Since we are removing paravirt_enabled() replace it with a
logical equivalent. Even though PNPBIOS is x86 specific we
add an arch-specific type call, which can be implemented by
any architecture to show how other legacy attribute devices
can later be also checked for with other ACPI legacy attribute
flags.
This implicates the first ACPI 5.2.9.3 IA-PC Boot Architecture
ACPI_FADT_LEGACY_DEVICES flag device, and shows how to add more.
The reason pnpbios gets a defined structure and as such uses
a different approach than the RTC legacy quirk is that ACPI
has a respective RTC flag, while pnpbios does not. We fold
the pnpbios quirk under ACPI_FADT_LEGACY_DEVICES ACPI flag
use case, and use a struct of possible devices to enable
future extensions of this.
As per 0-day, this bumps the vmlinux size using i386-tinyconfig as
follows:
TOTAL TEXT init.text x86_early_init_platform_quirks()
+32 +28 +28 +28
That's 4 byte overhead total, the rest is cleared out on init
as its all __init text.
v2: split out subarch handlng on switch to make it easier
later to add other subarchs. The 'fall-through' switch
handling can be confusing and we'll remove it later
when we add handling for X86_SUBARCH_CE4100.
v3: document vmlinux size impact as per 0-day, and also
explain why pnpbios is treated differently than the
RTC legacy feature.
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andrew.cooper3@citrix.com
Cc: andriy.shevchenko@linux.intel.com
Cc: bigeasy@linutronix.de
Cc: boris.ostrovsky@oracle.com
Cc: david.vrabel@citrix.com
Cc: ffainelli@freebox.fr
Cc: george.dunlap@citrix.com
Cc: glin@suse.com
Cc: jgross@suse.com
Cc: jlee@suse.com
Cc: josh@joshtriplett.org
Cc: julien.grall@linaro.org
Cc: konrad.wilk@oracle.com
Cc: kozerkov@parallels.com
Cc: lenb@kernel.org
Cc: lguest@lists.ozlabs.org
Cc: linux-acpi@vger.kernel.org
Cc: lv.zheng@intel.com
Cc: matt@codeblueprint.co.uk
Cc: mbizon@freebox.fr
Cc: rjw@rjwysocki.net
Cc: robert.moore@intel.com
Cc: rusty@rustcorp.com.au
Cc: tiwai@suse.de
Cc: toshi.kani@hp.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1460592286-300-12-git-send-email-mcgrof@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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.
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andrew.cooper3@citrix.com
Cc: andriy.shevchenko@linux.intel.com
Cc: bigeasy@linutronix.de
Cc: boris.ostrovsky@oracle.com
Cc: david.vrabel@citrix.com
Cc: ffainelli@freebox.fr
Cc: george.dunlap@citrix.com
Cc: glin@suse.com
Cc: jlee@suse.com
Cc: josh@joshtriplett.org
Cc: julien.grall@linaro.org
Cc: konrad.wilk@oracle.com
Cc: kozerkov@parallels.com
Cc: lenb@kernel.org
Cc: lguest@lists.ozlabs.org
Cc: linux-acpi@vger.kernel.org
Cc: lv.zheng@intel.com
Cc: matt@codeblueprint.co.uk
Cc: mbizon@freebox.fr
Cc: rjw@rjwysocki.net
Cc: robert.moore@intel.com
Cc: rusty@rustcorp.com.au
Cc: tiwai@suse.de
Cc: toshi.kani@hp.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1460592286-300-5-git-send-email-mcgrof@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Luis R. Rodriguez