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linux-next/drivers/infiniband/hw/mthca/mthca_catas.c
Jack Morgenstein d841064777 IB/mthca: Don't allow userspace open while recovering from catastrophic error
Userspace apps are supposed to release all ib device resources if they
receive a fatal async event (IBV_EVENT_DEVICE_FATAL).  However, the
app has no way of knowing when the device has come back up, except to
repeatedly attempt ibv_open_device() until it succeeds.

However, currently there is no protection against the open succeeding
while the device is in being removed following the fatal event.  In
this case, the open will succeed, but as a result the device waits in
the middle of its removal until the new app releases its resources --
and the new app will not do so, since the open succeeded at a point
following the fatal event generation.

This patch adds an "active" flag to the device. The active flag is set
to false (in the fatal event flow) before the "fatal" event is
generated, so any subsequent ibv_dev_open() call to the device will
fail until the device comes back up, thus preventing the above
deadlock.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
2009-09-05 20:36:16 -07:00

194 lines
5.0 KiB
C

/*
* Copyright (c) 2005 Cisco Systems. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include "mthca_dev.h"
enum {
MTHCA_CATAS_POLL_INTERVAL = 5 * HZ,
MTHCA_CATAS_TYPE_INTERNAL = 0,
MTHCA_CATAS_TYPE_UPLINK = 3,
MTHCA_CATAS_TYPE_DDR = 4,
MTHCA_CATAS_TYPE_PARITY = 5,
};
static DEFINE_SPINLOCK(catas_lock);
static LIST_HEAD(catas_list);
static struct workqueue_struct *catas_wq;
static struct work_struct catas_work;
static int catas_reset_disable;
module_param_named(catas_reset_disable, catas_reset_disable, int, 0644);
MODULE_PARM_DESC(catas_reset_disable, "disable reset on catastrophic event if nonzero");
static void catas_reset(struct work_struct *work)
{
struct mthca_dev *dev, *tmpdev;
LIST_HEAD(tlist);
int ret;
mutex_lock(&mthca_device_mutex);
spin_lock_irq(&catas_lock);
list_splice_init(&catas_list, &tlist);
spin_unlock_irq(&catas_lock);
list_for_each_entry_safe(dev, tmpdev, &tlist, catas_err.list) {
ret = __mthca_restart_one(dev->pdev);
if (ret)
mthca_err(dev, "Reset failed (%d)\n", ret);
else
mthca_dbg(dev, "Reset succeeded\n");
}
mutex_unlock(&mthca_device_mutex);
}
static void handle_catas(struct mthca_dev *dev)
{
struct ib_event event;
unsigned long flags;
const char *type;
int i;
event.device = &dev->ib_dev;
event.event = IB_EVENT_DEVICE_FATAL;
event.element.port_num = 0;
dev->active = false;
ib_dispatch_event(&event);
switch (swab32(readl(dev->catas_err.map)) >> 24) {
case MTHCA_CATAS_TYPE_INTERNAL:
type = "internal error";
break;
case MTHCA_CATAS_TYPE_UPLINK:
type = "uplink bus error";
break;
case MTHCA_CATAS_TYPE_DDR:
type = "DDR data error";
break;
case MTHCA_CATAS_TYPE_PARITY:
type = "internal parity error";
break;
default:
type = "unknown error";
break;
}
mthca_err(dev, "Catastrophic error detected: %s\n", type);
for (i = 0; i < dev->catas_err.size; ++i)
mthca_err(dev, " buf[%02x]: %08x\n",
i, swab32(readl(dev->catas_err.map + i)));
if (catas_reset_disable)
return;
spin_lock_irqsave(&catas_lock, flags);
list_add(&dev->catas_err.list, &catas_list);
queue_work(catas_wq, &catas_work);
spin_unlock_irqrestore(&catas_lock, flags);
}
static void poll_catas(unsigned long dev_ptr)
{
struct mthca_dev *dev = (struct mthca_dev *) dev_ptr;
int i;
for (i = 0; i < dev->catas_err.size; ++i)
if (readl(dev->catas_err.map + i)) {
handle_catas(dev);
return;
}
mod_timer(&dev->catas_err.timer,
round_jiffies(jiffies + MTHCA_CATAS_POLL_INTERVAL));
}
void mthca_start_catas_poll(struct mthca_dev *dev)
{
unsigned long addr;
init_timer(&dev->catas_err.timer);
dev->catas_err.map = NULL;
addr = pci_resource_start(dev->pdev, 0) +
((pci_resource_len(dev->pdev, 0) - 1) &
dev->catas_err.addr);
dev->catas_err.map = ioremap(addr, dev->catas_err.size * 4);
if (!dev->catas_err.map) {
mthca_warn(dev, "couldn't map catastrophic error region "
"at 0x%lx/0x%x\n", addr, dev->catas_err.size * 4);
return;
}
dev->catas_err.timer.data = (unsigned long) dev;
dev->catas_err.timer.function = poll_catas;
dev->catas_err.timer.expires = jiffies + MTHCA_CATAS_POLL_INTERVAL;
INIT_LIST_HEAD(&dev->catas_err.list);
add_timer(&dev->catas_err.timer);
}
void mthca_stop_catas_poll(struct mthca_dev *dev)
{
del_timer_sync(&dev->catas_err.timer);
if (dev->catas_err.map)
iounmap(dev->catas_err.map);
spin_lock_irq(&catas_lock);
list_del(&dev->catas_err.list);
spin_unlock_irq(&catas_lock);
}
int __init mthca_catas_init(void)
{
INIT_WORK(&catas_work, catas_reset);
catas_wq = create_singlethread_workqueue("mthca_catas");
if (!catas_wq)
return -ENOMEM;
return 0;
}
void mthca_catas_cleanup(void)
{
destroy_workqueue(catas_wq);
}