11a59d1b8SThomas 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>
12*f39650deSAndy Shevchenko #include <linux/panic_notifier.h>
131da177e4SLinus Torvalds #include "ibmasm.h"
141da177e4SLinus Torvalds #include "dot_command.h"
1588187605SMax Asbock #include "lowlevel.h"
161da177e4SLinus Torvalds
171da177e4SLinus Torvalds static int suspend_heartbeats = 0;
181da177e4SLinus Torvalds
191da177e4SLinus Torvalds /*
201da177e4SLinus Torvalds * Once the driver indicates to the service processor that it is running
211da177e4SLinus Torvalds * - see send_os_state() - the service processor sends periodic heartbeats
221da177e4SLinus Torvalds * to the driver. The driver must respond to the heartbeats or else the OS
231da177e4SLinus Torvalds * will be rebooted.
241da177e4SLinus Torvalds * In the case of a panic the interrupt handler continues to work and thus
251da177e4SLinus Torvalds * continues to respond to heartbeats, making the service processor believe
261da177e4SLinus Torvalds * the OS is still running and thus preventing a reboot.
271da177e4SLinus Torvalds * To prevent this from happening a callback is added the panic_notifier_list.
281da177e4SLinus Torvalds * Before responding to a heartbeat the driver checks if a panic has happened,
291da177e4SLinus Torvalds * if yes it suspends heartbeat, causing the service processor to reboot as
301da177e4SLinus Torvalds * expected.
311da177e4SLinus Torvalds */
panic_happened(struct notifier_block * n,unsigned long val,void * v)321da177e4SLinus Torvalds static int panic_happened(struct notifier_block *n, unsigned long val, void *v)
331da177e4SLinus Torvalds {
341da177e4SLinus Torvalds suspend_heartbeats = 1;
351da177e4SLinus Torvalds return 0;
361da177e4SLinus Torvalds }
371da177e4SLinus Torvalds
381da177e4SLinus Torvalds static struct notifier_block panic_notifier = { panic_happened, NULL, 1 };
391da177e4SLinus Torvalds
ibmasm_register_panic_notifier(void)401da177e4SLinus Torvalds void ibmasm_register_panic_notifier(void)
411da177e4SLinus Torvalds {
42e041c683SAlan Stern atomic_notifier_chain_register(&panic_notifier_list, &panic_notifier);
431da177e4SLinus Torvalds }
441da177e4SLinus Torvalds
ibmasm_unregister_panic_notifier(void)451da177e4SLinus Torvalds void ibmasm_unregister_panic_notifier(void)
461da177e4SLinus Torvalds {
47e041c683SAlan Stern atomic_notifier_chain_unregister(&panic_notifier_list,
48e041c683SAlan Stern &panic_notifier);
491da177e4SLinus Torvalds }
501da177e4SLinus Torvalds
511da177e4SLinus Torvalds
ibmasm_heartbeat_init(struct service_processor * sp)521da177e4SLinus Torvalds int ibmasm_heartbeat_init(struct service_processor *sp)
531da177e4SLinus Torvalds {
5488187605SMax Asbock sp->heartbeat = ibmasm_new_command(sp, HEARTBEAT_BUFFER_SIZE);
551da177e4SLinus Torvalds if (sp->heartbeat == NULL)
561da177e4SLinus Torvalds return -ENOMEM;
571da177e4SLinus Torvalds
581da177e4SLinus Torvalds return 0;
591da177e4SLinus Torvalds }
601da177e4SLinus Torvalds
ibmasm_heartbeat_exit(struct service_processor * sp)611da177e4SLinus Torvalds void ibmasm_heartbeat_exit(struct service_processor *sp)
621da177e4SLinus Torvalds {
6388187605SMax Asbock char tsbuf[32];
6488187605SMax Asbock
656e574195SHarvey Harrison dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
6688187605SMax Asbock ibmasm_wait_for_response(sp->heartbeat, IBMASM_CMD_TIMEOUT_NORMAL);
676e574195SHarvey Harrison dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
6888187605SMax Asbock suspend_heartbeats = 1;
691da177e4SLinus Torvalds command_put(sp->heartbeat);
701da177e4SLinus Torvalds }
711da177e4SLinus Torvalds
ibmasm_receive_heartbeat(struct service_processor * sp,void * message,size_t size)721da177e4SLinus Torvalds void ibmasm_receive_heartbeat(struct service_processor *sp, void *message, size_t size)
731da177e4SLinus Torvalds {
741da177e4SLinus Torvalds struct command *cmd = sp->heartbeat;
751da177e4SLinus Torvalds struct dot_command_header *header = (struct dot_command_header *)cmd->buffer;
7688187605SMax Asbock char tsbuf[32];
771da177e4SLinus Torvalds
786e574195SHarvey Harrison dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
791da177e4SLinus Torvalds if (suspend_heartbeats)
801da177e4SLinus Torvalds return;
811da177e4SLinus Torvalds
821da177e4SLinus Torvalds /* return the received dot command to sender */
831da177e4SLinus Torvalds cmd->status = IBMASM_CMD_PENDING;
841da177e4SLinus Torvalds size = min(size, cmd->buffer_size);
8588187605SMax Asbock memcpy_fromio(cmd->buffer, message, size);
861da177e4SLinus Torvalds header->type = sp_write;
871da177e4SLinus Torvalds ibmasm_exec_command(sp, cmd);
881da177e4SLinus Torvalds }
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