1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * core function to access sclp interface
4 *
5 * Copyright IBM Corp. 1999, 2009
6 *
7 * Author(s): Martin Peschke <mpeschke@de.ibm.com>
8 * Martin Schwidefsky <schwidefsky@de.ibm.com>
9 */
10
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>
23 #include <asm/irq.h>
24 #include <asm/debug.h>
25
26 #include "sclp.h"
27
28 #define SCLP_HEADER "sclp: "
29
30 struct sclp_trace_entry {
31 char id[4] __nonstring;
32 u32 a;
33 u64 b;
34 };
35
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
39
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);
43
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);
47
48 /* Lock to protect internal data consistency. */
49 static DEFINE_SPINLOCK(sclp_lock);
50
51 /* Mask of events that we can send to the sclp interface. */
52 static sccb_mask_t sclp_receive_mask;
53
54 /* Mask of events that we can receive from the sclp interface. */
55 static sccb_mask_t sclp_send_mask;
56
57 /* List of registered event listeners and senders. */
58 static LIST_HEAD(sclp_reg_list);
59
60 /* List of queued requests. */
61 static LIST_HEAD(sclp_req_queue);
62
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;
68
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;
75
76 /* The currently active SCLP command word. */
77 static sclp_cmdw_t active_cmd;
78
sclp_trace(int prio,char * id,u32 a,u64 b,bool err)79 static inline void sclp_trace(int prio, char *id, u32 a, u64 b, bool err)
80 {
81 struct sclp_trace_entry e;
82
83 memset(&e, 0, sizeof(e));
84 strncpy(e.id, id, sizeof(e.id));
85 e.a = a;
86 e.b = b;
87 debug_event(&sclp_debug, prio, &e, sizeof(e));
88 if (err)
89 debug_event(&sclp_debug_err, 0, &e, sizeof(e));
90 }
91
no_zeroes_len(void * data,int len)92 static inline int no_zeroes_len(void *data, int len)
93 {
94 char *d = data;
95
96 /* Minimize trace area usage by not tracing trailing zeroes. */
97 while (len > SCLP_TRACE_ENTRY_SIZE && d[len - 1] == 0)
98 len--;
99
100 return len;
101 }
102
sclp_trace_bin(int prio,void * d,int len,int errlen)103 static inline void sclp_trace_bin(int prio, void *d, int len, int errlen)
104 {
105 debug_event(&sclp_debug, prio, d, no_zeroes_len(d, len));
106 if (errlen)
107 debug_event(&sclp_debug_err, 0, d, no_zeroes_len(d, errlen));
108 }
109
abbrev_len(sclp_cmdw_t cmd,struct sccb_header * sccb)110 static inline int abbrev_len(sclp_cmdw_t cmd, struct sccb_header *sccb)
111 {
112 struct evbuf_header *evbuf = (struct evbuf_header *)(sccb + 1);
113 int len = sccb->length, limit = SCLP_TRACE_MAX_SIZE;
114
115 /* Full SCCB tracing if debug level is set to max. */
116 if (sclp_debug.level == DEBUG_MAX_LEVEL)
117 return len;
118
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;
123
124 return min(len, limit);
125 }
126
sclp_trace_sccb(int prio,char * id,u32 a,u64 b,sclp_cmdw_t cmd,struct sccb_header * sccb,bool err)127 static inline void sclp_trace_sccb(int prio, char *id, u32 a, u64 b,
128 sclp_cmdw_t cmd, struct sccb_header *sccb,
129 bool err)
130 {
131 sclp_trace(prio, id, a, b, err);
132 if (sccb) {
133 sclp_trace_bin(prio + 1, sccb, abbrev_len(cmd, sccb),
134 err ? sccb->length : 0);
135 }
136 }
137
sclp_trace_evbuf(int prio,char * id,u32 a,u64 b,struct evbuf_header * evbuf,bool err)138 static inline void sclp_trace_evbuf(int prio, char *id, u32 a, u64 b,
139 struct evbuf_header *evbuf, bool err)
140 {
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);
145 }
146
sclp_trace_req(int prio,char * id,struct sclp_req * req,bool err)147 static inline void sclp_trace_req(int prio, char *id, struct sclp_req *req,
148 bool err)
149 {
150 struct sccb_header *sccb = req->sccb;
151 union {
152 struct {
153 u16 status;
154 u16 response;
155 u16 timeout;
156 u16 start_count;
157 };
158 u64 b;
159 } summary;
160
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;
165
166 sclp_trace(prio, id, __pa(sccb), summary.b, err);
167 }
168
sclp_trace_register(int prio,char * id,u32 a,u64 b,struct sclp_register * reg)169 static inline void sclp_trace_register(int prio, char *id, u32 a, u64 b,
170 struct sclp_register *reg)
171 {
172 struct {
173 u64 receive;
174 u64 send;
175 } d;
176
177 d.receive = reg->receive_mask;
178 d.send = reg->send_mask;
179
180 sclp_trace(prio, id, a, b, false);
181 sclp_trace_bin(prio, &d, sizeof(d), 0);
182 }
183
sclp_setup_console_pages(char * str)184 static int __init sclp_setup_console_pages(char *str)
185 {
186 int pages, rc;
187
188 rc = kstrtoint(str, 0, &pages);
189 if (!rc && pages >= SCLP_CONSOLE_PAGES)
190 sclp_console_pages = pages;
191 return 1;
192 }
193
194 __setup("sclp_con_pages=", sclp_setup_console_pages);
195
sclp_setup_console_drop(char * str)196 static int __init sclp_setup_console_drop(char *str)
197 {
198 int drop, rc;
199
200 rc = kstrtoint(str, 0, &drop);
201 if (!rc)
202 sclp_console_drop = drop;
203 return 1;
204 }
205
206 __setup("sclp_con_drop=", sclp_setup_console_drop);
207
208 /* Timer for request retries. */
209 static struct timer_list sclp_request_timer;
210
211 /* Timer for queued requests. */
212 static struct timer_list sclp_queue_timer;
213
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;
220
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;
226
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;
234
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;
240
241 /* Maximum retry counts */
242 #define SCLP_INIT_RETRY 3
243 #define SCLP_MASK_RETRY 3
244
245 /* Timeout intervals in seconds.*/
246 #define SCLP_BUSY_INTERVAL 10
247 #define SCLP_RETRY_INTERVAL 30
248
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);
254
255 static void
__sclp_queue_read_req(void)256 __sclp_queue_read_req(void)
257 {
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);
263 }
264 }
265
266 /* Set up request retry timer. Called while sclp_lock is locked. */
267 static inline void
__sclp_set_request_timer(unsigned long time,void (* cb)(struct timer_list *))268 __sclp_set_request_timer(unsigned long time, void (*cb)(struct timer_list *))
269 {
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);
274 }
275
sclp_request_timeout_restart(struct timer_list * unused)276 static void sclp_request_timeout_restart(struct timer_list *unused)
277 {
278 sclp_request_timeout(true);
279 }
280
sclp_request_timeout_normal(struct timer_list * unused)281 static void sclp_request_timeout_normal(struct timer_list *unused)
282 {
283 sclp_request_timeout(false);
284 }
285
286 /* Request timeout handler. Restart the request queue. If force_restart,
287 * force restart of running request. */
sclp_request_timeout(bool force_restart)288 static void sclp_request_timeout(bool force_restart)
289 {
290 unsigned long flags;
291
292 /* TMO: A timeout occurred (a=force_restart) */
293 sclp_trace(2, "TMO", force_restart, 0, true);
294
295 spin_lock_irqsave(&sclp_lock, flags);
296 if (force_restart) {
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;
302 }
303 } else {
304 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ,
305 sclp_request_timeout_normal);
306 }
307 spin_unlock_irqrestore(&sclp_lock, flags);
308 sclp_process_queue();
309 }
310
311 /*
312 * Returns the expire value in jiffies of the next pending request timeout,
313 * if any. Needs to be called with sclp_lock.
314 */
__sclp_req_queue_find_next_timeout(void)315 static unsigned long __sclp_req_queue_find_next_timeout(void)
316 {
317 unsigned long expires_next = 0;
318 struct sclp_req *req;
319
320 list_for_each_entry(req, &sclp_req_queue, list) {
321 if (!req->queue_expires)
322 continue;
323 if (!expires_next ||
324 (time_before(req->queue_expires, expires_next)))
325 expires_next = req->queue_expires;
326 }
327 return expires_next;
328 }
329
330 /*
331 * Returns expired request, if any, and removes it from the list.
332 */
__sclp_req_queue_remove_expired_req(void)333 static struct sclp_req *__sclp_req_queue_remove_expired_req(void)
334 {
335 unsigned long flags, now;
336 struct sclp_req *req;
337
338 spin_lock_irqsave(&sclp_lock, flags);
339 now = jiffies;
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)
343 continue;
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);
348 goto out;
349 }
350 }
351 }
352 req = NULL;
353 out:
354 spin_unlock_irqrestore(&sclp_lock, flags);
355 return req;
356 }
357
358 /*
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.
362 */
sclp_req_queue_timeout(struct timer_list * unused)363 static void sclp_req_queue_timeout(struct timer_list *unused)
364 {
365 unsigned long flags, expires_next;
366 struct sclp_req *req;
367
368 do {
369 req = __sclp_req_queue_remove_expired_req();
370
371 if (req) {
372 /* RQTM: Request timed out (a=sccb, b=summary) */
373 sclp_trace_req(2, "RQTM", req, true);
374 }
375
376 if (req && req->callback)
377 req->callback(req, req->callback_data);
378 } while (req);
379
380 spin_lock_irqsave(&sclp_lock, flags);
381 expires_next = __sclp_req_queue_find_next_timeout();
382 if (expires_next)
383 mod_timer(&sclp_queue_timer, expires_next);
384 spin_unlock_irqrestore(&sclp_lock, flags);
385 }
386
sclp_service_call_trace(sclp_cmdw_t command,void * sccb)387 static int sclp_service_call_trace(sclp_cmdw_t command, void *sccb)
388 {
389 static u64 srvc_count;
390 int rc;
391
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);
394
395 rc = sclp_service_call(command, sccb);
396
397 /* SRV2: Service call was issued (a=rc, b=SRVC sequence number) */
398 sclp_trace(0, "SRV2", -rc, ++srvc_count, rc != 0);
399
400 if (rc == 0)
401 active_cmd = command;
402
403 return rc;
404 }
405
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. */
409 static int
__sclp_start_request(struct sclp_req * req)410 __sclp_start_request(struct sclp_req *req)
411 {
412 int rc;
413
414 if (sclp_running_state != sclp_running_state_idle)
415 return 0;
416 del_timer(&sclp_request_timer);
417 rc = sclp_service_call_trace(req->command, req->sccb);
418 req->start_count++;
419
420 if (rc == 0) {
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);
426 return 0;
427 } else if (rc == -EBUSY) {
428 /* Try again later */
429 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ,
430 sclp_request_timeout_normal);
431 return 0;
432 }
433 /* Request failed */
434 req->status = SCLP_REQ_FAILED;
435 return rc;
436 }
437
438 /* Try to start queued requests. */
439 static void
sclp_process_queue(void)440 sclp_process_queue(void)
441 {
442 struct sclp_req *req;
443 int rc;
444 unsigned long flags;
445
446 spin_lock_irqsave(&sclp_lock, flags);
447 if (sclp_running_state != sclp_running_state_idle) {
448 spin_unlock_irqrestore(&sclp_lock, flags);
449 return;
450 }
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);
455 if (rc == 0)
456 break;
457 /* Request failed */
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);
463 break;
464 }
465 /* Post-processing for aborted request */
466 list_del(&req->list);
467
468 /* RQAB: Request aborted (a=sccb, b=summary) */
469 sclp_trace_req(2, "RQAB", req, true);
470
471 if (req->callback) {
472 spin_unlock_irqrestore(&sclp_lock, flags);
473 req->callback(req, req->callback_data);
474 spin_lock_irqsave(&sclp_lock, flags);
475 }
476 }
477 spin_unlock_irqrestore(&sclp_lock, flags);
478 }
479
__sclp_can_add_request(struct sclp_req * req)480 static int __sclp_can_add_request(struct sclp_req *req)
481 {
482 if (req == &sclp_init_req)
483 return 1;
484 if (sclp_init_state != sclp_init_state_initialized)
485 return 0;
486 if (sclp_activation_state != sclp_activation_state_active)
487 return 0;
488 return 1;
489 }
490
491 /* Queue a new request. Return zero on success, non-zero otherwise. */
492 int
sclp_add_request(struct sclp_req * req)493 sclp_add_request(struct sclp_req *req)
494 {
495 unsigned long flags;
496 int rc;
497
498 spin_lock_irqsave(&sclp_lock, flags);
499 if (!__sclp_can_add_request(req)) {
500 spin_unlock_irqrestore(&sclp_lock, flags);
501 return -EIO;
502 }
503
504 /* RQAD: Request was added (a=sccb, b=caller) */
505 sclp_trace(2, "RQAD", __pa(req->sccb), _RET_IP_, false);
506
507 req->status = SCLP_REQ_QUEUED;
508 req->start_count = 0;
509 list_add_tail(&req->list, &sclp_req_queue);
510 rc = 0;
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);
516 } else
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);
522 if (rc)
523 list_del(&req->list);
524 }
525 spin_unlock_irqrestore(&sclp_lock, flags);
526 return rc;
527 }
528
529 EXPORT_SYMBOL(sclp_add_request);
530
531 /* Dispatch events found in request buffer to registered listeners. Return 0
532 * if all events were dispatched, non-zero otherwise. */
533 static int
sclp_dispatch_evbufs(struct sccb_header * sccb)534 sclp_dispatch_evbufs(struct sccb_header *sccb)
535 {
536 unsigned long flags;
537 struct evbuf_header *evbuf;
538 struct list_head *l;
539 struct sclp_register *reg;
540 int offset;
541 int rc;
542
543 spin_lock_irqsave(&sclp_lock, flags);
544 rc = 0;
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)
550 break;
551 /* Search for event handler */
552 reg = NULL;
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))
556 break;
557 else
558 reg = NULL;
559 }
560
561 /* EVNT: Event callback (b=receiver) */
562 sclp_trace_evbuf(2, "EVNT", 0, reg ? (u64)reg->receiver_fn : 0,
563 evbuf, !reg);
564
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)
570 rc = -EOPNOTSUPP;
571 }
572 spin_unlock_irqrestore(&sclp_lock, flags);
573 return rc;
574 }
575
576 /* Read event data request callback. */
577 static void
sclp_read_cb(struct sclp_req * req,void * data)578 sclp_read_cb(struct sclp_req *req, void *data)
579 {
580 unsigned long flags;
581 struct sccb_header *sccb;
582
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);
590 }
591
592 /* Prepare read event data request. Called while sclp_lock is locked. */
__sclp_make_read_req(void)593 static void __sclp_make_read_req(void)
594 {
595 struct sccb_header *sccb;
596
597 sccb = (struct sccb_header *) sclp_read_sccb;
598 clear_page(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;
608 }
609
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 *
__sclp_find_req(u32 sccb)613 __sclp_find_req(u32 sccb)
614 {
615 struct list_head *l;
616 struct sclp_req *req;
617
618 list_for_each(l, &sclp_req_queue) {
619 req = list_entry(l, struct sclp_req, list);
620 if (sccb == __pa(req->sccb))
621 return req;
622 }
623 return NULL;
624 }
625
ok_response(u32 sccb_int,sclp_cmdw_t cmd)626 static bool ok_response(u32 sccb_int, sclp_cmdw_t cmd)
627 {
628 struct sccb_header *sccb = (struct sccb_header *)__va(sccb_int);
629 struct evbuf_header *evbuf;
630 u16 response;
631
632 if (!sccb)
633 return true;
634
635 /* Check SCCB response. */
636 response = sccb->response_code & 0xff;
637 if (response != 0x10 && response != 0x20)
638 return false;
639
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))
644 return false;
645 }
646
647 return true;
648 }
649
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. */
sclp_interrupt_handler(struct ext_code ext_code,unsigned int param32,unsigned long param64)653 static void sclp_interrupt_handler(struct ext_code ext_code,
654 unsigned int param32, unsigned long param64)
655 {
656 struct sclp_req *req;
657 u32 finished_sccb;
658 u32 evbuf_pending;
659
660 inc_irq_stat(IRQEXT_SCP);
661 spin_lock(&sclp_lock);
662 finished_sccb = param32 & 0xfffffff8;
663 evbuf_pending = param32 & 0x3;
664
665 /* INT: Interrupt received (a=intparm, b=cmd) */
666 sclp_trace_sccb(0, "INT", param32, active_cmd, active_cmd,
667 (struct sccb_header *)__va(finished_sccb),
668 !ok_response(finished_sccb, active_cmd));
669
670 if (finished_sccb) {
671 del_timer(&sclp_request_timer);
672 sclp_running_state = sclp_running_state_reset_pending;
673 req = __sclp_find_req(finished_sccb);
674 if (req) {
675 /* Request post-processing */
676 list_del(&req->list);
677 req->status = SCLP_REQ_DONE;
678
679 /* RQOK: Request success (a=sccb, b=summary) */
680 sclp_trace_req(2, "RQOK", req, false);
681
682 if (req->callback) {
683 spin_unlock(&sclp_lock);
684 req->callback(req, req->callback_data);
685 spin_lock(&sclp_lock);
686 }
687 } else {
688 /* UNEX: Unexpected SCCB completion (a=sccb address) */
689 sclp_trace(0, "UNEX", finished_sccb, 0, true);
690 }
691 sclp_running_state = sclp_running_state_idle;
692 active_cmd = 0;
693 }
694 if (evbuf_pending &&
695 sclp_activation_state == sclp_activation_state_active)
696 __sclp_queue_read_req();
697 spin_unlock(&sclp_lock);
698 sclp_process_queue();
699 }
700
701 /* Convert interval in jiffies to TOD ticks. */
702 static inline u64
sclp_tod_from_jiffies(unsigned long jiffies)703 sclp_tod_from_jiffies(unsigned long jiffies)
704 {
705 return (u64) (jiffies / HZ) << 32;
706 }
707
708 /* Wait until a currently running request finished. Note: while this function
709 * is running, no timers are served on the calling CPU. */
710 void
sclp_sync_wait(void)711 sclp_sync_wait(void)
712 {
713 unsigned long long old_tick;
714 unsigned long flags;
715 unsigned long cr0, cr0_sync;
716 static u64 sync_count;
717 u64 timeout;
718 int irq_context;
719
720 /* SYN1: Synchronous wait start (a=runstate, b=sync count) */
721 sclp_trace(4, "SYN1", sclp_running_state, ++sync_count, false);
722
723 /* We'll be disabling timer interrupts, so we need a custom timeout
724 * mechanism */
725 timeout = 0;
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 -
730 jiffies);
731 }
732 local_irq_save(flags);
733 /* Prevent bottom half from executing once we force interrupts open */
734 irq_context = in_interrupt();
735 if (!irq_context)
736 local_bh_disable();
737 /* Enable service-signal interruption, disable timer interrupts */
738 old_tick = local_tick_disable();
739 trace_hardirqs_on();
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 (get_tod_clock_fast() > timeout && del_timer(&sclp_request_timer))
749 sclp_request_timer.function(&sclp_request_timer);
750 cpu_relax();
751 }
752 local_irq_disable();
753 __ctl_load(cr0, 0, 0);
754 if (!irq_context)
755 _local_bh_enable();
756 local_tick_enable(old_tick);
757 local_irq_restore(flags);
758
759 /* SYN2: Synchronous wait end (a=runstate, b=sync_count) */
760 sclp_trace(4, "SYN2", sclp_running_state, sync_count, false);
761 }
762 EXPORT_SYMBOL(sclp_sync_wait);
763
764 /* Dispatch changes in send and receive mask to registered listeners. */
765 static void
sclp_dispatch_state_change(void)766 sclp_dispatch_state_change(void)
767 {
768 struct list_head *l;
769 struct sclp_register *reg;
770 unsigned long flags;
771 sccb_mask_t receive_mask;
772 sccb_mask_t send_mask;
773
774 do {
775 spin_lock_irqsave(&sclp_lock, flags);
776 reg = NULL;
777 list_for_each(l, &sclp_reg_list) {
778 reg = list_entry(l, struct sclp_register, list);
779 receive_mask = reg->send_mask & sclp_receive_mask;
780 send_mask = reg->receive_mask & sclp_send_mask;
781 if (reg->sclp_receive_mask != receive_mask ||
782 reg->sclp_send_mask != send_mask) {
783 reg->sclp_receive_mask = receive_mask;
784 reg->sclp_send_mask = send_mask;
785 break;
786 } else
787 reg = NULL;
788 }
789 spin_unlock_irqrestore(&sclp_lock, flags);
790 if (reg && reg->state_change_fn) {
791 /* STCG: State-change callback (b=callback) */
792 sclp_trace(2, "STCG", 0, (u64)reg->state_change_fn,
793 false);
794
795 reg->state_change_fn(reg);
796 }
797 } while (reg);
798 }
799
800 struct sclp_statechangebuf {
801 struct evbuf_header header;
802 u8 validity_sclp_active_facility_mask : 1;
803 u8 validity_sclp_receive_mask : 1;
804 u8 validity_sclp_send_mask : 1;
805 u8 validity_read_data_function_mask : 1;
806 u16 _zeros : 12;
807 u16 mask_length;
808 u64 sclp_active_facility_mask;
809 u8 masks[2 * 1021 + 4]; /* variable length */
810 /*
811 * u8 sclp_receive_mask[mask_length];
812 * u8 sclp_send_mask[mask_length];
813 * u32 read_data_function_mask;
814 */
815 } __attribute__((packed));
816
817
818 /* State change event callback. Inform listeners of changes. */
819 static void
sclp_state_change_cb(struct evbuf_header * evbuf)820 sclp_state_change_cb(struct evbuf_header *evbuf)
821 {
822 unsigned long flags;
823 struct sclp_statechangebuf *scbuf;
824
825 BUILD_BUG_ON(sizeof(struct sclp_statechangebuf) > PAGE_SIZE);
826
827 scbuf = (struct sclp_statechangebuf *) evbuf;
828 spin_lock_irqsave(&sclp_lock, flags);
829 if (scbuf->validity_sclp_receive_mask)
830 sclp_receive_mask = sccb_get_recv_mask(scbuf);
831 if (scbuf->validity_sclp_send_mask)
832 sclp_send_mask = sccb_get_send_mask(scbuf);
833 spin_unlock_irqrestore(&sclp_lock, flags);
834 if (scbuf->validity_sclp_active_facility_mask)
835 sclp.facilities = scbuf->sclp_active_facility_mask;
836 sclp_dispatch_state_change();
837 }
838
839 static struct sclp_register sclp_state_change_event = {
840 .receive_mask = EVTYP_STATECHANGE_MASK,
841 .receiver_fn = sclp_state_change_cb
842 };
843
844 /* Calculate receive and send mask of currently registered listeners.
845 * Called while sclp_lock is locked. */
846 static inline void
__sclp_get_mask(sccb_mask_t * receive_mask,sccb_mask_t * send_mask)847 __sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask)
848 {
849 struct list_head *l;
850 struct sclp_register *t;
851
852 *receive_mask = 0;
853 *send_mask = 0;
854 list_for_each(l, &sclp_reg_list) {
855 t = list_entry(l, struct sclp_register, list);
856 *receive_mask |= t->receive_mask;
857 *send_mask |= t->send_mask;
858 }
859 }
860
861 /* Register event listener. Return 0 on success, non-zero otherwise. */
862 int
sclp_register(struct sclp_register * reg)863 sclp_register(struct sclp_register *reg)
864 {
865 unsigned long flags;
866 sccb_mask_t receive_mask;
867 sccb_mask_t send_mask;
868 int rc;
869
870 /* REG: Event listener registered (b=caller) */
871 sclp_trace_register(2, "REG", 0, _RET_IP_, reg);
872
873 rc = sclp_init();
874 if (rc)
875 return rc;
876 spin_lock_irqsave(&sclp_lock, flags);
877 /* Check event mask for collisions */
878 __sclp_get_mask(&receive_mask, &send_mask);
879 if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) {
880 spin_unlock_irqrestore(&sclp_lock, flags);
881 return -EBUSY;
882 }
883 /* Trigger initial state change callback */
884 reg->sclp_receive_mask = 0;
885 reg->sclp_send_mask = 0;
886 list_add(®->list, &sclp_reg_list);
887 spin_unlock_irqrestore(&sclp_lock, flags);
888 rc = sclp_init_mask(1);
889 if (rc) {
890 spin_lock_irqsave(&sclp_lock, flags);
891 list_del(®->list);
892 spin_unlock_irqrestore(&sclp_lock, flags);
893 }
894 return rc;
895 }
896
897 EXPORT_SYMBOL(sclp_register);
898
899 /* Unregister event listener. */
900 void
sclp_unregister(struct sclp_register * reg)901 sclp_unregister(struct sclp_register *reg)
902 {
903 unsigned long flags;
904
905 /* UREG: Event listener unregistered (b=caller) */
906 sclp_trace_register(2, "UREG", 0, _RET_IP_, reg);
907
908 spin_lock_irqsave(&sclp_lock, flags);
909 list_del(®->list);
910 spin_unlock_irqrestore(&sclp_lock, flags);
911 sclp_init_mask(1);
912 }
913
914 EXPORT_SYMBOL(sclp_unregister);
915
916 /* Remove event buffers which are marked processed. Return the number of
917 * remaining event buffers. */
918 int
sclp_remove_processed(struct sccb_header * sccb)919 sclp_remove_processed(struct sccb_header *sccb)
920 {
921 struct evbuf_header *evbuf;
922 int unprocessed;
923 u16 remaining;
924
925 evbuf = (struct evbuf_header *) (sccb + 1);
926 unprocessed = 0;
927 remaining = sccb->length - sizeof(struct sccb_header);
928 while (remaining > 0) {
929 remaining -= evbuf->length;
930 if (evbuf->flags & 0x80) {
931 sccb->length -= evbuf->length;
932 memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length),
933 remaining);
934 } else {
935 unprocessed++;
936 evbuf = (struct evbuf_header *)
937 ((addr_t) evbuf + evbuf->length);
938 }
939 }
940 return unprocessed;
941 }
942
943 EXPORT_SYMBOL(sclp_remove_processed);
944
945 /* Prepare init mask request. Called while sclp_lock is locked. */
946 static inline void
__sclp_make_init_req(sccb_mask_t receive_mask,sccb_mask_t send_mask)947 __sclp_make_init_req(sccb_mask_t receive_mask, sccb_mask_t send_mask)
948 {
949 struct init_sccb *sccb = sclp_init_sccb;
950
951 clear_page(sccb);
952 memset(&sclp_init_req, 0, sizeof(struct sclp_req));
953 sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK;
954 sclp_init_req.status = SCLP_REQ_FILLED;
955 sclp_init_req.start_count = 0;
956 sclp_init_req.callback = NULL;
957 sclp_init_req.callback_data = NULL;
958 sclp_init_req.sccb = sccb;
959 sccb->header.length = sizeof(*sccb);
960 if (sclp_mask_compat_mode)
961 sccb->mask_length = SCLP_MASK_SIZE_COMPAT;
962 else
963 sccb->mask_length = sizeof(sccb_mask_t);
964 sccb_set_recv_mask(sccb, receive_mask);
965 sccb_set_send_mask(sccb, send_mask);
966 sccb_set_sclp_recv_mask(sccb, 0);
967 sccb_set_sclp_send_mask(sccb, 0);
968 }
969
970 /* Start init mask request. If calculate is non-zero, calculate the mask as
971 * requested by registered listeners. Use zero mask otherwise. Return 0 on
972 * success, non-zero otherwise. */
973 static int
sclp_init_mask(int calculate)974 sclp_init_mask(int calculate)
975 {
976 unsigned long flags;
977 struct init_sccb *sccb = sclp_init_sccb;
978 sccb_mask_t receive_mask;
979 sccb_mask_t send_mask;
980 int retry;
981 int rc;
982 unsigned long wait;
983
984 spin_lock_irqsave(&sclp_lock, flags);
985 /* Check if interface is in appropriate state */
986 if (sclp_mask_state != sclp_mask_state_idle) {
987 spin_unlock_irqrestore(&sclp_lock, flags);
988 return -EBUSY;
989 }
990 if (sclp_activation_state == sclp_activation_state_inactive) {
991 spin_unlock_irqrestore(&sclp_lock, flags);
992 return -EINVAL;
993 }
994 sclp_mask_state = sclp_mask_state_initializing;
995 /* Determine mask */
996 if (calculate)
997 __sclp_get_mask(&receive_mask, &send_mask);
998 else {
999 receive_mask = 0;
1000 send_mask = 0;
1001 }
1002 rc = -EIO;
1003 for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) {
1004 /* Prepare request */
1005 __sclp_make_init_req(receive_mask, send_mask);
1006 spin_unlock_irqrestore(&sclp_lock, flags);
1007 if (sclp_add_request(&sclp_init_req)) {
1008 /* Try again later */
1009 wait = jiffies + SCLP_BUSY_INTERVAL * HZ;
1010 while (time_before(jiffies, wait))
1011 sclp_sync_wait();
1012 spin_lock_irqsave(&sclp_lock, flags);
1013 continue;
1014 }
1015 while (sclp_init_req.status != SCLP_REQ_DONE &&
1016 sclp_init_req.status != SCLP_REQ_FAILED)
1017 sclp_sync_wait();
1018 spin_lock_irqsave(&sclp_lock, flags);
1019 if (sclp_init_req.status == SCLP_REQ_DONE &&
1020 sccb->header.response_code == 0x20) {
1021 /* Successful request */
1022 if (calculate) {
1023 sclp_receive_mask = sccb_get_sclp_recv_mask(sccb);
1024 sclp_send_mask = sccb_get_sclp_send_mask(sccb);
1025 } else {
1026 sclp_receive_mask = 0;
1027 sclp_send_mask = 0;
1028 }
1029 spin_unlock_irqrestore(&sclp_lock, flags);
1030 sclp_dispatch_state_change();
1031 spin_lock_irqsave(&sclp_lock, flags);
1032 rc = 0;
1033 break;
1034 }
1035 }
1036 sclp_mask_state = sclp_mask_state_idle;
1037 spin_unlock_irqrestore(&sclp_lock, flags);
1038 return rc;
1039 }
1040
1041 /* Deactivate SCLP interface. On success, new requests will be rejected,
1042 * events will no longer be dispatched. Return 0 on success, non-zero
1043 * otherwise. */
1044 int
sclp_deactivate(void)1045 sclp_deactivate(void)
1046 {
1047 unsigned long flags;
1048 int rc;
1049
1050 spin_lock_irqsave(&sclp_lock, flags);
1051 /* Deactivate can only be called when active */
1052 if (sclp_activation_state != sclp_activation_state_active) {
1053 spin_unlock_irqrestore(&sclp_lock, flags);
1054 return -EINVAL;
1055 }
1056 sclp_activation_state = sclp_activation_state_deactivating;
1057 spin_unlock_irqrestore(&sclp_lock, flags);
1058 rc = sclp_init_mask(0);
1059 spin_lock_irqsave(&sclp_lock, flags);
1060 if (rc == 0)
1061 sclp_activation_state = sclp_activation_state_inactive;
1062 else
1063 sclp_activation_state = sclp_activation_state_active;
1064 spin_unlock_irqrestore(&sclp_lock, flags);
1065 return rc;
1066 }
1067
1068 EXPORT_SYMBOL(sclp_deactivate);
1069
1070 /* Reactivate SCLP interface after sclp_deactivate. On success, new
1071 * requests will be accepted, events will be dispatched again. Return 0 on
1072 * success, non-zero otherwise. */
1073 int
sclp_reactivate(void)1074 sclp_reactivate(void)
1075 {
1076 unsigned long flags;
1077 int rc;
1078
1079 spin_lock_irqsave(&sclp_lock, flags);
1080 /* Reactivate can only be called when inactive */
1081 if (sclp_activation_state != sclp_activation_state_inactive) {
1082 spin_unlock_irqrestore(&sclp_lock, flags);
1083 return -EINVAL;
1084 }
1085 sclp_activation_state = sclp_activation_state_activating;
1086 spin_unlock_irqrestore(&sclp_lock, flags);
1087 rc = sclp_init_mask(1);
1088 spin_lock_irqsave(&sclp_lock, flags);
1089 if (rc == 0)
1090 sclp_activation_state = sclp_activation_state_active;
1091 else
1092 sclp_activation_state = sclp_activation_state_inactive;
1093 spin_unlock_irqrestore(&sclp_lock, flags);
1094 return rc;
1095 }
1096
1097 EXPORT_SYMBOL(sclp_reactivate);
1098
1099 /* Handler for external interruption used during initialization. Modify
1100 * request state to done. */
sclp_check_handler(struct ext_code ext_code,unsigned int param32,unsigned long param64)1101 static void sclp_check_handler(struct ext_code ext_code,
1102 unsigned int param32, unsigned long param64)
1103 {
1104 u32 finished_sccb;
1105
1106 inc_irq_stat(IRQEXT_SCP);
1107 finished_sccb = param32 & 0xfffffff8;
1108 /* Is this the interrupt we are waiting for? */
1109 if (finished_sccb == 0)
1110 return;
1111 if (finished_sccb != __pa(sclp_init_sccb))
1112 panic("sclp: unsolicited interrupt for buffer at 0x%x\n",
1113 finished_sccb);
1114 spin_lock(&sclp_lock);
1115 if (sclp_running_state == sclp_running_state_running) {
1116 sclp_init_req.status = SCLP_REQ_DONE;
1117 sclp_running_state = sclp_running_state_idle;
1118 }
1119 spin_unlock(&sclp_lock);
1120 }
1121
1122 /* Initial init mask request timed out. Modify request state to failed. */
1123 static void
sclp_check_timeout(struct timer_list * unused)1124 sclp_check_timeout(struct timer_list *unused)
1125 {
1126 unsigned long flags;
1127
1128 spin_lock_irqsave(&sclp_lock, flags);
1129 if (sclp_running_state == sclp_running_state_running) {
1130 sclp_init_req.status = SCLP_REQ_FAILED;
1131 sclp_running_state = sclp_running_state_idle;
1132 }
1133 spin_unlock_irqrestore(&sclp_lock, flags);
1134 }
1135
1136 /* Perform a check of the SCLP interface. Return zero if the interface is
1137 * available and there are no pending requests from a previous instance.
1138 * Return non-zero otherwise. */
1139 static int
sclp_check_interface(void)1140 sclp_check_interface(void)
1141 {
1142 struct init_sccb *sccb;
1143 unsigned long flags;
1144 int retry;
1145 int rc;
1146
1147 spin_lock_irqsave(&sclp_lock, flags);
1148 /* Prepare init mask command */
1149 rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler);
1150 if (rc) {
1151 spin_unlock_irqrestore(&sclp_lock, flags);
1152 return rc;
1153 }
1154 for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) {
1155 __sclp_make_init_req(0, 0);
1156 sccb = (struct init_sccb *) sclp_init_req.sccb;
1157 rc = sclp_service_call_trace(sclp_init_req.command, sccb);
1158 if (rc == -EIO)
1159 break;
1160 sclp_init_req.status = SCLP_REQ_RUNNING;
1161 sclp_running_state = sclp_running_state_running;
1162 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ,
1163 sclp_check_timeout);
1164 spin_unlock_irqrestore(&sclp_lock, flags);
1165 /* Enable service-signal interruption - needs to happen
1166 * with IRQs enabled. */
1167 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
1168 /* Wait for signal from interrupt or timeout */
1169 sclp_sync_wait();
1170 /* Disable service-signal interruption - needs to happen
1171 * with IRQs enabled. */
1172 irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL);
1173 spin_lock_irqsave(&sclp_lock, flags);
1174 del_timer(&sclp_request_timer);
1175 rc = -EBUSY;
1176 if (sclp_init_req.status == SCLP_REQ_DONE) {
1177 if (sccb->header.response_code == 0x20) {
1178 rc = 0;
1179 break;
1180 } else if (sccb->header.response_code == 0x74f0) {
1181 if (!sclp_mask_compat_mode) {
1182 sclp_mask_compat_mode = true;
1183 retry = 0;
1184 }
1185 }
1186 }
1187 }
1188 unregister_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler);
1189 spin_unlock_irqrestore(&sclp_lock, flags);
1190 return rc;
1191 }
1192
1193 /* Reboot event handler. Reset send and receive mask to prevent pending SCLP
1194 * events from interfering with rebooted system. */
1195 static int
sclp_reboot_event(struct notifier_block * this,unsigned long event,void * ptr)1196 sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr)
1197 {
1198 sclp_deactivate();
1199 return NOTIFY_DONE;
1200 }
1201
1202 static struct notifier_block sclp_reboot_notifier = {
1203 .notifier_call = sclp_reboot_event
1204 };
1205
con_pages_show(struct device_driver * dev,char * buf)1206 static ssize_t con_pages_show(struct device_driver *dev, char *buf)
1207 {
1208 return sprintf(buf, "%i\n", sclp_console_pages);
1209 }
1210
1211 static DRIVER_ATTR_RO(con_pages);
1212
con_drop_show(struct device_driver * dev,char * buf)1213 static ssize_t con_drop_show(struct device_driver *dev, char *buf)
1214 {
1215 return sprintf(buf, "%i\n", sclp_console_drop);
1216 }
1217
1218 static DRIVER_ATTR_RO(con_drop);
1219
con_full_show(struct device_driver * dev,char * buf)1220 static ssize_t con_full_show(struct device_driver *dev, char *buf)
1221 {
1222 return sprintf(buf, "%lu\n", sclp_console_full);
1223 }
1224
1225 static DRIVER_ATTR_RO(con_full);
1226
1227 static struct attribute *sclp_drv_attrs[] = {
1228 &driver_attr_con_pages.attr,
1229 &driver_attr_con_drop.attr,
1230 &driver_attr_con_full.attr,
1231 NULL,
1232 };
1233 static struct attribute_group sclp_drv_attr_group = {
1234 .attrs = sclp_drv_attrs,
1235 };
1236 static const struct attribute_group *sclp_drv_attr_groups[] = {
1237 &sclp_drv_attr_group,
1238 NULL,
1239 };
1240
1241 static struct platform_driver sclp_pdrv = {
1242 .driver = {
1243 .name = "sclp",
1244 .groups = sclp_drv_attr_groups,
1245 },
1246 };
1247
1248 /* Initialize SCLP driver. Return zero if driver is operational, non-zero
1249 * otherwise. */
1250 static int
sclp_init(void)1251 sclp_init(void)
1252 {
1253 unsigned long flags;
1254 int rc = 0;
1255
1256 spin_lock_irqsave(&sclp_lock, flags);
1257 /* Check for previous or running initialization */
1258 if (sclp_init_state != sclp_init_state_uninitialized)
1259 goto fail_unlock;
1260 sclp_init_state = sclp_init_state_initializing;
1261 sclp_read_sccb = (void *) __get_free_page(GFP_ATOMIC | GFP_DMA);
1262 sclp_init_sccb = (void *) __get_free_page(GFP_ATOMIC | GFP_DMA);
1263 BUG_ON(!sclp_read_sccb || !sclp_init_sccb);
1264 /* Set up variables */
1265 list_add(&sclp_state_change_event.list, &sclp_reg_list);
1266 timer_setup(&sclp_request_timer, NULL, 0);
1267 timer_setup(&sclp_queue_timer, sclp_req_queue_timeout, 0);
1268 /* Check interface */
1269 spin_unlock_irqrestore(&sclp_lock, flags);
1270 rc = sclp_check_interface();
1271 spin_lock_irqsave(&sclp_lock, flags);
1272 if (rc)
1273 goto fail_init_state_uninitialized;
1274 /* Register reboot handler */
1275 rc = register_reboot_notifier(&sclp_reboot_notifier);
1276 if (rc)
1277 goto fail_init_state_uninitialized;
1278 /* Register interrupt handler */
1279 rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_interrupt_handler);
1280 if (rc)
1281 goto fail_unregister_reboot_notifier;
1282 sclp_init_state = sclp_init_state_initialized;
1283 spin_unlock_irqrestore(&sclp_lock, flags);
1284 /* Enable service-signal external interruption - needs to happen with
1285 * IRQs enabled. */
1286 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
1287 sclp_init_mask(1);
1288 return 0;
1289
1290 fail_unregister_reboot_notifier:
1291 unregister_reboot_notifier(&sclp_reboot_notifier);
1292 fail_init_state_uninitialized:
1293 sclp_init_state = sclp_init_state_uninitialized;
1294 free_page((unsigned long) sclp_read_sccb);
1295 free_page((unsigned long) sclp_init_sccb);
1296 fail_unlock:
1297 spin_unlock_irqrestore(&sclp_lock, flags);
1298 return rc;
1299 }
1300
sclp_initcall(void)1301 static __init int sclp_initcall(void)
1302 {
1303 int rc;
1304
1305 rc = platform_driver_register(&sclp_pdrv);
1306 if (rc)
1307 return rc;
1308
1309 return sclp_init();
1310 }
1311
1312 arch_initcall(sclp_initcall);
1313