1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * IBM/3270 Driver - fullscreen driver. 4 * 5 * Author(s): 6 * Original 3270 Code for 2.4 written by Richard Hitt (UTS Global) 7 * Rewritten for 2.5/2.6 by Martin Schwidefsky <schwidefsky@de.ibm.com> 8 * Copyright IBM Corp. 2003, 2009 9 */ 10 11 #include <linux/memblock.h> 12 #include <linux/console.h> 13 #include <linux/init.h> 14 #include <linux/interrupt.h> 15 #include <linux/compat.h> 16 #include <linux/sched/signal.h> 17 #include <linux/module.h> 18 #include <linux/list.h> 19 #include <linux/slab.h> 20 #include <linux/types.h> 21 22 #include <uapi/asm/fs3270.h> 23 #include <asm/ccwdev.h> 24 #include <asm/cio.h> 25 #include <asm/ebcdic.h> 26 #include <asm/idals.h> 27 28 #include "raw3270.h" 29 #include "ctrlchar.h" 30 31 static struct raw3270_fn fs3270_fn; 32 33 struct fs3270 { 34 struct raw3270_view view; 35 struct pid *fs_pid; /* Pid of controlling program. */ 36 int read_command; /* ccw command to use for reads. */ 37 int write_command; /* ccw command to use for writes. */ 38 int attention; /* Got attention. */ 39 int active; /* Fullscreen view is active. */ 40 struct raw3270_request *init; /* single init request. */ 41 wait_queue_head_t wait; /* Init & attention wait queue. */ 42 struct idal_buffer *rdbuf; /* full-screen-deactivate buffer */ 43 size_t rdbuf_size; /* size of data returned by RDBUF */ 44 }; 45 46 static DEFINE_MUTEX(fs3270_mutex); 47 48 static void fs3270_wake_up(struct raw3270_request *rq, void *data) 49 { 50 wake_up((wait_queue_head_t *)data); 51 } 52 53 static inline int fs3270_working(struct fs3270 *fp) 54 { 55 /* 56 * The fullscreen view is in working order if the view 57 * has been activated AND the initial request is finished. 58 */ 59 return fp->active && raw3270_request_final(fp->init); 60 } 61 62 static int fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq) 63 { 64 struct fs3270 *fp; 65 int rc; 66 67 fp = (struct fs3270 *)view; 68 rq->callback = fs3270_wake_up; 69 rq->callback_data = &fp->wait; 70 71 do { 72 if (!fs3270_working(fp)) { 73 /* Fullscreen view isn't ready yet. */ 74 rc = wait_event_interruptible(fp->wait, 75 fs3270_working(fp)); 76 if (rc != 0) 77 break; 78 } 79 rc = raw3270_start(view, rq); 80 if (rc == 0) { 81 /* Started successfully. Now wait for completion. */ 82 wait_event(fp->wait, raw3270_request_final(rq)); 83 } 84 } while (rc == -EACCES); 85 return rc; 86 } 87 88 /* 89 * Switch to the fullscreen view. 90 */ 91 static void fs3270_reset_callback(struct raw3270_request *rq, void *data) 92 { 93 struct fs3270 *fp; 94 95 fp = (struct fs3270 *)rq->view; 96 raw3270_request_reset(rq); 97 wake_up(&fp->wait); 98 } 99 100 static void fs3270_restore_callback(struct raw3270_request *rq, void *data) 101 { 102 struct fs3270 *fp; 103 104 fp = (struct fs3270 *)rq->view; 105 if (rq->rc != 0 || rq->rescnt != 0) { 106 if (fp->fs_pid) 107 kill_pid(fp->fs_pid, SIGHUP, 1); 108 } 109 fp->rdbuf_size = 0; 110 raw3270_request_reset(rq); 111 wake_up(&fp->wait); 112 } 113 114 static int fs3270_activate(struct raw3270_view *view) 115 { 116 struct fs3270 *fp; 117 char *cp; 118 int rc; 119 120 fp = (struct fs3270 *)view; 121 122 /* If an old init command is still running just return. */ 123 if (!raw3270_request_final(fp->init)) 124 return 0; 125 126 raw3270_request_set_cmd(fp->init, TC_EWRITEA); 127 raw3270_request_set_idal(fp->init, fp->rdbuf); 128 fp->init->rescnt = 0; 129 cp = fp->rdbuf->data[0]; 130 if (fp->rdbuf_size == 0) { 131 /* No saved buffer. Just clear the screen. */ 132 fp->init->ccw.count = 1; 133 fp->init->callback = fs3270_reset_callback; 134 cp[0] = 0; 135 } else { 136 /* Restore fullscreen buffer saved by fs3270_deactivate. */ 137 fp->init->ccw.count = fp->rdbuf_size; 138 fp->init->callback = fs3270_restore_callback; 139 cp[0] = TW_KR; 140 cp[1] = TO_SBA; 141 cp[2] = cp[6]; 142 cp[3] = cp[7]; 143 cp[4] = TO_IC; 144 cp[5] = TO_SBA; 145 cp[6] = 0x40; 146 cp[7] = 0x40; 147 } 148 rc = raw3270_start_locked(view, fp->init); 149 fp->init->rc = rc; 150 if (rc) 151 fp->init->callback(fp->init, NULL); 152 else 153 fp->active = 1; 154 return rc; 155 } 156 157 /* 158 * Shutdown fullscreen view. 159 */ 160 static void fs3270_save_callback(struct raw3270_request *rq, void *data) 161 { 162 struct fs3270 *fp; 163 164 fp = (struct fs3270 *)rq->view; 165 166 /* Correct idal buffer element 0 address. */ 167 fp->rdbuf->data[0] -= 5; 168 fp->rdbuf->size += 5; 169 170 /* 171 * If the rdbuf command failed or the idal buffer is 172 * to small for the amount of data returned by the 173 * rdbuf command, then we have no choice but to send 174 * a SIGHUP to the application. 175 */ 176 if (rq->rc != 0 || rq->rescnt == 0) { 177 if (fp->fs_pid) 178 kill_pid(fp->fs_pid, SIGHUP, 1); 179 fp->rdbuf_size = 0; 180 } else { 181 fp->rdbuf_size = fp->rdbuf->size - rq->rescnt; 182 } 183 raw3270_request_reset(rq); 184 wake_up(&fp->wait); 185 } 186 187 static void fs3270_deactivate(struct raw3270_view *view) 188 { 189 struct fs3270 *fp; 190 191 fp = (struct fs3270 *)view; 192 fp->active = 0; 193 194 /* If an old init command is still running just return. */ 195 if (!raw3270_request_final(fp->init)) 196 return; 197 198 /* Prepare read-buffer request. */ 199 raw3270_request_set_cmd(fp->init, TC_RDBUF); 200 /* 201 * Hackish: skip first 5 bytes of the idal buffer to make 202 * room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence 203 * in the activation command. 204 */ 205 fp->rdbuf->data[0] += 5; 206 fp->rdbuf->size -= 5; 207 raw3270_request_set_idal(fp->init, fp->rdbuf); 208 fp->init->rescnt = 0; 209 fp->init->callback = fs3270_save_callback; 210 211 /* Start I/O to read in the 3270 buffer. */ 212 fp->init->rc = raw3270_start_locked(view, fp->init); 213 if (fp->init->rc) 214 fp->init->callback(fp->init, NULL); 215 } 216 217 static void fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, 218 struct irb *irb) 219 { 220 /* Handle ATTN. Set indication and wake waiters for attention. */ 221 if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) { 222 fp->attention = 1; 223 wake_up(&fp->wait); 224 } 225 226 if (rq) { 227 if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) 228 rq->rc = -EIO; 229 else 230 /* Normal end. Copy residual count. */ 231 rq->rescnt = irb->scsw.cmd.count; 232 } 233 } 234 235 /* 236 * Process reads from fullscreen 3270. 237 */ 238 static ssize_t fs3270_read(struct file *filp, char __user *data, 239 size_t count, loff_t *off) 240 { 241 struct fs3270 *fp; 242 struct raw3270_request *rq; 243 struct idal_buffer *ib; 244 ssize_t rc; 245 246 if (count == 0 || count > 65535) 247 return -EINVAL; 248 fp = filp->private_data; 249 if (!fp) 250 return -ENODEV; 251 ib = idal_buffer_alloc(count, 0); 252 if (IS_ERR(ib)) 253 return -ENOMEM; 254 rq = raw3270_request_alloc(0); 255 if (!IS_ERR(rq)) { 256 if (fp->read_command == 0 && fp->write_command != 0) 257 fp->read_command = 6; 258 raw3270_request_set_cmd(rq, fp->read_command ? : 2); 259 raw3270_request_set_idal(rq, ib); 260 rc = wait_event_interruptible(fp->wait, fp->attention); 261 fp->attention = 0; 262 if (rc == 0) { 263 rc = fs3270_do_io(&fp->view, rq); 264 if (rc == 0) { 265 count -= rq->rescnt; 266 if (idal_buffer_to_user(ib, data, count) != 0) 267 rc = -EFAULT; 268 else 269 rc = count; 270 } 271 } 272 raw3270_request_free(rq); 273 } else { 274 rc = PTR_ERR(rq); 275 } 276 idal_buffer_free(ib); 277 return rc; 278 } 279 280 /* 281 * Process writes to fullscreen 3270. 282 */ 283 static ssize_t fs3270_write(struct file *filp, const char __user *data, 284 size_t count, loff_t *off) 285 { 286 struct fs3270 *fp; 287 struct raw3270_request *rq; 288 struct idal_buffer *ib; 289 int write_command; 290 ssize_t rc; 291 292 fp = filp->private_data; 293 if (!fp) 294 return -ENODEV; 295 ib = idal_buffer_alloc(count, 0); 296 if (IS_ERR(ib)) 297 return -ENOMEM; 298 rq = raw3270_request_alloc(0); 299 if (!IS_ERR(rq)) { 300 if (idal_buffer_from_user(ib, data, count) == 0) { 301 write_command = fp->write_command ? : 1; 302 if (write_command == 5) 303 write_command = 13; 304 raw3270_request_set_cmd(rq, write_command); 305 raw3270_request_set_idal(rq, ib); 306 rc = fs3270_do_io(&fp->view, rq); 307 if (rc == 0) 308 rc = count - rq->rescnt; 309 } else { 310 rc = -EFAULT; 311 } 312 raw3270_request_free(rq); 313 } else { 314 rc = PTR_ERR(rq); 315 } 316 idal_buffer_free(ib); 317 return rc; 318 } 319 320 /* 321 * process ioctl commands for the tube driver 322 */ 323 static long fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 324 { 325 char __user *argp; 326 struct fs3270 *fp; 327 struct raw3270_iocb iocb; 328 int rc; 329 330 fp = filp->private_data; 331 if (!fp) 332 return -ENODEV; 333 if (is_compat_task()) 334 argp = compat_ptr(arg); 335 else 336 argp = (char __user *)arg; 337 rc = 0; 338 mutex_lock(&fs3270_mutex); 339 switch (cmd) { 340 case TUBICMD: 341 fp->read_command = arg; 342 break; 343 case TUBOCMD: 344 fp->write_command = arg; 345 break; 346 case TUBGETI: 347 rc = put_user(fp->read_command, argp); 348 break; 349 case TUBGETO: 350 rc = put_user(fp->write_command, argp); 351 break; 352 case TUBGETMOD: 353 iocb.model = fp->view.model; 354 iocb.line_cnt = fp->view.rows; 355 iocb.col_cnt = fp->view.cols; 356 iocb.pf_cnt = 24; 357 iocb.re_cnt = 20; 358 iocb.map = 0; 359 if (copy_to_user(argp, &iocb, sizeof(struct raw3270_iocb))) 360 rc = -EFAULT; 361 break; 362 } 363 mutex_unlock(&fs3270_mutex); 364 return rc; 365 } 366 367 /* 368 * Allocate fs3270 structure. 369 */ 370 static struct fs3270 *fs3270_alloc_view(void) 371 { 372 struct fs3270 *fp; 373 374 fp = kzalloc(sizeof(*fp), GFP_KERNEL); 375 if (!fp) 376 return ERR_PTR(-ENOMEM); 377 fp->init = raw3270_request_alloc(0); 378 if (IS_ERR(fp->init)) { 379 kfree(fp); 380 return ERR_PTR(-ENOMEM); 381 } 382 return fp; 383 } 384 385 /* 386 * Free fs3270 structure. 387 */ 388 static void fs3270_free_view(struct raw3270_view *view) 389 { 390 struct fs3270 *fp; 391 392 fp = (struct fs3270 *)view; 393 if (fp->rdbuf) 394 idal_buffer_free(fp->rdbuf); 395 raw3270_request_free(((struct fs3270 *)view)->init); 396 kfree(view); 397 } 398 399 /* 400 * Unlink fs3270 data structure from filp. 401 */ 402 static void fs3270_release(struct raw3270_view *view) 403 { 404 struct fs3270 *fp; 405 406 fp = (struct fs3270 *)view; 407 if (fp->fs_pid) 408 kill_pid(fp->fs_pid, SIGHUP, 1); 409 } 410 411 /* View to a 3270 device. Can be console, tty or fullscreen. */ 412 static struct raw3270_fn fs3270_fn = { 413 .activate = fs3270_activate, 414 .deactivate = fs3270_deactivate, 415 .intv = (void *)fs3270_irq, 416 .release = fs3270_release, 417 .free = fs3270_free_view 418 }; 419 420 /* 421 * This routine is called whenever a 3270 fullscreen device is opened. 422 */ 423 static int fs3270_open(struct inode *inode, struct file *filp) 424 { 425 struct fs3270 *fp; 426 struct idal_buffer *ib; 427 int minor, rc = 0; 428 429 if (imajor(file_inode(filp)) != IBM_FS3270_MAJOR) 430 return -ENODEV; 431 minor = iminor(file_inode(filp)); 432 /* Check for minor 0 multiplexer. */ 433 if (minor == 0) { 434 struct tty_struct *tty = get_current_tty(); 435 436 if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) { 437 tty_kref_put(tty); 438 return -ENODEV; 439 } 440 minor = tty->index; 441 tty_kref_put(tty); 442 } 443 mutex_lock(&fs3270_mutex); 444 /* Check if some other program is already using fullscreen mode. */ 445 fp = (struct fs3270 *)raw3270_find_view(&fs3270_fn, minor); 446 if (!IS_ERR(fp)) { 447 raw3270_put_view(&fp->view); 448 rc = -EBUSY; 449 goto out; 450 } 451 /* Allocate fullscreen view structure. */ 452 fp = fs3270_alloc_view(); 453 if (IS_ERR(fp)) { 454 rc = PTR_ERR(fp); 455 goto out; 456 } 457 458 init_waitqueue_head(&fp->wait); 459 fp->fs_pid = get_pid(task_pid(current)); 460 rc = raw3270_add_view(&fp->view, &fs3270_fn, minor, 461 RAW3270_VIEW_LOCK_BH); 462 if (rc) { 463 fs3270_free_view(&fp->view); 464 goto out; 465 } 466 467 /* Allocate idal-buffer. */ 468 ib = idal_buffer_alloc(2 * fp->view.rows * fp->view.cols + 5, 0); 469 if (IS_ERR(ib)) { 470 raw3270_put_view(&fp->view); 471 raw3270_del_view(&fp->view); 472 rc = PTR_ERR(ib); 473 goto out; 474 } 475 fp->rdbuf = ib; 476 477 rc = raw3270_activate_view(&fp->view); 478 if (rc) { 479 raw3270_put_view(&fp->view); 480 raw3270_del_view(&fp->view); 481 goto out; 482 } 483 stream_open(inode, filp); 484 filp->private_data = fp; 485 out: 486 mutex_unlock(&fs3270_mutex); 487 return rc; 488 } 489 490 /* 491 * This routine is called when the 3270 tty is closed. We wait 492 * for the remaining request to be completed. Then we clean up. 493 */ 494 static int fs3270_close(struct inode *inode, struct file *filp) 495 { 496 struct fs3270 *fp; 497 498 fp = filp->private_data; 499 filp->private_data = NULL; 500 if (fp) { 501 put_pid(fp->fs_pid); 502 fp->fs_pid = NULL; 503 raw3270_reset(&fp->view); 504 raw3270_put_view(&fp->view); 505 raw3270_del_view(&fp->view); 506 } 507 return 0; 508 } 509 510 static const struct file_operations fs3270_fops = { 511 .owner = THIS_MODULE, /* owner */ 512 .read = fs3270_read, /* read */ 513 .write = fs3270_write, /* write */ 514 .unlocked_ioctl = fs3270_ioctl, /* ioctl */ 515 .compat_ioctl = fs3270_ioctl, /* ioctl */ 516 .open = fs3270_open, /* open */ 517 .release = fs3270_close, /* release */ 518 .llseek = no_llseek, 519 }; 520 521 static void fs3270_create_cb(int minor) 522 { 523 __register_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub", &fs3270_fops); 524 device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, minor), 525 NULL, "3270/tub%d", minor); 526 } 527 528 static void fs3270_destroy_cb(int minor) 529 { 530 device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, minor)); 531 __unregister_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub"); 532 } 533 534 static struct raw3270_notifier fs3270_notifier = { 535 .create = fs3270_create_cb, 536 .destroy = fs3270_destroy_cb, 537 }; 538 539 /* 540 * 3270 fullscreen driver initialization. 541 */ 542 static int __init fs3270_init(void) 543 { 544 int rc; 545 546 rc = __register_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270", &fs3270_fops); 547 if (rc) 548 return rc; 549 device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, 0), 550 NULL, "3270/tub"); 551 raw3270_register_notifier(&fs3270_notifier); 552 return 0; 553 } 554 555 static void __exit fs3270_exit(void) 556 { 557 raw3270_unregister_notifier(&fs3270_notifier); 558 device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, 0)); 559 __unregister_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270"); 560 } 561 562 MODULE_LICENSE("GPL"); 563 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR); 564 565 module_init(fs3270_init); 566 module_exit(fs3270_exit); 567