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Subject[PATCH 4.14 039/107] powerpc/64s: Add new security feature flags for count cache flush
4.14-stable review patch.  If anyone has any objections, please let me know.


From: Michael Ellerman <>

commit dc8c6cce9a26a51fc19961accb978217a3ba8c75 upstream.

Add security feature flags to indicate the need for software to flush
the count cache on context switch, and for the presence of a hardware
assisted count cache flush.

Signed-off-by: Michael Ellerman <>
Signed-off-by: Greg Kroah-Hartman <>
arch/powerpc/include/asm/security_features.h | 6 ++++++
1 file changed, 6 insertions(+)

--- a/arch/powerpc/include/asm/security_features.h
+++ b/arch/powerpc/include/asm/security_features.h
@@ -59,6 +59,9 @@ static inline bool security_ftr_enabled(
// Indirect branch prediction cache disabled
#define SEC_FTR_COUNT_CACHE_DISABLED 0x0000000000000020ull

+// bcctr 2,0,0 triggers a hardware assisted count cache flush
+#define SEC_FTR_BCCTR_FLUSH_ASSIST 0x0000000000000800ull

// Features indicating need for Spectre/Meltdown mitigations

@@ -74,6 +77,9 @@ static inline bool security_ftr_enabled(
// Firmware configuration indicates user favours security over performance
#define SEC_FTR_FAVOUR_SECURITY 0x0000000000000200ull

+// Software required to flush count cache on context switch
+#define SEC_FTR_FLUSH_COUNT_CACHE 0x0000000000000400ull

// Features enabled by default

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