This adds a kernel config option that controls whether MAP_SYNC is enabled by
default. With POWER10, architecture is adding new pmem flush and sync
instructions. The kernel should prevent the usage of MAP_SYNC if applications
are not using the new instructions on newer hardware.

This config allows user to control whether MAP_SYNC should be enabled by
default or not.

Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
---
 arch/powerpc/platforms/Kconfig.cputype | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/powerpc/platforms/Kconfig.cputype 
b/arch/powerpc/platforms/Kconfig.cputype
index 27a81c291be8..f8694838ad4e 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -383,6 +383,15 @@ config PPC_KUEP
 
          If you're unsure, say Y.
 
+config ARCH_MAP_SYNC_DISABLE
+       bool "Disable synchronous fault support (MAP_SYNC)"
+       default y
+       help
+         Disable support for synchronous fault with nvdimm namespaces.
+
+         If you're unsure, say Y.
+
+
 config PPC_HAVE_KUAP
        bool
 
-- 
2.26.2

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