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 "ibmasm.h"
  24#include "dot_command.h"
  25
  26/*
  27 * Reverse Heartbeat, i.e. heartbeats sent from the driver to the
  28 * service processor.
  29 * These heartbeats are initiated by user level programs.
  30 */
  31
  32/* the reverse heartbeat dot command */
  33#pragma pack(1)
  34static struct {
  35        struct dot_command_header       header;
  36        unsigned char                   command[3];
  37} rhb_dot_cmd = {
  38        .header = {
  39                .type =         sp_read,
  40                .command_size = 3,
  41                .data_size =    0,
  42                .status =       0
  43        },
  44        .command = { 4, 3, 6 }
  45};
  46#pragma pack()
  47
  48void ibmasm_init_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb)
  49{
  50        init_waitqueue_head(&rhb->wait);
  51        rhb->stopped = 0;
  52}
  53
  54/**
  55 * start_reverse_heartbeat
  56 * Loop forever, sending a reverse heartbeat dot command to the service
  57 * processor, then sleeping. The loop comes to an end if the service
  58 * processor fails to respond 3 times or we were interrupted.
  59 */
  60int ibmasm_start_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb)
  61{
  62        struct command *cmd;
  63        int times_failed = 0;
  64        int result = 1;
  65
  66        cmd = ibmasm_new_command(sp, sizeof rhb_dot_cmd);
  67        if (!cmd)
  68                return -ENOMEM;
  69
  70        while (times_failed < 3) {
  71                memcpy(cmd->buffer, (void *)&rhb_dot_cmd, sizeof rhb_dot_cmd);
  72                cmd->status = IBMASM_CMD_PENDING;
  73                ibmasm_exec_command(sp, cmd);
  74                ibmasm_wait_for_response(cmd, IBMASM_CMD_TIMEOUT_NORMAL);
  75
  76                if (cmd->status != IBMASM_CMD_COMPLETE)
  77                        times_failed++;
  78
  79                wait_event_interruptible_timeout(rhb->wait,
  80                        rhb->stopped,
  81                        REVERSE_HEARTBEAT_TIMEOUT * HZ);
  82
  83                if (signal_pending(current) || rhb->stopped) {
  84                        result = -EINTR;
  85                        break;
  86                }
  87        }
  88        command_put(cmd);
  89        rhb->stopped = 0;
  90
  91        return result;
  92}
  93
  94void ibmasm_stop_reverse_heartbeat(struct reverse_heartbeat *rhb)
  95{
  96        rhb->stopped = 1;
  97        wake_up_interruptible(&rhb->wait);
  98}
  99