Commit | Line | Data |
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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> | |
f9e505a9 JS |
24 | #include <linux/mutex.h> |
25 | #include <linux/completion.h> | |
89eb8eb9 DN |
26 | #include <asm/sn/bte.h> |
27 | #include <asm/sn/sn_sal.h> | |
9335d48e | 28 | #include <asm/sn/xpc.h> |
89eb8eb9 DN |
29 | |
30 | ||
7aa6ba41 JS |
31 | /* |
32 | * Guarantee that the kzalloc'd memory is cacheline aligned. | |
33 | */ | |
34 | static void * | |
35 | xpc_kzalloc_cacheline_aligned(size_t size, gfp_t flags, void **base) | |
36 | { | |
37 | /* see if kzalloc will give us cachline aligned memory by default */ | |
38 | *base = kzalloc(size, flags); | |
39 | if (*base == NULL) { | |
40 | return NULL; | |
41 | } | |
42 | if ((u64) *base == L1_CACHE_ALIGN((u64) *base)) { | |
43 | return *base; | |
44 | } | |
45 | kfree(*base); | |
46 | ||
47 | /* nope, we'll have to do it ourselves */ | |
48 | *base = kzalloc(size + L1_CACHE_BYTES, flags); | |
49 | if (*base == NULL) { | |
50 | return NULL; | |
51 | } | |
52 | return (void *) L1_CACHE_ALIGN((u64) *base); | |
53 | } | |
54 | ||
55 | ||
89eb8eb9 DN |
56 | /* |
57 | * Set up the initial values for the XPartition Communication channels. | |
58 | */ | |
59 | static void | |
60 | xpc_initialize_channels(struct xpc_partition *part, partid_t partid) | |
61 | { | |
62 | int ch_number; | |
63 | struct xpc_channel *ch; | |
64 | ||
65 | ||
66 | for (ch_number = 0; ch_number < part->nchannels; ch_number++) { | |
67 | ch = &part->channels[ch_number]; | |
68 | ||
69 | ch->partid = partid; | |
70 | ch->number = ch_number; | |
71 | ch->flags = XPC_C_DISCONNECTED; | |
72 | ||
73 | ch->local_GP = &part->local_GPs[ch_number]; | |
74 | ch->local_openclose_args = | |
75 | &part->local_openclose_args[ch_number]; | |
76 | ||
77 | atomic_set(&ch->kthreads_assigned, 0); | |
78 | atomic_set(&ch->kthreads_idle, 0); | |
79 | atomic_set(&ch->kthreads_active, 0); | |
80 | ||
81 | atomic_set(&ch->references, 0); | |
82 | atomic_set(&ch->n_to_notify, 0); | |
83 | ||
84 | spin_lock_init(&ch->lock); | |
f9e505a9 JS |
85 | mutex_init(&ch->msg_to_pull_mutex); |
86 | init_completion(&ch->wdisconnect_wait); | |
89eb8eb9 DN |
87 | |
88 | atomic_set(&ch->n_on_msg_allocate_wq, 0); | |
89 | init_waitqueue_head(&ch->msg_allocate_wq); | |
90 | init_waitqueue_head(&ch->idle_wq); | |
91 | } | |
92 | } | |
93 | ||
94 | ||
95 | /* | |
96 | * Setup the infrastructure necessary to support XPartition Communication | |
97 | * between the specified remote partition and the local one. | |
98 | */ | |
99 | enum xpc_retval | |
100 | xpc_setup_infrastructure(struct xpc_partition *part) | |
101 | { | |
59a0a8aa | 102 | int ret, cpuid; |
89eb8eb9 DN |
103 | struct timer_list *timer; |
104 | partid_t partid = XPC_PARTID(part); | |
105 | ||
106 | ||
107 | /* | |
108 | * Zero out MOST of the entry for this partition. Only the fields | |
109 | * starting with `nchannels' will be zeroed. The preceding fields must | |
110 | * remain `viable' across partition ups and downs, since they may be | |
111 | * referenced during this memset() operation. | |
112 | */ | |
113 | memset(&part->nchannels, 0, sizeof(struct xpc_partition) - | |
114 | offsetof(struct xpc_partition, nchannels)); | |
115 | ||
116 | /* | |
117 | * Allocate all of the channel structures as a contiguous chunk of | |
118 | * memory. | |
119 | */ | |
7aa6ba41 | 120 | part->channels = kzalloc(sizeof(struct xpc_channel) * XPC_NCHANNELS, |
89eb8eb9 DN |
121 | GFP_KERNEL); |
122 | if (part->channels == NULL) { | |
123 | dev_err(xpc_chan, "can't get memory for channels\n"); | |
124 | return xpcNoMemory; | |
125 | } | |
89eb8eb9 DN |
126 | |
127 | part->nchannels = XPC_NCHANNELS; | |
128 | ||
129 | ||
130 | /* allocate all the required GET/PUT values */ | |
131 | ||
7aa6ba41 | 132 | part->local_GPs = xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE, |
89eb8eb9 DN |
133 | GFP_KERNEL, &part->local_GPs_base); |
134 | if (part->local_GPs == NULL) { | |
135 | kfree(part->channels); | |
136 | part->channels = NULL; | |
137 | dev_err(xpc_chan, "can't get memory for local get/put " | |
138 | "values\n"); | |
139 | return xpcNoMemory; | |
140 | } | |
89eb8eb9 | 141 | |
7aa6ba41 | 142 | part->remote_GPs = xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE, |
89eb8eb9 DN |
143 | GFP_KERNEL, &part->remote_GPs_base); |
144 | if (part->remote_GPs == NULL) { | |
89eb8eb9 DN |
145 | dev_err(xpc_chan, "can't get memory for remote get/put " |
146 | "values\n"); | |
7aa6ba41 JS |
147 | kfree(part->local_GPs_base); |
148 | part->local_GPs = NULL; | |
149 | kfree(part->channels); | |
150 | part->channels = NULL; | |
89eb8eb9 DN |
151 | return xpcNoMemory; |
152 | } | |
89eb8eb9 DN |
153 | |
154 | ||
155 | /* allocate all the required open and close args */ | |
156 | ||
7aa6ba41 | 157 | part->local_openclose_args = xpc_kzalloc_cacheline_aligned( |
89eb8eb9 DN |
158 | XPC_OPENCLOSE_ARGS_SIZE, GFP_KERNEL, |
159 | &part->local_openclose_args_base); | |
160 | if (part->local_openclose_args == NULL) { | |
7aa6ba41 | 161 | dev_err(xpc_chan, "can't get memory for local connect args\n"); |
89eb8eb9 DN |
162 | kfree(part->remote_GPs_base); |
163 | part->remote_GPs = NULL; | |
7aa6ba41 JS |
164 | kfree(part->local_GPs_base); |
165 | part->local_GPs = NULL; | |
166 | kfree(part->channels); | |
167 | part->channels = NULL; | |
89eb8eb9 DN |
168 | return xpcNoMemory; |
169 | } | |
89eb8eb9 | 170 | |
7aa6ba41 | 171 | part->remote_openclose_args = xpc_kzalloc_cacheline_aligned( |
89eb8eb9 DN |
172 | XPC_OPENCLOSE_ARGS_SIZE, GFP_KERNEL, |
173 | &part->remote_openclose_args_base); | |
174 | if (part->remote_openclose_args == NULL) { | |
7aa6ba41 | 175 | dev_err(xpc_chan, "can't get memory for remote connect args\n"); |
89eb8eb9 DN |
176 | kfree(part->local_openclose_args_base); |
177 | part->local_openclose_args = NULL; | |
7aa6ba41 JS |
178 | kfree(part->remote_GPs_base); |
179 | part->remote_GPs = NULL; | |
180 | kfree(part->local_GPs_base); | |
181 | part->local_GPs = NULL; | |
182 | kfree(part->channels); | |
183 | part->channels = NULL; | |
89eb8eb9 DN |
184 | return xpcNoMemory; |
185 | } | |
89eb8eb9 DN |
186 | |
187 | ||
188 | xpc_initialize_channels(part, partid); | |
189 | ||
190 | atomic_set(&part->nchannels_active, 0); | |
a607c389 | 191 | atomic_set(&part->nchannels_engaged, 0); |
89eb8eb9 DN |
192 | |
193 | ||
194 | /* local_IPI_amo were set to 0 by an earlier memset() */ | |
195 | ||
196 | /* Initialize this partitions AMO_t structure */ | |
197 | part->local_IPI_amo_va = xpc_IPI_init(partid); | |
198 | ||
199 | spin_lock_init(&part->IPI_lock); | |
200 | ||
201 | atomic_set(&part->channel_mgr_requests, 1); | |
202 | init_waitqueue_head(&part->channel_mgr_wq); | |
203 | ||
204 | sprintf(part->IPI_owner, "xpc%02d", partid); | |
121a4226 | 205 | ret = request_irq(SGI_XPC_NOTIFY, xpc_notify_IRQ_handler, IRQF_SHARED, |
89eb8eb9 DN |
206 | part->IPI_owner, (void *) (u64) partid); |
207 | if (ret != 0) { | |
89eb8eb9 DN |
208 | dev_err(xpc_chan, "can't register NOTIFY IRQ handler, " |
209 | "errno=%d\n", -ret); | |
7aa6ba41 JS |
210 | kfree(part->remote_openclose_args_base); |
211 | part->remote_openclose_args = NULL; | |
212 | kfree(part->local_openclose_args_base); | |
213 | part->local_openclose_args = NULL; | |
214 | kfree(part->remote_GPs_base); | |
215 | part->remote_GPs = NULL; | |
216 | kfree(part->local_GPs_base); | |
217 | part->local_GPs = NULL; | |
218 | kfree(part->channels); | |
219 | part->channels = NULL; | |
89eb8eb9 DN |
220 | return xpcLackOfResources; |
221 | } | |
222 | ||
223 | /* Setup a timer to check for dropped IPIs */ | |
224 | timer = &part->dropped_IPI_timer; | |
225 | init_timer(timer); | |
226 | timer->function = (void (*)(unsigned long)) xpc_dropped_IPI_check; | |
227 | timer->data = (unsigned long) part; | |
228 | timer->expires = jiffies + XPC_P_DROPPED_IPI_WAIT; | |
229 | add_timer(timer); | |
230 | ||
231 | /* | |
232 | * With the setting of the partition setup_state to XPC_P_SETUP, we're | |
233 | * declaring that this partition is ready to go. | |
234 | */ | |
821fe947 | 235 | part->setup_state = XPC_P_SETUP; |
89eb8eb9 DN |
236 | |
237 | ||
238 | /* | |
239 | * Setup the per partition specific variables required by the | |
240 | * remote partition to establish channel connections with us. | |
241 | * | |
242 | * The setting of the magic # indicates that these per partition | |
243 | * specific variables are ready to be used. | |
244 | */ | |
245 | xpc_vars_part[partid].GPs_pa = __pa(part->local_GPs); | |
246 | xpc_vars_part[partid].openclose_args_pa = | |
247 | __pa(part->local_openclose_args); | |
248 | xpc_vars_part[partid].IPI_amo_pa = __pa(part->local_IPI_amo_va); | |
59a0a8aa DN |
249 | cpuid = raw_smp_processor_id(); /* any CPU in this partition will do */ |
250 | xpc_vars_part[partid].IPI_nasid = cpuid_to_nasid(cpuid); | |
251 | xpc_vars_part[partid].IPI_phys_cpuid = cpu_physical_id(cpuid); | |
89eb8eb9 | 252 | xpc_vars_part[partid].nchannels = part->nchannels; |
821fe947 | 253 | xpc_vars_part[partid].magic = XPC_VP_MAGIC1; |
89eb8eb9 DN |
254 | |
255 | return xpcSuccess; | |
256 | } | |
257 | ||
258 | ||
259 | /* | |
260 | * Create a wrapper that hides the underlying mechanism for pulling a cacheline | |
261 | * (or multiple cachelines) from a remote partition. | |
262 | * | |
263 | * src must be a cacheline aligned physical address on the remote partition. | |
264 | * dst must be a cacheline aligned virtual address on this partition. | |
265 | * cnt must be an cacheline sized | |
266 | */ | |
267 | static enum xpc_retval | |
268 | xpc_pull_remote_cachelines(struct xpc_partition *part, void *dst, | |
269 | const void *src, size_t cnt) | |
270 | { | |
271 | bte_result_t bte_ret; | |
272 | ||
273 | ||
274 | DBUG_ON((u64) src != L1_CACHE_ALIGN((u64) src)); | |
275 | DBUG_ON((u64) dst != L1_CACHE_ALIGN((u64) dst)); | |
276 | DBUG_ON(cnt != L1_CACHE_ALIGN(cnt)); | |
277 | ||
278 | if (part->act_state == XPC_P_DEACTIVATING) { | |
279 | return part->reason; | |
280 | } | |
281 | ||
7682a4c6 DN |
282 | bte_ret = xp_bte_copy((u64) src, (u64) dst, (u64) cnt, |
283 | (BTE_NORMAL | BTE_WACQUIRE), NULL); | |
89eb8eb9 DN |
284 | if (bte_ret == BTE_SUCCESS) { |
285 | return xpcSuccess; | |
286 | } | |
287 | ||
288 | dev_dbg(xpc_chan, "xp_bte_copy() from partition %d failed, ret=%d\n", | |
289 | XPC_PARTID(part), bte_ret); | |
290 | ||
291 | return xpc_map_bte_errors(bte_ret); | |
292 | } | |
293 | ||
294 | ||
295 | /* | |
72fdbdce | 296 | * Pull the remote per partition specific variables from the specified |
89eb8eb9 DN |
297 | * partition. |
298 | */ | |
299 | enum xpc_retval | |
300 | xpc_pull_remote_vars_part(struct xpc_partition *part) | |
301 | { | |
302 | u8 buffer[L1_CACHE_BYTES * 2]; | |
303 | struct xpc_vars_part *pulled_entry_cacheline = | |
304 | (struct xpc_vars_part *) L1_CACHE_ALIGN((u64) buffer); | |
305 | struct xpc_vars_part *pulled_entry; | |
306 | u64 remote_entry_cacheline_pa, remote_entry_pa; | |
307 | partid_t partid = XPC_PARTID(part); | |
308 | enum xpc_retval ret; | |
309 | ||
310 | ||
311 | /* pull the cacheline that contains the variables we're interested in */ | |
312 | ||
313 | DBUG_ON(part->remote_vars_part_pa != | |
314 | L1_CACHE_ALIGN(part->remote_vars_part_pa)); | |
315 | DBUG_ON(sizeof(struct xpc_vars_part) != L1_CACHE_BYTES / 2); | |
316 | ||
317 | remote_entry_pa = part->remote_vars_part_pa + | |
318 | sn_partition_id * sizeof(struct xpc_vars_part); | |
319 | ||
320 | remote_entry_cacheline_pa = (remote_entry_pa & ~(L1_CACHE_BYTES - 1)); | |
321 | ||
322 | pulled_entry = (struct xpc_vars_part *) ((u64) pulled_entry_cacheline + | |
323 | (remote_entry_pa & (L1_CACHE_BYTES - 1))); | |
324 | ||
325 | ret = xpc_pull_remote_cachelines(part, pulled_entry_cacheline, | |
326 | (void *) remote_entry_cacheline_pa, | |
327 | L1_CACHE_BYTES); | |
328 | if (ret != xpcSuccess) { | |
329 | dev_dbg(xpc_chan, "failed to pull XPC vars_part from " | |
330 | "partition %d, ret=%d\n", partid, ret); | |
331 | return ret; | |
332 | } | |
333 | ||
334 | ||
335 | /* see if they've been set up yet */ | |
336 | ||
337 | if (pulled_entry->magic != XPC_VP_MAGIC1 && | |
338 | pulled_entry->magic != XPC_VP_MAGIC2) { | |
339 | ||
340 | if (pulled_entry->magic != 0) { | |
341 | dev_dbg(xpc_chan, "partition %d's XPC vars_part for " | |
342 | "partition %d has bad magic value (=0x%lx)\n", | |
343 | partid, sn_partition_id, pulled_entry->magic); | |
344 | return xpcBadMagic; | |
345 | } | |
346 | ||
347 | /* they've not been initialized yet */ | |
348 | return xpcRetry; | |
349 | } | |
350 | ||
351 | if (xpc_vars_part[partid].magic == XPC_VP_MAGIC1) { | |
352 | ||
353 | /* validate the variables */ | |
354 | ||
355 | if (pulled_entry->GPs_pa == 0 || | |
356 | pulled_entry->openclose_args_pa == 0 || | |
357 | pulled_entry->IPI_amo_pa == 0) { | |
358 | ||
359 | dev_err(xpc_chan, "partition %d's XPC vars_part for " | |
360 | "partition %d are not valid\n", partid, | |
361 | sn_partition_id); | |
362 | return xpcInvalidAddress; | |
363 | } | |
364 | ||
365 | /* the variables we imported look to be valid */ | |
366 | ||
367 | part->remote_GPs_pa = pulled_entry->GPs_pa; | |
368 | part->remote_openclose_args_pa = | |
369 | pulled_entry->openclose_args_pa; | |
370 | part->remote_IPI_amo_va = | |
371 | (AMO_t *) __va(pulled_entry->IPI_amo_pa); | |
372 | part->remote_IPI_nasid = pulled_entry->IPI_nasid; | |
373 | part->remote_IPI_phys_cpuid = pulled_entry->IPI_phys_cpuid; | |
374 | ||
375 | if (part->nchannels > pulled_entry->nchannels) { | |
376 | part->nchannels = pulled_entry->nchannels; | |
377 | } | |
378 | ||
379 | /* let the other side know that we've pulled their variables */ | |
380 | ||
821fe947 | 381 | xpc_vars_part[partid].magic = XPC_VP_MAGIC2; |
89eb8eb9 DN |
382 | } |
383 | ||
384 | if (pulled_entry->magic == XPC_VP_MAGIC1) { | |
385 | return xpcRetry; | |
386 | } | |
387 | ||
388 | return xpcSuccess; | |
389 | } | |
390 | ||
391 | ||
392 | /* | |
393 | * Get the IPI flags and pull the openclose args and/or remote GPs as needed. | |
394 | */ | |
395 | static u64 | |
396 | xpc_get_IPI_flags(struct xpc_partition *part) | |
397 | { | |
398 | unsigned long irq_flags; | |
399 | u64 IPI_amo; | |
400 | enum xpc_retval ret; | |
401 | ||
402 | ||
403 | /* | |
404 | * See if there are any IPI flags to be handled. | |
405 | */ | |
406 | ||
407 | spin_lock_irqsave(&part->IPI_lock, irq_flags); | |
408 | if ((IPI_amo = part->local_IPI_amo) != 0) { | |
409 | part->local_IPI_amo = 0; | |
410 | } | |
411 | spin_unlock_irqrestore(&part->IPI_lock, irq_flags); | |
412 | ||
413 | ||
414 | if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_amo)) { | |
415 | ret = xpc_pull_remote_cachelines(part, | |
416 | part->remote_openclose_args, | |
417 | (void *) part->remote_openclose_args_pa, | |
418 | XPC_OPENCLOSE_ARGS_SIZE); | |
419 | if (ret != xpcSuccess) { | |
420 | XPC_DEACTIVATE_PARTITION(part, ret); | |
421 | ||
422 | dev_dbg(xpc_chan, "failed to pull openclose args from " | |
423 | "partition %d, ret=%d\n", XPC_PARTID(part), | |
424 | ret); | |
425 | ||
426 | /* don't bother processing IPIs anymore */ | |
427 | IPI_amo = 0; | |
428 | } | |
429 | } | |
430 | ||
431 | if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_amo)) { | |
432 | ret = xpc_pull_remote_cachelines(part, part->remote_GPs, | |
433 | (void *) part->remote_GPs_pa, | |
434 | XPC_GP_SIZE); | |
435 | if (ret != xpcSuccess) { | |
436 | XPC_DEACTIVATE_PARTITION(part, ret); | |
437 | ||
438 | dev_dbg(xpc_chan, "failed to pull GPs from partition " | |
439 | "%d, ret=%d\n", XPC_PARTID(part), ret); | |
440 | ||
441 | /* don't bother processing IPIs anymore */ | |
442 | IPI_amo = 0; | |
443 | } | |
444 | } | |
445 | ||
446 | return IPI_amo; | |
447 | } | |
448 | ||
449 | ||
450 | /* | |
451 | * Allocate the local message queue and the notify queue. | |
452 | */ | |
453 | static enum xpc_retval | |
454 | xpc_allocate_local_msgqueue(struct xpc_channel *ch) | |
455 | { | |
456 | unsigned long irq_flags; | |
457 | int nentries; | |
458 | size_t nbytes; | |
459 | ||
460 | ||
461 | // >>> may want to check for ch->flags & XPC_C_DISCONNECTING between | |
462 | // >>> iterations of the for-loop, bail if set? | |
463 | ||
72fdbdce | 464 | // >>> should we impose a minimum #of entries? like 4 or 8? |
89eb8eb9 DN |
465 | for (nentries = ch->local_nentries; nentries > 0; nentries--) { |
466 | ||
467 | nbytes = nentries * ch->msg_size; | |
7aa6ba41 | 468 | ch->local_msgqueue = xpc_kzalloc_cacheline_aligned(nbytes, |
139366a0 | 469 | GFP_KERNEL, |
89eb8eb9 DN |
470 | &ch->local_msgqueue_base); |
471 | if (ch->local_msgqueue == NULL) { | |
472 | continue; | |
473 | } | |
89eb8eb9 DN |
474 | |
475 | nbytes = nentries * sizeof(struct xpc_notify); | |
7aa6ba41 | 476 | ch->notify_queue = kzalloc(nbytes, GFP_KERNEL); |
89eb8eb9 DN |
477 | if (ch->notify_queue == NULL) { |
478 | kfree(ch->local_msgqueue_base); | |
479 | ch->local_msgqueue = NULL; | |
480 | continue; | |
481 | } | |
89eb8eb9 DN |
482 | |
483 | spin_lock_irqsave(&ch->lock, irq_flags); | |
484 | if (nentries < ch->local_nentries) { | |
485 | dev_dbg(xpc_chan, "nentries=%d local_nentries=%d, " | |
486 | "partid=%d, channel=%d\n", nentries, | |
487 | ch->local_nentries, ch->partid, ch->number); | |
488 | ||
489 | ch->local_nentries = nentries; | |
490 | } | |
491 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
492 | return xpcSuccess; | |
493 | } | |
494 | ||
495 | dev_dbg(xpc_chan, "can't get memory for local message queue and notify " | |
496 | "queue, partid=%d, channel=%d\n", ch->partid, ch->number); | |
497 | return xpcNoMemory; | |
498 | } | |
499 | ||
500 | ||
501 | /* | |
502 | * Allocate the cached remote message queue. | |
503 | */ | |
504 | static enum xpc_retval | |
505 | xpc_allocate_remote_msgqueue(struct xpc_channel *ch) | |
506 | { | |
507 | unsigned long irq_flags; | |
508 | int nentries; | |
509 | size_t nbytes; | |
510 | ||
511 | ||
512 | DBUG_ON(ch->remote_nentries <= 0); | |
513 | ||
514 | // >>> may want to check for ch->flags & XPC_C_DISCONNECTING between | |
515 | // >>> iterations of the for-loop, bail if set? | |
516 | ||
72fdbdce | 517 | // >>> should we impose a minimum #of entries? like 4 or 8? |
89eb8eb9 DN |
518 | for (nentries = ch->remote_nentries; nentries > 0; nentries--) { |
519 | ||
520 | nbytes = nentries * ch->msg_size; | |
7aa6ba41 | 521 | ch->remote_msgqueue = xpc_kzalloc_cacheline_aligned(nbytes, |
139366a0 | 522 | GFP_KERNEL, |
89eb8eb9 DN |
523 | &ch->remote_msgqueue_base); |
524 | if (ch->remote_msgqueue == NULL) { | |
525 | continue; | |
526 | } | |
89eb8eb9 DN |
527 | |
528 | spin_lock_irqsave(&ch->lock, irq_flags); | |
529 | if (nentries < ch->remote_nentries) { | |
530 | dev_dbg(xpc_chan, "nentries=%d remote_nentries=%d, " | |
531 | "partid=%d, channel=%d\n", nentries, | |
532 | ch->remote_nentries, ch->partid, ch->number); | |
533 | ||
534 | ch->remote_nentries = nentries; | |
535 | } | |
536 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
537 | return xpcSuccess; | |
538 | } | |
539 | ||
540 | dev_dbg(xpc_chan, "can't get memory for cached remote message queue, " | |
541 | "partid=%d, channel=%d\n", ch->partid, ch->number); | |
542 | return xpcNoMemory; | |
543 | } | |
544 | ||
545 | ||
546 | /* | |
547 | * Allocate message queues and other stuff associated with a channel. | |
548 | * | |
549 | * Note: Assumes all of the channel sizes are filled in. | |
550 | */ | |
551 | static enum xpc_retval | |
552 | xpc_allocate_msgqueues(struct xpc_channel *ch) | |
553 | { | |
554 | unsigned long irq_flags; | |
89eb8eb9 DN |
555 | enum xpc_retval ret; |
556 | ||
557 | ||
558 | DBUG_ON(ch->flags & XPC_C_SETUP); | |
559 | ||
560 | if ((ret = xpc_allocate_local_msgqueue(ch)) != xpcSuccess) { | |
561 | return ret; | |
562 | } | |
563 | ||
564 | if ((ret = xpc_allocate_remote_msgqueue(ch)) != xpcSuccess) { | |
565 | kfree(ch->local_msgqueue_base); | |
566 | ch->local_msgqueue = NULL; | |
567 | kfree(ch->notify_queue); | |
568 | ch->notify_queue = NULL; | |
569 | return ret; | |
570 | } | |
571 | ||
89eb8eb9 DN |
572 | spin_lock_irqsave(&ch->lock, irq_flags); |
573 | ch->flags |= XPC_C_SETUP; | |
574 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
575 | ||
576 | return xpcSuccess; | |
577 | } | |
578 | ||
579 | ||
580 | /* | |
581 | * Process a connect message from a remote partition. | |
582 | * | |
583 | * Note: xpc_process_connect() is expecting to be called with the | |
584 | * spin_lock_irqsave held and will leave it locked upon return. | |
585 | */ | |
586 | static void | |
587 | xpc_process_connect(struct xpc_channel *ch, unsigned long *irq_flags) | |
588 | { | |
589 | enum xpc_retval ret; | |
590 | ||
591 | ||
592 | DBUG_ON(!spin_is_locked(&ch->lock)); | |
593 | ||
594 | if (!(ch->flags & XPC_C_OPENREQUEST) || | |
595 | !(ch->flags & XPC_C_ROPENREQUEST)) { | |
596 | /* nothing more to do for now */ | |
597 | return; | |
598 | } | |
599 | DBUG_ON(!(ch->flags & XPC_C_CONNECTING)); | |
600 | ||
601 | if (!(ch->flags & XPC_C_SETUP)) { | |
602 | spin_unlock_irqrestore(&ch->lock, *irq_flags); | |
603 | ret = xpc_allocate_msgqueues(ch); | |
604 | spin_lock_irqsave(&ch->lock, *irq_flags); | |
605 | ||
606 | if (ret != xpcSuccess) { | |
607 | XPC_DISCONNECT_CHANNEL(ch, ret, irq_flags); | |
608 | } | |
609 | if (ch->flags & (XPC_C_CONNECTED | XPC_C_DISCONNECTING)) { | |
610 | return; | |
611 | } | |
612 | ||
613 | DBUG_ON(!(ch->flags & XPC_C_SETUP)); | |
614 | DBUG_ON(ch->local_msgqueue == NULL); | |
615 | DBUG_ON(ch->remote_msgqueue == NULL); | |
616 | } | |
617 | ||
618 | if (!(ch->flags & XPC_C_OPENREPLY)) { | |
619 | ch->flags |= XPC_C_OPENREPLY; | |
620 | xpc_IPI_send_openreply(ch, irq_flags); | |
621 | } | |
622 | ||
623 | if (!(ch->flags & XPC_C_ROPENREPLY)) { | |
624 | return; | |
625 | } | |
626 | ||
627 | DBUG_ON(ch->remote_msgqueue_pa == 0); | |
628 | ||
629 | ch->flags = (XPC_C_CONNECTED | XPC_C_SETUP); /* clear all else */ | |
630 | ||
631 | dev_info(xpc_chan, "channel %d to partition %d connected\n", | |
632 | ch->number, ch->partid); | |
633 | ||
634 | spin_unlock_irqrestore(&ch->lock, *irq_flags); | |
a460ef8d | 635 | xpc_create_kthreads(ch, 1, 0); |
89eb8eb9 DN |
636 | spin_lock_irqsave(&ch->lock, *irq_flags); |
637 | } | |
638 | ||
639 | ||
a607c389 DN |
640 | /* |
641 | * Notify those who wanted to be notified upon delivery of their message. | |
642 | */ | |
643 | static void | |
644 | xpc_notify_senders(struct xpc_channel *ch, enum xpc_retval reason, s64 put) | |
645 | { | |
646 | struct xpc_notify *notify; | |
647 | u8 notify_type; | |
648 | s64 get = ch->w_remote_GP.get - 1; | |
649 | ||
650 | ||
651 | while (++get < put && atomic_read(&ch->n_to_notify) > 0) { | |
652 | ||
653 | notify = &ch->notify_queue[get % ch->local_nentries]; | |
654 | ||
655 | /* | |
656 | * See if the notify entry indicates it was associated with | |
657 | * a message who's sender wants to be notified. It is possible | |
658 | * that it is, but someone else is doing or has done the | |
659 | * notification. | |
660 | */ | |
661 | notify_type = notify->type; | |
662 | if (notify_type == 0 || | |
663 | cmpxchg(¬ify->type, notify_type, 0) != | |
664 | notify_type) { | |
665 | continue; | |
666 | } | |
667 | ||
668 | DBUG_ON(notify_type != XPC_N_CALL); | |
669 | ||
670 | atomic_dec(&ch->n_to_notify); | |
671 | ||
672 | if (notify->func != NULL) { | |
673 | dev_dbg(xpc_chan, "notify->func() called, notify=0x%p, " | |
674 | "msg_number=%ld, partid=%d, channel=%d\n", | |
675 | (void *) notify, get, ch->partid, ch->number); | |
676 | ||
677 | notify->func(reason, ch->partid, ch->number, | |
678 | notify->key); | |
679 | ||
680 | dev_dbg(xpc_chan, "notify->func() returned, " | |
681 | "notify=0x%p, msg_number=%ld, partid=%d, " | |
682 | "channel=%d\n", (void *) notify, get, | |
683 | ch->partid, ch->number); | |
684 | } | |
685 | } | |
686 | } | |
687 | ||
688 | ||
89eb8eb9 DN |
689 | /* |
690 | * Free up message queues and other stuff that were allocated for the specified | |
691 | * channel. | |
692 | * | |
693 | * Note: ch->reason and ch->reason_line are left set for debugging purposes, | |
694 | * they're cleared when XPC_C_DISCONNECTED is cleared. | |
695 | */ | |
696 | static void | |
697 | xpc_free_msgqueues(struct xpc_channel *ch) | |
698 | { | |
699 | DBUG_ON(!spin_is_locked(&ch->lock)); | |
700 | DBUG_ON(atomic_read(&ch->n_to_notify) != 0); | |
701 | ||
702 | ch->remote_msgqueue_pa = 0; | |
703 | ch->func = NULL; | |
704 | ch->key = NULL; | |
705 | ch->msg_size = 0; | |
706 | ch->local_nentries = 0; | |
707 | ch->remote_nentries = 0; | |
708 | ch->kthreads_assigned_limit = 0; | |
709 | ch->kthreads_idle_limit = 0; | |
710 | ||
711 | ch->local_GP->get = 0; | |
712 | ch->local_GP->put = 0; | |
713 | ch->remote_GP.get = 0; | |
714 | ch->remote_GP.put = 0; | |
715 | ch->w_local_GP.get = 0; | |
716 | ch->w_local_GP.put = 0; | |
717 | ch->w_remote_GP.get = 0; | |
718 | ch->w_remote_GP.put = 0; | |
719 | ch->next_msg_to_pull = 0; | |
720 | ||
721 | if (ch->flags & XPC_C_SETUP) { | |
722 | ch->flags &= ~XPC_C_SETUP; | |
723 | ||
724 | dev_dbg(xpc_chan, "ch->flags=0x%x, partid=%d, channel=%d\n", | |
725 | ch->flags, ch->partid, ch->number); | |
726 | ||
727 | kfree(ch->local_msgqueue_base); | |
728 | ch->local_msgqueue = NULL; | |
729 | kfree(ch->remote_msgqueue_base); | |
730 | ch->remote_msgqueue = NULL; | |
731 | kfree(ch->notify_queue); | |
732 | ch->notify_queue = NULL; | |
89eb8eb9 DN |
733 | } |
734 | } | |
735 | ||
736 | ||
737 | /* | |
738 | * spin_lock_irqsave() is expected to be held on entry. | |
739 | */ | |
740 | static void | |
741 | xpc_process_disconnect(struct xpc_channel *ch, unsigned long *irq_flags) | |
742 | { | |
743 | struct xpc_partition *part = &xpc_partitions[ch->partid]; | |
a607c389 | 744 | u32 channel_was_connected = (ch->flags & XPC_C_WASCONNECTED); |
89eb8eb9 DN |
745 | |
746 | ||
747 | DBUG_ON(!spin_is_locked(&ch->lock)); | |
748 | ||
749 | if (!(ch->flags & XPC_C_DISCONNECTING)) { | |
750 | return; | |
751 | } | |
752 | ||
753 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); | |
754 | ||
755 | /* make sure all activity has settled down first */ | |
756 | ||
a460ef8d DN |
757 | if (atomic_read(&ch->kthreads_assigned) > 0 || |
758 | atomic_read(&ch->references) > 0) { | |
89eb8eb9 DN |
759 | return; |
760 | } | |
a460ef8d DN |
761 | DBUG_ON((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) && |
762 | !(ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE)); | |
89eb8eb9 | 763 | |
a607c389 DN |
764 | if (part->act_state == XPC_P_DEACTIVATING) { |
765 | /* can't proceed until the other side disengages from us */ | |
766 | if (xpc_partition_engaged(1UL << ch->partid)) { | |
767 | return; | |
768 | } | |
89eb8eb9 | 769 | |
a607c389 | 770 | } else { |
89eb8eb9 DN |
771 | |
772 | /* as long as the other side is up do the full protocol */ | |
773 | ||
774 | if (!(ch->flags & XPC_C_RCLOSEREQUEST)) { | |
775 | return; | |
776 | } | |
777 | ||
778 | if (!(ch->flags & XPC_C_CLOSEREPLY)) { | |
779 | ch->flags |= XPC_C_CLOSEREPLY; | |
780 | xpc_IPI_send_closereply(ch, irq_flags); | |
781 | } | |
782 | ||
783 | if (!(ch->flags & XPC_C_RCLOSEREPLY)) { | |
784 | return; | |
785 | } | |
786 | } | |
787 | ||
a607c389 DN |
788 | /* wake those waiting for notify completion */ |
789 | if (atomic_read(&ch->n_to_notify) > 0) { | |
790 | /* >>> we do callout while holding ch->lock */ | |
791 | xpc_notify_senders(ch, ch->reason, ch->w_local_GP.put); | |
792 | } | |
793 | ||
89eb8eb9 DN |
794 | /* both sides are disconnected now */ |
795 | ||
4c2cd966 | 796 | if (ch->flags & XPC_C_DISCONNECTINGCALLOUT_MADE) { |
246c7e33 DN |
797 | spin_unlock_irqrestore(&ch->lock, *irq_flags); |
798 | xpc_disconnect_callout(ch, xpcDisconnected); | |
799 | spin_lock_irqsave(&ch->lock, *irq_flags); | |
800 | } | |
801 | ||
a607c389 DN |
802 | /* it's now safe to free the channel's message queues */ |
803 | xpc_free_msgqueues(ch); | |
804 | ||
805 | /* mark disconnected, clear all other flags except XPC_C_WDISCONNECT */ | |
806 | ch->flags = (XPC_C_DISCONNECTED | (ch->flags & XPC_C_WDISCONNECT)); | |
89eb8eb9 DN |
807 | |
808 | atomic_dec(&part->nchannels_active); | |
809 | ||
a607c389 | 810 | if (channel_was_connected) { |
89eb8eb9 DN |
811 | dev_info(xpc_chan, "channel %d to partition %d disconnected, " |
812 | "reason=%d\n", ch->number, ch->partid, ch->reason); | |
813 | } | |
a607c389 | 814 | |
a607c389 | 815 | if (ch->flags & XPC_C_WDISCONNECT) { |
f9e505a9 JS |
816 | /* we won't lose the CPU since we're holding ch->lock */ |
817 | complete(&ch->wdisconnect_wait); | |
e54af724 DN |
818 | } else if (ch->delayed_IPI_flags) { |
819 | if (part->act_state != XPC_P_DEACTIVATING) { | |
820 | /* time to take action on any delayed IPI flags */ | |
821 | spin_lock(&part->IPI_lock); | |
822 | XPC_SET_IPI_FLAGS(part->local_IPI_amo, ch->number, | |
823 | ch->delayed_IPI_flags); | |
824 | spin_unlock(&part->IPI_lock); | |
825 | } | |
826 | ch->delayed_IPI_flags = 0; | |
a607c389 | 827 | } |
89eb8eb9 DN |
828 | } |
829 | ||
830 | ||
831 | /* | |
832 | * Process a change in the channel's remote connection state. | |
833 | */ | |
834 | static void | |
835 | xpc_process_openclose_IPI(struct xpc_partition *part, int ch_number, | |
836 | u8 IPI_flags) | |
837 | { | |
838 | unsigned long irq_flags; | |
839 | struct xpc_openclose_args *args = | |
840 | &part->remote_openclose_args[ch_number]; | |
841 | struct xpc_channel *ch = &part->channels[ch_number]; | |
842 | enum xpc_retval reason; | |
843 | ||
844 | ||
845 | ||
846 | spin_lock_irqsave(&ch->lock, irq_flags); | |
847 | ||
e54af724 DN |
848 | again: |
849 | ||
850 | if ((ch->flags & XPC_C_DISCONNECTED) && | |
851 | (ch->flags & XPC_C_WDISCONNECT)) { | |
852 | /* | |
853 | * Delay processing IPI flags until thread waiting disconnect | |
854 | * has had a chance to see that the channel is disconnected. | |
855 | */ | |
856 | ch->delayed_IPI_flags |= IPI_flags; | |
857 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
858 | return; | |
859 | } | |
860 | ||
89eb8eb9 DN |
861 | |
862 | if (IPI_flags & XPC_IPI_CLOSEREQUEST) { | |
863 | ||
864 | dev_dbg(xpc_chan, "XPC_IPI_CLOSEREQUEST (reason=%d) received " | |
865 | "from partid=%d, channel=%d\n", args->reason, | |
866 | ch->partid, ch->number); | |
867 | ||
868 | /* | |
869 | * If RCLOSEREQUEST is set, we're probably waiting for | |
870 | * RCLOSEREPLY. We should find it and a ROPENREQUEST packed | |
a607c389 | 871 | * with this RCLOSEREQUEST in the IPI_flags. |
89eb8eb9 DN |
872 | */ |
873 | ||
874 | if (ch->flags & XPC_C_RCLOSEREQUEST) { | |
875 | DBUG_ON(!(ch->flags & XPC_C_DISCONNECTING)); | |
876 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); | |
877 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREPLY)); | |
878 | DBUG_ON(ch->flags & XPC_C_RCLOSEREPLY); | |
879 | ||
880 | DBUG_ON(!(IPI_flags & XPC_IPI_CLOSEREPLY)); | |
881 | IPI_flags &= ~XPC_IPI_CLOSEREPLY; | |
882 | ch->flags |= XPC_C_RCLOSEREPLY; | |
883 | ||
884 | /* both sides have finished disconnecting */ | |
885 | xpc_process_disconnect(ch, &irq_flags); | |
e54af724 DN |
886 | DBUG_ON(!(ch->flags & XPC_C_DISCONNECTED)); |
887 | goto again; | |
89eb8eb9 DN |
888 | } |
889 | ||
890 | if (ch->flags & XPC_C_DISCONNECTED) { | |
89eb8eb9 | 891 | if (!(IPI_flags & XPC_IPI_OPENREQUEST)) { |
e54af724 DN |
892 | if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo, |
893 | ch_number) & XPC_IPI_OPENREQUEST)) { | |
894 | ||
895 | DBUG_ON(ch->delayed_IPI_flags != 0); | |
896 | spin_lock(&part->IPI_lock); | |
897 | XPC_SET_IPI_FLAGS(part->local_IPI_amo, | |
898 | ch_number, | |
899 | XPC_IPI_CLOSEREQUEST); | |
900 | spin_unlock(&part->IPI_lock); | |
901 | } | |
89eb8eb9 DN |
902 | spin_unlock_irqrestore(&ch->lock, irq_flags); |
903 | return; | |
904 | } | |
905 | ||
906 | XPC_SET_REASON(ch, 0, 0); | |
907 | ch->flags &= ~XPC_C_DISCONNECTED; | |
908 | ||
909 | atomic_inc(&part->nchannels_active); | |
910 | ch->flags |= (XPC_C_CONNECTING | XPC_C_ROPENREQUEST); | |
911 | } | |
912 | ||
913 | IPI_flags &= ~(XPC_IPI_OPENREQUEST | XPC_IPI_OPENREPLY); | |
914 | ||
915 | /* | |
916 | * The meaningful CLOSEREQUEST connection state fields are: | |
917 | * reason = reason connection is to be closed | |
918 | */ | |
919 | ||
920 | ch->flags |= XPC_C_RCLOSEREQUEST; | |
921 | ||
922 | if (!(ch->flags & XPC_C_DISCONNECTING)) { | |
923 | reason = args->reason; | |
924 | if (reason <= xpcSuccess || reason > xpcUnknownReason) { | |
925 | reason = xpcUnknownReason; | |
926 | } else if (reason == xpcUnregistering) { | |
927 | reason = xpcOtherUnregistering; | |
928 | } | |
929 | ||
930 | XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags); | |
e54af724 DN |
931 | |
932 | DBUG_ON(IPI_flags & XPC_IPI_CLOSEREPLY); | |
933 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
934 | return; | |
89eb8eb9 | 935 | } |
e54af724 DN |
936 | |
937 | xpc_process_disconnect(ch, &irq_flags); | |
89eb8eb9 DN |
938 | } |
939 | ||
940 | ||
941 | if (IPI_flags & XPC_IPI_CLOSEREPLY) { | |
942 | ||
943 | dev_dbg(xpc_chan, "XPC_IPI_CLOSEREPLY received from partid=%d," | |
944 | " channel=%d\n", ch->partid, ch->number); | |
945 | ||
946 | if (ch->flags & XPC_C_DISCONNECTED) { | |
947 | DBUG_ON(part->act_state != XPC_P_DEACTIVATING); | |
948 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
949 | return; | |
950 | } | |
951 | ||
952 | DBUG_ON(!(ch->flags & XPC_C_CLOSEREQUEST)); | |
e54af724 DN |
953 | |
954 | if (!(ch->flags & XPC_C_RCLOSEREQUEST)) { | |
955 | if ((XPC_GET_IPI_FLAGS(part->local_IPI_amo, ch_number) | |
956 | & XPC_IPI_CLOSEREQUEST)) { | |
957 | ||
958 | DBUG_ON(ch->delayed_IPI_flags != 0); | |
959 | spin_lock(&part->IPI_lock); | |
960 | XPC_SET_IPI_FLAGS(part->local_IPI_amo, | |
961 | ch_number, XPC_IPI_CLOSEREPLY); | |
962 | spin_unlock(&part->IPI_lock); | |
963 | } | |
964 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
965 | return; | |
966 | } | |
89eb8eb9 DN |
967 | |
968 | ch->flags |= XPC_C_RCLOSEREPLY; | |
969 | ||
970 | if (ch->flags & XPC_C_CLOSEREPLY) { | |
971 | /* both sides have finished disconnecting */ | |
972 | xpc_process_disconnect(ch, &irq_flags); | |
973 | } | |
974 | } | |
975 | ||
976 | ||
977 | if (IPI_flags & XPC_IPI_OPENREQUEST) { | |
978 | ||
979 | dev_dbg(xpc_chan, "XPC_IPI_OPENREQUEST (msg_size=%d, " | |
980 | "local_nentries=%d) received from partid=%d, " | |
981 | "channel=%d\n", args->msg_size, args->local_nentries, | |
982 | ch->partid, ch->number); | |
983 | ||
e54af724 DN |
984 | if (part->act_state == XPC_P_DEACTIVATING || |
985 | (ch->flags & XPC_C_ROPENREQUEST)) { | |
986 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
987 | return; | |
988 | } | |
989 | ||
990 | if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_WDISCONNECT)) { | |
991 | ch->delayed_IPI_flags |= XPC_IPI_OPENREQUEST; | |
89eb8eb9 DN |
992 | spin_unlock_irqrestore(&ch->lock, irq_flags); |
993 | return; | |
994 | } | |
995 | DBUG_ON(!(ch->flags & (XPC_C_DISCONNECTED | | |
996 | XPC_C_OPENREQUEST))); | |
997 | DBUG_ON(ch->flags & (XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY | | |
998 | XPC_C_OPENREPLY | XPC_C_CONNECTED)); | |
999 | ||
1000 | /* | |
1001 | * The meaningful OPENREQUEST connection state fields are: | |
1002 | * msg_size = size of channel's messages in bytes | |
1003 | * local_nentries = remote partition's local_nentries | |
1004 | */ | |
e54af724 DN |
1005 | if (args->msg_size == 0 || args->local_nentries == 0) { |
1006 | /* assume OPENREQUEST was delayed by mistake */ | |
1007 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1008 | return; | |
1009 | } | |
89eb8eb9 DN |
1010 | |
1011 | ch->flags |= (XPC_C_ROPENREQUEST | XPC_C_CONNECTING); | |
1012 | ch->remote_nentries = args->local_nentries; | |
1013 | ||
1014 | ||
1015 | if (ch->flags & XPC_C_OPENREQUEST) { | |
1016 | if (args->msg_size != ch->msg_size) { | |
1017 | XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes, | |
1018 | &irq_flags); | |
1019 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1020 | return; | |
1021 | } | |
1022 | } else { | |
1023 | ch->msg_size = args->msg_size; | |
1024 | ||
1025 | XPC_SET_REASON(ch, 0, 0); | |
1026 | ch->flags &= ~XPC_C_DISCONNECTED; | |
1027 | ||
1028 | atomic_inc(&part->nchannels_active); | |
1029 | } | |
1030 | ||
1031 | xpc_process_connect(ch, &irq_flags); | |
1032 | } | |
1033 | ||
1034 | ||
1035 | if (IPI_flags & XPC_IPI_OPENREPLY) { | |
1036 | ||
1037 | dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY (local_msgqueue_pa=0x%lx, " | |
1038 | "local_nentries=%d, remote_nentries=%d) received from " | |
1039 | "partid=%d, channel=%d\n", args->local_msgqueue_pa, | |
1040 | args->local_nentries, args->remote_nentries, | |
1041 | ch->partid, ch->number); | |
1042 | ||
1043 | if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) { | |
1044 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1045 | return; | |
1046 | } | |
e54af724 DN |
1047 | if (!(ch->flags & XPC_C_OPENREQUEST)) { |
1048 | XPC_DISCONNECT_CHANNEL(ch, xpcOpenCloseError, | |
1049 | &irq_flags); | |
1050 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1051 | return; | |
1052 | } | |
1053 | ||
89eb8eb9 DN |
1054 | DBUG_ON(!(ch->flags & XPC_C_ROPENREQUEST)); |
1055 | DBUG_ON(ch->flags & XPC_C_CONNECTED); | |
1056 | ||
1057 | /* | |
1058 | * The meaningful OPENREPLY connection state fields are: | |
1059 | * local_msgqueue_pa = physical address of remote | |
1060 | * partition's local_msgqueue | |
1061 | * local_nentries = remote partition's local_nentries | |
1062 | * remote_nentries = remote partition's remote_nentries | |
1063 | */ | |
1064 | DBUG_ON(args->local_msgqueue_pa == 0); | |
1065 | DBUG_ON(args->local_nentries == 0); | |
1066 | DBUG_ON(args->remote_nentries == 0); | |
1067 | ||
1068 | ch->flags |= XPC_C_ROPENREPLY; | |
1069 | ch->remote_msgqueue_pa = args->local_msgqueue_pa; | |
1070 | ||
1071 | if (args->local_nentries < ch->remote_nentries) { | |
1072 | dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new " | |
1073 | "remote_nentries=%d, old remote_nentries=%d, " | |
1074 | "partid=%d, channel=%d\n", | |
1075 | args->local_nentries, ch->remote_nentries, | |
1076 | ch->partid, ch->number); | |
1077 | ||
1078 | ch->remote_nentries = args->local_nentries; | |
1079 | } | |
1080 | if (args->remote_nentries < ch->local_nentries) { | |
1081 | dev_dbg(xpc_chan, "XPC_IPI_OPENREPLY: new " | |
1082 | "local_nentries=%d, old local_nentries=%d, " | |
1083 | "partid=%d, channel=%d\n", | |
1084 | args->remote_nentries, ch->local_nentries, | |
1085 | ch->partid, ch->number); | |
1086 | ||
1087 | ch->local_nentries = args->remote_nentries; | |
1088 | } | |
1089 | ||
1090 | xpc_process_connect(ch, &irq_flags); | |
1091 | } | |
1092 | ||
1093 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1094 | } | |
1095 | ||
1096 | ||
1097 | /* | |
1098 | * Attempt to establish a channel connection to a remote partition. | |
1099 | */ | |
1100 | static enum xpc_retval | |
1101 | xpc_connect_channel(struct xpc_channel *ch) | |
1102 | { | |
1103 | unsigned long irq_flags; | |
1104 | struct xpc_registration *registration = &xpc_registrations[ch->number]; | |
1105 | ||
1106 | ||
f9e505a9 | 1107 | if (mutex_trylock(®istration->mutex) == 0) { |
e54af724 | 1108 | return xpcRetry; |
89eb8eb9 DN |
1109 | } |
1110 | ||
1111 | if (!XPC_CHANNEL_REGISTERED(ch->number)) { | |
f9e505a9 | 1112 | mutex_unlock(®istration->mutex); |
89eb8eb9 DN |
1113 | return xpcUnregistered; |
1114 | } | |
1115 | ||
1116 | spin_lock_irqsave(&ch->lock, irq_flags); | |
1117 | ||
1118 | DBUG_ON(ch->flags & XPC_C_CONNECTED); | |
1119 | DBUG_ON(ch->flags & XPC_C_OPENREQUEST); | |
1120 | ||
1121 | if (ch->flags & XPC_C_DISCONNECTING) { | |
1122 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
f9e505a9 | 1123 | mutex_unlock(®istration->mutex); |
89eb8eb9 DN |
1124 | return ch->reason; |
1125 | } | |
1126 | ||
1127 | ||
1128 | /* add info from the channel connect registration to the channel */ | |
1129 | ||
1130 | ch->kthreads_assigned_limit = registration->assigned_limit; | |
1131 | ch->kthreads_idle_limit = registration->idle_limit; | |
1132 | DBUG_ON(atomic_read(&ch->kthreads_assigned) != 0); | |
1133 | DBUG_ON(atomic_read(&ch->kthreads_idle) != 0); | |
1134 | DBUG_ON(atomic_read(&ch->kthreads_active) != 0); | |
1135 | ||
1136 | ch->func = registration->func; | |
1137 | DBUG_ON(registration->func == NULL); | |
1138 | ch->key = registration->key; | |
1139 | ||
1140 | ch->local_nentries = registration->nentries; | |
1141 | ||
1142 | if (ch->flags & XPC_C_ROPENREQUEST) { | |
1143 | if (registration->msg_size != ch->msg_size) { | |
1144 | /* the local and remote sides aren't the same */ | |
1145 | ||
1146 | /* | |
1147 | * Because XPC_DISCONNECT_CHANNEL() can block we're | |
1148 | * forced to up the registration sema before we unlock | |
1149 | * the channel lock. But that's okay here because we're | |
1150 | * done with the part that required the registration | |
1151 | * sema. XPC_DISCONNECT_CHANNEL() requires that the | |
1152 | * channel lock be locked and will unlock and relock | |
1153 | * the channel lock as needed. | |
1154 | */ | |
f9e505a9 | 1155 | mutex_unlock(®istration->mutex); |
89eb8eb9 DN |
1156 | XPC_DISCONNECT_CHANNEL(ch, xpcUnequalMsgSizes, |
1157 | &irq_flags); | |
1158 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1159 | return xpcUnequalMsgSizes; | |
1160 | } | |
1161 | } else { | |
1162 | ch->msg_size = registration->msg_size; | |
1163 | ||
1164 | XPC_SET_REASON(ch, 0, 0); | |
1165 | ch->flags &= ~XPC_C_DISCONNECTED; | |
1166 | ||
1167 | atomic_inc(&xpc_partitions[ch->partid].nchannels_active); | |
1168 | } | |
1169 | ||
f9e505a9 | 1170 | mutex_unlock(®istration->mutex); |
89eb8eb9 DN |
1171 | |
1172 | ||
1173 | /* initiate the connection */ | |
1174 | ||
1175 | ch->flags |= (XPC_C_OPENREQUEST | XPC_C_CONNECTING); | |
1176 | xpc_IPI_send_openrequest(ch, &irq_flags); | |
1177 | ||
1178 | xpc_process_connect(ch, &irq_flags); | |
1179 | ||
1180 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1181 | ||
1182 | return xpcSuccess; | |
1183 | } | |
1184 | ||
1185 | ||
89eb8eb9 DN |
1186 | /* |
1187 | * Clear some of the msg flags in the local message queue. | |
1188 | */ | |
1189 | static inline void | |
1190 | xpc_clear_local_msgqueue_flags(struct xpc_channel *ch) | |
1191 | { | |
1192 | struct xpc_msg *msg; | |
1193 | s64 get; | |
1194 | ||
1195 | ||
1196 | get = ch->w_remote_GP.get; | |
1197 | do { | |
1198 | msg = (struct xpc_msg *) ((u64) ch->local_msgqueue + | |
1199 | (get % ch->local_nentries) * ch->msg_size); | |
1200 | msg->flags = 0; | |
1201 | } while (++get < (volatile s64) ch->remote_GP.get); | |
1202 | } | |
1203 | ||
1204 | ||
1205 | /* | |
1206 | * Clear some of the msg flags in the remote message queue. | |
1207 | */ | |
1208 | static inline void | |
1209 | xpc_clear_remote_msgqueue_flags(struct xpc_channel *ch) | |
1210 | { | |
1211 | struct xpc_msg *msg; | |
1212 | s64 put; | |
1213 | ||
1214 | ||
1215 | put = ch->w_remote_GP.put; | |
1216 | do { | |
1217 | msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue + | |
1218 | (put % ch->remote_nentries) * ch->msg_size); | |
1219 | msg->flags = 0; | |
1220 | } while (++put < (volatile s64) ch->remote_GP.put); | |
1221 | } | |
1222 | ||
1223 | ||
1224 | static void | |
1225 | xpc_process_msg_IPI(struct xpc_partition *part, int ch_number) | |
1226 | { | |
1227 | struct xpc_channel *ch = &part->channels[ch_number]; | |
1228 | int nmsgs_sent; | |
1229 | ||
1230 | ||
1231 | ch->remote_GP = part->remote_GPs[ch_number]; | |
1232 | ||
1233 | ||
1234 | /* See what, if anything, has changed for each connected channel */ | |
1235 | ||
1236 | xpc_msgqueue_ref(ch); | |
1237 | ||
1238 | if (ch->w_remote_GP.get == ch->remote_GP.get && | |
1239 | ch->w_remote_GP.put == ch->remote_GP.put) { | |
1240 | /* nothing changed since GPs were last pulled */ | |
1241 | xpc_msgqueue_deref(ch); | |
1242 | return; | |
1243 | } | |
1244 | ||
1245 | if (!(ch->flags & XPC_C_CONNECTED)){ | |
1246 | xpc_msgqueue_deref(ch); | |
1247 | return; | |
1248 | } | |
1249 | ||
1250 | ||
1251 | /* | |
1252 | * First check to see if messages recently sent by us have been | |
1253 | * received by the other side. (The remote GET value will have | |
1254 | * changed since we last looked at it.) | |
1255 | */ | |
1256 | ||
1257 | if (ch->w_remote_GP.get != ch->remote_GP.get) { | |
1258 | ||
1259 | /* | |
1260 | * We need to notify any senders that want to be notified | |
1261 | * that their sent messages have been received by their | |
1262 | * intended recipients. We need to do this before updating | |
1263 | * w_remote_GP.get so that we don't allocate the same message | |
1264 | * queue entries prematurely (see xpc_allocate_msg()). | |
1265 | */ | |
1266 | if (atomic_read(&ch->n_to_notify) > 0) { | |
1267 | /* | |
1268 | * Notify senders that messages sent have been | |
1269 | * received and delivered by the other side. | |
1270 | */ | |
1271 | xpc_notify_senders(ch, xpcMsgDelivered, | |
1272 | ch->remote_GP.get); | |
1273 | } | |
1274 | ||
1275 | /* | |
1276 | * Clear msg->flags in previously sent messages, so that | |
1277 | * they're ready for xpc_allocate_msg(). | |
1278 | */ | |
1279 | xpc_clear_local_msgqueue_flags(ch); | |
1280 | ||
821fe947 | 1281 | ch->w_remote_GP.get = ch->remote_GP.get; |
89eb8eb9 DN |
1282 | |
1283 | dev_dbg(xpc_chan, "w_remote_GP.get changed to %ld, partid=%d, " | |
1284 | "channel=%d\n", ch->w_remote_GP.get, ch->partid, | |
1285 | ch->number); | |
1286 | ||
1287 | /* | |
1288 | * If anyone was waiting for message queue entries to become | |
1289 | * available, wake them up. | |
1290 | */ | |
1291 | if (atomic_read(&ch->n_on_msg_allocate_wq) > 0) { | |
1292 | wake_up(&ch->msg_allocate_wq); | |
1293 | } | |
1294 | } | |
1295 | ||
1296 | ||
1297 | /* | |
1298 | * Now check for newly sent messages by the other side. (The remote | |
1299 | * PUT value will have changed since we last looked at it.) | |
1300 | */ | |
1301 | ||
1302 | if (ch->w_remote_GP.put != ch->remote_GP.put) { | |
1303 | /* | |
1304 | * Clear msg->flags in previously received messages, so that | |
1305 | * they're ready for xpc_get_deliverable_msg(). | |
1306 | */ | |
1307 | xpc_clear_remote_msgqueue_flags(ch); | |
1308 | ||
821fe947 | 1309 | ch->w_remote_GP.put = ch->remote_GP.put; |
89eb8eb9 DN |
1310 | |
1311 | dev_dbg(xpc_chan, "w_remote_GP.put changed to %ld, partid=%d, " | |
1312 | "channel=%d\n", ch->w_remote_GP.put, ch->partid, | |
1313 | ch->number); | |
1314 | ||
1315 | nmsgs_sent = ch->w_remote_GP.put - ch->w_local_GP.get; | |
1316 | if (nmsgs_sent > 0) { | |
1317 | dev_dbg(xpc_chan, "msgs waiting to be copied and " | |
1318 | "delivered=%d, partid=%d, channel=%d\n", | |
1319 | nmsgs_sent, ch->partid, ch->number); | |
1320 | ||
4c2cd966 | 1321 | if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) { |
89eb8eb9 DN |
1322 | xpc_activate_kthreads(ch, nmsgs_sent); |
1323 | } | |
1324 | } | |
1325 | } | |
1326 | ||
1327 | xpc_msgqueue_deref(ch); | |
1328 | } | |
1329 | ||
1330 | ||
1331 | void | |
1332 | xpc_process_channel_activity(struct xpc_partition *part) | |
1333 | { | |
1334 | unsigned long irq_flags; | |
1335 | u64 IPI_amo, IPI_flags; | |
1336 | struct xpc_channel *ch; | |
1337 | int ch_number; | |
a607c389 | 1338 | u32 ch_flags; |
89eb8eb9 DN |
1339 | |
1340 | ||
1341 | IPI_amo = xpc_get_IPI_flags(part); | |
1342 | ||
1343 | /* | |
1344 | * Initiate channel connections for registered channels. | |
1345 | * | |
1346 | * For each connected channel that has pending messages activate idle | |
1347 | * kthreads and/or create new kthreads as needed. | |
1348 | */ | |
1349 | ||
1350 | for (ch_number = 0; ch_number < part->nchannels; ch_number++) { | |
1351 | ch = &part->channels[ch_number]; | |
1352 | ||
1353 | ||
1354 | /* | |
1355 | * Process any open or close related IPI flags, and then deal | |
1356 | * with connecting or disconnecting the channel as required. | |
1357 | */ | |
1358 | ||
1359 | IPI_flags = XPC_GET_IPI_FLAGS(IPI_amo, ch_number); | |
1360 | ||
1361 | if (XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(IPI_flags)) { | |
1362 | xpc_process_openclose_IPI(part, ch_number, IPI_flags); | |
1363 | } | |
1364 | ||
a607c389 | 1365 | ch_flags = ch->flags; /* need an atomic snapshot of flags */ |
89eb8eb9 | 1366 | |
a607c389 | 1367 | if (ch_flags & XPC_C_DISCONNECTING) { |
89eb8eb9 DN |
1368 | spin_lock_irqsave(&ch->lock, irq_flags); |
1369 | xpc_process_disconnect(ch, &irq_flags); | |
1370 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1371 | continue; | |
1372 | } | |
1373 | ||
1374 | if (part->act_state == XPC_P_DEACTIVATING) { | |
1375 | continue; | |
1376 | } | |
1377 | ||
a607c389 DN |
1378 | if (!(ch_flags & XPC_C_CONNECTED)) { |
1379 | if (!(ch_flags & XPC_C_OPENREQUEST)) { | |
1380 | DBUG_ON(ch_flags & XPC_C_SETUP); | |
89eb8eb9 DN |
1381 | (void) xpc_connect_channel(ch); |
1382 | } else { | |
1383 | spin_lock_irqsave(&ch->lock, irq_flags); | |
1384 | xpc_process_connect(ch, &irq_flags); | |
1385 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1386 | } | |
1387 | continue; | |
1388 | } | |
1389 | ||
1390 | ||
1391 | /* | |
1392 | * Process any message related IPI flags, this may involve the | |
1393 | * activation of kthreads to deliver any pending messages sent | |
1394 | * from the other partition. | |
1395 | */ | |
1396 | ||
1397 | if (XPC_ANY_MSG_IPI_FLAGS_SET(IPI_flags)) { | |
1398 | xpc_process_msg_IPI(part, ch_number); | |
1399 | } | |
1400 | } | |
1401 | } | |
1402 | ||
1403 | ||
1404 | /* | |
a607c389 DN |
1405 | * XPC's heartbeat code calls this function to inform XPC that a partition is |
1406 | * going down. XPC responds by tearing down the XPartition Communication | |
89eb8eb9 DN |
1407 | * infrastructure used for the just downed partition. |
1408 | * | |
1409 | * XPC's heartbeat code will never call this function and xpc_partition_up() | |
1410 | * at the same time. Nor will it ever make multiple calls to either function | |
1411 | * at the same time. | |
1412 | */ | |
1413 | void | |
a607c389 | 1414 | xpc_partition_going_down(struct xpc_partition *part, enum xpc_retval reason) |
89eb8eb9 DN |
1415 | { |
1416 | unsigned long irq_flags; | |
1417 | int ch_number; | |
1418 | struct xpc_channel *ch; | |
1419 | ||
1420 | ||
1421 | dev_dbg(xpc_chan, "deactivating partition %d, reason=%d\n", | |
1422 | XPC_PARTID(part), reason); | |
1423 | ||
1424 | if (!xpc_part_ref(part)) { | |
1425 | /* infrastructure for this partition isn't currently set up */ | |
1426 | return; | |
1427 | } | |
1428 | ||
1429 | ||
a607c389 | 1430 | /* disconnect channels associated with the partition going down */ |
89eb8eb9 DN |
1431 | |
1432 | for (ch_number = 0; ch_number < part->nchannels; ch_number++) { | |
1433 | ch = &part->channels[ch_number]; | |
1434 | ||
89eb8eb9 DN |
1435 | xpc_msgqueue_ref(ch); |
1436 | spin_lock_irqsave(&ch->lock, irq_flags); | |
1437 | ||
1438 | XPC_DISCONNECT_CHANNEL(ch, reason, &irq_flags); | |
1439 | ||
1440 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1441 | xpc_msgqueue_deref(ch); | |
1442 | } | |
1443 | ||
1444 | xpc_wakeup_channel_mgr(part); | |
1445 | ||
1446 | xpc_part_deref(part); | |
1447 | } | |
1448 | ||
1449 | ||
1450 | /* | |
1451 | * Teardown the infrastructure necessary to support XPartition Communication | |
1452 | * between the specified remote partition and the local one. | |
1453 | */ | |
1454 | void | |
1455 | xpc_teardown_infrastructure(struct xpc_partition *part) | |
1456 | { | |
1457 | partid_t partid = XPC_PARTID(part); | |
1458 | ||
1459 | ||
1460 | /* | |
1461 | * We start off by making this partition inaccessible to local | |
1462 | * processes by marking it as no longer setup. Then we make it | |
1463 | * inaccessible to remote processes by clearing the XPC per partition | |
1464 | * specific variable's magic # (which indicates that these variables | |
1465 | * are no longer valid) and by ignoring all XPC notify IPIs sent to | |
1466 | * this partition. | |
1467 | */ | |
1468 | ||
a607c389 | 1469 | DBUG_ON(atomic_read(&part->nchannels_engaged) != 0); |
89eb8eb9 DN |
1470 | DBUG_ON(atomic_read(&part->nchannels_active) != 0); |
1471 | DBUG_ON(part->setup_state != XPC_P_SETUP); | |
1472 | part->setup_state = XPC_P_WTEARDOWN; | |
1473 | ||
1474 | xpc_vars_part[partid].magic = 0; | |
1475 | ||
1476 | ||
1477 | free_irq(SGI_XPC_NOTIFY, (void *) (u64) partid); | |
1478 | ||
1479 | ||
1480 | /* | |
72fdbdce | 1481 | * Before proceeding with the teardown we have to wait until all |
89eb8eb9 DN |
1482 | * existing references cease. |
1483 | */ | |
1484 | wait_event(part->teardown_wq, (atomic_read(&part->references) == 0)); | |
1485 | ||
1486 | ||
1487 | /* now we can begin tearing down the infrastructure */ | |
1488 | ||
1489 | part->setup_state = XPC_P_TORNDOWN; | |
1490 | ||
1491 | /* in case we've still got outstanding timers registered... */ | |
1492 | del_timer_sync(&part->dropped_IPI_timer); | |
1493 | ||
1494 | kfree(part->remote_openclose_args_base); | |
1495 | part->remote_openclose_args = NULL; | |
1496 | kfree(part->local_openclose_args_base); | |
1497 | part->local_openclose_args = NULL; | |
1498 | kfree(part->remote_GPs_base); | |
1499 | part->remote_GPs = NULL; | |
1500 | kfree(part->local_GPs_base); | |
1501 | part->local_GPs = NULL; | |
1502 | kfree(part->channels); | |
1503 | part->channels = NULL; | |
1504 | part->local_IPI_amo_va = NULL; | |
1505 | } | |
1506 | ||
1507 | ||
1508 | /* | |
1509 | * Called by XP at the time of channel connection registration to cause | |
1510 | * XPC to establish connections to all currently active partitions. | |
1511 | */ | |
1512 | void | |
1513 | xpc_initiate_connect(int ch_number) | |
1514 | { | |
1515 | partid_t partid; | |
1516 | struct xpc_partition *part; | |
1517 | struct xpc_channel *ch; | |
1518 | ||
1519 | ||
1520 | DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS); | |
1521 | ||
1522 | for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) { | |
1523 | part = &xpc_partitions[partid]; | |
1524 | ||
1525 | if (xpc_part_ref(part)) { | |
1526 | ch = &part->channels[ch_number]; | |
1527 | ||
e54af724 DN |
1528 | /* |
1529 | * Initiate the establishment of a connection on the | |
1530 | * newly registered channel to the remote partition. | |
1531 | */ | |
1532 | xpc_wakeup_channel_mgr(part); | |
89eb8eb9 DN |
1533 | xpc_part_deref(part); |
1534 | } | |
1535 | } | |
1536 | } | |
1537 | ||
1538 | ||
1539 | void | |
1540 | xpc_connected_callout(struct xpc_channel *ch) | |
1541 | { | |
89eb8eb9 DN |
1542 | /* let the registerer know that a connection has been established */ |
1543 | ||
1544 | if (ch->func != NULL) { | |
1545 | dev_dbg(xpc_chan, "ch->func() called, reason=xpcConnected, " | |
1546 | "partid=%d, channel=%d\n", ch->partid, ch->number); | |
1547 | ||
1548 | ch->func(xpcConnected, ch->partid, ch->number, | |
1549 | (void *) (u64) ch->local_nentries, ch->key); | |
1550 | ||
1551 | dev_dbg(xpc_chan, "ch->func() returned, reason=xpcConnected, " | |
1552 | "partid=%d, channel=%d\n", ch->partid, ch->number); | |
1553 | } | |
89eb8eb9 DN |
1554 | } |
1555 | ||
1556 | ||
1557 | /* | |
1558 | * Called by XP at the time of channel connection unregistration to cause | |
1559 | * XPC to teardown all current connections for the specified channel. | |
1560 | * | |
1561 | * Before returning xpc_initiate_disconnect() will wait until all connections | |
1562 | * on the specified channel have been closed/torndown. So the caller can be | |
1563 | * assured that they will not be receiving any more callouts from XPC to the | |
1564 | * function they registered via xpc_connect(). | |
1565 | * | |
1566 | * Arguments: | |
1567 | * | |
1568 | * ch_number - channel # to unregister. | |
1569 | */ | |
1570 | void | |
1571 | xpc_initiate_disconnect(int ch_number) | |
1572 | { | |
1573 | unsigned long irq_flags; | |
1574 | partid_t partid; | |
1575 | struct xpc_partition *part; | |
1576 | struct xpc_channel *ch; | |
1577 | ||
1578 | ||
1579 | DBUG_ON(ch_number < 0 || ch_number >= XPC_NCHANNELS); | |
1580 | ||
1581 | /* initiate the channel disconnect for every active partition */ | |
1582 | for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) { | |
1583 | part = &xpc_partitions[partid]; | |
1584 | ||
1585 | if (xpc_part_ref(part)) { | |
1586 | ch = &part->channels[ch_number]; | |
1587 | xpc_msgqueue_ref(ch); | |
1588 | ||
1589 | spin_lock_irqsave(&ch->lock, irq_flags); | |
1590 | ||
a607c389 DN |
1591 | if (!(ch->flags & XPC_C_DISCONNECTED)) { |
1592 | ch->flags |= XPC_C_WDISCONNECT; | |
1593 | ||
1594 | XPC_DISCONNECT_CHANNEL(ch, xpcUnregistering, | |
89eb8eb9 | 1595 | &irq_flags); |
a607c389 | 1596 | } |
89eb8eb9 DN |
1597 | |
1598 | spin_unlock_irqrestore(&ch->lock, irq_flags); | |
1599 | ||
1600 | xpc_msgqueue_deref(ch); | |
1601 | xpc_part_deref(part); | |
1602 | } | |
1603 | } | |
1604 | ||
1605 | xpc_disconnect_wait(ch_number); | |
1606 | } | |
1607 | ||
1608 | ||
1609 | /* | |
1610 | * To disconnect a channel, and reflect it back to all who may be waiting. | |
1611 | * | |
a607c389 DN |
1612 | * An OPEN is not allowed until XPC_C_DISCONNECTING is cleared by |
1613 | * xpc_process_disconnect(), and if set, XPC_C_WDISCONNECT is cleared by | |
1614 | * xpc_disconnect_wait(). | |
89eb8eb9 DN |
1615 | * |
1616 | * THE CHANNEL IS TO BE LOCKED BY THE CALLER AND WILL REMAIN LOCKED UPON RETURN. | |
1617 | */ | |
1618 | void | |
1619 | xpc_disconnect_channel(const int line, struct xpc_channel *ch, | |
1620 | enum xpc_retval reason, unsigned long *irq_flags) | |
1621 | { | |
a607c389 | 1622 | u32 channel_was_connected = (ch->flags & XPC_C_CONNECTED); |
89eb8eb9 DN |
1623 | |
1624 | ||
1625 | DBUG_ON(!spin_is_locked(&ch->lock)); | |
1626 | ||
1627 | if (ch->flags & (XPC_C_DISCONNECTING | XPC_C_DISCONNECTED)) { | |
1628 | return; | |
1629 | } | |
1630 | DBUG_ON(!(ch->flags & (XPC_C_CONNECTING | XPC_C_CONNECTED))); | |
1631 | ||
1632 | dev_dbg(xpc_chan, "reason=%d, line=%d, partid=%d, channel=%d\n", | |
1633 | reason, line, ch->partid, ch->number); | |
1634 | ||
1635 | XPC_SET_REASON(ch, reason, line); | |
1636 | ||
a607c389 | 1637 | ch->flags |= (XPC_C_CLOSEREQUEST | XPC_C_DISCONNECTING); |
89eb8eb9 DN |
1638 | /* some of these may not have been set */ |
1639 | ch->flags &= ~(XPC_C_OPENREQUEST | XPC_C_OPENREPLY | | |
1640 | XPC_C_ROPENREQUEST | XPC_C_ROPENREPLY | | |
1641 | XPC_C_CONNECTING | XPC_C_CONNECTED); | |
1642 | ||
89eb8eb9 DN |
1643 | xpc_IPI_send_closerequest(ch, irq_flags); |
1644 | ||
a607c389 | 1645 | if (channel_was_connected) { |
89eb8eb9 DN |
1646 | ch->flags |= XPC_C_WASCONNECTED; |
1647 | } | |
1648 | ||
a607c389 DN |
1649 | spin_unlock_irqrestore(&ch->lock, *irq_flags); |
1650 | ||
1651 | /* wake all idle kthreads so they can exit */ | |
89eb8eb9 | 1652 | if (atomic_read(&ch->kthreads_idle) > 0) { |
89eb8eb9 | 1653 | wake_up_all(&ch->idle_wq); |
a460ef8d DN |
1654 | |
1655 | } else if ((ch->flags & XPC_C_CONNECTEDCALLOUT_MADE) && | |
1656 | !(ch->flags & XPC_C_DISCONNECTINGCALLOUT)) { | |
1657 | /* start a kthread that will do the xpcDisconnecting callout */ | |
1658 | xpc_create_kthreads(ch, 1, 1); | |
89eb8eb9 DN |
1659 | } |
1660 | ||
89eb8eb9 | 1661 | /* wake those waiting to allocate an entry from the local msg queue */ |
89eb8eb9 DN |
1662 | if (atomic_read(&ch->n_on_msg_allocate_wq) > 0) { |
1663 | wake_up(&ch->msg_allocate_wq); | |
1664 | } | |
1665 | ||
89eb8eb9 DN |
1666 | spin_lock_irqsave(&ch->lock, *irq_flags); |
1667 | } | |
1668 | ||
1669 | ||
1670 | void | |
246c7e33 | 1671 | xpc_disconnect_callout(struct xpc_channel *ch, enum xpc_retval reason) |
89eb8eb9 DN |
1672 | { |
1673 | /* | |
a607c389 | 1674 | * Let the channel's registerer know that the channel is being |
89eb8eb9 | 1675 | * disconnected. We don't want to do this if the registerer was never |
a607c389 | 1676 | * informed of a connection being made. |
89eb8eb9 DN |
1677 | */ |
1678 | ||
1679 | if (ch->func != NULL) { | |
246c7e33 DN |
1680 | dev_dbg(xpc_chan, "ch->func() called, reason=%d, partid=%d, " |
1681 | "channel=%d\n", reason, ch->partid, ch->number); | |
89eb8eb9 | 1682 | |
246c7e33 | 1683 | ch->func(reason, ch->partid, ch->number, NULL, ch->key); |
89eb8eb9 | 1684 | |
246c7e33 DN |
1685 | dev_dbg(xpc_chan, "ch->func() returned, reason=%d, partid=%d, " |
1686 | "channel=%d\n", reason, ch->partid, ch->number); | |
89eb8eb9 DN |
1687 | } |
1688 | } | |
1689 | ||
1690 | ||
1691 | /* | |
1692 | * Wait for a message entry to become available for the specified channel, | |
1693 | * but don't wait any longer than 1 jiffy. | |
1694 | */ | |
1695 | static enum xpc_retval | |
1696 | xpc_allocate_msg_wait(struct xpc_channel *ch) | |
1697 | { | |
1698 | enum xpc_retval ret; | |
1699 | ||
1700 | ||
1701 | if (ch->flags & XPC_C_DISCONNECTING) { | |
1702 | DBUG_ON(ch->reason == xpcInterrupted); // >>> Is this true? | |
1703 | return ch->reason; | |
1704 | } | |
1705 | ||
1706 | atomic_inc(&ch->n_on_msg_allocate_wq); | |
1707 | ret = interruptible_sleep_on_timeout(&ch->msg_allocate_wq, 1); | |
1708 | atomic_dec(&ch->n_on_msg_allocate_wq); | |
1709 | ||
1710 | if (ch->flags & XPC_C_DISCONNECTING) { | |
1711 | ret = ch->reason; | |
1712 | DBUG_ON(ch->reason == xpcInterrupted); // >>> Is this true? | |
1713 | } else if (ret == 0) { | |
1714 | ret = xpcTimeout; | |
1715 | } else { | |
1716 | ret = xpcInterrupted; | |
1717 | } | |
1718 | ||
1719 | return ret; | |
1720 | } | |
1721 | ||
1722 | ||
1723 | /* | |
1724 | * Allocate an entry for a message from the message queue associated with the | |
1725 | * specified channel. | |
1726 | */ | |
1727 | static enum xpc_retval | |
1728 | xpc_allocate_msg(struct xpc_channel *ch, u32 flags, | |
1729 | struct xpc_msg **address_of_msg) | |
1730 | { | |
1731 | struct xpc_msg *msg; | |
1732 | enum xpc_retval ret; | |
1733 | s64 put; | |
1734 | ||
1735 | ||
1736 | /* this reference will be dropped in xpc_send_msg() */ | |
1737 | xpc_msgqueue_ref(ch); | |
1738 | ||
1739 | if (ch->flags & XPC_C_DISCONNECTING) { | |
1740 | xpc_msgqueue_deref(ch); | |
1741 | return ch->reason; | |
1742 | } | |
1743 | if (!(ch->flags & XPC_C_CONNECTED)) { | |
1744 | xpc_msgqueue_deref(ch); | |
1745 | return xpcNotConnected; | |
1746 | } | |
1747 | ||
1748 | ||
1749 | /* | |
1750 | * Get the next available message entry from the local message queue. | |
1751 | * If none are available, we'll make sure that we grab the latest | |
1752 | * GP values. | |
1753 | */ | |
1754 | ret = xpcTimeout; | |
1755 | ||
1756 | while (1) { | |
1757 | ||
1758 | put = (volatile s64) ch->w_local_GP.put; | |
1759 | if (put - (volatile s64) ch->w_remote_GP.get < | |
1760 | ch->local_nentries) { | |
1761 | ||
1762 | /* There are available message entries. We need to try | |
1763 | * to secure one for ourselves. We'll do this by trying | |
1764 | * to increment w_local_GP.put as long as someone else | |
1765 | * doesn't beat us to it. If they do, we'll have to | |
1766 | * try again. | |
1767 | */ | |
1768 | if (cmpxchg(&ch->w_local_GP.put, put, put + 1) == | |
1769 | put) { | |
1770 | /* we got the entry referenced by put */ | |
1771 | break; | |
1772 | } | |
1773 | continue; /* try again */ | |
1774 | } | |
1775 | ||
1776 | ||
1777 | /* | |
1778 | * There aren't any available msg entries at this time. | |
1779 | * | |
1780 | * In waiting for a message entry to become available, | |
1781 | * we set a timeout in case the other side is not | |
1782 | * sending completion IPIs. This lets us fake an IPI | |
1783 | * that will cause the IPI handler to fetch the latest | |
1784 | * GP values as if an IPI was sent by the other side. | |
1785 | */ | |
1786 | if (ret == xpcTimeout) { | |
1787 | xpc_IPI_send_local_msgrequest(ch); | |
1788 | } | |
1789 | ||
1790 | if (flags & XPC_NOWAIT) { | |
1791 | xpc_msgqueue_deref(ch); | |
1792 | return xpcNoWait; | |
1793 | } | |
1794 | ||
1795 | ret = xpc_allocate_msg_wait(ch); | |
1796 | if (ret != xpcInterrupted && ret != xpcTimeout) { | |
1797 | xpc_msgqueue_deref(ch); | |
1798 | return ret; | |
1799 | } | |
1800 | } | |
1801 | ||
1802 | ||
1803 | /* get the message's address and initialize it */ | |
1804 | msg = (struct xpc_msg *) ((u64) ch->local_msgqueue + | |
1805 | (put % ch->local_nentries) * ch->msg_size); | |
1806 | ||
1807 | ||
1808 | DBUG_ON(msg->flags != 0); | |
1809 | msg->number = put; | |
1810 | ||
1811 | dev_dbg(xpc_chan, "w_local_GP.put changed to %ld; msg=0x%p, " | |
1812 | "msg_number=%ld, partid=%d, channel=%d\n", put + 1, | |
1813 | (void *) msg, msg->number, ch->partid, ch->number); | |
1814 | ||
1815 | *address_of_msg = msg; | |
1816 | ||
1817 | return xpcSuccess; | |
1818 | } | |
1819 | ||
1820 | ||
1821 | /* | |
1822 | * Allocate an entry for a message from the message queue associated with the | |
1823 | * specified channel. NOTE that this routine can sleep waiting for a message | |
1824 | * entry to become available. To not sleep, pass in the XPC_NOWAIT flag. | |
1825 | * | |
1826 | * Arguments: | |
1827 | * | |
1828 | * partid - ID of partition to which the channel is connected. | |
1829 | * ch_number - channel #. | |
1830 | * flags - see xpc.h for valid flags. | |
1831 | * payload - address of the allocated payload area pointer (filled in on | |
1832 | * return) in which the user-defined message is constructed. | |
1833 | */ | |
1834 | enum xpc_retval | |
1835 | xpc_initiate_allocate(partid_t partid, int ch_number, u32 flags, void **payload) | |
1836 | { | |
1837 | struct xpc_partition *part = &xpc_partitions[partid]; | |
1838 | enum xpc_retval ret = xpcUnknownReason; | |
27f4aa3d | 1839 | struct xpc_msg *msg = NULL; |
89eb8eb9 DN |
1840 | |
1841 | ||
1842 | DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS); | |
1843 | DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); | |
1844 | ||
1845 | *payload = NULL; | |
1846 | ||
1847 | if (xpc_part_ref(part)) { | |
1848 | ret = xpc_allocate_msg(&part->channels[ch_number], flags, &msg); | |
1849 | xpc_part_deref(part); | |
1850 | ||
1851 | if (msg != NULL) { | |
1852 | *payload = &msg->payload; | |
1853 | } | |
1854 | } | |
1855 | ||
1856 | return ret; | |
1857 | } | |
1858 | ||
1859 | ||
1860 | /* | |
1861 | * Now we actually send the messages that are ready to be sent by advancing | |
1862 | * the local message queue's Put value and then send an IPI to the recipient | |
1863 | * partition. | |
1864 | */ | |
1865 | static void | |
1866 | xpc_send_msgs(struct xpc_channel *ch, s64 initial_put) | |
1867 | { | |
1868 | struct xpc_msg *msg; | |
1869 | s64 put = initial_put + 1; | |
1870 | int send_IPI = 0; | |
1871 | ||
1872 | ||
1873 | while (1) { | |
1874 | ||
1875 | while (1) { | |
1876 | if (put == (volatile s64) ch->w_local_GP.put) { | |
1877 | break; | |
1878 | } | |
1879 | ||
1880 | msg = (struct xpc_msg *) ((u64) ch->local_msgqueue + | |
1881 | (put % ch->local_nentries) * ch->msg_size); | |
1882 | ||
1883 | if (!(msg->flags & XPC_M_READY)) { | |
1884 | break; | |
1885 | } | |
1886 | ||
1887 | put++; | |
1888 | } | |
1889 | ||
1890 | if (put == initial_put) { | |
1891 | /* nothing's changed */ | |
1892 | break; | |
1893 | } | |
1894 | ||
1895 | if (cmpxchg_rel(&ch->local_GP->put, initial_put, put) != | |
1896 | initial_put) { | |
1897 | /* someone else beat us to it */ | |
1898 | DBUG_ON((volatile s64) ch->local_GP->put < initial_put); | |
1899 | break; | |
1900 | } | |
1901 | ||
1902 | /* we just set the new value of local_GP->put */ | |
1903 | ||
1904 | dev_dbg(xpc_chan, "local_GP->put changed to %ld, partid=%d, " | |
1905 | "channel=%d\n", put, ch->partid, ch->number); | |
1906 | ||
1907 | send_IPI = 1; | |
1908 | ||
1909 | /* | |
1910 | * We need to ensure that the message referenced by | |
1911 | * local_GP->put is not XPC_M_READY or that local_GP->put | |
1912 | * equals w_local_GP.put, so we'll go have a look. | |
1913 | */ | |
1914 | initial_put = put; | |
1915 | } | |
1916 | ||
1917 | if (send_IPI) { | |
1918 | xpc_IPI_send_msgrequest(ch); | |
1919 | } | |
1920 | } | |
1921 | ||
1922 | ||
1923 | /* | |
1924 | * Common code that does the actual sending of the message by advancing the | |
1925 | * local message queue's Put value and sends an IPI to the partition the | |
1926 | * message is being sent to. | |
1927 | */ | |
1928 | static enum xpc_retval | |
1929 | xpc_send_msg(struct xpc_channel *ch, struct xpc_msg *msg, u8 notify_type, | |
1930 | xpc_notify_func func, void *key) | |
1931 | { | |
1932 | enum xpc_retval ret = xpcSuccess; | |
a607c389 | 1933 | struct xpc_notify *notify = notify; |
89eb8eb9 DN |
1934 | s64 put, msg_number = msg->number; |
1935 | ||
1936 | ||
1937 | DBUG_ON(notify_type == XPC_N_CALL && func == NULL); | |
1938 | DBUG_ON((((u64) msg - (u64) ch->local_msgqueue) / ch->msg_size) != | |
1939 | msg_number % ch->local_nentries); | |
1940 | DBUG_ON(msg->flags & XPC_M_READY); | |
1941 | ||
1942 | if (ch->flags & XPC_C_DISCONNECTING) { | |
1943 | /* drop the reference grabbed in xpc_allocate_msg() */ | |
1944 | xpc_msgqueue_deref(ch); | |
1945 | return ch->reason; | |
1946 | } | |
1947 | ||
1948 | if (notify_type != 0) { | |
1949 | /* | |
1950 | * Tell the remote side to send an ACK interrupt when the | |
1951 | * message has been delivered. | |
1952 | */ | |
1953 | msg->flags |= XPC_M_INTERRUPT; | |
1954 | ||
1955 | atomic_inc(&ch->n_to_notify); | |
1956 | ||
1957 | notify = &ch->notify_queue[msg_number % ch->local_nentries]; | |
1958 | notify->func = func; | |
1959 | notify->key = key; | |
821fe947 | 1960 | notify->type = notify_type; |
89eb8eb9 DN |
1961 | |
1962 | // >>> is a mb() needed here? | |
1963 | ||
1964 | if (ch->flags & XPC_C_DISCONNECTING) { | |
1965 | /* | |
1966 | * An error occurred between our last error check and | |
1967 | * this one. We will try to clear the type field from | |
1968 | * the notify entry. If we succeed then | |
1969 | * xpc_disconnect_channel() didn't already process | |
1970 | * the notify entry. | |
1971 | */ | |
1972 | if (cmpxchg(¬ify->type, notify_type, 0) == | |
1973 | notify_type) { | |
1974 | atomic_dec(&ch->n_to_notify); | |
1975 | ret = ch->reason; | |
1976 | } | |
1977 | ||
1978 | /* drop the reference grabbed in xpc_allocate_msg() */ | |
1979 | xpc_msgqueue_deref(ch); | |
1980 | return ret; | |
1981 | } | |
1982 | } | |
1983 | ||
1984 | msg->flags |= XPC_M_READY; | |
1985 | ||
1986 | /* | |
1987 | * The preceding store of msg->flags must occur before the following | |
1988 | * load of ch->local_GP->put. | |
1989 | */ | |
1990 | mb(); | |
1991 | ||
1992 | /* see if the message is next in line to be sent, if so send it */ | |
1993 | ||
1994 | put = ch->local_GP->put; | |
1995 | if (put == msg_number) { | |
1996 | xpc_send_msgs(ch, put); | |
1997 | } | |
1998 | ||
1999 | /* drop the reference grabbed in xpc_allocate_msg() */ | |
2000 | xpc_msgqueue_deref(ch); | |
2001 | return ret; | |
2002 | } | |
2003 | ||
2004 | ||
2005 | /* | |
2006 | * Send a message previously allocated using xpc_initiate_allocate() on the | |
2007 | * specified channel connected to the specified partition. | |
2008 | * | |
2009 | * This routine will not wait for the message to be received, nor will | |
2010 | * notification be given when it does happen. Once this routine has returned | |
2011 | * the message entry allocated via xpc_initiate_allocate() is no longer | |
2012 | * accessable to the caller. | |
2013 | * | |
2014 | * This routine, although called by users, does not call xpc_part_ref() to | |
2015 | * ensure that the partition infrastructure is in place. It relies on the | |
2016 | * fact that we called xpc_msgqueue_ref() in xpc_allocate_msg(). | |
2017 | * | |
2018 | * Arguments: | |
2019 | * | |
2020 | * partid - ID of partition to which the channel is connected. | |
2021 | * ch_number - channel # to send message on. | |
2022 | * payload - pointer to the payload area allocated via | |
2023 | * xpc_initiate_allocate(). | |
2024 | */ | |
2025 | enum xpc_retval | |
2026 | xpc_initiate_send(partid_t partid, int ch_number, void *payload) | |
2027 | { | |
2028 | struct xpc_partition *part = &xpc_partitions[partid]; | |
2029 | struct xpc_msg *msg = XPC_MSG_ADDRESS(payload); | |
2030 | enum xpc_retval ret; | |
2031 | ||
2032 | ||
2033 | dev_dbg(xpc_chan, "msg=0x%p, partid=%d, channel=%d\n", (void *) msg, | |
2034 | partid, ch_number); | |
2035 | ||
2036 | DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS); | |
2037 | DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); | |
2038 | DBUG_ON(msg == NULL); | |
2039 | ||
2040 | ret = xpc_send_msg(&part->channels[ch_number], msg, 0, NULL, NULL); | |
2041 | ||
2042 | return ret; | |
2043 | } | |
2044 | ||
2045 | ||
2046 | /* | |
2047 | * Send a message previously allocated using xpc_initiate_allocate on the | |
2048 | * specified channel connected to the specified partition. | |
2049 | * | |
2050 | * This routine will not wait for the message to be sent. Once this routine | |
2051 | * has returned the message entry allocated via xpc_initiate_allocate() is no | |
2052 | * longer accessable to the caller. | |
2053 | * | |
2054 | * Once the remote end of the channel has received the message, the function | |
2055 | * passed as an argument to xpc_initiate_send_notify() will be called. This | |
2056 | * allows the sender to free up or re-use any buffers referenced by the | |
2057 | * message, but does NOT mean the message has been processed at the remote | |
2058 | * end by a receiver. | |
2059 | * | |
2060 | * If this routine returns an error, the caller's function will NOT be called. | |
2061 | * | |
2062 | * This routine, although called by users, does not call xpc_part_ref() to | |
2063 | * ensure that the partition infrastructure is in place. It relies on the | |
2064 | * fact that we called xpc_msgqueue_ref() in xpc_allocate_msg(). | |
2065 | * | |
2066 | * Arguments: | |
2067 | * | |
2068 | * partid - ID of partition to which the channel is connected. | |
2069 | * ch_number - channel # to send message on. | |
2070 | * payload - pointer to the payload area allocated via | |
2071 | * xpc_initiate_allocate(). | |
2072 | * func - function to call with asynchronous notification of message | |
2073 | * receipt. THIS FUNCTION MUST BE NON-BLOCKING. | |
2074 | * key - user-defined key to be passed to the function when it's called. | |
2075 | */ | |
2076 | enum xpc_retval | |
2077 | xpc_initiate_send_notify(partid_t partid, int ch_number, void *payload, | |
2078 | xpc_notify_func func, void *key) | |
2079 | { | |
2080 | struct xpc_partition *part = &xpc_partitions[partid]; | |
2081 | struct xpc_msg *msg = XPC_MSG_ADDRESS(payload); | |
2082 | enum xpc_retval ret; | |
2083 | ||
2084 | ||
2085 | dev_dbg(xpc_chan, "msg=0x%p, partid=%d, channel=%d\n", (void *) msg, | |
2086 | partid, ch_number); | |
2087 | ||
2088 | DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS); | |
2089 | DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); | |
2090 | DBUG_ON(msg == NULL); | |
2091 | DBUG_ON(func == NULL); | |
2092 | ||
2093 | ret = xpc_send_msg(&part->channels[ch_number], msg, XPC_N_CALL, | |
2094 | func, key); | |
2095 | return ret; | |
2096 | } | |
2097 | ||
2098 | ||
2099 | static struct xpc_msg * | |
2100 | xpc_pull_remote_msg(struct xpc_channel *ch, s64 get) | |
2101 | { | |
2102 | struct xpc_partition *part = &xpc_partitions[ch->partid]; | |
2103 | struct xpc_msg *remote_msg, *msg; | |
2104 | u32 msg_index, nmsgs; | |
2105 | u64 msg_offset; | |
2106 | enum xpc_retval ret; | |
2107 | ||
2108 | ||
f9e505a9 | 2109 | if (mutex_lock_interruptible(&ch->msg_to_pull_mutex) != 0) { |
89eb8eb9 DN |
2110 | /* we were interrupted by a signal */ |
2111 | return NULL; | |
2112 | } | |
2113 | ||
2114 | while (get >= ch->next_msg_to_pull) { | |
2115 | ||
2116 | /* pull as many messages as are ready and able to be pulled */ | |
2117 | ||
2118 | msg_index = ch->next_msg_to_pull % ch->remote_nentries; | |
2119 | ||
2120 | DBUG_ON(ch->next_msg_to_pull >= | |
2121 | (volatile s64) ch->w_remote_GP.put); | |
2122 | nmsgs = (volatile s64) ch->w_remote_GP.put - | |
2123 | ch->next_msg_to_pull; | |
2124 | if (msg_index + nmsgs > ch->remote_nentries) { | |
2125 | /* ignore the ones that wrap the msg queue for now */ | |
2126 | nmsgs = ch->remote_nentries - msg_index; | |
2127 | } | |
2128 | ||
2129 | msg_offset = msg_index * ch->msg_size; | |
2130 | msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue + | |
2131 | msg_offset); | |
2132 | remote_msg = (struct xpc_msg *) (ch->remote_msgqueue_pa + | |
2133 | msg_offset); | |
2134 | ||
2135 | if ((ret = xpc_pull_remote_cachelines(part, msg, remote_msg, | |
2136 | nmsgs * ch->msg_size)) != xpcSuccess) { | |
2137 | ||
2138 | dev_dbg(xpc_chan, "failed to pull %d msgs starting with" | |
2139 | " msg %ld from partition %d, channel=%d, " | |
2140 | "ret=%d\n", nmsgs, ch->next_msg_to_pull, | |
2141 | ch->partid, ch->number, ret); | |
2142 | ||
2143 | XPC_DEACTIVATE_PARTITION(part, ret); | |
2144 | ||
f9e505a9 | 2145 | mutex_unlock(&ch->msg_to_pull_mutex); |
89eb8eb9 DN |
2146 | return NULL; |
2147 | } | |
2148 | ||
2149 | mb(); /* >>> this may not be needed, we're not sure */ | |
2150 | ||
2151 | ch->next_msg_to_pull += nmsgs; | |
2152 | } | |
2153 | ||
f9e505a9 | 2154 | mutex_unlock(&ch->msg_to_pull_mutex); |
89eb8eb9 DN |
2155 | |
2156 | /* return the message we were looking for */ | |
2157 | msg_offset = (get % ch->remote_nentries) * ch->msg_size; | |
2158 | msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue + msg_offset); | |
2159 | ||
2160 | return msg; | |
2161 | } | |
2162 | ||
2163 | ||
2164 | /* | |
2165 | * Get a message to be delivered. | |
2166 | */ | |
2167 | static struct xpc_msg * | |
2168 | xpc_get_deliverable_msg(struct xpc_channel *ch) | |
2169 | { | |
2170 | struct xpc_msg *msg = NULL; | |
2171 | s64 get; | |
2172 | ||
2173 | ||
2174 | do { | |
2175 | if ((volatile u32) ch->flags & XPC_C_DISCONNECTING) { | |
2176 | break; | |
2177 | } | |
2178 | ||
2179 | get = (volatile s64) ch->w_local_GP.get; | |
2180 | if (get == (volatile s64) ch->w_remote_GP.put) { | |
2181 | break; | |
2182 | } | |
2183 | ||
2184 | /* There are messages waiting to be pulled and delivered. | |
2185 | * We need to try to secure one for ourselves. We'll do this | |
2186 | * by trying to increment w_local_GP.get and hope that no one | |
2187 | * else beats us to it. If they do, we'll we'll simply have | |
2188 | * to try again for the next one. | |
2189 | */ | |
2190 | ||
2191 | if (cmpxchg(&ch->w_local_GP.get, get, get + 1) == get) { | |
2192 | /* we got the entry referenced by get */ | |
2193 | ||
2194 | dev_dbg(xpc_chan, "w_local_GP.get changed to %ld, " | |
2195 | "partid=%d, channel=%d\n", get + 1, | |
2196 | ch->partid, ch->number); | |
2197 | ||
2198 | /* pull the message from the remote partition */ | |
2199 | ||
2200 | msg = xpc_pull_remote_msg(ch, get); | |
2201 | ||
2202 | DBUG_ON(msg != NULL && msg->number != get); | |
2203 | DBUG_ON(msg != NULL && (msg->flags & XPC_M_DONE)); | |
2204 | DBUG_ON(msg != NULL && !(msg->flags & XPC_M_READY)); | |
2205 | ||
2206 | break; | |
2207 | } | |
2208 | ||
2209 | } while (1); | |
2210 | ||
2211 | return msg; | |
2212 | } | |
2213 | ||
2214 | ||
2215 | /* | |
2216 | * Deliver a message to its intended recipient. | |
2217 | */ | |
2218 | void | |
2219 | xpc_deliver_msg(struct xpc_channel *ch) | |
2220 | { | |
2221 | struct xpc_msg *msg; | |
2222 | ||
2223 | ||
2224 | if ((msg = xpc_get_deliverable_msg(ch)) != NULL) { | |
2225 | ||
2226 | /* | |
2227 | * This ref is taken to protect the payload itself from being | |
2228 | * freed before the user is finished with it, which the user | |
2229 | * indicates by calling xpc_initiate_received(). | |
2230 | */ | |
2231 | xpc_msgqueue_ref(ch); | |
2232 | ||
2233 | atomic_inc(&ch->kthreads_active); | |
2234 | ||
2235 | if (ch->func != NULL) { | |
2236 | dev_dbg(xpc_chan, "ch->func() called, msg=0x%p, " | |
2237 | "msg_number=%ld, partid=%d, channel=%d\n", | |
2238 | (void *) msg, msg->number, ch->partid, | |
2239 | ch->number); | |
2240 | ||
2241 | /* deliver the message to its intended recipient */ | |
2242 | ch->func(xpcMsgReceived, ch->partid, ch->number, | |
2243 | &msg->payload, ch->key); | |
2244 | ||
2245 | dev_dbg(xpc_chan, "ch->func() returned, msg=0x%p, " | |
2246 | "msg_number=%ld, partid=%d, channel=%d\n", | |
2247 | (void *) msg, msg->number, ch->partid, | |
2248 | ch->number); | |
2249 | } | |
2250 | ||
2251 | atomic_dec(&ch->kthreads_active); | |
2252 | } | |
2253 | } | |
2254 | ||
2255 | ||
2256 | /* | |
2257 | * Now we actually acknowledge the messages that have been delivered and ack'd | |
2258 | * by advancing the cached remote message queue's Get value and if requested | |
2259 | * send an IPI to the message sender's partition. | |
2260 | */ | |
2261 | static void | |
2262 | xpc_acknowledge_msgs(struct xpc_channel *ch, s64 initial_get, u8 msg_flags) | |
2263 | { | |
2264 | struct xpc_msg *msg; | |
2265 | s64 get = initial_get + 1; | |
2266 | int send_IPI = 0; | |
2267 | ||
2268 | ||
2269 | while (1) { | |
2270 | ||
2271 | while (1) { | |
2272 | if (get == (volatile s64) ch->w_local_GP.get) { | |
2273 | break; | |
2274 | } | |
2275 | ||
2276 | msg = (struct xpc_msg *) ((u64) ch->remote_msgqueue + | |
2277 | (get % ch->remote_nentries) * ch->msg_size); | |
2278 | ||
2279 | if (!(msg->flags & XPC_M_DONE)) { | |
2280 | break; | |
2281 | } | |
2282 | ||
2283 | msg_flags |= msg->flags; | |
2284 | get++; | |
2285 | } | |
2286 | ||
2287 | if (get == initial_get) { | |
2288 | /* nothing's changed */ | |
2289 | break; | |
2290 | } | |
2291 | ||
2292 | if (cmpxchg_rel(&ch->local_GP->get, initial_get, get) != | |
2293 | initial_get) { | |
2294 | /* someone else beat us to it */ | |
2295 | DBUG_ON((volatile s64) ch->local_GP->get <= | |
2296 | initial_get); | |
2297 | break; | |
2298 | } | |
2299 | ||
2300 | /* we just set the new value of local_GP->get */ | |
2301 | ||
2302 | dev_dbg(xpc_chan, "local_GP->get changed to %ld, partid=%d, " | |
2303 | "channel=%d\n", get, ch->partid, ch->number); | |
2304 | ||
2305 | send_IPI = (msg_flags & XPC_M_INTERRUPT); | |
2306 | ||
2307 | /* | |
2308 | * We need to ensure that the message referenced by | |
2309 | * local_GP->get is not XPC_M_DONE or that local_GP->get | |
2310 | * equals w_local_GP.get, so we'll go have a look. | |
2311 | */ | |
2312 | initial_get = get; | |
2313 | } | |
2314 | ||
2315 | if (send_IPI) { | |
2316 | xpc_IPI_send_msgrequest(ch); | |
2317 | } | |
2318 | } | |
2319 | ||
2320 | ||
2321 | /* | |
2322 | * Acknowledge receipt of a delivered message. | |
2323 | * | |
2324 | * If a message has XPC_M_INTERRUPT set, send an interrupt to the partition | |
2325 | * that sent the message. | |
2326 | * | |
2327 | * This function, although called by users, does not call xpc_part_ref() to | |
2328 | * ensure that the partition infrastructure is in place. It relies on the | |
2329 | * fact that we called xpc_msgqueue_ref() in xpc_deliver_msg(). | |
2330 | * | |
2331 | * Arguments: | |
2332 | * | |
2333 | * partid - ID of partition to which the channel is connected. | |
2334 | * ch_number - channel # message received on. | |
2335 | * payload - pointer to the payload area allocated via | |
2336 | * xpc_initiate_allocate(). | |
2337 | */ | |
2338 | void | |
2339 | xpc_initiate_received(partid_t partid, int ch_number, void *payload) | |
2340 | { | |
2341 | struct xpc_partition *part = &xpc_partitions[partid]; | |
2342 | struct xpc_channel *ch; | |
2343 | struct xpc_msg *msg = XPC_MSG_ADDRESS(payload); | |
2344 | s64 get, msg_number = msg->number; | |
2345 | ||
2346 | ||
2347 | DBUG_ON(partid <= 0 || partid >= XP_MAX_PARTITIONS); | |
2348 | DBUG_ON(ch_number < 0 || ch_number >= part->nchannels); | |
2349 | ||
2350 | ch = &part->channels[ch_number]; | |
2351 | ||
2352 | dev_dbg(xpc_chan, "msg=0x%p, msg_number=%ld, partid=%d, channel=%d\n", | |
2353 | (void *) msg, msg_number, ch->partid, ch->number); | |
2354 | ||
2355 | DBUG_ON((((u64) msg - (u64) ch->remote_msgqueue) / ch->msg_size) != | |
2356 | msg_number % ch->remote_nentries); | |
2357 | DBUG_ON(msg->flags & XPC_M_DONE); | |
2358 | ||
2359 | msg->flags |= XPC_M_DONE; | |
2360 | ||
2361 | /* | |
2362 | * The preceding store of msg->flags must occur before the following | |
2363 | * load of ch->local_GP->get. | |
2364 | */ | |
2365 | mb(); | |
2366 | ||
2367 | /* | |
2368 | * See if this message is next in line to be acknowledged as having | |
2369 | * been delivered. | |
2370 | */ | |
2371 | get = ch->local_GP->get; | |
2372 | if (get == msg_number) { | |
2373 | xpc_acknowledge_msgs(ch, get, msg->flags); | |
2374 | } | |
2375 | ||
2376 | /* the call to xpc_msgqueue_ref() was done by xpc_deliver_msg() */ | |
2377 | xpc_msgqueue_deref(ch); | |
2378 | } | |
2379 |