IB/mlx5: Implement DEVX hot unplug for async command FD

Implement DEVX hot unplug for the async command FD.

This is done by managing a list of the inflight commands and wait until
all launched work is completed as part of
devx_hot_unplug_async_cmd_event_file.

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

diff --git a/drivers/infiniband/hw/mlx5/devx.c b/drivers/infiniband/hw/mlx5/devx.c
index 234e413..84ef296 100644 (file)
--- a/drivers/infiniband/hw/mlx5/devx.c
+++ b/drivers/infiniband/hw/mlx5/devx.c
@@ -1184,6 +1184,7 @@ struct devx_async_event_queue {
        wait_queue_head_t       poll_wait;
        struct list_head        event_list;
        atomic_t                bytes_in_use;
+       u8                      is_destroyed:1;
 };
 
 struct devx_async_cmd_event_file {
@@ -1198,6 +1199,7 @@ static void devx_init_event_queue(struct devx_async_event_queue *ev_queue)
        INIT_LIST_HEAD(&ev_queue->event_list);
        init_waitqueue_head(&ev_queue->poll_wait);
        atomic_set(&ev_queue->bytes_in_use, 0);
+       ev_queue->is_destroyed = 0;
 }
 
 static int UVERBS_HANDLER(MLX5_IB_METHOD_DEVX_ASYNC_CMD_FD_ALLOC)(
@@ -1488,9 +1490,15 @@ static ssize_t devx_async_cmd_event_read(struct file *filp, char __user *buf,
 
                if (wait_event_interruptible(
                            ev_queue->poll_wait,
-                           !list_empty(&ev_queue->event_list))) {
+                           (!list_empty(&ev_queue->event_list) ||
+                            ev_queue->is_destroyed))) {
                        return -ERESTARTSYS;
                }
+
+               if (list_empty(&ev_queue->event_list) &&
+                   ev_queue->is_destroyed)
+                       return -EIO;
+
                spin_lock_irq(&ev_queue->lock);
        }
 
@@ -1544,7 +1552,9 @@ static __poll_t devx_async_cmd_event_poll(struct file *filp,
        poll_wait(filp, &ev_queue->poll_wait, wait);
 
        spin_lock_irq(&ev_queue->lock);
-       if (!list_empty(&ev_queue->event_list))
+       if (ev_queue->is_destroyed)
+               pollflags = EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
+       else if (!list_empty(&ev_queue->event_list))
                pollflags = EPOLLIN | EPOLLRDNORM;
        spin_unlock_irq(&ev_queue->lock);
 
@@ -1565,6 +1575,14 @@ static int devx_hot_unplug_async_cmd_event_file(struct ib_uobject *uobj,
        struct devx_async_cmd_event_file *comp_ev_file =
                container_of(uobj, struct devx_async_cmd_event_file,
                             uobj);
+       struct devx_async_event_queue *ev_queue = &comp_ev_file->ev_queue;
+
+       spin_lock_irq(&ev_queue->lock);
+       ev_queue->is_destroyed = 1;
+       spin_unlock_irq(&ev_queue->lock);
+
+       if (why == RDMA_REMOVE_DRIVER_REMOVE)
+               wake_up_interruptible(&ev_queue->poll_wait);
 
        mlx5_cmd_cleanup_async_ctx(&comp_ev_file->async_ctx);
        return 0;