From: "H. Peter Anvin" <hpa@zytor.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave@sr71.net>,
linux-kernel@vger.kernel.org, x86@kernel.org,
Andi Kleen <ak@linux.intel.com>
Subject: Re: [RFC][PATCH 3/3] x86: make MP a required-feature on 64-bit
Date: Fri, 20 Jun 2014 11:57:21 -0700 [thread overview]
Message-ID: <53A48411.6080602@zytor.com> (raw)
In-Reply-To: <20140620181518.GG11391@pd.tnic>
On 06/20/2014 11:15 AM, Borislav Petkov wrote:
> On Fri, Jun 20, 2014 at 10:50:25AM -0700, H. Peter Anvin wrote:
>> Looking at the AMD init code, there is a whole bunch of other 32/64-bit
>> differences that are clearly bogus. I also see that amd_k7_smp_check()
>> doesn't even *exist* on 64 bits, and that init_amd_k7() which calls
>> amd_k7_smp_check() only is ever called for family == 6, despite having
>> tests for family 7 and above in it.
>
> No, K7 is family 6. The tests are for c->x86_model, or am I looking at
> the wrong place?
>
> OTOH, init_amd() could probably use a cleanup of moving the per-family
> code into init_amd_<fam>() functions and extending the switch-case.
>
> I'll take a look.
>
Ah, yes, you're right.
This code is clearly not applicable to any 64-bit CPU, so cpu_has_mp is
simply a noop on 64 bits... so no need for Dave H. to worry about it at
all; we should get rid of it and replace it with cpu_has() in the AMD code.
I actually have Linus' old dual-processor K7 sitting in my garage, but
$DEITY knows if it actually runs.
-hpa
next prev parent reply other threads:[~2014-06-20 18:57 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-20 16:17 [RFC][PATCH 1/3] x86: introduce disabled-features Dave Hansen
2014-06-20 16:17 ` [RFC][PATCH 2/3] x86: add more disabled features Dave Hansen
2014-06-20 16:17 ` [RFC][PATCH 3/3] x86: make MP a required-feature on 64-bit Dave Hansen
2014-06-20 16:23 ` H. Peter Anvin
2014-06-20 16:30 ` Dave Hansen
2014-06-20 16:37 ` H. Peter Anvin
2014-06-20 17:43 ` Borislav Petkov
2014-06-20 17:47 ` H. Peter Anvin
2014-06-20 18:05 ` Borislav Petkov
2014-06-20 18:16 ` Dave Jones
2014-06-20 18:48 ` Borislav Petkov
2014-06-20 18:54 ` H. Peter Anvin
2014-06-20 20:00 ` Borislav Petkov
2014-06-20 20:22 ` H. Peter Anvin
2014-06-20 20:35 ` Borislav Petkov
2014-06-20 17:50 ` H. Peter Anvin
2014-06-20 18:15 ` Borislav Petkov
2014-06-20 18:57 ` H. Peter Anvin [this message]
2014-06-20 20:37 ` Borislav Petkov
2014-06-23 6:11 ` Andi Kleen
2014-06-20 16:20 ` [RFC][PATCH 1/3] x86: introduce disabled-features H. Peter Anvin
2014-06-20 17:20 ` Dave Hansen
2014-06-20 20:40 ` Dave Hansen
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