On Mon, Apr 20, 2020 at 10:50 PM Jithu Joseph <jithu.joseph@xxxxxxxxx> wrote: > > Slim Bootloader(SBL) [1] is a small open-source boot firmware, > designed for running on certain Intel platforms. SBL can be > thought-of as fulfilling the role of a minimal BIOS > implementation, i.e initializing the hardware and booting > Operating System. > > Since SBL is not UEFI compliant, firmware update cannot be triggered > using standard UEFI runtime services. Further considering performance > impact, SBL doesn't look for a firmware update image on every reset > and does so only when firmware update signal is asserted. > > SBL exposes an ACPI-WMI device which comes up in sysfs as > /sys/bus/wmi/44FADEB1xxx and this driver adds a > "firmware_update_request" device attribute. This attribute normally > has a value of 0 and userspace can signal SBL to update firmware, > on next reboot, by writing a value of 1: > > echo 1 > /sys/bus/wmi/devices/44FADEB1-B204-40F2-8581-394BBDC1B651/firmware_update_request > > This driver only implements a signaling mechanism, the actual firmware > update process and various details like firmware update image format, > firmware image location etc are defined by SBL [2] and are not in the > scope of this driver. I have noticed that it misses ABI documentation. So, please add. Also some comments below. ... > [1] https://slimbootloader.github.io > [2] https://slimbootloader.github.io/security/firmware-update.html Can you add a DocLink: tag below for the reference to the official documentation? ... > +SLIM BOOTLOADER (SBL) FIRMWARE UPDATE WMI DRIVER > +M: Jithu Joseph <jithu.joseph@xxxxxxxxx> > +R: Maurice Ma <maurice.ma@xxxxxxxxx> > +S: Maintained > +W: https://slimbootloader.github.io/security/firmware-update.html > +F: drivers/platform/x86/sbl_fwu_wmi.c I hope you run latest and greatest version of checkpatch.pl and it's okay with this section. ... > @@ -114,6 +114,16 @@ config XIAOMI_WMI > To compile this driver as a module, choose M here: the module will > be called xiaomi-wmi. > > +config SBL_FWU_WMI > + tristate "WMI driver for Slim Bootloader firmware update signaling" > + depends on ACPI_WMI > + help > + Say Y here if you want to be able to use the WMI interface to signal > + Slim Bootloader to trigger update on next reboot. > + > + To compile this driver as a module, choose M here: the module will > + be called sbl-fwu-wmi. > @@ -15,6 +15,7 @@ obj-$(CONFIG_INTEL_WMI_THUNDERBOLT) += intel-wmi-thunderbolt.o > obj-$(CONFIG_MXM_WMI) += mxm-wmi.o > obj-$(CONFIG_PEAQ_WMI) += peaq-wmi.o > obj-$(CONFIG_XIAOMI_WMI) += xiaomi-wmi.o > +obj-$(CONFIG_SBL_FWU_WMI) += sbl_fwu_wmi.o I didn't get an ordering schema in above files. Shouldn't be rather alphasort? ... > +static ssize_t firmware_update_request_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + bool val; > + int ret; > + > + ret = kstrtobool(buf, &val); > + if (ret) > + return ret; > + > + ret = set_fwu_request(dev, val ? 1 : 0); Hmm... If you are going to extend this, why not to pass integer directly? (And thus take one from user) > + if (ret) > + return ret; > + > + return count; > +} > + Extra blank line. > +static DEVICE_ATTR_RW(firmware_update_request); > + > +static struct attribute *firmware_update_attrs[] = { > + &dev_attr_firmware_update_request.attr, > + NULL > +}; > + Extra blank line. > +ATTRIBUTE_GROUPS(firmware_update); ... > +MODULE_DEVICE_TABLE(wmi, sbl_fwu_wmi_id_table); Move it closer to the table structure. -- With Best Regards, Andy Shevchenko
