Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6
[linux-2.6] / 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                 hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data));
277                 break;
278
279         case MSG_TYPE_ERROR:    /* ignored ... */
280         case MSG_TYPE_TERMENV:  /* ignored ... */
281         case MSG_TYPE_TERMIOS:  /* ignored ... */
282                 break;
283         }
284
285 out_remove_buffer:
286         list_del(&rb->list);
287         destroy_tty_buffer(rb);
288         *has_more_data = !list_empty(&priv->tty_inqueue);
289
290 out_written:
291         return written;
292 }
293
294 /**
295  * hvc_iucv_get_chars() - HVC get_chars operation.
296  * @vtermno:    HVC virtual terminal number.
297  * @buf:        Pointer to a buffer to store data
298  * @count:      Size of buffer available for writing
299  *
300  * The HVC thread calls this method to read characters from the back-end.
301  * If an IUCV communication path has been established, pending IUCV messages
302  * are received and data is copied into buffer @buf up to @count bytes.
303  *
304  * Locking:     The routine gets called under an irqsave() spinlock; and
305  *              the routine locks the struct hvc_iucv_private->lock to call
306  *              helper functions.
307  */
308 static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count)
309 {
310         struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);
311         int written;
312         int has_more_data;
313
314         if (count <= 0)
315                 return 0;
316
317         if (!priv)
318                 return -ENODEV;
319
320         spin_lock(&priv->lock);
321         has_more_data = 0;
322         written = hvc_iucv_write(priv, buf, count, &has_more_data);
323         spin_unlock(&priv->lock);
324
325         /* if there are still messages on the queue... schedule another run */
326         if (has_more_data)
327                 hvc_kick();
328
329         return written;
330 }
331
332 /**
333  * hvc_iucv_queue() - Buffer terminal data for sending.
334  * @priv:       Pointer to struct hvc_iucv_private instance.
335  * @buf:        Buffer containing data to send.
336  * @count:      Size of buffer and amount of data to send.
337  *
338  * The function queues data for sending. To actually send the buffered data,
339  * a work queue function is scheduled (with QUEUE_SNDBUF_DELAY).
340  * The function returns the number of data bytes that has been buffered.
341  *
342  * If the device is not connected, data is ignored and the function returns
343  * @count.
344  * If the buffer is full, the function returns 0.
345  * If an existing IUCV communicaton path has been severed, -EPIPE is returned
346  * (that can be passed to HVC layer to cause a tty hangup).
347  */
348 static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf,
349                           int count)
350 {
351         size_t len;
352
353         if (priv->iucv_state == IUCV_DISCONN)
354                 return count;                   /* ignore data */
355
356         if (priv->iucv_state == IUCV_SEVERED)
357                 return -EPIPE;
358
359         len = min_t(size_t, count, SNDBUF_SIZE - priv->sndbuf_len);
360         if (!len)
361                 return 0;
362
363         memcpy(priv->sndbuf + priv->sndbuf_len, buf, len);
364         priv->sndbuf_len += len;
365
366         if (priv->iucv_state == IUCV_CONNECTED)
367                 schedule_delayed_work(&priv->sndbuf_work, QUEUE_SNDBUF_DELAY);
368
369         return len;
370 }
371
372 /**
373  * hvc_iucv_send() - Send an IUCV message containing terminal data.
374  * @priv:       Pointer to struct hvc_iucv_private instance.
375  *
376  * If an IUCV communication path has been established, the buffered output data
377  * is sent via an IUCV message and the number of bytes sent is returned.
378  * Returns 0 if there is no established IUCV communication path or
379  * -EPIPE if an existing IUCV communicaton path has been severed.
380  */
381 static int hvc_iucv_send(struct hvc_iucv_private *priv)
382 {
383         struct iucv_tty_buffer *sb;
384         int rc, len;
385
386         if (priv->iucv_state == IUCV_SEVERED)
387                 return -EPIPE;
388
389         if (priv->iucv_state == IUCV_DISCONN)
390                 return -EIO;
391
392         if (!priv->sndbuf_len)
393                 return 0;
394
395         /* allocate internal buffer to store msg data and also compute total
396          * message length */
397         sb = alloc_tty_buffer(priv->sndbuf_len, GFP_ATOMIC);
398         if (!sb)
399                 return -ENOMEM;
400
401         memcpy(sb->mbuf->data, priv->sndbuf, priv->sndbuf_len);
402         sb->mbuf->datalen = (u16) priv->sndbuf_len;
403         sb->msg.length = MSG_SIZE(sb->mbuf->datalen);
404
405         list_add_tail(&sb->list, &priv->tty_outqueue);
406
407         rc = __iucv_message_send(priv->path, &sb->msg, 0, 0,
408                                  (void *) sb->mbuf, sb->msg.length);
409         if (rc) {
410                 /* drop the message here; however we might want to handle
411                  * 0x03 (msg limit reached) by trying again... */
412                 list_del(&sb->list);
413                 destroy_tty_buffer(sb);
414         }
415         len = priv->sndbuf_len;
416         priv->sndbuf_len = 0;
417
418         return len;
419 }
420
421 /**
422  * hvc_iucv_sndbuf_work() - Send buffered data over IUCV
423  * @work:       Work structure.
424  *
425  * This work queue function sends buffered output data over IUCV and,
426  * if not all buffered data could be sent, reschedules itself.
427  */
428 static void hvc_iucv_sndbuf_work(struct work_struct *work)
429 {
430         struct hvc_iucv_private *priv;
431
432         priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work);
433         if (!priv)
434                 return;
435
436         spin_lock_bh(&priv->lock);
437         hvc_iucv_send(priv);
438         spin_unlock_bh(&priv->lock);
439 }
440
441 /**
442  * hvc_iucv_put_chars() - HVC put_chars operation.
443  * @vtermno:    HVC virtual terminal number.
444  * @buf:        Pointer to an buffer to read data from
445  * @count:      Size of buffer available for reading
446  *
447  * The HVC thread calls this method to write characters to the back-end.
448  * The function calls hvc_iucv_queue() to queue terminal data for sending.
449  *
450  * Locking:     The method gets called under an irqsave() spinlock; and
451  *              locks struct hvc_iucv_private->lock.
452  */
453 static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count)
454 {
455         struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);
456         int queued;
457
458         if (count <= 0)
459                 return 0;
460
461         if (!priv)
462                 return -ENODEV;
463
464         spin_lock(&priv->lock);
465         queued = hvc_iucv_queue(priv, buf, count);
466         spin_unlock(&priv->lock);
467
468         return queued;
469 }
470
471 /**
472  * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time.
473  * @hp: Pointer to the HVC device (struct hvc_struct)
474  * @id: Additional data (originally passed to hvc_alloc): the index of an struct
475  *      hvc_iucv_private instance.
476  *
477  * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private
478  * instance that is derived from @id. Always returns 0.
479  *
480  * Locking:     struct hvc_iucv_private->lock, spin_lock_bh
481  */
482 static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id)
483 {
484         struct hvc_iucv_private *priv;
485
486         priv = hvc_iucv_get_private(id);
487         if (!priv)
488                 return 0;
489
490         spin_lock_bh(&priv->lock);
491         priv->tty_state = TTY_OPENED;
492         spin_unlock_bh(&priv->lock);
493
494         return 0;
495 }
496
497 /**
498  * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance.
499  * @priv:       Pointer to the struct hvc_iucv_private instance.
500  */
501 static void hvc_iucv_cleanup(struct hvc_iucv_private *priv)
502 {
503         destroy_tty_buffer_list(&priv->tty_outqueue);
504         destroy_tty_buffer_list(&priv->tty_inqueue);
505
506         priv->tty_state = TTY_CLOSED;
507         priv->iucv_state = IUCV_DISCONN;
508
509         priv->sndbuf_len = 0;
510 }
511
512 /**
513  * tty_outqueue_empty() - Test if the tty outq is empty
514  * @priv:       Pointer to struct hvc_iucv_private instance.
515  */
516 static inline int tty_outqueue_empty(struct hvc_iucv_private *priv)
517 {
518         int rc;
519
520         spin_lock_bh(&priv->lock);
521         rc = list_empty(&priv->tty_outqueue);
522         spin_unlock_bh(&priv->lock);
523
524         return rc;
525 }
526
527 /**
528  * flush_sndbuf_sync() - Flush send buffer and wait for completion
529  * @priv:       Pointer to struct hvc_iucv_private instance.
530  *
531  * The routine cancels a pending sndbuf work, calls hvc_iucv_send()
532  * to flush any buffered terminal output data and waits for completion.
533  */
534 static void flush_sndbuf_sync(struct hvc_iucv_private *priv)
535 {
536         int sync_wait;
537
538         cancel_delayed_work_sync(&priv->sndbuf_work);
539
540         spin_lock_bh(&priv->lock);
541         hvc_iucv_send(priv);            /* force sending buffered data */
542         sync_wait = !list_empty(&priv->tty_outqueue); /* anything queued ? */
543         spin_unlock_bh(&priv->lock);
544
545         if (sync_wait)
546                 wait_event_timeout(priv->sndbuf_waitq,
547                                    tty_outqueue_empty(priv), HZ/10);
548 }
549
550 /**
551  * hvc_iucv_hangup() - Sever IUCV path and schedule hvc tty hang up
552  * @priv:       Pointer to hvc_iucv_private structure
553  *
554  * This routine severs an existing IUCV communication path and hangs
555  * up the underlying HVC terminal device.
556  * The hang-up occurs only if an IUCV communication path is established;
557  * otherwise there is no need to hang up the terminal device.
558  *
559  * The IUCV HVC hang-up is separated into two steps:
560  * 1. After the IUCV path has been severed, the iucv_state is set to
561  *    IUCV_SEVERED.
562  * 2. Later, when the HVC thread calls hvc_iucv_get_chars(), the
563  *    IUCV_SEVERED state causes the tty hang-up in the HVC layer.
564  *
565  * If the tty has not yet been opened, clean up the hvc_iucv_private
566  * structure to allow re-connects.
567  * If the tty has been opened, let get_chars() return -EPIPE to signal
568  * the HVC layer to hang up the tty and, if so, wake up the HVC thread
569  * to call get_chars()...
570  *
571  * Special notes on hanging up a HVC terminal instantiated as console:
572  * Hang-up:     1. do_tty_hangup() replaces file ops (= hung_up_tty_fops)
573  *              2. do_tty_hangup() calls tty->ops->close() for console_filp
574  *                      => no hangup notifier is called by HVC (default)
575  *              2. hvc_close() returns because of tty_hung_up_p(filp)
576  *                      => no delete notifier is called!
577  * Finally, the back-end is not being notified, thus, the tty session is
578  * kept active (TTY_OPEN) to be ready for re-connects.
579  *
580  * Locking:     spin_lock(&priv->lock) w/o disabling bh
581  */
582 static void hvc_iucv_hangup(struct hvc_iucv_private *priv)
583 {
584         struct iucv_path *path;
585
586         path = NULL;
587         spin_lock(&priv->lock);
588         if (priv->iucv_state == IUCV_CONNECTED) {
589                 path = priv->path;
590                 priv->path = NULL;
591                 priv->iucv_state = IUCV_SEVERED;
592                 if (priv->tty_state == TTY_CLOSED)
593                         hvc_iucv_cleanup(priv);
594                 else
595                         /* console is special (see above) */
596                         if (priv->is_console) {
597                                 hvc_iucv_cleanup(priv);
598                                 priv->tty_state = TTY_OPENED;
599                         } else
600                                 hvc_kick();
601         }
602         spin_unlock(&priv->lock);
603
604         /* finally sever path (outside of priv->lock due to lock ordering) */
605         if (path) {
606                 iucv_path_sever(path, NULL);
607                 iucv_path_free(path);
608         }
609 }
610
611 /**
612  * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups.
613  * @hp:         Pointer to the HVC device (struct hvc_struct)
614  * @id:         Additional data (originally passed to hvc_alloc):
615  *              the index of an struct hvc_iucv_private instance.
616  *
617  * This routine notifies the HVC back-end that a tty hangup (carrier loss,
618  * virtual or otherwise) has occured.
619  * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup())
620  * to keep an existing IUCV communication path established.
621  * (Background: vhangup() is called from user space (by getty or login) to
622  *              disable writing to the tty by other applications).
623  * If the tty has been opened and an established IUCV path has been severed
624  * (we caused the tty hangup), the function calls hvc_iucv_cleanup().
625  *
626  * Locking:     struct hvc_iucv_private->lock
627  */
628 static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id)
629 {
630         struct hvc_iucv_private *priv;
631
632         priv = hvc_iucv_get_private(id);
633         if (!priv)
634                 return;
635
636         flush_sndbuf_sync(priv);
637
638         spin_lock_bh(&priv->lock);
639         /* NOTE: If the hangup was scheduled by ourself (from the iucv
640          *       path_servered callback [IUCV_SEVERED]), we have to clean up
641          *       our structure and to set state to TTY_CLOSED.
642          *       If the tty was hung up otherwise (e.g. vhangup()), then we
643          *       ignore this hangup and keep an established IUCV path open...
644          *       (...the reason is that we are not able to connect back to the
645          *       client if we disconnect on hang up) */
646         priv->tty_state = TTY_CLOSED;
647
648         if (priv->iucv_state == IUCV_SEVERED)
649                 hvc_iucv_cleanup(priv);
650         spin_unlock_bh(&priv->lock);
651 }
652
653 /**
654  * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time.
655  * @hp:         Pointer to the HVC device (struct hvc_struct)
656  * @id:         Additional data (originally passed to hvc_alloc):
657  *              the index of an struct hvc_iucv_private instance.
658  *
659  * This routine notifies the HVC back-end that the last tty device fd has been
660  * closed.  The function calls hvc_iucv_cleanup() to clean up the struct
661  * hvc_iucv_private instance.
662  *
663  * Locking:     struct hvc_iucv_private->lock
664  */
665 static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id)
666 {
667         struct hvc_iucv_private *priv;
668         struct iucv_path        *path;
669
670         priv = hvc_iucv_get_private(id);
671         if (!priv)
672                 return;
673
674         flush_sndbuf_sync(priv);
675
676         spin_lock_bh(&priv->lock);
677         path = priv->path;              /* save reference to IUCV path */
678         priv->path = NULL;
679         hvc_iucv_cleanup(priv);
680         spin_unlock_bh(&priv->lock);
681
682         /* sever IUCV path outside of priv->lock due to lock ordering of:
683          * priv->lock <--> iucv_table_lock */
684         if (path) {
685                 iucv_path_sever(path, NULL);
686                 iucv_path_free(path);
687         }
688 }
689
690 /**
691  * hvc_iucv_filter_connreq() - Filter connection request based on z/VM user ID
692  * @ipvmid:     Originating z/VM user ID (right padded with blanks)
693  *
694  * Returns 0 if the z/VM user ID @ipvmid is allowed to connection, otherwise
695  * non-zero.
696  */
697 static int hvc_iucv_filter_connreq(u8 ipvmid[8])
698 {
699         size_t i;
700
701         /* Note: default policy is ACCEPT if no filter is set */
702         if (!hvc_iucv_filter_size)
703                 return 0;
704
705         for (i = 0; i < hvc_iucv_filter_size; i++)
706                 if (0 == memcmp(ipvmid, hvc_iucv_filter + (8 * i), 8))
707                         return 0;
708         return 1;
709 }
710
711 /**
712  * hvc_iucv_path_pending() - IUCV handler to process a connection request.
713  * @path:       Pending path (struct iucv_path)
714  * @ipvmid:     z/VM system identifier of originator
715  * @ipuser:     User specified data for this path
716  *              (AF_IUCV: port/service name and originator port)
717  *
718  * The function uses the @ipuser data to determine if the pending path belongs
719  * to a terminal managed by this device driver.
720  * If the path belongs to this driver, ensure that the terminal is not accessed
721  * multiple times (only one connection to a terminal is allowed).
722  * If the terminal is not yet connected, the pending path is accepted and is
723  * associated to the appropriate struct hvc_iucv_private instance.
724  *
725  * Returns 0 if @path belongs to a terminal managed by the this device driver;
726  * otherwise returns -ENODEV in order to dispatch this path to other handlers.
727  *
728  * Locking:     struct hvc_iucv_private->lock
729  */
730 static  int hvc_iucv_path_pending(struct iucv_path *path,
731                                   u8 ipvmid[8], u8 ipuser[16])
732 {
733         struct hvc_iucv_private *priv;
734         u8 nuser_data[16];
735         u8 vm_user_id[9];
736         int i, rc;
737
738         priv = NULL;
739         for (i = 0; i < hvc_iucv_devices; i++)
740                 if (hvc_iucv_table[i] &&
741                     (0 == memcmp(hvc_iucv_table[i]->srv_name, ipuser, 8))) {
742                         priv = hvc_iucv_table[i];
743                         break;
744                 }
745         if (!priv)
746                 return -ENODEV;
747
748         /* Enforce that ipvmid is allowed to connect to us */
749         read_lock(&hvc_iucv_filter_lock);
750         rc = hvc_iucv_filter_connreq(ipvmid);
751         read_unlock(&hvc_iucv_filter_lock);
752         if (rc) {
753                 iucv_path_sever(path, ipuser);
754                 iucv_path_free(path);
755                 memcpy(vm_user_id, ipvmid, 8);
756                 vm_user_id[8] = 0;
757                 pr_info("A connection request from z/VM user ID %s "
758                         "was refused\n", vm_user_id);
759                 return 0;
760         }
761
762         spin_lock(&priv->lock);
763
764         /* If the terminal is already connected or being severed, then sever
765          * this path to enforce that there is only ONE established communication
766          * path per terminal. */
767         if (priv->iucv_state != IUCV_DISCONN) {
768                 iucv_path_sever(path, ipuser);
769                 iucv_path_free(path);
770                 goto out_path_handled;
771         }
772
773         /* accept path */
774         memcpy(nuser_data, ipuser + 8, 8);  /* remote service (for af_iucv) */
775         memcpy(nuser_data + 8, ipuser, 8);  /* local service  (for af_iucv) */
776         path->msglim = 0xffff;              /* IUCV MSGLIMIT */
777         path->flags &= ~IUCV_IPRMDATA;      /* TODO: use IUCV_IPRMDATA */
778         rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv);
779         if (rc) {
780                 iucv_path_sever(path, ipuser);
781                 iucv_path_free(path);
782                 goto out_path_handled;
783         }
784         priv->path = path;
785         priv->iucv_state = IUCV_CONNECTED;
786
787         /* flush buffered output data... */
788         schedule_delayed_work(&priv->sndbuf_work, 5);
789
790 out_path_handled:
791         spin_unlock(&priv->lock);
792         return 0;
793 }
794
795 /**
796  * hvc_iucv_path_severed() - IUCV handler to process a path sever.
797  * @path:       Pending path (struct iucv_path)
798  * @ipuser:     User specified data for this path
799  *              (AF_IUCV: port/service name and originator port)
800  *
801  * This function calls the hvc_iucv_hangup() function for the
802  * respective IUCV HVC terminal.
803  *
804  * Locking:     struct hvc_iucv_private->lock
805  */
806 static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16])
807 {
808         struct hvc_iucv_private *priv = path->private;
809
810         hvc_iucv_hangup(priv);
811 }
812
813 /**
814  * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message.
815  * @path:       Pending path (struct iucv_path)
816  * @msg:        Pointer to the IUCV message
817  *
818  * The function puts an incoming message on the input queue for later
819  * processing (by hvc_iucv_get_chars() / hvc_iucv_write()).
820  * If the tty has not yet been opened, the message is rejected.
821  *
822  * Locking:     struct hvc_iucv_private->lock
823  */
824 static void hvc_iucv_msg_pending(struct iucv_path *path,
825                                  struct iucv_message *msg)
826 {
827         struct hvc_iucv_private *priv = path->private;
828         struct iucv_tty_buffer *rb;
829
830         /* reject messages that exceed max size of iucv_tty_msg->datalen */
831         if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) {
832                 iucv_message_reject(path, msg);
833                 return;
834         }
835
836         spin_lock(&priv->lock);
837
838         /* reject messages if tty has not yet been opened */
839         if (priv->tty_state == TTY_CLOSED) {
840                 iucv_message_reject(path, msg);
841                 goto unlock_return;
842         }
843
844         /* allocate tty buffer to save iucv msg only */
845         rb = alloc_tty_buffer(0, GFP_ATOMIC);
846         if (!rb) {
847                 iucv_message_reject(path, msg);
848                 goto unlock_return;     /* -ENOMEM */
849         }
850         rb->msg = *msg;
851
852         list_add_tail(&rb->list, &priv->tty_inqueue);
853
854         hvc_kick();     /* wake up hvc thread */
855
856 unlock_return:
857         spin_unlock(&priv->lock);
858 }
859
860 /**
861  * hvc_iucv_msg_complete() - IUCV handler to process message completion
862  * @path:       Pending path (struct iucv_path)
863  * @msg:        Pointer to the IUCV message
864  *
865  * The function is called upon completion of message delivery to remove the
866  * message from the outqueue. Additional delivery information can be found
867  * msg->audit: rejected messages (0x040000 (IPADRJCT)), and
868  *             purged messages   (0x010000 (IPADPGNR)).
869  *
870  * Locking:     struct hvc_iucv_private->lock
871  */
872 static void hvc_iucv_msg_complete(struct iucv_path *path,
873                                   struct iucv_message *msg)
874 {
875         struct hvc_iucv_private *priv = path->private;
876         struct iucv_tty_buffer  *ent, *next;
877         LIST_HEAD(list_remove);
878
879         spin_lock(&priv->lock);
880         list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list)
881                 if (ent->msg.id == msg->id) {
882                         list_move(&ent->list, &list_remove);
883                         break;
884                 }
885         wake_up(&priv->sndbuf_waitq);
886         spin_unlock(&priv->lock);
887         destroy_tty_buffer_list(&list_remove);
888 }
889
890 /**
891  * hvc_iucv_pm_freeze() - Freeze PM callback
892  * @dev:        IUVC HVC terminal device
893  *
894  * Sever an established IUCV communication path and
895  * trigger a hang-up of the underlying HVC terminal.
896  */
897 static int hvc_iucv_pm_freeze(struct device *dev)
898 {
899         struct hvc_iucv_private *priv = dev_get_drvdata(dev);
900
901         local_bh_disable();
902         hvc_iucv_hangup(priv);
903         local_bh_enable();
904
905         return 0;
906 }
907
908 /**
909  * hvc_iucv_pm_restore_thaw() - Thaw and restore PM callback
910  * @dev:        IUVC HVC terminal device
911  *
912  * Wake up the HVC thread to trigger hang-up and respective
913  * HVC back-end notifier invocations.
914  */
915 static int hvc_iucv_pm_restore_thaw(struct device *dev)
916 {
917         hvc_kick();
918         return 0;
919 }
920
921
922 /* HVC operations */
923 static struct hv_ops hvc_iucv_ops = {
924         .get_chars = hvc_iucv_get_chars,
925         .put_chars = hvc_iucv_put_chars,
926         .notifier_add = hvc_iucv_notifier_add,
927         .notifier_del = hvc_iucv_notifier_del,
928         .notifier_hangup = hvc_iucv_notifier_hangup,
929 };
930
931 /* Suspend / resume device operations */
932 static struct dev_pm_ops hvc_iucv_pm_ops = {
933         .freeze   = hvc_iucv_pm_freeze,
934         .thaw     = hvc_iucv_pm_restore_thaw,
935         .restore  = hvc_iucv_pm_restore_thaw,
936 };
937
938 /* IUCV HVC device driver */
939 static struct device_driver hvc_iucv_driver = {
940         .name = KMSG_COMPONENT,
941         .bus  = &iucv_bus,
942         .pm   = &hvc_iucv_pm_ops,
943 };
944
945 /**
946  * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance
947  * @id:                 hvc_iucv_table index
948  * @is_console:         Flag if the instance is used as Linux console
949  *
950  * This function allocates a new hvc_iucv_private structure and stores
951  * the instance in hvc_iucv_table at index @id.
952  * Returns 0 on success; otherwise non-zero.
953  */
954 static int __init hvc_iucv_alloc(int id, unsigned int is_console)
955 {
956         struct hvc_iucv_private *priv;
957         char name[9];
958         int rc;
959
960         priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL);
961         if (!priv)
962                 return -ENOMEM;
963
964         spin_lock_init(&priv->lock);
965         INIT_LIST_HEAD(&priv->tty_outqueue);
966         INIT_LIST_HEAD(&priv->tty_inqueue);
967         INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work);
968         init_waitqueue_head(&priv->sndbuf_waitq);
969
970         priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL);
971         if (!priv->sndbuf) {
972                 kfree(priv);
973                 return -ENOMEM;
974         }
975
976         /* set console flag */
977         priv->is_console = is_console;
978
979         /* allocate hvc device */
980         priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /*             PAGE_SIZE */
981                               HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256);
982         if (IS_ERR(priv->hvc)) {
983                 rc = PTR_ERR(priv->hvc);
984                 goto out_error_hvc;
985         }
986
987         /* notify HVC thread instead of using polling */
988         priv->hvc->irq_requested = 1;
989
990         /* setup iucv related information */
991         snprintf(name, 9, "lnxhvc%-2d", id);
992         memcpy(priv->srv_name, name, 8);
993         ASCEBC(priv->srv_name, 8);
994
995         /* create and setup device */
996         priv->dev = kzalloc(sizeof(*priv->dev), GFP_KERNEL);
997         if (!priv->dev) {
998                 rc = -ENOMEM;
999                 goto out_error_dev;
1000         }
1001         dev_set_name(priv->dev, "hvc_iucv%d", id);
1002         dev_set_drvdata(priv->dev, priv);
1003         priv->dev->bus = &iucv_bus;
1004         priv->dev->parent = iucv_root;
1005         priv->dev->driver = &hvc_iucv_driver;
1006         priv->dev->release = (void (*)(struct device *)) kfree;
1007         rc = device_register(priv->dev);
1008         if (rc) {
1009                 kfree(priv->dev);
1010                 goto out_error_dev;
1011         }
1012
1013         hvc_iucv_table[id] = priv;
1014         return 0;
1015
1016 out_error_dev:
1017         hvc_remove(priv->hvc);
1018 out_error_hvc:
1019         free_page((unsigned long) priv->sndbuf);
1020         kfree(priv);
1021
1022         return rc;
1023 }
1024
1025 /**
1026  * hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances
1027  */
1028 static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv)
1029 {
1030         hvc_remove(priv->hvc);
1031         device_unregister(priv->dev);
1032         free_page((unsigned long) priv->sndbuf);
1033         kfree(priv);
1034 }
1035
1036 /**
1037  * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID
1038  * @filter:     String containing a comma-separated list of z/VM user IDs
1039  */
1040 static const char *hvc_iucv_parse_filter(const char *filter, char *dest)
1041 {
1042         const char *nextdelim, *residual;
1043         size_t len;
1044
1045         nextdelim = strchr(filter, ',');
1046         if (nextdelim) {
1047                 len = nextdelim - filter;
1048                 residual = nextdelim + 1;
1049         } else {
1050                 len = strlen(filter);
1051                 residual = filter + len;
1052         }
1053
1054         if (len == 0)
1055                 return ERR_PTR(-EINVAL);
1056
1057         /* check for '\n' (if called from sysfs) */
1058         if (filter[len - 1] == '\n')
1059                 len--;
1060
1061         if (len > 8)
1062                 return ERR_PTR(-EINVAL);
1063
1064         /* pad with blanks and save upper case version of user ID */
1065         memset(dest, ' ', 8);
1066         while (len--)
1067                 dest[len] = toupper(filter[len]);
1068         return residual;
1069 }
1070
1071 /**
1072  * hvc_iucv_setup_filter() - Set up z/VM user ID filter
1073  * @filter:     String consisting of a comma-separated list of z/VM user IDs
1074  *
1075  * The function parses the @filter string and creates an array containing
1076  * the list of z/VM user ID filter entries.
1077  * Return code 0 means success, -EINVAL if the filter is syntactically
1078  * incorrect, -ENOMEM if there was not enough memory to allocate the
1079  * filter list array, or -ENOSPC if too many z/VM user IDs have been specified.
1080  */
1081 static int hvc_iucv_setup_filter(const char *val)
1082 {
1083         const char *residual;
1084         int err;
1085         size_t size, count;
1086         void *array, *old_filter;
1087
1088         count = strlen(val);
1089         if (count == 0 || (count == 1 && val[0] == '\n')) {
1090                 size  = 0;
1091                 array = NULL;
1092                 goto out_replace_filter;        /* clear filter */
1093         }
1094
1095         /* count user IDs in order to allocate sufficient memory */
1096         size = 1;
1097         residual = val;
1098         while ((residual = strchr(residual, ',')) != NULL) {
1099                 residual++;
1100                 size++;
1101         }
1102
1103         /* check if the specified list exceeds the filter limit */
1104         if (size > MAX_VMID_FILTER)
1105                 return -ENOSPC;
1106
1107         array = kzalloc(size * 8, GFP_KERNEL);
1108         if (!array)
1109                 return -ENOMEM;
1110
1111         count = size;
1112         residual = val;
1113         while (*residual && count) {
1114                 residual = hvc_iucv_parse_filter(residual,
1115                                                  array + ((size - count) * 8));
1116                 if (IS_ERR(residual)) {
1117                         err = PTR_ERR(residual);
1118                         kfree(array);
1119                         goto out_err;
1120                 }
1121                 count--;
1122         }
1123
1124 out_replace_filter:
1125         write_lock_bh(&hvc_iucv_filter_lock);
1126         old_filter = hvc_iucv_filter;
1127         hvc_iucv_filter_size = size;
1128         hvc_iucv_filter = array;
1129         write_unlock_bh(&hvc_iucv_filter_lock);
1130         kfree(old_filter);
1131
1132         err = 0;
1133 out_err:
1134         return err;
1135 }
1136
1137 /**
1138  * param_set_vmidfilter() - Set z/VM user ID filter parameter
1139  * @val:        String consisting of a comma-separated list of z/VM user IDs
1140  * @kp:         Kernel parameter pointing to hvc_iucv_filter array
1141  *
1142  * The function sets up the z/VM user ID filter specified as comma-separated
1143  * list of user IDs in @val.
1144  * Note: If it is called early in the boot process, @val is stored and
1145  *       parsed later in hvc_iucv_init().
1146  */
1147 static int param_set_vmidfilter(const char *val, struct kernel_param *kp)
1148 {
1149         int rc;
1150
1151         if (!MACHINE_IS_VM || !hvc_iucv_devices)
1152                 return -ENODEV;
1153
1154         if (!val)
1155                 return -EINVAL;
1156
1157         rc = 0;
1158         if (slab_is_available())
1159                 rc = hvc_iucv_setup_filter(val);
1160         else
1161                 hvc_iucv_filter_string = val;   /* defer... */
1162         return rc;
1163 }
1164
1165 /**
1166  * param_get_vmidfilter() - Get z/VM user ID filter
1167  * @buffer:     Buffer to store z/VM user ID filter,
1168  *              (buffer size assumption PAGE_SIZE)
1169  * @kp:         Kernel parameter pointing to the hvc_iucv_filter array
1170  *
1171  * The function stores the filter as a comma-separated list of z/VM user IDs
1172  * in @buffer. Typically, sysfs routines call this function for attr show.
1173  */
1174 static int param_get_vmidfilter(char *buffer, struct kernel_param *kp)
1175 {
1176         int rc;
1177         size_t index, len;
1178         void *start, *end;
1179
1180         if (!MACHINE_IS_VM || !hvc_iucv_devices)
1181                 return -ENODEV;
1182
1183         rc = 0;
1184         read_lock_bh(&hvc_iucv_filter_lock);
1185         for (index = 0; index < hvc_iucv_filter_size; index++) {
1186                 start = hvc_iucv_filter + (8 * index);
1187                 end   = memchr(start, ' ', 8);
1188                 len   = (end) ? end - start : 8;
1189                 memcpy(buffer + rc, start, len);
1190                 rc += len;
1191                 buffer[rc++] = ',';
1192         }
1193         read_unlock_bh(&hvc_iucv_filter_lock);
1194         if (rc)
1195                 buffer[--rc] = '\0';    /* replace last comma and update rc */
1196         return rc;
1197 }
1198
1199 #define param_check_vmidfilter(name, p) __param_check(name, p, void)
1200
1201 /**
1202  * hvc_iucv_init() - z/VM IUCV HVC device driver initialization
1203  */
1204 static int __init hvc_iucv_init(void)
1205 {
1206         int rc;
1207         unsigned int i;
1208
1209         if (!hvc_iucv_devices)
1210                 return -ENODEV;
1211
1212         if (!MACHINE_IS_VM) {
1213                 pr_notice("The z/VM IUCV HVC device driver cannot "
1214                            "be used without z/VM\n");
1215                 rc = -ENODEV;
1216                 goto out_error;
1217         }
1218
1219         if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) {
1220                 pr_err("%lu is not a valid value for the hvc_iucv= "
1221                         "kernel parameter\n", hvc_iucv_devices);
1222                 rc = -EINVAL;
1223                 goto out_error;
1224         }
1225
1226         /* register IUCV HVC device driver */
1227         rc = driver_register(&hvc_iucv_driver);
1228         if (rc)
1229                 goto out_error;
1230
1231         /* parse hvc_iucv_allow string and create z/VM user ID filter list */
1232         if (hvc_iucv_filter_string) {
1233                 rc = hvc_iucv_setup_filter(hvc_iucv_filter_string);
1234                 switch (rc) {
1235                 case 0:
1236                         break;
1237                 case -ENOMEM:
1238                         pr_err("Allocating memory failed with "
1239                                 "reason code=%d\n", 3);
1240                         goto out_error;
1241                 case -EINVAL:
1242                         pr_err("hvc_iucv_allow= does not specify a valid "
1243                                 "z/VM user ID list\n");
1244                         goto out_error;
1245                 case -ENOSPC:
1246                         pr_err("hvc_iucv_allow= specifies too many "
1247                                 "z/VM user IDs\n");
1248                         goto out_error;
1249                 default:
1250                         goto out_error;
1251                 }
1252         }
1253
1254         hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT,
1255                                            sizeof(struct iucv_tty_buffer),
1256                                            0, 0, NULL);
1257         if (!hvc_iucv_buffer_cache) {
1258                 pr_err("Allocating memory failed with reason code=%d\n", 1);
1259                 rc = -ENOMEM;
1260                 goto out_error;
1261         }
1262
1263         hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR,
1264                                                     hvc_iucv_buffer_cache);
1265         if (!hvc_iucv_mempool) {
1266                 pr_err("Allocating memory failed with reason code=%d\n", 2);
1267                 kmem_cache_destroy(hvc_iucv_buffer_cache);
1268                 rc = -ENOMEM;
1269                 goto out_error;
1270         }
1271
1272         /* register the first terminal device as console
1273          * (must be done before allocating hvc terminal devices) */
1274         rc = hvc_instantiate(HVC_IUCV_MAGIC, IUCV_HVC_CON_IDX, &hvc_iucv_ops);
1275         if (rc) {
1276                 pr_err("Registering HVC terminal device as "
1277                        "Linux console failed\n");
1278                 goto out_error_memory;
1279         }
1280
1281         /* allocate hvc_iucv_private structs */
1282         for (i = 0; i < hvc_iucv_devices; i++) {
1283                 rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0);
1284                 if (rc) {
1285                         pr_err("Creating a new HVC terminal device "
1286                                 "failed with error code=%d\n", rc);
1287                         goto out_error_hvc;
1288                 }
1289         }
1290
1291         /* register IUCV callback handler */
1292         rc = iucv_register(&hvc_iucv_handler, 0);
1293         if (rc) {
1294                 pr_err("Registering IUCV handlers failed with error code=%d\n",
1295                         rc);
1296                 goto out_error_iucv;
1297         }
1298
1299         return 0;
1300
1301 out_error_iucv:
1302         iucv_unregister(&hvc_iucv_handler, 0);
1303 out_error_hvc:
1304         for (i = 0; i < hvc_iucv_devices; i++)
1305                 if (hvc_iucv_table[i])
1306                         hvc_iucv_destroy(hvc_iucv_table[i]);
1307 out_error_memory:
1308         mempool_destroy(hvc_iucv_mempool);
1309         kmem_cache_destroy(hvc_iucv_buffer_cache);
1310 out_error:
1311         if (hvc_iucv_filter)
1312                 kfree(hvc_iucv_filter);
1313         hvc_iucv_devices = 0; /* ensure that we do not provide any device */
1314         return rc;
1315 }
1316
1317 /**
1318  * hvc_iucv_config() - Parsing of hvc_iucv=  kernel command line parameter
1319  * @val:        Parameter value (numeric)
1320  */
1321 static  int __init hvc_iucv_config(char *val)
1322 {
1323          return strict_strtoul(val, 10, &hvc_iucv_devices);
1324 }
1325
1326
1327 device_initcall(hvc_iucv_init);
1328 __setup("hvc_iucv=", hvc_iucv_config);
1329 core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640);