LXR linux/drivers/misc/ibmasm/r

   1
   2/*
   3 * This program is free software; you can redistribute it and/or modify
   4 * it under the terms of the GNU General Public License as published by
   5 * the Free Software Foundation; either version 2 of the License, or
   6 * (at your option) any later version.
   7 *
   8 * This program is distributed in the hope that it will be useful,
   9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 * GNU General Public License for more details.
  12 *
  13 * You should have received a copy of the GNU General Public License
  14 * along with this program; if not, write to the Free Software
  15 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  16 *
  17 * Copyright (C) IBM Corporation, 2004
  18 *
  19 * Author: Max Asböck <amax@us.ibm.com>
  20 *
  21 */
  22
  23#include <linux/sched.h>
  24#include "ibmasm.h"
  25#include "dot_command.h"
  26
  27/*
  28 * Reverse Heartbeat, i.e. heartbeats sent from the driver to the
  29 * service processor.
  30 * These heartbeats are initiated by user level programs.
  31 */
  32
  33/* the reverse heartbeat dot command */
  34#pragma pack(1)
  35static struct {
  36        struct dot_command_header       header;
  37        unsigned char                   command[3];
  38} rhb_dot_cmd = {
  39        .header = {
  40                .type =         sp_read,
  41                .command_size = 3,
  42                .data_size =    0,
  43                .status =       0
  44        },
  45        .command = { 4, 3, 6 }
  46};
  47#pragma pack()
  48
  49void ibmasm_init_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb)
  50{
  51        init_waitqueue_head(&rhb->wait);
  52        rhb->stopped = 0;
  53}
  54
  55/**
  56 * start_reverse_heartbeat
  57 * Loop forever, sending a reverse heartbeat dot command to the service
  58 * processor, then sleeping. The loop comes to an end if the service
  59 * processor fails to respond 3 times or we were interrupted.
  60 */
  61int ibmasm_start_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb)
  62{
  63        struct command *cmd;
  64        int times_failed = 0;
  65        int result = 1;
  66
  67        cmd = ibmasm_new_command(sp, sizeof rhb_dot_cmd);
  68        if (!cmd)
  69                return -ENOMEM;
  70
  71        while (times_failed < 3) {
  72                memcpy(cmd->buffer, (void *)&rhb_dot_cmd, sizeof rhb_dot_cmd);
  73                cmd->status = IBMASM_CMD_PENDING;
  74                ibmasm_exec_command(sp, cmd);
  75                ibmasm_wait_for_response(cmd, IBMASM_CMD_TIMEOUT_NORMAL);
  76
  77                if (cmd->status != IBMASM_CMD_COMPLETE)
  78                        times_failed++;
  79
  80                wait_event_interruptible_timeout(rhb->wait,
  81                        rhb->stopped,
  82                        REVERSE_HEARTBEAT_TIMEOUT * HZ);
  83
  84                if (signal_pending(current) || rhb->stopped) {
  85                        result = -EINTR;
  86                        break;
  87                }
  88        }
  89        command_put(cmd);
  90        rhb->stopped = 0;
  91
  92        return result;
  93}
  94
  95void ibmasm_stop_reverse_heartbeat(struct reverse_heartbeat *rhb)
  96{
  97        rhb->stopped = 1;
  98        wake_up_interruptible(&rhb->wait);
  99}
 100