1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * SCLP VT220 terminal driver. 4 * 5 * Copyright IBM Corp. 2003, 2009 6 * 7 * Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com> 8 */ 9 10 #include <linux/module.h> 11 #include <linux/spinlock.h> 12 #include <linux/panic_notifier.h> 13 #include <linux/list.h> 14 #include <linux/wait.h> 15 #include <linux/timer.h> 16 #include <linux/kernel.h> 17 #include <linux/sysrq.h> 18 #include <linux/tty.h> 19 #include <linux/tty_driver.h> 20 #include <linux/tty_flip.h> 21 #include <linux/errno.h> 22 #include <linux/mm.h> 23 #include <linux/major.h> 24 #include <linux/console.h> 25 #include <linux/kdev_t.h> 26 #include <linux/interrupt.h> 27 #include <linux/init.h> 28 #include <linux/reboot.h> 29 #include <linux/slab.h> 30 31 #include <linux/uaccess.h> 32 #include "sclp.h" 33 #include "ctrlchar.h" 34 35 #define SCLP_VT220_MAJOR TTY_MAJOR 36 #define SCLP_VT220_MINOR 65 37 #define SCLP_VT220_DRIVER_NAME "sclp_vt220" 38 #define SCLP_VT220_DEVICE_NAME "ttysclp" 39 #define SCLP_VT220_CONSOLE_NAME "ttysclp" 40 #define SCLP_VT220_CONSOLE_INDEX 0 /* console=ttysclp0 */ 41 42 /* Representation of a single write request */ 43 struct sclp_vt220_request { 44 struct list_head list; 45 struct sclp_req sclp_req; 46 int retry_count; 47 }; 48 49 /* VT220 SCCB */ 50 struct sclp_vt220_sccb { 51 struct sccb_header header; 52 struct evbuf_header evbuf; 53 }; 54 55 #define SCLP_VT220_MAX_CHARS_PER_BUFFER (PAGE_SIZE - \ 56 sizeof(struct sclp_vt220_request) - \ 57 sizeof(struct sclp_vt220_sccb)) 58 59 /* Structures and data needed to register tty driver */ 60 static struct tty_driver *sclp_vt220_driver; 61 62 static struct tty_port sclp_vt220_port; 63 64 /* Lock to protect internal data from concurrent access */ 65 static DEFINE_SPINLOCK(sclp_vt220_lock); 66 67 /* List of empty pages to be used as write request buffers */ 68 static LIST_HEAD(sclp_vt220_empty); 69 70 /* List of pending requests */ 71 static LIST_HEAD(sclp_vt220_outqueue); 72 73 /* Flag that output queue is currently running */ 74 static int sclp_vt220_queue_running; 75 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 87 /* Counter controlling core driver initialization. */ 88 static int __initdata sclp_vt220_init_count; 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); 96 static int __sclp_vt220_emit(struct sclp_vt220_request *request); 97 static void sclp_vt220_emit_current(void); 98 99 /* Registration structure for SCLP output event buffers */ 100 static struct sclp_register sclp_vt220_register = { 101 .send_mask = EVTYP_VT220MSG_MASK, 102 }; 103 104 /* Registration structure for SCLP input event buffers */ 105 static struct sclp_register sclp_vt220_register_input = { 106 .receive_mask = EVTYP_VT220MSG_MASK, 107 .receiver_fn = sclp_vt220_receiver_fn, 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); 127 list_add_tail((struct list_head *) page, &sclp_vt220_empty); 128 /* Check if there is a pending buffer on the out queue. */ 129 request = NULL; 130 if (!list_empty(&sclp_vt220_outqueue)) 131 request = list_entry(sclp_vt220_outqueue.next, 132 struct sclp_vt220_request, list); 133 if (!request) { 134 sclp_vt220_queue_running = 0; 135 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 136 break; 137 } 138 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 139 } while (__sclp_vt220_emit(request)); 140 if (request == NULL && sclp_vt220_flush_later) 141 sclp_vt220_emit_current(); 142 tty_port_tty_wakeup(&sclp_vt220_port); 143 } 144 145 #define SCLP_BUFFER_MAX_RETRY 1 146 147 /* 148 * Callback through which the result of a write request is reported by the 149 * SCLP. 150 */ 151 static void 152 sclp_vt220_callback(struct sclp_req *request, void *data) 153 { 154 struct sclp_vt220_request *vt220_request; 155 struct sclp_vt220_sccb *sccb; 156 157 vt220_request = (struct sclp_vt220_request *) data; 158 if (request->status == SCLP_REQ_FAILED) { 159 sclp_vt220_process_queue(vt220_request); 160 return; 161 } 162 sccb = (struct sclp_vt220_sccb *) vt220_request->sclp_req.sccb; 163 164 /* Check SCLP response code and choose suitable action */ 165 switch (sccb->header.response_code) { 166 case 0x0020 : 167 break; 168 169 case 0x05f0: /* Target resource in improper state */ 170 break; 171 172 case 0x0340: /* Contained SCLP equipment check */ 173 if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) 174 break; 175 /* Remove processed buffers and requeue rest */ 176 if (sclp_remove_processed((struct sccb_header *) sccb) > 0) { 177 /* Not all buffers were processed */ 178 sccb->header.response_code = 0x0000; 179 vt220_request->sclp_req.status = SCLP_REQ_FILLED; 180 if (sclp_add_request(request) == 0) 181 return; 182 } 183 break; 184 185 case 0x0040: /* SCLP equipment check */ 186 if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) 187 break; 188 sccb->header.response_code = 0x0000; 189 vt220_request->sclp_req.status = SCLP_REQ_FILLED; 190 if (sclp_add_request(request) == 0) 191 return; 192 break; 193 194 default: 195 break; 196 } 197 sclp_vt220_process_queue(vt220_request); 198 } 199 200 /* 201 * Emit vt220 request buffer to SCLP. Return zero on success, non-zero 202 * otherwise. 203 */ 204 static int 205 __sclp_vt220_emit(struct sclp_vt220_request *request) 206 { 207 request->sclp_req.command = SCLP_CMDW_WRITE_EVENT_DATA; 208 request->sclp_req.status = SCLP_REQ_FILLED; 209 request->sclp_req.callback = sclp_vt220_callback; 210 request->sclp_req.callback_data = (void *) request; 211 212 return sclp_add_request(&request->sclp_req); 213 } 214 215 /* 216 * Queue and emit current request. 217 */ 218 static void 219 sclp_vt220_emit_current(void) 220 { 221 unsigned long flags; 222 struct sclp_vt220_request *request; 223 struct sclp_vt220_sccb *sccb; 224 225 spin_lock_irqsave(&sclp_vt220_lock, flags); 226 if (sclp_vt220_current_request) { 227 sccb = (struct sclp_vt220_sccb *) 228 sclp_vt220_current_request->sclp_req.sccb; 229 /* Only emit buffers with content */ 230 if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) { 231 list_add_tail(&sclp_vt220_current_request->list, 232 &sclp_vt220_outqueue); 233 sclp_vt220_current_request = NULL; 234 if (timer_pending(&sclp_vt220_timer)) 235 del_timer(&sclp_vt220_timer); 236 } 237 sclp_vt220_flush_later = 0; 238 } 239 if (sclp_vt220_queue_running) 240 goto out_unlock; 241 if (list_empty(&sclp_vt220_outqueue)) 242 goto out_unlock; 243 request = list_first_entry(&sclp_vt220_outqueue, 244 struct sclp_vt220_request, list); 245 sclp_vt220_queue_running = 1; 246 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 247 248 if (__sclp_vt220_emit(request)) 249 sclp_vt220_process_queue(request); 250 return; 251 out_unlock: 252 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 253 } 254 255 #define SCLP_NORMAL_WRITE 0x00 256 257 /* 258 * Helper function to initialize a page with the sclp request structure. 259 */ 260 static struct sclp_vt220_request * 261 sclp_vt220_initialize_page(void *page) 262 { 263 struct sclp_vt220_request *request; 264 struct sclp_vt220_sccb *sccb; 265 266 /* Place request structure at end of page */ 267 request = ((struct sclp_vt220_request *) 268 ((addr_t) page + PAGE_SIZE)) - 1; 269 request->retry_count = 0; 270 request->sclp_req.sccb = page; 271 /* SCCB goes at start of page */ 272 sccb = (struct sclp_vt220_sccb *) page; 273 memset((void *) sccb, 0, sizeof(struct sclp_vt220_sccb)); 274 sccb->header.length = sizeof(struct sclp_vt220_sccb); 275 sccb->header.function_code = SCLP_NORMAL_WRITE; 276 sccb->header.response_code = 0x0000; 277 sccb->evbuf.type = EVTYP_VT220MSG; 278 sccb->evbuf.length = sizeof(struct evbuf_header); 279 280 return request; 281 } 282 283 static inline unsigned int 284 sclp_vt220_space_left(struct sclp_vt220_request *request) 285 { 286 struct sclp_vt220_sccb *sccb; 287 sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; 288 return PAGE_SIZE - sizeof(struct sclp_vt220_request) - 289 sccb->header.length; 290 } 291 292 static inline unsigned int 293 sclp_vt220_chars_stored(struct sclp_vt220_request *request) 294 { 295 struct sclp_vt220_sccb *sccb; 296 sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; 297 return sccb->evbuf.length - sizeof(struct evbuf_header); 298 } 299 300 /* 301 * Add msg to buffer associated with request. Return the number of characters 302 * added. 303 */ 304 static int 305 sclp_vt220_add_msg(struct sclp_vt220_request *request, 306 const unsigned char *msg, int count, int convertlf) 307 { 308 struct sclp_vt220_sccb *sccb; 309 void *buffer; 310 unsigned char c; 311 int from; 312 int to; 313 314 if (count > sclp_vt220_space_left(request)) 315 count = sclp_vt220_space_left(request); 316 if (count <= 0) 317 return 0; 318 319 sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb; 320 buffer = (void *) ((addr_t) sccb + sccb->header.length); 321 322 if (convertlf) { 323 /* Perform Linefeed conversion (0x0a -> 0x0a 0x0d)*/ 324 for (from=0, to=0; 325 (from < count) && (to < sclp_vt220_space_left(request)); 326 from++) { 327 /* Retrieve character */ 328 c = msg[from]; 329 /* Perform conversion */ 330 if (c == 0x0a) { 331 if (to + 1 < sclp_vt220_space_left(request)) { 332 ((unsigned char *) buffer)[to++] = c; 333 ((unsigned char *) buffer)[to++] = 0x0d; 334 } else 335 break; 336 337 } else 338 ((unsigned char *) buffer)[to++] = c; 339 } 340 sccb->header.length += to; 341 sccb->evbuf.length += to; 342 return from; 343 } else { 344 memcpy(buffer, (const void *) msg, count); 345 sccb->header.length += count; 346 sccb->evbuf.length += count; 347 return count; 348 } 349 } 350 351 /* 352 * Emit buffer after having waited long enough for more data to arrive. 353 */ 354 static void 355 sclp_vt220_timeout(struct timer_list *unused) 356 { 357 sclp_vt220_emit_current(); 358 } 359 360 #define BUFFER_MAX_DELAY HZ/20 361 362 /* 363 * Drop oldest console buffer if sclp_con_drop is set 364 */ 365 static int 366 sclp_vt220_drop_buffer(void) 367 { 368 struct list_head *list; 369 struct sclp_vt220_request *request; 370 void *page; 371 372 if (!sclp_console_drop) 373 return 0; 374 list = sclp_vt220_outqueue.next; 375 if (sclp_vt220_queue_running) 376 /* The first element is in I/O */ 377 list = list->next; 378 if (list == &sclp_vt220_outqueue) 379 return 0; 380 list_del(list); 381 request = list_entry(list, struct sclp_vt220_request, list); 382 page = request->sclp_req.sccb; 383 list_add_tail((struct list_head *) page, &sclp_vt220_empty); 384 return 1; 385 } 386 387 /* 388 * Internal implementation of the write function. Write COUNT bytes of data 389 * from memory at BUF 390 * to the SCLP interface. In case that the data does not fit into the current 391 * write buffer, emit the current one and allocate a new one. If there are no 392 * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE 393 * is non-zero, the buffer will be scheduled for emitting after a timeout - 394 * otherwise the user has to explicitly call the flush function. 395 * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message 396 * buffer should be converted to 0x0a 0x0d. After completion, return the number 397 * of bytes written. 398 */ 399 static int 400 __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule, 401 int convertlf, int may_fail) 402 { 403 unsigned long flags; 404 void *page; 405 int written; 406 int overall_written; 407 408 if (count <= 0) 409 return 0; 410 overall_written = 0; 411 spin_lock_irqsave(&sclp_vt220_lock, flags); 412 do { 413 /* Create an sclp output buffer if none exists yet */ 414 if (sclp_vt220_current_request == NULL) { 415 if (list_empty(&sclp_vt220_empty)) 416 sclp_console_full++; 417 while (list_empty(&sclp_vt220_empty)) { 418 if (may_fail) 419 goto out; 420 if (sclp_vt220_drop_buffer()) 421 break; 422 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 423 424 sclp_sync_wait(); 425 spin_lock_irqsave(&sclp_vt220_lock, flags); 426 } 427 page = (void *) sclp_vt220_empty.next; 428 list_del((struct list_head *) page); 429 sclp_vt220_current_request = 430 sclp_vt220_initialize_page(page); 431 } 432 /* Try to write the string to the current request buffer */ 433 written = sclp_vt220_add_msg(sclp_vt220_current_request, 434 buf, count, convertlf); 435 overall_written += written; 436 if (written == count) 437 break; 438 /* 439 * Not all characters could be written to the current 440 * output buffer. Emit the buffer, create a new buffer 441 * and then output the rest of the string. 442 */ 443 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 444 sclp_vt220_emit_current(); 445 spin_lock_irqsave(&sclp_vt220_lock, flags); 446 buf += written; 447 count -= written; 448 } while (count > 0); 449 /* Setup timer to output current console buffer after some time */ 450 if (sclp_vt220_current_request != NULL && 451 !timer_pending(&sclp_vt220_timer) && do_schedule) { 452 sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY; 453 add_timer(&sclp_vt220_timer); 454 } 455 out: 456 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 457 return overall_written; 458 } 459 460 /* 461 * This routine is called by the kernel to write a series of 462 * characters to the tty device. The characters may come from 463 * user space or kernel space. This routine will return the 464 * number of characters actually accepted for writing. 465 */ 466 static int 467 sclp_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count) 468 { 469 return __sclp_vt220_write(buf, count, 1, 0, 1); 470 } 471 472 #define SCLP_VT220_SESSION_ENDED 0x01 473 #define SCLP_VT220_SESSION_STARTED 0x80 474 #define SCLP_VT220_SESSION_DATA 0x00 475 476 #ifdef CONFIG_MAGIC_SYSRQ 477 478 static int sysrq_pressed; 479 static struct sysrq_work sysrq; 480 481 static void sclp_vt220_reset_session(void) 482 { 483 sysrq_pressed = 0; 484 } 485 486 static void sclp_vt220_handle_input(const char *buffer, unsigned int count) 487 { 488 int i; 489 490 for (i = 0; i < count; i++) { 491 /* Handle magic sys request */ 492 if (buffer[i] == ('O' ^ 0100)) { /* CTRL-O */ 493 /* 494 * If pressed again, reset sysrq_pressed 495 * and flip CTRL-O character 496 */ 497 sysrq_pressed = !sysrq_pressed; 498 if (sysrq_pressed) 499 continue; 500 } else if (sysrq_pressed) { 501 sysrq.key = buffer[i]; 502 schedule_sysrq_work(&sysrq); 503 sysrq_pressed = 0; 504 continue; 505 } 506 tty_insert_flip_char(&sclp_vt220_port, buffer[i], 0); 507 } 508 } 509 510 #else 511 512 static void sclp_vt220_reset_session(void) 513 { 514 } 515 516 static void sclp_vt220_handle_input(const char *buffer, unsigned int count) 517 { 518 tty_insert_flip_string(&sclp_vt220_port, buffer, count); 519 } 520 521 #endif 522 523 /* 524 * Called by the SCLP to report incoming event buffers. 525 */ 526 static void 527 sclp_vt220_receiver_fn(struct evbuf_header *evbuf) 528 { 529 char *buffer; 530 unsigned int count; 531 532 buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header)); 533 count = evbuf->length - sizeof(struct evbuf_header); 534 535 switch (*buffer) { 536 case SCLP_VT220_SESSION_ENDED: 537 case SCLP_VT220_SESSION_STARTED: 538 sclp_vt220_reset_session(); 539 break; 540 case SCLP_VT220_SESSION_DATA: 541 /* Send input to line discipline */ 542 buffer++; 543 count--; 544 sclp_vt220_handle_input(buffer, count); 545 tty_flip_buffer_push(&sclp_vt220_port); 546 break; 547 } 548 } 549 550 /* 551 * This routine is called when a particular tty device is opened. 552 */ 553 static int 554 sclp_vt220_open(struct tty_struct *tty, struct file *filp) 555 { 556 if (tty->count == 1) { 557 tty_port_tty_set(&sclp_vt220_port, tty); 558 if (!tty->winsize.ws_row && !tty->winsize.ws_col) { 559 tty->winsize.ws_row = 24; 560 tty->winsize.ws_col = 80; 561 } 562 } 563 return 0; 564 } 565 566 /* 567 * This routine is called when a particular tty device is closed. 568 */ 569 static void 570 sclp_vt220_close(struct tty_struct *tty, struct file *filp) 571 { 572 if (tty->count == 1) 573 tty_port_tty_set(&sclp_vt220_port, NULL); 574 } 575 576 /* 577 * This routine is called by the kernel to write a single 578 * character to the tty device. If the kernel uses this routine, 579 * it must call the flush_chars() routine (if defined) when it is 580 * done stuffing characters into the driver. 581 */ 582 static int 583 sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch) 584 { 585 return __sclp_vt220_write(&ch, 1, 0, 0, 1); 586 } 587 588 /* 589 * This routine is called by the kernel after it has written a 590 * series of characters to the tty device using put_char(). 591 */ 592 static void 593 sclp_vt220_flush_chars(struct tty_struct *tty) 594 { 595 if (!sclp_vt220_queue_running) 596 sclp_vt220_emit_current(); 597 else 598 sclp_vt220_flush_later = 1; 599 } 600 601 /* 602 * This routine returns the numbers of characters the tty driver 603 * will accept for queuing to be written. This number is subject 604 * to change as output buffers get emptied, or if the output flow 605 * control is acted. 606 */ 607 static unsigned int 608 sclp_vt220_write_room(struct tty_struct *tty) 609 { 610 unsigned long flags; 611 struct list_head *l; 612 unsigned int count; 613 614 spin_lock_irqsave(&sclp_vt220_lock, flags); 615 count = 0; 616 if (sclp_vt220_current_request != NULL) 617 count = sclp_vt220_space_left(sclp_vt220_current_request); 618 list_for_each(l, &sclp_vt220_empty) 619 count += SCLP_VT220_MAX_CHARS_PER_BUFFER; 620 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 621 return count; 622 } 623 624 /* 625 * Return number of buffered chars. 626 */ 627 static unsigned int 628 sclp_vt220_chars_in_buffer(struct tty_struct *tty) 629 { 630 unsigned long flags; 631 struct list_head *l; 632 struct sclp_vt220_request *r; 633 unsigned int count = 0; 634 635 spin_lock_irqsave(&sclp_vt220_lock, flags); 636 if (sclp_vt220_current_request != NULL) 637 count = sclp_vt220_chars_stored(sclp_vt220_current_request); 638 list_for_each(l, &sclp_vt220_outqueue) { 639 r = list_entry(l, struct sclp_vt220_request, list); 640 count += sclp_vt220_chars_stored(r); 641 } 642 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 643 return count; 644 } 645 646 /* 647 * Pass on all buffers to the hardware. Return only when there are no more 648 * buffers pending. 649 */ 650 static void 651 sclp_vt220_flush_buffer(struct tty_struct *tty) 652 { 653 sclp_vt220_emit_current(); 654 } 655 656 /* Release allocated pages. */ 657 static void __init __sclp_vt220_free_pages(void) 658 { 659 struct list_head *page, *p; 660 661 list_for_each_safe(page, p, &sclp_vt220_empty) { 662 list_del(page); 663 free_page((unsigned long) page); 664 } 665 } 666 667 /* Release memory and unregister from sclp core. Controlled by init counting - 668 * only the last invoker will actually perform these actions. */ 669 static void __init __sclp_vt220_cleanup(void) 670 { 671 sclp_vt220_init_count--; 672 if (sclp_vt220_init_count != 0) 673 return; 674 sclp_unregister(&sclp_vt220_register); 675 __sclp_vt220_free_pages(); 676 tty_port_destroy(&sclp_vt220_port); 677 } 678 679 /* Allocate buffer pages and register with sclp core. Controlled by init 680 * counting - only the first invoker will actually perform these actions. */ 681 static int __init __sclp_vt220_init(int num_pages) 682 { 683 void *page; 684 int i; 685 int rc; 686 687 sclp_vt220_init_count++; 688 if (sclp_vt220_init_count != 1) 689 return 0; 690 timer_setup(&sclp_vt220_timer, sclp_vt220_timeout, 0); 691 tty_port_init(&sclp_vt220_port); 692 sclp_vt220_current_request = NULL; 693 sclp_vt220_buffered_chars = 0; 694 sclp_vt220_flush_later = 0; 695 696 /* Allocate pages for output buffering */ 697 rc = -ENOMEM; 698 for (i = 0; i < num_pages; i++) { 699 page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); 700 if (!page) 701 goto out; 702 list_add_tail(page, &sclp_vt220_empty); 703 } 704 rc = sclp_register(&sclp_vt220_register); 705 out: 706 if (rc) { 707 __sclp_vt220_free_pages(); 708 sclp_vt220_init_count--; 709 tty_port_destroy(&sclp_vt220_port); 710 } 711 return rc; 712 } 713 714 static const struct tty_operations sclp_vt220_ops = { 715 .open = sclp_vt220_open, 716 .close = sclp_vt220_close, 717 .write = sclp_vt220_write, 718 .put_char = sclp_vt220_put_char, 719 .flush_chars = sclp_vt220_flush_chars, 720 .write_room = sclp_vt220_write_room, 721 .chars_in_buffer = sclp_vt220_chars_in_buffer, 722 .flush_buffer = sclp_vt220_flush_buffer, 723 }; 724 725 /* 726 * Register driver with SCLP and Linux and initialize internal tty structures. 727 */ 728 static int __init sclp_vt220_tty_init(void) 729 { 730 struct tty_driver *driver; 731 int rc; 732 733 /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve 734 * symmetry between VM and LPAR systems regarding ttyS1. */ 735 driver = alloc_tty_driver(1); 736 if (!driver) 737 return -ENOMEM; 738 rc = __sclp_vt220_init(MAX_KMEM_PAGES); 739 if (rc) 740 goto out_driver; 741 742 driver->driver_name = SCLP_VT220_DRIVER_NAME; 743 driver->name = SCLP_VT220_DEVICE_NAME; 744 driver->major = SCLP_VT220_MAJOR; 745 driver->minor_start = SCLP_VT220_MINOR; 746 driver->type = TTY_DRIVER_TYPE_SYSTEM; 747 driver->subtype = SYSTEM_TYPE_TTY; 748 driver->init_termios = tty_std_termios; 749 driver->flags = TTY_DRIVER_REAL_RAW; 750 tty_set_operations(driver, &sclp_vt220_ops); 751 tty_port_link_device(&sclp_vt220_port, driver, 0); 752 753 rc = tty_register_driver(driver); 754 if (rc) 755 goto out_init; 756 rc = sclp_register(&sclp_vt220_register_input); 757 if (rc) 758 goto out_reg; 759 sclp_vt220_driver = driver; 760 return 0; 761 762 out_reg: 763 tty_unregister_driver(driver); 764 out_init: 765 __sclp_vt220_cleanup(); 766 out_driver: 767 put_tty_driver(driver); 768 return rc; 769 } 770 __initcall(sclp_vt220_tty_init); 771 772 static void __sclp_vt220_flush_buffer(void) 773 { 774 unsigned long flags; 775 776 sclp_vt220_emit_current(); 777 spin_lock_irqsave(&sclp_vt220_lock, flags); 778 if (timer_pending(&sclp_vt220_timer)) 779 del_timer(&sclp_vt220_timer); 780 while (sclp_vt220_queue_running) { 781 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 782 sclp_sync_wait(); 783 spin_lock_irqsave(&sclp_vt220_lock, flags); 784 } 785 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 786 } 787 788 #ifdef CONFIG_SCLP_VT220_CONSOLE 789 790 static void 791 sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count) 792 { 793 __sclp_vt220_write((const unsigned char *) buf, count, 1, 1, 0); 794 } 795 796 static struct tty_driver * 797 sclp_vt220_con_device(struct console *c, int *index) 798 { 799 *index = 0; 800 return sclp_vt220_driver; 801 } 802 803 static int 804 sclp_vt220_notify(struct notifier_block *self, 805 unsigned long event, void *data) 806 { 807 __sclp_vt220_flush_buffer(); 808 return NOTIFY_OK; 809 } 810 811 static struct notifier_block on_panic_nb = { 812 .notifier_call = sclp_vt220_notify, 813 .priority = 1, 814 }; 815 816 static struct notifier_block on_reboot_nb = { 817 .notifier_call = sclp_vt220_notify, 818 .priority = 1, 819 }; 820 821 /* Structure needed to register with printk */ 822 static struct console sclp_vt220_console = 823 { 824 .name = SCLP_VT220_CONSOLE_NAME, 825 .write = sclp_vt220_con_write, 826 .device = sclp_vt220_con_device, 827 .flags = CON_PRINTBUFFER, 828 .index = SCLP_VT220_CONSOLE_INDEX 829 }; 830 831 static int __init 832 sclp_vt220_con_init(void) 833 { 834 int rc; 835 836 rc = __sclp_vt220_init(sclp_console_pages); 837 if (rc) 838 return rc; 839 /* Attach linux console */ 840 atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb); 841 register_reboot_notifier(&on_reboot_nb); 842 register_console(&sclp_vt220_console); 843 return 0; 844 } 845 846 console_initcall(sclp_vt220_con_init); 847 #endif /* CONFIG_SCLP_VT220_CONSOLE */ 848 849