diff options
| author | Arnd Bergmann <arnd@arndb.de> | 2019-10-01 16:23:35 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2019-10-03 10:51:17 +0200 |
| commit | 87d6021b814353d7b353afcc3698ffe49de7d4ec (patch) | |
| tree | 6d511c8c400caacd3b5b7cc5125a0a78eed67f77 /arch/x86/Kconfig.cpu | |
| parent | e6b44ce1925a8329a937c57f0d60ba0d9bb5d226 (diff) | |
x86/math-emu: Limit MATH_EMULATION to 486SX compatibles
The FPU emulation code is old and fragile in places, try to limit its
use to builds for CPUs that actually use it. As far as I can tell,
this is only true for i486sx compatibles, including the Cyrix 486SLC,
AMD Am486SX and ÉLAN SC410, UMC U5S amd DM&P VortexSX86, all of which
were relatively short-lived and got replaced with i486DX compatible
processors soon after introduction, though some of the embedded versions
remained available much longer.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Bill Metzenthen <billm@melbpc.org.au>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191001142344.1274185-2-arnd@arndb.de
Diffstat (limited to 'arch/x86/Kconfig.cpu')
| -rw-r--r-- | arch/x86/Kconfig.cpu | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu index 8e29c991ba3e..af9c967782f6 100644 --- a/arch/x86/Kconfig.cpu +++ b/arch/x86/Kconfig.cpu @@ -50,12 +50,19 @@ choice See each option's help text for additional details. If you don't know what to do, choose "486". +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 "486" + bool "486DX" depends on X86_32 ---help--- Select this for an 486-class CPU such as AMD/Cyrix/IBM/Intel - 486DX/DX2/DX4 or SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or U5S. + 486DX/DX2/DX4 and UMC U5D. config M586 bool "586/K5/5x86/6x86/6x86MX" @@ -312,20 +319,20 @@ config X86_L1_CACHE_SHIFT int default "7" if MPENTIUM4 || MPSC default "6" if MK7 || MK8 || MPENTIUMM || MCORE2 || MATOM || MVIAC7 || X86_GENERIC || GENERIC_CPU - default "4" if MELAN || M486 || MGEODEGX1 + default "4" if MELAN || M486SX || M486 || MGEODEGX1 default "5" if MWINCHIP3D || MWINCHIPC6 || MCRUSOE || MEFFICEON || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2 || MGEODE_LX config X86_F00F_BUG def_bool y - depends on M586MMX || M586TSC || M586 || M486 + depends on M586MMX || M586TSC || M586 || M486SX || M486 config X86_INVD_BUG def_bool y - depends on M486 + depends on M486SX || M486 config X86_ALIGNMENT_16 def_bool y - depends on MWINCHIP3D || MWINCHIPC6 || MCYRIXIII || MELAN || MK6 || M586MMX || M586TSC || M586 || M486 || MVIAC3_2 || MGEODEGX1 + depends on MWINCHIP3D || MWINCHIPC6 || MCYRIXIII || MELAN || MK6 || M586MMX || M586TSC || M586 || M486SX || M486 || MVIAC3_2 || MGEODEGX1 config X86_INTEL_USERCOPY def_bool y @@ -378,7 +385,7 @@ config X86_MINIMUM_CPU_FAMILY config X86_DEBUGCTLMSR def_bool y - depends on !(MK6 || MWINCHIPC6 || MWINCHIP3D || MCYRIXIII || M586MMX || M586TSC || M586 || M486) && !UML + depends on !(MK6 || MWINCHIPC6 || MWINCHIP3D || MCYRIXIII || M586MMX || M586TSC || M586 || M486SX || M486) && !UML menuconfig PROCESSOR_SELECT bool "Supported processor vendors" if EXPERT @@ -402,7 +409,7 @@ config CPU_SUP_INTEL config CPU_SUP_CYRIX_32 default y bool "Support Cyrix processors" if PROCESSOR_SELECT - depends on M486 || M586 || M586TSC || M586MMX || (EXPERT && !64BIT) + depends on M486SX || M486 || M586 || M586TSC || M586MMX || (EXPERT && !64BIT) ---help--- This enables detection, tunings and quirks for Cyrix processors @@ -470,7 +477,7 @@ config CPU_SUP_TRANSMETA_32 config CPU_SUP_UMC_32 default y bool "Support UMC processors" if PROCESSOR_SELECT - depends on M486 || (EXPERT && !64BIT) + depends on M486SX || M486 || (EXPERT && !64BIT) ---help--- This enables detection, tunings and quirks for UMC processors |