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1// SPDX-License-Identifier: GPL-2.0-or-later2 3/*4 *5 * Copyright (C) IBM Corporation, 20046 *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 the16 * service processor.17 * These heartbeats are initiated by user level programs.18 */19 20/* the reverse heartbeat dot command */21#pragma pack(1)22static 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 = 031 },32 .command = { 4, 3, 6 }33};34#pragma pack()35 36void 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_heartbeat44 * Loop forever, sending a reverse heartbeat dot command to the service45 * processor, then sleeping. The loop comes to an end if the service46 * processor fails to respond 3 times or we were interrupted.47 */48int 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 82void ibmasm_stop_reverse_heartbeat(struct reverse_heartbeat *rhb)83{84 rhb->stopped = 1;85 wake_up_interruptible(&rhb->wait);86}87