net/mlx4_core: Disallow releasing VF QPs which have steering rules

VF QPs must not be released when they have steering rules attached to them.

For that end, introduce a reference count field to the QP object in the
SRIOV resource tracker which is incremented/decremented when steering rules
are attached/detached to it. QPs can be released by VF only when their
ref count is zero.

Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
index b0ccdb5..1391b52 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
+++ b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
@@ -99,6 +99,7 @@ struct res_qp {
        struct list_head        mcg_list;
        spinlock_t              mcg_spl;
        int                     local_qpn;
+       atomic_t                ref_count;
 };
 
 enum res_mtt_states {
@@ -197,6 +198,7 @@ enum res_fs_rule_states {
 
 struct res_fs_rule {
        struct res_common       com;
+       int                     qpn;
 };
 
 static void *res_tracker_lookup(struct rb_root *root, u64 res_id)
@@ -447,6 +449,7 @@ static struct res_common *alloc_qp_tr(int id)
        ret->local_qpn = id;
        INIT_LIST_HEAD(&ret->mcg_list);
        spin_lock_init(&ret->mcg_spl);
+       atomic_set(&ret->ref_count, 0);
 
        return &ret->com;
 }
@@ -554,7 +557,7 @@ static struct res_common *alloc_xrcdn_tr(int id)
        return &ret->com;
 }
 
-static struct res_common *alloc_fs_rule_tr(u64 id)
+static struct res_common *alloc_fs_rule_tr(u64 id, int qpn)
 {
        struct res_fs_rule *ret;
 
@@ -564,7 +567,7 @@ static struct res_common *alloc_fs_rule_tr(u64 id)
 
        ret->com.res_id = id;
        ret->com.state = RES_FS_RULE_ALLOCATED;
-
+       ret->qpn = qpn;
        return &ret->com;
 }
 
@@ -602,7 +605,7 @@ static struct res_common *alloc_tr(u64 id, enum mlx4_resource type, int slave,
                ret = alloc_xrcdn_tr(id);
                break;
        case RES_FS_RULE:
-               ret = alloc_fs_rule_tr(id);
+               ret = alloc_fs_rule_tr(id, extra);
                break;
        default:
                return NULL;
@@ -671,10 +674,14 @@ undo:
 
 static int remove_qp_ok(struct res_qp *res)
 {
-       if (res->com.state == RES_QP_BUSY)
+       if (res->com.state == RES_QP_BUSY || atomic_read(&res->ref_count) ||
+           !list_empty(&res->mcg_list)) {
+               pr_err("resource tracker: fail to remove qp, state %d, ref_count %d\n",
+                      res->com.state, atomic_read(&res->ref_count));
                return -EBUSY;
-       else if (res->com.state != RES_QP_RESERVED)
+       } else if (res->com.state != RES_QP_RESERVED) {
                return -EPERM;
+       }
 
        return 0;
 }
@@ -3124,6 +3131,7 @@ int mlx4_QP_FLOW_STEERING_ATTACH_wrapper(struct mlx4_dev *dev, int slave,
        struct list_head *rlist = &tracker->slave_list[slave].res_list[RES_MAC];
        int err;
        int qpn;
+       struct res_qp *rqp;
        struct mlx4_net_trans_rule_hw_ctrl *ctrl;
        struct _rule_hw  *rule_header;
        int header_id;
@@ -3134,7 +3142,7 @@ int mlx4_QP_FLOW_STEERING_ATTACH_wrapper(struct mlx4_dev *dev, int slave,
 
        ctrl = (struct mlx4_net_trans_rule_hw_ctrl *)inbox->buf;
        qpn = be32_to_cpu(ctrl->qpn) & 0xffffff;
-       err = get_res(dev, slave, qpn, RES_QP, NULL);
+       err = get_res(dev, slave, qpn, RES_QP, &rqp);
        if (err) {
                pr_err("Steering rule with qpn 0x%x rejected.\n", qpn);
                return err;
@@ -3175,14 +3183,16 @@ int mlx4_QP_FLOW_STEERING_ATTACH_wrapper(struct mlx4_dev *dev, int slave,
        if (err)
                goto err_put;
 
-       err = add_res_range(dev, slave, vhcr->out_param, 1, RES_FS_RULE, 0);
+       err = add_res_range(dev, slave, vhcr->out_param, 1, RES_FS_RULE, qpn);
        if (err) {
                mlx4_err(dev, "Fail to add flow steering resources.\n ");
                /* detach rule*/
                mlx4_cmd(dev, vhcr->out_param, 0, 0,
                         MLX4_QP_FLOW_STEERING_DETACH, MLX4_CMD_TIME_CLASS_A,
                         MLX4_CMD_NATIVE);
+               goto err_put;
        }
+       atomic_inc(&rqp->ref_count);
 err_put:
        put_res(dev, slave, qpn, RES_QP);
        return err;
@@ -3195,20 +3205,35 @@ int mlx4_QP_FLOW_STEERING_DETACH_wrapper(struct mlx4_dev *dev, int slave,
                                         struct mlx4_cmd_info *cmd)
 {
        int err;
+       struct res_qp *rqp;
+       struct res_fs_rule *rrule;
 
        if (dev->caps.steering_mode !=
            MLX4_STEERING_MODE_DEVICE_MANAGED)
                return -EOPNOTSUPP;
 
+       err = get_res(dev, slave, vhcr->in_param, RES_FS_RULE, &rrule);
+       if (err)
+               return err;
+       /* Release the rule form busy state before removal */
+       put_res(dev, slave, vhcr->in_param, RES_FS_RULE);
+       err = get_res(dev, slave, rrule->qpn, RES_QP, &rqp);
+       if (err)
+               return err;
+
        err = rem_res_range(dev, slave, vhcr->in_param, 1, RES_FS_RULE, 0);
        if (err) {
                mlx4_err(dev, "Fail to remove flow steering resources.\n ");
-               return err;
+               goto out;
        }
 
        err = mlx4_cmd(dev, vhcr->in_param, 0, 0,
                       MLX4_QP_FLOW_STEERING_DETACH, MLX4_CMD_TIME_CLASS_A,
                       MLX4_CMD_NATIVE);
+       if (!err)
+               atomic_dec(&rqp->ref_count);
+out:
+       put_res(dev, slave, rrule->qpn, RES_QP);
        return err;
 }