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>
This commit is contained in:
Will Deacon 2018-02-05 15:34:16 +00:00 committed by Catalin Marinas
parent 439e70e27a
commit 669474e772
2 changed files with 8 additions and 0 deletions

View file

@ -115,6 +115,13 @@
hint #16
.endm
/*
* Value prediction barrier
*/
.macro csdb
hint #20
.endm
/*
* NOP sequence
*/

View file

@ -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)