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From: Ingo Molnar <mingo@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
	"Ahmed S . Darwish" <darwi@linutronix.de>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	Ard Biesheuvel <ardb@kernel.org>, Arnd Bergmann <arnd@kernel.org>,
	Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	"H . Peter Anvin" <hpa@zytor.com>,
	John Ogness <john.ogness@linutronix.de>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH 09/15] x86/fpu: Remove the 'no387' boot option
Date: Fri, 25 Apr 2025 10:42:06 +0200	[thread overview]
Message-ID: <20250425084216.3913608-10-mingo@kernel.org> (raw)
In-Reply-To: <20250425084216.3913608-1-mingo@kernel.org>

Without math emulation there's no point to this option.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 Documentation/admin-guide/kernel-parameters.txt |  4 ----
 arch/x86/Kconfig                                | 20 +++++++++-----------
 arch/x86/kernel/cpu/common.c                    |  7 -------
 3 files changed, 9 insertions(+), 22 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index d9fd26b95b34..6d391d76336f 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4049,10 +4049,6 @@
 			These settings can be accessed at runtime via
 			the nmi_watchdog and hardlockup_panic sysctls.
 
-	no387		[BUGS=X86-32] Tells the kernel to use the 387 maths
-			emulation library even if a 387 maths coprocessor
-			is present.
-
 	no4lvl		[RISCV,EARLY] Disable 4-level and 5-level paging modes.
 			Forces kernel to use 3-level paging instead.
 
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index cd9dd10b15d2..137b5ddf1f86 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2725,18 +2725,16 @@ menuconfig APM
 	  1) make sure that you have enough swap space and that it is
 	  enabled.
 	  2) pass the "idle=poll" option to the kernel
-	  3) switch on floating point emulation in the kernel and pass
-	  the "no387" option to the kernel
-	  4) pass the "floppy=nodma" option to the kernel
-	  5) pass the "mem=4M" option to the kernel (thereby disabling
+	  3) pass the "floppy=nodma" option to the kernel
+	  4) pass the "mem=4M" option to the kernel (thereby disabling
 	  all but the first 4 MB of RAM)
-	  6) make sure that the CPU is not over clocked.
-	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
-	  8) disable the cache from your BIOS settings
-	  9) install a fan for the video card or exchange video RAM
-	  10) install a better fan for the CPU
-	  11) exchange RAM chips
-	  12) exchange the motherboard.
+	  5) make sure that the CPU is not over clocked.
+	  6) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
+	  7) disable the cache from your BIOS settings
+	  8) install a fan for the video card or exchange video RAM
+	  9) install a better fan for the CPU
+	  10) exchange RAM chips
+	  11) exchange the motherboard.
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called apm.
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 12126adbc3a9..1755ef511fd7 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1574,13 +1574,6 @@ static void __init cpu_parse_early_param(void)
 	int arglen;
 
 #ifdef CONFIG_X86_32
-	if (cmdline_find_option_bool(boot_command_line, "no387"))
-#ifdef CONFIG_MATH_EMULATION
-		setup_clear_cpu_cap(X86_FEATURE_FPU);
-#else
-		pr_err("Option 'no387' required CONFIG_MATH_EMULATION enabled.\n");
-#endif
-
 	if (cmdline_find_option_bool(boot_command_line, "nofxsr"))
 		setup_clear_cpu_cap(X86_FEATURE_FXSR);
 #endif
-- 
2.45.2


  parent reply	other threads:[~2025-04-25  8:42 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-25  8:41 [RFC PATCH 0/15] x86: Remove support for TSC-less and CX8-less CPUs Ingo Molnar
2025-04-25  8:41 ` [PATCH 01/15] x86/cpu: Remove M486/M486SX/ELAN support Ingo Molnar
2025-04-25  8:41 ` [PATCH 02/15] x86/cpu: Remove CONFIG_MWINCHIP3D/MWINCHIPC6 Ingo Molnar
2025-04-25  8:42 ` [PATCH 03/15] x86/cpu: Remove CPU_SUP_UMC_32 support Ingo Molnar
2025-04-25  8:42 ` [PATCH 04/15] x86/cpu: Remove TSC-less CONFIG_M586 support Ingo Molnar
2025-04-25 15:09   ` H. Peter Anvin
2025-04-25  8:42 ` [PATCH 05/15] x86/cpu, x86/platform, watchdog: Remove CONFIG_X86_RDC321X support Ingo Molnar
2025-04-25  8:42 ` [PATCH 06/15] x86/cpu: Remove the CONFIG_X86_INVD_BUG quirk Ingo Molnar
2025-04-25  8:42 ` [PATCH 07/15] x86/cpu, cpufreq: Remove AMD ELAN support Ingo Molnar
2025-04-25  8:42 ` [PATCH 08/15] x86/fpu: Remove MATH_EMULATION and related glue code Ingo Molnar
2025-04-25  8:42 ` Ingo Molnar [this message]
2025-04-25  8:42 ` [PATCH 10/15] x86/fpu: Remove the math-emu/ FPU emulation library Ingo Molnar
2025-04-25  8:42 ` [PATCH 11/15] x86/cpu: Make CONFIG_X86_TSC unconditional Ingo Molnar
2025-04-25  8:42 ` [PATCH 12/15] x86: Remove !CONFIG_X86_TSC code Ingo Molnar
2025-04-25  8:42 ` [PATCH 13/15] x86/cpu: Make CONFIG_X86_CX8 unconditional Ingo Molnar
2025-04-25 12:10   ` Arnd Bergmann
2025-04-25 15:15     ` H. Peter Anvin
2025-04-25 21:54       ` Arnd Bergmann
2025-04-27  9:25         ` Ingo Molnar
2025-04-27 17:32           ` Arnd Bergmann
2025-04-27 21:26             ` H. Peter Anvin
2025-04-28  9:16             ` Ingo Molnar
2025-04-28 11:21               ` Arnd Bergmann
2025-04-29 10:22                 ` Ingo Molnar
2025-04-29 12:10                   ` Arnd Bergmann
2025-04-27  8:15     ` Ingo Molnar
2025-04-25  8:42 ` [PATCH 14/15] x86/percpu: Remove !CONFIG_X86_CX8 methods Ingo Molnar
2025-04-25 14:05   ` Uros Bizjak
2025-04-27  7:46     ` [PATCH -v2 " Ingo Molnar
2025-04-25  8:42 ` [PATCH 15/15] x86/atomics: " Ingo Molnar
2025-04-25 13:55   ` Arnd Bergmann
2025-04-25 14:10   ` Uros Bizjak
2025-04-25 15:00     ` Brian Gerst
2025-04-27  8:23       ` Ingo Molnar
2025-04-27  8:26     ` Ingo Molnar
2025-04-27 10:31       ` Uros Bizjak
2025-05-15  8:49         ` Ingo Molnar
2025-04-25 11:13 ` [RFC PATCH 0/15] x86: Remove support for TSC-less and CX8-less CPUs Arnd Bergmann
2025-04-26  8:26 ` Pavel Machek
2025-05-05  8:53 ` Maciej W. Rozycki
2025-05-05 12:48   ` H. Peter Anvin
2025-05-05 13:04     ` Maciej W. Rozycki
2025-05-05 19:57       ` H. Peter Anvin
2025-05-05 20:54         ` Borislav Petkov
2025-05-06 13:51           ` Maciej W. Rozycki
2025-05-06 14:16             ` Borislav Petkov
2025-05-08 14:51               ` Maciej W. Rozycki
2025-05-08 20:11                 ` Borislav Petkov
2025-05-12 12:55                   ` Maciej W. Rozycki
2025-05-12 13:48                     ` Borislav Petkov
2025-05-12 17:29                       ` Maciej W. Rozycki
2025-05-13  2:00                         ` Linus Torvalds
2025-05-13  3:48                           ` H. Peter Anvin
2025-05-13  5:43                           ` John Paul Adrian Glaubitz
2025-05-13 21:55                             ` Maciej W. Rozycki
2025-05-13 22:02                               ` Linus Torvalds
2025-05-13 22:06                                 ` H. Peter Anvin
2025-05-15 16:32                                 ` Maciej W. Rozycki
2025-05-06 13:48         ` Maciej W. Rozycki
2025-05-06 13:54           ` John Paul Adrian Glaubitz
2025-05-05 15:59   ` Linus Torvalds
2025-05-06 13:53     ` Maciej W. Rozycki
2025-05-06 16:44       ` H. Peter Anvin
2025-05-06 17:11         ` Linus Torvalds
2025-05-06 17:51           ` H. Peter Anvin
2025-05-08 14:54             ` Maciej W. Rozycki
2025-05-08 14:53           ` Maciej W. Rozycki
2025-05-08 14:51         ` Maciej W. Rozycki
2025-05-15  8:56 [PATCH -v2 " Ingo Molnar
2025-05-15  8:56 ` [PATCH 09/15] x86/fpu: Remove the 'no387' boot option Ingo Molnar
2025-12-14  8:46 [PATCH -v3 0/15] x86: Remove support for TSC-less and CX8-less CPUs Ingo Molnar
2025-12-14  8:46 ` [PATCH 09/15] x86/fpu: Remove the 'no387' boot option Ingo Molnar

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