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Groups > linux.kernel > #1536791
| From | Borislav Petkov <bp@alien8.de> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [RFC PATCH 4/6] x86/fpu: Fix "x86/fpu: Legacy x87 FPU detected" message |
| Date | 2016-12-06 10:30 +0100 |
| Message-ID | <sLket-bc-5@gated-at.bofh.it> (permalink) |
| References | <sLcqB-3CS-9@gated-at.bofh.it> <sLcqB-3CS-13@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Mon, Dec 05, 2016 at 05:01:13PM -0800, Andy Lutomirski wrote:
> That message isn't at all clear -- what does "Legacy x87" even
> mean?
>
> Clarify it. If there's no FPU, say "x86/fpu: No FPU detected". If
> there's an FPU that doesn't have XSAVE, say "x86/fpu: Pre-XSAVE x87
> FPU detected".
>
> Signed-off-by: Andy Lutomirski <luto@kernel.org>
> ---
> arch/x86/kernel/fpu/xstate.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
> index 1d7770447b3e..2d592b1c75e4 100644
> --- a/arch/x86/kernel/fpu/xstate.c
> +++ b/arch/x86/kernel/fpu/xstate.c
> @@ -705,8 +705,13 @@ void __init fpu__init_system_xstate(void)
> WARN_ON_FPU(!on_boot_cpu);
> on_boot_cpu = 0;
>
> + if (!boot_cpu_has(X86_FEATURE_FPU)) {
> + pr_info("x86/fpu: No FPU detected.\n");
> + return;
> + }
> +
> if (!boot_cpu_has(X86_FEATURE_XSAVE)) {
> - pr_info("x86/fpu: Legacy x87 FPU detected.\n");
> + pr_info("x86/fpu: Pre-XSAVE x87 FPU detected.\n");
Well, there's also FXSAVE and FSAVE. The legacy thing kinda made sense
to me here.
Maybe say something like this:
pr_info("x86/fpu: FPU detected: FSAVE|FXSAVE|XSAVE support\n", ...
and use X86_FEATURE_XSAVE and X86_FEATURE_FXSR to print the respective
*SAVE string...? FSAVE we issue by default.
Hmm.
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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[RFC PATCH 0/6] CPUID and FPU fixes Andy Lutomirski <luto@kernel.org> - 2016-12-06 02:10 +0100
[RFC PATCH 4/6] x86/fpu: Fix "x86/fpu: Legacy x87 FPU detected" message Andy Lutomirski <luto@kernel.org> - 2016-12-06 02:10 +0100
Re: [RFC PATCH 4/6] x86/fpu: Fix "x86/fpu: Legacy x87 FPU detected" message Borislav Petkov <bp@alien8.de> - 2016-12-06 10:30 +0100
Re: [RFC PATCH 4/6] x86/fpu: Fix "x86/fpu: Legacy x87 FPU detected" message Andy Lutomirski <luto@amacapital.net> - 2016-12-06 19:10 +0100
Re: [RFC PATCH 4/6] x86/fpu: Fix "x86/fpu: Legacy x87 FPU detected" message Borislav Petkov <bp@alien8.de> - 2016-12-06 19:10 +0100
[RFC PATCH 5/6] x86/fpu: Fix CPUID-less FPU detection Andy Lutomirski <luto@kernel.org> - 2016-12-06 02:10 +0100
Re: [RFC PATCH 5/6] x86/fpu: Fix CPUID-less FPU detection Borislav Petkov <bp@alien8.de> - 2016-12-06 10:50 +0100
Re: [RFC PATCH 5/6] x86/fpu: Fix CPUID-less FPU detection Andy Lutomirski <luto@amacapital.net> - 2016-12-06 19:00 +0100
Re: [RFC PATCH 5/6] x86/fpu: Fix CPUID-less FPU detection Borislav Petkov <bp@alien8.de> - 2016-12-07 10:50 +0100
[RFC PATCH 6/6] x86/fpu: Fix the "Giving up, no FPU found" test Andy Lutomirski <luto@kernel.org> - 2016-12-06 02:10 +0100
[RFC PATCH 3/6] x86/cpu: Re-apply forced caps every time cpu caps are re-read Andy Lutomirski <luto@kernel.org> - 2016-12-06 02:10 +0100
Re: [RFC PATCH 3/6] x86/cpu: Re-apply forced caps every time cpu caps are re-read Borislav Petkov <bp@alien8.de> - 2016-12-06 10:00 +0100
[RFC PATCH 2/6] x86/cpu: Factor out application of forced cpu caps Andy Lutomirski <luto@kernel.org> - 2016-12-06 02:10 +0100
Re: [RFC PATCH 2/6] x86/cpu: Factor out application of forced cpu caps Borislav Petkov <bp@alien8.de> - 2016-12-06 09:40 +0100
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