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 HVC_IUCV_MAGIC 0xc9e4c3e5 33 #define MAX_HVC_IUCV_LINES HVC_ALLOC_TTY_ADAPTERS 34 #define MEMPOOL_MIN_NR (PAGE_SIZE / sizeof(struct iucv_tty_buffer)/4) 35 36 /* IUCV TTY message */ 37 #define MSG_VERSION 0x02 /* Message version */ 38 #define MSG_TYPE_ERROR 0x01 /* Error message */ 39 #define MSG_TYPE_TERMENV 0x02 /* Terminal environment variable */ 40 #define MSG_TYPE_TERMIOS 0x04 /* Terminal IO struct update */ 41 #define MSG_TYPE_WINSIZE 0x08 /* Terminal window size update */ 42 #define MSG_TYPE_DATA 0x10 /* Terminal data */ 43 44 struct iucv_tty_msg { 45 u8 version; /* Message version */ 46 u8 type; /* Message type */ 47 #define MSG_MAX_DATALEN ((u16)(~0)) 48 u16 datalen; /* Payload length */ 49 u8 data[]; /* Payload buffer */ 50 } __attribute__((packed)); 51 #define MSG_SIZE(s) ((s) + offsetof(struct iucv_tty_msg, data)) 52 53 enum iucv_state_t { 54 IUCV_DISCONN = 0, 55 IUCV_CONNECTED = 1, 56 IUCV_SEVERED = 2, 57 }; 58 59 enum tty_state_t { 60 TTY_CLOSED = 0, 61 TTY_OPENED = 1, 62 }; 63 64 struct hvc_iucv_private { 65 struct hvc_struct *hvc; /* HVC struct reference */ 66 u8 srv_name[8]; /* IUCV service name (ebcdic) */ 67 unsigned char is_console; /* Linux console usage flag */ 68 enum iucv_state_t iucv_state; /* IUCV connection status */ 69 enum tty_state_t tty_state; /* TTY status */ 70 struct iucv_path *path; /* IUCV path pointer */ 71 spinlock_t lock; /* hvc_iucv_private lock */ 72 #define SNDBUF_SIZE (PAGE_SIZE) /* must be < MSG_MAX_DATALEN */ 73 void *sndbuf; /* send buffer */ 74 size_t sndbuf_len; /* length of send buffer */ 75 #define QUEUE_SNDBUF_DELAY (HZ / 25) 76 struct delayed_work sndbuf_work; /* work: send iucv msg(s) */ 77 wait_queue_head_t sndbuf_waitq; /* wait for send completion */ 78 struct list_head tty_outqueue; /* outgoing IUCV messages */ 79 struct list_head tty_inqueue; /* incoming IUCV messages */ 80 struct device *dev; /* device structure */ 81 u8 info_path[16]; /* IUCV path info (dev attr) */ 82 }; 83 84 struct iucv_tty_buffer { 85 struct list_head list; /* list pointer */ 86 struct iucv_message msg; /* store an IUCV message */ 87 size_t offset; /* data buffer offset */ 88 struct iucv_tty_msg *mbuf; /* buffer to store input/output data */ 89 }; 90 91 /* IUCV callback handler */ 92 static int hvc_iucv_path_pending(struct iucv_path *, u8 *, u8 *); 93 static void hvc_iucv_path_severed(struct iucv_path *, u8 *); 94 static void hvc_iucv_msg_pending(struct iucv_path *, struct iucv_message *); 95 static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *); 96 97 98 /* Kernel module parameter: use one terminal device as default */ 99 static unsigned long hvc_iucv_devices = 1; 100 101 /* Array of allocated hvc iucv tty lines... */ 102 static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES]; 103 #define IUCV_HVC_CON_IDX (0) 104 /* List of z/VM user ID filter entries (struct iucv_vmid_filter) */ 105 #define MAX_VMID_FILTER (500) 106 #define FILTER_WILDCARD_CHAR '*' 107 static size_t hvc_iucv_filter_size; 108 static void *hvc_iucv_filter; 109 static const char *hvc_iucv_filter_string; 110 static DEFINE_RWLOCK(hvc_iucv_filter_lock); 111 112 /* Kmem cache and mempool for iucv_tty_buffer elements */ 113 static struct kmem_cache *hvc_iucv_buffer_cache; 114 static mempool_t *hvc_iucv_mempool; 115 116 /* IUCV handler callback functions */ 117 static struct iucv_handler hvc_iucv_handler = { 118 .path_pending = hvc_iucv_path_pending, 119 .path_severed = hvc_iucv_path_severed, 120 .message_complete = hvc_iucv_msg_complete, 121 .message_pending = hvc_iucv_msg_pending, 122 }; 123 124 125 /** 126 * hvc_iucv_get_private() - Return a struct hvc_iucv_private instance. 127 * @num: The HVC virtual terminal number (vtermno) 128 * 129 * This function returns the struct hvc_iucv_private instance that corresponds 130 * to the HVC virtual terminal number specified as parameter @num. 131 */ 132 static struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num) 133 { 134 if ((num < HVC_IUCV_MAGIC) || (num - HVC_IUCV_MAGIC > hvc_iucv_devices)) 135 return NULL; 136 return hvc_iucv_table[num - HVC_IUCV_MAGIC]; 137 } 138 139 /** 140 * alloc_tty_buffer() - Return a new struct iucv_tty_buffer element. 141 * @size: Size of the internal buffer used to store data. 142 * @flags: Memory allocation flags passed to mempool. 143 * 144 * This function allocates a new struct iucv_tty_buffer element and, optionally, 145 * allocates an internal data buffer with the specified size @size. 146 * The internal data buffer is always allocated with GFP_DMA which is 147 * required for receiving and sending data with IUCV. 148 * Note: The total message size arises from the internal buffer size and the 149 * members of the iucv_tty_msg structure. 150 * The function returns NULL if memory allocation has failed. 151 */ 152 static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags) 153 { 154 struct iucv_tty_buffer *bufp; 155 156 bufp = mempool_alloc(hvc_iucv_mempool, flags); 157 if (!bufp) 158 return NULL; 159 memset(bufp, 0, sizeof(*bufp)); 160 161 if (size > 0) { 162 bufp->msg.length = MSG_SIZE(size); 163 bufp->mbuf = kmalloc(bufp->msg.length, flags | GFP_DMA); 164 if (!bufp->mbuf) { 165 mempool_free(bufp, hvc_iucv_mempool); 166 return NULL; 167 } 168 bufp->mbuf->version = MSG_VERSION; 169 bufp->mbuf->type = MSG_TYPE_DATA; 170 bufp->mbuf->datalen = (u16) size; 171 } 172 return bufp; 173 } 174 175 /** 176 * destroy_tty_buffer() - destroy struct iucv_tty_buffer element. 177 * @bufp: Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL. 178 */ 179 static void destroy_tty_buffer(struct iucv_tty_buffer *bufp) 180 { 181 kfree(bufp->mbuf); 182 mempool_free(bufp, hvc_iucv_mempool); 183 } 184 185 /** 186 * destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element. 187 * @list: List containing struct iucv_tty_buffer elements. 188 */ 189 static void destroy_tty_buffer_list(struct list_head *list) 190 { 191 struct iucv_tty_buffer *ent, *next; 192 193 list_for_each_entry_safe(ent, next, list, list) { 194 list_del(&ent->list); 195 destroy_tty_buffer(ent); 196 } 197 } 198 199 /** 200 * hvc_iucv_write() - Receive IUCV message & write data to HVC buffer. 201 * @priv: Pointer to struct hvc_iucv_private 202 * @buf: HVC buffer for writing received terminal data. 203 * @count: HVC buffer size. 204 * @has_more_data: Pointer to an int variable. 205 * 206 * The function picks up pending messages from the input queue and receives 207 * the message data that is then written to the specified buffer @buf. 208 * If the buffer size @count is less than the data message size, the 209 * message is kept on the input queue and @has_more_data is set to 1. 210 * If all message data has been written, the message is removed from 211 * the input queue. 212 * 213 * The function returns the number of bytes written to the terminal, zero if 214 * there are no pending data messages available or if there is no established 215 * IUCV path. 216 * If the IUCV path has been severed, then -EPIPE is returned to cause a 217 * hang up (that is issued by the HVC layer). 218 */ 219 static int hvc_iucv_write(struct hvc_iucv_private *priv, 220 char *buf, int count, int *has_more_data) 221 { 222 struct iucv_tty_buffer *rb; 223 int written; 224 int rc; 225 226 /* immediately return if there is no IUCV connection */ 227 if (priv->iucv_state == IUCV_DISCONN) 228 return 0; 229 230 /* if the IUCV path has been severed, return -EPIPE to inform the 231 * HVC layer to hang up the tty device. */ 232 if (priv->iucv_state == IUCV_SEVERED) 233 return -EPIPE; 234 235 /* check if there are pending messages */ 236 if (list_empty(&priv->tty_inqueue)) 237 return 0; 238 239 /* receive an iucv message and flip data to the tty (ldisc) */ 240 rb = list_first_entry(&priv->tty_inqueue, struct iucv_tty_buffer, list); 241 242 written = 0; 243 if (!rb->mbuf) { /* message not yet received ... */ 244 /* allocate mem to store msg data; if no memory is available 245 * then leave the buffer on the list and re-try later */ 246 rb->mbuf = kmalloc(rb->msg.length, GFP_ATOMIC | GFP_DMA); 247 if (!rb->mbuf) 248 return -ENOMEM; 249 250 rc = __iucv_message_receive(priv->path, &rb->msg, 0, 251 rb->mbuf, rb->msg.length, NULL); 252 switch (rc) { 253 case 0: /* Successful */ 254 break; 255 case 2: /* No message found */ 256 case 9: /* Message purged */ 257 break; 258 default: 259 written = -EIO; 260 } 261 /* remove buffer if an error has occurred or received data 262 * is not correct */ 263 if (rc || (rb->mbuf->version != MSG_VERSION) || 264 (rb->msg.length != MSG_SIZE(rb->mbuf->datalen))) 265 goto out_remove_buffer; 266 } 267 268 switch (rb->mbuf->type) { 269 case MSG_TYPE_DATA: 270 written = min_t(int, rb->mbuf->datalen - rb->offset, count); 271 memcpy(buf, rb->mbuf->data + rb->offset, written); 272 if (written < (rb->mbuf->datalen - rb->offset)) { 273 rb->offset += written; 274 *has_more_data = 1; 275 goto out_written; 276 } 277 break; 278 279 case MSG_TYPE_WINSIZE: 280 if (rb->mbuf->datalen != sizeof(struct winsize)) 281 break; 282 /* The caller must ensure that the hvc is locked, which 283 * is the case when called from hvc_iucv_get_chars() */ 284 __hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data)); 285 break; 286 287 case MSG_TYPE_ERROR: /* ignored ... */ 288 case MSG_TYPE_TERMENV: /* ignored ... */ 289 case MSG_TYPE_TERMIOS: /* ignored ... */ 290 break; 291 } 292 293 out_remove_buffer: 294 list_del(&rb->list); 295 destroy_tty_buffer(rb); 296 *has_more_data = !list_empty(&priv->tty_inqueue); 297 298 out_written: 299 return written; 300 } 301 302 /** 303 * hvc_iucv_get_chars() - HVC get_chars operation. 304 * @vtermno: HVC virtual terminal number. 305 * @buf: Pointer to a buffer to store data 306 * @count: Size of buffer available for writing 307 * 308 * The HVC thread calls this method to read characters from the back-end. 309 * If an IUCV communication path has been established, pending IUCV messages 310 * are received and data is copied into buffer @buf up to @count bytes. 311 * 312 * Locking: The routine gets called under an irqsave() spinlock; and 313 * the routine locks the struct hvc_iucv_private->lock to call 314 * helper functions. 315 */ 316 static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count) 317 { 318 struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); 319 int written; 320 int has_more_data; 321 322 if (count <= 0) 323 return 0; 324 325 if (!priv) 326 return -ENODEV; 327 328 spin_lock(&priv->lock); 329 has_more_data = 0; 330 written = hvc_iucv_write(priv, buf, count, &has_more_data); 331 spin_unlock(&priv->lock); 332 333 /* if there are still messages on the queue... schedule another run */ 334 if (has_more_data) 335 hvc_kick(); 336 337 return written; 338 } 339 340 /** 341 * hvc_iucv_queue() - Buffer terminal data for sending. 342 * @priv: Pointer to struct hvc_iucv_private instance. 343 * @buf: Buffer containing data to send. 344 * @count: Size of buffer and amount of data to send. 345 * 346 * The function queues data for sending. To actually send the buffered data, 347 * a work queue function is scheduled (with QUEUE_SNDBUF_DELAY). 348 * The function returns the number of data bytes that has been buffered. 349 * 350 * If the device is not connected, data is ignored and the function returns 351 * @count. 352 * If the buffer is full, the function returns 0. 353 * If an existing IUCV communicaton path has been severed, -EPIPE is returned 354 * (that can be passed to HVC layer to cause a tty hangup). 355 */ 356 static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf, 357 int count) 358 { 359 size_t len; 360 361 if (priv->iucv_state == IUCV_DISCONN) 362 return count; /* ignore data */ 363 364 if (priv->iucv_state == IUCV_SEVERED) 365 return -EPIPE; 366 367 len = min_t(size_t, count, SNDBUF_SIZE - priv->sndbuf_len); 368 if (!len) 369 return 0; 370 371 memcpy(priv->sndbuf + priv->sndbuf_len, buf, len); 372 priv->sndbuf_len += len; 373 374 if (priv->iucv_state == IUCV_CONNECTED) 375 schedule_delayed_work(&priv->sndbuf_work, QUEUE_SNDBUF_DELAY); 376 377 return len; 378 } 379 380 /** 381 * hvc_iucv_send() - Send an IUCV message containing terminal data. 382 * @priv: Pointer to struct hvc_iucv_private instance. 383 * 384 * If an IUCV communication path has been established, the buffered output data 385 * is sent via an IUCV message and the number of bytes sent is returned. 386 * Returns 0 if there is no established IUCV communication path or 387 * -EPIPE if an existing IUCV communicaton path has been severed. 388 */ 389 static int hvc_iucv_send(struct hvc_iucv_private *priv) 390 { 391 struct iucv_tty_buffer *sb; 392 int rc, len; 393 394 if (priv->iucv_state == IUCV_SEVERED) 395 return -EPIPE; 396 397 if (priv->iucv_state == IUCV_DISCONN) 398 return -EIO; 399 400 if (!priv->sndbuf_len) 401 return 0; 402 403 /* allocate internal buffer to store msg data and also compute total 404 * message length */ 405 sb = alloc_tty_buffer(priv->sndbuf_len, GFP_ATOMIC); 406 if (!sb) 407 return -ENOMEM; 408 409 memcpy(sb->mbuf->data, priv->sndbuf, priv->sndbuf_len); 410 sb->mbuf->datalen = (u16) priv->sndbuf_len; 411 sb->msg.length = MSG_SIZE(sb->mbuf->datalen); 412 413 list_add_tail(&sb->list, &priv->tty_outqueue); 414 415 rc = __iucv_message_send(priv->path, &sb->msg, 0, 0, 416 (void *) sb->mbuf, sb->msg.length); 417 if (rc) { 418 /* drop the message here; however we might want to handle 419 * 0x03 (msg limit reached) by trying again... */ 420 list_del(&sb->list); 421 destroy_tty_buffer(sb); 422 } 423 len = priv->sndbuf_len; 424 priv->sndbuf_len = 0; 425 426 return len; 427 } 428 429 /** 430 * hvc_iucv_sndbuf_work() - Send buffered data over IUCV 431 * @work: Work structure. 432 * 433 * This work queue function sends buffered output data over IUCV and, 434 * if not all buffered data could be sent, reschedules itself. 435 */ 436 static void hvc_iucv_sndbuf_work(struct work_struct *work) 437 { 438 struct hvc_iucv_private *priv; 439 440 priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work); 441 442 spin_lock_bh(&priv->lock); 443 hvc_iucv_send(priv); 444 spin_unlock_bh(&priv->lock); 445 } 446 447 /** 448 * hvc_iucv_put_chars() - HVC put_chars operation. 449 * @vtermno: HVC virtual terminal number. 450 * @buf: Pointer to an buffer to read data from 451 * @count: Size of buffer available for reading 452 * 453 * The HVC thread calls this method to write characters to the back-end. 454 * The function calls hvc_iucv_queue() to queue terminal data for sending. 455 * 456 * Locking: The method gets called under an irqsave() spinlock; and 457 * locks struct hvc_iucv_private->lock. 458 */ 459 static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count) 460 { 461 struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); 462 int queued; 463 464 if (count <= 0) 465 return 0; 466 467 if (!priv) 468 return -ENODEV; 469 470 spin_lock(&priv->lock); 471 queued = hvc_iucv_queue(priv, buf, count); 472 spin_unlock(&priv->lock); 473 474 return queued; 475 } 476 477 /** 478 * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time. 479 * @hp: Pointer to the HVC device (struct hvc_struct) 480 * @id: Additional data (originally passed to hvc_alloc): the index of an struct 481 * hvc_iucv_private instance. 482 * 483 * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private 484 * instance that is derived from @id. Always returns 0. 485 * 486 * Locking: struct hvc_iucv_private->lock, spin_lock_bh 487 */ 488 static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id) 489 { 490 struct hvc_iucv_private *priv; 491 492 priv = hvc_iucv_get_private(id); 493 if (!priv) 494 return 0; 495 496 spin_lock_bh(&priv->lock); 497 priv->tty_state = TTY_OPENED; 498 spin_unlock_bh(&priv->lock); 499 500 return 0; 501 } 502 503 /** 504 * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance. 505 * @priv: Pointer to the struct hvc_iucv_private instance. 506 */ 507 static void hvc_iucv_cleanup(struct hvc_iucv_private *priv) 508 { 509 destroy_tty_buffer_list(&priv->tty_outqueue); 510 destroy_tty_buffer_list(&priv->tty_inqueue); 511 512 priv->tty_state = TTY_CLOSED; 513 priv->iucv_state = IUCV_DISCONN; 514 515 priv->sndbuf_len = 0; 516 } 517 518 /** 519 * tty_outqueue_empty() - Test if the tty outq is empty 520 * @priv: Pointer to struct hvc_iucv_private instance. 521 */ 522 static inline int tty_outqueue_empty(struct hvc_iucv_private *priv) 523 { 524 int rc; 525 526 spin_lock_bh(&priv->lock); 527 rc = list_empty(&priv->tty_outqueue); 528 spin_unlock_bh(&priv->lock); 529 530 return rc; 531 } 532 533 /** 534 * flush_sndbuf_sync() - Flush send buffer and wait for completion 535 * @priv: Pointer to struct hvc_iucv_private instance. 536 * 537 * The routine cancels a pending sndbuf work, calls hvc_iucv_send() 538 * to flush any buffered terminal output data and waits for completion. 539 */ 540 static void flush_sndbuf_sync(struct hvc_iucv_private *priv) 541 { 542 int sync_wait; 543 544 cancel_delayed_work_sync(&priv->sndbuf_work); 545 546 spin_lock_bh(&priv->lock); 547 hvc_iucv_send(priv); /* force sending buffered data */ 548 sync_wait = !list_empty(&priv->tty_outqueue); /* anything queued ? */ 549 spin_unlock_bh(&priv->lock); 550 551 if (sync_wait) 552 wait_event_timeout(priv->sndbuf_waitq, 553 tty_outqueue_empty(priv), HZ/10); 554 } 555 556 /** 557 * hvc_iucv_hangup() - Sever IUCV path and schedule hvc tty hang up 558 * @priv: Pointer to hvc_iucv_private structure 559 * 560 * This routine severs an existing IUCV communication path and hangs 561 * up the underlying HVC terminal device. 562 * The hang-up occurs only if an IUCV communication path is established; 563 * otherwise there is no need to hang up the terminal device. 564 * 565 * The IUCV HVC hang-up is separated into two steps: 566 * 1. After the IUCV path has been severed, the iucv_state is set to 567 * IUCV_SEVERED. 568 * 2. Later, when the HVC thread calls hvc_iucv_get_chars(), the 569 * IUCV_SEVERED state causes the tty hang-up in the HVC layer. 570 * 571 * If the tty has not yet been opened, clean up the hvc_iucv_private 572 * structure to allow re-connects. 573 * If the tty has been opened, let get_chars() return -EPIPE to signal 574 * the HVC layer to hang up the tty and, if so, wake up the HVC thread 575 * to call get_chars()... 576 * 577 * Special notes on hanging up a HVC terminal instantiated as console: 578 * Hang-up: 1. do_tty_hangup() replaces file ops (= hung_up_tty_fops) 579 * 2. do_tty_hangup() calls tty->ops->close() for console_filp 580 * => no hangup notifier is called by HVC (default) 581 * 2. hvc_close() returns because of tty_hung_up_p(filp) 582 * => no delete notifier is called! 583 * Finally, the back-end is not being notified, thus, the tty session is 584 * kept active (TTY_OPEN) to be ready for re-connects. 585 * 586 * Locking: spin_lock(&priv->lock) w/o disabling bh 587 */ 588 static void hvc_iucv_hangup(struct hvc_iucv_private *priv) 589 { 590 struct iucv_path *path; 591 592 path = NULL; 593 spin_lock(&priv->lock); 594 if (priv->iucv_state == IUCV_CONNECTED) { 595 path = priv->path; 596 priv->path = NULL; 597 priv->iucv_state = IUCV_SEVERED; 598 if (priv->tty_state == TTY_CLOSED) 599 hvc_iucv_cleanup(priv); 600 else 601 /* console is special (see above) */ 602 if (priv->is_console) { 603 hvc_iucv_cleanup(priv); 604 priv->tty_state = TTY_OPENED; 605 } else 606 hvc_kick(); 607 } 608 spin_unlock(&priv->lock); 609 610 /* finally sever path (outside of priv->lock due to lock ordering) */ 611 if (path) { 612 iucv_path_sever(path, NULL); 613 iucv_path_free(path); 614 } 615 } 616 617 /** 618 * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups. 619 * @hp: Pointer to the HVC device (struct hvc_struct) 620 * @id: Additional data (originally passed to hvc_alloc): 621 * the index of an struct hvc_iucv_private instance. 622 * 623 * This routine notifies the HVC back-end that a tty hangup (carrier loss, 624 * virtual or otherwise) has occurred. 625 * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup()) 626 * to keep an existing IUCV communication path established. 627 * (Background: vhangup() is called from user space (by getty or login) to 628 * disable writing to the tty by other applications). 629 * If the tty has been opened and an established IUCV path has been severed 630 * (we caused the tty hangup), the function calls hvc_iucv_cleanup(). 631 * 632 * Locking: struct hvc_iucv_private->lock 633 */ 634 static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id) 635 { 636 struct hvc_iucv_private *priv; 637 638 priv = hvc_iucv_get_private(id); 639 if (!priv) 640 return; 641 642 flush_sndbuf_sync(priv); 643 644 spin_lock_bh(&priv->lock); 645 /* NOTE: If the hangup was scheduled by ourself (from the iucv 646 * path_servered callback [IUCV_SEVERED]), we have to clean up 647 * our structure and to set state to TTY_CLOSED. 648 * If the tty was hung up otherwise (e.g. vhangup()), then we 649 * ignore this hangup and keep an established IUCV path open... 650 * (...the reason is that we are not able to connect back to the 651 * client if we disconnect on hang up) */ 652 priv->tty_state = TTY_CLOSED; 653 654 if (priv->iucv_state == IUCV_SEVERED) 655 hvc_iucv_cleanup(priv); 656 spin_unlock_bh(&priv->lock); 657 } 658 659 /** 660 * hvc_iucv_dtr_rts() - HVC notifier for handling DTR/RTS 661 * @hp: Pointer the HVC device (struct hvc_struct) 662 * @raise: Non-zero to raise or zero to lower DTR/RTS lines 663 * 664 * This routine notifies the HVC back-end to raise or lower DTR/RTS 665 * lines. Raising DTR/RTS is ignored. Lowering DTR/RTS indicates to 666 * drop the IUCV connection (similar to hang up the modem). 667 */ 668 static void hvc_iucv_dtr_rts(struct hvc_struct *hp, int raise) 669 { 670 struct hvc_iucv_private *priv; 671 struct iucv_path *path; 672 673 /* Raising the DTR/RTS is ignored as IUCV connections can be 674 * established at any times. 675 */ 676 if (raise) 677 return; 678 679 priv = hvc_iucv_get_private(hp->vtermno); 680 if (!priv) 681 return; 682 683 /* Lowering the DTR/RTS lines disconnects an established IUCV 684 * connection. 685 */ 686 flush_sndbuf_sync(priv); 687 688 spin_lock_bh(&priv->lock); 689 path = priv->path; /* save reference to IUCV path */ 690 priv->path = NULL; 691 priv->iucv_state = IUCV_DISCONN; 692 spin_unlock_bh(&priv->lock); 693 694 /* Sever IUCV path outside of priv->lock due to lock ordering of: 695 * priv->lock <--> iucv_table_lock */ 696 if (path) { 697 iucv_path_sever(path, NULL); 698 iucv_path_free(path); 699 } 700 } 701 702 /** 703 * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time. 704 * @hp: Pointer to the HVC device (struct hvc_struct) 705 * @id: Additional data (originally passed to hvc_alloc): 706 * the index of an struct hvc_iucv_private instance. 707 * 708 * This routine notifies the HVC back-end that the last tty device fd has been 709 * closed. The function cleans up tty resources. The clean-up of the IUCV 710 * connection is done in hvc_iucv_dtr_rts() and depends on the HUPCL termios 711 * control setting. 712 * 713 * Locking: struct hvc_iucv_private->lock 714 */ 715 static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id) 716 { 717 struct hvc_iucv_private *priv; 718 719 priv = hvc_iucv_get_private(id); 720 if (!priv) 721 return; 722 723 flush_sndbuf_sync(priv); 724 725 spin_lock_bh(&priv->lock); 726 destroy_tty_buffer_list(&priv->tty_outqueue); 727 destroy_tty_buffer_list(&priv->tty_inqueue); 728 priv->tty_state = TTY_CLOSED; 729 priv->sndbuf_len = 0; 730 spin_unlock_bh(&priv->lock); 731 } 732 733 /** 734 * hvc_iucv_filter_connreq() - Filter connection request based on z/VM user ID 735 * @ipvmid: Originating z/VM user ID (right padded with blanks) 736 * 737 * Returns 0 if the z/VM user ID that is specified with @ipvmid is permitted to 738 * connect, otherwise non-zero. 739 */ 740 static int hvc_iucv_filter_connreq(u8 ipvmid[8]) 741 { 742 const char *wildcard, *filter_entry; 743 size_t i, len; 744 745 /* Note: default policy is ACCEPT if no filter is set */ 746 if (!hvc_iucv_filter_size) 747 return 0; 748 749 for (i = 0; i < hvc_iucv_filter_size; i++) { 750 filter_entry = hvc_iucv_filter + (8 * i); 751 752 /* If a filter entry contains the filter wildcard character, 753 * reduce the length to match the leading portion of the user 754 * ID only (wildcard match). Characters following the wildcard 755 * are ignored. 756 */ 757 wildcard = strnchr(filter_entry, 8, FILTER_WILDCARD_CHAR); 758 len = (wildcard) ? wildcard - filter_entry : 8; 759 if (0 == memcmp(ipvmid, filter_entry, len)) 760 return 0; 761 } 762 return 1; 763 } 764 765 /** 766 * hvc_iucv_path_pending() - IUCV handler to process a connection request. 767 * @path: Pending path (struct iucv_path) 768 * @ipvmid: z/VM system identifier of originator 769 * @ipuser: User specified data for this path 770 * (AF_IUCV: port/service name and originator port) 771 * 772 * The function uses the @ipuser data to determine if the pending path belongs 773 * to a terminal managed by this device driver. 774 * If the path belongs to this driver, ensure that the terminal is not accessed 775 * multiple times (only one connection to a terminal is allowed). 776 * If the terminal is not yet connected, the pending path is accepted and is 777 * associated to the appropriate struct hvc_iucv_private instance. 778 * 779 * Returns 0 if @path belongs to a terminal managed by the this device driver; 780 * otherwise returns -ENODEV in order to dispatch this path to other handlers. 781 * 782 * Locking: struct hvc_iucv_private->lock 783 */ 784 static int hvc_iucv_path_pending(struct iucv_path *path, u8 *ipvmid, 785 u8 *ipuser) 786 { 787 struct hvc_iucv_private *priv, *tmp; 788 u8 wildcard[9] = "lnxhvc "; 789 int i, rc, find_unused; 790 u8 nuser_data[16]; 791 u8 vm_user_id[9]; 792 793 ASCEBC(wildcard, sizeof(wildcard)); 794 find_unused = !memcmp(wildcard, ipuser, 8); 795 796 /* First, check if the pending path request is managed by this 797 * IUCV handler: 798 * - find a disconnected device if ipuser contains the wildcard 799 * - find the device that matches the terminal ID in ipuser 800 */ 801 priv = NULL; 802 for (i = 0; i < hvc_iucv_devices; i++) { 803 tmp = hvc_iucv_table[i]; 804 if (!tmp) 805 continue; 806 807 if (find_unused) { 808 spin_lock(&tmp->lock); 809 if (tmp->iucv_state == IUCV_DISCONN) 810 priv = tmp; 811 spin_unlock(&tmp->lock); 812 813 } else if (!memcmp(tmp->srv_name, ipuser, 8)) 814 priv = tmp; 815 if (priv) 816 break; 817 } 818 if (!priv) 819 return -ENODEV; 820 821 /* Enforce that ipvmid is allowed to connect to us */ 822 read_lock(&hvc_iucv_filter_lock); 823 rc = hvc_iucv_filter_connreq(ipvmid); 824 read_unlock(&hvc_iucv_filter_lock); 825 if (rc) { 826 iucv_path_sever(path, ipuser); 827 iucv_path_free(path); 828 memcpy(vm_user_id, ipvmid, 8); 829 vm_user_id[8] = 0; 830 pr_info("A connection request from z/VM user ID %s " 831 "was refused\n", vm_user_id); 832 return 0; 833 } 834 835 spin_lock(&priv->lock); 836 837 /* If the terminal is already connected or being severed, then sever 838 * this path to enforce that there is only ONE established communication 839 * path per terminal. */ 840 if (priv->iucv_state != IUCV_DISCONN) { 841 iucv_path_sever(path, ipuser); 842 iucv_path_free(path); 843 goto out_path_handled; 844 } 845 846 /* accept path */ 847 memcpy(nuser_data, ipuser + 8, 8); /* remote service (for af_iucv) */ 848 memcpy(nuser_data + 8, ipuser, 8); /* local service (for af_iucv) */ 849 path->msglim = 0xffff; /* IUCV MSGLIMIT */ 850 path->flags &= ~IUCV_IPRMDATA; /* TODO: use IUCV_IPRMDATA */ 851 rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv); 852 if (rc) { 853 iucv_path_sever(path, ipuser); 854 iucv_path_free(path); 855 goto out_path_handled; 856 } 857 priv->path = path; 858 priv->iucv_state = IUCV_CONNECTED; 859 860 /* store path information */ 861 memcpy(priv->info_path, ipvmid, 8); 862 memcpy(priv->info_path + 8, ipuser + 8, 8); 863 864 /* flush buffered output data... */ 865 schedule_delayed_work(&priv->sndbuf_work, 5); 866 867 out_path_handled: 868 spin_unlock(&priv->lock); 869 return 0; 870 } 871 872 /** 873 * hvc_iucv_path_severed() - IUCV handler to process a path sever. 874 * @path: Pending path (struct iucv_path) 875 * @ipuser: User specified data for this path 876 * (AF_IUCV: port/service name and originator port) 877 * 878 * This function calls the hvc_iucv_hangup() function for the 879 * respective IUCV HVC terminal. 880 * 881 * Locking: struct hvc_iucv_private->lock 882 */ 883 static void hvc_iucv_path_severed(struct iucv_path *path, u8 *ipuser) 884 { 885 struct hvc_iucv_private *priv = path->private; 886 887 hvc_iucv_hangup(priv); 888 } 889 890 /** 891 * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message. 892 * @path: Pending path (struct iucv_path) 893 * @msg: Pointer to the IUCV message 894 * 895 * The function puts an incoming message on the input queue for later 896 * processing (by hvc_iucv_get_chars() / hvc_iucv_write()). 897 * If the tty has not yet been opened, the message is rejected. 898 * 899 * Locking: struct hvc_iucv_private->lock 900 */ 901 static void hvc_iucv_msg_pending(struct iucv_path *path, 902 struct iucv_message *msg) 903 { 904 struct hvc_iucv_private *priv = path->private; 905 struct iucv_tty_buffer *rb; 906 907 /* reject messages that exceed max size of iucv_tty_msg->datalen */ 908 if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) { 909 iucv_message_reject(path, msg); 910 return; 911 } 912 913 spin_lock(&priv->lock); 914 915 /* reject messages if tty has not yet been opened */ 916 if (priv->tty_state == TTY_CLOSED) { 917 iucv_message_reject(path, msg); 918 goto unlock_return; 919 } 920 921 /* allocate tty buffer to save iucv msg only */ 922 rb = alloc_tty_buffer(0, GFP_ATOMIC); 923 if (!rb) { 924 iucv_message_reject(path, msg); 925 goto unlock_return; /* -ENOMEM */ 926 } 927 rb->msg = *msg; 928 929 list_add_tail(&rb->list, &priv->tty_inqueue); 930 931 hvc_kick(); /* wake up hvc thread */ 932 933 unlock_return: 934 spin_unlock(&priv->lock); 935 } 936 937 /** 938 * hvc_iucv_msg_complete() - IUCV handler to process message completion 939 * @path: Pending path (struct iucv_path) 940 * @msg: Pointer to the IUCV message 941 * 942 * The function is called upon completion of message delivery to remove the 943 * message from the outqueue. Additional delivery information can be found 944 * msg->audit: rejected messages (0x040000 (IPADRJCT)), and 945 * purged messages (0x010000 (IPADPGNR)). 946 * 947 * Locking: struct hvc_iucv_private->lock 948 */ 949 static void hvc_iucv_msg_complete(struct iucv_path *path, 950 struct iucv_message *msg) 951 { 952 struct hvc_iucv_private *priv = path->private; 953 struct iucv_tty_buffer *ent, *next; 954 LIST_HEAD(list_remove); 955 956 spin_lock(&priv->lock); 957 list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list) 958 if (ent->msg.id == msg->id) { 959 list_move(&ent->list, &list_remove); 960 break; 961 } 962 wake_up(&priv->sndbuf_waitq); 963 spin_unlock(&priv->lock); 964 destroy_tty_buffer_list(&list_remove); 965 } 966 967 static ssize_t hvc_iucv_dev_termid_show(struct device *dev, 968 struct device_attribute *attr, 969 char *buf) 970 { 971 struct hvc_iucv_private *priv = dev_get_drvdata(dev); 972 size_t len; 973 974 len = sizeof(priv->srv_name); 975 memcpy(buf, priv->srv_name, len); 976 EBCASC(buf, len); 977 buf[len++] = '\n'; 978 return len; 979 } 980 981 static ssize_t hvc_iucv_dev_state_show(struct device *dev, 982 struct device_attribute *attr, 983 char *buf) 984 { 985 struct hvc_iucv_private *priv = dev_get_drvdata(dev); 986 return sprintf(buf, "%u:%u\n", priv->iucv_state, priv->tty_state); 987 } 988 989 static ssize_t hvc_iucv_dev_peer_show(struct device *dev, 990 struct device_attribute *attr, 991 char *buf) 992 { 993 struct hvc_iucv_private *priv = dev_get_drvdata(dev); 994 char vmid[9], ipuser[9]; 995 996 memset(vmid, 0, sizeof(vmid)); 997 memset(ipuser, 0, sizeof(ipuser)); 998 999 spin_lock_bh(&priv->lock); 1000 if (priv->iucv_state == IUCV_CONNECTED) { 1001 memcpy(vmid, priv->info_path, 8); 1002 memcpy(ipuser, priv->info_path + 8, 8); 1003 } 1004 spin_unlock_bh(&priv->lock); 1005 EBCASC(ipuser, 8); 1006 1007 return sprintf(buf, "%s:%s\n", vmid, ipuser); 1008 } 1009 1010 1011 /* HVC operations */ 1012 static const struct hv_ops hvc_iucv_ops = { 1013 .get_chars = hvc_iucv_get_chars, 1014 .put_chars = hvc_iucv_put_chars, 1015 .notifier_add = hvc_iucv_notifier_add, 1016 .notifier_del = hvc_iucv_notifier_del, 1017 .notifier_hangup = hvc_iucv_notifier_hangup, 1018 .dtr_rts = hvc_iucv_dtr_rts, 1019 }; 1020 1021 /* IUCV HVC device attributes */ 1022 static DEVICE_ATTR(termid, 0640, hvc_iucv_dev_termid_show, NULL); 1023 static DEVICE_ATTR(state, 0640, hvc_iucv_dev_state_show, NULL); 1024 static DEVICE_ATTR(peer, 0640, hvc_iucv_dev_peer_show, NULL); 1025 static struct attribute *hvc_iucv_dev_attrs[] = { 1026 &dev_attr_termid.attr, 1027 &dev_attr_state.attr, 1028 &dev_attr_peer.attr, 1029 NULL, 1030 }; 1031 static struct attribute_group hvc_iucv_dev_attr_group = { 1032 .attrs = hvc_iucv_dev_attrs, 1033 }; 1034 static const struct attribute_group *hvc_iucv_dev_attr_groups[] = { 1035 &hvc_iucv_dev_attr_group, 1036 NULL, 1037 }; 1038 1039 1040 /** 1041 * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance 1042 * @id: hvc_iucv_table index 1043 * @is_console: Flag if the instance is used as Linux console 1044 * 1045 * This function allocates a new hvc_iucv_private structure and stores 1046 * the instance in hvc_iucv_table at index @id. 1047 * Returns 0 on success; otherwise non-zero. 1048 */ 1049 static int __init hvc_iucv_alloc(int id, unsigned int is_console) 1050 { 1051 struct hvc_iucv_private *priv; 1052 char name[9]; 1053 int rc; 1054 1055 priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL); 1056 if (!priv) 1057 return -ENOMEM; 1058 1059 spin_lock_init(&priv->lock); 1060 INIT_LIST_HEAD(&priv->tty_outqueue); 1061 INIT_LIST_HEAD(&priv->tty_inqueue); 1062 INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work); 1063 init_waitqueue_head(&priv->sndbuf_waitq); 1064 1065 priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL); 1066 if (!priv->sndbuf) { 1067 kfree(priv); 1068 return -ENOMEM; 1069 } 1070 1071 /* set console flag */ 1072 priv->is_console = is_console; 1073 1074 /* allocate hvc device */ 1075 priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /* PAGE_SIZE */ 1076 HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256); 1077 if (IS_ERR(priv->hvc)) { 1078 rc = PTR_ERR(priv->hvc); 1079 goto out_error_hvc; 1080 } 1081 1082 /* notify HVC thread instead of using polling */ 1083 priv->hvc->irq_requested = 1; 1084 1085 /* setup iucv related information */ 1086 snprintf(name, 9, "lnxhvc%-2d", id); 1087 memcpy(priv->srv_name, name, 8); 1088 ASCEBC(priv->srv_name, 8); 1089 1090 /* create and setup device */ 1091 priv->dev = kzalloc(sizeof(*priv->dev), GFP_KERNEL); 1092 if (!priv->dev) { 1093 rc = -ENOMEM; 1094 goto out_error_dev; 1095 } 1096 dev_set_name(priv->dev, "hvc_iucv%d", id); 1097 dev_set_drvdata(priv->dev, priv); 1098 priv->dev->bus = &iucv_bus; 1099 priv->dev->parent = iucv_root; 1100 priv->dev->groups = hvc_iucv_dev_attr_groups; 1101 priv->dev->release = (void (*)(struct device *)) kfree; 1102 rc = device_register(priv->dev); 1103 if (rc) { 1104 put_device(priv->dev); 1105 goto out_error_dev; 1106 } 1107 1108 hvc_iucv_table[id] = priv; 1109 return 0; 1110 1111 out_error_dev: 1112 hvc_remove(priv->hvc); 1113 out_error_hvc: 1114 free_page((unsigned long) priv->sndbuf); 1115 kfree(priv); 1116 1117 return rc; 1118 } 1119 1120 /** 1121 * hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances 1122 */ 1123 static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv) 1124 { 1125 hvc_remove(priv->hvc); 1126 device_unregister(priv->dev); 1127 free_page((unsigned long) priv->sndbuf); 1128 kfree(priv); 1129 } 1130 1131 /** 1132 * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID 1133 * @filter: String containing a comma-separated list of z/VM user IDs 1134 * @dest: Location where to store the parsed z/VM user ID 1135 */ 1136 static const char *hvc_iucv_parse_filter(const char *filter, char *dest) 1137 { 1138 const char *nextdelim, *residual; 1139 size_t len; 1140 1141 nextdelim = strchr(filter, ','); 1142 if (nextdelim) { 1143 len = nextdelim - filter; 1144 residual = nextdelim + 1; 1145 } else { 1146 len = strlen(filter); 1147 residual = filter + len; 1148 } 1149 1150 if (len == 0) 1151 return ERR_PTR(-EINVAL); 1152 1153 /* check for '\n' (if called from sysfs) */ 1154 if (filter[len - 1] == '\n') 1155 len--; 1156 1157 /* prohibit filter entries containing the wildcard character only */ 1158 if (len == 1 && *filter == FILTER_WILDCARD_CHAR) 1159 return ERR_PTR(-EINVAL); 1160 1161 if (len > 8) 1162 return ERR_PTR(-EINVAL); 1163 1164 /* pad with blanks and save upper case version of user ID */ 1165 memset(dest, ' ', 8); 1166 while (len--) 1167 dest[len] = toupper(filter[len]); 1168 return residual; 1169 } 1170 1171 /** 1172 * hvc_iucv_setup_filter() - Set up z/VM user ID filter 1173 * @filter: String consisting of a comma-separated list of z/VM user IDs 1174 * 1175 * The function parses the @filter string and creates an array containing 1176 * the list of z/VM user ID filter entries. 1177 * Return code 0 means success, -EINVAL if the filter is syntactically 1178 * incorrect, -ENOMEM if there was not enough memory to allocate the 1179 * filter list array, or -ENOSPC if too many z/VM user IDs have been specified. 1180 */ 1181 static int hvc_iucv_setup_filter(const char *val) 1182 { 1183 const char *residual; 1184 int err; 1185 size_t size, count; 1186 void *array, *old_filter; 1187 1188 count = strlen(val); 1189 if (count == 0 || (count == 1 && val[0] == '\n')) { 1190 size = 0; 1191 array = NULL; 1192 goto out_replace_filter; /* clear filter */ 1193 } 1194 1195 /* count user IDs in order to allocate sufficient memory */ 1196 size = 1; 1197 residual = val; 1198 while ((residual = strchr(residual, ',')) != NULL) { 1199 residual++; 1200 size++; 1201 } 1202 1203 /* check if the specified list exceeds the filter limit */ 1204 if (size > MAX_VMID_FILTER) 1205 return -ENOSPC; 1206 1207 array = kcalloc(size, 8, GFP_KERNEL); 1208 if (!array) 1209 return -ENOMEM; 1210 1211 count = size; 1212 residual = val; 1213 while (*residual && count) { 1214 residual = hvc_iucv_parse_filter(residual, 1215 array + ((size - count) * 8)); 1216 if (IS_ERR(residual)) { 1217 err = PTR_ERR(residual); 1218 kfree(array); 1219 goto out_err; 1220 } 1221 count--; 1222 } 1223 1224 out_replace_filter: 1225 write_lock_bh(&hvc_iucv_filter_lock); 1226 old_filter = hvc_iucv_filter; 1227 hvc_iucv_filter_size = size; 1228 hvc_iucv_filter = array; 1229 write_unlock_bh(&hvc_iucv_filter_lock); 1230 kfree(old_filter); 1231 1232 err = 0; 1233 out_err: 1234 return err; 1235 } 1236 1237 /** 1238 * param_set_vmidfilter() - Set z/VM user ID filter parameter 1239 * @val: String consisting of a comma-separated list of z/VM user IDs 1240 * @kp: Kernel parameter pointing to hvc_iucv_filter array 1241 * 1242 * The function sets up the z/VM user ID filter specified as comma-separated 1243 * list of user IDs in @val. 1244 * Note: If it is called early in the boot process, @val is stored and 1245 * parsed later in hvc_iucv_init(). 1246 */ 1247 static int param_set_vmidfilter(const char *val, const struct kernel_param *kp) 1248 { 1249 int rc; 1250 1251 if (!MACHINE_IS_VM || !hvc_iucv_devices) 1252 return -ENODEV; 1253 1254 if (!val) 1255 return -EINVAL; 1256 1257 rc = 0; 1258 if (slab_is_available()) 1259 rc = hvc_iucv_setup_filter(val); 1260 else 1261 hvc_iucv_filter_string = val; /* defer... */ 1262 return rc; 1263 } 1264 1265 /** 1266 * param_get_vmidfilter() - Get z/VM user ID filter 1267 * @buffer: Buffer to store z/VM user ID filter, 1268 * (buffer size assumption PAGE_SIZE) 1269 * @kp: Kernel parameter pointing to the hvc_iucv_filter array 1270 * 1271 * The function stores the filter as a comma-separated list of z/VM user IDs 1272 * in @buffer. Typically, sysfs routines call this function for attr show. 1273 */ 1274 static int param_get_vmidfilter(char *buffer, const struct kernel_param *kp) 1275 { 1276 int rc; 1277 size_t index, len; 1278 void *start, *end; 1279 1280 if (!MACHINE_IS_VM || !hvc_iucv_devices) 1281 return -ENODEV; 1282 1283 rc = 0; 1284 read_lock_bh(&hvc_iucv_filter_lock); 1285 for (index = 0; index < hvc_iucv_filter_size; index++) { 1286 start = hvc_iucv_filter + (8 * index); 1287 end = memchr(start, ' ', 8); 1288 len = (end) ? end - start : 8; 1289 memcpy(buffer + rc, start, len); 1290 rc += len; 1291 buffer[rc++] = ','; 1292 } 1293 read_unlock_bh(&hvc_iucv_filter_lock); 1294 if (rc) 1295 buffer[--rc] = '\0'; /* replace last comma and update rc */ 1296 return rc; 1297 } 1298 1299 #define param_check_vmidfilter(name, p) __param_check(name, p, void) 1300 1301 static const struct kernel_param_ops param_ops_vmidfilter = { 1302 .set = param_set_vmidfilter, 1303 .get = param_get_vmidfilter, 1304 }; 1305 1306 /** 1307 * hvc_iucv_init() - z/VM IUCV HVC device driver initialization 1308 */ 1309 static int __init hvc_iucv_init(void) 1310 { 1311 int rc; 1312 unsigned int i; 1313 1314 if (!hvc_iucv_devices) 1315 return -ENODEV; 1316 1317 if (!MACHINE_IS_VM) { 1318 pr_notice("The z/VM IUCV HVC device driver cannot " 1319 "be used without z/VM\n"); 1320 rc = -ENODEV; 1321 goto out_error; 1322 } 1323 1324 if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) { 1325 pr_err("%lu is not a valid value for the hvc_iucv= " 1326 "kernel parameter\n", hvc_iucv_devices); 1327 rc = -EINVAL; 1328 goto out_error; 1329 } 1330 1331 /* parse hvc_iucv_allow string and create z/VM user ID filter list */ 1332 if (hvc_iucv_filter_string) { 1333 rc = hvc_iucv_setup_filter(hvc_iucv_filter_string); 1334 switch (rc) { 1335 case 0: 1336 break; 1337 case -ENOMEM: 1338 pr_err("Allocating memory failed with " 1339 "reason code=%d\n", 3); 1340 goto out_error; 1341 case -EINVAL: 1342 pr_err("hvc_iucv_allow= does not specify a valid " 1343 "z/VM user ID list\n"); 1344 goto out_error; 1345 case -ENOSPC: 1346 pr_err("hvc_iucv_allow= specifies too many " 1347 "z/VM user IDs\n"); 1348 goto out_error; 1349 default: 1350 goto out_error; 1351 } 1352 } 1353 1354 hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT, 1355 sizeof(struct iucv_tty_buffer), 1356 0, 0, NULL); 1357 if (!hvc_iucv_buffer_cache) { 1358 pr_err("Allocating memory failed with reason code=%d\n", 1); 1359 rc = -ENOMEM; 1360 goto out_error; 1361 } 1362 1363 hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR, 1364 hvc_iucv_buffer_cache); 1365 if (!hvc_iucv_mempool) { 1366 pr_err("Allocating memory failed with reason code=%d\n", 2); 1367 kmem_cache_destroy(hvc_iucv_buffer_cache); 1368 rc = -ENOMEM; 1369 goto out_error; 1370 } 1371 1372 /* register the first terminal device as console 1373 * (must be done before allocating hvc terminal devices) */ 1374 rc = hvc_instantiate(HVC_IUCV_MAGIC, IUCV_HVC_CON_IDX, &hvc_iucv_ops); 1375 if (rc) { 1376 pr_err("Registering HVC terminal device as " 1377 "Linux console failed\n"); 1378 goto out_error_memory; 1379 } 1380 1381 /* allocate hvc_iucv_private structs */ 1382 for (i = 0; i < hvc_iucv_devices; i++) { 1383 rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0); 1384 if (rc) { 1385 pr_err("Creating a new HVC terminal device " 1386 "failed with error code=%d\n", rc); 1387 goto out_error_hvc; 1388 } 1389 } 1390 1391 /* register IUCV callback handler */ 1392 rc = iucv_register(&hvc_iucv_handler, 0); 1393 if (rc) { 1394 pr_err("Registering IUCV handlers failed with error code=%d\n", 1395 rc); 1396 goto out_error_hvc; 1397 } 1398 1399 return 0; 1400 1401 out_error_hvc: 1402 for (i = 0; i < hvc_iucv_devices; i++) 1403 if (hvc_iucv_table[i]) 1404 hvc_iucv_destroy(hvc_iucv_table[i]); 1405 out_error_memory: 1406 mempool_destroy(hvc_iucv_mempool); 1407 kmem_cache_destroy(hvc_iucv_buffer_cache); 1408 out_error: 1409 kfree(hvc_iucv_filter); 1410 hvc_iucv_devices = 0; /* ensure that we do not provide any device */ 1411 return rc; 1412 } 1413 1414 /** 1415 * hvc_iucv_config() - Parsing of hvc_iucv= kernel command line parameter 1416 * @val: Parameter value (numeric) 1417 */ 1418 static int __init hvc_iucv_config(char *val) 1419 { 1420 return kstrtoul(val, 10, &hvc_iucv_devices); 1421 } 1422 1423 1424 device_initcall(hvc_iucv_init); 1425 __setup("hvc_iucv=", hvc_iucv_config); 1426 core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640); 1427