linux/drivers/misc/ibmasm/heartbeat.c
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00

88 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* IBM ASM Service Processor Device Driver
*
* Copyright (C) IBM Corporation, 2004
*
* Author: Max Asböck <amax@us.ibm.com>
*/
#include <linux/notifier.h>
#include "ibmasm.h"
#include "dot_command.h"
#include "lowlevel.h"
static int suspend_heartbeats = 0;
/*
* Once the driver indicates to the service processor that it is running
* - see send_os_state() - the service processor sends periodic heartbeats
* to the driver. The driver must respond to the heartbeats or else the OS
* will be rebooted.
* In the case of a panic the interrupt handler continues to work and thus
* continues to respond to heartbeats, making the service processor believe
* the OS is still running and thus preventing a reboot.
* To prevent this from happening a callback is added the panic_notifier_list.
* Before responding to a heartbeat the driver checks if a panic has happened,
* if yes it suspends heartbeat, causing the service processor to reboot as
* expected.
*/
static int panic_happened(struct notifier_block *n, unsigned long val, void *v)
{
suspend_heartbeats = 1;
return 0;
}
static struct notifier_block panic_notifier = { panic_happened, NULL, 1 };
void ibmasm_register_panic_notifier(void)
{
atomic_notifier_chain_register(&panic_notifier_list, &panic_notifier);
}
void ibmasm_unregister_panic_notifier(void)
{
atomic_notifier_chain_unregister(&panic_notifier_list,
&panic_notifier);
}
int ibmasm_heartbeat_init(struct service_processor *sp)
{
sp->heartbeat = ibmasm_new_command(sp, HEARTBEAT_BUFFER_SIZE);
if (sp->heartbeat == NULL)
return -ENOMEM;
return 0;
}
void ibmasm_heartbeat_exit(struct service_processor *sp)
{
char tsbuf[32];
dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
ibmasm_wait_for_response(sp->heartbeat, IBMASM_CMD_TIMEOUT_NORMAL);
dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
suspend_heartbeats = 1;
command_put(sp->heartbeat);
}
void ibmasm_receive_heartbeat(struct service_processor *sp, void *message, size_t size)
{
struct command *cmd = sp->heartbeat;
struct dot_command_header *header = (struct dot_command_header *)cmd->buffer;
char tsbuf[32];
dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
if (suspend_heartbeats)
return;
/* return the received dot command to sender */
cmd->status = IBMASM_CMD_PENDING;
size = min(size, cmd->buffer_size);
memcpy_fromio(cmd->buffer, message, size);
header->type = sp_write;
ibmasm_exec_command(sp, cmd);
}