drm/i915/guc: Add host2guc notification for suspend and resume

Add host2guc interface to notify GuC power state changes when
enter or resume from power saving state.

v3: Move intel_guc_suspend to i915_drm_suspend for consistency.

v2: Add GuC suspend/resume to runtime suspend/resume too

v1: Change to a more flexible way when fill host to GuC scratch
data in order to remove hard coding.

Signed-off-by: Alex Dai <yu.dai@intel.com>
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index 0b1797f..036b42b 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -923,3 +923,53 @@
 	gem_release_guc_obj(guc->ctx_pool_obj);
 	guc->ctx_pool_obj = NULL;
 }
+
+/**
+ * intel_guc_suspend() - notify GuC entering suspend state
+ * @dev:	drm device
+ */
+int intel_guc_suspend(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_guc *guc = &dev_priv->guc;
+	struct intel_context *ctx;
+	u32 data[3];
+
+	if (!i915.enable_guc_submission)
+		return 0;
+
+	ctx = dev_priv->ring[RCS].default_context;
+
+	data[0] = HOST2GUC_ACTION_ENTER_S_STATE;
+	/* any value greater than GUC_POWER_D0 */
+	data[1] = GUC_POWER_D1;
+	/* first page is shared data with GuC */
+	data[2] = i915_gem_obj_ggtt_offset(ctx->engine[RCS].state);
+
+	return host2guc_action(guc, data, ARRAY_SIZE(data));
+}
+
+
+/**
+ * intel_guc_resume() - notify GuC resuming from suspend state
+ * @dev:	drm device
+ */
+int intel_guc_resume(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_guc *guc = &dev_priv->guc;
+	struct intel_context *ctx;
+	u32 data[3];
+
+	if (!i915.enable_guc_submission)
+		return 0;
+
+	ctx = dev_priv->ring[RCS].default_context;
+
+	data[0] = HOST2GUC_ACTION_EXIT_S_STATE;
+	data[1] = GUC_POWER_D0;
+	/* first page is shared data with GuC */
+	data[2] = i915_gem_obj_ggtt_offset(ctx->engine[RCS].state);
+
+	return host2guc_action(guc, data, ARRAY_SIZE(data));
+}