drm/i915: Lift intel_engines_resume() to callers

Since the reset path wants to recover the engines itself, it only wants
to reinitialise the hardware using i915_gem_init_hw(). Pull the call to
intel_engines_resume() to the module init/resume path so we can avoid it
during reset.

Fixes: 79ffac8599 ("drm/i915: Invert the GEM wakeref hierarchy")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190626154549.10066-3-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gem/i915_gem_pm.c

@@ -254,14 +254,15 @@ void i915_gem_resume(struct drm_i915_private *i915)
 	i915_gem_restore_gtt_mappings(i915);
 	i915_gem_restore_fences(i915);
 
+	if (i915_gem_init_hw(i915))
+		goto err_wedged;
+
 	/*
 	 * As we didn't flush the kernel context before suspend, we cannot
 	 * guarantee that the context image is complete. So let's just reset
 	 * it and start again.
 	 */
-	intel_gt_resume(&i915->gt);
-
-	if (i915_gem_init_hw(i915))
+	if (intel_gt_resume(&i915->gt))
 		goto err_wedged;
 
 	intel_uc_resume(i915);

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

@@ -142,27 +142,3 @@ void intel_engine_init__pm(struct intel_engine_cs *engine)
 {
 	intel_wakeref_init(&engine->wakeref);
 }
-
-int intel_engines_resume(struct drm_i915_private *i915)
-{
-	struct intel_engine_cs *engine;
-	enum intel_engine_id id;
-	int err = 0;
-
-	intel_gt_pm_get(&i915->gt);
-	for_each_engine(engine, i915, id) {
-		intel_engine_pm_get(engine);
-		engine->serial++; /* kernel context lost */
-		err = engine->resume(engine);
-		intel_engine_pm_put(engine);
-		if (err) {
-			dev_err(i915->drm.dev,
-				"Failed to restart %s (%d)\n",
-				engine->name, err);
-			break;
-		}
-	}
-	intel_gt_pm_put(&i915->gt);
-
-	return err;
-}

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

@@ -31,6 +31,4 @@ void intel_engine_park(struct intel_engine_cs *engine);
 
 void intel_engine_init__pm(struct intel_engine_cs *engine);
 
-int intel_engines_resume(struct drm_i915_private *i915);
-
 #endif /* INTEL_ENGINE_PM_H */

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

@@ -5,6 +5,7 @@
  */
 
 #include "i915_drv.h"
+#include "intel_engine_pm.h"
 #include "intel_gt_pm.h"
 #include "intel_pm.h"
 #include "intel_wakeref.h"
@@ -122,10 +123,11 @@ void intel_gt_sanitize(struct intel_gt *gt, bool force)
 		intel_engine_reset(engine, false);
 }
 
-void intel_gt_resume(struct intel_gt *gt)
+int intel_gt_resume(struct intel_gt *gt)
 {
 	struct intel_engine_cs *engine;
 	enum intel_engine_id id;
+	int err = 0;
 
 	/*
 	 * After resume, we may need to poke into the pinned kernel
@@ -133,9 +135,12 @@ void intel_gt_resume(struct intel_gt *gt)
 	 * Only the kernel contexts should remain pinned over suspend,
 	 * allowing us to fixup the user contexts on their first pin.
 	 */
+	intel_gt_pm_get(gt);
 	for_each_engine(engine, gt->i915, id) {
 		struct intel_context *ce;
 
+		intel_engine_pm_get(engine);
+
 		ce = engine->kernel_context;
 		if (ce)
 			ce->ops->reset(ce);
@@ -143,5 +148,19 @@ void intel_gt_resume(struct intel_gt *gt)
 		ce = engine->preempt_context;
 		if (ce)
 			ce->ops->reset(ce);
+
+		engine->serial++; /* kernel context lost */
+		err = engine->resume(engine);
+
+		intel_engine_pm_put(engine);
+		if (err) {
+			dev_err(gt->i915->drm.dev,
+				"Failed to restart %s (%d)\n",
+				engine->name, err);
+			break;
+		}
 	}
+	intel_gt_pm_put(gt);
+
+	return err;
 }

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

@@ -22,6 +22,6 @@ void intel_gt_pm_put(struct intel_gt *gt);
 void intel_gt_pm_init_early(struct intel_gt *gt);
 
 void intel_gt_sanitize(struct intel_gt *gt, bool force);
-void intel_gt_resume(struct intel_gt *gt);
+int intel_gt_resume(struct intel_gt *gt);
 
 #endif /* INTEL_GT_PM_H */

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

@@ -949,6 +949,21 @@ static int do_reset(struct drm_i915_private *i915,
 	return gt_reset(i915, stalled_mask);
 }
 
+static int resume(struct drm_i915_private *i915)
+{
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	int ret;
+
+	for_each_engine(engine, i915, id) {
+		ret = engine->resume(engine);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 /**
  * i915_reset - reset chip after a hang
  * @i915: #drm_i915_private to reset
@@ -1023,9 +1038,13 @@ void i915_reset(struct drm_i915_private *i915,
 	if (ret) {
 		DRM_ERROR("Failed to initialise HW following reset (%d)\n",
 			  ret);
-		goto error;
+		goto taint;
 	}
 
+	ret = resume(i915);
+	if (ret)
+		goto taint;
+
 	i915_queue_hangcheck(i915);
 
 finish:

drivers/gpu/drm/i915/i915_gem.c

@@ -46,7 +46,6 @@
 #include "gem/i915_gem_ioctls.h"
 #include "gem/i915_gem_pm.h"
 #include "gem/i915_gemfs.h"
-#include "gt/intel_engine_pm.h"
 #include "gt/intel_gt.h"
 #include "gt/intel_gt_pm.h"
 #include "gt/intel_mocs.h"
@@ -1192,12 +1191,17 @@ static void init_unused_rings(struct intel_gt *gt)
 	}
 }
 
-static int init_hw(struct intel_gt *gt)
+int i915_gem_init_hw(struct drm_i915_private *i915)
 {
-	struct drm_i915_private *i915 = gt->i915;
-	struct intel_uncore *uncore = gt->uncore;
+	struct intel_uncore *uncore = &i915->uncore;
+	struct intel_gt *gt = &i915->gt;
 	int ret;
 
+	BUG_ON(!i915->kernel_context);
+	ret = i915_terminally_wedged(i915);
+	if (ret)
+		return ret;
+
 	gt->last_init_time = ktime_get();
 
 	/* Double layer security blanket, see i915_gem_init() */
@@ -1248,51 +1252,10 @@ static int init_hw(struct intel_gt *gt)
 
 	intel_mocs_init_l3cc_table(gt);
 
-	intel_uncore_forcewake_put(uncore, FORCEWAKE_ALL);
-
-	return 0;
+	intel_engines_set_scheduler_caps(i915);
 
 out:
 	intel_uncore_forcewake_put(uncore, FORCEWAKE_ALL);
-
-	return ret;
-}
-
-int i915_gem_init_hw(struct drm_i915_private *i915)
-{
-	struct intel_uncore *uncore = &i915->uncore;
-	int ret;
-
-	BUG_ON(!i915->kernel_context);
-	ret = i915_terminally_wedged(i915);
-	if (ret)
-		return ret;
-
-	/* Double layer security blanket, see i915_gem_init() */
-	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
-
-	ret = init_hw(&i915->gt);
-	if (ret)
-		goto err_init;
-
-	/* Only when the HW is re-initialised, can we replay the requests */
-	ret = intel_engines_resume(i915);
-	if (ret)
-		goto err_engines;
-
-	intel_uncore_forcewake_put(uncore, FORCEWAKE_ALL);
-
-	intel_engines_set_scheduler_caps(i915);
-
-	return 0;
-
-err_engines:
-	intel_uc_fini_hw(i915);
-err_init:
-	intel_uncore_forcewake_put(uncore, FORCEWAKE_ALL);
-
-	intel_engines_set_scheduler_caps(i915);
-
 	return ret;
 }
 
@@ -1524,6 +1487,11 @@ int i915_gem_init(struct drm_i915_private *dev_priv)
 	if (ret)
 		goto err_uc_init;
 
+	/* Only when the HW is re-initialised, can we replay the requests */
+	ret = intel_gt_resume(&dev_priv->gt);
+	if (ret)
+		goto err_init_hw;
+
 	/*
 	 * Despite its name intel_init_clock_gating applies both display
 	 * clock gating workarounds; GT mmio workarounds and the occasional
@@ -1537,20 +1505,20 @@ int i915_gem_init(struct drm_i915_private *dev_priv)
 
 	ret = intel_engines_verify_workarounds(dev_priv);
 	if (ret)
-		goto err_init_hw;
+		goto err_gt;
 
 	ret = __intel_engines_record_defaults(dev_priv);
 	if (ret)
-		goto err_init_hw;
+		goto err_gt;
 
 	if (i915_inject_load_failure()) {
 		ret = -ENODEV;
-		goto err_init_hw;
+		goto err_gt;
 	}
 
 	if (i915_inject_load_failure()) {
 		ret = -EIO;
-		goto err_init_hw;
+		goto err_gt;
 	}
 
 	intel_uncore_forcewake_put(&dev_priv->uncore, FORCEWAKE_ALL);
@@ -1564,7 +1532,7 @@ int i915_gem_init(struct drm_i915_private *dev_priv)
 	 * HW as irrevisibly wedged, but keep enough state around that the
 	 * driver doesn't explode during runtime.
 	 */
-err_init_hw:
+err_gt:
 	mutex_unlock(&dev_priv->drm.struct_mutex);
 
 	i915_gem_set_wedged(dev_priv);
@@ -1574,6 +1542,7 @@ int i915_gem_init(struct drm_i915_private *dev_priv)
 	i915_gem_drain_workqueue(dev_priv);
 
 	mutex_lock(&dev_priv->drm.struct_mutex);
+err_init_hw:
 	intel_uc_fini_hw(dev_priv);
 err_uc_init:
 	intel_uc_fini(dev_priv);