[PATCH libdrm] intel: drm_intel_bo_gem_create_from_* on platforms w/o HW tiling

[Imre Deak]

On Tue, Jan 21, 2020 at 10:40:48PM +0000, Eric Engestrom wrote:
> On Monday, 2020-01-20 18:43:43 +0200, Imre Deak wrote:
> > Platforms without a HW detiler doesn't support the get_tiling IOCTL.
> > Fix the drm_intel_bo_gem_create_from_* functions assuming the default
> > no-tiling, no-swizzling setting for the GEM buffer in this case.
> > 
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > ---
> >  intel/intel_bufmgr_gem.c | 42 +++++++++++++++++++++++++---------------
> >  1 file changed, 26 insertions(+), 16 deletions(-)
> > 
> > diff --git a/intel/intel_bufmgr_gem.c b/intel/intel_bufmgr_gem.c
> > index fbf48730..fc249ef1 100644
> > --- a/intel/intel_bufmgr_gem.c
> > +++ b/intel/intel_bufmgr_gem.c
> > @@ -1069,6 +1069,27 @@ check_bo_alloc_userptr(drm_intel_bufmgr *bufmgr,
> >  					  tiling_mode, stride, size, flags);
> >  }
> >  
> > +static int get_tiling_mode(drm_intel_bufmgr_gem *bufmgr_gem,
> > +			   uint32_t gem_handle,
> > +			   uint32_t *tiling_mode,
> > +			   uint32_t *swizzle_mode)
> > +{
> > +	struct drm_i915_gem_get_tiling get_tiling;
> > +	int ret;
> > +
> > +	memclear(get_tiling);
> > +	ret = drmIoctl(bufmgr_gem->fd,
> > +		       DRM_IOCTL_I915_GEM_GET_TILING,
> > +		       &get_tiling);
> 
> You're missing `get_tiling.handle = gem_handle;`

Err, thanks for catching that, will resend fixing it.

> Or better yet, just initialise `get_tiling` and get rid of the memclear():
>   struct drm_i915_gem_get_tiling get_tiling = {
>     .handle = gem_handle,
>   };
> 
> With either fix:
> Reviewed-by: Eric Engestrom <eric at engestrom.ch>
> 
> FYI, I've posted the following MR for the equivalent Mesa changes:
> https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3497
> 
> > +	if (ret != 0 && errno != EOPNOTSUPP)
> > +		return ret;
> > +
> > +	*tiling_mode = get_tiling.tiling_mode;
> > +	*swizzle_mode = get_tiling.swizzle_mode;
> > +
> > +	return 0;
> > +}
> > +
> >  /**
> >   * Returns a drm_intel_bo wrapping the given buffer object handle.
> >   *
> > @@ -1084,7 +1105,6 @@ drm_intel_bo_gem_create_from_name(drm_intel_bufmgr *bufmgr,
> >  	drm_intel_bo_gem *bo_gem;
> >  	int ret;
> >  	struct drm_gem_open open_arg;
> > -	struct drm_i915_gem_get_tiling get_tiling;
> >  
> >  	/* At the moment most applications only have a few named bo.
> >  	 * For instance, in a DRI client only the render buffers passed
> > @@ -1146,16 +1166,11 @@ drm_intel_bo_gem_create_from_name(drm_intel_bufmgr *bufmgr,
> >  	HASH_ADD(name_hh, bufmgr_gem->name_table,
> >  		 global_name, sizeof(bo_gem->global_name), bo_gem);
> >  
> > -	memclear(get_tiling);
> > -	get_tiling.handle = bo_gem->gem_handle;
> > -	ret = drmIoctl(bufmgr_gem->fd,
> > -		       DRM_IOCTL_I915_GEM_GET_TILING,
> > -		       &get_tiling);
> > +	ret = get_tiling_mode(bufmgr_gem, bo_gem->gem_handle,
> > +			      &bo_gem->tiling_mode, &bo_gem->swizzle_mode);
> >  	if (ret != 0)
> >  		goto err_unref;
> >  
> > -	bo_gem->tiling_mode = get_tiling.tiling_mode;
> > -	bo_gem->swizzle_mode = get_tiling.swizzle_mode;
> >  	/* XXX stride is unknown */
> >  	drm_intel_bo_gem_set_in_aperture_size(bufmgr_gem, bo_gem, 0);
> >  	DBG("bo_create_from_handle: %d (%s)\n", handle, bo_gem->name);
> > @@ -2634,7 +2649,6 @@ drm_intel_bo_gem_create_from_prime(drm_intel_bufmgr *bufmgr, int prime_fd, int s
> >  	int ret;
> >  	uint32_t handle;
> >  	drm_intel_bo_gem *bo_gem;
> > -	struct drm_i915_gem_get_tiling get_tiling;
> >  
> >  	pthread_mutex_lock(&bufmgr_gem->lock);
> >  	ret = drmPrimeFDToHandle(bufmgr_gem->fd, prime_fd, &handle);
> > @@ -2688,15 +2702,11 @@ drm_intel_bo_gem_create_from_prime(drm_intel_bufmgr *bufmgr, int prime_fd, int s
> >  	bo_gem->has_error = false;
> >  	bo_gem->reusable = false;
> >  
> > -	memclear(get_tiling);
> > -	get_tiling.handle = bo_gem->gem_handle;
> > -	if (drmIoctl(bufmgr_gem->fd,
> > -		     DRM_IOCTL_I915_GEM_GET_TILING,
> > -		     &get_tiling))
> > +	ret = get_tiling_mode(bufmgr_gem, handle,
> > +			      &bo_gem->tiling_mode, &bo_gem->swizzle_mode);
> > +	if (ret)
> >  		goto err;
> >  
> > -	bo_gem->tiling_mode = get_tiling.tiling_mode;
> > -	bo_gem->swizzle_mode = get_tiling.swizzle_mode;
> >  	/* XXX stride is unknown */
> >  	drm_intel_bo_gem_set_in_aperture_size(bufmgr_gem, bo_gem, 0);
> >