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89eb8eb9 DN |
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) 2004-2005 Silicon Graphics, Inc. All Rights Reserved. | |
7 | */ | |
8 | ||
9 | ||
10 | /* | |
11 | * Cross Partition Communication (XPC) channel support. | |
12 | * | |
13 | * This is the part of XPC that manages the channels and | |
14 | * sends/receives messages across them to/from other partitions. | |
15 | * | |
16 | */ | |
17 | ||
18 | ||
19 | #include <linux/kernel.h> | |
20 | #include <linux/init.h> | |
21 | #include <linux/sched.h> | |
22 | #include <linux/cache.h> | |
23 | #include <linux/interrupt.h> | |
24 | #include <linux/slab.h> | |
25 | #include <asm/sn/bte.h> | |
26 | #include <asm/sn/sn_sal.h> | |
27 | #include "xpc.h" | |
28 | ||
29 | ||
30 | /* | |
31 | * Set up the initial values for the XPartition Communication channels. | |
32 | */ | |
33 | static void | |
34 | xpc_initialize_channels(struct xpc_partition *part, partid_t partid) | |
35 | { | |
36 | int ch_number; | |
37 | struct xpc_channel *ch; | |
38 | ||
39 | ||
40 | for (ch_number = 0; ch_number < part->nchannels; ch_number++) { | |
41 | ch = &part->channels[ch_number]; | |
42 | ||
43 | ch->partid = partid; | |
44 | ch->number = ch_number; | |
45 | ch->flags = XPC_C_DISCONNECTED; | |
46 | ||
47 | ch->local_GP = &part->local_GPs[ch_number]; | |
48 | ch->local_openclose_args = | |
49 | &part->local_openclose_args[ch_number]; | |
50 | ||
51 | atomic_set(&ch->kthreads_assigned, 0); | |
52 | atomic_set(&ch->kthreads_idle, 0); | |
53 | atomic_set(&ch->kthreads_active, 0); | |
54 | ||
55 | atomic_set(&ch->references, 0); | |
56 | atomic_set(&ch->n_to_notify, 0); | |
57 | ||
58 | spin_lock_init(&ch->lock); | |
59 | sema_init(&ch->msg_to_pull_sema, 1); /* mutex */ | |
a607c389 | 60 | sema_init(&ch->wdisconnect_sema, 0); /* event wait */ |
89eb8eb9 DN |
61 | |
62 | atomic_set(&ch->n_on_msg_allocate_wq, 0); | |
63 | init_waitqueue_head(&ch->msg_allocate_wq); | |
64 | init_waitqueue_head(&ch->idle_wq); | |
65 | } | |
66 | } | |
67 | ||
68 | ||
69 | /* | |
70 | * Setup the infrastructure necessary to support XPartition Communication | |
71 | * between the specified remote partition and the local one. | |
72 | */ | |
73 | enum xpc_retval | |
74 | xpc_setup_infrastructure(struct xpc_partition *part) | |
75 | { | |
59a0a8aa | 76 | int ret, cpuid; |
89eb8eb9 DN |
77 | struct timer_list *timer; |
78 | partid_t partid = XPC_PARTID(part); | |
79 | ||
80 | ||
81 | /* | |
82 | * Zero out MOST of the entry for this partition. Only the fields | |
83 | * starting with `nchannels' will be zeroed. The preceding fields must | |
84 | * remain `viable' across partition ups and downs, since they may be | |
85 | * referenced during this memset() operation. | |
86 | */ | |
87 | memset(&part->nchannels, 0, sizeof(struct xpc_partition) - | |
88 | offsetof(struct xpc_partition, nchannels)); | |
89 | ||
90 | /* | |
91 | * Allocate all of the channel structures as a contiguous chunk of | |
92 | * memory. | |
93 | */ | |
94 | part->channels = kmalloc(sizeof(struct xpc_channel) * XPC_NCHANNELS, | |
95 | GFP_KERNEL); | |
96 | if (part->channels == NULL) { | |
97 | dev_err(xpc_chan, "can't get memory for channels\n"); | |
98 | return xpcNoMemory; | |
99 | } | |
100 | memset(part->channels, 0, sizeof(struct xpc_channel) * XPC_NCHANNELS); | |
101 | ||
102 | part->nchannels = XPC_NCHANNELS; | |
103 | ||
104 | ||
105 | /* allocate all the required GET/PUT values */ | |
106 | ||
107 | part->local_GPs = xpc_kmalloc_cacheline_aligned(XPC_GP_SIZE, | |
108 | GFP_KERNEL, &part->local_GPs_base); | |
109 | if (part->local_GPs == NULL) { | |
110 | kfree(part->channels); | |
111 | part->channels = NULL; | |
112 | dev_err(xpc_chan, "can't get memory for local get/put " | |
113 | "values\n"); | |
114 | return xpcNoMemory; | |
115 | } | |
116 | memset(part->local_GPs, 0, XPC_GP_SIZE); | |
117 | ||
118 | part->remote_GPs = xpc_kmalloc_cacheline_aligned(XPC_GP_SIZE, | |
119 | GFP_KERNEL, &part->remote_GPs_base); | |
120 | if (part->remote_GPs == NULL) { | |
121 | kfree(part->channels); | |
122 | part->channels = NULL; | |
123 | kfree(part->local_GPs_base); | |
124 | part->local_GPs = NULL; | |
125 | dev_err(xpc_chan, "can't get memory for remote get/put " | |
126 | "values\n"); | |
127 | return xpcNoMemory; | |
128 | } | |
129 | memset(part->remote_GPs, 0, XPC_GP_SIZE); | |
130 | ||
131 | ||
132 | /* allocate all the required open and close args */ | |
133 | ||
134 | part->local_openclose_args = xpc_kmalloc_cacheline_aligned( | |
135 | XPC_OPENCLOSE_ARGS_SIZE, GFP_KERNEL, | |
136 | &part->local_openclose_args_base); | |
137 | if (part->local_openclose_args == NULL) { | |
138 | kfree(part->channels); | |
139 | part->channels = NULL; | |
140 | kfree(part->local_GPs_base); | |
141 | part->local_GPs = NULL; | |
142 | kfree(part->remote_GPs_base); | |
143 | part->remote_GPs = NULL; | |
144 | dev_err(xpc_chan, "can't get memory for local connect args\n"); | |
145 | return xpcNoMemory; | |
146 | } | |
147 | memset(part->local_openclose_args, 0, XPC_OPENCLOSE_ARGS_SIZE); | |
148 | ||
149 | part->remote_openclose_args = xpc_kmalloc_cacheline_aligned( | |
150 | XPC_OPENCLOSE_ARGS_SIZE, GFP_KERNEL, | |
151 | &part->remote_openclose_args_base); | |
152 | if (part->remote_openclose_args == NULL) { | |
153 | kfree(part->channels); | |
154 | part->channels = NULL; | |
155 | kfree(part->local_GPs_base); | |
156 | part->local_GPs = NULL; | |
157 | kfree(part->remote_GPs_base); | |
158 | part->remote_GPs = NULL; | |
159 | kfree(part->local_openclose_args_base); | |
160 | part->local_openclose_args = NULL; | |
161 | dev_err(xpc_chan, "can't get memory for remote connect args\n"); | |
162 | return xpcNoMemory; | |
163 | } | |
164 | memset(part->remote_openclose_args, 0, XPC_OPENCLOSE_ARGS_SIZE); | |
165 | ||
166 | ||
167 | xpc_initialize_channels(part, partid); | |
168 | ||
169 | atomic_set(&part->nchannels_active, 0); | |
a607c389 | 170 | atomic_set(&part->nchannels_engaged, 0); |
89eb8eb9 DN |
171 | |
172 | ||
173 | /* local_IPI_amo were set to 0 by an earlier memset() */ | |
174 | ||
175 | /* Initialize this partitions AMO_t structure */ | |
176 | part->local_IPI_amo_va = xpc_IPI_init(partid); | |
177 | ||
178 | spin_lock_init(&part->IPI_lock); | |
179 | ||
180 | atomic_set(&part->channel_mgr_requests, 1); | |
181 | init_waitqueue_head(&part->channel_mgr_wq); | |
182 | ||
183 | sprintf(part->IPI_owner, "xpc%02d", partid); | |
184 | ret = request_irq(SGI_XPC_NOTIFY, xpc_notify_IRQ_handler, SA_SHIRQ, | |
185 | part->IPI_owner, (void *) (u64) partid); | |
186 | if (ret != 0) { | |
187 | kfree(part->channels); | |
188 | part->channels = NULL; | |
189 | kfree(part->local_GPs_base); | |
190 | part->local_GPs = NULL; | |
191 | kfree(part->remote_GPs_base); | |
192 | part->remote_GPs = NULL; | |
193 | kfree(part->local_openclose_args_base); | |
194 | part->local_openclose_args = NULL; | |
195 | kfree(part->remote_openclose_args_base); | |
196 | part->remote_openclose_args = NULL; | |
197 | dev_err(xpc_chan, "can't register NOTIFY IRQ handler, " | |
198 | "errno=%d\n", -ret); | |
199 | return xpcLackOfResources; | |
200 | } | |
201 | ||
202 | /* Setup a timer to check for dropped IPIs */ | |
203 | timer = &part->dropped_IPI_timer; | |
204 | init_timer(timer); | |
205 | timer->function = (void (*)(unsigned long)) xpc_dropped_IPI_check; | |
206 | timer->data = (unsigned long) part; | |
207 | timer->expires = jiffies + XPC_P_DROPPED_IPI_WAIT; | |
208 | add_timer(timer); | |
209 | ||
210 | /* | |
211 | * With the setting of the partition setup_state to XPC_P_SETUP, we're | |
212 | * declaring that this partition is ready to go. | |
213 | */ | |
821fe947 | 214 | part->setup_state = XPC_P_SETUP; |
89eb8eb9 DN |
215 | |
216 | ||
217 | /* | |
218 | * Setup the per partition specific variables required by the | |
219 | * remote partition to establish channel connections with us. | |
220 | * | |
221 | * The setting of the magic # indicates that these per partition | |
222 | * specific variables are ready to be used. | |
223 | */ | |
224 | xpc_vars_part[partid].GPs_pa = __pa(part->local_GPs); | |
225 | xpc_vars_part[partid].openclose_args_pa = | |
226 | __pa(part->local_openclose_args); | |
227 | xpc_vars_part[partid].IPI_amo_pa = __pa(part->local_IPI_amo_va); | |
59a0a8aa DN |
228 | cpuid = raw_smp_processor_id(); /* any CPU in this partition will do */ |
229 | xpc_vars_part[partid].IPI_nasid = cpuid_to_nasid(cpuid); | |
230 | xpc_vars_part[partid].IPI_phys_cpuid = cpu_physical_id(cpuid); | |
89eb8eb9 | 231 | xpc_vars_part[partid].nchannels = part->nchannels; |
821fe947 | 232 | xpc_vars_part[partid].magic = XPC_VP_MAGIC1; |
89eb8eb9 DN |
233 | |
234 | return xpcSuccess; | |
235 | } | |
236 | ||
237 | ||
238 | /* | |
239 | * Create a wrapper that hides the underlying mechanism for pulling a cacheline | |
240 | * (or multiple cachelines) from a remote partition. | |
241 | * | |
242 | * src must be a cacheline aligned physical address on the remote partition. | |
243 | * dst must be a cacheline aligned virtual address on this partition. | |
244 | * cnt must be an cacheline sized | |
245 | */ | |
246 | static enum xpc_retval | |
247 | xpc_pull_remote_cachelines(struct xpc_partition *part, void *dst, | |
248 | const void *src, size_t cnt) | |
249 | { | |
250 | bte_result_t bte_ret; | |
251 | ||
252 | ||
253 | DBUG_ON((u64) src != L1_CACHE_ALIGN((u64) src)); | |
254 | DBUG_ON((u64) dst != L1_CACHE_ALIGN((u64) dst)); | |
255 | DBUG_ON(cnt != L1_CACHE_ALIGN(cnt)); | |
256 | ||
257 | if (part->act_state == XPC_P_DEACTIVATING) { | |
258 | return part->reason; | |
259 | } | |
260 | ||
261 | bte_ret = xp_bte_copy((u64) src, (u64) ia64_tpa((u64) dst), | |
262 | (u64) cnt, (BTE_NORMAL | BTE_WACQUIRE), NULL); | |
263 | if (bte_ret == BTE_SUCCESS) { | |
264 | return xpcSuccess; | |
265 | } | |
266 | ||
267 | dev_dbg(xpc_chan, "xp_bte_copy() from partition %d failed, ret=%d\n", | |
268 | XPC_PARTID(part), bte_ret); | |
269 | ||
270 | return xpc_map_bte_errors(bte_ret); | |
271 | } | |
272 | ||
273 | ||
274 | /* | |
275 | * Pull the remote per partititon specific variables from the specified | |
276 | * partition. | |
277 | */ | |
278 | enum xpc_retval | |
279 | xpc_pull_remote_vars_part(struct xpc_partition *part) | |
280 | { | |
281 | u8 buffer[L1_CACHE_BYTES * 2]; | |
282 | struct xpc_vars_part *pulled_entry_cacheline = | |
283 | (struct xpc_vars_part *) L1_CACHE_ALIGN((u64) buffer); | |
284 | struct xpc_vars_part *pulled_entry; | |
285 | u64 remote_entry_cacheline_pa, remote_entry_pa; | |
286 | partid_t partid = XPC_PARTID(part); | |
287 | enum xpc_retval ret; | |
288 | ||
289 | ||
290 | /* pull the cacheline that contains the variables we're interested in */ | |
291 | ||
292 | DBUG_ON(part->remote_vars_part_pa != | |
293 | L1_CACHE_ALIGN(part->remote_vars_part_pa)); | |
294 | DBUG_ON(sizeof(struct xpc_vars_part) != L1_CACHE_BYTES / 2); | |
295 | ||
296 | remote_entry_pa = part->remote_vars_part_pa + | |
297 | sn_partition_id * sizeof(struct xpc_vars_part); | |
298 | ||
299 | remote_entry_cacheline_pa = (remote_entry_pa & ~(L1_CACHE_BYTES - 1)); | |
300 | ||
301 | pulled_entry = (struct xpc_vars_part *) ((u64) pulled_entry_cacheline + | |
302 | (remote_entry_pa & (L1_CACHE_BYTES - 1))); | |
303 | ||
304 | ret = xpc_pull_remote_cachelines(part, pulled_entry_cacheline, | |
305 | (void *) remote_entry_cacheline_pa, | |
306 | L1_CACHE_BYTES); | |
307 | if (ret != xpcSuccess) { | |
308 | dev_dbg(xpc_chan, "failed to pull XPC vars_part from " | |
309 | "partition %d, ret=%d\n", partid, ret); | |
310 | return ret; | |
311 | } | |
312 | ||
313 | ||
314 | /* see if they've been set up yet */ | |
315 | ||
316 | if (pulled_entry->magic != XPC_VP_MAGIC1 && | |
317 | pulled_entry->magic != XPC_VP_MAGIC2) { | |
318 | ||
319 | if (pulled_entry->magic != 0) { | |
320 | dev_dbg(xpc_chan, "partition %d's XPC vars_part for " | |
321 | "partition %d has bad magic value (=0x%lx)\n", | |
322 | partid, sn_partition_id, pulled_entry->magic); | |
323 | return xpcBadMagic; | |
324 | } | |
325 | ||
326 | /* they've not been initialized yet */ | |
327 | return xpcRetry; | |
328 | } | |
329 | ||
330 | if (xpc_vars_part[partid].magic == XPC_VP_MAGIC1) { | |
331 | ||
332 | /* validate the variables */ | |
333 | ||
334 | if (pulled_entry->GPs_pa == 0 || | |
335 | pulled_entry->openclose_args_pa == 0 || | |
336 | pulled_entry->IPI_amo_pa == 0) { | |
337 | ||
338 | dev_err(xpc_chan, "partition %d's XPC vars_part for " | |
339 | "partition %d are not valid\n", partid, | |
340 | sn_partition_id); | |
341 | return xpcInvalidAddress; | |
342 | } | |
343 | ||
344 | /* the variables we imported look to be valid */ | |
345 | ||
346 | part->remote_GPs_pa = pulled_entry->GPs_pa; | |
347 | part->remote_openclose_args_pa = | |
348 | pulled_entry->openclose_args_pa; | |
349 | part->remote_IPI_amo_va = | |
350 | (AMO_t *) __va(pulled_entry->IPI_amo_pa); | |
351 | part->remote_IPI_nasid = pulled_entry->IPI_nasid; | |
352 | part->remote_IPI_phys_cpuid = pulled_entry->IPI_phys_cpuid; | |
353 | ||
354 | if (part->nchannels > pulled_entry->nchannels) { | |
355 | part->nchannels = pulled_entry->nchannels; | |
356 | } | |
357 | ||
358 | /* let the other side know that we've pulled their variables */ | |
359 | ||
821fe947 | 360 | xpc_vars_part[partid].magic = XPC_VP_MAGIC2; |
89eb8eb9 DN |
361 | } |
362 | ||
363 | if (pulled_entry->magic == XPC_VP_MAGIC1) { | |
364 | return xpcRetry; | |
365 | } | |
366 | ||
367 | return xpcSuccess; | |
368 | } | |
369 | ||
370 | ||
371 | /* | |
372 | * Get the IPI flags and pull the openclose args and/or remote GPs as needed. | |
373 | */ | |
374 | static u64 | |
375 | xpc_get_IPI_flags(struct xpc_partition *part) | |
376 | { | |
377 | unsigned long irq_flags; | |
378 | u64 IPI_amo; | |
379 | enum xpc_retval ret; | |
380 | ||
381 | ||
382 | /* | |
383 | * See if there are any IPI flags to be handled. | |
384 | */ | |
385 | ||
386 | spin_lock_irqsave(&part->IPI_lock, irq_flags); | |
387 | if ((IPI_amo = part->local_IPI_amo) != 0) { | |
388 | part->local_IPI_amo = 0; | |
389 | } | |
390 | spin_unlock_irqrestore(&part->IPI_lock, irq_flags); | |
391 | ||
392 | ||
393 | if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_amo)) { | |
394 | ret = xpc_pull_remote_cachelines(part, | |
395 | part->remote_openclose_args, | |
396 | (void *) part->remote_openclose_args_pa, | |
397 | XPC_OPENCLOSE_ARGS_SIZE); | |
398 | if (ret != xpcSuccess) { | |
399 | XPC_DEACTIVATE_PARTITION(part, ret); | |
400 | ||
401 | dev_dbg(xpc_chan, "failed to pull openclose args from " | |
402 | "partition %d, ret=%d\n", XPC_PARTID(part), | |
403 | ret); | |
404 | ||
405 | /* don't bother processing IPIs anymore */ | |
406 | IPI_amo = 0; | |
407 | } | |
408 | } | |
409 | ||
410 | if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_amo)) { | |
411 | ret = xpc_pull_remote_cachelines(part, part->remote_GPs, | |
412 | (void *) part->remote_GPs_pa, | |
413 | XPC_GP_SIZE); | |
414 | if (ret != xpcSuccess) { | |
415 | XPC_DEACTIVATE_PARTITION(part, ret); | |
416 | ||
417 | dev_dbg(xpc_chan, "failed to pull GPs from partition " | |
418 | "%d, ret=%d\n", XPC_PARTID(part), ret); | |
419 | ||
420 | /* don't bother processing IPIs anymore */ | |
421 | IPI_amo = 0; | |
422 | } | |
423 | } | |
424 | ||
425 | return IPI_amo; | |
426 | } | |
427 | ||
428 | ||
429 | /* | |
430 | * Allocate the local message queue and the notify queue. | |
431 | */ | |
432 | static enum xpc_retval | |
433 | xpc_allocate_local_msgqueue(struct xpc_channel *ch) | |
434 | { | |
435 | unsigned long irq_flags; | |
436 | int nentries; | |
437 | size_t nbytes; | |
438 | ||
439 | ||
440 | // >>> may want to check for ch->flags & XPC_C_DISCONNECTING between | |
441 | // >>> iterations of the for-loop, bail if set? | |
442 | ||
443 | // >>> should we impose a minumum #of entries? like 4 or 8? | |
444 | for (nentries = ch->local_nentries; nentries > 0; nentries--) { | |
445 | ||
446 | nbytes = nentries * ch->msg_size; | |
447 | ch->local_msgqueue = xpc_kmalloc_cacheline_aligned(nbytes, | |
448 | (GFP_KERNEL | GFP_DMA), | |
449 | &ch->local_msgqueue_base); | |
450 | if (ch->local_msgqueue == NULL) { | |
451 | continue; | |
452 | } | |
453 | memset(ch->local_msgqueue, 0, nbytes); | |
454 | ||
455 | nbytes = nentries * sizeof(struct xpc_notify); | |
456 | ch->notify_queue = kmalloc(nbytes, (GFP_KERNEL | GFP_DMA)); | |
457 | if (ch->notify_queue == NULL) { | |
458 | kfree(ch->local_msgqueue_base); | |
459 | ch->local_msgqueue = NULL; | |
460 | continue; | |
461 | } | |
462 | memset(ch->notify_queue, 0, nbytes); | |
463 | ||
464 | spin_lock_irqsave(&ch->lock, irq_flags); | |
465 | if (nentries < ch->local_nentries) { | |
466 | dev_dbg(xpc_chan, "nentries=%d local_nentries=%d, " | |
467 | "partid=%d, channel=%d\n", nentries, | |
468 | ch->local_nentries, ch->partid, ch->number); | |
469 | ||
470 | ch->local_nentries = nentries; | |
471 | } | |
472 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
473 | return xpcSuccess; | |
474 | } | |
475 | ||
476 | dev_dbg(xpc_chan, "can't get memory for local message queue and notify " | |
477 | "queue, partid=%d, channel=%d\n", ch->partid, ch->number); | |
478 | return xpcNoMemory; | |
479 | } | |
480 | ||
481 | ||
482 | /* | |
483 | * Allocate the cached remote message queue. | |
484 | */ | |
485 | static enum xpc_retval | |
486 | xpc_allocate_remote_msgqueue(struct xpc_channel *ch) | |
487 | { | |
488 | unsigned long irq_flags; | |
489 | int nentries; | |
490 | size_t nbytes; | |
491 | ||
492 | ||
493 | DBUG_ON(ch->remote_nentries <= 0); | |
494 | ||
495 | // >>> may want to check for ch->flags & XPC_C_DISCONNECTING between | |
496 | // >>> iterations of the for-loop, bail if set? | |
497 | ||
498 | // >>> should we impose a minumum #of entries? like 4 or 8? | |
499 | for (nentries = ch->remote_nentries; nentries > 0; nentries--) { | |
500 | ||
501 | nbytes = nentries * ch->msg_size; | |
502 | ch->remote_msgqueue = xpc_kmalloc_cacheline_aligned(nbytes, | |
503 | (GFP_KERNEL | GFP_DMA), | |
504 | &ch->remote_msgqueue_base); | |
505 | if (ch->remote_msgqueue == NULL) { | |
506 | continue; | |
507 | } | |
508 | memset(ch->remote_msgqueue, 0, nbytes); | |
509 | ||
510 | spin_lock_irqsave(&ch->lock, irq_flags); | |
511 | if (nentries < ch->remote_nentries) { | |
512 | dev_dbg(xpc_chan, "nentries=%d remote_nentries=%d, " | |
513 | "partid=%d, channel=%d\n", nentries, | |
514 | ch->remote_nentries, ch->partid, ch->number); | |
515 | ||
516 | ch->remote_nentries = nentries; | |
517 | } | |
518 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
519 | return xpcSuccess; | |
520 | } | |
521 | ||
522 | dev_dbg(xpc_chan, "can't get memory for cached remote message queue, " | |
523 | "partid=%d, channel=%d\n", ch->partid, ch->number); | |
524 | return xpcNoMemory; | |
525 | } | |
526 | ||
527 | ||
528 | /* | |
529 | * Allocate message queues and other stuff associated with a channel. | |
530 | * | |
531 | * Note: Assumes all of the channel sizes are filled in. | |
532 | */ | |
533 | static enum xpc_retval | |
534 | xpc_allocate_msgqueues(struct xpc_channel *ch) | |
535 | { | |
536 | unsigned long irq_flags; | |
537 | int i; | |
538 | enum xpc_retval ret; | |
539 | ||
540 | ||
541 | DBUG_ON(ch->flags & XPC_C_SETUP); | |
542 | ||
543 | if ((ret = xpc_allocate_local_msgqueue(ch)) != xpcSuccess) { | |
544 | return ret; | |
545 | } | |
546 | ||
547 | if ((ret = xpc_allocate_remote_msgqueue(ch)) != xpcSuccess) { | |
548 | kfree(ch->local_msgqueue_base); | |
549 | ch->local_msgqueue = NULL; | |
550 | kfree(ch->notify_queue); | |
551 | ch->notify_queue = NULL; | |
552 | return ret; | |
553 | } | |
554 | ||
555 | for (i = 0; i < ch->local_nentries; i++) { | |
556 | /* use a semaphore as an event wait queue */ | |
557 | sema_init(&ch->notify_queue[i].sema, 0); | |
558 | } | |
559 | ||
89eb8eb9 DN |
560 | spin_lock_irqsave(&ch->lock, irq_flags); |
561 | ch->flags |= XPC_C_SETUP; | |
562 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
563 | ||
564 | return xpcSuccess; | |
565 | } | |
566 | ||
567 | ||
568 | /* | |
569 | * Process a connect message from a remote partition. | |
570 | * | |
571 | * Note: xpc_process_connect() is expecting to be called with the | |
572 | * spin_lock_irqsave held and will leave it locked upon return. | |
573 | */ | |
574 | static void | |
575 | xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags) | |
576 | { | |
577 | enum xpc_retval ret; | |
578 | ||
579 | ||
580 | DBUG_ON(!spin_is_locked(&ch->lock)); | |
581 | ||
582 | if (!(ch->flags & XPC_C_OPENREQUEST) || | |
583 | !(ch->flags & XPC_C_ROPENREQUEST)) { | |
584 | /* nothing more to do for now */ | |
585 | return; | |
586 | } | |
587 | DBUG_ON(!(ch->flags & XPC_C_CONNECTING)); | |
588 | ||
589 | if (!(ch->flags & XPC_C_SETUP)) { | |
590 | spin_unlock_irqrestore(&ch->lock, *irq_flags); | |
591 | ret = xpc_allocate_msgqueues(ch); | |
592 | spin_lock_irqsave(&ch->lock, *irq_flags); | |
593 | ||
594 | if (ret != xpcSuccess) { | |
595 | XPC_DISCONNECT_CHANNEL(ch, ret, irq_flags); | |
596 | } | |
597 | if (ch->flags & (XPC_C_CONNECTED | XPC_C_DISCONNECTING)) { | |
598 | return; | |
599 | } | |
600 | ||
601 | DBUG_ON(!(ch->flags & XPC_C_SETUP)); | |
602 | DBUG_ON(ch->local_msgqueue == NULL); | |
603 | DBUG_ON(ch->remote_msgqueue == NULL); | |
604 | } | |
605 | ||
606 | if (!(ch->flags & XPC_C_OPENREPLY)) { | |
607 | ch->flags |= XPC_C_OPENREPLY; | |
608 | xpc_IPI_send_openreply(ch, irq_flags); | |
609 | } | |
610 | ||
611 | if (!(ch->flags & XPC_C_ROPENREPLY)) { | |
612 | return; | |
613 | } | |
614 | ||
615 | DBUG_ON(ch->remote_msgqueue_pa == 0); | |
616 | ||
617 | ch->flags = (XPC_C_CONNECTED | XPC_C_SETUP); /* clear all else */ | |
618 | ||
619 | dev_info(xpc_chan, "channel %d to partition %d connected\n", | |
620 | ch->number, ch->partid); | |
621 | ||
622 | spin_unlock_irqrestore(&ch->lock, *irq_flags); | |
623 | xpc_create_kthreads(ch, 1); | |
624 | spin_lock_irqsave(&ch->lock, *irq_flags); | |
625 | } | |
626 | ||
627 | ||
a607c389 DN |
628 | /* |
629 | * Notify those who wanted to be notified upon delivery of their message. | |
630 | */ | |
631 | static void | |
632 | xpc_notify_senders(struct xpc_channel *ch, enum xpc_retval reason, s64 put) | |
633 | { | |
634 | struct xpc_notify *notify; | |
635 | u8 notify_type; | |
636 | s64 get = ch->w_remote_GP.get - 1; | |
637 | ||
638 | ||
639 | while (++get < put && atomic_read(&ch->n_to_notify) > 0) { | |
640 | ||
641 | notify = &ch->notify_queue[get % ch->local_nentries]; | |
642 | ||
643 | /* | |
644 | * See if the notify entry indicates it was associated with | |
645 | * a message who's sender wants to be notified. It is possible | |
646 | * that it is, but someone else is doing or has done the | |
647 | * notification. | |
648 | */ | |
649 | notify_type = notify->type; | |
650 | if (notify_type == 0 || | |
651 | cmpxchg(¬ify->type, notify_type, 0) != | |
652 | notify_type) { | |
653 | continue; | |
654 | } | |
655 | ||
656 | DBUG_ON(notify_type != XPC_N_CALL); | |
657 | ||
658 | atomic_dec(&ch->n_to_notify); | |
659 | ||
660 | if (notify->func != NULL) { | |
661 | dev_dbg(xpc_chan, "notify->func() called, notify=0x%p, " | |
662 | "msg_number=%ld, partid=%d, channel=%d\n", | |
663 | (void *) notify, get, ch->partid, ch->number); | |
664 | ||
665 | notify->func(reason, ch->partid, ch->number, | |
666 | notify->key); | |
667 | ||
668 | dev_dbg(xpc_chan, "notify->func() returned, " | |
669 | "notify=0x%p, msg_number=%ld, partid=%d, " | |
670 | "channel=%d\n", (void *) notify, get, | |
671 | ch->partid, ch->number); | |
672 | } | |
673 | } | |
674 | } | |
675 | ||
676 | ||
89eb8eb9 DN |
677 | /* |
678 | * Free up message queues and other stuff that were allocated for the specified | |
679 | * channel. | |
680 | * | |
681 | * Note: ch->reason and ch->reason_line are left set for debugging purposes, | |
682 | * they're cleared when XPC_C_DISCONNECTED is cleared. | |
683 | */ | |
684 | static void | |
685 | xpc_free_msgqueues(struct xpc_channel *ch) | |
686 | { | |
687 | DBUG_ON(!spin_is_locked(&ch->lock)); | |
688 | DBUG_ON(atomic_read(&ch->n_to_notify) != 0); | |
689 | ||
690 | ch->remote_msgqueue_pa = 0; | |
691 | ch->func = NULL; | |
692 | ch->key = NULL; | |
693 | ch->msg_size = 0; | |
694 | ch->local_nentries = 0; | |
695 | ch->remote_nentries = 0; | |
696 | ch->kthreads_assigned_limit = 0; | |
697 | ch->kthreads_idle_limit = 0; | |
698 | ||
699 | ch->local_GP->get = 0; | |
700 | ch->local_GP->put = 0; | |
701 | ch->remote_GP.get = 0; | |
702 | ch->remote_GP.put = 0; | |
703 | ch->w_local_GP.get = 0; | |
704 | ch->w_local_GP.put = 0; | |
705 | ch->w_remote_GP.get = 0; | |
706 | ch->w_remote_GP.put = 0; | |
707 | ch->next_msg_to_pull = 0; | |
708 | ||
709 | if (ch->flags & XPC_C_SETUP) { | |
710 | ch->flags &= ~XPC_C_SETUP; | |
711 | ||
712 | dev_dbg(xpc_chan, "ch->flags=0x%x, partid=%d, channel=%d\n", | |
713 | ch->flags, ch->partid, ch->number); | |
714 | ||
715 | kfree(ch->local_msgqueue_base); | |
716 | ch->local_msgqueue = NULL; | |
717 | kfree(ch->remote_msgqueue_base); | |
718 | ch->remote_msgqueue = NULL; | |
719 | kfree(ch->notify_queue); | |
720 | ch->notify_queue = NULL; | |
89eb8eb9 DN |
721 | } |
722 | } | |
723 | ||
724 | ||
725 | /* | |
726 | * spin_lock_irqsave() is expected to be held on entry. | |
727 | */ | |
728 | static void | |
729 | xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags) | |
730 | { | |
731 | struct xpc_partition *part = &xpc_partitions[ch->partid]; | |
a607c389 | 732 | u32 channel_was_connected = (ch->flags & XPC_C_WASCONNECTED); |
89eb8eb9 DN |
733 | |
734 | ||
735 | DBUG_ON(!spin_is_locked(&ch->lock)); | |
736 | ||
737 | if (!(ch->flags & XPC_C_DISCONNECTING)) { | |
738 | return; | |
739 | } | |
740 | ||
741 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); | |
742 | ||
743 | /* make sure all activity has settled down first */ | |
744 | ||
745 | if (atomic_read(&ch->references) > 0) { | |
746 | return; | |
747 | } | |
748 | DBUG_ON(atomic_read(&ch->kthreads_assigned) != 0); | |
749 | ||
a607c389 DN |
750 | if (part->act_state == XPC_P_DEACTIVATING) { |
751 | /* can't proceed until the other side disengages from us */ | |
752 | if (xpc_partition_engaged(1UL << ch->partid)) { | |
753 | return; | |
754 | } | |
89eb8eb9 | 755 | |
a607c389 | 756 | } else { |
89eb8eb9 DN |
757 | |
758 | /* as long as the other side is up do the full protocol */ | |
759 | ||
760 | if (!(ch->flags & XPC_C_RCLOSEREQUEST)) { | |
761 | return; | |
762 | } | |
763 | ||
764 | if (!(ch->flags & XPC_C_CLOSEREPLY)) { | |
765 | ch->flags |= XPC_C_CLOSEREPLY; | |
766 | xpc_IPI_send_closereply(ch, irq_flags); | |
767 | } | |
768 | ||
769 | if (!(ch->flags & XPC_C_RCLOSEREPLY)) { | |
770 | return; | |
771 | } | |
772 | } | |
773 | ||
a607c389 DN |
774 | /* wake those waiting for notify completion */ |
775 | if (atomic_read(&ch->n_to_notify) > 0) { | |
776 | /* >>> we do callout while holding ch->lock */ | |
777 | xpc_notify_senders(ch, ch->reason, ch->w_local_GP.put); | |
778 | } | |
779 | ||
89eb8eb9 DN |
780 | /* both sides are disconnected now */ |
781 | ||
a607c389 DN |
782 | /* it's now safe to free the channel's message queues */ |
783 | xpc_free_msgqueues(ch); | |
784 | ||
785 | /* mark disconnected, clear all other flags except XPC_C_WDISCONNECT */ | |
786 | ch->flags = (XPC_C_DISCONNECTED | (ch->flags & XPC_C_WDISCONNECT)); | |
89eb8eb9 DN |
787 | |
788 | atomic_dec(&part->nchannels_active); | |
789 | ||
a607c389 | 790 | if (channel_was_connected) { |
89eb8eb9 DN |
791 | dev_info(xpc_chan, "channel %d to partition %d disconnected, " |
792 | "reason=%d\n", ch->number, ch->partid, ch->reason); | |
793 | } | |
a607c389 | 794 | |
a607c389 DN |
795 | if (ch->flags & XPC_C_WDISCONNECT) { |
796 | spin_unlock_irqrestore(&ch->lock, *irq_flags); | |
797 | up(&ch->wdisconnect_sema); | |
798 | spin_lock_irqsave(&ch->lock, *irq_flags); | |
e54af724 DN |
799 | |
800 | } else if (ch->delayed_IPI_flags) { | |
801 | if (part->act_state != XPC_P_DEACTIVATING) { | |
802 | /* time to take action on any delayed IPI flags */ | |
803 | spin_lock(&part->IPI_lock); | |
804 | XPC_SET_IPI_FLAGS(part->local_IPI_amo, ch->number, | |
805 | ch->delayed_IPI_flags); | |
806 | spin_unlock(&part->IPI_lock); | |
807 | } | |
808 | ch->delayed_IPI_flags = 0; | |
a607c389 | 809 | } |
89eb8eb9 DN |
810 | } |
811 | ||
812 | ||
813 | /* | |
814 | * Process a change in the channel's remote connection state. | |
815 | */ | |
816 | static void | |
817 | xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number, | |
818 | u8 IPI_flags) | |
819 | { | |
820 | unsigned long irq_flags; | |
821 | struct xpc_openclose_args *args = | |
822 | &part->remote_openclose_args[ch_number]; | |
823 | struct xpc_channel *ch = &part->channels[ch_number]; | |
824 | enum xpc_retval reason; | |
825 | ||
826 | ||
827 | ||
828 | spin_lock_irqsave(&ch->lock, irq_flags); | |
829 | ||
e54af724 DN |
830 | again: |
831 | ||
832 | if ((ch->flags & XPC_C_DISCONNECTED) && | |
833 | (ch->flags & XPC_C_WDISCONNECT)) { | |
834 | /* | |
835 | * Delay processing IPI flags until thread waiting disconnect | |
836 | * has had a chance to see that the channel is disconnected. | |
837 | */ | |
838 | ch->delayed_IPI_flags |= IPI_flags; | |
839 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
840 | return; | |
841 | } | |
842 | ||
89eb8eb9 DN |
843 | |
844 | if (IPI_flags & XPC_IPI_CLOSEREQUEST) { | |
845 | ||
846 | dev_dbg(xpc_chan, "XPC_IPI_CLOSEREQUEST (reason=%d) received " | |
847 | "from partid=%d, channel=%d\n", args->reason, | |
848 | ch->partid, ch->number); | |
849 | ||
850 | /* | |
851 | * If RCLOSEREQUEST is set, we're probably waiting for | |
852 | * RCLOSEREPLY. We should find it and a ROPENREQUEST packed | |
a607c389 | 853 | * with this RCLOSEREQUEST in the IPI_flags. |
89eb8eb9 DN |
854 | */ |
855 | ||
856 | if (ch->flags & XPC_C_RCLOSEREQUEST) { | |
857 | DBUG_ON(!(ch->flags & XPC_C_DISCONNECTING)); | |
858 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); | |
859 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREPLY)); | |
860 | DBUG_ON(ch->flags & XPC_C_RCLOSEREPLY); | |
861 | ||
862 | DBUG_ON(!(IPI_flags & XPC_IPI_CLOSEREPLY)); | |
863 | IPI_flags &= ~XPC_IPI_CLOSEREPLY; | |
864 | ch->flags |= XPC_C_RCLOSEREPLY; | |
865 | ||
866 | /* both sides have finished disconnecting */ | |
867 | xpc_process_disconnect(ch, &irq_flags); | |
e54af724 DN |
868 | DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED)); |
869 | goto again; | |
89eb8eb9 DN |
870 | } |
871 | ||
872 | if (ch->flags & XPC_C_DISCONNECTED) { | |
89eb8eb9 | 873 | if (!(IPI_flags & XPC_IPI_OPENREQUEST)) { |
e54af724 DN |
874 | if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo, |
875 | ch_number) & XPC_IPI_OPENREQUEST)) { | |
876 | ||
877 | DBUG_ON(ch->delayed_IPI_flags != 0); | |
878 | spin_lock(&part->IPI_lock); | |
879 | XPC_SET_IPI_FLAGS(part->local_IPI_amo, | |
880 | ch_number, | |
881 | XPC_IPI_CLOSEREQUEST); | |
882 | spin_unlock(&part->IPI_lock); | |
883 | } | |
89eb8eb9 DN |
884 | spin_unlock_irqrestore(&ch->lock, irq_flags); |
885 | return; | |
886 | } | |
887 | ||
888 | XPC_SET_REASON(ch, 0, 0); | |
889 | ch->flags &= ~XPC_C_DISCONNECTED; | |
890 | ||
891 | atomic_inc(&part->nchannels_active); | |
892 | ch->flags |= (XPC_C_CONNECTING | XPC_C_ROPENREQUEST); | |
893 | } | |
894 | ||
895 | IPI_flags &= ~(XPC_IPI_OPENREQUEST | XPC_IPI_OPENREPLY); | |
896 | ||
897 | /* | |
898 | * The meaningful CLOSEREQUEST connection state fields are: | |
899 | * reason = reason connection is to be closed | |
900 | */ | |
901 | ||
902 | ch->flags |= XPC_C_RCLOSEREQUEST; | |
903 | ||
904 | if (!(ch->flags & XPC_C_DISCONNECTING)) { | |
905 | reason = args->reason; | |
906 | if (reason <= xpcSuccess || reason > xpcUnknownReason) { | |
907 | reason = xpcUnknownReason; | |
908 | } else if (reason == xpcUnregistering) { | |
909 | reason = xpcOtherUnregistering; | |
910 | } | |
911 | ||
912 | XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags); | |
e54af724 DN |
913 | |
914 | DBUG_ON(IPI_flags & XPC_IPI_CLOSEREPLY); | |
915 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
916 | return; | |
89eb8eb9 | 917 | } |
e54af724 DN |
918 | |
919 | xpc_process_disconnect(ch, &irq_flags); | |
89eb8eb9 DN |
920 | } |
921 | ||
922 | ||
923 | if (IPI_flags & XPC_IPI_CLOSEREPLY) { | |
924 | ||
925 | dev_dbg(xpc_chan, "XPC_IPI_CLOSEREPLY received from partid=%d," | |
926 | " channel=%d\n", ch->partid, ch->number); | |
927 | ||
928 | if (ch->flags & XPC_C_DISCONNECTED) { | |
929 | DBUG_ON(part->act_state != XPC_P_DEACTIVATING); | |
930 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
931 | return; | |
932 | } | |
933 | ||
934 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); | |
e54af724 DN |
935 | |
936 | if (!(ch->flags & XPC_C_RCLOSEREQUEST)) { | |
937 | if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo, ch_number) | |
938 | & XPC_IPI_CLOSEREQUEST)) { | |
939 | ||
940 | DBUG_ON(ch->delayed_IPI_flags != 0); | |
941 | spin_lock(&part->IPI_lock); | |
942 | XPC_SET_IPI_FLAGS(part->local_IPI_amo, | |
943 | ch_number, XPC_IPI_CLOSEREPLY); | |
944 | spin_unlock(&part->IPI_lock); | |
945 | } | |
946 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
947 | return; | |
948 | } | |
89eb8eb9 DN |
949 | |
950 | ch->flags |= XPC_C_RCLOSEREPLY; | |
951 | ||
952 | if (ch->flags & XPC_C_CLOSEREPLY) { | |
953 | /* both sides have finished disconnecting */ | |
954 | xpc_process_disconnect(ch, &irq_flags); | |
955 | } | |
956 | } | |
957 | ||
958 | ||
959 | if (IPI_flags & XPC_IPI_OPENREQUEST) { | |
960 | ||
961 | dev_dbg(xpc_chan, "XPC_IPI_OPENREQUEST (msg_size=%d, " | |
962 | "local_nentries=%d) received from partid=%d, " | |
963 | "channel=%d\n", args->msg_size, args->local_nentries, | |
964 | ch->partid, ch->number); | |
965 | ||
e54af724 DN |
966 | if (part->act_state == XPC_P_DEACTIVATING || |
967 | (ch->flags & XPC_C_ROPENREQUEST)) { | |
968 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
969 | return; | |
970 | } | |
971 | ||
972 | if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) { | |
973 | ch->delayed_IPI_flags |= XPC_IPI_OPENREQUEST; | |
89eb8eb9 DN |
974 | spin_unlock_irqrestore(&ch->lock, irq_flags); |
975 | return; | |
976 | } | |
977 | DBUG_ON(!(ch->flags & (XPC_C_DISCONNECTED | | |
978 | XPC_C_OPENREQUEST))); | |
979 | DBUG_ON(ch->flags & (XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY | | |
980 | XPC_C_OPENREPLY | XPC_C_CONNECTED)); | |
981 | ||
982 | /* | |
983 | * The meaningful OPENREQUEST connection state fields are: | |
984 | * msg_size = size of channel's messages in bytes | |
985 | * local_nentries = remote partition's local_nentries | |
986 | */ | |
e54af724 DN |
987 | if (args->msg_size == 0 || args->local_nentries == 0) { |
988 | /* assume OPENREQUEST was delayed by mistake */ | |
989 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
990 | return; | |
991 | } | |
89eb8eb9 DN |
992 | |
993 | ch->flags |= (XPC_C_ROPENREQUEST | XPC_C_CONNECTING); | |
994 | ch->remote_nentries = args->local_nentries; | |
995 | ||
996 | ||
997 | if (ch->flags & XPC_C_OPENREQUEST) { | |
998 | if (args->msg_size != ch->msg_size) { | |
999 | XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes, | |
1000 | &irq_flags); | |
1001 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1002 | return; | |
1003 | } | |
1004 | } else { | |
1005 | ch->msg_size = args->msg_size; | |
1006 | ||
1007 | XPC_SET_REASON(ch, 0, 0); | |
1008 | ch->flags &= ~XPC_C_DISCONNECTED; | |
1009 | ||
1010 | atomic_inc(&part->nchannels_active); | |
1011 | } | |
1012 | ||
1013 | xpc_process_connect(ch, &irq_flags); | |
1014 | } | |
1015 | ||
1016 | ||
1017 | if (IPI_flags & XPC_IPI_OPENREPLY) { | |
1018 | ||
1019 | dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY (local_msgqueue_pa=0x%lx, " | |
1020 | "local_nentries=%d, remote_nentries=%d) received from " | |
1021 | "partid=%d, channel=%d\n", args->local_msgqueue_pa, | |
1022 | args->local_nentries, args->remote_nentries, | |
1023 | ch->partid, ch->number); | |
1024 | ||
1025 | if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) { | |
1026 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1027 | return; | |
1028 | } | |
e54af724 DN |
1029 | if (!(ch->flags & XPC_C_OPENREQUEST)) { |
1030 | XPC_DISCONNECT_CHANNEL(ch, xpcOpenCloseError, | |
1031 | &irq_flags); | |
1032 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1033 | return; | |
1034 | } | |
1035 | ||
89eb8eb9 DN |
1036 | DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST)); |
1037 | DBUG_ON(ch->flags & XPC_C_CONNECTED); | |
1038 | ||
1039 | /* | |
1040 | * The meaningful OPENREPLY connection state fields are: | |
1041 | * local_msgqueue_pa = physical address of remote | |
1042 | * partition's local_msgqueue | |
1043 | * local_nentries = remote partition's local_nentries | |
1044 | * remote_nentries = remote partition's remote_nentries | |
1045 | */ | |
1046 | DBUG_ON(args->local_msgqueue_pa == 0); | |
1047 | DBUG_ON(args->local_nentries == 0); | |
1048 | DBUG_ON(args->remote_nentries == 0); | |
1049 | ||
1050 | ch->flags |= XPC_C_ROPENREPLY; | |
1051 | ch->remote_msgqueue_pa = args->local_msgqueue_pa; | |
1052 | ||
1053 | if (args->local_nentries < ch->remote_nentries) { | |
1054 | dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new " | |
1055 | "remote_nentries=%d, old remote_nentries=%d, " | |
1056 | "partid=%d, channel=%d\n", | |
1057 | args->local_nentries, ch->remote_nentries, | |
1058 | ch->partid, ch->number); | |
1059 | ||
1060 | ch->remote_nentries = args->local_nentries; | |
1061 | } | |
1062 | if (args->remote_nentries < ch->local_nentries) { | |
1063 | dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new " | |
1064 | "local_nentries=%d, old local_nentries=%d, " | |
1065 | "partid=%d, channel=%d\n", | |
1066 | args->remote_nentries, ch->local_nentries, | |
1067 | ch->partid, ch->number); | |
1068 | ||
1069 | ch->local_nentries = args->remote_nentries; | |
1070 | } | |
1071 | ||
1072 | xpc_process_connect(ch, &irq_flags); | |
1073 | } | |
1074 | ||
1075 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1076 | } | |
1077 | ||
1078 | ||
1079 | /* | |
1080 | * Attempt to establish a channel connection to a remote partition. | |
1081 | */ | |
1082 | static enum xpc_retval | |
1083 | xpc_connect_channel(struct xpc_channel *ch) | |
1084 | { | |
1085 | unsigned long irq_flags; | |
1086 | struct xpc_registration *registration = &xpc_registrations[ch->number]; | |
1087 | ||
1088 | ||
e54af724 DN |
1089 | if (down_trylock(®istration->sema) != 0) { |
1090 | return xpcRetry; | |
89eb8eb9 DN |
1091 | } |
1092 | ||
1093 | if (!XPC_CHANNEL_REGISTERED(ch->number)) { | |
1094 | up(®istration->sema); | |
1095 | return xpcUnregistered; | |
1096 | } | |
1097 | ||
1098 | spin_lock_irqsave(&ch->lock, irq_flags); | |
1099 | ||
1100 | DBUG_ON(ch->flags & XPC_C_CONNECTED); | |
1101 | DBUG_ON(ch->flags & XPC_C_OPENREQUEST); | |
1102 | ||
1103 | if (ch->flags & XPC_C_DISCONNECTING) { | |
1104 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1105 | up(®istration->sema); | |
1106 | return ch->reason; | |
1107 | } | |
1108 | ||
1109 | ||
1110 | /* add info from the channel connect registration to the channel */ | |
1111 | ||
1112 | ch->kthreads_assigned_limit = registration->assigned_limit; | |
1113 | ch->kthreads_idle_limit = registration->idle_limit; | |
1114 | DBUG_ON(atomic_read(&ch->kthreads_assigned) != 0); | |
1115 | DBUG_ON(atomic_read(&ch->kthreads_idle) != 0); | |
1116 | DBUG_ON(atomic_read(&ch->kthreads_active) != 0); | |
1117 | ||
1118 | ch->func = registration->func; | |
1119 | DBUG_ON(registration->func == NULL); | |
1120 | ch->key = registration->key; | |
1121 | ||
1122 | ch->local_nentries = registration->nentries; | |
1123 | ||
1124 | if (ch->flags & XPC_C_ROPENREQUEST) { | |
1125 | if (registration->msg_size != ch->msg_size) { | |
1126 | /* the local and remote sides aren't the same */ | |
1127 | ||
1128 | /* | |
1129 | * Because XPC_DISCONNECT_CHANNEL() can block we're | |
1130 | * forced to up the registration sema before we unlock | |
1131 | * the channel lock. But that's okay here because we're | |
1132 | * done with the part that required the registration | |
1133 | * sema. XPC_DISCONNECT_CHANNEL() requires that the | |
1134 | * channel lock be locked and will unlock and relock | |
1135 | * the channel lock as needed. | |
1136 | */ | |
1137 | up(®istration->sema); | |
1138 | XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes, | |
1139 | &irq_flags); | |
1140 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1141 | return xpcUnequalMsgSizes; | |
1142 | } | |
1143 | } else { | |
1144 | ch->msg_size = registration->msg_size; | |
1145 | ||
1146 | XPC_SET_REASON(ch, 0, 0); | |
1147 | ch->flags &= ~XPC_C_DISCONNECTED; | |
1148 | ||
1149 | atomic_inc(&xpc_partitions[ch->partid].nchannels_active); | |
1150 | } | |
1151 | ||
1152 | up(®istration->sema); | |
1153 | ||
1154 | ||
1155 | /* initiate the connection */ | |
1156 | ||
1157 | ch->flags |= (XPC_C_OPENREQUEST | XPC_C_CONNECTING); | |
1158 | xpc_IPI_send_openrequest(ch, &irq_flags); | |
1159 | ||
1160 | xpc_process_connect(ch, &irq_flags); | |
1161 | ||
1162 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1163 | ||
1164 | return xpcSuccess; | |
1165 | } | |
1166 | ||
1167 | ||
89eb8eb9 DN |
1168 | /* |
1169 | * Clear some of the msg flags in the local message queue. | |
1170 | */ | |
1171 | static inline void | |
1172 | xpc_clear_local_msgqueue_flags(struct xpc_channel *ch) | |
1173 | { | |
1174 | struct xpc_msg *msg; | |
1175 | s64 get; | |
1176 | ||
1177 | ||
1178 | get = ch->w_remote_GP.get; | |
1179 | do { | |
1180 | msg = (struct xpc_msg *) ((u64) ch->local_msgqueue + | |
1181 | (get % ch->local_nentries) * ch->msg_size); | |
1182 | msg->flags = 0; | |
1183 | } while (++get < (volatile s64) ch->remote_GP.get); | |
1184 | } | |
1185 | ||
1186 | ||
1187 | /* | |
1188 | * Clear some of the msg flags in the remote message queue. | |
1189 | */ | |
1190 | static inline void | |
1191 | xpc_clear_remote_msgqueue_flags(struct xpc_channel *ch) | |
1192 | { | |
1193 | struct xpc_msg *msg; | |
1194 | s64 put; | |
1195 | ||
1196 | ||
1197 | put = ch->w_remote_GP.put; | |
1198 | do { | |
1199 | msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue + | |
1200 | (put % ch->remote_nentries) * ch->msg_size); | |
1201 | msg->flags = 0; | |
1202 | } while (++put < (volatile s64) ch->remote_GP.put); | |
1203 | } | |
1204 | ||
1205 | ||
1206 | static void | |
1207 | xpc_process_msg_IPI(struct xpc_partition *part, int ch_number) | |
1208 | { | |
1209 | struct xpc_channel *ch = &part->channels[ch_number]; | |
1210 | int nmsgs_sent; | |
1211 | ||
1212 | ||
1213 | ch->remote_GP = part->remote_GPs[ch_number]; | |
1214 | ||
1215 | ||
1216 | /* See what, if anything, has changed for each connected channel */ | |
1217 | ||
1218 | xpc_msgqueue_ref(ch); | |
1219 | ||
1220 | if (ch->w_remote_GP.get == ch->remote_GP.get && | |
1221 | ch->w_remote_GP.put == ch->remote_GP.put) { | |
1222 | /* nothing changed since GPs were last pulled */ | |
1223 | xpc_msgqueue_deref(ch); | |
1224 | return; | |
1225 | } | |
1226 | ||
1227 | if (!(ch->flags & XPC_C_CONNECTED)){ | |
1228 | xpc_msgqueue_deref(ch); | |
1229 | return; | |
1230 | } | |
1231 | ||
1232 | ||
1233 | /* | |
1234 | * First check to see if messages recently sent by us have been | |
1235 | * received by the other side. (The remote GET value will have | |
1236 | * changed since we last looked at it.) | |
1237 | */ | |
1238 | ||
1239 | if (ch->w_remote_GP.get != ch->remote_GP.get) { | |
1240 | ||
1241 | /* | |
1242 | * We need to notify any senders that want to be notified | |
1243 | * that their sent messages have been received by their | |
1244 | * intended recipients. We need to do this before updating | |
1245 | * w_remote_GP.get so that we don't allocate the same message | |
1246 | * queue entries prematurely (see xpc_allocate_msg()). | |
1247 | */ | |
1248 | if (atomic_read(&ch->n_to_notify) > 0) { | |
1249 | /* | |
1250 | * Notify senders that messages sent have been | |
1251 | * received and delivered by the other side. | |
1252 | */ | |
1253 | xpc_notify_senders(ch, xpcMsgDelivered, | |
1254 | ch->remote_GP.get); | |
1255 | } | |
1256 | ||
1257 | /* | |
1258 | * Clear msg->flags in previously sent messages, so that | |
1259 | * they're ready for xpc_allocate_msg(). | |
1260 | */ | |
1261 | xpc_clear_local_msgqueue_flags(ch); | |
1262 | ||
821fe947 | 1263 | ch->w_remote_GP.get = ch->remote_GP.get; |
89eb8eb9 DN |
1264 | |
1265 | dev_dbg(xpc_chan, "w_remote_GP.get changed to %ld, partid=%d, " | |
1266 | "channel=%d\n", ch->w_remote_GP.get, ch->partid, | |
1267 | ch->number); | |
1268 | ||
1269 | /* | |
1270 | * If anyone was waiting for message queue entries to become | |
1271 | * available, wake them up. | |
1272 | */ | |
1273 | if (atomic_read(&ch->n_on_msg_allocate_wq) > 0) { | |
1274 | wake_up(&ch->msg_allocate_wq); | |
1275 | } | |
1276 | } | |
1277 | ||
1278 | ||
1279 | /* | |
1280 | * Now check for newly sent messages by the other side. (The remote | |
1281 | * PUT value will have changed since we last looked at it.) | |
1282 | */ | |
1283 | ||
1284 | if (ch->w_remote_GP.put != ch->remote_GP.put) { | |
1285 | /* | |
1286 | * Clear msg->flags in previously received messages, so that | |
1287 | * they're ready for xpc_get_deliverable_msg(). | |
1288 | */ | |
1289 | xpc_clear_remote_msgqueue_flags(ch); | |
1290 | ||
821fe947 | 1291 | ch->w_remote_GP.put = ch->remote_GP.put; |
89eb8eb9 DN |
1292 | |
1293 | dev_dbg(xpc_chan, "w_remote_GP.put changed to %ld, partid=%d, " | |
1294 | "channel=%d\n", ch->w_remote_GP.put, ch->partid, | |
1295 | ch->number); | |
1296 | ||
1297 | nmsgs_sent = ch->w_remote_GP.put - ch->w_local_GP.get; | |
1298 | if (nmsgs_sent > 0) { | |
1299 | dev_dbg(xpc_chan, "msgs waiting to be copied and " | |
1300 | "delivered=%d, partid=%d, channel=%d\n", | |
1301 | nmsgs_sent, ch->partid, ch->number); | |
1302 | ||
1303 | if (ch->flags & XPC_C_CONNECTCALLOUT) { | |
1304 | xpc_activate_kthreads(ch, nmsgs_sent); | |
1305 | } | |
1306 | } | |
1307 | } | |
1308 | ||
1309 | xpc_msgqueue_deref(ch); | |
1310 | } | |
1311 | ||
1312 | ||
1313 | void | |
1314 | xpc_process_channel_activity(struct xpc_partition *part) | |
1315 | { | |
1316 | unsigned long irq_flags; | |
1317 | u64 IPI_amo, IPI_flags; | |
1318 | struct xpc_channel *ch; | |
1319 | int ch_number; | |
a607c389 | 1320 | u32 ch_flags; |
89eb8eb9 DN |
1321 | |
1322 | ||
1323 | IPI_amo = xpc_get_IPI_flags(part); | |
1324 | ||
1325 | /* | |
1326 | * Initiate channel connections for registered channels. | |
1327 | * | |
1328 | * For each connected channel that has pending messages activate idle | |
1329 | * kthreads and/or create new kthreads as needed. | |
1330 | */ | |
1331 | ||
1332 | for (ch_number = 0; ch_number < part->nchannels; ch_number++) { | |
1333 | ch = &part->channels[ch_number]; | |
1334 | ||
1335 | ||
1336 | /* | |
1337 | * Process any open or close related IPI flags, and then deal | |
1338 | * with connecting or disconnecting the channel as required. | |
1339 | */ | |
1340 | ||
1341 | IPI_flags = XPC_GET_IPI_FLAGS(IPI_amo, ch_number); | |
1342 | ||
1343 | if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_flags)) { | |
1344 | xpc_process_openclose_IPI(part, ch_number, IPI_flags); | |
1345 | } | |
1346 | ||
a607c389 | 1347 | ch_flags = ch->flags; /* need an atomic snapshot of flags */ |
89eb8eb9 | 1348 | |
a607c389 | 1349 | if (ch_flags & XPC_C_DISCONNECTING) { |
89eb8eb9 DN |
1350 | spin_lock_irqsave(&ch->lock, irq_flags); |
1351 | xpc_process_disconnect(ch, &irq_flags); | |
1352 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1353 | continue; | |
1354 | } | |
1355 | ||
1356 | if (part->act_state == XPC_P_DEACTIVATING) { | |
1357 | continue; | |
1358 | } | |
1359 | ||
a607c389 DN |
1360 | if (!(ch_flags & XPC_C_CONNECTED)) { |
1361 | if (!(ch_flags & XPC_C_OPENREQUEST)) { | |
1362 | DBUG_ON(ch_flags & XPC_C_SETUP); | |
89eb8eb9 DN |
1363 | (void) xpc_connect_channel(ch); |
1364 | } else { | |
1365 | spin_lock_irqsave(&ch->lock, irq_flags); | |
1366 | xpc_process_connect(ch, &irq_flags); | |
1367 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1368 | } | |
1369 | continue; | |
1370 | } | |
1371 | ||
1372 | ||
1373 | /* | |
1374 | * Process any message related IPI flags, this may involve the | |
1375 | * activation of kthreads to deliver any pending messages sent | |
1376 | * from the other partition. | |
1377 | */ | |
1378 | ||
1379 | if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_flags)) { | |
1380 | xpc_process_msg_IPI(part, ch_number); | |
1381 | } | |
1382 | } | |
1383 | } | |
1384 | ||
1385 | ||
1386 | /* | |
a607c389 DN |
1387 | * XPC's heartbeat code calls this function to inform XPC that a partition is |
1388 | * going down. XPC responds by tearing down the XPartition Communication | |
89eb8eb9 DN |
1389 | * infrastructure used for the just downed partition. |
1390 | * | |
1391 | * XPC's heartbeat code will never call this function and xpc_partition_up() | |
1392 | * at the same time. Nor will it ever make multiple calls to either function | |
1393 | * at the same time. | |
1394 | */ | |
1395 | void | |
a607c389 | 1396 | xpc_partition_going_down(struct xpc_partition *part, enum xpc_retval reason) |
89eb8eb9 DN |
1397 | { |
1398 | unsigned long irq_flags; | |
1399 | int ch_number; | |
1400 | struct xpc_channel *ch; | |
1401 | ||
1402 | ||
1403 | dev_dbg(xpc_chan, "deactivating partition %d, reason=%d\n", | |
1404 | XPC_PARTID(part), reason); | |
1405 | ||
1406 | if (!xpc_part_ref(part)) { | |
1407 | /* infrastructure for this partition isn't currently set up */ | |
1408 | return; | |
1409 | } | |
1410 | ||
1411 | ||
a607c389 | 1412 | /* disconnect channels associated with the partition going down */ |
89eb8eb9 DN |
1413 | |
1414 | for (ch_number = 0; ch_number < part->nchannels; ch_number++) { | |
1415 | ch = &part->channels[ch_number]; | |
1416 | ||
89eb8eb9 DN |
1417 | xpc_msgqueue_ref(ch); |
1418 | spin_lock_irqsave(&ch->lock, irq_flags); | |
1419 | ||
1420 | XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags); | |
1421 | ||
1422 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1423 | xpc_msgqueue_deref(ch); | |
1424 | } | |
1425 | ||
1426 | xpc_wakeup_channel_mgr(part); | |
1427 | ||
1428 | xpc_part_deref(part); | |
1429 | } | |
1430 | ||
1431 | ||
1432 | /* | |
1433 | * Teardown the infrastructure necessary to support XPartition Communication | |
1434 | * between the specified remote partition and the local one. | |
1435 | */ | |
1436 | void | |
1437 | xpc_teardown_infrastructure(struct xpc_partition *part) | |
1438 | { | |
1439 | partid_t partid = XPC_PARTID(part); | |
1440 | ||
1441 | ||
1442 | /* | |
1443 | * We start off by making this partition inaccessible to local | |
1444 | * processes by marking it as no longer setup. Then we make it | |
1445 | * inaccessible to remote processes by clearing the XPC per partition | |
1446 | * specific variable's magic # (which indicates that these variables | |
1447 | * are no longer valid) and by ignoring all XPC notify IPIs sent to | |
1448 | * this partition. | |
1449 | */ | |
1450 | ||
a607c389 | 1451 | DBUG_ON(atomic_read(&part->nchannels_engaged) != 0); |
89eb8eb9 DN |
1452 | DBUG_ON(atomic_read(&part->nchannels_active) != 0); |
1453 | DBUG_ON(part->setup_state != XPC_P_SETUP); | |
1454 | part->setup_state = XPC_P_WTEARDOWN; | |
1455 | ||
1456 | xpc_vars_part[partid].magic = 0; | |
1457 | ||
1458 | ||
1459 | free_irq(SGI_XPC_NOTIFY, (void *) (u64) partid); | |
1460 | ||
1461 | ||
1462 | /* | |
1463 | * Before proceding with the teardown we have to wait until all | |
1464 | * existing references cease. | |
1465 | */ | |
1466 | wait_event(part->teardown_wq, (atomic_read(&part->references) == 0)); | |
1467 | ||
1468 | ||
1469 | /* now we can begin tearing down the infrastructure */ | |
1470 | ||
1471 | part->setup_state = XPC_P_TORNDOWN; | |
1472 | ||
1473 | /* in case we've still got outstanding timers registered... */ | |
1474 | del_timer_sync(&part->dropped_IPI_timer); | |
1475 | ||
1476 | kfree(part->remote_openclose_args_base); | |
1477 | part->remote_openclose_args = NULL; | |
1478 | kfree(part->local_openclose_args_base); | |
1479 | part->local_openclose_args = NULL; | |
1480 | kfree(part->remote_GPs_base); | |
1481 | part->remote_GPs = NULL; | |
1482 | kfree(part->local_GPs_base); | |
1483 | part->local_GPs = NULL; | |
1484 | kfree(part->channels); | |
1485 | part->channels = NULL; | |
1486 | part->local_IPI_amo_va = NULL; | |
1487 | } | |
1488 | ||
1489 | ||
1490 | /* | |
1491 | * Called by XP at the time of channel connection registration to cause | |
1492 | * XPC to establish connections to all currently active partitions. | |
1493 | */ | |
1494 | void | |
1495 | xpc_initiate_connect(int ch_number) | |
1496 | { | |
1497 | partid_t partid; | |
1498 | struct xpc_partition *part; | |
1499 | struct xpc_channel *ch; | |
1500 | ||
1501 | ||
1502 | DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS); | |
1503 | ||
1504 | for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) { | |
1505 | part = &xpc_partitions[partid]; | |
1506 | ||
1507 | if (xpc_part_ref(part)) { | |
1508 | ch = &part->channels[ch_number]; | |
1509 | ||
e54af724 DN |
1510 | /* |
1511 | * Initiate the establishment of a connection on the | |
1512 | * newly registered channel to the remote partition. | |
1513 | */ | |
1514 | xpc_wakeup_channel_mgr(part); | |
89eb8eb9 DN |
1515 | xpc_part_deref(part); |
1516 | } | |
1517 | } | |
1518 | } | |
1519 | ||
1520 | ||
1521 | void | |
1522 | xpc_connected_callout(struct xpc_channel *ch) | |
1523 | { | |
89eb8eb9 DN |
1524 | /* let the registerer know that a connection has been established */ |
1525 | ||
1526 | if (ch->func != NULL) { | |
1527 | dev_dbg(xpc_chan, "ch->func() called, reason=xpcConnected, " | |
1528 | "partid=%d, channel=%d\n", ch->partid, ch->number); | |
1529 | ||
1530 | ch->func(xpcConnected, ch->partid, ch->number, | |
1531 | (void *) (u64) ch->local_nentries, ch->key); | |
1532 | ||
1533 | dev_dbg(xpc_chan, "ch->func() returned, reason=xpcConnected, " | |
1534 | "partid=%d, channel=%d\n", ch->partid, ch->number); | |
1535 | } | |
89eb8eb9 DN |
1536 | } |
1537 | ||
1538 | ||
1539 | /* | |
1540 | * Called by XP at the time of channel connection unregistration to cause | |
1541 | * XPC to teardown all current connections for the specified channel. | |
1542 | * | |
1543 | * Before returning xpc_initiate_disconnect() will wait until all connections | |
1544 | * on the specified channel have been closed/torndown. So the caller can be | |
1545 | * assured that they will not be receiving any more callouts from XPC to the | |
1546 | * function they registered via xpc_connect(). | |
1547 | * | |
1548 | * Arguments: | |
1549 | * | |
1550 | * ch_number - channel # to unregister. | |
1551 | */ | |
1552 | void | |
1553 | xpc_initiate_disconnect(int ch_number) | |
1554 | { | |
1555 | unsigned long irq_flags; | |
1556 | partid_t partid; | |
1557 | struct xpc_partition *part; | |
1558 | struct xpc_channel *ch; | |
1559 | ||
1560 | ||
1561 | DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS); | |
1562 | ||
1563 | /* initiate the channel disconnect for every active partition */ | |
1564 | for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) { | |
1565 | part = &xpc_partitions[partid]; | |
1566 | ||
1567 | if (xpc_part_ref(part)) { | |
1568 | ch = &part->channels[ch_number]; | |
1569 | xpc_msgqueue_ref(ch); | |
1570 | ||
1571 | spin_lock_irqsave(&ch->lock, irq_flags); | |
1572 | ||
a607c389 DN |
1573 | if (!(ch->flags & XPC_C_DISCONNECTED)) { |
1574 | ch->flags |= XPC_C_WDISCONNECT; | |
1575 | ||
1576 | XPC_DISCONNECT_CHANNEL(ch, xpcUnregistering, | |
89eb8eb9 | 1577 | &irq_flags); |
a607c389 | 1578 | } |
89eb8eb9 DN |
1579 | |
1580 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1581 | ||
1582 | xpc_msgqueue_deref(ch); | |
1583 | xpc_part_deref(part); | |
1584 | } | |
1585 | } | |
1586 | ||
1587 | xpc_disconnect_wait(ch_number); | |
1588 | } | |
1589 | ||
1590 | ||
1591 | /* | |
1592 | * To disconnect a channel, and reflect it back to all who may be waiting. | |
1593 | * | |
a607c389 DN |
1594 | * An OPEN is not allowed until XPC_C_DISCONNECTING is cleared by |
1595 | * xpc_process_disconnect(), and if set, XPC_C_WDISCONNECT is cleared by | |
1596 | * xpc_disconnect_wait(). | |
89eb8eb9 DN |
1597 | * |
1598 | * THE CHANNEL IS TO BE LOCKED BY THE CALLER AND WILL REMAIN LOCKED UPON RETURN. | |
1599 | */ | |
1600 | void | |
1601 | xpc_disconnect_channel(const int line, struct xpc_channel *ch, | |
1602 | enum xpc_retval reason, unsigned long *irq_flags) | |
1603 | { | |
a607c389 | 1604 | u32 channel_was_connected = (ch->flags & XPC_C_CONNECTED); |
89eb8eb9 DN |
1605 | |
1606 | ||
1607 | DBUG_ON(!spin_is_locked(&ch->lock)); | |
1608 | ||
1609 | if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) { | |
1610 | return; | |
1611 | } | |
1612 | DBUG_ON(!(ch->flags & (XPC_C_CONNECTING | XPC_C_CONNECTED))); | |
1613 | ||
1614 | dev_dbg(xpc_chan, "reason=%d, line=%d, partid=%d, channel=%d\n", | |
1615 | reason, line, ch->partid, ch->number); | |
1616 | ||
1617 | XPC_SET_REASON(ch, reason, line); | |
1618 | ||
a607c389 | 1619 | ch->flags |= (XPC_C_CLOSEREQUEST | XPC_C_DISCONNECTING); |
89eb8eb9 DN |
1620 | /* some of these may not have been set */ |
1621 | ch->flags &= ~(XPC_C_OPENREQUEST | XPC_C_OPENREPLY | | |
1622 | XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY | | |
1623 | XPC_C_CONNECTING | XPC_C_CONNECTED); | |
1624 | ||
89eb8eb9 DN |
1625 | xpc_IPI_send_closerequest(ch, irq_flags); |
1626 | ||
a607c389 | 1627 | if (channel_was_connected) { |
89eb8eb9 DN |
1628 | ch->flags |= XPC_C_WASCONNECTED; |
1629 | } | |
1630 | ||
a607c389 DN |
1631 | spin_unlock_irqrestore(&ch->lock, *irq_flags); |
1632 | ||
1633 | /* wake all idle kthreads so they can exit */ | |
89eb8eb9 | 1634 | if (atomic_read(&ch->kthreads_idle) > 0) { |
89eb8eb9 DN |
1635 | wake_up_all(&ch->idle_wq); |
1636 | } | |
1637 | ||
89eb8eb9 | 1638 | /* wake those waiting to allocate an entry from the local msg queue */ |
89eb8eb9 DN |
1639 | if (atomic_read(&ch->n_on_msg_allocate_wq) > 0) { |
1640 | wake_up(&ch->msg_allocate_wq); | |
1641 | } | |
1642 | ||
89eb8eb9 DN |
1643 | spin_lock_irqsave(&ch->lock, *irq_flags); |
1644 | } | |
1645 | ||
1646 | ||
1647 | void | |
a607c389 | 1648 | xpc_disconnecting_callout(struct xpc_channel *ch) |
89eb8eb9 DN |
1649 | { |
1650 | /* | |
a607c389 | 1651 | * Let the channel's registerer know that the channel is being |
89eb8eb9 | 1652 | * disconnected. We don't want to do this if the registerer was never |
a607c389 | 1653 | * informed of a connection being made. |
89eb8eb9 DN |
1654 | */ |
1655 | ||
1656 | if (ch->func != NULL) { | |
a607c389 DN |
1657 | dev_dbg(xpc_chan, "ch->func() called, reason=xpcDisconnecting," |
1658 | " partid=%d, channel=%d\n", ch->partid, ch->number); | |
89eb8eb9 | 1659 | |
a607c389 DN |
1660 | ch->func(xpcDisconnecting, ch->partid, ch->number, NULL, |
1661 | ch->key); | |
89eb8eb9 | 1662 | |
a607c389 DN |
1663 | dev_dbg(xpc_chan, "ch->func() returned, reason=" |
1664 | "xpcDisconnecting, partid=%d, channel=%d\n", | |
1665 | ch->partid, ch->number); | |
89eb8eb9 DN |
1666 | } |
1667 | } | |
1668 | ||
1669 | ||
1670 | /* | |
1671 | * Wait for a message entry to become available for the specified channel, | |
1672 | * but don't wait any longer than 1 jiffy. | |
1673 | */ | |
1674 | static enum xpc_retval | |
1675 | xpc_allocate_msg_wait(struct xpc_channel *ch) | |
1676 | { | |
1677 | enum xpc_retval ret; | |
1678 | ||
1679 | ||
1680 | if (ch->flags & XPC_C_DISCONNECTING) { | |
1681 | DBUG_ON(ch->reason == xpcInterrupted); // >>> Is this true? | |
1682 | return ch->reason; | |
1683 | } | |
1684 | ||
1685 | atomic_inc(&ch->n_on_msg_allocate_wq); | |
1686 | ret = interruptible_sleep_on_timeout(&ch->msg_allocate_wq, 1); | |
1687 | atomic_dec(&ch->n_on_msg_allocate_wq); | |
1688 | ||
1689 | if (ch->flags & XPC_C_DISCONNECTING) { | |
1690 | ret = ch->reason; | |
1691 | DBUG_ON(ch->reason == xpcInterrupted); // >>> Is this true? | |
1692 | } else if (ret == 0) { | |
1693 | ret = xpcTimeout; | |
1694 | } else { | |
1695 | ret = xpcInterrupted; | |
1696 | } | |
1697 | ||
1698 | return ret; | |
1699 | } | |
1700 | ||
1701 | ||
1702 | /* | |
1703 | * Allocate an entry for a message from the message queue associated with the | |
1704 | * specified channel. | |
1705 | */ | |
1706 | static enum xpc_retval | |
1707 | xpc_allocate_msg(struct xpc_channel *ch, u32 flags, | |
1708 | struct xpc_msg **address_of_msg) | |
1709 | { | |
1710 | struct xpc_msg *msg; | |
1711 | enum xpc_retval ret; | |
1712 | s64 put; | |
1713 | ||
1714 | ||
1715 | /* this reference will be dropped in xpc_send_msg() */ | |
1716 | xpc_msgqueue_ref(ch); | |
1717 | ||
1718 | if (ch->flags & XPC_C_DISCONNECTING) { | |
1719 | xpc_msgqueue_deref(ch); | |
1720 | return ch->reason; | |
1721 | } | |
1722 | if (!(ch->flags & XPC_C_CONNECTED)) { | |
1723 | xpc_msgqueue_deref(ch); | |
1724 | return xpcNotConnected; | |
1725 | } | |
1726 | ||
1727 | ||
1728 | /* | |
1729 | * Get the next available message entry from the local message queue. | |
1730 | * If none are available, we'll make sure that we grab the latest | |
1731 | * GP values. | |
1732 | */ | |
1733 | ret = xpcTimeout; | |
1734 | ||
1735 | while (1) { | |
1736 | ||
1737 | put = (volatile s64) ch->w_local_GP.put; | |
1738 | if (put - (volatile s64) ch->w_remote_GP.get < | |
1739 | ch->local_nentries) { | |
1740 | ||
1741 | /* There are available message entries. We need to try | |
1742 | * to secure one for ourselves. We'll do this by trying | |
1743 | * to increment w_local_GP.put as long as someone else | |
1744 | * doesn't beat us to it. If they do, we'll have to | |
1745 | * try again. | |
1746 | */ | |
1747 | if (cmpxchg(&ch->w_local_GP.put, put, put + 1) == | |
1748 | put) { | |
1749 | /* we got the entry referenced by put */ | |
1750 | break; | |
1751 | } | |
1752 | continue; /* try again */ | |
1753 | } | |
1754 | ||
1755 | ||
1756 | /* | |
1757 | * There aren't any available msg entries at this time. | |
1758 | * | |
1759 | * In waiting for a message entry to become available, | |
1760 | * we set a timeout in case the other side is not | |
1761 | * sending completion IPIs. This lets us fake an IPI | |
1762 | * that will cause the IPI handler to fetch the latest | |
1763 | * GP values as if an IPI was sent by the other side. | |
1764 | */ | |
1765 | if (ret == xpcTimeout) { | |
1766 | xpc_IPI_send_local_msgrequest(ch); | |
1767 | } | |
1768 | ||
1769 | if (flags & XPC_NOWAIT) { | |
1770 | xpc_msgqueue_deref(ch); | |
1771 | return xpcNoWait; | |
1772 | } | |
1773 | ||
1774 | ret = xpc_allocate_msg_wait(ch); | |
1775 | if (ret != xpcInterrupted && ret != xpcTimeout) { | |
1776 | xpc_msgqueue_deref(ch); | |
1777 | return ret; | |
1778 | } | |
1779 | } | |
1780 | ||
1781 | ||
1782 | /* get the message's address and initialize it */ | |
1783 | msg = (struct xpc_msg *) ((u64) ch->local_msgqueue + | |
1784 | (put % ch->local_nentries) * ch->msg_size); | |
1785 | ||
1786 | ||
1787 | DBUG_ON(msg->flags != 0); | |
1788 | msg->number = put; | |
1789 | ||
1790 | dev_dbg(xpc_chan, "w_local_GP.put changed to %ld; msg=0x%p, " | |
1791 | "msg_number=%ld, partid=%d, channel=%d\n", put + 1, | |
1792 | (void *) msg, msg->number, ch->partid, ch->number); | |
1793 | ||
1794 | *address_of_msg = msg; | |
1795 | ||
1796 | return xpcSuccess; | |
1797 | } | |
1798 | ||
1799 | ||
1800 | /* | |
1801 | * Allocate an entry for a message from the message queue associated with the | |
1802 | * specified channel. NOTE that this routine can sleep waiting for a message | |
1803 | * entry to become available. To not sleep, pass in the XPC_NOWAIT flag. | |
1804 | * | |
1805 | * Arguments: | |
1806 | * | |
1807 | * partid - ID of partition to which the channel is connected. | |
1808 | * ch_number - channel #. | |
1809 | * flags - see xpc.h for valid flags. | |
1810 | * payload - address of the allocated payload area pointer (filled in on | |
1811 | * return) in which the user-defined message is constructed. | |
1812 | */ | |
1813 | enum xpc_retval | |
1814 | xpc_initiate_allocate(partid_t partid, int ch_number, u32 flags, void **payload) | |
1815 | { | |
1816 | struct xpc_partition *part = &xpc_partitions[partid]; | |
1817 | enum xpc_retval ret = xpcUnknownReason; | |
1818 | struct xpc_msg *msg; | |
1819 | ||
1820 | ||
1821 | DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS); | |
1822 | DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); | |
1823 | ||
1824 | *payload = NULL; | |
1825 | ||
1826 | if (xpc_part_ref(part)) { | |
1827 | ret = xpc_allocate_msg(&part->channels[ch_number], flags, &msg); | |
1828 | xpc_part_deref(part); | |
1829 | ||
1830 | if (msg != NULL) { | |
1831 | *payload = &msg->payload; | |
1832 | } | |
1833 | } | |
1834 | ||
1835 | return ret; | |
1836 | } | |
1837 | ||
1838 | ||
1839 | /* | |
1840 | * Now we actually send the messages that are ready to be sent by advancing | |
1841 | * the local message queue's Put value and then send an IPI to the recipient | |
1842 | * partition. | |
1843 | */ | |
1844 | static void | |
1845 | xpc_send_msgs(struct xpc_channel *ch, s64 initial_put) | |
1846 | { | |
1847 | struct xpc_msg *msg; | |
1848 | s64 put = initial_put + 1; | |
1849 | int send_IPI = 0; | |
1850 | ||
1851 | ||
1852 | while (1) { | |
1853 | ||
1854 | while (1) { | |
1855 | if (put == (volatile s64) ch->w_local_GP.put) { | |
1856 | break; | |
1857 | } | |
1858 | ||
1859 | msg = (struct xpc_msg *) ((u64) ch->local_msgqueue + | |
1860 | (put % ch->local_nentries) * ch->msg_size); | |
1861 | ||
1862 | if (!(msg->flags & XPC_M_READY)) { | |
1863 | break; | |
1864 | } | |
1865 | ||
1866 | put++; | |
1867 | } | |
1868 | ||
1869 | if (put == initial_put) { | |
1870 | /* nothing's changed */ | |
1871 | break; | |
1872 | } | |
1873 | ||
1874 | if (cmpxchg_rel(&ch->local_GP->put, initial_put, put) != | |
1875 | initial_put) { | |
1876 | /* someone else beat us to it */ | |
1877 | DBUG_ON((volatile s64) ch->local_GP->put < initial_put); | |
1878 | break; | |
1879 | } | |
1880 | ||
1881 | /* we just set the new value of local_GP->put */ | |
1882 | ||
1883 | dev_dbg(xpc_chan, "local_GP->put changed to %ld, partid=%d, " | |
1884 | "channel=%d\n", put, ch->partid, ch->number); | |
1885 | ||
1886 | send_IPI = 1; | |
1887 | ||
1888 | /* | |
1889 | * We need to ensure that the message referenced by | |
1890 | * local_GP->put is not XPC_M_READY or that local_GP->put | |
1891 | * equals w_local_GP.put, so we'll go have a look. | |
1892 | */ | |
1893 | initial_put = put; | |
1894 | } | |
1895 | ||
1896 | if (send_IPI) { | |
1897 | xpc_IPI_send_msgrequest(ch); | |
1898 | } | |
1899 | } | |
1900 | ||
1901 | ||
1902 | /* | |
1903 | * Common code that does the actual sending of the message by advancing the | |
1904 | * local message queue's Put value and sends an IPI to the partition the | |
1905 | * message is being sent to. | |
1906 | */ | |
1907 | static enum xpc_retval | |
1908 | xpc_send_msg(struct xpc_channel *ch, struct xpc_msg *msg, u8 notify_type, | |
1909 | xpc_notify_func func, void *key) | |
1910 | { | |
1911 | enum xpc_retval ret = xpcSuccess; | |
a607c389 | 1912 | struct xpc_notify *notify = notify; |
89eb8eb9 DN |
1913 | s64 put, msg_number = msg->number; |
1914 | ||
1915 | ||
1916 | DBUG_ON(notify_type == XPC_N_CALL && func == NULL); | |
1917 | DBUG_ON((((u64) msg - (u64) ch->local_msgqueue) / ch->msg_size) != | |
1918 | msg_number % ch->local_nentries); | |
1919 | DBUG_ON(msg->flags & XPC_M_READY); | |
1920 | ||
1921 | if (ch->flags & XPC_C_DISCONNECTING) { | |
1922 | /* drop the reference grabbed in xpc_allocate_msg() */ | |
1923 | xpc_msgqueue_deref(ch); | |
1924 | return ch->reason; | |
1925 | } | |
1926 | ||
1927 | if (notify_type != 0) { | |
1928 | /* | |
1929 | * Tell the remote side to send an ACK interrupt when the | |
1930 | * message has been delivered. | |
1931 | */ | |
1932 | msg->flags |= XPC_M_INTERRUPT; | |
1933 | ||
1934 | atomic_inc(&ch->n_to_notify); | |
1935 | ||
1936 | notify = &ch->notify_queue[msg_number % ch->local_nentries]; | |
1937 | notify->func = func; | |
1938 | notify->key = key; | |
821fe947 | 1939 | notify->type = notify_type; |
89eb8eb9 DN |
1940 | |
1941 | // >>> is a mb() needed here? | |
1942 | ||
1943 | if (ch->flags & XPC_C_DISCONNECTING) { | |
1944 | /* | |
1945 | * An error occurred between our last error check and | |
1946 | * this one. We will try to clear the type field from | |
1947 | * the notify entry. If we succeed then | |
1948 | * xpc_disconnect_channel() didn't already process | |
1949 | * the notify entry. | |
1950 | */ | |
1951 | if (cmpxchg(¬ify->type, notify_type, 0) == | |
1952 | notify_type) { | |
1953 | atomic_dec(&ch->n_to_notify); | |
1954 | ret = ch->reason; | |
1955 | } | |
1956 | ||
1957 | /* drop the reference grabbed in xpc_allocate_msg() */ | |
1958 | xpc_msgqueue_deref(ch); | |
1959 | return ret; | |
1960 | } | |
1961 | } | |
1962 | ||
1963 | msg->flags |= XPC_M_READY; | |
1964 | ||
1965 | /* | |
1966 | * The preceding store of msg->flags must occur before the following | |
1967 | * load of ch->local_GP->put. | |
1968 | */ | |
1969 | mb(); | |
1970 | ||
1971 | /* see if the message is next in line to be sent, if so send it */ | |
1972 | ||
1973 | put = ch->local_GP->put; | |
1974 | if (put == msg_number) { | |
1975 | xpc_send_msgs(ch, put); | |
1976 | } | |
1977 | ||
1978 | /* drop the reference grabbed in xpc_allocate_msg() */ | |
1979 | xpc_msgqueue_deref(ch); | |
1980 | return ret; | |
1981 | } | |
1982 | ||
1983 | ||
1984 | /* | |
1985 | * Send a message previously allocated using xpc_initiate_allocate() on the | |
1986 | * specified channel connected to the specified partition. | |
1987 | * | |
1988 | * This routine will not wait for the message to be received, nor will | |
1989 | * notification be given when it does happen. Once this routine has returned | |
1990 | * the message entry allocated via xpc_initiate_allocate() is no longer | |
1991 | * accessable to the caller. | |
1992 | * | |
1993 | * This routine, although called by users, does not call xpc_part_ref() to | |
1994 | * ensure that the partition infrastructure is in place. It relies on the | |
1995 | * fact that we called xpc_msgqueue_ref() in xpc_allocate_msg(). | |
1996 | * | |
1997 | * Arguments: | |
1998 | * | |
1999 | * partid - ID of partition to which the channel is connected. | |
2000 | * ch_number - channel # to send message on. | |
2001 | * payload - pointer to the payload area allocated via | |
2002 | * xpc_initiate_allocate(). | |
2003 | */ | |
2004 | enum xpc_retval | |
2005 | xpc_initiate_send(partid_t partid, int ch_number, void *payload) | |
2006 | { | |
2007 | struct xpc_partition *part = &xpc_partitions[partid]; | |
2008 | struct xpc_msg *msg = XPC_MSG_ADDRESS(payload); | |
2009 | enum xpc_retval ret; | |
2010 | ||
2011 | ||
2012 | dev_dbg(xpc_chan, "msg=0x%p, partid=%d, channel=%d\n", (void *) msg, | |
2013 | partid, ch_number); | |
2014 | ||
2015 | DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS); | |
2016 | DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); | |
2017 | DBUG_ON(msg == NULL); | |
2018 | ||
2019 | ret = xpc_send_msg(&part->channels[ch_number], msg, 0, NULL, NULL); | |
2020 | ||
2021 | return ret; | |
2022 | } | |
2023 | ||
2024 | ||
2025 | /* | |
2026 | * Send a message previously allocated using xpc_initiate_allocate on the | |
2027 | * specified channel connected to the specified partition. | |
2028 | * | |
2029 | * This routine will not wait for the message to be sent. Once this routine | |
2030 | * has returned the message entry allocated via xpc_initiate_allocate() is no | |
2031 | * longer accessable to the caller. | |
2032 | * | |
2033 | * Once the remote end of the channel has received the message, the function | |
2034 | * passed as an argument to xpc_initiate_send_notify() will be called. This | |
2035 | * allows the sender to free up or re-use any buffers referenced by the | |
2036 | * message, but does NOT mean the message has been processed at the remote | |
2037 | * end by a receiver. | |
2038 | * | |
2039 | * If this routine returns an error, the caller's function will NOT be called. | |
2040 | * | |
2041 | * This routine, although called by users, does not call xpc_part_ref() to | |
2042 | * ensure that the partition infrastructure is in place. It relies on the | |
2043 | * fact that we called xpc_msgqueue_ref() in xpc_allocate_msg(). | |
2044 | * | |
2045 | * Arguments: | |
2046 | * | |
2047 | * partid - ID of partition to which the channel is connected. | |
2048 | * ch_number - channel # to send message on. | |
2049 | * payload - pointer to the payload area allocated via | |
2050 | * xpc_initiate_allocate(). | |
2051 | * func - function to call with asynchronous notification of message | |
2052 | * receipt. THIS FUNCTION MUST BE NON-BLOCKING. | |
2053 | * key - user-defined key to be passed to the function when it's called. | |
2054 | */ | |
2055 | enum xpc_retval | |
2056 | xpc_initiate_send_notify(partid_t partid, int ch_number, void *payload, | |
2057 | xpc_notify_func func, void *key) | |
2058 | { | |
2059 | struct xpc_partition *part = &xpc_partitions[partid]; | |
2060 | struct xpc_msg *msg = XPC_MSG_ADDRESS(payload); | |
2061 | enum xpc_retval ret; | |
2062 | ||
2063 | ||
2064 | dev_dbg(xpc_chan, "msg=0x%p, partid=%d, channel=%d\n", (void *) msg, | |
2065 | partid, ch_number); | |
2066 | ||
2067 | DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS); | |
2068 | DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); | |
2069 | DBUG_ON(msg == NULL); | |
2070 | DBUG_ON(func == NULL); | |
2071 | ||
2072 | ret = xpc_send_msg(&part->channels[ch_number], msg, XPC_N_CALL, | |
2073 | func, key); | |
2074 | return ret; | |
2075 | } | |
2076 | ||
2077 | ||
2078 | static struct xpc_msg * | |
2079 | xpc_pull_remote_msg(struct xpc_channel *ch, s64 get) | |
2080 | { | |
2081 | struct xpc_partition *part = &xpc_partitions[ch->partid]; | |
2082 | struct xpc_msg *remote_msg, *msg; | |
2083 | u32 msg_index, nmsgs; | |
2084 | u64 msg_offset; | |
2085 | enum xpc_retval ret; | |
2086 | ||
2087 | ||
2088 | if (down_interruptible(&ch->msg_to_pull_sema) != 0) { | |
2089 | /* we were interrupted by a signal */ | |
2090 | return NULL; | |
2091 | } | |
2092 | ||
2093 | while (get >= ch->next_msg_to_pull) { | |
2094 | ||
2095 | /* pull as many messages as are ready and able to be pulled */ | |
2096 | ||
2097 | msg_index = ch->next_msg_to_pull % ch->remote_nentries; | |
2098 | ||
2099 | DBUG_ON(ch->next_msg_to_pull >= | |
2100 | (volatile s64) ch->w_remote_GP.put); | |
2101 | nmsgs = (volatile s64) ch->w_remote_GP.put - | |
2102 | ch->next_msg_to_pull; | |
2103 | if (msg_index + nmsgs > ch->remote_nentries) { | |
2104 | /* ignore the ones that wrap the msg queue for now */ | |
2105 | nmsgs = ch->remote_nentries - msg_index; | |
2106 | } | |
2107 | ||
2108 | msg_offset = msg_index * ch->msg_size; | |
2109 | msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue + | |
2110 | msg_offset); | |
2111 | remote_msg = (struct xpc_msg *) (ch->remote_msgqueue_pa + | |
2112 | msg_offset); | |
2113 | ||
2114 | if ((ret = xpc_pull_remote_cachelines(part, msg, remote_msg, | |
2115 | nmsgs * ch->msg_size)) != xpcSuccess) { | |
2116 | ||
2117 | dev_dbg(xpc_chan, "failed to pull %d msgs starting with" | |
2118 | " msg %ld from partition %d, channel=%d, " | |
2119 | "ret=%d\n", nmsgs, ch->next_msg_to_pull, | |
2120 | ch->partid, ch->number, ret); | |
2121 | ||
2122 | XPC_DEACTIVATE_PARTITION(part, ret); | |
2123 | ||
2124 | up(&ch->msg_to_pull_sema); | |
2125 | return NULL; | |
2126 | } | |
2127 | ||
2128 | mb(); /* >>> this may not be needed, we're not sure */ | |
2129 | ||
2130 | ch->next_msg_to_pull += nmsgs; | |
2131 | } | |
2132 | ||
2133 | up(&ch->msg_to_pull_sema); | |
2134 | ||
2135 | /* return the message we were looking for */ | |
2136 | msg_offset = (get % ch->remote_nentries) * ch->msg_size; | |
2137 | msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue + msg_offset); | |
2138 | ||
2139 | return msg; | |
2140 | } | |
2141 | ||
2142 | ||
2143 | /* | |
2144 | * Get a message to be delivered. | |
2145 | */ | |
2146 | static struct xpc_msg * | |
2147 | xpc_get_deliverable_msg(struct xpc_channel *ch) | |
2148 | { | |
2149 | struct xpc_msg *msg = NULL; | |
2150 | s64 get; | |
2151 | ||
2152 | ||
2153 | do { | |
2154 | if ((volatile u32) ch->flags & XPC_C_DISCONNECTING) { | |
2155 | break; | |
2156 | } | |
2157 | ||
2158 | get = (volatile s64) ch->w_local_GP.get; | |
2159 | if (get == (volatile s64) ch->w_remote_GP.put) { | |
2160 | break; | |
2161 | } | |
2162 | ||
2163 | /* There are messages waiting to be pulled and delivered. | |
2164 | * We need to try to secure one for ourselves. We'll do this | |
2165 | * by trying to increment w_local_GP.get and hope that no one | |
2166 | * else beats us to it. If they do, we'll we'll simply have | |
2167 | * to try again for the next one. | |
2168 | */ | |
2169 | ||
2170 | if (cmpxchg(&ch->w_local_GP.get, get, get + 1) == get) { | |
2171 | /* we got the entry referenced by get */ | |
2172 | ||
2173 | dev_dbg(xpc_chan, "w_local_GP.get changed to %ld, " | |
2174 | "partid=%d, channel=%d\n", get + 1, | |
2175 | ch->partid, ch->number); | |
2176 | ||
2177 | /* pull the message from the remote partition */ | |
2178 | ||
2179 | msg = xpc_pull_remote_msg(ch, get); | |
2180 | ||
2181 | DBUG_ON(msg != NULL && msg->number != get); | |
2182 | DBUG_ON(msg != NULL && (msg->flags & XPC_M_DONE)); | |
2183 | DBUG_ON(msg != NULL && !(msg->flags & XPC_M_READY)); | |
2184 | ||
2185 | break; | |
2186 | } | |
2187 | ||
2188 | } while (1); | |
2189 | ||
2190 | return msg; | |
2191 | } | |
2192 | ||
2193 | ||
2194 | /* | |
2195 | * Deliver a message to its intended recipient. | |
2196 | */ | |
2197 | void | |
2198 | xpc_deliver_msg(struct xpc_channel *ch) | |
2199 | { | |
2200 | struct xpc_msg *msg; | |
2201 | ||
2202 | ||
2203 | if ((msg = xpc_get_deliverable_msg(ch)) != NULL) { | |
2204 | ||
2205 | /* | |
2206 | * This ref is taken to protect the payload itself from being | |
2207 | * freed before the user is finished with it, which the user | |
2208 | * indicates by calling xpc_initiate_received(). | |
2209 | */ | |
2210 | xpc_msgqueue_ref(ch); | |
2211 | ||
2212 | atomic_inc(&ch->kthreads_active); | |
2213 | ||
2214 | if (ch->func != NULL) { | |
2215 | dev_dbg(xpc_chan, "ch->func() called, msg=0x%p, " | |
2216 | "msg_number=%ld, partid=%d, channel=%d\n", | |
2217 | (void *) msg, msg->number, ch->partid, | |
2218 | ch->number); | |
2219 | ||
2220 | /* deliver the message to its intended recipient */ | |
2221 | ch->func(xpcMsgReceived, ch->partid, ch->number, | |
2222 | &msg->payload, ch->key); | |
2223 | ||
2224 | dev_dbg(xpc_chan, "ch->func() returned, msg=0x%p, " | |
2225 | "msg_number=%ld, partid=%d, channel=%d\n", | |
2226 | (void *) msg, msg->number, ch->partid, | |
2227 | ch->number); | |
2228 | } | |
2229 | ||
2230 | atomic_dec(&ch->kthreads_active); | |
2231 | } | |
2232 | } | |
2233 | ||
2234 | ||
2235 | /* | |
2236 | * Now we actually acknowledge the messages that have been delivered and ack'd | |
2237 | * by advancing the cached remote message queue's Get value and if requested | |
2238 | * send an IPI to the message sender's partition. | |
2239 | */ | |
2240 | static void | |
2241 | xpc_acknowledge_msgs(struct xpc_channel *ch, s64 initial_get, u8 msg_flags) | |
2242 | { | |
2243 | struct xpc_msg *msg; | |
2244 | s64 get = initial_get + 1; | |
2245 | int send_IPI = 0; | |
2246 | ||
2247 | ||
2248 | while (1) { | |
2249 | ||
2250 | while (1) { | |
2251 | if (get == (volatile s64) ch->w_local_GP.get) { | |
2252 | break; | |
2253 | } | |
2254 | ||
2255 | msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue + | |
2256 | (get % ch->remote_nentries) * ch->msg_size); | |
2257 | ||
2258 | if (!(msg->flags & XPC_M_DONE)) { | |
2259 | break; | |
2260 | } | |
2261 | ||
2262 | msg_flags |= msg->flags; | |
2263 | get++; | |
2264 | } | |
2265 | ||
2266 | if (get == initial_get) { | |
2267 | /* nothing's changed */ | |
2268 | break; | |
2269 | } | |
2270 | ||
2271 | if (cmpxchg_rel(&ch->local_GP->get, initial_get, get) != | |
2272 | initial_get) { | |
2273 | /* someone else beat us to it */ | |
2274 | DBUG_ON((volatile s64) ch->local_GP->get <= | |
2275 | initial_get); | |
2276 | break; | |
2277 | } | |
2278 | ||
2279 | /* we just set the new value of local_GP->get */ | |
2280 | ||
2281 | dev_dbg(xpc_chan, "local_GP->get changed to %ld, partid=%d, " | |
2282 | "channel=%d\n", get, ch->partid, ch->number); | |
2283 | ||
2284 | send_IPI = (msg_flags & XPC_M_INTERRUPT); | |
2285 | ||
2286 | /* | |
2287 | * We need to ensure that the message referenced by | |
2288 | * local_GP->get is not XPC_M_DONE or that local_GP->get | |
2289 | * equals w_local_GP.get, so we'll go have a look. | |
2290 | */ | |
2291 | initial_get = get; | |
2292 | } | |
2293 | ||
2294 | if (send_IPI) { | |
2295 | xpc_IPI_send_msgrequest(ch); | |
2296 | } | |
2297 | } | |
2298 | ||
2299 | ||
2300 | /* | |
2301 | * Acknowledge receipt of a delivered message. | |
2302 | * | |
2303 | * If a message has XPC_M_INTERRUPT set, send an interrupt to the partition | |
2304 | * that sent the message. | |
2305 | * | |
2306 | * This function, although called by users, does not call xpc_part_ref() to | |
2307 | * ensure that the partition infrastructure is in place. It relies on the | |
2308 | * fact that we called xpc_msgqueue_ref() in xpc_deliver_msg(). | |
2309 | * | |
2310 | * Arguments: | |
2311 | * | |
2312 | * partid - ID of partition to which the channel is connected. | |
2313 | * ch_number - channel # message received on. | |
2314 | * payload - pointer to the payload area allocated via | |
2315 | * xpc_initiate_allocate(). | |
2316 | */ | |
2317 | void | |
2318 | xpc_initiate_received(partid_t partid, int ch_number, void *payload) | |
2319 | { | |
2320 | struct xpc_partition *part = &xpc_partitions[partid]; | |
2321 | struct xpc_channel *ch; | |
2322 | struct xpc_msg *msg = XPC_MSG_ADDRESS(payload); | |
2323 | s64 get, msg_number = msg->number; | |
2324 | ||
2325 | ||
2326 | DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS); | |
2327 | DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); | |
2328 | ||
2329 | ch = &part->channels[ch_number]; | |
2330 | ||
2331 | dev_dbg(xpc_chan, "msg=0x%p, msg_number=%ld, partid=%d, channel=%d\n", | |
2332 | (void *) msg, msg_number, ch->partid, ch->number); | |
2333 | ||
2334 | DBUG_ON((((u64) msg - (u64) ch->remote_msgqueue) / ch->msg_size) != | |
2335 | msg_number % ch->remote_nentries); | |
2336 | DBUG_ON(msg->flags & XPC_M_DONE); | |
2337 | ||
2338 | msg->flags |= XPC_M_DONE; | |
2339 | ||
2340 | /* | |
2341 | * The preceding store of msg->flags must occur before the following | |
2342 | * load of ch->local_GP->get. | |
2343 | */ | |
2344 | mb(); | |
2345 | ||
2346 | /* | |
2347 | * See if this message is next in line to be acknowledged as having | |
2348 | * been delivered. | |
2349 | */ | |
2350 | get = ch->local_GP->get; | |
2351 | if (get == msg_number) { | |
2352 | xpc_acknowledge_msgs(ch, get, msg->flags); | |
2353 | } | |
2354 | ||
2355 | /* the call to xpc_msgqueue_ref() was done by xpc_deliver_msg() */ | |
2356 | xpc_msgqueue_deref(ch); | |
2357 | } | |
2358 |