drm/i915/guc: Take engine PM when a context is pinned with GuC submission

Taking a PM reference to prevent intel_gt_wait_for_idle from short
circuiting while any user context has scheduling enabled. Returning GT
idle when it is not can cause all sorts of issues throughout the stack.

v2:
 (Daniel Vetter)
  - Add might_lock annotations to pin / unpin function
v3:
 (CI)
  - Drop intel_engine_pm_might_put from unpin path as an async put is
    used
v4:
 (John Harrison)
  - Make intel_engine_pm_might_get/put work with GuC virtual engines
  - Update commit message
v5:
  - Update commit message again

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/20211014172005.27155-4-matthew.brost@intel.com

1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_gt_pm.h b/drivers/gpu/drm/i915/gt/intel_gt_pm.h
index 05de6c1af25b..bc898df7a48c 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_pm.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt_pm.h
@@ -31,6 +31,11 @@ static inline bool intel_gt_pm_get_if_awake(struct intel_gt *gt)
 	return intel_wakeref_get_if_active(&gt->wakeref);
 }
 
+static inline void intel_gt_pm_might_get(struct intel_gt *gt)
+{
+	intel_wakeref_might_get(&gt->wakeref);
+}
+
 static inline void intel_gt_pm_put(struct intel_gt *gt)
 {
 	intel_wakeref_put(&gt->wakeref);
@@ -41,6 +46,11 @@ static inline void intel_gt_pm_put_async(struct intel_gt *gt)
 	intel_wakeref_put_async(&gt->wakeref);
 }
 
+static inline void intel_gt_pm_might_put(struct intel_gt *gt)
+{
+	intel_wakeref_might_put(&gt->wakeref);
+}
+
 #define with_intel_gt_pm(gt, tmp) \
 	for (tmp = 1, intel_gt_pm_get(gt); tmp; \
 	     intel_gt_pm_put(gt), tmp = 0)