From: Jason Gunthorpe <jgg@nvidia.com>
Date: Wed, 4 Nov 2020 17:40:59 -0400
Subject: RDMA/cm: Make the local_id_table xarray non-irq
Patch-mainline: v5.10-rc5
Git-commit: eb73060b971aa04e4f7421b8c9c0363918608b72
References: jsc#SLE-15176

The xarray is never mutated from an IRQ handler, only from work queues
under a spinlock_irq. Thus there is no reason for it be an IRQ type
xarray.

This was copied over from the original IDR code, but the recent rework put
the xarray inside another spinlock_irq which will unbalance the unlocking.

Fixes: c206f8bad15d ("RDMA/cm: Make it clearer how concurrency works in cm_req_handler()")
Link: https://lore.kernel.org/r/0-v1-808b6da3bd3f+1857-cm_xarray_no_irq_jgg@nvidia.com
Reported-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/core/cm.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -859,8 +859,8 @@ static struct cm_id_private *cm_alloc_id
 	atomic_set(&cm_id_priv->work_count, -1);
 	refcount_set(&cm_id_priv->refcount, 1);
 
-	ret = xa_alloc_cyclic_irq(&cm.local_id_table, &id, NULL, xa_limit_32b,
-				  &cm.local_id_next, GFP_KERNEL);
+	ret = xa_alloc_cyclic(&cm.local_id_table, &id, NULL, xa_limit_32b,
+			      &cm.local_id_next, GFP_KERNEL);
 	if (ret < 0)
 		goto error;
 	cm_id_priv->id.local_id = (__force __be32)id ^ cm.random_id_operand;
@@ -878,8 +878,8 @@ error:
  */
 static void cm_finalize_id(struct cm_id_private *cm_id_priv)
 {
-	xa_store_irq(&cm.local_id_table, cm_local_id(cm_id_priv->id.local_id),
-		     cm_id_priv, GFP_KERNEL);
+	xa_store(&cm.local_id_table, cm_local_id(cm_id_priv->id.local_id),
+		 cm_id_priv, GFP_ATOMIC);
 }
 
 struct ib_cm_id *ib_create_cm_id(struct ib_device *device,
@@ -1169,7 +1169,7 @@ retest:
 	spin_unlock(&cm.lock);
 	spin_unlock_irq(&cm_id_priv->lock);
 
-	xa_erase_irq(&cm.local_id_table, cm_local_id(cm_id->local_id));
+	xa_erase(&cm.local_id_table, cm_local_id(cm_id->local_id));
 	cm_deref_id(cm_id_priv);
 	wait_for_completion(&cm_id_priv->comp);
 	while ((work = cm_dequeue_work(cm_id_priv)) != NULL)
@@ -4507,7 +4507,7 @@ static int __init ib_cm_init(void)
 	cm.remote_id_table = RB_ROOT;
 	cm.remote_qp_table = RB_ROOT;
 	cm.remote_sidr_table = RB_ROOT;
-	xa_init_flags(&cm.local_id_table, XA_FLAGS_ALLOC | XA_FLAGS_LOCK_IRQ);
+	xa_init_flags(&cm.local_id_table, XA_FLAGS_ALLOC);
 	get_random_bytes(&cm.random_id_operand, sizeof cm.random_id_operand);
 	INIT_LIST_HEAD(&cm.timewait_list);