From c852f320584600a372646055d8229e063949eee7 Mon Sep 17 00:00:00 2001 From: Punit Agrawal Date: Tue, 18 Nov 2014 11:41:26 +0000 Subject: arm64: Emulate CP15 Barrier instructions The CP15 barrier instructions (CP15ISB, CP15DSB and CP15DMB) are deprecated in the ARMv7 architecture, superseded by ISB, DSB and DMB instructions respectively. Some implementations may provide the ability to disable the CP15 barriers by disabling the CP15BEN bit in SCTLR_EL1. If not enabled, the encodings for these instructions become undefined. To support legacy software using these instructions, this patch register hooks to - * emulate CP15 barriers and warn the user about their use * toggle CP15BEN in SCTLR_EL1 Signed-off-by: Punit Agrawal Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon --- Documentation/arm64/legacy_instructions.txt | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'Documentation/arm64') diff --git a/Documentation/arm64/legacy_instructions.txt b/Documentation/arm64/legacy_instructions.txt index 5ab58614b7ed..a3b3da2ec6ed 100644 --- a/Documentation/arm64/legacy_instructions.txt +++ b/Documentation/arm64/legacy_instructions.txt @@ -38,3 +38,8 @@ Supported legacy instructions Node: /proc/sys/abi/swp Status: Obsolete Default: Undef (0) + +* CP15 Barriers +Node: /proc/sys/abi/cp15_barrier +Status: Deprecated +Default: Emulate (1) -- cgit