[Intel-gfx] [PATCH v13 17/21] drm/i915: Split i915_gem_suspend into gem quiescing and HW suspend

[Sagar Arun Kamble]

GTT mappings are to be suspended post idling GPU and display suspend.
Currently GPU was reset in i915_gem_suspend and then GTT mappings were
suspended in i915_drm_suspend. Also part of i915_gem_suspend was about
suspending HW operations. This separated the HW/GEM suspend across reset.

To achieve the complete GEM/HW suspend prior to GPU reset we need to
separate i915_gem_suspend functionality into gem quiescing and HW
suspend. With this patch new function i915_gem_quiesce is created that
will ensure GEM is idle. i915_gem_hw_suspend will ensure all GPU HW
operations are suspended. These currently are RPS, GTT mappings
suspension.

With this patch drm suspend sequence is gem_quiesce followed by
gem_hw_suspend. Unload sequence is gem_quiesce->gem_hw_suspend->gem_fini.

v2. Split i915_gem_suspend to accommodate GTT mappings suspend as that is
not to be done till display suspend. (Chris)

v3: s/i915_gem_quiescent/i915_gem_quiesce and s/i915_gem_suspend/
i915_gem_hw_suspend. gem_hw_suspend has to be done prior to gem_fini as
engine state/GuC software state would be needed to suspend HW.
s/dev_priv/i915 in i915_gem_quiesce and i915_gem_hw_suspend.
Doing GuC suspend before suspending GTT mappings as GuC needs to access
the shared data. Limiting struct_mutex lock to only gem_sanitize.

Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Michał Winiarski <michal.winiarski at intel.com>
Cc: Oscar Mateo <oscar.mateo at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c | 11 +++++++----
 drivers/gpu/drm/i915/i915_drv.h |  3 ++-
 drivers/gpu/drm/i915/i915_gem.c | 29 ++++++++++++++++++++++-------
 3 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 8ed3e57..198e774e 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -693,8 +693,9 @@ static int i915_load_modeset_init(struct drm_device *dev)
 	return 0;
 
 cleanup_gem:
-	if (i915_gem_suspend(dev_priv))
+	if (i915_gem_quiesce(dev_priv))
 		DRM_ERROR("failed to idle hardware; continuing to unload!\n");
+	i915_gem_hw_suspend(dev_priv);
 	i915_gem_fini(dev_priv);
 cleanup_uc:
 	intel_uc_fini_fw(dev_priv);
@@ -1395,9 +1396,11 @@ void i915_driver_unload(struct drm_device *dev)
 
 	i915_driver_unregister(dev_priv);
 
-	if (i915_gem_suspend(dev_priv))
+	if (i915_gem_quiesce(dev_priv))
 		DRM_ERROR("failed to idle hardware; continuing to unload!\n");
 
+	i915_gem_hw_suspend(dev_priv);
+
 	intel_display_power_get(dev_priv, POWER_DOMAIN_INIT);
 
 	drm_atomic_helper_shutdown(dev);
@@ -1540,7 +1543,7 @@ static int i915_drm_suspend(struct drm_device *dev)
 
 	pci_save_state(pdev);
 
-	error = i915_gem_suspend(dev_priv);
+	error = i915_gem_quiesce(dev_priv);
 	if (error) {
 		dev_err(&pdev->dev,
 			"GEM idle failed, resume might fail\n");
@@ -1558,7 +1561,7 @@ static int i915_drm_suspend(struct drm_device *dev)
 
 	intel_suspend_hw(dev_priv);
 
-	i915_gem_suspend_gtt_mappings(dev_priv);
+	i915_gem_hw_suspend(dev_priv);
 
 	i915_save_state(dev_priv);
 
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index bc21da2..f51abc6 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3716,7 +3716,8 @@ void i915_gem_reset_engine(struct intel_engine_cs *engine,
 void i915_gem_cleanup_engines(struct drm_i915_private *dev_priv);
 int i915_gem_wait_for_idle(struct drm_i915_private *dev_priv,
 			   unsigned int flags);
-int __must_check i915_gem_suspend(struct drm_i915_private *dev_priv);
+int __must_check i915_gem_quiesce(struct drm_i915_private *dev_priv);
+void i915_gem_hw_suspend(struct drm_i915_private *dev_priv);
 void i915_gem_resume(struct drm_i915_private *dev_priv);
 int i915_gem_fault(struct vm_fault *vmf);
 int i915_gem_object_wait(struct drm_i915_gem_object *obj,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index bcf3ca5..f1a785a 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4650,13 +4650,12 @@ void i915_gem_sanitize(struct drm_i915_private *i915)
 	}
 }
 
-int i915_gem_suspend(struct drm_i915_private *dev_priv)
+int i915_gem_quiesce(struct drm_i915_private *dev_priv)
 {
 	struct drm_device *dev = &dev_priv->drm;
 	int ret;
 
 	intel_runtime_pm_get(dev_priv);
-	intel_suspend_gt_powersave(dev_priv);
 
 	mutex_lock(&dev->struct_mutex);
 
@@ -4703,6 +4702,26 @@ int i915_gem_suspend(struct drm_i915_private *dev_priv)
 		goto err_unlock;
 	mutex_unlock(&dev->struct_mutex);
 
+	intel_runtime_pm_put(dev_priv);
+	return 0;
+
+err_unlock:
+	mutex_unlock(&dev->struct_mutex);
+	intel_runtime_pm_put(dev_priv);
+	return ret;
+}
+
+void i915_gem_hw_suspend(struct drm_i915_private *dev_priv)
+{
+	struct drm_device *dev = &dev_priv->drm;
+
+	intel_runtime_pm_get(dev_priv);
+	intel_suspend_gt_powersave(dev_priv);
+
+	mutex_lock(&dev->struct_mutex);
+
+	i915_gem_suspend_gtt_mappings(dev_priv);
+
 	/*
 	 * Neither the BIOS, ourselves or any other kernel
 	 * expects the system to be in execlists mode on startup,
@@ -4724,13 +4743,9 @@ int i915_gem_suspend(struct drm_i915_private *dev_priv)
 	 */
 	i915_gem_sanitize(dev_priv);
 
-	intel_runtime_pm_put(dev_priv);
-	return 0;
-
-err_unlock:
 	mutex_unlock(&dev->struct_mutex);
+
 	intel_runtime_pm_put(dev_priv);
-	return ret;
 }
 
 void i915_gem_resume(struct drm_i915_private *dev_priv)
-- 
1.9.1