From 1330e3bc544a1951d81b7f3c7d4cecf77d906f67 Mon Sep 17 00:00:00 2001
From: "Luis R. Rodriguez" <mcgrof@kernel.org>
Date: Wed, 13 Apr 2016 17:04:36 -0700
Subject: x86/init: Use a platform legacy quirk for EBDA
This replaces the paravirt_enabled() check with a
proper x86 legacy platform quirk.
As per 0-day, this bumps the vmlinux size using i386-tinyconfig as
follows:
TOTAL TEXT init.text x86_early_init_platform_quirks()
+39 +35 +35 +25
That's a 4 byte total overhead, the rest is all cleared out
upon init as its all __init text.
v2: document 0-day vmlinux size impact
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: 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/1460592286-300-7-git-send-email-mcgrof@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/head.c | 2 +-
arch/x86/kernel/platform-quirks.c | 4 ++++
2 files changed, 5 insertions(+), 1 deletion(-)
(limited to 'arch/x86/kernel')
diff --git a/arch/x86/kernel/head.c b/arch/x86/kernel/head.c
index 992f442ca155..afe65dffee80 100644
--- a/arch/x86/kernel/head.c
+++ b/arch/x86/kernel/head.c
@@ -38,7 +38,7 @@ void __init reserve_ebda_region(void)
* that the paravirt case can handle memory setup
* correctly, without our help.
*/
- if (paravirt_enabled())
+ if (!x86_platform.legacy.ebda_search)
return;
/* end of low (conventional) memory */
diff --git a/arch/x86/kernel/platform-quirks.c b/arch/x86/kernel/platform-quirks.c
index 021a5f973ce3..01b159781d96 100644
--- a/arch/x86/kernel/platform-quirks.c
+++ b/arch/x86/kernel/platform-quirks.c
@@ -7,8 +7,12 @@
void __init x86_early_init_platform_quirks(void)
{
x86_platform.legacy.rtc = 1;
+ x86_platform.legacy.ebda_search = 0;
switch (boot_params.hdr.hardware_subarch) {
+ case X86_SUBARCH_PC:
+ x86_platform.legacy.ebda_search = 1;
+ break;
case X86_SUBARCH_XEN:
case X86_SUBARCH_LGUEST:
case X86_SUBARCH_INTEL_MID:
--
cgit v1.2.3-70-g09d2