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