drm/i915/guc: Defer context unpin until scheduling is disabled

With GuC scheduling, it isn't safe to unpin a context while scheduling
is enabled for that context as the GuC may touch some of the pinned
state (e.g. LRC). To ensure scheduling isn't enabled when an unpin is
done, a call back is added to intel_context_unpin when pin count == 1
to disable scheduling for that context. When the response CTB is
received it is safe to do the final unpin.

Future patches may add a heuristic / delay to schedule the disable
call back to avoid thrashing on schedule enable / disable.

v2:
 (John H)
  - s/drm_dbg/drm_err
 (Daneiel)
  - Clean up sched state function

Cc: John Harrison <john.c.harrison@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210721215101.139794-9-matthew.brost@intel.com

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.h b/drivers/gpu/drm/i915/gt/uc/intel_guc.h
index 7fd6c3e343e4..4d470ebeda95 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc.h
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.h
@@ -248,6 +248,8 @@ int intel_guc_reset_engine(struct intel_guc *guc,
 
 int intel_guc_deregister_done_process_msg(struct intel_guc *guc,
 					  const u32 *msg, u32 len);
+int intel_guc_sched_done_process_msg(struct intel_guc *guc,
+				     const u32 *msg, u32 len);
 
 void intel_guc_load_status(struct intel_guc *guc, struct drm_printer *p);