1 | /* |
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 |
4 | * for more details. |
5 | * |
6 | * Copyright (c) 2004-2009 Silicon Graphics, Inc. All Rights Reserved. |
7 | */ |
8 | |
9 | /* |
10 | * Cross Partition Communication (XPC) channel support. |
11 | * |
12 | * This is the part of XPC that manages the channels and |
13 | * sends/receives messages across them to/from other partitions. |
14 | * |
15 | */ |
16 | |
17 | #include <linux/device.h> |
18 | #include "xpc.h" |
19 | |
20 | /* |
21 | * Process a connect message from a remote partition. |
22 | * |
23 | * Note: xpc_process_connect() is expecting to be called with the |
24 | * spin_lock_irqsave held and will leave it locked upon return. |
25 | */ |
26 | static void |
27 | xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags) |
28 | { |
29 | enum xp_retval ret; |
30 | |
31 | lockdep_assert_held(&ch->lock); |
32 | |
33 | if (!(ch->flags & XPC_C_OPENREQUEST) || |
34 | !(ch->flags & XPC_C_ROPENREQUEST)) { |
35 | /* nothing more to do for now */ |
36 | return; |
37 | } |
38 | DBUG_ON(!(ch->flags & XPC_C_CONNECTING)); |
39 | |
40 | if (!(ch->flags & XPC_C_SETUP)) { |
41 | spin_unlock_irqrestore(lock: &ch->lock, flags: *irq_flags); |
42 | ret = xpc_arch_ops.setup_msg_structures(ch); |
43 | spin_lock_irqsave(&ch->lock, *irq_flags); |
44 | |
45 | if (ret != xpSuccess) |
46 | XPC_DISCONNECT_CHANNEL(ch, ret, irq_flags); |
47 | else |
48 | ch->flags |= XPC_C_SETUP; |
49 | |
50 | if (ch->flags & XPC_C_DISCONNECTING) |
51 | return; |
52 | } |
53 | |
54 | if (!(ch->flags & XPC_C_OPENREPLY)) { |
55 | ch->flags |= XPC_C_OPENREPLY; |
56 | xpc_arch_ops.send_chctl_openreply(ch, irq_flags); |
57 | } |
58 | |
59 | if (!(ch->flags & XPC_C_ROPENREPLY)) |
60 | return; |
61 | |
62 | if (!(ch->flags & XPC_C_OPENCOMPLETE)) { |
63 | ch->flags |= (XPC_C_OPENCOMPLETE | XPC_C_CONNECTED); |
64 | xpc_arch_ops.send_chctl_opencomplete(ch, irq_flags); |
65 | } |
66 | |
67 | if (!(ch->flags & XPC_C_ROPENCOMPLETE)) |
68 | return; |
69 | |
70 | dev_info(xpc_chan, "channel %d to partition %d connected\n" , |
71 | ch->number, ch->partid); |
72 | |
73 | ch->flags = (XPC_C_CONNECTED | XPC_C_SETUP); /* clear all else */ |
74 | } |
75 | |
76 | /* |
77 | * spin_lock_irqsave() is expected to be held on entry. |
78 | */ |
79 | static void |
80 | xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags) |
81 | { |
82 | struct xpc_partition *part = &xpc_partitions[ch->partid]; |
83 | u32 channel_was_connected = (ch->flags & XPC_C_WASCONNECTED); |
84 | |
85 | lockdep_assert_held(&ch->lock); |
86 | |
87 | if (!(ch->flags & XPC_C_DISCONNECTING)) |
88 | return; |
89 | |
90 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); |
91 | |
92 | /* make sure all activity has settled down first */ |
93 | |
94 | if (atomic_read(v: &ch->kthreads_assigned) > 0 || |
95 | atomic_read(v: &ch->references) > 0) { |
96 | return; |
97 | } |
98 | DBUG_ON((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) && |
99 | !(ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE)); |
100 | |
101 | if (part->act_state == XPC_P_AS_DEACTIVATING) { |
102 | /* can't proceed until the other side disengages from us */ |
103 | if (xpc_arch_ops.partition_engaged(ch->partid)) |
104 | return; |
105 | |
106 | } else { |
107 | |
108 | /* as long as the other side is up do the full protocol */ |
109 | |
110 | if (!(ch->flags & XPC_C_RCLOSEREQUEST)) |
111 | return; |
112 | |
113 | if (!(ch->flags & XPC_C_CLOSEREPLY)) { |
114 | ch->flags |= XPC_C_CLOSEREPLY; |
115 | xpc_arch_ops.send_chctl_closereply(ch, irq_flags); |
116 | } |
117 | |
118 | if (!(ch->flags & XPC_C_RCLOSEREPLY)) |
119 | return; |
120 | } |
121 | |
122 | /* wake those waiting for notify completion */ |
123 | if (atomic_read(v: &ch->n_to_notify) > 0) { |
124 | /* we do callout while holding ch->lock, callout can't block */ |
125 | xpc_arch_ops.notify_senders_of_disconnect(ch); |
126 | } |
127 | |
128 | /* both sides are disconnected now */ |
129 | |
130 | if (ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE) { |
131 | spin_unlock_irqrestore(lock: &ch->lock, flags: *irq_flags); |
132 | xpc_disconnect_callout(ch, xpDisconnected); |
133 | spin_lock_irqsave(&ch->lock, *irq_flags); |
134 | } |
135 | |
136 | DBUG_ON(atomic_read(&ch->n_to_notify) != 0); |
137 | |
138 | /* it's now safe to free the channel's message queues */ |
139 | xpc_arch_ops.teardown_msg_structures(ch); |
140 | |
141 | ch->func = NULL; |
142 | ch->key = NULL; |
143 | ch->entry_size = 0; |
144 | ch->local_nentries = 0; |
145 | ch->remote_nentries = 0; |
146 | ch->kthreads_assigned_limit = 0; |
147 | ch->kthreads_idle_limit = 0; |
148 | |
149 | /* |
150 | * Mark the channel disconnected and clear all other flags, including |
151 | * XPC_C_SETUP (because of call to |
152 | * xpc_arch_ops.teardown_msg_structures()) but not including |
153 | * XPC_C_WDISCONNECT (if it was set). |
154 | */ |
155 | ch->flags = (XPC_C_DISCONNECTED | (ch->flags & XPC_C_WDISCONNECT)); |
156 | |
157 | atomic_dec(v: &part->nchannels_active); |
158 | |
159 | if (channel_was_connected) { |
160 | dev_info(xpc_chan, "channel %d to partition %d disconnected, " |
161 | "reason=%d\n" , ch->number, ch->partid, ch->reason); |
162 | } |
163 | |
164 | if (ch->flags & XPC_C_WDISCONNECT) { |
165 | /* we won't lose the CPU since we're holding ch->lock */ |
166 | complete(&ch->wdisconnect_wait); |
167 | } else if (ch->delayed_chctl_flags) { |
168 | if (part->act_state != XPC_P_AS_DEACTIVATING) { |
169 | /* time to take action on any delayed chctl flags */ |
170 | spin_lock(lock: &part->chctl_lock); |
171 | part->chctl.flags[ch->number] |= |
172 | ch->delayed_chctl_flags; |
173 | spin_unlock(lock: &part->chctl_lock); |
174 | } |
175 | ch->delayed_chctl_flags = 0; |
176 | } |
177 | } |
178 | |
179 | /* |
180 | * Process a change in the channel's remote connection state. |
181 | */ |
182 | static void |
183 | xpc_process_openclose_chctl_flags(struct xpc_partition *part, int ch_number, |
184 | u8 chctl_flags) |
185 | { |
186 | unsigned long irq_flags; |
187 | struct xpc_openclose_args *args = |
188 | &part->remote_openclose_args[ch_number]; |
189 | struct xpc_channel *ch = &part->channels[ch_number]; |
190 | enum xp_retval reason; |
191 | enum xp_retval ret; |
192 | int create_kthread = 0; |
193 | |
194 | spin_lock_irqsave(&ch->lock, irq_flags); |
195 | |
196 | again: |
197 | |
198 | if ((ch->flags & XPC_C_DISCONNECTED) && |
199 | (ch->flags & XPC_C_WDISCONNECT)) { |
200 | /* |
201 | * Delay processing chctl flags until thread waiting disconnect |
202 | * has had a chance to see that the channel is disconnected. |
203 | */ |
204 | ch->delayed_chctl_flags |= chctl_flags; |
205 | goto out; |
206 | } |
207 | |
208 | if (chctl_flags & XPC_CHCTL_CLOSEREQUEST) { |
209 | |
210 | dev_dbg(xpc_chan, "XPC_CHCTL_CLOSEREQUEST (reason=%d) received " |
211 | "from partid=%d, channel=%d\n" , args->reason, |
212 | ch->partid, ch->number); |
213 | |
214 | /* |
215 | * If RCLOSEREQUEST is set, we're probably waiting for |
216 | * RCLOSEREPLY. We should find it and a ROPENREQUEST packed |
217 | * with this RCLOSEREQUEST in the chctl_flags. |
218 | */ |
219 | |
220 | if (ch->flags & XPC_C_RCLOSEREQUEST) { |
221 | DBUG_ON(!(ch->flags & XPC_C_DISCONNECTING)); |
222 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); |
223 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREPLY)); |
224 | DBUG_ON(ch->flags & XPC_C_RCLOSEREPLY); |
225 | |
226 | DBUG_ON(!(chctl_flags & XPC_CHCTL_CLOSEREPLY)); |
227 | chctl_flags &= ~XPC_CHCTL_CLOSEREPLY; |
228 | ch->flags |= XPC_C_RCLOSEREPLY; |
229 | |
230 | /* both sides have finished disconnecting */ |
231 | xpc_process_disconnect(ch, irq_flags: &irq_flags); |
232 | DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED)); |
233 | goto again; |
234 | } |
235 | |
236 | if (ch->flags & XPC_C_DISCONNECTED) { |
237 | if (!(chctl_flags & XPC_CHCTL_OPENREQUEST)) { |
238 | if (part->chctl.flags[ch_number] & |
239 | XPC_CHCTL_OPENREQUEST) { |
240 | |
241 | DBUG_ON(ch->delayed_chctl_flags != 0); |
242 | spin_lock(lock: &part->chctl_lock); |
243 | part->chctl.flags[ch_number] |= |
244 | XPC_CHCTL_CLOSEREQUEST; |
245 | spin_unlock(lock: &part->chctl_lock); |
246 | } |
247 | goto out; |
248 | } |
249 | |
250 | XPC_SET_REASON(ch, 0, 0); |
251 | ch->flags &= ~XPC_C_DISCONNECTED; |
252 | |
253 | atomic_inc(v: &part->nchannels_active); |
254 | ch->flags |= (XPC_C_CONNECTING | XPC_C_ROPENREQUEST); |
255 | } |
256 | |
257 | chctl_flags &= ~(XPC_CHCTL_OPENREQUEST | XPC_CHCTL_OPENREPLY | |
258 | XPC_CHCTL_OPENCOMPLETE); |
259 | |
260 | /* |
261 | * The meaningful CLOSEREQUEST connection state fields are: |
262 | * reason = reason connection is to be closed |
263 | */ |
264 | |
265 | ch->flags |= XPC_C_RCLOSEREQUEST; |
266 | |
267 | if (!(ch->flags & XPC_C_DISCONNECTING)) { |
268 | reason = args->reason; |
269 | if (reason <= xpSuccess || reason > xpUnknownReason) |
270 | reason = xpUnknownReason; |
271 | else if (reason == xpUnregistering) |
272 | reason = xpOtherUnregistering; |
273 | |
274 | XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags); |
275 | |
276 | DBUG_ON(chctl_flags & XPC_CHCTL_CLOSEREPLY); |
277 | goto out; |
278 | } |
279 | |
280 | xpc_process_disconnect(ch, irq_flags: &irq_flags); |
281 | } |
282 | |
283 | if (chctl_flags & XPC_CHCTL_CLOSEREPLY) { |
284 | |
285 | dev_dbg(xpc_chan, "XPC_CHCTL_CLOSEREPLY received from partid=" |
286 | "%d, channel=%d\n" , ch->partid, ch->number); |
287 | |
288 | if (ch->flags & XPC_C_DISCONNECTED) { |
289 | DBUG_ON(part->act_state != XPC_P_AS_DEACTIVATING); |
290 | goto out; |
291 | } |
292 | |
293 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); |
294 | |
295 | if (!(ch->flags & XPC_C_RCLOSEREQUEST)) { |
296 | if (part->chctl.flags[ch_number] & |
297 | XPC_CHCTL_CLOSEREQUEST) { |
298 | |
299 | DBUG_ON(ch->delayed_chctl_flags != 0); |
300 | spin_lock(lock: &part->chctl_lock); |
301 | part->chctl.flags[ch_number] |= |
302 | XPC_CHCTL_CLOSEREPLY; |
303 | spin_unlock(lock: &part->chctl_lock); |
304 | } |
305 | goto out; |
306 | } |
307 | |
308 | ch->flags |= XPC_C_RCLOSEREPLY; |
309 | |
310 | if (ch->flags & XPC_C_CLOSEREPLY) { |
311 | /* both sides have finished disconnecting */ |
312 | xpc_process_disconnect(ch, irq_flags: &irq_flags); |
313 | } |
314 | } |
315 | |
316 | if (chctl_flags & XPC_CHCTL_OPENREQUEST) { |
317 | |
318 | dev_dbg(xpc_chan, "XPC_CHCTL_OPENREQUEST (entry_size=%d, " |
319 | "local_nentries=%d) received from partid=%d, " |
320 | "channel=%d\n" , args->entry_size, args->local_nentries, |
321 | ch->partid, ch->number); |
322 | |
323 | if (part->act_state == XPC_P_AS_DEACTIVATING || |
324 | (ch->flags & XPC_C_ROPENREQUEST)) { |
325 | goto out; |
326 | } |
327 | |
328 | if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) { |
329 | ch->delayed_chctl_flags |= XPC_CHCTL_OPENREQUEST; |
330 | goto out; |
331 | } |
332 | DBUG_ON(!(ch->flags & (XPC_C_DISCONNECTED | |
333 | XPC_C_OPENREQUEST))); |
334 | DBUG_ON(ch->flags & (XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY | |
335 | XPC_C_OPENREPLY | XPC_C_CONNECTED)); |
336 | |
337 | /* |
338 | * The meaningful OPENREQUEST connection state fields are: |
339 | * entry_size = size of channel's messages in bytes |
340 | * local_nentries = remote partition's local_nentries |
341 | */ |
342 | if (args->entry_size == 0 || args->local_nentries == 0) { |
343 | /* assume OPENREQUEST was delayed by mistake */ |
344 | goto out; |
345 | } |
346 | |
347 | ch->flags |= (XPC_C_ROPENREQUEST | XPC_C_CONNECTING); |
348 | ch->remote_nentries = args->local_nentries; |
349 | |
350 | if (ch->flags & XPC_C_OPENREQUEST) { |
351 | if (args->entry_size != ch->entry_size) { |
352 | XPC_DISCONNECT_CHANNEL(ch, xpUnequalMsgSizes, |
353 | &irq_flags); |
354 | goto out; |
355 | } |
356 | } else { |
357 | ch->entry_size = args->entry_size; |
358 | |
359 | XPC_SET_REASON(ch, 0, 0); |
360 | ch->flags &= ~XPC_C_DISCONNECTED; |
361 | |
362 | atomic_inc(v: &part->nchannels_active); |
363 | } |
364 | |
365 | xpc_process_connect(ch, irq_flags: &irq_flags); |
366 | } |
367 | |
368 | if (chctl_flags & XPC_CHCTL_OPENREPLY) { |
369 | |
370 | dev_dbg(xpc_chan, "XPC_CHCTL_OPENREPLY (local_msgqueue_pa=" |
371 | "0x%lx, local_nentries=%d, remote_nentries=%d) " |
372 | "received from partid=%d, channel=%d\n" , |
373 | args->local_msgqueue_pa, args->local_nentries, |
374 | args->remote_nentries, ch->partid, ch->number); |
375 | |
376 | if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) |
377 | goto out; |
378 | |
379 | if (!(ch->flags & XPC_C_OPENREQUEST)) { |
380 | XPC_DISCONNECT_CHANNEL(ch, xpOpenCloseError, |
381 | &irq_flags); |
382 | goto out; |
383 | } |
384 | |
385 | DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST)); |
386 | DBUG_ON(ch->flags & XPC_C_CONNECTED); |
387 | |
388 | /* |
389 | * The meaningful OPENREPLY connection state fields are: |
390 | * local_msgqueue_pa = physical address of remote |
391 | * partition's local_msgqueue |
392 | * local_nentries = remote partition's local_nentries |
393 | * remote_nentries = remote partition's remote_nentries |
394 | */ |
395 | DBUG_ON(args->local_msgqueue_pa == 0); |
396 | DBUG_ON(args->local_nentries == 0); |
397 | DBUG_ON(args->remote_nentries == 0); |
398 | |
399 | ret = xpc_arch_ops.save_remote_msgqueue_pa(ch, |
400 | args->local_msgqueue_pa); |
401 | if (ret != xpSuccess) { |
402 | XPC_DISCONNECT_CHANNEL(ch, ret, &irq_flags); |
403 | goto out; |
404 | } |
405 | ch->flags |= XPC_C_ROPENREPLY; |
406 | |
407 | if (args->local_nentries < ch->remote_nentries) { |
408 | dev_dbg(xpc_chan, "XPC_CHCTL_OPENREPLY: new " |
409 | "remote_nentries=%d, old remote_nentries=%d, " |
410 | "partid=%d, channel=%d\n" , |
411 | args->local_nentries, ch->remote_nentries, |
412 | ch->partid, ch->number); |
413 | |
414 | ch->remote_nentries = args->local_nentries; |
415 | } |
416 | if (args->remote_nentries < ch->local_nentries) { |
417 | dev_dbg(xpc_chan, "XPC_CHCTL_OPENREPLY: new " |
418 | "local_nentries=%d, old local_nentries=%d, " |
419 | "partid=%d, channel=%d\n" , |
420 | args->remote_nentries, ch->local_nentries, |
421 | ch->partid, ch->number); |
422 | |
423 | ch->local_nentries = args->remote_nentries; |
424 | } |
425 | |
426 | xpc_process_connect(ch, irq_flags: &irq_flags); |
427 | } |
428 | |
429 | if (chctl_flags & XPC_CHCTL_OPENCOMPLETE) { |
430 | |
431 | dev_dbg(xpc_chan, "XPC_CHCTL_OPENCOMPLETE received from " |
432 | "partid=%d, channel=%d\n" , ch->partid, ch->number); |
433 | |
434 | if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) |
435 | goto out; |
436 | |
437 | if (!(ch->flags & XPC_C_OPENREQUEST) || |
438 | !(ch->flags & XPC_C_OPENREPLY)) { |
439 | XPC_DISCONNECT_CHANNEL(ch, xpOpenCloseError, |
440 | &irq_flags); |
441 | goto out; |
442 | } |
443 | |
444 | DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST)); |
445 | DBUG_ON(!(ch->flags & XPC_C_ROPENREPLY)); |
446 | DBUG_ON(!(ch->flags & XPC_C_CONNECTED)); |
447 | |
448 | ch->flags |= XPC_C_ROPENCOMPLETE; |
449 | |
450 | xpc_process_connect(ch, irq_flags: &irq_flags); |
451 | create_kthread = 1; |
452 | } |
453 | |
454 | out: |
455 | spin_unlock_irqrestore(lock: &ch->lock, flags: irq_flags); |
456 | |
457 | if (create_kthread) |
458 | xpc_create_kthreads(ch, 1, 0); |
459 | } |
460 | |
461 | /* |
462 | * Attempt to establish a channel connection to a remote partition. |
463 | */ |
464 | static enum xp_retval |
465 | xpc_connect_channel(struct xpc_channel *ch) |
466 | { |
467 | unsigned long irq_flags; |
468 | struct xpc_registration *registration = &xpc_registrations[ch->number]; |
469 | |
470 | if (mutex_trylock(lock: ®istration->mutex) == 0) |
471 | return xpRetry; |
472 | |
473 | if (!XPC_CHANNEL_REGISTERED(ch->number)) { |
474 | mutex_unlock(lock: ®istration->mutex); |
475 | return xpUnregistered; |
476 | } |
477 | |
478 | spin_lock_irqsave(&ch->lock, irq_flags); |
479 | |
480 | DBUG_ON(ch->flags & XPC_C_CONNECTED); |
481 | DBUG_ON(ch->flags & XPC_C_OPENREQUEST); |
482 | |
483 | if (ch->flags & XPC_C_DISCONNECTING) { |
484 | spin_unlock_irqrestore(lock: &ch->lock, flags: irq_flags); |
485 | mutex_unlock(lock: ®istration->mutex); |
486 | return ch->reason; |
487 | } |
488 | |
489 | /* add info from the channel connect registration to the channel */ |
490 | |
491 | ch->kthreads_assigned_limit = registration->assigned_limit; |
492 | ch->kthreads_idle_limit = registration->idle_limit; |
493 | DBUG_ON(atomic_read(&ch->kthreads_assigned) != 0); |
494 | DBUG_ON(atomic_read(&ch->kthreads_idle) != 0); |
495 | DBUG_ON(atomic_read(&ch->kthreads_active) != 0); |
496 | |
497 | ch->func = registration->func; |
498 | DBUG_ON(registration->func == NULL); |
499 | ch->key = registration->key; |
500 | |
501 | ch->local_nentries = registration->nentries; |
502 | |
503 | if (ch->flags & XPC_C_ROPENREQUEST) { |
504 | if (registration->entry_size != ch->entry_size) { |
505 | /* the local and remote sides aren't the same */ |
506 | |
507 | /* |
508 | * Because XPC_DISCONNECT_CHANNEL() can block we're |
509 | * forced to up the registration sema before we unlock |
510 | * the channel lock. But that's okay here because we're |
511 | * done with the part that required the registration |
512 | * sema. XPC_DISCONNECT_CHANNEL() requires that the |
513 | * channel lock be locked and will unlock and relock |
514 | * the channel lock as needed. |
515 | */ |
516 | mutex_unlock(lock: ®istration->mutex); |
517 | XPC_DISCONNECT_CHANNEL(ch, xpUnequalMsgSizes, |
518 | &irq_flags); |
519 | spin_unlock_irqrestore(lock: &ch->lock, flags: irq_flags); |
520 | return xpUnequalMsgSizes; |
521 | } |
522 | } else { |
523 | ch->entry_size = registration->entry_size; |
524 | |
525 | XPC_SET_REASON(ch, 0, 0); |
526 | ch->flags &= ~XPC_C_DISCONNECTED; |
527 | |
528 | atomic_inc(v: &xpc_partitions[ch->partid].nchannels_active); |
529 | } |
530 | |
531 | mutex_unlock(lock: ®istration->mutex); |
532 | |
533 | /* initiate the connection */ |
534 | |
535 | ch->flags |= (XPC_C_OPENREQUEST | XPC_C_CONNECTING); |
536 | xpc_arch_ops.send_chctl_openrequest(ch, &irq_flags); |
537 | |
538 | xpc_process_connect(ch, irq_flags: &irq_flags); |
539 | |
540 | spin_unlock_irqrestore(lock: &ch->lock, flags: irq_flags); |
541 | |
542 | return xpSuccess; |
543 | } |
544 | |
545 | void |
546 | xpc_process_sent_chctl_flags(struct xpc_partition *part) |
547 | { |
548 | unsigned long irq_flags; |
549 | union xpc_channel_ctl_flags chctl; |
550 | struct xpc_channel *ch; |
551 | int ch_number; |
552 | u32 ch_flags; |
553 | |
554 | chctl.all_flags = xpc_arch_ops.get_chctl_all_flags(part); |
555 | |
556 | /* |
557 | * Initiate channel connections for registered channels. |
558 | * |
559 | * For each connected channel that has pending messages activate idle |
560 | * kthreads and/or create new kthreads as needed. |
561 | */ |
562 | |
563 | for (ch_number = 0; ch_number < part->nchannels; ch_number++) { |
564 | ch = &part->channels[ch_number]; |
565 | |
566 | /* |
567 | * Process any open or close related chctl flags, and then deal |
568 | * with connecting or disconnecting the channel as required. |
569 | */ |
570 | |
571 | if (chctl.flags[ch_number] & XPC_OPENCLOSE_CHCTL_FLAGS) { |
572 | xpc_process_openclose_chctl_flags(part, ch_number, |
573 | chctl_flags: chctl.flags[ch_number]); |
574 | } |
575 | |
576 | ch_flags = ch->flags; /* need an atomic snapshot of flags */ |
577 | |
578 | if (ch_flags & XPC_C_DISCONNECTING) { |
579 | spin_lock_irqsave(&ch->lock, irq_flags); |
580 | xpc_process_disconnect(ch, irq_flags: &irq_flags); |
581 | spin_unlock_irqrestore(lock: &ch->lock, flags: irq_flags); |
582 | continue; |
583 | } |
584 | |
585 | if (part->act_state == XPC_P_AS_DEACTIVATING) |
586 | continue; |
587 | |
588 | if (!(ch_flags & XPC_C_CONNECTED)) { |
589 | if (!(ch_flags & XPC_C_OPENREQUEST)) { |
590 | DBUG_ON(ch_flags & XPC_C_SETUP); |
591 | (void)xpc_connect_channel(ch); |
592 | } |
593 | continue; |
594 | } |
595 | |
596 | /* |
597 | * Process any message related chctl flags, this may involve |
598 | * the activation of kthreads to deliver any pending messages |
599 | * sent from the other partition. |
600 | */ |
601 | |
602 | if (chctl.flags[ch_number] & XPC_MSG_CHCTL_FLAGS) |
603 | xpc_arch_ops.process_msg_chctl_flags(part, ch_number); |
604 | } |
605 | } |
606 | |
607 | /* |
608 | * XPC's heartbeat code calls this function to inform XPC that a partition is |
609 | * going down. XPC responds by tearing down the XPartition Communication |
610 | * infrastructure used for the just downed partition. |
611 | * |
612 | * XPC's heartbeat code will never call this function and xpc_partition_up() |
613 | * at the same time. Nor will it ever make multiple calls to either function |
614 | * at the same time. |
615 | */ |
616 | void |
617 | xpc_partition_going_down(struct xpc_partition *part, enum xp_retval reason) |
618 | { |
619 | unsigned long irq_flags; |
620 | int ch_number; |
621 | struct xpc_channel *ch; |
622 | |
623 | dev_dbg(xpc_chan, "deactivating partition %d, reason=%d\n" , |
624 | XPC_PARTID(part), reason); |
625 | |
626 | if (!xpc_part_ref(part)) { |
627 | /* infrastructure for this partition isn't currently set up */ |
628 | return; |
629 | } |
630 | |
631 | /* disconnect channels associated with the partition going down */ |
632 | |
633 | for (ch_number = 0; ch_number < part->nchannels; ch_number++) { |
634 | ch = &part->channels[ch_number]; |
635 | |
636 | xpc_msgqueue_ref(ch); |
637 | spin_lock_irqsave(&ch->lock, irq_flags); |
638 | |
639 | XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags); |
640 | |
641 | spin_unlock_irqrestore(lock: &ch->lock, flags: irq_flags); |
642 | xpc_msgqueue_deref(ch); |
643 | } |
644 | |
645 | xpc_wakeup_channel_mgr(part); |
646 | |
647 | xpc_part_deref(part); |
648 | } |
649 | |
650 | /* |
651 | * Called by XP at the time of channel connection registration to cause |
652 | * XPC to establish connections to all currently active partitions. |
653 | */ |
654 | void |
655 | xpc_initiate_connect(int ch_number) |
656 | { |
657 | short partid; |
658 | struct xpc_partition *part; |
659 | |
660 | DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS); |
661 | |
662 | for (partid = 0; partid < xp_max_npartitions; partid++) { |
663 | part = &xpc_partitions[partid]; |
664 | |
665 | if (xpc_part_ref(part)) { |
666 | /* |
667 | * Initiate the establishment of a connection on the |
668 | * newly registered channel to the remote partition. |
669 | */ |
670 | xpc_wakeup_channel_mgr(part); |
671 | xpc_part_deref(part); |
672 | } |
673 | } |
674 | } |
675 | |
676 | void |
677 | xpc_connected_callout(struct xpc_channel *ch) |
678 | { |
679 | /* let the registerer know that a connection has been established */ |
680 | |
681 | if (ch->func != NULL) { |
682 | dev_dbg(xpc_chan, "ch->func() called, reason=xpConnected, " |
683 | "partid=%d, channel=%d\n" , ch->partid, ch->number); |
684 | |
685 | ch->func(xpConnected, ch->partid, ch->number, |
686 | (void *)(u64)ch->local_nentries, ch->key); |
687 | |
688 | dev_dbg(xpc_chan, "ch->func() returned, reason=xpConnected, " |
689 | "partid=%d, channel=%d\n" , ch->partid, ch->number); |
690 | } |
691 | } |
692 | |
693 | /* |
694 | * Called by XP at the time of channel connection unregistration to cause |
695 | * XPC to teardown all current connections for the specified channel. |
696 | * |
697 | * Before returning xpc_initiate_disconnect() will wait until all connections |
698 | * on the specified channel have been closed/torndown. So the caller can be |
699 | * assured that they will not be receiving any more callouts from XPC to the |
700 | * function they registered via xpc_connect(). |
701 | * |
702 | * Arguments: |
703 | * |
704 | * ch_number - channel # to unregister. |
705 | */ |
706 | void |
707 | xpc_initiate_disconnect(int ch_number) |
708 | { |
709 | unsigned long irq_flags; |
710 | short partid; |
711 | struct xpc_partition *part; |
712 | struct xpc_channel *ch; |
713 | |
714 | DBUG_ON(ch_number < 0 || ch_number >= XPC_MAX_NCHANNELS); |
715 | |
716 | /* initiate the channel disconnect for every active partition */ |
717 | for (partid = 0; partid < xp_max_npartitions; partid++) { |
718 | part = &xpc_partitions[partid]; |
719 | |
720 | if (xpc_part_ref(part)) { |
721 | ch = &part->channels[ch_number]; |
722 | xpc_msgqueue_ref(ch); |
723 | |
724 | spin_lock_irqsave(&ch->lock, irq_flags); |
725 | |
726 | if (!(ch->flags & XPC_C_DISCONNECTED)) { |
727 | ch->flags |= XPC_C_WDISCONNECT; |
728 | |
729 | XPC_DISCONNECT_CHANNEL(ch, xpUnregistering, |
730 | &irq_flags); |
731 | } |
732 | |
733 | spin_unlock_irqrestore(lock: &ch->lock, flags: irq_flags); |
734 | |
735 | xpc_msgqueue_deref(ch); |
736 | xpc_part_deref(part); |
737 | } |
738 | } |
739 | |
740 | xpc_disconnect_wait(ch_number); |
741 | } |
742 | |
743 | /* |
744 | * To disconnect a channel, and reflect it back to all who may be waiting. |
745 | * |
746 | * An OPEN is not allowed until XPC_C_DISCONNECTING is cleared by |
747 | * xpc_process_disconnect(), and if set, XPC_C_WDISCONNECT is cleared by |
748 | * xpc_disconnect_wait(). |
749 | * |
750 | * THE CHANNEL IS TO BE LOCKED BY THE CALLER AND WILL REMAIN LOCKED UPON RETURN. |
751 | */ |
752 | void |
753 | xpc_disconnect_channel(const int line, struct xpc_channel *ch, |
754 | enum xp_retval reason, unsigned long *irq_flags) |
755 | { |
756 | u32 channel_was_connected = (ch->flags & XPC_C_CONNECTED); |
757 | |
758 | lockdep_assert_held(&ch->lock); |
759 | |
760 | if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) |
761 | return; |
762 | |
763 | DBUG_ON(!(ch->flags & (XPC_C_CONNECTING | XPC_C_CONNECTED))); |
764 | |
765 | dev_dbg(xpc_chan, "reason=%d, line=%d, partid=%d, channel=%d\n" , |
766 | reason, line, ch->partid, ch->number); |
767 | |
768 | XPC_SET_REASON(ch, reason, line); |
769 | |
770 | ch->flags |= (XPC_C_CLOSEREQUEST | XPC_C_DISCONNECTING); |
771 | /* some of these may not have been set */ |
772 | ch->flags &= ~(XPC_C_OPENREQUEST | XPC_C_OPENREPLY | |
773 | XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY | |
774 | XPC_C_CONNECTING | XPC_C_CONNECTED); |
775 | |
776 | xpc_arch_ops.send_chctl_closerequest(ch, irq_flags); |
777 | |
778 | if (channel_was_connected) |
779 | ch->flags |= XPC_C_WASCONNECTED; |
780 | |
781 | spin_unlock_irqrestore(lock: &ch->lock, flags: *irq_flags); |
782 | |
783 | /* wake all idle kthreads so they can exit */ |
784 | if (atomic_read(v: &ch->kthreads_idle) > 0) { |
785 | wake_up_all(&ch->idle_wq); |
786 | |
787 | } else if ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) && |
788 | !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) { |
789 | /* start a kthread that will do the xpDisconnecting callout */ |
790 | xpc_create_kthreads(ch, 1, 1); |
791 | } |
792 | |
793 | /* wake those waiting to allocate an entry from the local msg queue */ |
794 | if (atomic_read(v: &ch->n_on_msg_allocate_wq) > 0) |
795 | wake_up(&ch->msg_allocate_wq); |
796 | |
797 | spin_lock_irqsave(&ch->lock, *irq_flags); |
798 | } |
799 | |
800 | void |
801 | xpc_disconnect_callout(struct xpc_channel *ch, enum xp_retval reason) |
802 | { |
803 | /* |
804 | * Let the channel's registerer know that the channel is being |
805 | * disconnected. We don't want to do this if the registerer was never |
806 | * informed of a connection being made. |
807 | */ |
808 | |
809 | if (ch->func != NULL) { |
810 | dev_dbg(xpc_chan, "ch->func() called, reason=%d, partid=%d, " |
811 | "channel=%d\n" , reason, ch->partid, ch->number); |
812 | |
813 | ch->func(reason, ch->partid, ch->number, NULL, ch->key); |
814 | |
815 | dev_dbg(xpc_chan, "ch->func() returned, reason=%d, partid=%d, " |
816 | "channel=%d\n" , reason, ch->partid, ch->number); |
817 | } |
818 | } |
819 | |
820 | /* |
821 | * Wait for a message entry to become available for the specified channel, |
822 | * but don't wait any longer than 1 jiffy. |
823 | */ |
824 | enum xp_retval |
825 | xpc_allocate_msg_wait(struct xpc_channel *ch) |
826 | { |
827 | enum xp_retval ret; |
828 | DEFINE_WAIT(wait); |
829 | |
830 | if (ch->flags & XPC_C_DISCONNECTING) { |
831 | DBUG_ON(ch->reason == xpInterrupted); |
832 | return ch->reason; |
833 | } |
834 | |
835 | atomic_inc(v: &ch->n_on_msg_allocate_wq); |
836 | prepare_to_wait(wq_head: &ch->msg_allocate_wq, wq_entry: &wait, TASK_INTERRUPTIBLE); |
837 | ret = schedule_timeout(timeout: 1); |
838 | finish_wait(wq_head: &ch->msg_allocate_wq, wq_entry: &wait); |
839 | atomic_dec(v: &ch->n_on_msg_allocate_wq); |
840 | |
841 | if (ch->flags & XPC_C_DISCONNECTING) { |
842 | ret = ch->reason; |
843 | DBUG_ON(ch->reason == xpInterrupted); |
844 | } else if (ret == 0) { |
845 | ret = xpTimeout; |
846 | } else { |
847 | ret = xpInterrupted; |
848 | } |
849 | |
850 | return ret; |
851 | } |
852 | |
853 | /* |
854 | * Send a message that contains the user's payload on the specified channel |
855 | * connected to the specified partition. |
856 | * |
857 | * NOTE that this routine can sleep waiting for a message entry to become |
858 | * available. To not sleep, pass in the XPC_NOWAIT flag. |
859 | * |
860 | * Once sent, this routine will not wait for the message to be received, nor |
861 | * will notification be given when it does happen. |
862 | * |
863 | * Arguments: |
864 | * |
865 | * partid - ID of partition to which the channel is connected. |
866 | * ch_number - channel # to send message on. |
867 | * flags - see xp.h for valid flags. |
868 | * payload - pointer to the payload which is to be sent. |
869 | * payload_size - size of the payload in bytes. |
870 | */ |
871 | enum xp_retval |
872 | xpc_initiate_send(short partid, int ch_number, u32 flags, void *payload, |
873 | u16 payload_size) |
874 | { |
875 | struct xpc_partition *part = &xpc_partitions[partid]; |
876 | enum xp_retval ret = xpUnknownReason; |
877 | |
878 | dev_dbg(xpc_chan, "payload=0x%p, partid=%d, channel=%d\n" , payload, |
879 | partid, ch_number); |
880 | |
881 | DBUG_ON(partid < 0 || partid >= xp_max_npartitions); |
882 | DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); |
883 | DBUG_ON(payload == NULL); |
884 | |
885 | if (xpc_part_ref(part)) { |
886 | ret = xpc_arch_ops.send_payload(&part->channels[ch_number], |
887 | flags, payload, payload_size, 0, NULL, NULL); |
888 | xpc_part_deref(part); |
889 | } |
890 | |
891 | return ret; |
892 | } |
893 | |
894 | /* |
895 | * Send a message that contains the user's payload on the specified channel |
896 | * connected to the specified partition. |
897 | * |
898 | * NOTE that this routine can sleep waiting for a message entry to become |
899 | * available. To not sleep, pass in the XPC_NOWAIT flag. |
900 | * |
901 | * This routine will not wait for the message to be sent or received. |
902 | * |
903 | * Once the remote end of the channel has received the message, the function |
904 | * passed as an argument to xpc_initiate_send_notify() will be called. This |
905 | * allows the sender to free up or re-use any buffers referenced by the |
906 | * message, but does NOT mean the message has been processed at the remote |
907 | * end by a receiver. |
908 | * |
909 | * If this routine returns an error, the caller's function will NOT be called. |
910 | * |
911 | * Arguments: |
912 | * |
913 | * partid - ID of partition to which the channel is connected. |
914 | * ch_number - channel # to send message on. |
915 | * flags - see xp.h for valid flags. |
916 | * payload - pointer to the payload which is to be sent. |
917 | * payload_size - size of the payload in bytes. |
918 | * func - function to call with asynchronous notification of message |
919 | * receipt. THIS FUNCTION MUST BE NON-BLOCKING. |
920 | * key - user-defined key to be passed to the function when it's called. |
921 | */ |
922 | enum xp_retval |
923 | xpc_initiate_send_notify(short partid, int ch_number, u32 flags, void *payload, |
924 | u16 payload_size, xpc_notify_func func, void *key) |
925 | { |
926 | struct xpc_partition *part = &xpc_partitions[partid]; |
927 | enum xp_retval ret = xpUnknownReason; |
928 | |
929 | dev_dbg(xpc_chan, "payload=0x%p, partid=%d, channel=%d\n" , payload, |
930 | partid, ch_number); |
931 | |
932 | DBUG_ON(partid < 0 || partid >= xp_max_npartitions); |
933 | DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); |
934 | DBUG_ON(payload == NULL); |
935 | DBUG_ON(func == NULL); |
936 | |
937 | if (xpc_part_ref(part)) { |
938 | ret = xpc_arch_ops.send_payload(&part->channels[ch_number], |
939 | flags, payload, payload_size, XPC_N_CALL, func, key); |
940 | xpc_part_deref(part); |
941 | } |
942 | return ret; |
943 | } |
944 | |
945 | /* |
946 | * Deliver a message's payload to its intended recipient. |
947 | */ |
948 | void |
949 | xpc_deliver_payload(struct xpc_channel *ch) |
950 | { |
951 | void *payload; |
952 | |
953 | payload = xpc_arch_ops.get_deliverable_payload(ch); |
954 | if (payload != NULL) { |
955 | |
956 | /* |
957 | * This ref is taken to protect the payload itself from being |
958 | * freed before the user is finished with it, which the user |
959 | * indicates by calling xpc_initiate_received(). |
960 | */ |
961 | xpc_msgqueue_ref(ch); |
962 | |
963 | atomic_inc(v: &ch->kthreads_active); |
964 | |
965 | if (ch->func != NULL) { |
966 | dev_dbg(xpc_chan, "ch->func() called, payload=0x%p " |
967 | "partid=%d channel=%d\n" , payload, ch->partid, |
968 | ch->number); |
969 | |
970 | /* deliver the message to its intended recipient */ |
971 | ch->func(xpMsgReceived, ch->partid, ch->number, payload, |
972 | ch->key); |
973 | |
974 | dev_dbg(xpc_chan, "ch->func() returned, payload=0x%p " |
975 | "partid=%d channel=%d\n" , payload, ch->partid, |
976 | ch->number); |
977 | } |
978 | |
979 | atomic_dec(v: &ch->kthreads_active); |
980 | } |
981 | } |
982 | |
983 | /* |
984 | * Acknowledge receipt of a delivered message's payload. |
985 | * |
986 | * This function, although called by users, does not call xpc_part_ref() to |
987 | * ensure that the partition infrastructure is in place. It relies on the |
988 | * fact that we called xpc_msgqueue_ref() in xpc_deliver_payload(). |
989 | * |
990 | * Arguments: |
991 | * |
992 | * partid - ID of partition to which the channel is connected. |
993 | * ch_number - channel # message received on. |
994 | * payload - pointer to the payload area allocated via |
995 | * xpc_initiate_send() or xpc_initiate_send_notify(). |
996 | */ |
997 | void |
998 | xpc_initiate_received(short partid, int ch_number, void *payload) |
999 | { |
1000 | struct xpc_partition *part = &xpc_partitions[partid]; |
1001 | struct xpc_channel *ch; |
1002 | |
1003 | DBUG_ON(partid < 0 || partid >= xp_max_npartitions); |
1004 | DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); |
1005 | |
1006 | ch = &part->channels[ch_number]; |
1007 | xpc_arch_ops.received_payload(ch, payload); |
1008 | |
1009 | /* the call to xpc_msgqueue_ref() was done by xpc_deliver_payload() */ |
1010 | xpc_msgqueue_deref(ch); |
1011 | } |
1012 | |