x86: add framework to disable CPUID bits on the command line

There are already various options to disable specific cpuid bits
on the command line. They all use their own variable. Add a generic
mask to make this easier in the future.

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

2 files changed, 5 insertions, 0 deletions

diff --git a/include/asm-x86/cpufeature.h b/include/asm-x86/cpufeature.h
index 29727bf0e177..b8f53f869e1f 100644
--- a/include/asm-x86/cpufeature.h
+++ b/include/asm-x86/cpufeature.h
@@ -131,6 +131,10 @@
 
 #define set_cpu_cap(c, bit)     set_bit(bit, (unsigned long *)((c)->x86_capability))
 #define clear_cpu_cap(c, bit)   clear_bit(bit, (unsigned long *)((c)->x86_capability))
+#define setup_clear_cpu_cap(bit) do { \
+        clear_cpu_cap(&boot_cpu_data, bit);     \
+        set_bit(bit, cleared_cpu_caps);         \
+} while (0)
 
 #define cpu_has_fpu             boot_cpu_has(X86_FEATURE_FPU)
 #define cpu_has_vme             boot_cpu_has(X86_FEATURE_VME)
diff --git a/include/asm-x86/processor.h b/include/asm-x86/processor.h
index 81ecfed83e47..ab4d0c2a3f8f 100644
--- a/include/asm-x86/processor.h
+++ b/include/asm-x86/processor.h
@@ -118,6 +118,7 @@ struct cpuinfo_x86 {
 extern struct cpuinfo_x86 boot_cpu_data;
 extern struct cpuinfo_x86 new_cpu_data;
 extern struct tss_struct doublefault_tss;
+extern __u32 cleared_cpu_caps[NCAPINTS];
 
 #ifdef CONFIG_SMP
 DECLARE_PER_CPU(struct cpuinfo_x86, cpu_info);