[PATCH v11 6/7] drm/xe/xe_sysctrl: Add System Controller power management support

["Anoop, Vijay" <anoop.c.vijay@intel.com>]

From: Anoop Vijay <anoop.c.vijay@intel.com>

Add suspend and resume handlers for System Controller to handle system
(S3/S4) and runtime power management transitions.

The handlers disable SoC remapper region before entering low power
states and restore remapper configuration and mailbox interface on
resume, re-establishing communication with firmware.

Signed-off-by: Anoop Vijay <anoop.c.vijay@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
---
v10: (Riana, Umesh)
- Added sysctrl suspend/resume handling

v11: (Badal)
- Remove explicit SoC remapper disable on suspend
---
 drivers/gpu/drm/xe/xe_pm.c      | 11 +++++++++
 drivers/gpu/drm/xe/xe_sysctrl.c | 44 +++++++++++++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_sysctrl.h |  2 ++
 3 files changed, 57 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
index 01185f10a883..abdddd44a575 100644
--- a/drivers/gpu/drm/xe/xe_pm.c
+++ b/drivers/gpu/drm/xe/xe_pm.c
@@ -26,6 +26,7 @@
 #include "xe_pcode.h"
 #include "xe_pxp.h"
 #include "xe_sriov_vf_ccs.h"
+#include "xe_sysctrl.h"
 #include "xe_trace.h"
 #include "xe_vm.h"
 #include "xe_wa.h"
@@ -206,6 +207,8 @@ int xe_pm_suspend(struct xe_device *xe)
 
 	xe_i2c_pm_suspend(xe);
 
+	xe_sysctrl_pm_suspend(xe);
+
 	drm_dbg(&xe->drm, "Device suspended\n");
 	xe_pm_block_end_signalling();
 
@@ -259,6 +262,8 @@ int xe_pm_resume(struct xe_device *xe)
 
 	xe_i2c_pm_resume(xe, true);
 
+	xe_sysctrl_pm_resume(xe);
+
 	xe_irq_resume(xe);
 
 	for_each_gt(gt, xe, id) {
@@ -618,6 +623,9 @@ int xe_pm_runtime_suspend(struct xe_device *xe)
 
 	xe_i2c_pm_suspend(xe);
 
+	if (xe->d3cold.allowed)
+		xe_sysctrl_pm_suspend(xe);
+
 	xe_rpm_lockmap_release(xe);
 	xe_pm_write_callback_task(xe, NULL);
 	return 0;
@@ -670,6 +678,9 @@ int xe_pm_runtime_resume(struct xe_device *xe)
 
 	xe_i2c_pm_resume(xe, xe->d3cold.allowed);
 
+	if (xe->d3cold.allowed)
+		xe_sysctrl_pm_resume(xe);
+
 	xe_irq_resume(xe);
 
 	for_each_gt(gt, xe, id) {
diff --git a/drivers/gpu/drm/xe/xe_sysctrl.c b/drivers/gpu/drm/xe/xe_sysctrl.c
index 84e3b70043a1..d8f1f8cc2244 100644
--- a/drivers/gpu/drm/xe/xe_sysctrl.c
+++ b/drivers/gpu/drm/xe/xe_sysctrl.c
@@ -82,3 +82,47 @@ int xe_sysctrl_init(struct xe_device *xe)
 
 	return 0;
 }
+
+/**
+ * xe_sysctrl_pm_suspend() - System Controller suspend handler
+ * @xe: xe device instance
+ *
+ * Invoked during system suspend (S3/S4) and runtime suspend to D3.
+ *
+ * The SoC remapper region is cleared automatically by hardware on D3
+ * cold entry. No action is required. This function is kept to preserve
+ * suspend/resume symmetry and provide a hook for future System Controller
+ * suspend handling.
+ */
+void xe_sysctrl_pm_suspend(struct xe_device *xe)
+{
+	if (!xe->info.has_sysctrl)
+		return;
+
+	if (IS_SRIOV_VF(xe))
+		return;
+
+	/* SoC remapper region is disabled automatically on D3 cold entry; no action required. */
+}
+
+/**
+ * xe_sysctrl_pm_resume() - System Controller resume handler
+ * @xe: xe device instance
+ *
+ * Invoked during system resume (S3/S4 to S0) and runtime resume from D3cold.
+ * Restores SoC remapper configuration and reinitializes mailbox interface.
+ */
+void xe_sysctrl_pm_resume(struct xe_device *xe)
+{
+	struct xe_sysctrl *sc = &xe->sc;
+
+	if (!xe->info.has_sysctrl)
+		return;
+
+	if (IS_SRIOV_VF(xe))
+		return;
+
+	xe->soc_remapper.set_sysctrl_region(xe, SYSCTRL_MAILBOX_INDEX);
+
+	xe_sysctrl_mailbox_init(sc);
+}
diff --git a/drivers/gpu/drm/xe/xe_sysctrl.h b/drivers/gpu/drm/xe/xe_sysctrl.h
index d5d8735038ae..a816feed8da6 100644
--- a/drivers/gpu/drm/xe/xe_sysctrl.h
+++ b/drivers/gpu/drm/xe/xe_sysctrl.h
@@ -17,5 +17,7 @@ static inline struct xe_device *sc_to_xe(struct xe_sysctrl *sc)
 }
 
 int xe_sysctrl_init(struct xe_device *xe);
+void xe_sysctrl_pm_suspend(struct xe_device *xe);
+void xe_sysctrl_pm_resume(struct xe_device *xe);
 
 #endif
-- 
2.43.0