 d36b691077
			
		
	
	
	d36b691077
	
	
	
		
			
			Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
		
			
				
	
	
		
			101 lines
		
	
	
	
		
			3.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			101 lines
		
	
	
	
		
			3.1 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| 
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| /*
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|  * IBM ASM Service Processor Device Driver
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License as published by
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|  * the Free Software Foundation; either version 2 of the License, or
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|  * (at your option) any later version.
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|  *
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|  * This program is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  * GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public License
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|  * along with this program; if not, write to the Free Software
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|  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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|  *
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|  * Copyright (C) IBM Corporation, 2004
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|  *
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|  * Author: Max Asböck <amax@us.ibm.com>
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|  *
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|  */
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| 
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| #include <linux/notifier.h>
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| #include "ibmasm.h"
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| #include "dot_command.h"
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| #include "lowlevel.h"
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| 
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| static int suspend_heartbeats = 0;
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| 
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| /*
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|  * Once the driver indicates to the service processor that it is running
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|  * - see send_os_state() - the service processor sends periodic heartbeats
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|  * to the driver. The driver must respond to the heartbeats or else the OS
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|  * will be rebooted.
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|  * In the case of a panic the interrupt handler continues to work and thus
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|  * continues to respond to heartbeats, making the service processor believe
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|  * the OS is still running and thus preventing a reboot.
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|  * To prevent this from happening a callback is added the panic_notifier_list.
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|  * Before responding to a heartbeat the driver checks if a panic has happened,
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|  * if yes it suspends heartbeat, causing the service processor to reboot as
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|  * expected.
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|  */
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| static int panic_happened(struct notifier_block *n, unsigned long val, void *v)
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| {
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| 	suspend_heartbeats = 1;
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| 	return 0;
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| }
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| 
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| static struct notifier_block panic_notifier = { panic_happened, NULL, 1 };
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| 
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| void ibmasm_register_panic_notifier(void)
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| {
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| 	atomic_notifier_chain_register(&panic_notifier_list, &panic_notifier);
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| }
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| 
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| void ibmasm_unregister_panic_notifier(void)
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| {
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| 	atomic_notifier_chain_unregister(&panic_notifier_list,
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| 			&panic_notifier);
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| }
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| 
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| 
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| int ibmasm_heartbeat_init(struct service_processor *sp)
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| {
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| 	sp->heartbeat = ibmasm_new_command(sp, HEARTBEAT_BUFFER_SIZE);
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| 	if (sp->heartbeat == NULL)
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| 		return -ENOMEM;
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| 
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| 	return 0;
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| }
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| 
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| void ibmasm_heartbeat_exit(struct service_processor *sp)
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| {
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| 	char tsbuf[32];
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| 
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| 	dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
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| 	ibmasm_wait_for_response(sp->heartbeat, IBMASM_CMD_TIMEOUT_NORMAL);
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| 	dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
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| 	suspend_heartbeats = 1;
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| 	command_put(sp->heartbeat);
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| }
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| 
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| void ibmasm_receive_heartbeat(struct service_processor *sp,  void *message, size_t size)
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| {
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| 	struct command *cmd = sp->heartbeat;
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| 	struct dot_command_header *header = (struct dot_command_header *)cmd->buffer;
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| 	char tsbuf[32];
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| 
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| 	dbg("%s:%d at %s\n", __func__, __LINE__, get_timestamp(tsbuf));
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| 	if (suspend_heartbeats)
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| 		return;
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| 
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| 	/* return the received dot command to sender */
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| 	cmd->status = IBMASM_CMD_PENDING;
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| 	size = min(size, cmd->buffer_size);
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| 	memcpy_fromio(cmd->buffer, message, size);
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| 	header->type = sp_write;
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| 	ibmasm_exec_command(sp, cmd);
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| }
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