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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 | * | |
9335d48e | 6 | * Copyright (c) 2004-2006 Silicon Graphics, Inc. All Rights Reserved. |
89eb8eb9 DN |
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> | |
f9e505a9 JS |
25 | #include <linux/mutex.h> |
26 | #include <linux/completion.h> | |
89eb8eb9 DN |
27 | #include <asm/sn/bte.h> |
28 | #include <asm/sn/sn_sal.h> | |
9335d48e | 29 | #include <asm/sn/xpc.h> |
89eb8eb9 DN |
30 | |
31 | ||
32 | /* | |
33 | * Set up the initial values for the XPartition Communication channels. | |
34 | */ | |
35 | static void | |
36 | xpc_initialize_channels(struct xpc_partition *part, partid_t partid) | |
37 | { | |
38 | int ch_number; | |
39 | struct xpc_channel *ch; | |
40 | ||
41 | ||
42 | for (ch_number = 0; ch_number < part->nchannels; ch_number++) { | |
43 | ch = &part->channels[ch_number]; | |
44 | ||
45 | ch->partid = partid; | |
46 | ch->number = ch_number; | |
47 | ch->flags = XPC_C_DISCONNECTED; | |
48 | ||
49 | ch->local_GP = &part->local_GPs[ch_number]; | |
50 | ch->local_openclose_args = | |
51 | &part->local_openclose_args[ch_number]; | |
52 | ||
53 | atomic_set(&ch->kthreads_assigned, 0); | |
54 | atomic_set(&ch->kthreads_idle, 0); | |
55 | atomic_set(&ch->kthreads_active, 0); | |
56 | ||
57 | atomic_set(&ch->references, 0); | |
58 | atomic_set(&ch->n_to_notify, 0); | |
59 | ||
60 | spin_lock_init(&ch->lock); | |
f9e505a9 JS |
61 | mutex_init(&ch->msg_to_pull_mutex); |
62 | init_completion(&ch->wdisconnect_wait); | |
89eb8eb9 DN |
63 | |
64 | atomic_set(&ch->n_on_msg_allocate_wq, 0); | |
65 | init_waitqueue_head(&ch->msg_allocate_wq); | |
66 | init_waitqueue_head(&ch->idle_wq); | |
67 | } | |
68 | } | |
69 | ||
70 | ||
71 | /* | |
72 | * Setup the infrastructure necessary to support XPartition Communication | |
73 | * between the specified remote partition and the local one. | |
74 | */ | |
75 | enum xpc_retval | |
76 | xpc_setup_infrastructure(struct xpc_partition *part) | |
77 | { | |
59a0a8aa | 78 | int ret, cpuid; |
89eb8eb9 DN |
79 | struct timer_list *timer; |
80 | partid_t partid = XPC_PARTID(part); | |
81 | ||
82 | ||
83 | /* | |
84 | * Zero out MOST of the entry for this partition. Only the fields | |
85 | * starting with `nchannels' will be zeroed. The preceding fields must | |
86 | * remain `viable' across partition ups and downs, since they may be | |
87 | * referenced during this memset() operation. | |
88 | */ | |
89 | memset(&part->nchannels, 0, sizeof(struct xpc_partition) - | |
90 | offsetof(struct xpc_partition, nchannels)); | |
91 | ||
92 | /* | |
93 | * Allocate all of the channel structures as a contiguous chunk of | |
94 | * memory. | |
95 | */ | |
96 | part->channels = kmalloc(sizeof(struct xpc_channel) * XPC_NCHANNELS, | |
97 | GFP_KERNEL); | |
98 | if (part->channels == NULL) { | |
99 | dev_err(xpc_chan, "can't get memory for channels\n"); | |
100 | return xpcNoMemory; | |
101 | } | |
102 | memset(part->channels, 0, sizeof(struct xpc_channel) * XPC_NCHANNELS); | |
103 | ||
104 | part->nchannels = XPC_NCHANNELS; | |
105 | ||
106 | ||
107 | /* allocate all the required GET/PUT values */ | |
108 | ||
109 | part->local_GPs = xpc_kmalloc_cacheline_aligned(XPC_GP_SIZE, | |
110 | GFP_KERNEL, &part->local_GPs_base); | |
111 | if (part->local_GPs == NULL) { | |
112 | kfree(part->channels); | |
113 | part->channels = NULL; | |
114 | dev_err(xpc_chan, "can't get memory for local get/put " | |
115 | "values\n"); | |
116 | return xpcNoMemory; | |
117 | } | |
118 | memset(part->local_GPs, 0, XPC_GP_SIZE); | |
119 | ||
120 | part->remote_GPs = xpc_kmalloc_cacheline_aligned(XPC_GP_SIZE, | |
121 | GFP_KERNEL, &part->remote_GPs_base); | |
122 | if (part->remote_GPs == NULL) { | |
123 | kfree(part->channels); | |
124 | part->channels = NULL; | |
125 | kfree(part->local_GPs_base); | |
126 | part->local_GPs = NULL; | |
127 | dev_err(xpc_chan, "can't get memory for remote get/put " | |
128 | "values\n"); | |
129 | return xpcNoMemory; | |
130 | } | |
131 | memset(part->remote_GPs, 0, XPC_GP_SIZE); | |
132 | ||
133 | ||
134 | /* allocate all the required open and close args */ | |
135 | ||
136 | part->local_openclose_args = xpc_kmalloc_cacheline_aligned( | |
137 | XPC_OPENCLOSE_ARGS_SIZE, GFP_KERNEL, | |
138 | &part->local_openclose_args_base); | |
139 | if (part->local_openclose_args == NULL) { | |
140 | kfree(part->channels); | |
141 | part->channels = NULL; | |
142 | kfree(part->local_GPs_base); | |
143 | part->local_GPs = NULL; | |
144 | kfree(part->remote_GPs_base); | |
145 | part->remote_GPs = NULL; | |
146 | dev_err(xpc_chan, "can't get memory for local connect args\n"); | |
147 | return xpcNoMemory; | |
148 | } | |
149 | memset(part->local_openclose_args, 0, XPC_OPENCLOSE_ARGS_SIZE); | |
150 | ||
151 | part->remote_openclose_args = xpc_kmalloc_cacheline_aligned( | |
152 | XPC_OPENCLOSE_ARGS_SIZE, GFP_KERNEL, | |
153 | &part->remote_openclose_args_base); | |
154 | if (part->remote_openclose_args == NULL) { | |
155 | kfree(part->channels); | |
156 | part->channels = NULL; | |
157 | kfree(part->local_GPs_base); | |
158 | part->local_GPs = NULL; | |
159 | kfree(part->remote_GPs_base); | |
160 | part->remote_GPs = NULL; | |
161 | kfree(part->local_openclose_args_base); | |
162 | part->local_openclose_args = NULL; | |
163 | dev_err(xpc_chan, "can't get memory for remote connect args\n"); | |
164 | return xpcNoMemory; | |
165 | } | |
166 | memset(part->remote_openclose_args, 0, XPC_OPENCLOSE_ARGS_SIZE); | |
167 | ||
168 | ||
169 | xpc_initialize_channels(part, partid); | |
170 | ||
171 | atomic_set(&part->nchannels_active, 0); | |
a607c389 | 172 | atomic_set(&part->nchannels_engaged, 0); |
89eb8eb9 DN |
173 | |
174 | ||
175 | /* local_IPI_amo were set to 0 by an earlier memset() */ | |
176 | ||
177 | /* Initialize this partitions AMO_t structure */ | |
178 | part->local_IPI_amo_va = xpc_IPI_init(partid); | |
179 | ||
180 | spin_lock_init(&part->IPI_lock); | |
181 | ||
182 | atomic_set(&part->channel_mgr_requests, 1); | |
183 | init_waitqueue_head(&part->channel_mgr_wq); | |
184 | ||
185 | sprintf(part->IPI_owner, "xpc%02d", partid); | |
186 | ret = request_irq(SGI_XPC_NOTIFY, xpc_notify_IRQ_handler, SA_SHIRQ, | |
187 | part->IPI_owner, (void *) (u64) partid); | |
188 | if (ret != 0) { | |
189 | kfree(part->channels); | |
190 | part->channels = NULL; | |
191 | kfree(part->local_GPs_base); | |
192 | part->local_GPs = NULL; | |
193 | kfree(part->remote_GPs_base); | |
194 | part->remote_GPs = NULL; | |
195 | kfree(part->local_openclose_args_base); | |
196 | part->local_openclose_args = NULL; | |
197 | kfree(part->remote_openclose_args_base); | |
198 | part->remote_openclose_args = NULL; | |
199 | dev_err(xpc_chan, "can't register NOTIFY IRQ handler, " | |
200 | "errno=%d\n", -ret); | |
201 | return xpcLackOfResources; | |
202 | } | |
203 | ||
204 | /* Setup a timer to check for dropped IPIs */ | |
205 | timer = &part->dropped_IPI_timer; | |
206 | init_timer(timer); | |
207 | timer->function = (void (*)(unsigned long)) xpc_dropped_IPI_check; | |
208 | timer->data = (unsigned long) part; | |
209 | timer->expires = jiffies + XPC_P_DROPPED_IPI_WAIT; | |
210 | add_timer(timer); | |
211 | ||
212 | /* | |
213 | * With the setting of the partition setup_state to XPC_P_SETUP, we're | |
214 | * declaring that this partition is ready to go. | |
215 | */ | |
821fe947 | 216 | part->setup_state = XPC_P_SETUP; |
89eb8eb9 DN |
217 | |
218 | ||
219 | /* | |
220 | * Setup the per partition specific variables required by the | |
221 | * remote partition to establish channel connections with us. | |
222 | * | |
223 | * The setting of the magic # indicates that these per partition | |
224 | * specific variables are ready to be used. | |
225 | */ | |
226 | xpc_vars_part[partid].GPs_pa = __pa(part->local_GPs); | |
227 | xpc_vars_part[partid].openclose_args_pa = | |
228 | __pa(part->local_openclose_args); | |
229 | xpc_vars_part[partid].IPI_amo_pa = __pa(part->local_IPI_amo_va); | |
59a0a8aa DN |
230 | cpuid = raw_smp_processor_id(); /* any CPU in this partition will do */ |
231 | xpc_vars_part[partid].IPI_nasid = cpuid_to_nasid(cpuid); | |
232 | xpc_vars_part[partid].IPI_phys_cpuid = cpu_physical_id(cpuid); | |
89eb8eb9 | 233 | xpc_vars_part[partid].nchannels = part->nchannels; |
821fe947 | 234 | xpc_vars_part[partid].magic = XPC_VP_MAGIC1; |
89eb8eb9 DN |
235 | |
236 | return xpcSuccess; | |
237 | } | |
238 | ||
239 | ||
240 | /* | |
241 | * Create a wrapper that hides the underlying mechanism for pulling a cacheline | |
242 | * (or multiple cachelines) from a remote partition. | |
243 | * | |
244 | * src must be a cacheline aligned physical address on the remote partition. | |
245 | * dst must be a cacheline aligned virtual address on this partition. | |
246 | * cnt must be an cacheline sized | |
247 | */ | |
248 | static enum xpc_retval | |
249 | xpc_pull_remote_cachelines(struct xpc_partition *part, void *dst, | |
250 | const void *src, size_t cnt) | |
251 | { | |
252 | bte_result_t bte_ret; | |
253 | ||
254 | ||
255 | DBUG_ON((u64) src != L1_CACHE_ALIGN((u64) src)); | |
256 | DBUG_ON((u64) dst != L1_CACHE_ALIGN((u64) dst)); | |
257 | DBUG_ON(cnt != L1_CACHE_ALIGN(cnt)); | |
258 | ||
259 | if (part->act_state == XPC_P_DEACTIVATING) { | |
260 | return part->reason; | |
261 | } | |
262 | ||
263 | bte_ret = xp_bte_copy((u64) src, (u64) ia64_tpa((u64) dst), | |
264 | (u64) cnt, (BTE_NORMAL | BTE_WACQUIRE), NULL); | |
265 | if (bte_ret == BTE_SUCCESS) { | |
266 | return xpcSuccess; | |
267 | } | |
268 | ||
269 | dev_dbg(xpc_chan, "xp_bte_copy() from partition %d failed, ret=%d\n", | |
270 | XPC_PARTID(part), bte_ret); | |
271 | ||
272 | return xpc_map_bte_errors(bte_ret); | |
273 | } | |
274 | ||
275 | ||
276 | /* | |
277 | * Pull the remote per partititon specific variables from the specified | |
278 | * partition. | |
279 | */ | |
280 | enum xpc_retval | |
281 | xpc_pull_remote_vars_part(struct xpc_partition *part) | |
282 | { | |
283 | u8 buffer[L1_CACHE_BYTES * 2]; | |
284 | struct xpc_vars_part *pulled_entry_cacheline = | |
285 | (struct xpc_vars_part *) L1_CACHE_ALIGN((u64) buffer); | |
286 | struct xpc_vars_part *pulled_entry; | |
287 | u64 remote_entry_cacheline_pa, remote_entry_pa; | |
288 | partid_t partid = XPC_PARTID(part); | |
289 | enum xpc_retval ret; | |
290 | ||
291 | ||
292 | /* pull the cacheline that contains the variables we're interested in */ | |
293 | ||
294 | DBUG_ON(part->remote_vars_part_pa != | |
295 | L1_CACHE_ALIGN(part->remote_vars_part_pa)); | |
296 | DBUG_ON(sizeof(struct xpc_vars_part) != L1_CACHE_BYTES / 2); | |
297 | ||
298 | remote_entry_pa = part->remote_vars_part_pa + | |
299 | sn_partition_id * sizeof(struct xpc_vars_part); | |
300 | ||
301 | remote_entry_cacheline_pa = (remote_entry_pa & ~(L1_CACHE_BYTES - 1)); | |
302 | ||
303 | pulled_entry = (struct xpc_vars_part *) ((u64) pulled_entry_cacheline + | |
304 | (remote_entry_pa & (L1_CACHE_BYTES - 1))); | |
305 | ||
306 | ret = xpc_pull_remote_cachelines(part, pulled_entry_cacheline, | |
307 | (void *) remote_entry_cacheline_pa, | |
308 | L1_CACHE_BYTES); | |
309 | if (ret != xpcSuccess) { | |
310 | dev_dbg(xpc_chan, "failed to pull XPC vars_part from " | |
311 | "partition %d, ret=%d\n", partid, ret); | |
312 | return ret; | |
313 | } | |
314 | ||
315 | ||
316 | /* see if they've been set up yet */ | |
317 | ||
318 | if (pulled_entry->magic != XPC_VP_MAGIC1 && | |
319 | pulled_entry->magic != XPC_VP_MAGIC2) { | |
320 | ||
321 | if (pulled_entry->magic != 0) { | |
322 | dev_dbg(xpc_chan, "partition %d's XPC vars_part for " | |
323 | "partition %d has bad magic value (=0x%lx)\n", | |
324 | partid, sn_partition_id, pulled_entry->magic); | |
325 | return xpcBadMagic; | |
326 | } | |
327 | ||
328 | /* they've not been initialized yet */ | |
329 | return xpcRetry; | |
330 | } | |
331 | ||
332 | if (xpc_vars_part[partid].magic == XPC_VP_MAGIC1) { | |
333 | ||
334 | /* validate the variables */ | |
335 | ||
336 | if (pulled_entry->GPs_pa == 0 || | |
337 | pulled_entry->openclose_args_pa == 0 || | |
338 | pulled_entry->IPI_amo_pa == 0) { | |
339 | ||
340 | dev_err(xpc_chan, "partition %d's XPC vars_part for " | |
341 | "partition %d are not valid\n", partid, | |
342 | sn_partition_id); | |
343 | return xpcInvalidAddress; | |
344 | } | |
345 | ||
346 | /* the variables we imported look to be valid */ | |
347 | ||
348 | part->remote_GPs_pa = pulled_entry->GPs_pa; | |
349 | part->remote_openclose_args_pa = | |
350 | pulled_entry->openclose_args_pa; | |
351 | part->remote_IPI_amo_va = | |
352 | (AMO_t *) __va(pulled_entry->IPI_amo_pa); | |
353 | part->remote_IPI_nasid = pulled_entry->IPI_nasid; | |
354 | part->remote_IPI_phys_cpuid = pulled_entry->IPI_phys_cpuid; | |
355 | ||
356 | if (part->nchannels > pulled_entry->nchannels) { | |
357 | part->nchannels = pulled_entry->nchannels; | |
358 | } | |
359 | ||
360 | /* let the other side know that we've pulled their variables */ | |
361 | ||
821fe947 | 362 | xpc_vars_part[partid].magic = XPC_VP_MAGIC2; |
89eb8eb9 DN |
363 | } |
364 | ||
365 | if (pulled_entry->magic == XPC_VP_MAGIC1) { | |
366 | return xpcRetry; | |
367 | } | |
368 | ||
369 | return xpcSuccess; | |
370 | } | |
371 | ||
372 | ||
373 | /* | |
374 | * Get the IPI flags and pull the openclose args and/or remote GPs as needed. | |
375 | */ | |
376 | static u64 | |
377 | xpc_get_IPI_flags(struct xpc_partition *part) | |
378 | { | |
379 | unsigned long irq_flags; | |
380 | u64 IPI_amo; | |
381 | enum xpc_retval ret; | |
382 | ||
383 | ||
384 | /* | |
385 | * See if there are any IPI flags to be handled. | |
386 | */ | |
387 | ||
388 | spin_lock_irqsave(&part->IPI_lock, irq_flags); | |
389 | if ((IPI_amo = part->local_IPI_amo) != 0) { | |
390 | part->local_IPI_amo = 0; | |
391 | } | |
392 | spin_unlock_irqrestore(&part->IPI_lock, irq_flags); | |
393 | ||
394 | ||
395 | if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_amo)) { | |
396 | ret = xpc_pull_remote_cachelines(part, | |
397 | part->remote_openclose_args, | |
398 | (void *) part->remote_openclose_args_pa, | |
399 | XPC_OPENCLOSE_ARGS_SIZE); | |
400 | if (ret != xpcSuccess) { | |
401 | XPC_DEACTIVATE_PARTITION(part, ret); | |
402 | ||
403 | dev_dbg(xpc_chan, "failed to pull openclose args from " | |
404 | "partition %d, ret=%d\n", XPC_PARTID(part), | |
405 | ret); | |
406 | ||
407 | /* don't bother processing IPIs anymore */ | |
408 | IPI_amo = 0; | |
409 | } | |
410 | } | |
411 | ||
412 | if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_amo)) { | |
413 | ret = xpc_pull_remote_cachelines(part, part->remote_GPs, | |
414 | (void *) part->remote_GPs_pa, | |
415 | XPC_GP_SIZE); | |
416 | if (ret != xpcSuccess) { | |
417 | XPC_DEACTIVATE_PARTITION(part, ret); | |
418 | ||
419 | dev_dbg(xpc_chan, "failed to pull GPs from partition " | |
420 | "%d, ret=%d\n", XPC_PARTID(part), ret); | |
421 | ||
422 | /* don't bother processing IPIs anymore */ | |
423 | IPI_amo = 0; | |
424 | } | |
425 | } | |
426 | ||
427 | return IPI_amo; | |
428 | } | |
429 | ||
430 | ||
431 | /* | |
432 | * Allocate the local message queue and the notify queue. | |
433 | */ | |
434 | static enum xpc_retval | |
435 | xpc_allocate_local_msgqueue(struct xpc_channel *ch) | |
436 | { | |
437 | unsigned long irq_flags; | |
438 | int nentries; | |
439 | size_t nbytes; | |
440 | ||
441 | ||
442 | // >>> may want to check for ch->flags & XPC_C_DISCONNECTING between | |
443 | // >>> iterations of the for-loop, bail if set? | |
444 | ||
445 | // >>> should we impose a minumum #of entries? like 4 or 8? | |
446 | for (nentries = ch->local_nentries; nentries > 0; nentries--) { | |
447 | ||
448 | nbytes = nentries * ch->msg_size; | |
449 | ch->local_msgqueue = xpc_kmalloc_cacheline_aligned(nbytes, | |
139366a0 | 450 | GFP_KERNEL, |
89eb8eb9 DN |
451 | &ch->local_msgqueue_base); |
452 | if (ch->local_msgqueue == NULL) { | |
453 | continue; | |
454 | } | |
455 | memset(ch->local_msgqueue, 0, nbytes); | |
456 | ||
457 | nbytes = nentries * sizeof(struct xpc_notify); | |
139366a0 | 458 | ch->notify_queue = kmalloc(nbytes, GFP_KERNEL); |
89eb8eb9 DN |
459 | if (ch->notify_queue == NULL) { |
460 | kfree(ch->local_msgqueue_base); | |
461 | ch->local_msgqueue = NULL; | |
462 | continue; | |
463 | } | |
464 | memset(ch->notify_queue, 0, nbytes); | |
465 | ||
466 | spin_lock_irqsave(&ch->lock, irq_flags); | |
467 | if (nentries < ch->local_nentries) { | |
468 | dev_dbg(xpc_chan, "nentries=%d local_nentries=%d, " | |
469 | "partid=%d, channel=%d\n", nentries, | |
470 | ch->local_nentries, ch->partid, ch->number); | |
471 | ||
472 | ch->local_nentries = nentries; | |
473 | } | |
474 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
475 | return xpcSuccess; | |
476 | } | |
477 | ||
478 | dev_dbg(xpc_chan, "can't get memory for local message queue and notify " | |
479 | "queue, partid=%d, channel=%d\n", ch->partid, ch->number); | |
480 | return xpcNoMemory; | |
481 | } | |
482 | ||
483 | ||
484 | /* | |
485 | * Allocate the cached remote message queue. | |
486 | */ | |
487 | static enum xpc_retval | |
488 | xpc_allocate_remote_msgqueue(struct xpc_channel *ch) | |
489 | { | |
490 | unsigned long irq_flags; | |
491 | int nentries; | |
492 | size_t nbytes; | |
493 | ||
494 | ||
495 | DBUG_ON(ch->remote_nentries <= 0); | |
496 | ||
497 | // >>> may want to check for ch->flags & XPC_C_DISCONNECTING between | |
498 | // >>> iterations of the for-loop, bail if set? | |
499 | ||
500 | // >>> should we impose a minumum #of entries? like 4 or 8? | |
501 | for (nentries = ch->remote_nentries; nentries > 0; nentries--) { | |
502 | ||
503 | nbytes = nentries * ch->msg_size; | |
504 | ch->remote_msgqueue = xpc_kmalloc_cacheline_aligned(nbytes, | |
139366a0 | 505 | GFP_KERNEL, |
89eb8eb9 DN |
506 | &ch->remote_msgqueue_base); |
507 | if (ch->remote_msgqueue == NULL) { | |
508 | continue; | |
509 | } | |
510 | memset(ch->remote_msgqueue, 0, nbytes); | |
511 | ||
512 | spin_lock_irqsave(&ch->lock, irq_flags); | |
513 | if (nentries < ch->remote_nentries) { | |
514 | dev_dbg(xpc_chan, "nentries=%d remote_nentries=%d, " | |
515 | "partid=%d, channel=%d\n", nentries, | |
516 | ch->remote_nentries, ch->partid, ch->number); | |
517 | ||
518 | ch->remote_nentries = nentries; | |
519 | } | |
520 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
521 | return xpcSuccess; | |
522 | } | |
523 | ||
524 | dev_dbg(xpc_chan, "can't get memory for cached remote message queue, " | |
525 | "partid=%d, channel=%d\n", ch->partid, ch->number); | |
526 | return xpcNoMemory; | |
527 | } | |
528 | ||
529 | ||
530 | /* | |
531 | * Allocate message queues and other stuff associated with a channel. | |
532 | * | |
533 | * Note: Assumes all of the channel sizes are filled in. | |
534 | */ | |
535 | static enum xpc_retval | |
536 | xpc_allocate_msgqueues(struct xpc_channel *ch) | |
537 | { | |
538 | unsigned long irq_flags; | |
89eb8eb9 DN |
539 | enum xpc_retval ret; |
540 | ||
541 | ||
542 | DBUG_ON(ch->flags & XPC_C_SETUP); | |
543 | ||
544 | if ((ret = xpc_allocate_local_msgqueue(ch)) != xpcSuccess) { | |
545 | return ret; | |
546 | } | |
547 | ||
548 | if ((ret = xpc_allocate_remote_msgqueue(ch)) != xpcSuccess) { | |
549 | kfree(ch->local_msgqueue_base); | |
550 | ch->local_msgqueue = NULL; | |
551 | kfree(ch->notify_queue); | |
552 | ch->notify_queue = NULL; | |
553 | return ret; | |
554 | } | |
555 | ||
89eb8eb9 DN |
556 | spin_lock_irqsave(&ch->lock, irq_flags); |
557 | ch->flags |= XPC_C_SETUP; | |
558 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
559 | ||
560 | return xpcSuccess; | |
561 | } | |
562 | ||
563 | ||
564 | /* | |
565 | * Process a connect message from a remote partition. | |
566 | * | |
567 | * Note: xpc_process_connect() is expecting to be called with the | |
568 | * spin_lock_irqsave held and will leave it locked upon return. | |
569 | */ | |
570 | static void | |
571 | xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags) | |
572 | { | |
573 | enum xpc_retval ret; | |
574 | ||
575 | ||
576 | DBUG_ON(!spin_is_locked(&ch->lock)); | |
577 | ||
578 | if (!(ch->flags & XPC_C_OPENREQUEST) || | |
579 | !(ch->flags & XPC_C_ROPENREQUEST)) { | |
580 | /* nothing more to do for now */ | |
581 | return; | |
582 | } | |
583 | DBUG_ON(!(ch->flags & XPC_C_CONNECTING)); | |
584 | ||
585 | if (!(ch->flags & XPC_C_SETUP)) { | |
586 | spin_unlock_irqrestore(&ch->lock, *irq_flags); | |
587 | ret = xpc_allocate_msgqueues(ch); | |
588 | spin_lock_irqsave(&ch->lock, *irq_flags); | |
589 | ||
590 | if (ret != xpcSuccess) { | |
591 | XPC_DISCONNECT_CHANNEL(ch, ret, irq_flags); | |
592 | } | |
593 | if (ch->flags & (XPC_C_CONNECTED | XPC_C_DISCONNECTING)) { | |
594 | return; | |
595 | } | |
596 | ||
597 | DBUG_ON(!(ch->flags & XPC_C_SETUP)); | |
598 | DBUG_ON(ch->local_msgqueue == NULL); | |
599 | DBUG_ON(ch->remote_msgqueue == NULL); | |
600 | } | |
601 | ||
602 | if (!(ch->flags & XPC_C_OPENREPLY)) { | |
603 | ch->flags |= XPC_C_OPENREPLY; | |
604 | xpc_IPI_send_openreply(ch, irq_flags); | |
605 | } | |
606 | ||
607 | if (!(ch->flags & XPC_C_ROPENREPLY)) { | |
608 | return; | |
609 | } | |
610 | ||
611 | DBUG_ON(ch->remote_msgqueue_pa == 0); | |
612 | ||
613 | ch->flags = (XPC_C_CONNECTED | XPC_C_SETUP); /* clear all else */ | |
614 | ||
615 | dev_info(xpc_chan, "channel %d to partition %d connected\n", | |
616 | ch->number, ch->partid); | |
617 | ||
618 | spin_unlock_irqrestore(&ch->lock, *irq_flags); | |
619 | xpc_create_kthreads(ch, 1); | |
620 | spin_lock_irqsave(&ch->lock, *irq_flags); | |
621 | } | |
622 | ||
623 | ||
a607c389 DN |
624 | /* |
625 | * Notify those who wanted to be notified upon delivery of their message. | |
626 | */ | |
627 | static void | |
628 | xpc_notify_senders(struct xpc_channel *ch, enum xpc_retval reason, s64 put) | |
629 | { | |
630 | struct xpc_notify *notify; | |
631 | u8 notify_type; | |
632 | s64 get = ch->w_remote_GP.get - 1; | |
633 | ||
634 | ||
635 | while (++get < put && atomic_read(&ch->n_to_notify) > 0) { | |
636 | ||
637 | notify = &ch->notify_queue[get % ch->local_nentries]; | |
638 | ||
639 | /* | |
640 | * See if the notify entry indicates it was associated with | |
641 | * a message who's sender wants to be notified. It is possible | |
642 | * that it is, but someone else is doing or has done the | |
643 | * notification. | |
644 | */ | |
645 | notify_type = notify->type; | |
646 | if (notify_type == 0 || | |
647 | cmpxchg(¬ify->type, notify_type, 0) != | |
648 | notify_type) { | |
649 | continue; | |
650 | } | |
651 | ||
652 | DBUG_ON(notify_type != XPC_N_CALL); | |
653 | ||
654 | atomic_dec(&ch->n_to_notify); | |
655 | ||
656 | if (notify->func != NULL) { | |
657 | dev_dbg(xpc_chan, "notify->func() called, notify=0x%p, " | |
658 | "msg_number=%ld, partid=%d, channel=%d\n", | |
659 | (void *) notify, get, ch->partid, ch->number); | |
660 | ||
661 | notify->func(reason, ch->partid, ch->number, | |
662 | notify->key); | |
663 | ||
664 | dev_dbg(xpc_chan, "notify->func() returned, " | |
665 | "notify=0x%p, msg_number=%ld, partid=%d, " | |
666 | "channel=%d\n", (void *) notify, get, | |
667 | ch->partid, ch->number); | |
668 | } | |
669 | } | |
670 | } | |
671 | ||
672 | ||
89eb8eb9 DN |
673 | /* |
674 | * Free up message queues and other stuff that were allocated for the specified | |
675 | * channel. | |
676 | * | |
677 | * Note: ch->reason and ch->reason_line are left set for debugging purposes, | |
678 | * they're cleared when XPC_C_DISCONNECTED is cleared. | |
679 | */ | |
680 | static void | |
681 | xpc_free_msgqueues(struct xpc_channel *ch) | |
682 | { | |
683 | DBUG_ON(!spin_is_locked(&ch->lock)); | |
684 | DBUG_ON(atomic_read(&ch->n_to_notify) != 0); | |
685 | ||
686 | ch->remote_msgqueue_pa = 0; | |
687 | ch->func = NULL; | |
688 | ch->key = NULL; | |
689 | ch->msg_size = 0; | |
690 | ch->local_nentries = 0; | |
691 | ch->remote_nentries = 0; | |
692 | ch->kthreads_assigned_limit = 0; | |
693 | ch->kthreads_idle_limit = 0; | |
694 | ||
695 | ch->local_GP->get = 0; | |
696 | ch->local_GP->put = 0; | |
697 | ch->remote_GP.get = 0; | |
698 | ch->remote_GP.put = 0; | |
699 | ch->w_local_GP.get = 0; | |
700 | ch->w_local_GP.put = 0; | |
701 | ch->w_remote_GP.get = 0; | |
702 | ch->w_remote_GP.put = 0; | |
703 | ch->next_msg_to_pull = 0; | |
704 | ||
705 | if (ch->flags & XPC_C_SETUP) { | |
706 | ch->flags &= ~XPC_C_SETUP; | |
707 | ||
708 | dev_dbg(xpc_chan, "ch->flags=0x%x, partid=%d, channel=%d\n", | |
709 | ch->flags, ch->partid, ch->number); | |
710 | ||
711 | kfree(ch->local_msgqueue_base); | |
712 | ch->local_msgqueue = NULL; | |
713 | kfree(ch->remote_msgqueue_base); | |
714 | ch->remote_msgqueue = NULL; | |
715 | kfree(ch->notify_queue); | |
716 | ch->notify_queue = NULL; | |
89eb8eb9 DN |
717 | } |
718 | } | |
719 | ||
720 | ||
721 | /* | |
722 | * spin_lock_irqsave() is expected to be held on entry. | |
723 | */ | |
724 | static void | |
725 | xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags) | |
726 | { | |
727 | struct xpc_partition *part = &xpc_partitions[ch->partid]; | |
a607c389 | 728 | u32 channel_was_connected = (ch->flags & XPC_C_WASCONNECTED); |
89eb8eb9 DN |
729 | |
730 | ||
731 | DBUG_ON(!spin_is_locked(&ch->lock)); | |
732 | ||
733 | if (!(ch->flags & XPC_C_DISCONNECTING)) { | |
734 | return; | |
735 | } | |
736 | ||
737 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); | |
738 | ||
739 | /* make sure all activity has settled down first */ | |
740 | ||
4c2cd966 DN |
741 | if (atomic_read(&ch->references) > 0 || |
742 | ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) && | |
743 | !(ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE))) { | |
89eb8eb9 DN |
744 | return; |
745 | } | |
746 | DBUG_ON(atomic_read(&ch->kthreads_assigned) != 0); | |
747 | ||
a607c389 DN |
748 | if (part->act_state == XPC_P_DEACTIVATING) { |
749 | /* can't proceed until the other side disengages from us */ | |
750 | if (xpc_partition_engaged(1UL << ch->partid)) { | |
751 | return; | |
752 | } | |
89eb8eb9 | 753 | |
a607c389 | 754 | } else { |
89eb8eb9 DN |
755 | |
756 | /* as long as the other side is up do the full protocol */ | |
757 | ||
758 | if (!(ch->flags & XPC_C_RCLOSEREQUEST)) { | |
759 | return; | |
760 | } | |
761 | ||
762 | if (!(ch->flags & XPC_C_CLOSEREPLY)) { | |
763 | ch->flags |= XPC_C_CLOSEREPLY; | |
764 | xpc_IPI_send_closereply(ch, irq_flags); | |
765 | } | |
766 | ||
767 | if (!(ch->flags & XPC_C_RCLOSEREPLY)) { | |
768 | return; | |
769 | } | |
770 | } | |
771 | ||
a607c389 DN |
772 | /* wake those waiting for notify completion */ |
773 | if (atomic_read(&ch->n_to_notify) > 0) { | |
774 | /* >>> we do callout while holding ch->lock */ | |
775 | xpc_notify_senders(ch, ch->reason, ch->w_local_GP.put); | |
776 | } | |
777 | ||
89eb8eb9 DN |
778 | /* both sides are disconnected now */ |
779 | ||
4c2cd966 | 780 | if (ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE) { |
246c7e33 DN |
781 | spin_unlock_irqrestore(&ch->lock, *irq_flags); |
782 | xpc_disconnect_callout(ch, xpcDisconnected); | |
783 | spin_lock_irqsave(&ch->lock, *irq_flags); | |
784 | } | |
785 | ||
a607c389 DN |
786 | /* it's now safe to free the channel's message queues */ |
787 | xpc_free_msgqueues(ch); | |
788 | ||
789 | /* mark disconnected, clear all other flags except XPC_C_WDISCONNECT */ | |
790 | ch->flags = (XPC_C_DISCONNECTED | (ch->flags & XPC_C_WDISCONNECT)); | |
89eb8eb9 DN |
791 | |
792 | atomic_dec(&part->nchannels_active); | |
793 | ||
a607c389 | 794 | if (channel_was_connected) { |
89eb8eb9 DN |
795 | dev_info(xpc_chan, "channel %d to partition %d disconnected, " |
796 | "reason=%d\n", ch->number, ch->partid, ch->reason); | |
797 | } | |
a607c389 | 798 | |
a607c389 | 799 | if (ch->flags & XPC_C_WDISCONNECT) { |
f9e505a9 JS |
800 | /* we won't lose the CPU since we're holding ch->lock */ |
801 | complete(&ch->wdisconnect_wait); | |
e54af724 DN |
802 | } else if (ch->delayed_IPI_flags) { |
803 | if (part->act_state != XPC_P_DEACTIVATING) { | |
804 | /* time to take action on any delayed IPI flags */ | |
805 | spin_lock(&part->IPI_lock); | |
806 | XPC_SET_IPI_FLAGS(part->local_IPI_amo, ch->number, | |
807 | ch->delayed_IPI_flags); | |
808 | spin_unlock(&part->IPI_lock); | |
809 | } | |
810 | ch->delayed_IPI_flags = 0; | |
a607c389 | 811 | } |
89eb8eb9 DN |
812 | } |
813 | ||
814 | ||
815 | /* | |
816 | * Process a change in the channel's remote connection state. | |
817 | */ | |
818 | static void | |
819 | xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number, | |
820 | u8 IPI_flags) | |
821 | { | |
822 | unsigned long irq_flags; | |
823 | struct xpc_openclose_args *args = | |
824 | &part->remote_openclose_args[ch_number]; | |
825 | struct xpc_channel *ch = &part->channels[ch_number]; | |
826 | enum xpc_retval reason; | |
827 | ||
828 | ||
829 | ||
830 | spin_lock_irqsave(&ch->lock, irq_flags); | |
831 | ||
e54af724 DN |
832 | again: |
833 | ||
834 | if ((ch->flags & XPC_C_DISCONNECTED) && | |
835 | (ch->flags & XPC_C_WDISCONNECT)) { | |
836 | /* | |
837 | * Delay processing IPI flags until thread waiting disconnect | |
838 | * has had a chance to see that the channel is disconnected. | |
839 | */ | |
840 | ch->delayed_IPI_flags |= IPI_flags; | |
841 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
842 | return; | |
843 | } | |
844 | ||
89eb8eb9 DN |
845 | |
846 | if (IPI_flags & XPC_IPI_CLOSEREQUEST) { | |
847 | ||
848 | dev_dbg(xpc_chan, "XPC_IPI_CLOSEREQUEST (reason=%d) received " | |
849 | "from partid=%d, channel=%d\n", args->reason, | |
850 | ch->partid, ch->number); | |
851 | ||
852 | /* | |
853 | * If RCLOSEREQUEST is set, we're probably waiting for | |
854 | * RCLOSEREPLY. We should find it and a ROPENREQUEST packed | |
a607c389 | 855 | * with this RCLOSEREQUEST in the IPI_flags. |
89eb8eb9 DN |
856 | */ |
857 | ||
858 | if (ch->flags & XPC_C_RCLOSEREQUEST) { | |
859 | DBUG_ON(!(ch->flags & XPC_C_DISCONNECTING)); | |
860 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); | |
861 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREPLY)); | |
862 | DBUG_ON(ch->flags & XPC_C_RCLOSEREPLY); | |
863 | ||
864 | DBUG_ON(!(IPI_flags & XPC_IPI_CLOSEREPLY)); | |
865 | IPI_flags &= ~XPC_IPI_CLOSEREPLY; | |
866 | ch->flags |= XPC_C_RCLOSEREPLY; | |
867 | ||
868 | /* both sides have finished disconnecting */ | |
869 | xpc_process_disconnect(ch, &irq_flags); | |
e54af724 DN |
870 | DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED)); |
871 | goto again; | |
89eb8eb9 DN |
872 | } |
873 | ||
874 | if (ch->flags & XPC_C_DISCONNECTED) { | |
89eb8eb9 | 875 | if (!(IPI_flags & XPC_IPI_OPENREQUEST)) { |
e54af724 DN |
876 | if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo, |
877 | ch_number) & XPC_IPI_OPENREQUEST)) { | |
878 | ||
879 | DBUG_ON(ch->delayed_IPI_flags != 0); | |
880 | spin_lock(&part->IPI_lock); | |
881 | XPC_SET_IPI_FLAGS(part->local_IPI_amo, | |
882 | ch_number, | |
883 | XPC_IPI_CLOSEREQUEST); | |
884 | spin_unlock(&part->IPI_lock); | |
885 | } | |
89eb8eb9 DN |
886 | spin_unlock_irqrestore(&ch->lock, irq_flags); |
887 | return; | |
888 | } | |
889 | ||
890 | XPC_SET_REASON(ch, 0, 0); | |
891 | ch->flags &= ~XPC_C_DISCONNECTED; | |
892 | ||
893 | atomic_inc(&part->nchannels_active); | |
894 | ch->flags |= (XPC_C_CONNECTING | XPC_C_ROPENREQUEST); | |
895 | } | |
896 | ||
897 | IPI_flags &= ~(XPC_IPI_OPENREQUEST | XPC_IPI_OPENREPLY); | |
898 | ||
899 | /* | |
900 | * The meaningful CLOSEREQUEST connection state fields are: | |
901 | * reason = reason connection is to be closed | |
902 | */ | |
903 | ||
904 | ch->flags |= XPC_C_RCLOSEREQUEST; | |
905 | ||
906 | if (!(ch->flags & XPC_C_DISCONNECTING)) { | |
907 | reason = args->reason; | |
908 | if (reason <= xpcSuccess || reason > xpcUnknownReason) { | |
909 | reason = xpcUnknownReason; | |
910 | } else if (reason == xpcUnregistering) { | |
911 | reason = xpcOtherUnregistering; | |
912 | } | |
913 | ||
914 | XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags); | |
e54af724 DN |
915 | |
916 | DBUG_ON(IPI_flags & XPC_IPI_CLOSEREPLY); | |
917 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
918 | return; | |
89eb8eb9 | 919 | } |
e54af724 DN |
920 | |
921 | xpc_process_disconnect(ch, &irq_flags); | |
89eb8eb9 DN |
922 | } |
923 | ||
924 | ||
925 | if (IPI_flags & XPC_IPI_CLOSEREPLY) { | |
926 | ||
927 | dev_dbg(xpc_chan, "XPC_IPI_CLOSEREPLY received from partid=%d," | |
928 | " channel=%d\n", ch->partid, ch->number); | |
929 | ||
930 | if (ch->flags & XPC_C_DISCONNECTED) { | |
931 | DBUG_ON(part->act_state != XPC_P_DEACTIVATING); | |
932 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
933 | return; | |
934 | } | |
935 | ||
936 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); | |
e54af724 DN |
937 | |
938 | if (!(ch->flags & XPC_C_RCLOSEREQUEST)) { | |
939 | if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo, ch_number) | |
940 | & XPC_IPI_CLOSEREQUEST)) { | |
941 | ||
942 | DBUG_ON(ch->delayed_IPI_flags != 0); | |
943 | spin_lock(&part->IPI_lock); | |
944 | XPC_SET_IPI_FLAGS(part->local_IPI_amo, | |
945 | ch_number, XPC_IPI_CLOSEREPLY); | |
946 | spin_unlock(&part->IPI_lock); | |
947 | } | |
948 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
949 | return; | |
950 | } | |
89eb8eb9 DN |
951 | |
952 | ch->flags |= XPC_C_RCLOSEREPLY; | |
953 | ||
954 | if (ch->flags & XPC_C_CLOSEREPLY) { | |
955 | /* both sides have finished disconnecting */ | |
956 | xpc_process_disconnect(ch, &irq_flags); | |
957 | } | |
958 | } | |
959 | ||
960 | ||
961 | if (IPI_flags & XPC_IPI_OPENREQUEST) { | |
962 | ||
963 | dev_dbg(xpc_chan, "XPC_IPI_OPENREQUEST (msg_size=%d, " | |
964 | "local_nentries=%d) received from partid=%d, " | |
965 | "channel=%d\n", args->msg_size, args->local_nentries, | |
966 | ch->partid, ch->number); | |
967 | ||
e54af724 DN |
968 | if (part->act_state == XPC_P_DEACTIVATING || |
969 | (ch->flags & XPC_C_ROPENREQUEST)) { | |
970 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
971 | return; | |
972 | } | |
973 | ||
974 | if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) { | |
975 | ch->delayed_IPI_flags |= XPC_IPI_OPENREQUEST; | |
89eb8eb9 DN |
976 | spin_unlock_irqrestore(&ch->lock, irq_flags); |
977 | return; | |
978 | } | |
979 | DBUG_ON(!(ch->flags & (XPC_C_DISCONNECTED | | |
980 | XPC_C_OPENREQUEST))); | |
981 | DBUG_ON(ch->flags & (XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY | | |
982 | XPC_C_OPENREPLY | XPC_C_CONNECTED)); | |
983 | ||
984 | /* | |
985 | * The meaningful OPENREQUEST connection state fields are: | |
986 | * msg_size = size of channel's messages in bytes | |
987 | * local_nentries = remote partition's local_nentries | |
988 | */ | |
e54af724 DN |
989 | if (args->msg_size == 0 || args->local_nentries == 0) { |
990 | /* assume OPENREQUEST was delayed by mistake */ | |
991 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
992 | return; | |
993 | } | |
89eb8eb9 DN |
994 | |
995 | ch->flags |= (XPC_C_ROPENREQUEST | XPC_C_CONNECTING); | |
996 | ch->remote_nentries = args->local_nentries; | |
997 | ||
998 | ||
999 | if (ch->flags & XPC_C_OPENREQUEST) { | |
1000 | if (args->msg_size != ch->msg_size) { | |
1001 | XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes, | |
1002 | &irq_flags); | |
1003 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1004 | return; | |
1005 | } | |
1006 | } else { | |
1007 | ch->msg_size = args->msg_size; | |
1008 | ||
1009 | XPC_SET_REASON(ch, 0, 0); | |
1010 | ch->flags &= ~XPC_C_DISCONNECTED; | |
1011 | ||
1012 | atomic_inc(&part->nchannels_active); | |
1013 | } | |
1014 | ||
1015 | xpc_process_connect(ch, &irq_flags); | |
1016 | } | |
1017 | ||
1018 | ||
1019 | if (IPI_flags & XPC_IPI_OPENREPLY) { | |
1020 | ||
1021 | dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY (local_msgqueue_pa=0x%lx, " | |
1022 | "local_nentries=%d, remote_nentries=%d) received from " | |
1023 | "partid=%d, channel=%d\n", args->local_msgqueue_pa, | |
1024 | args->local_nentries, args->remote_nentries, | |
1025 | ch->partid, ch->number); | |
1026 | ||
1027 | if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) { | |
1028 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1029 | return; | |
1030 | } | |
e54af724 DN |
1031 | if (!(ch->flags & XPC_C_OPENREQUEST)) { |
1032 | XPC_DISCONNECT_CHANNEL(ch, xpcOpenCloseError, | |
1033 | &irq_flags); | |
1034 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1035 | return; | |
1036 | } | |
1037 | ||
89eb8eb9 DN |
1038 | DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST)); |
1039 | DBUG_ON(ch->flags & XPC_C_CONNECTED); | |
1040 | ||
1041 | /* | |
1042 | * The meaningful OPENREPLY connection state fields are: | |
1043 | * local_msgqueue_pa = physical address of remote | |
1044 | * partition's local_msgqueue | |
1045 | * local_nentries = remote partition's local_nentries | |
1046 | * remote_nentries = remote partition's remote_nentries | |
1047 | */ | |
1048 | DBUG_ON(args->local_msgqueue_pa == 0); | |
1049 | DBUG_ON(args->local_nentries == 0); | |
1050 | DBUG_ON(args->remote_nentries == 0); | |
1051 | ||
1052 | ch->flags |= XPC_C_ROPENREPLY; | |
1053 | ch->remote_msgqueue_pa = args->local_msgqueue_pa; | |
1054 | ||
1055 | if (args->local_nentries < ch->remote_nentries) { | |
1056 | dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new " | |
1057 | "remote_nentries=%d, old remote_nentries=%d, " | |
1058 | "partid=%d, channel=%d\n", | |
1059 | args->local_nentries, ch->remote_nentries, | |
1060 | ch->partid, ch->number); | |
1061 | ||
1062 | ch->remote_nentries = args->local_nentries; | |
1063 | } | |
1064 | if (args->remote_nentries < ch->local_nentries) { | |
1065 | dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new " | |
1066 | "local_nentries=%d, old local_nentries=%d, " | |
1067 | "partid=%d, channel=%d\n", | |
1068 | args->remote_nentries, ch->local_nentries, | |
1069 | ch->partid, ch->number); | |
1070 | ||
1071 | ch->local_nentries = args->remote_nentries; | |
1072 | } | |
1073 | ||
1074 | xpc_process_connect(ch, &irq_flags); | |
1075 | } | |
1076 | ||
1077 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1078 | } | |
1079 | ||
1080 | ||
1081 | /* | |
1082 | * Attempt to establish a channel connection to a remote partition. | |
1083 | */ | |
1084 | static enum xpc_retval | |
1085 | xpc_connect_channel(struct xpc_channel *ch) | |
1086 | { | |
1087 | unsigned long irq_flags; | |
1088 | struct xpc_registration *registration = &xpc_registrations[ch->number]; | |
1089 | ||
1090 | ||
f9e505a9 | 1091 | if (mutex_trylock(®istration->mutex) == 0) { |
e54af724 | 1092 | return xpcRetry; |
89eb8eb9 DN |
1093 | } |
1094 | ||
1095 | if (!XPC_CHANNEL_REGISTERED(ch->number)) { | |
f9e505a9 | 1096 | mutex_unlock(®istration->mutex); |
89eb8eb9 DN |
1097 | return xpcUnregistered; |
1098 | } | |
1099 | ||
1100 | spin_lock_irqsave(&ch->lock, irq_flags); | |
1101 | ||
1102 | DBUG_ON(ch->flags & XPC_C_CONNECTED); | |
1103 | DBUG_ON(ch->flags & XPC_C_OPENREQUEST); | |
1104 | ||
1105 | if (ch->flags & XPC_C_DISCONNECTING) { | |
1106 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
f9e505a9 | 1107 | mutex_unlock(®istration->mutex); |
89eb8eb9 DN |
1108 | return ch->reason; |
1109 | } | |
1110 | ||
1111 | ||
1112 | /* add info from the channel connect registration to the channel */ | |
1113 | ||
1114 | ch->kthreads_assigned_limit = registration->assigned_limit; | |
1115 | ch->kthreads_idle_limit = registration->idle_limit; | |
1116 | DBUG_ON(atomic_read(&ch->kthreads_assigned) != 0); | |
1117 | DBUG_ON(atomic_read(&ch->kthreads_idle) != 0); | |
1118 | DBUG_ON(atomic_read(&ch->kthreads_active) != 0); | |
1119 | ||
1120 | ch->func = registration->func; | |
1121 | DBUG_ON(registration->func == NULL); | |
1122 | ch->key = registration->key; | |
1123 | ||
1124 | ch->local_nentries = registration->nentries; | |
1125 | ||
1126 | if (ch->flags & XPC_C_ROPENREQUEST) { | |
1127 | if (registration->msg_size != ch->msg_size) { | |
1128 | /* the local and remote sides aren't the same */ | |
1129 | ||
1130 | /* | |
1131 | * Because XPC_DISCONNECT_CHANNEL() can block we're | |
1132 | * forced to up the registration sema before we unlock | |
1133 | * the channel lock. But that's okay here because we're | |
1134 | * done with the part that required the registration | |
1135 | * sema. XPC_DISCONNECT_CHANNEL() requires that the | |
1136 | * channel lock be locked and will unlock and relock | |
1137 | * the channel lock as needed. | |
1138 | */ | |
f9e505a9 | 1139 | mutex_unlock(®istration->mutex); |
89eb8eb9 DN |
1140 | XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes, |
1141 | &irq_flags); | |
1142 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1143 | return xpcUnequalMsgSizes; | |
1144 | } | |
1145 | } else { | |
1146 | ch->msg_size = registration->msg_size; | |
1147 | ||
1148 | XPC_SET_REASON(ch, 0, 0); | |
1149 | ch->flags &= ~XPC_C_DISCONNECTED; | |
1150 | ||
1151 | atomic_inc(&xpc_partitions[ch->partid].nchannels_active); | |
1152 | } | |
1153 | ||
f9e505a9 | 1154 | mutex_unlock(®istration->mutex); |
89eb8eb9 DN |
1155 | |
1156 | ||
1157 | /* initiate the connection */ | |
1158 | ||
1159 | ch->flags |= (XPC_C_OPENREQUEST | XPC_C_CONNECTING); | |
1160 | xpc_IPI_send_openrequest(ch, &irq_flags); | |
1161 | ||
1162 | xpc_process_connect(ch, &irq_flags); | |
1163 | ||
1164 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1165 | ||
1166 | return xpcSuccess; | |
1167 | } | |
1168 | ||
1169 | ||
89eb8eb9 DN |
1170 | /* |
1171 | * Clear some of the msg flags in the local message queue. | |
1172 | */ | |
1173 | static inline void | |
1174 | xpc_clear_local_msgqueue_flags(struct xpc_channel *ch) | |
1175 | { | |
1176 | struct xpc_msg *msg; | |
1177 | s64 get; | |
1178 | ||
1179 | ||
1180 | get = ch->w_remote_GP.get; | |
1181 | do { | |
1182 | msg = (struct xpc_msg *) ((u64) ch->local_msgqueue + | |
1183 | (get % ch->local_nentries) * ch->msg_size); | |
1184 | msg->flags = 0; | |
1185 | } while (++get < (volatile s64) ch->remote_GP.get); | |
1186 | } | |
1187 | ||
1188 | ||
1189 | /* | |
1190 | * Clear some of the msg flags in the remote message queue. | |
1191 | */ | |
1192 | static inline void | |
1193 | xpc_clear_remote_msgqueue_flags(struct xpc_channel *ch) | |
1194 | { | |
1195 | struct xpc_msg *msg; | |
1196 | s64 put; | |
1197 | ||
1198 | ||
1199 | put = ch->w_remote_GP.put; | |
1200 | do { | |
1201 | msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue + | |
1202 | (put % ch->remote_nentries) * ch->msg_size); | |
1203 | msg->flags = 0; | |
1204 | } while (++put < (volatile s64) ch->remote_GP.put); | |
1205 | } | |
1206 | ||
1207 | ||
1208 | static void | |
1209 | xpc_process_msg_IPI(struct xpc_partition *part, int ch_number) | |
1210 | { | |
1211 | struct xpc_channel *ch = &part->channels[ch_number]; | |
1212 | int nmsgs_sent; | |
1213 | ||
1214 | ||
1215 | ch->remote_GP = part->remote_GPs[ch_number]; | |
1216 | ||
1217 | ||
1218 | /* See what, if anything, has changed for each connected channel */ | |
1219 | ||
1220 | xpc_msgqueue_ref(ch); | |
1221 | ||
1222 | if (ch->w_remote_GP.get == ch->remote_GP.get && | |
1223 | ch->w_remote_GP.put == ch->remote_GP.put) { | |
1224 | /* nothing changed since GPs were last pulled */ | |
1225 | xpc_msgqueue_deref(ch); | |
1226 | return; | |
1227 | } | |
1228 | ||
1229 | if (!(ch->flags & XPC_C_CONNECTED)){ | |
1230 | xpc_msgqueue_deref(ch); | |
1231 | return; | |
1232 | } | |
1233 | ||
1234 | ||
1235 | /* | |
1236 | * First check to see if messages recently sent by us have been | |
1237 | * received by the other side. (The remote GET value will have | |
1238 | * changed since we last looked at it.) | |
1239 | */ | |
1240 | ||
1241 | if (ch->w_remote_GP.get != ch->remote_GP.get) { | |
1242 | ||
1243 | /* | |
1244 | * We need to notify any senders that want to be notified | |
1245 | * that their sent messages have been received by their | |
1246 | * intended recipients. We need to do this before updating | |
1247 | * w_remote_GP.get so that we don't allocate the same message | |
1248 | * queue entries prematurely (see xpc_allocate_msg()). | |
1249 | */ | |
1250 | if (atomic_read(&ch->n_to_notify) > 0) { | |
1251 | /* | |
1252 | * Notify senders that messages sent have been | |
1253 | * received and delivered by the other side. | |
1254 | */ | |
1255 | xpc_notify_senders(ch, xpcMsgDelivered, | |
1256 | ch->remote_GP.get); | |
1257 | } | |
1258 | ||
1259 | /* | |
1260 | * Clear msg->flags in previously sent messages, so that | |
1261 | * they're ready for xpc_allocate_msg(). | |
1262 | */ | |
1263 | xpc_clear_local_msgqueue_flags(ch); | |
1264 | ||
821fe947 | 1265 | ch->w_remote_GP.get = ch->remote_GP.get; |
89eb8eb9 DN |
1266 | |
1267 | dev_dbg(xpc_chan, "w_remote_GP.get changed to %ld, partid=%d, " | |
1268 | "channel=%d\n", ch->w_remote_GP.get, ch->partid, | |
1269 | ch->number); | |
1270 | ||
1271 | /* | |
1272 | * If anyone was waiting for message queue entries to become | |
1273 | * available, wake them up. | |
1274 | */ | |
1275 | if (atomic_read(&ch->n_on_msg_allocate_wq) > 0) { | |
1276 | wake_up(&ch->msg_allocate_wq); | |
1277 | } | |
1278 | } | |
1279 | ||
1280 | ||
1281 | /* | |
1282 | * Now check for newly sent messages by the other side. (The remote | |
1283 | * PUT value will have changed since we last looked at it.) | |
1284 | */ | |
1285 | ||
1286 | if (ch->w_remote_GP.put != ch->remote_GP.put) { | |
1287 | /* | |
1288 | * Clear msg->flags in previously received messages, so that | |
1289 | * they're ready for xpc_get_deliverable_msg(). | |
1290 | */ | |
1291 | xpc_clear_remote_msgqueue_flags(ch); | |
1292 | ||
821fe947 | 1293 | ch->w_remote_GP.put = ch->remote_GP.put; |
89eb8eb9 DN |
1294 | |
1295 | dev_dbg(xpc_chan, "w_remote_GP.put changed to %ld, partid=%d, " | |
1296 | "channel=%d\n", ch->w_remote_GP.put, ch->partid, | |
1297 | ch->number); | |
1298 | ||
1299 | nmsgs_sent = ch->w_remote_GP.put - ch->w_local_GP.get; | |
1300 | if (nmsgs_sent > 0) { | |
1301 | dev_dbg(xpc_chan, "msgs waiting to be copied and " | |
1302 | "delivered=%d, partid=%d, channel=%d\n", | |
1303 | nmsgs_sent, ch->partid, ch->number); | |
1304 | ||
4c2cd966 | 1305 | if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) { |
89eb8eb9 DN |
1306 | xpc_activate_kthreads(ch, nmsgs_sent); |
1307 | } | |
1308 | } | |
1309 | } | |
1310 | ||
1311 | xpc_msgqueue_deref(ch); | |
1312 | } | |
1313 | ||
1314 | ||
1315 | void | |
1316 | xpc_process_channel_activity(struct xpc_partition *part) | |
1317 | { | |
1318 | unsigned long irq_flags; | |
1319 | u64 IPI_amo, IPI_flags; | |
1320 | struct xpc_channel *ch; | |
1321 | int ch_number; | |
a607c389 | 1322 | u32 ch_flags; |
89eb8eb9 DN |
1323 | |
1324 | ||
1325 | IPI_amo = xpc_get_IPI_flags(part); | |
1326 | ||
1327 | /* | |
1328 | * Initiate channel connections for registered channels. | |
1329 | * | |
1330 | * For each connected channel that has pending messages activate idle | |
1331 | * kthreads and/or create new kthreads as needed. | |
1332 | */ | |
1333 | ||
1334 | for (ch_number = 0; ch_number < part->nchannels; ch_number++) { | |
1335 | ch = &part->channels[ch_number]; | |
1336 | ||
1337 | ||
1338 | /* | |
1339 | * Process any open or close related IPI flags, and then deal | |
1340 | * with connecting or disconnecting the channel as required. | |
1341 | */ | |
1342 | ||
1343 | IPI_flags = XPC_GET_IPI_FLAGS(IPI_amo, ch_number); | |
1344 | ||
1345 | if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_flags)) { | |
1346 | xpc_process_openclose_IPI(part, ch_number, IPI_flags); | |
1347 | } | |
1348 | ||
a607c389 | 1349 | ch_flags = ch->flags; /* need an atomic snapshot of flags */ |
89eb8eb9 | 1350 | |
a607c389 | 1351 | if (ch_flags & XPC_C_DISCONNECTING) { |
89eb8eb9 DN |
1352 | spin_lock_irqsave(&ch->lock, irq_flags); |
1353 | xpc_process_disconnect(ch, &irq_flags); | |
1354 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1355 | continue; | |
1356 | } | |
1357 | ||
1358 | if (part->act_state == XPC_P_DEACTIVATING) { | |
1359 | continue; | |
1360 | } | |
1361 | ||
a607c389 DN |
1362 | if (!(ch_flags & XPC_C_CONNECTED)) { |
1363 | if (!(ch_flags & XPC_C_OPENREQUEST)) { | |
1364 | DBUG_ON(ch_flags & XPC_C_SETUP); | |
89eb8eb9 DN |
1365 | (void) xpc_connect_channel(ch); |
1366 | } else { | |
1367 | spin_lock_irqsave(&ch->lock, irq_flags); | |
1368 | xpc_process_connect(ch, &irq_flags); | |
1369 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1370 | } | |
1371 | continue; | |
1372 | } | |
1373 | ||
1374 | ||
1375 | /* | |
1376 | * Process any message related IPI flags, this may involve the | |
1377 | * activation of kthreads to deliver any pending messages sent | |
1378 | * from the other partition. | |
1379 | */ | |
1380 | ||
1381 | if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_flags)) { | |
1382 | xpc_process_msg_IPI(part, ch_number); | |
1383 | } | |
1384 | } | |
1385 | } | |
1386 | ||
1387 | ||
1388 | /* | |
a607c389 DN |
1389 | * XPC's heartbeat code calls this function to inform XPC that a partition is |
1390 | * going down. XPC responds by tearing down the XPartition Communication | |
89eb8eb9 DN |
1391 | * infrastructure used for the just downed partition. |
1392 | * | |
1393 | * XPC's heartbeat code will never call this function and xpc_partition_up() | |
1394 | * at the same time. Nor will it ever make multiple calls to either function | |
1395 | * at the same time. | |
1396 | */ | |
1397 | void | |
a607c389 | 1398 | xpc_partition_going_down(struct xpc_partition *part, enum xpc_retval reason) |
89eb8eb9 DN |
1399 | { |
1400 | unsigned long irq_flags; | |
1401 | int ch_number; | |
1402 | struct xpc_channel *ch; | |
1403 | ||
1404 | ||
1405 | dev_dbg(xpc_chan, "deactivating partition %d, reason=%d\n", | |
1406 | XPC_PARTID(part), reason); | |
1407 | ||
1408 | if (!xpc_part_ref(part)) { | |
1409 | /* infrastructure for this partition isn't currently set up */ | |
1410 | return; | |
1411 | } | |
1412 | ||
1413 | ||
a607c389 | 1414 | /* disconnect channels associated with the partition going down */ |
89eb8eb9 DN |
1415 | |
1416 | for (ch_number = 0; ch_number < part->nchannels; ch_number++) { | |
1417 | ch = &part->channels[ch_number]; | |
1418 | ||
89eb8eb9 DN |
1419 | xpc_msgqueue_ref(ch); |
1420 | spin_lock_irqsave(&ch->lock, irq_flags); | |
1421 | ||
1422 | XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags); | |
1423 | ||
1424 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1425 | xpc_msgqueue_deref(ch); | |
1426 | } | |
1427 | ||
1428 | xpc_wakeup_channel_mgr(part); | |
1429 | ||
1430 | xpc_part_deref(part); | |
1431 | } | |
1432 | ||
1433 | ||
1434 | /* | |
1435 | * Teardown the infrastructure necessary to support XPartition Communication | |
1436 | * between the specified remote partition and the local one. | |
1437 | */ | |
1438 | void | |
1439 | xpc_teardown_infrastructure(struct xpc_partition *part) | |
1440 | { | |
1441 | partid_t partid = XPC_PARTID(part); | |
1442 | ||
1443 | ||
1444 | /* | |
1445 | * We start off by making this partition inaccessible to local | |
1446 | * processes by marking it as no longer setup. Then we make it | |
1447 | * inaccessible to remote processes by clearing the XPC per partition | |
1448 | * specific variable's magic # (which indicates that these variables | |
1449 | * are no longer valid) and by ignoring all XPC notify IPIs sent to | |
1450 | * this partition. | |
1451 | */ | |
1452 | ||
a607c389 | 1453 | DBUG_ON(atomic_read(&part->nchannels_engaged) != 0); |
89eb8eb9 DN |
1454 | DBUG_ON(atomic_read(&part->nchannels_active) != 0); |
1455 | DBUG_ON(part->setup_state != XPC_P_SETUP); | |
1456 | part->setup_state = XPC_P_WTEARDOWN; | |
1457 | ||
1458 | xpc_vars_part[partid].magic = 0; | |
1459 | ||
1460 | ||
1461 | free_irq(SGI_XPC_NOTIFY, (void *) (u64) partid); | |
1462 | ||
1463 | ||
1464 | /* | |
1465 | * Before proceding with the teardown we have to wait until all | |
1466 | * existing references cease. | |
1467 | */ | |
1468 | wait_event(part->teardown_wq, (atomic_read(&part->references) == 0)); | |
1469 | ||
1470 | ||
1471 | /* now we can begin tearing down the infrastructure */ | |
1472 | ||
1473 | part->setup_state = XPC_P_TORNDOWN; | |
1474 | ||
1475 | /* in case we've still got outstanding timers registered... */ | |
1476 | del_timer_sync(&part->dropped_IPI_timer); | |
1477 | ||
1478 | kfree(part->remote_openclose_args_base); | |
1479 | part->remote_openclose_args = NULL; | |
1480 | kfree(part->local_openclose_args_base); | |
1481 | part->local_openclose_args = NULL; | |
1482 | kfree(part->remote_GPs_base); | |
1483 | part->remote_GPs = NULL; | |
1484 | kfree(part->local_GPs_base); | |
1485 | part->local_GPs = NULL; | |
1486 | kfree(part->channels); | |
1487 | part->channels = NULL; | |
1488 | part->local_IPI_amo_va = NULL; | |
1489 | } | |
1490 | ||
1491 | ||
1492 | /* | |
1493 | * Called by XP at the time of channel connection registration to cause | |
1494 | * XPC to establish connections to all currently active partitions. | |
1495 | */ | |
1496 | void | |
1497 | xpc_initiate_connect(int ch_number) | |
1498 | { | |
1499 | partid_t partid; | |
1500 | struct xpc_partition *part; | |
1501 | struct xpc_channel *ch; | |
1502 | ||
1503 | ||
1504 | DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS); | |
1505 | ||
1506 | for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) { | |
1507 | part = &xpc_partitions[partid]; | |
1508 | ||
1509 | if (xpc_part_ref(part)) { | |
1510 | ch = &part->channels[ch_number]; | |
1511 | ||
e54af724 DN |
1512 | /* |
1513 | * Initiate the establishment of a connection on the | |
1514 | * newly registered channel to the remote partition. | |
1515 | */ | |
1516 | xpc_wakeup_channel_mgr(part); | |
89eb8eb9 DN |
1517 | xpc_part_deref(part); |
1518 | } | |
1519 | } | |
1520 | } | |
1521 | ||
1522 | ||
1523 | void | |
1524 | xpc_connected_callout(struct xpc_channel *ch) | |
1525 | { | |
89eb8eb9 DN |
1526 | /* let the registerer know that a connection has been established */ |
1527 | ||
1528 | if (ch->func != NULL) { | |
1529 | dev_dbg(xpc_chan, "ch->func() called, reason=xpcConnected, " | |
1530 | "partid=%d, channel=%d\n", ch->partid, ch->number); | |
1531 | ||
1532 | ch->func(xpcConnected, ch->partid, ch->number, | |
1533 | (void *) (u64) ch->local_nentries, ch->key); | |
1534 | ||
1535 | dev_dbg(xpc_chan, "ch->func() returned, reason=xpcConnected, " | |
1536 | "partid=%d, channel=%d\n", ch->partid, ch->number); | |
1537 | } | |
89eb8eb9 DN |
1538 | } |
1539 | ||
1540 | ||
1541 | /* | |
1542 | * Called by XP at the time of channel connection unregistration to cause | |
1543 | * XPC to teardown all current connections for the specified channel. | |
1544 | * | |
1545 | * Before returning xpc_initiate_disconnect() will wait until all connections | |
1546 | * on the specified channel have been closed/torndown. So the caller can be | |
1547 | * assured that they will not be receiving any more callouts from XPC to the | |
1548 | * function they registered via xpc_connect(). | |
1549 | * | |
1550 | * Arguments: | |
1551 | * | |
1552 | * ch_number - channel # to unregister. | |
1553 | */ | |
1554 | void | |
1555 | xpc_initiate_disconnect(int ch_number) | |
1556 | { | |
1557 | unsigned long irq_flags; | |
1558 | partid_t partid; | |
1559 | struct xpc_partition *part; | |
1560 | struct xpc_channel *ch; | |
1561 | ||
1562 | ||
1563 | DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS); | |
1564 | ||
1565 | /* initiate the channel disconnect for every active partition */ | |
1566 | for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) { | |
1567 | part = &xpc_partitions[partid]; | |
1568 | ||
1569 | if (xpc_part_ref(part)) { | |
1570 | ch = &part->channels[ch_number]; | |
1571 | xpc_msgqueue_ref(ch); | |
1572 | ||
1573 | spin_lock_irqsave(&ch->lock, irq_flags); | |
1574 | ||
a607c389 DN |
1575 | if (!(ch->flags & XPC_C_DISCONNECTED)) { |
1576 | ch->flags |= XPC_C_WDISCONNECT; | |
1577 | ||
1578 | XPC_DISCONNECT_CHANNEL(ch, xpcUnregistering, | |
89eb8eb9 | 1579 | &irq_flags); |
a607c389 | 1580 | } |
89eb8eb9 DN |
1581 | |
1582 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1583 | ||
1584 | xpc_msgqueue_deref(ch); | |
1585 | xpc_part_deref(part); | |
1586 | } | |
1587 | } | |
1588 | ||
1589 | xpc_disconnect_wait(ch_number); | |
1590 | } | |
1591 | ||
1592 | ||
1593 | /* | |
1594 | * To disconnect a channel, and reflect it back to all who may be waiting. | |
1595 | * | |
a607c389 DN |
1596 | * An OPEN is not allowed until XPC_C_DISCONNECTING is cleared by |
1597 | * xpc_process_disconnect(), and if set, XPC_C_WDISCONNECT is cleared by | |
1598 | * xpc_disconnect_wait(). | |
89eb8eb9 DN |
1599 | * |
1600 | * THE CHANNEL IS TO BE LOCKED BY THE CALLER AND WILL REMAIN LOCKED UPON RETURN. | |
1601 | */ | |
1602 | void | |
1603 | xpc_disconnect_channel(const int line, struct xpc_channel *ch, | |
1604 | enum xpc_retval reason, unsigned long *irq_flags) | |
1605 | { | |
a607c389 | 1606 | u32 channel_was_connected = (ch->flags & XPC_C_CONNECTED); |
89eb8eb9 DN |
1607 | |
1608 | ||
1609 | DBUG_ON(!spin_is_locked(&ch->lock)); | |
1610 | ||
1611 | if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) { | |
1612 | return; | |
1613 | } | |
1614 | DBUG_ON(!(ch->flags & (XPC_C_CONNECTING | XPC_C_CONNECTED))); | |
1615 | ||
1616 | dev_dbg(xpc_chan, "reason=%d, line=%d, partid=%d, channel=%d\n", | |
1617 | reason, line, ch->partid, ch->number); | |
1618 | ||
1619 | XPC_SET_REASON(ch, reason, line); | |
1620 | ||
a607c389 | 1621 | ch->flags |= (XPC_C_CLOSEREQUEST | XPC_C_DISCONNECTING); |
89eb8eb9 DN |
1622 | /* some of these may not have been set */ |
1623 | ch->flags &= ~(XPC_C_OPENREQUEST | XPC_C_OPENREPLY | | |
1624 | XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY | | |
1625 | XPC_C_CONNECTING | XPC_C_CONNECTED); | |
1626 | ||
89eb8eb9 DN |
1627 | xpc_IPI_send_closerequest(ch, irq_flags); |
1628 | ||
a607c389 | 1629 | if (channel_was_connected) { |
89eb8eb9 DN |
1630 | ch->flags |= XPC_C_WASCONNECTED; |
1631 | } | |
1632 | ||
a607c389 DN |
1633 | spin_unlock_irqrestore(&ch->lock, *irq_flags); |
1634 | ||
1635 | /* wake all idle kthreads so they can exit */ | |
89eb8eb9 | 1636 | if (atomic_read(&ch->kthreads_idle) > 0) { |
89eb8eb9 DN |
1637 | wake_up_all(&ch->idle_wq); |
1638 | } | |
1639 | ||
89eb8eb9 | 1640 | /* wake those waiting to allocate an entry from the local msg queue */ |
89eb8eb9 DN |
1641 | if (atomic_read(&ch->n_on_msg_allocate_wq) > 0) { |
1642 | wake_up(&ch->msg_allocate_wq); | |
1643 | } | |
1644 | ||
89eb8eb9 DN |
1645 | spin_lock_irqsave(&ch->lock, *irq_flags); |
1646 | } | |
1647 | ||
1648 | ||
1649 | void | |
246c7e33 | 1650 | xpc_disconnect_callout(struct xpc_channel *ch, enum xpc_retval reason) |
89eb8eb9 DN |
1651 | { |
1652 | /* | |
a607c389 | 1653 | * Let the channel's registerer know that the channel is being |
89eb8eb9 | 1654 | * disconnected. We don't want to do this if the registerer was never |
a607c389 | 1655 | * informed of a connection being made. |
89eb8eb9 DN |
1656 | */ |
1657 | ||
1658 | if (ch->func != NULL) { | |
246c7e33 DN |
1659 | dev_dbg(xpc_chan, "ch->func() called, reason=%d, partid=%d, " |
1660 | "channel=%d\n", reason, ch->partid, ch->number); | |
89eb8eb9 | 1661 | |
246c7e33 | 1662 | ch->func(reason, ch->partid, ch->number, NULL, ch->key); |
89eb8eb9 | 1663 | |
246c7e33 DN |
1664 | dev_dbg(xpc_chan, "ch->func() returned, reason=%d, partid=%d, " |
1665 | "channel=%d\n", reason, 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 | ||
f9e505a9 | 2088 | if (mutex_lock_interruptible(&ch->msg_to_pull_mutex) != 0) { |
89eb8eb9 DN |
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 | ||
f9e505a9 | 2124 | mutex_unlock(&ch->msg_to_pull_mutex); |
89eb8eb9 DN |
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 | ||
f9e505a9 | 2133 | mutex_unlock(&ch->msg_to_pull_mutex); |
89eb8eb9 DN |
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 |