IB/uverbs: Extend CQ to get its own asynchronous event FD

Extend CQ to get its own asynchronous event FD.
The event FD is an optional attribute, in case wasn't given the ufile
event FD will be used.

Link: https://lore.kernel.org/r/20200519072711.257271-4-leon@kernel.orgSigned-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/uverbs.h

@@ -297,6 +297,24 @@ static inline u32 make_port_cap_flags(const struct ib_port_attr *attr)
 	return res;
 }
 
+static inline struct ib_uverbs_async_event_file *
+ib_uverbs_get_async_event(struct uverbs_attr_bundle *attrs,
+			  u16 id)
+{
+	struct ib_uobject *async_ev_file_uobj;
+	struct ib_uverbs_async_event_file *async_ev_file;
+
+	async_ev_file_uobj = uverbs_attr_get_uobject(attrs, id);
+	if (IS_ERR(async_ev_file_uobj))
+		async_ev_file = READ_ONCE(attrs->ufile->default_async_file);
+	else
+		async_ev_file = container_of(async_ev_file_uobj,
+				       struct ib_uverbs_async_event_file,
+				       uobj);
+	if (async_ev_file)
+		uverbs_uobject_get(&async_ev_file->uobj);
+	return async_ev_file;
+}
 
 void copy_port_attr_to_resp(struct ib_port_attr *attr,
 			    struct ib_uverbs_query_port_resp *resp,

drivers/infiniband/core/uverbs_std_types_cq.c

@@ -100,9 +100,8 @@ static int UVERBS_HANDLER(UVERBS_METHOD_CQ_CREATE)(
 		uverbs_uobject_get(ev_file_uobj);
 	}
 
-	obj->uevent.event_file = READ_ONCE(attrs->ufile->default_async_file);
-	if (obj->uevent.event_file)
-		uverbs_uobject_get(&obj->uevent.event_file->uobj);
+	obj->uevent.event_file = ib_uverbs_get_async_event(
+		attrs, UVERBS_ATTR_CREATE_CQ_EVENT_FD);
 
 	if (attr.comp_vector >= attrs->ufile->device->num_comp_vectors) {
 		ret = -EINVAL;
@@ -173,6 +172,10 @@ DECLARE_UVERBS_NAMED_METHOD(
 	UVERBS_ATTR_PTR_OUT(UVERBS_ATTR_CREATE_CQ_RESP_CQE,
 			    UVERBS_ATTR_TYPE(u32),
 			    UA_MANDATORY),
+	UVERBS_ATTR_FD(UVERBS_ATTR_CREATE_CQ_EVENT_FD,
+		       UVERBS_OBJECT_ASYNC_EVENT,
+		       UVERBS_ACCESS_READ,
+		       UA_OPTIONAL),
 	UVERBS_ATTR_UHW());
 
 static int UVERBS_HANDLER(UVERBS_METHOD_CQ_DESTROY)(

include/uapi/rdma/ib_user_ioctl_cmds.h

@@ -95,6 +95,7 @@ enum uverbs_attrs_create_cq_cmd_attr_ids {
 	UVERBS_ATTR_CREATE_CQ_COMP_VECTOR,
 	UVERBS_ATTR_CREATE_CQ_FLAGS,
 	UVERBS_ATTR_CREATE_CQ_RESP_CQE,
+	UVERBS_ATTR_CREATE_CQ_EVENT_FD,
 };
 
 enum uverbs_attrs_destroy_cq_cmd_attr_ids {