From: "H. Peter Anvin" <hpa@zytor.com>
To: Borislav Petkov <bp@alien8.de>, "Ahmed S. Darwish" <darwi@linutronix.de>
Cc: Brian Gerst <brgerst@gmail.com>, Ingo Molnar <mingo@kernel.org>,
linux-kernel@vger.kernel.org,
Andrew Cooper <andrew.cooper3@citrix.com>,
Ard Biesheuvel <ardb@kernel.org>, Arnd Bergmann <arnd@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
John Ogness <john.ogness@linutronix.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH -v3 0/15] x86: Remove support for TSC-less and CX8-less CPUs
Date: Tue, 6 Jan 2026 19:57:22 -0800 [thread overview]
Message-ID: <8cb799cb-a3ff-4257-b03d-661b893a2663@zytor.com> (raw)
In-Reply-To: <20260104130803.GDaVpmM7vNwP-k0Z0a@fat_crate.local>
On 2026-01-04 05:08, Borislav Petkov wrote:
> On Mon, Dec 15, 2025 at 02:55:27PM +0100, Ahmed S. Darwish wrote:
>> If it does, then we can also remove X86_FEATURE_CPUID from word 3:
>>
>> --- linux.orig/arch/x86/include/asm/cpufeatures.h
>> +++ linux/arch/x86/include/asm/cpufeatures.h
>> @@ -94,3 +94,3 @@
>> #define X86_FEATURE_NONSTOP_TSC ( 3*32+24) /* "nonstop_tsc" TSC does not stop in C states */
>> -#define X86_FEATURE_CPUID ( 3*32+25) /* "cpuid" CPU has CPUID instruction itself */
>> +/* Reserved ( 3*32+25) */
>
> s/Reserved/Free/
>
> so that it gets reused.
>
Please DON'T do this.
I have been cleaning up the boot code and it turns out that having this flag
available makes the error message generating code in the boot stub a lot nicer.
-hpa
next prev parent reply other threads:[~2026-01-07 3:57 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-14 8:46 Ingo Molnar
2025-12-14 8:46 ` [PATCH 01/15] x86/cpu: Remove M486/M486SX/ELAN support Ingo Molnar
2026-03-30 7:05 ` [tip: x86/platform] " tip-bot2 for Ingo Molnar
2026-03-30 9:45 ` tip-bot2 for Ingo Molnar
2025-12-14 8:46 ` [PATCH 02/15] x86/cpu: Remove CONFIG_MWINCHIP3D/MWINCHIPC6 Ingo Molnar
2025-12-14 8:46 ` [PATCH 03/15] x86/cpu: Remove CPU_SUP_UMC_32 support Ingo Molnar
2025-12-14 8:46 ` [PATCH 04/15] x86/cpu: Remove TSC-less CONFIG_M586 support Ingo Molnar
2025-12-14 8:46 ` [PATCH 05/15] x86/cpu, x86/platform, watchdog: Remove CONFIG_X86_RDC321X support Ingo Molnar
2025-12-14 8:46 ` [PATCH 06/15] x86/cpu: Remove the CONFIG_X86_INVD_BUG quirk Ingo Molnar
2025-12-14 8:46 ` [PATCH 07/15] x86/cpu, cpufreq: Remove AMD ELAN support Ingo Molnar
2025-12-14 8:46 ` [PATCH 08/15] x86/fpu: Remove MATH_EMULATION and related glue code Ingo Molnar
2025-12-14 8:46 ` [PATCH 09/15] x86/fpu: Remove the 'no387' boot option Ingo Molnar
2025-12-14 8:46 ` [PATCH 10/15] x86/fpu: Remove the math-emu/ FPU emulation library Ingo Molnar
2025-12-14 8:46 ` [PATCH 11/15] x86/cpu: Make CONFIG_X86_TSC unconditional Ingo Molnar
2025-12-14 8:47 ` [PATCH 12/15] x86: Remove !CONFIG_X86_TSC code Ingo Molnar
2025-12-14 8:47 ` [PATCH 13/15] x86/cpu: Make CONFIG_X86_CX8 unconditional Ingo Molnar
2025-12-14 8:47 ` [PATCH 14/15] x86/atomics: Remove !CONFIG_X86_CX8 methods Ingo Molnar
2025-12-14 8:47 ` [PATCH 15/15] x86/percpu: " Ingo Molnar
2025-12-14 9:38 ` Uros Bizjak
2025-12-15 7:05 ` [PATCH 15/15 -v4] " Ingo Molnar
2025-12-14 13:39 ` [PATCH -v3 0/15] x86: Remove support for TSC-less and CX8-less CPUs David Laight
2025-12-15 4:22 ` H. Peter Anvin
2025-12-15 2:39 ` Brian Gerst
2025-12-15 3:19 ` Linus Torvalds
2025-12-15 13:55 ` Ahmed S. Darwish
2026-01-04 13:08 ` Borislav Petkov
2026-01-07 3:57 ` H. Peter Anvin [this message]
2025-12-15 15:54 ` Arnd Bergmann
2026-01-03 22:59 ` Maciej W. Rozycki
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