[Intel-xe] [PATCH 1/2] RFC drm/xe: Disable ctb communication

[Riana Tauro]

During Runtime suspend, GuC is reset for both D0->D3hot/D3Cold
transistions. It is not necessary for GuC to reset for D0 -> D3hot,
only enable/disable ctb communication.

Modify the existing ct disable function to send a request
to disable ct communication if firmware is running.
Add a function to disable guc communication.

Signed-off-by: Riana Tauro <riana.tauro at intel.com>
---
 drivers/gpu/drm/xe/xe_guc.c    | 15 +++++++++++++++
 drivers/gpu/drm/xe/xe_guc.h    |  1 +
 drivers/gpu/drm/xe/xe_guc_ct.c | 11 ++++++++++-
 drivers/gpu/drm/xe/xe_guc_ct.h |  2 +-
 4 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
index 2493c5859948..3e4c00bee6bf 100644
--- a/drivers/gpu/drm/xe/xe_guc.c
+++ b/drivers/gpu/drm/xe/xe_guc.c
@@ -557,6 +557,21 @@ int xe_guc_enable_communication(struct xe_guc *guc)
 	return 0;
 }
 
+int xe_guc_disable_communication(struct xe_guc *guc)
+{
+	int err;
+	struct xe_guc_ct *ct = &guc->ct;
+
+	err = xe_guc_ct_disable(ct);
+	if (err)
+		return err;
+
+	/* Check for messages received during/after the CT disable */
+	guc_handle_mmio_msg(guc);
+
+	return 0;
+}
+
 int xe_guc_suspend(struct xe_guc *guc)
 {
 	int ret;
diff --git a/drivers/gpu/drm/xe/xe_guc.h b/drivers/gpu/drm/xe/xe_guc.h
index 3addd8fc674a..18cf5d02eea7 100644
--- a/drivers/gpu/drm/xe/xe_guc.h
+++ b/drivers/gpu/drm/xe/xe_guc.h
@@ -18,6 +18,7 @@ int xe_guc_post_load_init(struct xe_guc *guc);
 int xe_guc_reset(struct xe_guc *guc);
 int xe_guc_upload(struct xe_guc *guc);
 int xe_guc_min_load_for_hwconfig(struct xe_guc *guc);
+int xe_guc_disable_communication(struct xe_guc *guc);
 int xe_guc_enable_communication(struct xe_guc *guc);
 int xe_guc_suspend(struct xe_guc *guc);
 void xe_guc_notify(struct xe_guc *guc);
diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
index 59136b6a7c6f..64c2029b2752 100644
--- a/drivers/gpu/drm/xe/xe_guc_ct.c
+++ b/drivers/gpu/drm/xe/xe_guc_ct.c
@@ -21,6 +21,7 @@
 #include "xe_map.h"
 #include "xe_pm.h"
 #include "xe_trace.h"
+#include "xe_uc_fw.h"
 
 /* Used when a CT send wants to block and / or receive data */
 struct g2h_fence {
@@ -319,15 +320,23 @@ int xe_guc_ct_enable(struct xe_guc_ct *ct)
 	return err;
 }
 
-void xe_guc_ct_disable(struct xe_guc_ct *ct)
+int xe_guc_ct_disable(struct xe_guc_ct *ct)
 {
+	struct xe_guc *guc = ct_to_guc(ct);
+	int ret = 0;
+
 	mutex_lock(&ct->lock); /* Serialise dequeue_one_g2h() */
 	spin_lock_irq(&ct->fast_lock); /* Serialise CT fast-path */
 	ct->enabled = false; /* Finally disable CT communication */
 	spin_unlock_irq(&ct->fast_lock);
 	mutex_unlock(&ct->lock);
 
+	if (xe_uc_fw_is_running(&guc->fw))
+		ret = guc_ct_control_toggle(ct, false);
+
 	xa_destroy(&ct->fence_lookup);
+
+	return ret;
 }
 
 static bool h2g_has_room(struct xe_guc_ct *ct, u32 cmd_len)
diff --git a/drivers/gpu/drm/xe/xe_guc_ct.h b/drivers/gpu/drm/xe/xe_guc_ct.h
index f15f8a4857e0..1ad150c19ae3 100644
--- a/drivers/gpu/drm/xe/xe_guc_ct.h
+++ b/drivers/gpu/drm/xe/xe_guc_ct.h
@@ -12,7 +12,7 @@ struct drm_printer;
 
 int xe_guc_ct_init(struct xe_guc_ct *ct);
 int xe_guc_ct_enable(struct xe_guc_ct *ct);
-void xe_guc_ct_disable(struct xe_guc_ct *ct);
+int xe_guc_ct_disable(struct xe_guc_ct *ct);
 void xe_guc_ct_fast_path(struct xe_guc_ct *ct);
 
 struct xe_guc_ct_snapshot *
-- 
2.40.0