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Diffstat (limited to 'drivers/scsi/isci/remote_node_table.c')
| -rw-r--r-- | drivers/scsi/isci/remote_node_table.c | 598 |
1 files changed, 598 insertions, 0 deletions
diff --git a/drivers/scsi/isci/remote_node_table.c b/drivers/scsi/isci/remote_node_table.c new file mode 100644 index 000000000..301b31419 --- /dev/null +++ b/drivers/scsi/isci/remote_node_table.c @@ -0,0 +1,598 @@ +/* + * 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); + } +} + |