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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 | ||
1da177e4 LT |
30 | #define SCLP_VT220_MAJOR TTY_MAJOR |
31 | #define SCLP_VT220_MINOR 65 | |
32 | #define SCLP_VT220_DRIVER_NAME "sclp_vt220" | |
33 | #define SCLP_VT220_DEVICE_NAME "ttysclp" | |
34 | #define SCLP_VT220_CONSOLE_NAME "ttyS" | |
35 | #define SCLP_VT220_CONSOLE_INDEX 1 /* console=ttyS1 */ | |
36 | #define SCLP_VT220_BUF_SIZE 80 | |
37 | ||
38 | /* Representation of a single write request */ | |
39 | struct sclp_vt220_request { | |
40 | struct list_head list; | |
41 | struct sclp_req sclp_req; | |
42 | int retry_count; | |
43 | }; | |
44 | ||
45 | /* VT220 SCCB */ | |
46 | struct sclp_vt220_sccb { | |
47 | struct sccb_header header; | |
48 | struct evbuf_header evbuf; | |
49 | }; | |
50 | ||
51 | #define SCLP_VT220_MAX_CHARS_PER_BUFFER (PAGE_SIZE - \ | |
52 | sizeof(struct sclp_vt220_request) - \ | |
53 | sizeof(struct sclp_vt220_sccb)) | |
54 | ||
55 | /* Structures and data needed to register tty driver */ | |
56 | static struct tty_driver *sclp_vt220_driver; | |
57 | ||
58 | /* The tty_struct that the kernel associated with us */ | |
59 | static struct tty_struct *sclp_vt220_tty; | |
60 | ||
61 | /* Lock to protect internal data from concurrent access */ | |
62 | static spinlock_t sclp_vt220_lock; | |
63 | ||
64 | /* List of empty pages to be used as write request buffers */ | |
65 | static struct list_head sclp_vt220_empty; | |
66 | ||
67 | /* List of pending requests */ | |
68 | static struct list_head sclp_vt220_outqueue; | |
69 | ||
70 | /* Number of requests in outqueue */ | |
71 | static int sclp_vt220_outqueue_count; | |
72 | ||
1da177e4 LT |
73 | /* Timer used for delaying write requests to merge subsequent messages into |
74 | * a single buffer */ | |
75 | static struct timer_list sclp_vt220_timer; | |
76 | ||
77 | /* Pointer to current request buffer which has been partially filled but not | |
78 | * yet sent */ | |
79 | static struct sclp_vt220_request *sclp_vt220_current_request; | |
80 | ||
81 | /* Number of characters in current request buffer */ | |
82 | static int sclp_vt220_buffered_chars; | |
83 | ||
ad211790 PO |
84 | /* Counter controlling core driver initialization. */ |
85 | static int __initdata sclp_vt220_init_count; | |
1da177e4 LT |
86 | |
87 | /* Flag indicating that sclp_vt220_current_request should really | |
88 | * have been already queued but wasn't because the SCLP was processing | |
89 | * another buffer */ | |
90 | static int sclp_vt220_flush_later; | |
91 | ||
92 | static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf); | |
93 | static int __sclp_vt220_emit(struct sclp_vt220_request *request); | |
94 | static void sclp_vt220_emit_current(void); | |
95 | ||
96 | /* Registration structure for our interest in SCLP event buffers */ | |
97 | static struct sclp_register sclp_vt220_register = { | |
6d4740c8 SH |
98 | .send_mask = EVTYP_VT220MSG_MASK, |
99 | .receive_mask = EVTYP_VT220MSG_MASK, | |
1da177e4 LT |
100 | .state_change_fn = NULL, |
101 | .receiver_fn = sclp_vt220_receiver_fn | |
102 | }; | |
103 | ||
104 | ||
105 | /* | |
106 | * Put provided request buffer back into queue and check emit pending | |
107 | * buffers if necessary. | |
108 | */ | |
109 | static void | |
110 | sclp_vt220_process_queue(struct sclp_vt220_request *request) | |
111 | { | |
112 | unsigned long flags; | |
113 | void *page; | |
114 | ||
115 | do { | |
116 | /* Put buffer back to list of empty buffers */ | |
117 | page = request->sclp_req.sccb; | |
118 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
119 | /* Move request from outqueue to empty queue */ | |
120 | list_del(&request->list); | |
121 | sclp_vt220_outqueue_count--; | |
122 | list_add_tail((struct list_head *) page, &sclp_vt220_empty); | |
123 | /* Check if there is a pending buffer on the out queue. */ | |
124 | request = NULL; | |
125 | if (!list_empty(&sclp_vt220_outqueue)) | |
126 | request = list_entry(sclp_vt220_outqueue.next, | |
127 | struct sclp_vt220_request, list); | |
128 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
129 | } while (request && __sclp_vt220_emit(request)); | |
130 | if (request == NULL && sclp_vt220_flush_later) | |
131 | sclp_vt220_emit_current(); | |
1da177e4 LT |
132 | /* Check if the tty needs a wake up call */ |
133 | if (sclp_vt220_tty != NULL) { | |
134 | tty_wakeup(sclp_vt220_tty); | |
135 | } | |
136 | } | |
137 | ||
138 | #define SCLP_BUFFER_MAX_RETRY 1 | |
139 | ||
140 | /* | |
141 | * Callback through which the result of a write request is reported by the | |
142 | * SCLP. | |
143 | */ | |
144 | static void | |
145 | sclp_vt220_callback(struct sclp_req *request, void *data) | |
146 | { | |
147 | struct sclp_vt220_request *vt220_request; | |
148 | struct sclp_vt220_sccb *sccb; | |
149 | ||
150 | vt220_request = (struct sclp_vt220_request *) data; | |
151 | if (request->status == SCLP_REQ_FAILED) { | |
152 | sclp_vt220_process_queue(vt220_request); | |
153 | return; | |
154 | } | |
155 | sccb = (struct sclp_vt220_sccb *) vt220_request->sclp_req.sccb; | |
156 | ||
157 | /* Check SCLP response code and choose suitable action */ | |
158 | switch (sccb->header.response_code) { | |
159 | case 0x0020 : | |
160 | break; | |
161 | ||
162 | case 0x05f0: /* Target resource in improper state */ | |
163 | break; | |
164 | ||
165 | case 0x0340: /* Contained SCLP equipment check */ | |
166 | if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) | |
167 | break; | |
168 | /* Remove processed buffers and requeue rest */ | |
169 | if (sclp_remove_processed((struct sccb_header *) sccb) > 0) { | |
170 | /* Not all buffers were processed */ | |
171 | sccb->header.response_code = 0x0000; | |
172 | vt220_request->sclp_req.status = SCLP_REQ_FILLED; | |
173 | if (sclp_add_request(request) == 0) | |
174 | return; | |
175 | } | |
176 | break; | |
177 | ||
178 | case 0x0040: /* SCLP equipment check */ | |
179 | if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) | |
180 | break; | |
181 | sccb->header.response_code = 0x0000; | |
182 | vt220_request->sclp_req.status = SCLP_REQ_FILLED; | |
183 | if (sclp_add_request(request) == 0) | |
184 | return; | |
185 | break; | |
186 | ||
187 | default: | |
188 | break; | |
189 | } | |
190 | sclp_vt220_process_queue(vt220_request); | |
191 | } | |
192 | ||
193 | /* | |
194 | * Emit vt220 request buffer to SCLP. Return zero on success, non-zero | |
195 | * otherwise. | |
196 | */ | |
197 | static int | |
198 | __sclp_vt220_emit(struct sclp_vt220_request *request) | |
199 | { | |
d082d3ce | 200 | if (!(sclp_vt220_register.sclp_receive_mask & EVTYP_VT220MSG_MASK)) { |
1da177e4 LT |
201 | request->sclp_req.status = SCLP_REQ_FAILED; |
202 | return -EIO; | |
203 | } | |
ab14de6c | 204 | request->sclp_req.command = SCLP_CMDW_WRITE_EVENT_DATA; |
1da177e4 LT |
205 | request->sclp_req.status = SCLP_REQ_FILLED; |
206 | request->sclp_req.callback = sclp_vt220_callback; | |
207 | request->sclp_req.callback_data = (void *) request; | |
208 | ||
209 | return sclp_add_request(&request->sclp_req); | |
210 | } | |
211 | ||
212 | /* | |
213 | * Queue and emit given request. | |
214 | */ | |
215 | static void | |
216 | sclp_vt220_emit(struct sclp_vt220_request *request) | |
217 | { | |
218 | unsigned long flags; | |
219 | int count; | |
220 | ||
221 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
222 | list_add_tail(&request->list, &sclp_vt220_outqueue); | |
223 | count = sclp_vt220_outqueue_count++; | |
224 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
225 | /* Emit only the first buffer immediately - callback takes care of | |
226 | * the rest */ | |
227 | if (count == 0 && __sclp_vt220_emit(request)) | |
228 | sclp_vt220_process_queue(request); | |
229 | } | |
230 | ||
231 | /* | |
232 | * Queue and emit current request. Return zero on success, non-zero otherwise. | |
233 | */ | |
234 | static void | |
235 | sclp_vt220_emit_current(void) | |
236 | { | |
237 | unsigned long flags; | |
238 | struct sclp_vt220_request *request; | |
239 | struct sclp_vt220_sccb *sccb; | |
240 | ||
241 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
242 | request = NULL; | |
243 | if (sclp_vt220_current_request != NULL) { | |
244 | sccb = (struct sclp_vt220_sccb *) | |
245 | sclp_vt220_current_request->sclp_req.sccb; | |
246 | /* Only emit buffers with content */ | |
247 | if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) { | |
248 | request = sclp_vt220_current_request; | |
249 | sclp_vt220_current_request = NULL; | |
250 | if (timer_pending(&sclp_vt220_timer)) | |
251 | del_timer(&sclp_vt220_timer); | |
252 | } | |
253 | sclp_vt220_flush_later = 0; | |
254 | } | |
255 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
256 | if (request != NULL) | |
257 | sclp_vt220_emit(request); | |
258 | } | |
259 | ||
260 | #define SCLP_NORMAL_WRITE 0x00 | |
261 | ||
262 | /* | |
263 | * Helper function to initialize a page with the sclp request structure. | |
264 | */ | |
265 | static struct sclp_vt220_request * | |
266 | sclp_vt220_initialize_page(void *page) | |
267 | { | |
268 | struct sclp_vt220_request *request; | |
269 | struct sclp_vt220_sccb *sccb; | |
270 | ||
271 | /* Place request structure at end of page */ | |
272 | request = ((struct sclp_vt220_request *) | |
273 | ((addr_t) page + PAGE_SIZE)) - 1; | |
274 | request->retry_count = 0; | |
275 | request->sclp_req.sccb = page; | |
276 | /* SCCB goes at start of page */ | |
277 | sccb = (struct sclp_vt220_sccb *) page; | |
278 | memset((void *) sccb, 0, sizeof(struct sclp_vt220_sccb)); | |
279 | sccb->header.length = sizeof(struct sclp_vt220_sccb); | |
280 | sccb->header.function_code = SCLP_NORMAL_WRITE; | |
281 | sccb->header.response_code = 0x0000; | |
6d4740c8 | 282 | sccb->evbuf.type = EVTYP_VT220MSG; |
1da177e4 LT |
283 | sccb->evbuf.length = sizeof(struct evbuf_header); |
284 | ||
285 | return request; | |
286 | } | |
287 | ||
288 | static inline unsigned int | |
289 | sclp_vt220_space_left(struct sclp_vt220_request *request) | |
290 | { | |
291 | struct sclp_vt220_sccb *sccb; | |
292 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
293 | return PAGE_SIZE - sizeof(struct sclp_vt220_request) - | |
294 | sccb->header.length; | |
295 | } | |
296 | ||
297 | static inline unsigned int | |
298 | sclp_vt220_chars_stored(struct sclp_vt220_request *request) | |
299 | { | |
300 | struct sclp_vt220_sccb *sccb; | |
301 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
302 | return sccb->evbuf.length - sizeof(struct evbuf_header); | |
303 | } | |
304 | ||
305 | /* | |
306 | * Add msg to buffer associated with request. Return the number of characters | |
307 | * added. | |
308 | */ | |
309 | static int | |
310 | sclp_vt220_add_msg(struct sclp_vt220_request *request, | |
311 | const unsigned char *msg, int count, int convertlf) | |
312 | { | |
313 | struct sclp_vt220_sccb *sccb; | |
314 | void *buffer; | |
315 | unsigned char c; | |
316 | int from; | |
317 | int to; | |
318 | ||
319 | if (count > sclp_vt220_space_left(request)) | |
320 | count = sclp_vt220_space_left(request); | |
321 | if (count <= 0) | |
322 | return 0; | |
323 | ||
324 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
325 | buffer = (void *) ((addr_t) sccb + sccb->header.length); | |
326 | ||
327 | if (convertlf) { | |
328 | /* Perform Linefeed conversion (0x0a -> 0x0a 0x0d)*/ | |
329 | for (from=0, to=0; | |
330 | (from < count) && (to < sclp_vt220_space_left(request)); | |
331 | from++) { | |
332 | /* Retrieve character */ | |
333 | c = msg[from]; | |
334 | /* Perform conversion */ | |
335 | if (c == 0x0a) { | |
336 | if (to + 1 < sclp_vt220_space_left(request)) { | |
337 | ((unsigned char *) buffer)[to++] = c; | |
338 | ((unsigned char *) buffer)[to++] = 0x0d; | |
339 | } else | |
340 | break; | |
341 | ||
342 | } else | |
343 | ((unsigned char *) buffer)[to++] = c; | |
344 | } | |
345 | sccb->header.length += to; | |
346 | sccb->evbuf.length += to; | |
347 | return from; | |
348 | } else { | |
349 | memcpy(buffer, (const void *) msg, count); | |
350 | sccb->header.length += count; | |
351 | sccb->evbuf.length += count; | |
352 | return count; | |
353 | } | |
354 | } | |
355 | ||
356 | /* | |
357 | * Emit buffer after having waited long enough for more data to arrive. | |
358 | */ | |
359 | static void | |
360 | sclp_vt220_timeout(unsigned long data) | |
361 | { | |
362 | sclp_vt220_emit_current(); | |
363 | } | |
364 | ||
fa331ffc | 365 | #define BUFFER_MAX_DELAY HZ/20 |
1da177e4 LT |
366 | |
367 | /* | |
368 | * Internal implementation of the write function. Write COUNT bytes of data | |
369 | * from memory at BUF | |
370 | * to the SCLP interface. In case that the data does not fit into the current | |
371 | * write buffer, emit the current one and allocate a new one. If there are no | |
372 | * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE | |
373 | * is non-zero, the buffer will be scheduled for emitting after a timeout - | |
374 | * otherwise the user has to explicitly call the flush function. | |
375 | * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message | |
376 | * buffer should be converted to 0x0a 0x0d. After completion, return the number | |
377 | * of bytes written. | |
378 | */ | |
379 | static int | |
380 | __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule, | |
d4820e44 | 381 | int convertlf, int may_fail) |
1da177e4 LT |
382 | { |
383 | unsigned long flags; | |
384 | void *page; | |
385 | int written; | |
386 | int overall_written; | |
387 | ||
388 | if (count <= 0) | |
389 | return 0; | |
390 | overall_written = 0; | |
391 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
392 | do { | |
d4820e44 | 393 | /* Create an sclp output buffer if none exists yet */ |
1da177e4 LT |
394 | if (sclp_vt220_current_request == NULL) { |
395 | while (list_empty(&sclp_vt220_empty)) { | |
d1e23375 | 396 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); |
d4820e44 HC |
397 | if (may_fail) |
398 | goto out; | |
1da177e4 | 399 | else |
d4820e44 | 400 | sclp_sync_wait(); |
1da177e4 LT |
401 | spin_lock_irqsave(&sclp_vt220_lock, flags); |
402 | } | |
403 | page = (void *) sclp_vt220_empty.next; | |
404 | list_del((struct list_head *) page); | |
405 | sclp_vt220_current_request = | |
406 | sclp_vt220_initialize_page(page); | |
407 | } | |
408 | /* Try to write the string to the current request buffer */ | |
409 | written = sclp_vt220_add_msg(sclp_vt220_current_request, | |
410 | buf, count, convertlf); | |
411 | overall_written += written; | |
412 | if (written == count) | |
413 | break; | |
414 | /* | |
415 | * Not all characters could be written to the current | |
416 | * output buffer. Emit the buffer, create a new buffer | |
417 | * and then output the rest of the string. | |
418 | */ | |
419 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
420 | sclp_vt220_emit_current(); | |
421 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
422 | buf += written; | |
423 | count -= written; | |
424 | } while (count > 0); | |
425 | /* Setup timer to output current console buffer after some time */ | |
426 | if (sclp_vt220_current_request != NULL && | |
427 | !timer_pending(&sclp_vt220_timer) && do_schedule) { | |
428 | sclp_vt220_timer.function = sclp_vt220_timeout; | |
429 | sclp_vt220_timer.data = 0UL; | |
430 | sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY; | |
431 | add_timer(&sclp_vt220_timer); | |
432 | } | |
433 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
d4820e44 | 434 | out: |
1da177e4 LT |
435 | return overall_written; |
436 | } | |
437 | ||
438 | /* | |
439 | * This routine is called by the kernel to write a series of | |
440 | * characters to the tty device. The characters may come from | |
441 | * user space or kernel space. This routine will return the | |
442 | * number of characters actually accepted for writing. | |
443 | */ | |
444 | static int | |
445 | sclp_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count) | |
446 | { | |
d1e23375 | 447 | return __sclp_vt220_write(buf, count, 1, 0, 1); |
1da177e4 LT |
448 | } |
449 | ||
450 | #define SCLP_VT220_SESSION_ENDED 0x01 | |
451 | #define SCLP_VT220_SESSION_STARTED 0x80 | |
452 | #define SCLP_VT220_SESSION_DATA 0x00 | |
453 | ||
454 | /* | |
455 | * Called by the SCLP to report incoming event buffers. | |
456 | */ | |
457 | static void | |
458 | sclp_vt220_receiver_fn(struct evbuf_header *evbuf) | |
459 | { | |
460 | char *buffer; | |
461 | unsigned int count; | |
462 | ||
463 | /* Ignore input if device is not open */ | |
464 | if (sclp_vt220_tty == NULL) | |
465 | return; | |
466 | ||
467 | buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header)); | |
468 | count = evbuf->length - sizeof(struct evbuf_header); | |
469 | ||
470 | switch (*buffer) { | |
471 | case SCLP_VT220_SESSION_ENDED: | |
472 | case SCLP_VT220_SESSION_STARTED: | |
473 | break; | |
474 | case SCLP_VT220_SESSION_DATA: | |
475 | /* Send input to line discipline */ | |
476 | buffer++; | |
477 | count--; | |
33f0f88f | 478 | tty_insert_flip_string(sclp_vt220_tty, buffer, count); |
1da177e4 LT |
479 | tty_flip_buffer_push(sclp_vt220_tty); |
480 | break; | |
481 | } | |
482 | } | |
483 | ||
484 | /* | |
485 | * This routine is called when a particular tty device is opened. | |
486 | */ | |
487 | static int | |
488 | sclp_vt220_open(struct tty_struct *tty, struct file *filp) | |
489 | { | |
490 | if (tty->count == 1) { | |
491 | sclp_vt220_tty = tty; | |
492 | tty->driver_data = kmalloc(SCLP_VT220_BUF_SIZE, GFP_KERNEL); | |
493 | if (tty->driver_data == NULL) | |
494 | return -ENOMEM; | |
495 | tty->low_latency = 0; | |
496 | } | |
497 | return 0; | |
498 | } | |
499 | ||
500 | /* | |
501 | * This routine is called when a particular tty device is closed. | |
502 | */ | |
503 | static void | |
504 | sclp_vt220_close(struct tty_struct *tty, struct file *filp) | |
505 | { | |
506 | if (tty->count == 1) { | |
507 | sclp_vt220_tty = NULL; | |
508 | kfree(tty->driver_data); | |
509 | tty->driver_data = NULL; | |
510 | } | |
511 | } | |
512 | ||
513 | /* | |
514 | * This routine is called by the kernel to write a single | |
515 | * character to the tty device. If the kernel uses this routine, | |
516 | * it must call the flush_chars() routine (if defined) when it is | |
517 | * done stuffing characters into the driver. | |
1da177e4 | 518 | */ |
9e7c9a19 | 519 | static int |
1da177e4 LT |
520 | sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch) |
521 | { | |
d4820e44 | 522 | return __sclp_vt220_write(&ch, 1, 0, 0, 1); |
1da177e4 LT |
523 | } |
524 | ||
525 | /* | |
526 | * This routine is called by the kernel after it has written a | |
527 | * series of characters to the tty device using put_char(). | |
528 | */ | |
529 | static void | |
530 | sclp_vt220_flush_chars(struct tty_struct *tty) | |
531 | { | |
532 | if (sclp_vt220_outqueue_count == 0) | |
533 | sclp_vt220_emit_current(); | |
534 | else | |
535 | sclp_vt220_flush_later = 1; | |
536 | } | |
537 | ||
538 | /* | |
539 | * This routine returns the numbers of characters the tty driver | |
540 | * will accept for queuing to be written. This number is subject | |
541 | * to change as output buffers get emptied, or if the output flow | |
542 | * control is acted. | |
543 | */ | |
544 | static int | |
545 | sclp_vt220_write_room(struct tty_struct *tty) | |
546 | { | |
547 | unsigned long flags; | |
548 | struct list_head *l; | |
549 | int count; | |
550 | ||
551 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
552 | count = 0; | |
553 | if (sclp_vt220_current_request != NULL) | |
554 | count = sclp_vt220_space_left(sclp_vt220_current_request); | |
555 | list_for_each(l, &sclp_vt220_empty) | |
556 | count += SCLP_VT220_MAX_CHARS_PER_BUFFER; | |
557 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
558 | return count; | |
559 | } | |
560 | ||
561 | /* | |
562 | * Return number of buffered chars. | |
563 | */ | |
564 | static int | |
565 | sclp_vt220_chars_in_buffer(struct tty_struct *tty) | |
566 | { | |
567 | unsigned long flags; | |
568 | struct list_head *l; | |
569 | struct sclp_vt220_request *r; | |
570 | int count; | |
571 | ||
572 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
573 | count = 0; | |
574 | if (sclp_vt220_current_request != NULL) | |
575 | count = sclp_vt220_chars_stored(sclp_vt220_current_request); | |
576 | list_for_each(l, &sclp_vt220_outqueue) { | |
577 | r = list_entry(l, struct sclp_vt220_request, list); | |
578 | count += sclp_vt220_chars_stored(r); | |
579 | } | |
580 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
581 | return count; | |
582 | } | |
583 | ||
584 | static void | |
585 | __sclp_vt220_flush_buffer(void) | |
586 | { | |
587 | unsigned long flags; | |
588 | ||
589 | sclp_vt220_emit_current(); | |
590 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
591 | if (timer_pending(&sclp_vt220_timer)) | |
592 | del_timer(&sclp_vt220_timer); | |
593 | while (sclp_vt220_outqueue_count > 0) { | |
594 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
595 | sclp_sync_wait(); | |
596 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
597 | } | |
598 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
599 | } | |
600 | ||
601 | /* | |
602 | * Pass on all buffers to the hardware. Return only when there are no more | |
603 | * buffers pending. | |
604 | */ | |
605 | static void | |
606 | sclp_vt220_flush_buffer(struct tty_struct *tty) | |
607 | { | |
608 | sclp_vt220_emit_current(); | |
609 | } | |
610 | ||
ad211790 PO |
611 | /* Release allocated pages. */ |
612 | static void __init __sclp_vt220_free_pages(void) | |
5aaaf9f0 HC |
613 | { |
614 | struct list_head *page, *p; | |
615 | ||
616 | list_for_each_safe(page, p, &sclp_vt220_empty) { | |
617 | list_del(page); | |
618 | if (slab_is_available()) | |
619 | free_page((unsigned long) page); | |
620 | else | |
621 | free_bootmem((unsigned long) page, PAGE_SIZE); | |
622 | } | |
623 | } | |
624 | ||
ad211790 PO |
625 | /* Release memory and unregister from sclp core. Controlled by init counting - |
626 | * only the last invoker will actually perform these actions. */ | |
627 | static void __init __sclp_vt220_cleanup(void) | |
628 | { | |
629 | sclp_vt220_init_count--; | |
630 | if (sclp_vt220_init_count != 0) | |
631 | return; | |
632 | sclp_unregister(&sclp_vt220_register); | |
633 | __sclp_vt220_free_pages(); | |
634 | } | |
635 | ||
636 | /* Allocate buffer pages and register with sclp core. Controlled by init | |
637 | * counting - only the first invoker will actually perform these actions. */ | |
638 | static int __init __sclp_vt220_init(int num_pages) | |
1da177e4 LT |
639 | { |
640 | void *page; | |
641 | int i; | |
59eb1ca7 | 642 | int rc; |
1da177e4 | 643 | |
ad211790 PO |
644 | sclp_vt220_init_count++; |
645 | if (sclp_vt220_init_count != 1) | |
1da177e4 | 646 | return 0; |
1da177e4 LT |
647 | spin_lock_init(&sclp_vt220_lock); |
648 | INIT_LIST_HEAD(&sclp_vt220_empty); | |
649 | INIT_LIST_HEAD(&sclp_vt220_outqueue); | |
1da177e4 LT |
650 | init_timer(&sclp_vt220_timer); |
651 | sclp_vt220_current_request = NULL; | |
652 | sclp_vt220_buffered_chars = 0; | |
653 | sclp_vt220_outqueue_count = 0; | |
654 | sclp_vt220_tty = NULL; | |
655 | sclp_vt220_flush_later = 0; | |
656 | ||
657 | /* Allocate pages for output buffering */ | |
5aaaf9f0 HC |
658 | for (i = 0; i < num_pages; i++) { |
659 | if (slab_is_available()) | |
1da177e4 | 660 | page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); |
5aaaf9f0 HC |
661 | else |
662 | page = alloc_bootmem_low_pages(PAGE_SIZE); | |
663 | if (!page) { | |
ad211790 PO |
664 | rc = -ENOMEM; |
665 | goto out; | |
5aaaf9f0 | 666 | } |
1da177e4 LT |
667 | list_add_tail((struct list_head *) page, &sclp_vt220_empty); |
668 | } | |
59eb1ca7 | 669 | rc = sclp_register(&sclp_vt220_register); |
ad211790 | 670 | out: |
59eb1ca7 | 671 | if (rc) { |
ad211790 PO |
672 | __sclp_vt220_free_pages(); |
673 | sclp_vt220_init_count--; | |
59eb1ca7 CB |
674 | } |
675 | return rc; | |
1da177e4 LT |
676 | } |
677 | ||
b68e31d0 | 678 | static const struct tty_operations sclp_vt220_ops = { |
1da177e4 LT |
679 | .open = sclp_vt220_open, |
680 | .close = sclp_vt220_close, | |
681 | .write = sclp_vt220_write, | |
682 | .put_char = sclp_vt220_put_char, | |
683 | .flush_chars = sclp_vt220_flush_chars, | |
684 | .write_room = sclp_vt220_write_room, | |
685 | .chars_in_buffer = sclp_vt220_chars_in_buffer, | |
5aaaf9f0 | 686 | .flush_buffer = sclp_vt220_flush_buffer, |
1da177e4 LT |
687 | }; |
688 | ||
689 | /* | |
690 | * Register driver with SCLP and Linux and initialize internal tty structures. | |
691 | */ | |
5aaaf9f0 | 692 | static int __init sclp_vt220_tty_init(void) |
1da177e4 LT |
693 | { |
694 | struct tty_driver *driver; | |
695 | int rc; | |
696 | ||
697 | /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve | |
698 | * symmetry between VM and LPAR systems regarding ttyS1. */ | |
699 | driver = alloc_tty_driver(1); | |
700 | if (!driver) | |
701 | return -ENOMEM; | |
ad211790 | 702 | rc = __sclp_vt220_init(MAX_KMEM_PAGES); |
5aaaf9f0 HC |
703 | if (rc) |
704 | goto out_driver; | |
1da177e4 LT |
705 | |
706 | driver->owner = THIS_MODULE; | |
707 | driver->driver_name = SCLP_VT220_DRIVER_NAME; | |
708 | driver->name = SCLP_VT220_DEVICE_NAME; | |
709 | driver->major = SCLP_VT220_MAJOR; | |
710 | driver->minor_start = SCLP_VT220_MINOR; | |
711 | driver->type = TTY_DRIVER_TYPE_SYSTEM; | |
712 | driver->subtype = SYSTEM_TYPE_TTY; | |
713 | driver->init_termios = tty_std_termios; | |
714 | driver->flags = TTY_DRIVER_REAL_RAW; | |
715 | tty_set_operations(driver, &sclp_vt220_ops); | |
716 | ||
717 | rc = tty_register_driver(driver); | |
a12c53f4 | 718 | if (rc) |
59eb1ca7 | 719 | goto out_init; |
1da177e4 LT |
720 | sclp_vt220_driver = driver; |
721 | return 0; | |
1da177e4 | 722 | |
5aaaf9f0 | 723 | out_init: |
ad211790 | 724 | __sclp_vt220_cleanup(); |
5aaaf9f0 HC |
725 | out_driver: |
726 | put_tty_driver(driver); | |
727 | return rc; | |
728 | } | |
729 | __initcall(sclp_vt220_tty_init); | |
1da177e4 LT |
730 | |
731 | #ifdef CONFIG_SCLP_VT220_CONSOLE | |
732 | ||
733 | static void | |
734 | sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count) | |
735 | { | |
d1e23375 | 736 | __sclp_vt220_write((const unsigned char *) buf, count, 1, 1, 0); |
1da177e4 LT |
737 | } |
738 | ||
739 | static struct tty_driver * | |
740 | sclp_vt220_con_device(struct console *c, int *index) | |
741 | { | |
742 | *index = 0; | |
743 | return sclp_vt220_driver; | |
744 | } | |
745 | ||
746 | /* | |
747 | * This routine is called from panic when the kernel is going to give up. | |
748 | * We have to make sure that all buffers will be flushed to the SCLP. | |
749 | * Note that this function may be called from within an interrupt context. | |
750 | */ | |
751 | static void | |
752 | sclp_vt220_con_unblank(void) | |
753 | { | |
754 | __sclp_vt220_flush_buffer(); | |
755 | } | |
756 | ||
757 | /* Structure needed to register with printk */ | |
758 | static struct console sclp_vt220_console = | |
759 | { | |
760 | .name = SCLP_VT220_CONSOLE_NAME, | |
761 | .write = sclp_vt220_con_write, | |
762 | .device = sclp_vt220_con_device, | |
763 | .unblank = sclp_vt220_con_unblank, | |
764 | .flags = CON_PRINTBUFFER, | |
765 | .index = SCLP_VT220_CONSOLE_INDEX | |
766 | }; | |
767 | ||
768 | static int __init | |
769 | sclp_vt220_con_init(void) | |
770 | { | |
771 | int rc; | |
772 | ||
773 | if (!CONSOLE_IS_SCLP) | |
774 | return 0; | |
ad211790 | 775 | rc = __sclp_vt220_init(MAX_CONSOLE_PAGES); |
1da177e4 LT |
776 | if (rc) |
777 | return rc; | |
778 | /* Attach linux console */ | |
779 | register_console(&sclp_vt220_console); | |
780 | return 0; | |
781 | } | |
782 | ||
783 | console_initcall(sclp_vt220_con_init); | |
784 | #endif /* CONFIG_SCLP_VT220_CONSOLE */ | |
785 |