[RESEND PATCH v2] drm: Add getfb2 ioctl

[Li, Juston]

On Fri, 2019-12-13 at 23:36 +0200, Ville Syrjälä wrote:
> On Thu, Oct 03, 2019 at 11:31:25AM -0700, Juston Li wrote:
> > From: Daniel Stone <daniels at collabora.com>
> > 
> > getfb2 allows us to pass multiple planes and modifiers, just like
> > addfb2
> > over addfb.
> > 
> > Changes since v1:
> >  - unused modifiers set to 0 instead of DRM_FORMAT_MOD_INVALID
> >  - update ioctl number
> > 
> > Signed-off-by: Daniel Stone <daniels at collabora.com>
> > Signed-off-by: Juston Li <juston.li at intel.com>
> > ---
> >  drivers/gpu/drm/drm_crtc_internal.h |   2 +
> >  drivers/gpu/drm/drm_framebuffer.c   | 110
> > ++++++++++++++++++++++++++++
> >  drivers/gpu/drm/drm_ioctl.c         |   1 +
> >  include/uapi/drm/drm.h              |   2 +
> >  4 files changed, 115 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/drm_crtc_internal.h
> > b/drivers/gpu/drm/drm_crtc_internal.h
> > index c7d5e4c21423..16f2413403aa 100644
> > --- a/drivers/gpu/drm/drm_crtc_internal.h
> > +++ b/drivers/gpu/drm/drm_crtc_internal.h
> > @@ -216,6 +216,8 @@ int drm_mode_rmfb_ioctl(struct drm_device *dev,
> >  			void *data, struct drm_file *file_priv);
> >  int drm_mode_getfb(struct drm_device *dev,
> >  		   void *data, struct drm_file *file_priv);
> > +int drm_mode_getfb2_ioctl(struct drm_device *dev,
> > +			  void *data, struct drm_file *file_priv);
> >  int drm_mode_dirtyfb_ioctl(struct drm_device *dev,
> >  			   void *data, struct drm_file *file_priv);
> >  
> > diff --git a/drivers/gpu/drm/drm_framebuffer.c
> > b/drivers/gpu/drm/drm_framebuffer.c
> > index 57564318ceea..6db54f177443 100644
> > --- a/drivers/gpu/drm/drm_framebuffer.c
> > +++ b/drivers/gpu/drm/drm_framebuffer.c
> > @@ -31,6 +31,7 @@
> >  #include <drm/drm_file.h>
> >  #include <drm/drm_fourcc.h>
> >  #include <drm/drm_framebuffer.h>
> > +#include <drm/drm_gem.h>
> >  #include <drm/drm_print.h>
> >  #include <drm/drm_util.h>
> >  
> > @@ -548,7 +549,116 @@ int drm_mode_getfb(struct drm_device *dev,
> >  
> >  out:
> >  	drm_framebuffer_put(fb);
> > +	return ret;
> > +}
> > +
> > +/**
> > + * drm_mode_getfb2 - get extended FB info
> > + * @dev: drm device for the ioctl
> > + * @data: data pointer for the ioctl
> > + * @file_priv: drm file for the ioctl call
> > + *
> > + * Lookup the FB given its ID and return info about it.
> > + *
> > + * Called by the user via ioctl.
> > + *
> > + * Returns:
> > + * Zero on success, negative errno on failure.
> > + */
> > +int drm_mode_getfb2_ioctl(struct drm_device *dev,
> > +			  void *data, struct drm_file *file_priv)
> > +{
> > +	struct drm_mode_fb_cmd2 *r = data;
> > +	struct drm_framebuffer *fb;
> > +	unsigned int i;
> > +	int ret;
> > +
> > +	if (!drm_core_check_feature(dev, DRIVER_MODESET))
> > +		return -EINVAL;
> > +
> > +	fb = drm_framebuffer_lookup(dev, file_priv, r->fb_id);
> > +	if (!fb)
> > +		return -ENOENT;
> > +
> > +	/* For multi-plane framebuffers, we require the driver to place
> > the
> > +	 * GEM objects directly in the drm_framebuffer. For single-
> > plane
> > +	 * framebuffers, we can fall back to create_handle.
> > +	 */
> > +	if (!fb->obj[0] &&
> > +	    (fb->format->num_planes > 1 || !fb->funcs->create_handle))
> > {
> > +		ret = -ENODEV;
> > +		goto out;
> > +	}
> > +
> > +	r->height = fb->height;
> > +	r->width = fb->width;
> > +	r->pixel_format = fb->format->format;
> > +
> > +	r->flags = 0;
> > +	if (dev->mode_config.allow_fb_modifiers)
> > +		r->flags |= DRM_MODE_FB_MODIFIERS;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(r->handles); i++) {
> > +		r->handles[i] = 0;
> > +		r->pitches[i] = 0;
> > +		r->offsets[i] = 0;
> > +		r->modifier[i] = 0;
> > +	}
> >  
> > +	for (i = 0; i < fb->format->num_planes; i++) {
> > +		int j;
> > +
> > +		r->pitches[i] = fb->pitches[i];
> > +		r->offsets[i] = fb->offsets[i];
> > +		if (dev->mode_config.allow_fb_modifiers)
> > +			r->modifier[i] = fb->modifier;
> > +
> > +		/* If we reuse the same object for multiple planes,
> > also
> > +		 * return the same handle.
> > +		 */
> > +		for (j = 0; j < i; j++) {
> > +			if (fb->obj[i] == fb->obj[j]) {
> > +				r->handles[i] = r->handles[j];
> > +				break;
> > +			}
> > +		}
> > +
> > +		if (r->handles[i])
> > +			continue;
> > +
> > +		if (fb->obj[i]) {
> > +			ret = drm_gem_handle_create(file_priv, fb-
> > >obj[i],
> > +						    &r->handles[i]);
> > +		} else {
> > +			WARN_ON(i > 0);
> > +			ret = fb->funcs->create_handle(fb, file_priv,
> > +						       &r->handles[i]);
> > +		}
> 
> getfb1 doesn't allow non-master/root to see the handles. Here we
> don't
> seem to have that same protection?

Hmm yeah sorry I missed the protections handling.
I think we can just set the getfb2 ioctl flags as
DRM_MASTER|DRM_ROOT_ONLY

> > +
> > +		if (ret != 0)
> > +			goto out;
> 
> Could be just 'break;' and then we wouldn't even need the label.

Will do.

> 
> Rest lgtm.
> 

Much appreciated