2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (c) 2004-2008 Silicon Graphics, Inc. All Rights Reserved.
10 * Cross Partition Communication (XPC) channel support.
12 * This is the part of XPC that manages the channels and
13 * sends/receives messages across them to/from other partitions.
17 #include <linux/device.h>
21 * Process a connect message from a remote partition.
23 * Note: xpc_process_connect() is expecting to be called with the
24 * spin_lock_irqsave held and will leave it locked upon return.
27 xpc_process_connect(struct xpc_channel
*ch
, unsigned long *irq_flags
)
31 DBUG_ON(!spin_is_locked(&ch
->lock
));
33 if (!(ch
->flags
& XPC_C_OPENREQUEST
) ||
34 !(ch
->flags
& XPC_C_ROPENREQUEST
)) {
35 /* nothing more to do for now */
38 DBUG_ON(!(ch
->flags
& XPC_C_CONNECTING
));
40 if (!(ch
->flags
& XPC_C_SETUP
)) {
41 spin_unlock_irqrestore(&ch
->lock
, *irq_flags
);
42 ret
= xpc_setup_msg_structures(ch
);
43 spin_lock_irqsave(&ch
->lock
, *irq_flags
);
46 XPC_DISCONNECT_CHANNEL(ch
, ret
, irq_flags
);
48 ch
->flags
|= XPC_C_SETUP
;
50 if (ch
->flags
& (XPC_C_CONNECTED
| XPC_C_DISCONNECTING
))
54 if (!(ch
->flags
& XPC_C_OPENREPLY
)) {
55 ch
->flags
|= XPC_C_OPENREPLY
;
56 xpc_send_chctl_openreply(ch
, irq_flags
);
59 if (!(ch
->flags
& XPC_C_ROPENREPLY
))
62 ch
->flags
= (XPC_C_CONNECTED
| XPC_C_SETUP
); /* clear all else */
64 dev_info(xpc_chan
, "channel %d to partition %d connected\n",
65 ch
->number
, ch
->partid
);
67 spin_unlock_irqrestore(&ch
->lock
, *irq_flags
);
68 xpc_create_kthreads(ch
, 1, 0);
69 spin_lock_irqsave(&ch
->lock
, *irq_flags
);
73 * spin_lock_irqsave() is expected to be held on entry.
76 xpc_process_disconnect(struct xpc_channel
*ch
, unsigned long *irq_flags
)
78 struct xpc_partition
*part
= &xpc_partitions
[ch
->partid
];
79 u32 channel_was_connected
= (ch
->flags
& XPC_C_WASCONNECTED
);
81 DBUG_ON(!spin_is_locked(&ch
->lock
));
83 if (!(ch
->flags
& XPC_C_DISCONNECTING
))
86 DBUG_ON(!(ch
->flags
& XPC_C_CLOSEREQUEST
));
88 /* make sure all activity has settled down first */
90 if (atomic_read(&ch
->kthreads_assigned
) > 0 ||
91 atomic_read(&ch
->references
) > 0) {
94 DBUG_ON((ch
->flags
& XPC_C_CONNECTEDCALLOUT_MADE
) &&
95 !(ch
->flags
& XPC_C_DISCONNECTINGCALLOUT_MADE
));
97 if (part
->act_state
== XPC_P_AS_DEACTIVATING
) {
98 /* can't proceed until the other side disengages from us */
99 if (xpc_partition_engaged(ch
->partid
))
104 /* as long as the other side is up do the full protocol */
106 if (!(ch
->flags
& XPC_C_RCLOSEREQUEST
))
109 if (!(ch
->flags
& XPC_C_CLOSEREPLY
)) {
110 ch
->flags
|= XPC_C_CLOSEREPLY
;
111 xpc_send_chctl_closereply(ch
, irq_flags
);
114 if (!(ch
->flags
& XPC_C_RCLOSEREPLY
))
118 /* wake those waiting for notify completion */
119 if (atomic_read(&ch
->n_to_notify
) > 0) {
120 /* we do callout while holding ch->lock, callout can't block */
121 xpc_notify_senders_of_disconnect(ch
);
124 /* both sides are disconnected now */
126 if (ch
->flags
& XPC_C_DISCONNECTINGCALLOUT_MADE
) {
127 spin_unlock_irqrestore(&ch
->lock
, *irq_flags
);
128 xpc_disconnect_callout(ch
, xpDisconnected
);
129 spin_lock_irqsave(&ch
->lock
, *irq_flags
);
132 DBUG_ON(atomic_read(&ch
->n_to_notify
) != 0);
134 /* it's now safe to free the channel's message queues */
135 xpc_teardown_msg_structures(ch
);
140 ch
->local_nentries
= 0;
141 ch
->remote_nentries
= 0;
142 ch
->kthreads_assigned_limit
= 0;
143 ch
->kthreads_idle_limit
= 0;
146 * Mark the channel disconnected and clear all other flags, including
147 * XPC_C_SETUP (because of call to xpc_teardown_msg_structures()) but
148 * not including XPC_C_WDISCONNECT (if it was set).
150 ch
->flags
= (XPC_C_DISCONNECTED
| (ch
->flags
& XPC_C_WDISCONNECT
));
152 atomic_dec(&part
->nchannels_active
);
154 if (channel_was_connected
) {
155 dev_info(xpc_chan
, "channel %d to partition %d disconnected, "
156 "reason=%d\n", ch
->number
, ch
->partid
, ch
->reason
);
159 if (ch
->flags
& XPC_C_WDISCONNECT
) {
160 /* we won't lose the CPU since we're holding ch->lock */
161 complete(&ch
->wdisconnect_wait
);
162 } else if (ch
->delayed_chctl_flags
) {
163 if (part
->act_state
!= XPC_P_AS_DEACTIVATING
) {
164 /* time to take action on any delayed chctl flags */
165 spin_lock(&part
->chctl_lock
);
166 part
->chctl
.flags
[ch
->number
] |=
167 ch
->delayed_chctl_flags
;
168 spin_unlock(&part
->chctl_lock
);
170 ch
->delayed_chctl_flags
= 0;
175 * Process a change in the channel's remote connection state.
178 xpc_process_openclose_chctl_flags(struct xpc_partition
*part
, int ch_number
,
181 unsigned long irq_flags
;
182 struct xpc_openclose_args
*args
=
183 &part
->remote_openclose_args
[ch_number
];
184 struct xpc_channel
*ch
= &part
->channels
[ch_number
];
185 enum xp_retval reason
;
187 spin_lock_irqsave(&ch
->lock
, irq_flags
);
191 if ((ch
->flags
& XPC_C_DISCONNECTED
) &&
192 (ch
->flags
& XPC_C_WDISCONNECT
)) {
194 * Delay processing chctl flags until thread waiting disconnect
195 * has had a chance to see that the channel is disconnected.
197 ch
->delayed_chctl_flags
|= chctl_flags
;
198 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
202 if (chctl_flags
& XPC_CHCTL_CLOSEREQUEST
) {
204 dev_dbg(xpc_chan
, "XPC_CHCTL_CLOSEREQUEST (reason=%d) received "
205 "from partid=%d, channel=%d\n", args
->reason
,
206 ch
->partid
, ch
->number
);
209 * If RCLOSEREQUEST is set, we're probably waiting for
210 * RCLOSEREPLY. We should find it and a ROPENREQUEST packed
211 * with this RCLOSEREQUEST in the chctl_flags.
214 if (ch
->flags
& XPC_C_RCLOSEREQUEST
) {
215 DBUG_ON(!(ch
->flags
& XPC_C_DISCONNECTING
));
216 DBUG_ON(!(ch
->flags
& XPC_C_CLOSEREQUEST
));
217 DBUG_ON(!(ch
->flags
& XPC_C_CLOSEREPLY
));
218 DBUG_ON(ch
->flags
& XPC_C_RCLOSEREPLY
);
220 DBUG_ON(!(chctl_flags
& XPC_CHCTL_CLOSEREPLY
));
221 chctl_flags
&= ~XPC_CHCTL_CLOSEREPLY
;
222 ch
->flags
|= XPC_C_RCLOSEREPLY
;
224 /* both sides have finished disconnecting */
225 xpc_process_disconnect(ch
, &irq_flags
);
226 DBUG_ON(!(ch
->flags
& XPC_C_DISCONNECTED
));
230 if (ch
->flags
& XPC_C_DISCONNECTED
) {
231 if (!(chctl_flags
& XPC_CHCTL_OPENREQUEST
)) {
232 if (part
->chctl
.flags
[ch_number
] &
233 XPC_CHCTL_OPENREQUEST
) {
235 DBUG_ON(ch
->delayed_chctl_flags
!= 0);
236 spin_lock(&part
->chctl_lock
);
237 part
->chctl
.flags
[ch_number
] |=
238 XPC_CHCTL_CLOSEREQUEST
;
239 spin_unlock(&part
->chctl_lock
);
241 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
245 XPC_SET_REASON(ch
, 0, 0);
246 ch
->flags
&= ~XPC_C_DISCONNECTED
;
248 atomic_inc(&part
->nchannels_active
);
249 ch
->flags
|= (XPC_C_CONNECTING
| XPC_C_ROPENREQUEST
);
252 chctl_flags
&= ~(XPC_CHCTL_OPENREQUEST
| XPC_CHCTL_OPENREPLY
);
255 * The meaningful CLOSEREQUEST connection state fields are:
256 * reason = reason connection is to be closed
259 ch
->flags
|= XPC_C_RCLOSEREQUEST
;
261 if (!(ch
->flags
& XPC_C_DISCONNECTING
)) {
262 reason
= args
->reason
;
263 if (reason
<= xpSuccess
|| reason
> xpUnknownReason
)
264 reason
= xpUnknownReason
;
265 else if (reason
== xpUnregistering
)
266 reason
= xpOtherUnregistering
;
268 XPC_DISCONNECT_CHANNEL(ch
, reason
, &irq_flags
);
270 DBUG_ON(chctl_flags
& XPC_CHCTL_CLOSEREPLY
);
271 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
275 xpc_process_disconnect(ch
, &irq_flags
);
278 if (chctl_flags
& XPC_CHCTL_CLOSEREPLY
) {
280 dev_dbg(xpc_chan
, "XPC_CHCTL_CLOSEREPLY received from partid="
281 "%d, channel=%d\n", ch
->partid
, ch
->number
);
283 if (ch
->flags
& XPC_C_DISCONNECTED
) {
284 DBUG_ON(part
->act_state
!= XPC_P_AS_DEACTIVATING
);
285 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
289 DBUG_ON(!(ch
->flags
& XPC_C_CLOSEREQUEST
));
291 if (!(ch
->flags
& XPC_C_RCLOSEREQUEST
)) {
292 if (part
->chctl
.flags
[ch_number
] &
293 XPC_CHCTL_CLOSEREQUEST
) {
295 DBUG_ON(ch
->delayed_chctl_flags
!= 0);
296 spin_lock(&part
->chctl_lock
);
297 part
->chctl
.flags
[ch_number
] |=
298 XPC_CHCTL_CLOSEREPLY
;
299 spin_unlock(&part
->chctl_lock
);
301 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
305 ch
->flags
|= XPC_C_RCLOSEREPLY
;
307 if (ch
->flags
& XPC_C_CLOSEREPLY
) {
308 /* both sides have finished disconnecting */
309 xpc_process_disconnect(ch
, &irq_flags
);
313 if (chctl_flags
& XPC_CHCTL_OPENREQUEST
) {
315 dev_dbg(xpc_chan
, "XPC_CHCTL_OPENREQUEST (entry_size=%d, "
316 "local_nentries=%d) received from partid=%d, "
317 "channel=%d\n", args
->entry_size
, args
->local_nentries
,
318 ch
->partid
, ch
->number
);
320 if (part
->act_state
== XPC_P_AS_DEACTIVATING
||
321 (ch
->flags
& XPC_C_ROPENREQUEST
)) {
322 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
326 if (ch
->flags
& (XPC_C_DISCONNECTING
| XPC_C_WDISCONNECT
)) {
327 ch
->delayed_chctl_flags
|= XPC_CHCTL_OPENREQUEST
;
328 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
331 DBUG_ON(!(ch
->flags
& (XPC_C_DISCONNECTED
|
332 XPC_C_OPENREQUEST
)));
333 DBUG_ON(ch
->flags
& (XPC_C_ROPENREQUEST
| XPC_C_ROPENREPLY
|
334 XPC_C_OPENREPLY
| XPC_C_CONNECTED
));
337 * The meaningful OPENREQUEST connection state fields are:
338 * entry_size = size of channel's messages in bytes
339 * local_nentries = remote partition's local_nentries
341 if (args
->entry_size
== 0 || args
->local_nentries
== 0) {
342 /* assume OPENREQUEST was delayed by mistake */
343 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
347 ch
->flags
|= (XPC_C_ROPENREQUEST
| XPC_C_CONNECTING
);
348 ch
->remote_nentries
= args
->local_nentries
;
350 if (ch
->flags
& XPC_C_OPENREQUEST
) {
351 if (args
->entry_size
!= ch
->entry_size
) {
352 XPC_DISCONNECT_CHANNEL(ch
, xpUnequalMsgSizes
,
354 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
358 ch
->entry_size
= args
->entry_size
;
360 XPC_SET_REASON(ch
, 0, 0);
361 ch
->flags
&= ~XPC_C_DISCONNECTED
;
363 atomic_inc(&part
->nchannels_active
);
366 xpc_process_connect(ch
, &irq_flags
);
369 if (chctl_flags
& XPC_CHCTL_OPENREPLY
) {
371 dev_dbg(xpc_chan
, "XPC_CHCTL_OPENREPLY (local_msgqueue_pa="
372 "0x%lx, local_nentries=%d, remote_nentries=%d) "
373 "received from partid=%d, channel=%d\n",
374 args
->local_msgqueue_pa
, args
->local_nentries
,
375 args
->remote_nentries
, ch
->partid
, ch
->number
);
377 if (ch
->flags
& (XPC_C_DISCONNECTING
| XPC_C_DISCONNECTED
)) {
378 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
381 if (!(ch
->flags
& XPC_C_OPENREQUEST
)) {
382 XPC_DISCONNECT_CHANNEL(ch
, xpOpenCloseError
,
384 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
388 DBUG_ON(!(ch
->flags
& XPC_C_ROPENREQUEST
));
389 DBUG_ON(ch
->flags
& XPC_C_CONNECTED
);
392 * The meaningful OPENREPLY connection state fields are:
393 * local_msgqueue_pa = physical address of remote
394 * partition's local_msgqueue
395 * local_nentries = remote partition's local_nentries
396 * remote_nentries = remote partition's remote_nentries
398 DBUG_ON(args
->local_msgqueue_pa
== 0);
399 DBUG_ON(args
->local_nentries
== 0);
400 DBUG_ON(args
->remote_nentries
== 0);
402 ch
->flags
|= XPC_C_ROPENREPLY
;
403 xpc_save_remote_msgqueue_pa(ch
, args
->local_msgqueue_pa
);
405 if (args
->local_nentries
< ch
->remote_nentries
) {
406 dev_dbg(xpc_chan
, "XPC_CHCTL_OPENREPLY: new "
407 "remote_nentries=%d, old remote_nentries=%d, "
408 "partid=%d, channel=%d\n",
409 args
->local_nentries
, ch
->remote_nentries
,
410 ch
->partid
, ch
->number
);
412 ch
->remote_nentries
= args
->local_nentries
;
414 if (args
->remote_nentries
< ch
->local_nentries
) {
415 dev_dbg(xpc_chan
, "XPC_CHCTL_OPENREPLY: new "
416 "local_nentries=%d, old local_nentries=%d, "
417 "partid=%d, channel=%d\n",
418 args
->remote_nentries
, ch
->local_nentries
,
419 ch
->partid
, ch
->number
);
421 ch
->local_nentries
= args
->remote_nentries
;
424 xpc_process_connect(ch
, &irq_flags
);
427 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
431 * Attempt to establish a channel connection to a remote partition.
433 static enum xp_retval
434 xpc_connect_channel(struct xpc_channel
*ch
)
436 unsigned long irq_flags
;
437 struct xpc_registration
*registration
= &xpc_registrations
[ch
->number
];
439 if (mutex_trylock(®istration
->mutex
) == 0)
442 if (!XPC_CHANNEL_REGISTERED(ch
->number
)) {
443 mutex_unlock(®istration
->mutex
);
444 return xpUnregistered
;
447 spin_lock_irqsave(&ch
->lock
, irq_flags
);
449 DBUG_ON(ch
->flags
& XPC_C_CONNECTED
);
450 DBUG_ON(ch
->flags
& XPC_C_OPENREQUEST
);
452 if (ch
->flags
& XPC_C_DISCONNECTING
) {
453 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
454 mutex_unlock(®istration
->mutex
);
458 /* add info from the channel connect registration to the channel */
460 ch
->kthreads_assigned_limit
= registration
->assigned_limit
;
461 ch
->kthreads_idle_limit
= registration
->idle_limit
;
462 DBUG_ON(atomic_read(&ch
->kthreads_assigned
) != 0);
463 DBUG_ON(atomic_read(&ch
->kthreads_idle
) != 0);
464 DBUG_ON(atomic_read(&ch
->kthreads_active
) != 0);
466 ch
->func
= registration
->func
;
467 DBUG_ON(registration
->func
== NULL
);
468 ch
->key
= registration
->key
;
470 ch
->local_nentries
= registration
->nentries
;
472 if (ch
->flags
& XPC_C_ROPENREQUEST
) {
473 if (registration
->entry_size
!= ch
->entry_size
) {
474 /* the local and remote sides aren't the same */
477 * Because XPC_DISCONNECT_CHANNEL() can block we're
478 * forced to up the registration sema before we unlock
479 * the channel lock. But that's okay here because we're
480 * done with the part that required the registration
481 * sema. XPC_DISCONNECT_CHANNEL() requires that the
482 * channel lock be locked and will unlock and relock
483 * the channel lock as needed.
485 mutex_unlock(®istration
->mutex
);
486 XPC_DISCONNECT_CHANNEL(ch
, xpUnequalMsgSizes
,
488 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
489 return xpUnequalMsgSizes
;
492 ch
->entry_size
= registration
->entry_size
;
494 XPC_SET_REASON(ch
, 0, 0);
495 ch
->flags
&= ~XPC_C_DISCONNECTED
;
497 atomic_inc(&xpc_partitions
[ch
->partid
].nchannels_active
);
500 mutex_unlock(®istration
->mutex
);
502 /* initiate the connection */
504 ch
->flags
|= (XPC_C_OPENREQUEST
| XPC_C_CONNECTING
);
505 xpc_send_chctl_openrequest(ch
, &irq_flags
);
507 xpc_process_connect(ch
, &irq_flags
);
509 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
515 xpc_process_sent_chctl_flags(struct xpc_partition
*part
)
517 unsigned long irq_flags
;
518 union xpc_channel_ctl_flags chctl
;
519 struct xpc_channel
*ch
;
523 chctl
.all_flags
= xpc_get_chctl_all_flags(part
);
526 * Initiate channel connections for registered channels.
528 * For each connected channel that has pending messages activate idle
529 * kthreads and/or create new kthreads as needed.
532 for (ch_number
= 0; ch_number
< part
->nchannels
; ch_number
++) {
533 ch
= &part
->channels
[ch_number
];
536 * Process any open or close related chctl flags, and then deal
537 * with connecting or disconnecting the channel as required.
540 if (chctl
.flags
[ch_number
] & XPC_OPENCLOSE_CHCTL_FLAGS
) {
541 xpc_process_openclose_chctl_flags(part
, ch_number
,
542 chctl
.flags
[ch_number
]);
545 ch_flags
= ch
->flags
; /* need an atomic snapshot of flags */
547 if (ch_flags
& XPC_C_DISCONNECTING
) {
548 spin_lock_irqsave(&ch
->lock
, irq_flags
);
549 xpc_process_disconnect(ch
, &irq_flags
);
550 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
554 if (part
->act_state
== XPC_P_AS_DEACTIVATING
)
557 if (!(ch_flags
& XPC_C_CONNECTED
)) {
558 if (!(ch_flags
& XPC_C_OPENREQUEST
)) {
559 DBUG_ON(ch_flags
& XPC_C_SETUP
);
560 (void)xpc_connect_channel(ch
);
562 spin_lock_irqsave(&ch
->lock
, irq_flags
);
563 xpc_process_connect(ch
, &irq_flags
);
564 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
570 * Process any message related chctl flags, this may involve
571 * the activation of kthreads to deliver any pending messages
572 * sent from the other partition.
575 if (chctl
.flags
[ch_number
] & XPC_MSG_CHCTL_FLAGS
)
576 xpc_process_msg_chctl_flags(part
, ch_number
);
581 * XPC's heartbeat code calls this function to inform XPC that a partition is
582 * going down. XPC responds by tearing down the XPartition Communication
583 * infrastructure used for the just downed partition.
585 * XPC's heartbeat code will never call this function and xpc_partition_up()
586 * at the same time. Nor will it ever make multiple calls to either function
590 xpc_partition_going_down(struct xpc_partition
*part
, enum xp_retval reason
)
592 unsigned long irq_flags
;
594 struct xpc_channel
*ch
;
596 dev_dbg(xpc_chan
, "deactivating partition %d, reason=%d\n",
597 XPC_PARTID(part
), reason
);
599 if (!xpc_part_ref(part
)) {
600 /* infrastructure for this partition isn't currently set up */
604 /* disconnect channels associated with the partition going down */
606 for (ch_number
= 0; ch_number
< part
->nchannels
; ch_number
++) {
607 ch
= &part
->channels
[ch_number
];
609 xpc_msgqueue_ref(ch
);
610 spin_lock_irqsave(&ch
->lock
, irq_flags
);
612 XPC_DISCONNECT_CHANNEL(ch
, reason
, &irq_flags
);
614 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
615 xpc_msgqueue_deref(ch
);
618 xpc_wakeup_channel_mgr(part
);
620 xpc_part_deref(part
);
624 * Called by XP at the time of channel connection registration to cause
625 * XPC to establish connections to all currently active partitions.
628 xpc_initiate_connect(int ch_number
)
631 struct xpc_partition
*part
;
632 struct xpc_channel
*ch
;
634 DBUG_ON(ch_number
< 0 || ch_number
>= XPC_MAX_NCHANNELS
);
636 for (partid
= 0; partid
< xp_max_npartitions
; partid
++) {
637 part
= &xpc_partitions
[partid
];
639 if (xpc_part_ref(part
)) {
640 ch
= &part
->channels
[ch_number
];
643 * Initiate the establishment of a connection on the
644 * newly registered channel to the remote partition.
646 xpc_wakeup_channel_mgr(part
);
647 xpc_part_deref(part
);
653 xpc_connected_callout(struct xpc_channel
*ch
)
655 /* let the registerer know that a connection has been established */
657 if (ch
->func
!= NULL
) {
658 dev_dbg(xpc_chan
, "ch->func() called, reason=xpConnected, "
659 "partid=%d, channel=%d\n", ch
->partid
, ch
->number
);
661 ch
->func(xpConnected
, ch
->partid
, ch
->number
,
662 (void *)(u64
)ch
->local_nentries
, ch
->key
);
664 dev_dbg(xpc_chan
, "ch->func() returned, reason=xpConnected, "
665 "partid=%d, channel=%d\n", ch
->partid
, ch
->number
);
670 * Called by XP at the time of channel connection unregistration to cause
671 * XPC to teardown all current connections for the specified channel.
673 * Before returning xpc_initiate_disconnect() will wait until all connections
674 * on the specified channel have been closed/torndown. So the caller can be
675 * assured that they will not be receiving any more callouts from XPC to the
676 * function they registered via xpc_connect().
680 * ch_number - channel # to unregister.
683 xpc_initiate_disconnect(int ch_number
)
685 unsigned long irq_flags
;
687 struct xpc_partition
*part
;
688 struct xpc_channel
*ch
;
690 DBUG_ON(ch_number
< 0 || ch_number
>= XPC_MAX_NCHANNELS
);
692 /* initiate the channel disconnect for every active partition */
693 for (partid
= 0; partid
< xp_max_npartitions
; partid
++) {
694 part
= &xpc_partitions
[partid
];
696 if (xpc_part_ref(part
)) {
697 ch
= &part
->channels
[ch_number
];
698 xpc_msgqueue_ref(ch
);
700 spin_lock_irqsave(&ch
->lock
, irq_flags
);
702 if (!(ch
->flags
& XPC_C_DISCONNECTED
)) {
703 ch
->flags
|= XPC_C_WDISCONNECT
;
705 XPC_DISCONNECT_CHANNEL(ch
, xpUnregistering
,
709 spin_unlock_irqrestore(&ch
->lock
, irq_flags
);
711 xpc_msgqueue_deref(ch
);
712 xpc_part_deref(part
);
716 xpc_disconnect_wait(ch_number
);
720 * To disconnect a channel, and reflect it back to all who may be waiting.
722 * An OPEN is not allowed until XPC_C_DISCONNECTING is cleared by
723 * xpc_process_disconnect(), and if set, XPC_C_WDISCONNECT is cleared by
724 * xpc_disconnect_wait().
726 * THE CHANNEL IS TO BE LOCKED BY THE CALLER AND WILL REMAIN LOCKED UPON RETURN.
729 xpc_disconnect_channel(const int line
, struct xpc_channel
*ch
,
730 enum xp_retval reason
, unsigned long *irq_flags
)
732 u32 channel_was_connected
= (ch
->flags
& XPC_C_CONNECTED
);
734 DBUG_ON(!spin_is_locked(&ch
->lock
));
736 if (ch
->flags
& (XPC_C_DISCONNECTING
| XPC_C_DISCONNECTED
))
739 DBUG_ON(!(ch
->flags
& (XPC_C_CONNECTING
| XPC_C_CONNECTED
)));
741 dev_dbg(xpc_chan
, "reason=%d, line=%d, partid=%d, channel=%d\n",
742 reason
, line
, ch
->partid
, ch
->number
);
744 XPC_SET_REASON(ch
, reason
, line
);
746 ch
->flags
|= (XPC_C_CLOSEREQUEST
| XPC_C_DISCONNECTING
);
747 /* some of these may not have been set */
748 ch
->flags
&= ~(XPC_C_OPENREQUEST
| XPC_C_OPENREPLY
|
749 XPC_C_ROPENREQUEST
| XPC_C_ROPENREPLY
|
750 XPC_C_CONNECTING
| XPC_C_CONNECTED
);
752 xpc_send_chctl_closerequest(ch
, irq_flags
);
754 if (channel_was_connected
)
755 ch
->flags
|= XPC_C_WASCONNECTED
;
757 spin_unlock_irqrestore(&ch
->lock
, *irq_flags
);
759 /* wake all idle kthreads so they can exit */
760 if (atomic_read(&ch
->kthreads_idle
) > 0) {
761 wake_up_all(&ch
->idle_wq
);
763 } else if ((ch
->flags
& XPC_C_CONNECTEDCALLOUT_MADE
) &&
764 !(ch
->flags
& XPC_C_DISCONNECTINGCALLOUT
)) {
765 /* start a kthread that will do the xpDisconnecting callout */
766 xpc_create_kthreads(ch
, 1, 1);
769 /* wake those waiting to allocate an entry from the local msg queue */
770 if (atomic_read(&ch
->n_on_msg_allocate_wq
) > 0)
771 wake_up(&ch
->msg_allocate_wq
);
773 spin_lock_irqsave(&ch
->lock
, *irq_flags
);
777 xpc_disconnect_callout(struct xpc_channel
*ch
, enum xp_retval reason
)
780 * Let the channel's registerer know that the channel is being
781 * disconnected. We don't want to do this if the registerer was never
782 * informed of a connection being made.
785 if (ch
->func
!= NULL
) {
786 dev_dbg(xpc_chan
, "ch->func() called, reason=%d, partid=%d, "
787 "channel=%d\n", reason
, ch
->partid
, ch
->number
);
789 ch
->func(reason
, ch
->partid
, ch
->number
, NULL
, ch
->key
);
791 dev_dbg(xpc_chan
, "ch->func() returned, reason=%d, partid=%d, "
792 "channel=%d\n", reason
, ch
->partid
, ch
->number
);
797 * Wait for a message entry to become available for the specified channel,
798 * but don't wait any longer than 1 jiffy.
801 xpc_allocate_msg_wait(struct xpc_channel
*ch
)
805 if (ch
->flags
& XPC_C_DISCONNECTING
) {
806 DBUG_ON(ch
->reason
== xpInterrupted
);
810 atomic_inc(&ch
->n_on_msg_allocate_wq
);
811 ret
= interruptible_sleep_on_timeout(&ch
->msg_allocate_wq
, 1);
812 atomic_dec(&ch
->n_on_msg_allocate_wq
);
814 if (ch
->flags
& XPC_C_DISCONNECTING
) {
816 DBUG_ON(ch
->reason
== xpInterrupted
);
817 } else if (ret
== 0) {
827 * Send a message that contains the user's payload on the specified channel
828 * connected to the specified partition.
830 * NOTE that this routine can sleep waiting for a message entry to become
831 * available. To not sleep, pass in the XPC_NOWAIT flag.
833 * Once sent, this routine will not wait for the message to be received, nor
834 * will notification be given when it does happen.
838 * partid - ID of partition to which the channel is connected.
839 * ch_number - channel # to send message on.
840 * flags - see xp.h for valid flags.
841 * payload - pointer to the payload which is to be sent.
842 * payload_size - size of the payload in bytes.
845 xpc_initiate_send(short partid
, int ch_number
, u32 flags
, void *payload
,
848 struct xpc_partition
*part
= &xpc_partitions
[partid
];
849 enum xp_retval ret
= xpUnknownReason
;
851 dev_dbg(xpc_chan
, "payload=0x%p, partid=%d, channel=%d\n", payload
,
854 DBUG_ON(partid
< 0 || partid
>= xp_max_npartitions
);
855 DBUG_ON(ch_number
< 0 || ch_number
>= part
->nchannels
);
856 DBUG_ON(payload
== NULL
);
858 if (xpc_part_ref(part
)) {
859 ret
= xpc_send_payload(&part
->channels
[ch_number
], flags
,
860 payload
, payload_size
, 0, NULL
, NULL
);
861 xpc_part_deref(part
);
868 * Send a message that contains the user's payload on the specified channel
869 * connected to the specified partition.
871 * NOTE that this routine can sleep waiting for a message entry to become
872 * available. To not sleep, pass in the XPC_NOWAIT flag.
874 * This routine will not wait for the message to be sent or received.
876 * Once the remote end of the channel has received the message, the function
877 * passed as an argument to xpc_initiate_send_notify() will be called. This
878 * allows the sender to free up or re-use any buffers referenced by the
879 * message, but does NOT mean the message has been processed at the remote
882 * If this routine returns an error, the caller's function will NOT be called.
886 * partid - ID of partition to which the channel is connected.
887 * ch_number - channel # to send message on.
888 * flags - see xp.h for valid flags.
889 * payload - pointer to the payload which is to be sent.
890 * payload_size - size of the payload in bytes.
891 * func - function to call with asynchronous notification of message
892 * receipt. THIS FUNCTION MUST BE NON-BLOCKING.
893 * key - user-defined key to be passed to the function when it's called.
896 xpc_initiate_send_notify(short partid
, int ch_number
, u32 flags
, void *payload
,
897 u16 payload_size
, xpc_notify_func func
, void *key
)
899 struct xpc_partition
*part
= &xpc_partitions
[partid
];
900 enum xp_retval ret
= xpUnknownReason
;
902 dev_dbg(xpc_chan
, "payload=0x%p, partid=%d, channel=%d\n", payload
,
905 DBUG_ON(partid
< 0 || partid
>= xp_max_npartitions
);
906 DBUG_ON(ch_number
< 0 || ch_number
>= part
->nchannels
);
907 DBUG_ON(payload
== NULL
);
908 DBUG_ON(func
== NULL
);
910 if (xpc_part_ref(part
)) {
911 ret
= xpc_send_payload(&part
->channels
[ch_number
], flags
,
912 payload
, payload_size
, XPC_N_CALL
, func
,
914 xpc_part_deref(part
);
920 * Deliver a message's payload to its intended recipient.
923 xpc_deliver_payload(struct xpc_channel
*ch
)
927 payload
= xpc_get_deliverable_payload(ch
);
928 if (payload
!= NULL
) {
931 * This ref is taken to protect the payload itself from being
932 * freed before the user is finished with it, which the user
933 * indicates by calling xpc_initiate_received().
935 xpc_msgqueue_ref(ch
);
937 atomic_inc(&ch
->kthreads_active
);
939 if (ch
->func
!= NULL
) {
940 dev_dbg(xpc_chan
, "ch->func() called, payload=0x%p "
941 "partid=%d channel=%d\n", payload
, ch
->partid
,
944 /* deliver the message to its intended recipient */
945 ch
->func(xpMsgReceived
, ch
->partid
, ch
->number
, payload
,
948 dev_dbg(xpc_chan
, "ch->func() returned, payload=0x%p "
949 "partid=%d channel=%d\n", payload
, ch
->partid
,
953 atomic_dec(&ch
->kthreads_active
);
958 * Acknowledge receipt of a delivered message's payload.
960 * This function, although called by users, does not call xpc_part_ref() to
961 * ensure that the partition infrastructure is in place. It relies on the
962 * fact that we called xpc_msgqueue_ref() in xpc_deliver_payload().
966 * partid - ID of partition to which the channel is connected.
967 * ch_number - channel # message received on.
968 * payload - pointer to the payload area allocated via
969 * xpc_initiate_send() or xpc_initiate_send_notify().
972 xpc_initiate_received(short partid
, int ch_number
, void *payload
)
974 struct xpc_partition
*part
= &xpc_partitions
[partid
];
975 struct xpc_channel
*ch
;
977 DBUG_ON(partid
< 0 || partid
>= xp_max_npartitions
);
978 DBUG_ON(ch_number
< 0 || ch_number
>= part
->nchannels
);
980 ch
= &part
->channels
[ch_number
];
981 xpc_received_payload(ch
, payload
);
983 /* the call to xpc_msgqueue_ref() was done by xpc_deliver_payload() */
984 xpc_msgqueue_deref(ch
);