habanalabs: expose device security status through sysfs

In order for the user to know if he is running on a secured device
or not, a sysfs node is added.
Signed-off-by: Ofir Bitton <obitton@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

Documentation/ABI/testing/sysfs-driver-habanalabs

@@ -176,6 +176,12 @@ KernelVersion:  5.1
 Contact:        ogabbay@kernel.org
 Description:    Version of the device's preboot F/W code
 
+What:           /sys/class/habanalabs/hl<n>/security_enabled
+Date:           Oct 2022
+KernelVersion:  6.1
+Contact:        obitton@habana.ai
+Description:    Displays the device's security status
+
 What:           /sys/class/habanalabs/hl<n>/soft_reset
 Date:           Jan 2019
 KernelVersion:  5.1

drivers/misc/habanalabs/common/sysfs.c

@@ -375,6 +375,14 @@ static ssize_t eeprom_read_handler(struct file *filp, struct kobject *kobj,
 	return max_size;
 }
 
+static ssize_t security_enabled_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct hl_device *hdev = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", hdev->asic_prop.fw_security_enabled);
+}
+
 static DEVICE_ATTR_RO(armcp_kernel_ver);
 static DEVICE_ATTR_RO(armcp_ver);
 static DEVICE_ATTR_RO(cpld_ver);
@@ -393,6 +401,7 @@ static DEVICE_ATTR_RO(status);
 static DEVICE_ATTR_RO(thermal_ver);
 static DEVICE_ATTR_RO(uboot_ver);
 static DEVICE_ATTR_RO(fw_os_ver);
+static DEVICE_ATTR_RO(security_enabled);
 
 static struct bin_attribute bin_attr_eeprom = {
 	.attr = {.name = "eeprom", .mode = (0444)},
@@ -417,6 +426,7 @@ static struct attribute *hl_dev_attrs[] = {
 	&dev_attr_thermal_ver.attr,
 	&dev_attr_uboot_ver.attr,
 	&dev_attr_fw_os_ver.attr,
+	&dev_attr_security_enabled.attr,
 	NULL,
 };