Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
62b74942 | 2 | * SCLP VT220 terminal driver. |
1da177e4 | 3 | * |
62b74942 MH |
4 | * Copyright IBM Corp. 2003, 2009 |
5 | * | |
6 | * Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com> | |
1da177e4 LT |
7 | */ |
8 | ||
1da177e4 LT |
9 | #include <linux/module.h> |
10 | #include <linux/spinlock.h> | |
11 | #include <linux/list.h> | |
12 | #include <linux/wait.h> | |
13 | #include <linux/timer.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/tty.h> | |
16 | #include <linux/tty_driver.h> | |
33f0f88f | 17 | #include <linux/tty_flip.h> |
1da177e4 LT |
18 | #include <linux/errno.h> |
19 | #include <linux/mm.h> | |
20 | #include <linux/major.h> | |
21 | #include <linux/console.h> | |
22 | #include <linux/kdev_t.h> | |
1da177e4 LT |
23 | #include <linux/interrupt.h> |
24 | #include <linux/init.h> | |
2332ce1a HS |
25 | #include <linux/reboot.h> |
26 | ||
1da177e4 LT |
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 | ||
62b74942 MH |
70 | /* Suspend mode flag */ |
71 | static int sclp_vt220_suspended; | |
72 | ||
73 | /* Flag that output queue is currently running */ | |
74 | static int sclp_vt220_queue_running; | |
1da177e4 | 75 | |
1da177e4 LT |
76 | /* Timer used for delaying write requests to merge subsequent messages into |
77 | * a single buffer */ | |
78 | static struct timer_list sclp_vt220_timer; | |
79 | ||
80 | /* Pointer to current request buffer which has been partially filled but not | |
81 | * yet sent */ | |
82 | static struct sclp_vt220_request *sclp_vt220_current_request; | |
83 | ||
84 | /* Number of characters in current request buffer */ | |
85 | static int sclp_vt220_buffered_chars; | |
86 | ||
ad211790 PO |
87 | /* Counter controlling core driver initialization. */ |
88 | static int __initdata sclp_vt220_init_count; | |
1da177e4 LT |
89 | |
90 | /* Flag indicating that sclp_vt220_current_request should really | |
91 | * have been already queued but wasn't because the SCLP was processing | |
92 | * another buffer */ | |
93 | static int sclp_vt220_flush_later; | |
94 | ||
95 | static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf); | |
62b74942 MH |
96 | static void sclp_vt220_pm_event_fn(struct sclp_register *reg, |
97 | enum sclp_pm_event sclp_pm_event); | |
1da177e4 LT |
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 = { | |
6d4740c8 SH |
103 | .send_mask = EVTYP_VT220MSG_MASK, |
104 | .receive_mask = EVTYP_VT220MSG_MASK, | |
1da177e4 | 105 | .state_change_fn = NULL, |
62b74942 MH |
106 | .receiver_fn = sclp_vt220_receiver_fn, |
107 | .pm_event_fn = sclp_vt220_pm_event_fn, | |
1da177e4 LT |
108 | }; |
109 | ||
110 | ||
111 | /* | |
112 | * Put provided request buffer back into queue and check emit pending | |
113 | * buffers if necessary. | |
114 | */ | |
115 | static void | |
116 | sclp_vt220_process_queue(struct sclp_vt220_request *request) | |
117 | { | |
118 | unsigned long flags; | |
119 | void *page; | |
120 | ||
121 | do { | |
122 | /* Put buffer back to list of empty buffers */ | |
123 | page = request->sclp_req.sccb; | |
124 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
125 | /* Move request from outqueue to empty queue */ | |
126 | list_del(&request->list); | |
1da177e4 LT |
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); | |
62b74942 MH |
133 | if (!request || sclp_vt220_suspended) { |
134 | sclp_vt220_queue_running = 0; | |
135 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
136 | break; | |
137 | } | |
1da177e4 | 138 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); |
62b74942 | 139 | } while (__sclp_vt220_emit(request)); |
1da177e4 LT |
140 | if (request == NULL && sclp_vt220_flush_later) |
141 | sclp_vt220_emit_current(); | |
1da177e4 LT |
142 | /* Check if the tty needs a wake up call */ |
143 | if (sclp_vt220_tty != NULL) { | |
144 | tty_wakeup(sclp_vt220_tty); | |
145 | } | |
146 | } | |
147 | ||
148 | #define SCLP_BUFFER_MAX_RETRY 1 | |
149 | ||
150 | /* | |
151 | * Callback through which the result of a write request is reported by the | |
152 | * SCLP. | |
153 | */ | |
154 | static void | |
155 | sclp_vt220_callback(struct sclp_req *request, void *data) | |
156 | { | |
157 | struct sclp_vt220_request *vt220_request; | |
158 | struct sclp_vt220_sccb *sccb; | |
159 | ||
160 | vt220_request = (struct sclp_vt220_request *) data; | |
161 | if (request->status == SCLP_REQ_FAILED) { | |
162 | sclp_vt220_process_queue(vt220_request); | |
163 | return; | |
164 | } | |
165 | sccb = (struct sclp_vt220_sccb *) vt220_request->sclp_req.sccb; | |
166 | ||
167 | /* Check SCLP response code and choose suitable action */ | |
168 | switch (sccb->header.response_code) { | |
169 | case 0x0020 : | |
170 | break; | |
171 | ||
172 | case 0x05f0: /* Target resource in improper state */ | |
173 | break; | |
174 | ||
175 | case 0x0340: /* Contained SCLP equipment check */ | |
176 | if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) | |
177 | break; | |
178 | /* Remove processed buffers and requeue rest */ | |
179 | if (sclp_remove_processed((struct sccb_header *) sccb) > 0) { | |
180 | /* Not all buffers were processed */ | |
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 | } | |
186 | break; | |
187 | ||
188 | case 0x0040: /* SCLP equipment check */ | |
189 | if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) | |
190 | break; | |
191 | sccb->header.response_code = 0x0000; | |
192 | vt220_request->sclp_req.status = SCLP_REQ_FILLED; | |
193 | if (sclp_add_request(request) == 0) | |
194 | return; | |
195 | break; | |
196 | ||
197 | default: | |
198 | break; | |
199 | } | |
200 | sclp_vt220_process_queue(vt220_request); | |
201 | } | |
202 | ||
203 | /* | |
204 | * Emit vt220 request buffer to SCLP. Return zero on success, non-zero | |
205 | * otherwise. | |
206 | */ | |
207 | static int | |
208 | __sclp_vt220_emit(struct sclp_vt220_request *request) | |
209 | { | |
d082d3ce | 210 | if (!(sclp_vt220_register.sclp_receive_mask & EVTYP_VT220MSG_MASK)) { |
1da177e4 LT |
211 | request->sclp_req.status = SCLP_REQ_FAILED; |
212 | return -EIO; | |
213 | } | |
ab14de6c | 214 | request->sclp_req.command = SCLP_CMDW_WRITE_EVENT_DATA; |
1da177e4 LT |
215 | request->sclp_req.status = SCLP_REQ_FILLED; |
216 | request->sclp_req.callback = sclp_vt220_callback; | |
217 | request->sclp_req.callback_data = (void *) request; | |
218 | ||
219 | return sclp_add_request(&request->sclp_req); | |
220 | } | |
221 | ||
222 | /* | |
62b74942 | 223 | * Queue and emit current request. |
1da177e4 LT |
224 | */ |
225 | static void | |
226 | sclp_vt220_emit_current(void) | |
227 | { | |
228 | unsigned long flags; | |
229 | struct sclp_vt220_request *request; | |
230 | struct sclp_vt220_sccb *sccb; | |
231 | ||
232 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
62b74942 | 233 | if (sclp_vt220_current_request) { |
1da177e4 LT |
234 | sccb = (struct sclp_vt220_sccb *) |
235 | sclp_vt220_current_request->sclp_req.sccb; | |
236 | /* Only emit buffers with content */ | |
237 | if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) { | |
62b74942 MH |
238 | list_add_tail(&sclp_vt220_current_request->list, |
239 | &sclp_vt220_outqueue); | |
1da177e4 LT |
240 | sclp_vt220_current_request = NULL; |
241 | if (timer_pending(&sclp_vt220_timer)) | |
242 | del_timer(&sclp_vt220_timer); | |
243 | } | |
244 | sclp_vt220_flush_later = 0; | |
245 | } | |
62b74942 MH |
246 | if (sclp_vt220_queue_running || sclp_vt220_suspended) |
247 | goto out_unlock; | |
248 | if (list_empty(&sclp_vt220_outqueue)) | |
249 | goto out_unlock; | |
250 | request = list_first_entry(&sclp_vt220_outqueue, | |
251 | struct sclp_vt220_request, list); | |
252 | sclp_vt220_queue_running = 1; | |
253 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
254 | ||
255 | if (__sclp_vt220_emit(request)) | |
256 | sclp_vt220_process_queue(request); | |
257 | return; | |
258 | out_unlock: | |
1da177e4 | 259 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); |
1da177e4 LT |
260 | } |
261 | ||
262 | #define SCLP_NORMAL_WRITE 0x00 | |
263 | ||
264 | /* | |
265 | * Helper function to initialize a page with the sclp request structure. | |
266 | */ | |
267 | static struct sclp_vt220_request * | |
268 | sclp_vt220_initialize_page(void *page) | |
269 | { | |
270 | struct sclp_vt220_request *request; | |
271 | struct sclp_vt220_sccb *sccb; | |
272 | ||
273 | /* Place request structure at end of page */ | |
274 | request = ((struct sclp_vt220_request *) | |
275 | ((addr_t) page + PAGE_SIZE)) - 1; | |
276 | request->retry_count = 0; | |
277 | request->sclp_req.sccb = page; | |
278 | /* SCCB goes at start of page */ | |
279 | sccb = (struct sclp_vt220_sccb *) page; | |
280 | memset((void *) sccb, 0, sizeof(struct sclp_vt220_sccb)); | |
281 | sccb->header.length = sizeof(struct sclp_vt220_sccb); | |
282 | sccb->header.function_code = SCLP_NORMAL_WRITE; | |
283 | sccb->header.response_code = 0x0000; | |
6d4740c8 | 284 | sccb->evbuf.type = EVTYP_VT220MSG; |
1da177e4 LT |
285 | sccb->evbuf.length = sizeof(struct evbuf_header); |
286 | ||
287 | return request; | |
288 | } | |
289 | ||
290 | static inline unsigned int | |
291 | sclp_vt220_space_left(struct sclp_vt220_request *request) | |
292 | { | |
293 | struct sclp_vt220_sccb *sccb; | |
294 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
295 | return PAGE_SIZE - sizeof(struct sclp_vt220_request) - | |
296 | sccb->header.length; | |
297 | } | |
298 | ||
299 | static inline unsigned int | |
300 | sclp_vt220_chars_stored(struct sclp_vt220_request *request) | |
301 | { | |
302 | struct sclp_vt220_sccb *sccb; | |
303 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
304 | return sccb->evbuf.length - sizeof(struct evbuf_header); | |
305 | } | |
306 | ||
307 | /* | |
308 | * Add msg to buffer associated with request. Return the number of characters | |
309 | * added. | |
310 | */ | |
311 | static int | |
312 | sclp_vt220_add_msg(struct sclp_vt220_request *request, | |
313 | const unsigned char *msg, int count, int convertlf) | |
314 | { | |
315 | struct sclp_vt220_sccb *sccb; | |
316 | void *buffer; | |
317 | unsigned char c; | |
318 | int from; | |
319 | int to; | |
320 | ||
321 | if (count > sclp_vt220_space_left(request)) | |
322 | count = sclp_vt220_space_left(request); | |
323 | if (count <= 0) | |
324 | return 0; | |
325 | ||
326 | sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; | |
327 | buffer = (void *) ((addr_t) sccb + sccb->header.length); | |
328 | ||
329 | if (convertlf) { | |
330 | /* Perform Linefeed conversion (0x0a -> 0x0a 0x0d)*/ | |
331 | for (from=0, to=0; | |
332 | (from < count) && (to < sclp_vt220_space_left(request)); | |
333 | from++) { | |
334 | /* Retrieve character */ | |
335 | c = msg[from]; | |
336 | /* Perform conversion */ | |
337 | if (c == 0x0a) { | |
338 | if (to + 1 < sclp_vt220_space_left(request)) { | |
339 | ((unsigned char *) buffer)[to++] = c; | |
340 | ((unsigned char *) buffer)[to++] = 0x0d; | |
341 | } else | |
342 | break; | |
343 | ||
344 | } else | |
345 | ((unsigned char *) buffer)[to++] = c; | |
346 | } | |
347 | sccb->header.length += to; | |
348 | sccb->evbuf.length += to; | |
349 | return from; | |
350 | } else { | |
351 | memcpy(buffer, (const void *) msg, count); | |
352 | sccb->header.length += count; | |
353 | sccb->evbuf.length += count; | |
354 | return count; | |
355 | } | |
356 | } | |
357 | ||
358 | /* | |
359 | * Emit buffer after having waited long enough for more data to arrive. | |
360 | */ | |
361 | static void | |
362 | sclp_vt220_timeout(unsigned long data) | |
363 | { | |
364 | sclp_vt220_emit_current(); | |
365 | } | |
366 | ||
fa331ffc | 367 | #define BUFFER_MAX_DELAY HZ/20 |
1da177e4 LT |
368 | |
369 | /* | |
370 | * Internal implementation of the write function. Write COUNT bytes of data | |
371 | * from memory at BUF | |
372 | * to the SCLP interface. In case that the data does not fit into the current | |
373 | * write buffer, emit the current one and allocate a new one. If there are no | |
374 | * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE | |
375 | * is non-zero, the buffer will be scheduled for emitting after a timeout - | |
376 | * otherwise the user has to explicitly call the flush function. | |
377 | * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message | |
378 | * buffer should be converted to 0x0a 0x0d. After completion, return the number | |
379 | * of bytes written. | |
380 | */ | |
381 | static int | |
382 | __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule, | |
d4820e44 | 383 | int convertlf, int may_fail) |
1da177e4 LT |
384 | { |
385 | unsigned long flags; | |
386 | void *page; | |
387 | int written; | |
388 | int overall_written; | |
389 | ||
390 | if (count <= 0) | |
391 | return 0; | |
392 | overall_written = 0; | |
393 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
394 | do { | |
d4820e44 | 395 | /* Create an sclp output buffer if none exists yet */ |
1da177e4 LT |
396 | if (sclp_vt220_current_request == NULL) { |
397 | while (list_empty(&sclp_vt220_empty)) { | |
d1e23375 | 398 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); |
62b74942 | 399 | if (may_fail || sclp_vt220_suspended) |
d4820e44 | 400 | goto out; |
1da177e4 | 401 | else |
d4820e44 | 402 | sclp_sync_wait(); |
1da177e4 LT |
403 | spin_lock_irqsave(&sclp_vt220_lock, flags); |
404 | } | |
405 | page = (void *) sclp_vt220_empty.next; | |
406 | list_del((struct list_head *) page); | |
407 | sclp_vt220_current_request = | |
408 | sclp_vt220_initialize_page(page); | |
409 | } | |
410 | /* Try to write the string to the current request buffer */ | |
411 | written = sclp_vt220_add_msg(sclp_vt220_current_request, | |
412 | buf, count, convertlf); | |
413 | overall_written += written; | |
414 | if (written == count) | |
415 | break; | |
416 | /* | |
417 | * Not all characters could be written to the current | |
418 | * output buffer. Emit the buffer, create a new buffer | |
419 | * and then output the rest of the string. | |
420 | */ | |
421 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
422 | sclp_vt220_emit_current(); | |
423 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
424 | buf += written; | |
425 | count -= written; | |
426 | } while (count > 0); | |
427 | /* Setup timer to output current console buffer after some time */ | |
428 | if (sclp_vt220_current_request != NULL && | |
429 | !timer_pending(&sclp_vt220_timer) && do_schedule) { | |
430 | sclp_vt220_timer.function = sclp_vt220_timeout; | |
431 | sclp_vt220_timer.data = 0UL; | |
432 | sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY; | |
433 | add_timer(&sclp_vt220_timer); | |
434 | } | |
435 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
d4820e44 | 436 | out: |
1da177e4 LT |
437 | return overall_written; |
438 | } | |
439 | ||
440 | /* | |
441 | * This routine is called by the kernel to write a series of | |
442 | * characters to the tty device. The characters may come from | |
443 | * user space or kernel space. This routine will return the | |
444 | * number of characters actually accepted for writing. | |
445 | */ | |
446 | static int | |
447 | sclp_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count) | |
448 | { | |
d1e23375 | 449 | return __sclp_vt220_write(buf, count, 1, 0, 1); |
1da177e4 LT |
450 | } |
451 | ||
452 | #define SCLP_VT220_SESSION_ENDED 0x01 | |
453 | #define SCLP_VT220_SESSION_STARTED 0x80 | |
454 | #define SCLP_VT220_SESSION_DATA 0x00 | |
455 | ||
456 | /* | |
457 | * Called by the SCLP to report incoming event buffers. | |
458 | */ | |
459 | static void | |
460 | sclp_vt220_receiver_fn(struct evbuf_header *evbuf) | |
461 | { | |
462 | char *buffer; | |
463 | unsigned int count; | |
464 | ||
465 | /* Ignore input if device is not open */ | |
466 | if (sclp_vt220_tty == NULL) | |
467 | return; | |
468 | ||
469 | buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header)); | |
470 | count = evbuf->length - sizeof(struct evbuf_header); | |
471 | ||
472 | switch (*buffer) { | |
473 | case SCLP_VT220_SESSION_ENDED: | |
474 | case SCLP_VT220_SESSION_STARTED: | |
475 | break; | |
476 | case SCLP_VT220_SESSION_DATA: | |
477 | /* Send input to line discipline */ | |
478 | buffer++; | |
479 | count--; | |
33f0f88f | 480 | tty_insert_flip_string(sclp_vt220_tty, buffer, count); |
1da177e4 LT |
481 | tty_flip_buffer_push(sclp_vt220_tty); |
482 | break; | |
483 | } | |
484 | } | |
485 | ||
486 | /* | |
487 | * This routine is called when a particular tty device is opened. | |
488 | */ | |
489 | static int | |
490 | sclp_vt220_open(struct tty_struct *tty, struct file *filp) | |
491 | { | |
492 | if (tty->count == 1) { | |
493 | sclp_vt220_tty = tty; | |
494 | tty->driver_data = kmalloc(SCLP_VT220_BUF_SIZE, GFP_KERNEL); | |
495 | if (tty->driver_data == NULL) | |
496 | return -ENOMEM; | |
497 | tty->low_latency = 0; | |
498 | } | |
499 | return 0; | |
500 | } | |
501 | ||
502 | /* | |
503 | * This routine is called when a particular tty device is closed. | |
504 | */ | |
505 | static void | |
506 | sclp_vt220_close(struct tty_struct *tty, struct file *filp) | |
507 | { | |
508 | if (tty->count == 1) { | |
509 | sclp_vt220_tty = NULL; | |
510 | kfree(tty->driver_data); | |
511 | tty->driver_data = NULL; | |
512 | } | |
513 | } | |
514 | ||
515 | /* | |
516 | * This routine is called by the kernel to write a single | |
517 | * character to the tty device. If the kernel uses this routine, | |
518 | * it must call the flush_chars() routine (if defined) when it is | |
519 | * done stuffing characters into the driver. | |
1da177e4 | 520 | */ |
9e7c9a19 | 521 | static int |
1da177e4 LT |
522 | sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch) |
523 | { | |
d4820e44 | 524 | return __sclp_vt220_write(&ch, 1, 0, 0, 1); |
1da177e4 LT |
525 | } |
526 | ||
527 | /* | |
528 | * This routine is called by the kernel after it has written a | |
529 | * series of characters to the tty device using put_char(). | |
530 | */ | |
531 | static void | |
532 | sclp_vt220_flush_chars(struct tty_struct *tty) | |
533 | { | |
62b74942 | 534 | if (!sclp_vt220_queue_running) |
1da177e4 LT |
535 | sclp_vt220_emit_current(); |
536 | else | |
537 | sclp_vt220_flush_later = 1; | |
538 | } | |
539 | ||
540 | /* | |
541 | * This routine returns the numbers of characters the tty driver | |
542 | * will accept for queuing to be written. This number is subject | |
543 | * to change as output buffers get emptied, or if the output flow | |
544 | * control is acted. | |
545 | */ | |
546 | static int | |
547 | sclp_vt220_write_room(struct tty_struct *tty) | |
548 | { | |
549 | unsigned long flags; | |
550 | struct list_head *l; | |
551 | int count; | |
552 | ||
553 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
554 | count = 0; | |
555 | if (sclp_vt220_current_request != NULL) | |
556 | count = sclp_vt220_space_left(sclp_vt220_current_request); | |
557 | list_for_each(l, &sclp_vt220_empty) | |
558 | count += SCLP_VT220_MAX_CHARS_PER_BUFFER; | |
559 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
560 | return count; | |
561 | } | |
562 | ||
563 | /* | |
564 | * Return number of buffered chars. | |
565 | */ | |
566 | static int | |
567 | sclp_vt220_chars_in_buffer(struct tty_struct *tty) | |
568 | { | |
569 | unsigned long flags; | |
570 | struct list_head *l; | |
571 | struct sclp_vt220_request *r; | |
572 | int count; | |
573 | ||
574 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
575 | count = 0; | |
576 | if (sclp_vt220_current_request != NULL) | |
577 | count = sclp_vt220_chars_stored(sclp_vt220_current_request); | |
578 | list_for_each(l, &sclp_vt220_outqueue) { | |
579 | r = list_entry(l, struct sclp_vt220_request, list); | |
580 | count += sclp_vt220_chars_stored(r); | |
581 | } | |
582 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
583 | return count; | |
584 | } | |
585 | ||
1da177e4 LT |
586 | /* |
587 | * Pass on all buffers to the hardware. Return only when there are no more | |
588 | * buffers pending. | |
589 | */ | |
590 | static void | |
591 | sclp_vt220_flush_buffer(struct tty_struct *tty) | |
592 | { | |
593 | sclp_vt220_emit_current(); | |
594 | } | |
595 | ||
ad211790 PO |
596 | /* Release allocated pages. */ |
597 | static void __init __sclp_vt220_free_pages(void) | |
5aaaf9f0 HC |
598 | { |
599 | struct list_head *page, *p; | |
600 | ||
601 | list_for_each_safe(page, p, &sclp_vt220_empty) { | |
602 | list_del(page); | |
5c0792f6 | 603 | free_page((unsigned long) page); |
5aaaf9f0 HC |
604 | } |
605 | } | |
606 | ||
ad211790 PO |
607 | /* Release memory and unregister from sclp core. Controlled by init counting - |
608 | * only the last invoker will actually perform these actions. */ | |
609 | static void __init __sclp_vt220_cleanup(void) | |
610 | { | |
611 | sclp_vt220_init_count--; | |
612 | if (sclp_vt220_init_count != 0) | |
613 | return; | |
614 | sclp_unregister(&sclp_vt220_register); | |
615 | __sclp_vt220_free_pages(); | |
616 | } | |
617 | ||
618 | /* Allocate buffer pages and register with sclp core. Controlled by init | |
619 | * counting - only the first invoker will actually perform these actions. */ | |
620 | static int __init __sclp_vt220_init(int num_pages) | |
1da177e4 LT |
621 | { |
622 | void *page; | |
623 | int i; | |
59eb1ca7 | 624 | int rc; |
1da177e4 | 625 | |
ad211790 PO |
626 | sclp_vt220_init_count++; |
627 | if (sclp_vt220_init_count != 1) | |
1da177e4 | 628 | return 0; |
1da177e4 LT |
629 | spin_lock_init(&sclp_vt220_lock); |
630 | INIT_LIST_HEAD(&sclp_vt220_empty); | |
631 | INIT_LIST_HEAD(&sclp_vt220_outqueue); | |
1da177e4 LT |
632 | init_timer(&sclp_vt220_timer); |
633 | sclp_vt220_current_request = NULL; | |
634 | sclp_vt220_buffered_chars = 0; | |
1da177e4 LT |
635 | sclp_vt220_tty = NULL; |
636 | sclp_vt220_flush_later = 0; | |
637 | ||
638 | /* Allocate pages for output buffering */ | |
5c0792f6 | 639 | rc = -ENOMEM; |
5aaaf9f0 | 640 | for (i = 0; i < num_pages; i++) { |
5c0792f6 HC |
641 | page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); |
642 | if (!page) | |
ad211790 | 643 | goto out; |
5c0792f6 | 644 | list_add_tail(page, &sclp_vt220_empty); |
1da177e4 | 645 | } |
59eb1ca7 | 646 | rc = sclp_register(&sclp_vt220_register); |
ad211790 | 647 | out: |
59eb1ca7 | 648 | if (rc) { |
ad211790 PO |
649 | __sclp_vt220_free_pages(); |
650 | sclp_vt220_init_count--; | |
59eb1ca7 CB |
651 | } |
652 | return rc; | |
1da177e4 LT |
653 | } |
654 | ||
b68e31d0 | 655 | static const struct tty_operations sclp_vt220_ops = { |
1da177e4 LT |
656 | .open = sclp_vt220_open, |
657 | .close = sclp_vt220_close, | |
658 | .write = sclp_vt220_write, | |
659 | .put_char = sclp_vt220_put_char, | |
660 | .flush_chars = sclp_vt220_flush_chars, | |
661 | .write_room = sclp_vt220_write_room, | |
662 | .chars_in_buffer = sclp_vt220_chars_in_buffer, | |
5aaaf9f0 | 663 | .flush_buffer = sclp_vt220_flush_buffer, |
1da177e4 LT |
664 | }; |
665 | ||
666 | /* | |
667 | * Register driver with SCLP and Linux and initialize internal tty structures. | |
668 | */ | |
5aaaf9f0 | 669 | static int __init sclp_vt220_tty_init(void) |
1da177e4 LT |
670 | { |
671 | struct tty_driver *driver; | |
672 | int rc; | |
673 | ||
674 | /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve | |
675 | * symmetry between VM and LPAR systems regarding ttyS1. */ | |
676 | driver = alloc_tty_driver(1); | |
677 | if (!driver) | |
678 | return -ENOMEM; | |
ad211790 | 679 | rc = __sclp_vt220_init(MAX_KMEM_PAGES); |
5aaaf9f0 HC |
680 | if (rc) |
681 | goto out_driver; | |
1da177e4 LT |
682 | |
683 | driver->owner = THIS_MODULE; | |
684 | driver->driver_name = SCLP_VT220_DRIVER_NAME; | |
685 | driver->name = SCLP_VT220_DEVICE_NAME; | |
686 | driver->major = SCLP_VT220_MAJOR; | |
687 | driver->minor_start = SCLP_VT220_MINOR; | |
688 | driver->type = TTY_DRIVER_TYPE_SYSTEM; | |
689 | driver->subtype = SYSTEM_TYPE_TTY; | |
690 | driver->init_termios = tty_std_termios; | |
691 | driver->flags = TTY_DRIVER_REAL_RAW; | |
692 | tty_set_operations(driver, &sclp_vt220_ops); | |
693 | ||
694 | rc = tty_register_driver(driver); | |
a12c53f4 | 695 | if (rc) |
59eb1ca7 | 696 | goto out_init; |
1da177e4 LT |
697 | sclp_vt220_driver = driver; |
698 | return 0; | |
1da177e4 | 699 | |
5aaaf9f0 | 700 | out_init: |
ad211790 | 701 | __sclp_vt220_cleanup(); |
5aaaf9f0 HC |
702 | out_driver: |
703 | put_tty_driver(driver); | |
704 | return rc; | |
705 | } | |
706 | __initcall(sclp_vt220_tty_init); | |
1da177e4 LT |
707 | |
708 | #ifdef CONFIG_SCLP_VT220_CONSOLE | |
709 | ||
710 | static void | |
711 | sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count) | |
712 | { | |
d1e23375 | 713 | __sclp_vt220_write((const unsigned char *) buf, count, 1, 1, 0); |
1da177e4 LT |
714 | } |
715 | ||
716 | static struct tty_driver * | |
717 | sclp_vt220_con_device(struct console *c, int *index) | |
718 | { | |
719 | *index = 0; | |
720 | return sclp_vt220_driver; | |
721 | } | |
722 | ||
b3b59d33 HC |
723 | static void __sclp_vt220_flush_buffer(void) |
724 | { | |
725 | unsigned long flags; | |
726 | ||
727 | sclp_vt220_emit_current(); | |
728 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
729 | if (timer_pending(&sclp_vt220_timer)) | |
730 | del_timer(&sclp_vt220_timer); | |
62b74942 | 731 | while (sclp_vt220_queue_running) { |
b3b59d33 HC |
732 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); |
733 | sclp_sync_wait(); | |
734 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
735 | } | |
736 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
737 | } | |
738 | ||
62b74942 MH |
739 | /* |
740 | * Resume console: If there are cached messages, emit them. | |
741 | */ | |
742 | static void sclp_vt220_resume(void) | |
743 | { | |
744 | unsigned long flags; | |
745 | ||
746 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
747 | sclp_vt220_suspended = 0; | |
748 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
749 | sclp_vt220_emit_current(); | |
750 | } | |
751 | ||
752 | /* | |
753 | * Suspend console: Set suspend flag and flush console | |
754 | */ | |
755 | static void sclp_vt220_suspend(void) | |
756 | { | |
757 | unsigned long flags; | |
758 | ||
759 | spin_lock_irqsave(&sclp_vt220_lock, flags); | |
760 | sclp_vt220_suspended = 1; | |
761 | spin_unlock_irqrestore(&sclp_vt220_lock, flags); | |
762 | __sclp_vt220_flush_buffer(); | |
763 | } | |
764 | ||
765 | static void sclp_vt220_pm_event_fn(struct sclp_register *reg, | |
766 | enum sclp_pm_event sclp_pm_event) | |
767 | { | |
768 | switch (sclp_pm_event) { | |
769 | case SCLP_PM_EVENT_FREEZE: | |
770 | sclp_vt220_suspend(); | |
771 | break; | |
772 | case SCLP_PM_EVENT_RESTORE: | |
773 | case SCLP_PM_EVENT_THAW: | |
774 | sclp_vt220_resume(); | |
775 | break; | |
776 | } | |
777 | } | |
778 | ||
2332ce1a HS |
779 | static int |
780 | sclp_vt220_notify(struct notifier_block *self, | |
781 | unsigned long event, void *data) | |
1da177e4 LT |
782 | { |
783 | __sclp_vt220_flush_buffer(); | |
2332ce1a | 784 | return NOTIFY_OK; |
1da177e4 LT |
785 | } |
786 | ||
2332ce1a HS |
787 | static struct notifier_block on_panic_nb = { |
788 | .notifier_call = sclp_vt220_notify, | |
789 | .priority = 1, | |
790 | }; | |
791 | ||
792 | static struct notifier_block on_reboot_nb = { | |
793 | .notifier_call = sclp_vt220_notify, | |
794 | .priority = 1, | |
795 | }; | |
796 | ||
1da177e4 LT |
797 | /* Structure needed to register with printk */ |
798 | static struct console sclp_vt220_console = | |
799 | { | |
800 | .name = SCLP_VT220_CONSOLE_NAME, | |
801 | .write = sclp_vt220_con_write, | |
802 | .device = sclp_vt220_con_device, | |
1da177e4 LT |
803 | .flags = CON_PRINTBUFFER, |
804 | .index = SCLP_VT220_CONSOLE_INDEX | |
805 | }; | |
806 | ||
807 | static int __init | |
808 | sclp_vt220_con_init(void) | |
809 | { | |
810 | int rc; | |
811 | ||
812 | if (!CONSOLE_IS_SCLP) | |
813 | return 0; | |
ad211790 | 814 | rc = __sclp_vt220_init(MAX_CONSOLE_PAGES); |
1da177e4 LT |
815 | if (rc) |
816 | return rc; | |
817 | /* Attach linux console */ | |
2332ce1a HS |
818 | atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb); |
819 | register_reboot_notifier(&on_reboot_nb); | |
1da177e4 LT |
820 | register_console(&sclp_vt220_console); |
821 | return 0; | |
822 | } | |
823 | ||
824 | console_initcall(sclp_vt220_con_init); | |
825 | #endif /* CONFIG_SCLP_VT220_CONSOLE */ | |
826 |