drm/xe/configfs: Dump custom settings when binding

Device configuration using configfs could be prepared long time prior
the driver load. Currently all the xe configfs entries are for things
that are important to have in the log if a non-default value is being
used. Add a info-level message about that with the individual entries
that are different than the default.

Based on previous patch by Michal Wajdeczko.

Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Link: https://lore.kernel.org/r/20250821-psmi-v5-12-34ab7550d3d8@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

3 files changed, 44 insertions, 0 deletions

diff --git a/drivers/gpu/drm/xe/xe_configfs.c b/drivers/gpu/drm/xe/xe_configfs.c
index 26c5e1b29263..29a12d02443d 100644
--- a/drivers/gpu/drm/xe/xe_configfs.c
+++ b/drivers/gpu/drm/xe/xe_configfs.c
@@ -442,6 +442,45 @@ static struct xe_config_group_device *find_xe_config_group_device(struct pci_dev
 	return to_xe_config_group_device(item);
 }
 
+static void dump_custom_dev_config(struct pci_dev *pdev,
+				   struct xe_config_group_device *dev)
+{
+#define PRI_CUSTOM_ATTR(fmt_, attr_) do { \
+		if (dev->config.attr_ != device_defaults.attr_) \
+			pci_info(pdev, "configfs: " __stringify(attr_) " = " fmt_ "\n", \
+				 dev->config.attr_); \
+	} while (0)
+
+	PRI_CUSTOM_ATTR("%llx", engines_allowed);
+	PRI_CUSTOM_ATTR("%d", enable_psmi);
+	PRI_CUSTOM_ATTR("%d", survivability_mode);
+
+#undef PRI_CUSTOM_ATTR
+}
+
+/**
+ * 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 different than the default value.
+ */
+void xe_configfs_check_device(struct pci_dev *pdev)
+{
+	struct xe_config_group_device *dev = find_xe_config_group_device(pdev);
+
+	if (!dev)
+		return;
+
+	/* memcmp here is safe as both are zero-initialized */
+	if (memcmp(&dev->config, &device_defaults, sizeof(dev->config))) {
+		pci_info(pdev, "Found custom settings in configfs\n");
+		dump_custom_dev_config(pdev, dev);
+	}
+
+	config_group_put(&dev->group);
+}
+
 /**
  * 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 603dd7796c8b..58c8c3164000 100644
--- a/drivers/gpu/drm/xe/xe_configfs.h
+++ b/drivers/gpu/drm/xe/xe_configfs.h
@@ -13,6 +13,7 @@ struct pci_dev;
 #if IS_ENABLED(CONFIG_CONFIGFS_FS)
 int xe_configfs_init(void);
 void xe_configfs_exit(void);
+void 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);
@@ -20,6 +21,7 @@ bool xe_configfs_get_psmi_enabled(struct pci_dev *pdev);
 #else
 static inline int xe_configfs_init(void) { return 0; }
 static inline void xe_configfs_exit(void) { }
+static inline void xe_configfs_check_device(struct pci_dev *pdev) { }
 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 419e29cebbba..a8bab19111c3 100644
--- a/drivers/gpu/drm/xe/xe_pci.c
+++ b/drivers/gpu/drm/xe/xe_pci.c
@@ -18,6 +18,7 @@
 #include "display/xe_display.h"
 #include "regs/xe_gt_regs.h"
 #include "regs/xe_regs.h"
+#include "xe_configfs.h"
 #include "xe_device.h"
 #include "xe_drv.h"
 #include "xe_gt.h"
@@ -816,6 +817,8 @@ 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"