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1// SPDX-License-Identifier: GPL-2.02/*3 * z/VM IUCV hypervisor console (HVC) device driver4 *5 * This HVC device driver provides terminal access using6 * z/VM IUCV communication paths.7 *8 * Copyright IBM Corp. 2008, 20139 *10 * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>11 */12#define KMSG_COMPONENT "hvc_iucv"13#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt14 15#include <linux/types.h>16#include <linux/slab.h>17#include <asm/ebcdic.h>18#include <linux/ctype.h>19#include <linux/delay.h>20#include <linux/device.h>21#include <linux/init.h>22#include <linux/mempool.h>23#include <linux/moduleparam.h>24#include <linux/tty.h>25#include <linux/wait.h>26#include <net/iucv/iucv.h>27 28#include "hvc_console.h"29 30 31/* General device driver settings */32#define MAX_HVC_IUCV_LINES HVC_ALLOC_TTY_ADAPTERS33#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 *, u8 *);92static void hvc_iucv_path_severed(struct iucv_path *, u8 *);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)105#define FILTER_WILDCARD_CHAR '*'106static size_t hvc_iucv_filter_size;107static void *hvc_iucv_filter;108static const char *hvc_iucv_filter_string;109static DEFINE_RWLOCK(hvc_iucv_filter_lock);110 111/* Kmem cache and mempool for iucv_tty_buffer elements */112static struct kmem_cache *hvc_iucv_buffer_cache;113static mempool_t *hvc_iucv_mempool;114 115/* IUCV handler callback functions */116static 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 corresponds129 * to the HVC virtual terminal number specified as parameter @num.130 */131static struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num)132{133 if (num > hvc_iucv_devices)134 return NULL;135 return hvc_iucv_table[num];136}137 138/**139 * alloc_tty_buffer() - Return a new struct iucv_tty_buffer element.140 * @size: Size of the internal buffer used to store data.141 * @flags: Memory allocation flags passed to mempool.142 *143 * This function allocates a new struct iucv_tty_buffer element and, optionally,144 * allocates an internal data buffer with the specified size @size.145 * The internal data buffer is always allocated with GFP_DMA which is146 * required for receiving and sending data with IUCV.147 * Note: The total message size arises from the internal buffer size and the148 * members of the iucv_tty_msg structure.149 * The function returns NULL if memory allocation has failed.150 */151static 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 */178static 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 */188static 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_private201 * @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 receives206 * 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, the208 * 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 from210 * the input queue.211 *212 * The function returns the number of bytes written to the terminal, zero if213 * there are no pending data messages available or if there is no established214 * IUCV path.215 * If the IUCV path has been severed, then -EPIPE is returned to cause a216 * hang up (that is issued by the HVC layer).217 */218static ssize_t hvc_iucv_write(struct hvc_iucv_private *priv,219 u8 *buf, size_t count, int *has_more_data)220{221 struct iucv_tty_buffer *rb;222 ssize_t 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 the230 * 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 available244 * 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 data261 * 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, which282 * 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 292out_remove_buffer:293 list_del(&rb->list);294 destroy_tty_buffer(rb);295 *has_more_data = !list_empty(&priv->tty_inqueue);296 297out_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 data305 * @count: Size of buffer available for writing306 *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 messages309 * are received and data is copied into buffer @buf up to @count bytes.310 *311 * Locking: The routine gets called under an irqsave() spinlock; and312 * the routine locks the struct hvc_iucv_private->lock to call313 * helper functions.314 */315static ssize_t hvc_iucv_get_chars(uint32_t vtermno, u8 *buf, size_t count)316{317 struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);318 ssize_t 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 returns350 * @count.351 * If the buffer is full, the function returns 0.352 * If an existing IUCV communicaton path has been severed, -EPIPE is returned353 * (that can be passed to HVC layer to cause a tty hangup).354 */355static ssize_t hvc_iucv_queue(struct hvc_iucv_private *priv, const u8 *buf,356 size_t 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 data384 * 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 or386 * -EPIPE if an existing IUCV communicaton path has been severed.387 */388static 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 total403 * 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 handle418 * 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 IUCV430 * @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 */435static void hvc_iucv_sndbuf_work(struct work_struct *work)436{437 struct hvc_iucv_private *priv;438 439 priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work);440 441 spin_lock_bh(&priv->lock);442 hvc_iucv_send(priv);443 spin_unlock_bh(&priv->lock);444}445 446/**447 * hvc_iucv_put_chars() - HVC put_chars operation.448 * @vtermno: HVC virtual terminal number.449 * @buf: Pointer to an buffer to read data from450 * @count: Size of buffer available for reading451 *452 * The HVC thread calls this method to write characters to the back-end.453 * The function calls hvc_iucv_queue() to queue terminal data for sending.454 *455 * Locking: The method gets called under an irqsave() spinlock; and456 * locks struct hvc_iucv_private->lock.457 */458static ssize_t hvc_iucv_put_chars(uint32_t vtermno, const u8 *buf, size_t count)459{460 struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);461 int queued;462 463 if (!count)464 return 0;465 466 if (!priv)467 return -ENODEV;468 469 spin_lock(&priv->lock);470 queued = hvc_iucv_queue(priv, buf, count);471 spin_unlock(&priv->lock);472 473 return queued;474}475 476/**477 * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time.478 * @hp: Pointer to the HVC device (struct hvc_struct)479 * @id: Additional data (originally passed to hvc_alloc): the index of an struct480 * hvc_iucv_private instance.481 *482 * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private483 * instance that is derived from @id. Always returns 0.484 *485 * Locking: struct hvc_iucv_private->lock, spin_lock_bh486 */487static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id)488{489 struct hvc_iucv_private *priv;490 491 priv = hvc_iucv_get_private(id);492 if (!priv)493 return 0;494 495 spin_lock_bh(&priv->lock);496 priv->tty_state = TTY_OPENED;497 spin_unlock_bh(&priv->lock);498 499 return 0;500}501 502/**503 * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance.504 * @priv: Pointer to the struct hvc_iucv_private instance.505 */506static void hvc_iucv_cleanup(struct hvc_iucv_private *priv)507{508 destroy_tty_buffer_list(&priv->tty_outqueue);509 destroy_tty_buffer_list(&priv->tty_inqueue);510 511 priv->tty_state = TTY_CLOSED;512 priv->iucv_state = IUCV_DISCONN;513 514 priv->sndbuf_len = 0;515}516 517/**518 * tty_outqueue_empty() - Test if the tty outq is empty519 * @priv: Pointer to struct hvc_iucv_private instance.520 */521static inline int tty_outqueue_empty(struct hvc_iucv_private *priv)522{523 int rc;524 525 spin_lock_bh(&priv->lock);526 rc = list_empty(&priv->tty_outqueue);527 spin_unlock_bh(&priv->lock);528 529 return rc;530}531 532/**533 * flush_sndbuf_sync() - Flush send buffer and wait for completion534 * @priv: Pointer to struct hvc_iucv_private instance.535 *536 * The routine cancels a pending sndbuf work, calls hvc_iucv_send()537 * to flush any buffered terminal output data and waits for completion.538 */539static void flush_sndbuf_sync(struct hvc_iucv_private *priv)540{541 int sync_wait;542 543 cancel_delayed_work_sync(&priv->sndbuf_work);544 545 spin_lock_bh(&priv->lock);546 hvc_iucv_send(priv); /* force sending buffered data */547 sync_wait = !list_empty(&priv->tty_outqueue); /* anything queued ? */548 spin_unlock_bh(&priv->lock);549 550 if (sync_wait)551 wait_event_timeout(priv->sndbuf_waitq,552 tty_outqueue_empty(priv), HZ/10);553}554 555/**556 * hvc_iucv_hangup() - Sever IUCV path and schedule hvc tty hang up557 * @priv: Pointer to hvc_iucv_private structure558 *559 * This routine severs an existing IUCV communication path and hangs560 * up the underlying HVC terminal device.561 * The hang-up occurs only if an IUCV communication path is established;562 * otherwise there is no need to hang up the terminal device.563 *564 * The IUCV HVC hang-up is separated into two steps:565 * 1. After the IUCV path has been severed, the iucv_state is set to566 * IUCV_SEVERED.567 * 2. Later, when the HVC thread calls hvc_iucv_get_chars(), the568 * IUCV_SEVERED state causes the tty hang-up in the HVC layer.569 *570 * If the tty has not yet been opened, clean up the hvc_iucv_private571 * structure to allow re-connects.572 * If the tty has been opened, let get_chars() return -EPIPE to signal573 * the HVC layer to hang up the tty and, if so, wake up the HVC thread574 * to call get_chars()...575 *576 * Special notes on hanging up a HVC terminal instantiated as console:577 * Hang-up: 1. do_tty_hangup() replaces file ops (= hung_up_tty_fops)578 * 2. do_tty_hangup() calls tty->ops->close() for console_filp579 * => no hangup notifier is called by HVC (default)580 * 2. hvc_close() returns because of tty_hung_up_p(filp)581 * => no delete notifier is called!582 * Finally, the back-end is not being notified, thus, the tty session is583 * kept active (TTY_OPEN) to be ready for re-connects.584 *585 * Locking: spin_lock(&priv->lock) w/o disabling bh586 */587static void hvc_iucv_hangup(struct hvc_iucv_private *priv)588{589 struct iucv_path *path;590 591 path = NULL;592 spin_lock(&priv->lock);593 if (priv->iucv_state == IUCV_CONNECTED) {594 path = priv->path;595 priv->path = NULL;596 priv->iucv_state = IUCV_SEVERED;597 if (priv->tty_state == TTY_CLOSED)598 hvc_iucv_cleanup(priv);599 else600 /* console is special (see above) */601 if (priv->is_console) {602 hvc_iucv_cleanup(priv);603 priv->tty_state = TTY_OPENED;604 } else605 hvc_kick();606 }607 spin_unlock(&priv->lock);608 609 /* finally sever path (outside of priv->lock due to lock ordering) */610 if (path) {611 iucv_path_sever(path, NULL);612 iucv_path_free(path);613 }614}615 616/**617 * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups.618 * @hp: Pointer to the HVC device (struct hvc_struct)619 * @id: Additional data (originally passed to hvc_alloc):620 * the index of an struct hvc_iucv_private instance.621 *622 * This routine notifies the HVC back-end that a tty hangup (carrier loss,623 * virtual or otherwise) has occurred.624 * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup())625 * to keep an existing IUCV communication path established.626 * (Background: vhangup() is called from user space (by getty or login) to627 * disable writing to the tty by other applications).628 * If the tty has been opened and an established IUCV path has been severed629 * (we caused the tty hangup), the function calls hvc_iucv_cleanup().630 *631 * Locking: struct hvc_iucv_private->lock632 */633static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id)634{635 struct hvc_iucv_private *priv;636 637 priv = hvc_iucv_get_private(id);638 if (!priv)639 return;640 641 flush_sndbuf_sync(priv);642 643 spin_lock_bh(&priv->lock);644 /* NOTE: If the hangup was scheduled by ourself (from the iucv645 * path_servered callback [IUCV_SEVERED]), we have to clean up646 * our structure and to set state to TTY_CLOSED.647 * If the tty was hung up otherwise (e.g. vhangup()), then we648 * ignore this hangup and keep an established IUCV path open...649 * (...the reason is that we are not able to connect back to the650 * client if we disconnect on hang up) */651 priv->tty_state = TTY_CLOSED;652 653 if (priv->iucv_state == IUCV_SEVERED)654 hvc_iucv_cleanup(priv);655 spin_unlock_bh(&priv->lock);656}657 658/**659 * hvc_iucv_dtr_rts() - HVC notifier for handling DTR/RTS660 * @hp: Pointer the HVC device (struct hvc_struct)661 * @active: True to raise or false to lower DTR/RTS lines662 *663 * This routine notifies the HVC back-end to raise or lower DTR/RTS664 * lines. Raising DTR/RTS is ignored. Lowering DTR/RTS indicates to665 * drop the IUCV connection (similar to hang up the modem).666 */667static void hvc_iucv_dtr_rts(struct hvc_struct *hp, bool active)668{669 struct hvc_iucv_private *priv;670 struct iucv_path *path;671 672 /* Raising the DTR/RTS is ignored as IUCV connections can be673 * established at any times.674 */675 if (active)676 return;677 678 priv = hvc_iucv_get_private(hp->vtermno);679 if (!priv)680 return;681 682 /* Lowering the DTR/RTS lines disconnects an established IUCV683 * connection.684 */685 flush_sndbuf_sync(priv);686 687 spin_lock_bh(&priv->lock);688 path = priv->path; /* save reference to IUCV path */689 priv->path = NULL;690 priv->iucv_state = IUCV_DISCONN;691 spin_unlock_bh(&priv->lock);692 693 /* Sever IUCV path outside of priv->lock due to lock ordering of:694 * priv->lock <--> iucv_table_lock */695 if (path) {696 iucv_path_sever(path, NULL);697 iucv_path_free(path);698 }699}700 701/**702 * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time.703 * @hp: Pointer to the HVC device (struct hvc_struct)704 * @id: Additional data (originally passed to hvc_alloc):705 * the index of an struct hvc_iucv_private instance.706 *707 * This routine notifies the HVC back-end that the last tty device fd has been708 * closed. The function cleans up tty resources. The clean-up of the IUCV709 * connection is done in hvc_iucv_dtr_rts() and depends on the HUPCL termios710 * control setting.711 *712 * Locking: struct hvc_iucv_private->lock713 */714static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id)715{716 struct hvc_iucv_private *priv;717 718 priv = hvc_iucv_get_private(id);719 if (!priv)720 return;721 722 flush_sndbuf_sync(priv);723 724 spin_lock_bh(&priv->lock);725 destroy_tty_buffer_list(&priv->tty_outqueue);726 destroy_tty_buffer_list(&priv->tty_inqueue);727 priv->tty_state = TTY_CLOSED;728 priv->sndbuf_len = 0;729 spin_unlock_bh(&priv->lock);730}731 732/**733 * hvc_iucv_filter_connreq() - Filter connection request based on z/VM user ID734 * @ipvmid: Originating z/VM user ID (right padded with blanks)735 *736 * Returns 0 if the z/VM user ID that is specified with @ipvmid is permitted to737 * connect, otherwise non-zero.738 */739static int hvc_iucv_filter_connreq(u8 ipvmid[8])740{741 const char *wildcard, *filter_entry;742 size_t i, len;743 744 /* Note: default policy is ACCEPT if no filter is set */745 if (!hvc_iucv_filter_size)746 return 0;747 748 for (i = 0; i < hvc_iucv_filter_size; i++) {749 filter_entry = hvc_iucv_filter + (8 * i);750 751 /* If a filter entry contains the filter wildcard character,752 * reduce the length to match the leading portion of the user753 * ID only (wildcard match). Characters following the wildcard754 * are ignored.755 */756 wildcard = strnchr(filter_entry, 8, FILTER_WILDCARD_CHAR);757 len = (wildcard) ? wildcard - filter_entry : 8;758 if (0 == memcmp(ipvmid, filter_entry, len))759 return 0;760 }761 return 1;762}763 764/**765 * hvc_iucv_path_pending() - IUCV handler to process a connection request.766 * @path: Pending path (struct iucv_path)767 * @ipvmid: z/VM system identifier of originator768 * @ipuser: User specified data for this path769 * (AF_IUCV: port/service name and originator port)770 *771 * The function uses the @ipuser data to determine if the pending path belongs772 * to a terminal managed by this device driver.773 * If the path belongs to this driver, ensure that the terminal is not accessed774 * multiple times (only one connection to a terminal is allowed).775 * If the terminal is not yet connected, the pending path is accepted and is776 * associated to the appropriate struct hvc_iucv_private instance.777 *778 * Returns 0 if @path belongs to a terminal managed by the this device driver;779 * otherwise returns -ENODEV in order to dispatch this path to other handlers.780 *781 * Locking: struct hvc_iucv_private->lock782 */783static int hvc_iucv_path_pending(struct iucv_path *path, u8 *ipvmid,784 u8 *ipuser)785{786 struct hvc_iucv_private *priv, *tmp;787 u8 wildcard[9] = "lnxhvc ";788 int i, rc, find_unused;789 u8 nuser_data[16];790 u8 vm_user_id[9];791 792 ASCEBC(wildcard, sizeof(wildcard));793 find_unused = !memcmp(wildcard, ipuser, 8);794 795 /* First, check if the pending path request is managed by this796 * IUCV handler:797 * - find a disconnected device if ipuser contains the wildcard798 * - find the device that matches the terminal ID in ipuser799 */800 priv = NULL;801 for (i = 0; i < hvc_iucv_devices; i++) {802 tmp = hvc_iucv_table[i];803 if (!tmp)804 continue;805 806 if (find_unused) {807 spin_lock(&tmp->lock);808 if (tmp->iucv_state == IUCV_DISCONN)809 priv = tmp;810 spin_unlock(&tmp->lock);811 812 } else if (!memcmp(tmp->srv_name, ipuser, 8))813 priv = tmp;814 if (priv)815 break;816 }817 if (!priv)818 return -ENODEV;819 820 /* Enforce that ipvmid is allowed to connect to us */821 read_lock(&hvc_iucv_filter_lock);822 rc = hvc_iucv_filter_connreq(ipvmid);823 read_unlock(&hvc_iucv_filter_lock);824 if (rc) {825 iucv_path_sever(path, ipuser);826 iucv_path_free(path);827 memcpy(vm_user_id, ipvmid, 8);828 vm_user_id[8] = 0;829 pr_info("A connection request from z/VM user ID %s "830 "was refused\n", vm_user_id);831 return 0;832 }833 834 spin_lock(&priv->lock);835 836 /* If the terminal is already connected or being severed, then sever837 * this path to enforce that there is only ONE established communication838 * path per terminal. */839 if (priv->iucv_state != IUCV_DISCONN) {840 iucv_path_sever(path, ipuser);841 iucv_path_free(path);842 goto out_path_handled;843 }844 845 /* accept path */846 memcpy(nuser_data, ipuser + 8, 8); /* remote service (for af_iucv) */847 memcpy(nuser_data + 8, ipuser, 8); /* local service (for af_iucv) */848 path->msglim = 0xffff; /* IUCV MSGLIMIT */849 path->flags &= ~IUCV_IPRMDATA; /* TODO: use IUCV_IPRMDATA */850 rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv);851 if (rc) {852 iucv_path_sever(path, ipuser);853 iucv_path_free(path);854 goto out_path_handled;855 }856 priv->path = path;857 priv->iucv_state = IUCV_CONNECTED;858 859 /* store path information */860 memcpy(priv->info_path, ipvmid, 8);861 memcpy(priv->info_path + 8, ipuser + 8, 8);862 863 /* flush buffered output data... */864 schedule_delayed_work(&priv->sndbuf_work, 5);865 866out_path_handled:867 spin_unlock(&priv->lock);868 return 0;869}870 871/**872 * hvc_iucv_path_severed() - IUCV handler to process a path sever.873 * @path: Pending path (struct iucv_path)874 * @ipuser: User specified data for this path875 * (AF_IUCV: port/service name and originator port)876 *877 * This function calls the hvc_iucv_hangup() function for the878 * respective IUCV HVC terminal.879 *880 * Locking: struct hvc_iucv_private->lock881 */882static void hvc_iucv_path_severed(struct iucv_path *path, u8 *ipuser)883{884 struct hvc_iucv_private *priv = path->private;885 886 hvc_iucv_hangup(priv);887}888 889/**890 * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message.891 * @path: Pending path (struct iucv_path)892 * @msg: Pointer to the IUCV message893 *894 * The function puts an incoming message on the input queue for later895 * processing (by hvc_iucv_get_chars() / hvc_iucv_write()).896 * If the tty has not yet been opened, the message is rejected.897 *898 * Locking: struct hvc_iucv_private->lock899 */900static void hvc_iucv_msg_pending(struct iucv_path *path,901 struct iucv_message *msg)902{903 struct hvc_iucv_private *priv = path->private;904 struct iucv_tty_buffer *rb;905 906 /* reject messages that exceed max size of iucv_tty_msg->datalen */907 if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) {908 iucv_message_reject(path, msg);909 return;910 }911 912 spin_lock(&priv->lock);913 914 /* reject messages if tty has not yet been opened */915 if (priv->tty_state == TTY_CLOSED) {916 iucv_message_reject(path, msg);917 goto unlock_return;918 }919 920 /* allocate tty buffer to save iucv msg only */921 rb = alloc_tty_buffer(0, GFP_ATOMIC);922 if (!rb) {923 iucv_message_reject(path, msg);924 goto unlock_return; /* -ENOMEM */925 }926 rb->msg = *msg;927 928 list_add_tail(&rb->list, &priv->tty_inqueue);929 930 hvc_kick(); /* wake up hvc thread */931 932unlock_return:933 spin_unlock(&priv->lock);934}935 936/**937 * hvc_iucv_msg_complete() - IUCV handler to process message completion938 * @path: Pending path (struct iucv_path)939 * @msg: Pointer to the IUCV message940 *941 * The function is called upon completion of message delivery to remove the942 * message from the outqueue. Additional delivery information can be found943 * msg->audit: rejected messages (0x040000 (IPADRJCT)), and944 * purged messages (0x010000 (IPADPGNR)).945 *946 * Locking: struct hvc_iucv_private->lock947 */948static void hvc_iucv_msg_complete(struct iucv_path *path,949 struct iucv_message *msg)950{951 struct hvc_iucv_private *priv = path->private;952 struct iucv_tty_buffer *ent, *next;953 LIST_HEAD(list_remove);954 955 spin_lock(&priv->lock);956 list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list)957 if (ent->msg.id == msg->id) {958 list_move(&ent->list, &list_remove);959 break;960 }961 wake_up(&priv->sndbuf_waitq);962 spin_unlock(&priv->lock);963 destroy_tty_buffer_list(&list_remove);964}965 966static ssize_t hvc_iucv_dev_termid_show(struct device *dev,967 struct device_attribute *attr,968 char *buf)969{970 struct hvc_iucv_private *priv = dev_get_drvdata(dev);971 size_t len;972 973 len = sizeof(priv->srv_name);974 memcpy(buf, priv->srv_name, len);975 EBCASC(buf, len);976 buf[len++] = '\n';977 return len;978}979 980static ssize_t hvc_iucv_dev_state_show(struct device *dev,981 struct device_attribute *attr,982 char *buf)983{984 struct hvc_iucv_private *priv = dev_get_drvdata(dev);985 return sprintf(buf, "%u:%u\n", priv->iucv_state, priv->tty_state);986}987 988static ssize_t hvc_iucv_dev_peer_show(struct device *dev,989 struct device_attribute *attr,990 char *buf)991{992 struct hvc_iucv_private *priv = dev_get_drvdata(dev);993 char vmid[9], ipuser[9];994 995 memset(vmid, 0, sizeof(vmid));996 memset(ipuser, 0, sizeof(ipuser));997 998 spin_lock_bh(&priv->lock);999 if (priv->iucv_state == IUCV_CONNECTED) {1000 memcpy(vmid, priv->info_path, 8);1001 memcpy(ipuser, priv->info_path + 8, 8);1002 }1003 spin_unlock_bh(&priv->lock);1004 EBCASC(ipuser, 8);1005 1006 return sprintf(buf, "%s:%s\n", vmid, ipuser);1007}1008 1009 1010/* HVC operations */1011static const struct hv_ops hvc_iucv_ops = {1012 .get_chars = hvc_iucv_get_chars,1013 .put_chars = hvc_iucv_put_chars,1014 .notifier_add = hvc_iucv_notifier_add,1015 .notifier_del = hvc_iucv_notifier_del,1016 .notifier_hangup = hvc_iucv_notifier_hangup,1017 .dtr_rts = hvc_iucv_dtr_rts,1018};1019 1020/* IUCV HVC device attributes */1021static DEVICE_ATTR(termid, 0640, hvc_iucv_dev_termid_show, NULL);1022static DEVICE_ATTR(state, 0640, hvc_iucv_dev_state_show, NULL);1023static DEVICE_ATTR(peer, 0640, hvc_iucv_dev_peer_show, NULL);1024static struct attribute *hvc_iucv_dev_attrs[] = {1025 &dev_attr_termid.attr,1026 &dev_attr_state.attr,1027 &dev_attr_peer.attr,1028 NULL,1029};1030static struct attribute_group hvc_iucv_dev_attr_group = {1031 .attrs = hvc_iucv_dev_attrs,1032};1033static const struct attribute_group *hvc_iucv_dev_attr_groups[] = {1034 &hvc_iucv_dev_attr_group,1035 NULL,1036};1037 1038/**1039 * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance1040 * @id: hvc_iucv_table index1041 * @is_console: Flag if the instance is used as Linux console1042 *1043 * This function allocates a new hvc_iucv_private structure and stores1044 * the instance in hvc_iucv_table at index @id.1045 * Returns 0 on success; otherwise non-zero.1046 */1047static int __init hvc_iucv_alloc(int id, unsigned int is_console)1048{1049 struct hvc_iucv_private *priv;1050 char name[9];1051 int rc;1052 1053 priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL);1054 if (!priv)1055 return -ENOMEM;1056 1057 spin_lock_init(&priv->lock);1058 INIT_LIST_HEAD(&priv->tty_outqueue);1059 INIT_LIST_HEAD(&priv->tty_inqueue);1060 INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work);1061 init_waitqueue_head(&priv->sndbuf_waitq);1062 1063 priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL);1064 if (!priv->sndbuf) {1065 kfree(priv);1066 return -ENOMEM;1067 }1068 1069 /* set console flag */1070 priv->is_console = is_console;1071 1072 /* allocate hvc device */1073 priv->hvc = hvc_alloc(id, /* PAGE_SIZE */1074 id, &hvc_iucv_ops, 256);1075 if (IS_ERR(priv->hvc)) {1076 rc = PTR_ERR(priv->hvc);1077 goto out_error_hvc;1078 }1079 1080 /* notify HVC thread instead of using polling */1081 priv->hvc->irq_requested = 1;1082 1083 /* setup iucv related information */1084 snprintf(name, 9, "lnxhvc%-2d", id);1085 memcpy(priv->srv_name, name, 8);1086 ASCEBC(priv->srv_name, 8);1087 1088 priv->dev = iucv_alloc_device(hvc_iucv_dev_attr_groups, NULL,1089 priv, "hvc_iucv%d", id);1090 if (!priv->dev) {1091 rc = -ENOMEM;1092 goto out_error_dev;1093 }1094 rc = device_register(priv->dev);1095 if (rc) {1096 put_device(priv->dev);1097 goto out_error_dev;1098 }1099 1100 hvc_iucv_table[id] = priv;1101 return 0;1102 1103out_error_dev:1104 hvc_remove(priv->hvc);1105out_error_hvc:1106 free_page((unsigned long) priv->sndbuf);1107 kfree(priv);1108 1109 return rc;1110}1111 1112/**1113 * hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances1114 */1115static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv)1116{1117 hvc_remove(priv->hvc);1118 device_unregister(priv->dev);1119 free_page((unsigned long) priv->sndbuf);1120 kfree(priv);1121}1122 1123/**1124 * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID1125 * @filter: String containing a comma-separated list of z/VM user IDs1126 * @dest: Location where to store the parsed z/VM user ID1127 */1128static const char *hvc_iucv_parse_filter(const char *filter, char *dest)1129{1130 const char *nextdelim, *residual;1131 size_t len;1132 1133 nextdelim = strchr(filter, ',');1134 if (nextdelim) {1135 len = nextdelim - filter;1136 residual = nextdelim + 1;1137 } else {1138 len = strlen(filter);1139 residual = filter + len;1140 }1141 1142 if (len == 0)1143 return ERR_PTR(-EINVAL);1144 1145 /* check for '\n' (if called from sysfs) */1146 if (filter[len - 1] == '\n')1147 len--;1148 1149 /* prohibit filter entries containing the wildcard character only */1150 if (len == 1 && *filter == FILTER_WILDCARD_CHAR)1151 return ERR_PTR(-EINVAL);1152 1153 if (len > 8)1154 return ERR_PTR(-EINVAL);1155 1156 /* pad with blanks and save upper case version of user ID */1157 memset(dest, ' ', 8);1158 while (len--)1159 dest[len] = toupper(filter[len]);1160 return residual;1161}1162 1163/**1164 * hvc_iucv_setup_filter() - Set up z/VM user ID filter1165 * @filter: String consisting of a comma-separated list of z/VM user IDs1166 *1167 * The function parses the @filter string and creates an array containing1168 * the list of z/VM user ID filter entries.1169 * Return code 0 means success, -EINVAL if the filter is syntactically1170 * incorrect, -ENOMEM if there was not enough memory to allocate the1171 * filter list array, or -ENOSPC if too many z/VM user IDs have been specified.1172 */1173static int hvc_iucv_setup_filter(const char *val)1174{1175 const char *residual;1176 int err;1177 size_t size, count;1178 void *array, *old_filter;1179 1180 count = strlen(val);1181 if (count == 0 || (count == 1 && val[0] == '\n')) {1182 size = 0;1183 array = NULL;1184 goto out_replace_filter; /* clear filter */1185 }1186 1187 /* count user IDs in order to allocate sufficient memory */1188 size = 1;1189 residual = val;1190 while ((residual = strchr(residual, ',')) != NULL) {1191 residual++;1192 size++;1193 }1194 1195 /* check if the specified list exceeds the filter limit */1196 if (size > MAX_VMID_FILTER)1197 return -ENOSPC;1198 1199 array = kcalloc(size, 8, GFP_KERNEL);1200 if (!array)1201 return -ENOMEM;1202 1203 count = size;1204 residual = val;1205 while (*residual && count) {1206 residual = hvc_iucv_parse_filter(residual,1207 array + ((size - count) * 8));1208 if (IS_ERR(residual)) {1209 err = PTR_ERR(residual);1210 kfree(array);1211 goto out_err;1212 }1213 count--;1214 }1215 1216out_replace_filter:1217 write_lock_bh(&hvc_iucv_filter_lock);1218 old_filter = hvc_iucv_filter;1219 hvc_iucv_filter_size = size;1220 hvc_iucv_filter = array;1221 write_unlock_bh(&hvc_iucv_filter_lock);1222 kfree(old_filter);1223 1224 err = 0;1225out_err:1226 return err;1227}1228 1229/**1230 * param_set_vmidfilter() - Set z/VM user ID filter parameter1231 * @val: String consisting of a comma-separated list of z/VM user IDs1232 * @kp: Kernel parameter pointing to hvc_iucv_filter array1233 *1234 * The function sets up the z/VM user ID filter specified as comma-separated1235 * list of user IDs in @val.1236 * Note: If it is called early in the boot process, @val is stored and1237 * parsed later in hvc_iucv_init().1238 */1239static int param_set_vmidfilter(const char *val, const struct kernel_param *kp)1240{1241 int rc;1242 1243 if (!MACHINE_IS_VM || !hvc_iucv_devices)1244 return -ENODEV;1245 1246 if (!val)1247 return -EINVAL;1248 1249 rc = 0;1250 if (slab_is_available())1251 rc = hvc_iucv_setup_filter(val);1252 else1253 hvc_iucv_filter_string = val; /* defer... */1254 return rc;1255}1256 1257/**1258 * param_get_vmidfilter() - Get z/VM user ID filter1259 * @buffer: Buffer to store z/VM user ID filter,1260 * (buffer size assumption PAGE_SIZE)1261 * @kp: Kernel parameter pointing to the hvc_iucv_filter array1262 *1263 * The function stores the filter as a comma-separated list of z/VM user IDs1264 * in @buffer. Typically, sysfs routines call this function for attr show.1265 */1266static int param_get_vmidfilter(char *buffer, const struct kernel_param *kp)1267{1268 int rc;1269 size_t index, len;1270 void *start, *end;1271 1272 if (!MACHINE_IS_VM || !hvc_iucv_devices)1273 return -ENODEV;1274 1275 rc = 0;1276 read_lock_bh(&hvc_iucv_filter_lock);1277 for (index = 0; index < hvc_iucv_filter_size; index++) {1278 start = hvc_iucv_filter + (8 * index);1279 end = memchr(start, ' ', 8);1280 len = (end) ? end - start : 8;1281 memcpy(buffer + rc, start, len);1282 rc += len;1283 buffer[rc++] = ',';1284 }1285 read_unlock_bh(&hvc_iucv_filter_lock);1286 if (rc)1287 buffer[--rc] = '\0'; /* replace last comma and update rc */1288 return rc;1289}1290 1291#define param_check_vmidfilter(name, p) __param_check(name, p, void)1292 1293static const struct kernel_param_ops param_ops_vmidfilter = {1294 .set = param_set_vmidfilter,1295 .get = param_get_vmidfilter,1296};1297 1298/**1299 * hvc_iucv_init() - z/VM IUCV HVC device driver initialization1300 */1301static int __init hvc_iucv_init(void)1302{1303 int rc;1304 unsigned int i;1305 1306 if (!hvc_iucv_devices)1307 return -ENODEV;1308 1309 if (!MACHINE_IS_VM) {1310 pr_notice("The z/VM IUCV HVC device driver cannot "1311 "be used without z/VM\n");1312 rc = -ENODEV;1313 goto out_error;1314 }1315 1316 if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) {1317 pr_err("%lu is not a valid value for the hvc_iucv= "1318 "kernel parameter\n", hvc_iucv_devices);1319 rc = -EINVAL;1320 goto out_error;1321 }1322 1323 /* parse hvc_iucv_allow string and create z/VM user ID filter list */1324 if (hvc_iucv_filter_string) {1325 rc = hvc_iucv_setup_filter(hvc_iucv_filter_string);1326 switch (rc) {1327 case 0:1328 break;1329 case -ENOMEM:1330 pr_err("Allocating memory failed with "1331 "reason code=%d\n", 3);1332 goto out_error;1333 case -EINVAL:1334 pr_err("hvc_iucv_allow= does not specify a valid "1335 "z/VM user ID list\n");1336 goto out_error;1337 case -ENOSPC:1338 pr_err("hvc_iucv_allow= specifies too many "1339 "z/VM user IDs\n");1340 goto out_error;1341 default:1342 goto out_error;1343 }1344 }1345 1346 hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT,1347 sizeof(struct iucv_tty_buffer),1348 0, 0, NULL);1349 if (!hvc_iucv_buffer_cache) {1350 pr_err("Allocating memory failed with reason code=%d\n", 1);1351 rc = -ENOMEM;1352 goto out_error;1353 }1354 1355 hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR,1356 hvc_iucv_buffer_cache);1357 if (!hvc_iucv_mempool) {1358 pr_err("Allocating memory failed with reason code=%d\n", 2);1359 kmem_cache_destroy(hvc_iucv_buffer_cache);1360 rc = -ENOMEM;1361 goto out_error;1362 }1363 1364 /* register the first terminal device as console1365 * (must be done before allocating hvc terminal devices) */1366 rc = hvc_instantiate(0, IUCV_HVC_CON_IDX, &hvc_iucv_ops);1367 if (rc) {1368 pr_err("Registering HVC terminal device as "1369 "Linux console failed\n");1370 goto out_error_memory;1371 }1372 1373 /* allocate hvc_iucv_private structs */1374 for (i = 0; i < hvc_iucv_devices; i++) {1375 rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0);1376 if (rc) {1377 pr_err("Creating a new HVC terminal device "1378 "failed with error code=%d\n", rc);1379 goto out_error_hvc;1380 }1381 }1382 1383 /* register IUCV callback handler */1384 rc = iucv_register(&hvc_iucv_handler, 0);1385 if (rc) {1386 pr_err("Registering IUCV handlers failed with error code=%d\n",1387 rc);1388 goto out_error_hvc;1389 }1390 1391 return 0;1392 1393out_error_hvc:1394 for (i = 0; i < hvc_iucv_devices; i++)1395 if (hvc_iucv_table[i])1396 hvc_iucv_destroy(hvc_iucv_table[i]);1397out_error_memory:1398 mempool_destroy(hvc_iucv_mempool);1399 kmem_cache_destroy(hvc_iucv_buffer_cache);1400out_error:1401 kfree(hvc_iucv_filter);1402 hvc_iucv_devices = 0; /* ensure that we do not provide any device */1403 return rc;1404}1405 1406/**1407 * hvc_iucv_config() - Parsing of hvc_iucv= kernel command line parameter1408 * @val: Parameter value (numeric)1409 */1410static int __init hvc_iucv_config(char *val)1411{1412 if (kstrtoul(val, 10, &hvc_iucv_devices))1413 pr_warn("hvc_iucv= invalid parameter value '%s'\n", val);1414 return 1;1415}1416 1417 1418device_initcall(hvc_iucv_init);1419__setup("hvc_iucv=", hvc_iucv_config);1420core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640);1421