From nobody Sun Feb 8 18:23:58 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B4B8B25EF80; Wed, 9 Apr 2025 12:04:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744200301; cv=none; b=Tjcfqo83EAKQG887ga060iHzSxaIpOKzhgnXr+3tccUCuA/jugCnNYWFLgIE4iirCq7PAc8R2SyyU/wxZXr/GoWCCqF3bRzeU1tzm4JpAFXqYcIr8q2zeEb964po4gN2E5ArwXSvTeaJH9jYhmbaNYBBhDeSnDNXeKpr/dAzpP8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744200301; c=relaxed/simple; bh=ce0FFNqWlVLeRmpKOWNjv2FdlSh6kWKIpb0LedlpZEY=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=OMkyWzpyKTNVD/NjDPGIhoY1ksCOmApzJ3Gm2JUxdpdKaRvGVoCBjdYRfGzC4IAGdrgQQ1ou68x/SGdLU05HNu61KRywZq/gu1vWG56L5S9ImGrOtI/uLQlojivHb7jqsr7nBF8FFfmGAnzC7sXrLyd7bbVLYZDpB5L/60oYPj4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=kwkqhIdq; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=x5OQe6dr; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="kwkqhIdq"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="x5OQe6dr" Date: Wed, 09 Apr 2025 12:04:57 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1744200298; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JNrAlN4hUGwH1wDNxfqz+gdRiqBA7UT39Qgw7OMeM4A=; b=kwkqhIdqyLfx869WYiv2P9CVINh7YLi/MImp9pTyuDfK0eMPil6N2AynRN+jgwckElqLc5 Al2Dtdec0EG3kbLhJhqlnZmmhSetev2iiDXJ9q9VbErGc4YfjYoiVddxfUCUGUWFBYX8Ys A3aasYTZTMwrxQDEJ7Z9XUbmySag8PotWbDVGFheJInK0CmB6sl2klj1G4lKAWQSAOzbep JB2EmZb9RnSfqSyiSa2BZk34ihTWQLoYr4XdNx7qZ4sgs/l6Q6L31WE4Cyu5lz20oPPa+X jokuLSYN8HL5NFB/UKFA1IISCB6x1bYiX5KP75t3EstcTUOCDk7BTJPTnFA62g== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1744200298; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JNrAlN4hUGwH1wDNxfqz+gdRiqBA7UT39Qgw7OMeM4A=; b=x5OQe6drp6z8Ikn44e9QvKs0JRSu6agSC1vXvdIy4bnsgzzkp8d/FDtM/SQ9aEi8iLGGHZ IY8NFjTcFaH/MoCw== From: "tip-bot2 for Naveen N Rao (AMD)" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/urgent] Documentation/x86: Update the naming of CPU features for /proc/cpuinfo Cc: "Naveen N Rao (AMD)" , "Borislav Petkov (AMD)" , Ingo Molnar , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20250409111341.GDZ_ZWZS4LckBcirLE@fat_crate.local> References: <20250409111341.GDZ_ZWZS4LckBcirLE@fat_crate.local> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <174420029744.31282.15541458842057716608.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the x86/urgent branch of tip: Commit-ID: af76f7d57ee9a3be7b3840595ce3e2bdedd594a7 Gitweb: https://git.kernel.org/tip/af76f7d57ee9a3be7b3840595ce3e2bde= dd594a7 Author: Naveen N Rao (AMD) AuthorDate: Wed, 09 Apr 2025 13:13:41 +02:00 Committer: Ingo Molnar CommitterDate: Wed, 09 Apr 2025 13:56:52 +02:00 Documentation/x86: Update the naming of CPU features for /proc/cpuinfo Commit: 78ce84b9e0a5 ("x86/cpufeatures: Flip the /proc/cpuinfo appearance logic") changed how CPU feature names should be specified. Update document to reflect the same. Signed-off-by: Naveen N Rao (AMD) Signed-off-by: Borislav Petkov (AMD) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20250409111341.GDZ_ZWZS4LckBcirLE@fat_crate= .local --- Documentation/arch/x86/cpuinfo.rst | 28 ++++++++++++---------------- 1 file changed, 12 insertions(+), 16 deletions(-) diff --git a/Documentation/arch/x86/cpuinfo.rst b/Documentation/arch/x86/cp= uinfo.rst index 6ef426a..7114f34 100644 --- a/Documentation/arch/x86/cpuinfo.rst +++ b/Documentation/arch/x86/cpuinfo.rst @@ -130,14 +130,18 @@ x86_cap/bug_flags[] arrays in kernel/cpu/capflags.c. = The names in the resulting x86_cap/bug_flags[] are used to populate /proc/cpuinfo. The nami= ng of flags in the x86_cap/bug_flags[] are as follows: =20 -a: The name of the flag is from the string in X86_FEATURE_ by defaul= t. ---------------------------------------------------------------------------= -- -By default, the flag in /proc/cpuinfo is extracted from the respect= ive -X86_FEATURE_ in cpufeatures.h. For example, the flag "avx2" is from -X86_FEATURE_AVX2. - -b: The naming can be overridden. --------------------------------- +a: Flags do not appear by default in /proc/cpuinfo +-------------------------------------------------- + +Feature flags are omitted by default from /proc/cpuinfo as it does not make +sense for the feature to be exposed to userspace in most cases. For exampl= e, +X86_FEATURE_ALWAYS is defined in cpufeatures.h but that flag is an internal +kernel feature used in the alternative runtime patching functionality. So = the +flag does not appear in /proc/cpuinfo. + +b: Specify a flag name if absolutely needed +------------------------------------------- + If the comment on the line for the #define X86_FEATURE_* starts with a double-quote character (""), the string inside the double-quote characters will be the name of the flags. For example, the flag "sse4_1" comes from @@ -148,14 +152,6 @@ needed. For instance, /proc/cpuinfo is a userspace int= erface and must remain constant. If, for some reason, the naming of X86_FEATURE_ changes, o= ne shall override the new naming with the name already used in /proc/cpuinfo. =20 -c: The naming override can be "", which means it will not appear in /proc/= cpuinfo. ---------------------------------------------------------------------------= -------- -The feature shall be omitted from /proc/cpuinfo if it does not make sense = for -the feature to be exposed to userspace. For example, X86_FEATURE_ALWAYS is -defined in cpufeatures.h but that flag is an internal kernel feature used -in the alternative runtime patching functionality. So, its name is overrid= den -with "". Its flag will not appear in /proc/cpuinfo. - Flags are missing when one or more of these happen =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D