drm/amdgpu: revert context to stop engine before mode2 reset

For some hang caused by slow tests, engine cannot be stopped which
may cause resume failure after reset. In this case, force halt
engine by reverting context addresses

Signed-off-by: Victor Zhao <Victor.Zhao@amd.com>
Acked-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amdgpu: save and restore gc hub regs

Save and restore gfxhub regs as they will be reset during mode 2

Signed-off-by: Victor Zhao <Victor.Zhao@amd.com>
Acked-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amdgpu: add gpu harvest support for yellow carp (v2)

Register callback in gfxhub functions to program the bypass groups in
gc_utcl2 corresponding to harvested SA.

v2: update comments (Alex)

Signed-off-by: Xiaomeng Hou <Xiaomeng.Hou@amd.com>
Signed-off-by: Aaron Liu <aaron.liu@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amdgpu: use function pointer for gfxhub functions

gfxhub functions are now called from function pointers,
instead of from asic-specific functions.

Signed-off-by: Oak Zeng <Oak.Zeng@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>