1/* 2 * hvc_iucv.c - 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, 2009 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 43struct 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 52enum iucv_state_t { 53 IUCV_DISCONN = 0, 54 IUCV_CONNECTED = 1, 55 IUCV_SEVERED = 2, 56}; 57 58enum tty_state_t { 59 TTY_CLOSED = 0, 60 TTY_OPENED = 1, 61}; 62 63struct 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 83struct 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 */ 91static int hvc_iucv_path_pending(struct iucv_path *, u8[8], u8[16]); 92static void hvc_iucv_path_severed(struct iucv_path *, u8[16]); 93static void hvc_iucv_msg_pending(struct iucv_path *, struct iucv_message *); 94static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *); 95 96 97/* Kernel module parameter: use one terminal device as default */ 98static unsigned long hvc_iucv_devices = 1; 99 100/* Array of allocated hvc iucv tty lines... */ 101static 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) 105static size_t hvc_iucv_filter_size; 106static void *hvc_iucv_filter; 107static const char *hvc_iucv_filter_string; 108static DEFINE_RWLOCK(hvc_iucv_filter_lock); 109 110/* Kmem cache and mempool for iucv_tty_buffer elements */ 111static struct kmem_cache *hvc_iucv_buffer_cache; 112static mempool_t *hvc_iucv_mempool; 113 114/* IUCV handler callback functions */ 115static struct iucv_handler hvc_iucv_handler = { 116 .path_pending = hvc_iucv_path_pending, 117 .path_severed = hvc_iucv_path_severed, 118 .message_complete = hvc_iucv_msg_complete, 119 .message_pending = hvc_iucv_msg_pending, 120}; 121 122 123/** 124 * hvc_iucv_get_private() - Return a struct hvc_iucv_private instance. 125 * @num: The HVC virtual terminal number (vtermno) 126 * 127 * This function returns the struct hvc_iucv_private instance that corresponds 128 * to the HVC virtual terminal number specified as parameter @num. 129 */ 130static struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num) 131{ 132 if ((num < HVC_IUCV_MAGIC) || (num - HVC_IUCV_MAGIC > hvc_iucv_devices)) 133 return NULL; 134 return hvc_iucv_table[num - HVC_IUCV_MAGIC]; 135} 136 137/** 138 * alloc_tty_buffer() - Return a new struct iucv_tty_buffer element. 139 * @size: Size of the internal buffer used to store data. 140 * @flags: Memory allocation flags passed to mempool. 141 * 142 * This function allocates a new struct iucv_tty_buffer element and, optionally, 143 * allocates an internal data buffer with the specified size @size. 144 * The internal data buffer is always allocated with GFP_DMA which is 145 * required for receiving and sending data with IUCV. 146 * Note: The total message size arises from the internal buffer size and the 147 * members of the iucv_tty_msg structure. 148 * The function returns NULL if memory allocation has failed. 149 */ 150static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags) 151{ 152 struct iucv_tty_buffer *bufp; 153 154 bufp = mempool_alloc(hvc_iucv_mempool, flags); 155 if (!bufp) 156 return NULL; 157 memset(bufp, 0, sizeof(*bufp)); 158 159 if (size > 0) { 160 bufp->msg.length = MSG_SIZE(size); 161 bufp->mbuf = kmalloc(bufp->msg.length, flags | GFP_DMA); 162 if (!bufp->mbuf) { 163 mempool_free(bufp, hvc_iucv_mempool); 164 return NULL; 165 } 166 bufp->mbuf->version = MSG_VERSION; 167 bufp->mbuf->type = MSG_TYPE_DATA; 168 bufp->mbuf->datalen = (u16) size; 169 } 170 return bufp; 171} 172 173/** 174 * destroy_tty_buffer() - destroy struct iucv_tty_buffer element. 175 * @bufp: Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL. 176 */ 177static void destroy_tty_buffer(struct iucv_tty_buffer *bufp) 178{ 179 kfree(bufp->mbuf); 180 mempool_free(bufp, hvc_iucv_mempool); 181} 182 183/** 184 * destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element. 185 * @list: List containing struct iucv_tty_buffer elements. 186 */ 187static void destroy_tty_buffer_list(struct list_head *list) 188{ 189 struct iucv_tty_buffer *ent, *next; 190 191 list_for_each_entry_safe(ent, next, list, list) { 192 list_del(&ent->list); 193 destroy_tty_buffer(ent); 194 } 195} 196 197/** 198 * hvc_iucv_write() - Receive IUCV message & write data to HVC buffer. 199 * @priv: Pointer to struct hvc_iucv_private 200 * @buf: HVC buffer for writing received terminal data. 201 * @count: HVC buffer size. 202 * @has_more_data: Pointer to an int variable. 203 * 204 * The function picks up pending messages from the input queue and receives 205 * the message data that is then written to the specified buffer @buf. 206 * If the buffer size @count is less than the data message size, the 207 * message is kept on the input queue and @has_more_data is set to 1. 208 * If all message data has been written, the message is removed from 209 * the input queue. 210 * 211 * The function returns the number of bytes written to the terminal, zero if 212 * there are no pending data messages available or if there is no established 213 * IUCV path. 214 * If the IUCV path has been severed, then -EPIPE is returned to cause a 215 * hang up (that is issued by the HVC layer). 216 */ 217static int hvc_iucv_write(struct hvc_iucv_private *priv, 218 char *buf, int count, int *has_more_data) 219{ 220 struct iucv_tty_buffer *rb; 221 int written; 222 int rc; 223 224 /* immediately return if there is no IUCV connection */ 225 if (priv->iucv_state == IUCV_DISCONN) 226 return 0; 227 228 /* if the IUCV path has been severed, return -EPIPE to inform the 229 * HVC layer to hang up the tty device. */ 230 if (priv->iucv_state == IUCV_SEVERED) 231 return -EPIPE; 232 233 /* check if there are pending messages */ 234 if (list_empty(&priv->tty_inqueue)) 235 return 0; 236 237 /* receive an iucv message and flip data to the tty (ldisc) */ 238 rb = list_first_entry(&priv->tty_inqueue, struct iucv_tty_buffer, list); 239 240 written = 0; 241 if (!rb->mbuf) { /* message not yet received ... */ 242 /* allocate mem to store msg data; if no memory is available 243 * then leave the buffer on the list and re-try later */ 244 rb->mbuf = kmalloc(rb->msg.length, GFP_ATOMIC | GFP_DMA); 245 if (!rb->mbuf) 246 return -ENOMEM; 247 248 rc = __iucv_message_receive(priv->path, &rb->msg, 0, 249 rb->mbuf, rb->msg.length, NULL); 250 switch (rc) { 251 case 0: /* Successful */ 252 break; 253 case 2: /* No message found */ 254 case 9: /* Message purged */ 255 break; 256 default: 257 written = -EIO; 258 } 259 /* remove buffer if an error has occurred or received data 260 * is not correct */ 261 if (rc || (rb->mbuf->version != MSG_VERSION) || 262 (rb->msg.length != MSG_SIZE(rb->mbuf->datalen))) 263 goto out_remove_buffer; 264 } 265 266 switch (rb->mbuf->type) { 267 case MSG_TYPE_DATA: 268 written = min_t(int, rb->mbuf->datalen - rb->offset, count); 269 memcpy(buf, rb->mbuf->data + rb->offset, written); 270 if (written < (rb->mbuf->datalen - rb->offset)) { 271 rb->offset += written; 272 *has_more_data = 1; 273 goto out_written; 274 } 275 break; 276 277 case MSG_TYPE_WINSIZE: 278 if (rb->mbuf->datalen != sizeof(struct winsize)) 279 break; 280 /* The caller must ensure that the hvc is locked, which 281 * is the case when called from hvc_iucv_get_chars() */ 282 __hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data)); 283 break; 284 285 case MSG_TYPE_ERROR: /* ignored ... */ 286 case MSG_TYPE_TERMENV: /* ignored ... */ 287 case MSG_TYPE_TERMIOS: /* ignored ... */ 288 break; 289 } 290 291out_remove_buffer: 292 list_del(&rb->list); 293 destroy_tty_buffer(rb); 294 *has_more_data = !list_empty(&priv->tty_inqueue); 295 296out_written: 297 return written; 298} 299 300/** 301 * hvc_iucv_get_chars() - HVC get_chars operation. 302 * @vtermno: HVC virtual terminal number. 303 * @buf: Pointer to a buffer to store data 304 * @count: Size of buffer available for writing 305 * 306 * The HVC thread calls this method to read characters from the back-end. 307 * If an IUCV communication path has been established, pending IUCV messages 308 * are received and data is copied into buffer @buf up to @count bytes. 309 * 310 * Locking: The routine gets called under an irqsave() spinlock; and 311 * the routine locks the struct hvc_iucv_private->lock to call 312 * helper functions. 313 */ 314static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count) 315{ 316 struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); 317 int written; 318 int has_more_data; 319 320 if (count <= 0) 321 return 0; 322 323 if (!priv) 324 return -ENODEV; 325 326 spin_lock(&priv->lock); 327 has_more_data = 0; 328 written = hvc_iucv_write(priv, buf, count, &has_more_data); 329 spin_unlock(&priv->lock); 330 331 /* if there are still messages on the queue... schedule another run */ 332 if (has_more_data) 333 hvc_kick(); 334 335 return written; 336} 337 338/** 339 * hvc_iucv_queue() - Buffer terminal data for sending. 340 * @priv: Pointer to struct hvc_iucv_private instance. 341 * @buf: Buffer containing data to send. 342 * @count: Size of buffer and amount of data to send. 343 * 344 * The function queues data for sending. To actually send the buffered data, 345 * a work queue function is scheduled (with QUEUE_SNDBUF_DELAY). 346 * The function returns the number of data bytes that has been buffered. 347 * 348 * If the device is not connected, data is ignored and the function returns 349 * @count. 350 * If the buffer is full, the function returns 0. 351 * If an existing IUCV communicaton path has been severed, -EPIPE is returned 352 * (that can be passed to HVC layer to cause a tty hangup). 353 */ 354static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf, 355 int count) 356{ 357 size_t len; 358 359 if (priv->iucv_state == IUCV_DISCONN) 360 return count; /* ignore data */ 361 362 if (priv->iucv_state == IUCV_SEVERED) 363 return -EPIPE; 364 365 len = min_t(size_t, count, SNDBUF_SIZE - priv->sndbuf_len); 366 if (!len) 367 return 0; 368 369 memcpy(priv->sndbuf + priv->sndbuf_len, buf, len); 370 priv->sndbuf_len += len; 371 372 if (priv->iucv_state == IUCV_CONNECTED) 373 schedule_delayed_work(&priv->sndbuf_work, QUEUE_SNDBUF_DELAY); 374 375 return len; 376} 377 378/** 379 * hvc_iucv_send() - Send an IUCV message containing terminal data. 380 * @priv: Pointer to struct hvc_iucv_private instance. 381 * 382 * If an IUCV communication path has been established, the buffered output data 383 * is sent via an IUCV message and the number of bytes sent is returned. 384 * Returns 0 if there is no established IUCV communication path or 385 * -EPIPE if an existing IUCV communicaton path has been severed. 386 */ 387static int hvc_iucv_send(struct hvc_iucv_private *priv) 388{ 389 struct iucv_tty_buffer *sb; 390 int rc, len; 391 392 if (priv->iucv_state == IUCV_SEVERED) 393 return -EPIPE; 394 395 if (priv->iucv_state == IUCV_DISCONN) 396 return -EIO; 397 398 if (!priv->sndbuf_len) 399 return 0; 400 401 /* allocate internal buffer to store msg data and also compute total 402 * message length */ 403 sb = alloc_tty_buffer(priv->sndbuf_len, GFP_ATOMIC); 404 if (!sb) 405 return -ENOMEM; 406 407 memcpy(sb->mbuf->data, priv->sndbuf, priv->sndbuf_len); 408 sb->mbuf->datalen = (u16) priv->sndbuf_len; 409 sb->msg.length = MSG_SIZE(sb->mbuf->datalen); 410 411 list_add_tail(&sb->list, &priv->tty_outqueue); 412 413 rc = __iucv_message_send(priv->path, &sb->msg, 0, 0, 414 (void *) sb->mbuf, sb->msg.length); 415 if (rc) { 416 /* drop the message here; however we might want to handle 417 * 0x03 (msg limit reached) by trying again... */ 418 list_del(&sb->list); 419 destroy_tty_buffer(sb); 420 } 421 len = priv->sndbuf_len; 422 priv->sndbuf_len = 0; 423 424 return len; 425} 426 427/** 428 * hvc_iucv_sndbuf_work() - Send buffered data over IUCV 429 * @work: Work structure. 430 * 431 * This work queue function sends buffered output data over IUCV and, 432 * if not all buffered data could be sent, reschedules itself. 433 */ 434static void hvc_iucv_sndbuf_work(struct work_struct *work) 435{ 436 struct hvc_iucv_private *priv; 437 438 priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work); 439 if (!priv) 440 return; 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 */ 459static 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 */ 488static 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 */ 507static 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 */ 522static 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 */ 540static 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 */ 588static 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 */ 634static 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 */ 668static 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 */ 715static 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 @ipvmid is allowed to connection, otherwise 738 * non-zero. 739 */ 740static int hvc_iucv_filter_connreq(u8 ipvmid[8]) 741{ 742 size_t i; 743 744 /* Note: default policy is ACCEPT if no filter is set */ 745 if (!hvc_iucv_filter_size) 746 return 0; 747 748 for (i = 0; i < hvc_iucv_filter_size; i++) 749 if (0 == memcmp(ipvmid, hvc_iucv_filter + (8 * i), 8)) 750 return 0; 751 return 1; 752} 753 754/** 755 * hvc_iucv_path_pending() - IUCV handler to process a connection request. 756 * @path: Pending path (struct iucv_path) 757 * @ipvmid: z/VM system identifier of originator 758 * @ipuser: User specified data for this path 759 * (AF_IUCV: port/service name and originator port) 760 * 761 * The function uses the @ipuser data to determine if the pending path belongs 762 * to a terminal managed by this device driver. 763 * If the path belongs to this driver, ensure that the terminal is not accessed 764 * multiple times (only one connection to a terminal is allowed). 765 * If the terminal is not yet connected, the pending path is accepted and is 766 * associated to the appropriate struct hvc_iucv_private instance. 767 * 768 * Returns 0 if @path belongs to a terminal managed by the this device driver; 769 * otherwise returns -ENODEV in order to dispatch this path to other handlers. 770 * 771 * Locking: struct hvc_iucv_private->lock 772 */ 773static int hvc_iucv_path_pending(struct iucv_path *path, 774 u8 ipvmid[8], u8 ipuser[16]) 775{ 776 struct hvc_iucv_private *priv, *tmp; 777 u8 wildcard[9] = "lnxhvc "; 778 int i, rc, find_unused; 779 u8 nuser_data[16]; 780 u8 vm_user_id[9]; 781 782 ASCEBC(wildcard, sizeof(wildcard)); 783 find_unused = !memcmp(wildcard, ipuser, 8); 784 785 /* First, check if the pending path request is managed by this 786 * IUCV handler: 787 * - find a disconnected device if ipuser contains the wildcard 788 * - find the device that matches the terminal ID in ipuser 789 */ 790 priv = NULL; 791 for (i = 0; i < hvc_iucv_devices; i++) { 792 tmp = hvc_iucv_table[i]; 793 if (!tmp) 794 continue; 795 796 if (find_unused) { 797 spin_lock(&tmp->lock); 798 if (tmp->iucv_state == IUCV_DISCONN) 799 priv = tmp; 800 spin_unlock(&tmp->lock); 801 802 } else if (!memcmp(tmp->srv_name, ipuser, 8)) 803 priv = tmp; 804 if (priv) 805 break; 806 } 807 if (!priv) 808 return -ENODEV; 809 810 /* Enforce that ipvmid is allowed to connect to us */ 811 read_lock(&hvc_iucv_filter_lock); 812 rc = hvc_iucv_filter_connreq(ipvmid); 813 read_unlock(&hvc_iucv_filter_lock); 814 if (rc) { 815 iucv_path_sever(path, ipuser); 816 iucv_path_free(path); 817 memcpy(vm_user_id, ipvmid, 8); 818 vm_user_id[8] = 0; 819 pr_info("A connection request from z/VM user ID %s " 820 "was refused\n", vm_user_id); 821 return 0; 822 } 823 824 spin_lock(&priv->lock); 825 826 /* If the terminal is already connected or being severed, then sever 827 * this path to enforce that there is only ONE established communication 828 * path per terminal. */ 829 if (priv->iucv_state != IUCV_DISCONN) { 830 iucv_path_sever(path, ipuser); 831 iucv_path_free(path); 832 goto out_path_handled; 833 } 834 835 /* accept path */ 836 memcpy(nuser_data, ipuser + 8, 8); /* remote service (for af_iucv) */ 837 memcpy(nuser_data + 8, ipuser, 8); /* local service (for af_iucv) */ 838 path->msglim = 0xffff; /* IUCV MSGLIMIT */ 839 path->flags &= ~IUCV_IPRMDATA; /* TODO: use IUCV_IPRMDATA */ 840 rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv); 841 if (rc) { 842 iucv_path_sever(path, ipuser); 843 iucv_path_free(path); 844 goto out_path_handled; 845 } 846 priv->path = path; 847 priv->iucv_state = IUCV_CONNECTED; 848 849 /* store path information */ 850 memcpy(priv->info_path, ipvmid, 8); 851 memcpy(priv->info_path + 8, ipuser + 8, 8); 852 853 /* flush buffered output data... */ 854 schedule_delayed_work(&priv->sndbuf_work, 5); 855 856out_path_handled: 857 spin_unlock(&priv->lock); 858 return 0; 859} 860 861/** 862 * hvc_iucv_path_severed() - IUCV handler to process a path sever. 863 * @path: Pending path (struct iucv_path) 864 * @ipuser: User specified data for this path 865 * (AF_IUCV: port/service name and originator port) 866 * 867 * This function calls the hvc_iucv_hangup() function for the 868 * respective IUCV HVC terminal. 869 * 870 * Locking: struct hvc_iucv_private->lock 871 */ 872static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16]) 873{ 874 struct hvc_iucv_private *priv = path->private; 875 876 hvc_iucv_hangup(priv); 877} 878 879/** 880 * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message. 881 * @path: Pending path (struct iucv_path) 882 * @msg: Pointer to the IUCV message 883 * 884 * The function puts an incoming message on the input queue for later 885 * processing (by hvc_iucv_get_chars() / hvc_iucv_write()). 886 * If the tty has not yet been opened, the message is rejected. 887 * 888 * Locking: struct hvc_iucv_private->lock 889 */ 890static void hvc_iucv_msg_pending(struct iucv_path *path, 891 struct iucv_message *msg) 892{ 893 struct hvc_iucv_private *priv = path->private; 894 struct iucv_tty_buffer *rb; 895 896 /* reject messages that exceed max size of iucv_tty_msg->datalen */ 897 if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) { 898 iucv_message_reject(path, msg); 899 return; 900 } 901 902 spin_lock(&priv->lock); 903 904 /* reject messages if tty has not yet been opened */ 905 if (priv->tty_state == TTY_CLOSED) { 906 iucv_message_reject(path, msg); 907 goto unlock_return; 908 } 909 910 /* allocate tty buffer to save iucv msg only */ 911 rb = alloc_tty_buffer(0, GFP_ATOMIC); 912 if (!rb) { 913 iucv_message_reject(path, msg); 914 goto unlock_return; /* -ENOMEM */ 915 } 916 rb->msg = *msg; 917 918 list_add_tail(&rb->list, &priv->tty_inqueue); 919 920 hvc_kick(); /* wake up hvc thread */ 921 922unlock_return: 923 spin_unlock(&priv->lock); 924} 925 926/** 927 * hvc_iucv_msg_complete() - IUCV handler to process message completion 928 * @path: Pending path (struct iucv_path) 929 * @msg: Pointer to the IUCV message 930 * 931 * The function is called upon completion of message delivery to remove the 932 * message from the outqueue. Additional delivery information can be found 933 * msg->audit: rejected messages (0x040000 (IPADRJCT)), and 934 * purged messages (0x010000 (IPADPGNR)). 935 * 936 * Locking: struct hvc_iucv_private->lock 937 */ 938static void hvc_iucv_msg_complete(struct iucv_path *path, 939 struct iucv_message *msg) 940{ 941 struct hvc_iucv_private *priv = path->private; 942 struct iucv_tty_buffer *ent, *next; 943 LIST_HEAD(list_remove); 944 945 spin_lock(&priv->lock); 946 list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list) 947 if (ent->msg.id == msg->id) { 948 list_move(&ent->list, &list_remove); 949 break; 950 } 951 wake_up(&priv->sndbuf_waitq); 952 spin_unlock(&priv->lock); 953 destroy_tty_buffer_list(&list_remove); 954} 955 956/** 957 * hvc_iucv_pm_freeze() - Freeze PM callback 958 * @dev: IUVC HVC terminal device 959 * 960 * Sever an established IUCV communication path and 961 * trigger a hang-up of the underlying HVC terminal. 962 */ 963static int hvc_iucv_pm_freeze(struct device *dev) 964{ 965 struct hvc_iucv_private *priv = dev_get_drvdata(dev); 966 967 local_bh_disable(); 968 hvc_iucv_hangup(priv); 969 local_bh_enable(); 970 971 return 0; 972} 973 974/** 975 * hvc_iucv_pm_restore_thaw() - Thaw and restore PM callback 976 * @dev: IUVC HVC terminal device 977 * 978 * Wake up the HVC thread to trigger hang-up and respective 979 * HVC back-end notifier invocations. 980 */ 981static int hvc_iucv_pm_restore_thaw(struct device *dev) 982{ 983 hvc_kick(); 984 return 0; 985} 986 987static ssize_t hvc_iucv_dev_termid_show(struct device *dev, 988 struct device_attribute *attr, 989 char *buf) 990{ 991 struct hvc_iucv_private *priv = dev_get_drvdata(dev); 992 size_t len; 993 994 len = sizeof(priv->srv_name); 995 memcpy(buf, priv->srv_name, len); 996 EBCASC(buf, len); 997 buf[len++] = '\n'; 998 return len; 999} 1000 1001static ssize_t hvc_iucv_dev_state_show(struct device *dev, 1002 struct device_attribute *attr, 1003 char *buf) 1004{ 1005 struct hvc_iucv_private *priv = dev_get_drvdata(dev); 1006 return sprintf(buf, "%u:%u\n", priv->iucv_state, priv->tty_state); 1007} 1008 1009static ssize_t hvc_iucv_dev_peer_show(struct device *dev, 1010 struct device_attribute *attr, 1011 char *buf) 1012{ 1013 struct hvc_iucv_private *priv = dev_get_drvdata(dev); 1014 char vmid[9], ipuser[9]; 1015 1016 memset(vmid, 0, sizeof(vmid)); 1017 memset(ipuser, 0, sizeof(ipuser)); 1018 1019 spin_lock_bh(&priv->lock); 1020 if (priv->iucv_state == IUCV_CONNECTED) { 1021 memcpy(vmid, priv->info_path, 8); 1022 memcpy(ipuser, priv->info_path + 8, 8); 1023 } 1024 spin_unlock_bh(&priv->lock); 1025 EBCASC(ipuser, 8); 1026 1027 return sprintf(buf, "%s:%s\n", vmid, ipuser); 1028} 1029 1030 1031/* HVC operations */ 1032static const struct hv_ops hvc_iucv_ops = { 1033 .get_chars = hvc_iucv_get_chars, 1034 .put_chars = hvc_iucv_put_chars, 1035 .notifier_add = hvc_iucv_notifier_add, 1036 .notifier_del = hvc_iucv_notifier_del, 1037 .notifier_hangup = hvc_iucv_notifier_hangup, 1038 .dtr_rts = hvc_iucv_dtr_rts, 1039}; 1040 1041/* Suspend / resume device operations */ 1042static const struct dev_pm_ops hvc_iucv_pm_ops = { 1043 .freeze = hvc_iucv_pm_freeze, 1044 .thaw = hvc_iucv_pm_restore_thaw, 1045 .restore = hvc_iucv_pm_restore_thaw, 1046}; 1047 1048/* IUCV HVC device driver */ 1049static struct device_driver hvc_iucv_driver = { 1050 .name = KMSG_COMPONENT, 1051 .bus = &iucv_bus, 1052 .pm = &hvc_iucv_pm_ops, 1053}; 1054 1055/* IUCV HVC device attributes */ 1056static DEVICE_ATTR(termid, 0640, hvc_iucv_dev_termid_show, NULL); 1057static DEVICE_ATTR(state, 0640, hvc_iucv_dev_state_show, NULL); 1058static DEVICE_ATTR(peer, 0640, hvc_iucv_dev_peer_show, NULL); 1059static struct attribute *hvc_iucv_dev_attrs[] = { 1060 &dev_attr_termid.attr, 1061 &dev_attr_state.attr, 1062 &dev_attr_peer.attr, 1063 NULL, 1064}; 1065static struct attribute_group hvc_iucv_dev_attr_group = { 1066 .attrs = hvc_iucv_dev_attrs, 1067}; 1068static const struct attribute_group *hvc_iucv_dev_attr_groups[] = { 1069 &hvc_iucv_dev_attr_group, 1070 NULL, 1071}; 1072 1073 1074/** 1075 * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance 1076 * @id: hvc_iucv_table index 1077 * @is_console: Flag if the instance is used as Linux console 1078 * 1079 * This function allocates a new hvc_iucv_private structure and stores 1080 * the instance in hvc_iucv_table at index @id. 1081 * Returns 0 on success; otherwise non-zero. 1082 */ 1083static int __init hvc_iucv_alloc(int id, unsigned int is_console) 1084{ 1085 struct hvc_iucv_private *priv; 1086 char name[9]; 1087 int rc; 1088 1089 priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL); 1090 if (!priv) 1091 return -ENOMEM; 1092 1093 spin_lock_init(&priv->lock); 1094 INIT_LIST_HEAD(&priv->tty_outqueue); 1095 INIT_LIST_HEAD(&priv->tty_inqueue); 1096 INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work); 1097 init_waitqueue_head(&priv->sndbuf_waitq); 1098 1099 priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL); 1100 if (!priv->sndbuf) { 1101 kfree(priv); 1102 return -ENOMEM; 1103 } 1104 1105 /* set console flag */ 1106 priv->is_console = is_console; 1107 1108 /* allocate hvc device */ 1109 priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /* PAGE_SIZE */ 1110 HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256); 1111 if (IS_ERR(priv->hvc)) { 1112 rc = PTR_ERR(priv->hvc); 1113 goto out_error_hvc; 1114 } 1115 1116 /* notify HVC thread instead of using polling */ 1117 priv->hvc->irq_requested = 1; 1118 1119 /* setup iucv related information */ 1120 snprintf(name, 9, "lnxhvc%-2d", id); 1121 memcpy(priv->srv_name, name, 8); 1122 ASCEBC(priv->srv_name, 8); 1123 1124 /* create and setup device */ 1125 priv->dev = kzalloc(sizeof(*priv->dev), GFP_KERNEL); 1126 if (!priv->dev) { 1127 rc = -ENOMEM; 1128 goto out_error_dev; 1129 } 1130 dev_set_name(priv->dev, "hvc_iucv%d", id); 1131 dev_set_drvdata(priv->dev, priv); 1132 priv->dev->bus = &iucv_bus; 1133 priv->dev->parent = iucv_root; 1134 priv->dev->driver = &hvc_iucv_driver; 1135 priv->dev->groups = hvc_iucv_dev_attr_groups; 1136 priv->dev->release = (void (*)(struct device *)) kfree; 1137 rc = device_register(priv->dev); 1138 if (rc) { 1139 put_device(priv->dev); 1140 goto out_error_dev; 1141 } 1142 1143 hvc_iucv_table[id] = priv; 1144 return 0; 1145 1146out_error_dev: 1147 hvc_remove(priv->hvc); 1148out_error_hvc: 1149 free_page((unsigned long) priv->sndbuf); 1150 kfree(priv); 1151 1152 return rc; 1153} 1154 1155/** 1156 * hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances 1157 */ 1158static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv) 1159{ 1160 hvc_remove(priv->hvc); 1161 device_unregister(priv->dev); 1162 free_page((unsigned long) priv->sndbuf); 1163 kfree(priv); 1164} 1165 1166/** 1167 * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID 1168 * @filter: String containing a comma-separated list of z/VM user IDs 1169 */ 1170static const char *hvc_iucv_parse_filter(const char *filter, char *dest) 1171{ 1172 const char *nextdelim, *residual; 1173 size_t len; 1174 1175 nextdelim = strchr(filter, ','); 1176 if (nextdelim) { 1177 len = nextdelim - filter; 1178 residual = nextdelim + 1; 1179 } else { 1180 len = strlen(filter); 1181 residual = filter + len; 1182 } 1183 1184 if (len == 0) 1185 return ERR_PTR(-EINVAL); 1186 1187 /* check for '\n' (if called from sysfs) */ 1188 if (filter[len - 1] == '\n') 1189 len--; 1190 1191 if (len > 8) 1192 return ERR_PTR(-EINVAL); 1193 1194 /* pad with blanks and save upper case version of user ID */ 1195 memset(dest, ' ', 8); 1196 while (len--) 1197 dest[len] = toupper(filter[len]); 1198 return residual; 1199} 1200 1201/** 1202 * hvc_iucv_setup_filter() - Set up z/VM user ID filter 1203 * @filter: String consisting of a comma-separated list of z/VM user IDs 1204 * 1205 * The function parses the @filter string and creates an array containing 1206 * the list of z/VM user ID filter entries. 1207 * Return code 0 means success, -EINVAL if the filter is syntactically 1208 * incorrect, -ENOMEM if there was not enough memory to allocate the 1209 * filter list array, or -ENOSPC if too many z/VM user IDs have been specified. 1210 */ 1211static int hvc_iucv_setup_filter(const char *val) 1212{ 1213 const char *residual; 1214 int err; 1215 size_t size, count; 1216 void *array, *old_filter; 1217 1218 count = strlen(val); 1219 if (count == 0 || (count == 1 && val[0] == '\n')) { 1220 size = 0; 1221 array = NULL; 1222 goto out_replace_filter; /* clear filter */ 1223 } 1224 1225 /* count user IDs in order to allocate sufficient memory */ 1226 size = 1; 1227 residual = val; 1228 while ((residual = strchr(residual, ',')) != NULL) { 1229 residual++; 1230 size++; 1231 } 1232 1233 /* check if the specified list exceeds the filter limit */ 1234 if (size > MAX_VMID_FILTER) 1235 return -ENOSPC; 1236 1237 array = kzalloc(size * 8, GFP_KERNEL); 1238 if (!array) 1239 return -ENOMEM; 1240 1241 count = size; 1242 residual = val; 1243 while (*residual && count) { 1244 residual = hvc_iucv_parse_filter(residual, 1245 array + ((size - count) * 8)); 1246 if (IS_ERR(residual)) { 1247 err = PTR_ERR(residual); 1248 kfree(array); 1249 goto out_err; 1250 } 1251 count--; 1252 } 1253 1254out_replace_filter: 1255 write_lock_bh(&hvc_iucv_filter_lock); 1256 old_filter = hvc_iucv_filter; 1257 hvc_iucv_filter_size = size; 1258 hvc_iucv_filter = array; 1259 write_unlock_bh(&hvc_iucv_filter_lock); 1260 kfree(old_filter); 1261 1262 err = 0; 1263out_err: 1264 return err; 1265} 1266 1267/** 1268 * param_set_vmidfilter() - Set z/VM user ID filter parameter 1269 * @val: String consisting of a comma-separated list of z/VM user IDs 1270 * @kp: Kernel parameter pointing to hvc_iucv_filter array 1271 * 1272 * The function sets up the z/VM user ID filter specified as comma-separated 1273 * list of user IDs in @val. 1274 * Note: If it is called early in the boot process, @val is stored and 1275 * parsed later in hvc_iucv_init(). 1276 */ 1277static int param_set_vmidfilter(const char *val, const struct kernel_param *kp) 1278{ 1279 int rc; 1280 1281 if (!MACHINE_IS_VM || !hvc_iucv_devices) 1282 return -ENODEV; 1283 1284 if (!val) 1285 return -EINVAL; 1286 1287 rc = 0; 1288 if (slab_is_available()) 1289 rc = hvc_iucv_setup_filter(val); 1290 else 1291 hvc_iucv_filter_string = val; /* defer... */ 1292 return rc; 1293} 1294 1295/** 1296 * param_get_vmidfilter() - Get z/VM user ID filter 1297 * @buffer: Buffer to store z/VM user ID filter, 1298 * (buffer size assumption PAGE_SIZE) 1299 * @kp: Kernel parameter pointing to the hvc_iucv_filter array 1300 * 1301 * The function stores the filter as a comma-separated list of z/VM user IDs 1302 * in @buffer. Typically, sysfs routines call this function for attr show. 1303 */ 1304static int param_get_vmidfilter(char *buffer, const struct kernel_param *kp) 1305{ 1306 int rc; 1307 size_t index, len; 1308 void *start, *end; 1309 1310 if (!MACHINE_IS_VM || !hvc_iucv_devices) 1311 return -ENODEV; 1312 1313 rc = 0; 1314 read_lock_bh(&hvc_iucv_filter_lock); 1315 for (index = 0; index < hvc_iucv_filter_size; index++) { 1316 start = hvc_iucv_filter + (8 * index); 1317 end = memchr(start, ' ', 8); 1318 len = (end) ? end - start : 8; 1319 memcpy(buffer + rc, start, len); 1320 rc += len; 1321 buffer[rc++] = ','; 1322 } 1323 read_unlock_bh(&hvc_iucv_filter_lock); 1324 if (rc) 1325 buffer[--rc] = '\0'; /* replace last comma and update rc */ 1326 return rc; 1327} 1328 1329#define param_check_vmidfilter(name, p) __param_check(name, p, void) 1330 1331static struct kernel_param_ops param_ops_vmidfilter = { 1332 .set = param_set_vmidfilter, 1333 .get = param_get_vmidfilter, 1334}; 1335 1336/** 1337 * hvc_iucv_init() - z/VM IUCV HVC device driver initialization 1338 */ 1339static int __init hvc_iucv_init(void) 1340{ 1341 int rc; 1342 unsigned int i; 1343 1344 if (!hvc_iucv_devices) 1345 return -ENODEV; 1346 1347 if (!MACHINE_IS_VM) { 1348 pr_notice("The z/VM IUCV HVC device driver cannot " 1349 "be used without z/VM\n"); 1350 rc = -ENODEV; 1351 goto out_error; 1352 } 1353 1354 if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) { 1355 pr_err("%lu is not a valid value for the hvc_iucv= " 1356 "kernel parameter\n", hvc_iucv_devices); 1357 rc = -EINVAL; 1358 goto out_error; 1359 } 1360 1361 /* register IUCV HVC device driver */ 1362 rc = driver_register(&hvc_iucv_driver); 1363 if (rc) 1364 goto out_error; 1365 1366 /* parse hvc_iucv_allow string and create z/VM user ID filter list */ 1367 if (hvc_iucv_filter_string) { 1368 rc = hvc_iucv_setup_filter(hvc_iucv_filter_string); 1369 switch (rc) { 1370 case 0: 1371 break; 1372 case -ENOMEM: 1373 pr_err("Allocating memory failed with " 1374 "reason code=%d\n", 3); 1375 goto out_error; 1376 case -EINVAL: 1377 pr_err("hvc_iucv_allow= does not specify a valid " 1378 "z/VM user ID list\n"); 1379 goto out_error; 1380 case -ENOSPC: 1381 pr_err("hvc_iucv_allow= specifies too many " 1382 "z/VM user IDs\n"); 1383 goto out_error; 1384 default: 1385 goto out_error; 1386 } 1387 } 1388 1389 hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT, 1390 sizeof(struct iucv_tty_buffer), 1391 0, 0, NULL); 1392 if (!hvc_iucv_buffer_cache) { 1393 pr_err("Allocating memory failed with reason code=%d\n", 1); 1394 rc = -ENOMEM; 1395 goto out_error; 1396 } 1397 1398 hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR, 1399 hvc_iucv_buffer_cache); 1400 if (!hvc_iucv_mempool) { 1401 pr_err("Allocating memory failed with reason code=%d\n", 2); 1402 kmem_cache_destroy(hvc_iucv_buffer_cache); 1403 rc = -ENOMEM; 1404 goto out_error; 1405 } 1406 1407 /* register the first terminal device as console 1408 * (must be done before allocating hvc terminal devices) */ 1409 rc = hvc_instantiate(HVC_IUCV_MAGIC, IUCV_HVC_CON_IDX, &hvc_iucv_ops); 1410 if (rc) { 1411 pr_err("Registering HVC terminal device as " 1412 "Linux console failed\n"); 1413 goto out_error_memory; 1414 } 1415 1416 /* allocate hvc_iucv_private structs */ 1417 for (i = 0; i < hvc_iucv_devices; i++) { 1418 rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0); 1419 if (rc) { 1420 pr_err("Creating a new HVC terminal device " 1421 "failed with error code=%d\n", rc); 1422 goto out_error_hvc; 1423 } 1424 } 1425 1426 /* register IUCV callback handler */ 1427 rc = iucv_register(&hvc_iucv_handler, 0); 1428 if (rc) { 1429 pr_err("Registering IUCV handlers failed with error code=%d\n", 1430 rc); 1431 goto out_error_hvc; 1432 } 1433 1434 return 0; 1435 1436out_error_hvc: 1437 for (i = 0; i < hvc_iucv_devices; i++) 1438 if (hvc_iucv_table[i]) 1439 hvc_iucv_destroy(hvc_iucv_table[i]); 1440out_error_memory: 1441 mempool_destroy(hvc_iucv_mempool); 1442 kmem_cache_destroy(hvc_iucv_buffer_cache); 1443out_error: 1444 kfree(hvc_iucv_filter); 1445 hvc_iucv_devices = 0; /* ensure that we do not provide any device */ 1446 return rc; 1447} 1448 1449/** 1450 * hvc_iucv_config() - Parsing of hvc_iucv= kernel command line parameter 1451 * @val: Parameter value (numeric) 1452 */ 1453static int __init hvc_iucv_config(char *val) 1454{ 1455 return kstrtoul(val, 10, &hvc_iucv_devices); 1456} 1457 1458 1459device_initcall(hvc_iucv_init); 1460__setup("hvc_iucv=", hvc_iucv_config); 1461core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640); 1462