drm/xe/sysfs: Simplify sysfs registration

Instead of manually maintaining each sysfs file define and use
attribute groups and register them using device managed function.
Then use is_visible() to filter-out unsupported attributes.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Raag Jadav <raag.jadav@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250916170029.3313-3-michal.wajdeczko@intel.com

Author: mwajdecz

drivers/gpu/drm/xe/xe_device_sysfs.c

@@ -71,6 +71,15 @@ vram_d3cold_threshold_store(struct device *dev, struct device_attribute *attr,
 
 static DEVICE_ATTR_RW(vram_d3cold_threshold);
 
+static struct attribute *vram_attrs[] = {
+	&dev_attr_vram_d3cold_threshold.attr,
+	NULL
+};
+
+static const struct attribute_group vram_attr_group = {
+	.attrs = vram_attrs,
+};
+
 static ssize_t
 lb_fan_control_version_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
@@ -149,41 +158,16 @@ lb_voltage_regulator_version_show(struct device *dev, struct device_attribute *a
 }
 static DEVICE_ATTR_ADMIN_RO(lb_voltage_regulator_version);
 
-static int late_bind_create_files(struct device *dev)
-{
-	struct xe_device *xe = pdev_to_xe_device(to_pci_dev(dev));
-	struct xe_tile *root = xe_device_get_root_tile(xe);
-	u32 cap = 0;
-	int ret;
-
-	xe_pm_runtime_get(xe);
-
-	ret = xe_pcode_read(root, PCODE_MBOX(PCODE_LATE_BINDING, GET_CAPABILITY_STATUS, 0),
-			    &cap, NULL);
-	if (ret) {
-		if (ret == -ENXIO) {
-			drm_dbg(&xe->drm, "Late binding not supported by firmware\n");
-			ret = 0;
-		}
-		goto out;
-	}
-
-	if (REG_FIELD_GET(V1_FAN_SUPPORTED, cap)) {
-		ret = sysfs_create_file(&dev->kobj, &dev_attr_lb_fan_control_version.attr);
-		if (ret)
-			goto out;
-	}
-
-	if (REG_FIELD_GET(VR_PARAMS_SUPPORTED, cap))
-		ret = sysfs_create_file(&dev->kobj, &dev_attr_lb_voltage_regulator_version.attr);
-out:
-	xe_pm_runtime_put(xe);
-
-	return ret;
-}
+static struct attribute *late_bind_attrs[] = {
+	&dev_attr_lb_fan_control_version.attr,
+	&dev_attr_lb_voltage_regulator_version.attr,
+	NULL
+};
 
-static void late_bind_remove_files(struct device *dev)
+static umode_t late_bind_attr_is_visible(struct kobject *kobj,
+					 struct attribute *attr, int n)
 {
+	struct device *dev = kobj_to_dev(kobj);
 	struct xe_device *xe = pdev_to_xe_device(to_pci_dev(dev));
 	struct xe_tile *root = xe_device_get_root_tile(xe);
 	u32 cap = 0;
@@ -193,18 +177,25 @@ static void late_bind_remove_files(struct device *dev)
 
 	ret = xe_pcode_read(root, PCODE_MBOX(PCODE_LATE_BINDING, GET_CAPABILITY_STATUS, 0),
 			    &cap, NULL);
+	xe_pm_runtime_put(xe);
 	if (ret)
-		goto out;
+		return 0;
 
-	if (REG_FIELD_GET(V1_FAN_SUPPORTED, cap))
-		sysfs_remove_file(&dev->kobj, &dev_attr_lb_fan_control_version.attr);
+	if (attr == &dev_attr_lb_fan_control_version.attr &&
+	    REG_FIELD_GET(V1_FAN_SUPPORTED, cap))
+		return attr->mode;
+	if (attr == &dev_attr_lb_voltage_regulator_version.attr &&
+	    REG_FIELD_GET(VR_PARAMS_SUPPORTED, cap))
+		return attr->mode;
 
-	if (REG_FIELD_GET(VR_PARAMS_SUPPORTED, cap))
-		sysfs_remove_file(&dev->kobj, &dev_attr_lb_voltage_regulator_version.attr);
-out:
-	xe_pm_runtime_put(xe);
+	return 0;
 }
 
+static const struct attribute_group late_bind_attr_group = {
+	.attrs = late_bind_attrs,
+	.is_visible = late_bind_attr_is_visible,
+};
+
 /**
  * DOC: PCIe Gen5 Limitations
  *
@@ -278,49 +269,36 @@ auto_link_downgrade_status_show(struct device *dev, struct device_attribute *att
 }
 static DEVICE_ATTR_ADMIN_RO(auto_link_downgrade_status);
 
-static const struct attribute *auto_link_downgrade_attrs[] = {
+static struct attribute *auto_link_downgrade_attrs[] = {
 	&dev_attr_auto_link_downgrade_capable.attr,
 	&dev_attr_auto_link_downgrade_status.attr,
 	NULL
 };
 
-static void xe_device_sysfs_fini(void *arg)
-{
-	struct xe_device *xe = arg;
-
-	if (xe->d3cold.capable)
-		sysfs_remove_file(&xe->drm.dev->kobj, &dev_attr_vram_d3cold_threshold.attr);
-
-	if (xe->info.platform == XE_BATTLEMAGE) {
-		sysfs_remove_files(&xe->drm.dev->kobj, auto_link_downgrade_attrs);
-		late_bind_remove_files(xe->drm.dev);
-	}
-}
+static const struct attribute_group auto_link_downgrade_attr_group = {
+	.attrs = auto_link_downgrade_attrs,
+};
 
 int xe_device_sysfs_init(struct xe_device *xe)
 {
 	struct device *dev = xe->drm.dev;
 	int ret;
 
 	if (xe->d3cold.capable) {
-		ret = sysfs_create_file(&dev->kobj, &dev_attr_vram_d3cold_threshold.attr);
+		ret = devm_device_add_group(dev, &vram_attr_group);
 		if (ret)
 			return ret;
 	}
 
 	if (xe->info.platform == XE_BATTLEMAGE && !IS_SRIOV_VF(xe)) {
-		ret = sysfs_create_files(&dev->kobj, auto_link_downgrade_attrs);
+		ret = devm_device_add_group(dev, &auto_link_downgrade_attr_group);
 		if (ret)
-			goto cleanup;
+			return ret;
 
-		ret = late_bind_create_files(dev);
+		ret = devm_device_add_group(dev, &late_bind_attr_group);
 		if (ret)
-			goto cleanup;
+			return ret;
 	}
 
-	return devm_add_action_or_reset(dev, xe_device_sysfs_fini, xe);
-
-cleanup:
-	xe_device_sysfs_fini(xe);
-	return ret;
+	return 0;
 }