1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * z/VM IUCV hypervisor console (HVC) device driver 4 * 5 * This HVC device driver provides terminal access using 6 * z/VM IUCV communication paths. 7 * 8 * Copyright IBM Corp. 2008, 2013 9 * 10 * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com> 11 */ 12 #define KMSG_COMPONENT "hvc_iucv" 13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 14 15 #include <linux/types.h> 16 #include <linux/slab.h> 17 #include <asm/ebcdic.h> 18 #include <linux/ctype.h> 19 #include <linux/delay.h> 20 #include <linux/device.h> 21 #include <linux/init.h> 22 #include <linux/mempool.h> 23 #include <linux/moduleparam.h> 24 #include <linux/tty.h> 25 #include <linux/wait.h> 26 #include <net/iucv/iucv.h> 27 28 #include "hvc_console.h" 29 30 31 /* General device driver settings */ 32 #define MAX_HVC_IUCV_LINES HVC_ALLOC_TTY_ADAPTERS 33 #define MEMPOOL_MIN_NR (PAGE_SIZE / sizeof(struct iucv_tty_buffer)/4) 34 35 /* IUCV TTY message */ 36 #define MSG_VERSION 0x02 /* Message version */ 37 #define MSG_TYPE_ERROR 0x01 /* Error message */ 38 #define MSG_TYPE_TERMENV 0x02 /* Terminal environment variable */ 39 #define MSG_TYPE_TERMIOS 0x04 /* Terminal IO struct update */ 40 #define MSG_TYPE_WINSIZE 0x08 /* Terminal window size update */ 41 #define MSG_TYPE_DATA 0x10 /* Terminal data */ 42 43 struct iucv_tty_msg { 44 u8 version; /* Message version */ 45 u8 type; /* Message type */ 46 #define MSG_MAX_DATALEN ((u16)(~0)) 47 u16 datalen; /* Payload length */ 48 u8 data[]; /* Payload buffer */ 49 } __attribute__((packed)); 50 #define MSG_SIZE(s) ((s) + offsetof(struct iucv_tty_msg, data)) 51 52 enum iucv_state_t { 53 IUCV_DISCONN = 0, 54 IUCV_CONNECTED = 1, 55 IUCV_SEVERED = 2, 56 }; 57 58 enum tty_state_t { 59 TTY_CLOSED = 0, 60 TTY_OPENED = 1, 61 }; 62 63 struct hvc_iucv_private { 64 struct hvc_struct *hvc; /* HVC struct reference */ 65 u8 srv_name[8]; /* IUCV service name (ebcdic) */ 66 unsigned char is_console; /* Linux console usage flag */ 67 enum iucv_state_t iucv_state; /* IUCV connection status */ 68 enum tty_state_t tty_state; /* TTY status */ 69 struct iucv_path *path; /* IUCV path pointer */ 70 spinlock_t lock; /* hvc_iucv_private lock */ 71 #define SNDBUF_SIZE (PAGE_SIZE) /* must be < MSG_MAX_DATALEN */ 72 void *sndbuf; /* send buffer */ 73 size_t sndbuf_len; /* length of send buffer */ 74 #define QUEUE_SNDBUF_DELAY (HZ / 25) 75 struct delayed_work sndbuf_work; /* work: send iucv msg(s) */ 76 wait_queue_head_t sndbuf_waitq; /* wait for send completion */ 77 struct list_head tty_outqueue; /* outgoing IUCV messages */ 78 struct list_head tty_inqueue; /* incoming IUCV messages */ 79 struct device *dev; /* device structure */ 80 u8 info_path[16]; /* IUCV path info (dev attr) */ 81 }; 82 83 struct iucv_tty_buffer { 84 struct list_head list; /* list pointer */ 85 struct iucv_message msg; /* store an IUCV message */ 86 size_t offset; /* data buffer offset */ 87 struct iucv_tty_msg *mbuf; /* buffer to store input/output data */ 88 }; 89 90 /* IUCV callback handler */ 91 static int hvc_iucv_path_pending(struct iucv_path *, u8 *, u8 *); 92 static void hvc_iucv_path_severed(struct iucv_path *, u8 *); 93 static void hvc_iucv_msg_pending(struct iucv_path *, struct iucv_message *); 94 static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *); 95 96 97 /* Kernel module parameter: use one terminal device as default */ 98 static unsigned long hvc_iucv_devices = 1; 99 100 /* Array of allocated hvc iucv tty lines... */ 101 static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES]; 102 #define IUCV_HVC_CON_IDX (0) 103 /* List of z/VM user ID filter entries (struct iucv_vmid_filter) */ 104 #define MAX_VMID_FILTER (500) 105 #define FILTER_WILDCARD_CHAR '*' 106 static size_t hvc_iucv_filter_size; 107 static void *hvc_iucv_filter; 108 static const char *hvc_iucv_filter_string; 109 static DEFINE_RWLOCK(hvc_iucv_filter_lock); 110 111 /* Kmem cache and mempool for iucv_tty_buffer elements */ 112 static struct kmem_cache *hvc_iucv_buffer_cache; 113 static mempool_t *hvc_iucv_mempool; 114 115 /* IUCV handler callback functions */ 116 static struct iucv_handler hvc_iucv_handler = { 117 .path_pending = hvc_iucv_path_pending, 118 .path_severed = hvc_iucv_path_severed, 119 .message_complete = hvc_iucv_msg_complete, 120 .message_pending = hvc_iucv_msg_pending, 121 }; 122 123 124 /** 125 * hvc_iucv_get_private() - Return a struct hvc_iucv_private instance. 126 * @num: The HVC virtual terminal number (vtermno) 127 * 128 * This function returns the struct hvc_iucv_private instance that corresponds 129 * to the HVC virtual terminal number specified as parameter @num. 130 */ 131 static struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num) 132 { 133 if (num > hvc_iucv_devices) 134 return NULL; 135 return hvc_iucv_table[num]; 136 } 137 138 /** 139 * alloc_tty_buffer() - Return a new struct iucv_tty_buffer element. 140 * @size: Size of the internal buffer used to store data. 141 * @flags: Memory allocation flags passed to mempool. 142 * 143 * This function allocates a new struct iucv_tty_buffer element and, optionally, 144 * allocates an internal data buffer with the specified size @size. 145 * The internal data buffer is always allocated with GFP_DMA which is 146 * required for receiving and sending data with IUCV. 147 * Note: The total message size arises from the internal buffer size and the 148 * members of the iucv_tty_msg structure. 149 * The function returns NULL if memory allocation has failed. 150 */ 151 static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags) 152 { 153 struct iucv_tty_buffer *bufp; 154 155 bufp = mempool_alloc(hvc_iucv_mempool, flags); 156 if (!bufp) 157 return NULL; 158 memset(bufp, 0, sizeof(*bufp)); 159 160 if (size > 0) { 161 bufp->msg.length = MSG_SIZE(size); 162 bufp->mbuf = kmalloc(bufp->msg.length, flags | GFP_DMA); 163 if (!bufp->mbuf) { 164 mempool_free(bufp, hvc_iucv_mempool); 165 return NULL; 166 } 167 bufp->mbuf->version = MSG_VERSION; 168 bufp->mbuf->type = MSG_TYPE_DATA; 169 bufp->mbuf->datalen = (u16) size; 170 } 171 return bufp; 172 } 173 174 /** 175 * destroy_tty_buffer() - destroy struct iucv_tty_buffer element. 176 * @bufp: Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL. 177 */ 178 static void destroy_tty_buffer(struct iucv_tty_buffer *bufp) 179 { 180 kfree(bufp->mbuf); 181 mempool_free(bufp, hvc_iucv_mempool); 182 } 183 184 /** 185 * destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element. 186 * @list: List containing struct iucv_tty_buffer elements. 187 */ 188 static void destroy_tty_buffer_list(struct list_head *list) 189 { 190 struct iucv_tty_buffer *ent, *next; 191 192 list_for_each_entry_safe(ent, next, list, list) { 193 list_del(&ent->list); 194 destroy_tty_buffer(ent); 195 } 196 } 197 198 /** 199 * hvc_iucv_write() - Receive IUCV message & write data to HVC buffer. 200 * @priv: Pointer to struct hvc_iucv_private 201 * @buf: HVC buffer for writing received terminal data. 202 * @count: HVC buffer size. 203 * @has_more_data: Pointer to an int variable. 204 * 205 * The function picks up pending messages from the input queue and receives 206 * the message data that is then written to the specified buffer @buf. 207 * If the buffer size @count is less than the data message size, the 208 * message is kept on the input queue and @has_more_data is set to 1. 209 * If all message data has been written, the message is removed from 210 * the input queue. 211 * 212 * The function returns the number of bytes written to the terminal, zero if 213 * there are no pending data messages available or if there is no established 214 * IUCV path. 215 * If the IUCV path has been severed, then -EPIPE is returned to cause a 216 * hang up (that is issued by the HVC layer). 217 */ 218 static int hvc_iucv_write(struct hvc_iucv_private *priv, 219 char *buf, int count, int *has_more_data) 220 { 221 struct iucv_tty_buffer *rb; 222 int written; 223 int rc; 224 225 /* immediately return if there is no IUCV connection */ 226 if (priv->iucv_state == IUCV_DISCONN) 227 return 0; 228 229 /* if the IUCV path has been severed, return -EPIPE to inform the 230 * HVC layer to hang up the tty device. */ 231 if (priv->iucv_state == IUCV_SEVERED) 232 return -EPIPE; 233 234 /* check if there are pending messages */ 235 if (list_empty(&priv->tty_inqueue)) 236 return 0; 237 238 /* receive an iucv message and flip data to the tty (ldisc) */ 239 rb = list_first_entry(&priv->tty_inqueue, struct iucv_tty_buffer, list); 240 241 written = 0; 242 if (!rb->mbuf) { /* message not yet received ... */ 243 /* allocate mem to store msg data; if no memory is available 244 * then leave the buffer on the list and re-try later */ 245 rb->mbuf = kmalloc(rb->msg.length, GFP_ATOMIC | GFP_DMA); 246 if (!rb->mbuf) 247 return -ENOMEM; 248 249 rc = __iucv_message_receive(priv->path, &rb->msg, 0, 250 rb->mbuf, rb->msg.length, NULL); 251 switch (rc) { 252 case 0: /* Successful */ 253 break; 254 case 2: /* No message found */ 255 case 9: /* Message purged */ 256 break; 257 default: 258 written = -EIO; 259 } 260 /* remove buffer if an error has occurred or received data 261 * is not correct */ 262 if (rc || (rb->mbuf->version != MSG_VERSION) || 263 (rb->msg.length != MSG_SIZE(rb->mbuf->datalen))) 264 goto out_remove_buffer; 265 } 266 267 switch (rb->mbuf->type) { 268 case MSG_TYPE_DATA: 269 written = min_t(int, rb->mbuf->datalen - rb->offset, count); 270 memcpy(buf, rb->mbuf->data + rb->offset, written); 271 if (written < (rb->mbuf->datalen - rb->offset)) { 272 rb->offset += written; 273 *has_more_data = 1; 274 goto out_written; 275 } 276 break; 277 278 case MSG_TYPE_WINSIZE: 279 if (rb->mbuf->datalen != sizeof(struct winsize)) 280 break; 281 /* The caller must ensure that the hvc is locked, which 282 * is the case when called from hvc_iucv_get_chars() */ 283 __hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data)); 284 break; 285 286 case MSG_TYPE_ERROR: /* ignored ... */ 287 case MSG_TYPE_TERMENV: /* ignored ... */ 288 case MSG_TYPE_TERMIOS: /* ignored ... */ 289 break; 290 } 291 292 out_remove_buffer: 293 list_del(&rb->list); 294 destroy_tty_buffer(rb); 295 *has_more_data = !list_empty(&priv->tty_inqueue); 296 297 out_written: 298 return written; 299 } 300 301 /** 302 * hvc_iucv_get_chars() - HVC get_chars operation. 303 * @vtermno: HVC virtual terminal number. 304 * @buf: Pointer to a buffer to store data 305 * @count: Size of buffer available for writing 306 * 307 * The HVC thread calls this method to read characters from the back-end. 308 * If an IUCV communication path has been established, pending IUCV messages 309 * are received and data is copied into buffer @buf up to @count bytes. 310 * 311 * Locking: The routine gets called under an irqsave() spinlock; and 312 * the routine locks the struct hvc_iucv_private->lock to call 313 * helper functions. 314 */ 315 static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count) 316 { 317 struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); 318 int written; 319 int has_more_data; 320 321 if (count <= 0) 322 return 0; 323 324 if (!priv) 325 return -ENODEV; 326 327 spin_lock(&priv->lock); 328 has_more_data = 0; 329 written = hvc_iucv_write(priv, buf, count, &has_more_data); 330 spin_unlock(&priv->lock); 331 332 /* if there are still messages on the queue... schedule another run */ 333 if (has_more_data) 334 hvc_kick(); 335 336 return written; 337 } 338 339 /** 340 * hvc_iucv_queue() - Buffer terminal data for sending. 341 * @priv: Pointer to struct hvc_iucv_private instance. 342 * @buf: Buffer containing data to send. 343 * @count: Size of buffer and amount of data to send. 344 * 345 * The function queues data for sending. To actually send the buffered data, 346 * a work queue function is scheduled (with QUEUE_SNDBUF_DELAY). 347 * The function returns the number of data bytes that has been buffered. 348 * 349 * If the device is not connected, data is ignored and the function returns 350 * @count. 351 * If the buffer is full, the function returns 0. 352 * If an existing IUCV communicaton path has been severed, -EPIPE is returned 353 * (that can be passed to HVC layer to cause a tty hangup). 354 */ 355 static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf, 356 int count) 357 { 358 size_t len; 359 360 if (priv->iucv_state == IUCV_DISCONN) 361 return count; /* ignore data */ 362 363 if (priv->iucv_state == IUCV_SEVERED) 364 return -EPIPE; 365 366 len = min_t(size_t, count, SNDBUF_SIZE - priv->sndbuf_len); 367 if (!len) 368 return 0; 369 370 memcpy(priv->sndbuf + priv->sndbuf_len, buf, len); 371 priv->sndbuf_len += len; 372 373 if (priv->iucv_state == IUCV_CONNECTED) 374 schedule_delayed_work(&priv->sndbuf_work, QUEUE_SNDBUF_DELAY); 375 376 return len; 377 } 378 379 /** 380 * hvc_iucv_send() - Send an IUCV message containing terminal data. 381 * @priv: Pointer to struct hvc_iucv_private instance. 382 * 383 * If an IUCV communication path has been established, the buffered output data 384 * is sent via an IUCV message and the number of bytes sent is returned. 385 * Returns 0 if there is no established IUCV communication path or 386 * -EPIPE if an existing IUCV communicaton path has been severed. 387 */ 388 static int hvc_iucv_send(struct hvc_iucv_private *priv) 389 { 390 struct iucv_tty_buffer *sb; 391 int rc, len; 392 393 if (priv->iucv_state == IUCV_SEVERED) 394 return -EPIPE; 395 396 if (priv->iucv_state == IUCV_DISCONN) 397 return -EIO; 398 399 if (!priv->sndbuf_len) 400 return 0; 401 402 /* allocate internal buffer to store msg data and also compute total 403 * message length */ 404 sb = alloc_tty_buffer(priv->sndbuf_len, GFP_ATOMIC); 405 if (!sb) 406 return -ENOMEM; 407 408 memcpy(sb->mbuf->data, priv->sndbuf, priv->sndbuf_len); 409 sb->mbuf->datalen = (u16) priv->sndbuf_len; 410 sb->msg.length = MSG_SIZE(sb->mbuf->datalen); 411 412 list_add_tail(&sb->list, &priv->tty_outqueue); 413 414 rc = __iucv_message_send(priv->path, &sb->msg, 0, 0, 415 (void *) sb->mbuf, sb->msg.length); 416 if (rc) { 417 /* drop the message here; however we might want to handle 418 * 0x03 (msg limit reached) by trying again... */ 419 list_del(&sb->list); 420 destroy_tty_buffer(sb); 421 } 422 len = priv->sndbuf_len; 423 priv->sndbuf_len = 0; 424 425 return len; 426 } 427 428 /** 429 * hvc_iucv_sndbuf_work() - Send buffered data over IUCV 430 * @work: Work structure. 431 * 432 * This work queue function sends buffered output data over IUCV and, 433 * if not all buffered data could be sent, reschedules itself. 434 */ 435 static void hvc_iucv_sndbuf_work(struct work_struct *work) 436 { 437 struct hvc_iucv_private *priv; 438 439 priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work); 440 441 spin_lock_bh(&priv->lock); 442 hvc_iucv_send(priv); 443 spin_unlock_bh(&priv->lock); 444 } 445 446 /** 447 * hvc_iucv_put_chars() - HVC put_chars operation. 448 * @vtermno: HVC virtual terminal number. 449 * @buf: Pointer to an buffer to read data from 450 * @count: Size of buffer available for reading 451 * 452 * The HVC thread calls this method to write characters to the back-end. 453 * The function calls hvc_iucv_queue() to queue terminal data for sending. 454 * 455 * Locking: The method gets called under an irqsave() spinlock; and 456 * locks struct hvc_iucv_private->lock. 457 */ 458 static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count) 459 { 460 struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); 461 int queued; 462 463 if (count <= 0) 464 return 0; 465 466 if (!priv) 467 return -ENODEV; 468 469 spin_lock(&priv->lock); 470 queued = hvc_iucv_queue(priv, buf, count); 471 spin_unlock(&priv->lock); 472 473 return queued; 474 } 475 476 /** 477 * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time. 478 * @hp: Pointer to the HVC device (struct hvc_struct) 479 * @id: Additional data (originally passed to hvc_alloc): the index of an struct 480 * hvc_iucv_private instance. 481 * 482 * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private 483 * instance that is derived from @id. Always returns 0. 484 * 485 * Locking: struct hvc_iucv_private->lock, spin_lock_bh 486 */ 487 static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id) 488 { 489 struct hvc_iucv_private *priv; 490 491 priv = hvc_iucv_get_private(id); 492 if (!priv) 493 return 0; 494 495 spin_lock_bh(&priv->lock); 496 priv->tty_state = TTY_OPENED; 497 spin_unlock_bh(&priv->lock); 498 499 return 0; 500 } 501 502 /** 503 * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance. 504 * @priv: Pointer to the struct hvc_iucv_private instance. 505 */ 506 static void hvc_iucv_cleanup(struct hvc_iucv_private *priv) 507 { 508 destroy_tty_buffer_list(&priv->tty_outqueue); 509 destroy_tty_buffer_list(&priv->tty_inqueue); 510 511 priv->tty_state = TTY_CLOSED; 512 priv->iucv_state = IUCV_DISCONN; 513 514 priv->sndbuf_len = 0; 515 } 516 517 /** 518 * tty_outqueue_empty() - Test if the tty outq is empty 519 * @priv: Pointer to struct hvc_iucv_private instance. 520 */ 521 static inline int tty_outqueue_empty(struct hvc_iucv_private *priv) 522 { 523 int rc; 524 525 spin_lock_bh(&priv->lock); 526 rc = list_empty(&priv->tty_outqueue); 527 spin_unlock_bh(&priv->lock); 528 529 return rc; 530 } 531 532 /** 533 * flush_sndbuf_sync() - Flush send buffer and wait for completion 534 * @priv: Pointer to struct hvc_iucv_private instance. 535 * 536 * The routine cancels a pending sndbuf work, calls hvc_iucv_send() 537 * to flush any buffered terminal output data and waits for completion. 538 */ 539 static void flush_sndbuf_sync(struct hvc_iucv_private *priv) 540 { 541 int sync_wait; 542 543 cancel_delayed_work_sync(&priv->sndbuf_work); 544 545 spin_lock_bh(&priv->lock); 546 hvc_iucv_send(priv); /* force sending buffered data */ 547 sync_wait = !list_empty(&priv->tty_outqueue); /* anything queued ? */ 548 spin_unlock_bh(&priv->lock); 549 550 if (sync_wait) 551 wait_event_timeout(priv->sndbuf_waitq, 552 tty_outqueue_empty(priv), HZ/10); 553 } 554 555 /** 556 * hvc_iucv_hangup() - Sever IUCV path and schedule hvc tty hang up 557 * @priv: Pointer to hvc_iucv_private structure 558 * 559 * This routine severs an existing IUCV communication path and hangs 560 * up the underlying HVC terminal device. 561 * The hang-up occurs only if an IUCV communication path is established; 562 * otherwise there is no need to hang up the terminal device. 563 * 564 * The IUCV HVC hang-up is separated into two steps: 565 * 1. After the IUCV path has been severed, the iucv_state is set to 566 * IUCV_SEVERED. 567 * 2. Later, when the HVC thread calls hvc_iucv_get_chars(), the 568 * IUCV_SEVERED state causes the tty hang-up in the HVC layer. 569 * 570 * If the tty has not yet been opened, clean up the hvc_iucv_private 571 * structure to allow re-connects. 572 * If the tty has been opened, let get_chars() return -EPIPE to signal 573 * the HVC layer to hang up the tty and, if so, wake up the HVC thread 574 * to call get_chars()... 575 * 576 * Special notes on hanging up a HVC terminal instantiated as console: 577 * Hang-up: 1. do_tty_hangup() replaces file ops (= hung_up_tty_fops) 578 * 2. do_tty_hangup() calls tty->ops->close() for console_filp 579 * => no hangup notifier is called by HVC (default) 580 * 2. hvc_close() returns because of tty_hung_up_p(filp) 581 * => no delete notifier is called! 582 * Finally, the back-end is not being notified, thus, the tty session is 583 * kept active (TTY_OPEN) to be ready for re-connects. 584 * 585 * Locking: spin_lock(&priv->lock) w/o disabling bh 586 */ 587 static void hvc_iucv_hangup(struct hvc_iucv_private *priv) 588 { 589 struct iucv_path *path; 590 591 path = NULL; 592 spin_lock(&priv->lock); 593 if (priv->iucv_state == IUCV_CONNECTED) { 594 path = priv->path; 595 priv->path = NULL; 596 priv->iucv_state = IUCV_SEVERED; 597 if (priv->tty_state == TTY_CLOSED) 598 hvc_iucv_cleanup(priv); 599 else 600 /* console is special (see above) */ 601 if (priv->is_console) { 602 hvc_iucv_cleanup(priv); 603 priv->tty_state = TTY_OPENED; 604 } else 605 hvc_kick(); 606 } 607 spin_unlock(&priv->lock); 608 609 /* finally sever path (outside of priv->lock due to lock ordering) */ 610 if (path) { 611 iucv_path_sever(path, NULL); 612 iucv_path_free(path); 613 } 614 } 615 616 /** 617 * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups. 618 * @hp: Pointer to the HVC device (struct hvc_struct) 619 * @id: Additional data (originally passed to hvc_alloc): 620 * the index of an struct hvc_iucv_private instance. 621 * 622 * This routine notifies the HVC back-end that a tty hangup (carrier loss, 623 * virtual or otherwise) has occurred. 624 * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup()) 625 * to keep an existing IUCV communication path established. 626 * (Background: vhangup() is called from user space (by getty or login) to 627 * disable writing to the tty by other applications). 628 * If the tty has been opened and an established IUCV path has been severed 629 * (we caused the tty hangup), the function calls hvc_iucv_cleanup(). 630 * 631 * Locking: struct hvc_iucv_private->lock 632 */ 633 static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id) 634 { 635 struct hvc_iucv_private *priv; 636 637 priv = hvc_iucv_get_private(id); 638 if (!priv) 639 return; 640 641 flush_sndbuf_sync(priv); 642 643 spin_lock_bh(&priv->lock); 644 /* NOTE: If the hangup was scheduled by ourself (from the iucv 645 * path_servered callback [IUCV_SEVERED]), we have to clean up 646 * our structure and to set state to TTY_CLOSED. 647 * If the tty was hung up otherwise (e.g. vhangup()), then we 648 * ignore this hangup and keep an established IUCV path open... 649 * (...the reason is that we are not able to connect back to the 650 * client if we disconnect on hang up) */ 651 priv->tty_state = TTY_CLOSED; 652 653 if (priv->iucv_state == IUCV_SEVERED) 654 hvc_iucv_cleanup(priv); 655 spin_unlock_bh(&priv->lock); 656 } 657 658 /** 659 * hvc_iucv_dtr_rts() - HVC notifier for handling DTR/RTS 660 * @hp: Pointer the HVC device (struct hvc_struct) 661 * @active: True to raise or false to lower DTR/RTS lines 662 * 663 * This routine notifies the HVC back-end to raise or lower DTR/RTS 664 * lines. Raising DTR/RTS is ignored. Lowering DTR/RTS indicates to 665 * drop the IUCV connection (similar to hang up the modem). 666 */ 667 static void hvc_iucv_dtr_rts(struct hvc_struct *hp, bool active) 668 { 669 struct hvc_iucv_private *priv; 670 struct iucv_path *path; 671 672 /* Raising the DTR/RTS is ignored as IUCV connections can be 673 * established at any times. 674 */ 675 if (active) 676 return; 677 678 priv = hvc_iucv_get_private(hp->vtermno); 679 if (!priv) 680 return; 681 682 /* Lowering the DTR/RTS lines disconnects an established IUCV 683 * connection. 684 */ 685 flush_sndbuf_sync(priv); 686 687 spin_lock_bh(&priv->lock); 688 path = priv->path; /* save reference to IUCV path */ 689 priv->path = NULL; 690 priv->iucv_state = IUCV_DISCONN; 691 spin_unlock_bh(&priv->lock); 692 693 /* Sever IUCV path outside of priv->lock due to lock ordering of: 694 * priv->lock <--> iucv_table_lock */ 695 if (path) { 696 iucv_path_sever(path, NULL); 697 iucv_path_free(path); 698 } 699 } 700 701 /** 702 * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time. 703 * @hp: Pointer to the HVC device (struct hvc_struct) 704 * @id: Additional data (originally passed to hvc_alloc): 705 * the index of an struct hvc_iucv_private instance. 706 * 707 * This routine notifies the HVC back-end that the last tty device fd has been 708 * closed. The function cleans up tty resources. The clean-up of the IUCV 709 * connection is done in hvc_iucv_dtr_rts() and depends on the HUPCL termios 710 * control setting. 711 * 712 * Locking: struct hvc_iucv_private->lock 713 */ 714 static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id) 715 { 716 struct hvc_iucv_private *priv; 717 718 priv = hvc_iucv_get_private(id); 719 if (!priv) 720 return; 721 722 flush_sndbuf_sync(priv); 723 724 spin_lock_bh(&priv->lock); 725 destroy_tty_buffer_list(&priv->tty_outqueue); 726 destroy_tty_buffer_list(&priv->tty_inqueue); 727 priv->tty_state = TTY_CLOSED; 728 priv->sndbuf_len = 0; 729 spin_unlock_bh(&priv->lock); 730 } 731 732 /** 733 * hvc_iucv_filter_connreq() - Filter connection request based on z/VM user ID 734 * @ipvmid: Originating z/VM user ID (right padded with blanks) 735 * 736 * Returns 0 if the z/VM user ID that is specified with @ipvmid is permitted to 737 * connect, otherwise non-zero. 738 */ 739 static int hvc_iucv_filter_connreq(u8 ipvmid[8]) 740 { 741 const char *wildcard, *filter_entry; 742 size_t i, len; 743 744 /* Note: default policy is ACCEPT if no filter is set */ 745 if (!hvc_iucv_filter_size) 746 return 0; 747 748 for (i = 0; i < hvc_iucv_filter_size; i++) { 749 filter_entry = hvc_iucv_filter + (8 * i); 750 751 /* If a filter entry contains the filter wildcard character, 752 * reduce the length to match the leading portion of the user 753 * ID only (wildcard match). Characters following the wildcard 754 * are ignored. 755 */ 756 wildcard = strnchr(filter_entry, 8, FILTER_WILDCARD_CHAR); 757 len = (wildcard) ? wildcard - filter_entry : 8; 758 if (0 == memcmp(ipvmid, filter_entry, len)) 759 return 0; 760 } 761 return 1; 762 } 763 764 /** 765 * hvc_iucv_path_pending() - IUCV handler to process a connection request. 766 * @path: Pending path (struct iucv_path) 767 * @ipvmid: z/VM system identifier of originator 768 * @ipuser: User specified data for this path 769 * (AF_IUCV: port/service name and originator port) 770 * 771 * The function uses the @ipuser data to determine if the pending path belongs 772 * to a terminal managed by this device driver. 773 * If the path belongs to this driver, ensure that the terminal is not accessed 774 * multiple times (only one connection to a terminal is allowed). 775 * If the terminal is not yet connected, the pending path is accepted and is 776 * associated to the appropriate struct hvc_iucv_private instance. 777 * 778 * Returns 0 if @path belongs to a terminal managed by the this device driver; 779 * otherwise returns -ENODEV in order to dispatch this path to other handlers. 780 * 781 * Locking: struct hvc_iucv_private->lock 782 */ 783 static int hvc_iucv_path_pending(struct iucv_path *path, u8 *ipvmid, 784 u8 *ipuser) 785 { 786 struct hvc_iucv_private *priv, *tmp; 787 u8 wildcard[9] = "lnxhvc "; 788 int i, rc, find_unused; 789 u8 nuser_data[16]; 790 u8 vm_user_id[9]; 791 792 ASCEBC(wildcard, sizeof(wildcard)); 793 find_unused = !memcmp(wildcard, ipuser, 8); 794 795 /* First, check if the pending path request is managed by this 796 * IUCV handler: 797 * - find a disconnected device if ipuser contains the wildcard 798 * - find the device that matches the terminal ID in ipuser 799 */ 800 priv = NULL; 801 for (i = 0; i < hvc_iucv_devices; i++) { 802 tmp = hvc_iucv_table[i]; 803 if (!tmp) 804 continue; 805 806 if (find_unused) { 807 spin_lock(&tmp->lock); 808 if (tmp->iucv_state == IUCV_DISCONN) 809 priv = tmp; 810 spin_unlock(&tmp->lock); 811 812 } else if (!memcmp(tmp->srv_name, ipuser, 8)) 813 priv = tmp; 814 if (priv) 815 break; 816 } 817 if (!priv) 818 return -ENODEV; 819 820 /* Enforce that ipvmid is allowed to connect to us */ 821 read_lock(&hvc_iucv_filter_lock); 822 rc = hvc_iucv_filter_connreq(ipvmid); 823 read_unlock(&hvc_iucv_filter_lock); 824 if (rc) { 825 iucv_path_sever(path, ipuser); 826 iucv_path_free(path); 827 memcpy(vm_user_id, ipvmid, 8); 828 vm_user_id[8] = 0; 829 pr_info("A connection request from z/VM user ID %s " 830 "was refused\n", vm_user_id); 831 return 0; 832 } 833 834 spin_lock(&priv->lock); 835 836 /* If the terminal is already connected or being severed, then sever 837 * this path to enforce that there is only ONE established communication 838 * path per terminal. */ 839 if (priv->iucv_state != IUCV_DISCONN) { 840 iucv_path_sever(path, ipuser); 841 iucv_path_free(path); 842 goto out_path_handled; 843 } 844 845 /* accept path */ 846 memcpy(nuser_data, ipuser + 8, 8); /* remote service (for af_iucv) */ 847 memcpy(nuser_data + 8, ipuser, 8); /* local service (for af_iucv) */ 848 path->msglim = 0xffff; /* IUCV MSGLIMIT */ 849 path->flags &= ~IUCV_IPRMDATA; /* TODO: use IUCV_IPRMDATA */ 850 rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv); 851 if (rc) { 852 iucv_path_sever(path, ipuser); 853 iucv_path_free(path); 854 goto out_path_handled; 855 } 856 priv->path = path; 857 priv->iucv_state = IUCV_CONNECTED; 858 859 /* store path information */ 860 memcpy(priv->info_path, ipvmid, 8); 861 memcpy(priv->info_path + 8, ipuser + 8, 8); 862 863 /* flush buffered output data... */ 864 schedule_delayed_work(&priv->sndbuf_work, 5); 865 866 out_path_handled: 867 spin_unlock(&priv->lock); 868 return 0; 869 } 870 871 /** 872 * hvc_iucv_path_severed() - IUCV handler to process a path sever. 873 * @path: Pending path (struct iucv_path) 874 * @ipuser: User specified data for this path 875 * (AF_IUCV: port/service name and originator port) 876 * 877 * This function calls the hvc_iucv_hangup() function for the 878 * respective IUCV HVC terminal. 879 * 880 * Locking: struct hvc_iucv_private->lock 881 */ 882 static void hvc_iucv_path_severed(struct iucv_path *path, u8 *ipuser) 883 { 884 struct hvc_iucv_private *priv = path->private; 885 886 hvc_iucv_hangup(priv); 887 } 888 889 /** 890 * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message. 891 * @path: Pending path (struct iucv_path) 892 * @msg: Pointer to the IUCV message 893 * 894 * The function puts an incoming message on the input queue for later 895 * processing (by hvc_iucv_get_chars() / hvc_iucv_write()). 896 * If the tty has not yet been opened, the message is rejected. 897 * 898 * Locking: struct hvc_iucv_private->lock 899 */ 900 static void hvc_iucv_msg_pending(struct iucv_path *path, 901 struct iucv_message *msg) 902 { 903 struct hvc_iucv_private *priv = path->private; 904 struct iucv_tty_buffer *rb; 905 906 /* reject messages that exceed max size of iucv_tty_msg->datalen */ 907 if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) { 908 iucv_message_reject(path, msg); 909 return; 910 } 911 912 spin_lock(&priv->lock); 913 914 /* reject messages if tty has not yet been opened */ 915 if (priv->tty_state == TTY_CLOSED) { 916 iucv_message_reject(path, msg); 917 goto unlock_return; 918 } 919 920 /* allocate tty buffer to save iucv msg only */ 921 rb = alloc_tty_buffer(0, GFP_ATOMIC); 922 if (!rb) { 923 iucv_message_reject(path, msg); 924 goto unlock_return; /* -ENOMEM */ 925 } 926 rb->msg = *msg; 927 928 list_add_tail(&rb->list, &priv->tty_inqueue); 929 930 hvc_kick(); /* wake up hvc thread */ 931 932 unlock_return: 933 spin_unlock(&priv->lock); 934 } 935 936 /** 937 * hvc_iucv_msg_complete() - IUCV handler to process message completion 938 * @path: Pending path (struct iucv_path) 939 * @msg: Pointer to the IUCV message 940 * 941 * The function is called upon completion of message delivery to remove the 942 * message from the outqueue. Additional delivery information can be found 943 * msg->audit: rejected messages (0x040000 (IPADRJCT)), and 944 * purged messages (0x010000 (IPADPGNR)). 945 * 946 * Locking: struct hvc_iucv_private->lock 947 */ 948 static void hvc_iucv_msg_complete(struct iucv_path *path, 949 struct iucv_message *msg) 950 { 951 struct hvc_iucv_private *priv = path->private; 952 struct iucv_tty_buffer *ent, *next; 953 LIST_HEAD(list_remove); 954 955 spin_lock(&priv->lock); 956 list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list) 957 if (ent->msg.id == msg->id) { 958 list_move(&ent->list, &list_remove); 959 break; 960 } 961 wake_up(&priv->sndbuf_waitq); 962 spin_unlock(&priv->lock); 963 destroy_tty_buffer_list(&list_remove); 964 } 965 966 static ssize_t hvc_iucv_dev_termid_show(struct device *dev, 967 struct device_attribute *attr, 968 char *buf) 969 { 970 struct hvc_iucv_private *priv = dev_get_drvdata(dev); 971 size_t len; 972 973 len = sizeof(priv->srv_name); 974 memcpy(buf, priv->srv_name, len); 975 EBCASC(buf, len); 976 buf[len++] = '\n'; 977 return len; 978 } 979 980 static ssize_t hvc_iucv_dev_state_show(struct device *dev, 981 struct device_attribute *attr, 982 char *buf) 983 { 984 struct hvc_iucv_private *priv = dev_get_drvdata(dev); 985 return sprintf(buf, "%u:%u\n", priv->iucv_state, priv->tty_state); 986 } 987 988 static ssize_t hvc_iucv_dev_peer_show(struct device *dev, 989 struct device_attribute *attr, 990 char *buf) 991 { 992 struct hvc_iucv_private *priv = dev_get_drvdata(dev); 993 char vmid[9], ipuser[9]; 994 995 memset(vmid, 0, sizeof(vmid)); 996 memset(ipuser, 0, sizeof(ipuser)); 997 998 spin_lock_bh(&priv->lock); 999 if (priv->iucv_state == IUCV_CONNECTED) { 1000 memcpy(vmid, priv->info_path, 8); 1001 memcpy(ipuser, priv->info_path + 8, 8); 1002 } 1003 spin_unlock_bh(&priv->lock); 1004 EBCASC(ipuser, 8); 1005 1006 return sprintf(buf, "%s:%s\n", vmid, ipuser); 1007 } 1008 1009 1010 /* HVC operations */ 1011 static const struct hv_ops hvc_iucv_ops = { 1012 .get_chars = hvc_iucv_get_chars, 1013 .put_chars = hvc_iucv_put_chars, 1014 .notifier_add = hvc_iucv_notifier_add, 1015 .notifier_del = hvc_iucv_notifier_del, 1016 .notifier_hangup = hvc_iucv_notifier_hangup, 1017 .dtr_rts = hvc_iucv_dtr_rts, 1018 }; 1019 1020 /* IUCV HVC device attributes */ 1021 static DEVICE_ATTR(termid, 0640, hvc_iucv_dev_termid_show, NULL); 1022 static DEVICE_ATTR(state, 0640, hvc_iucv_dev_state_show, NULL); 1023 static DEVICE_ATTR(peer, 0640, hvc_iucv_dev_peer_show, NULL); 1024 static struct attribute *hvc_iucv_dev_attrs[] = { 1025 &dev_attr_termid.attr, 1026 &dev_attr_state.attr, 1027 &dev_attr_peer.attr, 1028 NULL, 1029 }; 1030 static struct attribute_group hvc_iucv_dev_attr_group = { 1031 .attrs = hvc_iucv_dev_attrs, 1032 }; 1033 static const struct attribute_group *hvc_iucv_dev_attr_groups[] = { 1034 &hvc_iucv_dev_attr_group, 1035 NULL, 1036 }; 1037 1038 1039 /** 1040 * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance 1041 * @id: hvc_iucv_table index 1042 * @is_console: Flag if the instance is used as Linux console 1043 * 1044 * This function allocates a new hvc_iucv_private structure and stores 1045 * the instance in hvc_iucv_table at index @id. 1046 * Returns 0 on success; otherwise non-zero. 1047 */ 1048 static int __init hvc_iucv_alloc(int id, unsigned int is_console) 1049 { 1050 struct hvc_iucv_private *priv; 1051 char name[9]; 1052 int rc; 1053 1054 priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL); 1055 if (!priv) 1056 return -ENOMEM; 1057 1058 spin_lock_init(&priv->lock); 1059 INIT_LIST_HEAD(&priv->tty_outqueue); 1060 INIT_LIST_HEAD(&priv->tty_inqueue); 1061 INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work); 1062 init_waitqueue_head(&priv->sndbuf_waitq); 1063 1064 priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL); 1065 if (!priv->sndbuf) { 1066 kfree(priv); 1067 return -ENOMEM; 1068 } 1069 1070 /* set console flag */ 1071 priv->is_console = is_console; 1072 1073 /* allocate hvc device */ 1074 priv->hvc = hvc_alloc(id, /* PAGE_SIZE */ 1075 id, &hvc_iucv_ops, 256); 1076 if (IS_ERR(priv->hvc)) { 1077 rc = PTR_ERR(priv->hvc); 1078 goto out_error_hvc; 1079 } 1080 1081 /* notify HVC thread instead of using polling */ 1082 priv->hvc->irq_requested = 1; 1083 1084 /* setup iucv related information */ 1085 snprintf(name, 9, "lnxhvc%-2d", id); 1086 memcpy(priv->srv_name, name, 8); 1087 ASCEBC(priv->srv_name, 8); 1088 1089 /* create and setup device */ 1090 priv->dev = kzalloc(sizeof(*priv->dev), GFP_KERNEL); 1091 if (!priv->dev) { 1092 rc = -ENOMEM; 1093 goto out_error_dev; 1094 } 1095 dev_set_name(priv->dev, "hvc_iucv%d", id); 1096 dev_set_drvdata(priv->dev, priv); 1097 priv->dev->bus = &iucv_bus; 1098 priv->dev->parent = iucv_root; 1099 priv->dev->groups = hvc_iucv_dev_attr_groups; 1100 priv->dev->release = (void (*)(struct device *)) kfree; 1101 rc = device_register(priv->dev); 1102 if (rc) { 1103 put_device(priv->dev); 1104 goto out_error_dev; 1105 } 1106 1107 hvc_iucv_table[id] = priv; 1108 return 0; 1109 1110 out_error_dev: 1111 hvc_remove(priv->hvc); 1112 out_error_hvc: 1113 free_page((unsigned long) priv->sndbuf); 1114 kfree(priv); 1115 1116 return rc; 1117 } 1118 1119 /** 1120 * hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances 1121 */ 1122 static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv) 1123 { 1124 hvc_remove(priv->hvc); 1125 device_unregister(priv->dev); 1126 free_page((unsigned long) priv->sndbuf); 1127 kfree(priv); 1128 } 1129 1130 /** 1131 * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID 1132 * @filter: String containing a comma-separated list of z/VM user IDs 1133 * @dest: Location where to store the parsed z/VM user ID 1134 */ 1135 static const char *hvc_iucv_parse_filter(const char *filter, char *dest) 1136 { 1137 const char *nextdelim, *residual; 1138 size_t len; 1139 1140 nextdelim = strchr(filter, ','); 1141 if (nextdelim) { 1142 len = nextdelim - filter; 1143 residual = nextdelim + 1; 1144 } else { 1145 len = strlen(filter); 1146 residual = filter + len; 1147 } 1148 1149 if (len == 0) 1150 return ERR_PTR(-EINVAL); 1151 1152 /* check for '\n' (if called from sysfs) */ 1153 if (filter[len - 1] == '\n') 1154 len--; 1155 1156 /* prohibit filter entries containing the wildcard character only */ 1157 if (len == 1 && *filter == FILTER_WILDCARD_CHAR) 1158 return ERR_PTR(-EINVAL); 1159 1160 if (len > 8) 1161 return ERR_PTR(-EINVAL); 1162 1163 /* pad with blanks and save upper case version of user ID */ 1164 memset(dest, ' ', 8); 1165 while (len--) 1166 dest[len] = toupper(filter[len]); 1167 return residual; 1168 } 1169 1170 /** 1171 * hvc_iucv_setup_filter() - Set up z/VM user ID filter 1172 * @filter: String consisting of a comma-separated list of z/VM user IDs 1173 * 1174 * The function parses the @filter string and creates an array containing 1175 * the list of z/VM user ID filter entries. 1176 * Return code 0 means success, -EINVAL if the filter is syntactically 1177 * incorrect, -ENOMEM if there was not enough memory to allocate the 1178 * filter list array, or -ENOSPC if too many z/VM user IDs have been specified. 1179 */ 1180 static int hvc_iucv_setup_filter(const char *val) 1181 { 1182 const char *residual; 1183 int err; 1184 size_t size, count; 1185 void *array, *old_filter; 1186 1187 count = strlen(val); 1188 if (count == 0 || (count == 1 && val[0] == '\n')) { 1189 size = 0; 1190 array = NULL; 1191 goto out_replace_filter; /* clear filter */ 1192 } 1193 1194 /* count user IDs in order to allocate sufficient memory */ 1195 size = 1; 1196 residual = val; 1197 while ((residual = strchr(residual, ',')) != NULL) { 1198 residual++; 1199 size++; 1200 } 1201 1202 /* check if the specified list exceeds the filter limit */ 1203 if (size > MAX_VMID_FILTER) 1204 return -ENOSPC; 1205 1206 array = kcalloc(size, 8, GFP_KERNEL); 1207 if (!array) 1208 return -ENOMEM; 1209 1210 count = size; 1211 residual = val; 1212 while (*residual && count) { 1213 residual = hvc_iucv_parse_filter(residual, 1214 array + ((size - count) * 8)); 1215 if (IS_ERR(residual)) { 1216 err = PTR_ERR(residual); 1217 kfree(array); 1218 goto out_err; 1219 } 1220 count--; 1221 } 1222 1223 out_replace_filter: 1224 write_lock_bh(&hvc_iucv_filter_lock); 1225 old_filter = hvc_iucv_filter; 1226 hvc_iucv_filter_size = size; 1227 hvc_iucv_filter = array; 1228 write_unlock_bh(&hvc_iucv_filter_lock); 1229 kfree(old_filter); 1230 1231 err = 0; 1232 out_err: 1233 return err; 1234 } 1235 1236 /** 1237 * param_set_vmidfilter() - Set z/VM user ID filter parameter 1238 * @val: String consisting of a comma-separated list of z/VM user IDs 1239 * @kp: Kernel parameter pointing to hvc_iucv_filter array 1240 * 1241 * The function sets up the z/VM user ID filter specified as comma-separated 1242 * list of user IDs in @val. 1243 * Note: If it is called early in the boot process, @val is stored and 1244 * parsed later in hvc_iucv_init(). 1245 */ 1246 static int param_set_vmidfilter(const char *val, const struct kernel_param *kp) 1247 { 1248 int rc; 1249 1250 if (!MACHINE_IS_VM || !hvc_iucv_devices) 1251 return -ENODEV; 1252 1253 if (!val) 1254 return -EINVAL; 1255 1256 rc = 0; 1257 if (slab_is_available()) 1258 rc = hvc_iucv_setup_filter(val); 1259 else 1260 hvc_iucv_filter_string = val; /* defer... */ 1261 return rc; 1262 } 1263 1264 /** 1265 * param_get_vmidfilter() - Get z/VM user ID filter 1266 * @buffer: Buffer to store z/VM user ID filter, 1267 * (buffer size assumption PAGE_SIZE) 1268 * @kp: Kernel parameter pointing to the hvc_iucv_filter array 1269 * 1270 * The function stores the filter as a comma-separated list of z/VM user IDs 1271 * in @buffer. Typically, sysfs routines call this function for attr show. 1272 */ 1273 static int param_get_vmidfilter(char *buffer, const struct kernel_param *kp) 1274 { 1275 int rc; 1276 size_t index, len; 1277 void *start, *end; 1278 1279 if (!MACHINE_IS_VM || !hvc_iucv_devices) 1280 return -ENODEV; 1281 1282 rc = 0; 1283 read_lock_bh(&hvc_iucv_filter_lock); 1284 for (index = 0; index < hvc_iucv_filter_size; index++) { 1285 start = hvc_iucv_filter + (8 * index); 1286 end = memchr(start, ' ', 8); 1287 len = (end) ? end - start : 8; 1288 memcpy(buffer + rc, start, len); 1289 rc += len; 1290 buffer[rc++] = ','; 1291 } 1292 read_unlock_bh(&hvc_iucv_filter_lock); 1293 if (rc) 1294 buffer[--rc] = '\0'; /* replace last comma and update rc */ 1295 return rc; 1296 } 1297 1298 #define param_check_vmidfilter(name, p) __param_check(name, p, void) 1299 1300 static const struct kernel_param_ops param_ops_vmidfilter = { 1301 .set = param_set_vmidfilter, 1302 .get = param_get_vmidfilter, 1303 }; 1304 1305 /** 1306 * hvc_iucv_init() - z/VM IUCV HVC device driver initialization 1307 */ 1308 static int __init hvc_iucv_init(void) 1309 { 1310 int rc; 1311 unsigned int i; 1312 1313 if (!hvc_iucv_devices) 1314 return -ENODEV; 1315 1316 if (!MACHINE_IS_VM) { 1317 pr_notice("The z/VM IUCV HVC device driver cannot " 1318 "be used without z/VM\n"); 1319 rc = -ENODEV; 1320 goto out_error; 1321 } 1322 1323 if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) { 1324 pr_err("%lu is not a valid value for the hvc_iucv= " 1325 "kernel parameter\n", hvc_iucv_devices); 1326 rc = -EINVAL; 1327 goto out_error; 1328 } 1329 1330 /* parse hvc_iucv_allow string and create z/VM user ID filter list */ 1331 if (hvc_iucv_filter_string) { 1332 rc = hvc_iucv_setup_filter(hvc_iucv_filter_string); 1333 switch (rc) { 1334 case 0: 1335 break; 1336 case -ENOMEM: 1337 pr_err("Allocating memory failed with " 1338 "reason code=%d\n", 3); 1339 goto out_error; 1340 case -EINVAL: 1341 pr_err("hvc_iucv_allow= does not specify a valid " 1342 "z/VM user ID list\n"); 1343 goto out_error; 1344 case -ENOSPC: 1345 pr_err("hvc_iucv_allow= specifies too many " 1346 "z/VM user IDs\n"); 1347 goto out_error; 1348 default: 1349 goto out_error; 1350 } 1351 } 1352 1353 hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT, 1354 sizeof(struct iucv_tty_buffer), 1355 0, 0, NULL); 1356 if (!hvc_iucv_buffer_cache) { 1357 pr_err("Allocating memory failed with reason code=%d\n", 1); 1358 rc = -ENOMEM; 1359 goto out_error; 1360 } 1361 1362 hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR, 1363 hvc_iucv_buffer_cache); 1364 if (!hvc_iucv_mempool) { 1365 pr_err("Allocating memory failed with reason code=%d\n", 2); 1366 kmem_cache_destroy(hvc_iucv_buffer_cache); 1367 rc = -ENOMEM; 1368 goto out_error; 1369 } 1370 1371 /* register the first terminal device as console 1372 * (must be done before allocating hvc terminal devices) */ 1373 rc = hvc_instantiate(0, IUCV_HVC_CON_IDX, &hvc_iucv_ops); 1374 if (rc) { 1375 pr_err("Registering HVC terminal device as " 1376 "Linux console failed\n"); 1377 goto out_error_memory; 1378 } 1379 1380 /* allocate hvc_iucv_private structs */ 1381 for (i = 0; i < hvc_iucv_devices; i++) { 1382 rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0); 1383 if (rc) { 1384 pr_err("Creating a new HVC terminal device " 1385 "failed with error code=%d\n", rc); 1386 goto out_error_hvc; 1387 } 1388 } 1389 1390 /* register IUCV callback handler */ 1391 rc = iucv_register(&hvc_iucv_handler, 0); 1392 if (rc) { 1393 pr_err("Registering IUCV handlers failed with error code=%d\n", 1394 rc); 1395 goto out_error_hvc; 1396 } 1397 1398 return 0; 1399 1400 out_error_hvc: 1401 for (i = 0; i < hvc_iucv_devices; i++) 1402 if (hvc_iucv_table[i]) 1403 hvc_iucv_destroy(hvc_iucv_table[i]); 1404 out_error_memory: 1405 mempool_destroy(hvc_iucv_mempool); 1406 kmem_cache_destroy(hvc_iucv_buffer_cache); 1407 out_error: 1408 kfree(hvc_iucv_filter); 1409 hvc_iucv_devices = 0; /* ensure that we do not provide any device */ 1410 return rc; 1411 } 1412 1413 /** 1414 * hvc_iucv_config() - Parsing of hvc_iucv= kernel command line parameter 1415 * @val: Parameter value (numeric) 1416 */ 1417 static int __init hvc_iucv_config(char *val) 1418 { 1419 if (kstrtoul(val, 10, &hvc_iucv_devices)) 1420 pr_warn("hvc_iucv= invalid parameter value '%s'\n", val); 1421 return 1; 1422 } 1423 1424 1425 device_initcall(hvc_iucv_init); 1426 __setup("hvc_iucv=", hvc_iucv_config); 1427 core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640); 1428