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 *
61 */
62#include "remote_node_table.h"
63#include "remote_node_context.h"
64
65/**
66 *
67 * @remote_node_table: This is the remote node index table from which the
68 *    selection will be made.
69 * @group_table_index: This is the index to the group table from which to
70 *    search for an available selection.
71 *
72 * This routine will find the bit position in absolute bit terms of the next 32
73 * + bit position.  If there are available bits in the first u32 then it is
74 * just bit position. u32 This is the absolute bit position for an available
75 * group.
76 */
77static u32 sci_remote_node_table_get_group_index(
78	struct sci_remote_node_table *remote_node_table,
79	u32 group_table_index)
80{
81	u32 dword_index;
82	u32 *group_table;
83	u32 bit_index;
84
85	group_table = remote_node_table->remote_node_groups[group_table_index];
86
87	for (dword_index = 0; dword_index < remote_node_table->group_array_size; dword_index++) {
88		if (group_table[dword_index] != 0) {
89			for (bit_index = 0; bit_index < 32; bit_index++) {
90				if ((group_table[dword_index] & (1 << bit_index)) != 0) {
91					return (dword_index * 32) + bit_index;
92				}
93			}
94		}
95	}
96
97	return SCIC_SDS_REMOTE_NODE_TABLE_INVALID_INDEX;
98}
99
100/**
101 *
102 * @out]: remote_node_table This the remote node table in which to clear the
103 *    selector.
104 * @set_index: This is the remote node selector in which the change will be
105 *    made.
106 * @group_index: This is the bit index in the table to be modified.
107 *
108 * This method will clear the group index entry in the specified group index
109 * table. none
110 */
111static void sci_remote_node_table_clear_group_index(
112	struct sci_remote_node_table *remote_node_table,
113	u32 group_table_index,
114	u32 group_index)
115{
116	u32 dword_index;
117	u32 bit_index;
118	u32 *group_table;
119
120	BUG_ON(group_table_index >= SCU_STP_REMOTE_NODE_COUNT);
121	BUG_ON(group_index >= (u32)(remote_node_table->group_array_size * 32));
122
123	dword_index = group_index / 32;
124	bit_index   = group_index % 32;
125	group_table = remote_node_table->remote_node_groups[group_table_index];
126
127	group_table[dword_index] = group_table[dword_index] & ~(1 << bit_index);
128}
129
130/**
131 *
132 * @out]: remote_node_table This the remote node table in which to set the
133 *    selector.
134 * @group_table_index: This is the remote node selector in which the change
135 *    will be made.
136 * @group_index: This is the bit position in the table to be modified.
137 *
138 * This method will set the group index bit entry in the specified gropu index
139 * table. none
140 */
141static void sci_remote_node_table_set_group_index(
142	struct sci_remote_node_table *remote_node_table,
143	u32 group_table_index,
144	u32 group_index)
145{
146	u32 dword_index;
147	u32 bit_index;
148	u32 *group_table;
149
150	BUG_ON(group_table_index >= SCU_STP_REMOTE_NODE_COUNT);
151	BUG_ON(group_index >= (u32)(remote_node_table->group_array_size * 32));
152
153	dword_index = group_index / 32;
154	bit_index   = group_index % 32;
155	group_table = remote_node_table->remote_node_groups[group_table_index];
156
157	group_table[dword_index] = group_table[dword_index] | (1 << bit_index);
158}
159
160/**
161 *
162 * @out]: remote_node_table This is the remote node table in which to modify
163 *    the remote node availability.
164 * @remote_node_index: This is the remote node index that is being returned to
165 *    the table.
166 *
167 * This method will set the remote to available in the remote node allocation
168 * table. none
169 */
170static void sci_remote_node_table_set_node_index(
171	struct sci_remote_node_table *remote_node_table,
172	u32 remote_node_index)
173{
174	u32 dword_location;
175	u32 dword_remainder;
176	u32 slot_normalized;
177	u32 slot_position;
178
179	BUG_ON(
180		(remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
181		<= (remote_node_index / SCU_STP_REMOTE_NODE_COUNT)
182		);
183
184	dword_location  = remote_node_index / SCIC_SDS_REMOTE_NODES_PER_DWORD;
185	dword_remainder = remote_node_index % SCIC_SDS_REMOTE_NODES_PER_DWORD;
186	slot_normalized = (dword_remainder / SCU_STP_REMOTE_NODE_COUNT) * sizeof(u32);
187	slot_position   = remote_node_index % SCU_STP_REMOTE_NODE_COUNT;
188
189	remote_node_table->available_remote_nodes[dword_location] |=
190		1 << (slot_normalized + slot_position);
191}
192
193/**
194 *
195 * @out]: remote_node_table This is the remote node table from which to clear
196 *    the available remote node bit.
197 * @remote_node_index: This is the remote node index which is to be cleared
198 *    from the table.
199 *
200 * This method clears the remote node index from the table of available remote
201 * nodes. none
202 */
203static void sci_remote_node_table_clear_node_index(
204	struct sci_remote_node_table *remote_node_table,
205	u32 remote_node_index)
206{
207	u32 dword_location;
208	u32 dword_remainder;
209	u32 slot_position;
210	u32 slot_normalized;
211
212	BUG_ON(
213		(remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
214		<= (remote_node_index / SCU_STP_REMOTE_NODE_COUNT)
215		);
216
217	dword_location  = remote_node_index / SCIC_SDS_REMOTE_NODES_PER_DWORD;
218	dword_remainder = remote_node_index % SCIC_SDS_REMOTE_NODES_PER_DWORD;
219	slot_normalized = (dword_remainder / SCU_STP_REMOTE_NODE_COUNT) * sizeof(u32);
220	slot_position   = remote_node_index % SCU_STP_REMOTE_NODE_COUNT;
221
222	remote_node_table->available_remote_nodes[dword_location] &=
223		~(1 << (slot_normalized + slot_position));
224}
225
226/**
227 *
228 * @out]: remote_node_table The remote node table from which the slot will be
229 *    cleared.
230 * @group_index: The index for the slot that is to be cleared.
231 *
232 * This method clears the entire table slot at the specified slot index. none
233 */
234static void sci_remote_node_table_clear_group(
235	struct sci_remote_node_table *remote_node_table,
236	u32 group_index)
237{
238	u32 dword_location;
239	u32 dword_remainder;
240	u32 dword_value;
241
242	BUG_ON(
243		(remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
244		<= (group_index / SCU_STP_REMOTE_NODE_COUNT)
245		);
246
247	dword_location  = group_index / SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
248	dword_remainder = group_index % SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
249
250	dword_value = remote_node_table->available_remote_nodes[dword_location];
251	dword_value &= ~(SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE << (dword_remainder * 4));
252	remote_node_table->available_remote_nodes[dword_location] = dword_value;
253}
254
255/**
256 *
257 * @remote_node_table:
258 *
259 * THis method sets an entire remote node group in the remote node table.
260 */
261static void sci_remote_node_table_set_group(
262	struct sci_remote_node_table *remote_node_table,
263	u32 group_index)
264{
265	u32 dword_location;
266	u32 dword_remainder;
267	u32 dword_value;
268
269	BUG_ON(
270		(remote_node_table->available_nodes_array_size * SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD)
271		<= (group_index / SCU_STP_REMOTE_NODE_COUNT)
272		);
273
274	dword_location  = group_index / SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
275	dword_remainder = group_index % SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
276
277	dword_value = remote_node_table->available_remote_nodes[dword_location];
278	dword_value |= (SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE << (dword_remainder * 4));
279	remote_node_table->available_remote_nodes[dword_location] = dword_value;
280}
281
282/**
283 *
284 * @remote_node_table: This is the remote node table that for which the group
285 *    value is to be returned.
286 * @group_index: This is the group index to use to find the group value.
287 *
288 * This method will return the group value for the specified group index. The
289 * bit values at the specified remote node group index.
290 */
291static u8 sci_remote_node_table_get_group_value(
292	struct sci_remote_node_table *remote_node_table,
293	u32 group_index)
294{
295	u32 dword_location;
296	u32 dword_remainder;
297	u32 dword_value;
298
299	dword_location  = group_index / SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
300	dword_remainder = group_index % SCIC_SDS_REMOTE_NODE_SETS_PER_DWORD;
301
302	dword_value = remote_node_table->available_remote_nodes[dword_location];
303	dword_value &= (SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE << (dword_remainder * 4));
304	dword_value = dword_value >> (dword_remainder * 4);
305
306	return (u8)dword_value;
307}
308
309/**
310 *
311 * @out]: remote_node_table The remote that which is to be initialized.
312 * @remote_node_entries: The number of entries to put in the table.
313 *
314 * This method will initialize the remote node table for use. none
315 */
316void sci_remote_node_table_initialize(
317	struct sci_remote_node_table *remote_node_table,
318	u32 remote_node_entries)
319{
320	u32 index;
321
322	/*
323	 * Initialize the raw data we could improve the speed by only initializing
324	 * those entries that we are actually going to be used */
325	memset(
326		remote_node_table->available_remote_nodes,
327		0x00,
328		sizeof(remote_node_table->available_remote_nodes)
329		);
330
331	memset(
332		remote_node_table->remote_node_groups,
333		0x00,
334		sizeof(remote_node_table->remote_node_groups)
335		);
336
337	/* Initialize the available remote node sets */
338	remote_node_table->available_nodes_array_size = (u16)
339							(remote_node_entries / SCIC_SDS_REMOTE_NODES_PER_DWORD)
340							+ ((remote_node_entries % SCIC_SDS_REMOTE_NODES_PER_DWORD) != 0);
341
342
343	/* Initialize each full DWORD to a FULL SET of remote nodes */
344	for (index = 0; index < remote_node_entries; index++) {
345		sci_remote_node_table_set_node_index(remote_node_table, index);
346	}
347
348	remote_node_table->group_array_size = (u16)
349					      (remote_node_entries / (SCU_STP_REMOTE_NODE_COUNT * 32))
350					      + ((remote_node_entries % (SCU_STP_REMOTE_NODE_COUNT * 32)) != 0);
351
352	for (index = 0; index < (remote_node_entries / SCU_STP_REMOTE_NODE_COUNT); index++) {
353		/*
354		 * These are all guaranteed to be full slot values so fill them in the
355		 * available sets of 3 remote nodes */
356		sci_remote_node_table_set_group_index(remote_node_table, 2, index);
357	}
358
359	/* Now fill in any remainders that we may find */
360	if ((remote_node_entries % SCU_STP_REMOTE_NODE_COUNT) == 2) {
361		sci_remote_node_table_set_group_index(remote_node_table, 1, index);
362	} else if ((remote_node_entries % SCU_STP_REMOTE_NODE_COUNT) == 1) {
363		sci_remote_node_table_set_group_index(remote_node_table, 0, index);
364	}
365}
366
367/**
368 *
369 * @out]: remote_node_table The remote node table from which to allocate a
370 *    remote node.
371 * @table_index: The group index that is to be used for the search.
372 *
373 * This method will allocate a single RNi from the remote node table.  The
374 * table index will determine from which remote node group table to search.
375 * This search may fail and another group node table can be specified.  The
376 * function is designed to allow a serach of the available single remote node
377 * group up to the triple remote node group.  If an entry is found in the
378 * specified table the remote node is removed and the remote node groups are
379 * updated. The RNi value or an invalid remote node context if an RNi can not
380 * be found.
381 */
382static u16 sci_remote_node_table_allocate_single_remote_node(
383	struct sci_remote_node_table *remote_node_table,
384	u32 group_table_index)
385{
386	u8 index;
387	u8 group_value;
388	u32 group_index;
389	u16 remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;
390
391	group_index = sci_remote_node_table_get_group_index(
392		remote_node_table, group_table_index);
393
394	/* We could not find an available slot in the table selector 0 */
395	if (group_index != SCIC_SDS_REMOTE_NODE_TABLE_INVALID_INDEX) {
396		group_value = sci_remote_node_table_get_group_value(
397			remote_node_table, group_index);
398
399		for (index = 0; index < SCU_STP_REMOTE_NODE_COUNT; index++) {
400			if (((1 << index) & group_value) != 0) {
401				/* We have selected a bit now clear it */
402				remote_node_index = (u16)(group_index * SCU_STP_REMOTE_NODE_COUNT
403							  + index);
404
405				sci_remote_node_table_clear_group_index(
406					remote_node_table, group_table_index, group_index
407					);
408
409				sci_remote_node_table_clear_node_index(
410					remote_node_table, remote_node_index
411					);
412
413				if (group_table_index > 0) {
414					sci_remote_node_table_set_group_index(
415						remote_node_table, group_table_index - 1, group_index
416						);
417				}
418
419				break;
420			}
421		}
422	}
423
424	return remote_node_index;
425}
426
427/**
428 *
429 * @remote_node_table: This is the remote node table from which to allocate the
430 *    remote node entries.
431 * @group_table_index: THis is the group table index which must equal two (2)
432 *    for this operation.
433 *
434 * This method will allocate three consecutive remote node context entries. If
435 * there are no remaining triple entries the function will return a failure.
436 * The remote node index that represents three consecutive remote node entries
437 * or an invalid remote node context if none can be found.
438 */
439static u16 sci_remote_node_table_allocate_triple_remote_node(
440	struct sci_remote_node_table *remote_node_table,
441	u32 group_table_index)
442{
443	u32 group_index;
444	u16 remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;
445
446	group_index = sci_remote_node_table_get_group_index(
447		remote_node_table, group_table_index);
448
449	if (group_index != SCIC_SDS_REMOTE_NODE_TABLE_INVALID_INDEX) {
450		remote_node_index = (u16)group_index * SCU_STP_REMOTE_NODE_COUNT;
451
452		sci_remote_node_table_clear_group_index(
453			remote_node_table, group_table_index, group_index
454			);
455
456		sci_remote_node_table_clear_group(
457			remote_node_table, group_index
458			);
459	}
460
461	return remote_node_index;
462}
463
464/**
465 *
466 * @remote_node_table: This is the remote node table from which the remote node
467 *    allocation is to take place.
468 * @remote_node_count: This is ther remote node count which is one of
469 *    SCU_SSP_REMOTE_NODE_COUNT(1) or SCU_STP_REMOTE_NODE_COUNT(3).
470 *
471 * This method will allocate a remote node that mataches the remote node count
472 * specified by the caller.  Valid values for remote node count is
473 * SCU_SSP_REMOTE_NODE_COUNT(1) or SCU_STP_REMOTE_NODE_COUNT(3). u16 This is
474 * the remote node index that is returned or an invalid remote node context.
475 */
476u16 sci_remote_node_table_allocate_remote_node(
477	struct sci_remote_node_table *remote_node_table,
478	u32 remote_node_count)
479{
480	u16 remote_node_index = SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX;
481
482	if (remote_node_count == SCU_SSP_REMOTE_NODE_COUNT) {
483		remote_node_index =
484			sci_remote_node_table_allocate_single_remote_node(
485				remote_node_table, 0);
486
487		if (remote_node_index == SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX) {
488			remote_node_index =
489				sci_remote_node_table_allocate_single_remote_node(
490					remote_node_table, 1);
491		}
492
493		if (remote_node_index == SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX) {
494			remote_node_index =
495				sci_remote_node_table_allocate_single_remote_node(
496					remote_node_table, 2);
497		}
498	} else if (remote_node_count == SCU_STP_REMOTE_NODE_COUNT) {
499		remote_node_index =
500			sci_remote_node_table_allocate_triple_remote_node(
501				remote_node_table, 2);
502	}
503
504	return remote_node_index;
505}
506
507/**
508 *
509 * @remote_node_table:
510 *
511 * This method will free a single remote node index back to the remote node
512 * table.  This routine will update the remote node groups
513 */
514static void sci_remote_node_table_release_single_remote_node(
515	struct sci_remote_node_table *remote_node_table,
516	u16 remote_node_index)
517{
518	u32 group_index;
519	u8 group_value;
520
521	group_index = remote_node_index / SCU_STP_REMOTE_NODE_COUNT;
522
523	group_value = sci_remote_node_table_get_group_value(remote_node_table, group_index);
524
525	/*
526	 * Assert that we are not trying to add an entry to a slot that is already
527	 * full. */
528	BUG_ON(group_value == SCIC_SDS_REMOTE_NODE_TABLE_FULL_SLOT_VALUE);
529
530	if (group_value == 0x00) {
531		/*
532		 * There are no entries in this slot so it must be added to the single
533		 * slot table. */
534		sci_remote_node_table_set_group_index(remote_node_table, 0, group_index);
535	} else if ((group_value & (group_value - 1)) == 0) {
536		/*
537		 * There is only one entry in this slot so it must be moved from the
538		 * single slot table to the dual slot table */
539		sci_remote_node_table_clear_group_index(remote_node_table, 0, group_index);
540		sci_remote_node_table_set_group_index(remote_node_table, 1, group_index);
541	} else {
542		/*
543		 * There are two entries in the slot so it must be moved from the dual
544		 * slot table to the tripple slot table. */
545		sci_remote_node_table_clear_group_index(remote_node_table, 1, group_index);
546		sci_remote_node_table_set_group_index(remote_node_table, 2, group_index);
547	}
548
549	sci_remote_node_table_set_node_index(remote_node_table, remote_node_index);
550}
551
552/**
553 *
554 * @remote_node_table: This is the remote node table to which the remote node
555 *    index is to be freed.
556 *
557 * This method will release a group of three consecutive remote nodes back to
558 * the free remote nodes.
559 */
560static void sci_remote_node_table_release_triple_remote_node(
561	struct sci_remote_node_table *remote_node_table,
562	u16 remote_node_index)
563{
564	u32 group_index;
565
566	group_index = remote_node_index / SCU_STP_REMOTE_NODE_COUNT;
567
568	sci_remote_node_table_set_group_index(
569		remote_node_table, 2, group_index
570		);
571
572	sci_remote_node_table_set_group(remote_node_table, group_index);
573}
574
575/**
576 *
577 * @remote_node_table: The remote node table to which the remote node index is
578 *    to be freed.
579 * @remote_node_count: This is the count of consecutive remote nodes that are
580 *    to be freed.
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