linux/drivers/net/ethernet/emulex/benet/be_roce.c
Devesh Sharma f41647ef06 RDMA/be2net: Remove open and close entry points
Recently Dough Ledford reported a deadlock happening
between ocrdma-load sequence and NetworkManager service
issueing "open" on be2net interface.

The deadlock happens when any be2net hook (e.g. open/close) is called
in parallel to insmod ocrdma.ko.

A. be2net is sending administrative open/close event to ocrdma holding
   device_list_mutex. It does this from ndo_open/ndo_stop hooks of be2net.
   So sequence of locks is rtnl_lock---> device_list lock

B.  When new ocrdma roce device gets registered, infiniband stack now
    takes rtnl_lock in ib_register_device() in GID initialization routines.
    So sequence of locks in this path is device_list lock ---> rtnl_lock.

This improper locking sequence causes deadlock.

In order to resolve the above deadlock condition, ocrdma intorduced a
patch to stop listening to administrative open/close events generated from
be2net driver. It now depends on link-state-change async-event generated from
CNA. This change leaves behind dead code which used to generate administrative
open/close events. This patch cleans-up all that dead code from be2net.

Reported-by: Doug Ledford <dledford@redhat.com>
CC: Sathya Perla <sathya.perla@avagotech.com>
Signed-off-by: Padmanabh Ratnakar <padmanabh.ratnakar@avagotech.com>
Signed-off-by: Selvin Xavier <selvin.xavier@avagotech.com>
Signed-off-by: Devesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2015-12-28 11:45:55 -05:00

165 lines
4.4 KiB
C

/*
* Copyright (C) 2005 - 2015 Emulex
* All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation. The full GNU General
* Public License is included in this distribution in the file called COPYING.
*
* Contact Information:
* linux-drivers@emulex.com
*
* Emulex
* 3333 Susan Street
* Costa Mesa, CA 92626
*/
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/module.h>
#include "be.h"
#include "be_cmds.h"
static struct ocrdma_driver *ocrdma_drv;
static LIST_HEAD(be_adapter_list);
static DEFINE_MUTEX(be_adapter_list_lock);
static void _be_roce_dev_add(struct be_adapter *adapter)
{
struct be_dev_info dev_info;
int i, num_vec;
struct pci_dev *pdev = adapter->pdev;
if (!ocrdma_drv)
return;
if (ocrdma_drv->be_abi_version != BE_ROCE_ABI_VERSION) {
dev_warn(&pdev->dev, "Cannot initialize RoCE due to ocrdma ABI mismatch\n");
return;
}
if (pdev->device == OC_DEVICE_ID5) {
/* only msix is supported on these devices */
if (!msix_enabled(adapter))
return;
/* DPP region address and length */
dev_info.dpp_unmapped_addr = pci_resource_start(pdev, 2);
dev_info.dpp_unmapped_len = pci_resource_len(pdev, 2);
} else {
dev_info.dpp_unmapped_addr = 0;
dev_info.dpp_unmapped_len = 0;
}
dev_info.pdev = adapter->pdev;
dev_info.db = adapter->db;
dev_info.unmapped_db = adapter->roce_db.io_addr;
dev_info.db_page_size = adapter->roce_db.size;
dev_info.db_total_size = adapter->roce_db.total_size;
dev_info.netdev = adapter->netdev;
memcpy(dev_info.mac_addr, adapter->netdev->dev_addr, ETH_ALEN);
dev_info.dev_family = adapter->sli_family;
if (msix_enabled(adapter)) {
/* provide all the vectors, so that EQ creation response
* can decide which one to use.
*/
num_vec = adapter->num_msix_vec + adapter->num_msix_roce_vec;
dev_info.intr_mode = BE_INTERRUPT_MODE_MSIX;
dev_info.msix.num_vectors = min(num_vec, MAX_MSIX_VECTORS);
/* provide start index of the vector,
* so in case of linear usage,
* it can use the base as starting point.
*/
dev_info.msix.start_vector = adapter->num_evt_qs;
for (i = 0; i < dev_info.msix.num_vectors; i++) {
dev_info.msix.vector_list[i] =
adapter->msix_entries[i].vector;
}
} else {
dev_info.msix.num_vectors = 0;
dev_info.intr_mode = BE_INTERRUPT_MODE_INTX;
}
adapter->ocrdma_dev = ocrdma_drv->add(&dev_info);
}
void be_roce_dev_add(struct be_adapter *adapter)
{
if (be_roce_supported(adapter)) {
INIT_LIST_HEAD(&adapter->entry);
mutex_lock(&be_adapter_list_lock);
list_add_tail(&adapter->entry, &be_adapter_list);
/* invoke add() routine of roce driver only if
* valid driver registered with add method and add() is not yet
* invoked on a given adapter.
*/
_be_roce_dev_add(adapter);
mutex_unlock(&be_adapter_list_lock);
}
}
static void _be_roce_dev_remove(struct be_adapter *adapter)
{
if (ocrdma_drv && ocrdma_drv->remove && adapter->ocrdma_dev)
ocrdma_drv->remove(adapter->ocrdma_dev);
adapter->ocrdma_dev = NULL;
}
void be_roce_dev_remove(struct be_adapter *adapter)
{
if (be_roce_supported(adapter)) {
mutex_lock(&be_adapter_list_lock);
_be_roce_dev_remove(adapter);
list_del(&adapter->entry);
mutex_unlock(&be_adapter_list_lock);
}
}
void be_roce_dev_shutdown(struct be_adapter *adapter)
{
if (be_roce_supported(adapter)) {
mutex_lock(&be_adapter_list_lock);
if (ocrdma_drv && adapter->ocrdma_dev &&
ocrdma_drv->state_change_handler)
ocrdma_drv->state_change_handler(adapter->ocrdma_dev,
BE_DEV_SHUTDOWN);
mutex_unlock(&be_adapter_list_lock);
}
}
int be_roce_register_driver(struct ocrdma_driver *drv)
{
struct be_adapter *dev;
mutex_lock(&be_adapter_list_lock);
if (ocrdma_drv) {
mutex_unlock(&be_adapter_list_lock);
return -EINVAL;
}
ocrdma_drv = drv;
list_for_each_entry(dev, &be_adapter_list, entry) {
struct net_device *netdev;
_be_roce_dev_add(dev);
netdev = dev->netdev;
}
mutex_unlock(&be_adapter_list_lock);
return 0;
}
EXPORT_SYMBOL(be_roce_register_driver);
void be_roce_unregister_driver(struct ocrdma_driver *drv)
{
struct be_adapter *dev;
mutex_lock(&be_adapter_list_lock);
list_for_each_entry(dev, &be_adapter_list, entry) {
if (dev->ocrdma_dev)
_be_roce_dev_remove(dev);
}
ocrdma_drv = NULL;
mutex_unlock(&be_adapter_list_lock);
}
EXPORT_SYMBOL(be_roce_unregister_driver);