/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2004-2009 Silicon Graphics, Inc. All Rights Reserved.
*/
/*
* Cross Partition Communication (XPC) support - standard version.
*
* XPC provides a message passing capability that crosses partition
* boundaries. This module is made up of two parts:
*
* partition This part detects the presence/absence of other
* partitions. It provides a heartbeat and monitors
* the heartbeats of other partitions.
*
* channel This part manages the channels and sends/receives
* messages across them to/from other partitions.
*
* There are a couple of additional functions residing in XP, which
* provide an interface to XPC for its users.
*
*
* Caveats:
*
* . Currently on sn2, we have no way to determine which nasid an IRQ
* came from. Thus, xpc_send_IRQ_sn2() does a remote amo write
* followed by an IPI. The amo indicates where data is to be pulled
* from, so after the IPI arrives, the remote partition checks the amo
* word. The IPI can actually arrive before the amo however, so other
* code must periodically check for this case. Also, remote amo
* operations do not reliably time out. Thus we do a remote PIO read
* solely to know whether the remote partition is down and whether we
* should stop sending IPIs to it. This remote PIO read operation is
* set up in a special nofault region so SAL knows to ignore (and
* cleanup) any errors due to the remote amo write, PIO read, and/or
* PIO write operations.
*
* If/when new hardware solves this IPI problem, we should abandon
* the current approach.
*
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sysctl.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/kdebug.h>
#include <linux/kthread.h>
#include "xpc.h"
/* define two XPC debug device structures to be used with dev_dbg() et al */
struct device_driver xpc_dbg_name = {
.name = "xpc"
};
struct device xpc_part_dbg_subname = {
.init_name = "", /* set to "part" at xpc_init() time */
.driver = &xpc_dbg_name
};
struct device xpc_chan_dbg_subname = {
.init_name = "", /* set to "chan" at xpc_init() time */
.driver = &xpc_dbg_name
};
struct device *xpc_part = &xpc_part_dbg_subname;
struct device *xpc_chan = &xpc_chan_dbg_subname;
static int xpc_kdebug_ignore;
/* systune related variables for /proc/sys directories */
static int xpc_hb_interval = XPC_HB_DEFAULT_INTERVAL;
static int xpc_hb_min_interval = 1;
static int xpc_hb_max_interval = 10;
static int xpc_hb_check_interval = XPC_HB_CHECK_DEFAULT_INTERVAL;
static int xpc_hb_check_min_interval = 10;
static int xpc_hb_check_max_interval = 120;
int xpc_disengage_timelimit = XPC_DISENGAGE_DEFAULT_TIMELIMIT;
static int xpc_disengage_min_timelimit; /* = 0 */
static int xpc_disengage_max_timelimit = 120;
static ctl_table xpc_sys_xpc_hb_dir[] = {
{
.procname = "hb_interval",
.data = &xpc_hb_interval,
.maxlen