Re: [PATCH v2 2/8] firmware: smccc: Add support for Live Firmware Activation (LFA)

On Tue, Mar 17, 2026 at 11:33:28AM +0100, Andre Przywara wrote:

+
+/* A list of known GUIDs, to be shown in the "name" sysfs file. */
+static const struct fw_image_uuid {
+	const char *name;
+	const char *uuid;
+} fw_images_uuids[] = {
+	{
+		.name = "TF-A BL31 runtime",
+		.uuid = "47d4086d-4cfe-9846-9b95-2950cbbd5a00",
+	},
+	{
+		.name = "BL33 non-secure payload",
+		.uuid = "d6d0eea7-fcea-d54b-9782-9934f234b6e4",
+	},
+	{
+		.name = "TF-RMM",
+		.uuid = "6c0762a6-12f2-4b56-92cb-ba8f633606d9",
+	},
+};
+
+static struct kset *lfa_kset;
+static struct workqueue_struct *fw_images_update_wq;
+static struct work_struct fw_images_update_work;
+static struct attribute *image_default_attrs[LFA_ATTR_NR_IMAGES + 1];

Bunch of singletons here because (see later)...

+
+static const struct attribute_group image_attr_group = {
+	.attrs = image_default_attrs,
+};
+
+static const struct attribute_group *image_default_groups[] = {
+	&image_attr_group,
+	NULL
+};
+
+static int __init lfa_init(void)
+{
+	struct arm_smccc_1_2_regs reg = { 0 };
+	int err;
+
+	reg.a0 = LFA_1_0_FN_GET_VERSION;
+	arm_smccc_1_2_invoke(&reg, &reg);
+	if (reg.a0 == -LFA_NOT_SUPPORTED) {
+		pr_info("Live Firmware activation: no firmware agent found\n");
+		return -ENODEV;
+	}
+
+	pr_info("Live Firmware Activation: detected v%ld.%ld\n",
+		reg.a0 >> 16, reg.a0 & 0xffff);
+
+	fw_images_update_wq = alloc_workqueue("fw_images_update_wq",
+					      WQ_UNBOUND | WQ_MEM_RECLAIM, 1);
+	if (!fw_images_update_wq) {
+		pr_err("Live Firmware Activation: Failed to allocate workqueue.\n");
+
+		return -ENOMEM;
+	}
+	INIT_WORK(&fw_images_update_work, remove_invalid_fw_images);
+
+	init_image_default_attrs();
+	lfa_kset = kset_create_and_add("lfa", NULL, firmware_kobj);
+	if (!lfa_kset)
+		return -ENOMEM;
+
+	err = update_fw_images_tree();
+	if (err != 0) {
+		kset_unregister(lfa_kset);
+		destroy_workqueue(fw_images_update_wq);
+	}
+
+	return err;
+}
+module_init(lfa_init);

You do not use driver model, but 199x style of modprobing and performing
actions.

I do not understand why module load is already doign anything. This
looks like misinterpretation/misuse of Linux driver model - in a way,
you don't use it all and this is like back to 199x where modprobe was
already meaning you bind drivers...

Best regards,
Krzysztof