From 9ace5e0176f165f04537497143506621d33a0139 Mon Sep 17 00:00:00 2001 From: Eli Cohen Date: Tue, 22 Mar 2011 22:38:48 +0000 Subject: [PATCH] mlx4_core: reserve UARs for userspace consumers Do not allow a kernel consumer to allocate a UAR to serve for blue flame if the number of available UARs gets below MLX4_NUM_RESERVED_UARS (currently 8). This will allow userspace apps to open a device file and run things like ibv_devinfo. Signed-off-by: Eli Cohen Signed-off-by: David S. Miller --- drivers/net/mlx4/pd.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/net/mlx4/pd.c b/drivers/net/mlx4/pd.c index 5210a0f..1286b88 100644 --- a/drivers/net/mlx4/pd.c +++ b/drivers/net/mlx4/pd.c @@ -39,6 +39,10 @@ #include "mlx4.h" #include "icm.h" +enum { + MLX4_NUM_RESERVED_UARS = 8 +}; + int mlx4_pd_alloc(struct mlx4_dev *dev, u32 *pdn) { struct mlx4_priv *priv = mlx4_priv(dev); @@ -104,6 +108,10 @@ int mlx4_bf_alloc(struct mlx4_dev *dev, struct mlx4_bf *bf) if (!list_empty(&priv->bf_list)) uar = list_entry(priv->bf_list.next, struct mlx4_uar, bf_list); else { + if (mlx4_bitmap_avail(&priv->uar_table.bitmap) < MLX4_NUM_RESERVED_UARS) { + err = -ENOMEM; + goto out; + } uar = kmalloc(sizeof *uar, GFP_KERNEL); if (!uar) { err = -ENOMEM; -- 2.7.4