sgi-xpc: prevent false heartbeat failures
[linux-2.6.git] / drivers / misc / sgi-xp / xpc_sn2.c
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (c) 2008-2009 Silicon Graphics, Inc.  All Rights Reserved.
7  */
8
9 /*
10  * Cross Partition Communication (XPC) sn2-based functions.
11  *
12  *     Architecture specific implementation of common functions.
13  *
14  */
15
16 #include <linux/delay.h>
17 #include <asm/uncached.h>
18 #include <asm/sn/mspec.h>
19 #include <asm/sn/sn_sal.h>
20 #include "xpc.h"
21
22 /*
23  * Define the number of u64s required to represent all the C-brick nasids
24  * as a bitmap.  The cross-partition kernel modules deal only with
25  * C-brick nasids, thus the need for bitmaps which don't account for
26  * odd-numbered (non C-brick) nasids.
27  */
28 #define XPC_MAX_PHYSNODES_SN2   (MAX_NUMALINK_NODES / 2)
29 #define XP_NASID_MASK_BYTES_SN2 ((XPC_MAX_PHYSNODES_SN2 + 7) / 8)
30 #define XP_NASID_MASK_WORDS_SN2 ((XPC_MAX_PHYSNODES_SN2 + 63) / 64)
31
32 /*
33  * Memory for XPC's amo variables is allocated by the MSPEC driver. These
34  * pages are located in the lowest granule. The lowest granule uses 4k pages
35  * for cached references and an alternate TLB handler to never provide a
36  * cacheable mapping for the entire region. This will prevent speculative
37  * reading of cached copies of our lines from being issued which will cause
38  * a PI FSB Protocol error to be generated by the SHUB. For XPC, we need 64
39  * amo variables (based on XP_MAX_NPARTITIONS_SN2) to identify the senders of
40  * NOTIFY IRQs, 128 amo variables (based on XP_NASID_MASK_WORDS_SN2) to identify
41  * the senders of ACTIVATE IRQs, 1 amo variable to identify which remote
42  * partitions (i.e., XPCs) consider themselves currently engaged with the
43  * local XPC and 1 amo variable to request partition deactivation.
44  */
45 #define XPC_NOTIFY_IRQ_AMOS_SN2         0
46 #define XPC_ACTIVATE_IRQ_AMOS_SN2       (XPC_NOTIFY_IRQ_AMOS_SN2 + \
47                                          XP_MAX_NPARTITIONS_SN2)
48 #define XPC_ENGAGED_PARTITIONS_AMO_SN2  (XPC_ACTIVATE_IRQ_AMOS_SN2 + \
49                                          XP_NASID_MASK_WORDS_SN2)
50 #define XPC_DEACTIVATE_REQUEST_AMO_SN2  (XPC_ENGAGED_PARTITIONS_AMO_SN2 + 1)
51
52 /*
53  * Buffer used to store a local copy of portions of a remote partition's
54  * reserved page (either its header and part_nasids mask, or its vars).
55  */
56 static void *xpc_remote_copy_buffer_base_sn2;
57 static char *xpc_remote_copy_buffer_sn2;
58
59 static struct xpc_vars_sn2 *xpc_vars_sn2;
60 static struct xpc_vars_part_sn2 *xpc_vars_part_sn2;
61
62 static int
63 xpc_setup_partitions_sn_sn2(void)
64 {
65         /* nothing needs to be done */
66         return 0;
67 }
68
69 static void
70 xpc_teardown_partitions_sn_sn2(void)
71 {
72         /* nothing needs to be done */
73 }
74
75 /* SH_IPI_ACCESS shub register value on startup */
76 static u64 xpc_sh1_IPI_access_sn2;
77 static u64 xpc_sh2_IPI_access0_sn2;
78 static u64 xpc_sh2_IPI_access1_sn2;
79 static u64 xpc_sh2_IPI_access2_sn2;
80 static u64 xpc_sh2_IPI_access3_sn2;
81
82 /*
83  * Change protections to allow IPI operations.
84  */
85 static void
86 xpc_allow_IPI_ops_sn2(void)
87 {
88         int node;
89         int nasid;
90
91         /* !!! The following should get moved into SAL. */
92         if (is_shub2()) {
93                 xpc_sh2_IPI_access0_sn2 =
94                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS0));
95                 xpc_sh2_IPI_access1_sn2 =
96                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS1));
97                 xpc_sh2_IPI_access2_sn2 =
98                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS2));
99                 xpc_sh2_IPI_access3_sn2 =
100                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS3));
101
102                 for_each_online_node(node) {
103                         nasid = cnodeid_to_nasid(node);
104                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
105                               -1UL);
106                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
107                               -1UL);
108                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
109                               -1UL);
110                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
111                               -1UL);
112                 }
113         } else {
114                 xpc_sh1_IPI_access_sn2 =
115                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH1_IPI_ACCESS));
116
117                 for_each_online_node(node) {
118                         nasid = cnodeid_to_nasid(node);
119                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
120                               -1UL);
121                 }
122         }
123 }
124
125 /*
126  * Restrict protections to disallow IPI operations.
127  */
128 static void
129 xpc_disallow_IPI_ops_sn2(void)
130 {
131         int node;
132         int nasid;
133
134         /* !!! The following should get moved into SAL. */
135         if (is_shub2()) {
136                 for_each_online_node(node) {
137                         nasid = cnodeid_to_nasid(node);
138                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
139                               xpc_sh2_IPI_access0_sn2);
140                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
141                               xpc_sh2_IPI_access1_sn2);
142                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
143                               xpc_sh2_IPI_access2_sn2);
144                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
145                               xpc_sh2_IPI_access3_sn2);
146                 }
147         } else {
148                 for_each_online_node(node) {
149                         nasid = cnodeid_to_nasid(node);
150                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
151                               xpc_sh1_IPI_access_sn2);
152                 }
153         }
154 }
155
156 /*
157  * The following set of functions are used for the sending and receiving of
158  * IRQs (also known as IPIs). There are two flavors of IRQs, one that is
159  * associated with partition activity (SGI_XPC_ACTIVATE) and the other that
160  * is associated with channel activity (SGI_XPC_NOTIFY).
161  */
162
163 static u64
164 xpc_receive_IRQ_amo_sn2(struct amo *amo)
165 {
166         return FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_CLEAR);
167 }
168
169 static enum xp_retval
170 xpc_send_IRQ_sn2(struct amo *amo, u64 flag, int nasid, int phys_cpuid,
171                  int vector)
172 {
173         int ret = 0;
174         unsigned long irq_flags;
175
176         local_irq_save(irq_flags);
177
178         FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR, flag);
179         sn_send_IPI_phys(nasid, phys_cpuid, vector, 0);
180
181         /*
182          * We must always use the nofault function regardless of whether we
183          * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
184          * didn't, we'd never know that the other partition is down and would
185          * keep sending IRQs and amos to it until the heartbeat times out.
186          */
187         ret = xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->variable),
188                                                      xp_nofault_PIOR_target));
189
190         local_irq_restore(irq_flags);
191
192         return (ret == 0) ? xpSuccess : xpPioReadError;
193 }
194
195 static struct amo *
196 xpc_init_IRQ_amo_sn2(int index)
197 {
198         struct amo *amo = xpc_vars_sn2->amos_page + index;
199
200         (void)xpc_receive_IRQ_amo_sn2(amo);     /* clear amo variable */
201         return amo;
202 }
203
204 /*
205  * Functions associated with SGI_XPC_ACTIVATE IRQ.
206  */
207
208 /*
209  * Notify the heartbeat check thread that an activate IRQ has been received.
210  */
211 static irqreturn_t
212 xpc_handle_activate_IRQ_sn2(int irq, void *dev_id)
213 {
214         unsigned long irq_flags;
215
216         spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
217         xpc_activate_IRQ_rcvd++;
218         spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
219
220         wake_up_interruptible(&xpc_activate_IRQ_wq);
221         return IRQ_HANDLED;
222 }
223
224 /*
225  * Flag the appropriate amo variable and send an IRQ to the specified node.
226  */
227 static void
228 xpc_send_activate_IRQ_sn2(unsigned long amos_page_pa, int from_nasid,
229                           int to_nasid, int to_phys_cpuid)
230 {
231         struct amo *amos = (struct amo *)__va(amos_page_pa +
232                                               (XPC_ACTIVATE_IRQ_AMOS_SN2 *
233                                               sizeof(struct amo)));
234
235         (void)xpc_send_IRQ_sn2(&amos[BIT_WORD(from_nasid / 2)],
236                                BIT_MASK(from_nasid / 2), to_nasid,
237                                to_phys_cpuid, SGI_XPC_ACTIVATE);
238 }
239
240 static void
241 xpc_send_local_activate_IRQ_sn2(int from_nasid)
242 {
243         unsigned long irq_flags;
244         struct amo *amos = (struct amo *)__va(xpc_vars_sn2->amos_page_pa +
245                                               (XPC_ACTIVATE_IRQ_AMOS_SN2 *
246                                               sizeof(struct amo)));
247
248         /* fake the sending and receipt of an activate IRQ from remote nasid */
249         FETCHOP_STORE_OP(TO_AMO((u64)&amos[BIT_WORD(from_nasid / 2)].variable),
250                          FETCHOP_OR, BIT_MASK(from_nasid / 2));
251
252         spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
253         xpc_activate_IRQ_rcvd++;
254         spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
255
256         wake_up_interruptible(&xpc_activate_IRQ_wq);
257 }
258
259 /*
260  * Functions associated with SGI_XPC_NOTIFY IRQ.
261  */
262
263 /*
264  * Check to see if any chctl flags were sent from the specified partition.
265  */
266 static void
267 xpc_check_for_sent_chctl_flags_sn2(struct xpc_partition *part)
268 {
269         union xpc_channel_ctl_flags chctl;
270         unsigned long irq_flags;
271
272         chctl.all_flags = xpc_receive_IRQ_amo_sn2(part->sn.sn2.
273                                                   local_chctl_amo_va);
274         if (chctl.all_flags == 0)
275                 return;
276
277         spin_lock_irqsave(&part->chctl_lock, irq_flags);
278         part->chctl.all_flags |= chctl.all_flags;
279         spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
280
281         dev_dbg(xpc_chan, "received notify IRQ from partid=%d, chctl.all_flags="
282                 "0x%lx\n", XPC_PARTID(part), chctl.all_flags);
283
284         xpc_wakeup_channel_mgr(part);
285 }
286
287 /*
288  * Handle the receipt of a SGI_XPC_NOTIFY IRQ by seeing whether the specified
289  * partition actually sent it. Since SGI_XPC_NOTIFY IRQs may be shared by more
290  * than one partition, we use an amo structure per partition to indicate
291  * whether a partition has sent an IRQ or not.  If it has, then wake up the
292  * associated kthread to handle it.
293  *
294  * All SGI_XPC_NOTIFY IRQs received by XPC are the result of IRQs sent by XPC
295  * running on other partitions.
296  *
297  * Noteworthy Arguments:
298  *
299  *      irq - Interrupt ReQuest number. NOT USED.
300  *
301  *      dev_id - partid of IRQ's potential sender.
302  */
303 static irqreturn_t
304 xpc_handle_notify_IRQ_sn2(int irq, void *dev_id)
305 {
306         short partid = (short)(u64)dev_id;
307         struct xpc_partition *part = &xpc_partitions[partid];
308
309         DBUG_ON(partid < 0 || partid >= XP_MAX_NPARTITIONS_SN2);
310
311         if (xpc_part_ref(part)) {
312                 xpc_check_for_sent_chctl_flags_sn2(part);
313
314                 xpc_part_deref(part);
315         }
316         return IRQ_HANDLED;
317 }
318
319 /*
320  * Check to see if xpc_handle_notify_IRQ_sn2() dropped any IRQs on the floor
321  * because the write to their associated amo variable completed after the IRQ
322  * was received.
323  */
324 static void
325 xpc_check_for_dropped_notify_IRQ_sn2(struct xpc_partition *part)
326 {
327         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
328
329         if (xpc_part_ref(part)) {
330                 xpc_check_for_sent_chctl_flags_sn2(part);
331
332                 part_sn2->dropped_notify_IRQ_timer.expires = jiffies +
333                     XPC_DROPPED_NOTIFY_IRQ_WAIT_INTERVAL;
334                 add_timer(&part_sn2->dropped_notify_IRQ_timer);
335                 xpc_part_deref(part);
336         }
337 }
338
339 /*
340  * Send a notify IRQ to the remote partition that is associated with the
341  * specified channel.
342  */
343 static void
344 xpc_send_notify_IRQ_sn2(struct xpc_channel *ch, u8 chctl_flag,
345                         char *chctl_flag_string, unsigned long *irq_flags)
346 {
347         struct xpc_partition *part = &xpc_partitions[ch->partid];
348         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
349         union xpc_channel_ctl_flags chctl = { 0 };
350         enum xp_retval ret;
351
352         if (likely(part->act_state != XPC_P_AS_DEACTIVATING)) {
353                 chctl.flags[ch->number] = chctl_flag;
354                 ret = xpc_send_IRQ_sn2(part_sn2->remote_chctl_amo_va,
355                                        chctl.all_flags,
356                                        part_sn2->notify_IRQ_nasid,
357                                        part_sn2->notify_IRQ_phys_cpuid,
358                                        SGI_XPC_NOTIFY);
359                 dev_dbg(xpc_chan, "%s sent to partid=%d, channel=%d, ret=%d\n",
360                         chctl_flag_string, ch->partid, ch->number, ret);
361                 if (unlikely(ret != xpSuccess)) {
362                         if (irq_flags != NULL)
363                                 spin_unlock_irqrestore(&ch->lock, *irq_flags);
364                         XPC_DEACTIVATE_PARTITION(part, ret);
365                         if (irq_flags != NULL)
366                                 spin_lock_irqsave(&ch->lock, *irq_flags);
367                 }
368         }
369 }
370
371 #define XPC_SEND_NOTIFY_IRQ_SN2(_ch, _ipi_f, _irq_f) \
372                 xpc_send_notify_IRQ_sn2(_ch, _ipi_f, #_ipi_f, _irq_f)
373
374 /*
375  * Make it look like the remote partition, which is associated with the
376  * specified channel, sent us a notify IRQ. This faked IRQ will be handled
377  * by xpc_check_for_dropped_notify_IRQ_sn2().
378  */
379 static void
380 xpc_send_local_notify_IRQ_sn2(struct xpc_channel *ch, u8 chctl_flag,
381                               char *chctl_flag_string)
382 {
383         struct xpc_partition *part = &xpc_partitions[ch->partid];
384         union xpc_channel_ctl_flags chctl = { 0 };
385
386         chctl.flags[ch->number] = chctl_flag;
387         FETCHOP_STORE_OP(TO_AMO((u64)&part->sn.sn2.local_chctl_amo_va->
388                                 variable), FETCHOP_OR, chctl.all_flags);
389         dev_dbg(xpc_chan, "%s sent local from partid=%d, channel=%d\n",
390                 chctl_flag_string, ch->partid, ch->number);
391 }
392
393 #define XPC_SEND_LOCAL_NOTIFY_IRQ_SN2(_ch, _ipi_f) \
394                 xpc_send_local_notify_IRQ_sn2(_ch, _ipi_f, #_ipi_f)
395
396 static void
397 xpc_send_chctl_closerequest_sn2(struct xpc_channel *ch,
398                                 unsigned long *irq_flags)
399 {
400         struct xpc_openclose_args *args = ch->sn.sn2.local_openclose_args;
401
402         args->reason = ch->reason;
403         XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_CLOSEREQUEST, irq_flags);
404 }
405
406 static void
407 xpc_send_chctl_closereply_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
408 {
409         XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_CLOSEREPLY, irq_flags);
410 }
411
412 static void
413 xpc_send_chctl_openrequest_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
414 {
415         struct xpc_openclose_args *args = ch->sn.sn2.local_openclose_args;
416
417         args->entry_size = ch->entry_size;
418         args->local_nentries = ch->local_nentries;
419         XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_OPENREQUEST, irq_flags);
420 }
421
422 static void
423 xpc_send_chctl_openreply_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
424 {
425         struct xpc_openclose_args *args = ch->sn.sn2.local_openclose_args;
426
427         args->remote_nentries = ch->remote_nentries;
428         args->local_nentries = ch->local_nentries;
429         args->local_msgqueue_pa = xp_pa(ch->sn.sn2.local_msgqueue);
430         XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_OPENREPLY, irq_flags);
431 }
432
433 static void
434 xpc_send_chctl_msgrequest_sn2(struct xpc_channel *ch)
435 {
436         XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_MSGREQUEST, NULL);
437 }
438
439 static void
440 xpc_send_chctl_local_msgrequest_sn2(struct xpc_channel *ch)
441 {
442         XPC_SEND_LOCAL_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_MSGREQUEST);
443 }
444
445 static enum xp_retval
446 xpc_save_remote_msgqueue_pa_sn2(struct xpc_channel *ch,
447                                 unsigned long msgqueue_pa)
448 {
449         ch->sn.sn2.remote_msgqueue_pa = msgqueue_pa;
450         return xpSuccess;
451 }
452
453 /*
454  * This next set of functions are used to keep track of when a partition is
455  * potentially engaged in accessing memory belonging to another partition.
456  */
457
458 static void
459 xpc_indicate_partition_engaged_sn2(struct xpc_partition *part)
460 {
461         unsigned long irq_flags;
462         struct amo *amo = (struct amo *)__va(part->sn.sn2.remote_amos_page_pa +
463                                              (XPC_ENGAGED_PARTITIONS_AMO_SN2 *
464                                              sizeof(struct amo)));
465
466         local_irq_save(irq_flags);
467
468         /* set bit corresponding to our partid in remote partition's amo */
469         FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR,
470                          BIT(sn_partition_id));
471
472         /*
473          * We must always use the nofault function regardless of whether we
474          * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
475          * didn't, we'd never know that the other partition is down and would
476          * keep sending IRQs and amos to it until the heartbeat times out.
477          */
478         (void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
479                                                                variable),
480                                                      xp_nofault_PIOR_target));
481
482         local_irq_restore(irq_flags);
483 }
484
485 static void
486 xpc_indicate_partition_disengaged_sn2(struct xpc_partition *part)
487 {
488         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
489         unsigned long irq_flags;
490         struct amo *amo = (struct amo *)__va(part_sn2->remote_amos_page_pa +
491                                              (XPC_ENGAGED_PARTITIONS_AMO_SN2 *
492                                              sizeof(struct amo)));
493
494         local_irq_save(irq_flags);
495
496         /* clear bit corresponding to our partid in remote partition's amo */
497         FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
498                          ~BIT(sn_partition_id));
499
500         /*
501          * We must always use the nofault function regardless of whether we
502          * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
503          * didn't, we'd never know that the other partition is down and would
504          * keep sending IRQs and amos to it until the heartbeat times out.
505          */
506         (void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
507                                                                variable),
508                                                      xp_nofault_PIOR_target));
509
510         local_irq_restore(irq_flags);
511
512         /*
513          * Send activate IRQ to get other side to see that we've cleared our
514          * bit in their engaged partitions amo.
515          */
516         xpc_send_activate_IRQ_sn2(part_sn2->remote_amos_page_pa,
517                                   cnodeid_to_nasid(0),
518                                   part_sn2->activate_IRQ_nasid,
519                                   part_sn2->activate_IRQ_phys_cpuid);
520 }
521
522 static void
523 xpc_assume_partition_disengaged_sn2(short partid)
524 {
525         struct amo *amo = xpc_vars_sn2->amos_page +
526                           XPC_ENGAGED_PARTITIONS_AMO_SN2;
527
528         /* clear bit(s) based on partid mask in our partition's amo */
529         FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
530                          ~BIT(partid));
531 }
532
533 static int
534 xpc_partition_engaged_sn2(short partid)
535 {
536         struct amo *amo = xpc_vars_sn2->amos_page +
537                           XPC_ENGAGED_PARTITIONS_AMO_SN2;
538
539         /* our partition's amo variable ANDed with partid mask */
540         return (FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) &
541                 BIT(partid)) != 0;
542 }
543
544 static int
545 xpc_any_partition_engaged_sn2(void)
546 {
547         struct amo *amo = xpc_vars_sn2->amos_page +
548                           XPC_ENGAGED_PARTITIONS_AMO_SN2;
549
550         /* our partition's amo variable */
551         return FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) != 0;
552 }
553
554 /* original protection values for each node */
555 static u64 xpc_prot_vec_sn2[MAX_NUMNODES];
556
557 /*
558  * Change protections to allow amo operations on non-Shub 1.1 systems.
559  */
560 static enum xp_retval
561 xpc_allow_amo_ops_sn2(struct amo *amos_page)
562 {
563         enum xp_retval ret = xpSuccess;
564
565         /*
566          * On SHUB 1.1, we cannot call sn_change_memprotect() since the BIST
567          * collides with memory operations. On those systems we call
568          * xpc_allow_amo_ops_shub_wars_1_1_sn2() instead.
569          */
570         if (!enable_shub_wars_1_1())
571                 ret = xp_expand_memprotect(ia64_tpa((u64)amos_page), PAGE_SIZE);
572
573         return ret;
574 }
575
576 /*
577  * Change protections to allow amo operations on Shub 1.1 systems.
578  */
579 static void
580 xpc_allow_amo_ops_shub_wars_1_1_sn2(void)
581 {
582         int node;
583         int nasid;
584
585         if (!enable_shub_wars_1_1())
586                 return;
587
588         for_each_online_node(node) {
589                 nasid = cnodeid_to_nasid(node);
590                 /* save current protection values */
591                 xpc_prot_vec_sn2[node] =
592                     (u64)HUB_L((u64 *)GLOBAL_MMR_ADDR(nasid,
593                                                   SH1_MD_DQLP_MMR_DIR_PRIVEC0));
594                 /* open up everything */
595                 HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid,
596                                              SH1_MD_DQLP_MMR_DIR_PRIVEC0),
597                       -1UL);
598                 HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid,
599                                              SH1_MD_DQRP_MMR_DIR_PRIVEC0),
600                       -1UL);
601         }
602 }
603
604 static enum xp_retval
605 xpc_get_partition_rsvd_page_pa_sn2(void *buf, u64 *cookie, unsigned long *rp_pa,
606                                    size_t *len)
607 {
608         s64 status;
609         enum xp_retval ret;
610
611         status = sn_partition_reserved_page_pa((u64)buf, cookie, rp_pa, len);
612         if (status == SALRET_OK)
613                 ret = xpSuccess;
614         else if (status == SALRET_MORE_PASSES)
615                 ret = xpNeedMoreInfo;
616         else
617                 ret = xpSalError;
618
619         return ret;
620 }
621
622
623 static int
624 xpc_setup_rsvd_page_sn_sn2(struct xpc_rsvd_page *rp)
625 {
626         struct amo *amos_page;
627         int i;
628         int ret;
629
630         xpc_vars_sn2 = XPC_RP_VARS(rp);
631
632         rp->sn.sn2.vars_pa = xp_pa(xpc_vars_sn2);
633
634         /* vars_part array follows immediately after vars */
635         xpc_vars_part_sn2 = (struct xpc_vars_part_sn2 *)((u8 *)XPC_RP_VARS(rp) +
636                                                          XPC_RP_VARS_SIZE);
637
638         /*
639          * Before clearing xpc_vars_sn2, see if a page of amos had been
640          * previously allocated. If not we'll need to allocate one and set
641          * permissions so that cross-partition amos are allowed.
642          *
643          * The allocated amo page needs MCA reporting to remain disabled after
644          * XPC has unloaded.  To make this work, we keep a copy of the pointer
645          * to this page (i.e., amos_page) in the struct xpc_vars_sn2 structure,
646          * which is pointed to by the reserved page, and re-use that saved copy
647          * on subsequent loads of XPC. This amo page is never freed, and its
648          * memory protections are never restricted.
649          */
650         amos_page = xpc_vars_sn2->amos_page;
651         if (amos_page == NULL) {
652                 amos_page = (struct amo *)TO_AMO(uncached_alloc_page(0, 1));
653                 if (amos_page == NULL) {
654                         dev_err(xpc_part, "can't allocate page of amos\n");
655                         return -ENOMEM;
656                 }
657
658                 /*
659                  * Open up amo-R/W to cpu.  This is done on Shub 1.1 systems
660                  * when xpc_allow_amo_ops_shub_wars_1_1_sn2() is called.
661                  */
662                 ret = xpc_allow_amo_ops_sn2(amos_page);
663                 if (ret != xpSuccess) {
664                         dev_err(xpc_part, "can't allow amo operations\n");
665                         uncached_free_page(__IA64_UNCACHED_OFFSET |
666                                            TO_PHYS((u64)amos_page), 1);
667                         return -EPERM;
668                 }
669         }
670
671         /* clear xpc_vars_sn2 */
672         memset(xpc_vars_sn2, 0, sizeof(struct xpc_vars_sn2));
673
674         xpc_vars_sn2->version = XPC_V_VERSION;
675         xpc_vars_sn2->activate_IRQ_nasid = cpuid_to_nasid(0);
676         xpc_vars_sn2->activate_IRQ_phys_cpuid = cpu_physical_id(0);
677         xpc_vars_sn2->vars_part_pa = xp_pa(xpc_vars_part_sn2);
678         xpc_vars_sn2->amos_page_pa = ia64_tpa((u64)amos_page);
679         xpc_vars_sn2->amos_page = amos_page;    /* save for next load of XPC */
680
681         /* clear xpc_vars_part_sn2 */
682         memset((u64 *)xpc_vars_part_sn2, 0, sizeof(struct xpc_vars_part_sn2) *
683                XP_MAX_NPARTITIONS_SN2);
684
685         /* initialize the activate IRQ related amo variables */
686         for (i = 0; i < xpc_nasid_mask_nlongs; i++)
687                 (void)xpc_init_IRQ_amo_sn2(XPC_ACTIVATE_IRQ_AMOS_SN2 + i);
688
689         /* initialize the engaged remote partitions related amo variables */
690         (void)xpc_init_IRQ_amo_sn2(XPC_ENGAGED_PARTITIONS_AMO_SN2);
691         (void)xpc_init_IRQ_amo_sn2(XPC_DEACTIVATE_REQUEST_AMO_SN2);
692
693         return 0;
694 }
695
696 static int
697 xpc_hb_allowed_sn2(short partid, void *heartbeating_to_mask)
698 {
699         return test_bit(partid, heartbeating_to_mask);
700 }
701
702 static void
703 xpc_allow_hb_sn2(short partid)
704 {
705         DBUG_ON(xpc_vars_sn2 == NULL);
706         set_bit(partid, xpc_vars_sn2->heartbeating_to_mask);
707 }
708
709 static void
710 xpc_disallow_hb_sn2(short partid)
711 {
712         DBUG_ON(xpc_vars_sn2 == NULL);
713         clear_bit(partid, xpc_vars_sn2->heartbeating_to_mask);
714 }
715
716 static void
717 xpc_disallow_all_hbs_sn2(void)
718 {
719         DBUG_ON(xpc_vars_sn2 == NULL);
720         bitmap_zero(xpc_vars_sn2->heartbeating_to_mask, xp_max_npartitions);
721 }
722
723 static void
724 xpc_increment_heartbeat_sn2(void)
725 {
726         xpc_vars_sn2->heartbeat++;
727 }
728
729 static void
730 xpc_offline_heartbeat_sn2(void)
731 {
732         xpc_increment_heartbeat_sn2();
733         xpc_vars_sn2->heartbeat_offline = 1;
734 }
735
736 static void
737 xpc_online_heartbeat_sn2(void)
738 {
739         xpc_increment_heartbeat_sn2();
740         xpc_vars_sn2->heartbeat_offline = 0;
741 }
742
743 static void
744 xpc_heartbeat_init_sn2(void)
745 {
746         DBUG_ON(xpc_vars_sn2 == NULL);
747
748         bitmap_zero(xpc_vars_sn2->heartbeating_to_mask, XP_MAX_NPARTITIONS_SN2);
749         xpc_online_heartbeat_sn2();
750 }
751
752 static void
753 xpc_heartbeat_exit_sn2(void)
754 {
755         xpc_offline_heartbeat_sn2();
756 }
757
758 static enum xp_retval
759 xpc_get_remote_heartbeat_sn2(struct xpc_partition *part)
760 {
761         struct xpc_vars_sn2 *remote_vars;
762         enum xp_retval ret;
763
764         remote_vars = (struct xpc_vars_sn2 *)xpc_remote_copy_buffer_sn2;
765
766         /* pull the remote vars structure that contains the heartbeat */
767         ret = xp_remote_memcpy(xp_pa(remote_vars),
768                                part->sn.sn2.remote_vars_pa,
769                                XPC_RP_VARS_SIZE);
770         if (ret != xpSuccess)
771                 return ret;
772
773         dev_dbg(xpc_part, "partid=%d, heartbeat=%ld, last_heartbeat=%ld, "
774                 "heartbeat_offline=%ld, HB_mask[0]=0x%lx\n", XPC_PARTID(part),
775                 remote_vars->heartbeat, part->last_heartbeat,
776                 remote_vars->heartbeat_offline,
777                 remote_vars->heartbeating_to_mask[0]);
778
779         if ((remote_vars->heartbeat == part->last_heartbeat &&
780             !remote_vars->heartbeat_offline) ||
781             !xpc_hb_allowed_sn2(sn_partition_id,
782                                 remote_vars->heartbeating_to_mask)) {
783                 ret = xpNoHeartbeat;
784         } else {
785                 part->last_heartbeat = remote_vars->heartbeat;
786         }
787
788         return ret;
789 }
790
791 /*
792  * Get a copy of the remote partition's XPC variables from the reserved page.
793  *
794  * remote_vars points to a buffer that is cacheline aligned for BTE copies and
795  * assumed to be of size XPC_RP_VARS_SIZE.
796  */
797 static enum xp_retval
798 xpc_get_remote_vars_sn2(unsigned long remote_vars_pa,
799                         struct xpc_vars_sn2 *remote_vars)
800 {
801         enum xp_retval ret;
802
803         if (remote_vars_pa == 0)
804                 return xpVarsNotSet;
805
806         /* pull over the cross partition variables */
807         ret = xp_remote_memcpy(xp_pa(remote_vars), remote_vars_pa,
808                                XPC_RP_VARS_SIZE);
809         if (ret != xpSuccess)
810                 return ret;
811
812         if (XPC_VERSION_MAJOR(remote_vars->version) !=
813             XPC_VERSION_MAJOR(XPC_V_VERSION)) {
814                 return xpBadVersion;
815         }
816
817         return xpSuccess;
818 }
819
820 static void
821 xpc_request_partition_activation_sn2(struct xpc_rsvd_page *remote_rp,
822                                      unsigned long remote_rp_pa, int nasid)
823 {
824         xpc_send_local_activate_IRQ_sn2(nasid);
825 }
826
827 static void
828 xpc_request_partition_reactivation_sn2(struct xpc_partition *part)
829 {
830         xpc_send_local_activate_IRQ_sn2(part->sn.sn2.activate_IRQ_nasid);
831 }
832
833 static void
834 xpc_request_partition_deactivation_sn2(struct xpc_partition *part)
835 {
836         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
837         unsigned long irq_flags;
838         struct amo *amo = (struct amo *)__va(part_sn2->remote_amos_page_pa +
839                                              (XPC_DEACTIVATE_REQUEST_AMO_SN2 *
840                                              sizeof(struct amo)));
841
842         local_irq_save(irq_flags);
843
844         /* set bit corresponding to our partid in remote partition's amo */
845         FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR,
846                          BIT(sn_partition_id));
847
848         /*
849          * We must always use the nofault function regardless of whether we
850          * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
851          * didn't, we'd never know that the other partition is down and would
852          * keep sending IRQs and amos to it until the heartbeat times out.
853          */
854         (void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
855                                                                variable),
856                                                      xp_nofault_PIOR_target));
857
858         local_irq_restore(irq_flags);
859
860         /*
861          * Send activate IRQ to get other side to see that we've set our
862          * bit in their deactivate request amo.
863          */
864         xpc_send_activate_IRQ_sn2(part_sn2->remote_amos_page_pa,
865                                   cnodeid_to_nasid(0),
866                                   part_sn2->activate_IRQ_nasid,
867                                   part_sn2->activate_IRQ_phys_cpuid);
868 }
869
870 static void
871 xpc_cancel_partition_deactivation_request_sn2(struct xpc_partition *part)
872 {
873         unsigned long irq_flags;
874         struct amo *amo = (struct amo *)__va(part->sn.sn2.remote_amos_page_pa +
875                                              (XPC_DEACTIVATE_REQUEST_AMO_SN2 *
876                                              sizeof(struct amo)));
877
878         local_irq_save(irq_flags);
879
880         /* clear bit corresponding to our partid in remote partition's amo */
881         FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
882                          ~BIT(sn_partition_id));
883
884         /*
885          * We must always use the nofault function regardless of whether we
886          * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
887          * didn't, we'd never know that the other partition is down and would
888          * keep sending IRQs and amos to it until the heartbeat times out.
889          */
890         (void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
891                                                                variable),
892                                                      xp_nofault_PIOR_target));
893
894         local_irq_restore(irq_flags);
895 }
896
897 static int
898 xpc_partition_deactivation_requested_sn2(short partid)
899 {
900         struct amo *amo = xpc_vars_sn2->amos_page +
901                           XPC_DEACTIVATE_REQUEST_AMO_SN2;
902
903         /* our partition's amo variable ANDed with partid mask */
904         return (FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) &
905                 BIT(partid)) != 0;
906 }
907
908 /*
909  * Update the remote partition's info.
910  */
911 static void
912 xpc_update_partition_info_sn2(struct xpc_partition *part, u8 remote_rp_version,
913                               unsigned long *remote_rp_ts_jiffies,
914                               unsigned long remote_rp_pa,
915                               unsigned long remote_vars_pa,
916                               struct xpc_vars_sn2 *remote_vars)
917 {
918         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
919
920         part->remote_rp_version = remote_rp_version;
921         dev_dbg(xpc_part, "  remote_rp_version = 0x%016x\n",
922                 part->remote_rp_version);
923
924         part->remote_rp_ts_jiffies = *remote_rp_ts_jiffies;
925         dev_dbg(xpc_part, "  remote_rp_ts_jiffies = 0x%016lx\n",
926                 part->remote_rp_ts_jiffies);
927
928         part->remote_rp_pa = remote_rp_pa;
929         dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
930
931         part_sn2->remote_vars_pa = remote_vars_pa;
932         dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
933                 part_sn2->remote_vars_pa);
934
935         part->last_heartbeat = remote_vars->heartbeat - 1;
936         dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
937                 part->last_heartbeat);
938
939         part_sn2->remote_vars_part_pa = remote_vars->vars_part_pa;
940         dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
941                 part_sn2->remote_vars_part_pa);
942
943         part_sn2->activate_IRQ_nasid = remote_vars->activate_IRQ_nasid;
944         dev_dbg(xpc_part, "  activate_IRQ_nasid = 0x%x\n",
945                 part_sn2->activate_IRQ_nasid);
946
947         part_sn2->activate_IRQ_phys_cpuid =
948             remote_vars->activate_IRQ_phys_cpuid;
949         dev_dbg(xpc_part, "  activate_IRQ_phys_cpuid = 0x%x\n",
950                 part_sn2->activate_IRQ_phys_cpuid);
951
952         part_sn2->remote_amos_page_pa = remote_vars->amos_page_pa;
953         dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
954                 part_sn2->remote_amos_page_pa);
955
956         part_sn2->remote_vars_version = remote_vars->version;
957         dev_dbg(xpc_part, "  remote_vars_version = 0x%x\n",
958                 part_sn2->remote_vars_version);
959 }
960
961 /*
962  * Prior code has determined the nasid which generated a activate IRQ.
963  * Inspect that nasid to determine if its partition needs to be activated
964  * or deactivated.
965  *
966  * A partition is considered "awaiting activation" if our partition
967  * flags indicate it is not active and it has a heartbeat.  A
968  * partition is considered "awaiting deactivation" if our partition
969  * flags indicate it is active but it has no heartbeat or it is not
970  * sending its heartbeat to us.
971  *
972  * To determine the heartbeat, the remote nasid must have a properly
973  * initialized reserved page.
974  */
975 static void
976 xpc_identify_activate_IRQ_req_sn2(int nasid)
977 {
978         struct xpc_rsvd_page *remote_rp;
979         struct xpc_vars_sn2 *remote_vars;
980         unsigned long remote_rp_pa;
981         unsigned long remote_vars_pa;
982         int remote_rp_version;
983         int reactivate = 0;
984         unsigned long remote_rp_ts_jiffies = 0;
985         short partid;
986         struct xpc_partition *part;
987         struct xpc_partition_sn2 *part_sn2;
988         enum xp_retval ret;
989
990         /* pull over the reserved page structure */
991
992         remote_rp = (struct xpc_rsvd_page *)xpc_remote_copy_buffer_sn2;
993
994         ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rp_pa);
995         if (ret != xpSuccess) {
996                 dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
997                          "which sent interrupt, reason=%d\n", nasid, ret);
998                 return;
999         }
1000
1001         remote_vars_pa = remote_rp->sn.sn2.vars_pa;
1002         remote_rp_version = remote_rp->version;
1003         remote_rp_ts_jiffies = remote_rp->ts_jiffies;
1004
1005         partid = remote_rp->SAL_partid;
1006         part = &xpc_partitions[partid];
1007         part_sn2 = &part->sn.sn2;
1008
1009         /* pull over the cross partition variables */
1010
1011         remote_vars = (struct xpc_vars_sn2 *)xpc_remote_copy_buffer_sn2;
1012
1013         ret = xpc_get_remote_vars_sn2(remote_vars_pa, remote_vars);
1014         if (ret != xpSuccess) {
1015                 dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
1016                          "which sent interrupt, reason=%d\n", nasid, ret);
1017
1018                 XPC_DEACTIVATE_PARTITION(part, ret);
1019                 return;
1020         }
1021
1022         part->activate_IRQ_rcvd++;
1023
1024         dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
1025                 "%ld:0x%lx\n", (int)nasid, (int)partid, part->activate_IRQ_rcvd,
1026                 remote_vars->heartbeat, remote_vars->heartbeating_to_mask[0]);
1027
1028         if (xpc_partition_disengaged(part) &&
1029             part->act_state == XPC_P_AS_INACTIVE) {
1030
1031                 xpc_update_partition_info_sn2(part, remote_rp_version,
1032                                               &remote_rp_ts_jiffies,
1033                                               remote_rp_pa, remote_vars_pa,
1034                                               remote_vars);
1035
1036                 if (xpc_partition_deactivation_requested_sn2(partid)) {
1037                         /*
1038                          * Other side is waiting on us to deactivate even though
1039                          * we already have.
1040                          */
1041                         return;
1042                 }
1043
1044                 xpc_activate_partition(part);
1045                 return;
1046         }
1047
1048         DBUG_ON(part->remote_rp_version == 0);
1049         DBUG_ON(part_sn2->remote_vars_version == 0);
1050
1051         if (remote_rp_ts_jiffies != part->remote_rp_ts_jiffies) {
1052
1053                 /* the other side rebooted */
1054
1055                 DBUG_ON(xpc_partition_engaged_sn2(partid));
1056                 DBUG_ON(xpc_partition_deactivation_requested_sn2(partid));
1057
1058                 xpc_update_partition_info_sn2(part, remote_rp_version,
1059                                               &remote_rp_ts_jiffies,
1060                                               remote_rp_pa, remote_vars_pa,
1061                                               remote_vars);
1062                 reactivate = 1;
1063         }
1064
1065         if (part->disengage_timeout > 0 && !xpc_partition_disengaged(part)) {
1066                 /* still waiting on other side to disengage from us */
1067                 return;
1068         }
1069
1070         if (reactivate)
1071                 XPC_DEACTIVATE_PARTITION(part, xpReactivating);
1072         else if (xpc_partition_deactivation_requested_sn2(partid))
1073                 XPC_DEACTIVATE_PARTITION(part, xpOtherGoingDown);
1074 }
1075
1076 /*
1077  * Loop through the activation amo variables and process any bits
1078  * which are set.  Each bit indicates a nasid sending a partition
1079  * activation or deactivation request.
1080  *
1081  * Return #of IRQs detected.
1082  */
1083 int
1084 xpc_identify_activate_IRQ_sender_sn2(void)
1085 {
1086         int l;
1087         int b;
1088         unsigned long nasid_mask_long;
1089         u64 nasid;              /* remote nasid */
1090         int n_IRQs_detected = 0;
1091         struct amo *act_amos;
1092
1093         act_amos = xpc_vars_sn2->amos_page + XPC_ACTIVATE_IRQ_AMOS_SN2;
1094
1095         /* scan through activate amo variables looking for non-zero entries */
1096         for (l = 0; l < xpc_nasid_mask_nlongs; l++) {
1097
1098                 if (xpc_exiting)
1099                         break;
1100
1101                 nasid_mask_long = xpc_receive_IRQ_amo_sn2(&act_amos[l]);
1102
1103                 b = find_first_bit(&nasid_mask_long, BITS_PER_LONG);
1104                 if (b >= BITS_PER_LONG) {
1105                         /* no IRQs from nasids in this amo variable */
1106                         continue;
1107                 }
1108
1109                 dev_dbg(xpc_part, "amo[%d] gave back 0x%lx\n", l,
1110                         nasid_mask_long);
1111
1112                 /*
1113                  * If this nasid has been added to the machine since
1114                  * our partition was reset, this will retain the
1115                  * remote nasid in our reserved pages machine mask.
1116                  * This is used in the event of module reload.
1117                  */
1118                 xpc_mach_nasids[l] |= nasid_mask_long;
1119
1120                 /* locate the nasid(s) which sent interrupts */
1121
1122                 do {
1123                         n_IRQs_detected++;
1124                         nasid = (l * BITS_PER_LONG + b) * 2;
1125                         dev_dbg(xpc_part, "interrupt from nasid %ld\n", nasid);
1126                         xpc_identify_activate_IRQ_req_sn2(nasid);
1127
1128                         b = find_next_bit(&nasid_mask_long, BITS_PER_LONG,
1129                                           b + 1);
1130                 } while (b < BITS_PER_LONG);
1131         }
1132         return n_IRQs_detected;
1133 }
1134
1135 static void
1136 xpc_process_activate_IRQ_rcvd_sn2(void)
1137 {
1138         unsigned long irq_flags;
1139         int n_IRQs_expected;
1140         int n_IRQs_detected;
1141
1142         spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
1143         n_IRQs_expected = xpc_activate_IRQ_rcvd;
1144         xpc_activate_IRQ_rcvd = 0;
1145         spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
1146
1147         n_IRQs_detected = xpc_identify_activate_IRQ_sender_sn2();
1148         if (n_IRQs_detected < n_IRQs_expected) {
1149                 /* retry once to help avoid missing amo */
1150                 (void)xpc_identify_activate_IRQ_sender_sn2();
1151         }
1152 }
1153
1154 /*
1155  * Setup the channel structures that are sn2 specific.
1156  */
1157 static enum xp_retval
1158 xpc_setup_ch_structures_sn_sn2(struct xpc_partition *part)
1159 {
1160         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
1161         struct xpc_channel_sn2 *ch_sn2;
1162         enum xp_retval retval;
1163         int ret;
1164         int cpuid;
1165         int ch_number;
1166         struct timer_list *timer;
1167         short partid = XPC_PARTID(part);
1168
1169         /* allocate all the required GET/PUT values */
1170
1171         part_sn2->local_GPs =
1172             xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE, GFP_KERNEL,
1173                                           &part_sn2->local_GPs_base);
1174         if (part_sn2->local_GPs == NULL) {
1175                 dev_err(xpc_chan, "can't get memory for local get/put "
1176                         "values\n");
1177                 return xpNoMemory;
1178         }
1179
1180         part_sn2->remote_GPs =
1181             xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE, GFP_KERNEL,
1182                                           &part_sn2->remote_GPs_base);
1183         if (part_sn2->remote_GPs == NULL) {
1184                 dev_err(xpc_chan, "can't get memory for remote get/put "
1185                         "values\n");
1186                 retval = xpNoMemory;
1187                 goto out_1;
1188         }
1189
1190         part_sn2->remote_GPs_pa = 0;
1191
1192         /* allocate all the required open and close args */
1193
1194         part_sn2->local_openclose_args =
1195             xpc_kzalloc_cacheline_aligned(XPC_OPENCLOSE_ARGS_SIZE,
1196                                           GFP_KERNEL, &part_sn2->
1197                                           local_openclose_args_base);
1198         if (part_sn2->local_openclose_args == NULL) {
1199                 dev_err(xpc_chan, "can't get memory for local connect args\n");
1200                 retval = xpNoMemory;
1201                 goto out_2;
1202         }
1203
1204         part_sn2->remote_openclose_args_pa = 0;
1205
1206         part_sn2->local_chctl_amo_va = xpc_init_IRQ_amo_sn2(partid);
1207
1208         part_sn2->notify_IRQ_nasid = 0;
1209         part_sn2->notify_IRQ_phys_cpuid = 0;
1210         part_sn2->remote_chctl_amo_va = NULL;
1211
1212         sprintf(part_sn2->notify_IRQ_owner, "xpc%02d", partid);
1213         ret = request_irq(SGI_XPC_NOTIFY, xpc_handle_notify_IRQ_sn2,
1214                           IRQF_SHARED, part_sn2->notify_IRQ_owner,
1215                           (void *)(u64)partid);
1216         if (ret != 0) {
1217                 dev_err(xpc_chan, "can't register NOTIFY IRQ handler, "
1218                         "errno=%d\n", -ret);
1219                 retval = xpLackOfResources;
1220                 goto out_3;
1221         }
1222
1223         /* Setup a timer to check for dropped notify IRQs */
1224         timer = &part_sn2->dropped_notify_IRQ_timer;
1225         init_timer(timer);
1226         timer->function =
1227             (void (*)(unsigned long))xpc_check_for_dropped_notify_IRQ_sn2;
1228         timer->data = (unsigned long)part;
1229         timer->expires = jiffies + XPC_DROPPED_NOTIFY_IRQ_WAIT_INTERVAL;
1230         add_timer(timer);
1231
1232         for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
1233                 ch_sn2 = &part->channels[ch_number].sn.sn2;
1234
1235                 ch_sn2->local_GP = &part_sn2->local_GPs[ch_number];
1236                 ch_sn2->local_openclose_args =
1237                     &part_sn2->local_openclose_args[ch_number];
1238
1239                 mutex_init(&ch_sn2->msg_to_pull_mutex);
1240         }
1241
1242         /*
1243          * Setup the per partition specific variables required by the
1244          * remote partition to establish channel connections with us.
1245          *
1246          * The setting of the magic # indicates that these per partition
1247          * specific variables are ready to be used.
1248          */
1249         xpc_vars_part_sn2[partid].GPs_pa = xp_pa(part_sn2->local_GPs);
1250         xpc_vars_part_sn2[partid].openclose_args_pa =
1251             xp_pa(part_sn2->local_openclose_args);
1252         xpc_vars_part_sn2[partid].chctl_amo_pa =
1253             xp_pa(part_sn2->local_chctl_amo_va);
1254         cpuid = raw_smp_processor_id(); /* any CPU in this partition will do */
1255         xpc_vars_part_sn2[partid].notify_IRQ_nasid = cpuid_to_nasid(cpuid);
1256         xpc_vars_part_sn2[partid].notify_IRQ_phys_cpuid =
1257             cpu_physical_id(cpuid);
1258         xpc_vars_part_sn2[partid].nchannels = part->nchannels;
1259         xpc_vars_part_sn2[partid].magic = XPC_VP_MAGIC1_SN2;
1260
1261         return xpSuccess;
1262
1263         /* setup of ch structures failed */
1264 out_3:
1265         kfree(part_sn2->local_openclose_args_base);
1266         part_sn2->local_openclose_args = NULL;
1267 out_2:
1268         kfree(part_sn2->remote_GPs_base);
1269         part_sn2->remote_GPs = NULL;
1270 out_1:
1271         kfree(part_sn2->local_GPs_base);
1272         part_sn2->local_GPs = NULL;
1273         return retval;
1274 }
1275
1276 /*
1277  * Teardown the channel structures that are sn2 specific.
1278  */
1279 static void
1280 xpc_teardown_ch_structures_sn_sn2(struct xpc_partition *part)
1281 {
1282         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
1283         short partid = XPC_PARTID(part);
1284
1285         /*
1286          * Indicate that the variables specific to the remote partition are no
1287          * longer available for its use.
1288          */
1289         xpc_vars_part_sn2[partid].magic = 0;
1290
1291         /* in case we've still got outstanding timers registered... */
1292         del_timer_sync(&part_sn2->dropped_notify_IRQ_timer);
1293         free_irq(SGI_XPC_NOTIFY, (void *)(u64)partid);
1294
1295         kfree(part_sn2->local_openclose_args_base);
1296         part_sn2->local_openclose_args = NULL;
1297         kfree(part_sn2->remote_GPs_base);
1298         part_sn2->remote_GPs = NULL;
1299         kfree(part_sn2->local_GPs_base);
1300         part_sn2->local_GPs = NULL;
1301         part_sn2->local_chctl_amo_va = NULL;
1302 }
1303
1304 /*
1305  * Create a wrapper that hides the underlying mechanism for pulling a cacheline
1306  * (or multiple cachelines) from a remote partition.
1307  *
1308  * src_pa must be a cacheline aligned physical address on the remote partition.
1309  * dst must be a cacheline aligned virtual address on this partition.
1310  * cnt must be cacheline sized
1311  */
1312 /* ??? Replace this function by call to xp_remote_memcpy() or bte_copy()? */
1313 static enum xp_retval
1314 xpc_pull_remote_cachelines_sn2(struct xpc_partition *part, void *dst,
1315                                const unsigned long src_pa, size_t cnt)
1316 {
1317         enum xp_retval ret;
1318
1319         DBUG_ON(src_pa != L1_CACHE_ALIGN(src_pa));
1320         DBUG_ON((unsigned long)dst != L1_CACHE_ALIGN((unsigned long)dst));
1321         DBUG_ON(cnt != L1_CACHE_ALIGN(cnt));
1322
1323         if (part->act_state == XPC_P_AS_DEACTIVATING)
1324                 return part->reason;
1325
1326         ret = xp_remote_memcpy(xp_pa(dst), src_pa, cnt);
1327         if (ret != xpSuccess) {
1328                 dev_dbg(xpc_chan, "xp_remote_memcpy() from partition %d failed,"
1329                         " ret=%d\n", XPC_PARTID(part), ret);
1330         }
1331         return ret;
1332 }
1333
1334 /*
1335  * Pull the remote per partition specific variables from the specified
1336  * partition.
1337  */
1338 static enum xp_retval
1339 xpc_pull_remote_vars_part_sn2(struct xpc_partition *part)
1340 {
1341         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
1342         u8 buffer[L1_CACHE_BYTES * 2];
1343         struct xpc_vars_part_sn2 *pulled_entry_cacheline =
1344             (struct xpc_vars_part_sn2 *)L1_CACHE_ALIGN((u64)buffer);
1345         struct xpc_vars_part_sn2 *pulled_entry;
1346         unsigned long remote_entry_cacheline_pa;
1347         unsigned long remote_entry_pa;
1348         short partid = XPC_PARTID(part);
1349         enum xp_retval ret;
1350
1351         /* pull the cacheline that contains the variables we're interested in */
1352
1353         DBUG_ON(part_sn2->remote_vars_part_pa !=
1354                 L1_CACHE_ALIGN(part_sn2->remote_vars_part_pa));
1355         DBUG_ON(sizeof(struct xpc_vars_part_sn2) != L1_CACHE_BYTES / 2);
1356
1357         remote_entry_pa = part_sn2->remote_vars_part_pa +
1358             sn_partition_id * sizeof(struct xpc_vars_part_sn2);
1359
1360         remote_entry_cacheline_pa = (remote_entry_pa & ~(L1_CACHE_BYTES - 1));
1361
1362         pulled_entry = (struct xpc_vars_part_sn2 *)((u64)pulled_entry_cacheline
1363                                                     + (remote_entry_pa &
1364                                                     (L1_CACHE_BYTES - 1)));
1365
1366         ret = xpc_pull_remote_cachelines_sn2(part, pulled_entry_cacheline,
1367                                              remote_entry_cacheline_pa,
1368                                              L1_CACHE_BYTES);
1369         if (ret != xpSuccess) {
1370                 dev_dbg(xpc_chan, "failed to pull XPC vars_part from "
1371                         "partition %d, ret=%d\n", partid, ret);
1372                 return ret;
1373         }
1374
1375         /* see if they've been set up yet */
1376
1377         if (pulled_entry->magic != XPC_VP_MAGIC1_SN2 &&
1378             pulled_entry->magic != XPC_VP_MAGIC2_SN2) {
1379
1380                 if (pulled_entry->magic != 0) {
1381                         dev_dbg(xpc_chan, "partition %d's XPC vars_part for "
1382                                 "partition %d has bad magic value (=0x%lx)\n",
1383                                 partid, sn_partition_id, pulled_entry->magic);
1384                         return xpBadMagic;
1385                 }
1386
1387                 /* they've not been initialized yet */
1388                 return xpRetry;
1389         }
1390
1391         if (xpc_vars_part_sn2[partid].magic == XPC_VP_MAGIC1_SN2) {
1392
1393                 /* validate the variables */
1394
1395                 if (pulled_entry->GPs_pa == 0 ||
1396                     pulled_entry->openclose_args_pa == 0 ||
1397                     pulled_entry->chctl_amo_pa == 0) {
1398
1399                         dev_err(xpc_chan, "partition %d's XPC vars_part for "
1400                                 "partition %d are not valid\n", partid,
1401                                 sn_partition_id);
1402                         return xpInvalidAddress;
1403                 }
1404
1405                 /* the variables we imported look to be valid */
1406
1407                 part_sn2->remote_GPs_pa = pulled_entry->GPs_pa;
1408                 part_sn2->remote_openclose_args_pa =
1409                     pulled_entry->openclose_args_pa;
1410                 part_sn2->remote_chctl_amo_va =
1411                     (struct amo *)__va(pulled_entry->chctl_amo_pa);
1412                 part_sn2->notify_IRQ_nasid = pulled_entry->notify_IRQ_nasid;
1413                 part_sn2->notify_IRQ_phys_cpuid =
1414                     pulled_entry->notify_IRQ_phys_cpuid;
1415
1416                 if (part->nchannels > pulled_entry->nchannels)
1417                         part->nchannels = pulled_entry->nchannels;
1418
1419                 /* let the other side know that we've pulled their variables */
1420
1421                 xpc_vars_part_sn2[partid].magic = XPC_VP_MAGIC2_SN2;
1422         }
1423
1424         if (pulled_entry->magic == XPC_VP_MAGIC1_SN2)
1425                 return xpRetry;
1426
1427         return xpSuccess;
1428 }
1429
1430 /*
1431  * Establish first contact with the remote partititon. This involves pulling
1432  * the XPC per partition variables from the remote partition and waiting for
1433  * the remote partition to pull ours.
1434  */
1435 static enum xp_retval
1436 xpc_make_first_contact_sn2(struct xpc_partition *part)
1437 {
1438         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
1439         enum xp_retval ret;
1440
1441         /*
1442          * Register the remote partition's amos with SAL so it can handle
1443          * and cleanup errors within that address range should the remote
1444          * partition go down. We don't unregister this range because it is
1445          * difficult to tell when outstanding writes to the remote partition
1446          * are finished and thus when it is safe to unregister. This should
1447          * not result in wasted space in the SAL xp_addr_region table because
1448          * we should get the same page for remote_amos_page_pa after module
1449          * reloads and system reboots.
1450          */
1451         if (sn_register_xp_addr_region(part_sn2->remote_amos_page_pa,
1452                                        PAGE_SIZE, 1) < 0) {
1453                 dev_warn(xpc_part, "xpc_activating(%d) failed to register "
1454                          "xp_addr region\n", XPC_PARTID(part));
1455
1456                 ret = xpPhysAddrRegFailed;
1457                 XPC_DEACTIVATE_PARTITION(part, ret);
1458                 return ret;
1459         }
1460
1461         /*
1462          * Send activate IRQ to get other side to activate if they've not
1463          * already begun to do so.
1464          */
1465         xpc_send_activate_IRQ_sn2(part_sn2->remote_amos_page_pa,
1466                                   cnodeid_to_nasid(0),
1467                                   part_sn2->activate_IRQ_nasid,
1468                                   part_sn2->activate_IRQ_phys_cpuid);
1469
1470         while ((ret = xpc_pull_remote_vars_part_sn2(part)) != xpSuccess) {
1471                 if (ret != xpRetry) {
1472                         XPC_DEACTIVATE_PARTITION(part, ret);
1473                         return ret;
1474                 }
1475
1476                 dev_dbg(xpc_part, "waiting to make first contact with "
1477                         "partition %d\n", XPC_PARTID(part));
1478
1479                 /* wait a 1/4 of a second or so */
1480                 (void)msleep_interruptible(250);
1481
1482                 if (part->act_state == XPC_P_AS_DEACTIVATING)
1483                         return part->reason;
1484         }
1485
1486         return xpSuccess;
1487 }
1488
1489 /*
1490  * Get the chctl flags and pull the openclose args and/or remote GPs as needed.
1491  */
1492 static u64
1493 xpc_get_chctl_all_flags_sn2(struct xpc_partition *part)
1494 {
1495         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
1496         unsigned long irq_flags;
1497         union xpc_channel_ctl_flags chctl;
1498         enum xp_retval ret;
1499
1500         /*
1501          * See if there are any chctl flags to be handled.
1502          */
1503
1504         spin_lock_irqsave(&part->chctl_lock, irq_flags);
1505         chctl = part->chctl;
1506         if (chctl.all_flags != 0)
1507                 part->chctl.all_flags = 0;
1508
1509         spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
1510
1511         if (xpc_any_openclose_chctl_flags_set(&chctl)) {
1512                 ret = xpc_pull_remote_cachelines_sn2(part, part->
1513                                                      remote_openclose_args,
1514                                                      part_sn2->
1515                                                      remote_openclose_args_pa,
1516                                                      XPC_OPENCLOSE_ARGS_SIZE);
1517                 if (ret != xpSuccess) {
1518                         XPC_DEACTIVATE_PARTITION(part, ret);
1519
1520                         dev_dbg(xpc_chan, "failed to pull openclose args from "
1521                                 "partition %d, ret=%d\n", XPC_PARTID(part),
1522                                 ret);
1523
1524                         /* don't bother processing chctl flags anymore */
1525                         chctl.all_flags = 0;
1526                 }
1527         }
1528
1529         if (xpc_any_msg_chctl_flags_set(&chctl)) {
1530                 ret = xpc_pull_remote_cachelines_sn2(part, part_sn2->remote_GPs,
1531                                                      part_sn2->remote_GPs_pa,
1532                                                      XPC_GP_SIZE);
1533                 if (ret != xpSuccess) {
1534                         XPC_DEACTIVATE_PARTITION(part, ret);
1535
1536                         dev_dbg(xpc_chan, "failed to pull GPs from partition "
1537                                 "%d, ret=%d\n", XPC_PARTID(part), ret);
1538
1539                         /* don't bother processing chctl flags anymore */
1540                         chctl.all_flags = 0;
1541                 }
1542         }
1543
1544         return chctl.all_flags;
1545 }
1546
1547 /*
1548  * Allocate the local message queue and the notify queue.
1549  */
1550 static enum xp_retval
1551 xpc_allocate_local_msgqueue_sn2(struct xpc_channel *ch)
1552 {
1553         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1554         unsigned long irq_flags;
1555         int nentries;
1556         size_t nbytes;
1557
1558         for (nentries = ch->local_nentries; nentries > 0; nentries--) {
1559
1560                 nbytes = nentries * ch->entry_size;
1561                 ch_sn2->local_msgqueue =
1562                     xpc_kzalloc_cacheline_aligned(nbytes, GFP_KERNEL,
1563                                                   &ch_sn2->local_msgqueue_base);
1564                 if (ch_sn2->local_msgqueue == NULL)
1565                         continue;
1566
1567                 nbytes = nentries * sizeof(struct xpc_notify_sn2);
1568                 ch_sn2->notify_queue = kzalloc(nbytes, GFP_KERNEL);
1569                 if (ch_sn2->notify_queue == NULL) {
1570                         kfree(ch_sn2->local_msgqueue_base);
1571                         ch_sn2->local_msgqueue = NULL;
1572                         continue;
1573                 }
1574
1575                 spin_lock_irqsave(&ch->lock, irq_flags);
1576                 if (nentries < ch->local_nentries) {
1577                         dev_dbg(xpc_chan, "nentries=%d local_nentries=%d, "
1578                                 "partid=%d, channel=%d\n", nentries,
1579                                 ch->local_nentries, ch->partid, ch->number);
1580
1581                         ch->local_nentries = nentries;
1582                 }
1583                 spin_unlock_irqrestore(&ch->lock, irq_flags);
1584                 return xpSuccess;
1585         }
1586
1587         dev_dbg(xpc_chan, "can't get memory for local message queue and notify "
1588                 "queue, partid=%d, channel=%d\n", ch->partid, ch->number);
1589         return xpNoMemory;
1590 }
1591
1592 /*
1593  * Allocate the cached remote message queue.
1594  */
1595 static enum xp_retval
1596 xpc_allocate_remote_msgqueue_sn2(struct xpc_channel *ch)
1597 {
1598         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1599         unsigned long irq_flags;
1600         int nentries;
1601         size_t nbytes;
1602
1603         DBUG_ON(ch->remote_nentries <= 0);
1604
1605         for (nentries = ch->remote_nentries; nentries > 0; nentries--) {
1606
1607                 nbytes = nentries * ch->entry_size;
1608                 ch_sn2->remote_msgqueue =
1609                     xpc_kzalloc_cacheline_aligned(nbytes, GFP_KERNEL, &ch_sn2->
1610                                                   remote_msgqueue_base);
1611                 if (ch_sn2->remote_msgqueue == NULL)
1612                         continue;
1613
1614                 spin_lock_irqsave(&ch->lock, irq_flags);
1615                 if (nentries < ch->remote_nentries) {
1616                         dev_dbg(xpc_chan, "nentries=%d remote_nentries=%d, "
1617                                 "partid=%d, channel=%d\n", nentries,
1618                                 ch->remote_nentries, ch->partid, ch->number);
1619
1620                         ch->remote_nentries = nentries;
1621                 }
1622                 spin_unlock_irqrestore(&ch->lock, irq_flags);
1623                 return xpSuccess;
1624         }
1625
1626         dev_dbg(xpc_chan, "can't get memory for cached remote message queue, "
1627                 "partid=%d, channel=%d\n", ch->partid, ch->number);
1628         return xpNoMemory;
1629 }
1630
1631 /*
1632  * Allocate message queues and other stuff associated with a channel.
1633  *
1634  * Note: Assumes all of the channel sizes are filled in.
1635  */
1636 static enum xp_retval
1637 xpc_setup_msg_structures_sn2(struct xpc_channel *ch)
1638 {
1639         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1640         enum xp_retval ret;
1641
1642         DBUG_ON(ch->flags & XPC_C_SETUP);
1643
1644         ret = xpc_allocate_local_msgqueue_sn2(ch);
1645         if (ret == xpSuccess) {
1646
1647                 ret = xpc_allocate_remote_msgqueue_sn2(ch);
1648                 if (ret != xpSuccess) {
1649                         kfree(ch_sn2->local_msgqueue_base);
1650                         ch_sn2->local_msgqueue = NULL;
1651                         kfree(ch_sn2->notify_queue);
1652                         ch_sn2->notify_queue = NULL;
1653                 }
1654         }
1655         return ret;
1656 }
1657
1658 /*
1659  * Free up message queues and other stuff that were allocated for the specified
1660  * channel.
1661  */
1662 static void
1663 xpc_teardown_msg_structures_sn2(struct xpc_channel *ch)
1664 {
1665         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1666
1667         DBUG_ON(!spin_is_locked(&ch->lock));
1668
1669         ch_sn2->remote_msgqueue_pa = 0;
1670
1671         ch_sn2->local_GP->get = 0;
1672         ch_sn2->local_GP->put = 0;
1673         ch_sn2->remote_GP.get = 0;
1674         ch_sn2->remote_GP.put = 0;
1675         ch_sn2->w_local_GP.get = 0;
1676         ch_sn2->w_local_GP.put = 0;
1677         ch_sn2->w_remote_GP.get = 0;
1678         ch_sn2->w_remote_GP.put = 0;
1679         ch_sn2->next_msg_to_pull = 0;
1680
1681         if (ch->flags & XPC_C_SETUP) {
1682                 dev_dbg(xpc_chan, "ch->flags=0x%x, partid=%d, channel=%d\n",
1683                         ch->flags, ch->partid, ch->number);
1684
1685                 kfree(ch_sn2->local_msgqueue_base);
1686                 ch_sn2->local_msgqueue = NULL;
1687                 kfree(ch_sn2->remote_msgqueue_base);
1688                 ch_sn2->remote_msgqueue = NULL;
1689                 kfree(ch_sn2->notify_queue);
1690                 ch_sn2->notify_queue = NULL;
1691         }
1692 }
1693
1694 /*
1695  * Notify those who wanted to be notified upon delivery of their message.
1696  */
1697 static void
1698 xpc_notify_senders_sn2(struct xpc_channel *ch, enum xp_retval reason, s64 put)
1699 {
1700         struct xpc_notify_sn2 *notify;
1701         u8 notify_type;
1702         s64 get = ch->sn.sn2.w_remote_GP.get - 1;
1703
1704         while (++get < put && atomic_read(&ch->n_to_notify) > 0) {
1705
1706                 notify = &ch->sn.sn2.notify_queue[get % ch->local_nentries];
1707
1708                 /*
1709                  * See if the notify entry indicates it was associated with
1710                  * a message who's sender wants to be notified. It is possible
1711                  * that it is, but someone else is doing or has done the
1712                  * notification.
1713                  */
1714                 notify_type = notify->type;
1715                 if (notify_type == 0 ||
1716                     cmpxchg(&notify->type, notify_type, 0) != notify_type) {
1717                         continue;
1718                 }
1719
1720                 DBUG_ON(notify_type != XPC_N_CALL);
1721
1722                 atomic_dec(&ch->n_to_notify);
1723
1724                 if (notify->func != NULL) {
1725                         dev_dbg(xpc_chan, "notify->func() called, notify=0x%p "
1726                                 "msg_number=%ld partid=%d channel=%d\n",
1727                                 (void *)notify, get, ch->partid, ch->number);
1728
1729                         notify->func(reason, ch->partid, ch->number,
1730                                      notify->key);
1731
1732                         dev_dbg(xpc_chan, "notify->func() returned, notify=0x%p"
1733                                 " msg_number=%ld partid=%d channel=%d\n",
1734                                 (void *)notify, get, ch->partid, ch->number);
1735                 }
1736         }
1737 }
1738
1739 static void
1740 xpc_notify_senders_of_disconnect_sn2(struct xpc_channel *ch)
1741 {
1742         xpc_notify_senders_sn2(ch, ch->reason, ch->sn.sn2.w_local_GP.put);
1743 }
1744
1745 /*
1746  * Clear some of the msg flags in the local message queue.
1747  */
1748 static inline void
1749 xpc_clear_local_msgqueue_flags_sn2(struct xpc_channel *ch)
1750 {
1751         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1752         struct xpc_msg_sn2 *msg;
1753         s64 get;
1754
1755         get = ch_sn2->w_remote_GP.get;
1756         do {
1757                 msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->local_msgqueue +
1758                                              (get % ch->local_nentries) *
1759                                              ch->entry_size);
1760                 DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
1761                 msg->flags = 0;
1762         } while (++get < ch_sn2->remote_GP.get);
1763 }
1764
1765 /*
1766  * Clear some of the msg flags in the remote message queue.
1767  */
1768 static inline void
1769 xpc_clear_remote_msgqueue_flags_sn2(struct xpc_channel *ch)
1770 {
1771         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1772         struct xpc_msg_sn2 *msg;
1773         s64 put, remote_nentries = ch->remote_nentries;
1774
1775         /* flags are zeroed when the buffer is allocated */
1776         if (ch_sn2->remote_GP.put < remote_nentries)
1777                 return;
1778
1779         put = max(ch_sn2->w_remote_GP.put, remote_nentries);
1780         do {
1781                 msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue +
1782                                              (put % remote_nentries) *
1783                                              ch->entry_size);
1784                 DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
1785                 DBUG_ON(!(msg->flags & XPC_M_SN2_DONE));
1786                 DBUG_ON(msg->number != put - remote_nentries);
1787                 msg->flags = 0;
1788         } while (++put < ch_sn2->remote_GP.put);
1789 }
1790
1791 static int
1792 xpc_n_of_deliverable_payloads_sn2(struct xpc_channel *ch)
1793 {
1794         return ch->sn.sn2.w_remote_GP.put - ch->sn.sn2.w_local_GP.get;
1795 }
1796
1797 static void
1798 xpc_process_msg_chctl_flags_sn2(struct xpc_partition *part, int ch_number)
1799 {
1800         struct xpc_channel *ch = &part->channels[ch_number];
1801         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1802         int npayloads_sent;
1803
1804         ch_sn2->remote_GP = part->sn.sn2.remote_GPs[ch_number];
1805
1806         /* See what, if anything, has changed for each connected channel */
1807
1808         xpc_msgqueue_ref(ch);
1809
1810         if (ch_sn2->w_remote_GP.get == ch_sn2->remote_GP.get &&
1811             ch_sn2->w_remote_GP.put == ch_sn2->remote_GP.put) {
1812                 /* nothing changed since GPs were last pulled */
1813                 xpc_msgqueue_deref(ch);
1814                 return;
1815         }
1816
1817         if (!(ch->flags & XPC_C_CONNECTED)) {
1818                 xpc_msgqueue_deref(ch);
1819                 return;
1820         }
1821
1822         /*
1823          * First check to see if messages recently sent by us have been
1824          * received by the other side. (The remote GET value will have
1825          * changed since we last looked at it.)
1826          */
1827
1828         if (ch_sn2->w_remote_GP.get != ch_sn2->remote_GP.get) {
1829
1830                 /*
1831                  * We need to notify any senders that want to be notified
1832                  * that their sent messages have been received by their
1833                  * intended recipients. We need to do this before updating
1834                  * w_remote_GP.get so that we don't allocate the same message
1835                  * queue entries prematurely (see xpc_allocate_msg()).
1836                  */
1837                 if (atomic_read(&ch->n_to_notify) > 0) {
1838                         /*
1839                          * Notify senders that messages sent have been
1840                          * received and delivered by the other side.
1841                          */
1842                         xpc_notify_senders_sn2(ch, xpMsgDelivered,
1843                                                ch_sn2->remote_GP.get);
1844                 }
1845
1846                 /*
1847                  * Clear msg->flags in previously sent messages, so that
1848                  * they're ready for xpc_allocate_msg().
1849                  */
1850                 xpc_clear_local_msgqueue_flags_sn2(ch);
1851
1852                 ch_sn2->w_remote_GP.get = ch_sn2->remote_GP.get;
1853
1854                 dev_dbg(xpc_chan, "w_remote_GP.get changed to %ld, partid=%d, "
1855                         "channel=%d\n", ch_sn2->w_remote_GP.get, ch->partid,
1856                         ch->number);
1857
1858                 /*
1859                  * If anyone was waiting for message queue entries to become
1860                  * available, wake them up.
1861                  */
1862                 if (atomic_read(&ch->n_on_msg_allocate_wq) > 0)
1863                         wake_up(&ch->msg_allocate_wq);
1864         }
1865
1866         /*
1867          * Now check for newly sent messages by the other side. (The remote
1868          * PUT value will have changed since we last looked at it.)
1869          */
1870
1871         if (ch_sn2->w_remote_GP.put != ch_sn2->remote_GP.put) {
1872                 /*
1873                  * Clear msg->flags in previously received messages, so that
1874                  * they're ready for xpc_get_deliverable_payload_sn2().
1875                  */
1876                 xpc_clear_remote_msgqueue_flags_sn2(ch);
1877
1878                 smp_wmb(); /* ensure flags have been cleared before bte_copy */
1879                 ch_sn2->w_remote_GP.put = ch_sn2->remote_GP.put;
1880
1881                 dev_dbg(xpc_chan, "w_remote_GP.put changed to %ld, partid=%d, "
1882                         "channel=%d\n", ch_sn2->w_remote_GP.put, ch->partid,
1883                         ch->number);
1884
1885                 npayloads_sent = xpc_n_of_deliverable_payloads_sn2(ch);
1886                 if (npayloads_sent > 0) {
1887                         dev_dbg(xpc_chan, "msgs waiting to be copied and "
1888                                 "delivered=%d, partid=%d, channel=%d\n",
1889                                 npayloads_sent, ch->partid, ch->number);
1890
1891                         if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE)
1892                                 xpc_activate_kthreads(ch, npayloads_sent);
1893                 }
1894         }
1895
1896         xpc_msgqueue_deref(ch);
1897 }
1898
1899 static struct xpc_msg_sn2 *
1900 xpc_pull_remote_msg_sn2(struct xpc_channel *ch, s64 get)
1901 {
1902         struct xpc_partition *part = &xpc_partitions[ch->partid];
1903         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1904         unsigned long remote_msg_pa;
1905         struct xpc_msg_sn2 *msg;
1906         u32 msg_index;
1907         u32 nmsgs;
1908         u64 msg_offset;
1909         enum xp_retval ret;
1910
1911         if (mutex_lock_interruptible(&ch_sn2->msg_to_pull_mutex) != 0) {
1912                 /* we were interrupted by a signal */
1913                 return NULL;
1914         }
1915
1916         while (get >= ch_sn2->next_msg_to_pull) {
1917
1918                 /* pull as many messages as are ready and able to be pulled */
1919
1920                 msg_index = ch_sn2->next_msg_to_pull % ch->remote_nentries;
1921
1922                 DBUG_ON(ch_sn2->next_msg_to_pull >= ch_sn2->w_remote_GP.put);
1923                 nmsgs = ch_sn2->w_remote_GP.put - ch_sn2->next_msg_to_pull;
1924                 if (msg_index + nmsgs > ch->remote_nentries) {
1925                         /* ignore the ones that wrap the msg queue for now */
1926                         nmsgs = ch->remote_nentries - msg_index;
1927                 }
1928
1929                 msg_offset = msg_index * ch->entry_size;
1930                 msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue +
1931                     msg_offset);
1932                 remote_msg_pa = ch_sn2->remote_msgqueue_pa + msg_offset;
1933
1934                 ret = xpc_pull_remote_cachelines_sn2(part, msg, remote_msg_pa,
1935                                                      nmsgs * ch->entry_size);
1936                 if (ret != xpSuccess) {
1937
1938                         dev_dbg(xpc_chan, "failed to pull %d msgs starting with"
1939                                 " msg %ld from partition %d, channel=%d, "
1940                                 "ret=%d\n", nmsgs, ch_sn2->next_msg_to_pull,
1941                                 ch->partid, ch->number, ret);
1942
1943                         XPC_DEACTIVATE_PARTITION(part, ret);
1944
1945                         mutex_unlock(&ch_sn2->msg_to_pull_mutex);
1946                         return NULL;
1947                 }
1948
1949                 ch_sn2->next_msg_to_pull += nmsgs;
1950         }
1951
1952         mutex_unlock(&ch_sn2->msg_to_pull_mutex);
1953
1954         /* return the message we were looking for */
1955         msg_offset = (get % ch->remote_nentries) * ch->entry_size;
1956         msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue + msg_offset);
1957
1958         return msg;
1959 }
1960
1961 /*
1962  * Get the next deliverable message's payload.
1963  */
1964 static void *
1965 xpc_get_deliverable_payload_sn2(struct xpc_channel *ch)
1966 {
1967         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1968         struct xpc_msg_sn2 *msg;
1969         void *payload = NULL;
1970         s64 get;
1971
1972         do {
1973                 if (ch->flags & XPC_C_DISCONNECTING)
1974                         break;
1975
1976                 get = ch_sn2->w_local_GP.get;
1977                 smp_rmb();      /* guarantee that .get loads before .put */
1978                 if (get == ch_sn2->w_remote_GP.put)
1979                         break;
1980
1981                 /* There are messages waiting to be pulled and delivered.
1982                  * We need to try to secure one for ourselves. We'll do this
1983                  * by trying to increment w_local_GP.get and hope that no one
1984                  * else beats us to it. If they do, we'll we'll simply have
1985                  * to try again for the next one.
1986                  */
1987
1988                 if (cmpxchg(&ch_sn2->w_local_GP.get, get, get + 1) == get) {
1989                         /* we got the entry referenced by get */
1990
1991                         dev_dbg(xpc_chan, "w_local_GP.get changed to %ld, "
1992                                 "partid=%d, channel=%d\n", get + 1,
1993                                 ch->partid, ch->number);
1994
1995                         /* pull the message from the remote partition */
1996
1997                         msg = xpc_pull_remote_msg_sn2(ch, get);
1998
1999                         if (msg != NULL) {
2000                                 DBUG_ON(msg->number != get);
2001                                 DBUG_ON(msg->flags & XPC_M_SN2_DONE);
2002                                 DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
2003
2004                                 payload = &msg->payload;
2005                         }
2006                         break;
2007                 }
2008
2009         } while (1);
2010
2011         return payload;
2012 }
2013
2014 /*
2015  * Now we actually send the messages that are ready to be sent by advancing
2016  * the local message queue's Put value and then send a chctl msgrequest to the
2017  * recipient partition.
2018  */
2019 static void
2020 xpc_send_msgs_sn2(struct xpc_channel *ch, s64 initial_put)
2021 {
2022         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
2023         struct xpc_msg_sn2 *msg;
2024         s64 put = initial_put + 1;
2025         int send_msgrequest = 0;
2026
2027         while (1) {
2028
2029                 while (1) {
2030                         if (put == ch_sn2->w_local_GP.put)
2031                                 break;
2032
2033                         msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->
2034                                                      local_msgqueue + (put %
2035                                                      ch->local_nentries) *
2036                                                      ch->entry_size);
2037
2038                         if (!(msg->flags & XPC_M_SN2_READY))
2039                                 break;
2040
2041                         put++;
2042                 }
2043
2044                 if (put == initial_put) {
2045                         /* nothing's changed */
2046                         break;
2047                 }
2048
2049                 if (cmpxchg_rel(&ch_sn2->local_GP->put, initial_put, put) !=
2050                     initial_put) {
2051                         /* someone else beat us to it */
2052                         DBUG_ON(ch_sn2->local_GP->put < initial_put);
2053                         break;
2054                 }
2055
2056                 /* we just set the new value of local_GP->put */
2057
2058                 dev_dbg(xpc_chan, "local_GP->put changed to %ld, partid=%d, "
2059                         "channel=%d\n", put, ch->partid, ch->number);
2060
2061                 send_msgrequest = 1;
2062
2063                 /*
2064                  * We need to ensure that the message referenced by
2065                  * local_GP->put is not XPC_M_SN2_READY or that local_GP->put
2066                  * equals w_local_GP.put, so we'll go have a look.
2067                  */
2068                 initial_put = put;
2069         }
2070
2071         if (send_msgrequest)
2072                 xpc_send_chctl_msgrequest_sn2(ch);
2073 }
2074
2075 /*
2076  * Allocate an entry for a message from the message queue associated with the
2077  * specified channel.
2078  */
2079 static enum xp_retval
2080 xpc_allocate_msg_sn2(struct xpc_channel *ch, u32 flags,
2081                      struct xpc_msg_sn2 **address_of_msg)
2082 {
2083         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
2084         struct xpc_msg_sn2 *msg;
2085         enum xp_retval ret;
2086         s64 put;
2087
2088         /*
2089          * Get the next available message entry from the local message queue.
2090          * If none are available, we'll make sure that we grab the latest
2091          * GP values.
2092          */
2093         ret = xpTimeout;
2094
2095         while (1) {
2096
2097                 put = ch_sn2->w_local_GP.put;
2098                 smp_rmb();      /* guarantee that .put loads before .get */
2099                 if (put - ch_sn2->w_remote_GP.get < ch->local_nentries) {
2100
2101                         /* There are available message entries. We need to try
2102                          * to secure one for ourselves. We'll do this by trying
2103                          * to increment w_local_GP.put as long as someone else
2104                          * doesn't beat us to it. If they do, we'll have to
2105                          * try again.
2106                          */
2107                         if (cmpxchg(&ch_sn2->w_local_GP.put, put, put + 1) ==
2108                             put) {
2109                                 /* we got the entry referenced by put */
2110                                 break;
2111                         }
2112                         continue;       /* try again */
2113                 }
2114
2115                 /*
2116                  * There aren't any available msg entries at this time.
2117                  *
2118                  * In waiting for a message entry to become available,
2119                  * we set a timeout in case the other side is not sending
2120                  * completion interrupts. This lets us fake a notify IRQ
2121                  * that will cause the notify IRQ handler to fetch the latest
2122                  * GP values as if an interrupt was sent by the other side.
2123                  */
2124                 if (ret == xpTimeout)
2125                         xpc_send_chctl_local_msgrequest_sn2(ch);
2126
2127                 if (flags & XPC_NOWAIT)
2128                         return xpNoWait;
2129
2130                 ret = xpc_allocate_msg_wait(ch);
2131                 if (ret != xpInterrupted && ret != xpTimeout)
2132                         return ret;
2133         }
2134
2135         /* get the message's address and initialize it */
2136         msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->local_msgqueue +
2137                                      (put % ch->local_nentries) *
2138                                      ch->entry_size);
2139
2140         DBUG_ON(msg->flags != 0);
2141         msg->number = put;
2142
2143         dev_dbg(xpc_chan, "w_local_GP.put changed to %ld; msg=0x%p, "
2144                 "msg_number=%ld, partid=%d, channel=%d\n", put + 1,
2145                 (void *)msg, msg->number, ch->partid, ch->number);
2146
2147         *address_of_msg = msg;
2148         return xpSuccess;
2149 }
2150
2151 /*
2152  * Common code that does the actual sending of the message by advancing the
2153  * local message queue's Put value and sends a chctl msgrequest to the
2154  * partition the message is being sent to.
2155  */
2156 static enum xp_retval
2157 xpc_send_payload_sn2(struct xpc_channel *ch, u32 flags, void *payload,
2158                      u16 payload_size, u8 notify_type, xpc_notify_func func,
2159                      void *key)
2160 {
2161         enum xp_retval ret = xpSuccess;
2162         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
2163         struct xpc_msg_sn2 *msg = msg;
2164         struct xpc_notify_sn2 *notify = notify;
2165         s64 msg_number;
2166         s64 put;
2167
2168         DBUG_ON(notify_type == XPC_N_CALL && func == NULL);
2169
2170         if (XPC_MSG_SIZE(payload_size) > ch->entry_size)
2171                 return xpPayloadTooBig;
2172
2173         xpc_msgqueue_ref(ch);
2174
2175         if (ch->flags & XPC_C_DISCONNECTING) {
2176                 ret = ch->reason;
2177                 goto out_1;
2178         }
2179         if (!(ch->flags & XPC_C_CONNECTED)) {
2180                 ret = xpNotConnected;
2181                 goto out_1;
2182         }
2183
2184         ret = xpc_allocate_msg_sn2(ch, flags, &msg);
2185         if (ret != xpSuccess)
2186                 goto out_1;
2187
2188         msg_number = msg->number;
2189
2190         if (notify_type != 0) {
2191                 /*
2192                  * Tell the remote side to send an ACK interrupt when the
2193                  * message has been delivered.
2194                  */
2195                 msg->flags |= XPC_M_SN2_INTERRUPT;
2196
2197                 atomic_inc(&ch->n_to_notify);
2198
2199                 notify = &ch_sn2->notify_queue[msg_number % ch->local_nentries];
2200                 notify->func = func;
2201                 notify->key = key;
2202                 notify->type = notify_type;
2203
2204                 /* ??? Is a mb() needed here? */
2205
2206                 if (ch->flags & XPC_C_DISCONNECTING) {
2207                         /*
2208                          * An error occurred between our last error check and
2209                          * this one. We will try to clear the type field from
2210                          * the notify entry. If we succeed then
2211                          * xpc_disconnect_channel() didn't already process
2212                          * the notify entry.
2213                          */
2214                         if (cmpxchg(&notify->type, notify_type, 0) ==
2215                             notify_type) {
2216                                 atomic_dec(&ch->n_to_notify);
2217                                 ret = ch->reason;
2218                         }
2219                         goto out_1;
2220                 }
2221         }
2222
2223         memcpy(&msg->payload, payload, payload_size);
2224
2225         msg->flags |= XPC_M_SN2_READY;
2226
2227         /*
2228          * The preceding store of msg->flags must occur before the following
2229          * load of local_GP->put.
2230          */
2231         smp_mb();
2232
2233         /* see if the message is next in line to be sent, if so send it */
2234
2235         put = ch_sn2->local_GP->put;
2236         if (put == msg_number)
2237                 xpc_send_msgs_sn2(ch, put);
2238
2239 out_1:
2240         xpc_msgqueue_deref(ch);
2241         return ret;
2242 }
2243
2244 /*
2245  * Now we actually acknowledge the messages that have been delivered and ack'd
2246  * by advancing the cached remote message queue's Get value and if requested
2247  * send a chctl msgrequest to the message sender's partition.
2248  *
2249  * If a message has XPC_M_SN2_INTERRUPT set, send an interrupt to the partition
2250  * that sent the message.
2251  */
2252 static void
2253 xpc_acknowledge_msgs_sn2(struct xpc_channel *ch, s64 initial_get, u8 msg_flags)
2254 {
2255         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
2256         struct xpc_msg_sn2 *msg;
2257         s64 get = initial_get + 1;
2258         int send_msgrequest = 0;
2259
2260         while (1) {
2261
2262                 while (1) {
2263                         if (get == ch_sn2->w_local_GP.get)
2264                                 break;
2265
2266                         msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->
2267                                                      remote_msgqueue + (get %
2268                                                      ch->remote_nentries) *
2269                                                      ch->entry_size);
2270
2271                         if (!(msg->flags & XPC_M_SN2_DONE))
2272                                 break;
2273
2274                         msg_flags |= msg->flags;
2275                         get++;
2276                 }
2277
2278                 if (get == initial_get) {
2279                         /* nothing's changed */
2280                         break;
2281                 }
2282
2283                 if (cmpxchg_rel(&ch_sn2->local_GP->get, initial_get, get) !=
2284                     initial_get) {
2285                         /* someone else beat us to it */
2286                         DBUG_ON(ch_sn2->local_GP->get <= initial_get);
2287                         break;
2288                 }
2289
2290                 /* we just set the new value of local_GP->get */
2291
2292                 dev_dbg(xpc_chan, "local_GP->get changed to %ld, partid=%d, "
2293                         "channel=%d\n", get, ch->partid, ch->number);
2294
2295                 send_msgrequest = (msg_flags & XPC_M_SN2_INTERRUPT);
2296
2297                 /*
2298                  * We need to ensure that the message referenced by
2299                  * local_GP->get is not XPC_M_SN2_DONE or that local_GP->get
2300                  * equals w_local_GP.get, so we'll go have a look.
2301                  */
2302                 initial_get = get;
2303         }
2304
2305         if (send_msgrequest)
2306                 xpc_send_chctl_msgrequest_sn2(ch);
2307 }
2308
2309 static void
2310 xpc_received_payload_sn2(struct xpc_channel *ch, void *payload)
2311 {
2312         struct xpc_msg_sn2 *msg;
2313         s64 msg_number;
2314         s64 get;
2315
2316         msg = container_of(payload, struct xpc_msg_sn2, payload);
2317         msg_number = msg->number;
2318
2319         dev_dbg(xpc_chan, "msg=0x%p, msg_number=%ld, partid=%d, channel=%d\n",
2320                 (void *)msg, msg_number, ch->partid, ch->number);
2321
2322         DBUG_ON((((u64)msg - (u64)ch->sn.sn2.remote_msgqueue) / ch->entry_size) !=
2323                 msg_number % ch->remote_nentries);
2324         DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
2325         DBUG_ON(msg->flags & XPC_M_SN2_DONE);
2326
2327         msg->flags |= XPC_M_SN2_DONE;
2328
2329         /*
2330          * The preceding store of msg->flags must occur before the following
2331          * load of local_GP->get.
2332          */
2333         smp_mb();
2334
2335         /*
2336          * See if this message is next in line to be acknowledged as having
2337          * been delivered.
2338          */
2339         get = ch->sn.sn2.local_GP->get;
2340         if (get == msg_number)
2341                 xpc_acknowledge_msgs_sn2(ch, get, msg->flags);
2342 }
2343
2344 int
2345 xpc_init_sn2(void)
2346 {
2347         int ret;
2348         size_t buf_size;
2349
2350         xpc_setup_partitions_sn = xpc_setup_partitions_sn_sn2;
2351         xpc_teardown_partitions_sn = xpc_teardown_partitions_sn_sn2;
2352         xpc_get_partition_rsvd_page_pa = xpc_get_partition_rsvd_page_pa_sn2;
2353         xpc_setup_rsvd_page_sn = xpc_setup_rsvd_page_sn_sn2;
2354
2355         xpc_allow_hb = xpc_allow_hb_sn2;
2356         xpc_disallow_hb = xpc_disallow_hb_sn2;
2357         xpc_disallow_all_hbs = xpc_disallow_all_hbs_sn2;
2358         xpc_increment_heartbeat = xpc_increment_heartbeat_sn2;
2359         xpc_offline_heartbeat = xpc_offline_heartbeat_sn2;
2360         xpc_online_heartbeat = xpc_online_heartbeat_sn2;
2361         xpc_heartbeat_init = xpc_heartbeat_init_sn2;
2362         xpc_heartbeat_exit = xpc_heartbeat_exit_sn2;
2363         xpc_get_remote_heartbeat = xpc_get_remote_heartbeat_sn2;
2364
2365         xpc_request_partition_activation = xpc_request_partition_activation_sn2;
2366         xpc_request_partition_reactivation =
2367             xpc_request_partition_reactivation_sn2;
2368         xpc_request_partition_deactivation =
2369             xpc_request_partition_deactivation_sn2;
2370         xpc_cancel_partition_deactivation_request =
2371             xpc_cancel_partition_deactivation_request_sn2;
2372
2373         xpc_process_activate_IRQ_rcvd = xpc_process_activate_IRQ_rcvd_sn2;
2374         xpc_setup_ch_structures_sn = xpc_setup_ch_structures_sn_sn2;
2375         xpc_teardown_ch_structures_sn = xpc_teardown_ch_structures_sn_sn2;
2376         xpc_make_first_contact = xpc_make_first_contact_sn2;
2377
2378         xpc_get_chctl_all_flags = xpc_get_chctl_all_flags_sn2;
2379         xpc_send_chctl_closerequest = xpc_send_chctl_closerequest_sn2;
2380         xpc_send_chctl_closereply = xpc_send_chctl_closereply_sn2;
2381         xpc_send_chctl_openrequest = xpc_send_chctl_openrequest_sn2;
2382         xpc_send_chctl_openreply = xpc_send_chctl_openreply_sn2;
2383
2384         xpc_save_remote_msgqueue_pa = xpc_save_remote_msgqueue_pa_sn2;
2385
2386         xpc_setup_msg_structures = xpc_setup_msg_structures_sn2;
2387         xpc_teardown_msg_structures = xpc_teardown_msg_structures_sn2;
2388
2389         xpc_notify_senders_of_disconnect = xpc_notify_senders_of_disconnect_sn2;
2390         xpc_process_msg_chctl_flags = xpc_process_msg_chctl_flags_sn2;
2391         xpc_n_of_deliverable_payloads = xpc_n_of_deliverable_payloads_sn2;
2392         xpc_get_deliverable_payload = xpc_get_deliverable_payload_sn2;
2393
2394         xpc_indicate_partition_engaged = xpc_indicate_partition_engaged_sn2;
2395         xpc_indicate_partition_disengaged =
2396             xpc_indicate_partition_disengaged_sn2;
2397         xpc_partition_engaged = xpc_partition_engaged_sn2;
2398         xpc_any_partition_engaged = xpc_any_partition_engaged_sn2;
2399         xpc_assume_partition_disengaged = xpc_assume_partition_disengaged_sn2;
2400
2401         xpc_send_payload = xpc_send_payload_sn2;
2402         xpc_received_payload = xpc_received_payload_sn2;
2403
2404         if (offsetof(struct xpc_msg_sn2, payload) > XPC_MSG_HDR_MAX_SIZE) {
2405                 dev_err(xpc_part, "header portion of struct xpc_msg_sn2 is "
2406                         "larger than %d\n", XPC_MSG_HDR_MAX_SIZE);
2407                 return -E2BIG;
2408         }
2409
2410         buf_size = max(XPC_RP_VARS_SIZE,
2411                        XPC_RP_HEADER_SIZE + XP_NASID_MASK_BYTES_SN2);
2412         xpc_remote_copy_buffer_sn2 = xpc_kmalloc_cacheline_aligned(buf_size,
2413                                                                    GFP_KERNEL,
2414                                               &xpc_remote_copy_buffer_base_sn2);
2415         if (xpc_remote_copy_buffer_sn2 == NULL) {
2416                 dev_err(xpc_part, "can't get memory for remote copy buffer\n");
2417                 return -ENOMEM;
2418         }
2419
2420         /* open up protections for IPI and [potentially] amo operations */
2421         xpc_allow_IPI_ops_sn2();
2422         xpc_allow_amo_ops_shub_wars_1_1_sn2();
2423
2424         /*
2425          * This is safe to do before the xpc_hb_checker thread has started
2426          * because the handler releases a wait queue.  If an interrupt is
2427          * received before the thread is waiting, it will not go to sleep,
2428          * but rather immediately process the interrupt.
2429          */
2430         ret = request_irq(SGI_XPC_ACTIVATE, xpc_handle_activate_IRQ_sn2, 0,
2431                           "xpc hb", NULL);
2432         if (ret != 0) {
2433                 dev_err(xpc_part, "can't register ACTIVATE IRQ handler, "
2434                         "errno=%d\n", -ret);
2435                 xpc_disallow_IPI_ops_sn2();
2436                 kfree(xpc_remote_copy_buffer_base_sn2);
2437         }
2438         return ret;
2439 }
2440
2441 void
2442 xpc_exit_sn2(void)
2443 {
2444         free_irq(SGI_XPC_ACTIVATE, NULL);
2445         xpc_disallow_IPI_ops_sn2();
2446         kfree(xpc_remote_copy_buffer_base_sn2);
2447 }