IB/ehca: Rework destroy_eq()

The ibmebus_free_irq() function, which might sleep, was called with
interrupts disabled.  To fix this, make sure that no interrupts are
running by killing the interrupt tasklet.  Also lock the
shca_list_lock to protect against the poll_eqs_timer running
concurrently.

Signed-off-by: Alexander Schmidt <alexs@linux.vnet.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

3 files changed, 8 insertions, 4 deletions

diff --git a/drivers/infiniband/hw/ehca/ehca_classes.h b/drivers/infiniband/hw/ehca/ehca_classes.h
index c825142a2fb7..0136abd50dd4 100644
--- a/drivers/infiniband/hw/ehca/ehca_classes.h
+++ b/drivers/infiniband/hw/ehca/ehca_classes.h
@@ -375,6 +375,7 @@ extern rwlock_t ehca_qp_idr_lock;
 extern rwlock_t ehca_cq_idr_lock;
 extern struct idr ehca_qp_idr;
 extern struct idr ehca_cq_idr;
+extern spinlock_t shca_list_lock;
 
 extern int ehca_static_rate;
 extern int ehca_port_act_time;
diff --git a/drivers/infiniband/hw/ehca/ehca_eq.c b/drivers/infiniband/hw/ehca/ehca_eq.c
index 523e733c630e..3b87589b8ea0 100644
--- a/drivers/infiniband/hw/ehca/ehca_eq.c
+++ b/drivers/infiniband/hw/ehca/ehca_eq.c
@@ -169,12 +169,15 @@ int ehca_destroy_eq(struct ehca_shca *shca, struct ehca_eq *eq)
         unsigned long flags;
         u64 h_ret;
 
-        spin_lock_irqsave(&eq->spinlock, flags);
         ibmebus_free_irq(eq->ist, (void *)shca);
 
-        h_ret = hipz_h_destroy_eq(shca->ipz_hca_handle, eq);
+        spin_lock_irqsave(&shca_list_lock, flags);
+        eq->is_initialized = 0;
+        spin_unlock_irqrestore(&shca_list_lock, flags);
 
-        spin_unlock_irqrestore(&eq->spinlock, flags);
+        tasklet_kill(&eq->interrupt_task);
+
+        h_ret = hipz_h_destroy_eq(shca->ipz_hca_handle, eq);
 
         if (h_ret != H_SUCCESS) {
                 ehca_err(&shca->ib_device, "Can't free EQ resources.");
diff --git a/drivers/infiniband/hw/ehca/ehca_main.c b/drivers/infiniband/hw/ehca/ehca_main.c
index fb2d83c5bf01..129a6bebd6e3 100644
--- a/drivers/infiniband/hw/ehca/ehca_main.c
+++ b/drivers/infiniband/hw/ehca/ehca_main.c
@@ -123,7 +123,7 @@ DEFINE_IDR(ehca_qp_idr);
 DEFINE_IDR(ehca_cq_idr);
 
 static LIST_HEAD(shca_list); /* list of all registered ehcas */
-static DEFINE_SPINLOCK(shca_list_lock);
+DEFINE_SPINLOCK(shca_list_lock);
 
 static struct timer_list poll_eqs_timer;