_remove_file(&css
->device
,
842 &dev_attr_cm_enable
);
843 device_unregister(&css
->device
);
846 bus_unregister(&css_bus_type
);
848 s390_unregister_crw_handler(CRW_RSC_CSS
);
849 chsc_free_sei_area();
850 kfree(slow_subchannel_set
);
851 pr_alert("The CSS device driver initialization failed with "
856 int sch_is_pseudo_sch(struct subchannel
*sch
)
858 return sch
== to_css(sch
->dev
.parent
)->pseudo_subchannel
;
861 static int css_bus_match(struct device
*dev
, struct device_driver
*drv
)
863 struct subchannel
*sch
= to_subchannel(dev
);
864 struct css_driver
*driver
= to_cssdriver(drv
);
865 struct css_device_id
*id
;
867 for (id
= driver
->subchannel_type
; id
->match_flags
; id
++) {
868 if (sch
->st
== id
->type
)
875 static int css_probe(struct device
*dev
)
877 struct subchannel
*sch
;
880 sch
= to_subchannel(dev
);
881 sch
->driver
= to_cssdriver(dev
->driver
);
882 ret
= sch
->driver
->probe
? sch
->driver
->probe(sch
) : 0;
888 static int css_remove(struct device
*dev
)
890 struct subchannel
*sch
;
893 sch
= to_subchannel(dev
);
894 ret
= sch
->driver
->remove
? sch
->driver
->remove(sch
) : 0;
899 static void css_shutdown(struct device
*dev
)
901 struct subchannel
*sch
;
903 sch
= to_subchannel(dev
);
904 if (sch
->driver
&& sch
->driver
->shutdown
)
905 sch
->driver
->shutdown(sch
);
908 static int css_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
910 struct subchannel
*sch
= to_subchannel(dev
);
913 ret
= add_uevent_var(env
, "ST=%01X", sch
->st
);
916 ret
= add_uevent_var(env
, "MODALIAS=css:t%01X", sch
->st
);
920 struct bus_type css_bus_type
= {
922 .match
= css_bus_match
,
924 .remove
= css_remove
,
925 .shutdown
= css_shutdown
,
926 .uevent
= css_uevent
,
930 * css_driver_register - register a css driver
931 * @cdrv: css driver to register
933 * This is mainly a wrapper around driver_register that sets name
934 * and bus_type in the embedded struct device_driver correctly.
936 int css_driver_register(struct css_driver
*cdrv
)
938 cdrv
->drv
.name
= cdrv
->name
;
939 cdrv
->drv
.bus
= &css_bus_type
;
940 cdrv
->drv
.owner
= cdrv
->owner
;
941 return driver_register(&cdrv
->drv
);
943 EXPORT_SYMBOL_GPL(css_driver_register
);
946 * css_driver_unregister - unregister a css driver
947 * @cdrv: css driver to unregister
949 * This is a wrapper around driver_unregister.
951 void css_driver_unregister(struct css_driver
*cdrv
)
953 driver_unregister(&cdrv
->drv
);
955 EXPORT_SYMBOL_GPL(css_driver_unregister
);
957 subsys_initcall(init_channel_subsystem
);
959 MODULE_LICENSE("GPL");
960 EXPORT_SYMBOL(css_bus_type
);