[PATCH 3/5] drm/syncobj: add sync_file interaction.

[Daniel Vetter]

On Fri, May 12, 2017 at 10:34:55AM +1000, Dave Airlie wrote:
> From: Dave Airlie <airlied at redhat.com>
> 
> This interface allows importing the fence from a sync_file into
> an existing drm sync object, or exporting the fence attached to
> an existing drm sync object into a new sync file object.
> 
> This should only be used to interact with sync files where necessary.
> 
> Signed-off-by: Dave Airlie <airlied at redhat.com>

A bunch of nits around ioctl validation and stuff. lgtm otherwise, ack
with those addressed.
-Daniel

> ---
>  drivers/gpu/drm/drm_syncobj.c | 56 +++++++++++++++++++++++++++++++++++++++++++
>  include/uapi/drm/drm.h        |  6 +++--
>  2 files changed, 60 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
> index 9a8c690..69ef20a 100644
> --- a/drivers/gpu/drm/drm_syncobj.c
> +++ b/drivers/gpu/drm/drm_syncobj.c
> @@ -52,6 +52,7 @@
>  #include <linux/file.h>
>  #include <linux/fs.h>
>  #include <linux/anon_inodes.h>
> +#include <linux/sync_file.h>
>  
>  #include "drm_internal.h"
>  #include <drm/drm_syncobj.h>
> @@ -290,6 +291,48 @@ static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
>  	return 0;
>  }
>  
> +int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
> +				       int fd, int handle)
> +{
> +	struct dma_fence *fence = sync_file_get_fence(fd);
> +	if (!fence)
> +		return -EINVAL;
> +
> +	return drm_syncobj_replace_fence(file_private, handle, fence);
> +}
> +
> +int drm_syncobj_export_sync_file(struct drm_file *file_private,
> +				 int handle, int *p_fd)
> +{
> +	int ret;
> +	struct dma_fence *fence;
> +	struct sync_file *sync_file;
> +	int fd = get_unused_fd_flags(O_CLOEXEC);

I guess the idea was to use args->fd_flags here?

> +
> +	if (fd < 0)
> +		return fd;
> +
> +	ret = drm_syncobj_fence_get(file_private, handle, &fence);
> +	if (ret)
> +		goto err_put_fd;
> +
> +	sync_file = sync_file_create(fence);
> +	if (!sync_file) {
> +		ret = -EINVAL;
> +		goto err_fence_put;
> +	}
> +
> +	fd_install(fd, sync_file->file);
> +
> +	dma_fence_put(fence);
> +	*p_fd = fd;
> +	return 0;
> +err_fence_put:
> +	dma_fence_put(fence);
> +err_put_fd:
> +	put_unused_fd(fd);
> +	return ret;
> +}
>  /**
>   * drm_syncobj_open - initalizes syncobj file-private structures at devnode open time
>   * @dev: drm_device which is being opened by userspace
> @@ -372,6 +415,12 @@ drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
>  	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
>  		return -ENODEV;
>  
> +	if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_FENCE_SYNC_FILE)
> +		return drm_syncobj_export_sync_file(file_private, args->handle,
> +						    &args->fd);

Checks like in the wait ioctl that no other flags are set is missing in
both callbacks.

> +	else if (args->flags)
> +		return -EINVAL;
> +
>  	return drm_syncobj_handle_to_fd(file_private, args->handle,
>  					&args->fd);
>  }
> @@ -385,6 +434,13 @@ drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
>  	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
>  		return -ENODEV;
>  
> +	if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE_FENCE)
> +		return drm_syncobj_import_sync_file_fence(file_private,
> +							  args->fd,
> +							  args->handle);
> +	else if (args->flags)
> +		return -EINVAL;
> +
>  	return drm_syncobj_fd_to_handle(file_private, args->fd,
>  					&args->handle);
>  }
> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
> index db9e35e..d0e05f4 100644
> --- a/include/uapi/drm/drm.h
> +++ b/include/uapi/drm/drm.h
> @@ -707,13 +707,15 @@ struct drm_syncobj_destroy {
>  	__u32 pad;
>  };
>  
> +#define DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE_FENCE (1 << 0)
> +#define DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_FENCE_SYNC_FILE (1 << 0)
>  struct drm_syncobj_handle {
>  	__u32 handle;
>  	/** Flags.. only applicable for handle->fd */
> -	__u32 flags;
> +	__u32 fd_flags;
>  
>  	__s32 fd;
> -	__u32 pad;
> +	__u32 flags;

s/pad/fd_flags/ instead of the shuffle you've done here I presume?

Also I didn't spot any fd_flags validation anywhere.

>  };
>  
>  /* timeout_ns is relative timeout in nanoseconds */
> -- 
> 2.9.3
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch