drivers/char/hvc_iucv.c

   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 <asm/ebcdic.h>
  16 #include <linux/ctype.h>
  17 #include <linux/delay.h>
  18 #include <linux/device.h>
  19 #include <linux/init.h>
  20 #include <linux/mempool.h>
  21 #include <linux/moduleparam.h>
  22 #include <linux/tty.h>
  23 #include <linux/wait.h>
  24 #include <net/iucv/iucv.h>
  25
  26 #include "hvc_console.h"
  27
  28
  29 /* General device driver settings */
  30 #define HVC_IUCV_MAGIC          0xc9e4c3e5
  31 #define MAX_HVC_IUCV_LINES      HVC_ALLOC_TTY_ADAPTERS
  32 #define MEMPOOL_MIN_NR          (PAGE_SIZE / sizeof(struct iucv_tty_buffer)/4)
  33
  34 /* IUCV TTY message  */
  35 #define MSG_VERSION             0x02    /* Message version */
  36 #define MSG_TYPE_ERROR          0x01    /* Error message */
  37 #define MSG_TYPE_TERMENV        0x02    /* Terminal environment variable */
  38 #define MSG_TYPE_TERMIOS        0x04    /* Terminal IO struct update */
  39 #define MSG_TYPE_WINSIZE        0x08    /* Terminal window size update */
  40 #define MSG_TYPE_DATA           0x10    /* Terminal data */
  41
  42 struct iucv_tty_msg {
  43         u8      version;                /* Message version */
  44         u8      type;                   /* Message type */
  45 #define MSG_MAX_DATALEN         ((u16)(~0))
  46         u16     datalen;                /* Payload length */
  47         u8      data[];                 /* Payload buffer */
  48 } __attribute__((packed));
  49 #define MSG_SIZE(s)             ((s) + offsetof(struct iucv_tty_msg, data))
  50
  51 enum iucv_state_t {
  52         IUCV_DISCONN    = 0,
  53         IUCV_CONNECTED  = 1,
  54         IUCV_SEVERED    = 2,
  55 };
  56
  57 enum tty_state_t {
  58         TTY_CLOSED      = 0,
  59         TTY_OPENED      = 1,
  60 };
  61
  62 struct hvc_iucv_private {
  63         struct hvc_struct       *hvc;           /* HVC struct reference */
  64         u8                      srv_name[8];    /* IUCV service name (ebcdic) */
  65         unsigned char           is_console;     /* Linux console usage flag */
  66         enum iucv_state_t       iucv_state;     /* IUCV connection status */
  67         enum tty_state_t        tty_state;      /* TTY status */
  68         struct iucv_path        *path;          /* IUCV path pointer */
  69         spinlock_t              lock;           /* hvc_iucv_private lock */
  70 #define SNDBUF_SIZE             (PAGE_SIZE)     /* must be < MSG_MAX_DATALEN */
  71         void                    *sndbuf;        /* send buffer            */
  72         size_t                  sndbuf_len;     /* length of send buffer  */
  73 #define QUEUE_SNDBUF_DELAY      (HZ / 25)
  74         struct delayed_work     sndbuf_work;    /* work: send iucv msg(s) */
  75         wait_queue_head_t       sndbuf_waitq;   /* wait for send completion */
  76         struct list_head        tty_outqueue;   /* outgoing IUCV messages */
  77         struct list_head        tty_inqueue;    /* incoming IUCV messages */
  78         struct device           *dev;           /* device structure */
  79 };
  80
  81 struct iucv_tty_buffer {
  82         struct list_head        list;   /* list pointer */
  83         struct iucv_message     msg;    /* store an IUCV message */
  84         size_t                  offset; /* data buffer offset */
  85         struct iucv_tty_msg     *mbuf;  /* buffer to store input/output data */
  86 };
  87
  88 /* IUCV callback handler */
  89 static  int hvc_iucv_path_pending(struct iucv_path *, u8[8], u8[16]);
  90 static void hvc_iucv_path_severed(struct iucv_path *, u8[16]);
  91 static void hvc_iucv_msg_pending(struct iucv_path *, struct iucv_message *);
  92 static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *);
  93
  94
  95 /* Kernel module parameter: use one terminal device as default */
  96 static unsigned long hvc_iucv_devices = 1;
  97
  98 /* Array of allocated hvc iucv tty lines... */
  99 static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES];
 100 #define IUCV_HVC_CON_IDX        (0)
 101 /* List of z/VM user ID filter entries (struct iucv_vmid_filter) */
 102 #define MAX_VMID_FILTER         (500)
 103 static size_t hvc_iucv_filter_size;
 104 static void *hvc_iucv_filter;
 105 static const char *hvc_iucv_filter_string;
 106 static DEFINE_RWLOCK(hvc_iucv_filter_lock);
 107
 108 /* Kmem cache and mempool for iucv_tty_buffer elements */
 109 static struct kmem_cache *hvc_iucv_buffer_cache;
 110 static mempool_t *hvc_iucv_mempool;
 111
 112 /* IUCV handler callback functions */
 113 static struct iucv_handler hvc_iucv_handler = {
 114         .path_pending  = hvc_iucv_path_pending,
 115         .path_severed  = hvc_iucv_path_severed,
 116         .message_complete = hvc_iucv_msg_complete,
 117         .message_pending  = hvc_iucv_msg_pending,
 118 };
 119
 120
 121 /**
 122  * hvc_iucv_get_private() - Return a struct hvc_iucv_private instance.
 123  * @num:        The HVC virtual terminal number (vtermno)
 124  *
 125  * This function returns the struct hvc_iucv_private instance that corresponds
 126  * to the HVC virtual terminal number specified as parameter @num.
 127  */
 128 struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num)
 129 {
 130         if ((num < HVC_IUCV_MAGIC) || (num - HVC_IUCV_MAGIC > hvc_iucv_devices))
 131                 return NULL;
 132         return hvc_iucv_table[num - HVC_IUCV_MAGIC];
 133 }
 134
 135 /**
 136  * alloc_tty_buffer() - Return a new struct iucv_tty_buffer element.
 137  * @size:       Size of the internal buffer used to store data.
 138  * @flags:      Memory allocation flags passed to mempool.
 139  *
 140  * This function allocates a new struct iucv_tty_buffer element and, optionally,
 141  * allocates an internal data buffer with the specified size @size.
 142  * Note: The total message size arises from the internal buffer size and the
 143  *       members of the iucv_tty_msg structure.
 144  * The function returns NULL if memory allocation has failed.
 145  */
 146 static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags)
 147 {
 148         struct iucv_tty_buffer *bufp;
 149
 150         bufp = mempool_alloc(hvc_iucv_mempool, flags);
 151         if (!bufp)
 152                 return NULL;
 153         memset(bufp, 0, sizeof(*bufp));
 154
 155         if (size > 0) {
 156                 bufp->msg.length = MSG_SIZE(size);
 157                 bufp->mbuf = kmalloc(bufp->msg.length, flags);
 158                 if (!bufp->mbuf) {
 159                         mempool_free(bufp, hvc_iucv_mempool);
 160                         return NULL;
 161                 }
 162                 bufp->mbuf->version = MSG_VERSION;
 163                 bufp->mbuf->type    = MSG_TYPE_DATA;
 164                 bufp->mbuf->datalen = (u16) size;
 165         }
 166         return bufp;
 167 }
 168
 169 /**
 170  * destroy_tty_buffer() - destroy struct iucv_tty_buffer element.
 171  * @bufp:       Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL.
 172  */
 173 static void destroy_tty_buffer(struct iucv_tty_buffer *bufp)
 174 {
 175         kfree(bufp->mbuf);
 176         mempool_free(bufp, hvc_iucv_mempool);
 177 }
 178
 179 /**
 180  * destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element.
 181  * @list:       List containing struct iucv_tty_buffer elements.
 182  */
 183 static void destroy_tty_buffer_list(struct list_head *list)
 184 {
 185         struct iucv_tty_buffer *ent, *next;
 186
 187         list_for_each_entry_safe(ent, next, list, list) {
 188                 list_del(&ent->list);
 189                 destroy_tty_buffer(ent);
 190         }
 191 }
 192
 193 /**
 194  * hvc_iucv_write() - Receive IUCV message & write data to HVC buffer.
 195  * @priv:               Pointer to struct hvc_iucv_private
 196  * @buf:                HVC buffer for writing received terminal data.
 197  * @count:              HVC buffer size.
 198  * @has_more_data:      Pointer to an int variable.
 199  *
 200  * The function picks up pending messages from the input queue and receives
 201  * the message data that is then written to the specified buffer @buf.
 202  * If the buffer size @count is less than the data message size, the
 203  * message is kept on the input queue and @has_more_data is set to 1.
 204  * If all message data has been written, the message is removed from
 205  * the input queue.
 206  *
 207  * The function returns the number of bytes written to the terminal, zero if
 208  * there are no pending data messages available or if there is no established
 209  * IUCV path.
 210  * If the IUCV path has been severed, then -EPIPE is returned to cause a
 211  * hang up (that is issued by the HVC layer).
 212  */
 213 static int hvc_iucv_write(struct hvc_iucv_private *priv,
 214                           char *buf, int count, int *has_more_data)
 215 {
 216         struct iucv_tty_buffer *rb;
 217         int written;
 218         int rc;
 219
 220         /* immediately return if there is no IUCV connection */
 221         if (priv->iucv_state == IUCV_DISCONN)
 222                 return 0;
 223
 224         /* if the IUCV path has been severed, return -EPIPE to inform the
 225          * HVC layer to hang up the tty device. */
 226         if (priv->iucv_state == IUCV_SEVERED)
 227                 return -EPIPE;
 228
 229         /* check if there are pending messages */
 230         if (list_empty(&priv->tty_inqueue))
 231                 return 0;
 232
 233         /* receive an iucv message and flip data to the tty (ldisc) */
 234         rb = list_first_entry(&priv->tty_inqueue, struct iucv_tty_buffer, list);
 235
 236         written = 0;
 237         if (!rb->mbuf) { /* message not yet received ... */
 238                 /* allocate mem to store msg data; if no memory is available
 239                  * then leave the buffer on the list and re-try later */
 240                 rb->mbuf = kmalloc(rb->msg.length, GFP_ATOMIC);
 241                 if (!rb->mbuf)
 242                         return -ENOMEM;
 243
 244                 rc = __iucv_message_receive(priv->path, &rb->msg, 0,
 245                                             rb->mbuf, rb->msg.length, NULL);
 246                 switch (rc) {
 247                 case 0: /* Successful       */
 248                         break;
 249                 case 2: /* No message found */
 250                 case 9: /* Message purged   */
 251                         break;
 252                 default:
 253                         written = -EIO;
 254                 }
 255                 /* remove buffer if an error has occured or received data
 256                  * is not correct */
 257                 if (rc || (rb->mbuf->version != MSG_VERSION) ||
 258                           (rb->msg.length    != MSG_SIZE(rb->mbuf->datalen)))
 259                         goto out_remove_buffer;
 260         }
 261
 262         switch (rb->mbuf->type) {
 263         case MSG_TYPE_DATA:
 264                 written = min_t(int, rb->mbuf->datalen - rb->offset, count);
 265                 memcpy(buf, rb->mbuf->data + rb->offset, written);
 266                 if (written < (rb->mbuf->datalen - rb->offset)) {
 267                         rb->offset += written;
 268                         *has_more_data = 1;
 269                         goto out_written;
 270                 }
 271                 break;
 272
 273         case MSG_TYPE_WINSIZE:
 274                 if (rb->mbuf->datalen != sizeof(struct winsize))
 275                         break;
 276                 /* The caller must ensure that the hvc is locked, which
 277                  * is the case when called from hvc_iucv_get_chars() */
 278                 __hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data));
 279                 break;
 280
 281         case MSG_TYPE_ERROR:    /* ignored ... */
 282         case MSG_TYPE_TERMENV:  /* ignored ... */
 283         case MSG_TYPE_TERMIOS:  /* ignored ... */
 284                 break;
 285         }
 286
 287 out_remove_buffer:
 288         list_del(&rb->list);
 289         destroy_tty_buffer(rb);
 290         *has_more_data = !list_empty(&priv->tty_inqueue);
 291
 292 out_written:
 293         return written;
 294 }
 295
 296 /**
 297  * hvc_iucv_get_chars() - HVC get_chars operation.
 298  * @vtermno:    HVC virtual terminal number.
 299  * @buf:        Pointer to a buffer to store data
 300  * @count:      Size of buffer available for writing
 301  *
 302  * The HVC thread calls this method to read characters from the back-end.
 303  * If an IUCV communication path has been established, pending IUCV messages
 304  * are received and data is copied into buffer @buf up to @count bytes.
 305  *
 306  * Locking:     The routine gets called under an irqsave() spinlock; and
 307  *              the routine locks the struct hvc_iucv_private->lock to call
 308  *              helper functions.
 309  */
 310 static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count)
 311 {
 312         struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);
 313         int written;
 314         int has_more_data;
 315
 316         if (count <= 0)
 317                 return 0;
 318
 319         if (!priv)
 320                 return -ENODEV;
 321
 322         spin_lock(&priv->lock);
 323         has_more_data = 0;
 324         written = hvc_iucv_write(priv, buf, count, &has_more_data);
 325         spin_unlock(&priv->lock);
 326
 327         /* if there are still messages on the queue... schedule another run */
 328         if (has_more_data)
 329                 hvc_kick();
 330
 331         return written;
 332 }
 333
 334 /**
 335  * hvc_iucv_queue() - Buffer terminal data for sending.
 336  * @priv:       Pointer to struct hvc_iucv_private instance.
 337  * @buf:        Buffer containing data to send.
 338  * @count:      Size of buffer and amount of data to send.
 339  *
 340  * The function queues data for sending. To actually send the buffered data,
 341  * a work queue function is scheduled (with QUEUE_SNDBUF_DELAY).
 342  * The function returns the number of data bytes that has been buffered.
 343  *
 344  * If the device is not connected, data is ignored and the function returns
 345  * @count.
 346  * If the buffer is full, the function returns 0.
 347  * If an existing IUCV communicaton path has been severed, -EPIPE is returned
 348  * (that can be passed to HVC layer to cause a tty hangup).
 349  */
 350 static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf,
 351                           int count)
 352 {
 353         size_t len;
 354
 355         if (priv->iucv_state == IUCV_DISCONN)
 356                 return count;                   /* ignore data */
 357
 358         if (priv->iucv_state == IUCV_SEVERED)
 359                 return -EPIPE;
 360
 361         len = min_t(size_t, count, SNDBUF_SIZE - priv->sndbuf_len);
 362         if (!len)
 363                 return 0;
 364
 365         memcpy(priv->sndbuf + priv->sndbuf_len, buf, len);
 366         priv->sndbuf_len += len;
 367
 368         if (priv->iucv_state == IUCV_CONNECTED)
 369                 schedule_delayed_work(&priv->sndbuf_work, QUEUE_SNDBUF_DELAY);
 370
 371         return len;
 372 }
 373
 374 /**
 375  * hvc_iucv_send() - Send an IUCV message containing terminal data.
 376  * @priv:       Pointer to struct hvc_iucv_private instance.
 377  *
 378  * If an IUCV communication path has been established, the buffered output data
 379  * is sent via an IUCV message and the number of bytes sent is returned.
 380  * Returns 0 if there is no established IUCV communication path or
 381  * -EPIPE if an existing IUCV communicaton path has been severed.
 382  */
 383 static int hvc_iucv_send(struct hvc_iucv_private *priv)
 384 {
 385         struct iucv_tty_buffer *sb;
 386         int rc, len;
 387
 388         if (priv->iucv_state == IUCV_SEVERED)
 389                 return -EPIPE;
 390
 391         if (priv->iucv_state == IUCV_DISCONN)
 392                 return -EIO;
 393
 394         if (!priv->sndbuf_len)
 395                 return 0;
 396
 397         /* allocate internal buffer to store msg data and also compute total
 398          * message length */
 399         sb = alloc_tty_buffer(priv->sndbuf_len, GFP_ATOMIC);
 400         if (!sb)
 401                 return -ENOMEM;
 402
 403         memcpy(sb->mbuf->data, priv->sndbuf, priv->sndbuf_len);
 404         sb->mbuf->datalen = (u16) priv->sndbuf_len;
 405         sb->msg.length = MSG_SIZE(sb->mbuf->datalen);
 406
 407         list_add_tail(&sb->list, &priv->tty_outqueue);
 408
 409         rc = __iucv_message_send(priv->path, &sb->msg, 0, 0,
 410                                  (void *) sb->mbuf, sb->msg.length);
 411         if (rc) {
 412                 /* drop the message here; however we might want to handle
 413                  * 0x03 (msg limit reached) by trying again... */
 414                 list_del(&sb->list);
 415                 destroy_tty_buffer(sb);
 416         }
 417         len = priv->sndbuf_len;
 418         priv->sndbuf_len = 0;
 419
 420         return len;
 421 }
 422
 423 /**
 424  * hvc_iucv_sndbuf_work() - Send buffered data over IUCV
 425  * @work:       Work structure.
 426  *
 427  * This work queue function sends buffered output data over IUCV and,
 428  * if not all buffered data could be sent, reschedules itself.
 429  */
 430 static void hvc_iucv_sndbuf_work(struct work_struct *work)
 431 {
 432         struct hvc_iucv_private *priv;
 433
 434         priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work);
 435         if (!priv)
 436                 return;
 437
 438         spin_lock_bh(&priv->lock);
 439         hvc_iucv_send(priv);
 440         spin_unlock_bh(&priv->lock);
 441 }
 442
 443 /**
 444  * hvc_iucv_put_chars() - HVC put_chars operation.
 445  * @vtermno:    HVC virtual terminal number.
 446  * @buf:        Pointer to an buffer to read data from
 447  * @count:      Size of buffer available for reading
 448  *
 449  * The HVC thread calls this method to write characters to the back-end.
 450  * The function calls hvc_iucv_queue() to queue terminal data for sending.
 451  *
 452  * Locking:     The method gets called under an irqsave() spinlock; and
 453  *              locks struct hvc_iucv_private->lock.
 454  */
 455 static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count)
 456 {
 457         struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);
 458         int queued;
 459
 460         if (count <= 0)
 461                 return 0;
 462
 463         if (!priv)
 464                 return -ENODEV;
 465
 466         spin_lock(&priv->lock);
 467         queued = hvc_iucv_queue(priv, buf, count);
 468         spin_unlock(&priv->lock);
 469
 470         return queued;
 471 }
 472
 473 /**
 474  * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time.
 475  * @hp: Pointer to the HVC device (struct hvc_struct)
 476  * @id: Additional data (originally passed to hvc_alloc): the index of an struct
 477  *      hvc_iucv_private instance.
 478  *
 479  * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private
 480  * instance that is derived from @id. Always returns 0.
 481  *
 482  * Locking:     struct hvc_iucv_private->lock, spin_lock_bh
 483  */
 484 static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id)
 485 {
 486         struct hvc_iucv_private *priv;
 487
 488         priv = hvc_iucv_get_private(id);
 489         if (!priv)
 490                 return 0;
 491
 492         spin_lock_bh(&priv->lock);
 493         priv->tty_state = TTY_OPENED;
 494         spin_unlock_bh(&priv->lock);
 495
 496         return 0;
 497 }
 498
 499 /**
 500  * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance.
 501  * @priv:       Pointer to the struct hvc_iucv_private instance.
 502  */
 503 static void hvc_iucv_cleanup(struct hvc_iucv_private *priv)
 504 {
 505         destroy_tty_buffer_list(&priv->tty_outqueue);
 506         destroy_tty_buffer_list(&priv->tty_inqueue);
 507
 508         priv->tty_state = TTY_CLOSED;
 509         priv->iucv_state = IUCV_DISCONN;
 510
 511         priv->sndbuf_len = 0;
 512 }
 513
 514 /**
 515  * tty_outqueue_empty() - Test if the tty outq is empty
 516  * @priv:       Pointer to struct hvc_iucv_private instance.
 517  */
 518 static inline int tty_outqueue_empty(struct hvc_iucv_private *priv)
 519 {
 520         int rc;
 521
 522         spin_lock_bh(&priv->lock);
 523         rc = list_empty(&priv->tty_outqueue);
 524         spin_unlock_bh(&priv->lock);
 525
 526         return rc;
 527 }
 528
 529 /**
 530  * flush_sndbuf_sync() - Flush send buffer and wait for completion
 531  * @priv:       Pointer to struct hvc_iucv_private instance.
 532  *
 533  * The routine cancels a pending sndbuf work, calls hvc_iucv_send()
 534  * to flush any buffered terminal output data and waits for completion.
 535  */
 536 static void flush_sndbuf_sync(struct hvc_iucv_private *priv)
 537 {
 538         int sync_wait;
 539
 540         cancel_delayed_work_sync(&priv->sndbuf_work);
 541
 542         spin_lock_bh(&priv->lock);
 543         hvc_iucv_send(priv);            /* force sending buffered data */
 544         sync_wait = !list_empty(&priv->tty_outqueue); /* anything queued ? */
 545         spin_unlock_bh(&priv->lock);
 546
 547         if (sync_wait)
 548                 wait_event_timeout(priv->sndbuf_waitq,
 549                                    tty_outqueue_empty(priv), HZ/10);
 550 }
 551
 552 /**
 553  * hvc_iucv_hangup() - Sever IUCV path and schedule hvc tty hang up
 554  * @priv:       Pointer to hvc_iucv_private structure
 555  *
 556  * This routine severs an existing IUCV communication path and hangs
 557  * up the underlying HVC terminal device.
 558  * The hang-up occurs only if an IUCV communication path is established;
 559  * otherwise there is no need to hang up the terminal device.
 560  *
 561  * The IUCV HVC hang-up is separated into two steps:
 562  * 1. After the IUCV path has been severed, the iucv_state is set to
 563  *    IUCV_SEVERED.
 564  * 2. Later, when the HVC thread calls hvc_iucv_get_chars(), the
 565  *    IUCV_SEVERED state causes the tty hang-up in the HVC layer.
 566  *
 567  * If the tty has not yet been opened, clean up the hvc_iucv_private
 568  * structure to allow re-connects.
 569  * If the tty has been opened, let get_chars() return -EPIPE to signal
 570  * the HVC layer to hang up the tty and, if so, wake up the HVC thread
 571  * to call get_chars()...
 572  *
 573  * Special notes on hanging up a HVC terminal instantiated as console:
 574  * Hang-up:     1. do_tty_hangup() replaces file ops (= hung_up_tty_fops)
 575  *              2. do_tty_hangup() calls tty->ops->close() for console_filp
 576  *                      => no hangup notifier is called by HVC (default)
 577  *              2. hvc_close() returns because of tty_hung_up_p(filp)
 578  *                      => no delete notifier is called!
 579  * Finally, the back-end is not being notified, thus, the tty session is
 580  * kept active (TTY_OPEN) to be ready for re-connects.
 581  *
 582  * Locking:     spin_lock(&priv->lock) w/o disabling bh
 583  */
 584 static void hvc_iucv_hangup(struct hvc_iucv_private *priv)
 585 {
 586         struct iucv_path *path;
 587
 588         path = NULL;
 589         spin_lock(&priv->lock);
 590         if (priv->iucv_state == IUCV_CONNECTED) {
 591                 path = priv->path;
 592                 priv->path = NULL;
 593                 priv->iucv_state = IUCV_SEVERED;
 594                 if (priv->tty_state == TTY_CLOSED)
 595                         hvc_iucv_cleanup(priv);
 596                 else
 597                         /* console is special (see above) */
 598                         if (priv->is_console) {
 599                                 hvc_iucv_cleanup(priv);
 600                                 priv->tty_state = TTY_OPENED;
 601                         } else
 602                                 hvc_kick();
 603         }
 604         spin_unlock(&priv->lock);
 605
 606         /* finally sever path (outside of priv->lock due to lock ordering) */
 607         if (path) {
 608                 iucv_path_sever(path, NULL);
 609                 iucv_path_free(path);
 610         }
 611 }
 612
 613 /**
 614  * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups.
 615  * @hp:         Pointer to the HVC device (struct hvc_struct)
 616  * @id:         Additional data (originally passed to hvc_alloc):
 617  *              the index of an struct hvc_iucv_private instance.
 618  *
 619  * This routine notifies the HVC back-end that a tty hangup (carrier loss,
 620  * virtual or otherwise) has occured.
 621  * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup())
 622  * to keep an existing IUCV communication path established.
 623  * (Background: vhangup() is called from user space (by getty or login) to
 624  *              disable writing to the tty by other applications).
 625  * If the tty has been opened and an established IUCV path has been severed
 626  * (we caused the tty hangup), the function calls hvc_iucv_cleanup().
 627  *
 628  * Locking:     struct hvc_iucv_private->lock
 629  */
 630 static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id)
 631 {
 632         struct hvc_iucv_private *priv;
 633
 634         priv = hvc_iucv_get_private(id);
 635         if (!priv)
 636                 return;
 637
 638         flush_sndbuf_sync(priv);
 639
 640         spin_lock_bh(&priv->lock);
 641         /* NOTE: If the hangup was scheduled by ourself (from the iucv
 642          *       path_servered callback [IUCV_SEVERED]), we have to clean up
 643          *       our structure and to set state to TTY_CLOSED.
 644          *       If the tty was hung up otherwise (e.g. vhangup()), then we
 645          *       ignore this hangup and keep an established IUCV path open...
 646          *       (...the reason is that we are not able to connect back to the
 647          *       client if we disconnect on hang up) */
 648         priv->tty_state = TTY_CLOSED;
 649
 650         if (priv->iucv_state == IUCV_SEVERED)
 651                 hvc_iucv_cleanup(priv);
 652         spin_unlock_bh(&priv->lock);
 653 }
 654
 655 /**
 656  * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time.
 657  * @hp:         Pointer to the HVC device (struct hvc_struct)
 658  * @id:         Additional data (originally passed to hvc_alloc):
 659  *              the index of an struct hvc_iucv_private instance.
 660  *
 661  * This routine notifies the HVC back-end that the last tty device fd has been
 662  * closed.  The function calls hvc_iucv_cleanup() to clean up the struct
 663  * hvc_iucv_private instance.
 664  *
 665  * Locking:     struct hvc_iucv_private->lock
 666  */
 667 static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id)
 668 {
 669         struct hvc_iucv_private *priv;
 670         struct iucv_path        *path;
 671
 672         priv = hvc_iucv_get_private(id);
 673         if (!priv)
 674                 return;
 675
 676         flush_sndbuf_sync(priv);
 677
 678         spin_lock_bh(&priv->lock);
 679         path = priv->path;              /* save reference to IUCV path */
 680         priv->path = NULL;
 681         hvc_iucv_cleanup(priv);
 682         spin_unlock_bh(&priv->lock);
 683
 684         /* sever IUCV path outside of priv->lock due to lock ordering of:
 685          * priv->lock <--> iucv_table_lock */
 686         if (path) {
 687                 iucv_path_sever(path, NULL);
 688                 iucv_path_free(path);
 689         }
 690 }
 691
 692 /**
 693  * hvc_iucv_filter_connreq() - Filter connection request based on z/VM user ID
 694  * @ipvmid:     Originating z/VM user ID (right padded with blanks)
 695  *
 696  * Returns 0 if the z/VM user ID @ipvmid is allowed to connection, otherwise
 697  * non-zero.
 698  */
 699 static int hvc_iucv_filter_connreq(u8 ipvmid[8])
 700 {
 701         size_t i;
 702
 703         /* Note: default policy is ACCEPT if no filter is set */
 704         if (!hvc_iucv_filter_size)
 705                 return 0;
 706
 707         for (i = 0; i < hvc_iucv_filter_size; i++)
 708                 if (0 == memcmp(ipvmid, hvc_iucv_filter + (8 * i), 8))
 709                         return 0;
 710         return 1;
 711 }
 712
 713 /**
 714  * hvc_iucv_path_pending() - IUCV handler to process a connection request.
 715  * @path:       Pending path (struct iucv_path)
 716  * @ipvmid:     z/VM system identifier of originator
 717  * @ipuser:     User specified data for this path
 718  *              (AF_IUCV: port/service name and originator port)
 719  *
 720  * The function uses the @ipuser data to determine if the pending path belongs
 721  * to a terminal managed by this device driver.
 722  * If the path belongs to this driver, ensure that the terminal is not accessed
 723  * multiple times (only one connection to a terminal is allowed).
 724  * If the terminal is not yet connected, the pending path is accepted and is
 725  * associated to the appropriate struct hvc_iucv_private instance.
 726  *
 727  * Returns 0 if @path belongs to a terminal managed by the this device driver;
 728  * otherwise returns -ENODEV in order to dispatch this path to other handlers.
 729  *
 730  * Locking:     struct hvc_iucv_private->lock
 731  */
 732 static  int hvc_iucv_path_pending(struct iucv_path *path,
 733                                   u8 ipvmid[8], u8 ipuser[16])
 734 {
 735         struct hvc_iucv_private *priv;
 736         u8 nuser_data[16];
 737         u8 vm_user_id[9];
 738         int i, rc;
 739
 740         priv = NULL;
 741         for (i = 0; i < hvc_iucv_devices; i++)
 742                 if (hvc_iucv_table[i] &&
 743                     (0 == memcmp(hvc_iucv_table[i]->srv_name, ipuser, 8))) {
 744                         priv = hvc_iucv_table[i];
 745                         break;
 746                 }
 747         if (!priv)
 748                 return -ENODEV;
 749
 750         /* Enforce that ipvmid is allowed to connect to us */
 751         read_lock(&hvc_iucv_filter_lock);
 752         rc = hvc_iucv_filter_connreq(ipvmid);
 753         read_unlock(&hvc_iucv_filter_lock);
 754         if (rc) {
 755                 iucv_path_sever(path, ipuser);
 756                 iucv_path_free(path);
 757                 memcpy(vm_user_id, ipvmid, 8);
 758                 vm_user_id[8] = 0;
 759                 pr_info("A connection request from z/VM user ID %s "
 760                         "was refused\n", vm_user_id);
 761                 return 0;
 762         }
 763
 764         spin_lock(&priv->lock);
 765
 766         /* If the terminal is already connected or being severed, then sever
 767          * this path to enforce that there is only ONE established communication
 768          * path per terminal. */
 769         if (priv->iucv_state != IUCV_DISCONN) {
 770                 iucv_path_sever(path, ipuser);
 771                 iucv_path_free(path);
 772                 goto out_path_handled;
 773         }
 774
 775         /* accept path */
 776         memcpy(nuser_data, ipuser + 8, 8);  /* remote service (for af_iucv) */
 777         memcpy(nuser_data + 8, ipuser, 8);  /* local service  (for af_iucv) */
 778         path->msglim = 0xffff;              /* IUCV MSGLIMIT */
 779         path->flags &= ~IUCV_IPRMDATA;      /* TODO: use IUCV_IPRMDATA */
 780         rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv);
 781         if (rc) {
 782                 iucv_path_sever(path, ipuser);
 783                 iucv_path_free(path);
 784                 goto out_path_handled;
 785         }
 786         priv->path = path;
 787         priv->iucv_state = IUCV_CONNECTED;
 788
 789         /* flush buffered output data... */
 790         schedule_delayed_work(&priv->sndbuf_work, 5);
 791
 792 out_path_handled:
 793         spin_unlock(&priv->lock);
 794         return 0;
 795 }
 796
 797 /**
 798  * hvc_iucv_path_severed() - IUCV handler to process a path sever.
 799  * @path:       Pending path (struct iucv_path)
 800  * @ipuser:     User specified data for this path
 801  *              (AF_IUCV: port/service name and originator port)
 802  *
 803  * This function calls the hvc_iucv_hangup() function for the
 804  * respective IUCV HVC terminal.
 805  *
 806  * Locking:     struct hvc_iucv_private->lock
 807  */
 808 static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16])
 809 {
 810         struct hvc_iucv_private *priv = path->private;
 811
 812         hvc_iucv_hangup(priv);
 813 }
 814
 815 /**
 816  * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message.
 817  * @path:       Pending path (struct iucv_path)
 818  * @msg:        Pointer to the IUCV message
 819  *
 820  * The function puts an incoming message on the input queue for later
 821  * processing (by hvc_iucv_get_chars() / hvc_iucv_write()).
 822  * If the tty has not yet been opened, the message is rejected.
 823  *
 824  * Locking:     struct hvc_iucv_private->lock
 825  */
 826 static void hvc_iucv_msg_pending(struct iucv_path *path,
 827                                  struct iucv_message *msg)
 828 {
 829         struct hvc_iucv_private *priv = path->private;
 830         struct iucv_tty_buffer *rb;
 831
 832         /* reject messages that exceed max size of iucv_tty_msg->datalen */
 833         if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) {
 834                 iucv_message_reject(path, msg);
 835                 return;
 836         }
 837
 838         spin_lock(&priv->lock);
 839
 840         /* reject messages if tty has not yet been opened */
 841         if (priv->tty_state == TTY_CLOSED) {
 842                 iucv_message_reject(path, msg);
 843                 goto unlock_return;
 844         }
 845
 846         /* allocate tty buffer to save iucv msg only */
 847         rb = alloc_tty_buffer(0, GFP_ATOMIC);
 848         if (!rb) {
 849                 iucv_message_reject(path, msg);
 850                 goto unlock_return;     /* -ENOMEM */
 851         }
 852         rb->msg = *msg;
 853
 854         list_add_tail(&rb->list, &priv->tty_inqueue);
 855
 856         hvc_kick();     /* wake up hvc thread */
 857
 858 unlock_return:
 859         spin_unlock(&priv->lock);
 860 }
 861
 862 /**
 863  * hvc_iucv_msg_complete() - IUCV handler to process message completion
 864  * @path:       Pending path (struct iucv_path)
 865  * @msg:        Pointer to the IUCV message
 866  *
 867  * The function is called upon completion of message delivery to remove the
 868  * message from the outqueue. Additional delivery information can be found
 869  * msg->audit: rejected messages (0x040000 (IPADRJCT)), and
 870  *             purged messages   (0x010000 (IPADPGNR)).
 871  *
 872  * Locking:     struct hvc_iucv_private->lock
 873  */
 874 static void hvc_iucv_msg_complete(struct iucv_path *path,
 875                                   struct iucv_message *msg)
 876 {
 877         struct hvc_iucv_private *priv = path->private;
 878         struct iucv_tty_buffer  *ent, *next;
 879         LIST_HEAD(list_remove);
 880
 881         spin_lock(&priv->lock);
 882         list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list)
 883                 if (ent->msg.id == msg->id) {
 884                         list_move(&ent->list, &list_remove);
 885                         break;
 886                 }
 887         wake_up(&priv->sndbuf_waitq);
 888         spin_unlock(&priv->lock);
 889         destroy_tty_buffer_list(&list_remove);
 890 }
 891
 892 /**
 893  * hvc_iucv_pm_freeze() - Freeze PM callback
 894  * @dev:        IUVC HVC terminal device
 895  *
 896  * Sever an established IUCV communication path and
 897  * trigger a hang-up of the underlying HVC terminal.
 898  */
 899 static int hvc_iucv_pm_freeze(struct device *dev)
 900 {
 901         struct hvc_iucv_private *priv = dev_get_drvdata(dev);
 902
 903         local_bh_disable();
 904         hvc_iucv_hangup(priv);
 905         local_bh_enable();
 906
 907         return 0;
 908 }
 909
 910 /**
 911  * hvc_iucv_pm_restore_thaw() - Thaw and restore PM callback
 912  * @dev:        IUVC HVC terminal device
 913  *
 914  * Wake up the HVC thread to trigger hang-up and respective
 915  * HVC back-end notifier invocations.
 916  */
 917 static int hvc_iucv_pm_restore_thaw(struct device *dev)
 918 {
 919         hvc_kick();
 920         return 0;
 921 }
 922
 923
 924 /* HVC operations */
 925 static struct hv_ops hvc_iucv_ops = {
 926         .get_chars = hvc_iucv_get_chars,
 927         .put_chars = hvc_iucv_put_chars,
 928         .notifier_add = hvc_iucv_notifier_add,
 929         .notifier_del = hvc_iucv_notifier_del,
 930         .notifier_hangup = hvc_iucv_notifier_hangup,
 931 };
 932
 933 /* Suspend / resume device operations */
 934 static struct dev_pm_ops hvc_iucv_pm_ops = {
 935         .freeze   = hvc_iucv_pm_freeze,
 936         .thaw     = hvc_iucv_pm_restore_thaw,
 937         .restore  = hvc_iucv_pm_restore_thaw,
 938 };
 939
 940 /* IUCV HVC device driver */
 941 static struct device_driver hvc_iucv_driver = {
 942         .name = KMSG_COMPONENT,
 943         .bus  = &iucv_bus,
 944         .pm   = &hvc_iucv_pm_ops,
 945 };
 946
 947 /**
 948  * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance
 949  * @id:                 hvc_iucv_table index
 950  * @is_console:         Flag if the instance is used as Linux console
 951  *
 952  * This function allocates a new hvc_iucv_private structure and stores
 953  * the instance in hvc_iucv_table at index @id.
 954  * Returns 0 on success; otherwise non-zero.
 955  */
 956 static int __init hvc_iucv_alloc(int id, unsigned int is_console)
 957 {
 958         struct hvc_iucv_private *priv;
 959         char name[9];
 960         int rc;
 961
 962         priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL);
 963         if (!priv)
 964                 return -ENOMEM;
 965
 966         spin_lock_init(&priv->lock);
 967         INIT_LIST_HEAD(&priv->tty_outqueue);
 968         INIT_LIST_HEAD(&priv->tty_inqueue);
 969         INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work);
 970         init_waitqueue_head(&priv->sndbuf_waitq);
 971
 972         priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL);
 973         if (!priv->sndbuf) {
 974                 kfree(priv);
 975                 return -ENOMEM;
 976         }
 977
 978         /* set console flag */
 979         priv->is_console = is_console;
 980
 981         /* allocate hvc device */
 982         priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /*             PAGE_SIZE */
 983                               HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256);
 984         if (IS_ERR(priv->hvc)) {
 985                 rc = PTR_ERR(priv->hvc);
 986                 goto out_error_hvc;
 987         }
 988
 989         /* notify HVC thread instead of using polling */
 990         priv->hvc->irq_requested = 1;
 991
 992         /* setup iucv related information */
 993         snprintf(name, 9, "lnxhvc%-2d", id);
 994         memcpy(priv->srv_name, name, 8);
 995         ASCEBC(priv->srv_name, 8);
 996
 997         /* create and setup device */
 998         priv->dev = kzalloc(sizeof(*priv->dev), GFP_KERNEL);
 999         if (!priv->dev) {
1000                 rc = -ENOMEM;
1001                 goto out_error_dev;
1002         }
1003         dev_set_name(priv->dev, "hvc_iucv%d", id);
1004         dev_set_drvdata(priv->dev, priv);
1005         priv->dev->bus = &iucv_bus;
1006         priv->dev->parent = iucv_root;
1007         priv->dev->driver = &hvc_iucv_driver;
1008         priv->dev->release = (void (*)(struct device *)) kfree;
1009         rc = device_register(priv->dev);
1010         if (rc) {
1011                 put_device(priv->dev);
1012                 goto out_error_dev;
1013         }
1014
1015         hvc_iucv_table[id] = priv;
1016         return 0;
1017
1018 out_error_dev:
1019         hvc_remove(priv->hvc);
1020 out_error_hvc:
1021         free_page((unsigned long) priv->sndbuf);
1022         kfree(priv);
1023
1024         return rc;
1025 }
1026
1027 /**
1028  * hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances
1029  */
1030 static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv)
1031 {
1032         hvc_remove(priv->hvc);
1033         device_unregister(priv->dev);
1034         free_page((unsigned long) priv->sndbuf);
1035         kfree(priv);
1036 }
1037
1038 /**
1039  * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID
1040  * @filter:     String containing a comma-separated list of z/VM user IDs
1041  */
1042 static const char *hvc_iucv_parse_filter(const char *filter, char *dest)
1043 {
1044         const char *nextdelim, *residual;
1045         size_t len;
1046
1047         nextdelim = strchr(filter, ',');
1048         if (nextdelim) {
1049                 len = nextdelim - filter;
1050                 residual = nextdelim + 1;
1051         } else {
1052                 len = strlen(filter);
1053                 residual = filter + len;
1054         }
1055
1056         if (len == 0)
1057                 return ERR_PTR(-EINVAL);
1058
1059         /* check for '\n' (if called from sysfs) */
1060         if (filter[len - 1] == '\n')
1061                 len--;
1062
1063         if (len > 8)
1064                 return ERR_PTR(-EINVAL);
1065
1066         /* pad with blanks and save upper case version of user ID */
1067         memset(dest, ' ', 8);
1068         while (len--)
1069                 dest[len] = toupper(filter[len]);
1070         return residual;
1071 }
1072
1073 /**
1074  * hvc_iucv_setup_filter() - Set up z/VM user ID filter
1075  * @filter:     String consisting of a comma-separated list of z/VM user IDs
1076  *
1077  * The function parses the @filter string and creates an array containing
1078  * the list of z/VM user ID filter entries.
1079  * Return code 0 means success, -EINVAL if the filter is syntactically
1080  * incorrect, -ENOMEM if there was not enough memory to allocate the
1081  * filter list array, or -ENOSPC if too many z/VM user IDs have been specified.
1082  */
1083 static int hvc_iucv_setup_filter(const char *val)
1084 {
1085         const char *residual;
1086         int err;
1087         size_t size, count;
1088         void *array, *old_filter;
1089
1090         count = strlen(val);
1091         if (count == 0 || (count == 1 && val[0] == '\n')) {
1092                 size  = 0;
1093                 array = NULL;
1094                 goto out_replace_filter;        /* clear filter */
1095         }
1096
1097         /* count user IDs in order to allocate sufficient memory */
1098         size = 1;
1099         residual = val;
1100         while ((residual = strchr(residual, ',')) != NULL) {
1101                 residual++;
1102                 size++;
1103         }
1104
1105         /* check if the specified list exceeds the filter limit */
1106         if (size > MAX_VMID_FILTER)
1107                 return -ENOSPC;
1108
1109         array = kzalloc(size * 8, GFP_KERNEL);
1110         if (!array)
1111                 return -ENOMEM;
1112
1113         count = size;
1114         residual = val;
1115         while (*residual && count) {
1116                 residual = hvc_iucv_parse_filter(residual,
1117                                                  array + ((size - count) * 8));
1118                 if (IS_ERR(residual)) {
1119                         err = PTR_ERR(residual);
1120                         kfree(array);
1121                         goto out_err;
1122                 }
1123                 count--;
1124         }
1125
1126 out_replace_filter:
1127         write_lock_bh(&hvc_iucv_filter_lock);
1128         old_filter = hvc_iucv_filter;
1129         hvc_iucv_filter_size = size;
1130         hvc_iucv_filter = array;
1131         write_unlock_bh(&hvc_iucv_filter_lock);
1132         kfree(old_filter);
1133
1134         err = 0;
1135 out_err:
1136         return err;
1137 }
1138
1139 /**
1140  * param_set_vmidfilter() - Set z/VM user ID filter parameter
1141  * @val:        String consisting of a comma-separated list of z/VM user IDs
1142  * @kp:         Kernel parameter pointing to hvc_iucv_filter array
1143  *
1144  * The function sets up the z/VM user ID filter specified as comma-separated
1145  * list of user IDs in @val.
1146  * Note: If it is called early in the boot process, @val is stored and
1147  *       parsed later in hvc_iucv_init().
1148  */
1149 static int param_set_vmidfilter(const char *val, struct kernel_param *kp)
1150 {
1151         int rc;
1152
1153         if (!MACHINE_IS_VM || !hvc_iucv_devices)
1154                 return -ENODEV;
1155
1156         if (!val)
1157                 return -EINVAL;
1158
1159         rc = 0;
1160         if (slab_is_available())
1161                 rc = hvc_iucv_setup_filter(val);
1162         else
1163                 hvc_iucv_filter_string = val;   /* defer... */
1164         return rc;
1165 }
1166
1167 /**
1168  * param_get_vmidfilter() - Get z/VM user ID filter
1169  * @buffer:     Buffer to store z/VM user ID filter,
1170  *              (buffer size assumption PAGE_SIZE)
1171  * @kp:         Kernel parameter pointing to the hvc_iucv_filter array
1172  *
1173  * The function stores the filter as a comma-separated list of z/VM user IDs
1174  * in @buffer. Typically, sysfs routines call this function for attr show.
1175  */
1176 static int param_get_vmidfilter(char *buffer, struct kernel_param *kp)
1177 {
1178         int rc;
1179         size_t index, len;
1180         void *start, *end;
1181
1182         if (!MACHINE_IS_VM || !hvc_iucv_devices)
1183                 return -ENODEV;
1184
1185         rc = 0;
1186         read_lock_bh(&hvc_iucv_filter_lock);
1187         for (index = 0; index < hvc_iucv_filter_size; index++) {
1188                 start = hvc_iucv_filter + (8 * index);
1189                 end   = memchr(start, ' ', 8);
1190                 len   = (end) ? end - start : 8;
1191                 memcpy(buffer + rc, start, len);
1192                 rc += len;
1193                 buffer[rc++] = ',';
1194         }
1195         read_unlock_bh(&hvc_iucv_filter_lock);
1196         if (rc)
1197                 buffer[--rc] = '\0';    /* replace last comma and update rc */
1198         return rc;
1199 }
1200
1201 #define param_check_vmidfilter(name, p) __param_check(name, p, void)
1202
1203 /**
1204  * hvc_iucv_init() - z/VM IUCV HVC device driver initialization
1205  */
1206 static int __init hvc_iucv_init(void)
1207 {
1208         int rc;
1209         unsigned int i;
1210
1211         if (!hvc_iucv_devices)
1212                 return -ENODEV;
1213
1214         if (!MACHINE_IS_VM) {
1215                 pr_notice("The z/VM IUCV HVC device driver cannot "
1216                            "be used without z/VM\n");
1217                 rc = -ENODEV;
1218                 goto out_error;
1219         }
1220
1221         if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) {
1222                 pr_err("%lu is not a valid value for the hvc_iucv= "
1223                         "kernel parameter\n", hvc_iucv_devices);
1224                 rc = -EINVAL;
1225                 goto out_error;
1226         }
1227
1228         /* register IUCV HVC device driver */
1229         rc = driver_register(&hvc_iucv_driver);
1230         if (rc)
1231                 goto out_error;
1232
1233         /* parse hvc_iucv_allow string and create z/VM user ID filter list */
1234         if (hvc_iucv_filter_string) {
1235                 rc = hvc_iucv_setup_filter(hvc_iucv_filter_string);
1236                 switch (rc) {
1237                 case 0:
1238                         break;
1239                 case -ENOMEM:
1240                         pr_err("Allocating memory failed with "
1241                                 "reason code=%d\n", 3);
1242                         goto out_error;
1243                 case -EINVAL:
1244                         pr_err("hvc_iucv_allow= does not specify a valid "
1245                                 "z/VM user ID list\n");
1246                         goto out_error;
1247                 case -ENOSPC:
1248                         pr_err("hvc_iucv_allow= specifies too many "
1249                                 "z/VM user IDs\n");
1250                         goto out_error;
1251                 default:
1252                         goto out_error;
1253                 }
1254         }
1255
1256         hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT,
1257                                            sizeof(struct iucv_tty_buffer),
1258                                            0, 0, NULL);
1259         if (!hvc_iucv_buffer_cache) {
1260                 pr_err("Allocating memory failed with reason code=%d\n", 1);
1261                 rc = -ENOMEM;
1262                 goto out_error;
1263         }
1264
1265         hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR,
1266                                                     hvc_iucv_buffer_cache);
1267         if (!hvc_iucv_mempool) {
1268                 pr_err("Allocating memory failed with reason code=%d\n", 2);
1269                 kmem_cache_destroy(hvc_iucv_buffer_cache);
1270                 rc = -ENOMEM;
1271                 goto out_error;
1272         }
1273
1274         /* register the first terminal device as console
1275          * (must be done before allocating hvc terminal devices) */
1276         rc = hvc_instantiate(HVC_IUCV_MAGIC, IUCV_HVC_CON_IDX, &hvc_iucv_ops);
1277         if (rc) {
1278                 pr_err("Registering HVC terminal device as "
1279                        "Linux console failed\n");
1280                 goto out_error_memory;
1281         }
1282
1283         /* allocate hvc_iucv_private structs */
1284         for (i = 0; i < hvc_iucv_devices; i++) {
1285                 rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0);
1286                 if (rc) {
1287                         pr_err("Creating a new HVC terminal device "
1288                                 "failed with error code=%d\n", rc);
1289                         goto out_error_hvc;
1290                 }
1291         }
1292
1293         /* register IUCV callback handler */
1294         rc = iucv_register(&hvc_iucv_handler, 0);
1295         if (rc) {
1296                 pr_err("Registering IUCV handlers failed with error code=%d\n",
1297                         rc);
1298                 goto out_error_iucv;
1299         }
1300
1301         return 0;
1302
1303 out_error_iucv:
1304         iucv_unregister(&hvc_iucv_handler, 0);
1305 out_error_hvc:
1306         for (i = 0; i < hvc_iucv_devices; i++)
1307                 if (hvc_iucv_table[i])
1308                         hvc_iucv_destroy(hvc_iucv_table[i]);
1309 out_error_memory:
1310         mempool_destroy(hvc_iucv_mempool);
1311         kmem_cache_destroy(hvc_iucv_buffer_cache);
1312 out_error:
1313         if (hvc_iucv_filter)
1314                 kfree(hvc_iucv_filter);
1315         hvc_iucv_devices = 0; /* ensure that we do not provide any device */
1316         return rc;
1317 }
1318
1319 /**
1320  * hvc_iucv_config() - Parsing of hvc_iucv=  kernel command line parameter
1321  * @val:        Parameter value (numeric)
1322  */
1323 static  int __init hvc_iucv_config(char *val)
1324 {
1325          return strict_strtoul(val, 10, &hvc_iucv_devices);
1326 }
1327
1328
1329 device_initcall(hvc_iucv_init);
1330 __setup("hvc_iucv=", hvc_iucv_config);
1331 core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640);