[Intel-gfx] [PATCH v12 08/17] drm/i915/guc/slpc: Send SHUTDOWN event to stop SLPC tasks

[Sagar Arun Kamble]

From: Tom O'Rourke <Tom.O'Rourke at intel.com>

Send SLPC shutdown event during uc_fini_hw or prior to enabling SLPC
done while communicating updated parameters in shared data.

v1: Return void instead of ignored error code (Paulo). Removed WARN_ON
    for checking msb of gtt address of shared gem obj. (Chris)
    Added SLPC state update during disable, suspend and reset. Changed
    semantics of reset. It is supposed to just disable. (Sagar)

v2-v4: Rebase.

v5: Updated the input data structure. (Sagar)

v6: Rebase.

v7: s/i915_ggtt_offset/guc_ggtt_offset.

v8: Updated the status check post disabling to wait for 20us. (Sagar)

v9: Updated the status check wait time to 5ms for safe margin as it is
    handled similar to reset by SLPC. s/slpc_disabled/slpc_stopped

v10: Rebase.

Signed-off-by: Tom O'Rourke <Tom.O'Rourke at intel.com>
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Radoslaw Szwichtenberg <radoslaw.szwichtenberg at intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Sujaritha Sundaresan <sujaritha.sundaresan at intel.com>
Cc: Jeff McGee <jeff.mcgee at intel.com>
---
 drivers/gpu/drm/i915/intel_guc_slpc.c | 38 +++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_uc.c       |  6 +++---
 2 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_guc_slpc.c b/drivers/gpu/drm/i915/intel_guc_slpc.c
index bc2c717..7f75d218 100644
--- a/drivers/gpu/drm/i915/intel_guc_slpc.c
+++ b/drivers/gpu/drm/i915/intel_guc_slpc.c
@@ -368,6 +368,28 @@ static bool slpc_running(struct intel_guc_slpc *slpc)
 	return (data.global_state == SLPC_GLOBAL_STATE_RUNNING);
 }
 
+static void host2guc_slpc_shutdown(struct intel_guc_slpc *slpc)
+{
+	struct intel_guc *guc = slpc_to_guc(slpc);
+	u32 shared_data_gtt_offset = intel_guc_ggtt_offset(guc, slpc->vma);
+	struct slpc_event_input data = {0};
+
+	data.header.value = SLPC_EVENT(SLPC_EVENT_SHUTDOWN, 2);
+	data.args[0] = shared_data_gtt_offset;
+	data.args[1] = 0;
+
+	slpc_send(slpc, &data, 4);
+}
+
+static bool slpc_stopped(struct intel_guc_slpc *slpc)
+{
+	struct slpc_shared_data data;
+
+	slpc_read_shared_data(slpc, &data);
+
+	return (data.global_state == SLPC_GLOBAL_STATE_NOT_RUNNING);
+}
+
 /**
  * intel_guc_slpc_init() - Initialize the SLPC shared data structure.
  * @slpc: pointer to intel_guc_slpc.
@@ -448,8 +470,24 @@ int intel_guc_slpc_enable(struct intel_guc_slpc *slpc)
 	return 0;
 }
 
+/**
+ * intel_guc_slpc_disable() - Stop SLPC tasks.
+ * @slpc: pointer to intel_guc_slpc.
+ *
+ * This function will stop GuC SLPC tasks by sending Host to GuC action.
+ */
 void intel_guc_slpc_disable(struct intel_guc_slpc *slpc)
 {
+	mutex_lock(&slpc->lock);
+
+	host2guc_slpc_shutdown(slpc);
+
+	/* Ensure SLPC is not running */
+	if (wait_for(slpc_stopped(slpc), 5))
+		DRM_ERROR("SLPC not disabled! State = %s\n",
+			  slpc_get_state(slpc));
+
+	mutex_unlock(&slpc->lock);
 }
 
 /**
diff --git a/drivers/gpu/drm/i915/intel_uc.c b/drivers/gpu/drm/i915/intel_uc.c
index 5bf33c8..ece6687 100644
--- a/drivers/gpu/drm/i915/intel_uc.c
+++ b/drivers/gpu/drm/i915/intel_uc.c
@@ -359,6 +359,9 @@ void intel_uc_sanitize(struct drm_i915_private *i915)
 
 	GEM_BUG_ON(!HAS_GUC(i915));
 
+	if (USES_GUC_SLPC(dev_priv))
+		intel_guc_slpc_disable(&guc->slpc);
+
 	guc_disable_communication(guc);
 
 	intel_huc_sanitize(huc);
@@ -484,9 +487,6 @@ void intel_uc_fini_hw(struct drm_i915_private *dev_priv)
 	if (USES_GUC_SUBMISSION(dev_priv))
 		intel_guc_submission_disable(guc);
 
-	if (USES_GUC_SLPC(dev_priv))
-		intel_guc_slpc_disable(&guc->slpc);
-
 	guc_disable_communication(guc);
 }
 
-- 
2.7.4