x86/mm: Add a 'noinvpcid' boot option to turn off INVPCID

[pandora-kernel.git] / arch / x86 / kernel / cpu / common.c

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 83df01d..1477e70 100644 (file)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -155,6 +155,22 @@ static int __init x86_xsaveopt_setup(char *s)
 }
 __setup("noxsaveopt", x86_xsaveopt_setup);
 
+static int __init x86_noinvpcid_setup(char *s)
+{
+       /* noinvpcid doesn't accept parameters */
+       if (s)
+               return -EINVAL;
+
+       /* do not emit a message if the feature is not present */
+       if (!boot_cpu_has(X86_FEATURE_INVPCID))
+               return 0;
+
+       setup_clear_cpu_cap(X86_FEATURE_INVPCID);
+       pr_info("noinvpcid: INVPCID feature disabled\n");
+       return 0;
+}
+early_param("noinvpcid", x86_noinvpcid_setup);
+
 #ifdef CONFIG_X86_32
 static int cachesize_override __cpuinitdata = -1;
 static int disable_x86_serial_nr __cpuinitdata = 1;