drm/i915/gt: Skip TLB invalidations once wedged

[ Upstream commit e5a95c83ed ]

Skip all further TLB invalidations once the device is wedged and
had been reset, as, on such cases, it can no longer process instructions
on the GPU and the user no longer has access to the TLB's in each engine.

So, an attempt to do a TLB cache invalidation will produce a timeout.

That helps to reduce the performance regression introduced by TLB
invalidate logic.

Cc: stable@vger.kernel.org
Fixes: 7938d61591 ("drm/i915: Flush TLBs before releasing backing store")
Signed-off-by: Chris Wilson <chris.p.wilson@intel.com>
Cc: Fei Yang <fei.yang@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Acked-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/5aa86564b9ec5fe7fe605c1dd7de76855401ed73.1658924372.git.mchehab@kernel.org
(cherry picked from commit be0366f168)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/gpu/drm/i915/gt/intel_gt.c

@@ -949,6 +949,9 @@ void intel_gt_invalidate_tlbs(struct intel_gt *gt)
 	if (I915_SELFTEST_ONLY(gt->awake == -ENODEV))
 		return;
 
+	if (intel_gt_is_wedged(gt))
+		return;
+
 	if (GRAPHICS_VER(i915) == 12) {
 		regs = gen12_regs;
 		num = ARRAY_SIZE(gen12_regs);