1*1a59d1b8SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later 21da177e4SLinus Torvalds 31da177e4SLinus Torvalds /* 41da177e4SLinus Torvalds * IBM ASM Service Processor Device Driver 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * Copyright (C) IBM Corporation, 2004 71da177e4SLinus Torvalds * 8d36b6910SAl Viro * Author: Max Asböck <amax@us.ibm.com> 91da177e4SLinus Torvalds */ 101da177e4SLinus Torvalds 111da177e4SLinus Torvalds #include <linux/notifier.h> 121da177e4SLinus Torvalds #include "ibmasm.h" 131da177e4SLinus Torvalds #include "dot_command.h" 1488187605SMax Asbock #include "lowlevel.h" 151da177e4SLinus Torvalds 161da177e4SLinus Torvalds static int suspend_heartbeats = 0; 171da177e4SLinus Torvalds 181da177e4SLinus Torvalds /* 191da177e4SLinus Torvalds * Once the driver indicates to the service processor that it is running 201da177e4SLinus Torvalds * - see send_os_state() - the service processor sends periodic heartbeats 211da177e4SLinus Torvalds * to the driver. The driver must respond to the heartbeats or else the OS 221da177e4SLinus Torvalds * will be rebooted. 231da177e4SLinus Torvalds * In the case of a panic the interrupt handler continues to work and thus 241da177e4SLinus Torvalds * continues to respond to heartbeats, making the service processor believe 251da177e4SLinus Torvalds * the OS is still running and thus preventing a reboot. 261da177e4SLinus Torvalds * To prevent this from happening a callback is added the panic_notifier_list. 271da177e4SLinus Torvalds * Before responding to a heartbeat the driver checks if a panic has happened, 281da177e4SLinus Torvalds * if yes it suspends heartbeat, causing the service processor to reboot as 291da177e4SLinus Torvalds * expected. 301da177e4SLinus Torvalds */ 311da177e4SLinus Torvalds static int panic_happened(struct notifier_block *n, unsigned long val, void *v) 321da177e4SLinus Torvalds { 331da177e4SLinus Torvalds suspend_heartbeats = 1; 341da177e4SLinus Torvalds return 0; 351da177e4SLinus Torvalds } 361da177e4SLinus Torvalds 371da177e4SLinus Torvalds static struct notifier_block panic_notifier = { panic_happened, NULL, 1 }; 381da177e4SLinus Torvalds 391da177e4SLinus Torvalds void ibmasm_register_panic_notifier(void) 401da177e4SLinus Torvalds { 41e041c683SAlan Stern atomic_notifier_chain_register(&panic_notifier_list, &panic_notifier); 421da177e4SLinus Torvalds } 431da177e4SLinus Torvalds 441da177e4SLinus Torvalds void ibmasm_unregister_panic_notifier(void) 451da177e4SLinus Torvalds { 46e041c683SAlan Stern atomic_notifier_chain_unregister(&panic_notifier_list, 47e041c683SAlan Stern &panic_notifier); 481da177e4SLinus Torvalds } 491da177e4SLinus Torvalds 501da177e4SLinus Torvalds 511da177e4SLinus Torvalds int ibmasm_heartbeat_init(struct service_processor *sp) 521da177e4SLinus Torvalds { 5388187605SMax Asbock sp->heartbeat = ibmasm_new_command(sp, HEARTBEAT_BUFFER_SIZE); 541da177e4SLinus Torvalds if (sp->heartbeat == NULL) 551da177e4SLinus Torvalds return -ENOMEM; 561da177e4SLinus Torvalds 571da177e4SLinus Torvalds return 0; 581da177e4SLinus Torvalds } 591da177e4SLinus Torvalds 601da177e4SLinus Torvalds void ibmasm_heartbeat_exit(struct service_processor *sp) 611da177e4SLinus Torvalds { 6288187605SMax Asbock char tsbuf[32]; 6388187605SMax Asbock 646e574195SHarvey Harrison dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); 6588187605SMax Asbock ibmasm_wait_for_response(sp->heartbeat, IBMASM_CMD_TIMEOUT_NORMAL); 666e574195SHarvey Harrison dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); 6788187605SMax Asbock suspend_heartbeats = 1; 681da177e4SLinus Torvalds command_put(sp->heartbeat); 691da177e4SLinus Torvalds } 701da177e4SLinus Torvalds 711da177e4SLinus Torvalds void ibmasm_receive_heartbeat(struct service_processor *sp, void *message, size_t size) 721da177e4SLinus Torvalds { 731da177e4SLinus Torvalds struct command *cmd = sp->heartbeat; 741da177e4SLinus Torvalds struct dot_command_header *header = (struct dot_command_header *)cmd->buffer; 7588187605SMax Asbock char tsbuf[32]; 761da177e4SLinus Torvalds 776e574195SHarvey Harrison dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf)); 781da177e4SLinus Torvalds if (suspend_heartbeats) 791da177e4SLinus Torvalds return; 801da177e4SLinus Torvalds 811da177e4SLinus Torvalds /* return the received dot command to sender */ 821da177e4SLinus Torvalds cmd->status = IBMASM_CMD_PENDING; 831da177e4SLinus Torvalds size = min(size, cmd->buffer_size); 8488187605SMax Asbock memcpy_fromio(cmd->buffer, message, size); 851da177e4SLinus Torvalds header->type = sp_write; 861da177e4SLinus Torvalds ibmasm_exec_command(sp, cmd); 871da177e4SLinus Torvalds } 88