mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Ingo Molnar <mingo@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>
Subject: [GIT pull] x86 fix for 4.2
Date: Tue, 25 Aug 2015 10:13:55 +0200 (CEST)	[thread overview]
Message-ID: <alpine.DEB.2.11.1508251010350.15006@nanos> (raw)

Linus,

please pull the latest x86-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-for-linus

A single fix for a APIC regression introduced in 4.0 which went
undetected until now. I screwed up the x2apic cleanup in a subtle
way. The screwup is only visible on systems which have x2apic
preenabled in the BIOS and need to disable it during boot.

Thanks,

	tglx

------------------>
Thomas Gleixner (1):
      x86/apic: Fix fallout from x2apic cleanup


 arch/x86/kernel/apic/apic.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index dcb52850a28f..cde732c1b495 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1424,7 +1424,7 @@ static inline void __x2apic_disable(void)
 {
 	u64 msr;
 
-	if (cpu_has_apic)
+	if (!cpu_has_apic)
 		return;
 
 	rdmsrl(MSR_IA32_APICBASE, msr);
@@ -1483,10 +1483,13 @@ void x2apic_setup(void)
 
 static __init void x2apic_disable(void)
 {
-	u32 x2apic_id;
+	u32 x2apic_id, state = x2apic_state;
 
-	if (x2apic_state != X2APIC_ON)
-		goto out;
+	x2apic_mode = 0;
+	x2apic_state = X2APIC_DISABLED;
+
+	if (state != X2APIC_ON)
+		return;
 
 	x2apic_id = read_apic_id();
 	if (x2apic_id >= 255)
@@ -1494,9 +1497,6 @@ static __init void x2apic_disable(void)
 
 	__x2apic_disable();
 	register_lapic_address(mp_lapic_addr);
-out:
-	x2apic_state = X2APIC_DISABLED;
-	x2apic_mode = 0;
 }
 
 static __init void x2apic_enable(void)

                 reply	other threads:[~2015-08-25  8:14 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=alpine.DEB.2.11.1508251010350.15006@nanos \
    --to=tglx@linutronix.de \
    --cc=akpm@linux-foundation.org \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=torvalds@linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®