[PATCH 7/8] membarrier: Remove arm (32) support for SYNC_CORE

From: Andy Lutomirski
Date: Tue Jun 15 2021 - 23:21:42 EST


On arm32, the only way to safely flush icache from usermode is to call
cacheflush(2). This also handles any required pipeline flushes, so
membarrier's SYNC_CORE feature is useless on arm. Remove it.

Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/arm/Kconfig | 1 -
1 file changed, 1 deletion(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 24804f11302d..89a885fba724 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -10,7 +10,6 @@ config ARM
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_KEEPINITRD
select ARCH_HAS_KCOV
- select ARCH_HAS_MEMBARRIER_SYNC_CORE
select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
select ARCH_HAS_PHYS_TO_DMA
--
2.31.1