From d0266046ad54e0c964941364cd82a0d0478ce286 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 19 Mar 2018 16:41:26 +0100 Subject: [PATCH] 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) Signed-off-by: Thomas Gleixner Cc: torvalds@linux-foundation.org Link: https://lkml.kernel.org/r/20180319154717.705383007@infradead.org --- arch/x86/Kconfig | 11 ----------- arch/x86/include/asm/cpufeature.h | 8 -------- 2 files changed, 19 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 0fa71a78ec99..cb5b5907dbd6 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -393,17 +393,6 @@ 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) diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 736771c9822e..b27da9602a6d 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -140,7 +140,6 @@ extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit); #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 @@ t_no: 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)) -- 2.30.2