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 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 int sclp_console_drop = 1;
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));
84 strncpy(e.id, id, sizeof(e.id));
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, (u32)(addr_t)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)
200 rc = kstrtoint(str, 0, &drop);
202 sclp_console_drop = drop;
206 __setup("sclp_con_drop=", sclp_setup_console_drop);
208 /* Timer for request retries. */
209 static struct timer_list sclp_request_timer;
211 /* Timer for queued requests. */
212 static struct timer_list sclp_queue_timer;
214 /* Internal state: is a request active at the sclp? */
215 static volatile enum sclp_running_state_t {
216 sclp_running_state_idle,
217 sclp_running_state_running,
218 sclp_running_state_reset_pending
219 } sclp_running_state = sclp_running_state_idle;
221 /* Internal state: is a read request pending? */
222 static volatile enum sclp_reading_state_t {
223 sclp_reading_state_idle,
224 sclp_reading_state_reading
225 } sclp_reading_state = sclp_reading_state_idle;
227 /* Internal state: is the driver currently serving requests? */
228 static volatile enum sclp_activation_state_t {
229 sclp_activation_state_active,
230 sclp_activation_state_deactivating,
231 sclp_activation_state_inactive,
232 sclp_activation_state_activating
233 } sclp_activation_state = sclp_activation_state_active;
235 /* Internal state: is an init mask request pending? */
236 static volatile enum sclp_mask_state_t {
237 sclp_mask_state_idle,
238 sclp_mask_state_initializing
239 } sclp_mask_state = sclp_mask_state_idle;
241 /* Maximum retry counts */
242 #define SCLP_INIT_RETRY 3
243 #define SCLP_MASK_RETRY 3
245 /* Timeout intervals in seconds.*/
246 #define SCLP_BUSY_INTERVAL 10
247 #define SCLP_RETRY_INTERVAL 30
249 static void sclp_request_timeout(bool force_restart);
250 static void sclp_process_queue(void);
251 static void __sclp_make_read_req(void);
252 static int sclp_init_mask(int calculate);
253 static int sclp_init(void);
256 __sclp_queue_read_req(void)
258 if (sclp_reading_state == sclp_reading_state_idle) {
259 sclp_reading_state = sclp_reading_state_reading;
260 __sclp_make_read_req();
261 /* Add request to head of queue */
262 list_add(&sclp_read_req.list, &sclp_req_queue);
266 /* Set up request retry timer. Called while sclp_lock is locked. */
268 __sclp_set_request_timer(unsigned long time, void (*cb)(struct timer_list *))
270 del_timer(&sclp_request_timer);
271 sclp_request_timer.function = cb;
272 sclp_request_timer.expires = jiffies + time;
273 add_timer(&sclp_request_timer);
276 static void sclp_request_timeout_restart(struct timer_list *unused)
278 sclp_request_timeout(true);
281 static void sclp_request_timeout_normal(struct timer_list *unused)
283 sclp_request_timeout(false);
286 /* Request timeout handler. Restart the request queue. If force_restart,
287 * force restart of running request. */
288 static void sclp_request_timeout(bool force_restart)
292 /* TMO: A timeout occurred (a=force_restart) */
293 sclp_trace(2, "TMO", force_restart, 0, true);
295 spin_lock_irqsave(&sclp_lock, flags);
297 if (sclp_running_state == sclp_running_state_running) {
298 /* Break running state and queue NOP read event request
299 * to get a defined interface state. */
300 __sclp_queue_read_req();
301 sclp_running_state = sclp_running_state_idle;
304 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ,
305 sclp_request_timeout_normal);
307 spin_unlock_irqrestore(&sclp_lock, flags);
308 sclp_process_queue();
312 * Returns the expire value in jiffies of the next pending request timeout,
313 * if any. Needs to be called with sclp_lock.
315 static unsigned long __sclp_req_queue_find_next_timeout(void)
317 unsigned long expires_next = 0;
318 struct sclp_req *req;
320 list_for_each_entry(req, &sclp_req_queue, list) {
321 if (!req->queue_expires)
324 (time_before(req->queue_expires, expires_next)))
325 expires_next = req->queue_expires;
331 * Returns expired request, if any, and removes it from the list.
333 static struct sclp_req *__sclp_req_queue_remove_expired_req(void)
335 unsigned long flags, now;
336 struct sclp_req *req;
338 spin_lock_irqsave(&sclp_lock, flags);
340 /* Don't need list_for_each_safe because we break out after list_del */
341 list_for_each_entry(req, &sclp_req_queue, list) {
342 if (!req->queue_expires)
344 if (time_before_eq(req->queue_expires, now)) {
345 if (req->status == SCLP_REQ_QUEUED) {
346 req->status = SCLP_REQ_QUEUED_TIMEOUT;
347 list_del(&req->list);
354 spin_unlock_irqrestore(&sclp_lock, flags);
359 * Timeout handler for queued requests. Removes request from list and
360 * invokes callback. This timer can be set per request in situations where
361 * waiting too long would be harmful to the system, e.g. during SE reboot.
363 static void sclp_req_queue_timeout(struct timer_list *unused)
365 unsigned long flags, expires_next;
366 struct sclp_req *req;
369 req = __sclp_req_queue_remove_expired_req();
372 /* RQTM: Request timed out (a=sccb, b=summary) */
373 sclp_trace_req(2, "RQTM", req, true);
376 if (req && req->callback)
377 req->callback(req, req->callback_data);
380 spin_lock_irqsave(&sclp_lock, flags);
381 expires_next = __sclp_req_queue_find_next_timeout();
383 mod_timer(&sclp_queue_timer, expires_next);
384 spin_unlock_irqrestore(&sclp_lock, flags);
387 static int sclp_service_call_trace(sclp_cmdw_t command, void *sccb)
389 static u64 srvc_count;
392 /* SRV1: Service call about to be issued (a=command, b=sccb address) */
393 sclp_trace_sccb(0, "SRV1", command, (u64)sccb, command, sccb, false);
395 rc = sclp_service_call(command, sccb);
397 /* SRV2: Service call was issued (a=rc, b=SRVC sequence number) */
398 sclp_trace(0, "SRV2", -rc, ++srvc_count, rc != 0);
401 active_cmd = command;
406 /* Try to start a request. Return zero if the request was successfully
407 * started or if it will be started at a later time. Return non-zero otherwise.
408 * Called while sclp_lock is locked. */
410 __sclp_start_request(struct sclp_req *req)
414 if (sclp_running_state != sclp_running_state_idle)
416 del_timer(&sclp_request_timer);
417 rc = sclp_service_call_trace(req->command, req->sccb);
421 /* Successfully started request */
422 req->status = SCLP_REQ_RUNNING;
423 sclp_running_state = sclp_running_state_running;
424 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ,
425 sclp_request_timeout_restart);
427 } else if (rc == -EBUSY) {
428 /* Try again later */
429 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ,
430 sclp_request_timeout_normal);
434 req->status = SCLP_REQ_FAILED;
438 /* Try to start queued requests. */
440 sclp_process_queue(void)
442 struct sclp_req *req;
446 spin_lock_irqsave(&sclp_lock, flags);
447 if (sclp_running_state != sclp_running_state_idle) {
448 spin_unlock_irqrestore(&sclp_lock, flags);
451 del_timer(&sclp_request_timer);
452 while (!list_empty(&sclp_req_queue)) {
453 req = list_entry(sclp_req_queue.next, struct sclp_req, list);
454 rc = __sclp_start_request(req);
458 if (req->start_count > 1) {
459 /* Cannot abort already submitted request - could still
460 * be active at the SCLP */
461 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ,
462 sclp_request_timeout_normal);
465 /* Post-processing for aborted request */
466 list_del(&req->list);
468 /* RQAB: Request aborted (a=sccb, b=summary) */
469 sclp_trace_req(2, "RQAB", req, true);
472 spin_unlock_irqrestore(&sclp_lock, flags);
473 req->callback(req, req->callback_data);
474 spin_lock_irqsave(&sclp_lock, flags);
477 spin_unlock_irqrestore(&sclp_lock, flags);
480 static int __sclp_can_add_request(struct sclp_req *req)
482 if (req == &sclp_init_req)
484 if (sclp_init_state != sclp_init_state_initialized)
486 if (sclp_activation_state != sclp_activation_state_active)
491 /* Queue a new request. Return zero on success, non-zero otherwise. */
493 sclp_add_request(struct sclp_req *req)
498 spin_lock_irqsave(&sclp_lock, flags);
499 if (!__sclp_can_add_request(req)) {
500 spin_unlock_irqrestore(&sclp_lock, flags);
504 /* RQAD: Request was added (a=sccb, b=caller) */
505 sclp_trace(2, "RQAD", (u32)(addr_t)req->sccb, _RET_IP_, false);
507 req->status = SCLP_REQ_QUEUED;
508 req->start_count = 0;
509 list_add_tail(&req->list, &sclp_req_queue);
511 if (req->queue_timeout) {
512 req->queue_expires = jiffies + req->queue_timeout * HZ;
513 if (!timer_pending(&sclp_queue_timer) ||
514 time_after(sclp_queue_timer.expires, req->queue_expires))
515 mod_timer(&sclp_queue_timer, req->queue_expires);
517 req->queue_expires = 0;
518 /* Start if request is first in list */
519 if (sclp_running_state == sclp_running_state_idle &&
520 req->list.prev == &sclp_req_queue) {
521 rc = __sclp_start_request(req);
523 list_del(&req->list);
525 spin_unlock_irqrestore(&sclp_lock, flags);
529 EXPORT_SYMBOL(sclp_add_request);
531 /* Dispatch events found in request buffer to registered listeners. Return 0
532 * if all events were dispatched, non-zero otherwise. */
534 sclp_dispatch_evbufs(struct sccb_header *sccb)
537 struct evbuf_header *evbuf;
539 struct sclp_register *reg;
543 spin_lock_irqsave(&sclp_lock, flags);
545 for (offset = sizeof(struct sccb_header); offset < sccb->length;
546 offset += evbuf->length) {
547 evbuf = (struct evbuf_header *) ((addr_t) sccb + offset);
548 /* Check for malformed hardware response */
549 if (evbuf->length == 0)
551 /* Search for event handler */
553 list_for_each(l, &sclp_reg_list) {
554 reg = list_entry(l, struct sclp_register, list);
555 if (reg->receive_mask & SCLP_EVTYP_MASK(evbuf->type))
561 /* EVNT: Event callback (b=receiver) */
562 sclp_trace_evbuf(2, "EVNT", 0, reg ? (u64)reg->receiver_fn : 0,
565 if (reg && reg->receiver_fn) {
566 spin_unlock_irqrestore(&sclp_lock, flags);
567 reg->receiver_fn(evbuf);
568 spin_lock_irqsave(&sclp_lock, flags);
569 } else if (reg == NULL)
572 spin_unlock_irqrestore(&sclp_lock, flags);
576 /* Read event data request callback. */
578 sclp_read_cb(struct sclp_req *req, void *data)
581 struct sccb_header *sccb;
583 sccb = (struct sccb_header *) req->sccb;
584 if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 ||
585 sccb->response_code == 0x220))
586 sclp_dispatch_evbufs(sccb);
587 spin_lock_irqsave(&sclp_lock, flags);
588 sclp_reading_state = sclp_reading_state_idle;
589 spin_unlock_irqrestore(&sclp_lock, flags);
592 /* Prepare read event data request. Called while sclp_lock is locked. */
593 static void __sclp_make_read_req(void)
595 struct sccb_header *sccb;
597 sccb = (struct sccb_header *) sclp_read_sccb;
599 memset(&sclp_read_req, 0, sizeof(struct sclp_req));
600 sclp_read_req.command = SCLP_CMDW_READ_EVENT_DATA;
601 sclp_read_req.status = SCLP_REQ_QUEUED;
602 sclp_read_req.start_count = 0;
603 sclp_read_req.callback = sclp_read_cb;
604 sclp_read_req.sccb = sccb;
605 sccb->length = PAGE_SIZE;
606 sccb->function_code = 0;
607 sccb->control_mask[2] = 0x80;
610 /* Search request list for request with matching sccb. Return request if found,
611 * NULL otherwise. Called while sclp_lock is locked. */
612 static inline struct sclp_req *
613 __sclp_find_req(u32 sccb)
616 struct sclp_req *req;
618 list_for_each(l, &sclp_req_queue) {
619 req = list_entry(l, struct sclp_req, list);
620 if (sccb == (u32) (addr_t) req->sccb)
626 static bool ok_response(u32 sccb_int, sclp_cmdw_t cmd)
628 struct sccb_header *sccb = (struct sccb_header *)(addr_t)sccb_int;
629 struct evbuf_header *evbuf;
635 /* Check SCCB response. */
636 response = sccb->response_code & 0xff;
637 if (response != 0x10 && response != 0x20)
640 /* Check event-processed flag on outgoing events. */
641 if (cmd == SCLP_CMDW_WRITE_EVENT_DATA) {
642 evbuf = (struct evbuf_header *)(sccb + 1);
643 if (!(evbuf->flags & 0x80))
650 /* Handler for external interruption. Perform request post-processing.
651 * Prepare read event data request if necessary. Start processing of next
652 * request on queue. */
653 static void sclp_interrupt_handler(struct ext_code ext_code,
654 unsigned int param32, unsigned long param64)
656 struct sclp_req *req;
660 inc_irq_stat(IRQEXT_SCP);
661 spin_lock(&sclp_lock);
662 finished_sccb = param32 & 0xfffffff8;
663 evbuf_pending = param32 & 0x3;
665 /* INT: Interrupt received (a=intparm, b=cmd) */
666 sclp_trace_sccb(0, "INT", param32, active_cmd, active_cmd,
667 (struct sccb_header *)(addr_t)finished_sccb,
668 !ok_response(finished_sccb, active_cmd));
671 del_timer(&sclp_request_timer);
672 sclp_running_state = sclp_running_state_reset_pending;
673 req = __sclp_find_req(finished_sccb);
675 /* Request post-processing */
676 list_del(&req->list);
677 req->status = SCLP_REQ_DONE;
679 /* RQOK: Request success (a=sccb, b=summary) */
680 sclp_trace_req(2, "RQOK", req, false);
683 spin_unlock(&sclp_lock);
684 req->callback(req, req->callback_data);
685 spin_lock(&sclp_lock);
688 /* UNEX: Unexpected SCCB completion (a=sccb address) */
689 sclp_trace(0, "UNEX", finished_sccb, 0, true);
691 sclp_running_state = sclp_running_state_idle;
695 sclp_activation_state == sclp_activation_state_active)
696 __sclp_queue_read_req();
697 spin_unlock(&sclp_lock);
698 sclp_process_queue();
701 /* Convert interval in jiffies to TOD ticks. */
703 sclp_tod_from_jiffies(unsigned long jiffies)
705 return (u64) (jiffies / HZ) << 32;
708 /* Wait until a currently running request finished. Note: while this function
709 * is running, no timers are served on the calling CPU. */
713 unsigned long long old_tick;
715 unsigned long cr0, cr0_sync;
716 static u64 sync_count;
720 /* SYN1: Synchronous wait start (a=runstate, b=sync count) */
721 sclp_trace(4, "SYN1", sclp_running_state, ++sync_count, false);
723 /* We'll be disabling timer interrupts, so we need a custom timeout
726 if (timer_pending(&sclp_request_timer)) {
727 /* Get timeout TOD value */
728 timeout = get_tod_clock_fast() +
729 sclp_tod_from_jiffies(sclp_request_timer.expires -
732 local_irq_save(flags);
733 /* Prevent bottom half from executing once we force interrupts open */
734 irq_context = in_interrupt();
737 /* Enable service-signal interruption, disable timer interrupts */
738 old_tick = local_tick_disable();
740 __ctl_store(cr0, 0, 0);
741 cr0_sync = cr0 & ~CR0_IRQ_SUBCLASS_MASK;
742 cr0_sync |= 1UL << (63 - 54);
743 __ctl_load(cr0_sync, 0, 0);
744 __arch_local_irq_stosm(0x01);
745 /* Loop until driver state indicates finished request */
746 while (sclp_running_state != sclp_running_state_idle) {
747 /* Check for expired request timer */
748 if (timer_pending(&sclp_request_timer) &&
749 get_tod_clock_fast() > timeout &&
750 del_timer(&sclp_request_timer))
751 sclp_request_timer.function(&sclp_request_timer);
755 __ctl_load(cr0, 0, 0);
758 local_tick_enable(old_tick);
759 local_irq_restore(flags);
761 /* SYN2: Synchronous wait end (a=runstate, b=sync_count) */
762 sclp_trace(4, "SYN2", sclp_running_state, sync_count, false);
764 EXPORT_SYMBOL(sclp_sync_wait);
766 /* Dispatch changes in send and receive mask to registered listeners. */
768 sclp_dispatch_state_change(void)
771 struct sclp_register *reg;
773 sccb_mask_t receive_mask;
774 sccb_mask_t send_mask;
777 spin_lock_irqsave(&sclp_lock, flags);
779 list_for_each(l, &sclp_reg_list) {
780 reg = list_entry(l, struct sclp_register, list);
781 receive_mask = reg->send_mask & sclp_receive_mask;
782 send_mask = reg->receive_mask & sclp_send_mask;
783 if (reg->sclp_receive_mask != receive_mask ||
784 reg->sclp_send_mask != send_mask) {
785 reg->sclp_receive_mask = receive_mask;
786 reg->sclp_send_mask = send_mask;
791 spin_unlock_irqrestore(&sclp_lock, flags);
792 if (reg && reg->state_change_fn) {
793 /* STCG: State-change callback (b=callback) */
794 sclp_trace(2, "STCG", 0, (u64)reg->state_change_fn,
797 reg->state_change_fn(reg);
802 struct sclp_statechangebuf {
803 struct evbuf_header header;
804 u8 validity_sclp_active_facility_mask : 1;
805 u8 validity_sclp_receive_mask : 1;
806 u8 validity_sclp_send_mask : 1;
807 u8 validity_read_data_function_mask : 1;
810 u64 sclp_active_facility_mask;
811 u8 masks[2 * 1021 + 4]; /* variable length */
813 * u8 sclp_receive_mask[mask_length];
814 * u8 sclp_send_mask[mask_length];
815 * u32 read_data_function_mask;
817 } __attribute__((packed));
820 /* State change event callback. Inform listeners of changes. */
822 sclp_state_change_cb(struct evbuf_header *evbuf)
825 struct sclp_statechangebuf *scbuf;
827 BUILD_BUG_ON(sizeof(struct sclp_statechangebuf) > PAGE_SIZE);
829 scbuf = (struct sclp_statechangebuf *) evbuf;
830 spin_lock_irqsave(&sclp_lock, flags);
831 if (scbuf->validity_sclp_receive_mask)
832 sclp_receive_mask = sccb_get_recv_mask(scbuf);
833 if (scbuf->validity_sclp_send_mask)
834 sclp_send_mask = sccb_get_send_mask(scbuf);
835 spin_unlock_irqrestore(&sclp_lock, flags);
836 if (scbuf->validity_sclp_active_facility_mask)
837 sclp.facilities = scbuf->sclp_active_facility_mask;
838 sclp_dispatch_state_change();
841 static struct sclp_register sclp_state_change_event = {
842 .receive_mask = EVTYP_STATECHANGE_MASK,
843 .receiver_fn = sclp_state_change_cb
846 /* Calculate receive and send mask of currently registered listeners.
847 * Called while sclp_lock is locked. */
849 __sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask)
852 struct sclp_register *t;
856 list_for_each(l, &sclp_reg_list) {
857 t = list_entry(l, struct sclp_register, list);
858 *receive_mask |= t->receive_mask;
859 *send_mask |= t->send_mask;
863 /* Register event listener. Return 0 on success, non-zero otherwise. */
865 sclp_register(struct sclp_register *reg)
868 sccb_mask_t receive_mask;
869 sccb_mask_t send_mask;
872 /* REG: Event listener registered (b=caller) */
873 sclp_trace_register(2, "REG", 0, _RET_IP_, reg);
878 spin_lock_irqsave(&sclp_lock, flags);
879 /* Check event mask for collisions */
880 __sclp_get_mask(&receive_mask, &send_mask);
881 if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) {
882 spin_unlock_irqrestore(&sclp_lock, flags);
885 /* Trigger initial state change callback */
886 reg->sclp_receive_mask = 0;
887 reg->sclp_send_mask = 0;
888 list_add(®->list, &sclp_reg_list);
889 spin_unlock_irqrestore(&sclp_lock, flags);
890 rc = sclp_init_mask(1);
892 spin_lock_irqsave(&sclp_lock, flags);
893 list_del(®->list);
894 spin_unlock_irqrestore(&sclp_lock, flags);
899 EXPORT_SYMBOL(sclp_register);
901 /* Unregister event listener. */
903 sclp_unregister(struct sclp_register *reg)
907 /* UREG: Event listener unregistered (b=caller) */
908 sclp_trace_register(2, "UREG", 0, _RET_IP_, reg);
910 spin_lock_irqsave(&sclp_lock, flags);
911 list_del(®->list);
912 spin_unlock_irqrestore(&sclp_lock, flags);
916 EXPORT_SYMBOL(sclp_unregister);
918 /* Remove event buffers which are marked processed. Return the number of
919 * remaining event buffers. */
921 sclp_remove_processed(struct sccb_header *sccb)
923 struct evbuf_header *evbuf;
927 evbuf = (struct evbuf_header *) (sccb + 1);
929 remaining = sccb->length - sizeof(struct sccb_header);
930 while (remaining > 0) {
931 remaining -= evbuf->length;
932 if (evbuf->flags & 0x80) {
933 sccb->length -= evbuf->length;
934 memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length),
938 evbuf = (struct evbuf_header *)
939 ((addr_t) evbuf + evbuf->length);
945 EXPORT_SYMBOL(sclp_remove_processed);
947 /* Prepare init mask request. Called while sclp_lock is locked. */
949 __sclp_make_init_req(sccb_mask_t receive_mask, sccb_mask_t send_mask)
951 struct init_sccb *sccb = sclp_init_sccb;
954 memset(&sclp_init_req, 0, sizeof(struct sclp_req));
955 sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK;
956 sclp_init_req.status = SCLP_REQ_FILLED;
957 sclp_init_req.start_count = 0;
958 sclp_init_req.callback = NULL;
959 sclp_init_req.callback_data = NULL;
960 sclp_init_req.sccb = sccb;
961 sccb->header.length = sizeof(*sccb);
962 if (sclp_mask_compat_mode)
963 sccb->mask_length = SCLP_MASK_SIZE_COMPAT;
965 sccb->mask_length = sizeof(sccb_mask_t);
966 sccb_set_recv_mask(sccb, receive_mask);
967 sccb_set_send_mask(sccb, send_mask);
968 sccb_set_sclp_recv_mask(sccb, 0);
969 sccb_set_sclp_send_mask(sccb, 0);
972 /* Start init mask request. If calculate is non-zero, calculate the mask as
973 * requested by registered listeners. Use zero mask otherwise. Return 0 on
974 * success, non-zero otherwise. */
976 sclp_init_mask(int calculate)
979 struct init_sccb *sccb = sclp_init_sccb;
980 sccb_mask_t receive_mask;
981 sccb_mask_t send_mask;
986 spin_lock_irqsave(&sclp_lock, flags);
987 /* Check if interface is in appropriate state */
988 if (sclp_mask_state != sclp_mask_state_idle) {
989 spin_unlock_irqrestore(&sclp_lock, flags);
992 if (sclp_activation_state == sclp_activation_state_inactive) {
993 spin_unlock_irqrestore(&sclp_lock, flags);
996 sclp_mask_state = sclp_mask_state_initializing;
999 __sclp_get_mask(&receive_mask, &send_mask);
1005 for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) {
1006 /* Prepare request */
1007 __sclp_make_init_req(receive_mask, send_mask);
1008 spin_unlock_irqrestore(&sclp_lock, flags);
1009 if (sclp_add_request(&sclp_init_req)) {
1010 /* Try again later */
1011 wait = jiffies + SCLP_BUSY_INTERVAL * HZ;
1012 while (time_before(jiffies, wait))
1014 spin_lock_irqsave(&sclp_lock, flags);
1017 while (sclp_init_req.status != SCLP_REQ_DONE &&
1018 sclp_init_req.status != SCLP_REQ_FAILED)
1020 spin_lock_irqsave(&sclp_lock, flags);
1021 if (sclp_init_req.status == SCLP_REQ_DONE &&
1022 sccb->header.response_code == 0x20) {
1023 /* Successful request */
1025 sclp_receive_mask = sccb_get_sclp_recv_mask(sccb);
1026 sclp_send_mask = sccb_get_sclp_send_mask(sccb);
1028 sclp_receive_mask = 0;
1031 spin_unlock_irqrestore(&sclp_lock, flags);
1032 sclp_dispatch_state_change();
1033 spin_lock_irqsave(&sclp_lock, flags);
1038 sclp_mask_state = sclp_mask_state_idle;
1039 spin_unlock_irqrestore(&sclp_lock, flags);
1043 /* Deactivate SCLP interface. On success, new requests will be rejected,
1044 * events will no longer be dispatched. Return 0 on success, non-zero
1047 sclp_deactivate(void)
1049 unsigned long flags;
1052 spin_lock_irqsave(&sclp_lock, flags);
1053 /* Deactivate can only be called when active */
1054 if (sclp_activation_state != sclp_activation_state_active) {
1055 spin_unlock_irqrestore(&sclp_lock, flags);
1058 sclp_activation_state = sclp_activation_state_deactivating;
1059 spin_unlock_irqrestore(&sclp_lock, flags);
1060 rc = sclp_init_mask(0);
1061 spin_lock_irqsave(&sclp_lock, flags);
1063 sclp_activation_state = sclp_activation_state_inactive;
1065 sclp_activation_state = sclp_activation_state_active;
1066 spin_unlock_irqrestore(&sclp_lock, flags);
1070 EXPORT_SYMBOL(sclp_deactivate);
1072 /* Reactivate SCLP interface after sclp_deactivate. On success, new
1073 * requests will be accepted, events will be dispatched again. Return 0 on
1074 * success, non-zero otherwise. */
1076 sclp_reactivate(void)
1078 unsigned long flags;
1081 spin_lock_irqsave(&sclp_lock, flags);
1082 /* Reactivate can only be called when inactive */
1083 if (sclp_activation_state != sclp_activation_state_inactive) {
1084 spin_unlock_irqrestore(&sclp_lock, flags);
1087 sclp_activation_state = sclp_activation_state_activating;
1088 spin_unlock_irqrestore(&sclp_lock, flags);
1089 rc = sclp_init_mask(1);
1090 spin_lock_irqsave(&sclp_lock, flags);
1092 sclp_activation_state = sclp_activation_state_active;
1094 sclp_activation_state = sclp_activation_state_inactive;
1095 spin_unlock_irqrestore(&sclp_lock, flags);
1099 EXPORT_SYMBOL(sclp_reactivate);
1101 /* Handler for external interruption used during initialization. Modify
1102 * request state to done. */
1103 static void sclp_check_handler(struct ext_code ext_code,
1104 unsigned int param32, unsigned long param64)
1108 inc_irq_stat(IRQEXT_SCP);
1109 finished_sccb = param32 & 0xfffffff8;
1110 /* Is this the interrupt we are waiting for? */
1111 if (finished_sccb == 0)
1113 if (finished_sccb != (u32) (addr_t) sclp_init_sccb)
1114 panic("sclp: unsolicited interrupt for buffer at 0x%x\n",
1116 spin_lock(&sclp_lock);
1117 if (sclp_running_state == sclp_running_state_running) {
1118 sclp_init_req.status = SCLP_REQ_DONE;
1119 sclp_running_state = sclp_running_state_idle;
1121 spin_unlock(&sclp_lock);
1124 /* Initial init mask request timed out. Modify request state to failed. */
1126 sclp_check_timeout(struct timer_list *unused)
1128 unsigned long flags;
1130 spin_lock_irqsave(&sclp_lock, flags);
1131 if (sclp_running_state == sclp_running_state_running) {
1132 sclp_init_req.status = SCLP_REQ_FAILED;
1133 sclp_running_state = sclp_running_state_idle;
1135 spin_unlock_irqrestore(&sclp_lock, flags);
1138 /* Perform a check of the SCLP interface. Return zero if the interface is
1139 * available and there are no pending requests from a previous instance.
1140 * Return non-zero otherwise. */
1142 sclp_check_interface(void)
1144 struct init_sccb *sccb;
1145 unsigned long flags;
1149 spin_lock_irqsave(&sclp_lock, flags);
1150 /* Prepare init mask command */
1151 rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler);
1153 spin_unlock_irqrestore(&sclp_lock, flags);
1156 for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) {
1157 __sclp_make_init_req(0, 0);
1158 sccb = (struct init_sccb *) sclp_init_req.sccb;
1159 rc = sclp_service_call_trace(sclp_init_req.command, sccb);
1162 sclp_init_req.status = SCLP_REQ_RUNNING;
1163 sclp_running_state = sclp_running_state_running;
1164 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ,
1165 sclp_check_timeout);
1166 spin_unlock_irqrestore(&sclp_lock, flags);
1167 /* Enable service-signal interruption - needs to happen
1168 * with IRQs enabled. */
1169 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
1170 /* Wait for signal from interrupt or timeout */
1172 /* Disable service-signal interruption - needs to happen
1173 * with IRQs enabled. */
1174 irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL);
1175 spin_lock_irqsave(&sclp_lock, flags);
1176 del_timer(&sclp_request_timer);
1178 if (sclp_init_req.status == SCLP_REQ_DONE) {
1179 if (sccb->header.response_code == 0x20) {
1182 } else if (sccb->header.response_code == 0x74f0) {
1183 if (!sclp_mask_compat_mode) {
1184 sclp_mask_compat_mode = true;
1190 unregister_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler);
1191 spin_unlock_irqrestore(&sclp_lock, flags);
1195 /* Reboot event handler. Reset send and receive mask to prevent pending SCLP
1196 * events from interfering with rebooted system. */
1198 sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr)
1204 static struct notifier_block sclp_reboot_notifier = {
1205 .notifier_call = sclp_reboot_event
1208 static ssize_t con_pages_show(struct device_driver *dev, char *buf)
1210 return sprintf(buf, "%i\n", sclp_console_pages);
1213 static DRIVER_ATTR_RO(con_pages);
1215 static ssize_t con_drop_show(struct device_driver *dev, char *buf)
1217 return sprintf(buf, "%i\n", sclp_console_drop);
1220 static DRIVER_ATTR_RO(con_drop);
1222 static ssize_t con_full_show(struct device_driver *dev, char *buf)
1224 return sprintf(buf, "%lu\n", sclp_console_full);
1227 static DRIVER_ATTR_RO(con_full);
1229 static struct attribute *sclp_drv_attrs[] = {
1230 &driver_attr_con_pages.attr,
1231 &driver_attr_con_drop.attr,
1232 &driver_attr_con_full.attr,
1235 static struct attribute_group sclp_drv_attr_group = {
1236 .attrs = sclp_drv_attrs,
1238 static const struct attribute_group *sclp_drv_attr_groups[] = {
1239 &sclp_drv_attr_group,
1243 static struct platform_driver sclp_pdrv = {
1246 .groups = sclp_drv_attr_groups,
1250 /* Initialize SCLP driver. Return zero if driver is operational, non-zero
1255 unsigned long flags;
1258 spin_lock_irqsave(&sclp_lock, flags);
1259 /* Check for previous or running initialization */
1260 if (sclp_init_state != sclp_init_state_uninitialized)
1262 sclp_init_state = sclp_init_state_initializing;
1263 sclp_read_sccb = (void *) __get_free_page(GFP_ATOMIC | GFP_DMA);
1264 sclp_init_sccb = (void *) __get_free_page(GFP_ATOMIC | GFP_DMA);
1265 BUG_ON(!sclp_read_sccb || !sclp_init_sccb);
1266 /* Set up variables */
1267 list_add(&sclp_state_change_event.list, &sclp_reg_list);
1268 timer_setup(&sclp_request_timer, NULL, 0);
1269 timer_setup(&sclp_queue_timer, sclp_req_queue_timeout, 0);
1270 /* Check interface */
1271 spin_unlock_irqrestore(&sclp_lock, flags);
1272 rc = sclp_check_interface();
1273 spin_lock_irqsave(&sclp_lock, flags);
1275 goto fail_init_state_uninitialized;
1276 /* Register reboot handler */
1277 rc = register_reboot_notifier(&sclp_reboot_notifier);
1279 goto fail_init_state_uninitialized;
1280 /* Register interrupt handler */
1281 rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_interrupt_handler);
1283 goto fail_unregister_reboot_notifier;
1284 sclp_init_state = sclp_init_state_initialized;
1285 spin_unlock_irqrestore(&sclp_lock, flags);
1286 /* Enable service-signal external interruption - needs to happen with
1288 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
1292 fail_unregister_reboot_notifier:
1293 unregister_reboot_notifier(&sclp_reboot_notifier);
1294 fail_init_state_uninitialized:
1295 sclp_init_state = sclp_init_state_uninitialized;
1296 free_page((unsigned long) sclp_read_sccb);
1297 free_page((unsigned long) sclp_init_sccb);
1299 spin_unlock_irqrestore(&sclp_lock, flags);
1303 static __init int sclp_initcall(void)
1307 rc = platform_driver_register(&sclp_pdrv);
1314 arch_initcall(sclp_initcall);