Commit | Line | Data |
---|---|---|
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 | ||
1da177e4 LT |
74 | /* Timer used for delaying write requests to merge subsequent messages into |
75 | * a single buffer */ | |
76 | static struct timer_list sclp_vt220_timer; | |
77 | ||
78 | /* Pointer to current request buffer which has been partially filled but not | |
79 | * yet sent */ | |
80 | static struct sclp_vt220_request *sclp_vt220_current_request; | |
81 | ||
82 | /* Number of characters in current request buffer */ | |
83 | static int sclp_vt220_buffered_chars; | |
84 | ||
ad211790 PO |
85 | /* Counter controlling core driver initialization. */ |
86 | static int __initdata sclp_vt220_init_count; | |
1da177e4 LT |
87 | |
88 | /* Flag indicating that sclp_vt220_current_request should really | |
89 | * have been already queued but wasn't because the SCLP was processing | |
90 | * another buffer */ | |
91 | static int sclp_vt220_flush_later; | |
92 | ||
93 | static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf); | |
94 | static int __sclp_vt220_emit(struct sclp_vt220_request *request); | |
95 | static void sclp_vt220_emit_current(void); | |
96 | ||
97 | /* Registration structure for our interest in SCLP event buffers */ | |
98 | static struct sclp_register sclp_vt220_register = { | |
6d4740c8 SH |
99 | .send_mask = EVTYP_VT220MSG_MASK, |
100 | .receive_mask = EVTYP_VT220MSG_MASK, | |
1da177e4 LT |
101 | .state_change_fn = NULL, |
102 | .receiver_fn = sclp_vt220_receiver_fn | |
103 | }; | |
104 | ||
105 | ||
106 | /* | |
107 | * Put provided request buffer back into queue and check emit pending | |
108 | * buffers if necessary. | |
109 | */ | |
110 | static void | |
111 | sclp_vt220_process_queue(struct sclp_vt220_request *request) | |
112 | { | |
113 | unsigned long flags; | |
114 | void *page; | |
115 | ||
116 | do { | |
117 | /* Put buffer back to list of empty buffers */ | |
118 | page = request->sclp_req.sccb; | |
119 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
120 | /* Move request from outqueue to empty queue */ | |
121 | list_del(&request->list); | |
122 | sclp_vt220_outqueue_count--; | |
123 | list_add_tail((struct list_head *) page, &sclp_vt220_empty); | |
124 | /* Check if there is a pending buffer on the out queue. */ | |
125 | request = NULL; | |
126 | if (!list_empty(&sclp_vt220_outqueue)) | |
127 | request = list_entry(sclp_vt220_outqueue.next, | |
128 | struct sclp_vt220_request, list); | |
129 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
130 | } while (request && __sclp_vt220_emit(request)); | |
131 | if (request == NULL && sclp_vt220_flush_later) | |
132 | sclp_vt220_emit_current(); | |
1da177e4 LT |
133 | /* Check if the tty needs a wake up call */ |
134 | if (sclp_vt220_tty != NULL) { | |
135 | tty_wakeup(sclp_vt220_tty); | |
136 | } | |
137 | } | |
138 | ||
139 | #define SCLP_BUFFER_MAX_RETRY 1 | |
140 | ||
141 | /* | |
142 | * Callback through which the result of a write request is reported by the | |
143 | * SCLP. | |
144 | */ | |
145 | static void | |
146 | sclp_vt220_callback(struct sclp_req *request, void *data) | |
147 | { | |
148 | struct sclp_vt220_request *vt220_request; | |
149 | struct sclp_vt220_sccb *sccb; | |
150 | ||
151 | vt220_request = (struct sclp_vt220_request *) data; | |
152 | if (request->status == SCLP_REQ_FAILED) { | |
153 | sclp_vt220_process_queue(vt220_request); | |
154 | return; | |
155 | } | |
156 | sccb = (struct sclp_vt220_sccb *) vt220_request->sclp_req.sccb; | |
157 | ||
158 | /* Check SCLP response code and choose suitable action */ | |
159 | switch (sccb->header.response_code) { | |
160 | case 0x0020 : | |
161 | break; | |
162 | ||
163 | case 0x05f0: /* Target resource in improper state */ | |
164 | break; | |
165 | ||
166 | case 0x0340: /* Contained SCLP equipment check */ | |
167 | if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) | |
168 | break; | |
169 | /* Remove processed buffers and requeue rest */ | |
170 | if (sclp_remove_processed((struct sccb_header *) sccb) > 0) { | |
171 | /* Not all buffers were processed */ | |
172 | sccb->header.response_code = 0x0000; | |
173 | vt220_request->sclp_req.status = SCLP_REQ_FILLED; | |
174 | if (sclp_add_request(request) == 0) | |
175 | return; | |
176 | } | |
177 | break; | |
178 | ||
179 | case 0x0040: /* SCLP equipment check */ | |
180 | if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) | |
181 | break; | |
182 | sccb->header.response_code = 0x0000; | |
183 | vt220_request->sclp_req.status = SCLP_REQ_FILLED; | |
184 | if (sclp_add_request(request) == 0) | |
185 | return; | |
186 | break; | |
187 | ||
188 | default: | |
189 | break; | |
190 | } | |
191 | sclp_vt220_process_queue(vt220_request); | |
192 | } | |
193 | ||
194 | /* | |
195 | * Emit vt220 request buffer to SCLP. Return zero on success, non-zero | |
196 | * otherwise. | |
197 | */ | |
198 | static int | |
199 | __sclp_vt220_emit(struct sclp_vt220_request *request) | |
200 | { | |
d082d3ce | 201 | if (!(sclp_vt220_register.sclp_receive_mask & EVTYP_VT220MSG_MASK)) { |
1da177e4 LT |
202 | request->sclp_req.status = SCLP_REQ_FAILED; |
203 | return -EIO; | |
204 | } | |
ab14de6c | 205 | request->sclp_req.command = SCLP_CMDW_WRITE_EVENT_DATA; |
1da177e4 LT |
206 | request->sclp_req.status = SCLP_REQ_FILLED; |
207 | request->sclp_req.callback = sclp_vt220_callback; | |
208 | request->sclp_req.callback_data = (void *) request; | |
209 | ||
210 | return sclp_add_request(&request->sclp_req); | |
211 | } | |
212 | ||
213 | /* | |
214 | * Queue and emit given request. | |
215 | */ | |
216 | static void | |
217 | sclp_vt220_emit(struct sclp_vt220_request *request) | |
218 | { | |
219 | unsigned long flags; | |
220 | int count; | |
221 | ||
222 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
223 | list_add_tail(&request->list, &sclp_vt220_outqueue); | |
224 | count = sclp_vt220_outqueue_count++; | |
225 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
226 | /* Emit only the first buffer immediately - callback takes care of | |
227 | * the rest */ | |
228 | if (count == 0 && __sclp_vt220_emit(request)) | |
229 | sclp_vt220_process_queue(request); | |
230 | } | |
231 | ||
232 | /* | |
233 | * Queue and emit current request. Return zero on success, non-zero otherwise. | |
234 | */ | |
235 | static void | |
236 | sclp_vt220_emit_current(void) | |
237 | { | |
238 | unsigned long flags; | |
239 | struct sclp_vt220_request *request; | |
240 | struct sclp_vt220_sccb *sccb; | |
241 | ||
242 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
243 | request = NULL; | |
244 | if (sclp_vt220_current_request != NULL) { | |
245 | sccb = (struct sclp_vt220_sccb *) | |
246 | sclp_vt220_current_request->sclp_req.sccb; | |
247 | /* Only emit buffers with content */ | |
248 | if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) { | |
249 | request = sclp_vt220_current_request; | |
250 | sclp_vt220_current_request = NULL; | |
251 | if (timer_pending(&sclp_vt220_timer)) | |
252 | del_timer(&sclp_vt220_timer); | |
253 | } | |
254 | sclp_vt220_flush_later = 0; | |
255 | } | |
256 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
257 | if (request != NULL) | |
258 | sclp_vt220_emit(request); | |
259 | } | |
260 | ||
261 | #define SCLP_NORMAL_WRITE 0x00 | |
262 | ||
263 | /* | |
264 | * Helper function to initialize a page with the sclp request structure. | |
265 | */ | |
266 | static struct sclp_vt220_request * | |
267 | sclp_vt220_initialize_page(void *page) | |
268 | { | |
269 | struct sclp_vt220_request *request; | |
270 | struct sclp_vt220_sccb *sccb; | |
271 | ||
272 | /* Place request structure at end of page */ | |
273 | request = ((struct sclp_vt220_request *) | |
274 | ((addr_t) page + PAGE_SIZE)) - 1; | |
275 | request->retry_count = 0; | |
276 | request->sclp_req.sccb = page; | |
277 | /* SCCB goes at start of page */ | |
278 | sccb = (struct sclp_vt220_sccb *) page; | |
279 | memset((void *) sccb, 0, sizeof(struct sclp_vt220_sccb)); | |
280 | sccb->header.length = sizeof(struct sclp_vt220_sccb); | |
281 | sccb->header.function_code = SCLP_NORMAL_WRITE; | |
282 | sccb->header.response_code = 0x0000; | |
6d4740c8 | 283 | sccb->evbuf.type = EVTYP_VT220MSG; |
1da177e4 LT |
284 | sccb->evbuf.length = sizeof(struct evbuf_header); |
285 | ||
286 | return request; | |
287 | } | |
288 | ||
289 | static inline unsigned int | |
290 | sclp_vt220_space_left(struct sclp_vt220_request *request) | |
291 | { | |
292 | struct sclp_vt220_sccb *sccb; | |
293 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
294 | return PAGE_SIZE - sizeof(struct sclp_vt220_request) - | |
295 | sccb->header.length; | |
296 | } | |
297 | ||
298 | static inline unsigned int | |
299 | sclp_vt220_chars_stored(struct sclp_vt220_request *request) | |
300 | { | |
301 | struct sclp_vt220_sccb *sccb; | |
302 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
303 | return sccb->evbuf.length - sizeof(struct evbuf_header); | |
304 | } | |
305 | ||
306 | /* | |
307 | * Add msg to buffer associated with request. Return the number of characters | |
308 | * added. | |
309 | */ | |
310 | static int | |
311 | sclp_vt220_add_msg(struct sclp_vt220_request *request, | |
312 | const unsigned char *msg, int count, int convertlf) | |
313 | { | |
314 | struct sclp_vt220_sccb *sccb; | |
315 | void *buffer; | |
316 | unsigned char c; | |
317 | int from; | |
318 | int to; | |
319 | ||
320 | if (count > sclp_vt220_space_left(request)) | |
321 | count = sclp_vt220_space_left(request); | |
322 | if (count <= 0) | |
323 | return 0; | |
324 | ||
325 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
326 | buffer = (void *) ((addr_t) sccb + sccb->header.length); | |
327 | ||
328 | if (convertlf) { | |
329 | /* Perform Linefeed conversion (0x0a -> 0x0a 0x0d)*/ | |
330 | for (from=0, to=0; | |
331 | (from < count) && (to < sclp_vt220_space_left(request)); | |
332 | from++) { | |
333 | /* Retrieve character */ | |
334 | c = msg[from]; | |
335 | /* Perform conversion */ | |
336 | if (c == 0x0a) { | |
337 | if (to + 1 < sclp_vt220_space_left(request)) { | |
338 | ((unsigned char *) buffer)[to++] = c; | |
339 | ((unsigned char *) buffer)[to++] = 0x0d; | |
340 | } else | |
341 | break; | |
342 | ||
343 | } else | |
344 | ((unsigned char *) buffer)[to++] = c; | |
345 | } | |
346 | sccb->header.length += to; | |
347 | sccb->evbuf.length += to; | |
348 | return from; | |
349 | } else { | |
350 | memcpy(buffer, (const void *) msg, count); | |
351 | sccb->header.length += count; | |
352 | sccb->evbuf.length += count; | |
353 | return count; | |
354 | } | |
355 | } | |
356 | ||
357 | /* | |
358 | * Emit buffer after having waited long enough for more data to arrive. | |
359 | */ | |
360 | static void | |
361 | sclp_vt220_timeout(unsigned long data) | |
362 | { | |
363 | sclp_vt220_emit_current(); | |
364 | } | |
365 | ||
fa331ffc | 366 | #define BUFFER_MAX_DELAY HZ/20 |
1da177e4 LT |
367 | |
368 | /* | |
369 | * Internal implementation of the write function. Write COUNT bytes of data | |
370 | * from memory at BUF | |
371 | * to the SCLP interface. In case that the data does not fit into the current | |
372 | * write buffer, emit the current one and allocate a new one. If there are no | |
373 | * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE | |
374 | * is non-zero, the buffer will be scheduled for emitting after a timeout - | |
375 | * otherwise the user has to explicitly call the flush function. | |
376 | * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message | |
377 | * buffer should be converted to 0x0a 0x0d. After completion, return the number | |
378 | * of bytes written. | |
379 | */ | |
380 | static int | |
381 | __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule, | |
d4820e44 | 382 | int convertlf, int may_fail) |
1da177e4 LT |
383 | { |
384 | unsigned long flags; | |
385 | void *page; | |
386 | int written; | |
387 | int overall_written; | |
388 | ||
389 | if (count <= 0) | |
390 | return 0; | |
391 | overall_written = 0; | |
392 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
393 | do { | |
d4820e44 | 394 | /* Create an sclp output buffer if none exists yet */ |
1da177e4 LT |
395 | if (sclp_vt220_current_request == NULL) { |
396 | while (list_empty(&sclp_vt220_empty)) { | |
d1e23375 | 397 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); |
d4820e44 HC |
398 | if (may_fail) |
399 | goto out; | |
1da177e4 | 400 | else |
d4820e44 | 401 | sclp_sync_wait(); |
1da177e4 LT |
402 | spin_lock_irqsave(&sclp_vt220_lock, flags); |
403 | } | |
404 | page = (void *) sclp_vt220_empty.next; | |
405 | list_del((struct list_head *) page); | |
406 | sclp_vt220_current_request = | |
407 | sclp_vt220_initialize_page(page); | |
408 | } | |
409 | /* Try to write the string to the current request buffer */ | |
410 | written = sclp_vt220_add_msg(sclp_vt220_current_request, | |
411 | buf, count, convertlf); | |
412 | overall_written += written; | |
413 | if (written == count) | |
414 | break; | |
415 | /* | |
416 | * Not all characters could be written to the current | |
417 | * output buffer. Emit the buffer, create a new buffer | |
418 | * and then output the rest of the string. | |
419 | */ | |
420 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
421 | sclp_vt220_emit_current(); | |
422 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
423 | buf += written; | |
424 | count -= written; | |
425 | } while (count > 0); | |
426 | /* Setup timer to output current console buffer after some time */ | |
427 | if (sclp_vt220_current_request != NULL && | |
428 | !timer_pending(&sclp_vt220_timer) && do_schedule) { | |
429 | sclp_vt220_timer.function = sclp_vt220_timeout; | |
430 | sclp_vt220_timer.data = 0UL; | |
431 | sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY; | |
432 | add_timer(&sclp_vt220_timer); | |
433 | } | |
434 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
d4820e44 | 435 | out: |
1da177e4 LT |
436 | return overall_written; |
437 | } | |
438 | ||
439 | /* | |
440 | * This routine is called by the kernel to write a series of | |
441 | * characters to the tty device. The characters may come from | |
442 | * user space or kernel space. This routine will return the | |
443 | * number of characters actually accepted for writing. | |
444 | */ | |
445 | static int | |
446 | sclp_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count) | |
447 | { | |
d1e23375 | 448 | return __sclp_vt220_write(buf, count, 1, 0, 1); |
1da177e4 LT |
449 | } |
450 | ||
451 | #define SCLP_VT220_SESSION_ENDED 0x01 | |
452 | #define SCLP_VT220_SESSION_STARTED 0x80 | |
453 | #define SCLP_VT220_SESSION_DATA 0x00 | |
454 | ||
455 | /* | |
456 | * Called by the SCLP to report incoming event buffers. | |
457 | */ | |
458 | static void | |
459 | sclp_vt220_receiver_fn(struct evbuf_header *evbuf) | |
460 | { | |
461 | char *buffer; | |
462 | unsigned int count; | |
463 | ||
464 | /* Ignore input if device is not open */ | |
465 | if (sclp_vt220_tty == NULL) | |
466 | return; | |
467 | ||
468 | buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header)); | |
469 | count = evbuf->length - sizeof(struct evbuf_header); | |
470 | ||
471 | switch (*buffer) { | |
472 | case SCLP_VT220_SESSION_ENDED: | |
473 | case SCLP_VT220_SESSION_STARTED: | |
474 | break; | |
475 | case SCLP_VT220_SESSION_DATA: | |
476 | /* Send input to line discipline */ | |
477 | buffer++; | |
478 | count--; | |
33f0f88f | 479 | tty_insert_flip_string(sclp_vt220_tty, buffer, count); |
1da177e4 LT |
480 | tty_flip_buffer_push(sclp_vt220_tty); |
481 | break; | |
482 | } | |
483 | } | |
484 | ||
485 | /* | |
486 | * This routine is called when a particular tty device is opened. | |
487 | */ | |
488 | static int | |
489 | sclp_vt220_open(struct tty_struct *tty, struct file *filp) | |
490 | { | |
491 | if (tty->count == 1) { | |
492 | sclp_vt220_tty = tty; | |
493 | tty->driver_data = kmalloc(SCLP_VT220_BUF_SIZE, GFP_KERNEL); | |
494 | if (tty->driver_data == NULL) | |
495 | return -ENOMEM; | |
496 | tty->low_latency = 0; | |
497 | } | |
498 | return 0; | |
499 | } | |
500 | ||
501 | /* | |
502 | * This routine is called when a particular tty device is closed. | |
503 | */ | |
504 | static void | |
505 | sclp_vt220_close(struct tty_struct *tty, struct file *filp) | |
506 | { | |
507 | if (tty->count == 1) { | |
508 | sclp_vt220_tty = NULL; | |
509 | kfree(tty->driver_data); | |
510 | tty->driver_data = NULL; | |
511 | } | |
512 | } | |
513 | ||
514 | /* | |
515 | * This routine is called by the kernel to write a single | |
516 | * character to the tty device. If the kernel uses this routine, | |
517 | * it must call the flush_chars() routine (if defined) when it is | |
518 | * done stuffing characters into the driver. | |
1da177e4 | 519 | */ |
9e7c9a19 | 520 | static int |
1da177e4 LT |
521 | sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch) |
522 | { | |
d4820e44 | 523 | return __sclp_vt220_write(&ch, 1, 0, 0, 1); |
1da177e4 LT |
524 | } |
525 | ||
526 | /* | |
527 | * This routine is called by the kernel after it has written a | |
528 | * series of characters to the tty device using put_char(). | |
529 | */ | |
530 | static void | |
531 | sclp_vt220_flush_chars(struct tty_struct *tty) | |
532 | { | |
533 | if (sclp_vt220_outqueue_count == 0) | |
534 | sclp_vt220_emit_current(); | |
535 | else | |
536 | sclp_vt220_flush_later = 1; | |
537 | } | |
538 | ||
539 | /* | |
540 | * This routine returns the numbers of characters the tty driver | |
541 | * will accept for queuing to be written. This number is subject | |
542 | * to change as output buffers get emptied, or if the output flow | |
543 | * control is acted. | |
544 | */ | |
545 | static int | |
546 | sclp_vt220_write_room(struct tty_struct *tty) | |
547 | { | |
548 | unsigned long flags; | |
549 | struct list_head *l; | |
550 | int count; | |
551 | ||
552 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
553 | count = 0; | |
554 | if (sclp_vt220_current_request != NULL) | |
555 | count = sclp_vt220_space_left(sclp_vt220_current_request); | |
556 | list_for_each(l, &sclp_vt220_empty) | |
557 | count += SCLP_VT220_MAX_CHARS_PER_BUFFER; | |
558 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
559 | return count; | |
560 | } | |
561 | ||
562 | /* | |
563 | * Return number of buffered chars. | |
564 | */ | |
565 | static int | |
566 | sclp_vt220_chars_in_buffer(struct tty_struct *tty) | |
567 | { | |
568 | unsigned long flags; | |
569 | struct list_head *l; | |
570 | struct sclp_vt220_request *r; | |
571 | int count; | |
572 | ||
573 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
574 | count = 0; | |
575 | if (sclp_vt220_current_request != NULL) | |
576 | count = sclp_vt220_chars_stored(sclp_vt220_current_request); | |
577 | list_for_each(l, &sclp_vt220_outqueue) { | |
578 | r = list_entry(l, struct sclp_vt220_request, list); | |
579 | count += sclp_vt220_chars_stored(r); | |
580 | } | |
581 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
582 | return count; | |
583 | } | |
584 | ||
585 | static void | |
586 | __sclp_vt220_flush_buffer(void) | |
587 | { | |
588 | unsigned long flags; | |
589 | ||
590 | sclp_vt220_emit_current(); | |
591 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
592 | if (timer_pending(&sclp_vt220_timer)) | |
593 | del_timer(&sclp_vt220_timer); | |
594 | while (sclp_vt220_outqueue_count > 0) { | |
595 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
596 | sclp_sync_wait(); | |
597 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
598 | } | |
599 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
600 | } | |
601 | ||
602 | /* | |
603 | * Pass on all buffers to the hardware. Return only when there are no more | |
604 | * buffers pending. | |
605 | */ | |
606 | static void | |
607 | sclp_vt220_flush_buffer(struct tty_struct *tty) | |
608 | { | |
609 | sclp_vt220_emit_current(); | |
610 | } | |
611 | ||
ad211790 PO |
612 | /* Release allocated pages. */ |
613 | static void __init __sclp_vt220_free_pages(void) | |
5aaaf9f0 HC |
614 | { |
615 | struct list_head *page, *p; | |
616 | ||
617 | list_for_each_safe(page, p, &sclp_vt220_empty) { | |
618 | list_del(page); | |
619 | if (slab_is_available()) | |
620 | free_page((unsigned long) page); | |
621 | else | |
622 | free_bootmem((unsigned long) page, PAGE_SIZE); | |
623 | } | |
624 | } | |
625 | ||
ad211790 PO |
626 | /* Release memory and unregister from sclp core. Controlled by init counting - |
627 | * only the last invoker will actually perform these actions. */ | |
628 | static void __init __sclp_vt220_cleanup(void) | |
629 | { | |
630 | sclp_vt220_init_count--; | |
631 | if (sclp_vt220_init_count != 0) | |
632 | return; | |
633 | sclp_unregister(&sclp_vt220_register); | |
634 | __sclp_vt220_free_pages(); | |
635 | } | |
636 | ||
637 | /* Allocate buffer pages and register with sclp core. Controlled by init | |
638 | * counting - only the first invoker will actually perform these actions. */ | |
639 | static int __init __sclp_vt220_init(int num_pages) | |
1da177e4 LT |
640 | { |
641 | void *page; | |
642 | int i; | |
59eb1ca7 | 643 | int rc; |
1da177e4 | 644 | |
ad211790 PO |
645 | sclp_vt220_init_count++; |
646 | if (sclp_vt220_init_count != 1) | |
1da177e4 | 647 | return 0; |
1da177e4 LT |
648 | spin_lock_init(&sclp_vt220_lock); |
649 | INIT_LIST_HEAD(&sclp_vt220_empty); | |
650 | INIT_LIST_HEAD(&sclp_vt220_outqueue); | |
1da177e4 LT |
651 | init_timer(&sclp_vt220_timer); |
652 | sclp_vt220_current_request = NULL; | |
653 | sclp_vt220_buffered_chars = 0; | |
654 | sclp_vt220_outqueue_count = 0; | |
655 | sclp_vt220_tty = NULL; | |
656 | sclp_vt220_flush_later = 0; | |
657 | ||
658 | /* Allocate pages for output buffering */ | |
5aaaf9f0 HC |
659 | for (i = 0; i < num_pages; i++) { |
660 | if (slab_is_available()) | |
1da177e4 | 661 | page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); |
5aaaf9f0 HC |
662 | else |
663 | page = alloc_bootmem_low_pages(PAGE_SIZE); | |
664 | if (!page) { | |
ad211790 PO |
665 | rc = -ENOMEM; |
666 | goto out; | |
5aaaf9f0 | 667 | } |
1da177e4 LT |
668 | list_add_tail((struct list_head *) page, &sclp_vt220_empty); |
669 | } | |
59eb1ca7 | 670 | rc = sclp_register(&sclp_vt220_register); |
ad211790 | 671 | out: |
59eb1ca7 | 672 | if (rc) { |
ad211790 PO |
673 | __sclp_vt220_free_pages(); |
674 | sclp_vt220_init_count--; | |
59eb1ca7 CB |
675 | } |
676 | return rc; | |
1da177e4 LT |
677 | } |
678 | ||
b68e31d0 | 679 | static const struct tty_operations sclp_vt220_ops = { |
1da177e4 LT |
680 | .open = sclp_vt220_open, |
681 | .close = sclp_vt220_close, | |
682 | .write = sclp_vt220_write, | |
683 | .put_char = sclp_vt220_put_char, | |
684 | .flush_chars = sclp_vt220_flush_chars, | |
685 | .write_room = sclp_vt220_write_room, | |
686 | .chars_in_buffer = sclp_vt220_chars_in_buffer, | |
5aaaf9f0 | 687 | .flush_buffer = sclp_vt220_flush_buffer, |
1da177e4 LT |
688 | }; |
689 | ||
690 | /* | |
691 | * Register driver with SCLP and Linux and initialize internal tty structures. | |
692 | */ | |
5aaaf9f0 | 693 | static int __init sclp_vt220_tty_init(void) |
1da177e4 LT |
694 | { |
695 | struct tty_driver *driver; | |
696 | int rc; | |
697 | ||
698 | /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve | |
699 | * symmetry between VM and LPAR systems regarding ttyS1. */ | |
700 | driver = alloc_tty_driver(1); | |
701 | if (!driver) | |
702 | return -ENOMEM; | |
ad211790 | 703 | rc = __sclp_vt220_init(MAX_KMEM_PAGES); |
5aaaf9f0 HC |
704 | if (rc) |
705 | goto out_driver; | |
1da177e4 LT |
706 | |
707 | driver->owner = THIS_MODULE; | |
708 | driver->driver_name = SCLP_VT220_DRIVER_NAME; | |
709 | driver->name = SCLP_VT220_DEVICE_NAME; | |
710 | driver->major = SCLP_VT220_MAJOR; | |
711 | driver->minor_start = SCLP_VT220_MINOR; | |
712 | driver->type = TTY_DRIVER_TYPE_SYSTEM; | |
713 | driver->subtype = SYSTEM_TYPE_TTY; | |
714 | driver->init_termios = tty_std_termios; | |
715 | driver->flags = TTY_DRIVER_REAL_RAW; | |
716 | tty_set_operations(driver, &sclp_vt220_ops); | |
717 | ||
718 | rc = tty_register_driver(driver); | |
719 | if (rc) { | |
720 | printk(KERN_ERR SCLP_VT220_PRINT_HEADER | |
721 | "could not register tty - " | |
722 | "tty_register_driver returned %d\n", rc); | |
59eb1ca7 | 723 | goto out_init; |
1da177e4 LT |
724 | } |
725 | sclp_vt220_driver = driver; | |
726 | return 0; | |
1da177e4 | 727 | |
5aaaf9f0 | 728 | out_init: |
ad211790 | 729 | __sclp_vt220_cleanup(); |
5aaaf9f0 HC |
730 | out_driver: |
731 | put_tty_driver(driver); | |
732 | return rc; | |
733 | } | |
734 | __initcall(sclp_vt220_tty_init); | |
1da177e4 LT |
735 | |
736 | #ifdef CONFIG_SCLP_VT220_CONSOLE | |
737 | ||
738 | static void | |
739 | sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count) | |
740 | { | |
d1e23375 | 741 | __sclp_vt220_write((const unsigned char *) buf, count, 1, 1, 0); |
1da177e4 LT |
742 | } |
743 | ||
744 | static struct tty_driver * | |
745 | sclp_vt220_con_device(struct console *c, int *index) | |
746 | { | |
747 | *index = 0; | |
748 | return sclp_vt220_driver; | |
749 | } | |
750 | ||
751 | /* | |
752 | * This routine is called from panic when the kernel is going to give up. | |
753 | * We have to make sure that all buffers will be flushed to the SCLP. | |
754 | * Note that this function may be called from within an interrupt context. | |
755 | */ | |
756 | static void | |
757 | sclp_vt220_con_unblank(void) | |
758 | { | |
759 | __sclp_vt220_flush_buffer(); | |
760 | } | |
761 | ||
762 | /* Structure needed to register with printk */ | |
763 | static struct console sclp_vt220_console = | |
764 | { | |
765 | .name = SCLP_VT220_CONSOLE_NAME, | |
766 | .write = sclp_vt220_con_write, | |
767 | .device = sclp_vt220_con_device, | |
768 | .unblank = sclp_vt220_con_unblank, | |
769 | .flags = CON_PRINTBUFFER, | |
770 | .index = SCLP_VT220_CONSOLE_INDEX | |
771 | }; | |
772 | ||
773 | static int __init | |
774 | sclp_vt220_con_init(void) | |
775 | { | |
776 | int rc; | |
777 | ||
778 | if (!CONSOLE_IS_SCLP) | |
779 | return 0; | |
ad211790 | 780 | rc = __sclp_vt220_init(MAX_CONSOLE_PAGES); |
1da177e4 LT |
781 | if (rc) |
782 | return rc; | |
783 | /* Attach linux console */ | |
784 | register_console(&sclp_vt220_console); | |
785 | return 0; | |
786 | } | |
787 | ||
788 | console_initcall(sclp_vt220_con_init); | |
789 | #endif /* CONFIG_SCLP_VT220_CONSOLE */ | |
790 |