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From: "H. Peter Anvin" <hpa@zytor.com>
To: maximilian attems <max@stro.at>
Cc: 464962@bugs.debian.org, Joey Hess <joeyh@debian.org>,
	Ingo Molnar <mingo@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel@vger.kernel.org
Subject: Re: Bug#464962: immediate crash on boot on TM5800
Date: Tue, 12 Feb 2008 13:46:18 -0800	[thread overview]
Message-ID: <47B213AA.2090109@zytor.com> (raw)
In-Reply-To: <20080212212416.GH22054@baikonur.stro.at>

[-- Attachment #1: Type: text/plain, Size: 389 bytes --]

Thought some more about this, and since this probably means gcc will 
generate this for userspace code as well nowadays, tm5800 should 
probably be downgraded to a 586-class machine.  Hence the Linux policy 
of promoting it to a 686-class machine for having CMOV is actually 
incorrect, it doesn't have all the userspace-visible features of a 
686-class machine, lacking long NOP.

	-hpa


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diff --git a/arch/x86/kernel/cpu/transmeta.c b/arch/x86/kernel/cpu/transmeta.c
index 200fb3f..e8b422c 100644
--- a/arch/x86/kernel/cpu/transmeta.c
+++ b/arch/x86/kernel/cpu/transmeta.c
@@ -76,13 +76,6 @@ static void __cpuinit init_transmeta(struct cpuinfo_x86 *c)
 	/* All Transmeta CPUs have a constant TSC */
 	set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability);
 	
-	/* If we can run i686 user-space code, call us an i686 */
-#define USER686 ((1 << X86_FEATURE_TSC)|\
-		 (1 << X86_FEATURE_CX8)|\
-		 (1 << X86_FEATURE_CMOV))
-        if (c->x86 == 5 && (c->x86_capability[0] & USER686) == USER686)
-		c->x86 = 6;
-
 #ifdef CONFIG_SYSCTL
 	/* randomize_va_space slows us down enormously;
 	   it probably triggers retranslation of x86->native bytecode */

  parent reply	other threads:[~2008-02-12 21:47 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20080210031849.GA3370@dragon.kitenet.net>
     [not found] ` <20080210110659.GB8574@stro.at>
     [not found]   ` <20080210192139.GA17647@kodama.kitenet.net>
     [not found]     ` <20080212160522.GB5221@stro.at>
     [not found]       ` <20080212195254.GA6252@kodama.kitenet.net>
2008-02-12 20:10         ` maximilian attems
2008-02-12 20:32           ` H. Peter Anvin
2008-02-12 21:02             ` maximilian attems
2008-02-12 21:14               ` H. Peter Anvin
2008-02-12 21:24                 ` maximilian attems
2008-02-12 21:31                   ` H. Peter Anvin
2008-02-12 21:42                   ` H. Peter Anvin
2008-02-12 21:46                   ` H. Peter Anvin [this message]
2008-02-12 22:29                 ` Joey Hess
2008-02-12 20:35           ` Joey Hess

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