IB/mlx5: Fix long EEH recover time with NVMe offloads

On NVMe offloads connection with many IO queues, EEH takes long time to
recover. The culprit is the synchronize_srcu in the destroy_mkey. The
solution is to use synchronize_srcu only for ODP mkey.

Fixes: b4cfe44 ("IB/mlx5: Implement on demand paging by adding support for MMU notifiers")
Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/mr.c

@@ -73,7 +73,8 @@ static int destroy_mkey(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
 
 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
 	/* Wait until all page fault handlers using the mr complete. */
-	synchronize_srcu(&dev->mr_srcu);
+	if (mr->umem && mr->umem->is_odp)
+		synchronize_srcu(&dev->mr_srcu);
 #endif
 
 	return err;
@@ -237,6 +238,9 @@ static void remove_keys(struct mlx5_ib_dev *dev, int c, int num)
 {
 	struct mlx5_mr_cache *cache = &dev->cache;
 	struct mlx5_cache_ent *ent = &cache->ent[c];
+#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
+	bool odp_mkey_exist = false;
+#endif
 	struct mlx5_ib_mr *tmp_mr;
 	struct mlx5_ib_mr *mr;
 	LIST_HEAD(del_list);
@@ -249,6 +253,10 @@ static void remove_keys(struct mlx5_ib_dev *dev, int c, int num)
 			break;
 		}
 		mr = list_first_entry(&ent->head, struct mlx5_ib_mr, list);
+#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
+		if (mr->umem && mr->umem->is_odp)
+			odp_mkey_exist = true;
+#endif
 		list_move(&mr->list, &del_list);
 		ent->cur--;
 		ent->size--;
@@ -257,7 +265,8 @@ static void remove_keys(struct mlx5_ib_dev *dev, int c, int num)
 	}
 
 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
-	synchronize_srcu(&dev->mr_srcu);
+	if (odp_mkey_exist)
+		synchronize_srcu(&dev->mr_srcu);
 #endif
 
 	list_for_each_entry_safe(mr, tmp_mr, &del_list, list) {
@@ -572,6 +581,7 @@ static void clean_keys(struct mlx5_ib_dev *dev, int c)
 {
 	struct mlx5_mr_cache *cache = &dev->cache;
 	struct mlx5_cache_ent *ent = &cache->ent[c];
+	bool odp_mkey_exist = false;
 	struct mlx5_ib_mr *tmp_mr;
 	struct mlx5_ib_mr *mr;
 	LIST_HEAD(del_list);
@@ -584,6 +594,8 @@ static void clean_keys(struct mlx5_ib_dev *dev, int c)
 			break;
 		}
 		mr = list_first_entry(&ent->head, struct mlx5_ib_mr, list);
+		if (mr->umem && mr->umem->is_odp)
+			odp_mkey_exist = true;
 		list_move(&mr->list, &del_list);
 		ent->cur--;
 		ent->size--;
@@ -592,7 +604,8 @@ static void clean_keys(struct mlx5_ib_dev *dev, int c)
 	}
 
 #ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
-	synchronize_srcu(&dev->mr_srcu);
+	if (odp_mkey_exist)
+		synchronize_srcu(&dev->mr_srcu);
 #endif
 
 	list_for_each_entry_safe(mr, tmp_mr, &del_list, list) {