[PATCH v3 4/6] drm/xe/configfs: Check if device was preconfigured

[Michal Wajdeczko]

Since device configuration using configfs could be prepared long
time prior the driver load, add a debug log whether the current
device driver probe is using custom or default settings.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Lucas De Marchi <lucas.demarchi at intel.com>
---
 drivers/gpu/drm/xe/xe_configfs.c | 35 ++++++++++++++++++++++++++++++--
 drivers/gpu/drm/xe/xe_configfs.h |  2 ++
 drivers/gpu/drm/xe/xe_pci.c      |  3 +++
 3 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_configfs.c b/drivers/gpu/drm/xe/xe_configfs.c
index 36e2b45b305f..f83e8e9f070f 100644
--- a/drivers/gpu/drm/xe/xe_configfs.c
+++ b/drivers/gpu/drm/xe/xe_configfs.c
@@ -118,6 +118,17 @@ static struct xe_config_device *to_xe_config_device(struct config_item *item)
 	return container_of(to_config_group(item), struct xe_config_device, group);
 }
 
+static void xe_config_set_defaults(struct xe_config_device *dev)
+{
+	dev->engines_allowed = U64_MAX;
+	dev->survivability_mode = false;
+}
+
+static bool xe_config_is_default(const struct xe_config_device *dev)
+{
+	return dev->engines_allowed == U64_MAX && !dev->survivability_mode;
+}
+
 static ssize_t survivability_mode_show(struct config_item *item, char *page)
 {
 	struct xe_config_device *dev = to_xe_config_device(item);
@@ -281,8 +292,7 @@ static struct config_group *xe_config_make_device_group(struct config_group *gro
 	if (!dev)
 		return ERR_PTR(-ENOMEM);
 
-	/* Default values */
-	dev->engines_allowed = U64_MAX;
+	xe_config_set_defaults(dev);
 
 	config_group_init_type_name(&dev->group, name, &xe_config_device_type);
 
@@ -323,6 +333,27 @@ static struct xe_config_device *configfs_find_group(struct pci_dev *pdev)
 	return to_xe_config_device(item);
 }
 
+/**
+ * xe_configfs_check_device() - Test if device was configured by configfs
+ * @pdev: the &pci_dev device to test
+ *
+ * Try to find the configfs group that belongs to the specified pci device
+ * and print a diagnostic message if found.
+ *
+ * Return: true if config group is found, false otherwise
+ */
+bool xe_configfs_check_device(struct pci_dev *pdev)
+{
+	struct xe_config_device *cfg = configfs_find_group(pdev);
+
+	if (!cfg)
+		return false;
+
+	pci_dbg(pdev, "found %s settings in configfs\n",
+		xe_config_is_default(cfg) ? "default" : "custom");
+	return true;
+}
+
 /**
  * xe_configfs_get_survivability_mode - get configfs survivability mode attribute
  * @pdev: pci device
diff --git a/drivers/gpu/drm/xe/xe_configfs.h b/drivers/gpu/drm/xe/xe_configfs.h
index fb8764008089..cdccf1f9b716 100644
--- a/drivers/gpu/drm/xe/xe_configfs.h
+++ b/drivers/gpu/drm/xe/xe_configfs.h
@@ -13,12 +13,14 @@ struct pci_dev;
 #if IS_ENABLED(CONFIG_CONFIGFS_FS)
 int xe_configfs_init(void);
 void xe_configfs_exit(void);
+bool xe_configfs_check_device(struct pci_dev *pdev);
 bool xe_configfs_get_survivability_mode(struct pci_dev *pdev);
 void xe_configfs_clear_survivability_mode(struct pci_dev *pdev);
 u64 xe_configfs_get_engines_allowed(struct pci_dev *pdev);
 #else
 static inline int xe_configfs_init(void) { return 0; }
 static inline void xe_configfs_exit(void) { }
+static inline bool xe_configfs_check_device(struct pci_dev *pdev) { return false; }
 static inline bool xe_configfs_get_survivability_mode(struct pci_dev *pdev) { return false; }
 static inline void xe_configfs_clear_survivability_mode(struct pci_dev *pdev) { }
 static inline u64 xe_configfs_get_engines_allowed(struct pci_dev *pdev) { return U64_MAX; }
diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
index f4ea13527945..322dc52c4a0b 100644
--- a/drivers/gpu/drm/xe/xe_pci.c
+++ b/drivers/gpu/drm/xe/xe_pci.c
@@ -17,6 +17,7 @@
 
 #include "display/xe_display.h"
 #include "regs/xe_gt_regs.h"
+#include "xe_configfs.h"
 #include "xe_device.h"
 #include "xe_drv.h"
 #include "xe_gt.h"
@@ -770,6 +771,8 @@ static int xe_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct xe_device *xe;
 	int err;
 
+	xe_configfs_check_device(pdev);
+
 	if (desc->require_force_probe && !id_forced(pdev->device)) {
 		dev_info(&pdev->dev,
 			 "Your graphics device %04x is not officially supported\n"
-- 
2.47.1