[PATCH 3.16 038/370] IB/mlx5: Wait for all async command completions to complete

[Ben Hutchings]

3.16.42-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Eli Cohen <eli@xxxxxxxxxxxx>

commit acbda523884dcf45613bf6818d8ead5180df35c2 upstream.

Wait before continuing unload till all pending mkey async creation requests
are done.

Fixes: e126ba97dba9 ('mlx5: Add driver for Mellanox Connect-IB adapters')
Signed-off-by: Eli Cohen <eli@xxxxxxxxxxxx>
Signed-off-by: Maor Gottlieb <maorg@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/infiniband/hw/mlx5/mr.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -590,6 +590,33 @@ int mlx5_mr_cache_init(struct mlx5_ib_de
 	return 0;
 }
 
+static void wait_for_async_commands(struct mlx5_ib_dev *dev)
+{
+	struct mlx5_mr_cache *cache = &dev->cache;
+	struct mlx5_cache_ent *ent;
+	int total = 0;
+	int i;
+	int j;
+
+	for (i = 0; i < MAX_MR_CACHE_ENTRIES; i++) {
+		ent = &cache->ent[i];
+		for (j = 0 ; j < 1000; j++) {
+			if (!ent->pending)
+				break;
+			msleep(50);
+		}
+	}
+	for (i = 0; i < MAX_MR_CACHE_ENTRIES; i++) {
+		ent = &cache->ent[i];
+		total += ent->pending;
+	}
+
+	if (total)
+		mlx5_ib_warn(dev, "aborted while there are %d pending mr requests\n", total);
+	else
+		mlx5_ib_warn(dev, "done with all pending requests\n");
+}
+
 int mlx5_mr_cache_cleanup(struct mlx5_ib_dev *dev)
 {
 	int i;
@@ -603,6 +630,7 @@ int mlx5_mr_cache_cleanup(struct mlx5_ib
 		clean_keys(dev, i);
 
 	destroy_workqueue(dev->cache.wq);
+	wait_for_async_commands(dev);
 	del_timer_sync(&dev->delay_timer);
 
 	return 0;