drm/i915/guc: Fix for potential false positives in GuC hang selftest

Noticed that the hangcheck selftest is submitting a non-preemptoble
spinner. That means that even if the GuC does not die, the heartbeat
will still kick in and trigger a reset. Which is rather defeating the
purpose of the test - to verify that the heartbeat will kick in if the
GuC itself has died. The test is deliberately killing the GuC, so it
should never hit the case of a non-dead GuC. But it is not impossible
that the kill might fail at some future point due to other driver
re-work.

So, make the spinner pre-emptible. That way the heartbeat can get
through if the GuC is alive and context switching. Thus a reset only
happens if the GuC dies. Thus, if the kill should stop working the
test will now fail rather than claim to pass.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231114010016.234570-2-John.C.Harrison@Intel.com

drm/i915/guc: More debug print updates - GuC selftests

Update a bunch more debug prints to use the new GT based scheme.

v2: Also change prints to use %pe for error values (MichalW).
Fix a context leak on error due to a -- being too early.
Use the correct header file for the debug macros.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230207050717.1833718-5-John.C.Harrison@Intel.com

drm/i915/guc: don't hardcode BCS0 in guc_hang selftest

On MTL there are no BCS engines on the media GT, so we can't always use
BCS0 in the test. There is no actual reason to use a BCS engine over an
engine of a different class, so switch to using any available engine.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Acked-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221102214310.2829310-1-daniele.ceraolospurio@intel.com

drm/i915/guc: Add selftest for a hung GuC

Add a test to check that the hangcheck will recover from a submission
hang in the GuC.

Signed-off-by: Rahul Kumar Singh <rahul.kumar.singh@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220728182616.2417491-1-John.C.Harrison@Intel.com