IB/mlx5: Introduce MLX5_IB_OBJECT_DEVX_ASYNC_CMD_FD

Introduce MLX5_IB_OBJECT_DEVX_ASYNC_CMD_FD and its initial implementation.

This object is from type class FD and will be used to read DEVX async
commands completion.

The core layer should allow the driver to set object from type FD in a
safe mode, this option was added with a matching comment in place.

Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/mlx5/devx.c b/drivers/infiniband/hw/mlx5/devx.c
index 5a588f3cfb1b..9933bcf83a6b 100644
--- a/drivers/infiniband/hw/mlx5/devx.c
+++ b/drivers/infiniband/hw/mlx5/devx.c
@@ -1168,6 +1168,38 @@ static int UVERBS_HANDLER(MLX5_IB_METHOD_DEVX_OBJ_QUERY)(
 			      cmd_out, cmd_out_len);
 }
 
+struct devx_async_event_queue {
+	spinlock_t		lock;
+	wait_queue_head_t	poll_wait;
+	struct list_head	event_list;
+};
+
+struct devx_async_cmd_event_file {
+	struct ib_uobject		uobj;
+	struct devx_async_event_queue	ev_queue;
+};
+
+static void devx_init_event_queue(struct devx_async_event_queue *ev_queue)
+{
+	spin_lock_init(&ev_queue->lock);
+	INIT_LIST_HEAD(&ev_queue->event_list);
+	init_waitqueue_head(&ev_queue->poll_wait);
+}
+
+static int UVERBS_HANDLER(MLX5_IB_METHOD_DEVX_ASYNC_CMD_FD_ALLOC)(
+	struct uverbs_attr_bundle *attrs)
+{
+	struct devx_async_cmd_event_file *ev_file;
+
+	struct ib_uobject *uobj = uverbs_attr_get_uobject(
+		attrs, MLX5_IB_ATTR_DEVX_ASYNC_CMD_FD_ALLOC_HANDLE);
+
+	ev_file = container_of(uobj, struct devx_async_cmd_event_file,
+			       uobj);
+	devx_init_event_queue(&ev_file->ev_queue);
+	return 0;
+}
+
 static int devx_umem_get(struct mlx5_ib_dev *dev, struct ib_ucontext *ucontext,
 			 struct uverbs_attr_bundle *attrs,
 			 struct devx_umem *obj)
@@ -1313,6 +1345,38 @@ static int devx_umem_cleanup(struct ib_uobject *uobject,
 	return 0;
 }
 
+static ssize_t devx_async_cmd_event_read(struct file *filp, char __user *buf,
+					 size_t count, loff_t *pos)
+{
+	return -EINVAL;
+}
+
+static int devx_async_cmd_event_close(struct inode *inode, struct file *filp)
+{
+	uverbs_close_fd(filp);
+	return 0;
+}
+
+static __poll_t devx_async_cmd_event_poll(struct file *filp,
+					      struct poll_table_struct *wait)
+{
+	return 0;
+}
+
+const struct file_operations devx_async_cmd_event_fops = {
+	.owner	 = THIS_MODULE,
+	.read	 = devx_async_cmd_event_read,
+	.poll    = devx_async_cmd_event_poll,
+	.release = devx_async_cmd_event_close,
+	.llseek	 = no_llseek,
+};
+
+static int devx_hot_unplug_async_cmd_event_file(struct ib_uobject *uobj,
+						   enum rdma_remove_reason why)
+{
+	return 0;
+};
+
 DECLARE_UVERBS_NAMED_METHOD(
 	MLX5_IB_METHOD_DEVX_UMEM_REG,
 	UVERBS_ATTR_IDR(MLX5_IB_ATTR_DEVX_UMEM_REG_HANDLE,
@@ -1440,6 +1504,22 @@ DECLARE_UVERBS_NAMED_OBJECT(MLX5_IB_OBJECT_DEVX_UMEM,
 			    &UVERBS_METHOD(MLX5_IB_METHOD_DEVX_UMEM_REG),
 			    &UVERBS_METHOD(MLX5_IB_METHOD_DEVX_UMEM_DEREG));
 
+
+DECLARE_UVERBS_NAMED_METHOD(
+	MLX5_IB_METHOD_DEVX_ASYNC_CMD_FD_ALLOC,
+	UVERBS_ATTR_FD(MLX5_IB_ATTR_DEVX_ASYNC_CMD_FD_ALLOC_HANDLE,
+			MLX5_IB_OBJECT_DEVX_ASYNC_CMD_FD,
+			UVERBS_ACCESS_NEW,
+			UA_MANDATORY));
+
+DECLARE_UVERBS_NAMED_OBJECT(
+	MLX5_IB_OBJECT_DEVX_ASYNC_CMD_FD,
+	UVERBS_TYPE_ALLOC_FD(sizeof(struct devx_async_cmd_event_file),
+			     devx_hot_unplug_async_cmd_event_file,
+			     &devx_async_cmd_event_fops, "[devx_async_cmd]",
+			     O_RDONLY),
+	&UVERBS_METHOD(MLX5_IB_METHOD_DEVX_ASYNC_CMD_FD_ALLOC));
+
 static bool devx_is_supported(struct ib_device *device)
 {
 	struct mlx5_ib_dev *dev = to_mdev(device);
@@ -1457,5 +1537,8 @@ const struct uapi_definition mlx5_ib_devx_defs[] = {
 	UAPI_DEF_CHAIN_OBJ_TREE_NAMED(
 		MLX5_IB_OBJECT_DEVX_UMEM,
 		UAPI_DEF_IS_OBJ_SUPPORTED(devx_is_supported)),
+	UAPI_DEF_CHAIN_OBJ_TREE_NAMED(
+		MLX5_IB_OBJECT_DEVX_ASYNC_CMD_FD,
+		UAPI_DEF_IS_OBJ_SUPPORTED(devx_is_supported)),
 	{},
 };