Michel Dänzer authored Feb 24, 2016 and Michel Dänzer committed Feb 27, 2016

We can't create our own struct amdgpu_buffer representation in this case
because destroying that would make the GEM handle inaccessible to glamor
as well. So just get the handle directly via dma-buf.

(ported from radeon commit 391900a670addec39515f924265bfa9f8bfa9ec0,
 extended to cache BO handles in the private for non-DRI3 pixmaps as
 well)

v2: Swap whole pixmap privates instead of just BOs in
    amdgpu_dri2_exchange_buffers to avoid invalidating cached BO handles

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>