Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  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
/*
 * 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) 2004-2009 Silicon Graphics, Inc.  All Rights Reserved.
 */

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

#ifndef _DRIVERS_MISC_SGIXP_XPC_H
#define _DRIVERS_MISC_SGIXP_XPC_H

#include <linux/wait.h>
#include <linux/completion.h>
#include <linux/timer.h>
#include <linux/sched.h>
#include "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)

/* define frequency of the heartbeat and frequency how often it's checked */
#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 two 64-byte cachelines of the reserved page contain 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, SAL_partid, and SAL_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. When mapping nasid to bit in a mask (or bit to nasid) be sure
 *     to either divide or multiply by 2. 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
 *     'SAL_nasids_size'. (Local partition's mask pointers are xpc_part_nasids
 *     and xpc_mach_nasids.)
 *
 *     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.
 *
 * Note: Until 'ts_jiffies' is set non-zero, the partition XPC code has not been
 *       initialized.
 */
struct xpc_rsvd_page {
	u64 SAL_signature;	/* SAL: unique signature */
	u64 SAL_version;	/* SAL: version */
	short SAL_partid;	/* SAL: partition ID */
	short max_npartitions;	/* value of XPC_MAX_PARTITIONS */
	u8 version;
	u8 pad1[3];		/* align to next u64 in 1st 64-byte cacheline */
	unsigned long ts_jiffies; /* timestamp when rsvd pg was setup by XPC */
	union {
		struct {
			unsigned long heartbeat_gpa; /* phys addr */
			unsigned long activate_gru_mq_desc_gpa; /* phys addr */
		} uv;
	} sn;
	u64 pad2[9];		/* align to last u64 in 2nd 64-byte cacheline */
	u64 SAL_nasids_size;	/* SAL: size of each nasid mask in bytes */
};

#define XPC_RP_VERSION _XPC_VERSION(3, 0) /* version 3.0 of the reserved page */

/* the reserved page sizes and offsets */

#define XPC_RP_HEADER_SIZE	L1_CACHE_ALIGN(sizeof(struct xpc_rsvd_page))

#define XPC_RP_PART_NASIDS(_rp) ((unsigned long *)((u8 *)(_rp) + \
				 XPC_RP_HEADER_SIZE))
#define XPC_RP_MACH_NASIDS(_rp) (XPC_RP_PART_NASIDS(_rp) + \
				 xpc_nasid_mask_nlongs)


/*
 * The following structure describes the partition's heartbeat info which
 * will be periodically read by other partitions to determine whether this
 * XPC is still 'alive'.
 */
struct xpc_heartbeat_uv {
	unsigned long value;
	unsigned long offline;	/* if 0, heartbeat should be changing */
};

/*
 * Info pertinent to a GRU message queue using a watch list for irq generation.
 */
struct xpc_gru_mq_uv {
	void *address;		/* address of GRU message queue */
	unsigned int order;	/* size of GRU message queue as a power of 2 */
	int irq;		/* irq raised when message is received in mq */
	int mmr_blade;		/* blade where watchlist was allocated from */
	unsigned long mmr_offset; /* offset of irq mmr located on mmr_blade */
	unsigned long mmr_value; /* value of irq mmr located on mmr_blade */
	int watchlist_num;	/* number of watchlist allocatd by BIOS */
	void *gru_mq_desc;	/* opaque structure used by the GRU driver */
};

/*
 * The activate_mq is used to send/receive GRU messages that affect XPC's
 * partition active state and channel state. This is uv only.
 */
struct xpc_activate_mq_msghdr_uv {
	unsigned int gru_msg_hdr; /* FOR GRU INTERNAL USE ONLY */
	short partid;		/* sender's partid */
	u8 act_state;		/* sender's act_state at time msg sent */
	u8 type;		/* message's type */
	unsigned long rp_ts_jiffies; /* timestamp of sender's rp setup by XPC */
};

/* activate_mq defined message types */
#define XPC_ACTIVATE_MQ_MSG_SYNC_ACT_STATE_UV		0

#define XPC_ACTIVATE_MQ_MSG_ACTIVATE_REQ_UV		1
#define XPC_ACTIVATE_MQ_MSG_DEACTIVATE_REQ_UV		2

#define XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREQUEST_UV	3
#define XPC_ACTIVATE_MQ_MSG_CHCTL_CLOSEREPLY_UV		4
#define XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREQUEST_UV	5
#define XPC_ACTIVATE_MQ_MSG_CHCTL_OPENREPLY_UV		6
#define XPC_ACTIVATE_MQ_MSG_CHCTL_OPENCOMPLETE_UV	7

#define XPC_ACTIVATE_MQ_MSG_MARK_ENGAGED_UV		8
#define XPC_ACTIVATE_MQ_MSG_MARK_DISENGAGED_UV		9

struct xpc_activate_mq_msg_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
};

struct xpc_activate_mq_msg_activate_req_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
	unsigned long rp_gpa;
	unsigned long heartbeat_gpa;
	unsigned long activate_gru_mq_desc_gpa;
};

struct xpc_activate_mq_msg_deactivate_req_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
	enum xp_retval reason;
};

struct xpc_activate_mq_msg_chctl_closerequest_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
	short ch_number;
	enum xp_retval reason;
};

struct xpc_activate_mq_msg_chctl_closereply_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
	short ch_number;
};

struct xpc_activate_mq_msg_chctl_openrequest_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
	short ch_number;
	short entry_size;	/* size of notify_mq's GRU messages */
	short local_nentries;	/* ??? Is this needed? What is? */
};

struct xpc_activate_mq_msg_chctl_openreply_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
	short ch_number;
	short remote_nentries;	/* ??? Is this needed? What is? */
	short local_nentries;	/* ??? Is this needed? What is? */
	unsigned long notify_gru_mq_desc_gpa;
};

struct xpc_activate_mq_msg_chctl_opencomplete_uv {
	struct xpc_activate_mq_msghdr_uv hdr;
	short ch_number;
};

/*
 * 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 structure that contains arguments associated with opening and
 * closing a channel.
 */
struct xpc_openclose_args {
	u16 reason;		/* reason why channel is closing */
	u16 entry_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 */
	unsigned long local_msgqueue_pa; /* phys addr of local message queue */
};

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


/*
 * Structures to define a fifo singly-linked list.
 */

struct xpc_fifo_entry_uv {
	struct xpc_fifo_entry_uv *next;
};

struct xpc_fifo_head_uv {
	struct xpc_fifo_entry_uv *first;
	struct xpc_fifo_entry_uv *last;
	spinlock_t lock;
	int n_entries;
};

/*
 * The format of a uv XPC notify_mq GRU message is as follows:
 *
 * A user-defined message resides in the payload area. The max size of the
 * payload is defined by the user via xpc_connect().
 *
 * The size of a message (payload and header) sent via the GRU must be either 1
 * or 2 GRU_CACHE_LINE_BYTES in length.
 */

struct xpc_notify_mq_msghdr_uv {
	union {
		unsigned int gru_msg_hdr;	/* FOR GRU INTERNAL USE ONLY */
		struct xpc_fifo_entry_uv next;	/* FOR XPC INTERNAL USE ONLY */
	} u;
	short partid;		/* FOR XPC INTERNAL USE ONLY */
	u8 ch_number;		/* FOR XPC INTERNAL USE ONLY */
	u8 size;		/* FOR XPC INTERNAL USE ONLY */
	unsigned int msg_slot_number;	/* FOR XPC INTERNAL USE ONLY */
};

struct xpc_notify_mq_msg_uv {
	struct xpc_notify_mq_msghdr_uv hdr;
	unsigned long payload;
};

/* struct xpc_notify_sn2 type of notification */

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

/*
 * Define uv's version of the notify entry. It additionally is used to allocate
 * a msg slot on the remote partition into which is copied a sent message.
 */
struct xpc_send_msg_slot_uv {
	struct xpc_fifo_entry_uv next;
	unsigned int msg_slot_number;
	xpc_notify_func func;	/* user's notify function */
	void *key;		/* pointer to user's key */
};

/*
 * 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.
 */

struct xpc_channel_uv {
	void *cached_notify_gru_mq_desc; /* remote partition's notify mq's */
					 /* gru mq descriptor */

	struct xpc_send_msg_slot_uv *send_msg_slots;
	void *recv_msg_slots;	/* each slot will hold a xpc_notify_mq_msg_uv */
				/* structure plus the user's payload */

	struct xpc_fifo_head_uv msg_slot_free_list;
	struct xpc_fifo_head_uv recv_msg_list;	/* deliverable payloads */
};

struct xpc_channel {
	short partid;		/* ID of remote partition connected */
	spinlock_t lock;	/* lock for updating this structure */
	unsigned int flags;	/* general flags */

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

	u16 number;		/* channel # */

	u16 entry_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 */

	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_chctl_flags;	/* chctl flags received, but delayed */
				/* action until channel disconnected */

	atomic_t n_to_notify;	/* #of msg senders to notify */

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

	struct completion wdisconnect_wait;    /* wait for channel disconnect */

	/* kthread management related fields */

	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 */

	wait_queue_head_t idle_wq;	/* idle kthread wait queue */

	union {
		struct xpc_channel_uv uv;
	} sn;

} ____cacheline_aligned;

/* struct xpc_channel flags */

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

#define XPC_C_ROPENCOMPLETE	0x00000002    /* remote open channel complete */
#define XPC_C_OPENCOMPLETE	0x00000004     /* local open channel complete */
#define	XPC_C_ROPENREPLY	0x00000008	/* remote open channel reply */
#define	XPC_C_OPENREPLY		0x00000010	/* local open channel reply */
#define	XPC_C_ROPENREQUEST	0x00000020     /* remote open channel request */
#define	XPC_C_OPENREQUEST	0x00000040	/* local open channel request */

#define	XPC_C_SETUP		0x00000080 /* channel's msgqueues are alloc'd */
#define	XPC_C_CONNECTEDCALLOUT	0x00000100     /* connected callout initiated */
#define	XPC_C_CONNECTEDCALLOUT_MADE \
				0x00000200     /* connected callout completed */
#define	XPC_C_CONNECTED		0x00000400	/* local channel is connected */
#define	XPC_C_CONNECTING	0x00000800	/* channel is being connected */

#define	XPC_C_RCLOSEREPLY	0x00001000	/* remote close channel reply */
#define	XPC_C_CLOSEREPLY	0x00002000	/* local close channel reply */
#define	XPC_C_RCLOSEREQUEST	0x00004000    /* remote close channel request */
#define	XPC_C_CLOSEREQUEST	0x00008000     /* local close channel request */

#define	XPC_C_DISCONNECTED	0x00010000	/* channel is disconnected */
#define	XPC_C_DISCONNECTING	0x00020000   /* channel is being disconnected */
#define	XPC_C_DISCONNECTINGCALLOUT \
				0x00040000 /* disconnecting callout initiated */
#define	XPC_C_DISCONNECTINGCALLOUT_MADE \
				0x00080000 /* disconnecting callout completed */
#define	XPC_C_WDISCONNECT	0x00100000  /* waiting for channel disconnect */

/*
 * The channel control flags (chctl) union consists of a 64-bit variable which
 * 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 channel's byte
 * can have one or more of the chctl flags set in it.
 */

union xpc_channel_ctl_flags {
	u64 all_flags;
	u8 flags[XPC_MAX_NCHANNELS];
};

/* chctl flags */
#define	XPC_CHCTL_CLOSEREQUEST	0x01
#define	XPC_CHCTL_CLOSEREPLY	0x02
#define	XPC_CHCTL_OPENREQUEST	0x04
#define	XPC_CHCTL_OPENREPLY	0x08
#define XPC_CHCTL_OPENCOMPLETE	0x10
#define	XPC_CHCTL_MSGREQUEST	0x20

#define XPC_OPENCLOSE_CHCTL_FLAGS \
			(XPC_CHCTL_CLOSEREQUEST | XPC_CHCTL_CLOSEREPLY | \
			 XPC_CHCTL_OPENREQUEST | XPC_CHCTL_OPENREPLY | \
			 XPC_CHCTL_OPENCOMPLETE)
#define XPC_MSG_CHCTL_FLAGS	XPC_CHCTL_MSGREQUEST

static inline int
xpc_any_openclose_chctl_flags_set(union xpc_channel_ctl_flags *chctl)
{
	int ch_number;

	for (ch_number = 0; ch_number < XPC_MAX_NCHANNELS; ch_number++) {
		if (chctl->flags[ch_number] & XPC_OPENCLOSE_CHCTL_FLAGS)
			return 1;
	}
	return 0;
}

static inline int
xpc_any_msg_chctl_flags_set(union xpc_channel_ctl_flags *chctl)
{
	int ch_number;

	for (ch_number = 0; ch_number < XPC_MAX_NCHANNELS; ch_number++) {
		if (chctl->flags[ch_number] & XPC_MSG_CHCTL_FLAGS)
			return 1;
	}
	return 0;
}

struct xpc_partition_uv {
	unsigned long heartbeat_gpa; /* phys addr of partition's heartbeat */
	struct xpc_heartbeat_uv cached_heartbeat; /* cached copy of */
						  /* partition's heartbeat */
	unsigned long activate_gru_mq_desc_gpa;	/* phys addr of parititon's */
						/* activate mq's gru mq */
						/* descriptor */
	void *cached_activate_gru_mq_desc; /* cached copy of partition's */
					   /* activate mq's gru mq descriptor */
	struct mutex cached_activate_gru_mq_desc_mutex;
	spinlock_t flags_lock;	/* protect updating of flags */
	unsigned int flags;	/* general flags */
	u8 remote_act_state;	/* remote partition's act_state */
	u8 act_state_req;	/* act_state request from remote partition */
	enum xp_retval reason;	/* reason for deactivate act_state request */
};

/* struct xpc_partition_uv flags */

#define XPC_P_CACHED_ACTIVATE_GRU_MQ_DESC_UV	0x00000001
#define XPC_P_ENGAGED_UV			0x00000002

/* struct xpc_partition_uv act_state change requests */

#define XPC_P_ASR_ACTIVATE_UV		0x01
#define XPC_P_ASR_REACTIVATE_UV		0x02
#define XPC_P_ASR_DEACTIVATE_UV		0x03

struct xpc_partition {

	/* XPC HB infrastructure */

	u8 remote_rp_version;	/* version# of partition's rsvd pg */
	unsigned long remote_rp_ts_jiffies; /* timestamp when rsvd pg setup */
	unsigned long remote_rp_pa;	/* phys addr of partition's rsvd pg */
	u64 last_heartbeat;	/* HB at last read */
	u32 activate_IRQ_rcvd;	/* IRQs since activation */
	spinlock_t act_lock;	/* protect updating of act_state */
	u8 act_state;		/* from XPC HB viewpoint */
	enum xp_retval reason;	/* reason partition is deactivating */
	int reason_line;	/* line# deactivation initiated from */

	unsigned long disengage_timeout;	/* timeout in jiffies */
	struct timer_list disengage_timer;

	/* XPC infrastructure referencing and teardown control */

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

	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 */

	/* fields used for managing channel avialability and activity */

	union xpc_channel_ctl_flags chctl; /* chctl flags yet to be processed */
	spinlock_t chctl_lock;	/* chctl flags lock */

	void *remote_openclose_args_base;  /* base address of kmalloc'd space */
	struct xpc_openclose_args *remote_openclose_args; /* copy of remote's */
							  /* args */

	/* 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 */

	union {
		struct xpc_partition_uv uv;
	} sn;

} ____cacheline_aligned;

struct xpc_arch_operations {
	int (*setup_partitions) (void);
	void (*teardown_partitions) (void);
	void (*process_activate_IRQ_rcvd) (void);
	enum xp_retval (*get_partition_rsvd_page_pa)
		(void *, u64 *, unsigned long *, size_t *);
	int (*setup_rsvd_page) (struct xpc_rsvd_page *);

	void (*allow_hb) (short);
	void (*disallow_hb) (short);
	void (*disallow_all_hbs) (void);
	void (*increment_heartbeat) (void);
	void (*offline_heartbeat) (void);
	void (*online_heartbeat) (void);
	void (*heartbeat_init) (void);
	void (*heartbeat_exit) (void);
	enum xp_retval (*get_remote_heartbeat) (struct xpc_partition *);

	void (*request_partition_activation) (struct xpc_rsvd_page *,
						 unsigned long, int);
	void (*request_partition_reactivation) (struct xpc_partition *);
	void (*request_partition_deactivation) (struct xpc_partition *);
	void (*cancel_partition_deactivation_request) (struct xpc_partition *);
	enum xp_retval (*setup_ch_structures) (struct xpc_partition *);
	void (*teardown_ch_structures) (struct xpc_partition *);

	enum xp_retval (*make_first_contact) (struct xpc_partition *);

	u64 (*get_chctl_all_flags) (struct xpc_partition *);
	void (*send_chctl_closerequest) (struct xpc_channel *, unsigned long *);
	void (*send_chctl_closereply) (struct xpc_channel *, unsigned long *);
	void (*send_chctl_openrequest) (struct xpc_channel *, unsigned long *);
	void (*send_chctl_openreply) (struct xpc_channel *, unsigned long *);
	void (*send_chctl_opencomplete) (struct xpc_channel *, unsigned long *);
	void (*process_msg_chctl_flags) (struct xpc_partition *, int);

	enum xp_retval (*save_remote_msgqueue_pa) (struct xpc_channel *,
						      unsigned long);

	enum xp_retval (*setup_msg_structures) (struct xpc_channel *);
	void (*teardown_msg_structures) (struct xpc_channel *);

	void (*indicate_partition_engaged) (struct xpc_partition *);
	void (*indicate_partition_disengaged) (struct xpc_partition *);
	void (*assume_partition_disengaged) (short);
	int (*partition_engaged) (short);
	int (*any_partition_engaged) (void);

	int (*n_of_deliverable_payloads) (struct xpc_channel *);
	enum xp_retval (*send_payload) (struct xpc_channel *, u32, void *,
					   u16, u8, xpc_notify_func, void *);
	void *(*get_deliverable_payload) (struct xpc_channel *);
	void (*received_payload) (struct xpc_channel *, void *);
	void (*notify_senders_of_disconnect) (struct xpc_channel *);
};

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

#define	XPC_P_AS_INACTIVE	0x00	/* partition is not active */
#define XPC_P_AS_ACTIVATION_REQ	0x01	/* created thread to activate */
#define XPC_P_AS_ACTIVATING	0x02	/* activation thread started */
#define XPC_P_AS_ACTIVE		0x03	/* xpc_partition_up() was called */
#define XPC_P_AS_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_SS_UNSET		0x00	/* infrastructure was never setup */
#define XPC_P_SS_SETUP		0x01	/* infrastructure is setup */
#define XPC_P_SS_WTEARDOWN	0x02	/* waiting to teardown infrastructure */
#define XPC_P_SS_TORNDOWN	0x03	/* infrastructure is torndown */

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

/* interval in seconds to print 'waiting deactivation' messages */
#define XPC_DEACTIVATE_PRINTMSG_INTERVAL	10

#define XPC_PARTID(_p)	((short)((_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 struct xpc_arch_operations xpc_arch_ops;
extern int xpc_disengage_timelimit;
extern int xpc_disengage_timedout;
extern int xpc_activate_IRQ_rcvd;
extern spinlock_t xpc_activate_IRQ_rcvd_lock;
extern wait_queue_head_t xpc_activate_IRQ_wq;
extern void *xpc_kzalloc_cacheline_aligned(size_t, gfp_t, void **);
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_uv.c */
extern int xpc_init_uv(void);
extern void xpc_exit_uv(void);

/* found in xpc_partition.c */
extern int xpc_exiting;
extern int xpc_nasid_mask_nlongs;
extern struct xpc_rsvd_page *xpc_rsvd_page;
extern unsigned long *xpc_mach_nasids;
extern struct xpc_partition *xpc_partitions;
extern void *xpc_kmalloc_cacheline_aligned(size_t, gfp_t, void **);
extern int xpc_setup_rsvd_page(void);
extern void xpc_teardown_rsvd_page(void);
extern int xpc_identify_activate_IRQ_sender(void);
extern int xpc_partition_disengaged(struct xpc_partition *);
extern enum xp_retval xpc_mark_partition_active(struct xpc_partition *);
extern void xpc_mark_partition_inactive(struct xpc_partition *);
extern void xpc_discovery(void);
extern enum xp_retval xpc_get_remote_rp(int, unsigned long *,
					struct xpc_rsvd_page *,
					unsigned long *);
extern void xpc_deactivate_partition(const int, struct xpc_partition *,
				     enum xp_retval);
extern enum xp_retval xpc_initiate_partid_to_nasids(short, void *);

/* found in xpc_channel.c */
extern void xpc_initiate_connect(int);
extern void xpc_initiate_disconnect(int);
extern enum xp_retval xpc_allocate_msg_wait(struct xpc_channel *);
extern enum xp_retval xpc_initiate_send(short, int, u32, void *, u16);
extern enum xp_retval xpc_initiate_send_notify(short, int, u32, void *, u16,
					       xpc_notify_func, void *);
extern void xpc_initiate_received(short, int, void *);
extern void xpc_process_sent_chctl_flags(struct xpc_partition *);
extern void xpc_connected_callout(struct xpc_channel *);
extern void xpc_deliver_payload(struct xpc_channel *);
extern void xpc_disconnect_channel(const int, struct xpc_channel *,
				   enum xp_retval, unsigned long *);
extern void xpc_disconnect_callout(struct xpc_channel *, enum xp_retval);
extern void xpc_partition_going_down(struct xpc_partition *, enum xp_retval);

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_SS_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_SS_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; \
	}

#endif /* _DRIVERS_MISC_SGIXP_XPC_H */