Commit e7615c92 authored Mar 17, 2023 by Heiko Carstens Committed by Vasily Gorbik Mar 27, 2023

s390: enable ARCH_HAS_MEMBARRIER_SYNC_CORE



s390 trivially supports the ARCH_HAS_MEMBARRIER_SYNC_CORE requirements
since the used lpswe(y) instruction to return from any kernel context to
user space performs CPU serialization. This is very similar to arm, arm64
and powerpc.

See commit 70216e18 ("membarrier: Provide core serializing command,
*_SYNC_CORE") for further details.

Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

parent af90d7b6

Documentation/features/sched/membarrier-sync-core/arch-support.txt

+2 −2

Original line number	Diff line number	Diff line
		@@ -5,7 +5,7 @@
		#
		# Architecture requirements
		#
		# * arm/arm64/powerpc
		# * arm/arm64/powerpc/s390
		#
		# Rely on implicit context synchronization as a result of exception return
		# when returning from IPI handler, and when returning to user-space.
		@@ -45,7 +45,7 @@
		\| parisc: \| TODO \|
		\| powerpc: \| ok \|
		\| riscv: \| TODO \|
		\| s390: \| TODO \|
		\| s390: \| ok \|
		\| sh: \| TODO \|
		\| sparc: \| TODO \|
		\| um: \| TODO \|

arch/s390/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -76,6 +76,7 @@ config S390
		select ARCH_HAS_GCOV_PROFILE_ALL
		select ARCH_HAS_GIGANTIC_PAGE
		select ARCH_HAS_KCOV
		select ARCH_HAS_MEMBARRIER_SYNC_CORE
		select ARCH_HAS_MEM_ENCRYPT
		select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
		select ARCH_HAS_PTE_SPECIAL