[Intel-xe] [PATCH v2 1/2] drm/xe: Add helper functions to toggle CT communication

[Riana Tauro]

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

Add helper functions to toggle CT communication. Modify existing
guc communication function

v2: do not register/unregister ctb, toggle the enabled variable
    instead.
    enable irqs while toggling CT (Daniele)

Signed-off-by: Riana Tauro <riana.tauro at intel.com>
---
 drivers/gpu/drm/xe/xe_guc.c    | 36 ++++++++++++++++++++++++++++++----
 drivers/gpu/drm/xe/xe_guc.h    |  3 ++-
 drivers/gpu/drm/xe/xe_guc_ct.c | 15 ++++++++++++--
 drivers/gpu/drm/xe/xe_guc_ct.h |  1 +
 drivers/gpu/drm/xe/xe_uc.c     |  2 +-
 5 files changed, 49 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_guc.c b/drivers/gpu/drm/xe/xe_guc.c
index 84f0b5488783..40c7bf0c50c5 100644
--- a/drivers/gpu/drm/xe/xe_guc.c
+++ b/drivers/gpu/drm/xe/xe_guc.c
@@ -507,7 +507,7 @@ int xe_guc_min_load_for_hwconfig(struct xe_guc *guc)
 	if (ret)
 		return ret;
 
-	ret = xe_guc_enable_communication(guc);
+	ret = xe_guc_enable_communication(guc, true);
 	if (ret)
 		return ret;
 
@@ -560,16 +560,31 @@ static void guc_enable_irq(struct xe_guc *guc)
 	xe_mmio_rmw32(gt, GUC_SG_INTR_MASK, events, 0);
 }
 
-int xe_guc_enable_communication(struct xe_guc *guc)
+/**
+ * xe_guc_enable_communication - Enable GuC communication
+ * @guc: The GuC object
+ * @ctb_register: boolean to indicate if ctb registration needs to be done
+ *		  or toggling of the value.
+ *
+ * This function enables guc interrupts, toggles or registers CT communication
+ * and handles mmio messages.
+ *
+ * Return: 0 on success, negative error code on error.
+ */
+int xe_guc_enable_communication(struct xe_guc *guc, bool ctb_register)
 {
-	int err;
+	int err = 0;
 
 	guc_enable_irq(guc);
 
 	xe_mmio_rmw32(guc_to_gt(guc), PMINTRMSK,
 		      ARAT_EXPIRED_INTRMSK, 0);
 
-	err = xe_guc_ct_enable(&guc->ct);
+	if (ctb_register)
+		err = xe_guc_ct_enable(&guc->ct);
+	else
+		xe_guc_ct_toggle(&guc->ct, true);
+
 	if (err)
 		return err;
 
@@ -578,6 +593,19 @@ int xe_guc_enable_communication(struct xe_guc *guc)
 	return 0;
 }
 
+/**
+ * xe_guc_disable_communication - disables GuC communication
+ * @guc: The GuC object
+ *
+ * This function disables CT communication
+ */
+void xe_guc_disable_communication(struct xe_guc *guc)
+{
+	xe_guc_ct_toggle(&guc->ct, false);
+
+	guc_handle_mmio_msg(guc);
+}
+
 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..71dac0673e61 100644
--- a/drivers/gpu/drm/xe/xe_guc.h
+++ b/drivers/gpu/drm/xe/xe_guc.h
@@ -18,7 +18,8 @@ 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_enable_communication(struct xe_guc *guc);
+void xe_guc_disable_communication(struct xe_guc *guc);
+int xe_guc_enable_communication(struct xe_guc *guc, bool ctb_register);
 int xe_guc_suspend(struct xe_guc *guc);
 void xe_guc_notify(struct xe_guc *guc);
 int xe_guc_auth_huc(struct xe_guc *guc, u32 rsa_addr);
diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
index 8b686c8b3339..ff89a1a09f1f 100644
--- a/drivers/gpu/drm/xe/xe_guc_ct.c
+++ b/drivers/gpu/drm/xe/xe_guc_ct.c
@@ -319,14 +319,25 @@ int xe_guc_ct_enable(struct xe_guc_ct *ct)
 	return err;
 }
 
-void xe_guc_ct_disable(struct xe_guc_ct *ct)
+/**
+ * xe_guc_ct_toggle - Toggle GuC CT
+ * @ct: GuC CT
+ * @toggle: 0-disable, 1-enable
+ *
+ * This function enables or disables CT communication
+ */
+void xe_guc_ct_toggle(struct xe_guc_ct *ct, bool toggle)
 {
 	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 */
+	ct->enabled = toggle; /* Toggle CT communication */
 	spin_unlock_irq(&ct->fast_lock);
 	mutex_unlock(&ct->lock);
+}
 
+void xe_guc_ct_disable(struct xe_guc_ct *ct)
+{
+	xe_guc_ct_toggle(ct, false);
 	xa_destroy(&ct->fence_lookup);
 }
 
diff --git a/drivers/gpu/drm/xe/xe_guc_ct.h b/drivers/gpu/drm/xe/xe_guc_ct.h
index f15f8a4857e0..11166a7ce958 100644
--- a/drivers/gpu/drm/xe/xe_guc_ct.h
+++ b/drivers/gpu/drm/xe/xe_guc_ct.h
@@ -14,6 +14,7 @@ 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);
 void xe_guc_ct_fast_path(struct xe_guc_ct *ct);
+void xe_guc_ct_toggle(struct xe_guc_ct *ct, bool toggle);
 
 struct xe_guc_ct_snapshot *
 xe_guc_ct_snapshot_capture(struct xe_guc_ct *ct, bool atomic);
diff --git a/drivers/gpu/drm/xe/xe_uc.c b/drivers/gpu/drm/xe/xe_uc.c
index 784f53c5f282..bf75c39d929d 100644
--- a/drivers/gpu/drm/xe/xe_uc.c
+++ b/drivers/gpu/drm/xe/xe_uc.c
@@ -148,7 +148,7 @@ int xe_uc_init_hw(struct xe_uc *uc)
 	if (ret)
 		return ret;
 
-	ret = xe_guc_enable_communication(&uc->guc);
+	ret = xe_guc_enable_communication(&uc->guc, true);
 	if (ret)
 		return ret;
 
-- 
2.40.0