summaryrefslogtreecommitdiffstats
path: root/include/asm-ia64/sn/xpc.h
blob: e52b8508083be5dcd37243200795211b5423aff2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (c) 2004-2006 Silicon Graphics, Inc.  All Rights Reserved.
 */


/*
 * Cross Partition Communication (XPC) structures and macros.
 */

#ifndef _ASM_IA64_SN_XPC_H
#define _ASM_IA64_SN_XPC_H


#include <linux/interrupt.h>
#include <linux/sysctl.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/completion.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/sn/bte.h>
#include <asm/sn/clksupport.h>
#include <asm/sn/addrs.h>
#include <asm/sn/mspec.h>
#include <asm/sn/shub_mmr.h>
#include <asm/sn/xp.h>


/*
 * XPC Version numbers consist of a major and minor number. XPC can always
 * talk to versions with same major #, and never talk to versions with a
 * different major #.
 */
#define _XPC_VERSION(_maj, _min)	(((_maj) << 4) | ((_min) & 0xf))
#define XPC_VERSION_MAJOR(_v)		((_v) >> 4)
#define XPC_VERSION_MINOR(_v)		((_v) & 0xf)


/*
 * The next macros define word or bit representations for given
 * C-brick nasid in either the SAL provided bit array representing
 * nasids in the partition/machine or the AMO_t array used for
 * inter-partition initiation communications.
 *
 * For SN2 machines, C-Bricks are alway even numbered NASIDs.  As
 * such, some space will be saved by insisting that nasid information
 * passed from SAL always be packed for C-Bricks and the
 * cross-partition interrupts use the same packing scheme.
 */
#define XPC_NASID_W_INDEX(_n)	(((_n) / 64) / 2)
#define XPC_NASID_B_INDEX(_n)	(((_n) / 2) & (64 - 1))
#define XPC_NASID_IN_ARRAY(_n, _p) ((_p)[XPC_NASID_W_INDEX(_n)] & \
				    (1UL << XPC_NASID_B_INDEX(_n)))
#define XPC_NASID_FROM_W_B(_w, _b) (((_w) * 64 + (_b)) * 2)

#define XPC_HB_DEFAULT_INTERVAL		5	/* incr HB every x secs */
#define XPC_HB_CHECK_DEFAULT_INTERVAL	20	/* check HB every x secs */

/* define the process name of HB checker and the CPU it is pinned to */
#define XPC_HB_CHECK_THREAD_NAME	"xpc_hb"
#define XPC_HB_CHECK_CPU		0

/* define the process name of the discovery thread */
#define XPC_DISCOVERY_THREAD_NAME	"xpc_discovery"


/*
 * the reserved page
 *
 *   SAL reserves one page of memory per partition for XPC. Though a full page
 *   in length (16384 bytes), its starting address is not page aligned, but it
 *   is cacheline aligned. The reserved page consists of the following:
 *
 *   reserved page header
 *
 *     The first cacheline of the reserved page contains the header
 *     (struct xpc_rsvd_page). Before SAL initialization has completed,
 *     SAL has set up the following fields of the reserved page header:
 *     SAL_signature, SAL_version, partid, and nasids_size. The other
 *     fields are set up by XPC. (xpc_rsvd_page points to the local
 *     partition's reserved page.)
 *
 *   part_nasids mask
 *   mach_nasids mask
 *
 *     SAL also sets up two bitmaps (or masks), one that reflects the actual
 *     nasids in this partition (part_nasids), and the other that reflects
 *     the actual nasids in the entire machine (mach_nasids). We're only
 *     interested in the even numbered nasids (which contain the processors
 *     and/or memory), so we only need half as many bits to represent the
 *     nasids. The part_nasids mask is located starting at the first cacheline
 *     following the reserved page header. The mach_nasids mask follows right
 *     after the part_nasids mask. The size in bytes of each mask is reflected
 *     by the reserved page header field 'nasids_size'. (Local partition's
 *     mask pointers are xpc_part_nasids and xpc_mach_nasids.)
 *
 *   vars
 *   vars part
 *
 *     Immediately following the mach_nasids mask are the XPC variables
 *     required by other partitions. First are those that are generic to all
 *     partitions (vars), followed on the next available cacheline by those
 *     which are partition specific (vars part). These are setup by XPC.
 *     (Local partition's vars pointers are xpc_vars and xpc_vars_part.)
 *
 * Note: Until vars_pa is set, the partition XPC code has not been initialized.
 */
struct xpc_rsvd_page {
	u64 SAL_signature;	/* SAL: unique signature */
	u64 SAL_version;	/* SAL: version */
	u8 partid;		/* SAL: partition ID */
	u8 version;
	u8 pad1[6];		/* align to next u64 in cacheline */
	volatile u64 vars_pa;
	struct timespec stamp;	/* time when reserved page was setup by XPC */
	u64 pad2[9];		/* align to last u64 in cacheline */
	u64 nasids_size;	/* SAL: size of each nasid mask in bytes */
};

#define XPC_RP_VERSION _XPC_VERSION(1,1) /* version 1.1 of the reserved page */

#define XPC_SUPPORTS_RP_STAMP(_version) \
			(_version >= _XPC_VERSION(1,1))

/*
 * compare stamps - the return value is:
 *
 *	< 0,	if stamp1 < stamp2
 *	= 0,	if stamp1 == stamp2
 *	> 0,	if stamp1 > stamp2
 */
static inline int
xpc_compare_stamps(struct timespec *stamp1, struct timespec *stamp2)
{
	int ret;


	if ((ret = stamp1->tv_sec - stamp2->tv_sec) == 0) {
		ret = stamp1->tv_nsec - stamp2->tv_nsec;
	}
	return ret;
}


/*
 * Define the structures by which XPC variables can be exported to other
 * partitions. (There are two: struct xpc_vars and struct xpc_vars_part)
 */

/*
 * The following structure describes the partition generic variables
 * needed by other partitions in order to properly initialize.
 *
 * struct xpc_vars version number also applies to struct xpc_vars_part.
 * Changes to either structure and/or related functionality should be
 * reflected by incrementing either the major or minor version numbers
 * of struct xpc_vars.
 */
struct xpc_vars {
	u8 version;
	u64 heartbeat;
	u64 heartbeating_to_mask;
	u64 heartbeat_offline;	/* if 0, heartbeat should be changing */
	int act_nasid;
	int act_phys_cpuid;
	u64 vars_part_pa;
	u64 amos_page_pa;	/* paddr of page of AMOs from MSPEC driver */
	AMO_t *amos_page;	/* vaddr of page of AMOs from MSPEC driver */
};

#define XPC_V_VERSION _XPC_VERSION(3,1) /* version 3.1 of the cross vars */

#define XPC_SUPPORTS_DISENGAGE_REQUEST(_version) \
			(_version >= _XPC_VERSION(3,1))


static inline int
xpc_hb_allowed(partid_t partid, struct xpc_vars *vars)
{
	return ((vars->heartbeating_to_mask & (1UL << partid)) != 0);
}

static inline void
xpc_allow_hb(partid_t partid, struct xpc_vars *vars)
{
	u64 old_mask, new_mask;

	do {
		old_mask = vars->heartbeating_to_mask;
		new_mask = (old_mask | (1UL << partid));
	} while (cmpxchg(&vars->heartbeating_to_mask, old_mask, new_mask) !=
							old_mask);
}

static inline void
xpc_disallow_hb(partid_t partid, struct xpc_vars *vars)
{
	u64 old_mask, new_mask;

	do {
		old_mask = vars->heartbeating_to_mask;
		new_mask = (old_mask & ~(1UL << partid));
	} while (cmpxchg(&vars->heartbeating_to_mask, old_mask, new_mask) !=
							old_mask);
}


/*
 * The AMOs page consists of a number of AMO variables which are divided into
 * four groups, The first two groups are used to identify an IRQ's sender.
 * These two groups consist of 64 and 128 AMO variables respectively. The last
 * two groups, consisting of just one AMO variable each, are used to identify
 * the remote partitions that are currently engaged (from the viewpoint of
 * the XPC running on the remote partition).
 */
#define XPC_NOTIFY_IRQ_AMOS	   0
#define XPC_ACTIVATE_IRQ_AMOS	   (XPC_NOTIFY_IRQ_AMOS + XP_MAX_PARTITIONS)
#define XPC_ENGAGED_PARTITIONS_AMO (XPC_ACTIVATE_IRQ_AMOS + XP_NASID_MASK_WORDS)
#define XPC_DISENGAGE_REQUEST_AMO  (XPC_ENGAGED_PARTITIONS_AMO + 1)


/*
 * The following structure describes the per partition specific variables.
 *
 * An array of these structures, one per partition, will be defined. As a
 * partition becomes active XPC will copy the array entry corresponding to
 * itself from that partition. It is desirable that the size of this
 * structure evenly divide into a cacheline, such that none of the entries
 * in this array crosses a cacheline boundary. As it is now, each entry
 * occupies half a cacheline.
 */
struct xpc_vars_part {
	volatile u64 magic;

	u64 openclose_args_pa;	/* physical address of open and close args */
	u64 GPs_pa;		/* physical address of Get/Put values */

	u64 IPI_amo_pa;		/* physical address of IPI AMO_t structure */
	int IPI_nasid;		/* nasid of where to send IPIs */
	int IPI_phys_cpuid;	/* physical CPU ID of where to send IPIs */

	u8 nchannels;		/* #of defined channels supported */

	u8 reserved[23];	/* pad to a full 64 bytes */
};

/*
 * The vars_part MAGIC numbers play a part in the first contact protocol.
 *
 * MAGIC1 indicates that the per partition specific variables for a remote
 * partition have been initialized by this partition.
 *
 * MAGIC2 indicates that this partition has pulled the remote partititions
 * per partition variables that pertain to this partition.
 */
#define XPC_VP_MAGIC1	0x0053524156435058L  /* 'XPCVARS\0'L (little endian) */
#define XPC_VP_MAGIC2	0x0073726176435058L  /* 'XPCvars\0'L (little endian) */


/* the reserved page sizes and offsets */

#define XPC_RP_HEADER_SIZE	L1_CACHE_ALIGN(sizeof(struct xpc_rsvd_page))
#define XPC_RP_VARS_SIZE 	L1_CACHE_ALIGN(sizeof(struct xpc_vars))

#define XPC_RP_PART_NASIDS(_rp) (u64 *) ((u8 *) _rp + XPC_RP_HEADER_SIZE)
#define XPC_RP_MACH_NASIDS(_rp) (XPC_RP_PART_NASIDS(_rp) + xp_nasid_mask_words)
#define XPC_RP_VARS(_rp)	((struct xpc_vars *) XPC_RP_MACH_NASIDS(_rp) + xp_nasid_mask_words)
#define XPC_RP_VARS_PART(_rp)	(struct xpc_vars_part *) ((u8 *) XPC_RP_VARS(rp) + XPC_RP_VARS_SIZE)


/*
 * Functions registered by add_timer() or called by kernel_thread() only
 * allow for a single 64-bit argument. The following macros can be used to
 * pack and unpack two (32-bit, 16-bit or 8-bit) arguments into or out from
 * the passed argument.
 */
#define XPC_PACK_ARGS(_arg1, _arg2) \
			((((u64) _arg1) & 0xffffffff) | \
			((((u64) _arg2) & 0xffffffff) << 32))

#define XPC_UNPACK_ARG1(_args)	(((u64) _args) & 0xffffffff)
#define XPC_UNPACK_ARG2(_args)	((((u64) _args) >> 32) & 0xffffffff)



/*
 * Define a Get/Put value pair (pointers) used with a message queue.
 */
struct xpc_gp {
	volatile s64 get;	/* Get value */
	volatile s64 put;	/* Put value */
};

#define XPC_GP_SIZE \
		L1_CACHE_ALIGN(sizeof(struct xpc_gp) * XPC_NCHANNELS)



/*
 * Define a structure that contains arguments associated with opening and
 * closing a channel.
 */
struct xpc_openclose_args {
	u16 reason;		/* reason why channel is closing */
	u16 msg_size;		/* sizeof each message entry */
	u16 remote_nentries;	/* #of message entries in remote msg queue */
	u16 local_nentries;	/* #of message entries in local msg queue */
	u64 local_msgqueue_pa;	/* physical address of local message queue */
};

#define XPC_OPENCLOSE_ARGS_SIZE \
	      L1_CACHE_ALIGN(sizeof(struct xpc_openclose_args) * XPC_NCHANNELS)



/* struct xpc_msg flags */

#define	XPC_M_DONE		0x01	/* msg has been received/consumed */
#define	XPC_M_READY		0x02	/* msg is ready to be sent */
#define	XPC_M_INTERRUPT		0x04	/* send interrupt when msg consumed */


#define XPC_MSG_ADDRESS(_payload) \
		((struct xpc_msg *)((u8 *)(_payload) - XPC_MSG_PAYLOAD_OFFSET))



/*
 * Defines notify entry.
 *
 * This is used to notify a message's sender that their message was received
 * and consumed by the intended recipient.
 */
struct xpc_notify {
	volatile u8 type;		/* type of notification */

	/* the following two fields are only used if type == XPC_N_CALL */
	xpc_notify_func func;		/* user's notify function */
	void *key;			/* pointer to user's key */
};

/* struct xpc_notify type of notification */

#define	XPC_N_CALL		0x01	/* notify function provided by user */



/*
 * Define the structure that manages all the stuff required by a channel. In
 * particular, they are used to manage the messages sent across the channel.
 *
 * This structure is private to a partition, and is NOT shared across the
 * partition boundary.
 *
 * There is an array of these structures for each remote partition. It is
 * allocated at the time a partition becomes active. The array contains one
 * of these structures for each potential channel connection to that partition.
 *
 * Each of these structures manages two message queues (circular buffers).
 * They are allocated at the time a channel connection is made. One of
 * these message queues (local_msgqueue) holds the locally created messages
 * that are destined for the remote partition. The other of these message
 * queues (remote_msgqueue) is a locally cached copy of the remote partition's
 * own local_msgqueue.
 *
 * The following is a description of the Get/Put pointers used to manage these
 * two message queues. Consider the local_msgqueue to be on one partition
 * and the remote_msgqueue to be its cached copy on another partition. A
 * description of what each of the lettered areas contains is included.
 *
 *
 *                     local_msgqueue      remote_msgqueue
 *
 *                        |/////////|      |/////////|
 *    w_remote_GP.get --> +---------+      |/////////|
 *                        |    F    |      |/////////|
 *     remote_GP.get  --> +---------+      +---------+ <-- local_GP->get
 *                        |         |      |         |
 *                        |         |      |    E    |
 *                        |         |      |         |
 *                        |         |      +---------+ <-- w_local_GP.get
 *                        |    B    |      |/////////|
 *                        |         |      |////D////|
 *                        |         |      |/////////|
 *                        |         |      +---------+ <-- w_remote_GP.put
 *                        |         |      |////C////|
 *      local_GP->put --> +---------+      +---------+ <-- remote_GP.put
 *                        |         |      |/////////|
 *                        |    A    |      |/////////|
 *                        |         |      |/////////|
 *     w_local_GP.put --> +---------+      |/////////|
 *                        |/////////|      |/////////|
 *
 *
 *	    ( remote_GP.[get|put] are cached copies of the remote
 *	      partition's local_GP->[get|put], and thus their values can
 *	      lag behind their counterparts on the remote partition. )
 *
 *
 *  A - Messages that have been allocated, but have not yet been sent to the
 *	remote partition.
 *
 *  B - Messages that have been sent, but have not yet been acknowledged by the
 *      remote partition as having been received.
 *
 *  C - Area that needs to be prepared for the copying of sent messages, by
 *	the clearing of the message flags of any previously received messages.
 *
 *  D - Area into which sent messages are to be copied from the remote
 *	partition's local_msgqueue and then delivered to their intended
 *	recipients. [ To allow for a multi-message copy, another pointer
 *	(next_msg_to_pull) has been added to keep track of the next message
 *	number needing to be copied (pulled). It chases after w_remote_GP.put.
 *	Any messages lying between w_local_GP.get and next_msg_to_pull have
 *	been copied and are ready to be delivered. ]
 *
 *  E - Messages that have been copied and delivered, but have not yet been
 *	acknowledged by the recipient as having been received.
 *
 *  F - Messages that have been acknowledged, but XPC has not yet notified the
 *	sender that the message was received by its intended recipient.
 *	This is also an area that needs to be prepared for the allocating of
 *	new messages, by the clearing of the message flags of the acknowledged
 *	messages.
 */
struct xpc_channel {
	partid_t partid;		/* ID of remote partition connected */
	spinlock_t lock;		/* lock for updating this structure */
	u32 flags;			/* general flags */

	enum xpc_retval reason;		/* reason why channel is disconnect'g */
	int reason_line;		/* line# disconnect initiated from */

	u16 number;			/* channel # */

	u16 msg_size;			/* sizeof each msg entry */
	u16 local_nentries;		/* #of msg entries in local msg queue */
	u16 remote_nentries;		/* #of msg entries in remote msg queue*/

	void *local_msgqueue_base;	/* base address of kmalloc'd space */
	struct xpc_msg *local_msgqueue;	/* local message queue */
	void *remote_msgqueue_base;	/* base address of kmalloc'd space */
	struct xpc_msg *remote_msgqueue;/* cached copy of remote partition's */
					/* local message queue */
	u64 remote_msgqueue_pa;		/* phys addr of remote partition's */
					/* local message queue */

	atomic_t references;		/* #of external references to queues */

	atomic_t n_on_msg_allocate_wq;   /* #on msg allocation wait queue */
	wait_queue_head_t msg_allocate_wq; /* msg allocation wait queue */

	u8 delayed_IPI_flags;		/* IPI flags received, but delayed */
					/* action until channel disconnected */

	/* queue of msg senders who want to be notified when msg received */

	atomic_t n_to_notify;		/* #of msg senders to notify */
	struct xpc_notify *notify_queue;/* notify queue for messages sent */

	xpc_channel_func func;		/* user's channel function */
	void *key;			/* pointer to user's key */

	struct mutex msg_to_pull_mutex;	/* next msg to pull serialization */
	struct completion wdisconnect_wait; /* wait for channel disconnect */

	struct xpc_openclose_args *local_openclose_args; /* args passed on */
					/* opening or closing of channel */

	/* various flavors of local and remote Get/Put values */

	struct xpc_gp *local_GP;	/* local Get/Put values */
	struct xpc_gp remote_GP;	/* remote Get/Put values */
	struct xpc_gp w_local_GP;	/* working local Get/Put values */
	struct xpc_gp w_remote_GP;	/* working remote Get/Put values */
	s64 next_msg_to_pull;		/* Put value of next msg to pull */

	/* kthread management related fields */

// >>> rethink having kthreads_assigned_limit and kthreads_idle_limit; perhaps
// >>> allow the assigned limit be unbounded and let the idle limit be dynamic
// >>> dependent on activity over the last interval of time
	atomic_t kthreads_assigned;	/* #of kthreads assigned to channel */
	u32 kthreads_assigned_limit; 	/* limit on #of kthreads assigned */
	atomic_t kthreads_idle;		/* #of kthreads idle waiting for work */
	u32 kthreads_idle_limit;	/* limit on #of kthreads idle */
	atomic_t kthreads_active;	/* #of kthreads actively working */
	// >>> following field is temporary
	u32 kthreads_created;		/* total #of kthreads created */

	wait_queue_head_t idle_wq;	/* idle kthread wait queue */

} ____cacheline_aligned;


/* struct xpc_channel flags */

#define	XPC_C_WASCONNECTED	0x00000001 /* channel was connected */

#define	XPC_C_ROPENREPLY	0x00000002 /* remote open channel reply */
#define	XPC_C_OPENREPLY		0x00000004 /* local open channel reply */
#define	XPC_C_ROPENREQUEST	0x00000008 /* remote open channel request */
#define	XPC_C_OPENREQUEST	0x00000010 /* local open channel request */

#define	XPC_C_SETUP		0x00000020 /* channel's msgqueues are alloc'd */
#define	XPC_C_CONNECTEDCALLOUT	0x00000040 /* connected callout initiated */
#define	XPC_C_CONNECTEDCALLOUT_MADE \
				0x00000080 /* connected callout completed */
#define	XPC_C_CONNECTED		0x00000100 /* local channel is connected */
#define	XPC_C_CONNECTING	0x00000200 /* channel is being connected */

#define	XPC_C_RCLOSEREPLY	0x00000400 /* remote close channel reply */
#define	XPC_C_CLOSEREPLY	0x00000800 /* local close channel reply */
#define	XPC_C_RCLOSEREQUEST	0x00001000 /* remote close channel request */
#define	XPC_C_CLOSEREQUEST	0x00002000 /* local close channel request */

#define	XPC_C_DISCONNECTED	0x00004000 /* channel is disconnected */
#define	XPC_C_DISCONNECTING	0x00008000 /* channel is being disconnected */
#define	XPC_C_DISCONNECTINGCALLOUT \
				0x00010000 /* disconnecting callout initiated */
#define	XPC_C_DISCONNECTINGCALLOUT_MADE \
				0x00020000 /* disconnecting callout completed */
#define	XPC_C_WDISCONNECT	0x00040000 /* waiting for channel disconnect */



/*
 * Manages channels on a partition basis. There is one of these structures
 * for each partition (a partition will never utilize the structure that
 * represents itself).
 */
struct xpc_partition {

	/* XPC HB infrastructure */

	u8 remote_rp_version;		/* version# of partition's rsvd pg */
	struct timespec remote_rp_stamp;/* time when rsvd pg was initialized */
	u64 remote_rp_pa;		/* phys addr of partition's rsvd pg */
	u64 remote_vars_pa;		/* phys addr of partition's vars */
	u64 remote_vars_part_pa;	/* phys addr of partition's vars part */
	u64 last_heartbeat;		/* HB at last read */
	u64 remote_amos_page_pa;	/* phys addr of partition's amos page */
	int remote_act_nasid;		/* active part's act/deact nasid */
	int remote_act_phys_cpuid;	/* active part's act/deact phys cpuid */
	u32 act_IRQ_rcvd;		/* IRQs since activation */
	spinlock_t act_lock;		/* protect updating of act_state */
	u8 act_state;			/* from XPC HB viewpoint */
	u8 remote_vars_version;		/* version# of partition's vars */
	enum xpc_retval reason;		/* reason partition is deactivating */
	int reason_line;		/* line# deactivation initiated from */
	int reactivate_nasid;		/* nasid in partition to reactivate */

	unsigned long disengage_request_timeout; /* timeout in jiffies */
	struct timer_list disengage_request_timer;


	/* XPC infrastructure referencing and teardown control */

	volatile u8 setup_state;	/* infrastructure setup state */
	wait_queue_head_t teardown_wq;	/* kthread waiting to teardown infra */
	atomic_t references;		/* #of references to infrastructure */


	/*
	 * NONE OF THE PRECEDING FIELDS OF THIS STRUCTURE WILL BE CLEARED WHEN
	 * XPC SETS UP THE NECESSARY INFRASTRUCTURE TO SUPPORT CROSS PARTITION
	 * COMMUNICATION. ALL OF THE FOLLOWING FIELDS WILL BE CLEARED. (THE
	 * 'nchannels' FIELD MUST BE THE FIRST OF THE FIELDS TO BE CLEARED.)
	 */


	u8 nchannels;		   /* #of defined channels supported */
	atomic_t nchannels_active; /* #of channels that are not DISCONNECTED */
	atomic_t nchannels_engaged;/* #of channels engaged with remote part */
	struct xpc_channel *channels;/* array of channel structures */

	void *local_GPs_base;	  /* base address of kmalloc'd space */
	struct xpc_gp *local_GPs; /* local Get/Put values */
	void *remote_GPs_base;    /* base address of kmalloc'd space */
	struct xpc_gp *remote_GPs;/* copy of remote partition's local Get/Put */
				  /* values */
	u64 remote_GPs_pa;	  /* phys address of remote partition's local */
				  /* Get/Put values */


	/* fields used to pass args when opening or closing a channel */

	void *local_openclose_args_base;  /* base address of kmalloc'd space */
	struct xpc_openclose_args *local_openclose_args;  /* local's args */
	void *remote_openclose_args_base; /* base address of kmalloc'd space */
	struct xpc_openclose_args *remote_openclose_args; /* copy of remote's */
					  /* args */
	u64 remote_openclose_args_pa;	  /* phys addr of remote's args */


	/* IPI sending, receiving and handling related fields */

	int remote_IPI_nasid;	    /* nasid of where to send IPIs */
	int remote_IPI_phys_cpuid;  /* phys CPU ID of where to send IPIs */
	AMO_t *remote_IPI_amo_va;   /* address of remote IPI AMO_t structure */

	AMO_t *local_IPI_amo_va;    /* address of IPI AMO_t structure */
	u64 local_IPI_amo;	    /* IPI amo flags yet to be handled */
	char IPI_owner[8];	    /* IPI owner's name */
	struct timer_list dropped_IPI_timer; /* dropped IPI timer */

	spinlock_t IPI_lock;	    /* IPI handler lock */


	/* channel manager related fields */

	atomic_t channel_mgr_requests;	/* #of requests to activate chan mgr */
	wait_queue_head_t channel_mgr_wq; /* channel mgr's wait queue */

} ____cacheline_aligned;


/* struct xpc_partition act_state values (for XPC HB) */

#define	XPC_P_INACTIVE		0x00	/* partition is not active */
#define XPC_P_ACTIVATION_REQ	0x01	/* created thread to activate */
#define XPC_P_ACTIVATING	0x02	/* activation thread started */
#define XPC_P_ACTIVE		0x03	/* xpc_partition_up() was called */
#define XPC_P_DEACTIVATING	0x04	/* partition deactivation initiated */


#define XPC_DEACTIVATE_PARTITION(_p, _reason) \
			xpc_deactivate_partition(__LINE__, (_p), (_reason))


/* struct xpc_partition setup_state values */

#define XPC_P_UNSET		0x00	/* infrastructure was never setup */
#define XPC_P_SETUP		0x01	/* infrastructure is setup */
#define XPC_P_WTEARDOWN		0x02	/* waiting to teardown infrastructure */
#define XPC_P_TORNDOWN		0x03	/* infrastructure is torndown */



/*
 * struct xpc_partition IPI_timer #of seconds to wait before checking for
 * dropped IPIs. These occur whenever an IPI amo write doesn't complete until
 * after the IPI was received.
 */
#define XPC_P_DROPPED_IPI_WAIT	(0.25 * HZ)


/* number of seconds to wait for other partitions to disengage */
#define XPC_DISENGAGE_REQUEST_DEFAULT_TIMELIMIT	90

/* interval in seconds to print 'waiting disengagement' messages */
#define XPC_DISENGAGE_PRINTMSG_INTERVAL		10


#define XPC_PARTID(_p)	((partid_t) ((_p) - &xpc_partitions[0]))



/* found in xp_main.c */
extern struct xpc_registration xpc_registrations[];


/* found in xpc_main.c */
extern struct device *xpc_part;
extern struct device *xpc_chan;
extern int xpc_disengage_request_timelimit;
extern int xpc_disengage_request_timedout;
extern irqreturn_t xpc_notify_IRQ_handler(int, void *);
extern void xpc_dropped_IPI_check(struct xpc_partition *);
extern void xpc_activate_partition(struct xpc_partition *);
extern void xpc_activate_kthreads(struct xpc_channel *, int);
extern void xpc_create_kthreads(struct xpc_channel *, int, int);
extern void xpc_disconnect_wait(int);


/* found in xpc_partition.c */
extern int xpc_exiting;
extern struct xpc_vars *xpc_vars;
extern struct xpc_rsvd_page *xpc_rsvd_page;
extern struct xpc_vars_part *xpc_vars_part;
extern struct xpc_partition xpc_partitions[XP_MAX_PARTITIONS + 1];
extern char *xpc_remote_copy_buffer;
extern void *xpc_remote_copy_buffer_base;
extern void *xpc_kmalloc_cacheline_aligned(size_t, gfp_t, void **);
extern struct xpc_rsvd_page *xpc_rsvd_page_init(void);
extern void xpc_allow_IPI_ops(void);
extern void xpc_restrict_IPI_ops(void);
extern int xpc_identify_act_IRQ_sender(void);
extern int xpc_partition_disengaged(struct xpc_partition *);
extern enum xpc_retval xpc_mark_partition_active(struct xpc_partition *);
extern void xpc_mark_partition_inactive(struct xpc_partition *);
extern void xpc_discovery(void);
extern void xpc_check_remote_hb(void);
extern void xpc_deactivate_partition(const int, struct xpc_partition *,
						enum xpc_retval);
extern enum xpc_retval xpc_initiate_partid_to_nasids(partid_t, void *);


/* found in xpc_channel.c */
extern void xpc_initiate_connect(int);
extern void xpc_initiate_disconnect(int);
extern enum xpc_retval xpc_initiate_allocate(partid_t, int, u32, void **);
extern enum xpc_retval xpc_initiate_send(partid_t, int, void *);
extern enum xpc_retval xpc_initiate_send_notify(partid_t, int, void *,
						xpc_notify_func, void *);
extern void xpc_initiate_received(partid_t, int, void *);
extern enum xpc_retval xpc_setup_infrastructure(struct xpc_partition *);
extern enum xpc_retval xpc_pull_remote_vars_part(struct xpc_partition *);
extern void xpc_process_channel_activity(struct xpc_partition *);
extern void xpc_connected_callout(struct xpc_channel *);
extern void xpc_deliver_msg(struct xpc_channel *);
extern void xpc_disconnect_channel(const int, struct xpc_channel *,
					enum xpc_retval, unsigned long *);
extern void xpc_disconnect_callout(struct xpc_channel *, enum xpc_retval);
extern void xpc_partition_going_down(struct xpc_partition *, enum xpc_retval);
extern void xpc_teardown_infrastructure(struct xpc_partition *);



static inline void
xpc_wakeup_channel_mgr(struct xpc_partition *part)
{
	if (atomic_inc_return(&part->channel_mgr_requests) == 1) {
		wake_up(&part->channel_mgr_wq);
	}
}



/*
 * These next two inlines are used to keep us from tearing down a channel's
 * msg queues while a thread may be referencing them.
 */
static inline void
xpc_msgqueue_ref(struct xpc_channel *ch)
{
	atomic_inc(&ch->references);
}

static inline void
xpc_msgqueue_deref(struct xpc_channel *ch)
{
	s32 refs = atomic_dec_return(&ch->references);

	DBUG_ON(refs < 0);
	if (refs == 0) {
		xpc_wakeup_channel_mgr(&xpc_partitions[ch->partid]);
	}
}



#define XPC_DISCONNECT_CHANNEL(_ch, _reason, _irqflgs) \
		xpc_disconnect_channel(__LINE__, _ch, _reason, _irqflgs)


/*
 * These two inlines are used to keep us from tearing down a partition's
 * setup infrastructure while a thread may be referencing it.
 */
static inline void
xpc_part_deref(struct xpc_partition *part)
{
	s32 refs = atomic_dec_return(&part->references);


	DBUG_ON(refs < 0);
	if (refs == 0 && part->setup_state == XPC_P_WTEARDOWN) {
		wake_up(&part->teardown_wq);
	}
}

static inline int
xpc_part_ref(struct xpc_partition *part)
{
	int setup;


	atomic_inc(&part->references);
	setup = (part->setup_state == XPC_P_SETUP);
	if (!setup) {
		xpc_part_deref(part);
	}
	return setup;
}



/*
 * The following macro is to be used for the setting of the reason and
 * reason_line fields in both the struct xpc_channel and struct xpc_partition
 * structures.
 */
#define XPC_SET_REASON(_p, _reason, _line) \
	{ \
		(_p)->reason = _reason; \
		(_p)->reason_line = _line; \
	}



/*
 * This next set of inlines are used to keep track of when a partition is
 * potentially engaged in accessing memory belonging to another partition.
 */

static inline void
xpc_mark_partition_engaged(struct xpc_partition *part)
{
	unsigned long irq_flags;
	AMO_t *amo = (AMO_t *) __va(part->remote_amos_page_pa +
				(XPC_ENGAGED_PARTITIONS_AMO * sizeof(AMO_t)));


	local_irq_save(irq_flags);

	/* set bit corresponding to our partid in remote partition's AMO */
	FETCHOP_STORE_OP(TO_AMO((u64) &amo->variable), FETCHOP_OR,
						(1UL << sn_partition_id));
	/*
	 * We must always use the nofault function regardless of whether we
	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
	 * didn't, we'd never know that the other partition is down and would
	 * keep sending IPIs and AMOs to it until the heartbeat times out.
	 */
	(void) xp_nofault_PIOR((u64 *) GLOBAL_MMR_ADDR(NASID_GET(&amo->
				variable), xp_nofault_PIOR_target));

	local_irq_restore(irq_flags);
}

static inline void
xpc_mark_partition_disengaged(struct xpc_partition *part)
{
	unsigned long irq_flags;
	AMO_t *amo = (AMO_t *) __va(part->remote_amos_page_pa +
				(XPC_ENGAGED_PARTITIONS_AMO * sizeof(AMO_t)));


	local_irq_save(irq_flags);

	/* clear bit corresponding to our partid in remote partition's AMO */
	FETCHOP_STORE_OP(TO_AMO((u64) &amo->variable), FETCHOP_AND,
						~(1UL << sn_partition_id));
	/*
	 * We must always use the nofault function regardless of whether we
	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
	 * didn't, we'd never know that the other partition is down and would
	 * keep sending IPIs and AMOs to it until the heartbeat times out.
	 */
	(void) xp_nofault_PIOR((u64 *) GLOBAL_MMR_ADDR(NASID_GET(&amo->
				variable), xp_nofault_PIOR_target));

	local_irq_restore(irq_flags);
}

static inline void
xpc_request_partition_disengage(struct xpc_partition *part)
{
	unsigned long irq_flags;
	AMO_t *amo = (AMO_t *) __va(part->remote_amos_page_pa +
				(XPC_DISENGAGE_REQUEST_AMO * sizeof(AMO_t)));


	local_irq_save(irq_flags);

	/* set bit corresponding to our partid in remote partition's AMO */
	FETCHOP_STORE_OP(TO_AMO((u64) &amo->variable), FETCHOP_OR,
						(1UL << sn_partition_id));
	/*
	 * We must always use the nofault function regardless of whether we
	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
	 * didn't, we'd never know that the other partition is down and would
	 * keep sending IPIs and AMOs to it until the heartbeat times out.
	 */
	(void) xp_nofault_PIOR((u64 *) GLOBAL_MMR_ADDR(NASID_GET(&amo->
				variable), xp_nofault_PIOR_target));

	local_irq_restore(irq_flags);
}

static inline void
xpc_cancel_partition_disengage_request(struct xpc_partition *part)
{
	unsigned long irq_flags;
	AMO_t *amo = (AMO_t *) __va(part->remote_amos_page_pa +
				(XPC_DISENGAGE_REQUEST_AMO * sizeof(AMO_t)));


	local_irq_save(irq_flags);

	/* clear bit corresponding to our partid in remote partition's AMO */
	FETCHOP_STORE_OP(TO_AMO((u64) &amo->variable), FETCHOP_AND,
						~(1UL << sn_partition_id));
	/*
	 * We must always use the nofault function regardless of whether we
	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
	 * didn't, we'd never know that the other partition is down and would
	 * keep sending IPIs and AMOs to it until the heartbeat times out.
	 */
	(void) xp_nofault_PIOR((u64 *) GLOBAL_MMR_ADDR(NASID_GET(&amo->
				variable), xp_nofault_PIOR_target));

	local_irq_restore(irq_flags);
}

static inline u64
xpc_partition_engaged(u64 partid_mask)
{
	AMO_t *amo = xpc_vars->amos_page + XPC_ENGAGED_PARTITIONS_AMO;


	/* return our partition's AMO variable ANDed with partid_mask */
	return (FETCHOP_LOAD_OP(TO_AMO((u64) &amo->variable), FETCHOP_LOAD) &
								partid_mask);
}

static inline u64
xpc_partition_disengage_requested(u64 partid_mask)
{
	AMO_t *amo = xpc_vars->amos_page + XPC_DISENGAGE_REQUEST_AMO;


	/* return our partition's AMO variable ANDed with partid_mask */
	return (FETCHOP_LOAD_OP(TO_AMO((u64) &amo->variable), FETCHOP_LOAD) &
								partid_mask);
}

static inline void
xpc_clear_partition_engaged(u64 partid_mask)
{
	AMO_t *amo = xpc_vars->amos_page + XPC_ENGAGED_PARTITIONS_AMO;


	/* clear bit(s) based on partid_mask in our partition's AMO */
	FETCHOP_STORE_OP(TO_AMO((u64) &amo->variable), FETCHOP_AND,
								~partid_mask);
}

static inline void
xpc_clear_partition_disengage_request(u64 partid_mask)
{
	AMO_t *amo = xpc_vars->amos_page + XPC_DISENGAGE_REQUEST_AMO;


	/* clear bit(s) based on partid_mask in our partition's AMO */
	FETCHOP_STORE_OP(TO_AMO((u64) &amo->variable), FETCHOP_AND,
								~partid_mask);
}



/*
 * The following set of macros and inlines are used for the sending and
 * receiving of IPIs (also known as IRQs). There are two flavors of IPIs,
 * one that is associated with partition activity (SGI_XPC_ACTIVATE) and
 * the other that is associated with channel activity (SGI_XPC_NOTIFY).
 */

static inline u64
xpc_IPI_receive(AMO_t *amo)
{
	return FETCHOP_LOAD_OP(TO_AMO((u64) &amo->variable), FETCHOP_CLEAR);
}


static inline enum xpc_retval
xpc_IPI_send(AMO_t *amo, u64 flag, int nasid, int phys_cpuid, int vector)
{
	int ret = 0;
	unsigned long irq_flags;


	local_irq_save(irq_flags);

	FETCHOP_STORE_OP(TO_AMO((u64) &amo->variable), FETCHOP_OR, flag);
	sn_send_IPI_phys(nasid, phys_cpuid, vector, 0);

	/*
	 * We must always use the nofault function regardless of whether we
	 * are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
	 * didn't, we'd never know that the other partition is down and would
	 * keep sending IPIs and AMOs to it until the heartbeat times out.
	 */
	ret = xp_nofault_PIOR((u64 *) GLOBAL_MMR_ADDR(NASID_GET(&amo->variable),
				xp_nofault_PIOR_target));

	local_irq_restore(irq_flags);

	return ((ret == 0) ? xpcSuccess : xpcPioReadError);
}


/*
 * IPIs associated with SGI_XPC_ACTIVATE IRQ.
 */

/*
 * Flag the appropriate AMO variable and send an IPI to the specified node.
 */
static inline void
xpc_activate_IRQ_send(u64 amos_page_pa, int from_nasid, int to_nasid,
			int to_phys_cpuid)
{
	int w_index = XPC_NASID_W_INDEX(from_nasid);
	int b_index = XPC_NASID_B_INDEX(from_nasid);
	AMO_t *amos = (AMO_t *) __va(amos_page_pa +
				(XPC_ACTIVATE_IRQ_AMOS * sizeof(AMO_t)));


	(void) xpc_IPI_send(&amos[w_index], (1UL << b_index), to_nasid,
				to_phys_cpuid, SGI_XPC_ACTIVATE);
}

static inline void
xpc_IPI_send_activate(struct xpc_vars *vars)
{
	xpc_activate_IRQ_send(vars->amos_page_pa, cnodeid_to_nasid(0),
				vars->act_nasid, vars->act_phys_cpuid);
}

static inline void
xpc_IPI_send_activated(struct xpc_partition *part)
{
	xpc_activate_IRQ_send(part->remote_amos_page_pa, cnodeid_to_nasid(0),
			part->remote_act_nasid, part->remote_act_phys_cpuid);
}

static inline void
xpc_IPI_send_reactivate(struct xpc_partition *part)
{
	xpc_activate_IRQ_send(xpc_vars->amos_page_pa, part->reactivate_nasid,
				xpc_vars->act_nasid, xpc_vars->act_phys_cpuid);
}

static inline void
xpc_IPI_send_disengage(struct xpc_partition *part)
{
	xpc_activate_IRQ_send(part->remote_amos_page_pa, cnodeid_to_nasid(0),
			part->remote_act_nasid, part->remote_act_phys_cpuid);
}


/*
 * IPIs associated with SGI_XPC_NOTIFY IRQ.
 */

/*
 * Send an IPI to the remote partition that is associated with the
 * specified channel.
 */
#define XPC_NOTIFY_IRQ_SEND(_ch, _ipi_f, _irq_f) \
		xpc_notify_IRQ_send(_ch, _ipi_f, #_ipi_f, _irq_f)

static inline void
xpc_notify_IRQ_send(struct xpc_channel *ch, u8 ipi_flag, char *ipi_flag_string,
			unsigned long *irq_flags)
{
	struct xpc_partition *part = &xpc_partitions[ch->partid];
	enum xpc_retval ret;


	if (likely(part->act_state != XPC_P_DEACTIVATING)) {
		ret = xpc_IPI_send(part->remote_IPI_amo_va,
					(u64) ipi_flag << (ch->number * 8),
					part->remote_IPI_nasid,
					part->remote_IPI_phys_cpuid,
					SGI_XPC_NOTIFY);
		dev_dbg(xpc_chan, "%s sent to partid=%d, channel=%d, ret=%d\n",
			ipi_flag_string, ch->partid, ch->number, ret);
		if (unlikely(ret != xpcSuccess)) {
			if (irq_flags != NULL) {
				spin_unlock_irqrestore(&ch->lock, *irq_flags);
			}
			XPC_DEACTIVATE_PARTITION(part, ret);
			if (irq_flags != NULL) {
				spin_lock_irqsave(&ch->lock, *irq_flags);
			}
		}
	}
}


/*
 * Make it look like the remote partition, which is associated with the
 * specified channel, sent us an IPI. This faked IPI will be handled
 * by xpc_dropped_IPI_check().
 */
#define XPC_NOTIFY_IRQ_SEND_LOCAL(_ch, _ipi_f) \
		xpc_notify_IRQ_send_local(_ch, _ipi_f, #_ipi_f)

static inline void
xpc_notify_IRQ_send_local(struct xpc_channel *ch, u8 ipi_flag,
				char *ipi_flag_string)
{
	struct xpc_partition *part = &xpc_partitions[ch->partid];


	FETCHOP_STORE_OP(TO_AMO((u64) &part->local_IPI_amo_va->variable),
			FETCHOP_OR, ((u64) ipi_flag << (ch->number * 8)));
	dev_dbg(xpc_chan, "%s sent local from partid=%d, channel=%d\n",
		ipi_flag_string, ch->partid, ch->number);
}


/*
 * The sending and receiving of IPIs includes the setting of an AMO variable
 * to indicate the reason the IPI was sent. The 64-bit variable is divided
 * up into eight bytes, ordered from right to left. Byte zero pertains to
 * channel 0, byte one to channel 1, and so on. Each byte is described by
 * the following IPI flags.
 */

#define	XPC_IPI_CLOSEREQUEST	0x01
#define	XPC_IPI_CLOSEREPLY	0x02
#define	XPC_IPI_OPENREQUEST	0x04
#define	XPC_IPI_OPENREPLY	0x08
#define	XPC_IPI_MSGREQUEST	0x10


/* given an AMO variable and a channel#, get its associated IPI flags */
#define XPC_GET_IPI_FLAGS(_amo, _c)	((u8) (((_amo) >> ((_c) * 8)) & 0xff))
#define XPC_SET_IPI_FLAGS(_amo, _c, _f)	(_amo) |= ((u64) (_f) << ((_c) * 8))

#define	XPC_ANY_OPENCLOSE_IPI_FLAGS_SET(_amo) ((_amo) & __IA64_UL_CONST(0x0f0f0f0f0f0f0f0f))
#define XPC_ANY_MSG_IPI_FLAGS_SET(_amo)       ((_amo) & __IA64_UL_CONST(0x1010101010101010))


static inline void
xpc_IPI_send_closerequest(struct xpc_channel *ch, unsigned long *irq_flags)
{
	struct xpc_openclose_args *args = ch->local_openclose_args;


	args->reason = ch->reason;

	XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_CLOSEREQUEST, irq_flags);
}

static inline void
xpc_IPI_send_closereply(struct xpc_channel *ch, unsigned long *irq_flags)
{
	XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_CLOSEREPLY, irq_flags);
}

static inline void
xpc_IPI_send_openrequest(struct xpc_channel *ch, unsigned long *irq_flags)
{
	struct xpc_openclose_args *args = ch->local_openclose_args;


	args->msg_size = ch->msg_size;
	args->local_nentries = ch->local_nentries;

	XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_OPENREQUEST, irq_flags);
}

static inline void
xpc_IPI_send_openreply(struct xpc_channel *ch, unsigned long *irq_flags)
{
	struct xpc_openclose_args *args = ch->local_openclose_args;


	args->remote_nentries = ch->remote_nentries;
	args->local_nentries = ch->local_nentries;
	args->local_msgqueue_pa = __pa(ch->local_msgqueue);

	XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_OPENREPLY, irq_flags);
}

static inline void
xpc_IPI_send_msgrequest(struct xpc_channel *ch)
{
	XPC_NOTIFY_IRQ_SEND(ch, XPC_IPI_MSGREQUEST, NULL);
}

static inline void
xpc_IPI_send_local_msgrequest(struct xpc_channel *ch)
{
	XPC_NOTIFY_IRQ_SEND_LOCAL(ch, XPC_IPI_MSGREQUEST);
}


/*
 * Memory for XPC's AMO variables is allocated by the MSPEC driver. These
 * pages are located in the lowest granule. The lowest granule uses 4k pages
 * for cached references and an alternate TLB handler to never provide a
 * cacheable mapping for the entire region. This will prevent speculative
 * reading of cached copies of our lines from being issued which will cause
 * a PI FSB Protocol error to be generated by the SHUB. For XPC, we need 64
 * AMO variables (based on XP_MAX_PARTITIONS) for message notification and an
 * additional 128 AMO variables (based on XP_NASID_MASK_WORDS) for partition
 * activation and 2 AMO variables for partition deactivation.
 */
static inline AMO_t *
xpc_IPI_init(int index)
{
	AMO_t *amo = xpc_vars->amos_page + index;


	(void) xpc_IPI_receive(amo);	/* clear AMO variable */
	return amo;
}



static inline enum xpc_retval
xpc_map_bte_errors(bte_result_t error)
{
	switch (error) {
	case BTE_SUCCESS:	return xpcSuccess;
	case BTEFAIL_DIR:	return xpcBteDirectoryError;
	case BTEFAIL_POISON:	return xpcBtePoisonError;
	case BTEFAIL_WERR:	return xpcBteWriteError;
	case BTEFAIL_ACCESS:	return xpcBteAccessError;
	case BTEFAIL_PWERR:	return xpcBtePWriteError;
	case BTEFAIL_PRERR:	return xpcBtePReadError;
	case BTEFAIL_TOUT:	return xpcBteTimeOutError;
	case BTEFAIL_XTERR:	return xpcBteXtalkError;
	case BTEFAIL_NOTAVAIL:	return xpcBteNotAvailable;
	default:		return xpcBteUnmappedError;
	}
}



/*
 * Check to see if there is any channel activity to/from the specified
 * partition.
 */
static inline void
xpc_check_for_channel_activity(struct xpc_partition *part)
{
	u64 IPI_amo;
	unsigned long irq_flags;


	IPI_amo = xpc_IPI_receive(part->local_IPI_amo_va);
	if (IPI_amo == 0) {
		return;
	}

	spin_lock_irqsave(&part->IPI_lock, irq_flags);
	part->local_IPI_amo |= IPI_amo;
	spin_unlock_irqrestore(&part->IPI_lock, irq_flags);

	dev_dbg(xpc_chan, "received IPI from partid=%d, IPI_amo=0x%lx\n",
		XPC_PARTID(part), IPI_amo);

	xpc_wakeup_channel_mgr(part);
}


#endif /* _ASM_IA64_SN_XPC_H */

OpenPOWER on IntegriCloud