1 /* 2 * z/VM IUCV hypervisor console (HVC) device driver 3 * 4 * This HVC device driver provides terminal access using 5 * z/VM IUCV communication paths. 6 * 7 * Copyright IBM Corp. 2008, 2013 8 * 9 * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com> 10 */ 11 #define KMSG_COMPONENT "hvc_iucv" 12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 13 14 #include <linux/types.h> 15 #include <linux/slab.h> 16 #include <asm/ebcdic.h> 17 #include <linux/ctype.h> 18 #include <linux/delay.h> 19 #include <linux/device.h> 20 #include <linux/init.h> 21 #include <linux/mempool.h> 22 #include <linux/moduleparam.h> 23 #include <linux/tty.h> 24 #include <linux/wait.h> 25 #include <net/iucv/iucv.h> 26 27 #include "hvc_console.h" 28 29 30 /* General device driver settings */ 31 #define HVC_IUCV_MAGIC 0xc9e4c3e5 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_MAGIC) || (num - HVC_IUCV_MAGIC > hvc_iucv_devices)) 134 return NULL; 135 return hvc_iucv_table[num - HVC_IUCV_MAGIC]; 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 if (!priv) 441 return; 442 443 spin_lock_bh(&priv->lock); 444 hvc_iucv_send(priv); 445 spin_unlock_bh(&priv->lock); 446 } 447 448 /** 449 * hvc_iucv_put_chars() - HVC put_chars operation. 450 * @vtermno: HVC virtual terminal number. 451 * @buf: Pointer to an buffer to read data from 452 * @count: Size of buffer available for reading 453 * 454 * The HVC thread calls this method to write characters to the back-end. 455 * The function calls hvc_iucv_queue() to queue terminal data for sending. 456 * 457 * Locking: The method gets called under an irqsave() spinlock; and 458 * locks struct hvc_iucv_private->lock. 459 */ 460 static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count) 461 { 462 struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); 463 int queued; 464 465 if (count <= 0) 466 return 0; 467 468 if (!priv) 469 return -ENODEV; 470 471 spin_lock(&priv->lock); 472 queued = hvc_iucv_queue(priv, buf, count); 473 spin_unlock(&priv->lock); 474 475 return queued; 476 } 477 478 /** 479 * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time. 480 * @hp: Pointer to the HVC device (struct hvc_struct) 481 * @id: Additional data (originally passed to hvc_alloc): the index of an struct 482 * hvc_iucv_private instance. 483 * 484 * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private 485 * instance that is derived from @id. Always returns 0. 486 * 487 * Locking: struct hvc_iucv_private->lock, spin_lock_bh 488 */ 489 static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id) 490 { 491 struct hvc_iucv_private *priv; 492 493 priv = hvc_iucv_get_private(id); 494 if (!priv) 495 return 0; 496 497 spin_lock_bh(&priv->lock); 498 priv->tty_state = TTY_OPENED; 499 spin_unlock_bh(&priv->lock); 500 501 return 0; 502 } 503 504 /** 505 * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance. 506 * @priv: Pointer to the struct hvc_iucv_private instance. 507 */ 508 static void hvc_iucv_cleanup(struct hvc_iucv_private *priv) 509 { 510 destroy_tty_buffer_list(&priv->tty_outqueue); 511 destroy_tty_buffer_list(&priv->tty_inqueue); 512 513 priv->tty_state = TTY_CLOSED; 514 priv->iucv_state = IUCV_DISCONN; 515 516 priv->sndbuf_len = 0; 517 } 518 519 /** 520 * tty_outqueue_empty() - Test if the tty outq is empty 521 * @priv: Pointer to struct hvc_iucv_private instance. 522 */ 523 static inline int tty_outqueue_empty(struct hvc_iucv_private *priv) 524 { 525 int rc; 526 527 spin_lock_bh(&priv->lock); 528 rc = list_empty(&priv->tty_outqueue); 529 spin_unlock_bh(&priv->lock); 530 531 return rc; 532 } 533 534 /** 535 * flush_sndbuf_sync() - Flush send buffer and wait for completion 536 * @priv: Pointer to struct hvc_iucv_private instance. 537 * 538 * The routine cancels a pending sndbuf work, calls hvc_iucv_send() 539 * to flush any buffered terminal output data and waits for completion. 540 */ 541 static void flush_sndbuf_sync(struct hvc_iucv_private *priv) 542 { 543 int sync_wait; 544 545 cancel_delayed_work_sync(&priv->sndbuf_work); 546 547 spin_lock_bh(&priv->lock); 548 hvc_iucv_send(priv); /* force sending buffered data */ 549 sync_wait = !list_empty(&priv->tty_outqueue); /* anything queued ? */ 550 spin_unlock_bh(&priv->lock); 551 552 if (sync_wait) 553 wait_event_timeout(priv->sndbuf_waitq, 554 tty_outqueue_empty(priv), HZ/10); 555 } 556 557 /** 558 * hvc_iucv_hangup() - Sever IUCV path and schedule hvc tty hang up 559 * @priv: Pointer to hvc_iucv_private structure 560 * 561 * This routine severs an existing IUCV communication path and hangs 562 * up the underlying HVC terminal device. 563 * The hang-up occurs only if an IUCV communication path is established; 564 * otherwise there is no need to hang up the terminal device. 565 * 566 * The IUCV HVC hang-up is separated into two steps: 567 * 1. After the IUCV path has been severed, the iucv_state is set to 568 * IUCV_SEVERED. 569 * 2. Later, when the HVC thread calls hvc_iucv_get_chars(), the 570 * IUCV_SEVERED state causes the tty hang-up in the HVC layer. 571 * 572 * If the tty has not yet been opened, clean up the hvc_iucv_private 573 * structure to allow re-connects. 574 * If the tty has been opened, let get_chars() return -EPIPE to signal 575 * the HVC layer to hang up the tty and, if so, wake up the HVC thread 576 * to call get_chars()... 577 * 578 * Special notes on hanging up a HVC terminal instantiated as console: 579 * Hang-up: 1. do_tty_hangup() replaces file ops (= hung_up_tty_fops) 580 * 2. do_tty_hangup() calls tty->ops->close() for console_filp 581 * => no hangup notifier is called by HVC (default) 582 * 2. hvc_close() returns because of tty_hung_up_p(filp) 583 * => no delete notifier is called! 584 * Finally, the back-end is not being notified, thus, the tty session is 585 * kept active (TTY_OPEN) to be ready for re-connects. 586 * 587 * Locking: spin_lock(&priv->lock) w/o disabling bh 588 */ 589 static void hvc_iucv_hangup(struct hvc_iucv_private *priv) 590 { 591 struct iucv_path *path; 592 593 path = NULL; 594 spin_lock(&priv->lock); 595 if (priv->iucv_state == IUCV_CONNECTED) { 596 path = priv->path; 597 priv->path = NULL; 598 priv->iucv_state = IUCV_SEVERED; 599 if (priv->tty_state == TTY_CLOSED) 600 hvc_iucv_cleanup(priv); 601 else 602 /* console is special (see above) */ 603 if (priv->is_console) { 604 hvc_iucv_cleanup(priv); 605 priv->tty_state = TTY_OPENED; 606 } else 607 hvc_kick(); 608 } 609 spin_unlock(&priv->lock); 610 611 /* finally sever path (outside of priv->lock due to lock ordering) */ 612 if (path) { 613 iucv_path_sever(path, NULL); 614 iucv_path_free(path); 615 } 616 } 617 618 /** 619 * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups. 620 * @hp: Pointer to the HVC device (struct hvc_struct) 621 * @id: Additional data (originally passed to hvc_alloc): 622 * the index of an struct hvc_iucv_private instance. 623 * 624 * This routine notifies the HVC back-end that a tty hangup (carrier loss, 625 * virtual or otherwise) has occurred. 626 * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup()) 627 * to keep an existing IUCV communication path established. 628 * (Background: vhangup() is called from user space (by getty or login) to 629 * disable writing to the tty by other applications). 630 * If the tty has been opened and an established IUCV path has been severed 631 * (we caused the tty hangup), the function calls hvc_iucv_cleanup(). 632 * 633 * Locking: struct hvc_iucv_private->lock 634 */ 635 static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id) 636 { 637 struct hvc_iucv_private *priv; 638 639 priv = hvc_iucv_get_private(id); 640 if (!priv) 641 return; 642 643 flush_sndbuf_sync(priv); 644 645 spin_lock_bh(&priv->lock); 646 /* NOTE: If the hangup was scheduled by ourself (from the iucv 647 * path_servered callback [IUCV_SEVERED]), we have to clean up 648 * our structure and to set state to TTY_CLOSED. 649 * If the tty was hung up otherwise (e.g. vhangup()), then we 650 * ignore this hangup and keep an established IUCV path open... 651 * (...the reason is that we are not able to connect back to the 652 * client if we disconnect on hang up) */ 653 priv->tty_state = TTY_CLOSED; 654 655 if (priv->iucv_state == IUCV_SEVERED) 656 hvc_iucv_cleanup(priv); 657 spin_unlock_bh(&priv->lock); 658 } 659 660 /** 661 * hvc_iucv_dtr_rts() - HVC notifier for handling DTR/RTS 662 * @hp: Pointer the HVC device (struct hvc_struct) 663 * @raise: Non-zero to raise or zero to lower DTR/RTS lines 664 * 665 * This routine notifies the HVC back-end to raise or lower DTR/RTS 666 * lines. Raising DTR/RTS is ignored. Lowering DTR/RTS indicates to 667 * drop the IUCV connection (similar to hang up the modem). 668 */ 669 static void hvc_iucv_dtr_rts(struct hvc_struct *hp, int raise) 670 { 671 struct hvc_iucv_private *priv; 672 struct iucv_path *path; 673 674 /* Raising the DTR/RTS is ignored as IUCV connections can be 675 * established at any times. 676 */ 677 if (raise) 678 return; 679 680 priv = hvc_iucv_get_private(hp->vtermno); 681 if (!priv) 682 return; 683 684 /* Lowering the DTR/RTS lines disconnects an established IUCV 685 * connection. 686 */ 687 flush_sndbuf_sync(priv); 688 689 spin_lock_bh(&priv->lock); 690 path = priv->path; /* save reference to IUCV path */ 691 priv->path = NULL; 692 priv->iucv_state = IUCV_DISCONN; 693 spin_unlock_bh(&priv->lock); 694 695 /* Sever IUCV path outside of priv->lock due to lock ordering of: 696 * priv->lock <--> iucv_table_lock */ 697 if (path) { 698 iucv_path_sever(path, NULL); 699 iucv_path_free(path); 700 } 701 } 702 703 /** 704 * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time. 705 * @hp: Pointer to the HVC device (struct hvc_struct) 706 * @id: Additional data (originally passed to hvc_alloc): 707 * the index of an struct hvc_iucv_private instance. 708 * 709 * This routine notifies the HVC back-end that the last tty device fd has been 710 * closed. The function cleans up tty resources. The clean-up of the IUCV 711 * connection is done in hvc_iucv_dtr_rts() and depends on the HUPCL termios 712 * control setting. 713 * 714 * Locking: struct hvc_iucv_private->lock 715 */ 716 static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id) 717 { 718 struct hvc_iucv_private *priv; 719 720 priv = hvc_iucv_get_private(id); 721 if (!priv) 722 return; 723 724 flush_sndbuf_sync(priv); 725 726 spin_lock_bh(&priv->lock); 727 destroy_tty_buffer_list(&priv->tty_outqueue); 728 destroy_tty_buffer_list(&priv->tty_inqueue); 729 priv->tty_state = TTY_CLOSED; 730 priv->sndbuf_len = 0; 731 spin_unlock_bh(&priv->lock); 732 } 733 734 /** 735 * hvc_iucv_filter_connreq() - Filter connection request based on z/VM user ID 736 * @ipvmid: Originating z/VM user ID (right padded with blanks) 737 * 738 * Returns 0 if the z/VM user ID that is specified with @ipvmid is permitted to 739 * connect, otherwise non-zero. 740 */ 741 static int hvc_iucv_filter_connreq(u8 ipvmid[8]) 742 { 743 const char *wildcard, *filter_entry; 744 size_t i, len; 745 746 /* Note: default policy is ACCEPT if no filter is set */ 747 if (!hvc_iucv_filter_size) 748 return 0; 749 750 for (i = 0; i < hvc_iucv_filter_size; i++) { 751 filter_entry = hvc_iucv_filter + (8 * i); 752 753 /* If a filter entry contains the filter wildcard character, 754 * reduce the length to match the leading portion of the user 755 * ID only (wildcard match). Characters following the wildcard 756 * are ignored. 757 */ 758 wildcard = strnchr(filter_entry, 8, FILTER_WILDCARD_CHAR); 759 len = (wildcard) ? wildcard - filter_entry : 8; 760 if (0 == memcmp(ipvmid, filter_entry, len)) 761 return 0; 762 } 763 return 1; 764 } 765 766 /** 767 * hvc_iucv_path_pending() - IUCV handler to process a connection request. 768 * @path: Pending path (struct iucv_path) 769 * @ipvmid: z/VM system identifier of originator 770 * @ipuser: User specified data for this path 771 * (AF_IUCV: port/service name and originator port) 772 * 773 * The function uses the @ipuser data to determine if the pending path belongs 774 * to a terminal managed by this device driver. 775 * If the path belongs to this driver, ensure that the terminal is not accessed 776 * multiple times (only one connection to a terminal is allowed). 777 * If the terminal is not yet connected, the pending path is accepted and is 778 * associated to the appropriate struct hvc_iucv_private instance. 779 * 780 * Returns 0 if @path belongs to a terminal managed by the this device driver; 781 * otherwise returns -ENODEV in order to dispatch this path to other handlers. 782 * 783 * Locking: struct hvc_iucv_private->lock 784 */ 785 static int hvc_iucv_path_pending(struct iucv_path *path, u8 *ipvmid, 786 u8 *ipuser) 787 { 788 struct hvc_iucv_private *priv, *tmp; 789 u8 wildcard[9] = "lnxhvc "; 790 int i, rc, find_unused; 791 u8 nuser_data[16]; 792 u8 vm_user_id[9]; 793 794 ASCEBC(wildcard, sizeof(wildcard)); 795 find_unused = !memcmp(wildcard, ipuser, 8); 796 797 /* First, check if the pending path request is managed by this 798 * IUCV handler: 799 * - find a disconnected device if ipuser contains the wildcard 800 * - find the device that matches the terminal ID in ipuser 801 */ 802 priv = NULL; 803 for (i = 0; i < hvc_iucv_devices; i++) { 804 tmp = hvc_iucv_table[i]; 805 if (!tmp) 806 continue; 807 808 if (find_unused) { 809 spin_lock(&tmp->lock); 810 if (tmp->iucv_state == IUCV_DISCONN) 811 priv = tmp; 812 spin_unlock(&tmp->lock); 813 814 } else if (!memcmp(tmp->srv_name, ipuser, 8)) 815 priv = tmp; 816 if (priv) 817 break; 818 } 819 if (!priv) 820 return -ENODEV; 821 822 /* Enforce that ipvmid is allowed to connect to us */ 823 read_lock(&hvc_iucv_filter_lock); 824 rc = hvc_iucv_filter_connreq(ipvmid); 825 read_unlock(&hvc_iucv_filter_lock); 826 if (rc) { 827 iucv_path_sever(path, ipuser); 828 iucv_path_free(path); 829 memcpy(vm_user_id, ipvmid, 8); 830 vm_user_id[8] = 0; 831 pr_info("A connection request from z/VM user ID %s " 832 "was refused\n", vm_user_id); 833 return 0; 834 } 835 836 spin_lock(&priv->lock); 837 838 /* If the terminal is already connected or being severed, then sever 839 * this path to enforce that there is only ONE established communication 840 * path per terminal. */ 841 if (priv->iucv_state != IUCV_DISCONN) { 842 iucv_path_sever(path, ipuser); 843 iucv_path_free(path); 844 goto out_path_handled; 845 } 846 847 /* accept path */ 848 memcpy(nuser_data, ipuser + 8, 8); /* remote service (for af_iucv) */ 849 memcpy(nuser_data + 8, ipuser, 8); /* local service (for af_iucv) */ 850 path->msglim = 0xffff; /* IUCV MSGLIMIT */ 851 path->flags &= ~IUCV_IPRMDATA; /* TODO: use IUCV_IPRMDATA */ 852 rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv); 853 if (rc) { 854 iucv_path_sever(path, ipuser); 855 iucv_path_free(path); 856 goto out_path_handled; 857 } 858 priv->path = path; 859 priv->iucv_state = IUCV_CONNECTED; 860 861 /* store path information */ 862 memcpy(priv->info_path, ipvmid, 8); 863 memcpy(priv->info_path + 8, ipuser + 8, 8); 864 865 /* flush buffered output data... */ 866 schedule_delayed_work(&priv->sndbuf_work, 5); 867 868 out_path_handled: 869 spin_unlock(&priv->lock); 870 return 0; 871 } 872 873 /** 874 * hvc_iucv_path_severed() - IUCV handler to process a path sever. 875 * @path: Pending path (struct iucv_path) 876 * @ipuser: User specified data for this path 877 * (AF_IUCV: port/service name and originator port) 878 * 879 * This function calls the hvc_iucv_hangup() function for the 880 * respective IUCV HVC terminal. 881 * 882 * Locking: struct hvc_iucv_private->lock 883 */ 884 static void hvc_iucv_path_severed(struct iucv_path *path, u8 *ipuser) 885 { 886 struct hvc_iucv_private *priv = path->private; 887 888 hvc_iucv_hangup(priv); 889 } 890 891 /** 892 * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message. 893 * @path: Pending path (struct iucv_path) 894 * @msg: Pointer to the IUCV message 895 * 896 * The function puts an incoming message on the input queue for later 897 * processing (by hvc_iucv_get_chars() / hvc_iucv_write()). 898 * If the tty has not yet been opened, the message is rejected. 899 * 900 * Locking: struct hvc_iucv_private->lock 901 */ 902 static void hvc_iucv_msg_pending(struct iucv_path *path, 903 struct iucv_message *msg) 904 { 905 struct hvc_iucv_private *priv = path->private; 906 struct iucv_tty_buffer *rb; 907 908 /* reject messages that exceed max size of iucv_tty_msg->datalen */ 909 if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) { 910 iucv_message_reject(path, msg); 911 return; 912 } 913 914 spin_lock(&priv->lock); 915 916 /* reject messages if tty has not yet been opened */ 917 if (priv->tty_state == TTY_CLOSED) { 918 iucv_message_reject(path, msg); 919 goto unlock_return; 920 } 921 922 /* allocate tty buffer to save iucv msg only */ 923 rb = alloc_tty_buffer(0, GFP_ATOMIC); 924 if (!rb) { 925 iucv_message_reject(path, msg); 926 goto unlock_return; /* -ENOMEM */ 927 } 928 rb->msg = *msg; 929 930 list_add_tail(&rb->list, &priv->tty_inqueue); 931 932 hvc_kick(); /* wake up hvc thread */ 933 934 unlock_return: 935 spin_unlock(&priv->lock); 936 } 937 938 /** 939 * hvc_iucv_msg_complete() - IUCV handler to process message completion 940 * @path: Pending path (struct iucv_path) 941 * @msg: Pointer to the IUCV message 942 * 943 * The function is called upon completion of message delivery to remove the 944 * message from the outqueue. Additional delivery information can be found 945 * msg->audit: rejected messages (0x040000 (IPADRJCT)), and 946 * purged messages (0x010000 (IPADPGNR)). 947 * 948 * Locking: struct hvc_iucv_private->lock 949 */ 950 static void hvc_iucv_msg_complete(struct iucv_path *path, 951 struct iucv_message *msg) 952 { 953 struct hvc_iucv_private *priv = path->private; 954 struct iucv_tty_buffer *ent, *next; 955 LIST_HEAD(list_remove); 956 957 spin_lock(&priv->lock); 958 list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list) 959 if (ent->msg.id == msg->id) { 960 list_move(&ent->list, &list_remove); 961 break; 962 } 963 wake_up(&priv->sndbuf_waitq); 964 spin_unlock(&priv->lock); 965 destroy_tty_buffer_list(&list_remove); 966 } 967 968 /** 969 * hvc_iucv_pm_freeze() - Freeze PM callback 970 * @dev: IUVC HVC terminal device 971 * 972 * Sever an established IUCV communication path and 973 * trigger a hang-up of the underlying HVC terminal. 974 */ 975 static int hvc_iucv_pm_freeze(struct device *dev) 976 { 977 struct hvc_iucv_private *priv = dev_get_drvdata(dev); 978 979 local_bh_disable(); 980 hvc_iucv_hangup(priv); 981 local_bh_enable(); 982 983 return 0; 984 } 985 986 /** 987 * hvc_iucv_pm_restore_thaw() - Thaw and restore PM callback 988 * @dev: IUVC HVC terminal device 989 * 990 * Wake up the HVC thread to trigger hang-up and respective 991 * HVC back-end notifier invocations. 992 */ 993 static int hvc_iucv_pm_restore_thaw(struct device *dev) 994 { 995 hvc_kick(); 996 return 0; 997 } 998 999 static ssize_t hvc_iucv_dev_termid_show(struct device *dev, 1000 struct device_attribute *attr, 1001 char *buf) 1002 { 1003 struct hvc_iucv_private *priv = dev_get_drvdata(dev); 1004 size_t len; 1005 1006 len = sizeof(priv->srv_name); 1007 memcpy(buf, priv->srv_name, len); 1008 EBCASC(buf, len); 1009 buf[len++] = '\n'; 1010 return len; 1011 } 1012 1013 static ssize_t hvc_iucv_dev_state_show(struct device *dev, 1014 struct device_attribute *attr, 1015 char *buf) 1016 { 1017 struct hvc_iucv_private *priv = dev_get_drvdata(dev); 1018 return sprintf(buf, "%u:%u\n", priv->iucv_state, priv->tty_state); 1019 } 1020 1021 static ssize_t hvc_iucv_dev_peer_show(struct device *dev, 1022 struct device_attribute *attr, 1023 char *buf) 1024 { 1025 struct hvc_iucv_private *priv = dev_get_drvdata(dev); 1026 char vmid[9], ipuser[9]; 1027 1028 memset(vmid, 0, sizeof(vmid)); 1029 memset(ipuser, 0, sizeof(ipuser)); 1030 1031 spin_lock_bh(&priv->lock); 1032 if (priv->iucv_state == IUCV_CONNECTED) { 1033 memcpy(vmid, priv->info_path, 8); 1034 memcpy(ipuser, priv->info_path + 8, 8); 1035 } 1036 spin_unlock_bh(&priv->lock); 1037 EBCASC(ipuser, 8); 1038 1039 return sprintf(buf, "%s:%s\n", vmid, ipuser); 1040 } 1041 1042 1043 /* HVC operations */ 1044 static const struct hv_ops hvc_iucv_ops = { 1045 .get_chars = hvc_iucv_get_chars, 1046 .put_chars = hvc_iucv_put_chars, 1047 .notifier_add = hvc_iucv_notifier_add, 1048 .notifier_del = hvc_iucv_notifier_del, 1049 .notifier_hangup = hvc_iucv_notifier_hangup, 1050 .dtr_rts = hvc_iucv_dtr_rts, 1051 }; 1052 1053 /* Suspend / resume device operations */ 1054 static const struct dev_pm_ops hvc_iucv_pm_ops = { 1055 .freeze = hvc_iucv_pm_freeze, 1056 .thaw = hvc_iucv_pm_restore_thaw, 1057 .restore = hvc_iucv_pm_restore_thaw, 1058 }; 1059 1060 /* IUCV HVC device driver */ 1061 static struct device_driver hvc_iucv_driver = { 1062 .name = KMSG_COMPONENT, 1063 .bus = &iucv_bus, 1064 .pm = &hvc_iucv_pm_ops, 1065 }; 1066 1067 /* IUCV HVC device attributes */ 1068 static DEVICE_ATTR(termid, 0640, hvc_iucv_dev_termid_show, NULL); 1069 static DEVICE_ATTR(state, 0640, hvc_iucv_dev_state_show, NULL); 1070 static DEVICE_ATTR(peer, 0640, hvc_iucv_dev_peer_show, NULL); 1071 static struct attribute *hvc_iucv_dev_attrs[] = { 1072 &dev_attr_termid.attr, 1073 &dev_attr_state.attr, 1074 &dev_attr_peer.attr, 1075 NULL, 1076 }; 1077 static struct attribute_group hvc_iucv_dev_attr_group = { 1078 .attrs = hvc_iucv_dev_attrs, 1079 }; 1080 static const struct attribute_group *hvc_iucv_dev_attr_groups[] = { 1081 &hvc_iucv_dev_attr_group, 1082 NULL, 1083 }; 1084 1085 1086 /** 1087 * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance 1088 * @id: hvc_iucv_table index 1089 * @is_console: Flag if the instance is used as Linux console 1090 * 1091 * This function allocates a new hvc_iucv_private structure and stores 1092 * the instance in hvc_iucv_table at index @id. 1093 * Returns 0 on success; otherwise non-zero. 1094 */ 1095 static int __init hvc_iucv_alloc(int id, unsigned int is_console) 1096 { 1097 struct hvc_iucv_private *priv; 1098 char name[9]; 1099 int rc; 1100 1101 priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL); 1102 if (!priv) 1103 return -ENOMEM; 1104 1105 spin_lock_init(&priv->lock); 1106 INIT_LIST_HEAD(&priv->tty_outqueue); 1107 INIT_LIST_HEAD(&priv->tty_inqueue); 1108 INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work); 1109 init_waitqueue_head(&priv->sndbuf_waitq); 1110 1111 priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL); 1112 if (!priv->sndbuf) { 1113 kfree(priv); 1114 return -ENOMEM; 1115 } 1116 1117 /* set console flag */ 1118 priv->is_console = is_console; 1119 1120 /* allocate hvc device */ 1121 priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /* PAGE_SIZE */ 1122 HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256); 1123 if (IS_ERR(priv->hvc)) { 1124 rc = PTR_ERR(priv->hvc); 1125 goto out_error_hvc; 1126 } 1127 1128 /* notify HVC thread instead of using polling */ 1129 priv->hvc->irq_requested = 1; 1130 1131 /* setup iucv related information */ 1132 snprintf(name, 9, "lnxhvc%-2d", id); 1133 memcpy(priv->srv_name, name, 8); 1134 ASCEBC(priv->srv_name, 8); 1135 1136 /* create and setup device */ 1137 priv->dev = kzalloc(sizeof(*priv->dev), GFP_KERNEL); 1138 if (!priv->dev) { 1139 rc = -ENOMEM; 1140 goto out_error_dev; 1141 } 1142 dev_set_name(priv->dev, "hvc_iucv%d", id); 1143 dev_set_drvdata(priv->dev, priv); 1144 priv->dev->bus = &iucv_bus; 1145 priv->dev->parent = iucv_root; 1146 priv->dev->driver = &hvc_iucv_driver; 1147 priv->dev->groups = hvc_iucv_dev_attr_groups; 1148 priv->dev->release = (void (*)(struct device *)) kfree; 1149 rc = device_register(priv->dev); 1150 if (rc) { 1151 put_device(priv->dev); 1152 goto out_error_dev; 1153 } 1154 1155 hvc_iucv_table[id] = priv; 1156 return 0; 1157 1158 out_error_dev: 1159 hvc_remove(priv->hvc); 1160 out_error_hvc: 1161 free_page((unsigned long) priv->sndbuf); 1162 kfree(priv); 1163 1164 return rc; 1165 } 1166 1167 /** 1168 * hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances 1169 */ 1170 static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv) 1171 { 1172 hvc_remove(priv->hvc); 1173 device_unregister(priv->dev); 1174 free_page((unsigned long) priv->sndbuf); 1175 kfree(priv); 1176 } 1177 1178 /** 1179 * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID 1180 * @filter: String containing a comma-separated list of z/VM user IDs 1181 * @dest: Location where to store the parsed z/VM user ID 1182 */ 1183 static const char *hvc_iucv_parse_filter(const char *filter, char *dest) 1184 { 1185 const char *nextdelim, *residual; 1186 size_t len; 1187 1188 nextdelim = strchr(filter, ','); 1189 if (nextdelim) { 1190 len = nextdelim - filter; 1191 residual = nextdelim + 1; 1192 } else { 1193 len = strlen(filter); 1194 residual = filter + len; 1195 } 1196 1197 if (len == 0) 1198 return ERR_PTR(-EINVAL); 1199 1200 /* check for '\n' (if called from sysfs) */ 1201 if (filter[len - 1] == '\n') 1202 len--; 1203 1204 /* prohibit filter entries containing the wildcard character only */ 1205 if (len == 1 && *filter == FILTER_WILDCARD_CHAR) 1206 return ERR_PTR(-EINVAL); 1207 1208 if (len > 8) 1209 return ERR_PTR(-EINVAL); 1210 1211 /* pad with blanks and save upper case version of user ID */ 1212 memset(dest, ' ', 8); 1213 while (len--) 1214 dest[len] = toupper(filter[len]); 1215 return residual; 1216 } 1217 1218 /** 1219 * hvc_iucv_setup_filter() - Set up z/VM user ID filter 1220 * @filter: String consisting of a comma-separated list of z/VM user IDs 1221 * 1222 * The function parses the @filter string and creates an array containing 1223 * the list of z/VM user ID filter entries. 1224 * Return code 0 means success, -EINVAL if the filter is syntactically 1225 * incorrect, -ENOMEM if there was not enough memory to allocate the 1226 * filter list array, or -ENOSPC if too many z/VM user IDs have been specified. 1227 */ 1228 static int hvc_iucv_setup_filter(const char *val) 1229 { 1230 const char *residual; 1231 int err; 1232 size_t size, count; 1233 void *array, *old_filter; 1234 1235 count = strlen(val); 1236 if (count == 0 || (count == 1 && val[0] == '\n')) { 1237 size = 0; 1238 array = NULL; 1239 goto out_replace_filter; /* clear filter */ 1240 } 1241 1242 /* count user IDs in order to allocate sufficient memory */ 1243 size = 1; 1244 residual = val; 1245 while ((residual = strchr(residual, ',')) != NULL) { 1246 residual++; 1247 size++; 1248 } 1249 1250 /* check if the specified list exceeds the filter limit */ 1251 if (size > MAX_VMID_FILTER) 1252 return -ENOSPC; 1253 1254 array = kzalloc(size * 8, GFP_KERNEL); 1255 if (!array) 1256 return -ENOMEM; 1257 1258 count = size; 1259 residual = val; 1260 while (*residual && count) { 1261 residual = hvc_iucv_parse_filter(residual, 1262 array + ((size - count) * 8)); 1263 if (IS_ERR(residual)) { 1264 err = PTR_ERR(residual); 1265 kfree(array); 1266 goto out_err; 1267 } 1268 count--; 1269 } 1270 1271 out_replace_filter: 1272 write_lock_bh(&hvc_iucv_filter_lock); 1273 old_filter = hvc_iucv_filter; 1274 hvc_iucv_filter_size = size; 1275 hvc_iucv_filter = array; 1276 write_unlock_bh(&hvc_iucv_filter_lock); 1277 kfree(old_filter); 1278 1279 err = 0; 1280 out_err: 1281 return err; 1282 } 1283 1284 /** 1285 * param_set_vmidfilter() - Set z/VM user ID filter parameter 1286 * @val: String consisting of a comma-separated list of z/VM user IDs 1287 * @kp: Kernel parameter pointing to hvc_iucv_filter array 1288 * 1289 * The function sets up the z/VM user ID filter specified as comma-separated 1290 * list of user IDs in @val. 1291 * Note: If it is called early in the boot process, @val is stored and 1292 * parsed later in hvc_iucv_init(). 1293 */ 1294 static int param_set_vmidfilter(const char *val, const struct kernel_param *kp) 1295 { 1296 int rc; 1297 1298 if (!MACHINE_IS_VM || !hvc_iucv_devices) 1299 return -ENODEV; 1300 1301 if (!val) 1302 return -EINVAL; 1303 1304 rc = 0; 1305 if (slab_is_available()) 1306 rc = hvc_iucv_setup_filter(val); 1307 else 1308 hvc_iucv_filter_string = val; /* defer... */ 1309 return rc; 1310 } 1311 1312 /** 1313 * param_get_vmidfilter() - Get z/VM user ID filter 1314 * @buffer: Buffer to store z/VM user ID filter, 1315 * (buffer size assumption PAGE_SIZE) 1316 * @kp: Kernel parameter pointing to the hvc_iucv_filter array 1317 * 1318 * The function stores the filter as a comma-separated list of z/VM user IDs 1319 * in @buffer. Typically, sysfs routines call this function for attr show. 1320 */ 1321 static int param_get_vmidfilter(char *buffer, const struct kernel_param *kp) 1322 { 1323 int rc; 1324 size_t index, len; 1325 void *start, *end; 1326 1327 if (!MACHINE_IS_VM || !hvc_iucv_devices) 1328 return -ENODEV; 1329 1330 rc = 0; 1331 read_lock_bh(&hvc_iucv_filter_lock); 1332 for (index = 0; index < hvc_iucv_filter_size; index++) { 1333 start = hvc_iucv_filter + (8 * index); 1334 end = memchr(start, ' ', 8); 1335 len = (end) ? end - start : 8; 1336 memcpy(buffer + rc, start, len); 1337 rc += len; 1338 buffer[rc++] = ','; 1339 } 1340 read_unlock_bh(&hvc_iucv_filter_lock); 1341 if (rc) 1342 buffer[--rc] = '\0'; /* replace last comma and update rc */ 1343 return rc; 1344 } 1345 1346 #define param_check_vmidfilter(name, p) __param_check(name, p, void) 1347 1348 static const struct kernel_param_ops param_ops_vmidfilter = { 1349 .set = param_set_vmidfilter, 1350 .get = param_get_vmidfilter, 1351 }; 1352 1353 /** 1354 * hvc_iucv_init() - z/VM IUCV HVC device driver initialization 1355 */ 1356 static int __init hvc_iucv_init(void) 1357 { 1358 int rc; 1359 unsigned int i; 1360 1361 if (!hvc_iucv_devices) 1362 return -ENODEV; 1363 1364 if (!MACHINE_IS_VM) { 1365 pr_notice("The z/VM IUCV HVC device driver cannot " 1366 "be used without z/VM\n"); 1367 rc = -ENODEV; 1368 goto out_error; 1369 } 1370 1371 if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) { 1372 pr_err("%lu is not a valid value for the hvc_iucv= " 1373 "kernel parameter\n", hvc_iucv_devices); 1374 rc = -EINVAL; 1375 goto out_error; 1376 } 1377 1378 /* register IUCV HVC device driver */ 1379 rc = driver_register(&hvc_iucv_driver); 1380 if (rc) 1381 goto out_error; 1382 1383 /* parse hvc_iucv_allow string and create z/VM user ID filter list */ 1384 if (hvc_iucv_filter_string) { 1385 rc = hvc_iucv_setup_filter(hvc_iucv_filter_string); 1386 switch (rc) { 1387 case 0: 1388 break; 1389 case -ENOMEM: 1390 pr_err("Allocating memory failed with " 1391 "reason code=%d\n", 3); 1392 goto out_error; 1393 case -EINVAL: 1394 pr_err("hvc_iucv_allow= does not specify a valid " 1395 "z/VM user ID list\n"); 1396 goto out_error; 1397 case -ENOSPC: 1398 pr_err("hvc_iucv_allow= specifies too many " 1399 "z/VM user IDs\n"); 1400 goto out_error; 1401 default: 1402 goto out_error; 1403 } 1404 } 1405 1406 hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT, 1407 sizeof(struct iucv_tty_buffer), 1408 0, 0, NULL); 1409 if (!hvc_iucv_buffer_cache) { 1410 pr_err("Allocating memory failed with reason code=%d\n", 1); 1411 rc = -ENOMEM; 1412 goto out_error; 1413 } 1414 1415 hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR, 1416 hvc_iucv_buffer_cache); 1417 if (!hvc_iucv_mempool) { 1418 pr_err("Allocating memory failed with reason code=%d\n", 2); 1419 kmem_cache_destroy(hvc_iucv_buffer_cache); 1420 rc = -ENOMEM; 1421 goto out_error; 1422 } 1423 1424 /* register the first terminal device as console 1425 * (must be done before allocating hvc terminal devices) */ 1426 rc = hvc_instantiate(HVC_IUCV_MAGIC, IUCV_HVC_CON_IDX, &hvc_iucv_ops); 1427 if (rc) { 1428 pr_err("Registering HVC terminal device as " 1429 "Linux console failed\n"); 1430 goto out_error_memory; 1431 } 1432 1433 /* allocate hvc_iucv_private structs */ 1434 for (i = 0; i < hvc_iucv_devices; i++) { 1435 rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0); 1436 if (rc) { 1437 pr_err("Creating a new HVC terminal device " 1438 "failed with error code=%d\n", rc); 1439 goto out_error_hvc; 1440 } 1441 } 1442 1443 /* register IUCV callback handler */ 1444 rc = iucv_register(&hvc_iucv_handler, 0); 1445 if (rc) { 1446 pr_err("Registering IUCV handlers failed with error code=%d\n", 1447 rc); 1448 goto out_error_hvc; 1449 } 1450 1451 return 0; 1452 1453 out_error_hvc: 1454 for (i = 0; i < hvc_iucv_devices; i++) 1455 if (hvc_iucv_table[i]) 1456 hvc_iucv_destroy(hvc_iucv_table[i]); 1457 out_error_memory: 1458 mempool_destroy(hvc_iucv_mempool); 1459 kmem_cache_destroy(hvc_iucv_buffer_cache); 1460 out_error: 1461 kfree(hvc_iucv_filter); 1462 hvc_iucv_devices = 0; /* ensure that we do not provide any device */ 1463 return rc; 1464 } 1465 1466 /** 1467 * hvc_iucv_config() - Parsing of hvc_iucv= kernel command line parameter 1468 * @val: Parameter value (numeric) 1469 */ 1470 static int __init hvc_iucv_config(char *val) 1471 { 1472 return kstrtoul(val, 10, &hvc_iucv_devices); 1473 } 1474 1475 1476 device_initcall(hvc_iucv_init); 1477 __setup("hvc_iucv=", hvc_iucv_config); 1478 core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640); 1479