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https://github.com/torvalds/linux
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87d6021b81
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
53 lines
2.5 KiB
Text
53 lines
2.5 KiB
Text
# SPDX-License-Identifier: GPL-2.0
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# CPU tuning section - shared with UML.
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# Must change only cflags-y (or [yn]), not CFLAGS! That makes a difference for UML.
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#-mtune exists since gcc 3.4
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HAS_MTUNE := $(call cc-option-yn, -mtune=i386)
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ifeq ($(HAS_MTUNE),y)
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tune = $(call cc-option,-mtune=$(1),$(2))
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else
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tune = $(call cc-option,-mcpu=$(1),$(2))
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endif
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cflags-$(CONFIG_M486SX) += -march=i486
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cflags-$(CONFIG_M486) += -march=i486
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cflags-$(CONFIG_M586) += -march=i586
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cflags-$(CONFIG_M586TSC) += -march=i586
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cflags-$(CONFIG_M586MMX) += -march=pentium-mmx
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cflags-$(CONFIG_M686) += -march=i686
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cflags-$(CONFIG_MPENTIUMII) += -march=i686 $(call tune,pentium2)
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cflags-$(CONFIG_MPENTIUMIII) += -march=i686 $(call tune,pentium3)
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cflags-$(CONFIG_MPENTIUMM) += -march=i686 $(call tune,pentium3)
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cflags-$(CONFIG_MPENTIUM4) += -march=i686 $(call tune,pentium4)
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cflags-$(CONFIG_MK6) += -march=k6
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# Please note, that patches that add -march=athlon-xp and friends are pointless.
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# They make zero difference whatsosever to performance at this time.
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cflags-$(CONFIG_MK7) += -march=athlon
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cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8,-march=athlon)
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cflags-$(CONFIG_MCRUSOE) += -march=i686 -falign-functions=0 -falign-jumps=0 -falign-loops=0
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cflags-$(CONFIG_MEFFICEON) += -march=i686 $(call tune,pentium3) -falign-functions=0 -falign-jumps=0 -falign-loops=0
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cflags-$(CONFIG_MWINCHIPC6) += $(call cc-option,-march=winchip-c6,-march=i586)
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cflags-$(CONFIG_MWINCHIP3D) += $(call cc-option,-march=winchip2,-march=i586)
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cflags-$(CONFIG_MCYRIXIII) += $(call cc-option,-march=c3,-march=i486) -falign-functions=0 -falign-jumps=0 -falign-loops=0
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cflags-$(CONFIG_MVIAC3_2) += $(call cc-option,-march=c3-2,-march=i686)
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cflags-$(CONFIG_MVIAC7) += -march=i686
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cflags-$(CONFIG_MCORE2) += -march=i686 $(call tune,core2)
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cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom,$(call cc-option,-march=core2,-march=i686)) \
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$(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic))
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# AMD Elan support
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cflags-$(CONFIG_MELAN) += -march=i486
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# Geode GX1 support
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cflags-$(CONFIG_MGEODEGX1) += -march=pentium-mmx
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cflags-$(CONFIG_MGEODE_LX) += $(call cc-option,-march=geode,-march=pentium-mmx)
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# add at the end to overwrite eventual tuning options from earlier
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# cpu entries
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cflags-$(CONFIG_X86_GENERIC) += $(call tune,generic,$(call tune,i686))
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# Bug fix for binutils: this option is required in order to keep
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# binutils from generating NOPL instructions against our will.
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ifneq ($(CONFIG_X86_P6_NOP),y)
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cflags-y += $(call cc-option,-Wa$(comma)-mtune=generic32,)
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endif
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