e69244d295
Exception return implies context synchronization, so we can hook up the SYNC_CORE option to sys_membarrier() simply by selecting the Kconfig option, just like we've done for arm64 already. Cc: Orion Hodson <oth@google.com> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
57 lines
1.9 KiB
Plaintext
57 lines
1.9 KiB
Plaintext
#
|
|
# Feature name: membarrier-sync-core
|
|
# Kconfig: ARCH_HAS_MEMBARRIER_SYNC_CORE
|
|
# description: arch supports core serializing membarrier
|
|
#
|
|
# Architecture requirements
|
|
#
|
|
# * arm/arm64
|
|
#
|
|
# Rely on implicit context synchronization as a result of exception return
|
|
# 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: | ok |
|
|
| arm64: | ok |
|
|
| c6x: | TODO |
|
|
| h8300: | TODO |
|
|
| hexagon: | TODO |
|
|
| ia64: | TODO |
|
|
| m68k: | TODO |
|
|
| microblaze: | TODO |
|
|
| mips: | TODO |
|
|
| nds32: | TODO |
|
|
| nios2: | TODO |
|
|
| openrisc: | TODO |
|
|
| parisc: | TODO |
|
|
| powerpc: | TODO |
|
|
| riscv: | TODO |
|
|
| s390: | TODO |
|
|
| sh: | TODO |
|
|
| sparc: | TODO |
|
|
| um: | TODO |
|
|
| unicore32: | TODO |
|
|
| x86: | ok |
|
|
| xtensa: | TODO |
|
|
-----------------------
|