x86: debugctlmsr kconfig
This adds the (internal) Kconfig macro CONFIG_X86_DEBUGCTLMSR,
to be defined when configuring to support only hardware that
definitely supports MSR_IA32_DEBUGCTLMSR with the BTF flag.
The Intel documentation says "P6 family" and later processors all have it.
I think the Kconfig dependencies are right to have it set for those and
unset for others (i.e., when 586 and earlier are supported).
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index c301622..69e2ee4 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -399,3 +399,7 @@
default "4" if X86_32 && (X86_XADD || X86_CMPXCHG || X86_BSWAP || X86_WP_WORKS_OK)
default "3"
+config X86_DEBUGCTLMSR
+ bool
+ depends on !(M586MMX || M586TSC || M586 || M486 || M386)
+ default y