Commit 669474e7 authored Feb 05, 2018 by Will Deacon Committed by Catalin Marinas Feb 06, 2018

arm64: barrier: Add CSDB macros to control data-value prediction



For CPUs capable of data value prediction, CSDB waits for any outstanding
predictions to architecturally resolve before allowing speculative execution
to continue. Provide macros to expose it to the arch code.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

parent 439e70e2

arch/arm64/include/asm/assembler.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -115,6 +115,13 @@
		hint #16
		.endm

		/*
		* Value prediction barrier
		*/
		.macro csdb
		hint #20
		.endm

		/*
		* NOP sequence
		*/

arch/arm64/include/asm/barrier.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -32,6 +32,7 @@
		#define dsb(opt) asm volatile("dsb " #opt : : : "memory")

		#define psb_csync() asm volatile("hint #17" : : : "memory")
		#define csdb() asm volatile("hint #20" : : : "memory")

		#define mb() dsb(sy)
		#define rmb() dsb(ld)

Admin message