drm/i915: Markup paired operations on display power domains

The majority of runtime-pm operations are bounded and scoped within a
function; these are easy to verify that the wakeref are handled
correctly. We can employ the compiler to help us, and reduce the number
of wakerefs tracked when debugging, by passing around cookies provided
by the various rpm_get functions to their rpm_put counterpart. This
makes the pairing explicit, and given the required wakeref cookie the
compiler can verify that we pass an initialised value to the rpm_put
(quite handy for double checking error paths).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190114142129.24398-16-chris@chris-wilson.co.uk

1 files changed, 13 insertions, 4 deletions

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 71377ec49a10..5e5ceec7c004 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -2118,12 +2118,21 @@ bool intel_display_power_is_enabled(struct drm_i915_private *dev_priv,
 				    enum intel_display_power_domain domain);
 bool __intel_display_power_is_enabled(struct drm_i915_private *dev_priv,
 				      enum intel_display_power_domain domain);
-void intel_display_power_get(struct drm_i915_private *dev_priv,
-			     enum intel_display_power_domain domain);
-bool intel_display_power_get_if_enabled(struct drm_i915_private *dev_priv,
+intel_wakeref_t intel_display_power_get(struct drm_i915_private *dev_priv,
 					enum intel_display_power_domain domain);
+intel_wakeref_t
+intel_display_power_get_if_enabled(struct drm_i915_private *dev_priv,
+				   enum intel_display_power_domain domain);
+void intel_display_power_put_unchecked(struct drm_i915_private *dev_priv,
+				       enum intel_display_power_domain domain);
+#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_RUNTIME_PM)
 void intel_display_power_put(struct drm_i915_private *dev_priv,
-			     enum intel_display_power_domain domain);
+			     enum intel_display_power_domain domain,
+			     intel_wakeref_t wakeref);
+#else
+#define intel_display_power_put(i915, domain, wakeref) \
+	intel_display_power_put_unchecked(i915, domain)
+#endif
 void icl_dbuf_slices_update(struct drm_i915_private *dev_priv,
 			    u8 req_slices);