From: Borislav Petkov <bp@alien8.de>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Xin Li (Intel)" <xin@zytor.com>,
linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
tglx@linutronix.de, mingo@redhat.com,
dave.hansen@linux.intel.com, x86@kernel.org, will@kernel.org,
peterz@infradead.org, yury.norov@gmail.com,
akpm@linux-foundation.org, acme@kernel.org, namhyung@kernel.org,
brgerst@gmail.com, andrew.cooper3@citrix.com,
nik.borisov@suse.com
Subject: Re: [PATCH v5 1/5] x86/cpufeatures: Add {required,disabled} feature configs
Date: Sat, 15 Feb 2025 15:20:17 +0100 [thread overview]
Message-ID: <20250215142017.GCZ7CioRHgpm6a-eIZ@fat_crate.local> (raw)
In-Reply-To: <469D0BEE-76D6-4417-B5B0-0054D3F96784@zytor.com>
On Sat, Feb 15, 2025 at 02:12:35AM -0800, H. Peter Anvin wrote:
> CX8 is the name of the CPUID flag, for better or worse.
Right, so a separate patch:
git grep X86_CMPXCHG64
arch/x86/Kconfig:135: select ARCH_USE_CMPXCHG_LOCKREF if X86_CMPXCHG64
arch/x86/Kconfig.cpu:369:config X86_CMPXCHG64
arch/x86/Kconfig.cpu:383: default "5" if X86_32 && X86_CMPXCHG64
arch/x86/include/asm/asm-prototypes.h:19:#ifndef CONFIG_X86_CMPXCHG64
arch/x86/include/asm/atomic64_32.h:51:#ifdef CONFIG_X86_CMPXCHG64
arch/x86/include/asm/cmpxchg_32.h:72:#ifdef CONFIG_X86_CMPXCHG64
arch/x86/include/asm/required-features.h:26:#ifdef CONFIG_X86_CMPXCHG64
arch/x86/lib/Makefile:59:ifneq ($(CONFIG_X86_CMPXCHG64),y)
arch/x86/lib/cmpxchg8b_emu.S:10:#ifndef CONFIG_X86_CMPXCHG64
lib/atomic64_test.c:257:#elif defined(CONFIG_X86_CMPXCHG64)
tools/arch/x86/include/asm/required-features.h:26:#ifdef CONFIG_X86_CMPXCHG64
should be easy.
> It seems to me to be a bit silly to have dummy symbols that mean literally
> the same thing, but ...
Why if they're confined and encapsulated in a single file:
arch/x86/Kconfig.cpufeatures ?
Rest of the kernel doesn't need to know whether a feature is required or not,
right?
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2025-02-15 14:20 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-06 7:07 [PATCH v5 0/5] x86/cpufeatures: Automatically generate required and disabled feature masks Xin Li (Intel)
2025-01-06 7:07 ` [PATCH v5 1/5] x86/cpufeatures: Add {required,disabled} feature configs Xin Li (Intel)
2025-02-14 21:58 ` Borislav Petkov
2025-02-15 10:12 ` H. Peter Anvin
2025-02-15 14:20 ` Borislav Petkov [this message]
2025-02-15 14:27 ` H. Peter Anvin
2025-02-15 14:30 ` Borislav Petkov
2025-02-15 14:35 ` H. Peter Anvin
2025-02-15 14:44 ` Borislav Petkov
2025-01-06 7:07 ` [PATCH v5 2/5] x86/cpufeatures: Generate a feature mask header based on build config Xin Li (Intel)
2025-01-06 7:07 ` [PATCH v5 3/5] x86/cpufeatures: Remove {disabled,required}-features.h Xin Li (Intel)
2025-01-06 7:07 ` [PATCH v5 4/5] x86/cpufeatures: Use AWK to generate {REQUIRED|DISABLED}_MASK_BIT_SET Xin Li (Intel)
2025-01-06 7:07 ` [PATCH v5 5/5] x86/cpufeatures: Add the CPU feature bit for MSR immediate form instructions Xin Li (Intel)
2025-02-22 16:30 ` Borislav Petkov
2025-02-22 18:12 ` Borislav Petkov
2025-02-24 7:30 ` Xin Li
2025-02-24 17:27 ` H. Peter Anvin
2025-02-11 2:25 ` [PATCH v5 0/5] x86/cpufeatures: Automatically generate required and disabled feature masks Xin Li
2025-02-23 10:27 ` Borislav Petkov
2025-02-25 17:10 ` Xin Li
2025-02-25 17:49 ` Borislav Petkov
2025-02-25 17:54 ` Nikolay Borisov
2025-02-25 18:00 ` Borislav Petkov
2025-02-25 18:10 ` H. Peter Anvin
2025-02-25 18:15 ` Borislav Petkov
2025-02-25 18:37 ` Xin Li
2025-02-25 20:30 ` H. Peter Anvin
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