powerpc/64s: Add new security feature flags for count cache flush

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.

BugLink: https://bugs.launchpad.net/bugs/1822870
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
(cherry picked from commit dc8c6cce9a26a51fc19961accb978217a3ba8c75)
Signed-off-by: Manoj Iyer <manoj.iyer@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/arch/powerpc/include/asm/security_features.h b/arch/powerpc/include/asm/security_features.h
index 44989b22383c24b92caaf3dbb3d9831c79cd967f..a0d47bc18a5c0a70bf178068e8d5a4f3da659989 100644 (file)
--- 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(unsigned long feature)
 // 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(unsigned long feature)
 // 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
 #define SEC_FTR_DEFAULT \