Commit 4748aa16 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm: Expose a method for creating anonymous struct file around drm_minor



Sometimes we need to create a struct file to wrap a drm_device, as it
the user were to have opened /dev/dri/card0 but to do so anonymously
(i.e. for internal use). Provide a utility method to create a struct
file with the drm_device->driver.fops, that wrap the drm_device.

v2: Restrict usage to selftests

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20191107180601.30815-2-chris@chris-wilson.co.uk
parent 6349120d
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+42 −0
Original line number Diff line number Diff line
@@ -31,7 +31,9 @@
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include <linux/anon_inodes.h>
#include <linux/dma-fence.h>
#include <linux/file.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/poll.h>
@@ -754,3 +756,43 @@ void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
	spin_unlock_irqrestore(&dev->event_lock, irqflags);
}
EXPORT_SYMBOL(drm_send_event);

/**
 * mock_drm_getfile - Create a new struct file for the drm device
 * @minor: drm minor to wrap (e.g. #drm_device.primary)
 * @flags: file creation mode (O_RDWR etc)
 *
 * This create a new struct file that wraps a DRM file context around a
 * DRM minor. This mimicks userspace opening e.g. /dev/dri/card0, but without
 * invoking userspace. The struct file may be operated on using its f_op
 * (the drm_device.driver.fops) to mimick userspace operations, or be supplied
 * to userspace facing functions as an internal/anonymous client.
 *
 * RETURNS:
 * Pointer to newly created struct file, ERR_PTR on failure.
 */
struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags)
{
	struct drm_device *dev = minor->dev;
	struct drm_file *priv;
	struct file *file;

	priv = drm_file_alloc(minor);
	if (IS_ERR(priv))
		return ERR_CAST(priv);

	file = anon_inode_getfile("drm", dev->driver->fops, priv, flags);
	if (IS_ERR(file)) {
		drm_file_free(priv);
		return file;
	}

	/* Everyone shares a single global address space */
	file->f_mapping = dev->anon_inode->i_mapping;

	drm_dev_get(dev);
	priv->filp = file;

	return file;
}
EXPORT_SYMBOL_FOR_TESTS_ONLY(mock_drm_getfile);
+3 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ struct dma_fence;
struct drm_file;
struct drm_device;
struct device;
struct file;

/*
 * FIXME: Not sure we want to have drm_minor here in the end, but to avoid
@@ -387,4 +388,6 @@ void drm_event_cancel_free(struct drm_device *dev,
void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e);
void drm_send_event(struct drm_device *dev, struct drm_pending_event *e);

struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags);

#endif /* _DRM_FILE_H_ */