eaaa964942de97e91b0c5edfd7d3a6ff12bc4ed4
[linux-2.6.git] / drivers / misc / sgi-xp / xpc_sn2.c
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
7  */
8
9 /*
10  * Cross Partition Communication (XPC) sn2-based functions.
11  *
12  *     Architecture specific implementation of common functions.
13  *
14  */
15
16 #include <linux/delay.h>
17 #include <asm/uncached.h>
18 #include <asm/sn/mspec.h>
19 #include <asm/sn/sn_sal.h>
20 #include "xpc.h"
21
22 /*
23  * Define the number of u64s required to represent all the C-brick nasids
24  * as a bitmap.  The cross-partition kernel modules deal only with
25  * C-brick nasids, thus the need for bitmaps which don't account for
26  * odd-numbered (non C-brick) nasids.
27  */
28 #define XPC_MAX_PHYSNODES_SN2   (MAX_NUMALINK_NODES / 2)
29 #define XP_NASID_MASK_BYTES_SN2 ((XPC_MAX_PHYSNODES_SN2 + 7) / 8)
30 #define XP_NASID_MASK_WORDS_SN2 ((XPC_MAX_PHYSNODES_SN2 + 63) / 64)
31
32 /*
33  * Memory for XPC's amo variables is allocated by the MSPEC driver. These
34  * pages are located in the lowest granule. The lowest granule uses 4k pages
35  * for cached references and an alternate TLB handler to never provide a
36  * cacheable mapping for the entire region. This will prevent speculative
37  * reading of cached copies of our lines from being issued which will cause
38  * a PI FSB Protocol error to be generated by the SHUB. For XPC, we need 64
39  * amo variables (based on XP_MAX_NPARTITIONS_SN2) to identify the senders of
40  * NOTIFY IRQs, 128 amo variables (based on XP_NASID_MASK_WORDS_SN2) to identify
41  * the senders of ACTIVATE IRQs, 1 amo variable to identify which remote
42  * partitions (i.e., XPCs) consider themselves currently engaged with the
43  * local XPC and 1 amo variable to request partition deactivation.
44  */
45 #define XPC_NOTIFY_IRQ_AMOS_SN2         0
46 #define XPC_ACTIVATE_IRQ_AMOS_SN2       (XPC_NOTIFY_IRQ_AMOS_SN2 + \
47                                          XP_MAX_NPARTITIONS_SN2)
48 #define XPC_ENGAGED_PARTITIONS_AMO_SN2  (XPC_ACTIVATE_IRQ_AMOS_SN2 + \
49                                          XP_NASID_MASK_WORDS_SN2)
50 #define XPC_DEACTIVATE_REQUEST_AMO_SN2  (XPC_ENGAGED_PARTITIONS_AMO_SN2 + 1)
51
52 /*
53  * Buffer used to store a local copy of portions of a remote partition's
54  * reserved page (either its header and part_nasids mask, or its vars).
55  */
56 static void *xpc_remote_copy_buffer_base_sn2;
57 static char *xpc_remote_copy_buffer_sn2;
58
59 static struct xpc_vars_sn2 *xpc_vars_sn2;
60 static struct xpc_vars_part_sn2 *xpc_vars_part_sn2;
61
62 static int
63 xpc_setup_partitions_sn_sn2(void)
64 {
65         /* nothing needs to be done */
66         return 0;
67 }
68
69 static void
70 xpc_teardown_partitions_sn_sn2(void)
71 {
72         /* nothing needs to be done */
73 }
74
75 /* SH_IPI_ACCESS shub register value on startup */
76 static u64 xpc_sh1_IPI_access_sn2;
77 static u64 xpc_sh2_IPI_access0_sn2;
78 static u64 xpc_sh2_IPI_access1_sn2;
79 static u64 xpc_sh2_IPI_access2_sn2;
80 static u64 xpc_sh2_IPI_access3_sn2;
81
82 /*
83  * Change protections to allow IPI operations.
84  */
85 static void
86 xpc_allow_IPI_ops_sn2(void)
87 {
88         int node;
89         int nasid;
90
91         /* !!! The following should get moved into SAL. */
92         if (is_shub2()) {
93                 xpc_sh2_IPI_access0_sn2 =
94                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS0));
95                 xpc_sh2_IPI_access1_sn2 =
96                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS1));
97                 xpc_sh2_IPI_access2_sn2 =
98                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS2));
99                 xpc_sh2_IPI_access3_sn2 =
100                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS3));
101
102                 for_each_online_node(node) {
103                         nasid = cnodeid_to_nasid(node);
104                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
105                               -1UL);
106                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
107                               -1UL);
108                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
109                               -1UL);
110                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
111                               -1UL);
112                 }
113         } else {
114                 xpc_sh1_IPI_access_sn2 =
115                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH1_IPI_ACCESS));
116
117                 for_each_online_node(node) {
118                         nasid = cnodeid_to_nasid(node);
119                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
120                               -1UL);
121                 }
122         }
123 }
124
125 /*
126  * Restrict protections to disallow IPI operations.
127  */
128 static void
129 xpc_disallow_IPI_ops_sn2(void)
130 {
131         int node;
132         int nasid;
133
134         /* !!! The following should get moved into SAL. */
135         if (is_shub2()) {
136                 for_each_online_node(node) {
137                         nasid = cnodeid_to_nasid(node);
138                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
139                               xpc_sh2_IPI_access0_sn2);
140                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
141                               xpc_sh2_IPI_access1_sn2);
142                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
143                               xpc_sh2_IPI_access2_sn2);
144                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
145                               xpc_sh2_IPI_access3_sn2);
146                 }
147         } else {
148                 for_each_online_node(node) {
149                         nasid = cnodeid_to_nasid(node);
150                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
151                               xpc_sh1_IPI_access_sn2);
152                 }
153         }
154 }
155
156 /*
157  * The following set of functions are used for the sending and receiving of
158  * IRQs (also known as IPIs). There are two flavors of IRQs, one that is
159  * associated with partition activity (SGI_XPC_ACTIVATE) and the other that
160  * is associated with channel activity (SGI_XPC_NOTIFY).
161  */
162
163 static u64
164 xpc_receive_IRQ_amo_sn2(struct amo *amo)
165 {
166         return FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_CLEAR);
167 }
168
169 static enum xp_retval
170 xpc_send_IRQ_sn2(struct amo *amo, u64 flag, int nasid, int phys_cpuid,
171                  int vector)
172 {
173         int ret = 0;
174         unsigned long irq_flags;
175
176         local_irq_save(irq_flags);
177
178         FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR, flag);
179         sn_send_IPI_phys(nasid, phys_cpuid, vector, 0);
180
181         /*
182          * We must always use the nofault function regardless of whether we
183          * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
184          * didn't, we'd never know that the other partition is down and would
185          * keep sending IRQs and amos to it until the heartbeat times out.
186          */
187         ret = xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->variable),
188                                                      xp_nofault_PIOR_target));
189
190         local_irq_restore(irq_flags);
191
192         return (ret == 0) ? xpSuccess : xpPioReadError;
193 }
194
195 static struct amo *
196 xpc_init_IRQ_amo_sn2(int index)
197 {
198         struct amo *amo = xpc_vars_sn2->amos_page + index;
199
200         (void)xpc_receive_IRQ_amo_sn2(amo);     /* clear amo variable */
201         return amo;
202 }
203
204 /*
205  * Functions associated with SGI_XPC_ACTIVATE IRQ.
206  */
207
208 /*
209  * Notify the heartbeat check thread that an activate IRQ has been received.
210  */
211 static irqreturn_t
212 xpc_handle_activate_IRQ_sn2(int irq, void *dev_id)
213 {
214         unsigned long irq_flags;
215
216         spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
217         xpc_activate_IRQ_rcvd++;
218         spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
219
220         wake_up_interruptible(&xpc_activate_IRQ_wq);
221         return IRQ_HANDLED;
222 }
223
224 /*
225  * Flag the appropriate amo variable and send an IRQ to the specified node.
226  */
227 static void
228 xpc_send_activate_IRQ_sn2(unsigned long amos_page_pa, int from_nasid,
229                           int to_nasid, int to_phys_cpuid)
230 {
231         struct amo *amos = (struct amo *)__va(amos_page_pa +
232                                               (XPC_ACTIVATE_IRQ_AMOS_SN2 *
233                                               sizeof(struct amo)));
234
235         (void)xpc_send_IRQ_sn2(&amos[BIT_WORD(from_nasid / 2)],
236                                BIT_MASK(from_nasid / 2), to_nasid,
237                                to_phys_cpuid, SGI_XPC_ACTIVATE);
238 }
239
240 static void
241 xpc_send_local_activate_IRQ_sn2(int from_nasid)
242 {
243         unsigned long irq_flags;
244         struct amo *amos = (struct amo *)__va(xpc_vars_sn2->amos_page_pa +
245                                               (XPC_ACTIVATE_IRQ_AMOS_SN2 *
246                                               sizeof(struct amo)));
247
248         /* fake the sending and receipt of an activate IRQ from remote nasid */
249         FETCHOP_STORE_OP(TO_AMO((u64)&amos[BIT_WORD(from_nasid / 2)].variable),
250                          FETCHOP_OR, BIT_MASK(from_nasid / 2));
251
252         spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
253         xpc_activate_IRQ_rcvd++;
254         spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
255
256         wake_up_interruptible(&xpc_activate_IRQ_wq);
257 }
258
259 /*
260  * Functions associated with SGI_XPC_NOTIFY IRQ.
261  */
262
263 /*
264  * Check to see if any chctl flags were sent from the specified partition.
265  */
266 static void
267 xpc_check_for_sent_chctl_flags_sn2(struct xpc_partition *part)
268 {
269         union xpc_channel_ctl_flags chctl;
270         unsigned long irq_flags;
271
272         chctl.all_flags = xpc_receive_IRQ_amo_sn2(part->sn.sn2.
273                                                   local_chctl_amo_va);
274         if (chctl.all_flags == 0)
275                 return;
276
277         spin_lock_irqsave(&part->chctl_lock, irq_flags);
278         part->chctl.all_flags |= chctl.all_flags;
279         spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
280
281         dev_dbg(xpc_chan, "received notify IRQ from partid=%d, chctl.all_flags="
282                 "0x%lx\n", XPC_PARTID(part), chctl.all_flags);
283
284         xpc_wakeup_channel_mgr(part);
285 }
286
287 /*
288  * Handle the receipt of a SGI_XPC_NOTIFY IRQ by seeing whether the specified
289  * partition actually sent it. Since SGI_XPC_NOTIFY IRQs may be shared by more
290  * than one partition, we use an amo structure per partition to indicate
291  * whether a partition has sent an IRQ or not.  If it has, then wake up the
292  * associated kthread to handle it.
293  *
294  * All SGI_XPC_NOTIFY IRQs received by XPC are the result of IRQs sent by XPC
295  * running on other partitions.
296  *
297  * Noteworthy Arguments:
298  *
299  *      irq - Interrupt ReQuest number. NOT USED.
300  *
301  *      dev_id - partid of IRQ's potential sender.
302  */
303 static irqreturn_t
304 xpc_handle_notify_IRQ_sn2(int irq, void *dev_id)
305 {
306         short partid = (short)(u64)dev_id;
307         struct xpc_partition *part = &xpc_partitions[partid];
308
309         DBUG_ON(partid < 0 || partid >= XP_MAX_NPARTITIONS_SN2);
310
311         if (xpc_part_ref(part)) {
312                 xpc_check_for_sent_chctl_flags_sn2(part);
313
314                 xpc_part_deref(part);
315         }
316         return IRQ_HANDLED;
317 }
318
319 /*
320  * Check to see if xpc_handle_notify_IRQ_sn2() dropped any IRQs on the floor
321  * because the write to their associated amo variable completed after the IRQ
322  * was received.
323  */
324 static void
325 xpc_check_for_dropped_notify_IRQ_sn2(struct xpc_partition *part)
326 {
327         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
328
329         if (xpc_part_ref(part)) {
330                 xpc_check_for_sent_chctl_flags_sn2(part);
331
332                 part_sn2->dropped_notify_IRQ_timer.expires = jiffies +
333                     XPC_DROPPED_NOTIFY_IRQ_WAIT_INTERVAL;
334                 add_timer(&part_sn2->dropped_notify_IRQ_timer);
335                 xpc_part_deref(part);
336         }
337 }
338
339 /*
340  * Send a notify IRQ to the remote partition that is associated with the
341  * specified channel.
342  */
343 static void
344 xpc_send_notify_IRQ_sn2(struct xpc_channel *ch, u8 chctl_flag,
345                         char *chctl_flag_string, unsigned long *irq_flags)
346 {
347         struct xpc_partition *part = &xpc_partitions[ch->partid];
348         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
349         union xpc_channel_ctl_flags chctl = { 0 };
350         enum xp_retval ret;
351
352         if (likely(part->act_state != XPC_P_AS_DEACTIVATING)) {
353                 chctl.flags[ch->number] = chctl_flag;
354                 ret = xpc_send_IRQ_sn2(part_sn2->remote_chctl_amo_va,
355                                        chctl.all_flags,
356                                        part_sn2->notify_IRQ_nasid,
357                                        part_sn2->notify_IRQ_phys_cpuid,
358                                        SGI_XPC_NOTIFY);
359                 dev_dbg(xpc_chan, "%s sent to partid=%d, channel=%d, ret=%d\n",
360                         chctl_flag_string, ch->partid, ch->number, ret);
361                 if (unlikely(ret != xpSuccess)) {
362                         if (irq_flags != NULL)
363                                 spin_unlock_irqrestore(&ch->lock, *irq_flags);
364                         XPC_DEACTIVATE_PARTITION(part, ret);
365                         if (irq_flags != NULL)
366                                 spin_lock_irqsave(&ch->lock, *irq_flags);
367                 }
368         }
369 }
370
371 #define XPC_SEND_NOTIFY_IRQ_SN2(_ch, _ipi_f, _irq_f) \
372                 xpc_send_notify_IRQ_sn2(_ch, _ipi_f, #_ipi_f, _irq_f)
373
374 /*
375  * Make it look like the remote partition, which is associated with the
376  * specified channel, sent us a notify IRQ. This faked IRQ will be handled
377  * by xpc_check_for_dropped_notify_IRQ_sn2().
378  */
379 static void
380 xpc_send_local_notify_IRQ_sn2(struct xpc_channel *ch, u8 chctl_flag,
381                               char *chctl_flag_string)
382 {
383         struct xpc_partition *part = &xpc_partitions[ch->partid];
384         union xpc_channel_ctl_flags chctl = { 0 };
385
386         chctl.flags[ch->number] = chctl_flag;
387         FETCHOP_STORE_OP(TO_AMO((u64)&part->sn.sn2.local_chctl_amo_va->
388                                 variable), FETCHOP_OR, chctl.all_flags);
389         dev_dbg(xpc_chan, "%s sent local from partid=%d, channel=%d\n",
390                 chctl_flag_string, ch->partid, ch->number);
391 }
392
393 #define XPC_SEND_LOCAL_NOTIFY_IRQ_SN2(_ch, _ipi_f) \
394                 xpc_send_local_notify_IRQ_sn2(_ch, _ipi_f, #_ipi_f)
395
396 static void
397 xpc_send_chctl_closerequest_sn2(struct xpc_channel *ch,
398                                 unsigned long *irq_flags)
399 {
400         struct xpc_openclose_args *args = ch->sn.sn2.local_openclose_args;
401
402         args->reason = ch->reason;
403         XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_CLOSEREQUEST, irq_flags);
404 }
405
406 static void
407 xpc_send_chctl_closereply_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
408 {
409         XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_CLOSEREPLY, irq_flags);
410 }
411
412 static void
413 xpc_send_chctl_openrequest_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
414 {
415         struct xpc_openclose_args *args = ch->sn.sn2.local_openclose_args;
416
417         args->entry_size = ch->entry_size;
418         args->local_nentries = ch->local_nentries;
419         XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_OPENREQUEST, irq_flags);
420 }
421
422 static void
423 xpc_send_chctl_openreply_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
424 {
425         struct xpc_openclose_args *args = ch->sn.sn2.local_openclose_args;
426
427         args->remote_nentries = ch->remote_nentries;
428         args->local_nentries = ch->local_nentries;
429         args->local_msgqueue_pa = xp_pa(ch->sn.sn2.local_msgqueue);
430         XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_OPENREPLY, irq_flags);
431 }
432
433 static void
434 xpc_send_chctl_msgrequest_sn2(struct xpc_channel *ch)
435 {
436         XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_MSGREQUEST, NULL);
437 }
438
439 static void
440 xpc_send_chctl_local_msgrequest_sn2(struct xpc_channel *ch)
441 {
442         XPC_SEND_LOCAL_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_MSGREQUEST);
443 }
444
445 static enum xp_retval
446 xpc_save_remote_msgqueue_pa_sn2(struct xpc_channel *ch,
447                                 unsigned long msgqueue_pa)
448 {
449         ch->sn.sn2.remote_msgqueue_pa = msgqueue_pa;
450         return xpSuccess;
451 }
452
453 /*
454  * This next set of functions are used to keep track of when a partition is
455  * potentially engaged in accessing memory belonging to another partition.
456  */
457
458 static void
459 xpc_indicate_partition_engaged_sn2(struct xpc_partition *part)
460 {
461         unsigned long irq_flags;
462         struct amo *amo = (struct amo *)__va(part->sn.sn2.remote_amos_page_pa +
463                                              (XPC_ENGAGED_PARTITIONS_AMO_SN2 *
464                                              sizeof(struct amo)));
465
466         local_irq_save(irq_flags);
467
468         /* set bit corresponding to our partid in remote partition's amo */
469         FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR,
470                          BIT(sn_partition_id));
471
472         /*
473          * We must always use the nofault function regardless of whether we
474          * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
475          * didn't, we'd never know that the other partition is down and would
476          * keep sending IRQs and amos to it until the heartbeat times out.
477          */
478         (void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
479                                                                variable),
480                                                      xp_nofault_PIOR_target));
481
482         local_irq_restore(irq_flags);
483 }
484
485 static void
486 xpc_indicate_partition_disengaged_sn2(struct xpc_partition *part)
487 {
488         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
489         unsigned long irq_flags;
490         struct amo *amo = (struct amo *)__va(part_sn2->remote_amos_page_pa +
491                                              (XPC_ENGAGED_PARTITIONS_AMO_SN2 *
492                                              sizeof(struct amo)));
493
494         local_irq_save(irq_flags);
495
496         /* clear bit corresponding to our partid in remote partition's amo */
497         FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
498                          ~BIT(sn_partition_id));
499
500         /*
501          * We must always use the nofault function regardless of whether we
502          * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
503          * didn't, we'd never know that the other partition is down and would
504          * keep sending IRQs and amos to it until the heartbeat times out.
505          */
506         (void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
507                                                                variable),
508                                                      xp_nofault_PIOR_target));
509
510         local_irq_restore(irq_flags);
511
512         /*
513          * Send activate IRQ to get other side to see that we've cleared our
514          * bit in their engaged partitions amo.
515          */
516         xpc_send_activate_IRQ_sn2(part_sn2->remote_amos_page_pa,
517                                   cnodeid_to_nasid(0),
518                                   part_sn2->activate_IRQ_nasid,
519                                   part_sn2->activate_IRQ_phys_cpuid);
520 }
521
522 static void
523 xpc_assume_partition_disengaged_sn2(short partid)
524 {
525         struct amo *amo = xpc_vars_sn2->amos_page +
526                           XPC_ENGAGED_PARTITIONS_AMO_SN2;
527
528         /* clear bit(s) based on partid mask in our partition's amo */
529         FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
530                          ~BIT(partid));
531 }
532
533 static int
534 xpc_partition_engaged_sn2(short partid)
535 {
536         struct amo *amo = xpc_vars_sn2->amos_page +
537                           XPC_ENGAGED_PARTITIONS_AMO_SN2;
538
539         /* our partition's amo variable ANDed with partid mask */
540         return (FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) &
541                 BIT(partid)) != 0;
542 }
543
544 static int
545 xpc_any_partition_engaged_sn2(void)
546 {
547         struct amo *amo = xpc_vars_sn2->amos_page +
548                           XPC_ENGAGED_PARTITIONS_AMO_SN2;
549
550         /* our partition's amo variable */
551         return FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) != 0;
552 }
553
554 /* original protection values for each node */
555 static u64 xpc_prot_vec_sn2[MAX_NUMNODES];
556
557 /*
558  * Change protections to allow amo operations on non-Shub 1.1 systems.
559  */
560 static enum xp_retval
561 xpc_allow_amo_ops_sn2(struct amo *amos_page)
562 {
563         enum xp_retval ret = xpSuccess;
564
565         /*
566          * On SHUB 1.1, we cannot call sn_change_memprotect() since the BIST
567          * collides with memory operations. On those systems we call
568          * xpc_allow_amo_ops_shub_wars_1_1_sn2() instead.
569          */
570         if (!enable_shub_wars_1_1())
571                 ret = xp_expand_memprotect(ia64_tpa((u64)amos_page), PAGE_SIZE);
572
573         return ret;
574 }
575
576 /*
577  * Change protections to allow amo operations on Shub 1.1 systems.
578  */
579 static void
580 xpc_allow_amo_ops_shub_wars_1_1_sn2(void)
581 {
582         int node;
583         int nasid;
584
585         if (!enable_shub_wars_1_1())
586                 return;
587
588         for_each_online_node(node) {
589                 nasid = cnodeid_to_nasid(node);
590                 /* save current protection values */
591                 xpc_prot_vec_sn2[node] =
592                     (u64)HUB_L((u64 *)GLOBAL_MMR_ADDR(nasid,
593                                                   SH1_MD_DQLP_MMR_DIR_PRIVEC0));
594                 /* open up everything */
595                 HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid,
596                                              SH1_MD_DQLP_MMR_DIR_PRIVEC0),
597                       -1UL);
598                 HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid,
599                                              SH1_MD_DQRP_MMR_DIR_PRIVEC0),
600                       -1UL);
601         }
602 }
603
604 static enum xp_retval
605 xpc_get_partition_rsvd_page_pa_sn2(void *buf, u64 *cookie, unsigned long *rp_pa,
606                                    size_t *len)
607 {
608         s64 status;
609         enum xp_retval ret;
610
611         status = sn_partition_reserved_page_pa((u64)buf, cookie, rp_pa, len);
612         if (status == SALRET_OK)
613                 ret = xpSuccess;
614         else if (status == SALRET_MORE_PASSES)
615                 ret = xpNeedMoreInfo;
616         else
617                 ret = xpSalError;
618
619         return ret;
620 }
621
622
623 static int
624 xpc_setup_rsvd_page_sn_sn2(struct xpc_rsvd_page *rp)
625 {
626         struct amo *amos_page;
627         int i;
628         int ret;
629
630         xpc_vars_sn2 = XPC_RP_VARS(rp);
631
632         rp->sn.vars_pa = xp_pa(xpc_vars_sn2);
633
634         /* vars_part array follows immediately after vars */
635         xpc_vars_part_sn2 = (struct xpc_vars_part_sn2 *)((u8 *)XPC_RP_VARS(rp) +
636                                                          XPC_RP_VARS_SIZE);
637
638         /*
639          * Before clearing xpc_vars_sn2, see if a page of amos had been
640          * previously allocated. If not we'll need to allocate one and set
641          * permissions so that cross-partition amos are allowed.
642          *
643          * The allocated amo page needs MCA reporting to remain disabled after
644          * XPC has unloaded.  To make this work, we keep a copy of the pointer
645          * to this page (i.e., amos_page) in the struct xpc_vars_sn2 structure,
646          * which is pointed to by the reserved page, and re-use that saved copy
647          * on subsequent loads of XPC. This amo page is never freed, and its
648          * memory protections are never restricted.
649          */
650         amos_page = xpc_vars_sn2->amos_page;
651         if (amos_page == NULL) {
652                 amos_page = (struct amo *)TO_AMO(uncached_alloc_page(0, 1));
653                 if (amos_page == NULL) {
654                         dev_err(xpc_part, "can't allocate page of amos\n");
655                         return -ENOMEM;
656                 }
657
658                 /*
659                  * Open up amo-R/W to cpu.  This is done on Shub 1.1 systems
660                  * when xpc_allow_amo_ops_shub_wars_1_1_sn2() is called.
661                  */
662                 ret = xpc_allow_amo_ops_sn2(amos_page);
663                 if (ret != xpSuccess) {
664                         dev_err(xpc_part, "can't allow amo operations\n");
665                         uncached_free_page(__IA64_UNCACHED_OFFSET |
666                                            TO_PHYS((u64)amos_page), 1);
667                         return -EPERM;
668                 }
669         }
670
671         /* clear xpc_vars_sn2 */
672         memset(xpc_vars_sn2, 0, sizeof(struct xpc_vars_sn2));
673
674         xpc_vars_sn2->version = XPC_V_VERSION;
675         xpc_vars_sn2->activate_IRQ_nasid = cpuid_to_nasid(0);
676         xpc_vars_sn2->activate_IRQ_phys_cpuid = cpu_physical_id(0);
677         xpc_vars_sn2->vars_part_pa = xp_pa(xpc_vars_part_sn2);
678         xpc_vars_sn2->amos_page_pa = ia64_tpa((u64)amos_page);
679         xpc_vars_sn2->amos_page = amos_page;    /* save for next load of XPC */
680
681         /* clear xpc_vars_part_sn2 */
682         memset((u64 *)xpc_vars_part_sn2, 0, sizeof(struct xpc_vars_part_sn2) *
683                XP_MAX_NPARTITIONS_SN2);
684
685         /* initialize the activate IRQ related amo variables */
686         for (i = 0; i < xpc_nasid_mask_nlongs; i++)
687                 (void)xpc_init_IRQ_amo_sn2(XPC_ACTIVATE_IRQ_AMOS_SN2 + i);
688
689         /* initialize the engaged remote partitions related amo variables */
690         (void)xpc_init_IRQ_amo_sn2(XPC_ENGAGED_PARTITIONS_AMO_SN2);
691         (void)xpc_init_IRQ_amo_sn2(XPC_DEACTIVATE_REQUEST_AMO_SN2);
692
693         return 0;
694 }
695
696 static void
697 xpc_increment_heartbeat_sn2(void)
698 {
699         xpc_vars_sn2->heartbeat++;
700 }
701
702 static void
703 xpc_offline_heartbeat_sn2(void)
704 {
705         xpc_increment_heartbeat_sn2();
706         xpc_vars_sn2->heartbeat_offline = 1;
707 }
708
709 static void
710 xpc_online_heartbeat_sn2(void)
711 {
712         xpc_increment_heartbeat_sn2();
713         xpc_vars_sn2->heartbeat_offline = 0;
714 }
715
716 static void
717 xpc_heartbeat_init_sn2(void)
718 {
719         DBUG_ON(xpc_vars_sn2 == NULL);
720
721         bitmap_zero(xpc_vars_sn2->heartbeating_to_mask, XP_MAX_NPARTITIONS_SN2);
722         xpc_heartbeating_to_mask = &xpc_vars_sn2->heartbeating_to_mask[0];
723         xpc_online_heartbeat_sn2();
724 }
725
726 static void
727 xpc_heartbeat_exit_sn2(void)
728 {
729         xpc_offline_heartbeat_sn2();
730 }
731
732 static enum xp_retval
733 xpc_get_remote_heartbeat_sn2(struct xpc_partition *part)
734 {
735         struct xpc_vars_sn2 *remote_vars;
736         enum xp_retval ret;
737
738         remote_vars = (struct xpc_vars_sn2 *)xpc_remote_copy_buffer_sn2;
739
740         /* pull the remote vars structure that contains the heartbeat */
741         ret = xp_remote_memcpy(xp_pa(remote_vars),
742                                part->sn.sn2.remote_vars_pa,
743                                XPC_RP_VARS_SIZE);
744         if (ret != xpSuccess)
745                 return ret;
746
747         dev_dbg(xpc_part, "partid=%d, heartbeat=%ld, last_heartbeat=%ld, "
748                 "heartbeat_offline=%ld, HB_mask[0]=0x%lx\n", XPC_PARTID(part),
749                 remote_vars->heartbeat, part->last_heartbeat,
750                 remote_vars->heartbeat_offline,
751                 remote_vars->heartbeating_to_mask[0]);
752
753         if ((remote_vars->heartbeat == part->last_heartbeat &&
754             remote_vars->heartbeat_offline == 0) ||
755             !xpc_hb_allowed(sn_partition_id,
756                             &remote_vars->heartbeating_to_mask)) {
757                 ret = xpNoHeartbeat;
758         } else {
759                 part->last_heartbeat = remote_vars->heartbeat;
760         }
761
762         return ret;
763 }
764
765 /*
766  * Get a copy of the remote partition's XPC variables from the reserved page.
767  *
768  * remote_vars points to a buffer that is cacheline aligned for BTE copies and
769  * assumed to be of size XPC_RP_VARS_SIZE.
770  */
771 static enum xp_retval
772 xpc_get_remote_vars_sn2(unsigned long remote_vars_pa,
773                         struct xpc_vars_sn2 *remote_vars)
774 {
775         enum xp_retval ret;
776
777         if (remote_vars_pa == 0)
778                 return xpVarsNotSet;
779
780         /* pull over the cross partition variables */
781         ret = xp_remote_memcpy(xp_pa(remote_vars), remote_vars_pa,
782                                XPC_RP_VARS_SIZE);
783         if (ret != xpSuccess)
784                 return ret;
785
786         if (XPC_VERSION_MAJOR(remote_vars->version) !=
787             XPC_VERSION_MAJOR(XPC_V_VERSION)) {
788                 return xpBadVersion;
789         }
790
791         return xpSuccess;
792 }
793
794 static void
795 xpc_request_partition_activation_sn2(struct xpc_rsvd_page *remote_rp,
796                                      unsigned long remote_rp_pa, int nasid)
797 {
798         xpc_send_local_activate_IRQ_sn2(nasid);
799 }
800
801 static void
802 xpc_request_partition_reactivation_sn2(struct xpc_partition *part)
803 {
804         xpc_send_local_activate_IRQ_sn2(part->sn.sn2.activate_IRQ_nasid);
805 }
806
807 static void
808 xpc_request_partition_deactivation_sn2(struct xpc_partition *part)
809 {
810         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
811         unsigned long irq_flags;
812         struct amo *amo = (struct amo *)__va(part_sn2->remote_amos_page_pa +
813                                              (XPC_DEACTIVATE_REQUEST_AMO_SN2 *
814                                              sizeof(struct amo)));
815
816         local_irq_save(irq_flags);
817
818         /* set bit corresponding to our partid in remote partition's amo */
819         FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR,
820                          BIT(sn_partition_id));
821
822         /*
823          * We must always use the nofault function regardless of whether we
824          * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
825          * didn't, we'd never know that the other partition is down and would
826          * keep sending IRQs and amos to it until the heartbeat times out.
827          */
828         (void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
829                                                                variable),
830                                                      xp_nofault_PIOR_target));
831
832         local_irq_restore(irq_flags);
833
834         /*
835          * Send activate IRQ to get other side to see that we've set our
836          * bit in their deactivate request amo.
837          */
838         xpc_send_activate_IRQ_sn2(part_sn2->remote_amos_page_pa,
839                                   cnodeid_to_nasid(0),
840                                   part_sn2->activate_IRQ_nasid,
841                                   part_sn2->activate_IRQ_phys_cpuid);
842 }
843
844 static void
845 xpc_cancel_partition_deactivation_request_sn2(struct xpc_partition *part)
846 {
847         unsigned long irq_flags;
848         struct amo *amo = (struct amo *)__va(part->sn.sn2.remote_amos_page_pa +
849                                              (XPC_DEACTIVATE_REQUEST_AMO_SN2 *
850                                              sizeof(struct amo)));
851
852         local_irq_save(irq_flags);
853
854         /* clear bit corresponding to our partid in remote partition's amo */
855         FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
856                          ~BIT(sn_partition_id));
857
858         /*
859          * We must always use the nofault function regardless of whether we
860          * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
861          * didn't, we'd never know that the other partition is down and would
862          * keep sending IRQs and amos to it until the heartbeat times out.
863          */
864         (void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
865                                                                variable),
866                                                      xp_nofault_PIOR_target));
867
868         local_irq_restore(irq_flags);
869 }
870
871 static int
872 xpc_partition_deactivation_requested_sn2(short partid)
873 {
874         struct amo *amo = xpc_vars_sn2->amos_page +
875                           XPC_DEACTIVATE_REQUEST_AMO_SN2;
876
877         /* our partition's amo variable ANDed with partid mask */
878         return (FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) &
879                 BIT(partid)) != 0;
880 }
881
882 /*
883  * Update the remote partition's info.
884  */
885 static void
886 xpc_update_partition_info_sn2(struct xpc_partition *part, u8 remote_rp_version,
887                               unsigned long *remote_rp_ts_jiffies,
888                               unsigned long remote_rp_pa,
889                               unsigned long remote_vars_pa,
890                               struct xpc_vars_sn2 *remote_vars)
891 {
892         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
893
894         part->remote_rp_version = remote_rp_version;
895         dev_dbg(xpc_part, "  remote_rp_version = 0x%016x\n",
896                 part->remote_rp_version);
897
898         part->remote_rp_ts_jiffies = *remote_rp_ts_jiffies;
899         dev_dbg(xpc_part, "  remote_rp_ts_jiffies = 0x%016lx\n",
900                 part->remote_rp_ts_jiffies);
901
902         part->remote_rp_pa = remote_rp_pa;
903         dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
904
905         part_sn2->remote_vars_pa = remote_vars_pa;
906         dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
907                 part_sn2->remote_vars_pa);
908
909         part->last_heartbeat = remote_vars->heartbeat - 1;
910         dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
911                 part->last_heartbeat);
912
913         part_sn2->remote_vars_part_pa = remote_vars->vars_part_pa;
914         dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
915                 part_sn2->remote_vars_part_pa);
916
917         part_sn2->activate_IRQ_nasid = remote_vars->activate_IRQ_nasid;
918         dev_dbg(xpc_part, "  activate_IRQ_nasid = 0x%x\n",
919                 part_sn2->activate_IRQ_nasid);
920
921         part_sn2->activate_IRQ_phys_cpuid =
922             remote_vars->activate_IRQ_phys_cpuid;
923         dev_dbg(xpc_part, "  activate_IRQ_phys_cpuid = 0x%x\n",
924                 part_sn2->activate_IRQ_phys_cpuid);
925
926         part_sn2->remote_amos_page_pa = remote_vars->amos_page_pa;
927         dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
928                 part_sn2->remote_amos_page_pa);
929
930         part_sn2->remote_vars_version = remote_vars->version;
931         dev_dbg(xpc_part, "  remote_vars_version = 0x%x\n",
932                 part_sn2->remote_vars_version);
933 }
934
935 /*
936  * Prior code has determined the nasid which generated a activate IRQ.
937  * Inspect that nasid to determine if its partition needs to be activated
938  * or deactivated.
939  *
940  * A partition is considered "awaiting activation" if our partition
941  * flags indicate it is not active and it has a heartbeat.  A
942  * partition is considered "awaiting deactivation" if our partition
943  * flags indicate it is active but it has no heartbeat or it is not
944  * sending its heartbeat to us.
945  *
946  * To determine the heartbeat, the remote nasid must have a properly
947  * initialized reserved page.
948  */
949 static void
950 xpc_identify_activate_IRQ_req_sn2(int nasid)
951 {
952         struct xpc_rsvd_page *remote_rp;
953         struct xpc_vars_sn2 *remote_vars;
954         unsigned long remote_rp_pa;
955         unsigned long remote_vars_pa;
956         int remote_rp_version;
957         int reactivate = 0;
958         unsigned long remote_rp_ts_jiffies = 0;
959         short partid;
960         struct xpc_partition *part;
961         struct xpc_partition_sn2 *part_sn2;
962         enum xp_retval ret;
963
964         /* pull over the reserved page structure */
965
966         remote_rp = (struct xpc_rsvd_page *)xpc_remote_copy_buffer_sn2;
967
968         ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rp_pa);
969         if (ret != xpSuccess) {
970                 dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
971                          "which sent interrupt, reason=%d\n", nasid, ret);
972                 return;
973         }
974
975         remote_vars_pa = remote_rp->sn.vars_pa;
976         remote_rp_version = remote_rp->version;
977         remote_rp_ts_jiffies = remote_rp->ts_jiffies;
978
979         partid = remote_rp->SAL_partid;
980         part = &xpc_partitions[partid];
981         part_sn2 = &part->sn.sn2;
982
983         /* pull over the cross partition variables */
984
985         remote_vars = (struct xpc_vars_sn2 *)xpc_remote_copy_buffer_sn2;
986
987         ret = xpc_get_remote_vars_sn2(remote_vars_pa, remote_vars);
988         if (ret != xpSuccess) {
989                 dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
990                          "which sent interrupt, reason=%d\n", nasid, ret);
991
992                 XPC_DEACTIVATE_PARTITION(part, ret);
993                 return;
994         }
995
996         part->activate_IRQ_rcvd++;
997
998         dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
999                 "%ld:0x%lx\n", (int)nasid, (int)partid, part->activate_IRQ_rcvd,
1000                 remote_vars->heartbeat, remote_vars->heartbeating_to_mask[0]);
1001
1002         if (xpc_partition_disengaged(part) &&
1003             part->act_state == XPC_P_AS_INACTIVE) {
1004
1005                 xpc_update_partition_info_sn2(part, remote_rp_version,
1006                                               &remote_rp_ts_jiffies,
1007                                               remote_rp_pa, remote_vars_pa,
1008                                               remote_vars);
1009
1010                 if (xpc_partition_deactivation_requested_sn2(partid)) {
1011                         /*
1012                          * Other side is waiting on us to deactivate even though
1013                          * we already have.
1014                          */
1015                         return;
1016                 }
1017
1018                 xpc_activate_partition(part);
1019                 return;
1020         }
1021
1022         DBUG_ON(part->remote_rp_version == 0);
1023         DBUG_ON(part_sn2->remote_vars_version == 0);
1024
1025         if (remote_rp_ts_jiffies != part->remote_rp_ts_jiffies) {
1026
1027                 /* the other side rebooted */
1028
1029                 DBUG_ON(xpc_partition_engaged_sn2(partid));
1030                 DBUG_ON(xpc_partition_deactivation_requested_sn2(partid));
1031
1032                 xpc_update_partition_info_sn2(part, remote_rp_version,
1033                                               &remote_rp_ts_jiffies,
1034                                               remote_rp_pa, remote_vars_pa,
1035                                               remote_vars);
1036                 reactivate = 1;
1037         }
1038
1039         if (part->disengage_timeout > 0 && !xpc_partition_disengaged(part)) {
1040                 /* still waiting on other side to disengage from us */
1041                 return;
1042         }
1043
1044         if (reactivate)
1045                 XPC_DEACTIVATE_PARTITION(part, xpReactivating);
1046         else if (xpc_partition_deactivation_requested_sn2(partid))
1047                 XPC_DEACTIVATE_PARTITION(part, xpOtherGoingDown);
1048 }
1049
1050 /*
1051  * Loop through the activation amo variables and process any bits
1052  * which are set.  Each bit indicates a nasid sending a partition
1053  * activation or deactivation request.
1054  *
1055  * Return #of IRQs detected.
1056  */
1057 int
1058 xpc_identify_activate_IRQ_sender_sn2(void)
1059 {
1060         int l;
1061         int b;
1062         unsigned long nasid_mask_long;
1063         u64 nasid;              /* remote nasid */
1064         int n_IRQs_detected = 0;
1065         struct amo *act_amos;
1066
1067         act_amos = xpc_vars_sn2->amos_page + XPC_ACTIVATE_IRQ_AMOS_SN2;
1068
1069         /* scan through activate amo variables looking for non-zero entries */
1070         for (l = 0; l < xpc_nasid_mask_nlongs; l++) {
1071
1072                 if (xpc_exiting)
1073                         break;
1074
1075                 nasid_mask_long = xpc_receive_IRQ_amo_sn2(&act_amos[l]);
1076
1077                 b = find_first_bit(&nasid_mask_long, BITS_PER_LONG);
1078                 if (b >= BITS_PER_LONG) {
1079                         /* no IRQs from nasids in this amo variable */
1080                         continue;
1081                 }
1082
1083                 dev_dbg(xpc_part, "amo[%d] gave back 0x%lx\n", l,
1084                         nasid_mask_long);
1085
1086                 /*
1087                  * If this nasid has been added to the machine since
1088                  * our partition was reset, this will retain the
1089                  * remote nasid in our reserved pages machine mask.
1090                  * This is used in the event of module reload.
1091                  */
1092                 xpc_mach_nasids[l] |= nasid_mask_long;
1093
1094                 /* locate the nasid(s) which sent interrupts */
1095
1096                 do {
1097                         n_IRQs_detected++;
1098                         nasid = (l * BITS_PER_LONG + b) * 2;
1099                         dev_dbg(xpc_part, "interrupt from nasid %ld\n", nasid);
1100                         xpc_identify_activate_IRQ_req_sn2(nasid);
1101
1102                         b = find_next_bit(&nasid_mask_long, BITS_PER_LONG,
1103                                           b + 1);
1104                 } while (b < BITS_PER_LONG);
1105         }
1106         return n_IRQs_detected;
1107 }
1108
1109 static void
1110 xpc_process_activate_IRQ_rcvd_sn2(void)
1111 {
1112         unsigned long irq_flags;
1113         int n_IRQs_expected;
1114         int n_IRQs_detected;
1115
1116         spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
1117         n_IRQs_expected = xpc_activate_IRQ_rcvd;
1118         xpc_activate_IRQ_rcvd = 0;
1119         spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
1120
1121         n_IRQs_detected = xpc_identify_activate_IRQ_sender_sn2();
1122         if (n_IRQs_detected < n_IRQs_expected) {
1123                 /* retry once to help avoid missing amo */
1124                 (void)xpc_identify_activate_IRQ_sender_sn2();
1125         }
1126 }
1127
1128 /*
1129  * Setup the channel structures that are sn2 specific.
1130  */
1131 static enum xp_retval
1132 xpc_setup_ch_structures_sn_sn2(struct xpc_partition *part)
1133 {
1134         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
1135         struct xpc_channel_sn2 *ch_sn2;
1136         enum xp_retval retval;
1137         int ret;
1138         int cpuid;
1139         int ch_number;
1140         struct timer_list *timer;
1141         short partid = XPC_PARTID(part);
1142
1143         /* allocate all the required GET/PUT values */
1144
1145         part_sn2->local_GPs =
1146             xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE, GFP_KERNEL,
1147                                           &part_sn2->local_GPs_base);
1148         if (part_sn2->local_GPs == NULL) {
1149                 dev_err(xpc_chan, "can't get memory for local get/put "
1150                         "values\n");
1151                 return xpNoMemory;
1152         }
1153
1154         part_sn2->remote_GPs =
1155             xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE, GFP_KERNEL,
1156                                           &part_sn2->remote_GPs_base);
1157         if (part_sn2->remote_GPs == NULL) {
1158                 dev_err(xpc_chan, "can't get memory for remote get/put "
1159                         "values\n");
1160                 retval = xpNoMemory;
1161                 goto out_1;
1162         }
1163
1164         part_sn2->remote_GPs_pa = 0;
1165
1166         /* allocate all the required open and close args */
1167
1168         part_sn2->local_openclose_args =
1169             xpc_kzalloc_cacheline_aligned(XPC_OPENCLOSE_ARGS_SIZE,
1170                                           GFP_KERNEL, &part_sn2->
1171                                           local_openclose_args_base);
1172         if (part_sn2->local_openclose_args == NULL) {
1173                 dev_err(xpc_chan, "can't get memory for local connect args\n");
1174                 retval = xpNoMemory;
1175                 goto out_2;
1176         }
1177
1178         part_sn2->remote_openclose_args_pa = 0;
1179
1180         part_sn2->local_chctl_amo_va = xpc_init_IRQ_amo_sn2(partid);
1181
1182         part_sn2->notify_IRQ_nasid = 0;
1183         part_sn2->notify_IRQ_phys_cpuid = 0;
1184         part_sn2->remote_chctl_amo_va = NULL;
1185
1186         sprintf(part_sn2->notify_IRQ_owner, "xpc%02d", partid);
1187         ret = request_irq(SGI_XPC_NOTIFY, xpc_handle_notify_IRQ_sn2,
1188                           IRQF_SHARED, part_sn2->notify_IRQ_owner,
1189                           (void *)(u64)partid);
1190         if (ret != 0) {
1191                 dev_err(xpc_chan, "can't register NOTIFY IRQ handler, "
1192                         "errno=%d\n", -ret);
1193                 retval = xpLackOfResources;
1194                 goto out_3;
1195         }
1196
1197         /* Setup a timer to check for dropped notify IRQs */
1198         timer = &part_sn2->dropped_notify_IRQ_timer;
1199         init_timer(timer);
1200         timer->function =
1201             (void (*)(unsigned long))xpc_check_for_dropped_notify_IRQ_sn2;
1202         timer->data = (unsigned long)part;
1203         timer->expires = jiffies + XPC_DROPPED_NOTIFY_IRQ_WAIT_INTERVAL;
1204         add_timer(timer);
1205
1206         for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
1207                 ch_sn2 = &part->channels[ch_number].sn.sn2;
1208
1209                 ch_sn2->local_GP = &part_sn2->local_GPs[ch_number];
1210                 ch_sn2->local_openclose_args =
1211                     &part_sn2->local_openclose_args[ch_number];
1212
1213                 mutex_init(&ch_sn2->msg_to_pull_mutex);
1214         }
1215
1216         /*
1217          * Setup the per partition specific variables required by the
1218          * remote partition to establish channel connections with us.
1219          *
1220          * The setting of the magic # indicates that these per partition
1221          * specific variables are ready to be used.
1222          */
1223         xpc_vars_part_sn2[partid].GPs_pa = xp_pa(part_sn2->local_GPs);
1224         xpc_vars_part_sn2[partid].openclose_args_pa =
1225             xp_pa(part_sn2->local_openclose_args);
1226         xpc_vars_part_sn2[partid].chctl_amo_pa =
1227             xp_pa(part_sn2->local_chctl_amo_va);
1228         cpuid = raw_smp_processor_id(); /* any CPU in this partition will do */
1229         xpc_vars_part_sn2[partid].notify_IRQ_nasid = cpuid_to_nasid(cpuid);
1230         xpc_vars_part_sn2[partid].notify_IRQ_phys_cpuid =
1231             cpu_physical_id(cpuid);
1232         xpc_vars_part_sn2[partid].nchannels = part->nchannels;
1233         xpc_vars_part_sn2[partid].magic = XPC_VP_MAGIC1_SN2;
1234
1235         return xpSuccess;
1236
1237         /* setup of ch structures failed */
1238 out_3:
1239         kfree(part_sn2->local_openclose_args_base);
1240         part_sn2->local_openclose_args = NULL;
1241 out_2:
1242         kfree(part_sn2->remote_GPs_base);
1243         part_sn2->remote_GPs = NULL;
1244 out_1:
1245         kfree(part_sn2->local_GPs_base);
1246         part_sn2->local_GPs = NULL;
1247         return retval;
1248 }
1249
1250 /*
1251  * Teardown the channel structures that are sn2 specific.
1252  */
1253 static void
1254 xpc_teardown_ch_structures_sn_sn2(struct xpc_partition *part)
1255 {
1256         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
1257         short partid = XPC_PARTID(part);
1258
1259         /*
1260          * Indicate that the variables specific to the remote partition are no
1261          * longer available for its use.
1262          */
1263         xpc_vars_part_sn2[partid].magic = 0;
1264
1265         /* in case we've still got outstanding timers registered... */
1266         del_timer_sync(&part_sn2->dropped_notify_IRQ_timer);
1267         free_irq(SGI_XPC_NOTIFY, (void *)(u64)partid);
1268
1269         kfree(part_sn2->local_openclose_args_base);
1270         part_sn2->local_openclose_args = NULL;
1271         kfree(part_sn2->remote_GPs_base);
1272         part_sn2->remote_GPs = NULL;
1273         kfree(part_sn2->local_GPs_base);
1274         part_sn2->local_GPs = NULL;
1275         part_sn2->local_chctl_amo_va = NULL;
1276 }
1277
1278 /*
1279  * Create a wrapper that hides the underlying mechanism for pulling a cacheline
1280  * (or multiple cachelines) from a remote partition.
1281  *
1282  * src_pa must be a cacheline aligned physical address on the remote partition.
1283  * dst must be a cacheline aligned virtual address on this partition.
1284  * cnt must be cacheline sized
1285  */
1286 /* ??? Replace this function by call to xp_remote_memcpy() or bte_copy()? */
1287 static enum xp_retval
1288 xpc_pull_remote_cachelines_sn2(struct xpc_partition *part, void *dst,
1289                                const unsigned long src_pa, size_t cnt)
1290 {
1291         enum xp_retval ret;
1292
1293         DBUG_ON(src_pa != L1_CACHE_ALIGN(src_pa));
1294         DBUG_ON((unsigned long)dst != L1_CACHE_ALIGN((unsigned long)dst));
1295         DBUG_ON(cnt != L1_CACHE_ALIGN(cnt));
1296
1297         if (part->act_state == XPC_P_AS_DEACTIVATING)
1298                 return part->reason;
1299
1300         ret = xp_remote_memcpy(xp_pa(dst), src_pa, cnt);
1301         if (ret != xpSuccess) {
1302                 dev_dbg(xpc_chan, "xp_remote_memcpy() from partition %d failed,"
1303                         " ret=%d\n", XPC_PARTID(part), ret);
1304         }
1305         return ret;
1306 }
1307
1308 /*
1309  * Pull the remote per partition specific variables from the specified
1310  * partition.
1311  */
1312 static enum xp_retval
1313 xpc_pull_remote_vars_part_sn2(struct xpc_partition *part)
1314 {
1315         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
1316         u8 buffer[L1_CACHE_BYTES * 2];
1317         struct xpc_vars_part_sn2 *pulled_entry_cacheline =
1318             (struct xpc_vars_part_sn2 *)L1_CACHE_ALIGN((u64)buffer);
1319         struct xpc_vars_part_sn2 *pulled_entry;
1320         unsigned long remote_entry_cacheline_pa;
1321         unsigned long remote_entry_pa;
1322         short partid = XPC_PARTID(part);
1323         enum xp_retval ret;
1324
1325         /* pull the cacheline that contains the variables we're interested in */
1326
1327         DBUG_ON(part_sn2->remote_vars_part_pa !=
1328                 L1_CACHE_ALIGN(part_sn2->remote_vars_part_pa));
1329         DBUG_ON(sizeof(struct xpc_vars_part_sn2) != L1_CACHE_BYTES / 2);
1330
1331         remote_entry_pa = part_sn2->remote_vars_part_pa +
1332             sn_partition_id * sizeof(struct xpc_vars_part_sn2);
1333
1334         remote_entry_cacheline_pa = (remote_entry_pa & ~(L1_CACHE_BYTES - 1));
1335
1336         pulled_entry = (struct xpc_vars_part_sn2 *)((u64)pulled_entry_cacheline
1337                                                     + (remote_entry_pa &
1338                                                     (L1_CACHE_BYTES - 1)));
1339
1340         ret = xpc_pull_remote_cachelines_sn2(part, pulled_entry_cacheline,
1341                                              remote_entry_cacheline_pa,
1342                                              L1_CACHE_BYTES);
1343         if (ret != xpSuccess) {
1344                 dev_dbg(xpc_chan, "failed to pull XPC vars_part from "
1345                         "partition %d, ret=%d\n", partid, ret);
1346                 return ret;
1347         }
1348
1349         /* see if they've been set up yet */
1350
1351         if (pulled_entry->magic != XPC_VP_MAGIC1_SN2 &&
1352             pulled_entry->magic != XPC_VP_MAGIC2_SN2) {
1353
1354                 if (pulled_entry->magic != 0) {
1355                         dev_dbg(xpc_chan, "partition %d's XPC vars_part for "
1356                                 "partition %d has bad magic value (=0x%lx)\n",
1357                                 partid, sn_partition_id, pulled_entry->magic);
1358                         return xpBadMagic;
1359                 }
1360
1361                 /* they've not been initialized yet */
1362                 return xpRetry;
1363         }
1364
1365         if (xpc_vars_part_sn2[partid].magic == XPC_VP_MAGIC1_SN2) {
1366
1367                 /* validate the variables */
1368
1369                 if (pulled_entry->GPs_pa == 0 ||
1370                     pulled_entry->openclose_args_pa == 0 ||
1371                     pulled_entry->chctl_amo_pa == 0) {
1372
1373                         dev_err(xpc_chan, "partition %d's XPC vars_part for "
1374                                 "partition %d are not valid\n", partid,
1375                                 sn_partition_id);
1376                         return xpInvalidAddress;
1377                 }
1378
1379                 /* the variables we imported look to be valid */
1380
1381                 part_sn2->remote_GPs_pa = pulled_entry->GPs_pa;
1382                 part_sn2->remote_openclose_args_pa =
1383                     pulled_entry->openclose_args_pa;
1384                 part_sn2->remote_chctl_amo_va =
1385                     (struct amo *)__va(pulled_entry->chctl_amo_pa);
1386                 part_sn2->notify_IRQ_nasid = pulled_entry->notify_IRQ_nasid;
1387                 part_sn2->notify_IRQ_phys_cpuid =
1388                     pulled_entry->notify_IRQ_phys_cpuid;
1389
1390                 if (part->nchannels > pulled_entry->nchannels)
1391                         part->nchannels = pulled_entry->nchannels;
1392
1393                 /* let the other side know that we've pulled their variables */
1394
1395                 xpc_vars_part_sn2[partid].magic = XPC_VP_MAGIC2_SN2;
1396         }
1397
1398         if (pulled_entry->magic == XPC_VP_MAGIC1_SN2)
1399                 return xpRetry;
1400
1401         return xpSuccess;
1402 }
1403
1404 /*
1405  * Establish first contact with the remote partititon. This involves pulling
1406  * the XPC per partition variables from the remote partition and waiting for
1407  * the remote partition to pull ours.
1408  */
1409 static enum xp_retval
1410 xpc_make_first_contact_sn2(struct xpc_partition *part)
1411 {
1412         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
1413         enum xp_retval ret;
1414
1415         /*
1416          * Register the remote partition's amos with SAL so it can handle
1417          * and cleanup errors within that address range should the remote
1418          * partition go down. We don't unregister this range because it is
1419          * difficult to tell when outstanding writes to the remote partition
1420          * are finished and thus when it is safe to unregister. This should
1421          * not result in wasted space in the SAL xp_addr_region table because
1422          * we should get the same page for remote_amos_page_pa after module
1423          * reloads and system reboots.
1424          */
1425         if (sn_register_xp_addr_region(part_sn2->remote_amos_page_pa,
1426                                        PAGE_SIZE, 1) < 0) {
1427                 dev_warn(xpc_part, "xpc_activating(%d) failed to register "
1428                          "xp_addr region\n", XPC_PARTID(part));
1429
1430                 ret = xpPhysAddrRegFailed;
1431                 XPC_DEACTIVATE_PARTITION(part, ret);
1432                 return ret;
1433         }
1434
1435         /*
1436          * Send activate IRQ to get other side to activate if they've not
1437          * already begun to do so.
1438          */
1439         xpc_send_activate_IRQ_sn2(part_sn2->remote_amos_page_pa,
1440                                   cnodeid_to_nasid(0),
1441                                   part_sn2->activate_IRQ_nasid,
1442                                   part_sn2->activate_IRQ_phys_cpuid);
1443
1444         while ((ret = xpc_pull_remote_vars_part_sn2(part)) != xpSuccess) {
1445                 if (ret != xpRetry) {
1446                         XPC_DEACTIVATE_PARTITION(part, ret);
1447                         return ret;
1448                 }
1449
1450                 dev_dbg(xpc_part, "waiting to make first contact with "
1451                         "partition %d\n", XPC_PARTID(part));
1452
1453                 /* wait a 1/4 of a second or so */
1454                 (void)msleep_interruptible(250);
1455
1456                 if (part->act_state == XPC_P_AS_DEACTIVATING)
1457                         return part->reason;
1458         }
1459
1460         return xpSuccess;
1461 }
1462
1463 /*
1464  * Get the chctl flags and pull the openclose args and/or remote GPs as needed.
1465  */
1466 static u64
1467 xpc_get_chctl_all_flags_sn2(struct xpc_partition *part)
1468 {
1469         struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
1470         unsigned long irq_flags;
1471         union xpc_channel_ctl_flags chctl;
1472         enum xp_retval ret;
1473
1474         /*
1475          * See if there are any chctl flags to be handled.
1476          */
1477
1478         spin_lock_irqsave(&part->chctl_lock, irq_flags);
1479         chctl = part->chctl;
1480         if (chctl.all_flags != 0)
1481                 part->chctl.all_flags = 0;
1482
1483         spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
1484
1485         if (xpc_any_openclose_chctl_flags_set(&chctl)) {
1486                 ret = xpc_pull_remote_cachelines_sn2(part, part->
1487                                                      remote_openclose_args,
1488                                                      part_sn2->
1489                                                      remote_openclose_args_pa,
1490                                                      XPC_OPENCLOSE_ARGS_SIZE);
1491                 if (ret != xpSuccess) {
1492                         XPC_DEACTIVATE_PARTITION(part, ret);
1493
1494                         dev_dbg(xpc_chan, "failed to pull openclose args from "
1495                                 "partition %d, ret=%d\n", XPC_PARTID(part),
1496                                 ret);
1497
1498                         /* don't bother processing chctl flags anymore */
1499                         chctl.all_flags = 0;
1500                 }
1501         }
1502
1503         if (xpc_any_msg_chctl_flags_set(&chctl)) {
1504                 ret = xpc_pull_remote_cachelines_sn2(part, part_sn2->remote_GPs,
1505                                                      part_sn2->remote_GPs_pa,
1506                                                      XPC_GP_SIZE);
1507                 if (ret != xpSuccess) {
1508                         XPC_DEACTIVATE_PARTITION(part, ret);
1509
1510                         dev_dbg(xpc_chan, "failed to pull GPs from partition "
1511                                 "%d, ret=%d\n", XPC_PARTID(part), ret);
1512
1513                         /* don't bother processing chctl flags anymore */
1514                         chctl.all_flags = 0;
1515                 }
1516         }
1517
1518         return chctl.all_flags;
1519 }
1520
1521 /*
1522  * Allocate the local message queue and the notify queue.
1523  */
1524 static enum xp_retval
1525 xpc_allocate_local_msgqueue_sn2(struct xpc_channel *ch)
1526 {
1527         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1528         unsigned long irq_flags;
1529         int nentries;
1530         size_t nbytes;
1531
1532         for (nentries = ch->local_nentries; nentries > 0; nentries--) {
1533
1534                 nbytes = nentries * ch->entry_size;
1535                 ch_sn2->local_msgqueue =
1536                     xpc_kzalloc_cacheline_aligned(nbytes, GFP_KERNEL,
1537                                                   &ch_sn2->local_msgqueue_base);
1538                 if (ch_sn2->local_msgqueue == NULL)
1539                         continue;
1540
1541                 nbytes = nentries * sizeof(struct xpc_notify_sn2);
1542                 ch_sn2->notify_queue = kzalloc(nbytes, GFP_KERNEL);
1543                 if (ch_sn2->notify_queue == NULL) {
1544                         kfree(ch_sn2->local_msgqueue_base);
1545                         ch_sn2->local_msgqueue = NULL;
1546                         continue;
1547                 }
1548
1549                 spin_lock_irqsave(&ch->lock, irq_flags);
1550                 if (nentries < ch->local_nentries) {
1551                         dev_dbg(xpc_chan, "nentries=%d local_nentries=%d, "
1552                                 "partid=%d, channel=%d\n", nentries,
1553                                 ch->local_nentries, ch->partid, ch->number);
1554
1555                         ch->local_nentries = nentries;
1556                 }
1557                 spin_unlock_irqrestore(&ch->lock, irq_flags);
1558                 return xpSuccess;
1559         }
1560
1561         dev_dbg(xpc_chan, "can't get memory for local message queue and notify "
1562                 "queue, partid=%d, channel=%d\n", ch->partid, ch->number);
1563         return xpNoMemory;
1564 }
1565
1566 /*
1567  * Allocate the cached remote message queue.
1568  */
1569 static enum xp_retval
1570 xpc_allocate_remote_msgqueue_sn2(struct xpc_channel *ch)
1571 {
1572         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1573         unsigned long irq_flags;
1574         int nentries;
1575         size_t nbytes;
1576
1577         DBUG_ON(ch->remote_nentries <= 0);
1578
1579         for (nentries = ch->remote_nentries; nentries > 0; nentries--) {
1580
1581                 nbytes = nentries * ch->entry_size;
1582                 ch_sn2->remote_msgqueue =
1583                     xpc_kzalloc_cacheline_aligned(nbytes, GFP_KERNEL, &ch_sn2->
1584                                                   remote_msgqueue_base);
1585                 if (ch_sn2->remote_msgqueue == NULL)
1586                         continue;
1587
1588                 spin_lock_irqsave(&ch->lock, irq_flags);
1589                 if (nentries < ch->remote_nentries) {
1590                         dev_dbg(xpc_chan, "nentries=%d remote_nentries=%d, "
1591                                 "partid=%d, channel=%d\n", nentries,
1592                                 ch->remote_nentries, ch->partid, ch->number);
1593
1594                         ch->remote_nentries = nentries;
1595                 }
1596                 spin_unlock_irqrestore(&ch->lock, irq_flags);
1597                 return xpSuccess;
1598         }
1599
1600         dev_dbg(xpc_chan, "can't get memory for cached remote message queue, "
1601                 "partid=%d, channel=%d\n", ch->partid, ch->number);
1602         return xpNoMemory;
1603 }
1604
1605 /*
1606  * Allocate message queues and other stuff associated with a channel.
1607  *
1608  * Note: Assumes all of the channel sizes are filled in.
1609  */
1610 static enum xp_retval
1611 xpc_setup_msg_structures_sn2(struct xpc_channel *ch)
1612 {
1613         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1614         enum xp_retval ret;
1615
1616         DBUG_ON(ch->flags & XPC_C_SETUP);
1617
1618         ret = xpc_allocate_local_msgqueue_sn2(ch);
1619         if (ret == xpSuccess) {
1620
1621                 ret = xpc_allocate_remote_msgqueue_sn2(ch);
1622                 if (ret != xpSuccess) {
1623                         kfree(ch_sn2->local_msgqueue_base);
1624                         ch_sn2->local_msgqueue = NULL;
1625                         kfree(ch_sn2->notify_queue);
1626                         ch_sn2->notify_queue = NULL;
1627                 }
1628         }
1629         return ret;
1630 }
1631
1632 /*
1633  * Free up message queues and other stuff that were allocated for the specified
1634  * channel.
1635  */
1636 static void
1637 xpc_teardown_msg_structures_sn2(struct xpc_channel *ch)
1638 {
1639         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1640
1641         DBUG_ON(!spin_is_locked(&ch->lock));
1642
1643         ch_sn2->remote_msgqueue_pa = 0;
1644
1645         ch_sn2->local_GP->get = 0;
1646         ch_sn2->local_GP->put = 0;
1647         ch_sn2->remote_GP.get = 0;
1648         ch_sn2->remote_GP.put = 0;
1649         ch_sn2->w_local_GP.get = 0;
1650         ch_sn2->w_local_GP.put = 0;
1651         ch_sn2->w_remote_GP.get = 0;
1652         ch_sn2->w_remote_GP.put = 0;
1653         ch_sn2->next_msg_to_pull = 0;
1654
1655         if (ch->flags & XPC_C_SETUP) {
1656                 dev_dbg(xpc_chan, "ch->flags=0x%x, partid=%d, channel=%d\n",
1657                         ch->flags, ch->partid, ch->number);
1658
1659                 kfree(ch_sn2->local_msgqueue_base);
1660                 ch_sn2->local_msgqueue = NULL;
1661                 kfree(ch_sn2->remote_msgqueue_base);
1662                 ch_sn2->remote_msgqueue = NULL;
1663                 kfree(ch_sn2->notify_queue);
1664                 ch_sn2->notify_queue = NULL;
1665         }
1666 }
1667
1668 /*
1669  * Notify those who wanted to be notified upon delivery of their message.
1670  */
1671 static void
1672 xpc_notify_senders_sn2(struct xpc_channel *ch, enum xp_retval reason, s64 put)
1673 {
1674         struct xpc_notify_sn2 *notify;
1675         u8 notify_type;
1676         s64 get = ch->sn.sn2.w_remote_GP.get - 1;
1677
1678         while (++get < put && atomic_read(&ch->n_to_notify) > 0) {
1679
1680                 notify = &ch->sn.sn2.notify_queue[get % ch->local_nentries];
1681
1682                 /*
1683                  * See if the notify entry indicates it was associated with
1684                  * a message who's sender wants to be notified. It is possible
1685                  * that it is, but someone else is doing or has done the
1686                  * notification.
1687                  */
1688                 notify_type = notify->type;
1689                 if (notify_type == 0 ||
1690                     cmpxchg(&notify->type, notify_type, 0) != notify_type) {
1691                         continue;
1692                 }
1693
1694                 DBUG_ON(notify_type != XPC_N_CALL);
1695
1696                 atomic_dec(&ch->n_to_notify);
1697
1698                 if (notify->func != NULL) {
1699                         dev_dbg(xpc_chan, "notify->func() called, notify=0x%p "
1700                                 "msg_number=%ld partid=%d channel=%d\n",
1701                                 (void *)notify, get, ch->partid, ch->number);
1702
1703                         notify->func(reason, ch->partid, ch->number,
1704                                      notify->key);
1705
1706                         dev_dbg(xpc_chan, "notify->func() returned, notify=0x%p"
1707                                 " msg_number=%ld partid=%d channel=%d\n",
1708                                 (void *)notify, get, ch->partid, ch->number);
1709                 }
1710         }
1711 }
1712
1713 static void
1714 xpc_notify_senders_of_disconnect_sn2(struct xpc_channel *ch)
1715 {
1716         xpc_notify_senders_sn2(ch, ch->reason, ch->sn.sn2.w_local_GP.put);
1717 }
1718
1719 /*
1720  * Clear some of the msg flags in the local message queue.
1721  */
1722 static inline void
1723 xpc_clear_local_msgqueue_flags_sn2(struct xpc_channel *ch)
1724 {
1725         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1726         struct xpc_msg_sn2 *msg;
1727         s64 get;
1728
1729         get = ch_sn2->w_remote_GP.get;
1730         do {
1731                 msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->local_msgqueue +
1732                                              (get % ch->local_nentries) *
1733                                              ch->entry_size);
1734                 DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
1735                 msg->flags = 0;
1736         } while (++get < ch_sn2->remote_GP.get);
1737 }
1738
1739 /*
1740  * Clear some of the msg flags in the remote message queue.
1741  */
1742 static inline void
1743 xpc_clear_remote_msgqueue_flags_sn2(struct xpc_channel *ch)
1744 {
1745         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1746         struct xpc_msg_sn2 *msg;
1747         s64 put, remote_nentries = ch->remote_nentries;
1748
1749         /* flags are zeroed when the buffer is allocated */
1750         if (ch_sn2->remote_GP.put < remote_nentries)
1751                 return;
1752
1753         put = max(ch_sn2->w_remote_GP.put, remote_nentries);
1754         do {
1755                 msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue +
1756                                              (put % remote_nentries) *
1757                                              ch->entry_size);
1758                 DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
1759                 DBUG_ON(!(msg->flags & XPC_M_SN2_DONE));
1760                 DBUG_ON(msg->number != put - remote_nentries);
1761                 msg->flags = 0;
1762         } while (++put < ch_sn2->remote_GP.put);
1763 }
1764
1765 static int
1766 xpc_n_of_deliverable_payloads_sn2(struct xpc_channel *ch)
1767 {
1768         return ch->sn.sn2.w_remote_GP.put - ch->sn.sn2.w_local_GP.get;
1769 }
1770
1771 static void
1772 xpc_process_msg_chctl_flags_sn2(struct xpc_partition *part, int ch_number)
1773 {
1774         struct xpc_channel *ch = &part->channels[ch_number];
1775         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1776         int npayloads_sent;
1777
1778         ch_sn2->remote_GP = part->sn.sn2.remote_GPs[ch_number];
1779
1780         /* See what, if anything, has changed for each connected channel */
1781
1782         xpc_msgqueue_ref(ch);
1783
1784         if (ch_sn2->w_remote_GP.get == ch_sn2->remote_GP.get &&
1785             ch_sn2->w_remote_GP.put == ch_sn2->remote_GP.put) {
1786                 /* nothing changed since GPs were last pulled */
1787                 xpc_msgqueue_deref(ch);
1788                 return;
1789         }
1790
1791         if (!(ch->flags & XPC_C_CONNECTED)) {
1792                 xpc_msgqueue_deref(ch);
1793                 return;
1794         }
1795
1796         /*
1797          * First check to see if messages recently sent by us have been
1798          * received by the other side. (The remote GET value will have
1799          * changed since we last looked at it.)
1800          */
1801
1802         if (ch_sn2->w_remote_GP.get != ch_sn2->remote_GP.get) {
1803
1804                 /*
1805                  * We need to notify any senders that want to be notified
1806                  * that their sent messages have been received by their
1807                  * intended recipients. We need to do this before updating
1808                  * w_remote_GP.get so that we don't allocate the same message
1809                  * queue entries prematurely (see xpc_allocate_msg()).
1810                  */
1811                 if (atomic_read(&ch->n_to_notify) > 0) {
1812                         /*
1813                          * Notify senders that messages sent have been
1814                          * received and delivered by the other side.
1815                          */
1816                         xpc_notify_senders_sn2(ch, xpMsgDelivered,
1817                                                ch_sn2->remote_GP.get);
1818                 }
1819
1820                 /*
1821                  * Clear msg->flags in previously sent messages, so that
1822                  * they're ready for xpc_allocate_msg().
1823                  */
1824                 xpc_clear_local_msgqueue_flags_sn2(ch);
1825
1826                 ch_sn2->w_remote_GP.get = ch_sn2->remote_GP.get;
1827
1828                 dev_dbg(xpc_chan, "w_remote_GP.get changed to %ld, partid=%d, "
1829                         "channel=%d\n", ch_sn2->w_remote_GP.get, ch->partid,
1830                         ch->number);
1831
1832                 /*
1833                  * If anyone was waiting for message queue entries to become
1834                  * available, wake them up.
1835                  */
1836                 if (atomic_read(&ch->n_on_msg_allocate_wq) > 0)
1837                         wake_up(&ch->msg_allocate_wq);
1838         }
1839
1840         /*
1841          * Now check for newly sent messages by the other side. (The remote
1842          * PUT value will have changed since we last looked at it.)
1843          */
1844
1845         if (ch_sn2->w_remote_GP.put != ch_sn2->remote_GP.put) {
1846                 /*
1847                  * Clear msg->flags in previously received messages, so that
1848                  * they're ready for xpc_get_deliverable_payload_sn2().
1849                  */
1850                 xpc_clear_remote_msgqueue_flags_sn2(ch);
1851
1852                 smp_wmb(); /* ensure flags have been cleared before bte_copy */
1853                 ch_sn2->w_remote_GP.put = ch_sn2->remote_GP.put;
1854
1855                 dev_dbg(xpc_chan, "w_remote_GP.put changed to %ld, partid=%d, "
1856                         "channel=%d\n", ch_sn2->w_remote_GP.put, ch->partid,
1857                         ch->number);
1858
1859                 npayloads_sent = xpc_n_of_deliverable_payloads_sn2(ch);
1860                 if (npayloads_sent > 0) {
1861                         dev_dbg(xpc_chan, "msgs waiting to be copied and "
1862                                 "delivered=%d, partid=%d, channel=%d\n",
1863                                 npayloads_sent, ch->partid, ch->number);
1864
1865                         if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE)
1866                                 xpc_activate_kthreads(ch, npayloads_sent);
1867                 }
1868         }
1869
1870         xpc_msgqueue_deref(ch);
1871 }
1872
1873 static struct xpc_msg_sn2 *
1874 xpc_pull_remote_msg_sn2(struct xpc_channel *ch, s64 get)
1875 {
1876         struct xpc_partition *part = &xpc_partitions[ch->partid];
1877         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1878         unsigned long remote_msg_pa;
1879         struct xpc_msg_sn2 *msg;
1880         u32 msg_index;
1881         u32 nmsgs;
1882         u64 msg_offset;
1883         enum xp_retval ret;
1884
1885         if (mutex_lock_interruptible(&ch_sn2->msg_to_pull_mutex) != 0) {
1886                 /* we were interrupted by a signal */
1887                 return NULL;
1888         }
1889
1890         while (get >= ch_sn2->next_msg_to_pull) {
1891
1892                 /* pull as many messages as are ready and able to be pulled */
1893
1894                 msg_index = ch_sn2->next_msg_to_pull % ch->remote_nentries;
1895
1896                 DBUG_ON(ch_sn2->next_msg_to_pull >= ch_sn2->w_remote_GP.put);
1897                 nmsgs = ch_sn2->w_remote_GP.put - ch_sn2->next_msg_to_pull;
1898                 if (msg_index + nmsgs > ch->remote_nentries) {
1899                         /* ignore the ones that wrap the msg queue for now */
1900                         nmsgs = ch->remote_nentries - msg_index;
1901                 }
1902
1903                 msg_offset = msg_index * ch->entry_size;
1904                 msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue +
1905                     msg_offset);
1906                 remote_msg_pa = ch_sn2->remote_msgqueue_pa + msg_offset;
1907
1908                 ret = xpc_pull_remote_cachelines_sn2(part, msg, remote_msg_pa,
1909                                                      nmsgs * ch->entry_size);
1910                 if (ret != xpSuccess) {
1911
1912                         dev_dbg(xpc_chan, "failed to pull %d msgs starting with"
1913                                 " msg %ld from partition %d, channel=%d, "
1914                                 "ret=%d\n", nmsgs, ch_sn2->next_msg_to_pull,
1915                                 ch->partid, ch->number, ret);
1916
1917                         XPC_DEACTIVATE_PARTITION(part, ret);
1918
1919                         mutex_unlock(&ch_sn2->msg_to_pull_mutex);
1920                         return NULL;
1921                 }
1922
1923                 ch_sn2->next_msg_to_pull += nmsgs;
1924         }
1925
1926         mutex_unlock(&ch_sn2->msg_to_pull_mutex);
1927
1928         /* return the message we were looking for */
1929         msg_offset = (get % ch->remote_nentries) * ch->entry_size;
1930         msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue + msg_offset);
1931
1932         return msg;
1933 }
1934
1935 /*
1936  * Get the next deliverable message's payload.
1937  */
1938 static void *
1939 xpc_get_deliverable_payload_sn2(struct xpc_channel *ch)
1940 {
1941         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1942         struct xpc_msg_sn2 *msg;
1943         void *payload = NULL;
1944         s64 get;
1945
1946         do {
1947                 if (ch->flags & XPC_C_DISCONNECTING)
1948                         break;
1949
1950                 get = ch_sn2->w_local_GP.get;
1951                 smp_rmb();      /* guarantee that .get loads before .put */
1952                 if (get == ch_sn2->w_remote_GP.put)
1953                         break;
1954
1955                 /* There are messages waiting to be pulled and delivered.
1956                  * We need to try to secure one for ourselves. We'll do this
1957                  * by trying to increment w_local_GP.get and hope that no one
1958                  * else beats us to it. If they do, we'll we'll simply have
1959                  * to try again for the next one.
1960                  */
1961
1962                 if (cmpxchg(&ch_sn2->w_local_GP.get, get, get + 1) == get) {
1963                         /* we got the entry referenced by get */
1964
1965                         dev_dbg(xpc_chan, "w_local_GP.get changed to %ld, "
1966                                 "partid=%d, channel=%d\n", get + 1,
1967                                 ch->partid, ch->number);
1968
1969                         /* pull the message from the remote partition */
1970
1971                         msg = xpc_pull_remote_msg_sn2(ch, get);
1972
1973                         if (msg != NULL) {
1974                                 DBUG_ON(msg->number != get);
1975                                 DBUG_ON(msg->flags & XPC_M_SN2_DONE);
1976                                 DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
1977
1978                                 payload = &msg->payload;
1979                         }
1980                         break;
1981                 }
1982
1983         } while (1);
1984
1985         return payload;
1986 }
1987
1988 /*
1989  * Now we actually send the messages that are ready to be sent by advancing
1990  * the local message queue's Put value and then send a chctl msgrequest to the
1991  * recipient partition.
1992  */
1993 static void
1994 xpc_send_msgs_sn2(struct xpc_channel *ch, s64 initial_put)
1995 {
1996         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
1997         struct xpc_msg_sn2 *msg;
1998         s64 put = initial_put + 1;
1999         int send_msgrequest = 0;
2000
2001         while (1) {
2002
2003                 while (1) {
2004                         if (put == ch_sn2->w_local_GP.put)
2005                                 break;
2006
2007                         msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->
2008                                                      local_msgqueue + (put %
2009                                                      ch->local_nentries) *
2010                                                      ch->entry_size);
2011
2012                         if (!(msg->flags & XPC_M_SN2_READY))
2013                                 break;
2014
2015                         put++;
2016                 }
2017
2018                 if (put == initial_put) {
2019                         /* nothing's changed */
2020                         break;
2021                 }
2022
2023                 if (cmpxchg_rel(&ch_sn2->local_GP->put, initial_put, put) !=
2024                     initial_put) {
2025                         /* someone else beat us to it */
2026                         DBUG_ON(ch_sn2->local_GP->put < initial_put);
2027                         break;
2028                 }
2029
2030                 /* we just set the new value of local_GP->put */
2031
2032                 dev_dbg(xpc_chan, "local_GP->put changed to %ld, partid=%d, "
2033                         "channel=%d\n", put, ch->partid, ch->number);
2034
2035                 send_msgrequest = 1;
2036
2037                 /*
2038                  * We need to ensure that the message referenced by
2039                  * local_GP->put is not XPC_M_SN2_READY or that local_GP->put
2040                  * equals w_local_GP.put, so we'll go have a look.
2041                  */
2042                 initial_put = put;
2043         }
2044
2045         if (send_msgrequest)
2046                 xpc_send_chctl_msgrequest_sn2(ch);
2047 }
2048
2049 /*
2050  * Allocate an entry for a message from the message queue associated with the
2051  * specified channel.
2052  */
2053 static enum xp_retval
2054 xpc_allocate_msg_sn2(struct xpc_channel *ch, u32 flags,
2055                      struct xpc_msg_sn2 **address_of_msg)
2056 {
2057         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
2058         struct xpc_msg_sn2 *msg;
2059         enum xp_retval ret;
2060         s64 put;
2061
2062         /*
2063          * Get the next available message entry from the local message queue.
2064          * If none are available, we'll make sure that we grab the latest
2065          * GP values.
2066          */
2067         ret = xpTimeout;
2068
2069         while (1) {
2070
2071                 put = ch_sn2->w_local_GP.put;
2072                 smp_rmb();      /* guarantee that .put loads before .get */
2073                 if (put - ch_sn2->w_remote_GP.get < ch->local_nentries) {
2074
2075                         /* There are available message entries. We need to try
2076                          * to secure one for ourselves. We'll do this by trying
2077                          * to increment w_local_GP.put as long as someone else
2078                          * doesn't beat us to it. If they do, we'll have to
2079                          * try again.
2080                          */
2081                         if (cmpxchg(&ch_sn2->w_local_GP.put, put, put + 1) ==
2082                             put) {
2083                                 /* we got the entry referenced by put */
2084                                 break;
2085                         }
2086                         continue;       /* try again */
2087                 }
2088
2089                 /*
2090                  * There aren't any available msg entries at this time.
2091                  *
2092                  * In waiting for a message entry to become available,
2093                  * we set a timeout in case the other side is not sending
2094                  * completion interrupts. This lets us fake a notify IRQ
2095                  * that will cause the notify IRQ handler to fetch the latest
2096                  * GP values as if an interrupt was sent by the other side.
2097                  */
2098                 if (ret == xpTimeout)
2099                         xpc_send_chctl_local_msgrequest_sn2(ch);
2100
2101                 if (flags & XPC_NOWAIT)
2102                         return xpNoWait;
2103
2104                 ret = xpc_allocate_msg_wait(ch);
2105                 if (ret != xpInterrupted && ret != xpTimeout)
2106                         return ret;
2107         }
2108
2109         /* get the message's address and initialize it */
2110         msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->local_msgqueue +
2111                                      (put % ch->local_nentries) *
2112                                      ch->entry_size);
2113
2114         DBUG_ON(msg->flags != 0);
2115         msg->number = put;
2116
2117         dev_dbg(xpc_chan, "w_local_GP.put changed to %ld; msg=0x%p, "
2118                 "msg_number=%ld, partid=%d, channel=%d\n", put + 1,
2119                 (void *)msg, msg->number, ch->partid, ch->number);
2120
2121         *address_of_msg = msg;
2122         return xpSuccess;
2123 }
2124
2125 /*
2126  * Common code that does the actual sending of the message by advancing the
2127  * local message queue's Put value and sends a chctl msgrequest to the
2128  * partition the message is being sent to.
2129  */
2130 static enum xp_retval
2131 xpc_send_payload_sn2(struct xpc_channel *ch, u32 flags, void *payload,
2132                      u16 payload_size, u8 notify_type, xpc_notify_func func,
2133                      void *key)
2134 {
2135         enum xp_retval ret = xpSuccess;
2136         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
2137         struct xpc_msg_sn2 *msg = msg;
2138         struct xpc_notify_sn2 *notify = notify;
2139         s64 msg_number;
2140         s64 put;
2141
2142         DBUG_ON(notify_type == XPC_N_CALL && func == NULL);
2143
2144         if (XPC_MSG_SIZE(payload_size) > ch->entry_size)
2145                 return xpPayloadTooBig;
2146
2147         xpc_msgqueue_ref(ch);
2148
2149         if (ch->flags & XPC_C_DISCONNECTING) {
2150                 ret = ch->reason;
2151                 goto out_1;
2152         }
2153         if (!(ch->flags & XPC_C_CONNECTED)) {
2154                 ret = xpNotConnected;
2155                 goto out_1;
2156         }
2157
2158         ret = xpc_allocate_msg_sn2(ch, flags, &msg);
2159         if (ret != xpSuccess)
2160                 goto out_1;
2161
2162         msg_number = msg->number;
2163
2164         if (notify_type != 0) {
2165                 /*
2166                  * Tell the remote side to send an ACK interrupt when the
2167                  * message has been delivered.
2168                  */
2169                 msg->flags |= XPC_M_SN2_INTERRUPT;
2170
2171                 atomic_inc(&ch->n_to_notify);
2172
2173                 notify = &ch_sn2->notify_queue[msg_number % ch->local_nentries];
2174                 notify->func = func;
2175                 notify->key = key;
2176                 notify->type = notify_type;
2177
2178                 /* ??? Is a mb() needed here? */
2179
2180                 if (ch->flags & XPC_C_DISCONNECTING) {
2181                         /*
2182                          * An error occurred between our last error check and
2183                          * this one. We will try to clear the type field from
2184                          * the notify entry. If we succeed then
2185                          * xpc_disconnect_channel() didn't already process
2186                          * the notify entry.
2187                          */
2188                         if (cmpxchg(&notify->type, notify_type, 0) ==
2189                             notify_type) {
2190                                 atomic_dec(&ch->n_to_notify);
2191                                 ret = ch->reason;
2192                         }
2193                         goto out_1;
2194                 }
2195         }
2196
2197         memcpy(&msg->payload, payload, payload_size);
2198
2199         msg->flags |= XPC_M_SN2_READY;
2200
2201         /*
2202          * The preceding store of msg->flags must occur before the following
2203          * load of local_GP->put.
2204          */
2205         smp_mb();
2206
2207         /* see if the message is next in line to be sent, if so send it */
2208
2209         put = ch_sn2->local_GP->put;
2210         if (put == msg_number)
2211                 xpc_send_msgs_sn2(ch, put);
2212
2213 out_1:
2214         xpc_msgqueue_deref(ch);
2215         return ret;
2216 }
2217
2218 /*
2219  * Now we actually acknowledge the messages that have been delivered and ack'd
2220  * by advancing the cached remote message queue's Get value and if requested
2221  * send a chctl msgrequest to the message sender's partition.
2222  *
2223  * If a message has XPC_M_SN2_INTERRUPT set, send an interrupt to the partition
2224  * that sent the message.
2225  */
2226 static void
2227 xpc_acknowledge_msgs_sn2(struct xpc_channel *ch, s64 initial_get, u8 msg_flags)
2228 {
2229         struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
2230         struct xpc_msg_sn2 *msg;
2231         s64 get = initial_get + 1;
2232         int send_msgrequest = 0;
2233
2234         while (1) {
2235
2236                 while (1) {
2237                         if (get == ch_sn2->w_local_GP.get)
2238                                 break;
2239
2240                         msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->
2241                                                      remote_msgqueue + (get %
2242                                                      ch->remote_nentries) *
2243                                                      ch->entry_size);
2244
2245                         if (!(msg->flags & XPC_M_SN2_DONE))
2246                                 break;
2247
2248                         msg_flags |= msg->flags;
2249                         get++;
2250                 }
2251
2252                 if (get == initial_get) {
2253                         /* nothing's changed */
2254                         break;
2255                 }
2256
2257                 if (cmpxchg_rel(&ch_sn2->local_GP->get, initial_get, get) !=
2258                     initial_get) {
2259                         /* someone else beat us to it */
2260                         DBUG_ON(ch_sn2->local_GP->get <= initial_get);
2261                         break;
2262                 }
2263
2264                 /* we just set the new value of local_GP->get */
2265
2266                 dev_dbg(xpc_chan, "local_GP->get changed to %ld, partid=%d, "
2267                         "channel=%d\n", get, ch->partid, ch->number);
2268
2269                 send_msgrequest = (msg_flags & XPC_M_SN2_INTERRUPT);
2270
2271                 /*
2272                  * We need to ensure that the message referenced by
2273                  * local_GP->get is not XPC_M_SN2_DONE or that local_GP->get
2274                  * equals w_local_GP.get, so we'll go have a look.
2275                  */
2276                 initial_get = get;
2277         }
2278
2279         if (send_msgrequest)
2280                 xpc_send_chctl_msgrequest_sn2(ch);
2281 }
2282
2283 static void
2284 xpc_received_payload_sn2(struct xpc_channel *ch, void *payload)
2285 {
2286         struct xpc_msg_sn2 *msg;
2287         s64 msg_number;
2288         s64 get;
2289
2290         msg = container_of(payload, struct xpc_msg_sn2, payload);
2291         msg_number = msg->number;
2292
2293         dev_dbg(xpc_chan, "msg=0x%p, msg_number=%ld, partid=%d, channel=%d\n",
2294                 (void *)msg, msg_number, ch->partid, ch->number);
2295
2296         DBUG_ON((((u64)msg - (u64)ch->sn.sn2.remote_msgqueue) / ch->entry_size) !=
2297                 msg_number % ch->remote_nentries);
2298         DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
2299         DBUG_ON(msg->flags & XPC_M_SN2_DONE);
2300
2301         msg->flags |= XPC_M_SN2_DONE;
2302
2303         /*
2304          * The preceding store of msg->flags must occur before the following
2305          * load of local_GP->get.
2306          */
2307         smp_mb();
2308
2309         /*
2310          * See if this message is next in line to be acknowledged as having
2311          * been delivered.
2312          */
2313         get = ch->sn.sn2.local_GP->get;
2314         if (get == msg_number)
2315                 xpc_acknowledge_msgs_sn2(ch, get, msg->flags);
2316 }
2317
2318 int
2319 xpc_init_sn2(void)
2320 {
2321         int ret;
2322         size_t buf_size;
2323
2324         xpc_setup_partitions_sn = xpc_setup_partitions_sn_sn2;
2325         xpc_teardown_partitions_sn = xpc_teardown_partitions_sn_sn2;
2326         xpc_get_partition_rsvd_page_pa = xpc_get_partition_rsvd_page_pa_sn2;
2327         xpc_setup_rsvd_page_sn = xpc_setup_rsvd_page_sn_sn2;
2328         xpc_increment_heartbeat = xpc_increment_heartbeat_sn2;
2329         xpc_offline_heartbeat = xpc_offline_heartbeat_sn2;
2330         xpc_online_heartbeat = xpc_online_heartbeat_sn2;
2331         xpc_heartbeat_init = xpc_heartbeat_init_sn2;
2332         xpc_heartbeat_exit = xpc_heartbeat_exit_sn2;
2333         xpc_get_remote_heartbeat = xpc_get_remote_heartbeat_sn2;
2334
2335         xpc_request_partition_activation = xpc_request_partition_activation_sn2;
2336         xpc_request_partition_reactivation =
2337             xpc_request_partition_reactivation_sn2;
2338         xpc_request_partition_deactivation =
2339             xpc_request_partition_deactivation_sn2;
2340         xpc_cancel_partition_deactivation_request =
2341             xpc_cancel_partition_deactivation_request_sn2;
2342
2343         xpc_process_activate_IRQ_rcvd = xpc_process_activate_IRQ_rcvd_sn2;
2344         xpc_setup_ch_structures_sn = xpc_setup_ch_structures_sn_sn2;
2345         xpc_teardown_ch_structures_sn = xpc_teardown_ch_structures_sn_sn2;
2346         xpc_make_first_contact = xpc_make_first_contact_sn2;
2347
2348         xpc_get_chctl_all_flags = xpc_get_chctl_all_flags_sn2;
2349         xpc_send_chctl_closerequest = xpc_send_chctl_closerequest_sn2;
2350         xpc_send_chctl_closereply = xpc_send_chctl_closereply_sn2;
2351         xpc_send_chctl_openrequest = xpc_send_chctl_openrequest_sn2;
2352         xpc_send_chctl_openreply = xpc_send_chctl_openreply_sn2;
2353
2354         xpc_save_remote_msgqueue_pa = xpc_save_remote_msgqueue_pa_sn2;
2355
2356         xpc_setup_msg_structures = xpc_setup_msg_structures_sn2;
2357         xpc_teardown_msg_structures = xpc_teardown_msg_structures_sn2;
2358
2359         xpc_notify_senders_of_disconnect = xpc_notify_senders_of_disconnect_sn2;
2360         xpc_process_msg_chctl_flags = xpc_process_msg_chctl_flags_sn2;
2361         xpc_n_of_deliverable_payloads = xpc_n_of_deliverable_payloads_sn2;
2362         xpc_get_deliverable_payload = xpc_get_deliverable_payload_sn2;
2363
2364         xpc_indicate_partition_engaged = xpc_indicate_partition_engaged_sn2;
2365         xpc_indicate_partition_disengaged =
2366             xpc_indicate_partition_disengaged_sn2;
2367         xpc_partition_engaged = xpc_partition_engaged_sn2;
2368         xpc_any_partition_engaged = xpc_any_partition_engaged_sn2;
2369         xpc_assume_partition_disengaged = xpc_assume_partition_disengaged_sn2;
2370
2371         xpc_send_payload = xpc_send_payload_sn2;
2372         xpc_received_payload = xpc_received_payload_sn2;
2373
2374         if (offsetof(struct xpc_msg_sn2, payload) > XPC_MSG_HDR_MAX_SIZE) {
2375                 dev_err(xpc_part, "header portion of struct xpc_msg_sn2 is "
2376                         "larger than %d\n", XPC_MSG_HDR_MAX_SIZE);
2377                 return -E2BIG;
2378         }
2379
2380         buf_size = max(XPC_RP_VARS_SIZE,
2381                        XPC_RP_HEADER_SIZE + XP_NASID_MASK_BYTES_SN2);
2382         xpc_remote_copy_buffer_sn2 = xpc_kmalloc_cacheline_aligned(buf_size,
2383                                                                    GFP_KERNEL,
2384                                               &xpc_remote_copy_buffer_base_sn2);
2385         if (xpc_remote_copy_buffer_sn2 == NULL) {
2386                 dev_err(xpc_part, "can't get memory for remote copy buffer\n");
2387                 return -ENOMEM;
2388         }
2389
2390         /* open up protections for IPI and [potentially] amo operations */
2391         xpc_allow_IPI_ops_sn2();
2392         xpc_allow_amo_ops_shub_wars_1_1_sn2();
2393
2394         /*
2395          * This is safe to do before the xpc_hb_checker thread has started
2396          * because the handler releases a wait queue.  If an interrupt is
2397          * received before the thread is waiting, it will not go to sleep,
2398          * but rather immediately process the interrupt.
2399          */
2400         ret = request_irq(SGI_XPC_ACTIVATE, xpc_handle_activate_IRQ_sn2, 0,
2401                           "xpc hb", NULL);
2402         if (ret != 0) {
2403                 dev_err(xpc_part, "can't register ACTIVATE IRQ handler, "
2404                         "errno=%d\n", -ret);
2405                 xpc_disallow_IPI_ops_sn2();
2406                 kfree(xpc_remote_copy_buffer_base_sn2);
2407         }
2408         return ret;
2409 }
2410
2411 void
2412 xpc_exit_sn2(void)
2413 {
2414         free_irq(SGI_XPC_ACTIVATE, NULL);
2415         xpc_disallow_IPI_ops_sn2();
2416         kfree(xpc_remote_copy_buffer_base_sn2);
2417 }