mlx5_core: Change optimal_reclaimed_pages for better performance

Change optimal_reclaimed_pages() to increase the output size of each
reclaim pages command. This change reduces significantly the amount of
reclaim pages commands issued to FW when the driver is unloaded which
reduces the overall driver unload time.

Signed-off-by: Moshe Lazer <moshel@mellanox.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/net/ethernet/mellanox/mlx5/core/pagealloc.c

@@ -454,14 +454,19 @@ int mlx5_satisfy_startup_pages(struct mlx5_core_dev *dev, int boot)
 	return give_pages(dev, func_id, npages, 0);
 }
 
+enum {
+	MLX5_BLKS_FOR_RECLAIM_PAGES = 12
+};
+
 static int optimal_reclaimed_pages(void)
 {
 	struct mlx5_cmd_prot_block *block;
 	struct mlx5_cmd_layout *lay;
 	int ret;
 
-	ret = (sizeof(lay->in) + sizeof(block->data) -
-	       sizeof(struct mlx5_manage_pages_outbox)) / 8;
+	ret = (sizeof(lay->out) + MLX5_BLKS_FOR_RECLAIM_PAGES * sizeof(block->data) -
+	       sizeof(struct mlx5_manage_pages_outbox)) /
+	       FIELD_SIZEOF(struct mlx5_manage_pages_outbox, pas[0]);
 
 	return ret;
 }