From nobody Thu Apr 2 05:51:56 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 C8BB433D4E9; Mon, 30 Mar 2026 07:06:01 +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=1774854363; cv=none; b=M+M3B7PWHGirRERRLMWmVxgm9ycNn/ypxtoVHeL7yt3OCzbxLyxxJd0MgspyMW6LCbU5utj58lKQH9sxywNymJiGfFJCus6Qij5fwppyjcZo9OJNxqZ+IlskGrhVBXf3CJ9hD/KZfGEXepOTv5sxRUAWpPMPQaMGb1yD27/nmLA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774854363; c=relaxed/simple; bh=X3su1+xYW5wSJuAAJBIsMGDLyVXCIDGyecZFGuPjd8M=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=iFq9puxG/OTG4kS5+SO9feShjjAzqJ5B+HIPQATykUYwAT+IcV4/2TELi1iG4DDQ36ZRPDyaurwE9Jhw9Kv9tIwDArhLz5h3NGHzNLQL5ztaUk2LtRfX09ntOreGyu3zwlykl33E0YJ+4Cs4PQU9KYNQTTVgpGH3kmgdzu6tGcE= 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=mkuoTkbv; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=nkeP+kGs; 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="mkuoTkbv"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="nkeP+kGs" Date: Mon, 30 Mar 2026 07:05:47 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1774854353; 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=8E/SDeZmrsYmxAz6PcNd80OjTzBC2SxWKdxsLOKxr9o=; b=mkuoTkbvEcBlSkOq+tQObENyAetQnNyojclNrZ66Zawr8ro/fuNtWpqIyS7Oqfwqtihw48 tJa8cyzH9rxujyiLOC3P/XMe9XRq0J0846bzUJBs14b9X/2V3vH4GGGz1Z042k2UN0jp+c kXWOyCFKvJDviFhSmh1MZfpJR5/23BlZO/WgZJpvinbM/4sLU66Hue7W7aLqdHzeeYeBNc 5loix8Ky9Rg0eCgeWwzbziCQYHtL5Fu9VUH3mkv/nV2T58gP8XmJu98H98i3BLtSqP1bwE TDZ7PwL7APc/SnE/qUt6On4i1UhXRq7bKxZ2KZ+76d/lnYI005H8qhwxMlRjNA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1774854353; 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=8E/SDeZmrsYmxAz6PcNd80OjTzBC2SxWKdxsLOKxr9o=; b=nkeP+kGsfT55t8w8OWodnPKIH8CvlB2kxVMLZjdClmZRAeF/HQfdSdCoRFZwgiigeIB+Bg PMUQgTIbSI1KpLBQ== From: "tip-bot2 for Ingo Molnar" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/platform] x86/cpu: Remove M486/M486SX/ELAN support Cc: Linus Torvalds , Ingo Molnar , Arnd Bergmann , Dave Hansen , "Ahmed S. Darwish" , Ard Biesheuvel , Arnd Bergmann , "H. Peter Anvin" , John Ogness , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20251214084710.3606385-2-mingo@kernel.org> References: <20251214084710.3606385-2-mingo@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <177485434762.1647592.11669999891936628676.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/platform branch of tip: Commit-ID: 7d246d15b140cf99eb7cc89b8cca9ef9e3a85660 Gitweb: https://git.kernel.org/tip/7d246d15b140cf99eb7cc89b8cca9ef9e= 3a85660 Author: Ingo Molnar AuthorDate: Sun, 14 Dec 2025 09:46:49 +01:00 Committer: Ingo Molnar CommitterDate: Mon, 30 Mar 2026 08:54:32 +02:00 x86/cpu: Remove M486/M486SX/ELAN support In the x86 architecture we have various complicated hardware emulation facilities on x86-32 to support ancient 32-bit CPUs that very very few people are using with modern kernels. This compatibility glue is sometimes even causing problems that people spend time to resolve, which time could be spent on other things. As Linus recently remarked: > I really get the feeling that it's time to leave i486 support behind. > There's zero real reason for anybody to waste one second of > development effort on this kind of issue. Implement the first step and remove M486/M486SX/ELAN support: CONFIG_M486SX CONFIG_M486 CONFIG_MELAN [ There's no recent M486=3Dy kernel package for any mainstream x86 32-bit distribution available that I've been able to find, so actual users should not be impacted, and any legacy users can keep using older kernels. ] Suggested-by: Linus Torvalds Signed-off-by: Ingo Molnar Reviewed-by: Arnd Bergmann Acked-by: Dave Hansen Cc: Ahmed S. Darwish Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: H. Peter Anvin Cc: John Ogness Link: https://patch.msgid.link/20251214084710.3606385-2-mingo@kernel.org --- arch/x86/Kconfig | 10 +-------- arch/x86/Kconfig.cpu | 42 ++++++-------------------------- arch/x86/Makefile_32.cpu | 2 +-- arch/x86/include/asm/vermagic.h | 6 +----- 4 files changed, 9 insertions(+), 51 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index e2df1b1..6627b6d 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -446,11 +446,6 @@ config SMP uniprocessor machines. On a uniprocessor machine, the kernel will run faster if you say N here. =20 - Note that if you say Y here and choose architecture "586" or - "Pentium" under "Processor family", the kernel will not work on 486 - architectures. Similarly, multiprocessor kernels for the "PPro" - architecture may not work on all Pentium based boards. - People using multiprocessor machines who say Y here should also say Y to "Enhanced Real Time Clock Support", below. The "Advanced Power Management" code will be disabled if you say Y here. @@ -2771,11 +2766,6 @@ menuconfig APM manpage ("man 8 hdparm") for that), and it doesn't turn off VESA-compliant "green" monitors. =20 - This driver does not support the TI 4000M TravelMate and the ACER - 486/DX4/75 because they don't have compliant BIOSes. Many "green" - desktop machines also don't have compliant BIOSes, and this driver - may cause those machines to panic during the boot phase. - Generally, if you don't have a battery in your machine, there isn't much point in using this driver and you should say N. If you get random kernel OOPSes or reboots that don't seem to be related to diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu index f928cf6..0239e5f 100644 --- a/arch/x86/Kconfig.cpu +++ b/arch/x86/Kconfig.cpu @@ -8,19 +8,18 @@ choice This is the processor type of your CPU. This information is used for optimizing purposes. In order to compile a kernel that can run on all supported x86 CPU types (albeit not - optimally fast), you can specify "486" here. + optimally fast), you can specify "586" here. =20 - Note that the 386 is no longer supported, this includes + Note that the 386 and 486 is no longer supported, this includes AMD/Cyrix/Intel 386DX/DXL/SL/SLC/SX, Cyrix/TI 486DLC/DLC2, - UMC 486SX-S and the NexGen Nx586. + UMC 486SX-S and the NexGen Nx586, AMD ELAN and all 486 based + CPUs. =20 The kernel will not necessarily run on earlier architectures than the one you have chosen, e.g. a Pentium optimized kernel will run on a PPro, but not necessarily on a i486. =20 Here are the settings recommended for greatest speed: - - "486" for the AMD/Cyrix/IBM/Intel 486DX/DX2/DX4 or - SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or U5S. - "586" for generic Pentium CPUs lacking the TSC (time stamp counter) register. - "Pentium-Classic" for the Intel Pentium. @@ -46,20 +45,6 @@ choice See each option's help text for additional details. If you don't know what to do, choose "Pentium-Pro". =20 -config M486SX - bool "486SX" - depends on X86_32 - help - Select this for an 486-class CPU without an FPU such as - AMD/Cyrix/IBM/Intel SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5S. - -config M486 - bool "486DX" - depends on X86_32 - help - Select this for an 486-class CPU such as AMD/Cyrix/IBM/Intel - 486DX/DX2/DX4 and UMC U5D. - config M586 bool "586/K5/5x86/6x86/6x86MX" depends on X86_32 @@ -188,14 +173,6 @@ config MWINCHIP3D stores for this CPU, which can increase performance of some operations. =20 -config MELAN - bool "AMD Elan" - depends on X86_32 - help - Select this for an AMD Elan processor. - - Do not use this option for K6/Athlon/Opteron processors! - config MGEODEGX1 bool "GeodeGX1" depends on X86_32 @@ -292,12 +269,12 @@ config X86_L1_CACHE_SHIFT int default "7" if MPENTIUM4 default "6" if MK7 || MPENTIUMM || MATOM || MVIAC7 || X86_GENERIC || X86_= 64 - default "4" if MELAN || M486SX || M486 || MGEODEGX1 + default "4" if MGEODEGX1 default "5" if MWINCHIP3D || MWINCHIPC6 || MCRUSOE || MEFFICEON || MCYRIX= III || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M5= 86 || MVIAC3_2 || MGEODE_LX =20 config X86_F00F_BUG def_bool y - depends on M586MMX || M586TSC || M586 || M486SX || M486 + depends on M586MMX || M586TSC || M586 =20 config X86_INVD_BUG def_bool y @@ -305,7 +282,7 @@ config X86_INVD_BUG =20 config X86_ALIGNMENT_16 def_bool y - depends on MWINCHIP3D || MWINCHIPC6 || MCYRIXIII || MELAN || MK6 || M586M= MX || M586TSC || M586 || M486SX || M486 || MVIAC3_2 || MGEODEGX1 + depends on MWINCHIP3D || MWINCHIPC6 || MCYRIXIII || MK6 || M586MMX || M58= 6TSC || M586 || MVIAC3_2 || MGEODEGX1 =20 config X86_INTEL_USERCOPY def_bool y @@ -338,11 +315,10 @@ config X86_MINIMUM_CPU_FAMILY default "64" if X86_64 default "6" if X86_32 && (MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTI= UMII || M686 || MVIAC3_2 || MVIAC7 || MEFFICEON || MATOM || MK7) default "5" if X86_32 && X86_CX8 - default "4" =20 config X86_DEBUGCTLMSR def_bool y - depends on !(MK6 || MWINCHIPC6 || MWINCHIP3D || MCYRIXIII || M586MMX || M= 586TSC || M586 || M486SX || M486) && !UML + depends on !(MK6 || MWINCHIPC6 || MWINCHIP3D || MCYRIXIII || M586MMX || M= 586TSC || M586) && !UML =20 config IA32_FEAT_CTL def_bool y @@ -378,7 +354,7 @@ config CPU_SUP_INTEL config CPU_SUP_CYRIX_32 default y bool "Support Cyrix processors" if PROCESSOR_SELECT - depends on M486SX || M486 || M586 || M586TSC || M586MMX || (EXPERT && !64= BIT) + depends on M586 || M586TSC || M586MMX || (EXPERT && !64BIT) help This enables detection, tunings and quirks for Cyrix processors =20 diff --git a/arch/x86/Makefile_32.cpu b/arch/x86/Makefile_32.cpu index a3dda95..7c9898c 100644 --- a/arch/x86/Makefile_32.cpu +++ b/arch/x86/Makefile_32.cpu @@ -10,8 +10,6 @@ else align :=3D -falign-functions=3D0 -falign-jumps=3D0 -falign-loops=3D0 endif =20 -cflags-$(CONFIG_M486SX) +=3D -march=3Di486 -cflags-$(CONFIG_M486) +=3D -march=3Di486 cflags-$(CONFIG_M586) +=3D -march=3Di586 cflags-$(CONFIG_M586TSC) +=3D -march=3Di586 cflags-$(CONFIG_M586MMX) +=3D -march=3Dpentium-mmx diff --git a/arch/x86/include/asm/vermagic.h b/arch/x86/include/asm/vermagi= c.h index 5d47125..eda233a 100644 --- a/arch/x86/include/asm/vermagic.h +++ b/arch/x86/include/asm/vermagic.h @@ -5,10 +5,6 @@ =20 #ifdef CONFIG_X86_64 /* X86_64 does not define MODULE_PROC_FAMILY */ -#elif defined CONFIG_M486SX -#define MODULE_PROC_FAMILY "486SX " -#elif defined CONFIG_M486 -#define MODULE_PROC_FAMILY "486 " #elif defined CONFIG_M586 #define MODULE_PROC_FAMILY "586 " #elif defined CONFIG_M586TSC @@ -31,8 +27,6 @@ #define MODULE_PROC_FAMILY "K6 " #elif defined CONFIG_MK7 #define MODULE_PROC_FAMILY "K7 " -#elif defined CONFIG_MELAN -#define MODULE_PROC_FAMILY "ELAN " #elif defined CONFIG_MCRUSOE #define MODULE_PROC_FAMILY "CRUSOE " #elif defined CONFIG_MEFFICEON