[PATCH 2/4] drm/xe: Save and restore PCI state

[Aravind Iddamsetty <aravind.iddamsetty@xxxxxxxxxxxxxxx>]

Save and restore PCI states where ever needed.

Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty@xxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/xe/xe_device_types.h |  3 ++
 drivers/gpu/drm/xe/xe_pci.c          | 48 ++++++++++++++++++++++++++--
 drivers/gpu/drm/xe/xe_pci.h          |  4 ++-
 3 files changed, 51 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
index 8244b177a6a3..0a66555229e9 100644
--- a/drivers/gpu/drm/xe/xe_device_types.h
+++ b/drivers/gpu/drm/xe/xe_device_types.h
@@ -462,6 +462,9 @@ struct xe_device {
 	/** @needs_flr_on_fini: requests function-reset on fini */
 	bool needs_flr_on_fini;
 
+	/** @pci_state: PCI state of device */
+	struct pci_saved_state *pci_state;
+
 	/* private: */
 
 #if IS_ENABLED(CONFIG_DRM_XE_DISPLAY)
diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
index 65ea44672cab..fd45f235b35c 100644
--- a/drivers/gpu/drm/xe/xe_pci.c
+++ b/drivers/gpu/drm/xe/xe_pci.c
@@ -391,6 +391,41 @@ MODULE_DEVICE_TABLE(pci, pciidlist);
 
 #undef INTEL_VGA_DEVICE
 
+static bool xe_save_pci_state(struct pci_dev *pdev)
+{
+	struct xe_device *xe = pci_get_drvdata(pdev);
+
+	if (pci_save_state(pdev))
+		return false;
+
+	kfree(xe->pci_state);
+
+	xe->pci_state = pci_store_saved_state(pdev);
+	if (!xe->pci_state) {
+		drm_err(&xe->drm, "Failed to store PCI saved state\n");
+		return false;
+	}
+
+	return true;
+}
+
+void xe_load_pci_state(struct pci_dev *pdev)
+{
+	struct xe_device *xe = pci_get_drvdata(pdev);
+	int ret;
+
+	if (!xe->pci_state)
+		return;
+
+	ret = pci_load_saved_state(pdev, xe->pci_state);
+	if (ret) {
+		drm_warn(&xe->drm, "Failed to load PCI state err:%d\n", ret);
+		return;
+	}
+
+	pci_restore_state(pdev);
+}
+
 /* is device_id present in comma separated list of ids */
 static bool device_id_in_list(u16 device_id, const char *devices, bool negative)
 {
@@ -696,6 +731,8 @@ static void xe_pci_remove(struct pci_dev *pdev)
 
 	xe_device_remove(xe);
 	xe_pm_runtime_fini(xe);
+
+	kfree(xe->pci_state);
 	pci_set_drvdata(pdev, NULL);
 }
 
@@ -796,6 +833,9 @@ static int xe_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	drm_dbg(&xe->drm, "d3cold: capable=%s\n",
 		str_yes_no(xe->d3cold.capable));
 
+	if (xe_save_pci_state(pdev))
+		pci_restore_state(pdev);
+
 	return 0;
 
 err_driver_cleanup:
@@ -847,7 +887,7 @@ static int xe_pci_suspend(struct device *dev)
 	 */
 	d3cold_toggle(pdev, D3COLD_ENABLE);
 
-	pci_save_state(pdev);
+	xe_save_pci_state(pdev);
 	pci_disable_device(pdev);
 
 	return 0;
@@ -871,6 +911,8 @@ static int xe_pci_resume(struct device *dev)
 
 	pci_set_master(pdev);
 
+	xe_load_pci_state(pdev);
+
 	err = xe_pm_resume(pdev_to_xe_device(pdev));
 	if (err)
 		return err;
@@ -888,7 +930,7 @@ static int xe_pci_runtime_suspend(struct device *dev)
 	if (err)
 		return err;
 
-	pci_save_state(pdev);
+	xe_save_pci_state(pdev);
 
 	if (xe->d3cold.allowed) {
 		d3cold_toggle(pdev, D3COLD_ENABLE);
@@ -913,7 +955,7 @@ static int xe_pci_runtime_resume(struct device *dev)
 	if (err)
 		return err;
 
-	pci_restore_state(pdev);
+	xe_load_pci_state(pdev);
 
 	if (xe->d3cold.allowed) {
 		err = pci_enable_device(pdev);
diff --git a/drivers/gpu/drm/xe/xe_pci.h b/drivers/gpu/drm/xe/xe_pci.h
index 611c1209b14c..73b90a430d1f 100644
--- a/drivers/gpu/drm/xe/xe_pci.h
+++ b/drivers/gpu/drm/xe/xe_pci.h
@@ -6,7 +6,9 @@
 #ifndef _XE_PCI_H_
 #define _XE_PCI_H_
 
+struct pci_dev;
+
 int xe_register_pci_driver(void);
 void xe_unregister_pci_driver(void);
-
+void xe_load_pci_state(struct pci_dev *pdev);
 #endif
-- 
2.25.1