1 // SPDX-License-Identifier: GPL-2.0
3 * core function to access sclp interface
5 * Copyright IBM Corp. 1999, 2009
7 * Author(s): Martin Peschke <mpeschke@de.ibm.com>
8 * Martin Schwidefsky <schwidefsky@de.ibm.com>
11 #include <linux/kernel_stat.h>
12 #include <linux/module.h>
13 #include <linux/err.h>
14 #include <linux/panic_notifier.h>
15 #include <linux/spinlock.h>
16 #include <linux/interrupt.h>
17 #include <linux/timer.h>
18 #include <linux/reboot.h>
19 #include <linux/jiffies.h>
20 #include <linux/init.h>
21 #include <linux/platform_device.h>
22 #include <asm/types.h>
24 #include <asm/debug.h>
28 #define SCLP_HEADER "sclp: "
30 struct sclp_trace_entry
{
31 char id
[4] __nonstring
;
36 #define SCLP_TRACE_ENTRY_SIZE sizeof(struct sclp_trace_entry)
37 #define SCLP_TRACE_MAX_SIZE 128
38 #define SCLP_TRACE_EVENT_MAX_SIZE 64
40 /* Debug trace area intended for all entries in abbreviated form. */
41 DEFINE_STATIC_DEBUG_INFO(sclp_debug
, "sclp", 8, 1, SCLP_TRACE_ENTRY_SIZE
,
42 &debug_hex_ascii_view
);
44 /* Error trace area intended for full entries relating to failed requests. */
45 DEFINE_STATIC_DEBUG_INFO(sclp_debug_err
, "sclp_err", 4, 1,
46 SCLP_TRACE_ENTRY_SIZE
, &debug_hex_ascii_view
);
48 /* Lock to protect internal data consistency. */
49 static DEFINE_SPINLOCK(sclp_lock
);
51 /* Mask of events that we can send to the sclp interface. */
52 static sccb_mask_t sclp_receive_mask
;
54 /* Mask of events that we can receive from the sclp interface. */
55 static sccb_mask_t sclp_send_mask
;
57 /* List of registered event listeners and senders. */
58 static LIST_HEAD(sclp_reg_list
);
60 /* List of queued requests. */
61 static LIST_HEAD(sclp_req_queue
);
63 /* Data for read and init requests. */
64 static struct sclp_req sclp_read_req
;
65 static struct sclp_req sclp_init_req
;
66 static void *sclp_read_sccb
;
67 static struct init_sccb
*sclp_init_sccb
;
69 /* Number of console pages to allocate, used by sclp_con.c and sclp_vt220.c */
70 int sclp_console_pages
= SCLP_CONSOLE_PAGES
;
71 /* Flag to indicate if buffer pages are dropped on buffer full condition */
72 bool sclp_console_drop
= true;
73 /* Number of times the console dropped buffer pages */
74 unsigned long sclp_console_full
;
76 /* The currently active SCLP command word. */
77 static sclp_cmdw_t active_cmd
;
79 static inline void sclp_trace(int prio
, char *id
, u32 a
, u64 b
, bool err
)
81 struct sclp_trace_entry e
;
83 memset(&e
, 0, sizeof(e
));
87 debug_event(&sclp_debug
, prio
, &e
, sizeof(e
));
89 debug_event(&sclp_debug_err
, 0, &e
, sizeof(e
));
92 static inline int no_zeroes_len(void *data
, int len
)
96 /* Minimize trace area usage by not tracing trailing zeroes. */
97 while (len
> SCLP_TRACE_ENTRY_SIZE
&& d
[len
- 1] == 0)
103 static inline void sclp_trace_bin(int prio
, void *d
, int len
, int errlen
)
105 debug_event(&sclp_debug
, prio
, d
, no_zeroes_len(d
, len
));
107 debug_event(&sclp_debug_err
, 0, d
, no_zeroes_len(d
, errlen
));
110 static inline int abbrev_len(sclp_cmdw_t cmd
, struct sccb_header
*sccb
)
112 struct evbuf_header
*evbuf
= (struct evbuf_header
*)(sccb
+ 1);
113 int len
= sccb
->length
, limit
= SCLP_TRACE_MAX_SIZE
;
115 /* Full SCCB tracing if debug level is set to max. */
116 if (sclp_debug
.level
== DEBUG_MAX_LEVEL
)
119 /* Minimal tracing for console writes. */
120 if (cmd
== SCLP_CMDW_WRITE_EVENT_DATA
&&
121 (evbuf
->type
== EVTYP_MSG
|| evbuf
->type
== EVTYP_VT220MSG
))
122 limit
= SCLP_TRACE_ENTRY_SIZE
;
124 return min(len
, limit
);
127 static inline void sclp_trace_sccb(int prio
, char *id
, u32 a
, u64 b
,
128 sclp_cmdw_t cmd
, struct sccb_header
*sccb
,
131 sclp_trace(prio
, id
, a
, b
, err
);
133 sclp_trace_bin(prio
+ 1, sccb
, abbrev_len(cmd
, sccb
),
134 err
? sccb
->length
: 0);
138 static inline void sclp_trace_evbuf(int prio
, char *id
, u32 a
, u64 b
,
139 struct evbuf_header
*evbuf
, bool err
)
141 sclp_trace(prio
, id
, a
, b
, err
);
142 sclp_trace_bin(prio
+ 1, evbuf
,
143 min((int)evbuf
->length
, (int)SCLP_TRACE_EVENT_MAX_SIZE
),
144 err
? evbuf
->length
: 0);
147 static inline void sclp_trace_req(int prio
, char *id
, struct sclp_req
*req
,
150 struct sccb_header
*sccb
= req
->sccb
;
161 summary
.status
= req
->status
;
162 summary
.response
= sccb
? sccb
->response_code
: 0;
163 summary
.timeout
= (u16
)req
->queue_timeout
;
164 summary
.start_count
= (u16
)req
->start_count
;
166 sclp_trace(prio
, id
, __pa(sccb
), summary
.b
, err
);
169 static inline void sclp_trace_register(int prio
, char *id
, u32 a
, u64 b
,
170 struct sclp_register
*reg
)
177 d
.receive
= reg
->receive_mask
;
178 d
.send
= reg
->send_mask
;
180 sclp_trace(prio
, id
, a
, b
, false);
181 sclp_trace_bin(prio
, &d
, sizeof(d
), 0);
184 static int __init
sclp_setup_console_pages(char *str
)
188 rc
= kstrtoint(str
, 0, &pages
);
189 if (!rc
&& pages
>= SCLP_CONSOLE_PAGES
)
190 sclp_console_pages
= pages
;
194 __setup("sclp_con_pages=", sclp_setup_console_pages
);
196 static int __init
sclp_setup_console_drop(char *str
)
198 return kstrtobool(str
, &sclp_console_drop
) == 0;
201 __setup("sclp_con_drop=", sclp_setup_console_drop
);
203 /* Timer for request retries. */
204 static struct timer_list sclp_request_timer
;
206 /* Timer for queued requests. */
207 static struct timer_list sclp_queue_timer
;
209 /* Internal state: is a request active at the sclp? */
210 static volatile enum sclp_running_state_t
{
211 sclp_running_state_idle
,
212 sclp_running_state_running
,
213 sclp_running_state_reset_pending
214 } sclp_running_state
= sclp_running_state_idle
;
216 /* Internal state: is a read request pending? */
217 static volatile enum sclp_reading_state_t
{
218 sclp_reading_state_idle
,
219 sclp_reading_state_reading
220 } sclp_reading_state
= sclp_reading_state_idle
;
222 /* Internal state: is the driver currently serving requests? */
223 static volatile enum sclp_activation_state_t
{
224 sclp_activation_state_active
,
225 sclp_activation_state_deactivating
,
226 sclp_activation_state_inactive
,
227 sclp_activation_state_activating
228 } sclp_activation_state
= sclp_activation_state_active
;
230 /* Internal state: is an init mask request pending? */
231 static volatile enum sclp_mask_state_t
{
232 sclp_mask_state_idle
,
233 sclp_mask_state_initializing
234 } sclp_mask_state
= sclp_mask_state_idle
;
236 /* Maximum retry counts */
237 #define SCLP_INIT_RETRY 3
238 #define SCLP_MASK_RETRY 3
240 /* Timeout intervals in seconds.*/
241 #define SCLP_BUSY_INTERVAL 10
242 #define SCLP_RETRY_INTERVAL 30
244 static void sclp_request_timeout(bool force_restart
);
245 static void sclp_process_queue(void);
246 static void __sclp_make_read_req(void);
247 static int sclp_init_mask(int calculate
);
248 static int sclp_init(void);
251 __sclp_queue_read_req(void)
253 if (sclp_reading_state
== sclp_reading_state_idle
) {
254 sclp_reading_state
= sclp_reading_state_reading
;
255 __sclp_make_read_req();
256 /* Add request to head of queue */
257 list_add(&sclp_read_req
.list
, &sclp_req_queue
);
261 /* Set up request retry timer. Called while sclp_lock is locked. */
263 __sclp_set_request_timer(unsigned long time
, void (*cb
)(struct timer_list
*))
265 del_timer(&sclp_request_timer
);
266 sclp_request_timer
.function
= cb
;
267 sclp_request_timer
.expires
= jiffies
+ time
;
268 add_timer(&sclp_request_timer
);
271 static void sclp_request_timeout_restart(struct timer_list
*unused
)
273 sclp_request_timeout(true);
276 static void sclp_request_timeout_normal(struct timer_list
*unused
)
278 sclp_request_timeout(false);
281 /* Request timeout handler. Restart the request queue. If force_restart,
282 * force restart of running request. */
283 static void sclp_request_timeout(bool force_restart
)
287 /* TMO: A timeout occurred (a=force_restart) */
288 sclp_trace(2, "TMO", force_restart
, 0, true);
290 spin_lock_irqsave(&sclp_lock
, flags
);
292 if (sclp_running_state
== sclp_running_state_running
) {
293 /* Break running state and queue NOP read event request
294 * to get a defined interface state. */
295 __sclp_queue_read_req();
296 sclp_running_state
= sclp_running_state_idle
;
299 __sclp_set_request_timer(SCLP_BUSY_INTERVAL
* HZ
,
300 sclp_request_timeout_normal
);
302 spin_unlock_irqrestore(&sclp_lock
, flags
);
303 sclp_process_queue();
307 * Returns the expire value in jiffies of the next pending request timeout,
308 * if any. Needs to be called with sclp_lock.
310 static unsigned long __sclp_req_queue_find_next_timeout(void)
312 unsigned long expires_next
= 0;
313 struct sclp_req
*req
;
315 list_for_each_entry(req
, &sclp_req_queue
, list
) {
316 if (!req
->queue_expires
)
319 (time_before(req
->queue_expires
, expires_next
)))
320 expires_next
= req
->queue_expires
;
326 * Returns expired request, if any, and removes it from the list.
328 static struct sclp_req
*__sclp_req_queue_remove_expired_req(void)
330 unsigned long flags
, now
;
331 struct sclp_req
*req
;
333 spin_lock_irqsave(&sclp_lock
, flags
);
335 /* Don't need list_for_each_safe because we break out after list_del */
336 list_for_each_entry(req
, &sclp_req_queue
, list
) {
337 if (!req
->queue_expires
)
339 if (time_before_eq(req
->queue_expires
, now
)) {
340 if (req
->status
== SCLP_REQ_QUEUED
) {
341 req
->status
= SCLP_REQ_QUEUED_TIMEOUT
;
342 list_del(&req
->list
);
349 spin_unlock_irqrestore(&sclp_lock
, flags
);
354 * Timeout handler for queued requests. Removes request from list and
355 * invokes callback. This timer can be set per request in situations where
356 * waiting too long would be harmful to the system, e.g. during SE reboot.
358 static void sclp_req_queue_timeout(struct timer_list
*unused
)
360 unsigned long flags
, expires_next
;
361 struct sclp_req
*req
;
364 req
= __sclp_req_queue_remove_expired_req();
367 /* RQTM: Request timed out (a=sccb, b=summary) */
368 sclp_trace_req(2, "RQTM", req
, true);
371 if (req
&& req
->callback
)
372 req
->callback(req
, req
->callback_data
);
375 spin_lock_irqsave(&sclp_lock
, flags
);
376 expires_next
= __sclp_req_queue_find_next_timeout();
378 mod_timer(&sclp_queue_timer
, expires_next
);
379 spin_unlock_irqrestore(&sclp_lock
, flags
);
382 static int sclp_service_call_trace(sclp_cmdw_t command
, void *sccb
)
384 static u64 srvc_count
;
387 /* SRV1: Service call about to be issued (a=command, b=sccb address) */
388 sclp_trace_sccb(0, "SRV1", command
, (u64
)sccb
, command
, sccb
, false);
390 rc
= sclp_service_call(command
, sccb
);
392 /* SRV2: Service call was issued (a=rc, b=SRVC sequence number) */
393 sclp_trace(0, "SRV2", -rc
, ++srvc_count
, rc
!= 0);
396 active_cmd
= command
;
401 /* Try to start a request. Return zero if the request was successfully
402 * started or if it will be started at a later time. Return non-zero otherwise.
403 * Called while sclp_lock is locked. */
405 __sclp_start_request(struct sclp_req
*req
)
409 if (sclp_running_state
!= sclp_running_state_idle
)
411 del_timer(&sclp_request_timer
);
412 rc
= sclp_service_call_trace(req
->command
, req
->sccb
);
416 /* Successfully started request */
417 req
->status
= SCLP_REQ_RUNNING
;
418 sclp_running_state
= sclp_running_state_running
;
419 __sclp_set_request_timer(SCLP_RETRY_INTERVAL
* HZ
,
420 sclp_request_timeout_restart
);
422 } else if (rc
== -EBUSY
) {
423 /* Try again later */
424 __sclp_set_request_timer(SCLP_BUSY_INTERVAL
* HZ
,
425 sclp_request_timeout_normal
);
429 req
->status
= SCLP_REQ_FAILED
;
433 /* Try to start queued requests. */
435 sclp_process_queue(void)
437 struct sclp_req
*req
;
441 spin_lock_irqsave(&sclp_lock
, flags
);
442 if (sclp_running_state
!= sclp_running_state_idle
) {
443 spin_unlock_irqrestore(&sclp_lock
, flags
);
446 del_timer(&sclp_request_timer
);
447 while (!list_empty(&sclp_req_queue
)) {
448 req
= list_entry(sclp_req_queue
.next
, struct sclp_req
, list
);
449 rc
= __sclp_start_request(req
);
453 if (req
->start_count
> 1) {
454 /* Cannot abort already submitted request - could still
455 * be active at the SCLP */
456 __sclp_set_request_timer(SCLP_BUSY_INTERVAL
* HZ
,
457 sclp_request_timeout_normal
);
460 /* Post-processing for aborted request */
461 list_del(&req
->list
);
463 /* RQAB: Request aborted (a=sccb, b=summary) */
464 sclp_trace_req(2, "RQAB", req
, true);
467 spin_unlock_irqrestore(&sclp_lock
, flags
);
468 req
->callback(req
, req
->callback_data
);
469 spin_lock_irqsave(&sclp_lock
, flags
);
472 spin_unlock_irqrestore(&sclp_lock
, flags
);
475 static int __sclp_can_add_request(struct sclp_req
*req
)
477 if (req
== &sclp_init_req
)
479 if (sclp_init_state
!= sclp_init_state_initialized
)
481 if (sclp_activation_state
!= sclp_activation_state_active
)
486 /* Queue a new request. Return zero on success, non-zero otherwise. */
488 sclp_add_request(struct sclp_req
*req
)
493 spin_lock_irqsave(&sclp_lock
, flags
);
494 if (!__sclp_can_add_request(req
)) {
495 spin_unlock_irqrestore(&sclp_lock
, flags
);
499 /* RQAD: Request was added (a=sccb, b=caller) */
500 sclp_trace(2, "RQAD", __pa(req
->sccb
), _RET_IP_
, false);
502 req
->status
= SCLP_REQ_QUEUED
;
503 req
->start_count
= 0;
504 list_add_tail(&req
->list
, &sclp_req_queue
);
506 if (req
->queue_timeout
) {
507 req
->queue_expires
= jiffies
+ req
->queue_timeout
* HZ
;
508 if (!timer_pending(&sclp_queue_timer
) ||
509 time_after(sclp_queue_timer
.expires
, req
->queue_expires
))
510 mod_timer(&sclp_queue_timer
, req
->queue_expires
);
512 req
->queue_expires
= 0;
513 /* Start if request is first in list */
514 if (sclp_running_state
== sclp_running_state_idle
&&
515 req
->list
.prev
== &sclp_req_queue
) {
516 rc
= __sclp_start_request(req
);
518 list_del(&req
->list
);
520 spin_unlock_irqrestore(&sclp_lock
, flags
);
524 EXPORT_SYMBOL(sclp_add_request
);
526 /* Dispatch events found in request buffer to registered listeners. Return 0
527 * if all events were dispatched, non-zero otherwise. */
529 sclp_dispatch_evbufs(struct sccb_header
*sccb
)
532 struct evbuf_header
*evbuf
;
534 struct sclp_register
*reg
;
538 spin_lock_irqsave(&sclp_lock
, flags
);
540 for (offset
= sizeof(struct sccb_header
); offset
< sccb
->length
;
541 offset
+= evbuf
->length
) {
542 evbuf
= (struct evbuf_header
*) ((addr_t
) sccb
+ offset
);
543 /* Check for malformed hardware response */
544 if (evbuf
->length
== 0)
546 /* Search for event handler */
548 list_for_each(l
, &sclp_reg_list
) {
549 reg
= list_entry(l
, struct sclp_register
, list
);
550 if (reg
->receive_mask
& SCLP_EVTYP_MASK(evbuf
->type
))
556 /* EVNT: Event callback (b=receiver) */
557 sclp_trace_evbuf(2, "EVNT", 0, reg
? (u64
)reg
->receiver_fn
: 0,
560 if (reg
&& reg
->receiver_fn
) {
561 spin_unlock_irqrestore(&sclp_lock
, flags
);
562 reg
->receiver_fn(evbuf
);
563 spin_lock_irqsave(&sclp_lock
, flags
);
564 } else if (reg
== NULL
)
567 spin_unlock_irqrestore(&sclp_lock
, flags
);
571 /* Read event data request callback. */
573 sclp_read_cb(struct sclp_req
*req
, void *data
)
576 struct sccb_header
*sccb
;
578 sccb
= (struct sccb_header
*) req
->sccb
;
579 if (req
->status
== SCLP_REQ_DONE
&& (sccb
->response_code
== 0x20 ||
580 sccb
->response_code
== 0x220))
581 sclp_dispatch_evbufs(sccb
);
582 spin_lock_irqsave(&sclp_lock
, flags
);
583 sclp_reading_state
= sclp_reading_state_idle
;
584 spin_unlock_irqrestore(&sclp_lock
, flags
);
587 /* Prepare read event data request. Called while sclp_lock is locked. */
588 static void __sclp_make_read_req(void)
590 struct sccb_header
*sccb
;
592 sccb
= (struct sccb_header
*) sclp_read_sccb
;
594 memset(&sclp_read_req
, 0, sizeof(struct sclp_req
));
595 sclp_read_req
.command
= SCLP_CMDW_READ_EVENT_DATA
;
596 sclp_read_req
.status
= SCLP_REQ_QUEUED
;
597 sclp_read_req
.start_count
= 0;
598 sclp_read_req
.callback
= sclp_read_cb
;
599 sclp_read_req
.sccb
= sccb
;
600 sccb
->length
= PAGE_SIZE
;
601 sccb
->function_code
= 0;
602 sccb
->control_mask
[2] = 0x80;
605 /* Search request list for request with matching sccb. Return request if found,
606 * NULL otherwise. Called while sclp_lock is locked. */
607 static inline struct sclp_req
*
608 __sclp_find_req(u32 sccb
)
611 struct sclp_req
*req
;
613 list_for_each(l
, &sclp_req_queue
) {
614 req
= list_entry(l
, struct sclp_req
, list
);
615 if (sccb
== __pa(req
->sccb
))
621 static bool ok_response(u32 sccb_int
, sclp_cmdw_t cmd
)
623 struct sccb_header
*sccb
= (struct sccb_header
*)__va(sccb_int
);
624 struct evbuf_header
*evbuf
;
630 /* Check SCCB response. */
631 response
= sccb
->response_code
& 0xff;
632 if (response
!= 0x10 && response
!= 0x20)
635 /* Check event-processed flag on outgoing events. */
636 if (cmd
== SCLP_CMDW_WRITE_EVENT_DATA
) {
637 evbuf
= (struct evbuf_header
*)(sccb
+ 1);
638 if (!(evbuf
->flags
& 0x80))
645 /* Handler for external interruption. Perform request post-processing.
646 * Prepare read event data request if necessary. Start processing of next
647 * request on queue. */
648 static void sclp_interrupt_handler(struct ext_code ext_code
,
649 unsigned int param32
, unsigned long param64
)
651 struct sclp_req
*req
;
655 inc_irq_stat(IRQEXT_SCP
);
656 spin_lock(&sclp_lock
);
657 finished_sccb
= param32
& 0xfffffff8;
658 evbuf_pending
= param32
& 0x3;
660 /* INT: Interrupt received (a=intparm, b=cmd) */
661 sclp_trace_sccb(0, "INT", param32
, active_cmd
, active_cmd
,
662 (struct sccb_header
*)__va(finished_sccb
),
663 !ok_response(finished_sccb
, active_cmd
));
666 del_timer(&sclp_request_timer
);
667 sclp_running_state
= sclp_running_state_reset_pending
;
668 req
= __sclp_find_req(finished_sccb
);
670 /* Request post-processing */
671 list_del(&req
->list
);
672 req
->status
= SCLP_REQ_DONE
;
674 /* RQOK: Request success (a=sccb, b=summary) */
675 sclp_trace_req(2, "RQOK", req
, false);
678 spin_unlock(&sclp_lock
);
679 req
->callback(req
, req
->callback_data
);
680 spin_lock(&sclp_lock
);
683 /* UNEX: Unexpected SCCB completion (a=sccb address) */
684 sclp_trace(0, "UNEX", finished_sccb
, 0, true);
686 sclp_running_state
= sclp_running_state_idle
;
690 sclp_activation_state
== sclp_activation_state_active
)
691 __sclp_queue_read_req();
692 spin_unlock(&sclp_lock
);
693 sclp_process_queue();
696 /* Convert interval in jiffies to TOD ticks. */
698 sclp_tod_from_jiffies(unsigned long jiffies
)
700 return (u64
) (jiffies
/ HZ
) << 32;
703 /* Wait until a currently running request finished. Note: while this function
704 * is running, no timers are served on the calling CPU. */
708 unsigned long long old_tick
;
709 struct ctlreg cr0
, cr0_sync
;
711 static u64 sync_count
;
715 /* SYN1: Synchronous wait start (a=runstate, b=sync count) */
716 sclp_trace(4, "SYN1", sclp_running_state
, ++sync_count
, false);
718 /* We'll be disabling timer interrupts, so we need a custom timeout
721 if (timer_pending(&sclp_request_timer
)) {
722 /* Get timeout TOD value */
723 timeout
= get_tod_clock_fast() +
724 sclp_tod_from_jiffies(sclp_request_timer
.expires
-
727 local_irq_save(flags
);
728 /* Prevent bottom half from executing once we force interrupts open */
729 irq_context
= in_interrupt();
732 /* Enable service-signal interruption, disable timer interrupts */
733 old_tick
= local_tick_disable();
735 local_ctl_store(0, &cr0
);
736 cr0_sync
.val
= cr0
.val
& ~CR0_IRQ_SUBCLASS_MASK
;
737 cr0_sync
.val
|= 1UL << (63 - 54);
738 local_ctl_load(0, &cr0_sync
);
739 arch_local_irq_enable_external();
740 /* Loop until driver state indicates finished request */
741 while (sclp_running_state
!= sclp_running_state_idle
) {
742 /* Check for expired request timer */
743 if (get_tod_clock_fast() > timeout
&& del_timer(&sclp_request_timer
))
744 sclp_request_timer
.function(&sclp_request_timer
);
748 local_ctl_load(0, &cr0
);
751 local_tick_enable(old_tick
);
752 local_irq_restore(flags
);
754 /* SYN2: Synchronous wait end (a=runstate, b=sync_count) */
755 sclp_trace(4, "SYN2", sclp_running_state
, sync_count
, false);
757 EXPORT_SYMBOL(sclp_sync_wait
);
759 /* Dispatch changes in send and receive mask to registered listeners. */
761 sclp_dispatch_state_change(void)
764 struct sclp_register
*reg
;
766 sccb_mask_t receive_mask
;
767 sccb_mask_t send_mask
;
770 spin_lock_irqsave(&sclp_lock
, flags
);
772 list_for_each(l
, &sclp_reg_list
) {
773 reg
= list_entry(l
, struct sclp_register
, list
);
774 receive_mask
= reg
->send_mask
& sclp_receive_mask
;
775 send_mask
= reg
->receive_mask
& sclp_send_mask
;
776 if (reg
->sclp_receive_mask
!= receive_mask
||
777 reg
->sclp_send_mask
!= send_mask
) {
778 reg
->sclp_receive_mask
= receive_mask
;
779 reg
->sclp_send_mask
= send_mask
;
784 spin_unlock_irqrestore(&sclp_lock
, flags
);
785 if (reg
&& reg
->state_change_fn
) {
786 /* STCG: State-change callback (b=callback) */
787 sclp_trace(2, "STCG", 0, (u64
)reg
->state_change_fn
,
790 reg
->state_change_fn(reg
);
795 struct sclp_statechangebuf
{
796 struct evbuf_header header
;
797 u8 validity_sclp_active_facility_mask
: 1;
798 u8 validity_sclp_receive_mask
: 1;
799 u8 validity_sclp_send_mask
: 1;
800 u8 validity_read_data_function_mask
: 1;
803 u64 sclp_active_facility_mask
;
804 u8 masks
[2 * 1021 + 4]; /* variable length */
806 * u8 sclp_receive_mask[mask_length];
807 * u8 sclp_send_mask[mask_length];
808 * u32 read_data_function_mask;
810 } __attribute__((packed
));
813 /* State change event callback. Inform listeners of changes. */
815 sclp_state_change_cb(struct evbuf_header
*evbuf
)
818 struct sclp_statechangebuf
*scbuf
;
820 BUILD_BUG_ON(sizeof(struct sclp_statechangebuf
) > PAGE_SIZE
);
822 scbuf
= (struct sclp_statechangebuf
*) evbuf
;
823 spin_lock_irqsave(&sclp_lock
, flags
);
824 if (scbuf
->validity_sclp_receive_mask
)
825 sclp_receive_mask
= sccb_get_recv_mask(scbuf
);
826 if (scbuf
->validity_sclp_send_mask
)
827 sclp_send_mask
= sccb_get_send_mask(scbuf
);
828 spin_unlock_irqrestore(&sclp_lock
, flags
);
829 if (scbuf
->validity_sclp_active_facility_mask
)
830 sclp
.facilities
= scbuf
->sclp_active_facility_mask
;
831 sclp_dispatch_state_change();
834 static struct sclp_register sclp_state_change_event
= {
835 .receive_mask
= EVTYP_STATECHANGE_MASK
,
836 .receiver_fn
= sclp_state_change_cb
839 /* Calculate receive and send mask of currently registered listeners.
840 * Called while sclp_lock is locked. */
842 __sclp_get_mask(sccb_mask_t
*receive_mask
, sccb_mask_t
*send_mask
)
845 struct sclp_register
*t
;
849 list_for_each(l
, &sclp_reg_list
) {
850 t
= list_entry(l
, struct sclp_register
, list
);
851 *receive_mask
|= t
->receive_mask
;
852 *send_mask
|= t
->send_mask
;
856 /* Register event listener. Return 0 on success, non-zero otherwise. */
858 sclp_register(struct sclp_register
*reg
)
861 sccb_mask_t receive_mask
;
862 sccb_mask_t send_mask
;
865 /* REG: Event listener registered (b=caller) */
866 sclp_trace_register(2, "REG", 0, _RET_IP_
, reg
);
871 spin_lock_irqsave(&sclp_lock
, flags
);
872 /* Check event mask for collisions */
873 __sclp_get_mask(&receive_mask
, &send_mask
);
874 if (reg
->receive_mask
& receive_mask
|| reg
->send_mask
& send_mask
) {
875 spin_unlock_irqrestore(&sclp_lock
, flags
);
878 /* Trigger initial state change callback */
879 reg
->sclp_receive_mask
= 0;
880 reg
->sclp_send_mask
= 0;
881 list_add(®
->list
, &sclp_reg_list
);
882 spin_unlock_irqrestore(&sclp_lock
, flags
);
883 rc
= sclp_init_mask(1);
885 spin_lock_irqsave(&sclp_lock
, flags
);
886 list_del(®
->list
);
887 spin_unlock_irqrestore(&sclp_lock
, flags
);
892 EXPORT_SYMBOL(sclp_register
);
894 /* Unregister event listener. */
896 sclp_unregister(struct sclp_register
*reg
)
900 /* UREG: Event listener unregistered (b=caller) */
901 sclp_trace_register(2, "UREG", 0, _RET_IP_
, reg
);
903 spin_lock_irqsave(&sclp_lock
, flags
);
904 list_del(®
->list
);
905 spin_unlock_irqrestore(&sclp_lock
, flags
);
909 EXPORT_SYMBOL(sclp_unregister
);
911 /* Remove event buffers which are marked processed. Return the number of
912 * remaining event buffers. */
914 sclp_remove_processed(struct sccb_header
*sccb
)
916 struct evbuf_header
*evbuf
;
920 evbuf
= (struct evbuf_header
*) (sccb
+ 1);
922 remaining
= sccb
->length
- sizeof(struct sccb_header
);
923 while (remaining
> 0) {
924 remaining
-= evbuf
->length
;
925 if (evbuf
->flags
& 0x80) {
926 sccb
->length
-= evbuf
->length
;
927 memcpy(evbuf
, (void *) ((addr_t
) evbuf
+ evbuf
->length
),
931 evbuf
= (struct evbuf_header
*)
932 ((addr_t
) evbuf
+ evbuf
->length
);
938 EXPORT_SYMBOL(sclp_remove_processed
);
940 /* Prepare init mask request. Called while sclp_lock is locked. */
942 __sclp_make_init_req(sccb_mask_t receive_mask
, sccb_mask_t send_mask
)
944 struct init_sccb
*sccb
= sclp_init_sccb
;
947 memset(&sclp_init_req
, 0, sizeof(struct sclp_req
));
948 sclp_init_req
.command
= SCLP_CMDW_WRITE_EVENT_MASK
;
949 sclp_init_req
.status
= SCLP_REQ_FILLED
;
950 sclp_init_req
.start_count
= 0;
951 sclp_init_req
.callback
= NULL
;
952 sclp_init_req
.callback_data
= NULL
;
953 sclp_init_req
.sccb
= sccb
;
954 sccb
->header
.length
= sizeof(*sccb
);
955 if (sclp_mask_compat_mode
)
956 sccb
->mask_length
= SCLP_MASK_SIZE_COMPAT
;
958 sccb
->mask_length
= sizeof(sccb_mask_t
);
959 sccb_set_recv_mask(sccb
, receive_mask
);
960 sccb_set_send_mask(sccb
, send_mask
);
961 sccb_set_sclp_recv_mask(sccb
, 0);
962 sccb_set_sclp_send_mask(sccb
, 0);
965 /* Start init mask request. If calculate is non-zero, calculate the mask as
966 * requested by registered listeners. Use zero mask otherwise. Return 0 on
967 * success, non-zero otherwise. */
969 sclp_init_mask(int calculate
)
972 struct init_sccb
*sccb
= sclp_init_sccb
;
973 sccb_mask_t receive_mask
;
974 sccb_mask_t send_mask
;
979 spin_lock_irqsave(&sclp_lock
, flags
);
980 /* Check if interface is in appropriate state */
981 if (sclp_mask_state
!= sclp_mask_state_idle
) {
982 spin_unlock_irqrestore(&sclp_lock
, flags
);
985 if (sclp_activation_state
== sclp_activation_state_inactive
) {
986 spin_unlock_irqrestore(&sclp_lock
, flags
);
989 sclp_mask_state
= sclp_mask_state_initializing
;
992 __sclp_get_mask(&receive_mask
, &send_mask
);
998 for (retry
= 0; retry
<= SCLP_MASK_RETRY
; retry
++) {
999 /* Prepare request */
1000 __sclp_make_init_req(receive_mask
, send_mask
);
1001 spin_unlock_irqrestore(&sclp_lock
, flags
);
1002 if (sclp_add_request(&sclp_init_req
)) {
1003 /* Try again later */
1004 wait
= jiffies
+ SCLP_BUSY_INTERVAL
* HZ
;
1005 while (time_before(jiffies
, wait
))
1007 spin_lock_irqsave(&sclp_lock
, flags
);
1010 while (sclp_init_req
.status
!= SCLP_REQ_DONE
&&
1011 sclp_init_req
.status
!= SCLP_REQ_FAILED
)
1013 spin_lock_irqsave(&sclp_lock
, flags
);
1014 if (sclp_init_req
.status
== SCLP_REQ_DONE
&&
1015 sccb
->header
.response_code
== 0x20) {
1016 /* Successful request */
1018 sclp_receive_mask
= sccb_get_sclp_recv_mask(sccb
);
1019 sclp_send_mask
= sccb_get_sclp_send_mask(sccb
);
1021 sclp_receive_mask
= 0;
1024 spin_unlock_irqrestore(&sclp_lock
, flags
);
1025 sclp_dispatch_state_change();
1026 spin_lock_irqsave(&sclp_lock
, flags
);
1031 sclp_mask_state
= sclp_mask_state_idle
;
1032 spin_unlock_irqrestore(&sclp_lock
, flags
);
1036 /* Deactivate SCLP interface. On success, new requests will be rejected,
1037 * events will no longer be dispatched. Return 0 on success, non-zero
1040 sclp_deactivate(void)
1042 unsigned long flags
;
1045 spin_lock_irqsave(&sclp_lock
, flags
);
1046 /* Deactivate can only be called when active */
1047 if (sclp_activation_state
!= sclp_activation_state_active
) {
1048 spin_unlock_irqrestore(&sclp_lock
, flags
);
1051 sclp_activation_state
= sclp_activation_state_deactivating
;
1052 spin_unlock_irqrestore(&sclp_lock
, flags
);
1053 rc
= sclp_init_mask(0);
1054 spin_lock_irqsave(&sclp_lock
, flags
);
1056 sclp_activation_state
= sclp_activation_state_inactive
;
1058 sclp_activation_state
= sclp_activation_state_active
;
1059 spin_unlock_irqrestore(&sclp_lock
, flags
);
1063 EXPORT_SYMBOL(sclp_deactivate
);
1065 /* Reactivate SCLP interface after sclp_deactivate. On success, new
1066 * requests will be accepted, events will be dispatched again. Return 0 on
1067 * success, non-zero otherwise. */
1069 sclp_reactivate(void)
1071 unsigned long flags
;
1074 spin_lock_irqsave(&sclp_lock
, flags
);
1075 /* Reactivate can only be called when inactive */
1076 if (sclp_activation_state
!= sclp_activation_state_inactive
) {
1077 spin_unlock_irqrestore(&sclp_lock
, flags
);
1080 sclp_activation_state
= sclp_activation_state_activating
;
1081 spin_unlock_irqrestore(&sclp_lock
, flags
);
1082 rc
= sclp_init_mask(1);
1083 spin_lock_irqsave(&sclp_lock
, flags
);
1085 sclp_activation_state
= sclp_activation_state_active
;
1087 sclp_activation_state
= sclp_activation_state_inactive
;
1088 spin_unlock_irqrestore(&sclp_lock
, flags
);
1092 EXPORT_SYMBOL(sclp_reactivate
);
1094 /* Handler for external interruption used during initialization. Modify
1095 * request state to done. */
1096 static void sclp_check_handler(struct ext_code ext_code
,
1097 unsigned int param32
, unsigned long param64
)
1101 inc_irq_stat(IRQEXT_SCP
);
1102 finished_sccb
= param32
& 0xfffffff8;
1103 /* Is this the interrupt we are waiting for? */
1104 if (finished_sccb
== 0)
1106 if (finished_sccb
!= __pa(sclp_init_sccb
))
1107 panic("sclp: unsolicited interrupt for buffer at 0x%x\n",
1109 spin_lock(&sclp_lock
);
1110 if (sclp_running_state
== sclp_running_state_running
) {
1111 sclp_init_req
.status
= SCLP_REQ_DONE
;
1112 sclp_running_state
= sclp_running_state_idle
;
1114 spin_unlock(&sclp_lock
);
1117 /* Initial init mask request timed out. Modify request state to failed. */
1119 sclp_check_timeout(struct timer_list
*unused
)
1121 unsigned long flags
;
1123 spin_lock_irqsave(&sclp_lock
, flags
);
1124 if (sclp_running_state
== sclp_running_state_running
) {
1125 sclp_init_req
.status
= SCLP_REQ_FAILED
;
1126 sclp_running_state
= sclp_running_state_idle
;
1128 spin_unlock_irqrestore(&sclp_lock
, flags
);
1131 /* Perform a check of the SCLP interface. Return zero if the interface is
1132 * available and there are no pending requests from a previous instance.
1133 * Return non-zero otherwise. */
1135 sclp_check_interface(void)
1137 struct init_sccb
*sccb
;
1138 unsigned long flags
;
1142 spin_lock_irqsave(&sclp_lock
, flags
);
1143 /* Prepare init mask command */
1144 rc
= register_external_irq(EXT_IRQ_SERVICE_SIG
, sclp_check_handler
);
1146 spin_unlock_irqrestore(&sclp_lock
, flags
);
1149 for (retry
= 0; retry
<= SCLP_INIT_RETRY
; retry
++) {
1150 __sclp_make_init_req(0, 0);
1151 sccb
= (struct init_sccb
*) sclp_init_req
.sccb
;
1152 rc
= sclp_service_call_trace(sclp_init_req
.command
, sccb
);
1155 sclp_init_req
.status
= SCLP_REQ_RUNNING
;
1156 sclp_running_state
= sclp_running_state_running
;
1157 __sclp_set_request_timer(SCLP_RETRY_INTERVAL
* HZ
,
1158 sclp_check_timeout
);
1159 spin_unlock_irqrestore(&sclp_lock
, flags
);
1160 /* Enable service-signal interruption - needs to happen
1161 * with IRQs enabled. */
1162 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL
);
1163 /* Wait for signal from interrupt or timeout */
1165 /* Disable service-signal interruption - needs to happen
1166 * with IRQs enabled. */
1167 irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL
);
1168 spin_lock_irqsave(&sclp_lock
, flags
);
1169 del_timer(&sclp_request_timer
);
1171 if (sclp_init_req
.status
== SCLP_REQ_DONE
) {
1172 if (sccb
->header
.response_code
== 0x20) {
1175 } else if (sccb
->header
.response_code
== 0x74f0) {
1176 if (!sclp_mask_compat_mode
) {
1177 sclp_mask_compat_mode
= true;
1183 unregister_external_irq(EXT_IRQ_SERVICE_SIG
, sclp_check_handler
);
1184 spin_unlock_irqrestore(&sclp_lock
, flags
);
1188 /* Reboot event handler. Reset send and receive mask to prevent pending SCLP
1189 * events from interfering with rebooted system. */
1191 sclp_reboot_event(struct notifier_block
*this, unsigned long event
, void *ptr
)
1197 static struct notifier_block sclp_reboot_notifier
= {
1198 .notifier_call
= sclp_reboot_event
,
1199 .priority
= INT_MIN
,
1202 static ssize_t
con_pages_show(struct device_driver
*dev
, char *buf
)
1204 return sysfs_emit(buf
, "%i\n", sclp_console_pages
);
1207 static DRIVER_ATTR_RO(con_pages
);
1209 static ssize_t
con_drop_store(struct device_driver
*dev
, const char *buf
, size_t count
)
1213 rc
= kstrtobool(buf
, &sclp_console_drop
);
1217 static ssize_t
con_drop_show(struct device_driver
*dev
, char *buf
)
1219 return sysfs_emit(buf
, "%i\n", sclp_console_drop
);
1222 static DRIVER_ATTR_RW(con_drop
);
1224 static ssize_t
con_full_show(struct device_driver
*dev
, char *buf
)
1226 return sysfs_emit(buf
, "%lu\n", sclp_console_full
);
1229 static DRIVER_ATTR_RO(con_full
);
1231 static struct attribute
*sclp_drv_attrs
[] = {
1232 &driver_attr_con_pages
.attr
,
1233 &driver_attr_con_drop
.attr
,
1234 &driver_attr_con_full
.attr
,
1237 static struct attribute_group sclp_drv_attr_group
= {
1238 .attrs
= sclp_drv_attrs
,
1240 static const struct attribute_group
*sclp_drv_attr_groups
[] = {
1241 &sclp_drv_attr_group
,
1245 static struct platform_driver sclp_pdrv
= {
1248 .groups
= sclp_drv_attr_groups
,
1252 /* Initialize SCLP driver. Return zero if driver is operational, non-zero
1257 unsigned long flags
;
1260 spin_lock_irqsave(&sclp_lock
, flags
);
1261 /* Check for previous or running initialization */
1262 if (sclp_init_state
!= sclp_init_state_uninitialized
)
1264 sclp_init_state
= sclp_init_state_initializing
;
1265 sclp_read_sccb
= (void *) __get_free_page(GFP_ATOMIC
| GFP_DMA
);
1266 sclp_init_sccb
= (void *) __get_free_page(GFP_ATOMIC
| GFP_DMA
);
1267 BUG_ON(!sclp_read_sccb
|| !sclp_init_sccb
);
1268 /* Set up variables */
1269 list_add(&sclp_state_change_event
.list
, &sclp_reg_list
);
1270 timer_setup(&sclp_request_timer
, NULL
, 0);
1271 timer_setup(&sclp_queue_timer
, sclp_req_queue_timeout
, 0);
1272 /* Check interface */
1273 spin_unlock_irqrestore(&sclp_lock
, flags
);
1274 rc
= sclp_check_interface();
1275 spin_lock_irqsave(&sclp_lock
, flags
);
1277 goto fail_init_state_uninitialized
;
1278 /* Register reboot handler */
1279 rc
= register_reboot_notifier(&sclp_reboot_notifier
);
1281 goto fail_init_state_uninitialized
;
1282 /* Register interrupt handler */
1283 rc
= register_external_irq(EXT_IRQ_SERVICE_SIG
, sclp_interrupt_handler
);
1285 goto fail_unregister_reboot_notifier
;
1286 sclp_init_state
= sclp_init_state_initialized
;
1287 spin_unlock_irqrestore(&sclp_lock
, flags
);
1288 /* Enable service-signal external interruption - needs to happen with
1290 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL
);
1294 fail_unregister_reboot_notifier
:
1295 unregister_reboot_notifier(&sclp_reboot_notifier
);
1296 fail_init_state_uninitialized
:
1297 list_del(&sclp_state_change_event
.list
);
1298 sclp_init_state
= sclp_init_state_uninitialized
;
1299 free_page((unsigned long) sclp_read_sccb
);
1300 free_page((unsigned long) sclp_init_sccb
);
1302 spin_unlock_irqrestore(&sclp_lock
, flags
);
1306 static __init
int sclp_initcall(void)
1310 rc
= platform_driver_register(&sclp_pdrv
);
1317 arch_initcall(sclp_initcall
);