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/signal.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) 35 static 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 49 void 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 */ 61 int 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 95 void ibmasm_stop_reverse_heartbeat(struct reverse_heartbeat *rhb) 96 { 97 rhb->stopped = 1; 98 wake_up_interruptible(&rhb->wait); 99 } 100