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/*

 * IBM ASM Service Processor Device Driver

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

 *

 * Copyright (C) IBM Corporation, 2004

 *

 * Author: Max Asböck <amax@us.ibm.com>

 *

 */

#include "ibmasm.h"

#include "lowlevel.h"

static void exec_next_command(struct service_processor *sp);

static void free_command(struct kobject *kobj);

static struct kobj_type ibmasm_cmd_kobj_type = {

        .release = free_command,

};

static atomic_t command_count = ATOMIC_INIT(0);

struct command *ibmasm_new_command(struct service_processor *sp, size_t buffer_size)

{

        struct command *cmd;

        if (buffer_size > IBMASM_CMD_MAX_BUFFER_SIZE)

                return NULL;

        cmd = kzalloc(sizeof(struct command), GFP_KERNEL);

        if (cmd == NULL)

                return NULL;

        cmd->buffer = kzalloc(buffer_size, GFP_KERNEL);

        if (cmd->buffer == NULL) {

                kfree(cmd);

                return NULL;

        }

        cmd->buffer_size = buffer_size;

        kobject_init(&cmd->kobj);

        cmd->kobj.ktype = &ibmasm_cmd_kobj_type;

        cmd->lock = &sp->lock;

        cmd->status = IBMASM_CMD_PENDING;

        init_waitqueue_head(&cmd->wait);

        INIT_LIST_HEAD(&cmd->queue_node);

        atomic_inc(&command_count);

        dbg("command count: %d\n", atomic_read(&command_count));

        return cmd;

}

static void free_command(struct kobject *kobj)

{

        struct command *cmd = to_command(kobj);

        list_del(&cmd->queue_node);

        atomic_dec(&command_count);

        dbg("command count: %d\n", atomic_read(&command_count));

        kfree(cmd->buffer);

        kfree(cmd);

}

static void enqueue_command(struct service_processor *sp, struct command *cmd)

{

        list_add_tail(&cmd->queue_node, &sp->command_queue);

}

static struct command *dequeue_command(struct service_processor *sp)

{

        struct command *cmd;

        struct list_head *next;

        if (list_empty(&sp->command_queue))

                return NULL;

        next = sp->command_queue.next;

        list_del_init(next);

        cmd = list_entry(next, struct command, queue_node);

        return cmd;

}

static inline void do_exec_command(struct service_processor *sp)

{

        char tsbuf[32];

        dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));

        if (ibmasm_send_i2o_message(sp)) {

                sp->current_command->status = IBMASM_CMD_FAILED;

                wake_up(&sp->current_command->wait);

                command_put(sp->current_command);

                exec_next_command(sp);

        }

}

/**

 * exec_command

 * send a command to a service processor

 * Commands are executed sequentially. One command (sp->current_command)

 * is sent to the service processor. Once the interrupt handler gets a

 * message of type command_response, the message is copied into

 * the current commands buffer,

 */

void ibmasm_exec_command(struct service_processor *sp, struct command *cmd)

{

        unsigned long flags;

        char tsbuf[32];

        dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));

        spin_lock_irqsave(&sp->lock, flags);

        if (!sp->current_command) {

                sp->current_command = cmd;

                command_get(sp->current_command);

                spin_unlock_irqrestore(&sp->lock, flags);

                do_exec_command(sp);

        } else {

                enqueue_command(sp, cmd);

                spin_unlock_irqrestore(&sp->lock, flags);

        }

}

static void exec_next_command(struct service_processor *sp)

{

        unsigned long flags;

        char tsbuf[32];

        dbg("%s:%d at %s\n", __FUNCTION__, __LINE__, get_timestamp(tsbuf));

        spin_lock_irqsave(&sp->lock, flags);

        sp->current_command = dequeue_command(sp);

        if (sp->current_command) {

                command_get(sp->current_command);

                spin_unlock_irqrestore(&sp->lock, flags);

                do_exec_command(sp);

        } else {

                spin_unlock_irqrestore(&sp->lock, flags);

        }

}

/**

 * Sleep until a command has failed or a response has been received

 * and the command status been updated by the interrupt handler.

 * (see receive_response).

 */

void ibmasm_wait_for_response(struct command *cmd, int timeout)

{

        wait_event_interruptible_timeout(cmd->wait,

                                cmd->status == IBMASM_CMD_COMPLETE ||

                                cmd->status == IBMASM_CMD_FAILED,

                                timeout * HZ);

}

/**

 * receive_command_response

 * called by the interrupt handler when a dot command of type command_response

 * was received.

 */

void ibmasm_receive_command_response(struct service_processor *sp, void *response, size_t size)

{

        struct command *cmd = sp->current_command;

        if (!sp->current_command)

                return;

        memcpy_fromio(cmd->buffer, response, min(size, cmd->buffer_size));

        cmd->status = IBMASM_CMD_COMPLETE;

        wake_up(&sp->current_command->wait);

        command_put(sp->current_command);

        exec_next_command(sp);

}