RDMA/uverbs: Implement an ioctl that can call write and write_ex handlers

Now that the handlers do not process their own udata we can make a
sensible ioctl that wrappers them. The ioctl follows the same format as
the write_ex() and has the user explicitly specify the core and driver
in/out opaque structures and a command number.

This works for all forms of write commands.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 60 insertions, 0 deletions

diff --git a/drivers/infiniband/core/uverbs_std_types_device.c b/drivers/infiniband/core/uverbs_std_types_device.c
new file mode 100644
index 000000000000..aafb251b7d37
--- /dev/null
+++ b/drivers/infiniband/core/uverbs_std_types_device.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/*
+ * Copyright (c) 2018, Mellanox Technologies inc.  All rights reserved.
+ */
+
+#include <rdma/uverbs_std_types.h>
+#include "rdma_core.h"
+#include "uverbs.h"
+
+/*
+ * This ioctl method allows calling any defined write or write_ex
+ * handler. This essentially replaces the hdr/ex_hdr system with the ioctl
+ * marshalling, and brings the non-ex path into the same marshalling as the ex
+ * path.
+ */
+static int UVERBS_HANDLER(UVERBS_METHOD_INVOKE_WRITE)(
+	struct uverbs_attr_bundle *attrs)
+{
+	struct uverbs_api *uapi = attrs->ufile->device->uapi;
+	const struct uverbs_api_write_method *method_elm;
+	u32 cmd;
+	int rc;
+
+	rc = uverbs_get_const(&cmd, attrs, UVERBS_ATTR_WRITE_CMD);
+	if (rc)
+		return rc;
+
+	method_elm = uapi_get_method(uapi, cmd);
+	if (IS_ERR(method_elm))
+		return PTR_ERR(method_elm);
+
+	uverbs_fill_udata(attrs, &attrs->ucore, UVERBS_ATTR_CORE_IN,
+			  UVERBS_ATTR_CORE_OUT);
+
+	if (attrs->ucore.inlen < method_elm->req_size ||
+	    attrs->ucore.outlen < method_elm->resp_size)
+		return -ENOSPC;
+
+	return method_elm->handler(attrs);
+}
+
+DECLARE_UVERBS_NAMED_METHOD(UVERBS_METHOD_INVOKE_WRITE,
+			    UVERBS_ATTR_CONST_IN(UVERBS_ATTR_WRITE_CMD,
+						 enum ib_uverbs_write_cmds,
+						 UA_MANDATORY),
+			    UVERBS_ATTR_PTR_IN(UVERBS_ATTR_CORE_IN,
+					       UVERBS_ATTR_MIN_SIZE(sizeof(u32)),
+					       UA_OPTIONAL),
+			    UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_CORE_OUT,
+						UVERBS_ATTR_MIN_SIZE(0),
+						UA_OPTIONAL),
+			    UVERBS_ATTR_UHW());
+
+DECLARE_UVERBS_GLOBAL_METHODS(UVERBS_OBJECT_DEVICE,
+			      &UVERBS_METHOD(UVERBS_METHOD_INVOKE_WRITE));
+
+const struct uapi_definition uverbs_def_obj_device[] = {
+	UAPI_DEF_CHAIN_OBJ_TREE_NAMED(UVERBS_OBJECT_DEVICE),
+	{},
+};