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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * drivers/s390/char/sclp_vt220.c | |
3 | * SCLP VT220 terminal driver. | |
4 | * | |
5 | * S390 version | |
59eb1ca7 | 6 | * Copyright IBM Corp. 2003,2008 |
1da177e4 LT |
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/errno.h> |
20 | #include <linux/mm.h> | |
21 | #include <linux/major.h> | |
22 | #include <linux/console.h> | |
23 | #include <linux/kdev_t.h> | |
24 | #include <linux/bootmem.h> | |
25 | #include <linux/interrupt.h> | |
26 | #include <linux/init.h> | |
27 | #include <asm/uaccess.h> | |
28 | #include "sclp.h" | |
29 | ||
30 | #define SCLP_VT220_PRINT_HEADER "sclp vt220 tty driver: " | |
31 | #define SCLP_VT220_MAJOR TTY_MAJOR | |
32 | #define SCLP_VT220_MINOR 65 | |
33 | #define SCLP_VT220_DRIVER_NAME "sclp_vt220" | |
34 | #define SCLP_VT220_DEVICE_NAME "ttysclp" | |
35 | #define SCLP_VT220_CONSOLE_NAME "ttyS" | |
36 | #define SCLP_VT220_CONSOLE_INDEX 1 /* console=ttyS1 */ | |
37 | #define SCLP_VT220_BUF_SIZE 80 | |
38 | ||
39 | /* Representation of a single write request */ | |
40 | struct sclp_vt220_request { | |
41 | struct list_head list; | |
42 | struct sclp_req sclp_req; | |
43 | int retry_count; | |
44 | }; | |
45 | ||
46 | /* VT220 SCCB */ | |
47 | struct sclp_vt220_sccb { | |
48 | struct sccb_header header; | |
49 | struct evbuf_header evbuf; | |
50 | }; | |
51 | ||
52 | #define SCLP_VT220_MAX_CHARS_PER_BUFFER (PAGE_SIZE - \ | |
53 | sizeof(struct sclp_vt220_request) - \ | |
54 | sizeof(struct sclp_vt220_sccb)) | |
55 | ||
56 | /* Structures and data needed to register tty driver */ | |
57 | static struct tty_driver *sclp_vt220_driver; | |
58 | ||
59 | /* The tty_struct that the kernel associated with us */ | |
60 | static struct tty_struct *sclp_vt220_tty; | |
61 | ||
62 | /* Lock to protect internal data from concurrent access */ | |
63 | static spinlock_t sclp_vt220_lock; | |
64 | ||
65 | /* List of empty pages to be used as write request buffers */ | |
66 | static struct list_head sclp_vt220_empty; | |
67 | ||
68 | /* List of pending requests */ | |
69 | static struct list_head sclp_vt220_outqueue; | |
70 | ||
71 | /* Number of requests in outqueue */ | |
72 | static int sclp_vt220_outqueue_count; | |
73 | ||
74 | /* Wait queue used to delay write requests while we've run out of buffers */ | |
75 | static wait_queue_head_t sclp_vt220_waitq; | |
76 | ||
77 | /* Timer used for delaying write requests to merge subsequent messages into | |
78 | * a single buffer */ | |
79 | static struct timer_list sclp_vt220_timer; | |
80 | ||
81 | /* Pointer to current request buffer which has been partially filled but not | |
82 | * yet sent */ | |
83 | static struct sclp_vt220_request *sclp_vt220_current_request; | |
84 | ||
85 | /* Number of characters in current request buffer */ | |
86 | static int sclp_vt220_buffered_chars; | |
87 | ||
88 | /* Flag indicating whether this driver has already been initialized */ | |
89 | static int sclp_vt220_initialized = 0; | |
90 | ||
91 | /* Flag indicating that sclp_vt220_current_request should really | |
92 | * have been already queued but wasn't because the SCLP was processing | |
93 | * another buffer */ | |
94 | static int sclp_vt220_flush_later; | |
95 | ||
96 | static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf); | |
97 | static int __sclp_vt220_emit(struct sclp_vt220_request *request); | |
98 | static void sclp_vt220_emit_current(void); | |
99 | ||
100 | /* Registration structure for our interest in SCLP event buffers */ | |
101 | static struct sclp_register sclp_vt220_register = { | |
6d4740c8 SH |
102 | .send_mask = EVTYP_VT220MSG_MASK, |
103 | .receive_mask = EVTYP_VT220MSG_MASK, | |
1da177e4 LT |
104 | .state_change_fn = NULL, |
105 | .receiver_fn = sclp_vt220_receiver_fn | |
106 | }; | |
107 | ||
108 | ||
109 | /* | |
110 | * Put provided request buffer back into queue and check emit pending | |
111 | * buffers if necessary. | |
112 | */ | |
113 | static void | |
114 | sclp_vt220_process_queue(struct sclp_vt220_request *request) | |
115 | { | |
116 | unsigned long flags; | |
117 | void *page; | |
118 | ||
119 | do { | |
120 | /* Put buffer back to list of empty buffers */ | |
121 | page = request->sclp_req.sccb; | |
122 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
123 | /* Move request from outqueue to empty queue */ | |
124 | list_del(&request->list); | |
125 | sclp_vt220_outqueue_count--; | |
126 | list_add_tail((struct list_head *) page, &sclp_vt220_empty); | |
127 | /* Check if there is a pending buffer on the out queue. */ | |
128 | request = NULL; | |
129 | if (!list_empty(&sclp_vt220_outqueue)) | |
130 | request = list_entry(sclp_vt220_outqueue.next, | |
131 | struct sclp_vt220_request, list); | |
132 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
133 | } while (request && __sclp_vt220_emit(request)); | |
134 | if (request == NULL && sclp_vt220_flush_later) | |
135 | sclp_vt220_emit_current(); | |
136 | wake_up(&sclp_vt220_waitq); | |
137 | /* Check if the tty needs a wake up call */ | |
138 | if (sclp_vt220_tty != NULL) { | |
139 | tty_wakeup(sclp_vt220_tty); | |
140 | } | |
141 | } | |
142 | ||
143 | #define SCLP_BUFFER_MAX_RETRY 1 | |
144 | ||
145 | /* | |
146 | * Callback through which the result of a write request is reported by the | |
147 | * SCLP. | |
148 | */ | |
149 | static void | |
150 | sclp_vt220_callback(struct sclp_req *request, void *data) | |
151 | { | |
152 | struct sclp_vt220_request *vt220_request; | |
153 | struct sclp_vt220_sccb *sccb; | |
154 | ||
155 | vt220_request = (struct sclp_vt220_request *) data; | |
156 | if (request->status == SCLP_REQ_FAILED) { | |
157 | sclp_vt220_process_queue(vt220_request); | |
158 | return; | |
159 | } | |
160 | sccb = (struct sclp_vt220_sccb *) vt220_request->sclp_req.sccb; | |
161 | ||
162 | /* Check SCLP response code and choose suitable action */ | |
163 | switch (sccb->header.response_code) { | |
164 | case 0x0020 : | |
165 | break; | |
166 | ||
167 | case 0x05f0: /* Target resource in improper state */ | |
168 | break; | |
169 | ||
170 | case 0x0340: /* Contained SCLP equipment check */ | |
171 | if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) | |
172 | break; | |
173 | /* Remove processed buffers and requeue rest */ | |
174 | if (sclp_remove_processed((struct sccb_header *) sccb) > 0) { | |
175 | /* Not all buffers were processed */ | |
176 | sccb->header.response_code = 0x0000; | |
177 | vt220_request->sclp_req.status = SCLP_REQ_FILLED; | |
178 | if (sclp_add_request(request) == 0) | |
179 | return; | |
180 | } | |
181 | break; | |
182 | ||
183 | case 0x0040: /* SCLP equipment check */ | |
184 | if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) | |
185 | break; | |
186 | sccb->header.response_code = 0x0000; | |
187 | vt220_request->sclp_req.status = SCLP_REQ_FILLED; | |
188 | if (sclp_add_request(request) == 0) | |
189 | return; | |
190 | break; | |
191 | ||
192 | default: | |
193 | break; | |
194 | } | |
195 | sclp_vt220_process_queue(vt220_request); | |
196 | } | |
197 | ||
198 | /* | |
199 | * Emit vt220 request buffer to SCLP. Return zero on success, non-zero | |
200 | * otherwise. | |
201 | */ | |
202 | static int | |
203 | __sclp_vt220_emit(struct sclp_vt220_request *request) | |
204 | { | |
d082d3ce | 205 | if (!(sclp_vt220_register.sclp_receive_mask & EVTYP_VT220MSG_MASK)) { |
1da177e4 LT |
206 | request->sclp_req.status = SCLP_REQ_FAILED; |
207 | return -EIO; | |
208 | } | |
ab14de6c | 209 | request->sclp_req.command = SCLP_CMDW_WRITE_EVENT_DATA; |
1da177e4 LT |
210 | request->sclp_req.status = SCLP_REQ_FILLED; |
211 | request->sclp_req.callback = sclp_vt220_callback; | |
212 | request->sclp_req.callback_data = (void *) request; | |
213 | ||
214 | return sclp_add_request(&request->sclp_req); | |
215 | } | |
216 | ||
217 | /* | |
218 | * Queue and emit given request. | |
219 | */ | |
220 | static void | |
221 | sclp_vt220_emit(struct sclp_vt220_request *request) | |
222 | { | |
223 | unsigned long flags; | |
224 | int count; | |
225 | ||
226 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
227 | list_add_tail(&request->list, &sclp_vt220_outqueue); | |
228 | count = sclp_vt220_outqueue_count++; | |
229 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
230 | /* Emit only the first buffer immediately - callback takes care of | |
231 | * the rest */ | |
232 | if (count == 0 && __sclp_vt220_emit(request)) | |
233 | sclp_vt220_process_queue(request); | |
234 | } | |
235 | ||
236 | /* | |
237 | * Queue and emit current request. Return zero on success, non-zero otherwise. | |
238 | */ | |
239 | static void | |
240 | sclp_vt220_emit_current(void) | |
241 | { | |
242 | unsigned long flags; | |
243 | struct sclp_vt220_request *request; | |
244 | struct sclp_vt220_sccb *sccb; | |
245 | ||
246 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
247 | request = NULL; | |
248 | if (sclp_vt220_current_request != NULL) { | |
249 | sccb = (struct sclp_vt220_sccb *) | |
250 | sclp_vt220_current_request->sclp_req.sccb; | |
251 | /* Only emit buffers with content */ | |
252 | if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) { | |
253 | request = sclp_vt220_current_request; | |
254 | sclp_vt220_current_request = NULL; | |
255 | if (timer_pending(&sclp_vt220_timer)) | |
256 | del_timer(&sclp_vt220_timer); | |
257 | } | |
258 | sclp_vt220_flush_later = 0; | |
259 | } | |
260 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
261 | if (request != NULL) | |
262 | sclp_vt220_emit(request); | |
263 | } | |
264 | ||
265 | #define SCLP_NORMAL_WRITE 0x00 | |
266 | ||
267 | /* | |
268 | * Helper function to initialize a page with the sclp request structure. | |
269 | */ | |
270 | static struct sclp_vt220_request * | |
271 | sclp_vt220_initialize_page(void *page) | |
272 | { | |
273 | struct sclp_vt220_request *request; | |
274 | struct sclp_vt220_sccb *sccb; | |
275 | ||
276 | /* Place request structure at end of page */ | |
277 | request = ((struct sclp_vt220_request *) | |
278 | ((addr_t) page + PAGE_SIZE)) - 1; | |
279 | request->retry_count = 0; | |
280 | request->sclp_req.sccb = page; | |
281 | /* SCCB goes at start of page */ | |
282 | sccb = (struct sclp_vt220_sccb *) page; | |
283 | memset((void *) sccb, 0, sizeof(struct sclp_vt220_sccb)); | |
284 | sccb->header.length = sizeof(struct sclp_vt220_sccb); | |
285 | sccb->header.function_code = SCLP_NORMAL_WRITE; | |
286 | sccb->header.response_code = 0x0000; | |
6d4740c8 | 287 | sccb->evbuf.type = EVTYP_VT220MSG; |
1da177e4 LT |
288 | sccb->evbuf.length = sizeof(struct evbuf_header); |
289 | ||
290 | return request; | |
291 | } | |
292 | ||
293 | static inline unsigned int | |
294 | sclp_vt220_space_left(struct sclp_vt220_request *request) | |
295 | { | |
296 | struct sclp_vt220_sccb *sccb; | |
297 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
298 | return PAGE_SIZE - sizeof(struct sclp_vt220_request) - | |
299 | sccb->header.length; | |
300 | } | |
301 | ||
302 | static inline unsigned int | |
303 | sclp_vt220_chars_stored(struct sclp_vt220_request *request) | |
304 | { | |
305 | struct sclp_vt220_sccb *sccb; | |
306 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
307 | return sccb->evbuf.length - sizeof(struct evbuf_header); | |
308 | } | |
309 | ||
310 | /* | |
311 | * Add msg to buffer associated with request. Return the number of characters | |
312 | * added. | |
313 | */ | |
314 | static int | |
315 | sclp_vt220_add_msg(struct sclp_vt220_request *request, | |
316 | const unsigned char *msg, int count, int convertlf) | |
317 | { | |
318 | struct sclp_vt220_sccb *sccb; | |
319 | void *buffer; | |
320 | unsigned char c; | |
321 | int from; | |
322 | int to; | |
323 | ||
324 | if (count > sclp_vt220_space_left(request)) | |
325 | count = sclp_vt220_space_left(request); | |
326 | if (count <= 0) | |
327 | return 0; | |
328 | ||
329 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
330 | buffer = (void *) ((addr_t) sccb + sccb->header.length); | |
331 | ||
332 | if (convertlf) { | |
333 | /* Perform Linefeed conversion (0x0a -> 0x0a 0x0d)*/ | |
334 | for (from=0, to=0; | |
335 | (from < count) && (to < sclp_vt220_space_left(request)); | |
336 | from++) { | |
337 | /* Retrieve character */ | |
338 | c = msg[from]; | |
339 | /* Perform conversion */ | |
340 | if (c == 0x0a) { | |
341 | if (to + 1 < sclp_vt220_space_left(request)) { | |
342 | ((unsigned char *) buffer)[to++] = c; | |
343 | ((unsigned char *) buffer)[to++] = 0x0d; | |
344 | } else | |
345 | break; | |
346 | ||
347 | } else | |
348 | ((unsigned char *) buffer)[to++] = c; | |
349 | } | |
350 | sccb->header.length += to; | |
351 | sccb->evbuf.length += to; | |
352 | return from; | |
353 | } else { | |
354 | memcpy(buffer, (const void *) msg, count); | |
355 | sccb->header.length += count; | |
356 | sccb->evbuf.length += count; | |
357 | return count; | |
358 | } | |
359 | } | |
360 | ||
361 | /* | |
362 | * Emit buffer after having waited long enough for more data to arrive. | |
363 | */ | |
364 | static void | |
365 | sclp_vt220_timeout(unsigned long data) | |
366 | { | |
367 | sclp_vt220_emit_current(); | |
368 | } | |
369 | ||
fa331ffc | 370 | #define BUFFER_MAX_DELAY HZ/20 |
1da177e4 LT |
371 | |
372 | /* | |
373 | * Internal implementation of the write function. Write COUNT bytes of data | |
374 | * from memory at BUF | |
375 | * to the SCLP interface. In case that the data does not fit into the current | |
376 | * write buffer, emit the current one and allocate a new one. If there are no | |
377 | * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE | |
378 | * is non-zero, the buffer will be scheduled for emitting after a timeout - | |
379 | * otherwise the user has to explicitly call the flush function. | |
380 | * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message | |
381 | * buffer should be converted to 0x0a 0x0d. After completion, return the number | |
382 | * of bytes written. | |
383 | */ | |
384 | static int | |
385 | __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule, | |
d1e23375 | 386 | int convertlf, int may_schedule) |
1da177e4 LT |
387 | { |
388 | unsigned long flags; | |
389 | void *page; | |
390 | int written; | |
391 | int overall_written; | |
392 | ||
393 | if (count <= 0) | |
394 | return 0; | |
395 | overall_written = 0; | |
396 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
397 | do { | |
398 | /* Create a sclp output buffer if none exists yet */ | |
399 | if (sclp_vt220_current_request == NULL) { | |
400 | while (list_empty(&sclp_vt220_empty)) { | |
d1e23375 HC |
401 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); |
402 | if (in_interrupt() || !may_schedule) | |
1da177e4 LT |
403 | sclp_sync_wait(); |
404 | else | |
405 | wait_event(sclp_vt220_waitq, | |
406 | !list_empty(&sclp_vt220_empty)); | |
407 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
408 | } | |
409 | page = (void *) sclp_vt220_empty.next; | |
410 | list_del((struct list_head *) page); | |
411 | sclp_vt220_current_request = | |
412 | sclp_vt220_initialize_page(page); | |
413 | } | |
414 | /* Try to write the string to the current request buffer */ | |
415 | written = sclp_vt220_add_msg(sclp_vt220_current_request, | |
416 | buf, count, convertlf); | |
417 | overall_written += written; | |
418 | if (written == count) | |
419 | break; | |
420 | /* | |
421 | * Not all characters could be written to the current | |
422 | * output buffer. Emit the buffer, create a new buffer | |
423 | * and then output the rest of the string. | |
424 | */ | |
425 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
426 | sclp_vt220_emit_current(); | |
427 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
428 | buf += written; | |
429 | count -= written; | |
430 | } while (count > 0); | |
431 | /* Setup timer to output current console buffer after some time */ | |
432 | if (sclp_vt220_current_request != NULL && | |
433 | !timer_pending(&sclp_vt220_timer) && do_schedule) { | |
434 | sclp_vt220_timer.function = sclp_vt220_timeout; | |
435 | sclp_vt220_timer.data = 0UL; | |
436 | sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY; | |
437 | add_timer(&sclp_vt220_timer); | |
438 | } | |
439 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
440 | return overall_written; | |
441 | } | |
442 | ||
443 | /* | |
444 | * This routine is called by the kernel to write a series of | |
445 | * characters to the tty device. The characters may come from | |
446 | * user space or kernel space. This routine will return the | |
447 | * number of characters actually accepted for writing. | |
448 | */ | |
449 | static int | |
450 | sclp_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count) | |
451 | { | |
d1e23375 | 452 | return __sclp_vt220_write(buf, count, 1, 0, 1); |
1da177e4 LT |
453 | } |
454 | ||
455 | #define SCLP_VT220_SESSION_ENDED 0x01 | |
456 | #define SCLP_VT220_SESSION_STARTED 0x80 | |
457 | #define SCLP_VT220_SESSION_DATA 0x00 | |
458 | ||
459 | /* | |
460 | * Called by the SCLP to report incoming event buffers. | |
461 | */ | |
462 | static void | |
463 | sclp_vt220_receiver_fn(struct evbuf_header *evbuf) | |
464 | { | |
465 | char *buffer; | |
466 | unsigned int count; | |
467 | ||
468 | /* Ignore input if device is not open */ | |
469 | if (sclp_vt220_tty == NULL) | |
470 | return; | |
471 | ||
472 | buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header)); | |
473 | count = evbuf->length - sizeof(struct evbuf_header); | |
474 | ||
475 | switch (*buffer) { | |
476 | case SCLP_VT220_SESSION_ENDED: | |
477 | case SCLP_VT220_SESSION_STARTED: | |
478 | break; | |
479 | case SCLP_VT220_SESSION_DATA: | |
480 | /* Send input to line discipline */ | |
481 | buffer++; | |
482 | count--; | |
33f0f88f | 483 | tty_insert_flip_string(sclp_vt220_tty, buffer, count); |
1da177e4 LT |
484 | tty_flip_buffer_push(sclp_vt220_tty); |
485 | break; | |
486 | } | |
487 | } | |
488 | ||
489 | /* | |
490 | * This routine is called when a particular tty device is opened. | |
491 | */ | |
492 | static int | |
493 | sclp_vt220_open(struct tty_struct *tty, struct file *filp) | |
494 | { | |
495 | if (tty->count == 1) { | |
496 | sclp_vt220_tty = tty; | |
497 | tty->driver_data = kmalloc(SCLP_VT220_BUF_SIZE, GFP_KERNEL); | |
498 | if (tty->driver_data == NULL) | |
499 | return -ENOMEM; | |
500 | tty->low_latency = 0; | |
501 | } | |
502 | return 0; | |
503 | } | |
504 | ||
505 | /* | |
506 | * This routine is called when a particular tty device is closed. | |
507 | */ | |
508 | static void | |
509 | sclp_vt220_close(struct tty_struct *tty, struct file *filp) | |
510 | { | |
511 | if (tty->count == 1) { | |
512 | sclp_vt220_tty = NULL; | |
513 | kfree(tty->driver_data); | |
514 | tty->driver_data = NULL; | |
515 | } | |
516 | } | |
517 | ||
518 | /* | |
519 | * This routine is called by the kernel to write a single | |
520 | * character to the tty device. If the kernel uses this routine, | |
521 | * it must call the flush_chars() routine (if defined) when it is | |
522 | * done stuffing characters into the driver. | |
523 | * | |
524 | * NOTE: include/linux/tty_driver.h specifies that a character should be | |
525 | * ignored if there is no room in the queue. This driver implements a different | |
526 | * semantic in that it will block when there is no more room left. | |
527 | */ | |
528 | static void | |
529 | sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch) | |
530 | { | |
d1e23375 | 531 | __sclp_vt220_write(&ch, 1, 0, 0, 1); |
1da177e4 LT |
532 | } |
533 | ||
534 | /* | |
535 | * This routine is called by the kernel after it has written a | |
536 | * series of characters to the tty device using put_char(). | |
537 | */ | |
538 | static void | |
539 | sclp_vt220_flush_chars(struct tty_struct *tty) | |
540 | { | |
541 | if (sclp_vt220_outqueue_count == 0) | |
542 | sclp_vt220_emit_current(); | |
543 | else | |
544 | sclp_vt220_flush_later = 1; | |
545 | } | |
546 | ||
547 | /* | |
548 | * This routine returns the numbers of characters the tty driver | |
549 | * will accept for queuing to be written. This number is subject | |
550 | * to change as output buffers get emptied, or if the output flow | |
551 | * control is acted. | |
552 | */ | |
553 | static int | |
554 | sclp_vt220_write_room(struct tty_struct *tty) | |
555 | { | |
556 | unsigned long flags; | |
557 | struct list_head *l; | |
558 | int count; | |
559 | ||
560 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
561 | count = 0; | |
562 | if (sclp_vt220_current_request != NULL) | |
563 | count = sclp_vt220_space_left(sclp_vt220_current_request); | |
564 | list_for_each(l, &sclp_vt220_empty) | |
565 | count += SCLP_VT220_MAX_CHARS_PER_BUFFER; | |
566 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
567 | return count; | |
568 | } | |
569 | ||
570 | /* | |
571 | * Return number of buffered chars. | |
572 | */ | |
573 | static int | |
574 | sclp_vt220_chars_in_buffer(struct tty_struct *tty) | |
575 | { | |
576 | unsigned long flags; | |
577 | struct list_head *l; | |
578 | struct sclp_vt220_request *r; | |
579 | int count; | |
580 | ||
581 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
582 | count = 0; | |
583 | if (sclp_vt220_current_request != NULL) | |
584 | count = sclp_vt220_chars_stored(sclp_vt220_current_request); | |
585 | list_for_each(l, &sclp_vt220_outqueue) { | |
586 | r = list_entry(l, struct sclp_vt220_request, list); | |
587 | count += sclp_vt220_chars_stored(r); | |
588 | } | |
589 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
590 | return count; | |
591 | } | |
592 | ||
593 | static void | |
594 | __sclp_vt220_flush_buffer(void) | |
595 | { | |
596 | unsigned long flags; | |
597 | ||
598 | sclp_vt220_emit_current(); | |
599 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
600 | if (timer_pending(&sclp_vt220_timer)) | |
601 | del_timer(&sclp_vt220_timer); | |
602 | while (sclp_vt220_outqueue_count > 0) { | |
603 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
604 | sclp_sync_wait(); | |
605 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
606 | } | |
607 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
608 | } | |
609 | ||
610 | /* | |
611 | * Pass on all buffers to the hardware. Return only when there are no more | |
612 | * buffers pending. | |
613 | */ | |
614 | static void | |
615 | sclp_vt220_flush_buffer(struct tty_struct *tty) | |
616 | { | |
617 | sclp_vt220_emit_current(); | |
618 | } | |
619 | ||
620 | /* | |
621 | * Initialize all relevant components and register driver with system. | |
622 | */ | |
5aaaf9f0 HC |
623 | static void __init __sclp_vt220_cleanup(void) |
624 | { | |
625 | struct list_head *page, *p; | |
626 | ||
627 | list_for_each_safe(page, p, &sclp_vt220_empty) { | |
628 | list_del(page); | |
629 | if (slab_is_available()) | |
630 | free_page((unsigned long) page); | |
631 | else | |
632 | free_bootmem((unsigned long) page, PAGE_SIZE); | |
633 | } | |
59eb1ca7 CB |
634 | if (!list_empty(&sclp_vt220_register.list)) |
635 | sclp_unregister(&sclp_vt220_register); | |
636 | sclp_vt220_initialized = 0; | |
5aaaf9f0 HC |
637 | } |
638 | ||
639 | static int __init __sclp_vt220_init(void) | |
1da177e4 LT |
640 | { |
641 | void *page; | |
642 | int i; | |
5aaaf9f0 | 643 | int num_pages; |
59eb1ca7 | 644 | int rc; |
1da177e4 LT |
645 | |
646 | if (sclp_vt220_initialized) | |
647 | return 0; | |
648 | sclp_vt220_initialized = 1; | |
649 | spin_lock_init(&sclp_vt220_lock); | |
650 | INIT_LIST_HEAD(&sclp_vt220_empty); | |
651 | INIT_LIST_HEAD(&sclp_vt220_outqueue); | |
652 | init_waitqueue_head(&sclp_vt220_waitq); | |
653 | init_timer(&sclp_vt220_timer); | |
654 | sclp_vt220_current_request = NULL; | |
655 | sclp_vt220_buffered_chars = 0; | |
656 | sclp_vt220_outqueue_count = 0; | |
657 | sclp_vt220_tty = NULL; | |
658 | sclp_vt220_flush_later = 0; | |
659 | ||
660 | /* Allocate pages for output buffering */ | |
5aaaf9f0 HC |
661 | num_pages = slab_is_available() ? MAX_KMEM_PAGES : MAX_CONSOLE_PAGES; |
662 | for (i = 0; i < num_pages; i++) { | |
663 | if (slab_is_available()) | |
1da177e4 | 664 | page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); |
5aaaf9f0 HC |
665 | else |
666 | page = alloc_bootmem_low_pages(PAGE_SIZE); | |
667 | if (!page) { | |
668 | __sclp_vt220_cleanup(); | |
1da177e4 | 669 | return -ENOMEM; |
5aaaf9f0 | 670 | } |
1da177e4 LT |
671 | list_add_tail((struct list_head *) page, &sclp_vt220_empty); |
672 | } | |
59eb1ca7 CB |
673 | rc = sclp_register(&sclp_vt220_register); |
674 | if (rc) { | |
675 | printk(KERN_ERR SCLP_VT220_PRINT_HEADER | |
676 | "could not register vt220 - " | |
677 | "sclp_register returned %d\n", rc); | |
678 | __sclp_vt220_cleanup(); | |
679 | } | |
680 | return rc; | |
1da177e4 LT |
681 | } |
682 | ||
b68e31d0 | 683 | static const struct tty_operations sclp_vt220_ops = { |
1da177e4 LT |
684 | .open = sclp_vt220_open, |
685 | .close = sclp_vt220_close, | |
686 | .write = sclp_vt220_write, | |
687 | .put_char = sclp_vt220_put_char, | |
688 | .flush_chars = sclp_vt220_flush_chars, | |
689 | .write_room = sclp_vt220_write_room, | |
690 | .chars_in_buffer = sclp_vt220_chars_in_buffer, | |
5aaaf9f0 | 691 | .flush_buffer = sclp_vt220_flush_buffer, |
1da177e4 LT |
692 | }; |
693 | ||
694 | /* | |
695 | * Register driver with SCLP and Linux and initialize internal tty structures. | |
696 | */ | |
5aaaf9f0 | 697 | static int __init sclp_vt220_tty_init(void) |
1da177e4 LT |
698 | { |
699 | struct tty_driver *driver; | |
700 | int rc; | |
59eb1ca7 | 701 | int cleanup; |
1da177e4 LT |
702 | |
703 | /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve | |
704 | * symmetry between VM and LPAR systems regarding ttyS1. */ | |
705 | driver = alloc_tty_driver(1); | |
706 | if (!driver) | |
707 | return -ENOMEM; | |
59eb1ca7 | 708 | cleanup = !sclp_vt220_initialized; |
5aaaf9f0 HC |
709 | rc = __sclp_vt220_init(); |
710 | if (rc) | |
711 | goto out_driver; | |
1da177e4 LT |
712 | |
713 | driver->owner = THIS_MODULE; | |
714 | driver->driver_name = SCLP_VT220_DRIVER_NAME; | |
715 | driver->name = SCLP_VT220_DEVICE_NAME; | |
716 | driver->major = SCLP_VT220_MAJOR; | |
717 | driver->minor_start = SCLP_VT220_MINOR; | |
718 | driver->type = TTY_DRIVER_TYPE_SYSTEM; | |
719 | driver->subtype = SYSTEM_TYPE_TTY; | |
720 | driver->init_termios = tty_std_termios; | |
721 | driver->flags = TTY_DRIVER_REAL_RAW; | |
722 | tty_set_operations(driver, &sclp_vt220_ops); | |
723 | ||
724 | rc = tty_register_driver(driver); | |
725 | if (rc) { | |
726 | printk(KERN_ERR SCLP_VT220_PRINT_HEADER | |
727 | "could not register tty - " | |
728 | "tty_register_driver returned %d\n", rc); | |
59eb1ca7 | 729 | goto out_init; |
1da177e4 LT |
730 | } |
731 | sclp_vt220_driver = driver; | |
732 | return 0; | |
1da177e4 | 733 | |
5aaaf9f0 | 734 | out_init: |
59eb1ca7 CB |
735 | if (cleanup) |
736 | __sclp_vt220_cleanup(); | |
5aaaf9f0 HC |
737 | out_driver: |
738 | put_tty_driver(driver); | |
739 | return rc; | |
740 | } | |
741 | __initcall(sclp_vt220_tty_init); | |
1da177e4 LT |
742 | |
743 | #ifdef CONFIG_SCLP_VT220_CONSOLE | |
744 | ||
745 | static void | |
746 | sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count) | |
747 | { | |
d1e23375 | 748 | __sclp_vt220_write((const unsigned char *) buf, count, 1, 1, 0); |
1da177e4 LT |
749 | } |
750 | ||
751 | static struct tty_driver * | |
752 | sclp_vt220_con_device(struct console *c, int *index) | |
753 | { | |
754 | *index = 0; | |
755 | return sclp_vt220_driver; | |
756 | } | |
757 | ||
758 | /* | |
759 | * This routine is called from panic when the kernel is going to give up. | |
760 | * We have to make sure that all buffers will be flushed to the SCLP. | |
761 | * Note that this function may be called from within an interrupt context. | |
762 | */ | |
763 | static void | |
764 | sclp_vt220_con_unblank(void) | |
765 | { | |
766 | __sclp_vt220_flush_buffer(); | |
767 | } | |
768 | ||
769 | /* Structure needed to register with printk */ | |
770 | static struct console sclp_vt220_console = | |
771 | { | |
772 | .name = SCLP_VT220_CONSOLE_NAME, | |
773 | .write = sclp_vt220_con_write, | |
774 | .device = sclp_vt220_con_device, | |
775 | .unblank = sclp_vt220_con_unblank, | |
776 | .flags = CON_PRINTBUFFER, | |
777 | .index = SCLP_VT220_CONSOLE_INDEX | |
778 | }; | |
779 | ||
780 | static int __init | |
781 | sclp_vt220_con_init(void) | |
782 | { | |
783 | int rc; | |
784 | ||
785 | if (!CONSOLE_IS_SCLP) | |
786 | return 0; | |
5aaaf9f0 | 787 | rc = __sclp_vt220_init(); |
1da177e4 LT |
788 | if (rc) |
789 | return rc; | |
790 | /* Attach linux console */ | |
791 | register_console(&sclp_vt220_console); | |
792 | return 0; | |
793 | } | |
794 | ||
795 | console_initcall(sclp_vt220_con_init); | |
796 | #endif /* CONFIG_SCLP_VT220_CONSOLE */ | |
797 |