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