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.
 */

#include "remote_node_table.h"
#include "remote_node_context.h"

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;
}

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);
}

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);
}

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);
}

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));
}

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;
}

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;
}

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;
}

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);
    }
}

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;
}

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;
}

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;
}

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);
}

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);
}

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);
    }
}