1 // SPDX-License-Identifier: GPL-2.0-or-later 2 3 /* 4 * 5 * Copyright (C) IBM Corporation, 2004 6 * 7 * Author: Max Asböck <amax@us.ibm.com> 8 */ 9 10 #include <linux/sched/signal.h> 11 #include "ibmasm.h" 12 #include "dot_command.h" 13 14 /* 15 * Reverse Heartbeat, i.e. heartbeats sent from the driver to the 16 * service processor. 17 * These heartbeats are initiated by user level programs. 18 */ 19 20 /* the reverse heartbeat dot command */ 21 #pragma pack(1) 22 static struct { 23 struct dot_command_header header; 24 unsigned char command[3]; 25 } rhb_dot_cmd = { 26 .header = { 27 .type = sp_read, 28 .command_size = 3, 29 .data_size = 0, 30 .status = 0 31 }, 32 .command = { 4, 3, 6 } 33 }; 34 #pragma pack() 35 36 void ibmasm_init_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb) 37 { 38 init_waitqueue_head(&rhb->wait); 39 rhb->stopped = 0; 40 } 41 42 /* 43 * start_reverse_heartbeat 44 * Loop forever, sending a reverse heartbeat dot command to the service 45 * processor, then sleeping. The loop comes to an end if the service 46 * processor fails to respond 3 times or we were interrupted. 47 */ 48 int ibmasm_start_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb) 49 { 50 struct command *cmd; 51 int times_failed = 0; 52 int result = 1; 53 54 cmd = ibmasm_new_command(sp, sizeof rhb_dot_cmd); 55 if (!cmd) 56 return -ENOMEM; 57 58 while (times_failed < 3) { 59 memcpy(cmd->buffer, (void *)&rhb_dot_cmd, sizeof rhb_dot_cmd); 60 cmd->status = IBMASM_CMD_PENDING; 61 ibmasm_exec_command(sp, cmd); 62 ibmasm_wait_for_response(cmd, IBMASM_CMD_TIMEOUT_NORMAL); 63 64 if (cmd->status != IBMASM_CMD_COMPLETE) 65 times_failed++; 66 67 wait_event_interruptible_timeout(rhb->wait, 68 rhb->stopped, 69 REVERSE_HEARTBEAT_TIMEOUT * HZ); 70 71 if (signal_pending(current) || rhb->stopped) { 72 result = -EINTR; 73 break; 74 } 75 } 76 command_put(cmd); 77 rhb->stopped = 0; 78 79 return result; 80 } 81 82 void ibmasm_stop_reverse_heartbeat(struct reverse_heartbeat *rhb) 83 { 84 rhb->stopped = 1; 85 wake_up_interruptible(&rhb->wait); 86 } 87