membarrier-sync-core: Document architecture support (6a546c7e) · Commits · 戴 / test

Ensure we gather architecture requirements about each architecture supporting the "sync_core" membarrier command in a single file under Documentation/features. Signed-off-by:

Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrea Parri <parri.andrea@gmail.com> Cc: Andrew Hunter <ahh@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Avi Kivity <avi@scylladb.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Dave Watson <davejwatson@fb.com> Cc: David Sehr <sehr@google.com> Cc: Greg Hackmann <ghackmann@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maged Michael <maged.michael@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Link: http://lkml.kernel.org/r/1518208256-22034-1-git-send-email-mathieu.desnoyers@efficios.com Signed-off-by:

Ingo Molnar <mingo@kernel.org>

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

0 → 100644

+62 −0

Original line number	Diff line number	Diff line
		#
		# Feature name: membarrier-sync-core
		# Kconfig: ARCH_HAS_MEMBARRIER_SYNC_CORE
		# description: arch supports core serializing membarrier
		#
		# Architecture requirements
		#
		# * arm64
		#
		# Rely on eret context synchronization when returning from IPI handler, and
		# when returning to user-space.
		#
		# * x86
		#
		# x86-32 uses IRET as return from interrupt, which takes care of the IPI.
		# However, it uses both IRET and SYSEXIT to go back to user-space. The IRET
		# instruction is core serializing, but not SYSEXIT.
		#
		# x86-64 uses IRET as return from interrupt, which takes care of the IPI.
		# However, it can return to user-space through either SYSRETL (compat code),
		# SYSRETQ, or IRET.
		#
		# Given that neither SYSRET{L,Q}, nor SYSEXIT, are core serializing, we rely
		# instead on write_cr3() performed by switch_mm() to provide core serialization
		# after changing the current mm, and deal with the special case of kthread ->
		# uthread (temporarily keeping current mm into active_mm) by issuing a
		# sync_core_before_usermode() in that specific case.
		#
		-----------------------
		\| arch \|status\|
		-----------------------
		\| alpha: \| TODO \|
		\| arc: \| TODO \|
		\| arm: \| TODO \|
		\| arm64: \| ok \|
		\| blackfin: \| TODO \|
		\| c6x: \| TODO \|
		\| cris: \| TODO \|
		\| frv: \| TODO \|
		\| h8300: \| TODO \|
		\| hexagon: \| TODO \|
		\| ia64: \| TODO \|
		\| m32r: \| TODO \|
		\| m68k: \| TODO \|
		\| metag: \| TODO \|
		\| microblaze: \| TODO \|
		\| mips: \| TODO \|
		\| mn10300: \| TODO \|
		\| nios2: \| TODO \|
		\| openrisc: \| TODO \|
		\| parisc: \| TODO \|
		\| powerpc: \| TODO \|
		\| s390: \| TODO \|
		\| score: \| TODO \|
		\| sh: \| TODO \|
		\| sparc: \| TODO \|
		\| tile: \| TODO \|
		\| um: \| TODO \|
		\| unicore32: \| TODO \|
		\| x86: \| ok \|
		\| xtensa: \| TODO \|
		-----------------------

Original line number	Diff line number	Diff line
		#
		# Feature name: membarrier-sync-core
		# Kconfig: ARCH_HAS_MEMBARRIER_SYNC_CORE
		# description: arch supports core serializing membarrier
		#
		# Architecture requirements
		#
		# * arm64
		#
		# Rely on eret context synchronization when returning from IPI handler, and
		# when returning to user-space.
		#
		# * x86
		#
		# x86-32 uses IRET as return from interrupt, which takes care of the IPI.
		# However, it uses both IRET and SYSEXIT to go back to user-space. The IRET
		# instruction is core serializing, but not SYSEXIT.
		#
		# x86-64 uses IRET as return from interrupt, which takes care of the IPI.
		# However, it can return to user-space through either SYSRETL (compat code),
		# SYSRETQ, or IRET.
		#
		# Given that neither SYSRET{L,Q}, nor SYSEXIT, are core serializing, we rely
		# instead on write_cr3() performed by switch_mm() to provide core serialization
		# after changing the current mm, and deal with the special case of kthread ->
		# uthread (temporarily keeping current mm into active_mm) by issuing a
		# sync_core_before_usermode() in that specific case.
		#
		-----------------------
		\| arch \|status\|
		-----------------------
		\| alpha: \| TODO \|
		\| arc: \| TODO \|
		\| arm: \| TODO \|
		\| arm64: \| ok \|
		\| blackfin: \| TODO \|
		\| c6x: \| TODO \|
		\| cris: \| TODO \|
		\| frv: \| TODO \|
		\| h8300: \| TODO \|
		\| hexagon: \| TODO \|
		\| ia64: \| TODO \|
		\| m32r: \| TODO \|
		\| m68k: \| TODO \|
		\| metag: \| TODO \|
		\| microblaze: \| TODO \|
		\| mips: \| TODO \|
		\| mn10300: \| TODO \|
		\| nios2: \| TODO \|
		\| openrisc: \| TODO \|
		\| parisc: \| TODO \|
		\| powerpc: \| TODO \|
		\| s390: \| TODO \|
		\| score: \| TODO \|
		\| sh: \| TODO \|
		\| sparc: \| TODO \|
		\| tile: \| TODO \|
		\| um: \| TODO \|
		\| unicore32: \| TODO \|
		\| x86: \| ok \|
		\| xtensa: \| TODO \|
		-----------------------

Admin message