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From: Chris Bainbridge <chris.bainbridge@gmail.com>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH] x86: set Pentium M as PAE capable
Date: Tue, 25 Feb 2014 13:01:47 +0700	[thread overview]
Message-ID: <20140225060146.GA4339@debian.local> (raw)

Pentium M is PAE capable but does not indicate so in the CPUID response.
This is an issue now that some distributions are no longer shipping
non-PAE kernels (those distributions no longer boot on Pentium M). This
small patch fixes the issue by forcing the PAE capability on Pentium M.

For more discussion see https://bugs.launchpad.net/baltix/+bug/930447

Signed-off-by: Chris Bainbridge <chris.bainbridge@gmail.com>

---

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index bbe1b8b..97996aa 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -226,6 +226,12 @@ static void intel_workarounds(struct cpuinfo_x86 *c)
 		clear_cpu_cap(c, X86_FEATURE_SEP);
 
 	/*
+	 * PAE CPUID bug: Pentium M reports no PAE but has PAE
+	 */
+	if ((c->x86 == 6) && ((c->x86_model == 9) || (c->x86_model == 13)))
+		set_cpu_cap(c, X86_FEATURE_PAE);
+
+	/*
 	 * P4 Xeon errata 037 workaround.
 	 * Hardware prefetcher may cause stale data to be loaded into the cache.
 	 */

             reply	other threads:[~2014-02-25  6:02 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-25  6:01 Chris Bainbridge [this message]
2014-02-25 10:45 ` [PATCH] x86: set Pentium M as PAE capable H. Peter Anvin
2014-02-25 11:35   ` Borislav Petkov
2014-02-25 12:06   ` Peter Hurley
2014-02-25 12:07   ` One Thousand Gnomes
2014-02-25 16:26   ` Dave Jones
2014-02-25 17:16     ` H. Peter Anvin
2014-02-26 12:12       ` Chris Bainbridge
2014-02-26 13:18         ` Borislav Petkov
2014-02-26 15:49           ` Dave Jones
2014-02-26 17:18             ` Borislav Petkov
2014-02-26 17:20               ` Dave Jones
2014-02-26 17:28                 ` Borislav Petkov
2014-02-28  7:30             ` Chris Bainbridge
     [not found]               ` <CAKKYfmFgVjYwvThpB0FBB+ggOwULWKLpz7ADT1eojno_KtD9yw@mail.gmail.com>
2014-02-28 14:00                 ` Chris Bainbridge
2014-03-02 20:56                   ` Andreas Mohr
2014-03-02 20:59                     ` H. Peter Anvin
2014-03-02 21:02                     ` Dave Jones
2014-03-02 21:04                       ` Borislav Petkov
2014-03-02 21:13                         ` Andreas Mohr
2014-03-02 21:42                       ` Gene Heskett
2014-03-03 12:31                         ` One Thousand Gnomes
2014-03-03  8:04                     ` Chris Bainbridge
2014-03-03 19:29                       ` Borislav Petkov
2014-03-04  5:01                         ` Chris Bainbridge
2014-03-04  5:04                           ` H. Peter Anvin
2014-03-04  6:06                             ` Chris Bainbridge
2014-03-04 10:44                               ` Borislav Petkov
2014-03-05  4:17                                 ` Chris Bainbridge
2014-03-07 11:40                                 ` [PATCH] x86: Add forcepae parameter for booting PAE kernels on PAE-disabled Pentium M Chris Bainbridge
2014-03-10 10:25                                   ` Borislav Petkov
2014-03-20 23:30                                   ` [tip:x86/cpu] x86, cpu: " tip-bot for Chris Bainbridge
2014-03-20 23:33                                   ` tip-bot for Chris Bainbridge
2014-03-20 23:30             ` [tip:x86/cpu] Rename TAINT_UNSAFE_SMP to TAINT_CPU_OUT_OF_SPEC tip-bot for Dave Jones
2014-02-26 16:46           ` [PATCH] x86: set Pentium M as PAE capable H. Peter Anvin
2014-02-26 16:44         ` Matthew Garrett
2014-02-26 16:45           ` H. Peter Anvin
2014-02-26 17:10             ` Matthew Garrett
2014-02-26 17:57               ` H. Peter Anvin
2014-03-03  0:11                 ` H. Peter Anvin
2014-03-02 19:05 Roland Kletzing

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