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 "ttyS" 40 #define SCLP_VT220_CONSOLE_INDEX 1 /* console=ttyS1 */ 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 /* Suspend mode flag */ 74 static int sclp_vt220_suspended; 75 76 /* Flag that output queue is currently running */ 77 static int sclp_vt220_queue_running; 78 79 /* Timer used for delaying write requests to merge subsequent messages into 80 * a single buffer */ 81 static struct timer_list sclp_vt220_timer; 82 83 /* Pointer to current request buffer which has been partially filled but not 84 * yet sent */ 85 static struct sclp_vt220_request *sclp_vt220_current_request; 86 87 /* Number of characters in current request buffer */ 88 static int sclp_vt220_buffered_chars; 89 90 /* Counter controlling core driver initialization. */ 91 static int __initdata sclp_vt220_init_count; 92 93 /* Flag indicating that sclp_vt220_current_request should really 94 * have been already queued but wasn't because the SCLP was processing 95 * another buffer */ 96 static int sclp_vt220_flush_later; 97 98 static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf); 99 static void sclp_vt220_pm_event_fn(struct sclp_register *reg, 100 enum sclp_pm_event sclp_pm_event); 101 static int __sclp_vt220_emit(struct sclp_vt220_request *request); 102 static void sclp_vt220_emit_current(void); 103 104 /* Registration structure for SCLP output event buffers */ 105 static struct sclp_register sclp_vt220_register = { 106 .send_mask = EVTYP_VT220MSG_MASK, 107 .pm_event_fn = sclp_vt220_pm_event_fn, 108 }; 109 110 /* Registration structure for SCLP input event buffers */ 111 static struct sclp_register sclp_vt220_register_input = { 112 .receive_mask = EVTYP_VT220MSG_MASK, 113 .receiver_fn = sclp_vt220_receiver_fn, 114 }; 115 116 117 /* 118 * Put provided request buffer back into queue and check emit pending 119 * buffers if necessary. 120 */ 121 static void 122 sclp_vt220_process_queue(struct sclp_vt220_request *request) 123 { 124 unsigned long flags; 125 void *page; 126 127 do { 128 /* Put buffer back to list of empty buffers */ 129 page = request->sclp_req.sccb; 130 spin_lock_irqsave(&sclp_vt220_lock, flags); 131 /* Move request from outqueue to empty queue */ 132 list_del(&request->list); 133 list_add_tail((struct list_head *) page, &sclp_vt220_empty); 134 /* Check if there is a pending buffer on the out queue. */ 135 request = NULL; 136 if (!list_empty(&sclp_vt220_outqueue)) 137 request = list_entry(sclp_vt220_outqueue.next, 138 struct sclp_vt220_request, list); 139 if (!request || sclp_vt220_suspended) { 140 sclp_vt220_queue_running = 0; 141 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 142 break; 143 } 144 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 145 } while (__sclp_vt220_emit(request)); 146 if (request == NULL && sclp_vt220_flush_later) 147 sclp_vt220_emit_current(); 148 tty_port_tty_wakeup(&sclp_vt220_port); 149 } 150 151 #define SCLP_BUFFER_MAX_RETRY 1 152 153 /* 154 * Callback through which the result of a write request is reported by the 155 * SCLP. 156 */ 157 static void 158 sclp_vt220_callback(struct sclp_req *request, void *data) 159 { 160 struct sclp_vt220_request *vt220_request; 161 struct sclp_vt220_sccb *sccb; 162 163 vt220_request = (struct sclp_vt220_request *) data; 164 if (request->status == SCLP_REQ_FAILED) { 165 sclp_vt220_process_queue(vt220_request); 166 return; 167 } 168 sccb = (struct sclp_vt220_sccb *) vt220_request->sclp_req.sccb; 169 170 /* Check SCLP response code and choose suitable action */ 171 switch (sccb->header.response_code) { 172 case 0x0020 : 173 break; 174 175 case 0x05f0: /* Target resource in improper state */ 176 break; 177 178 case 0x0340: /* Contained SCLP equipment check */ 179 if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) 180 break; 181 /* Remove processed buffers and requeue rest */ 182 if (sclp_remove_processed((struct sccb_header *) sccb) > 0) { 183 /* Not all buffers were processed */ 184 sccb->header.response_code = 0x0000; 185 vt220_request->sclp_req.status = SCLP_REQ_FILLED; 186 if (sclp_add_request(request) == 0) 187 return; 188 } 189 break; 190 191 case 0x0040: /* SCLP equipment check */ 192 if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY) 193 break; 194 sccb->header.response_code = 0x0000; 195 vt220_request->sclp_req.status = SCLP_REQ_FILLED; 196 if (sclp_add_request(request) == 0) 197 return; 198 break; 199 200 default: 201 break; 202 } 203 sclp_vt220_process_queue(vt220_request); 204 } 205 206 /* 207 * Emit vt220 request buffer to SCLP. Return zero on success, non-zero 208 * otherwise. 209 */ 210 static int 211 __sclp_vt220_emit(struct sclp_vt220_request *request) 212 { 213 request->sclp_req.command = SCLP_CMDW_WRITE_EVENT_DATA; 214 request->sclp_req.status = SCLP_REQ_FILLED; 215 request->sclp_req.callback = sclp_vt220_callback; 216 request->sclp_req.callback_data = (void *) request; 217 218 return sclp_add_request(&request->sclp_req); 219 } 220 221 /* 222 * Queue and emit current request. 223 */ 224 static void 225 sclp_vt220_emit_current(void) 226 { 227 unsigned long flags; 228 struct sclp_vt220_request *request; 229 struct sclp_vt220_sccb *sccb; 230 231 spin_lock_irqsave(&sclp_vt220_lock, flags); 232 if (sclp_vt220_current_request) { 233 sccb = (struct sclp_vt220_sccb *) 234 sclp_vt220_current_request->sclp_req.sccb; 235 /* Only emit buffers with content */ 236 if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) { 237 list_add_tail(&sclp_vt220_current_request->list, 238 &sclp_vt220_outqueue); 239 sclp_vt220_current_request = NULL; 240 if (timer_pending(&sclp_vt220_timer)) 241 del_timer(&sclp_vt220_timer); 242 } 243 sclp_vt220_flush_later = 0; 244 } 245 if (sclp_vt220_queue_running || sclp_vt220_suspended) 246 goto out_unlock; 247 if (list_empty(&sclp_vt220_outqueue)) 248 goto out_unlock; 249 request = list_first_entry(&sclp_vt220_outqueue, 250 struct sclp_vt220_request, list); 251 sclp_vt220_queue_running = 1; 252 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 253 254 if (__sclp_vt220_emit(request)) 255 sclp_vt220_process_queue(request); 256 return; 257 out_unlock: 258 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 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; 283 sccb->evbuf.type = EVTYP_VT220MSG; 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(struct timer_list *unused) 362 { 363 sclp_vt220_emit_current(); 364 } 365 366 #define BUFFER_MAX_DELAY HZ/20 367 368 /* 369 * Drop oldest console buffer if sclp_con_drop is set 370 */ 371 static int 372 sclp_vt220_drop_buffer(void) 373 { 374 struct list_head *list; 375 struct sclp_vt220_request *request; 376 void *page; 377 378 if (!sclp_console_drop) 379 return 0; 380 list = sclp_vt220_outqueue.next; 381 if (sclp_vt220_queue_running) 382 /* The first element is in I/O */ 383 list = list->next; 384 if (list == &sclp_vt220_outqueue) 385 return 0; 386 list_del(list); 387 request = list_entry(list, struct sclp_vt220_request, list); 388 page = request->sclp_req.sccb; 389 list_add_tail((struct list_head *) page, &sclp_vt220_empty); 390 return 1; 391 } 392 393 /* 394 * Internal implementation of the write function. Write COUNT bytes of data 395 * from memory at BUF 396 * to the SCLP interface. In case that the data does not fit into the current 397 * write buffer, emit the current one and allocate a new one. If there are no 398 * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE 399 * is non-zero, the buffer will be scheduled for emitting after a timeout - 400 * otherwise the user has to explicitly call the flush function. 401 * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message 402 * buffer should be converted to 0x0a 0x0d. After completion, return the number 403 * of bytes written. 404 */ 405 static int 406 __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule, 407 int convertlf, int may_fail) 408 { 409 unsigned long flags; 410 void *page; 411 int written; 412 int overall_written; 413 414 if (count <= 0) 415 return 0; 416 overall_written = 0; 417 spin_lock_irqsave(&sclp_vt220_lock, flags); 418 do { 419 /* Create an sclp output buffer if none exists yet */ 420 if (sclp_vt220_current_request == NULL) { 421 if (list_empty(&sclp_vt220_empty)) 422 sclp_console_full++; 423 while (list_empty(&sclp_vt220_empty)) { 424 if (may_fail || sclp_vt220_suspended) 425 goto out; 426 if (sclp_vt220_drop_buffer()) 427 break; 428 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 429 430 sclp_sync_wait(); 431 spin_lock_irqsave(&sclp_vt220_lock, flags); 432 } 433 page = (void *) sclp_vt220_empty.next; 434 list_del((struct list_head *) page); 435 sclp_vt220_current_request = 436 sclp_vt220_initialize_page(page); 437 } 438 /* Try to write the string to the current request buffer */ 439 written = sclp_vt220_add_msg(sclp_vt220_current_request, 440 buf, count, convertlf); 441 overall_written += written; 442 if (written == count) 443 break; 444 /* 445 * Not all characters could be written to the current 446 * output buffer. Emit the buffer, create a new buffer 447 * and then output the rest of the string. 448 */ 449 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 450 sclp_vt220_emit_current(); 451 spin_lock_irqsave(&sclp_vt220_lock, flags); 452 buf += written; 453 count -= written; 454 } while (count > 0); 455 /* Setup timer to output current console buffer after some time */ 456 if (sclp_vt220_current_request != NULL && 457 !timer_pending(&sclp_vt220_timer) && do_schedule) { 458 sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY; 459 add_timer(&sclp_vt220_timer); 460 } 461 out: 462 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 463 return overall_written; 464 } 465 466 /* 467 * This routine is called by the kernel to write a series of 468 * characters to the tty device. The characters may come from 469 * user space or kernel space. This routine will return the 470 * number of characters actually accepted for writing. 471 */ 472 static int 473 sclp_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count) 474 { 475 return __sclp_vt220_write(buf, count, 1, 0, 1); 476 } 477 478 #define SCLP_VT220_SESSION_ENDED 0x01 479 #define SCLP_VT220_SESSION_STARTED 0x80 480 #define SCLP_VT220_SESSION_DATA 0x00 481 482 #ifdef CONFIG_MAGIC_SYSRQ 483 484 static int sysrq_pressed; 485 static struct sysrq_work sysrq; 486 487 static void sclp_vt220_reset_session(void) 488 { 489 sysrq_pressed = 0; 490 } 491 492 static void sclp_vt220_handle_input(const char *buffer, unsigned int count) 493 { 494 int i; 495 496 for (i = 0; i < count; i++) { 497 /* Handle magic sys request */ 498 if (buffer[i] == ('O' ^ 0100)) { /* CTRL-O */ 499 /* 500 * If pressed again, reset sysrq_pressed 501 * and flip CTRL-O character 502 */ 503 sysrq_pressed = !sysrq_pressed; 504 if (sysrq_pressed) 505 continue; 506 } else if (sysrq_pressed) { 507 sysrq.key = buffer[i]; 508 schedule_sysrq_work(&sysrq); 509 sysrq_pressed = 0; 510 continue; 511 } 512 tty_insert_flip_char(&sclp_vt220_port, buffer[i], 0); 513 } 514 } 515 516 #else 517 518 static void sclp_vt220_reset_session(void) 519 { 520 } 521 522 static void sclp_vt220_handle_input(const char *buffer, unsigned int count) 523 { 524 tty_insert_flip_string(&sclp_vt220_port, buffer, count); 525 } 526 527 #endif 528 529 /* 530 * Called by the SCLP to report incoming event buffers. 531 */ 532 static void 533 sclp_vt220_receiver_fn(struct evbuf_header *evbuf) 534 { 535 char *buffer; 536 unsigned int count; 537 538 buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header)); 539 count = evbuf->length - sizeof(struct evbuf_header); 540 541 switch (*buffer) { 542 case SCLP_VT220_SESSION_ENDED: 543 case SCLP_VT220_SESSION_STARTED: 544 sclp_vt220_reset_session(); 545 break; 546 case SCLP_VT220_SESSION_DATA: 547 /* Send input to line discipline */ 548 buffer++; 549 count--; 550 sclp_vt220_handle_input(buffer, count); 551 tty_flip_buffer_push(&sclp_vt220_port); 552 break; 553 } 554 } 555 556 /* 557 * This routine is called when a particular tty device is opened. 558 */ 559 static int 560 sclp_vt220_open(struct tty_struct *tty, struct file *filp) 561 { 562 if (tty->count == 1) { 563 tty_port_tty_set(&sclp_vt220_port, tty); 564 if (!tty->winsize.ws_row && !tty->winsize.ws_col) { 565 tty->winsize.ws_row = 24; 566 tty->winsize.ws_col = 80; 567 } 568 } 569 return 0; 570 } 571 572 /* 573 * This routine is called when a particular tty device is closed. 574 */ 575 static void 576 sclp_vt220_close(struct tty_struct *tty, struct file *filp) 577 { 578 if (tty->count == 1) 579 tty_port_tty_set(&sclp_vt220_port, NULL); 580 } 581 582 /* 583 * This routine is called by the kernel to write a single 584 * character to the tty device. If the kernel uses this routine, 585 * it must call the flush_chars() routine (if defined) when it is 586 * done stuffing characters into the driver. 587 */ 588 static int 589 sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch) 590 { 591 return __sclp_vt220_write(&ch, 1, 0, 0, 1); 592 } 593 594 /* 595 * This routine is called by the kernel after it has written a 596 * series of characters to the tty device using put_char(). 597 */ 598 static void 599 sclp_vt220_flush_chars(struct tty_struct *tty) 600 { 601 if (!sclp_vt220_queue_running) 602 sclp_vt220_emit_current(); 603 else 604 sclp_vt220_flush_later = 1; 605 } 606 607 /* 608 * This routine returns the numbers of characters the tty driver 609 * will accept for queuing to be written. This number is subject 610 * to change as output buffers get emptied, or if the output flow 611 * control is acted. 612 */ 613 static int 614 sclp_vt220_write_room(struct tty_struct *tty) 615 { 616 unsigned long flags; 617 struct list_head *l; 618 int count; 619 620 spin_lock_irqsave(&sclp_vt220_lock, flags); 621 count = 0; 622 if (sclp_vt220_current_request != NULL) 623 count = sclp_vt220_space_left(sclp_vt220_current_request); 624 list_for_each(l, &sclp_vt220_empty) 625 count += SCLP_VT220_MAX_CHARS_PER_BUFFER; 626 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 627 return count; 628 } 629 630 /* 631 * Return number of buffered chars. 632 */ 633 static int 634 sclp_vt220_chars_in_buffer(struct tty_struct *tty) 635 { 636 unsigned long flags; 637 struct list_head *l; 638 struct sclp_vt220_request *r; 639 int count; 640 641 spin_lock_irqsave(&sclp_vt220_lock, flags); 642 count = 0; 643 if (sclp_vt220_current_request != NULL) 644 count = sclp_vt220_chars_stored(sclp_vt220_current_request); 645 list_for_each(l, &sclp_vt220_outqueue) { 646 r = list_entry(l, struct sclp_vt220_request, list); 647 count += sclp_vt220_chars_stored(r); 648 } 649 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 650 return count; 651 } 652 653 /* 654 * Pass on all buffers to the hardware. Return only when there are no more 655 * buffers pending. 656 */ 657 static void 658 sclp_vt220_flush_buffer(struct tty_struct *tty) 659 { 660 sclp_vt220_emit_current(); 661 } 662 663 /* Release allocated pages. */ 664 static void __init __sclp_vt220_free_pages(void) 665 { 666 struct list_head *page, *p; 667 668 list_for_each_safe(page, p, &sclp_vt220_empty) { 669 list_del(page); 670 free_page((unsigned long) page); 671 } 672 } 673 674 /* Release memory and unregister from sclp core. Controlled by init counting - 675 * only the last invoker will actually perform these actions. */ 676 static void __init __sclp_vt220_cleanup(void) 677 { 678 sclp_vt220_init_count--; 679 if (sclp_vt220_init_count != 0) 680 return; 681 sclp_unregister(&sclp_vt220_register); 682 __sclp_vt220_free_pages(); 683 tty_port_destroy(&sclp_vt220_port); 684 } 685 686 /* Allocate buffer pages and register with sclp core. Controlled by init 687 * counting - only the first invoker will actually perform these actions. */ 688 static int __init __sclp_vt220_init(int num_pages) 689 { 690 void *page; 691 int i; 692 int rc; 693 694 sclp_vt220_init_count++; 695 if (sclp_vt220_init_count != 1) 696 return 0; 697 timer_setup(&sclp_vt220_timer, sclp_vt220_timeout, 0); 698 tty_port_init(&sclp_vt220_port); 699 sclp_vt220_current_request = NULL; 700 sclp_vt220_buffered_chars = 0; 701 sclp_vt220_flush_later = 0; 702 703 /* Allocate pages for output buffering */ 704 rc = -ENOMEM; 705 for (i = 0; i < num_pages; i++) { 706 page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); 707 if (!page) 708 goto out; 709 list_add_tail(page, &sclp_vt220_empty); 710 } 711 rc = sclp_register(&sclp_vt220_register); 712 out: 713 if (rc) { 714 __sclp_vt220_free_pages(); 715 sclp_vt220_init_count--; 716 tty_port_destroy(&sclp_vt220_port); 717 } 718 return rc; 719 } 720 721 static const struct tty_operations sclp_vt220_ops = { 722 .open = sclp_vt220_open, 723 .close = sclp_vt220_close, 724 .write = sclp_vt220_write, 725 .put_char = sclp_vt220_put_char, 726 .flush_chars = sclp_vt220_flush_chars, 727 .write_room = sclp_vt220_write_room, 728 .chars_in_buffer = sclp_vt220_chars_in_buffer, 729 .flush_buffer = sclp_vt220_flush_buffer, 730 }; 731 732 /* 733 * Register driver with SCLP and Linux and initialize internal tty structures. 734 */ 735 static int __init sclp_vt220_tty_init(void) 736 { 737 struct tty_driver *driver; 738 int rc; 739 740 /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve 741 * symmetry between VM and LPAR systems regarding ttyS1. */ 742 driver = alloc_tty_driver(1); 743 if (!driver) 744 return -ENOMEM; 745 rc = __sclp_vt220_init(MAX_KMEM_PAGES); 746 if (rc) 747 goto out_driver; 748 749 driver->driver_name = SCLP_VT220_DRIVER_NAME; 750 driver->name = SCLP_VT220_DEVICE_NAME; 751 driver->major = SCLP_VT220_MAJOR; 752 driver->minor_start = SCLP_VT220_MINOR; 753 driver->type = TTY_DRIVER_TYPE_SYSTEM; 754 driver->subtype = SYSTEM_TYPE_TTY; 755 driver->init_termios = tty_std_termios; 756 driver->flags = TTY_DRIVER_REAL_RAW; 757 tty_set_operations(driver, &sclp_vt220_ops); 758 tty_port_link_device(&sclp_vt220_port, driver, 0); 759 760 rc = tty_register_driver(driver); 761 if (rc) 762 goto out_init; 763 rc = sclp_register(&sclp_vt220_register_input); 764 if (rc) 765 goto out_reg; 766 sclp_vt220_driver = driver; 767 return 0; 768 769 out_reg: 770 tty_unregister_driver(driver); 771 out_init: 772 __sclp_vt220_cleanup(); 773 out_driver: 774 put_tty_driver(driver); 775 return rc; 776 } 777 __initcall(sclp_vt220_tty_init); 778 779 static void __sclp_vt220_flush_buffer(void) 780 { 781 unsigned long flags; 782 783 sclp_vt220_emit_current(); 784 spin_lock_irqsave(&sclp_vt220_lock, flags); 785 if (timer_pending(&sclp_vt220_timer)) 786 del_timer(&sclp_vt220_timer); 787 while (sclp_vt220_queue_running) { 788 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 789 sclp_sync_wait(); 790 spin_lock_irqsave(&sclp_vt220_lock, flags); 791 } 792 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 793 } 794 795 /* 796 * Resume console: If there are cached messages, emit them. 797 */ 798 static void sclp_vt220_resume(void) 799 { 800 unsigned long flags; 801 802 spin_lock_irqsave(&sclp_vt220_lock, flags); 803 sclp_vt220_suspended = 0; 804 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 805 sclp_vt220_emit_current(); 806 } 807 808 /* 809 * Suspend console: Set suspend flag and flush console 810 */ 811 static void sclp_vt220_suspend(void) 812 { 813 unsigned long flags; 814 815 spin_lock_irqsave(&sclp_vt220_lock, flags); 816 sclp_vt220_suspended = 1; 817 spin_unlock_irqrestore(&sclp_vt220_lock, flags); 818 __sclp_vt220_flush_buffer(); 819 } 820 821 static void sclp_vt220_pm_event_fn(struct sclp_register *reg, 822 enum sclp_pm_event sclp_pm_event) 823 { 824 switch (sclp_pm_event) { 825 case SCLP_PM_EVENT_FREEZE: 826 sclp_vt220_suspend(); 827 break; 828 case SCLP_PM_EVENT_RESTORE: 829 case SCLP_PM_EVENT_THAW: 830 sclp_vt220_resume(); 831 break; 832 } 833 } 834 835 #ifdef CONFIG_SCLP_VT220_CONSOLE 836 837 static void 838 sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count) 839 { 840 __sclp_vt220_write((const unsigned char *) buf, count, 1, 1, 0); 841 } 842 843 static struct tty_driver * 844 sclp_vt220_con_device(struct console *c, int *index) 845 { 846 *index = 0; 847 return sclp_vt220_driver; 848 } 849 850 static int 851 sclp_vt220_notify(struct notifier_block *self, 852 unsigned long event, void *data) 853 { 854 __sclp_vt220_flush_buffer(); 855 return NOTIFY_OK; 856 } 857 858 static struct notifier_block on_panic_nb = { 859 .notifier_call = sclp_vt220_notify, 860 .priority = 1, 861 }; 862 863 static struct notifier_block on_reboot_nb = { 864 .notifier_call = sclp_vt220_notify, 865 .priority = 1, 866 }; 867 868 /* Structure needed to register with printk */ 869 static struct console sclp_vt220_console = 870 { 871 .name = SCLP_VT220_CONSOLE_NAME, 872 .write = sclp_vt220_con_write, 873 .device = sclp_vt220_con_device, 874 .flags = CON_PRINTBUFFER, 875 .index = SCLP_VT220_CONSOLE_INDEX 876 }; 877 878 static int __init 879 sclp_vt220_con_init(void) 880 { 881 int rc; 882 883 rc = __sclp_vt220_init(sclp_console_pages); 884 if (rc) 885 return rc; 886 /* Attach linux console */ 887 atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb); 888 register_reboot_notifier(&on_reboot_nb); 889 register_console(&sclp_vt220_console); 890 return 0; 891 } 892 893 console_initcall(sclp_vt220_con_init); 894 #endif /* CONFIG_SCLP_VT220_CONSOLE */ 895 896