On 14/04/16 02:04, Luis R. Rodriguez wrote: > We have 4 types of x86 platforms that disable RTC: > > * Intel MID > * Lguest - uses paravirt > * Xen dom-U - uses paravirt > * x86 on legacy systems annotated with an ACPI legacy flag > > We can consolidate all of these into a platform specific legacy > quirk set early in boot through i386_start_kernel() and through > x86_64_start_reservations(). This deals with the RTC quirks which > we can rely on through the hardware subarch, the ACPI check can > be dealt with separately. > > For Xen things are bit more complex given that the @X86_SUBARCH_XEN > x86_hardware_subarch is shared on for Xen which uses the PV path for > both domU and dom0. Since the semantics for differentiating between > the two are Xen specific we provide a platform helper to help override > default legacy features -- x86_platform.set_legacy_features(). Use > of this helper is highly discouraged, its only purpose should be > to account for the lack of semantics available within your given > x86_hardware_subarch. > > As per 0-day, this bumps the vmlinux size using i386-tinyconfig as > follows: > > TOTAL TEXT init.text x86_early_init_platform_quirks() > +70 +62 +62 +43 > > Only 8 bytes overhead total, as the main increase in size is > all removed via __init. > > v4: split the subarch check from the ACPI check, clarify > on the ACPI change commit log why ordering works > v5: add x86_platform.set_legacy_features() to account for dom0, > add also size impact on vmlinux as per 0-day report > v6: Use __init on xen_dom0_set_legacy_features() > > Suggested-by: Ingo Molnar <mingo@xxxxxxxxxx> > Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx> Reviewed-by: Juergen Gross <jgross@xxxxxxxx> Juergen -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
