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 bool sclp_console_drop = true;
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
sclpint_to_sccb(u32 sccb_int)79 static inline struct sccb_header *sclpint_to_sccb(u32 sccb_int)
80 {
81 if (sccb_int)
82 return __va(sccb_int);
83 return NULL;
84 }
85
sclp_trace(int prio,char * id,u32 a,u64 b,bool err)86 static inline void sclp_trace(int prio, char *id, u32 a, u64 b, bool err)
87 {
88 struct sclp_trace_entry e;
89
90 memset(&e, 0, sizeof(e));
91 strtomem(e.id, id);
92 e.a = a;
93 e.b = b;
94 debug_event(&sclp_debug, prio, &e, sizeof(e));
95 if (err)
96 debug_event(&sclp_debug_err, 0, &e, sizeof(e));
97 }
98
no_zeroes_len(void * data,int len)99 static inline int no_zeroes_len(void *data, int len)
100 {
101 char *d = data;
102
103 /* Minimize trace area usage by not tracing trailing zeroes. */
104 while (len > SCLP_TRACE_ENTRY_SIZE && d[len - 1] == 0)
105 len--;
106
107 return len;
108 }
109
sclp_trace_bin(int prio,void * d,int len,int errlen)110 static inline void sclp_trace_bin(int prio, void *d, int len, int errlen)
111 {
112 debug_event(&sclp_debug, prio, d, no_zeroes_len(d, len));
113 if (errlen)
114 debug_event(&sclp_debug_err, 0, d, no_zeroes_len(d, errlen));
115 }
116
abbrev_len(sclp_cmdw_t cmd,struct sccb_header * sccb)117 static inline int abbrev_len(sclp_cmdw_t cmd, struct sccb_header *sccb)
118 {
119 struct evbuf_header *evbuf = (struct evbuf_header *)(sccb + 1);
120 int len = sccb->length, limit = SCLP_TRACE_MAX_SIZE;
121
122 /* Full SCCB tracing if debug level is set to max. */
123 if (sclp_debug.level == DEBUG_MAX_LEVEL)
124 return len;
125
126 /* Minimal tracing for console writes. */
127 if (cmd == SCLP_CMDW_WRITE_EVENT_DATA &&
128 (evbuf->type == EVTYP_MSG || evbuf->type == EVTYP_VT220MSG))
129 limit = SCLP_TRACE_ENTRY_SIZE;
130
131 return min(len, limit);
132 }
133
sclp_trace_sccb(int prio,char * id,u32 a,u64 b,sclp_cmdw_t cmd,struct sccb_header * sccb,bool err)134 static inline void sclp_trace_sccb(int prio, char *id, u32 a, u64 b,
135 sclp_cmdw_t cmd, struct sccb_header *sccb,
136 bool err)
137 {
138 sclp_trace(prio, id, a, b, err);
139 if (sccb) {
140 sclp_trace_bin(prio + 1, sccb, abbrev_len(cmd, sccb),
141 err ? sccb->length : 0);
142 }
143 }
144
sclp_trace_evbuf(int prio,char * id,u32 a,u64 b,struct evbuf_header * evbuf,bool err)145 static inline void sclp_trace_evbuf(int prio, char *id, u32 a, u64 b,
146 struct evbuf_header *evbuf, bool err)
147 {
148 sclp_trace(prio, id, a, b, err);
149 sclp_trace_bin(prio + 1, evbuf,
150 min((int)evbuf->length, (int)SCLP_TRACE_EVENT_MAX_SIZE),
151 err ? evbuf->length : 0);
152 }
153
sclp_trace_req(int prio,char * id,struct sclp_req * req,bool err)154 static inline void sclp_trace_req(int prio, char *id, struct sclp_req *req,
155 bool err)
156 {
157 struct sccb_header *sccb = req->sccb;
158 union {
159 struct {
160 u16 status;
161 u16 response;
162 u16 timeout;
163 u16 start_count;
164 };
165 u64 b;
166 } summary;
167
168 summary.status = req->status;
169 summary.response = sccb ? sccb->response_code : 0;
170 summary.timeout = (u16)req->queue_timeout;
171 summary.start_count = (u16)req->start_count;
172
173 sclp_trace(prio, id, __pa(sccb), summary.b, err);
174 }
175
sclp_trace_register(int prio,char * id,u32 a,u64 b,struct sclp_register * reg)176 static inline void sclp_trace_register(int prio, char *id, u32 a, u64 b,
177 struct sclp_register *reg)
178 {
179 struct {
180 u64 receive;
181 u64 send;
182 } d;
183
184 d.receive = reg->receive_mask;
185 d.send = reg->send_mask;
186
187 sclp_trace(prio, id, a, b, false);
188 sclp_trace_bin(prio, &d, sizeof(d), 0);
189 }
190
sclp_setup_console_pages(char * str)191 static int __init sclp_setup_console_pages(char *str)
192 {
193 int pages, rc;
194
195 rc = kstrtoint(str, 0, &pages);
196 if (!rc && pages >= SCLP_CONSOLE_PAGES)
197 sclp_console_pages = pages;
198 return 1;
199 }
200
201 __setup("sclp_con_pages=", sclp_setup_console_pages);
202
sclp_setup_console_drop(char * str)203 static int __init sclp_setup_console_drop(char *str)
204 {
205 return kstrtobool(str, &sclp_console_drop) == 0;
206 }
207
208 __setup("sclp_con_drop=", sclp_setup_console_drop);
209
210 /* Timer for request retries. */
211 static struct timer_list sclp_request_timer;
212
213 /* Timer for queued requests. */
214 static struct timer_list sclp_queue_timer;
215
216 /* Internal state: is a request active at the sclp? */
217 static volatile enum sclp_running_state_t {
218 sclp_running_state_idle,
219 sclp_running_state_running,
220 sclp_running_state_reset_pending
221 } sclp_running_state = sclp_running_state_idle;
222
223 /* Internal state: is a read request pending? */
224 static volatile enum sclp_reading_state_t {
225 sclp_reading_state_idle,
226 sclp_reading_state_reading
227 } sclp_reading_state = sclp_reading_state_idle;
228
229 /* Internal state: is the driver currently serving requests? */
230 static volatile enum sclp_activation_state_t {
231 sclp_activation_state_active,
232 sclp_activation_state_deactivating,
233 sclp_activation_state_inactive,
234 sclp_activation_state_activating
235 } sclp_activation_state = sclp_activation_state_active;
236
237 /* Internal state: is an init mask request pending? */
238 static volatile enum sclp_mask_state_t {
239 sclp_mask_state_idle,
240 sclp_mask_state_initializing
241 } sclp_mask_state = sclp_mask_state_idle;
242
243 /* Maximum retry counts */
244 #define SCLP_INIT_RETRY 3
245 #define SCLP_MASK_RETRY 3
246
247 /* Timeout intervals in seconds.*/
248 #define SCLP_BUSY_INTERVAL 10
249 #define SCLP_RETRY_INTERVAL 30
250
251 static void sclp_request_timeout(bool force_restart);
252 static void sclp_process_queue(void);
253 static void __sclp_make_read_req(void);
254 static int sclp_init_mask(int calculate);
255
256 static void
__sclp_queue_read_req(void)257 __sclp_queue_read_req(void)
258 {
259 if (sclp_reading_state == sclp_reading_state_idle) {
260 sclp_reading_state = sclp_reading_state_reading;
261 __sclp_make_read_req();
262 /* Add request to head of queue */
263 list_add(&sclp_read_req.list, &sclp_req_queue);
264 }
265 }
266
267 /* Set up request retry timer. Called while sclp_lock is locked. */
268 static inline void
__sclp_set_request_timer(unsigned long time,void (* cb)(struct timer_list *))269 __sclp_set_request_timer(unsigned long time, void (*cb)(struct timer_list *))
270 {
271 del_timer(&sclp_request_timer);
272 sclp_request_timer.function = cb;
273 sclp_request_timer.expires = jiffies + time;
274 add_timer(&sclp_request_timer);
275 }
276
sclp_request_timeout_restart(struct timer_list * unused)277 static void sclp_request_timeout_restart(struct timer_list *unused)
278 {
279 sclp_request_timeout(true);
280 }
281
sclp_request_timeout_normal(struct timer_list * unused)282 static void sclp_request_timeout_normal(struct timer_list *unused)
283 {
284 sclp_request_timeout(false);
285 }
286
287 /* Request timeout handler. Restart the request queue. If force_restart,
288 * force restart of running request. */
sclp_request_timeout(bool force_restart)289 static void sclp_request_timeout(bool force_restart)
290 {
291 unsigned long flags;
292
293 /* TMO: A timeout occurred (a=force_restart) */
294 sclp_trace(2, "TMO", force_restart, 0, true);
295
296 spin_lock_irqsave(&sclp_lock, flags);
297 if (force_restart) {
298 if (sclp_running_state == sclp_running_state_running) {
299 /* Break running state and queue NOP read event request
300 * to get a defined interface state. */
301 __sclp_queue_read_req();
302 sclp_running_state = sclp_running_state_idle;
303 }
304 } else {
305 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ,
306 sclp_request_timeout_normal);
307 }
308 spin_unlock_irqrestore(&sclp_lock, flags);
309 sclp_process_queue();
310 }
311
312 /*
313 * Returns the expire value in jiffies of the next pending request timeout,
314 * if any. Needs to be called with sclp_lock.
315 */
__sclp_req_queue_find_next_timeout(void)316 static unsigned long __sclp_req_queue_find_next_timeout(void)
317 {
318 unsigned long expires_next = 0;
319 struct sclp_req *req;
320
321 list_for_each_entry(req, &sclp_req_queue, list) {
322 if (!req->queue_expires)
323 continue;
324 if (!expires_next ||
325 (time_before(req->queue_expires, expires_next)))
326 expires_next = req->queue_expires;
327 }
328 return expires_next;
329 }
330
331 /*
332 * Returns expired request, if any, and removes it from the list.
333 */
__sclp_req_queue_remove_expired_req(void)334 static struct sclp_req *__sclp_req_queue_remove_expired_req(void)
335 {
336 unsigned long flags, now;
337 struct sclp_req *req;
338
339 spin_lock_irqsave(&sclp_lock, flags);
340 now = jiffies;
341 /* Don't need list_for_each_safe because we break out after list_del */
342 list_for_each_entry(req, &sclp_req_queue, list) {
343 if (!req->queue_expires)
344 continue;
345 if (time_before_eq(req->queue_expires, now)) {
346 if (req->status == SCLP_REQ_QUEUED) {
347 req->status = SCLP_REQ_QUEUED_TIMEOUT;
348 list_del(&req->list);
349 goto out;
350 }
351 }
352 }
353 req = NULL;
354 out:
355 spin_unlock_irqrestore(&sclp_lock, flags);
356 return req;
357 }
358
359 /*
360 * Timeout handler for queued requests. Removes request from list and
361 * invokes callback. This timer can be set per request in situations where
362 * waiting too long would be harmful to the system, e.g. during SE reboot.
363 */
sclp_req_queue_timeout(struct timer_list * unused)364 static void sclp_req_queue_timeout(struct timer_list *unused)
365 {
366 unsigned long flags, expires_next;
367 struct sclp_req *req;
368
369 do {
370 req = __sclp_req_queue_remove_expired_req();
371
372 if (req) {
373 /* RQTM: Request timed out (a=sccb, b=summary) */
374 sclp_trace_req(2, "RQTM", req, true);
375 }
376
377 if (req && req->callback)
378 req->callback(req, req->callback_data);
379 } while (req);
380
381 spin_lock_irqsave(&sclp_lock, flags);
382 expires_next = __sclp_req_queue_find_next_timeout();
383 if (expires_next)
384 mod_timer(&sclp_queue_timer, expires_next);
385 spin_unlock_irqrestore(&sclp_lock, flags);
386 }
387
sclp_service_call_trace(sclp_cmdw_t command,void * sccb)388 static int sclp_service_call_trace(sclp_cmdw_t command, void *sccb)
389 {
390 static u64 srvc_count;
391 int rc;
392
393 /* SRV1: Service call about to be issued (a=command, b=sccb address) */
394 sclp_trace_sccb(0, "SRV1", command, (u64)sccb, command, sccb, false);
395
396 rc = sclp_service_call(command, sccb);
397
398 /* SRV2: Service call was issued (a=rc, b=SRVC sequence number) */
399 sclp_trace(0, "SRV2", -rc, ++srvc_count, rc != 0);
400
401 if (rc == 0)
402 active_cmd = command;
403
404 return rc;
405 }
406
407 /* Try to start a request. Return zero if the request was successfully
408 * started or if it will be started at a later time. Return non-zero otherwise.
409 * Called while sclp_lock is locked. */
410 static int
__sclp_start_request(struct sclp_req * req)411 __sclp_start_request(struct sclp_req *req)
412 {
413 int rc;
414
415 if (sclp_running_state != sclp_running_state_idle)
416 return 0;
417 del_timer(&sclp_request_timer);
418 rc = sclp_service_call_trace(req->command, req->sccb);
419 req->start_count++;
420
421 if (rc == 0) {
422 /* Successfully started request */
423 req->status = SCLP_REQ_RUNNING;
424 sclp_running_state = sclp_running_state_running;
425 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ,
426 sclp_request_timeout_restart);
427 return 0;
428 } else if (rc == -EBUSY) {
429 /* Try again later */
430 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ,
431 sclp_request_timeout_normal);
432 return 0;
433 }
434 /* Request failed */
435 req->status = SCLP_REQ_FAILED;
436 return rc;
437 }
438
439 /* Try to start queued requests. */
440 static void
sclp_process_queue(void)441 sclp_process_queue(void)
442 {
443 struct sclp_req *req;
444 int rc;
445 unsigned long flags;
446
447 spin_lock_irqsave(&sclp_lock, flags);
448 if (sclp_running_state != sclp_running_state_idle) {
449 spin_unlock_irqrestore(&sclp_lock, flags);
450 return;
451 }
452 del_timer(&sclp_request_timer);
453 while (!list_empty(&sclp_req_queue)) {
454 req = list_entry(sclp_req_queue.next, struct sclp_req, list);
455 rc = __sclp_start_request(req);
456 if (rc == 0)
457 break;
458 /* Request failed */
459 if (req->start_count > 1) {
460 /* Cannot abort already submitted request - could still
461 * be active at the SCLP */
462 __sclp_set_request_timer(SCLP_BUSY_INTERVAL * HZ,
463 sclp_request_timeout_normal);
464 break;
465 }
466 /* Post-processing for aborted request */
467 list_del(&req->list);
468
469 /* RQAB: Request aborted (a=sccb, b=summary) */
470 sclp_trace_req(2, "RQAB", req, true);
471
472 if (req->callback) {
473 spin_unlock_irqrestore(&sclp_lock, flags);
474 req->callback(req, req->callback_data);
475 spin_lock_irqsave(&sclp_lock, flags);
476 }
477 }
478 spin_unlock_irqrestore(&sclp_lock, flags);
479 }
480
__sclp_can_add_request(struct sclp_req * req)481 static int __sclp_can_add_request(struct sclp_req *req)
482 {
483 if (req == &sclp_init_req)
484 return 1;
485 if (sclp_init_state != sclp_init_state_initialized)
486 return 0;
487 if (sclp_activation_state != sclp_activation_state_active)
488 return 0;
489 return 1;
490 }
491
492 /* Queue a new request. Return zero on success, non-zero otherwise. */
493 int
sclp_add_request(struct sclp_req * req)494 sclp_add_request(struct sclp_req *req)
495 {
496 unsigned long flags;
497 int rc;
498
499 spin_lock_irqsave(&sclp_lock, flags);
500 if (!__sclp_can_add_request(req)) {
501 spin_unlock_irqrestore(&sclp_lock, flags);
502 return -EIO;
503 }
504
505 /* RQAD: Request was added (a=sccb, b=caller) */
506 sclp_trace(2, "RQAD", __pa(req->sccb), _RET_IP_, false);
507
508 req->status = SCLP_REQ_QUEUED;
509 req->start_count = 0;
510 list_add_tail(&req->list, &sclp_req_queue);
511 rc = 0;
512 if (req->queue_timeout) {
513 req->queue_expires = jiffies + req->queue_timeout * HZ;
514 if (!timer_pending(&sclp_queue_timer) ||
515 time_after(sclp_queue_timer.expires, req->queue_expires))
516 mod_timer(&sclp_queue_timer, req->queue_expires);
517 } else
518 req->queue_expires = 0;
519 /* Start if request is first in list */
520 if (sclp_running_state == sclp_running_state_idle &&
521 req->list.prev == &sclp_req_queue) {
522 rc = __sclp_start_request(req);
523 if (rc)
524 list_del(&req->list);
525 }
526 spin_unlock_irqrestore(&sclp_lock, flags);
527 return rc;
528 }
529
530 EXPORT_SYMBOL(sclp_add_request);
531
532 /* Dispatch events found in request buffer to registered listeners. Return 0
533 * if all events were dispatched, non-zero otherwise. */
534 static int
sclp_dispatch_evbufs(struct sccb_header * sccb)535 sclp_dispatch_evbufs(struct sccb_header *sccb)
536 {
537 unsigned long flags;
538 struct evbuf_header *evbuf;
539 struct list_head *l;
540 struct sclp_register *reg;
541 int offset;
542 int rc;
543
544 spin_lock_irqsave(&sclp_lock, flags);
545 rc = 0;
546 for (offset = sizeof(struct sccb_header); offset < sccb->length;
547 offset += evbuf->length) {
548 evbuf = (struct evbuf_header *) ((addr_t) sccb + offset);
549 /* Check for malformed hardware response */
550 if (evbuf->length == 0)
551 break;
552 /* Search for event handler */
553 reg = NULL;
554 list_for_each(l, &sclp_reg_list) {
555 reg = list_entry(l, struct sclp_register, list);
556 if (reg->receive_mask & SCLP_EVTYP_MASK(evbuf->type))
557 break;
558 else
559 reg = NULL;
560 }
561
562 /* EVNT: Event callback (b=receiver) */
563 sclp_trace_evbuf(2, "EVNT", 0, reg ? (u64)reg->receiver_fn : 0,
564 evbuf, !reg);
565
566 if (reg && reg->receiver_fn) {
567 spin_unlock_irqrestore(&sclp_lock, flags);
568 reg->receiver_fn(evbuf);
569 spin_lock_irqsave(&sclp_lock, flags);
570 } else if (reg == NULL)
571 rc = -EOPNOTSUPP;
572 }
573 spin_unlock_irqrestore(&sclp_lock, flags);
574 return rc;
575 }
576
577 /* Read event data request callback. */
578 static void
sclp_read_cb(struct sclp_req * req,void * data)579 sclp_read_cb(struct sclp_req *req, void *data)
580 {
581 unsigned long flags;
582 struct sccb_header *sccb;
583
584 sccb = (struct sccb_header *) req->sccb;
585 if (req->status == SCLP_REQ_DONE && (sccb->response_code == 0x20 ||
586 sccb->response_code == 0x220))
587 sclp_dispatch_evbufs(sccb);
588 spin_lock_irqsave(&sclp_lock, flags);
589 sclp_reading_state = sclp_reading_state_idle;
590 spin_unlock_irqrestore(&sclp_lock, flags);
591 }
592
593 /* Prepare read event data request. Called while sclp_lock is locked. */
__sclp_make_read_req(void)594 static void __sclp_make_read_req(void)
595 {
596 struct sccb_header *sccb;
597
598 sccb = (struct sccb_header *) sclp_read_sccb;
599 clear_page(sccb);
600 memset(&sclp_read_req, 0, sizeof(struct sclp_req));
601 sclp_read_req.command = SCLP_CMDW_READ_EVENT_DATA;
602 sclp_read_req.status = SCLP_REQ_QUEUED;
603 sclp_read_req.start_count = 0;
604 sclp_read_req.callback = sclp_read_cb;
605 sclp_read_req.sccb = sccb;
606 sccb->length = PAGE_SIZE;
607 sccb->function_code = 0;
608 sccb->control_mask[2] = 0x80;
609 }
610
611 /* Search request list for request with matching sccb. Return request if found,
612 * NULL otherwise. Called while sclp_lock is locked. */
613 static inline struct sclp_req *
__sclp_find_req(u32 sccb)614 __sclp_find_req(u32 sccb)
615 {
616 struct list_head *l;
617 struct sclp_req *req;
618
619 list_for_each(l, &sclp_req_queue) {
620 req = list_entry(l, struct sclp_req, list);
621 if (sccb == __pa(req->sccb))
622 return req;
623 }
624 return NULL;
625 }
626
ok_response(u32 sccb_int,sclp_cmdw_t cmd)627 static bool ok_response(u32 sccb_int, sclp_cmdw_t cmd)
628 {
629 struct sccb_header *sccb = sclpint_to_sccb(sccb_int);
630 struct evbuf_header *evbuf;
631 u16 response;
632
633 if (!sccb)
634 return true;
635
636 /* Check SCCB response. */
637 response = sccb->response_code & 0xff;
638 if (response != 0x10 && response != 0x20)
639 return false;
640
641 /* Check event-processed flag on outgoing events. */
642 if (cmd == SCLP_CMDW_WRITE_EVENT_DATA) {
643 evbuf = (struct evbuf_header *)(sccb + 1);
644 if (!(evbuf->flags & 0x80))
645 return false;
646 }
647
648 return true;
649 }
650
651 /* Handler for external interruption. Perform request post-processing.
652 * Prepare read event data request if necessary. Start processing of next
653 * request on queue. */
sclp_interrupt_handler(struct ext_code ext_code,unsigned int param32,unsigned long param64)654 static void sclp_interrupt_handler(struct ext_code ext_code,
655 unsigned int param32, unsigned long param64)
656 {
657 struct sclp_req *req;
658 u32 finished_sccb;
659 u32 evbuf_pending;
660
661 inc_irq_stat(IRQEXT_SCP);
662 spin_lock(&sclp_lock);
663 finished_sccb = param32 & 0xfffffff8;
664 evbuf_pending = param32 & 0x3;
665
666 /* INT: Interrupt received (a=intparm, b=cmd) */
667 sclp_trace_sccb(0, "INT", param32, active_cmd, active_cmd,
668 sclpint_to_sccb(finished_sccb),
669 !ok_response(finished_sccb, active_cmd));
670
671 if (finished_sccb) {
672 del_timer(&sclp_request_timer);
673 sclp_running_state = sclp_running_state_reset_pending;
674 req = __sclp_find_req(finished_sccb);
675 if (req) {
676 /* Request post-processing */
677 list_del(&req->list);
678 req->status = SCLP_REQ_DONE;
679
680 /* RQOK: Request success (a=sccb, b=summary) */
681 sclp_trace_req(2, "RQOK", req, false);
682
683 if (req->callback) {
684 spin_unlock(&sclp_lock);
685 req->callback(req, req->callback_data);
686 spin_lock(&sclp_lock);
687 }
688 } else {
689 /* UNEX: Unexpected SCCB completion (a=sccb address) */
690 sclp_trace(0, "UNEX", finished_sccb, 0, true);
691 }
692 sclp_running_state = sclp_running_state_idle;
693 active_cmd = 0;
694 }
695 if (evbuf_pending &&
696 sclp_activation_state == sclp_activation_state_active)
697 __sclp_queue_read_req();
698 spin_unlock(&sclp_lock);
699 sclp_process_queue();
700 }
701
702 /* Convert interval in jiffies to TOD ticks. */
703 static inline u64
sclp_tod_from_jiffies(unsigned long jiffies)704 sclp_tod_from_jiffies(unsigned long jiffies)
705 {
706 return (u64) (jiffies / HZ) << 32;
707 }
708
709 /* Wait until a currently running request finished. Note: while this function
710 * is running, no timers are served on the calling CPU. */
711 void
sclp_sync_wait(void)712 sclp_sync_wait(void)
713 {
714 unsigned long long old_tick;
715 struct ctlreg cr0, cr0_sync;
716 unsigned long flags;
717 static u64 sync_count;
718 u64 timeout;
719 int irq_context;
720
721 /* SYN1: Synchronous wait start (a=runstate, b=sync count) */
722 sclp_trace(4, "SYN1", sclp_running_state, ++sync_count, false);
723
724 /* We'll be disabling timer interrupts, so we need a custom timeout
725 * mechanism */
726 timeout = 0;
727 if (timer_pending(&sclp_request_timer)) {
728 /* Get timeout TOD value */
729 timeout = get_tod_clock_fast() +
730 sclp_tod_from_jiffies(sclp_request_timer.expires -
731 jiffies);
732 }
733 local_irq_save(flags);
734 /* Prevent bottom half from executing once we force interrupts open */
735 irq_context = in_interrupt();
736 if (!irq_context)
737 local_bh_disable();
738 /* Enable service-signal interruption, disable timer interrupts */
739 old_tick = local_tick_disable();
740 trace_hardirqs_on();
741 local_ctl_store(0, &cr0);
742 cr0_sync.val = cr0.val & ~CR0_IRQ_SUBCLASS_MASK;
743 cr0_sync.val |= 1UL << (63 - 54);
744 local_ctl_load(0, &cr0_sync);
745 arch_local_irq_enable_external();
746 /* Loop until driver state indicates finished request */
747 while (sclp_running_state != sclp_running_state_idle) {
748 /* Check for expired request timer */
749 if (get_tod_clock_fast() > timeout && del_timer(&sclp_request_timer))
750 sclp_request_timer.function(&sclp_request_timer);
751 cpu_relax();
752 }
753 local_irq_disable();
754 local_ctl_load(0, &cr0);
755 if (!irq_context)
756 _local_bh_enable();
757 local_tick_enable(old_tick);
758 local_irq_restore(flags);
759
760 /* SYN2: Synchronous wait end (a=runstate, b=sync_count) */
761 sclp_trace(4, "SYN2", sclp_running_state, sync_count, false);
762 }
763 EXPORT_SYMBOL(sclp_sync_wait);
764
765 /* Dispatch changes in send and receive mask to registered listeners. */
766 static void
sclp_dispatch_state_change(void)767 sclp_dispatch_state_change(void)
768 {
769 struct list_head *l;
770 struct sclp_register *reg;
771 unsigned long flags;
772 sccb_mask_t receive_mask;
773 sccb_mask_t send_mask;
774
775 do {
776 spin_lock_irqsave(&sclp_lock, flags);
777 reg = NULL;
778 list_for_each(l, &sclp_reg_list) {
779 reg = list_entry(l, struct sclp_register, list);
780 receive_mask = reg->send_mask & sclp_receive_mask;
781 send_mask = reg->receive_mask & sclp_send_mask;
782 if (reg->sclp_receive_mask != receive_mask ||
783 reg->sclp_send_mask != send_mask) {
784 reg->sclp_receive_mask = receive_mask;
785 reg->sclp_send_mask = send_mask;
786 break;
787 } else
788 reg = NULL;
789 }
790 spin_unlock_irqrestore(&sclp_lock, flags);
791 if (reg && reg->state_change_fn) {
792 /* STCG: State-change callback (b=callback) */
793 sclp_trace(2, "STCG", 0, (u64)reg->state_change_fn,
794 false);
795
796 reg->state_change_fn(reg);
797 }
798 } while (reg);
799 }
800
801 struct sclp_statechangebuf {
802 struct evbuf_header header;
803 u8 validity_sclp_active_facility_mask : 1;
804 u8 validity_sclp_receive_mask : 1;
805 u8 validity_sclp_send_mask : 1;
806 u8 validity_read_data_function_mask : 1;
807 u16 _zeros : 12;
808 u16 mask_length;
809 u64 sclp_active_facility_mask;
810 u8 masks[2 * 1021 + 4]; /* variable length */
811 /*
812 * u8 sclp_receive_mask[mask_length];
813 * u8 sclp_send_mask[mask_length];
814 * u32 read_data_function_mask;
815 */
816 } __attribute__((packed));
817
818
819 /* State change event callback. Inform listeners of changes. */
820 static void
sclp_state_change_cb(struct evbuf_header * evbuf)821 sclp_state_change_cb(struct evbuf_header *evbuf)
822 {
823 unsigned long flags;
824 struct sclp_statechangebuf *scbuf;
825
826 BUILD_BUG_ON(sizeof(struct sclp_statechangebuf) > PAGE_SIZE);
827
828 scbuf = (struct sclp_statechangebuf *) evbuf;
829 spin_lock_irqsave(&sclp_lock, flags);
830 if (scbuf->validity_sclp_receive_mask)
831 sclp_receive_mask = sccb_get_recv_mask(scbuf);
832 if (scbuf->validity_sclp_send_mask)
833 sclp_send_mask = sccb_get_send_mask(scbuf);
834 spin_unlock_irqrestore(&sclp_lock, flags);
835 if (scbuf->validity_sclp_active_facility_mask)
836 sclp.facilities = scbuf->sclp_active_facility_mask;
837 sclp_dispatch_state_change();
838 }
839
840 static struct sclp_register sclp_state_change_event = {
841 .receive_mask = EVTYP_STATECHANGE_MASK,
842 .receiver_fn = sclp_state_change_cb
843 };
844
845 /* Calculate receive and send mask of currently registered listeners.
846 * Called while sclp_lock is locked. */
847 static inline void
__sclp_get_mask(sccb_mask_t * receive_mask,sccb_mask_t * send_mask)848 __sclp_get_mask(sccb_mask_t *receive_mask, sccb_mask_t *send_mask)
849 {
850 struct list_head *l;
851 struct sclp_register *t;
852
853 *receive_mask = 0;
854 *send_mask = 0;
855 list_for_each(l, &sclp_reg_list) {
856 t = list_entry(l, struct sclp_register, list);
857 *receive_mask |= t->receive_mask;
858 *send_mask |= t->send_mask;
859 }
860 }
861
862 /* Register event listener. Return 0 on success, non-zero otherwise. */
863 int
sclp_register(struct sclp_register * reg)864 sclp_register(struct sclp_register *reg)
865 {
866 unsigned long flags;
867 sccb_mask_t receive_mask;
868 sccb_mask_t send_mask;
869 int rc;
870
871 /* REG: Event listener registered (b=caller) */
872 sclp_trace_register(2, "REG", 0, _RET_IP_, reg);
873
874 rc = sclp_init();
875 if (rc)
876 return rc;
877 spin_lock_irqsave(&sclp_lock, flags);
878 /* Check event mask for collisions */
879 __sclp_get_mask(&receive_mask, &send_mask);
880 if (reg->receive_mask & receive_mask || reg->send_mask & send_mask) {
881 spin_unlock_irqrestore(&sclp_lock, flags);
882 return -EBUSY;
883 }
884 /* Trigger initial state change callback */
885 reg->sclp_receive_mask = 0;
886 reg->sclp_send_mask = 0;
887 list_add(®->list, &sclp_reg_list);
888 spin_unlock_irqrestore(&sclp_lock, flags);
889 rc = sclp_init_mask(1);
890 if (rc) {
891 spin_lock_irqsave(&sclp_lock, flags);
892 list_del(®->list);
893 spin_unlock_irqrestore(&sclp_lock, flags);
894 }
895 return rc;
896 }
897
898 EXPORT_SYMBOL(sclp_register);
899
900 /* Unregister event listener. */
901 void
sclp_unregister(struct sclp_register * reg)902 sclp_unregister(struct sclp_register *reg)
903 {
904 unsigned long flags;
905
906 /* UREG: Event listener unregistered (b=caller) */
907 sclp_trace_register(2, "UREG", 0, _RET_IP_, reg);
908
909 spin_lock_irqsave(&sclp_lock, flags);
910 list_del(®->list);
911 spin_unlock_irqrestore(&sclp_lock, flags);
912 sclp_init_mask(1);
913 }
914
915 EXPORT_SYMBOL(sclp_unregister);
916
917 /* Remove event buffers which are marked processed. Return the number of
918 * remaining event buffers. */
919 int
sclp_remove_processed(struct sccb_header * sccb)920 sclp_remove_processed(struct sccb_header *sccb)
921 {
922 struct evbuf_header *evbuf;
923 int unprocessed;
924 u16 remaining;
925
926 evbuf = (struct evbuf_header *) (sccb + 1);
927 unprocessed = 0;
928 remaining = sccb->length - sizeof(struct sccb_header);
929 while (remaining > 0) {
930 remaining -= evbuf->length;
931 if (evbuf->flags & 0x80) {
932 sccb->length -= evbuf->length;
933 memcpy(evbuf, (void *) ((addr_t) evbuf + evbuf->length),
934 remaining);
935 } else {
936 unprocessed++;
937 evbuf = (struct evbuf_header *)
938 ((addr_t) evbuf + evbuf->length);
939 }
940 }
941 return unprocessed;
942 }
943
944 EXPORT_SYMBOL(sclp_remove_processed);
945
946 /* Prepare init mask request. Called while sclp_lock is locked. */
947 static inline void
__sclp_make_init_req(sccb_mask_t receive_mask,sccb_mask_t send_mask)948 __sclp_make_init_req(sccb_mask_t receive_mask, sccb_mask_t send_mask)
949 {
950 struct init_sccb *sccb = sclp_init_sccb;
951
952 clear_page(sccb);
953 memset(&sclp_init_req, 0, sizeof(struct sclp_req));
954 sclp_init_req.command = SCLP_CMDW_WRITE_EVENT_MASK;
955 sclp_init_req.status = SCLP_REQ_FILLED;
956 sclp_init_req.start_count = 0;
957 sclp_init_req.callback = NULL;
958 sclp_init_req.callback_data = NULL;
959 sclp_init_req.sccb = sccb;
960 sccb->header.length = sizeof(*sccb);
961 if (sclp_mask_compat_mode)
962 sccb->mask_length = SCLP_MASK_SIZE_COMPAT;
963 else
964 sccb->mask_length = sizeof(sccb_mask_t);
965 sccb_set_recv_mask(sccb, receive_mask);
966 sccb_set_send_mask(sccb, send_mask);
967 sccb_set_sclp_recv_mask(sccb, 0);
968 sccb_set_sclp_send_mask(sccb, 0);
969 }
970
971 /* Start init mask request. If calculate is non-zero, calculate the mask as
972 * requested by registered listeners. Use zero mask otherwise. Return 0 on
973 * success, non-zero otherwise. */
974 static int
sclp_init_mask(int calculate)975 sclp_init_mask(int calculate)
976 {
977 unsigned long flags;
978 struct init_sccb *sccb = sclp_init_sccb;
979 sccb_mask_t receive_mask;
980 sccb_mask_t send_mask;
981 int retry;
982 int rc;
983 unsigned long wait;
984
985 spin_lock_irqsave(&sclp_lock, flags);
986 /* Check if interface is in appropriate state */
987 if (sclp_mask_state != sclp_mask_state_idle) {
988 spin_unlock_irqrestore(&sclp_lock, flags);
989 return -EBUSY;
990 }
991 if (sclp_activation_state == sclp_activation_state_inactive) {
992 spin_unlock_irqrestore(&sclp_lock, flags);
993 return -EINVAL;
994 }
995 sclp_mask_state = sclp_mask_state_initializing;
996 /* Determine mask */
997 if (calculate)
998 __sclp_get_mask(&receive_mask, &send_mask);
999 else {
1000 receive_mask = 0;
1001 send_mask = 0;
1002 }
1003 rc = -EIO;
1004 for (retry = 0; retry <= SCLP_MASK_RETRY; retry++) {
1005 /* Prepare request */
1006 __sclp_make_init_req(receive_mask, send_mask);
1007 spin_unlock_irqrestore(&sclp_lock, flags);
1008 if (sclp_add_request(&sclp_init_req)) {
1009 /* Try again later */
1010 wait = jiffies + SCLP_BUSY_INTERVAL * HZ;
1011 while (time_before(jiffies, wait))
1012 sclp_sync_wait();
1013 spin_lock_irqsave(&sclp_lock, flags);
1014 continue;
1015 }
1016 while (sclp_init_req.status != SCLP_REQ_DONE &&
1017 sclp_init_req.status != SCLP_REQ_FAILED)
1018 sclp_sync_wait();
1019 spin_lock_irqsave(&sclp_lock, flags);
1020 if (sclp_init_req.status == SCLP_REQ_DONE &&
1021 sccb->header.response_code == 0x20) {
1022 /* Successful request */
1023 if (calculate) {
1024 sclp_receive_mask = sccb_get_sclp_recv_mask(sccb);
1025 sclp_send_mask = sccb_get_sclp_send_mask(sccb);
1026 } else {
1027 sclp_receive_mask = 0;
1028 sclp_send_mask = 0;
1029 }
1030 spin_unlock_irqrestore(&sclp_lock, flags);
1031 sclp_dispatch_state_change();
1032 spin_lock_irqsave(&sclp_lock, flags);
1033 rc = 0;
1034 break;
1035 }
1036 }
1037 sclp_mask_state = sclp_mask_state_idle;
1038 spin_unlock_irqrestore(&sclp_lock, flags);
1039 return rc;
1040 }
1041
1042 /* Deactivate SCLP interface. On success, new requests will be rejected,
1043 * events will no longer be dispatched. Return 0 on success, non-zero
1044 * otherwise. */
1045 int
sclp_deactivate(void)1046 sclp_deactivate(void)
1047 {
1048 unsigned long flags;
1049 int rc;
1050
1051 spin_lock_irqsave(&sclp_lock, flags);
1052 /* Deactivate can only be called when active */
1053 if (sclp_activation_state != sclp_activation_state_active) {
1054 spin_unlock_irqrestore(&sclp_lock, flags);
1055 return -EINVAL;
1056 }
1057 sclp_activation_state = sclp_activation_state_deactivating;
1058 spin_unlock_irqrestore(&sclp_lock, flags);
1059 rc = sclp_init_mask(0);
1060 spin_lock_irqsave(&sclp_lock, flags);
1061 if (rc == 0)
1062 sclp_activation_state = sclp_activation_state_inactive;
1063 else
1064 sclp_activation_state = sclp_activation_state_active;
1065 spin_unlock_irqrestore(&sclp_lock, flags);
1066 return rc;
1067 }
1068
1069 EXPORT_SYMBOL(sclp_deactivate);
1070
1071 /* Reactivate SCLP interface after sclp_deactivate. On success, new
1072 * requests will be accepted, events will be dispatched again. Return 0 on
1073 * success, non-zero otherwise. */
1074 int
sclp_reactivate(void)1075 sclp_reactivate(void)
1076 {
1077 unsigned long flags;
1078 int rc;
1079
1080 spin_lock_irqsave(&sclp_lock, flags);
1081 /* Reactivate can only be called when inactive */
1082 if (sclp_activation_state != sclp_activation_state_inactive) {
1083 spin_unlock_irqrestore(&sclp_lock, flags);
1084 return -EINVAL;
1085 }
1086 sclp_activation_state = sclp_activation_state_activating;
1087 spin_unlock_irqrestore(&sclp_lock, flags);
1088 rc = sclp_init_mask(1);
1089 spin_lock_irqsave(&sclp_lock, flags);
1090 if (rc == 0)
1091 sclp_activation_state = sclp_activation_state_active;
1092 else
1093 sclp_activation_state = sclp_activation_state_inactive;
1094 spin_unlock_irqrestore(&sclp_lock, flags);
1095 return rc;
1096 }
1097
1098 EXPORT_SYMBOL(sclp_reactivate);
1099
1100 /* Handler for external interruption used during initialization. Modify
1101 * request state to done. */
sclp_check_handler(struct ext_code ext_code,unsigned int param32,unsigned long param64)1102 static void sclp_check_handler(struct ext_code ext_code,
1103 unsigned int param32, unsigned long param64)
1104 {
1105 u32 finished_sccb;
1106
1107 inc_irq_stat(IRQEXT_SCP);
1108 finished_sccb = param32 & 0xfffffff8;
1109 /* Is this the interrupt we are waiting for? */
1110 if (finished_sccb == 0)
1111 return;
1112 if (finished_sccb != __pa(sclp_init_sccb))
1113 panic("sclp: unsolicited interrupt for buffer at 0x%x\n",
1114 finished_sccb);
1115 spin_lock(&sclp_lock);
1116 if (sclp_running_state == sclp_running_state_running) {
1117 sclp_init_req.status = SCLP_REQ_DONE;
1118 sclp_running_state = sclp_running_state_idle;
1119 }
1120 spin_unlock(&sclp_lock);
1121 }
1122
1123 /* Initial init mask request timed out. Modify request state to failed. */
1124 static void
sclp_check_timeout(struct timer_list * unused)1125 sclp_check_timeout(struct timer_list *unused)
1126 {
1127 unsigned long flags;
1128
1129 spin_lock_irqsave(&sclp_lock, flags);
1130 if (sclp_running_state == sclp_running_state_running) {
1131 sclp_init_req.status = SCLP_REQ_FAILED;
1132 sclp_running_state = sclp_running_state_idle;
1133 }
1134 spin_unlock_irqrestore(&sclp_lock, flags);
1135 }
1136
1137 /* Perform a check of the SCLP interface. Return zero if the interface is
1138 * available and there are no pending requests from a previous instance.
1139 * Return non-zero otherwise. */
1140 static int
sclp_check_interface(void)1141 sclp_check_interface(void)
1142 {
1143 struct init_sccb *sccb;
1144 unsigned long flags;
1145 int retry;
1146 int rc;
1147
1148 spin_lock_irqsave(&sclp_lock, flags);
1149 /* Prepare init mask command */
1150 rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler);
1151 if (rc) {
1152 spin_unlock_irqrestore(&sclp_lock, flags);
1153 return rc;
1154 }
1155 for (retry = 0; retry <= SCLP_INIT_RETRY; retry++) {
1156 __sclp_make_init_req(0, 0);
1157 sccb = (struct init_sccb *) sclp_init_req.sccb;
1158 rc = sclp_service_call_trace(sclp_init_req.command, sccb);
1159 if (rc == -EIO)
1160 break;
1161 sclp_init_req.status = SCLP_REQ_RUNNING;
1162 sclp_running_state = sclp_running_state_running;
1163 __sclp_set_request_timer(SCLP_RETRY_INTERVAL * HZ,
1164 sclp_check_timeout);
1165 spin_unlock_irqrestore(&sclp_lock, flags);
1166 /* Enable service-signal interruption - needs to happen
1167 * with IRQs enabled. */
1168 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
1169 /* Wait for signal from interrupt or timeout */
1170 sclp_sync_wait();
1171 /* Disable service-signal interruption - needs to happen
1172 * with IRQs enabled. */
1173 irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL);
1174 spin_lock_irqsave(&sclp_lock, flags);
1175 del_timer(&sclp_request_timer);
1176 rc = -EBUSY;
1177 if (sclp_init_req.status == SCLP_REQ_DONE) {
1178 if (sccb->header.response_code == 0x20) {
1179 rc = 0;
1180 break;
1181 } else if (sccb->header.response_code == 0x74f0) {
1182 if (!sclp_mask_compat_mode) {
1183 sclp_mask_compat_mode = true;
1184 retry = 0;
1185 }
1186 }
1187 }
1188 }
1189 unregister_external_irq(EXT_IRQ_SERVICE_SIG, sclp_check_handler);
1190 spin_unlock_irqrestore(&sclp_lock, flags);
1191 return rc;
1192 }
1193
1194 /* Reboot event handler. Reset send and receive mask to prevent pending SCLP
1195 * events from interfering with rebooted system. */
1196 static int
sclp_reboot_event(struct notifier_block * this,unsigned long event,void * ptr)1197 sclp_reboot_event(struct notifier_block *this, unsigned long event, void *ptr)
1198 {
1199 sclp_deactivate();
1200 return NOTIFY_DONE;
1201 }
1202
1203 static struct notifier_block sclp_reboot_notifier = {
1204 .notifier_call = sclp_reboot_event,
1205 .priority = INT_MIN,
1206 };
1207
con_pages_show(struct device_driver * dev,char * buf)1208 static ssize_t con_pages_show(struct device_driver *dev, char *buf)
1209 {
1210 return sysfs_emit(buf, "%i\n", sclp_console_pages);
1211 }
1212
1213 static DRIVER_ATTR_RO(con_pages);
1214
con_drop_store(struct device_driver * dev,const char * buf,size_t count)1215 static ssize_t con_drop_store(struct device_driver *dev, const char *buf, size_t count)
1216 {
1217 int rc;
1218
1219 rc = kstrtobool(buf, &sclp_console_drop);
1220 return rc ?: count;
1221 }
1222
con_drop_show(struct device_driver * dev,char * buf)1223 static ssize_t con_drop_show(struct device_driver *dev, char *buf)
1224 {
1225 return sysfs_emit(buf, "%i\n", sclp_console_drop);
1226 }
1227
1228 static DRIVER_ATTR_RW(con_drop);
1229
con_full_show(struct device_driver * dev,char * buf)1230 static ssize_t con_full_show(struct device_driver *dev, char *buf)
1231 {
1232 return sysfs_emit(buf, "%lu\n", sclp_console_full);
1233 }
1234
1235 static DRIVER_ATTR_RO(con_full);
1236
1237 static struct attribute *sclp_drv_attrs[] = {
1238 &driver_attr_con_pages.attr,
1239 &driver_attr_con_drop.attr,
1240 &driver_attr_con_full.attr,
1241 NULL,
1242 };
1243 static struct attribute_group sclp_drv_attr_group = {
1244 .attrs = sclp_drv_attrs,
1245 };
1246 static const struct attribute_group *sclp_drv_attr_groups[] = {
1247 &sclp_drv_attr_group,
1248 NULL,
1249 };
1250
1251 static struct platform_driver sclp_pdrv = {
1252 .driver = {
1253 .name = "sclp",
1254 .groups = sclp_drv_attr_groups,
1255 },
1256 };
1257
1258 /* Initialize SCLP driver. Return zero if driver is operational, non-zero
1259 * otherwise. */
sclp_init(void)1260 int sclp_init(void)
1261 {
1262 unsigned long flags;
1263 int rc = 0;
1264
1265 spin_lock_irqsave(&sclp_lock, flags);
1266 /* Check for previous or running initialization */
1267 if (sclp_init_state != sclp_init_state_uninitialized)
1268 goto fail_unlock;
1269 sclp_init_state = sclp_init_state_initializing;
1270 sclp_read_sccb = (void *) __get_free_page(GFP_ATOMIC | GFP_DMA);
1271 sclp_init_sccb = (void *) __get_free_page(GFP_ATOMIC | GFP_DMA);
1272 BUG_ON(!sclp_read_sccb || !sclp_init_sccb);
1273 /* Set up variables */
1274 list_add(&sclp_state_change_event.list, &sclp_reg_list);
1275 timer_setup(&sclp_request_timer, NULL, 0);
1276 timer_setup(&sclp_queue_timer, sclp_req_queue_timeout, 0);
1277 /* Check interface */
1278 spin_unlock_irqrestore(&sclp_lock, flags);
1279 rc = sclp_check_interface();
1280 spin_lock_irqsave(&sclp_lock, flags);
1281 if (rc)
1282 goto fail_init_state_uninitialized;
1283 /* Register reboot handler */
1284 rc = register_reboot_notifier(&sclp_reboot_notifier);
1285 if (rc)
1286 goto fail_init_state_uninitialized;
1287 /* Register interrupt handler */
1288 rc = register_external_irq(EXT_IRQ_SERVICE_SIG, sclp_interrupt_handler);
1289 if (rc)
1290 goto fail_unregister_reboot_notifier;
1291 sclp_init_state = sclp_init_state_initialized;
1292 spin_unlock_irqrestore(&sclp_lock, flags);
1293 /* Enable service-signal external interruption - needs to happen with
1294 * IRQs enabled. */
1295 irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
1296 sclp_init_mask(1);
1297 return 0;
1298
1299 fail_unregister_reboot_notifier:
1300 unregister_reboot_notifier(&sclp_reboot_notifier);
1301 fail_init_state_uninitialized:
1302 list_del(&sclp_state_change_event.list);
1303 sclp_init_state = sclp_init_state_uninitialized;
1304 free_page((unsigned long) sclp_read_sccb);
1305 free_page((unsigned long) sclp_init_sccb);
1306 fail_unlock:
1307 spin_unlock_irqrestore(&sclp_lock, flags);
1308 return rc;
1309 }
1310
sclp_initcall(void)1311 static __init int sclp_initcall(void)
1312 {
1313 return platform_driver_register(&sclp_pdrv);
1314 }
1315
1316 arch_initcall(sclp_initcall);
1317