IB/mlx5: Remove support for IB_DEVICE_LOCAL_DMA_LKEY

Commit 96249d70dd70 ("IB/core: Guarantee that a local_dma_lkey
is available") allows ULPs that make use of the local dma key to keep
working as before by allocating a DMA MR with local permissions and
converted these consumers to use the MR associated with the PD
rather then device->local_dma_lkey.

ConnectIB has some known issues with memory registration
using the local_dma_lkey (SEND, RDMA, RECV seems to work ok).

Thus don't expose support for it (remove device->local_dma_lkey
setting), and take advantage of the above commit such that no regression
is introduced to working systems.

The local_dma_lkey support will be restored in CX4 depending on FW
capability query.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/mlx5/main.c

@@ -245,7 +245,6 @@ static int mlx5_ib_query_device(struct ib_device *ibdev,
 		props->device_cap_flags |= IB_DEVICE_BAD_QKEY_CNTR;
 	if (MLX5_CAP_GEN(mdev, apm))
 		props->device_cap_flags |= IB_DEVICE_AUTO_PATH_MIG;
-	props->device_cap_flags |= IB_DEVICE_LOCAL_DMA_LKEY;
 	if (MLX5_CAP_GEN(mdev, xrc))
 		props->device_cap_flags |= IB_DEVICE_XRC;
 	props->device_cap_flags |= IB_DEVICE_MEM_MGT_EXTENSIONS;
@@ -1245,18 +1244,10 @@ static int create_dev_resources(struct mlx5_ib_resources *devr)
 	struct ib_srq_init_attr attr;
 	struct mlx5_ib_dev *dev;
 	struct ib_cq_init_attr cq_attr = {.cqe = 1};
-	u32 rsvd_lkey;
 	int ret = 0;
 
 	dev = container_of(devr, struct mlx5_ib_dev, devr);
 
-	ret = mlx5_core_query_special_context(dev->mdev, &rsvd_lkey);
-	if (ret) {
-		pr_err("Failed to query special context %d\n", ret);
-		return ret;
-	}
-	dev->ib_dev.local_dma_lkey = rsvd_lkey;
-
 	devr->p0 = mlx5_ib_alloc_pd(&dev->ib_dev, NULL, NULL);
 	if (IS_ERR(devr->p0)) {
 		ret = PTR_ERR(devr->p0);
@@ -1418,6 +1409,7 @@ static void *mlx5_ib_add(struct mlx5_core_dev *mdev)
 	strlcpy(dev->ib_dev.name, "mlx5_%d", IB_DEVICE_NAME_MAX);
 	dev->ib_dev.owner		= THIS_MODULE;
 	dev->ib_dev.node_type		= RDMA_NODE_IB_CA;
+	dev->ib_dev.local_dma_lkey	= 0 /* not supported for now */;
 	dev->num_ports		= MLX5_CAP_GEN(mdev, num_ports);
 	dev->ib_dev.phys_port_cnt     = dev->num_ports;
 	dev->ib_dev.num_comp_vectors    =

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

@@ -200,25 +200,3 @@ int mlx5_cmd_teardown_hca(struct mlx5_core_dev *dev)
 
 	return err;
 }
-
-int mlx5_core_query_special_context(struct mlx5_core_dev *dev, u32 *rsvd_lkey)
-{
-	struct mlx5_cmd_query_special_contexts_mbox_in in;
-	struct mlx5_cmd_query_special_contexts_mbox_out out;
-	int err;
-
-	memset(&in, 0, sizeof(in));
-	memset(&out, 0, sizeof(out));
-	in.hdr.opcode = cpu_to_be16(MLX5_CMD_OP_QUERY_SPECIAL_CONTEXTS);
-	err = mlx5_cmd_exec(dev, &in, sizeof(in), &out, sizeof(out));
-	if (err)
-		return err;
-
-	if (out.hdr.status)
-		err = mlx5_cmd_status_to_err(&out.hdr);
-
-	*rsvd_lkey = be32_to_cpu(out.resd_lkey);
-
-	return err;
-}
-EXPORT_SYMBOL(mlx5_core_query_special_context);

include/linux/mlx5/device.h

@@ -402,17 +402,6 @@ struct mlx5_cmd_teardown_hca_mbox_out {
 	u8			rsvd[8];
 };
 
-struct mlx5_cmd_query_special_contexts_mbox_in {
-	struct mlx5_inbox_hdr	hdr;
-	u8			rsvd[8];
-};
-
-struct mlx5_cmd_query_special_contexts_mbox_out {
-	struct mlx5_outbox_hdr	hdr;
-	__be32                  dump_fill_mkey;
-	__be32                  resd_lkey;
-};
-
 struct mlx5_cmd_layout {
 	u8		type;
 	u8		rsvd0[3];

include/linux/mlx5/driver.h

@@ -845,7 +845,6 @@ void *mlx5_get_protocol_dev(struct mlx5_core_dev *mdev, int protocol);
 int mlx5_register_interface(struct mlx5_interface *intf);
 void mlx5_unregister_interface(struct mlx5_interface *intf);
 int mlx5_core_query_vendor_id(struct mlx5_core_dev *mdev, u32 *vendor_id);
-int mlx5_core_query_special_context(struct mlx5_core_dev *dev, u32 *rsvd_lkey);
 
 struct mlx5_profile {
 	u64	mask;