drm/i915/gt: Add selftests for TLB invalidation

Check that we invalidate the TLB cache, the updated physical addresses
are immediately visible to the HW, and there is no retention of the old
physical address for concurrent HW access.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[ahajda: adjust to upstream driver, v2+]
Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
[tursulin: Small indentation fix.]
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230130165058.1647414-1-andrzej.hajda@intel.com

Author: ickle

drivers/gpu/drm/i915/gt/intel_gpu_commands.h

@@ -394,6 +394,7 @@
 #define MI_LOAD_URB_MEM         MI_INSTR(0x2C, 0)
 #define MI_STORE_URB_MEM        MI_INSTR(0x2D, 0)
 #define MI_CONDITIONAL_BATCH_BUFFER_END MI_INSTR(0x36, 0)
+#define  MI_DO_COMPARE		REG_BIT(21)
 
 #define STATE_BASE_ADDRESS \
 	((0x3 << 29) | (0x0 << 27) | (0x1 << 24) | (0x1 << 16))

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

@@ -1205,3 +1205,7 @@ void intel_gt_invalidate_tlb(struct intel_gt *gt, u32 seqno)
 		mutex_unlock(&gt->tlb.invalidate_lock);
 	}
 }
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftest_tlb.c"
+#endif