2 * hvc_iucv.c - z/VM IUCV hypervisor console (HVC) device driver
4 * This HVC device driver provides terminal access using
5 * z/VM IUCV communication paths.
7 * Copyright IBM Corp. 2008, 2009
9 * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
11 #define KMSG_COMPONENT "hvc_iucv"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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>
26 #include "hvc_console.h"
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)
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 */
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))
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 */
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 */
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 *);
95 /* Kernel module parameter: use one terminal device as default */
96 static unsigned long hvc_iucv_devices = 1;
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);
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;
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,
122 * hvc_iucv_get_private() - Return a struct hvc_iucv_private instance.
123 * @num: The HVC virtual terminal number (vtermno)
125 * This function returns the struct hvc_iucv_private instance that corresponds
126 * to the HVC virtual terminal number specified as parameter @num.
128 struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num)
130 if ((num < HVC_IUCV_MAGIC) || (num - HVC_IUCV_MAGIC > hvc_iucv_devices))
132 return hvc_iucv_table[num - HVC_IUCV_MAGIC];
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.
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.
146 static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags)
148 struct iucv_tty_buffer *bufp;
150 bufp = mempool_alloc(hvc_iucv_mempool, flags);
153 memset(bufp, 0, sizeof(*bufp));
156 bufp->msg.length = MSG_SIZE(size);
157 bufp->mbuf = kmalloc(bufp->msg.length, flags);
159 mempool_free(bufp, hvc_iucv_mempool);
162 bufp->mbuf->version = MSG_VERSION;
163 bufp->mbuf->type = MSG_TYPE_DATA;
164 bufp->mbuf->datalen = (u16) size;
170 * destroy_tty_buffer() - destroy struct iucv_tty_buffer element.
171 * @bufp: Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL.
173 static void destroy_tty_buffer(struct iucv_tty_buffer *bufp)
176 mempool_free(bufp, hvc_iucv_mempool);
180 * destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element.
181 * @list: List containing struct iucv_tty_buffer elements.
183 static void destroy_tty_buffer_list(struct list_head *list)
185 struct iucv_tty_buffer *ent, *next;
187 list_for_each_entry_safe(ent, next, list, list) {
188 list_del(&ent->list);
189 destroy_tty_buffer(ent);
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.
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
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
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).
213 static int hvc_iucv_write(struct hvc_iucv_private *priv,
214 char *buf, int count, int *has_more_data)
216 struct iucv_tty_buffer *rb;
220 /* immediately return if there is no IUCV connection */
221 if (priv->iucv_state == IUCV_DISCONN)
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)
229 /* check if there are pending messages */
230 if (list_empty(&priv->tty_inqueue))
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);
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);
244 rc = __iucv_message_receive(priv->path, &rb->msg, 0,
245 rb->mbuf, rb->msg.length, NULL);
247 case 0: /* Successful */
249 case 2: /* No message found */
250 case 9: /* Message purged */
255 /* remove buffer if an error has occured or received data
257 if (rc || (rb->mbuf->version != MSG_VERSION) ||
258 (rb->msg.length != MSG_SIZE(rb->mbuf->datalen)))
259 goto out_remove_buffer;
262 switch (rb->mbuf->type) {
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;
273 case MSG_TYPE_WINSIZE:
274 if (rb->mbuf->datalen != sizeof(struct winsize))
276 /* The caller must ensure that the hvc is locked, which
277 * is the case when called from hvc_iucv_get_chars() */
278 __hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data));
281 case MSG_TYPE_ERROR: /* ignored ... */
282 case MSG_TYPE_TERMENV: /* ignored ... */
283 case MSG_TYPE_TERMIOS: /* ignored ... */
289 destroy_tty_buffer(rb);
290 *has_more_data = !list_empty(&priv->tty_inqueue);
297 * hvc_iucv_get_chars() - HVC get_chars operation.
298 * @vtermno: HVC virtual terminal number.
299 * @buf: Pointer to a buffer to store data
300 * @count: Size of buffer available for writing
302 * The HVC thread calls this method to read characters from the back-end.
303 * If an IUCV communication path has been established, pending IUCV messages
304 * are received and data is copied into buffer @buf up to @count bytes.
306 * Locking: The routine gets called under an irqsave() spinlock; and
307 * the routine locks the struct hvc_iucv_private->lock to call
310 static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count)
312 struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);
322 spin_lock(&priv->lock);
324 written = hvc_iucv_write(priv, buf, count, &has_more_data);
325 spin_unlock(&priv->lock);
327 /* if there are still messages on the queue... schedule another run */
335 * hvc_iucv_queue() - Buffer terminal data for sending.
336 * @priv: Pointer to struct hvc_iucv_private instance.
337 * @buf: Buffer containing data to send.
338 * @count: Size of buffer and amount of data to send.
340 * The function queues data for sending. To actually send the buffered data,
341 * a work queue function is scheduled (with QUEUE_SNDBUF_DELAY).
342 * The function returns the number of data bytes that has been buffered.
344 * If the device is not connected, data is ignored and the function returns
346 * If the buffer is full, the function returns 0.
347 * If an existing IUCV communicaton path has been severed, -EPIPE is returned
348 * (that can be passed to HVC layer to cause a tty hangup).
350 static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf,
355 if (priv->iucv_state == IUCV_DISCONN)
356 return count; /* ignore data */
358 if (priv->iucv_state == IUCV_SEVERED)
361 len = min_t(size_t, count, SNDBUF_SIZE - priv->sndbuf_len);
365 memcpy(priv->sndbuf + priv->sndbuf_len, buf, len);
366 priv->sndbuf_len += len;
368 if (priv->iucv_state == IUCV_CONNECTED)
369 schedule_delayed_work(&priv->sndbuf_work, QUEUE_SNDBUF_DELAY);
375 * hvc_iucv_send() - Send an IUCV message containing terminal data.
376 * @priv: Pointer to struct hvc_iucv_private instance.
378 * If an IUCV communication path has been established, the buffered output data
379 * is sent via an IUCV message and the number of bytes sent is returned.
380 * Returns 0 if there is no established IUCV communication path or
381 * -EPIPE if an existing IUCV communicaton path has been severed.
383 static int hvc_iucv_send(struct hvc_iucv_private *priv)
385 struct iucv_tty_buffer *sb;
388 if (priv->iucv_state == IUCV_SEVERED)
391 if (priv->iucv_state == IUCV_DISCONN)
394 if (!priv->sndbuf_len)
397 /* allocate internal buffer to store msg data and also compute total
399 sb = alloc_tty_buffer(priv->sndbuf_len, GFP_ATOMIC);
403 memcpy(sb->mbuf->data, priv->sndbuf, priv->sndbuf_len);
404 sb->mbuf->datalen = (u16) priv->sndbuf_len;
405 sb->msg.length = MSG_SIZE(sb->mbuf->datalen);
407 list_add_tail(&sb->list, &priv->tty_outqueue);
409 rc = __iucv_message_send(priv->path, &sb->msg, 0, 0,
410 (void *) sb->mbuf, sb->msg.length);
412 /* drop the message here; however we might want to handle
413 * 0x03 (msg limit reached) by trying again... */
415 destroy_tty_buffer(sb);
417 len = priv->sndbuf_len;
418 priv->sndbuf_len = 0;
424 * hvc_iucv_sndbuf_work() - Send buffered data over IUCV
425 * @work: Work structure.
427 * This work queue function sends buffered output data over IUCV and,
428 * if not all buffered data could be sent, reschedules itself.
430 static void hvc_iucv_sndbuf_work(struct work_struct *work)
432 struct hvc_iucv_private *priv;
434 priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work);
438 spin_lock_bh(&priv->lock);
440 spin_unlock_bh(&priv->lock);
444 * hvc_iucv_put_chars() - HVC put_chars operation.
445 * @vtermno: HVC virtual terminal number.
446 * @buf: Pointer to an buffer to read data from
447 * @count: Size of buffer available for reading
449 * The HVC thread calls this method to write characters to the back-end.
450 * The function calls hvc_iucv_queue() to queue terminal data for sending.
452 * Locking: The method gets called under an irqsave() spinlock; and
453 * locks struct hvc_iucv_private->lock.
455 static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count)
457 struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno);
466 spin_lock(&priv->lock);
467 queued = hvc_iucv_queue(priv, buf, count);
468 spin_unlock(&priv->lock);
474 * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time.
475 * @hp: Pointer to the HVC device (struct hvc_struct)
476 * @id: Additional data (originally passed to hvc_alloc): the index of an struct
477 * hvc_iucv_private instance.
479 * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private
480 * instance that is derived from @id. Always returns 0.
482 * Locking: struct hvc_iucv_private->lock, spin_lock_bh
484 static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id)
486 struct hvc_iucv_private *priv;
488 priv = hvc_iucv_get_private(id);
492 spin_lock_bh(&priv->lock);
493 priv->tty_state = TTY_OPENED;
494 spin_unlock_bh(&priv->lock);
500 * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance.
501 * @priv: Pointer to the struct hvc_iucv_private instance.
503 static void hvc_iucv_cleanup(struct hvc_iucv_private *priv)
505 destroy_tty_buffer_list(&priv->tty_outqueue);
506 destroy_tty_buffer_list(&priv->tty_inqueue);
508 priv->tty_state = TTY_CLOSED;
509 priv->iucv_state = IUCV_DISCONN;
511 priv->sndbuf_len = 0;
515 * tty_outqueue_empty() - Test if the tty outq is empty
516 * @priv: Pointer to struct hvc_iucv_private instance.
518 static inline int tty_outqueue_empty(struct hvc_iucv_private *priv)
522 spin_lock_bh(&priv->lock);
523 rc = list_empty(&priv->tty_outqueue);
524 spin_unlock_bh(&priv->lock);
530 * flush_sndbuf_sync() - Flush send buffer and wait for completion
531 * @priv: Pointer to struct hvc_iucv_private instance.
533 * The routine cancels a pending sndbuf work, calls hvc_iucv_send()
534 * to flush any buffered terminal output data and waits for completion.
536 static void flush_sndbuf_sync(struct hvc_iucv_private *priv)
540 cancel_delayed_work_sync(&priv->sndbuf_work);
542 spin_lock_bh(&priv->lock);
543 hvc_iucv_send(priv); /* force sending buffered data */
544 sync_wait = !list_empty(&priv->tty_outqueue); /* anything queued ? */
545 spin_unlock_bh(&priv->lock);
548 wait_event_timeout(priv->sndbuf_waitq,
549 tty_outqueue_empty(priv), HZ/10);
553 * hvc_iucv_hangup() - Sever IUCV path and schedule hvc tty hang up
554 * @priv: Pointer to hvc_iucv_private structure
556 * This routine severs an existing IUCV communication path and hangs
557 * up the underlying HVC terminal device.
558 * The hang-up occurs only if an IUCV communication path is established;
559 * otherwise there is no need to hang up the terminal device.
561 * The IUCV HVC hang-up is separated into two steps:
562 * 1. After the IUCV path has been severed, the iucv_state is set to
564 * 2. Later, when the HVC thread calls hvc_iucv_get_chars(), the
565 * IUCV_SEVERED state causes the tty hang-up in the HVC layer.
567 * If the tty has not yet been opened, clean up the hvc_iucv_private
568 * structure to allow re-connects.
569 * If the tty has been opened, let get_chars() return -EPIPE to signal
570 * the HVC layer to hang up the tty and, if so, wake up the HVC thread
571 * to call get_chars()...
573 * Special notes on hanging up a HVC terminal instantiated as console:
574 * Hang-up: 1. do_tty_hangup() replaces file ops (= hung_up_tty_fops)
575 * 2. do_tty_hangup() calls tty->ops->close() for console_filp
576 * => no hangup notifier is called by HVC (default)
577 * 2. hvc_close() returns because of tty_hung_up_p(filp)
578 * => no delete notifier is called!
579 * Finally, the back-end is not being notified, thus, the tty session is
580 * kept active (TTY_OPEN) to be ready for re-connects.
582 * Locking: spin_lock(&priv->lock) w/o disabling bh
584 static void hvc_iucv_hangup(struct hvc_iucv_private *priv)
586 struct iucv_path *path;
589 spin_lock(&priv->lock);
590 if (priv->iucv_state == IUCV_CONNECTED) {
593 priv->iucv_state = IUCV_SEVERED;
594 if (priv->tty_state == TTY_CLOSED)
595 hvc_iucv_cleanup(priv);
597 /* console is special (see above) */
598 if (priv->is_console) {
599 hvc_iucv_cleanup(priv);
600 priv->tty_state = TTY_OPENED;
604 spin_unlock(&priv->lock);
606 /* finally sever path (outside of priv->lock due to lock ordering) */
608 iucv_path_sever(path, NULL);
609 iucv_path_free(path);
614 * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups.
615 * @hp: Pointer to the HVC device (struct hvc_struct)
616 * @id: Additional data (originally passed to hvc_alloc):
617 * the index of an struct hvc_iucv_private instance.
619 * This routine notifies the HVC back-end that a tty hangup (carrier loss,
620 * virtual or otherwise) has occured.
621 * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup())
622 * to keep an existing IUCV communication path established.
623 * (Background: vhangup() is called from user space (by getty or login) to
624 * disable writing to the tty by other applications).
625 * If the tty has been opened and an established IUCV path has been severed
626 * (we caused the tty hangup), the function calls hvc_iucv_cleanup().
628 * Locking: struct hvc_iucv_private->lock
630 static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id)
632 struct hvc_iucv_private *priv;
634 priv = hvc_iucv_get_private(id);
638 flush_sndbuf_sync(priv);
640 spin_lock_bh(&priv->lock);
641 /* NOTE: If the hangup was scheduled by ourself (from the iucv
642 * path_servered callback [IUCV_SEVERED]), we have to clean up
643 * our structure and to set state to TTY_CLOSED.
644 * If the tty was hung up otherwise (e.g. vhangup()), then we
645 * ignore this hangup and keep an established IUCV path open...
646 * (...the reason is that we are not able to connect back to the
647 * client if we disconnect on hang up) */
648 priv->tty_state = TTY_CLOSED;
650 if (priv->iucv_state == IUCV_SEVERED)
651 hvc_iucv_cleanup(priv);
652 spin_unlock_bh(&priv->lock);
656 * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time.
657 * @hp: Pointer to the HVC device (struct hvc_struct)
658 * @id: Additional data (originally passed to hvc_alloc):
659 * the index of an struct hvc_iucv_private instance.
661 * This routine notifies the HVC back-end that the last tty device fd has been
662 * closed. The function calls hvc_iucv_cleanup() to clean up the struct
663 * hvc_iucv_private instance.
665 * Locking: struct hvc_iucv_private->lock
667 static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id)
669 struct hvc_iucv_private *priv;
670 struct iucv_path *path;
672 priv = hvc_iucv_get_private(id);
676 flush_sndbuf_sync(priv);
678 spin_lock_bh(&priv->lock);
679 path = priv->path; /* save reference to IUCV path */
681 hvc_iucv_cleanup(priv);
682 spin_unlock_bh(&priv->lock);
684 /* sever IUCV path outside of priv->lock due to lock ordering of:
685 * priv->lock <--> iucv_table_lock */
687 iucv_path_sever(path, NULL);
688 iucv_path_free(path);
693 * hvc_iucv_filter_connreq() - Filter connection request based on z/VM user ID
694 * @ipvmid: Originating z/VM user ID (right padded with blanks)
696 * Returns 0 if the z/VM user ID @ipvmid is allowed to connection, otherwise
699 static int hvc_iucv_filter_connreq(u8 ipvmid[8])
703 /* Note: default policy is ACCEPT if no filter is set */
704 if (!hvc_iucv_filter_size)
707 for (i = 0; i < hvc_iucv_filter_size; i++)
708 if (0 == memcmp(ipvmid, hvc_iucv_filter + (8 * i), 8))
714 * hvc_iucv_path_pending() - IUCV handler to process a connection request.
715 * @path: Pending path (struct iucv_path)
716 * @ipvmid: z/VM system identifier of originator
717 * @ipuser: User specified data for this path
718 * (AF_IUCV: port/service name and originator port)
720 * The function uses the @ipuser data to determine if the pending path belongs
721 * to a terminal managed by this device driver.
722 * If the path belongs to this driver, ensure that the terminal is not accessed
723 * multiple times (only one connection to a terminal is allowed).
724 * If the terminal is not yet connected, the pending path is accepted and is
725 * associated to the appropriate struct hvc_iucv_private instance.
727 * Returns 0 if @path belongs to a terminal managed by the this device driver;
728 * otherwise returns -ENODEV in order to dispatch this path to other handlers.
730 * Locking: struct hvc_iucv_private->lock
732 static int hvc_iucv_path_pending(struct iucv_path *path,
733 u8 ipvmid[8], u8 ipuser[16])
735 struct hvc_iucv_private *priv;
741 for (i = 0; i < hvc_iucv_devices; i++)
742 if (hvc_iucv_table[i] &&
743 (0 == memcmp(hvc_iucv_table[i]->srv_name, ipuser, 8))) {
744 priv = hvc_iucv_table[i];
750 /* Enforce that ipvmid is allowed to connect to us */
751 read_lock(&hvc_iucv_filter_lock);
752 rc = hvc_iucv_filter_connreq(ipvmid);
753 read_unlock(&hvc_iucv_filter_lock);
755 iucv_path_sever(path, ipuser);
756 iucv_path_free(path);
757 memcpy(vm_user_id, ipvmid, 8);
759 pr_info("A connection request from z/VM user ID %s "
760 "was refused\n", vm_user_id);
764 spin_lock(&priv->lock);
766 /* If the terminal is already connected or being severed, then sever
767 * this path to enforce that there is only ONE established communication
768 * path per terminal. */
769 if (priv->iucv_state != IUCV_DISCONN) {
770 iucv_path_sever(path, ipuser);
771 iucv_path_free(path);
772 goto out_path_handled;
776 memcpy(nuser_data, ipuser + 8, 8); /* remote service (for af_iucv) */
777 memcpy(nuser_data + 8, ipuser, 8); /* local service (for af_iucv) */
778 path->msglim = 0xffff; /* IUCV MSGLIMIT */
779 path->flags &= ~IUCV_IPRMDATA; /* TODO: use IUCV_IPRMDATA */
780 rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv);
782 iucv_path_sever(path, ipuser);
783 iucv_path_free(path);
784 goto out_path_handled;
787 priv->iucv_state = IUCV_CONNECTED;
789 /* flush buffered output data... */
790 schedule_delayed_work(&priv->sndbuf_work, 5);
793 spin_unlock(&priv->lock);
798 * hvc_iucv_path_severed() - IUCV handler to process a path sever.
799 * @path: Pending path (struct iucv_path)
800 * @ipuser: User specified data for this path
801 * (AF_IUCV: port/service name and originator port)
803 * This function calls the hvc_iucv_hangup() function for the
804 * respective IUCV HVC terminal.
806 * Locking: struct hvc_iucv_private->lock
808 static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16])
810 struct hvc_iucv_private *priv = path->private;
812 hvc_iucv_hangup(priv);
816 * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message.
817 * @path: Pending path (struct iucv_path)
818 * @msg: Pointer to the IUCV message
820 * The function puts an incoming message on the input queue for later
821 * processing (by hvc_iucv_get_chars() / hvc_iucv_write()).
822 * If the tty has not yet been opened, the message is rejected.
824 * Locking: struct hvc_iucv_private->lock
826 static void hvc_iucv_msg_pending(struct iucv_path *path,
827 struct iucv_message *msg)
829 struct hvc_iucv_private *priv = path->private;
830 struct iucv_tty_buffer *rb;
832 /* reject messages that exceed max size of iucv_tty_msg->datalen */
833 if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) {
834 iucv_message_reject(path, msg);
838 spin_lock(&priv->lock);
840 /* reject messages if tty has not yet been opened */
841 if (priv->tty_state == TTY_CLOSED) {
842 iucv_message_reject(path, msg);
846 /* allocate tty buffer to save iucv msg only */
847 rb = alloc_tty_buffer(0, GFP_ATOMIC);
849 iucv_message_reject(path, msg);
850 goto unlock_return; /* -ENOMEM */
854 list_add_tail(&rb->list, &priv->tty_inqueue);
856 hvc_kick(); /* wake up hvc thread */
859 spin_unlock(&priv->lock);
863 * hvc_iucv_msg_complete() - IUCV handler to process message completion
864 * @path: Pending path (struct iucv_path)
865 * @msg: Pointer to the IUCV message
867 * The function is called upon completion of message delivery to remove the
868 * message from the outqueue. Additional delivery information can be found
869 * msg->audit: rejected messages (0x040000 (IPADRJCT)), and
870 * purged messages (0x010000 (IPADPGNR)).
872 * Locking: struct hvc_iucv_private->lock
874 static void hvc_iucv_msg_complete(struct iucv_path *path,
875 struct iucv_message *msg)
877 struct hvc_iucv_private *priv = path->private;
878 struct iucv_tty_buffer *ent, *next;
879 LIST_HEAD(list_remove);
881 spin_lock(&priv->lock);
882 list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list)
883 if (ent->msg.id == msg->id) {
884 list_move(&ent->list, &list_remove);
887 wake_up(&priv->sndbuf_waitq);
888 spin_unlock(&priv->lock);
889 destroy_tty_buffer_list(&list_remove);
893 * hvc_iucv_pm_freeze() - Freeze PM callback
894 * @dev: IUVC HVC terminal device
896 * Sever an established IUCV communication path and
897 * trigger a hang-up of the underlying HVC terminal.
899 static int hvc_iucv_pm_freeze(struct device *dev)
901 struct hvc_iucv_private *priv = dev_get_drvdata(dev);
904 hvc_iucv_hangup(priv);
911 * hvc_iucv_pm_restore_thaw() - Thaw and restore PM callback
912 * @dev: IUVC HVC terminal device
914 * Wake up the HVC thread to trigger hang-up and respective
915 * HVC back-end notifier invocations.
917 static int hvc_iucv_pm_restore_thaw(struct device *dev)
925 static struct hv_ops hvc_iucv_ops = {
926 .get_chars = hvc_iucv_get_chars,
927 .put_chars = hvc_iucv_put_chars,
928 .notifier_add = hvc_iucv_notifier_add,
929 .notifier_del = hvc_iucv_notifier_del,
930 .notifier_hangup = hvc_iucv_notifier_hangup,
933 /* Suspend / resume device operations */
934 static const struct dev_pm_ops hvc_iucv_pm_ops = {
935 .freeze = hvc_iucv_pm_freeze,
936 .thaw = hvc_iucv_pm_restore_thaw,
937 .restore = hvc_iucv_pm_restore_thaw,
940 /* IUCV HVC device driver */
941 static struct device_driver hvc_iucv_driver = {
942 .name = KMSG_COMPONENT,
944 .pm = &hvc_iucv_pm_ops,
948 * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance
949 * @id: hvc_iucv_table index
950 * @is_console: Flag if the instance is used as Linux console
952 * This function allocates a new hvc_iucv_private structure and stores
953 * the instance in hvc_iucv_table at index @id.
954 * Returns 0 on success; otherwise non-zero.
956 static int __init hvc_iucv_alloc(int id, unsigned int is_console)
958 struct hvc_iucv_private *priv;
962 priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL);
966 spin_lock_init(&priv->lock);
967 INIT_LIST_HEAD(&priv->tty_outqueue);
968 INIT_LIST_HEAD(&priv->tty_inqueue);
969 INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work);
970 init_waitqueue_head(&priv->sndbuf_waitq);
972 priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL);
978 /* set console flag */
979 priv->is_console = is_console;
981 /* allocate hvc device */
982 priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /* PAGE_SIZE */
983 HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256);
984 if (IS_ERR(priv->hvc)) {
985 rc = PTR_ERR(priv->hvc);
989 /* notify HVC thread instead of using polling */
990 priv->hvc->irq_requested = 1;
992 /* setup iucv related information */
993 snprintf(name, 9, "lnxhvc%-2d", id);
994 memcpy(priv->srv_name, name, 8);
995 ASCEBC(priv->srv_name, 8);
997 /* create and setup device */
998 priv->dev = kzalloc(sizeof(*priv->dev), GFP_KERNEL);
1003 dev_set_name(priv->dev, "hvc_iucv%d", id);
1004 dev_set_drvdata(priv->dev, priv);
1005 priv->dev->bus = &iucv_bus;
1006 priv->dev->parent = iucv_root;
1007 priv->dev->driver = &hvc_iucv_driver;
1008 priv->dev->release = (void (*)(struct device *)) kfree;
1009 rc = device_register(priv->dev);
1011 put_device(priv->dev);
1015 hvc_iucv_table[id] = priv;
1019 hvc_remove(priv->hvc);
1021 free_page((unsigned long) priv->sndbuf);
1028 * hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances
1030 static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv)
1032 hvc_remove(priv->hvc);
1033 device_unregister(priv->dev);
1034 free_page((unsigned long) priv->sndbuf);
1039 * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID
1040 * @filter: String containing a comma-separated list of z/VM user IDs
1042 static const char *hvc_iucv_parse_filter(const char *filter, char *dest)
1044 const char *nextdelim, *residual;
1047 nextdelim = strchr(filter, ',');
1049 len = nextdelim - filter;
1050 residual = nextdelim + 1;
1052 len = strlen(filter);
1053 residual = filter + len;
1057 return ERR_PTR(-EINVAL);
1059 /* check for '\n' (if called from sysfs) */
1060 if (filter[len - 1] == '\n')
1064 return ERR_PTR(-EINVAL);
1066 /* pad with blanks and save upper case version of user ID */
1067 memset(dest, ' ', 8);
1069 dest[len] = toupper(filter[len]);
1074 * hvc_iucv_setup_filter() - Set up z/VM user ID filter
1075 * @filter: String consisting of a comma-separated list of z/VM user IDs
1077 * The function parses the @filter string and creates an array containing
1078 * the list of z/VM user ID filter entries.
1079 * Return code 0 means success, -EINVAL if the filter is syntactically
1080 * incorrect, -ENOMEM if there was not enough memory to allocate the
1081 * filter list array, or -ENOSPC if too many z/VM user IDs have been specified.
1083 static int hvc_iucv_setup_filter(const char *val)
1085 const char *residual;
1088 void *array, *old_filter;
1090 count = strlen(val);
1091 if (count == 0 || (count == 1 && val[0] == '\n')) {
1094 goto out_replace_filter; /* clear filter */
1097 /* count user IDs in order to allocate sufficient memory */
1100 while ((residual = strchr(residual, ',')) != NULL) {
1105 /* check if the specified list exceeds the filter limit */
1106 if (size > MAX_VMID_FILTER)
1109 array = kzalloc(size * 8, GFP_KERNEL);
1115 while (*residual && count) {
1116 residual = hvc_iucv_parse_filter(residual,
1117 array + ((size - count) * 8));
1118 if (IS_ERR(residual)) {
1119 err = PTR_ERR(residual);
1127 write_lock_bh(&hvc_iucv_filter_lock);
1128 old_filter = hvc_iucv_filter;
1129 hvc_iucv_filter_size = size;
1130 hvc_iucv_filter = array;
1131 write_unlock_bh(&hvc_iucv_filter_lock);
1140 * param_set_vmidfilter() - Set z/VM user ID filter parameter
1141 * @val: String consisting of a comma-separated list of z/VM user IDs
1142 * @kp: Kernel parameter pointing to hvc_iucv_filter array
1144 * The function sets up the z/VM user ID filter specified as comma-separated
1145 * list of user IDs in @val.
1146 * Note: If it is called early in the boot process, @val is stored and
1147 * parsed later in hvc_iucv_init().
1149 static int param_set_vmidfilter(const char *val, struct kernel_param *kp)
1153 if (!MACHINE_IS_VM || !hvc_iucv_devices)
1160 if (slab_is_available())
1161 rc = hvc_iucv_setup_filter(val);
1163 hvc_iucv_filter_string = val; /* defer... */
1168 * param_get_vmidfilter() - Get z/VM user ID filter
1169 * @buffer: Buffer to store z/VM user ID filter,
1170 * (buffer size assumption PAGE_SIZE)
1171 * @kp: Kernel parameter pointing to the hvc_iucv_filter array
1173 * The function stores the filter as a comma-separated list of z/VM user IDs
1174 * in @buffer. Typically, sysfs routines call this function for attr show.
1176 static int param_get_vmidfilter(char *buffer, struct kernel_param *kp)
1182 if (!MACHINE_IS_VM || !hvc_iucv_devices)
1186 read_lock_bh(&hvc_iucv_filter_lock);
1187 for (index = 0; index < hvc_iucv_filter_size; index++) {
1188 start = hvc_iucv_filter + (8 * index);
1189 end = memchr(start, ' ', 8);
1190 len = (end) ? end - start : 8;
1191 memcpy(buffer + rc, start, len);
1195 read_unlock_bh(&hvc_iucv_filter_lock);
1197 buffer[--rc] = '\0'; /* replace last comma and update rc */
1201 #define param_check_vmidfilter(name, p) __param_check(name, p, void)
1204 * hvc_iucv_init() - z/VM IUCV HVC device driver initialization
1206 static int __init hvc_iucv_init(void)
1211 if (!hvc_iucv_devices)
1214 if (!MACHINE_IS_VM) {
1215 pr_notice("The z/VM IUCV HVC device driver cannot "
1216 "be used without z/VM\n");
1221 if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) {
1222 pr_err("%lu is not a valid value for the hvc_iucv= "
1223 "kernel parameter\n", hvc_iucv_devices);
1228 /* register IUCV HVC device driver */
1229 rc = driver_register(&hvc_iucv_driver);
1233 /* parse hvc_iucv_allow string and create z/VM user ID filter list */
1234 if (hvc_iucv_filter_string) {
1235 rc = hvc_iucv_setup_filter(hvc_iucv_filter_string);
1240 pr_err("Allocating memory failed with "
1241 "reason code=%d\n", 3);
1244 pr_err("hvc_iucv_allow= does not specify a valid "
1245 "z/VM user ID list\n");
1248 pr_err("hvc_iucv_allow= specifies too many "
1256 hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT,
1257 sizeof(struct iucv_tty_buffer),
1259 if (!hvc_iucv_buffer_cache) {
1260 pr_err("Allocating memory failed with reason code=%d\n", 1);
1265 hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR,
1266 hvc_iucv_buffer_cache);
1267 if (!hvc_iucv_mempool) {
1268 pr_err("Allocating memory failed with reason code=%d\n", 2);
1269 kmem_cache_destroy(hvc_iucv_buffer_cache);
1274 /* register the first terminal device as console
1275 * (must be done before allocating hvc terminal devices) */
1276 rc = hvc_instantiate(HVC_IUCV_MAGIC, IUCV_HVC_CON_IDX, &hvc_iucv_ops);
1278 pr_err("Registering HVC terminal device as "
1279 "Linux console failed\n");
1280 goto out_error_memory;
1283 /* allocate hvc_iucv_private structs */
1284 for (i = 0; i < hvc_iucv_devices; i++) {
1285 rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0);
1287 pr_err("Creating a new HVC terminal device "
1288 "failed with error code=%d\n", rc);
1293 /* register IUCV callback handler */
1294 rc = iucv_register(&hvc_iucv_handler, 0);
1296 pr_err("Registering IUCV handlers failed with error code=%d\n",
1298 goto out_error_iucv;
1304 iucv_unregister(&hvc_iucv_handler, 0);
1306 for (i = 0; i < hvc_iucv_devices; i++)
1307 if (hvc_iucv_table[i])
1308 hvc_iucv_destroy(hvc_iucv_table[i]);
1310 mempool_destroy(hvc_iucv_mempool);
1311 kmem_cache_destroy(hvc_iucv_buffer_cache);
1313 if (hvc_iucv_filter)
1314 kfree(hvc_iucv_filter);
1315 hvc_iucv_devices = 0; /* ensure that we do not provide any device */
1320 * hvc_iucv_config() - Parsing of hvc_iucv= kernel command line parameter
1321 * @val: Parameter value (numeric)
1323 static int __init hvc_iucv_config(char *val)
1325 return strict_strtoul(val, 10, &hvc_iucv_devices);
1329 device_initcall(hvc_iucv_init);
1330 __setup("hvc_iucv=", hvc_iucv_config);
1331 core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640);