x86: add noclflush option

To disable CLFLUSH usage, especially in change_page_attr().

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 7 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index dfc9563fc4f..56b7ea8e6c7 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -542,6 +542,13 @@ void __cpuinit detect_ht(struct cpuinfo_x86 *c)
 }
 #endif
 
+static __init int setup_noclflush(char *arg)
+{
+	setup_clear_cpu_cap(X86_FEATURE_CLFLSH);
+	return 1;
+}
+__setup("noclflush", setup_noclflush);
+
 void __cpuinit print_cpu_info(struct cpuinfo_x86 *c)
 {
 	char *vendor = NULL;