1/*
2 * This file is provided under a dual BSD/GPLv2 license. When using or
3 * redistributing this file, you may do so under either license.
4 *
5 * GPL LICENSE SUMMARY
6 *
7 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of version 2 of the GNU General Public License as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful, but
14 * WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
21 * The full GNU General Public License is included in this distribution
22 * in the file called LICENSE.GPL.
23 *
24 * BSD LICENSE
25 *
26 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
27 * All rights reserved.
28 *
29 * Redistribution and use in source and binary forms, with or without
30 * modification, are permitted provided that the following conditions
31 * are met:
32 *
33 * * Redistributions of source code must retain the above copyright
34 * notice, this list of conditions and the following disclaimer.
35 * * Redistributions in binary form must reproduce the above copyright
36 * notice, this list of conditions and the following disclaimer in
37 * the documentation and/or other materials provided with the
38 * distribution.
39 * * Neither the name of Intel Corporation nor the names of its
40 * contributors may be used to endorse or promote products derived
41 * from this software without specific prior written permission.
42 *
43 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
44 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
45 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
46 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
47 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
48 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
49 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
50 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
51 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
52 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
53 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
54 */
55
56/*
57 * This file contains the implementation of the SCIC_SDS_REMOTE_NODE_TABLE
58 * public, protected, and private methods.
59 */
60#include "remote_node_table.h"
61#include "remote_node_context.h"
62
63/**
64 * sci_remote_node_table_get_group_index()
65 * @remote_node_table: This is the remote node index table from which the
66 * selection will be made.
67 * @group_table_index: This is the index to the group table from which to
68 * search for an available selection.
69 *
70 * This routine will find the bit position in absolute bit terms of the next 32
71 * + bit position. If there are available bits in the first u32 then it is
72 * just bit position. u32 This is the absolute bit position for an available
73 * group.
74 */
75static u32 sci_remote_node_table_get_group_index(
76 struct sci_remote_node_table *remote_node_table,
77 u32 group_table_index)
78{
79 u32 dword_index;
80 u32 *group_table;
81 u32 bit_index;
82
83 group_table = remote_node_table->remote_node_groups[group_table_index];
84
85 for (dword_index = 0; dword_index < remote_node_table->group_array_size; dword_index++) {
86 if (group_table[dword_index] != 0) {
87 for (bit_index = 0; bit_index < 32; bit_index++) {
88 if ((group_table[dword_index] & (1 << bit_index)) != 0) {
89 return (dword_index * 32) + bit_index;
90 }
91 }
92 }
93 }
94
95 return SCIC_SDS_REMOTE_NODE_TABLE_INVALID_INDEX;
96}
97
98/**
99 * sci_remote_node_table_clear_group_index()
100 * @remote_node_table: This the remote node table in which to clear the
101 * selector.
102 * @group_table_index: This is the remote node selector in which the change will be
103 * made.
104 * @group_index: This is the bit index in the table to be modified.
105 *
106 * This method will clear the group index entry in the specified group index
107 * table. none
108 */
109static void sci_remote_node_table_clear_group_index(
110 struct sci_remote_node_table *remote_node_table,
111 u32 group_table_index,
112 u32 group_index)
113{
114 u32 dword_index;
115 u32 bit_index;
116 u32 *group_table;
117
118 BUG_ON(group_table_index >= SCU_STP_REMOTE_NODE_COUNT);
119 BUG_ON(group_index >= (u32)(remote_node_table->group_array_size * 32));
120
121 dword_index = group_index / 32;
122 bit_index = group_index % 32;
123 group_table = remote_node_table->remote_node_groups[group_table_index];
124
125 group_table[dword_index] = group_table[dword_index] & ~(1 << bit_index);
126}
127
128/**
129 * sci_remote_node_table_set_group_index()
130 * @remote_node_table: This the remote node table in which to set the
131 * selector.
132 * @group_table_index: This is the remote node selector in which the change
133 * will be made.
134 * @group_index: This is the bit position in the table to be modified.
135 *
136 * This method will set the group index bit entry in the specified gropu index
137 * table. none
138 */
139static void sci_remote_node_table_set_group_index(
140 struct sci_remote_node_table *remote_node_table,
141 u32 group_table_index,
142 u32 group_index)
143{
144 u32 dword_index;
145 u32 bit_index;
146 u32 *group_table;
147
148 BUG_ON(group_table_index >= SCU_STP_REMOTE_NODE_COUNT);
149 BUG_ON(group_index >= (u32)(remote_node_table->group_array_size * 32));
150
151 dword_index = group_index / 32;
152 bit_index = group_index % 32;
153 group_table = remote_node_table->remote_node_groups[group_table_index];
154
155 group_table[dword_index] = group_table[dword_index] | (1 << bit_index);
156}
157
158/**
159 * sci_remote_node_table_set_node_index()
160 * @remote_node_table: This is the remote node table in which to modify
161 * the remote node availability.
162 * @remote_node_index: This is the remote node index that is being returned to
163 * the table.
164 *
165 * This method will set the remote to available in the remote node allocation
166 * table. none
167 */
168static void sci_remote_node_table_set_node_index(
169 struct sci_remote_node_table *remote_node_table,
170 u32 remote_node_index)
171{
172 u32 dword_location;
173 u32 dword_remainder;
174 u32 slot_normalized;
175 u32 slot_position;
176
177 BUG_ON(
178 (remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
179 <= (remote_node_index / SCU_STP_REMOTE_NODE_COUNT)
180 );
181
182 dword_location = remote_node_index / SCIC_SDS_REMOTE_NODES_PER_DWORD;
183 dword_remainder = remote_node_index % SCIC_SDS_REMOTE_NODES_PER_DWORD;
184 slot_normalized = (dword_remainder / SCU_STP_REMOTE_NODE_COUNT) * sizeof(u32);
185 slot_position = remote_node_index % SCU_STP_REMOTE_NODE_COUNT;
186
187 remote_node_table->available_remote_nodes[dword_location] |=
188 1 << (slot_normalized + slot_position);
189}
190
191/**
192 * sci_remote_node_table_clear_node_index()
193 * @remote_node_table: This is the remote node table from which to clear
194 * the available remote node bit.
195 * @remote_node_index: This is the remote node index which is to be cleared
196 * from the table.
197 *
198 * This method clears the remote node index from the table of available remote
199 * nodes. none
200 */
201static void sci_remote_node_table_clear_node_index(
202 struct sci_remote_node_table *remote_node_table,
203 u32 remote_node_index)
204{
205 u32 dword_location;
206 u32 dword_remainder;
207 u32 slot_position;
208 u32 slot_normalized;
209
210 BUG_ON(
211 (remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
212 <= (remote_node_index / SCU_STP_REMOTE_NODE_COUNT)
213 );
214
215 dword_location = remote_node_index / SCIC_SDS_REMOTE_NODES_PER_DWORD;
216 dword_remainder = remote_node_index % SCIC_SDS_REMOTE_NODES_PER_DWORD;
217 slot_normalized = (dword_remainder / SCU_STP_REMOTE_NODE_COUNT) * sizeof(u32);
218 slot_position = remote_node_index % SCU_STP_REMOTE_NODE_COUNT;
219
220 remote_node_table->available_remote_nodes[dword_location] &=
221 ~(1 << (slot_normalized + slot_position));
222}
223
224/**
225 * sci_remote_node_table_clear_group()
226 * @remote_node_table: The remote node table from which the slot will be
227 * cleared.
228 * @group_index: The index for the slot that is to be cleared.
229 *
230 * This method clears the entire table slot at the specified slot index. none
231 */
232static void sci_remote_node_table_clear_group(
233 struct sci_remote_node_table *remote_node_table,
234 u32 group_index)
235{
236 u32 dword_location;
237 u32 dword_remainder;
238 u32 dword_value;
239
240 BUG_ON(
241 (remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
242 <= (group_index / SCU_STP_REMOTE_NODE_COUNT)
243 );
244
245 dword_location = group_index / SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
246 dword_remainder = group_index % SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
247
248 dword_value = remote_node_table->available_remote_nodes[dword_location];
249 dword_value &= ~(SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE << (dword_remainder * 4));
250 remote_node_table->available_remote_nodes[dword_location] = dword_value;
251}
252
253/*
254 * sci_remote_node_table_set_group()
255 *
256 * THis method sets an entire remote node group in the remote node table.
257 */
258static void sci_remote_node_table_set_group(
259 struct sci_remote_node_table *remote_node_table,
260 u32 group_index)
261{
262 u32 dword_location;
263 u32 dword_remainder;
264 u32 dword_value;
265
266 BUG_ON(
267 (remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
268 <= (group_index / SCU_STP_REMOTE_NODE_COUNT)
269 );
270
271 dword_location = group_index / SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
272 dword_remainder = group_index % SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
273
274 dword_value = remote_node_table->available_remote_nodes[dword_location];
275 dword_value |= (SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE << (dword_remainder * 4));
276 remote_node_table->available_remote_nodes[dword_location] = dword_value;
277}
278
279/**
280 * sci_remote_node_table_get_group_value()
281 * @remote_node_table: This is the remote node table that for which the group
282 * value is to be returned.
283 * @group_index: This is the group index to use to find the group value.
284 *
285 * This method will return the group value for the specified group index. The
286 * bit values at the specified remote node group index.
287 */
288static u8 sci_remote_node_table_get_group_value(
289 struct sci_remote_node_table *remote_node_table,
290 u32 group_index)
291{
292 u32 dword_location;
293 u32 dword_remainder;
294 u32 dword_value;
295
296 dword_location = group_index / SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
297 dword_remainder = group_index % SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
298
299 dword_value = remote_node_table->available_remote_nodes[dword_location];
300 dword_value &= (SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE << (dword_remainder * 4));
301 dword_value = dword_value >> (dword_remainder * 4);
302
303 return (u8)dword_value;
304}
305
306/**
307 * sci_remote_node_table_initialize()
308 * @remote_node_table: The remote that which is to be initialized.
309 * @remote_node_entries: The number of entries to put in the table.
310 *
311 * This method will initialize the remote node table for use. none
312 */
313void sci_remote_node_table_initialize(
314 struct sci_remote_node_table *remote_node_table,
315 u32 remote_node_entries)
316{
317 u32 index;
318
319 /*
320 * Initialize the raw data we could improve the speed by only initializing
321 * those entries that we are actually going to be used */
322 memset(
323 remote_node_table->available_remote_nodes,
324 0x00,
325 sizeof(remote_node_table->available_remote_nodes)
326 );
327
328 memset(
329 remote_node_table->remote_node_groups,
330 0x00,
331 sizeof(remote_node_table->remote_node_groups)
332 );
333
334 /* Initialize the available remote node sets */
335 remote_node_table->available_nodes_array_size = (u16)
336 (remote_node_entries / SCIC_SDS_REMOTE_NODES_PER_DWORD)
337 + ((remote_node_entries % SCIC_SDS_REMOTE_NODES_PER_DWORD) != 0);
338
339
340 /* Initialize each full DWORD to a FULL SET of remote nodes */
341 for (index = 0; index < remote_node_entries; index++) {
342 sci_remote_node_table_set_node_index(remote_node_table, remote_node_index: index);
343 }
344
345 remote_node_table->group_array_size = (u16)
346 (remote_node_entries / (SCU_STP_REMOTE_NODE_COUNT * 32))
347 + ((remote_node_entries % (SCU_STP_REMOTE_NODE_COUNT * 32)) != 0);
348
349 for (index = 0; index < (remote_node_entries / SCU_STP_REMOTE_NODE_COUNT); index++) {
350 /*
351 * These are all guaranteed to be full slot values so fill them in the
352 * available sets of 3 remote nodes */
353 sci_remote_node_table_set_group_index(remote_node_table, group_table_index: 2, group_index: index);
354 }
355
356 /* Now fill in any remainders that we may find */
357 if ((remote_node_entries % SCU_STP_REMOTE_NODE_COUNT) == 2) {
358 sci_remote_node_table_set_group_index(remote_node_table, group_table_index: 1, group_index: index);
359 } else if ((remote_node_entries % SCU_STP_REMOTE_NODE_COUNT) == 1) {
360 sci_remote_node_table_set_group_index(remote_node_table, group_table_index: 0, group_index: index);
361 }
362}
363
364/**
365 * sci_remote_node_table_allocate_single_remote_node()
366 * @remote_node_table: The remote node table from which to allocate a
367 * remote node.
368 * @group_table_index: The group index that is to be used for the search.
369 *
370 * This method will allocate a single RNi from the remote node table. The
371 * table index will determine from which remote node group table to search.
372 * This search may fail and another group node table can be specified. The
373 * function is designed to allow a serach of the available single remote node
374 * group up to the triple remote node group. If an entry is found in the
375 * specified table the remote node is removed and the remote node groups are
376 * updated. The RNi value or an invalid remote node context if an RNi can not
377 * be found.
378 */
379static u16 sci_remote_node_table_allocate_single_remote_node(
380 struct sci_remote_node_table *remote_node_table,
381 u32 group_table_index)
382{
383 u8 index;
384 u8 group_value;
385 u32 group_index;
386 u16 remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;
387
388 group_index = sci_remote_node_table_get_group_index(
389 remote_node_table, group_table_index);
390
391 /* We could not find an available slot in the table selector 0 */
392 if (group_index != SCIC_SDS_REMOTE_NODE_TABLE_INVALID_INDEX) {
393 group_value = sci_remote_node_table_get_group_value(
394 remote_node_table, group_index);
395
396 for (index = 0; index < SCU_STP_REMOTE_NODE_COUNT; index++) {
397 if (((1 << index) & group_value) != 0) {
398 /* We have selected a bit now clear it */
399 remote_node_index = (u16)(group_index * SCU_STP_REMOTE_NODE_COUNT
400 + index);
401
402 sci_remote_node_table_clear_group_index(
403 remote_node_table, group_table_index, group_index
404 );
405
406 sci_remote_node_table_clear_node_index(
407 remote_node_table, remote_node_index
408 );
409
410 if (group_table_index > 0) {
411 sci_remote_node_table_set_group_index(
412 remote_node_table, group_table_index: group_table_index - 1, group_index
413 );
414 }
415
416 break;
417 }
418 }
419 }
420
421 return remote_node_index;
422}
423
424/**
425 * sci_remote_node_table_allocate_triple_remote_node()
426 * @remote_node_table: This is the remote node table from which to allocate the
427 * remote node entries.
428 * @group_table_index: This is the group table index which must equal two (2)
429 * for this operation.
430 *
431 * This method will allocate three consecutive remote node context entries. If
432 * there are no remaining triple entries the function will return a failure.
433 * The remote node index that represents three consecutive remote node entries
434 * or an invalid remote node context if none can be found.
435 */
436static u16 sci_remote_node_table_allocate_triple_remote_node(
437 struct sci_remote_node_table *remote_node_table,
438 u32 group_table_index)
439{
440 u32 group_index;
441 u16 remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;
442
443 group_index = sci_remote_node_table_get_group_index(
444 remote_node_table, group_table_index);
445
446 if (group_index != SCIC_SDS_REMOTE_NODE_TABLE_INVALID_INDEX) {
447 remote_node_index = (u16)group_index * SCU_STP_REMOTE_NODE_COUNT;
448
449 sci_remote_node_table_clear_group_index(
450 remote_node_table, group_table_index, group_index
451 );
452
453 sci_remote_node_table_clear_group(
454 remote_node_table, group_index
455 );
456 }
457
458 return remote_node_index;
459}
460
461/**
462 * sci_remote_node_table_allocate_remote_node()
463 * @remote_node_table: This is the remote node table from which the remote node
464 * allocation is to take place.
465 * @remote_node_count: This is ther remote node count which is one of
466 * SCU_SSP_REMOTE_NODE_COUNT(1) or SCU_STP_REMOTE_NODE_COUNT(3).
467 *
468 * This method will allocate a remote node that mataches the remote node count
469 * specified by the caller. Valid values for remote node count is
470 * SCU_SSP_REMOTE_NODE_COUNT(1) or SCU_STP_REMOTE_NODE_COUNT(3). u16 This is
471 * the remote node index that is returned or an invalid remote node context.
472 */
473u16 sci_remote_node_table_allocate_remote_node(
474 struct sci_remote_node_table *remote_node_table,
475 u32 remote_node_count)
476{
477 u16 remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;
478
479 if (remote_node_count == SCU_SSP_REMOTE_NODE_COUNT) {
480 remote_node_index =
481 sci_remote_node_table_allocate_single_remote_node(
482 remote_node_table, group_table_index: 0);
483
484 if (remote_node_index == SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX) {
485 remote_node_index =
486 sci_remote_node_table_allocate_single_remote_node(
487 remote_node_table, group_table_index: 1);
488 }
489
490 if (remote_node_index == SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX) {
491 remote_node_index =
492 sci_remote_node_table_allocate_single_remote_node(
493 remote_node_table, group_table_index: 2);
494 }
495 } else if (remote_node_count == SCU_STP_REMOTE_NODE_COUNT) {
496 remote_node_index =
497 sci_remote_node_table_allocate_triple_remote_node(
498 remote_node_table, group_table_index: 2);
499 }
500
501 return remote_node_index;
502}
503
504/**
505 * sci_remote_node_table_release_single_remote_node()
506 * @remote_node_table: This is the remote node table from which the remote node
507 * release is to take place.
508 * @remote_node_index: This is the remote node index that is being released.
509 * This method will free a single remote node index back to the remote node
510 * table. This routine will update the remote node groups
511 */
512static void sci_remote_node_table_release_single_remote_node(
513 struct sci_remote_node_table *remote_node_table,
514 u16 remote_node_index)
515{
516 u32 group_index;
517 u8 group_value;
518
519 group_index = remote_node_index / SCU_STP_REMOTE_NODE_COUNT;
520
521 group_value = sci_remote_node_table_get_group_value(remote_node_table, group_index);
522
523 /*
524 * Assert that we are not trying to add an entry to a slot that is already
525 * full. */
526 BUG_ON(group_value == SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE);
527
528 if (group_value == 0x00) {
529 /*
530 * There are no entries in this slot so it must be added to the single
531 * slot table. */
532 sci_remote_node_table_set_group_index(remote_node_table, group_table_index: 0, group_index);
533 } else if ((group_value & (group_value - 1)) == 0) {
534 /*
535 * There is only one entry in this slot so it must be moved from the
536 * single slot table to the dual slot table */
537 sci_remote_node_table_clear_group_index(remote_node_table, group_table_index: 0, group_index);
538 sci_remote_node_table_set_group_index(remote_node_table, group_table_index: 1, group_index);
539 } else {
540 /*
541 * There are two entries in the slot so it must be moved from the dual
542 * slot table to the tripple slot table. */
543 sci_remote_node_table_clear_group_index(remote_node_table, group_table_index: 1, group_index);
544 sci_remote_node_table_set_group_index(remote_node_table, group_table_index: 2, group_index);
545 }
546
547 sci_remote_node_table_set_node_index(remote_node_table, remote_node_index);
548}
549
550/**
551 * sci_remote_node_table_release_triple_remote_node()
552 * @remote_node_table: This is the remote node table to which the remote node
553 * index is to be freed.
554 * @remote_node_index: This is the remote node index that is being released.
555 *
556 * This method will release a group of three consecutive remote nodes back to
557 * the free remote nodes.
558 */
559static void sci_remote_node_table_release_triple_remote_node(
560 struct sci_remote_node_table *remote_node_table,
561 u16 remote_node_index)
562{
563 u32 group_index;
564
565 group_index = remote_node_index / SCU_STP_REMOTE_NODE_COUNT;
566
567 sci_remote_node_table_set_group_index(
568 remote_node_table, group_table_index: 2, group_index
569 );
570
571 sci_remote_node_table_set_group(remote_node_table, group_index);
572}
573
574/**
575 * sci_remote_node_table_release_remote_node_index()
576 * @remote_node_table: The remote node table to which the remote node index is
577 * to be freed.
578 * @remote_node_count: This is the count of consecutive remote nodes that are
579 * to be freed.
580 * @remote_node_index: This is the remote node index that is being released.
581 *
582 * This method will release the remote node index back into the remote node
583 * table free pool.
584 */
585void sci_remote_node_table_release_remote_node_index(
586 struct sci_remote_node_table *remote_node_table,
587 u32 remote_node_count,
588 u16 remote_node_index)
589{
590 if (remote_node_count == SCU_SSP_REMOTE_NODE_COUNT) {
591 sci_remote_node_table_release_single_remote_node(
592 remote_node_table, remote_node_index);
593 } else if (remote_node_count == SCU_STP_REMOTE_NODE_COUNT) {
594 sci_remote_node_table_release_triple_remote_node(
595 remote_node_table, remote_node_index);
596 }
597}
598
599

source code of linux/drivers/scsi/isci/remote_node_table.c