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>

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 4bd326d0322c7de7f013a3a5bea4c295c32ea132..f0f29ddf33a269694cdad172fbeacd3ed6d66f3d 100644 (file)
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -57,6 +57,8 @@ DEFINE_PER_CPU(struct gdt_page, gdt_page) = { .gdt = {
 } };
 EXPORT_PER_CPU_SYMBOL_GPL(gdt_page);
 
+__u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata;
+
 static int cachesize_override __cpuinitdata = -1;
 static int disable_x86_fxsr __cpuinitdata;
 static int disable_x86_serial_nr __cpuinitdata = 1;
@@ -497,6 +499,10 @@ void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
                        boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
        }
 
+       /* Clear all flags overriden by options */
+       for (i = 0; i < NCAPINTS; i++)
+               c->x86_capability[i] ^= cleared_cpu_caps[i];
+
        /* Init Machine Check Exception if available. */
        mcheck_init(c);
 

diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 7edb43f0b27961713f214070c776816e83155ceb..df159520bbd220b3db0af639375f7bd2c79c61fd 100644 (file)
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -80,6 +80,8 @@
 struct cpuinfo_x86 boot_cpu_data __read_mostly;
 EXPORT_SYMBOL(boot_cpu_data);
 
+__u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata;
+
 unsigned long mmu_cr4_features;
 
 /* Boot loader ID as an integer, for the benefit of proc_dointvec */
@@ -1013,6 +1015,10 @@ void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
                        boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
        }
 
+       /* Clear all flags overriden by options */
+       for (i = 0; i < NCAPINTS; i++)
+               c->x86_capability[i] ^= cleared_cpu_caps[i];
+
 #ifdef CONFIG_X86_MCE
        mcheck_init(c);
 #endif

diff --git a/include/asm-x86/cpufeature.h b/include/asm-x86/cpufeature.h
index 29727bf0e17756a9ee8bf55906ff4649a65f6cc8..b8f53f869e1f0c3152df94032048597c3127c0f5 100644 (file)
--- 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 81ecfed83e47a5fc4ad8f1df1e876883bb779705..ab4d0c2a3f8f286b792e2b2b724c6186849fb5e3 100644 (file)
--- 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);