intel_gtt: Harden against changes to kernel mappings of the GTT
intel_gtt: Harden against changes to kernel mappings of the GTT

Rather than use the common mmio segment which will be in future
restricted to just the registers and so exclude the GTT portion on all
architectures, explicitly mmap the GTT ourselves. Repeat this mmapping
with a couple of flags until we matching the existing kernel mapping.

Signed-off-by: Chris Wilson <711c73f64afdce07b7e38039a96d2224209e9a6c@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <c1b6782c4af8f0673da8923a0702a1832e5940f4@ffwll.ch>

mv0/intel-gpu-tools,tiagovignatti/intel-gpu-tools,ChrisCummins/intel-gpu-tools,dlespiau/intel-gpu-tools,chenxianqin/intel-gpu-tools,mv0/intel-gpu-tools,mv0/intel-gpu-tools,tiagovignatti/intel-gpu-tools,dlespiau/checkmate-test-igt,rib/intel-gpu-tools,chenxianqin/intel-gpu-tools,rib/intel-gpu-tools,chenxianqin/intel-gpu-tools,tiagovignatti/intel-gpu-tools,rib/intel-gpu-tools,erikarn/intel-gpu-tools,dlespiau/checkmate-test-igt,rib/intel-gpu-tools,erikarn/intel-gpu-tools,mv0/intel-gpu-tools,yipdw/intel-gpu-tools,dlespiau/checkmate-test-igt,erikarn/intel-gpu-tools,yipdw/intel-gpu-tools,erikarn/intel-gpu-tools,dlespiau/checkmate-test-igt,yipdw/intel-gpu-tools,tiagovignatti/intel-gpu-tools,ChrisCummins/intel-gpu-tools,dlespiau/intel-gpu-tools,ChrisCummins/intel-gpu-tools,ChrisCummins/intel-gpu-tools,dlespiau/intel-gpu-tools,yipdw/intel-gpu-tools,chenxianqin/intel-gpu-tools