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1da177e4 LT |
1 | /* |
2 | * drivers/s390/char/sclp_vt220.c | |
3 | * SCLP VT220 terminal driver. | |
4 | * | |
5 | * S390 version | |
6 | * Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation | |
7 | * Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com> | |
8 | */ | |
9 | ||
1da177e4 LT |
10 | #include <linux/module.h> |
11 | #include <linux/spinlock.h> | |
12 | #include <linux/list.h> | |
13 | #include <linux/wait.h> | |
14 | #include <linux/timer.h> | |
15 | #include <linux/kernel.h> | |
16 | #include <linux/tty.h> | |
17 | #include <linux/tty_driver.h> | |
33f0f88f | 18 | #include <linux/tty_flip.h> |
1da177e4 LT |
19 | #include <linux/sched.h> |
20 | #include <linux/errno.h> | |
21 | #include <linux/mm.h> | |
22 | #include <linux/major.h> | |
23 | #include <linux/console.h> | |
24 | #include <linux/kdev_t.h> | |
25 | #include <linux/bootmem.h> | |
26 | #include <linux/interrupt.h> | |
27 | #include <linux/init.h> | |
28 | #include <asm/uaccess.h> | |
29 | #include "sclp.h" | |
30 | ||
31 | #define SCLP_VT220_PRINT_HEADER "sclp vt220 tty driver: " | |
32 | #define SCLP_VT220_MAJOR TTY_MAJOR | |
33 | #define SCLP_VT220_MINOR 65 | |
34 | #define SCLP_VT220_DRIVER_NAME "sclp_vt220" | |
35 | #define SCLP_VT220_DEVICE_NAME "ttysclp" | |
36 | #define SCLP_VT220_CONSOLE_NAME "ttyS" | |
37 | #define SCLP_VT220_CONSOLE_INDEX 1 /* console=ttyS1 */ | |
38 | #define SCLP_VT220_BUF_SIZE 80 | |
39 | ||
40 | /* Representation of a single write request */ | |
41 | struct sclp_vt220_request { | |
42 | struct list_head list; | |
43 | struct sclp_req sclp_req; | |
44 | int retry_count; | |
45 | }; | |
46 | ||
47 | /* VT220 SCCB */ | |
48 | struct sclp_vt220_sccb { | |
49 | struct sccb_header header; | |
50 | struct evbuf_header evbuf; | |
51 | }; | |
52 | ||
53 | #define SCLP_VT220_MAX_CHARS_PER_BUFFER (PAGE_SIZE - \ | |
54 | sizeof(struct sclp_vt220_request) - \ | |
55 | sizeof(struct sclp_vt220_sccb)) | |
56 | ||
57 | /* Structures and data needed to register tty driver */ | |
58 | static struct tty_driver *sclp_vt220_driver; | |
59 | ||
60 | /* The tty_struct that the kernel associated with us */ | |
61 | static struct tty_struct *sclp_vt220_tty; | |
62 | ||
63 | /* Lock to protect internal data from concurrent access */ | |
64 | static spinlock_t sclp_vt220_lock; | |
65 | ||
66 | /* List of empty pages to be used as write request buffers */ | |
67 | static struct list_head sclp_vt220_empty; | |
68 | ||
69 | /* List of pending requests */ | |
70 | static struct list_head sclp_vt220_outqueue; | |
71 | ||
72 | /* Number of requests in outqueue */ | |
73 | static int sclp_vt220_outqueue_count; | |
74 | ||
75 | /* Wait queue used to delay write requests while we've run out of buffers */ | |
76 | static wait_queue_head_t sclp_vt220_waitq; | |
77 | ||
78 | /* Timer used for delaying write requests to merge subsequent messages into | |
79 | * a single buffer */ | |
80 | static struct timer_list sclp_vt220_timer; | |
81 | ||
82 | /* Pointer to current request buffer which has been partially filled but not | |
83 | * yet sent */ | |
84 | static struct sclp_vt220_request *sclp_vt220_current_request; | |
85 | ||
86 | /* Number of characters in current request buffer */ | |
87 | static int sclp_vt220_buffered_chars; | |
88 | ||
89 | /* Flag indicating whether this driver has already been initialized */ | |
90 | static int sclp_vt220_initialized = 0; | |
91 | ||
92 | /* Flag indicating that sclp_vt220_current_request should really | |
93 | * have been already queued but wasn't because the SCLP was processing | |
94 | * another buffer */ | |
95 | static int sclp_vt220_flush_later; | |
96 | ||
97 | static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf); | |
98 | static int __sclp_vt220_emit(struct sclp_vt220_request *request); | |
99 | static void sclp_vt220_emit_current(void); | |
100 | ||
101 | /* Registration structure for our interest in SCLP event buffers */ | |
102 | static struct sclp_register sclp_vt220_register = { | |
103 | .send_mask = EvTyp_VT220Msg_Mask, | |
104 | .receive_mask = EvTyp_VT220Msg_Mask, | |
105 | .state_change_fn = NULL, | |
106 | .receiver_fn = sclp_vt220_receiver_fn | |
107 | }; | |
108 | ||
109 | ||
110 | /* | |
111 | * Put provided request buffer back into queue and check emit pending | |
112 | * buffers if necessary. | |
113 | */ | |
114 | static void | |
115 | sclp_vt220_process_queue(struct sclp_vt220_request *request) | |
116 | { | |
117 | unsigned long flags; | |
118 | void *page; | |
119 | ||
120 | do { | |
121 | /* Put buffer back to list of empty buffers */ | |
122 | page = request->sclp_req.sccb; | |
123 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
124 | /* Move request from outqueue to empty queue */ | |
125 | list_del(&request->list); | |
126 | sclp_vt220_outqueue_count--; | |
127 | list_add_tail((struct list_head *) page, &sclp_vt220_empty); | |
128 | /* Check if there is a pending buffer on the out queue. */ | |
129 | request = NULL; | |
130 | if (!list_empty(&sclp_vt220_outqueue)) | |
131 | request = list_entry(sclp_vt220_outqueue.next, | |
132 | struct sclp_vt220_request, list); | |
133 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
134 | } while (request && __sclp_vt220_emit(request)); | |
135 | if (request == NULL && sclp_vt220_flush_later) | |
136 | sclp_vt220_emit_current(); | |
137 | wake_up(&sclp_vt220_waitq); | |
138 | /* Check if the tty needs a wake up call */ | |
139 | if (sclp_vt220_tty != NULL) { | |
140 | tty_wakeup(sclp_vt220_tty); | |
141 | } | |
142 | } | |
143 | ||
144 | #define SCLP_BUFFER_MAX_RETRY 1 | |
145 | ||
146 | /* | |
147 | * Callback through which the result of a write request is reported by the | |
148 | * SCLP. | |
149 | */ | |
150 | static void | |
151 | sclp_vt220_callback(struct sclp_req *request, void *data) | |
152 | { | |
153 | struct sclp_vt220_request *vt220_request; | |
154 | struct sclp_vt220_sccb *sccb; | |
155 | ||
156 | vt220_request = (struct sclp_vt220_request *) data; | |
157 | if (request->status == SCLP_REQ_FAILED) { | |
158 | sclp_vt220_process_queue(vt220_request); | |
159 | return; | |
160 | } | |
161 | sccb = (struct sclp_vt220_sccb *) vt220_request->sclp_req.sccb; | |
162 | ||
163 | /* Check SCLP response code and choose suitable action */ | |
164 | switch (sccb->header.response_code) { | |
165 | case 0x0020 : | |
166 | break; | |
167 | ||
168 | case 0x05f0: /* Target resource in improper state */ | |
169 | break; | |
170 | ||
171 | case 0x0340: /* Contained SCLP equipment check */ | |
172 | if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) | |
173 | break; | |
174 | /* Remove processed buffers and requeue rest */ | |
175 | if (sclp_remove_processed((struct sccb_header *) sccb) > 0) { | |
176 | /* Not all buffers were processed */ | |
177 | sccb->header.response_code = 0x0000; | |
178 | vt220_request->sclp_req.status = SCLP_REQ_FILLED; | |
179 | if (sclp_add_request(request) == 0) | |
180 | return; | |
181 | } | |
182 | break; | |
183 | ||
184 | case 0x0040: /* SCLP equipment check */ | |
185 | if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) | |
186 | break; | |
187 | sccb->header.response_code = 0x0000; | |
188 | vt220_request->sclp_req.status = SCLP_REQ_FILLED; | |
189 | if (sclp_add_request(request) == 0) | |
190 | return; | |
191 | break; | |
192 | ||
193 | default: | |
194 | break; | |
195 | } | |
196 | sclp_vt220_process_queue(vt220_request); | |
197 | } | |
198 | ||
199 | /* | |
200 | * Emit vt220 request buffer to SCLP. Return zero on success, non-zero | |
201 | * otherwise. | |
202 | */ | |
203 | static int | |
204 | __sclp_vt220_emit(struct sclp_vt220_request *request) | |
205 | { | |
206 | if (!(sclp_vt220_register.sclp_send_mask & EvTyp_VT220Msg_Mask)) { | |
207 | request->sclp_req.status = SCLP_REQ_FAILED; | |
208 | return -EIO; | |
209 | } | |
210 | request->sclp_req.command = SCLP_CMDW_WRITEDATA; | |
211 | request->sclp_req.status = SCLP_REQ_FILLED; | |
212 | request->sclp_req.callback = sclp_vt220_callback; | |
213 | request->sclp_req.callback_data = (void *) request; | |
214 | ||
215 | return sclp_add_request(&request->sclp_req); | |
216 | } | |
217 | ||
218 | /* | |
219 | * Queue and emit given request. | |
220 | */ | |
221 | static void | |
222 | sclp_vt220_emit(struct sclp_vt220_request *request) | |
223 | { | |
224 | unsigned long flags; | |
225 | int count; | |
226 | ||
227 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
228 | list_add_tail(&request->list, &sclp_vt220_outqueue); | |
229 | count = sclp_vt220_outqueue_count++; | |
230 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
231 | /* Emit only the first buffer immediately - callback takes care of | |
232 | * the rest */ | |
233 | if (count == 0 && __sclp_vt220_emit(request)) | |
234 | sclp_vt220_process_queue(request); | |
235 | } | |
236 | ||
237 | /* | |
238 | * Queue and emit current request. Return zero on success, non-zero otherwise. | |
239 | */ | |
240 | static void | |
241 | sclp_vt220_emit_current(void) | |
242 | { | |
243 | unsigned long flags; | |
244 | struct sclp_vt220_request *request; | |
245 | struct sclp_vt220_sccb *sccb; | |
246 | ||
247 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
248 | request = NULL; | |
249 | if (sclp_vt220_current_request != NULL) { | |
250 | sccb = (struct sclp_vt220_sccb *) | |
251 | sclp_vt220_current_request->sclp_req.sccb; | |
252 | /* Only emit buffers with content */ | |
253 | if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) { | |
254 | request = sclp_vt220_current_request; | |
255 | sclp_vt220_current_request = NULL; | |
256 | if (timer_pending(&sclp_vt220_timer)) | |
257 | del_timer(&sclp_vt220_timer); | |
258 | } | |
259 | sclp_vt220_flush_later = 0; | |
260 | } | |
261 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
262 | if (request != NULL) | |
263 | sclp_vt220_emit(request); | |
264 | } | |
265 | ||
266 | #define SCLP_NORMAL_WRITE 0x00 | |
267 | ||
268 | /* | |
269 | * Helper function to initialize a page with the sclp request structure. | |
270 | */ | |
271 | static struct sclp_vt220_request * | |
272 | sclp_vt220_initialize_page(void *page) | |
273 | { | |
274 | struct sclp_vt220_request *request; | |
275 | struct sclp_vt220_sccb *sccb; | |
276 | ||
277 | /* Place request structure at end of page */ | |
278 | request = ((struct sclp_vt220_request *) | |
279 | ((addr_t) page + PAGE_SIZE)) - 1; | |
280 | request->retry_count = 0; | |
281 | request->sclp_req.sccb = page; | |
282 | /* SCCB goes at start of page */ | |
283 | sccb = (struct sclp_vt220_sccb *) page; | |
284 | memset((void *) sccb, 0, sizeof(struct sclp_vt220_sccb)); | |
285 | sccb->header.length = sizeof(struct sclp_vt220_sccb); | |
286 | sccb->header.function_code = SCLP_NORMAL_WRITE; | |
287 | sccb->header.response_code = 0x0000; | |
288 | sccb->evbuf.type = EvTyp_VT220Msg; | |
289 | sccb->evbuf.length = sizeof(struct evbuf_header); | |
290 | ||
291 | return request; | |
292 | } | |
293 | ||
294 | static inline unsigned int | |
295 | sclp_vt220_space_left(struct sclp_vt220_request *request) | |
296 | { | |
297 | struct sclp_vt220_sccb *sccb; | |
298 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
299 | return PAGE_SIZE - sizeof(struct sclp_vt220_request) - | |
300 | sccb->header.length; | |
301 | } | |
302 | ||
303 | static inline unsigned int | |
304 | sclp_vt220_chars_stored(struct sclp_vt220_request *request) | |
305 | { | |
306 | struct sclp_vt220_sccb *sccb; | |
307 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
308 | return sccb->evbuf.length - sizeof(struct evbuf_header); | |
309 | } | |
310 | ||
311 | /* | |
312 | * Add msg to buffer associated with request. Return the number of characters | |
313 | * added. | |
314 | */ | |
315 | static int | |
316 | sclp_vt220_add_msg(struct sclp_vt220_request *request, | |
317 | const unsigned char *msg, int count, int convertlf) | |
318 | { | |
319 | struct sclp_vt220_sccb *sccb; | |
320 | void *buffer; | |
321 | unsigned char c; | |
322 | int from; | |
323 | int to; | |
324 | ||
325 | if (count > sclp_vt220_space_left(request)) | |
326 | count = sclp_vt220_space_left(request); | |
327 | if (count <= 0) | |
328 | return 0; | |
329 | ||
330 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
331 | buffer = (void *) ((addr_t) sccb + sccb->header.length); | |
332 | ||
333 | if (convertlf) { | |
334 | /* Perform Linefeed conversion (0x0a -> 0x0a 0x0d)*/ | |
335 | for (from=0, to=0; | |
336 | (from < count) && (to < sclp_vt220_space_left(request)); | |
337 | from++) { | |
338 | /* Retrieve character */ | |
339 | c = msg[from]; | |
340 | /* Perform conversion */ | |
341 | if (c == 0x0a) { | |
342 | if (to + 1 < sclp_vt220_space_left(request)) { | |
343 | ((unsigned char *) buffer)[to++] = c; | |
344 | ((unsigned char *) buffer)[to++] = 0x0d; | |
345 | } else | |
346 | break; | |
347 | ||
348 | } else | |
349 | ((unsigned char *) buffer)[to++] = c; | |
350 | } | |
351 | sccb->header.length += to; | |
352 | sccb->evbuf.length += to; | |
353 | return from; | |
354 | } else { | |
355 | memcpy(buffer, (const void *) msg, count); | |
356 | sccb->header.length += count; | |
357 | sccb->evbuf.length += count; | |
358 | return count; | |
359 | } | |
360 | } | |
361 | ||
362 | /* | |
363 | * Emit buffer after having waited long enough for more data to arrive. | |
364 | */ | |
365 | static void | |
366 | sclp_vt220_timeout(unsigned long data) | |
367 | { | |
368 | sclp_vt220_emit_current(); | |
369 | } | |
370 | ||
371 | #define BUFFER_MAX_DELAY HZ/2 | |
372 | ||
373 | /* | |
374 | * Internal implementation of the write function. Write COUNT bytes of data | |
375 | * from memory at BUF | |
376 | * to the SCLP interface. In case that the data does not fit into the current | |
377 | * write buffer, emit the current one and allocate a new one. If there are no | |
378 | * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE | |
379 | * is non-zero, the buffer will be scheduled for emitting after a timeout - | |
380 | * otherwise the user has to explicitly call the flush function. | |
381 | * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message | |
382 | * buffer should be converted to 0x0a 0x0d. After completion, return the number | |
383 | * of bytes written. | |
384 | */ | |
385 | static int | |
386 | __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule, | |
387 | int convertlf) | |
388 | { | |
389 | unsigned long flags; | |
390 | void *page; | |
391 | int written; | |
392 | int overall_written; | |
393 | ||
394 | if (count <= 0) | |
395 | return 0; | |
396 | overall_written = 0; | |
397 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
398 | do { | |
399 | /* Create a sclp output buffer if none exists yet */ | |
400 | if (sclp_vt220_current_request == NULL) { | |
401 | while (list_empty(&sclp_vt220_empty)) { | |
402 | spin_unlock_irqrestore(&sclp_vt220_lock, | |
403 | flags); | |
404 | if (in_interrupt()) | |
405 | sclp_sync_wait(); | |
406 | else | |
407 | wait_event(sclp_vt220_waitq, | |
408 | !list_empty(&sclp_vt220_empty)); | |
409 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
410 | } | |
411 | page = (void *) sclp_vt220_empty.next; | |
412 | list_del((struct list_head *) page); | |
413 | sclp_vt220_current_request = | |
414 | sclp_vt220_initialize_page(page); | |
415 | } | |
416 | /* Try to write the string to the current request buffer */ | |
417 | written = sclp_vt220_add_msg(sclp_vt220_current_request, | |
418 | buf, count, convertlf); | |
419 | overall_written += written; | |
420 | if (written == count) | |
421 | break; | |
422 | /* | |
423 | * Not all characters could be written to the current | |
424 | * output buffer. Emit the buffer, create a new buffer | |
425 | * and then output the rest of the string. | |
426 | */ | |
427 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
428 | sclp_vt220_emit_current(); | |
429 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
430 | buf += written; | |
431 | count -= written; | |
432 | } while (count > 0); | |
433 | /* Setup timer to output current console buffer after some time */ | |
434 | if (sclp_vt220_current_request != NULL && | |
435 | !timer_pending(&sclp_vt220_timer) && do_schedule) { | |
436 | sclp_vt220_timer.function = sclp_vt220_timeout; | |
437 | sclp_vt220_timer.data = 0UL; | |
438 | sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY; | |
439 | add_timer(&sclp_vt220_timer); | |
440 | } | |
441 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
442 | return overall_written; | |
443 | } | |
444 | ||
445 | /* | |
446 | * This routine is called by the kernel to write a series of | |
447 | * characters to the tty device. The characters may come from | |
448 | * user space or kernel space. This routine will return the | |
449 | * number of characters actually accepted for writing. | |
450 | */ | |
451 | static int | |
452 | sclp_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count) | |
453 | { | |
454 | return __sclp_vt220_write(buf, count, 1, 0); | |
455 | } | |
456 | ||
457 | #define SCLP_VT220_SESSION_ENDED 0x01 | |
458 | #define SCLP_VT220_SESSION_STARTED 0x80 | |
459 | #define SCLP_VT220_SESSION_DATA 0x00 | |
460 | ||
461 | /* | |
462 | * Called by the SCLP to report incoming event buffers. | |
463 | */ | |
464 | static void | |
465 | sclp_vt220_receiver_fn(struct evbuf_header *evbuf) | |
466 | { | |
467 | char *buffer; | |
468 | unsigned int count; | |
469 | ||
470 | /* Ignore input if device is not open */ | |
471 | if (sclp_vt220_tty == NULL) | |
472 | return; | |
473 | ||
474 | buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header)); | |
475 | count = evbuf->length - sizeof(struct evbuf_header); | |
476 | ||
477 | switch (*buffer) { | |
478 | case SCLP_VT220_SESSION_ENDED: | |
479 | case SCLP_VT220_SESSION_STARTED: | |
480 | break; | |
481 | case SCLP_VT220_SESSION_DATA: | |
482 | /* Send input to line discipline */ | |
483 | buffer++; | |
484 | count--; | |
33f0f88f | 485 | tty_insert_flip_string(sclp_vt220_tty, buffer, count); |
1da177e4 LT |
486 | tty_flip_buffer_push(sclp_vt220_tty); |
487 | break; | |
488 | } | |
489 | } | |
490 | ||
491 | /* | |
492 | * This routine is called when a particular tty device is opened. | |
493 | */ | |
494 | static int | |
495 | sclp_vt220_open(struct tty_struct *tty, struct file *filp) | |
496 | { | |
497 | if (tty->count == 1) { | |
498 | sclp_vt220_tty = tty; | |
499 | tty->driver_data = kmalloc(SCLP_VT220_BUF_SIZE, GFP_KERNEL); | |
500 | if (tty->driver_data == NULL) | |
501 | return -ENOMEM; | |
502 | tty->low_latency = 0; | |
503 | } | |
504 | return 0; | |
505 | } | |
506 | ||
507 | /* | |
508 | * This routine is called when a particular tty device is closed. | |
509 | */ | |
510 | static void | |
511 | sclp_vt220_close(struct tty_struct *tty, struct file *filp) | |
512 | { | |
513 | if (tty->count == 1) { | |
514 | sclp_vt220_tty = NULL; | |
515 | kfree(tty->driver_data); | |
516 | tty->driver_data = NULL; | |
517 | } | |
518 | } | |
519 | ||
520 | /* | |
521 | * This routine is called by the kernel to write a single | |
522 | * character to the tty device. If the kernel uses this routine, | |
523 | * it must call the flush_chars() routine (if defined) when it is | |
524 | * done stuffing characters into the driver. | |
525 | * | |
526 | * NOTE: include/linux/tty_driver.h specifies that a character should be | |
527 | * ignored if there is no room in the queue. This driver implements a different | |
528 | * semantic in that it will block when there is no more room left. | |
529 | */ | |
530 | static void | |
531 | sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch) | |
532 | { | |
533 | __sclp_vt220_write(&ch, 1, 0, 0); | |
534 | } | |
535 | ||
536 | /* | |
537 | * This routine is called by the kernel after it has written a | |
538 | * series of characters to the tty device using put_char(). | |
539 | */ | |
540 | static void | |
541 | sclp_vt220_flush_chars(struct tty_struct *tty) | |
542 | { | |
543 | if (sclp_vt220_outqueue_count == 0) | |
544 | sclp_vt220_emit_current(); | |
545 | else | |
546 | sclp_vt220_flush_later = 1; | |
547 | } | |
548 | ||
549 | /* | |
550 | * This routine returns the numbers of characters the tty driver | |
551 | * will accept for queuing to be written. This number is subject | |
552 | * to change as output buffers get emptied, or if the output flow | |
553 | * control is acted. | |
554 | */ | |
555 | static int | |
556 | sclp_vt220_write_room(struct tty_struct *tty) | |
557 | { | |
558 | unsigned long flags; | |
559 | struct list_head *l; | |
560 | int count; | |
561 | ||
562 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
563 | count = 0; | |
564 | if (sclp_vt220_current_request != NULL) | |
565 | count = sclp_vt220_space_left(sclp_vt220_current_request); | |
566 | list_for_each(l, &sclp_vt220_empty) | |
567 | count += SCLP_VT220_MAX_CHARS_PER_BUFFER; | |
568 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
569 | return count; | |
570 | } | |
571 | ||
572 | /* | |
573 | * Return number of buffered chars. | |
574 | */ | |
575 | static int | |
576 | sclp_vt220_chars_in_buffer(struct tty_struct *tty) | |
577 | { | |
578 | unsigned long flags; | |
579 | struct list_head *l; | |
580 | struct sclp_vt220_request *r; | |
581 | int count; | |
582 | ||
583 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
584 | count = 0; | |
585 | if (sclp_vt220_current_request != NULL) | |
586 | count = sclp_vt220_chars_stored(sclp_vt220_current_request); | |
587 | list_for_each(l, &sclp_vt220_outqueue) { | |
588 | r = list_entry(l, struct sclp_vt220_request, list); | |
589 | count += sclp_vt220_chars_stored(r); | |
590 | } | |
591 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
592 | return count; | |
593 | } | |
594 | ||
595 | static void | |
596 | __sclp_vt220_flush_buffer(void) | |
597 | { | |
598 | unsigned long flags; | |
599 | ||
600 | sclp_vt220_emit_current(); | |
601 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
602 | if (timer_pending(&sclp_vt220_timer)) | |
603 | del_timer(&sclp_vt220_timer); | |
604 | while (sclp_vt220_outqueue_count > 0) { | |
605 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
606 | sclp_sync_wait(); | |
607 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
608 | } | |
609 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
610 | } | |
611 | ||
612 | /* | |
613 | * Pass on all buffers to the hardware. Return only when there are no more | |
614 | * buffers pending. | |
615 | */ | |
616 | static void | |
617 | sclp_vt220_flush_buffer(struct tty_struct *tty) | |
618 | { | |
619 | sclp_vt220_emit_current(); | |
620 | } | |
621 | ||
622 | /* | |
623 | * Initialize all relevant components and register driver with system. | |
624 | */ | |
625 | static int | |
626 | __sclp_vt220_init(int early) | |
627 | { | |
628 | void *page; | |
629 | int i; | |
630 | ||
631 | if (sclp_vt220_initialized) | |
632 | return 0; | |
633 | sclp_vt220_initialized = 1; | |
634 | spin_lock_init(&sclp_vt220_lock); | |
635 | INIT_LIST_HEAD(&sclp_vt220_empty); | |
636 | INIT_LIST_HEAD(&sclp_vt220_outqueue); | |
637 | init_waitqueue_head(&sclp_vt220_waitq); | |
638 | init_timer(&sclp_vt220_timer); | |
639 | sclp_vt220_current_request = NULL; | |
640 | sclp_vt220_buffered_chars = 0; | |
641 | sclp_vt220_outqueue_count = 0; | |
642 | sclp_vt220_tty = NULL; | |
643 | sclp_vt220_flush_later = 0; | |
644 | ||
645 | /* Allocate pages for output buffering */ | |
646 | for (i = 0; i < (early ? MAX_CONSOLE_PAGES : MAX_KMEM_PAGES); i++) { | |
647 | if (early) | |
648 | page = alloc_bootmem_low_pages(PAGE_SIZE); | |
649 | else | |
650 | page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); | |
651 | if (!page) | |
652 | return -ENOMEM; | |
653 | list_add_tail((struct list_head *) page, &sclp_vt220_empty); | |
654 | } | |
655 | return 0; | |
656 | } | |
657 | ||
b68e31d0 | 658 | static const struct tty_operations sclp_vt220_ops = { |
1da177e4 LT |
659 | .open = sclp_vt220_open, |
660 | .close = sclp_vt220_close, | |
661 | .write = sclp_vt220_write, | |
662 | .put_char = sclp_vt220_put_char, | |
663 | .flush_chars = sclp_vt220_flush_chars, | |
664 | .write_room = sclp_vt220_write_room, | |
665 | .chars_in_buffer = sclp_vt220_chars_in_buffer, | |
666 | .flush_buffer = sclp_vt220_flush_buffer | |
667 | }; | |
668 | ||
669 | /* | |
670 | * Register driver with SCLP and Linux and initialize internal tty structures. | |
671 | */ | |
672 | int __init | |
673 | sclp_vt220_tty_init(void) | |
674 | { | |
675 | struct tty_driver *driver; | |
676 | int rc; | |
677 | ||
678 | /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve | |
679 | * symmetry between VM and LPAR systems regarding ttyS1. */ | |
680 | driver = alloc_tty_driver(1); | |
681 | if (!driver) | |
682 | return -ENOMEM; | |
683 | rc = __sclp_vt220_init(0); | |
684 | if (rc) { | |
685 | put_tty_driver(driver); | |
686 | return rc; | |
687 | } | |
688 | rc = sclp_register(&sclp_vt220_register); | |
689 | if (rc) { | |
690 | printk(KERN_ERR SCLP_VT220_PRINT_HEADER | |
691 | "could not register tty - " | |
692 | "sclp_register returned %d\n", rc); | |
693 | put_tty_driver(driver); | |
694 | return rc; | |
695 | } | |
696 | ||
697 | driver->owner = THIS_MODULE; | |
698 | driver->driver_name = SCLP_VT220_DRIVER_NAME; | |
699 | driver->name = SCLP_VT220_DEVICE_NAME; | |
700 | driver->major = SCLP_VT220_MAJOR; | |
701 | driver->minor_start = SCLP_VT220_MINOR; | |
702 | driver->type = TTY_DRIVER_TYPE_SYSTEM; | |
703 | driver->subtype = SYSTEM_TYPE_TTY; | |
704 | driver->init_termios = tty_std_termios; | |
705 | driver->flags = TTY_DRIVER_REAL_RAW; | |
706 | tty_set_operations(driver, &sclp_vt220_ops); | |
707 | ||
708 | rc = tty_register_driver(driver); | |
709 | if (rc) { | |
710 | printk(KERN_ERR SCLP_VT220_PRINT_HEADER | |
711 | "could not register tty - " | |
712 | "tty_register_driver returned %d\n", rc); | |
713 | put_tty_driver(driver); | |
714 | return rc; | |
715 | } | |
716 | sclp_vt220_driver = driver; | |
717 | return 0; | |
718 | } | |
719 | ||
720 | module_init(sclp_vt220_tty_init); | |
721 | ||
722 | #ifdef CONFIG_SCLP_VT220_CONSOLE | |
723 | ||
724 | static void | |
725 | sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count) | |
726 | { | |
727 | __sclp_vt220_write((const unsigned char *) buf, count, 1, 1); | |
728 | } | |
729 | ||
730 | static struct tty_driver * | |
731 | sclp_vt220_con_device(struct console *c, int *index) | |
732 | { | |
733 | *index = 0; | |
734 | return sclp_vt220_driver; | |
735 | } | |
736 | ||
737 | /* | |
738 | * This routine is called from panic when the kernel is going to give up. | |
739 | * We have to make sure that all buffers will be flushed to the SCLP. | |
740 | * Note that this function may be called from within an interrupt context. | |
741 | */ | |
742 | static void | |
743 | sclp_vt220_con_unblank(void) | |
744 | { | |
745 | __sclp_vt220_flush_buffer(); | |
746 | } | |
747 | ||
748 | /* Structure needed to register with printk */ | |
749 | static struct console sclp_vt220_console = | |
750 | { | |
751 | .name = SCLP_VT220_CONSOLE_NAME, | |
752 | .write = sclp_vt220_con_write, | |
753 | .device = sclp_vt220_con_device, | |
754 | .unblank = sclp_vt220_con_unblank, | |
755 | .flags = CON_PRINTBUFFER, | |
756 | .index = SCLP_VT220_CONSOLE_INDEX | |
757 | }; | |
758 | ||
759 | static int __init | |
760 | sclp_vt220_con_init(void) | |
761 | { | |
762 | int rc; | |
763 | ||
764 | if (!CONSOLE_IS_SCLP) | |
765 | return 0; | |
766 | rc = __sclp_vt220_init(1); | |
767 | if (rc) | |
768 | return rc; | |
769 | /* Attach linux console */ | |
770 | register_console(&sclp_vt220_console); | |
771 | return 0; | |
772 | } | |
773 | ||
774 | console_initcall(sclp_vt220_con_init); | |
775 | #endif /* CONFIG_SCLP_VT220_CONSOLE */ | |
776 |