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 the some of the embedded
versions remained available much longer.
Signed-off-by: Arnd Bergmann <a...@arndb.de>
---
arch/x86/Kconfig | 2 +-
arch/x86/Kconfig.cpu | 25 ++++++++++++++++---------
arch/x86/Makefile_32.cpu | 1 +
arch/x86/include/asm/module.h | 2 ++
4 files changed, 20 insertions(+), 10 deletions(-)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f4d9d1e55e5c..77b02387bd0c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1751,7 +1751,7 @@ config X86_RESERVE_LOW
config MATH_EMULATION
bool
depends on MODIFY_LDT_SYSCALL
- prompt "Math emulation" if X86_32
+ prompt "Math emulation" if X86_32 && (M486SX || MELAN)
---help---
Linux can emulate a math coprocessor (used for floating point
operations) if you don't have one. 486DX and Pentium processors have
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 228705a1232a..5f7bff9885a1 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"
@@ -313,20 +320,20 @@ 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
@@ -379,7 +386,7 @@ 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
@@ -403,7 +410,7 @@ 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
@@ -471,7 +478,7 @@ 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
diff --git a/arch/x86/Makefile_32.cpu b/arch/x86/Makefile_32.cpu
index 1f5faf8606b4..cd3056759880 100644
--- a/arch/x86/Makefile_32.cpu
+++ b/arch/x86/Makefile_32.cpu
@@ -10,6 +10,7 @@ else
tune = $(call cc-option,-mcpu=$(1),$(2))
endif
+cflags-$(CONFIG_M486SX) += -march=i486
cflags-$(CONFIG_M486) += -march=i486
cflags-$(CONFIG_M586) += -march=i586
cflags-$(CONFIG_M586TSC) += -march=i586
diff --git a/arch/x86/include/asm/module.h b/arch/x86/include/asm/module.h
index 7948a17febb4..c215d2762488 100644
--- a/arch/x86/include/asm/module.h
+++ b/arch/x86/include/asm/module.h
@@ -15,6 +15,8 @@ struct mod_arch_specific {
#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
--
2.20.0
