bnx2: Use mutex on slow path cnic calls.

The slow path calls to the cnic driver are sleepable calls so we
cannot use rcu_read_lock().  Use mutex for these slow path calls
instead.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Reviewed-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 6 deletions

diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index b70cc99962fc..06b901152d44 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -399,9 +399,11 @@ static int bnx2_unregister_cnic(struct net_device *dev)
         struct bnx2_napi *bnapi = &bp->bnx2_napi[0];
         struct cnic_eth_dev *cp = &bp->cnic_eth_dev;
 
+        mutex_lock(&bp->cnic_lock);
         cp->drv_state = 0;
         bnapi->cnic_present = 0;
         rcu_assign_pointer(bp->cnic_ops, NULL);
+        mutex_unlock(&bp->cnic_lock);
         synchronize_rcu();
         return 0;
 }
@@ -429,13 +431,13 @@ bnx2_cnic_stop(struct bnx2 *bp)
         struct cnic_ops *c_ops;
         struct cnic_ctl_info info;
 
-        rcu_read_lock();
-        c_ops = rcu_dereference(bp->cnic_ops);
+        mutex_lock(&bp->cnic_lock);
+        c_ops = bp->cnic_ops;
         if (c_ops) {
                 info.cmd = CNIC_CTL_STOP_CMD;
                 c_ops->cnic_ctl(bp->cnic_data, &info);
         }
-        rcu_read_unlock();
+        mutex_unlock(&bp->cnic_lock);
 }
 
 static void
@@ -444,8 +446,8 @@ bnx2_cnic_start(struct bnx2 *bp)
         struct cnic_ops *c_ops;
         struct cnic_ctl_info info;
 
-        rcu_read_lock();
-        c_ops = rcu_dereference(bp->cnic_ops);
+        mutex_lock(&bp->cnic_lock);
+        c_ops = bp->cnic_ops;
         if (c_ops) {
                 if (!(bp->flags & BNX2_FLAG_USING_MSIX)) {
                         struct bnx2_napi *bnapi = &bp->bnx2_napi[0];
@@ -455,7 +457,7 @@ bnx2_cnic_start(struct bnx2 *bp)
                 info.cmd = CNIC_CTL_START_CMD;
                 c_ops->cnic_ctl(bp->cnic_data, &info);
         }
-        rcu_read_unlock();
+        mutex_unlock(&bp->cnic_lock);
 }
 
 #else
@@ -7663,6 +7665,9 @@ bnx2_init_board(struct pci_dev *pdev, struct net_device *dev)
 
         spin_lock_init(&bp->phy_lock);
         spin_lock_init(&bp->indirect_lock);
+#ifdef BCM_CNIC
+        mutex_init(&bp->cnic_lock);
+#endif
         INIT_WORK(&bp->reset_task, bnx2_reset_task);
 
         dev->base_addr = dev->mem_start = pci_resource_start(pdev, 0);