r_heartbeat.c

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/*
 * 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 <[email protected]>
 *
 */

#include <linux/sched.h>
#include "ibmasm.h"
#include "dot_command.h"

/*
 * Reverse Heartbeat, i.e. heartbeats sent from the driver to the
 * service processor.
 * These heartbeats are initiated by user level programs.
 */

/* the reverse heartbeat dot command */
#pragma pack(1)
static struct {
    struct dot_command_header   header;
    unsigned char           command[3];
} rhb_dot_cmd = {
    .header = {
        .type =     sp_read,
        .command_size = 3,
        .data_size =    0,
        .status =   0
    },
    .command = { 4, 3, 6 }
};
#pragma pack()

void ibmasm_init_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb)
{
    init_waitqueue_head(&rhb->wait);
    rhb->stopped = 0;
}

int ibmasm_start_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb)
{
    struct command *cmd;
    int times_failed = 0;
    int result = 1;

    cmd = ibmasm_new_command(sp, sizeof rhb_dot_cmd);
    if (!cmd)
        return -ENOMEM;

    while (times_failed < 3) {
        memcpy(cmd->buffer, (void *)&rhb_dot_cmd, sizeof rhb_dot_cmd);
        cmd->status = IBMASM_CMD_PENDING;
        ibmasm_exec_command(sp, cmd);
        ibmasm_wait_for_response(cmd, IBMASM_CMD_TIMEOUT_NORMAL);

        if (cmd->status != IBMASM_CMD_COMPLETE)
            times_failed++;

        wait_event_interruptible_timeout(rhb->wait,
            rhb->stopped,
            REVERSE_HEARTBEAT_TIMEOUT * HZ);

        if (signal_pending(current) || rhb->stopped) {
            result = -EINTR;
            break;
        }
    }
    command_put(cmd);
    rhb->stopped = 0;

    return result;
}

void ibmasm_stop_reverse_heartbeat(struct reverse_heartbeat *rhb)
{
    rhb->stopped = 1;
    wake_up_interruptible(&rhb->wait);
}