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>
17 #include "../s390mach.h"
20 #include "cio_debug.h"
27 int css_init_done
= 0;
28 static int need_reprobe
= 0;
29 static int max_ssid
= 0;
31 struct channel_subsystem
*channel_subsystems
[__MAX_CSSID
+ 1];
33 int css_characteristics_avail
= 0;
36 for_each_subchannel(int(*fn
)(struct subchannel_id
, void *), void *data
)
38 struct subchannel_id schid
;
41 init_subchannel_id(&schid
);
45 ret
= fn(schid
, data
);
48 } while (schid
.sch_no
++ < __MAX_SUBCHANNEL
);
50 } while (schid
.ssid
++ < max_ssid
);
57 int (*fn_known_sch
)(struct subchannel
*, void *);
58 int (*fn_unknown_sch
)(struct subchannel_id
, void *);
61 static int call_fn_known_sch(struct device
*dev
, void *data
)
63 struct subchannel
*sch
= to_subchannel(dev
);
64 struct cb_data
*cb
= data
;
67 idset_sch_del(cb
->set
, sch
->schid
);
69 rc
= cb
->fn_known_sch(sch
, cb
->data
);
73 static int call_fn_unknown_sch(struct subchannel_id schid
, void *data
)
75 struct cb_data
*cb
= data
;
78 if (idset_sch_contains(cb
->set
, schid
))
79 rc
= cb
->fn_unknown_sch(schid
, cb
->data
);
83 int for_each_subchannel_staged(int (*fn_known
)(struct subchannel
*, void *),
84 int (*fn_unknown
)(struct subchannel_id
,
90 cb
.set
= idset_sch_new();
95 cb
.fn_known_sch
= fn_known
;
96 cb
.fn_unknown_sch
= fn_unknown
;
97 /* Process registered subchannels. */
98 rc
= bus_for_each_dev(&css_bus_type
, NULL
, &cb
, call_fn_known_sch
);
101 /* Process unregistered subchannels. */
103 rc
= for_each_subchannel(call_fn_unknown_sch
, &cb
);
110 static struct subchannel
*
111 css_alloc_subchannel(struct subchannel_id schid
)
113 struct subchannel
*sch
;
116 sch
= kmalloc (sizeof (*sch
), GFP_KERNEL
| GFP_DMA
);
118 return ERR_PTR(-ENOMEM
);
119 ret
= cio_validate_subchannel (sch
, schid
);
128 css_free_subchannel(struct subchannel
*sch
)
131 /* Reset intparm to zeroes. */
132 sch
->schib
.pmcw
.intparm
= 0;
140 css_subchannel_release(struct device
*dev
)
142 struct subchannel
*sch
;
144 sch
= to_subchannel(dev
);
145 if (!cio_is_console(sch
->schid
)) {
151 static int css_sch_device_register(struct subchannel
*sch
)
155 mutex_lock(&sch
->reg_mutex
);
156 ret
= device_register(&sch
->dev
);
157 mutex_unlock(&sch
->reg_mutex
);
162 * css_sch_device_unregister - unregister a subchannel
163 * @sch: subchannel to be unregistered
165 void css_sch_device_unregister(struct subchannel
*sch
)
167 mutex_lock(&sch
->reg_mutex
);
168 device_unregister(&sch
->dev
);
169 mutex_unlock(&sch
->reg_mutex
);
171 EXPORT_SYMBOL_GPL(css_sch_device_unregister
);
173 static void ssd_from_pmcw(struct chsc_ssd_info
*ssd
, struct pmcw
*pmcw
)
178 memset(ssd
, 0, sizeof(struct chsc_ssd_info
));
179 ssd
->path_mask
= pmcw
->pim
;
180 for (i
= 0; i
< 8; i
++) {
182 if (pmcw
->pim
& mask
) {
183 chp_id_init(&ssd
->chpid
[i
]);
184 ssd
->chpid
[i
].id
= pmcw
->chpid
[i
];
189 static void ssd_register_chpids(struct chsc_ssd_info
*ssd
)
194 for (i
= 0; i
< 8; i
++) {
196 if (ssd
->path_mask
& mask
)
197 if (!chp_is_registered(ssd
->chpid
[i
]))
198 chp_new(ssd
->chpid
[i
]);
202 void css_update_ssd_info(struct subchannel
*sch
)
206 if (cio_is_console(sch
->schid
)) {
207 /* Console is initialized too early for functions requiring
208 * memory allocation. */
209 ssd_from_pmcw(&sch
->ssd_info
, &sch
->schib
.pmcw
);
211 ret
= chsc_get_ssd_info(sch
->schid
, &sch
->ssd_info
);
213 ssd_from_pmcw(&sch
->ssd_info
, &sch
->schib
.pmcw
);
214 ssd_register_chpids(&sch
->ssd_info
);
218 static ssize_t
type_show(struct device
*dev
, struct device_attribute
*attr
,
221 struct subchannel
*sch
= to_subchannel(dev
);
223 return sprintf(buf
, "%01x\n", sch
->st
);
226 static DEVICE_ATTR(type
, 0444, type_show
, NULL
);
228 static ssize_t
modalias_show(struct device
*dev
, struct device_attribute
*attr
,
231 struct subchannel
*sch
= to_subchannel(dev
);
233 return sprintf(buf
, "css:t%01X\n", sch
->st
);
236 static DEVICE_ATTR(modalias
, 0444, modalias_show
, NULL
);
238 static struct attribute
*subch_attrs
[] = {
240 &dev_attr_modalias
.attr
,
244 static struct attribute_group subch_attr_group
= {
245 .attrs
= subch_attrs
,
248 static struct attribute_group
*default_subch_attr_groups
[] = {
253 static int css_register_subchannel(struct subchannel
*sch
)
257 /* Initialize the subchannel structure */
258 sch
->dev
.parent
= &channel_subsystems
[0]->device
;
259 sch
->dev
.bus
= &css_bus_type
;
260 sch
->dev
.release
= &css_subchannel_release
;
261 sch
->dev
.groups
= default_subch_attr_groups
;
263 * We don't want to generate uevents for I/O subchannels that don't
264 * have a working ccw device behind them since they will be
265 * unregistered before they can be used anyway, so we delay the add
266 * uevent until after device recognition was successful.
267 * Note that we suppress the uevent for all subchannel types;
268 * the subchannel driver can decide itself when it wants to inform
269 * userspace of its existence.
271 sch
->dev
.uevent_suppress
= 1;
272 css_update_ssd_info(sch
);
273 /* make it known to the system */
274 ret
= css_sch_device_register(sch
);
276 CIO_MSG_EVENT(0, "Could not register sch 0.%x.%04x: %d\n",
277 sch
->schid
.ssid
, sch
->schid
.sch_no
, ret
);
282 * No driver matched. Generate the uevent now so that
283 * a fitting driver module may be loaded based on the
286 sch
->dev
.uevent_suppress
= 0;
287 kobject_uevent(&sch
->dev
.kobj
, KOBJ_ADD
);
292 int css_probe_device(struct subchannel_id schid
)
295 struct subchannel
*sch
;
297 sch
= css_alloc_subchannel(schid
);
300 ret
= css_register_subchannel(sch
);
302 css_free_subchannel(sch
);
307 check_subchannel(struct device
* dev
, void * data
)
309 struct subchannel
*sch
;
310 struct subchannel_id
*schid
= data
;
312 sch
= to_subchannel(dev
);
313 return schid_equal(&sch
->schid
, schid
);
317 get_subchannel_by_schid(struct subchannel_id schid
)
321 dev
= bus_find_device(&css_bus_type
, NULL
,
322 &schid
, check_subchannel
);
324 return dev
? to_subchannel(dev
) : NULL
;
328 * css_sch_is_valid() - check if a subchannel is valid
329 * @schib: subchannel information block for the subchannel
331 int css_sch_is_valid(struct schib
*schib
)
333 if ((schib
->pmcw
.st
== SUBCHANNEL_TYPE_IO
) && !schib
->pmcw
.dnv
)
335 if ((schib
->pmcw
.st
== SUBCHANNEL_TYPE_MSG
) && !schib
->pmcw
.w
)
339 EXPORT_SYMBOL_GPL(css_sch_is_valid
);
341 static int css_evaluate_new_subchannel(struct subchannel_id schid
, int slow
)
346 /* Will be done on the slow path. */
349 if (stsch_err(schid
, &schib
) || !css_sch_is_valid(&schib
)) {
350 /* Unusable - ignore. */
353 CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, unknown, "
354 "slow path.\n", schid
.ssid
, schid
.sch_no
, CIO_OPER
);
356 return css_probe_device(schid
);
359 static int css_evaluate_known_subchannel(struct subchannel
*sch
, int slow
)
364 if (sch
->driver
->sch_event
)
365 ret
= sch
->driver
->sch_event(sch
, slow
);
368 "Got subchannel machine check but "
369 "no sch_event handler provided.\n");
374 static void css_evaluate_subchannel(struct subchannel_id schid
, int slow
)
376 struct subchannel
*sch
;
379 sch
= get_subchannel_by_schid(schid
);
381 ret
= css_evaluate_known_subchannel(sch
, slow
);
382 put_device(&sch
->dev
);
384 ret
= css_evaluate_new_subchannel(schid
, slow
);
386 css_schedule_eval(schid
);
389 static struct idset
*slow_subchannel_set
;
390 static spinlock_t slow_subchannel_lock
;
392 static int __init
slow_subchannel_init(void)
394 spin_lock_init(&slow_subchannel_lock
);
395 slow_subchannel_set
= idset_sch_new();
396 if (!slow_subchannel_set
) {
397 CIO_MSG_EVENT(0, "could not allocate slow subchannel set\n");
403 static int slow_eval_known_fn(struct subchannel
*sch
, void *data
)
408 spin_lock_irq(&slow_subchannel_lock
);
409 eval
= idset_sch_contains(slow_subchannel_set
, sch
->schid
);
410 idset_sch_del(slow_subchannel_set
, sch
->schid
);
411 spin_unlock_irq(&slow_subchannel_lock
);
413 rc
= css_evaluate_known_subchannel(sch
, 1);
415 css_schedule_eval(sch
->schid
);
420 static int slow_eval_unknown_fn(struct subchannel_id schid
, void *data
)
425 spin_lock_irq(&slow_subchannel_lock
);
426 eval
= idset_sch_contains(slow_subchannel_set
, schid
);
427 idset_sch_del(slow_subchannel_set
, schid
);
428 spin_unlock_irq(&slow_subchannel_lock
);
430 rc
= css_evaluate_new_subchannel(schid
, 1);
433 css_schedule_eval(schid
);
439 /* These should abort looping */
448 static void css_slow_path_func(struct work_struct
*unused
)
450 CIO_TRACE_EVENT(4, "slowpath");
451 for_each_subchannel_staged(slow_eval_known_fn
, slow_eval_unknown_fn
,
455 static DECLARE_WORK(slow_path_work
, css_slow_path_func
);
456 struct workqueue_struct
*slow_path_wq
;
458 void css_schedule_eval(struct subchannel_id schid
)
462 spin_lock_irqsave(&slow_subchannel_lock
, flags
);
463 idset_sch_add(slow_subchannel_set
, schid
);
464 queue_work(slow_path_wq
, &slow_path_work
);
465 spin_unlock_irqrestore(&slow_subchannel_lock
, flags
);
468 void css_schedule_eval_all(void)
472 spin_lock_irqsave(&slow_subchannel_lock
, flags
);
473 idset_fill(slow_subchannel_set
);
474 queue_work(slow_path_wq
, &slow_path_work
);
475 spin_unlock_irqrestore(&slow_subchannel_lock
, flags
);
478 void css_wait_for_slow_path(void)
480 flush_workqueue(ccw_device_notify_work
);
481 flush_workqueue(slow_path_wq
);
484 /* Reprobe subchannel if unregistered. */
485 static int reprobe_subchannel(struct subchannel_id schid
, void *data
)
489 CIO_MSG_EVENT(6, "cio: reprobe 0.%x.%04x\n",
490 schid
.ssid
, schid
.sch_no
);
494 ret
= css_probe_device(schid
);
501 /* These should abort looping */
510 /* Work function used to reprobe all unregistered subchannels. */
511 static void reprobe_all(struct work_struct
*unused
)
515 CIO_MSG_EVENT(4, "reprobe start\n");
518 /* Make sure initial subchannel scan is done. */
519 wait_event(ccw_device_init_wq
,
520 atomic_read(&ccw_device_init_count
) == 0);
521 ret
= for_each_subchannel_staged(NULL
, reprobe_subchannel
, NULL
);
523 CIO_MSG_EVENT(4, "reprobe done (rc=%d, need_reprobe=%d)\n", ret
,
527 static DECLARE_WORK(css_reprobe_work
, reprobe_all
);
529 /* Schedule reprobing of all unregistered subchannels. */
530 void css_schedule_reprobe(void)
533 queue_work(slow_path_wq
, &css_reprobe_work
);
536 EXPORT_SYMBOL_GPL(css_schedule_reprobe
);
539 * Called from the machine check handler for subchannel report words.
541 static void css_process_crw(struct crw
*crw0
, struct crw
*crw1
, int overflow
)
543 struct subchannel_id mchk_schid
;
546 css_schedule_eval_all();
549 CIO_CRW_EVENT(2, "CRW0 reports slct=%d, oflw=%d, "
550 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
551 crw0
->slct
, crw0
->oflw
, crw0
->chn
, crw0
->rsc
, crw0
->anc
,
552 crw0
->erc
, crw0
->rsid
);
554 CIO_CRW_EVENT(2, "CRW1 reports slct=%d, oflw=%d, "
555 "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
556 crw1
->slct
, crw1
->oflw
, crw1
->chn
, crw1
->rsc
,
557 crw1
->anc
, crw1
->erc
, crw1
->rsid
);
558 init_subchannel_id(&mchk_schid
);
559 mchk_schid
.sch_no
= crw0
->rsid
;
561 mchk_schid
.ssid
= (crw1
->rsid
>> 8) & 3;
564 * Since we are always presented with IPI in the CRW, we have to
565 * use stsch() to find out if the subchannel in question has come
568 css_evaluate_subchannel(mchk_schid
, 0);
572 __init_channel_subsystem(struct subchannel_id schid
, void *data
)
574 struct subchannel
*sch
;
577 if (cio_is_console(schid
))
578 sch
= cio_get_console_subchannel();
580 sch
= css_alloc_subchannel(schid
);
589 panic("Out of memory in init_channel_subsystem\n");
590 /* -ENXIO: no more subchannels. */
593 /* -EIO: this subchannel set not supported. */
601 * We register ALL valid subchannels in ioinfo, even those
602 * that have been present before init_channel_subsystem.
603 * These subchannels can't have been registered yet (kmalloc
604 * not working) so we do it now. This is true e.g. for the
605 * console subchannel.
607 css_register_subchannel(sch
);
612 css_generate_pgid(struct channel_subsystem
*css
, u32 tod_high
)
614 if (css_characteristics_avail
&& css_general_characteristics
.mcss
) {
615 css
->global_pgid
.pgid_high
.ext_cssid
.version
= 0x80;
616 css
->global_pgid
.pgid_high
.ext_cssid
.cssid
= css
->cssid
;
619 css
->global_pgid
.pgid_high
.cpu_addr
= hard_smp_processor_id();
621 css
->global_pgid
.pgid_high
.cpu_addr
= 0;
624 css
->global_pgid
.cpu_id
= ((cpuid_t
*) __LC_CPUID
)->ident
;
625 css
->global_pgid
.cpu_model
= ((cpuid_t
*) __LC_CPUID
)->machine
;
626 css
->global_pgid
.tod_high
= tod_high
;
631 channel_subsystem_release(struct device
*dev
)
633 struct channel_subsystem
*css
;
636 mutex_destroy(&css
->mutex
);
641 css_cm_enable_show(struct device
*dev
, struct device_attribute
*attr
,
644 struct channel_subsystem
*css
= to_css(dev
);
649 mutex_lock(&css
->mutex
);
650 ret
= sprintf(buf
, "%x\n", css
->cm_enabled
);
651 mutex_unlock(&css
->mutex
);
656 css_cm_enable_store(struct device
*dev
, struct device_attribute
*attr
,
657 const char *buf
, size_t count
)
659 struct channel_subsystem
*css
= to_css(dev
);
663 ret
= strict_strtoul(buf
, 16, &val
);
666 mutex_lock(&css
->mutex
);
669 ret
= css
->cm_enabled
? chsc_secm(css
, 0) : 0;
672 ret
= css
->cm_enabled
? 0 : chsc_secm(css
, 1);
677 mutex_unlock(&css
->mutex
);
678 return ret
< 0 ? ret
: count
;
681 static DEVICE_ATTR(cm_enable
, 0644, css_cm_enable_show
, css_cm_enable_store
);
683 static int __init
setup_css(int nr
)
687 struct channel_subsystem
*css
;
689 css
= channel_subsystems
[nr
];
690 memset(css
, 0, sizeof(struct channel_subsystem
));
691 css
->pseudo_subchannel
=
692 kzalloc(sizeof(*css
->pseudo_subchannel
), GFP_KERNEL
);
693 if (!css
->pseudo_subchannel
)
695 css
->pseudo_subchannel
->dev
.parent
= &css
->device
;
696 css
->pseudo_subchannel
->dev
.release
= css_subchannel_release
;
697 sprintf(css
->pseudo_subchannel
->dev
.bus_id
, "defunct");
698 ret
= cio_create_sch_lock(css
->pseudo_subchannel
);
700 kfree(css
->pseudo_subchannel
);
703 mutex_init(&css
->mutex
);
706 sprintf(css
->device
.bus_id
, "css%x", nr
);
707 css
->device
.release
= channel_subsystem_release
;
708 tod_high
= (u32
) (get_clock() >> 32);
709 css_generate_pgid(css
, tod_high
);
713 static int css_reboot_event(struct notifier_block
*this,
720 for (i
= 0; i
<= __MAX_CSSID
; i
++) {
721 struct channel_subsystem
*css
;
723 css
= channel_subsystems
[i
];
724 mutex_lock(&css
->mutex
);
726 if (chsc_secm(css
, 0))
728 mutex_unlock(&css
->mutex
);
734 static struct notifier_block css_reboot_notifier
= {
735 .notifier_call
= css_reboot_event
,
739 * Now that the driver core is running, we can setup our channel subsystem.
740 * The struct subchannel's are created during probing (except for the
741 * static console subchannel).
744 init_channel_subsystem (void)
748 ret
= chsc_determine_css_characteristics();
750 goto out
; /* No need to continue. */
752 css_characteristics_avail
= 1;
754 ret
= chsc_alloc_sei_area();
758 ret
= slow_subchannel_init();
762 ret
= s390_register_crw_handler(CRW_RSC_SCH
, css_process_crw
);
766 if ((ret
= bus_register(&css_bus_type
)))
769 /* Try to enable MSS. */
770 ret
= chsc_enable_facility(CHSC_SDA_OC_MSS
);
772 case 0: /* Success. */
773 max_ssid
= __MAX_SSID
;
780 /* Setup css structure. */
781 for (i
= 0; i
<= __MAX_CSSID
; i
++) {
782 struct channel_subsystem
*css
;
784 css
= kmalloc(sizeof(struct channel_subsystem
), GFP_KERNEL
);
789 channel_subsystems
[i
] = css
;
793 ret
= device_register(&css
->device
);
796 if (css_characteristics_avail
&&
797 css_chsc_characteristics
.secm
) {
798 ret
= device_create_file(&css
->device
,
799 &dev_attr_cm_enable
);
803 ret
= device_register(&css
->pseudo_subchannel
->dev
);
807 ret
= register_reboot_notifier(&css_reboot_notifier
);
814 for_each_subchannel(__init_channel_subsystem
, NULL
);
817 device_unregister(&channel_subsystems
[i
]->pseudo_subchannel
->dev
);
819 device_remove_file(&channel_subsystems
[i
]->device
,
820 &dev_attr_cm_enable
);
822 device_unregister(&channel_subsystems
[i
]->device
);
824 kfree(channel_subsystems
[i
]->pseudo_subchannel
->lock
);
825 kfree(channel_subsystems
[i
]->pseudo_subchannel
);
827 kfree(channel_subsystems
[i
]);
830 struct channel_subsystem
*css
;
833 css
= channel_subsystems
[i
];
834 device_unregister(&css
->pseudo_subchannel
->dev
);
835 if (css_characteristics_avail
&& css_chsc_characteristics
.secm
)
836 device_remove_file(&css
->device
,
837 &dev_attr_cm_enable
);
838 device_unregister(&css
->device
);
841 bus_unregister(&css_bus_type
);
843 s390_unregister_crw_handler(CRW_RSC_CSS
);
844 chsc_free_sei_area();
845 kfree(slow_subchannel_set
);
846 printk(KERN_WARNING
"cio: failed to initialize css driver (%d)!\n",
851 int sch_is_pseudo_sch(struct subchannel
*sch
)
853 return sch
== to_css(sch
->dev
.parent
)->pseudo_subchannel
;
857 * find a driver for a subchannel. They identify by the subchannel
858 * type with the exception that the console subchannel driver has its own
859 * subchannel type although the device is an i/o subchannel
862 css_bus_match (struct device
*dev
, struct device_driver
*drv
)
864 struct subchannel
*sch
= to_subchannel(dev
);
865 struct css_driver
*driver
= to_cssdriver(drv
);
867 if (sch
->st
== driver
->subchannel_type
)
873 static int css_probe(struct device
*dev
)
875 struct subchannel
*sch
;
878 sch
= to_subchannel(dev
);
879 sch
->driver
= to_cssdriver(dev
->driver
);
880 ret
= sch
->driver
->probe
? sch
->driver
->probe(sch
) : 0;
886 static int css_remove(struct device
*dev
)
888 struct subchannel
*sch
;
891 sch
= to_subchannel(dev
);
892 ret
= sch
->driver
->remove
? sch
->driver
->remove(sch
) : 0;
897 static void css_shutdown(struct device
*dev
)
899 struct subchannel
*sch
;
901 sch
= to_subchannel(dev
);
902 if (sch
->driver
&& sch
->driver
->shutdown
)
903 sch
->driver
->shutdown(sch
);
906 static int css_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
908 struct subchannel
*sch
= to_subchannel(dev
);
911 ret
= add_uevent_var(env
, "ST=%01X", sch
->st
);
914 ret
= add_uevent_var(env
, "MODALIAS=css:t%01X", sch
->st
);
918 struct bus_type css_bus_type
= {
920 .match
= css_bus_match
,
922 .remove
= css_remove
,
923 .shutdown
= css_shutdown
,
924 .uevent
= css_uevent
,
928 * css_driver_register - register a css driver
929 * @cdrv: css driver to register
931 * This is mainly a wrapper around driver_register that sets name
932 * and bus_type in the embedded struct device_driver correctly.
934 int css_driver_register(struct css_driver
*cdrv
)
936 cdrv
->drv
.name
= cdrv
->name
;
937 cdrv
->drv
.bus
= &css_bus_type
;
938 cdrv
->drv
.owner
= cdrv
->owner
;
939 return driver_register(&cdrv
->drv
);
941 EXPORT_SYMBOL_GPL(css_driver_register
);
944 * css_driver_unregister - unregister a css driver
945 * @cdrv: css driver to unregister
947 * This is a wrapper around driver_unregister.
949 void css_driver_unregister(struct css_driver
*cdrv
)
951 driver_unregister(&cdrv
->drv
);
953 EXPORT_SYMBOL_GPL(css_driver_unregister
);
955 subsys_initcall(init_channel_subsystem
);
957 MODULE_LICENSE("GPL");
958 EXPORT_SYMBOL(css_bus_type
);
959 EXPORT_SYMBOL_GPL(css_characteristics_avail
);