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    Subject[PATCH 24/24] x86: Remove FAST_FEATURE_TESTS
    Since we want to rely on static branches to avoid speculation, remove
    any possible fallback code for static_cpu_has.

    Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
    ---
    arch/x86/Kconfig | 11 -----------
    arch/x86/include/asm/cpufeature.h | 8 --------
    2 files changed, 19 deletions(-)

    --- a/arch/x86/Kconfig
    +++ b/arch/x86/Kconfig
    @@ -389,17 +389,6 @@ config X86_FEATURE_NAMES

    If in doubt, say Y.

    -config X86_FAST_FEATURE_TESTS
    - bool "Fast CPU feature tests" if EMBEDDED
    - default y
    - ---help---
    - Some fast-paths in the kernel depend on the capabilities of the CPU.
    - Say Y here for the kernel to patch in the appropriate code at runtime
    - based on the capabilities of the CPU. The infrastructure for patching
    - code at runtime takes up some additional space; space-constrained
    - embedded systems may wish to say N here to produce smaller, slightly
    - slower code.
    -
    config X86_X2APIC
    bool "Support x2apic"
    depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
    --- a/arch/x86/include/asm/cpufeature.h
    +++ b/arch/x86/include/asm/cpufeature.h
    @@ -137,7 +137,6 @@ extern void clear_cpu_cap(struct cpuinfo

    #define setup_force_cpu_bug(bit) setup_force_cpu_cap(bit)

    -#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_X86_FAST_FEATURE_TESTS)
    /*
    * Static testing of CPU features. Used the same as boot_cpu_has().
    * These will statically patch the target code for additional
    @@ -196,13 +195,6 @@ static __always_inline __pure bool _stat
    boot_cpu_has(bit) : \
    _static_cpu_has(bit) \
    )
    -#else
    -/*
    - * Fall back to dynamic for gcc versions which don't support asm goto. Should be
    - * a minority now anyway.
    - */
    -#define static_cpu_has(bit) boot_cpu_has(bit)
    -#endif

    #define cpu_has_bug(c, bit) cpu_has(c, (bit))
    #define set_cpu_bug(c, bit) set_cpu_cap(c, (bit))

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