Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d0266046 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Thomas Gleixner
Browse files

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: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: torvalds@linux-foundation.org
Link: https://lkml.kernel.org/r/20180319154717.705383007@infradead.org
parent e501ce95

arch/x86/Kconfig

+0 −11
Original line number Diff line number Diff line
@@ -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)

arch/x86/include/asm/cpufeature.h

+0 −8
Original line number Diff line number Diff line
@@ -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 @@ static __always_inline __pure bool _static_cpu_has(u16 bit) 
		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))