aboutsummaryrefslogtreecommitdiff
path: root/drivers/scsi/isci/remote_node_table.c
blob: 301b3141945ec26799d254d02d75daaf22556a07 (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
/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 * The full GNU General Public License is included in this distribution
 * in the file called LICENSE.GPL.
 *
 * BSD LICENSE
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *   * Neither the name of Intel Corporation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * This file contains the implementation of the SCIC_SDS_REMOTE_NODE_TABLE
 *    public, protected, and private methods.
 *
 *
 */
#include "remote_node_table.h"
#include "remote_node_context.h"

/**
 *
 * @remote_node_table: This is the remote node index table from which the
 *    selection will be made.
 * @group_table_index: This is the index to the group table from which to
 *    search for an available selection.
 *
 * This routine will find the bit position in absolute bit terms of the next 32
 * + bit position.  If there are available bits in the first u32 then it is
 * just bit position. u32 This is the absolute bit position for an available
 * group.
 */
static u32 sci_remote_node_table_get_group_index(
	struct sci_remote_node_table *remote_node_table,
	u32 group_table_index)
{
	u32 dword_index;
	u32 *group_table;
	u32 bit_index;

	group_table = remote_node_table->remote_node_groups[group_table_index];

	for (dword_index = 0; dword_index < remote_node_table->group_array_size; dword_index++) {
		if (group_table[dword_index] != 0) {
			for (bit_index = 0; bit_index < 32; bit_index++) {
				if ((group_table[dword_index] & (1 << bit_index)) != 0) {
					return (dword_index * 32) + bit_index;
				}
			}
		}
	}

	return SCIC_SDS_REMOTE_NODE_TABLE_INVALID_INDEX;
}

/**
 *
 * @out]: remote_node_table This the remote node table in which to clear the
 *    selector.
 * @set_index: This is the remote node selector in which the change will be
 *    made.
 * @group_index: This is the bit index in the table to be modified.
 *
 * This method will clear the group index entry in the specified group index
 * table. none
 */
static void sci_remote_node_table_clear_group_index(
	struct sci_remote_node_table *remote_node_table,
	u32 group_table_index,
	u32 group_index)
{
	u32 dword_index;
	u32 bit_index;
	u32 *group_table;

	BUG_ON(group_table_index >= SCU_STP_REMOTE_NODE_COUNT);
	BUG_ON(group_index >= (u32)(remote_node_table->group_array_size * 32));

	dword_index = group_index / 32;
	bit_index   = group_index % 32;
	group_table = remote_node_table->remote_node_groups[group_table_index];

	group_table[dword_index] = group_table[dword_index] & ~(1 << bit_index);
}

/**
 *
 * @out]: remote_node_table This the remote node table in which to set the
 *    selector.
 * @group_table_index: This is the remote node selector in which the change
 *    will be made.
 * @group_index: This is the bit position in the table to be modified.
 *
 * This method will set the group index bit entry in the specified gropu index
 * table. none
 */
static void sci_remote_node_table_set_group_index(
	struct sci_remote_node_table *remote_node_table,
	u32 group_table_index,
	u32 group_index)
{
	u32 dword_index;
	u32 bit_index;
	u32 *group_table;

	BUG_ON(group_table_index >= SCU_STP_REMOTE_NODE_COUNT);
	BUG_ON(group_index >= (u32)(remote_node_table->group_array_size * 32));

	dword_index = group_index / 32;
	bit_index   = group_index % 32;
	group_table = remote_node_table->remote_node_groups[group_table_index];

	group_table[dword_index] = group_table[dword_index] | (1 << bit_index);
}

/**
 *
 * @out]: remote_node_table This is the remote node table in which to modify
 *    the remote node availability.
 * @remote_node_index: This is the remote node index that is being returned to
 *    the table.
 *
 * This method will set the remote to available in the remote node allocation
 * table. none
 */
static void sci_remote_node_table_set_node_index(
	struct sci_remote_node_table *remote_node_table,
	u32 remote_node_index)
{
	u32 dword_location;
	u32 dword_remainder;
	u32 slot_normalized;
	u32 slot_position;

	BUG_ON(
		(remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
		<= (remote_node_index / SCU_STP_REMOTE_NODE_COUNT)
		);

	dword_location  = remote_node_index / SCIC_SDS_REMOTE_NODES_PER_DWORD;
	dword_remainder = remote_node_index % SCIC_SDS_REMOTE_NODES_PER_DWORD;
	slot_normalized = (dword_remainder / SCU_STP_REMOTE_NODE_COUNT) * sizeof(u32);
	slot_position   = remote_node_index % SCU_STP_REMOTE_NODE_COUNT;

	remote_node_table->available_remote_nodes[dword_location] |=
		1 << (slot_normalized + slot_position);
}

/**
 *
 * @out]: remote_node_table This is the remote node table from which to clear
 *    the available remote node bit.
 * @remote_node_index: This is the remote node index which is to be cleared
 *    from the table.
 *
 * This method clears the remote node index from the table of available remote
 * nodes. none
 */
static void sci_remote_node_table_clear_node_index(
	struct sci_remote_node_table *remote_node_table,
	u32 remote_node_index)
{
	u32 dword_location;
	u32 dword_remainder;
	u32 slot_position;
	u32 slot_normalized;

	BUG_ON(
		(remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
		<= (remote_node_index / SCU_STP_REMOTE_NODE_COUNT)
		);

	dword_location  = remote_node_index / SCIC_SDS_REMOTE_NODES_PER_DWORD;
	dword_remainder = remote_node_index % SCIC_SDS_REMOTE_NODES_PER_DWORD;
	slot_normalized = (dword_remainder / SCU_STP_REMOTE_NODE_COUNT) * sizeof(u32);
	slot_position   = remote_node_index % SCU_STP_REMOTE_NODE_COUNT;

	remote_node_table->available_remote_nodes[dword_location] &=
		~(1 << (slot_normalized + slot_position));
}

/**
 *
 * @out]: remote_node_table The remote node table from which the slot will be
 *    cleared.
 * @group_index: The index for the slot that is to be cleared.
 *
 * This method clears the entire table slot at the specified slot index. none
 */
static void sci_remote_node_table_clear_group(
	struct sci_remote_node_table *remote_node_table,
	u32 group_index)
{
	u32 dword_location;
	u32 dword_remainder;
	u32 dword_value;

	BUG_ON(
		(remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
		<= (group_index / SCU_STP_REMOTE_NODE_COUNT)
		);

	dword_location  = group_index / SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
	dword_remainder = group_index % SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;

	dword_value = remote_node_table->available_remote_nodes[dword_location];
	dword_value &= ~(SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE << (dword_remainder * 4));
	remote_node_table->available_remote_nodes[dword_location] = dword_value;
}

/**
 *
 * @remote_node_table:
 *
 * THis method sets an entire remote node group in the remote node table.
 */
static void sci_remote_node_table_set_group(
	struct sci_remote_node_table *remote_node_table,
	u32 group_index)
{
	u32 dword_location;
	u32 dword_remainder;
	u32 dword_value;

	BUG_ON(
		(remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
		<= (group_index / SCU_STP_REMOTE_NODE_COUNT)
		);

	dword_location  = group_index / SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
	dword_remainder = group_index % SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;

	dword_value = remote_node_table->available_remote_nodes[dword_location];
	dword_value |= (SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE << (dword_remainder * 4));
	remote_node_table->available_remote_nodes[dword_location] = dword_value;
}

/**
 *
 * @remote_node_table: This is the remote node table that for which the group
 *    value is to be returned.
 * @group_index: This is the group index to use to find the group value.
 *
 * This method will return the group value for the specified group index. The
 * bit values at the specified remote node group index.
 */
static u8 sci_remote_node_table_get_group_value(
	struct sci_remote_node_table *remote_node_table,
	u32 group_index)
{
	u32 dword_location;
	u32 dword_remainder;
	u32 dword_value;

	dword_location  = group_index / SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
	dword_remainder = group_index % SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;

	dword_value = remote_node_table->available_remote_nodes[dword_location];
	dword_value &= (SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE << (dword_remainder * 4));
	dword_value = dword_value >> (dword_remainder * 4);

	return (u8)dword_value;
}

/**
 *
 * @out]: remote_node_table The remote that which is to be initialized.
 * @remote_node_entries: The number of entries to put in the table.
 *
 * This method will initialize the remote node table for use. none
 */
void sci_remote_node_table_initialize(
	struct sci_remote_node_table *remote_node_table,
	u32 remote_node_entries)
{
	u32 index;

	/*
	 * Initialize the raw data we could improve the speed by only initializing
	 * those entries that we are actually going to be used */
	memset(
		remote_node_table->available_remote_nodes,
		0x00,
		sizeof(remote_node_table->available_remote_nodes)
		);

	memset(
		remote_node_table->remote_node_groups,
		0x00,
		sizeof(remote_node_table->remote_node_groups)
		);

	/* Initialize the available remote node sets */
	remote_node_table->available_nodes_array_size = (u16)
							(remote_node_entries / SCIC_SDS_REMOTE_NODES_PER_DWORD)
							+ ((remote_node_entries % SCIC_SDS_REMOTE_NODES_PER_DWORD) != 0);


	/* Initialize each full DWORD to a FULL SET of remote nodes */
	for (index = 0; index < remote_node_entries; index++) {
		sci_remote_node_table_set_node_index(remote_node_table, index);
	}

	remote_node_table->group_array_size = (u16)
					      (remote_node_entries / (SCU_STP_REMOTE_NODE_COUNT * 32))
					      + ((remote_node_entries % (SCU_STP_REMOTE_NODE_COUNT * 32)) != 0);

	for (index = 0; index < (remote_node_entries / SCU_STP_REMOTE_NODE_COUNT); index++) {
		/*
		 * These are all guaranteed to be full slot values so fill them in the
		 * available sets of 3 remote nodes */
		sci_remote_node_table_set_group_index(remote_node_table, 2, index);
	}

	/* Now fill in any remainders that we may find */
	if ((remote_node_entries % SCU_STP_REMOTE_NODE_COUNT) == 2) {
		sci_remote_node_table_set_group_index(remote_node_table, 1, index);
	} else if ((remote_node_entries % SCU_STP_REMOTE_NODE_COUNT) == 1) {
		sci_remote_node_table_set_group_index(remote_node_table, 0, index);
	}
}

/**
 *
 * @out]: remote_node_table The remote node table from which to allocate a
 *    remote node.
 * @table_index: The group index that is to be used for the search.
 *
 * This method will allocate a single RNi from the remote node table.  The
 * table index will determine from which remote node group table to search.
 * This search may fail and another group node table can be specified.  The
 * function is designed to allow a serach of the available single remote node
 * group up to the triple remote node group.  If an entry is found in the
 * specified table the remote node is removed and the remote node groups are
 * updated. The RNi value or an invalid remote node context if an RNi can not
 * be found.
 */
static u16 sci_remote_node_table_allocate_single_remote_node(
	struct sci_remote_node_table *remote_node_table,
	u32 group_table_index)
{
	u8 index;
	u8 group_value;
	u32 group_index;
	u16 remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;

	group_index = sci_remote_node_table_get_group_index(
		remote_node_table, group_table_index);

	/* We could not find an available slot in the table selector 0 */
	if (group_index != SCIC_SDS_REMOTE_NODE_TABLE_INVALID_INDEX) {
		group_value = sci_remote_node_table_get_group_value(
			remote_node_table, group_index);

		for (index = 0; index < SCU_STP_REMOTE_NODE_COUNT; index++) {
			if (((1 << index) & group_value) != 0) {
				/* We have selected a bit now clear it */
				remote_node_index = (u16)(group_index * SCU_STP_REMOTE_NODE_COUNT
							  + index);

				sci_remote_node_table_clear_group_index(
					remote_node_table, group_table_index, group_index
					);

				sci_remote_node_table_clear_node_index(
					remote_node_table, remote_node_index
					);

				if (group_table_index > 0) {
					sci_remote_node_table_set_group_index(
						remote_node_table, group_table_index - 1, group_index
						);
				}

				break;
			}
		}
	}

	return remote_node_index;
}

/**
 *
 * @remote_node_table: This is the remote node table from which to allocate the
 *    remote node entries.
 * @group_table_index: THis is the group table index which must equal two (2)
 *    for this operation.
 *
 * This method will allocate three consecutive remote node context entries. If
 * there are no remaining triple entries the function will return a failure.
 * The remote node index that represents three consecutive remote node entries
 * or an invalid remote node context if none can be found.
 */
static u16 sci_remote_node_table_allocate_triple_remote_node(
	struct sci_remote_node_table *remote_node_table,
	u32 group_table_index)
{
	u32 group_index;
	u16 remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;

	group_index = sci_remote_node_table_get_group_index(
		remote_node_table, group_table_index);

	if (group_index != SCIC_SDS_REMOTE_NODE_TABLE_INVALID_INDEX) {
		remote_node_index = (u16)group_index * SCU_STP_REMOTE_NODE_COUNT;

		sci_remote_node_table_clear_group_index(
			remote_node_table, group_table_index, group_index
			);

		sci_remote_node_table_clear_group(
			remote_node_table, group_index
			);
	}

	return remote_node_index;
}

/**
 *
 * @remote_node_table: This is the remote node table from which the remote node
 *    allocation is to take place.
 * @remote_node_count: This is ther remote node count which is one of
 *    SCU_SSP_REMOTE_NODE_COUNT(1) or SCU_STP_REMOTE_NODE_COUNT(3).
 *
 * This method will allocate a remote node that mataches the remote node count
 * specified by the caller.  Valid values for remote node count is
 * SCU_SSP_REMOTE_NODE_COUNT(1) or SCU_STP_REMOTE_NODE_COUNT(3). u16 This is
 * the remote node index that is returned or an invalid remote node context.
 */
u16 sci_remote_node_table_allocate_remote_node(
	struct sci_remote_node_table *remote_node_table,
	u32 remote_node_count)
{
	u16 remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;

	if (remote_node_count == SCU_SSP_REMOTE_NODE_COUNT) {
		remote_node_index =
			sci_remote_node_table_allocate_single_remote_node(
				remote_node_table, 0);

		if (remote_node_index == SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX) {
			remote_node_index =
				sci_remote_node_table_allocate_single_remote_node(
					remote_node_table, 1);
		}

		if (remote_node_index == SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX) {
			remote_node_index =
				sci_remote_node_table_allocate_single_remote_node(
					remote_node_table, 2);
		}
	} else if (remote_node_count == SCU_STP_REMOTE_NODE_COUNT) {
		remote_node_index =
			sci_remote_node_table_allocate_triple_remote_node(
				remote_node_table, 2);
	}

	return remote_node_index;
}

/**
 *
 * @remote_node_table:
 *
 * This method will free a single remote node index back to the remote node
 * table.  This routine will update the remote node groups
 */
static void sci_remote_node_table_release_single_remote_node(
	struct sci_remote_node_table *remote_node_table,
	u16 remote_node_index)
{
	u32 group_index;
	u8 group_value;

	group_index = remote_node_index / SCU_STP_REMOTE_NODE_COUNT;

	group_value = sci_remote_node_table_get_group_value(remote_node_table, group_index);

	/*
	 * Assert that we are not trying to add an entry to a slot that is already
	 * full. */
	BUG_ON(group_value == SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE);

	if (group_value == 0x00) {
		/*
		 * There are no entries in this slot so it must be added to the single
		 * slot table. */
		sci_remote_node_table_set_group_index(remote_node_table, 0, group_index);
	} else if ((group_value & (group_value - 1)) == 0) {
		/*
		 * There is only one entry in this slot so it must be moved from the
		 * single slot table to the dual slot table */
		sci_remote_node_table_clear_group_index(remote_node_table, 0, group_index);
		sci_remote_node_table_set_group_index(remote_node_table, 1, group_index);
	} else {
		/*
		 * There are two entries in the slot so it must be moved from the dual
		 * slot table to the tripple slot table. */
		sci_remote_node_table_clear_group_index(remote_node_table, 1, group_index);
		sci_remote_node_table_set_group_index(remote_node_table, 2, group_index);
	}

	sci_remote_node_table_set_node_index(remote_node_table, remote_node_index);
}

/**
 *
 * @remote_node_table: This is the remote node table to which the remote node
 *    index is to be freed.
 *
 * This method will release a group of three consecutive remote nodes back to
 * the free remote nodes.
 */
static void sci_remote_node_table_release_triple_remote_node(
	struct sci_remote_node_table *remote_node_table,
	u16 remote_node_index)
{
	u32 group_index;

	group_index = remote_node_index / SCU_STP_REMOTE_NODE_COUNT;

	sci_remote_node_table_set_group_index(
		remote_node_table, 2, group_index
		);

	sci_remote_node_table_set_group(remote_node_table, group_index);
}

/**
 *
 * @remote_node_table: The remote node table to which the remote node index is
 *    to be freed.
 * @remote_node_count: This is the count of consecutive remote nodes that are
 *    to be freed.
 *
 * This method will release the remote node index back into the remote node
 * table free pool.
 */
void sci_remote_node_table_release_remote_node_index(
	struct sci_remote_node_table *remote_node_table,
	u32 remote_node_count,
	u16 remote_node_index)
{
	if (remote_node_count == SCU_SSP_REMOTE_NODE_COUNT) {
		sci_remote_node_table_release_single_remote_node(
			remote_node_table, remote_node_index);
	} else if (remote_node_count == SCU_STP_REMOTE_NODE_COUNT) {
		sci_remote_node_table_release_triple_remote_node(
			remote_node_table, remote_node_index);
	}
}