Patch "RDMA/mlx5: Fix validation of max_rd_atomic caps for DC" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    RDMA/mlx5: Fix validation of max_rd_atomic caps for DC

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     rdma-mlx5-fix-validation-of-max_rd_atomic-caps-for-d.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 3c95e94eb9f48431d8040f207902f074ddce693e
Author: Maor Gottlieb <maorg@xxxxxxxxxx>
Date:   Wed Dec 28 14:56:10 2022 +0200

    RDMA/mlx5: Fix validation of max_rd_atomic caps for DC
    
    [ Upstream commit 8de8482fe5732fbef4f5af82bc0c0362c804cd1f ]
    
    Currently, when modifying DC, we validate max_rd_atomic user attribute
    against the RC cap, validate against DC. RC and DC QP types have different
    device limitations.
    
    This can cause userspace created DC QPs to malfunction.
    
    Fixes: c32a4f296e1d ("IB/mlx5: Add support for DC Initiator QP")
    Link: https://lore.kernel.org/r/0c5aee72cea188c3bb770f4207cce7abc9b6fc74.1672231736.git.leonro@xxxxxxxxxx
    Signed-off-by: Maor Gottlieb <maorg@xxxxxxxxxx>
    Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
index e5abbcfc1d57..55b05a3e31b8 100644
--- a/drivers/infiniband/hw/mlx5/qp.c
+++ b/drivers/infiniband/hw/mlx5/qp.c
@@ -4499,6 +4499,40 @@ static bool mlx5_ib_modify_qp_allowed(struct mlx5_ib_dev *dev,
 	return false;
 }
 
+static int validate_rd_atomic(struct mlx5_ib_dev *dev, struct ib_qp_attr *attr,
+			      int attr_mask, enum ib_qp_type qp_type)
+{
+	int log_max_ra_res;
+	int log_max_ra_req;
+
+	if (qp_type == MLX5_IB_QPT_DCI) {
+		log_max_ra_res = 1 << MLX5_CAP_GEN(dev->mdev,
+						   log_max_ra_res_dc);
+		log_max_ra_req = 1 << MLX5_CAP_GEN(dev->mdev,
+						   log_max_ra_req_dc);
+	} else {
+		log_max_ra_res = 1 << MLX5_CAP_GEN(dev->mdev,
+						   log_max_ra_res_qp);
+		log_max_ra_req = 1 << MLX5_CAP_GEN(dev->mdev,
+						   log_max_ra_req_qp);
+	}
+
+	if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC &&
+	    attr->max_rd_atomic > log_max_ra_res) {
+		mlx5_ib_dbg(dev, "invalid max_rd_atomic value %d\n",
+			    attr->max_rd_atomic);
+		return false;
+	}
+
+	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC &&
+	    attr->max_dest_rd_atomic > log_max_ra_req) {
+		mlx5_ib_dbg(dev, "invalid max_dest_rd_atomic value %d\n",
+			    attr->max_dest_rd_atomic);
+		return false;
+	}
+	return true;
+}
+
 int mlx5_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 		      int attr_mask, struct ib_udata *udata)
 {
@@ -4586,21 +4620,8 @@ int mlx5_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 		goto out;
 	}
 
-	if (attr_mask & IB_QP_MAX_QP_RD_ATOMIC &&
-	    attr->max_rd_atomic >
-	    (1 << MLX5_CAP_GEN(dev->mdev, log_max_ra_res_qp))) {
-		mlx5_ib_dbg(dev, "invalid max_rd_atomic value %d\n",
-			    attr->max_rd_atomic);
-		goto out;
-	}
-
-	if (attr_mask & IB_QP_MAX_DEST_RD_ATOMIC &&
-	    attr->max_dest_rd_atomic >
-	    (1 << MLX5_CAP_GEN(dev->mdev, log_max_ra_req_qp))) {
-		mlx5_ib_dbg(dev, "invalid max_dest_rd_atomic value %d\n",
-			    attr->max_dest_rd_atomic);
+	if (!validate_rd_atomic(dev, attr, attr_mask, qp_type))
 		goto out;
-	}
 
 	if (cur_state == new_state && cur_state == IB_QPS_RESET) {
 		err = 0;