[PATCH 2/5] drm/i915/guc: Release all client doorbells on suspend and acquire on resume

[Sagar Arun Kamble]

Before GT device suspend, i915 should release GuC client doorbells by
stopping doorbell controller snooping and doorbell deallocation through
GuC. They need to be acquired again on resume. This will also resolve
the driver unload issue with GuC, where doorbell deallocation was being
done post GEM suspend.
Release function is called from guc_suspend prior to sending sleep action
during runtime and drm suspend. Acquiral is different in runtime and drm
resume paths as on drm resume we are currently doing full reinit. Release
should be done in synchronization with acquire hence GuC suspend/resume
along with doorbell release/acquire should be under struct_mutex. Upcoming
suspend and resume restructuring for GuC will update these changes.

Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski at intel.com>
Cc: Michel Thierry <michel.thierry at intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Arkadiusz Hiler <arkadiusz.hiler at intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_drv.c            |  3 +++
 drivers/gpu/drm/i915/i915_gem.c            |  5 +++--
 drivers/gpu/drm/i915/i915_guc_submission.c | 20 ++++++++++++++++----
 drivers/gpu/drm/i915/i915_guc_submission.h |  2 ++
 drivers/gpu/drm/i915/intel_guc.c           |  2 ++
 5 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index e7e9e06..3df8a7d 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -47,6 +47,7 @@
 #include <drm/i915_drm.h>
 
 #include "i915_drv.h"
+#include "i915_guc_submission.h"
 #include "i915_trace.h"
 #include "i915_vgpu.h"
 #include "intel_drv.h"
@@ -2615,6 +2616,8 @@ static int intel_runtime_resume(struct device *kdev)
 
 	intel_guc_resume(dev_priv);
 
+	i915_guc_clients_acquire_doorbells(&dev_priv->guc);
+
 	if (IS_GEN9_LP(dev_priv)) {
 		bxt_disable_dc9(dev_priv);
 		bxt_display_core_init(dev_priv, true);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 6a71805..cbce714 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -29,13 +29,14 @@
 #include <drm/drm_vma_manager.h>
 #include <drm/i915_drm.h>
 #include "i915_drv.h"
+#include "i915_gemfs.h"
 #include "i915_gem_clflush.h"
-#include "i915_vgpu.h"
+#include "i915_guc_submission.h"
 #include "i915_trace.h"
+#include "i915_vgpu.h"
 #include "intel_drv.h"
 #include "intel_frontbuffer.h"
 #include "intel_mocs.h"
-#include "i915_gemfs.h"
 #include <linux/dma-fence-array.h>
 #include <linux/kthread.h>
 #include <linux/reservation.h>
diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index b6486dc..b989edf 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -1047,10 +1047,6 @@ static void guc_client_free(struct i915_guc_client *client)
 	 * Be sure to drop any locks
 	 */
 
-	/* FIXME: in many cases, by the time we get here the GuC has been
-	 * reset, so we cannot destroy the doorbell properly. Ignore the
-	 * error message for now */
-	destroy_doorbell(client, true);
 	guc_stage_desc_fini(client->guc, client);
 	i915_gem_object_unpin_map(client->vma->obj);
 	i915_vma_unpin_and_release(&client->vma);
@@ -1102,6 +1098,21 @@ static void guc_clients_destroy(struct intel_guc *guc)
 	guc_client_free(client);
 }
 
+void i915_guc_clients_acquire_doorbells(struct intel_guc *guc)
+{
+	if (guc->fw.load_status != INTEL_UC_FIRMWARE_SUCCESS)
+		return;
+
+	create_doorbell(guc->execbuf_client);
+	create_doorbell(guc->preempt_client);
+}
+
+void i915_guc_clients_release_doorbells(struct intel_guc *guc)
+{
+	destroy_doorbell(guc->preempt_client, true);
+	destroy_doorbell(guc->execbuf_client, true);
+}
+
 static void guc_policy_init(struct guc_policy *policy)
 {
 	policy->execution_quantum = POLICY_DEFAULT_EXECUTION_QUANTUM_US;
@@ -1423,6 +1434,7 @@ int i915_guc_submission_enable(struct drm_i915_private *dev_priv)
 	} else {
 		guc_reset_wq(guc->execbuf_client);
 		guc_reset_wq(guc->preempt_client);
+		i915_guc_clients_acquire_doorbells(guc);
 	}
 
 	err = intel_guc_sample_forcewake(guc);
diff --git a/drivers/gpu/drm/i915/i915_guc_submission.h b/drivers/gpu/drm/i915/i915_guc_submission.h
index cb4353b..1d5cf22 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.h
+++ b/drivers/gpu/drm/i915/i915_guc_submission.h
@@ -72,6 +72,8 @@ struct i915_guc_client {
 	u64 submissions[I915_NUM_ENGINES];
 };
 
+void i915_guc_clients_acquire_doorbells(struct intel_guc *guc);
+void i915_guc_clients_release_doorbells(struct intel_guc *guc);
 int i915_guc_submission_init(struct drm_i915_private *dev_priv);
 int i915_guc_submission_enable(struct drm_i915_private *dev_priv);
 void i915_guc_submission_disable(struct drm_i915_private *dev_priv);
diff --git a/drivers/gpu/drm/i915/intel_guc.c b/drivers/gpu/drm/i915/intel_guc.c
index 9678630..b6eb5ac 100644
--- a/drivers/gpu/drm/i915/intel_guc.c
+++ b/drivers/gpu/drm/i915/intel_guc.c
@@ -274,6 +274,8 @@ int intel_guc_suspend(struct drm_i915_private *dev_priv)
 	if (guc->fw.load_status != INTEL_UC_FIRMWARE_SUCCESS)
 		return 0;
 
+	i915_guc_clients_release_doorbells(&dev_priv->guc);
+
 	gen9_disable_guc_interrupts(dev_priv);
 
 	data[0] = INTEL_GUC_ACTION_ENTER_S_STATE;
-- 
1.9.1