linux/drivers/scsi/isci/remote_node_table.c

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/*
* 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);
}
}