1 files changed, 21 insertions, 29 deletions

diff --git a/drivers/infiniband/hw/ehca/ehca_cq.c b/drivers/infiniband/hw/ehca/ehca_cq.c
index 67f0670fe3b1..01d4a148bd71 100644
--- a/drivers/infiniband/hw/ehca/ehca_cq.c
+++ b/drivers/infiniband/hw/ehca/ehca_cq.c
@@ -56,11 +56,11 @@ int ehca_cq_assign_qp(struct ehca_cq *cq, struct ehca_qp *qp)
 {
         unsigned int qp_num = qp->real_qp_num;
         unsigned int key = qp_num & (QP_HASHTAB_LEN-1);
-        unsigned long spl_flags;
+        unsigned long flags;
 
-        spin_lock_irqsave(&cq->spinlock, spl_flags);
+        spin_lock_irqsave(&cq->spinlock, flags);
         hlist_add_head(&qp->list_entries, &cq->qp_hashtab[key]);
-        spin_unlock_irqrestore(&cq->spinlock, spl_flags);
+        spin_unlock_irqrestore(&cq->spinlock, flags);
 
         ehca_dbg(cq->ib_cq.device, "cq_num=%x real_qp_num=%x",
                  cq->cq_number, qp_num);
@@ -74,9 +74,9 @@ int ehca_cq_unassign_qp(struct ehca_cq *cq, unsigned int real_qp_num)
         unsigned int key = real_qp_num & (QP_HASHTAB_LEN-1);
         struct hlist_node *iter;
         struct ehca_qp *qp;
-        unsigned long spl_flags;
+        unsigned long flags;
 
-        spin_lock_irqsave(&cq->spinlock, spl_flags);
+        spin_lock_irqsave(&cq->spinlock, flags);
         hlist_for_each(iter, &cq->qp_hashtab[key]) {
                 qp = hlist_entry(iter, struct ehca_qp, list_entries);
                 if (qp->real_qp_num == real_qp_num) {
@@ -88,7 +88,7 @@ int ehca_cq_unassign_qp(struct ehca_cq *cq, unsigned int real_qp_num)
                         break;
                 }
         }
-        spin_unlock_irqrestore(&cq->spinlock, spl_flags);
+        spin_unlock_irqrestore(&cq->spinlock, flags);
         if (ret)
                 ehca_err(cq->ib_cq.device,
                          "qp not found cq_num=%x real_qp_num=%x",
@@ -146,6 +146,7 @@ struct ib_cq *ehca_create_cq(struct ib_device *device, int cqe, int comp_vector,
         spin_lock_init(&my_cq->spinlock);
         spin_lock_init(&my_cq->cb_lock);
         spin_lock_init(&my_cq->task_lock);
+        atomic_set(&my_cq->nr_events, 0);
         init_waitqueue_head(&my_cq->wait_completion);
         my_cq->ownpid = current->tgid;
 
@@ -162,9 +163,9 @@ struct ib_cq *ehca_create_cq(struct ib_device *device, int cqe, int comp_vector,
                         goto create_cq_exit1;
                 }
 
-                spin_lock_irqsave(&ehca_cq_idr_lock, flags);
+                write_lock_irqsave(&ehca_cq_idr_lock, flags);
                 ret = idr_get_new(&ehca_cq_idr, my_cq, &my_cq->token);
-                spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);
+                write_unlock_irqrestore(&ehca_cq_idr_lock, flags);
 
         } while (ret == -EAGAIN);
 
@@ -293,9 +294,9 @@ create_cq_exit3:
                          "cq_num=%x h_ret=%lx", my_cq, my_cq->cq_number, h_ret);
 
 create_cq_exit2:
-        spin_lock_irqsave(&ehca_cq_idr_lock, flags);
+        write_lock_irqsave(&ehca_cq_idr_lock, flags);
         idr_remove(&ehca_cq_idr, my_cq->token);
-        spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);
+        write_unlock_irqrestore(&ehca_cq_idr_lock, flags);
 
 create_cq_exit1:
         kmem_cache_free(cq_cache, my_cq);
@@ -303,16 +304,6 @@ create_cq_exit1:
         return cq;
 }
 
-static int get_cq_nr_events(struct ehca_cq *my_cq)
-{
-        int ret;
-        unsigned long flags;
-        spin_lock_irqsave(&ehca_cq_idr_lock, flags);
-        ret = my_cq->nr_events;
-        spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);
-        return ret;
-}
-
 int ehca_destroy_cq(struct ib_cq *cq)
 {
         u64 h_ret;
@@ -339,17 +330,18 @@ int ehca_destroy_cq(struct ib_cq *cq)
                 }
         }
 
-        spin_lock_irqsave(&ehca_cq_idr_lock, flags);
-        while (my_cq->nr_events) {
-                spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);
-                wait_event(my_cq->wait_completion, !get_cq_nr_events(my_cq));
-                spin_lock_irqsave(&ehca_cq_idr_lock, flags);
-                /* recheck nr_events to assure no cqe has just arrived */
-        }
-
+        /*
+         * remove the CQ from the idr first to make sure
+         * no more interrupt tasklets will touch this CQ
+         */
+        write_lock_irqsave(&ehca_cq_idr_lock, flags);
         idr_remove(&ehca_cq_idr, my_cq->token);
-        spin_unlock_irqrestore(&ehca_cq_idr_lock, flags);
+        write_unlock_irqrestore(&ehca_cq_idr_lock, flags);
+
+        /* now wait until all pending events have completed */
+        wait_event(my_cq->wait_completion, !atomic_read(&my_cq->nr_events));
 
+        /* nobody's using our CQ any longer -- we can destroy it */
         h_ret = hipz_h_destroy_cq(adapter_handle, my_cq, 0);
         if (h_ret == H_R_STATE) {
                 /* cq in err: read err data and destroy it forcibly */