Re: [PATCH V1] accel/amdxdna: Remove amdxdna_flush()

[Mario Limonciello <superm1@kernel.org>]

On 12/15/25 9:13 PM, Lizhi Hou wrote:
> amdxdna_flush() was introduced to ensure that the device does not access
> a process address space after it has been freed. However, this is no
> longer necessary because the driver now increments the mm reference count
> when a command is submitted and decrements it only after the command has
> completed. This guarantees that the process address space remains valid
> for the entire duration of command execution. Remove amdxdna_flush to
> simplify the teardown path.
> 
> Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>> ---
>   drivers/accel/amdxdna/amdxdna_pci_drv.c | 29 ++++++++++---------------
>   1 file changed, 11 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/accel/amdxdna/amdxdna_pci_drv.c b/drivers/accel/amdxdna/amdxdna_pci_drv.c
> index 1973ab67721b..fcf7e7869007 100644
> --- a/drivers/accel/amdxdna/amdxdna_pci_drv.c
> +++ b/drivers/accel/amdxdna/amdxdna_pci_drv.c
> @@ -105,43 +105,38 @@ static int amdxdna_drm_open(struct drm_device *ddev, struct drm_file *filp)
>   	return ret;
>   }
>   
> -static void amdxdna_drm_close(struct drm_device *ddev, struct drm_file *filp)
> +static void amdxdna_client_cleanup(struct amdxdna_client *client)
>   {
> -	struct amdxdna_client *client = filp->driver_priv;
> -	struct amdxdna_dev *xdna = to_xdna_dev(ddev);
> -
> -	XDNA_DBG(xdna, "closing pid %d", client->pid);
> -
> +	list_del(&client->node);
> +	amdxdna_hwctx_remove_all(client);
>   	xa_destroy(&client->hwctx_xa);
>   	cleanup_srcu_struct(&client->hwctx_srcu);
>   	mutex_destroy(&client->mm_lock);
> +
>   	if (client->dev_heap)
>   		drm_gem_object_put(to_gobj(client->dev_heap));
>   
>   	iommu_sva_unbind_device(client->sva);
>   
> -	XDNA_DBG(xdna, "pid %d closed", client->pid);
>   	kfree(client);
>   }
>   
> -static int amdxdna_flush(struct file *f, fl_owner_t id)
> +static void amdxdna_drm_close(struct drm_device *ddev, struct drm_file *filp)
>   {
> -	struct drm_file *filp = f->private_data;
>   	struct amdxdna_client *client = filp->driver_priv;
> -	struct amdxdna_dev *xdna = client->xdna;
> +	struct amdxdna_dev *xdna = to_xdna_dev(ddev);
>   	int idx;
>   
> -	XDNA_DBG(xdna, "PID %d flushing...", client->pid);
> +	XDNA_DBG(xdna, "closing pid %d", client->pid);
> +
>   	if (!drm_dev_enter(&xdna->ddev, &idx))
> -		return 0;
> +		return;
>   
>   	mutex_lock(&xdna->dev_lock);
> -	list_del_init(&client->node);
> -	amdxdna_hwctx_remove_all(client);
> +	amdxdna_client_cleanup(client);
>   	mutex_unlock(&xdna->dev_lock);
>   
>   	drm_dev_exit(idx);
> -	return 0;
>   }
>   
>   static int amdxdna_drm_get_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
> @@ -217,7 +212,6 @@ static const struct file_operations amdxdna_fops = {
>   	.owner		= THIS_MODULE,
>   	.open		= accel_open,
>   	.release	= drm_release,
> -	.flush		= amdxdna_flush,
>   	.unlocked_ioctl	= drm_ioctl,
>   	.compat_ioctl	= drm_compat_ioctl,
>   	.poll		= drm_poll,
> @@ -333,8 +327,7 @@ static void amdxdna_remove(struct pci_dev *pdev)
>   	client = list_first_entry_or_null(&xdna->client_list,
>   					  struct amdxdna_client, node);
>   	while (client) {
> -		list_del_init(&client->node);
> -		amdxdna_hwctx_remove_all(client);
> +		amdxdna_client_cleanup(client);
>   
>   		client = list_first_entry_or_null(&xdna->client_list,
>   						  struct amdxdna_client, node);